Documents published in 2001 : Scipedia

DRIVER AGE DIFFERENCES IN DAY AND NIGHT GAP ACCEPTANCE CAPABILITIES
S. Dissanayake, P. Yi, J. Lu

Collection of open articles in transport research (2002). Vol. 2002, 9

Abstract
Performance of Two-way Stop-controlled (TWSC) intersections is greatly affected by the gap acceptance capabilities of drivers. However, there have been no detailed studies conducted regarding driver age differences in gap acceptance capabilities under different light conditions. Therefore, this study was conducted to fill the lack of information in that area, by considering three driver age groups (old, middle, and young), two maneuvers (left-turn, and through), and two light conditions (daytime, and nighttime). Field observations were made at several TWSC intersections and data were collected at these sites regarding available and accepted gaps on the major street and age group of minor street drivers, both during daytime and nighttime. Statistical analysis conducted in this study with a 5% level of significance revealed that there were significant differences in gap acceptance capabilities among the three driver age groups under both light conditions. Only older drivers indicated statistically different gap acceptance capabilities depending on the light condition, where they illustrated longer critical gap values during nighttime. Document type: Article
Abstract
Performance of Two-way Stop-controlled (TWSC) intersections is greatly affected by the gap acceptance capabilities of drivers. However, there have been no detailed studies [...]
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Impacts of lower speed limits in South Australia
R. Zito, B. Stazic, J. Woolley, M. Taylor, C. Dyson

Collection of open articles in transport research (2002). Vol. 2002, 8

Abstract
ustralia has recently undergone a change of urban speed limits in most of its jurisdictions. The political and social shift in attitudes required for this change is significant in a country that has a strong reliance on the use of the private motor vehicle. At present five states and one territory have lowered the speed limit in urban areas from 60km/h to 50km/h. Of the remaining two states and territories, one has already implemented lower speed limits (40km/h) in small areas within cities. In the majority of cases, the only criterion for judging the success of such schemes is an observed reduction in both speeds and crash numbers. This paper reports on a more holistic assessment of such schemes taking into account factors in addition to speed and crashes including: traffic volume displacement, physical road network characteristics, environmental factors, community ownership and acceptance, enforcement effort and impact on travel times. The research work has included the analysis of extensive traffic data, community surveys and focus groups, the collection of environmental and travel time data from an instrumented probe vehicle and the computer modelling of road networks. The work reported is based on over 10 years of working with a 40km/h lower urban speed limit area in South Australia. The paper expands the notion of using speed and crash outcomes as the only criteria for measuring the success of lower speed limit schemes. Document type: Article
Abstract
ustralia has recently undergone a change of urban speed limits in most of its jurisdictions. The political and social shift in attitudes required for this change is significant [...]
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Environmental Effects of a Kilometre Charge in Road Transport: an Investigation for the Netherlands
P. Peeters, P. Rietveld, B. Ubbels

Collection of closed articles in transport research (2002). Vol. 2002, 9

Abstract
This study discusses the potential environmental effects of a kilometre charge for car traffic in the Netherlands. This kilometre charge would replace the existing taxes on new cars and on car ownership. It would lead to a substantial increase in the variable costs of car use. It may lead to a doubling of these costs while at the same time the average costs of car use would not increase because the fixed taxes are strongly reduced. Four alternatives for the kilometre charge are formulated. These are estimated to lead to substantial reductions of energy and certain emissions. © 2002 Elsevier Science Ltd. All rights reserved.
Abstract
This study discusses the potential environmental effects of a kilometre charge for car traffic in the Netherlands. This kilometre charge would replace the existing taxes on [...]
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Policy Scenarios for Achieving Sustainable Transportation in Europe
C. Rodenburg, B. Ubbels, P. Nijkamp

Collection of closed articles in transport research (2002). Vol. 2002, 8

Abstract
The relationship between globalization and transport volumes is complex because of many causes. Rising incomes, more leisure time, new technologies and the ageing of the population are just a few examples of trends that will influence the future development of the transport sector in terms of both passenger and freight transport. This means that the future of the transport sector is characterized by uncertainty. The aim of this paper is to map out the possible impacts of current globalization trends on the European transport sector in terms of transport flows and carbon dioxide emissions by means of a novel multilayer assessment model. By applying a scenario approach and designing four contrasting development paths seen from a European perspective, the alternative futures of the sector are assessed in terms of transport volumes and emissions. The empirical findings appear to result almost everywhere in a (strong) growth of transport and emissions. Hence, the intriguing research question is now whether the introduction of specific environmentally benign policies in Europe could change this development. Consequently, the paper confronts the foreseen EU objectives with current policies, as creating sustainable mobility is a key element in EU transport policy. Our findings indicate, however, that the achievement of sustainable mobility is rather problematic. Effective policy implementation and (as yet uncertain) new technology developments may offer new opportunities to achieve a more balanced development of the transport sector. However, in most cases, only a combination of strict environmental policies (including transport policy) and a fundamental change of lifestyles in the mobile society is likely to lead to a decrease in carbon dioxide emissions in the next 20 years.
Abstract
The relationship between globalization and transport volumes is complex because of many causes. Rising incomes, more leisure time, new technologies and the ageing of the population [...]
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Occupant Safety Design Approaches using Physical Testing and Numerical Simulation.
D. Vilela, L. Linzmaier, P. Altamore, J. Carvalho, M. Benar

Collection of closed articles in transport research (2001). Vol. 2001, 7

Abstract
The vehicle design environment from a crashworthiness and safety perspective has become increasingly complex in recent years. New legal requirements imposed by the European Union (EU) and the United States National Highway Traffic Safety Administration (NHTSA) have created a design space of great complexity with many parameters that must be balanced to arrive at an overall design that performs adequately in all of these situations. The customer introduces further complexity through the addition of Consumer requirements in many markets that will influence a purchasing decision. In order to design to all of these conditions, an approach of using physical testing solely has problems associated with it. Due to the prohibitive nature of vehicle prototypes and limited availability during Engineering Development, other tools such a Computer Aided Engineering (CAE) have become popular. This paper will discuss the design space and modeling methods for creating an occupant crashworthiness model suitable for studying vehicle structural and restraint system effects. The results of parametric studies showing injury trends for a given vehicle/restraint system combination will be presented. Copyright © 2001 Society of Automotive Engineers, Inc.
Abstract
The vehicle design environment from a crashworthiness and safety perspective has become increasingly complex in recent years. New legal requirements imposed by the European [...]
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Developments in air transport economics: introduction
P. Nijkamp, E. Pels

Collection of closed articles in transport research (2002). Vol. 2002, 7
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Price elasticities of demand for passenger air travel: a meta-analysis
M. Brons, P. Rietveld, P. Nijkamp, E. Pels

Collection of closed articles in transport research (2002). Vol. 2002, 5

Abstract
The demand for air transport is largely determined by the spending capacity of customers. This paper aims to offer more insight into the determinants of price elasticities in the aviation sector. It seeks to indentify both common and contrasting factors that influence the price elasticities, on the basis of a comparative analysis among a large number of empirical studies in this field. By means of meta-analytical methods, the relative importance of several driving forces such as distance, type of ticket and the nature of study is investigated. © 2002 Elsevier Science Ltd. All rights reserved.
Abstract
The demand for air transport is largely determined by the spending capacity of customers. This paper aims to offer more insight into the determinants of price elasticities [...]
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Will reactivation of the Iron Rhine railroad decrease survival of badgers (Meles meles) in Meinweg National Park, the Netherlands
V. Grift, W. Nieuwenhuizen

Collection of closed articles in transport research (2002). Vol. 2002, 2

Abstract
Met verschillende variaties is het effect van hergebruik van een goederenspoorlijn op de ontwikkeling van een dassenpopulatie in Midden-Limburg onderzoch
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Dynamic problem selection in air traffic control training: a comparison between performance, mental effort and mental efficiency
R. Rikers, J. Merriënboer, F. Paas, G. Camp

Collection of closed articles in transport research (2001). Vol. 2001, 3

Abstract
The differential effects on training and training outcome of four methods of problem selection were investigated in a computer-based training for air traffic control. In one method, training problems were given to the participants in a fixed predetermined sequence, from simple to complex. In the other methods, problems were selected dynamically, based on three different learner variables. These were mental effort, performance and mental efficiency, which is a variable that combines mental effort and performance measures to determine problem efficiency. After the training, transfer was measured. The hypothesis that dynamic problem selection would lead to more efficient training than non-dynamic problem selection was confirmed. The second hypothesis, that dynamic problem selection based on mental efficiency would lead to more efficient training and better transfer than dynamic problem selection based on performance or mental effort alone was not supported. However, the efficiency measures of the three variables were distorted by the differential effects of these variables on the acquisition phase. A possible explanation for the results is that selection based on performance stimulates rule automation, whereas selection based on mental effort or mental efficiency leads to schema acquisition.
Abstract
The differential effects on training and training outcome of four methods of problem selection were investigated in a computer-based training for air traffic control. In one [...]
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OPTIMAL CONGESTION CHARGES IN GENERAL EQUILIBRIUM
D. Moon, C. Park

Collection of open articles in transport research (2002). Vol. 2002, 7

Abstract
This paper deals with pricing and investment decision problems of multi-route and multi-period highway systems in which the congestion is a significant factor in the assessment of system costs. This study approaches this congestion pricing scheme with two different social welfare maximization problems, both of which search for the optimal solutions through general equilibrium analysis. These two optimization problems have an identical structure except financial constraints that reflect different decision environments. One welfare maximization problem involves estimating the first-best social optimal solution. This problem yields the optimal solution for the implementation scheme to impose the differentiated congestion charge for each trip alternative in terms of travel route and trip period. The optimal congestion charge for this problem has the expression similar to that derived in previous studies dealing with congestion pricing. Another maximization problem involves characterizing the second-best optimal solution. In this problem, it is assumed to impose the congestion toll only on a single highway link. This problem yields the second-best congestion toll different from the first-best one. This second-best optimal congestion toll has the structure to reflect its impact on other highway links exempt from the congestion charge program. Document type: Article
Abstract
This paper deals with pricing and investment decision problems of multi-route and multi-period highway systems in which the congestion is a significant factor in the assessment [...]
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DESIGN OF A USER CHARGE FOR HEAVY-DUTY VEHICLES ON GERMAN MOTORWAYS CONSIDERING THE OBJECTIVES OF EFFICIENCY, FAIRNESS AND ENVIRONMENTAL PROTECTION
C. Doll, W. Rothengatter

Collection of open articles in transport research (2002). Vol. 2002, 6

Abstract
The German government plans to introduce a kilometre charge on motorways for heavy duty vehicles "12t, beginning in the year 2003. According to an EU Directive the charge has to be orientated to the average infrastructure costs and can be differentiated according to the environmental performance (“EURO Standard”) of the vehicles. Based on the possible differentiation of the user charge this paper analyses the probable impacts on the transport market and on basic environmental indicators. Three scenarios are constructed: first, a modest user charge only on motorways; second, a higher user charge on the whole network of federal roads with a given level of service of the railways; and third, the previous scenario combined with an improved level of service of the railways. The result is that only in the case of the third scenario the hope of environmental policy is realistic that road transport can be reduced and environmental quality significantly improved through a road user charging scheme. Document type: Article
Abstract
The German government plans to introduce a kilometre charge on motorways for heavy duty vehicles "12t, beginning in the year 2003. According to an EU Directive the charge [...]
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Air traffic noise and hypertension in Stockholm County
S. Pattenden

Collection of open articles in transport research (2001). Vol. 2001, 3

Abstract
On any given day, according to The Economist , over 4 million people take to the skies. A quarter of a million people are airborne at any moment.1 Health impacts of noise can begin even before birth, and with high levels and an increasing distribution of exposure, any associations between aircraft noise and morbidity are clearly of relevance to public health.2 3 Rosenlund et al (page 769) assess associations between blood pressure and aircraft noise by comparing two study populations, around Arlanda airport and in another part of Stockholm County. Noise contours are constructed over the region for maximum noise level (MNL) and an energy averaged level (FBN). Health outcomes of people living in proximity tend on … Document type: Article
Abstract
On any given day, according to The Economist , over 4 million people take to the skies. A quarter of a million people are airborne at any moment.1 Health impacts of noise [...]
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DYNAMIC SPEED ADAPTATION IN ADVERSE CONDITIONS
A. Varhelyi

Collection of open articles in transport research (2002). Vol. 2002, 4

Abstract
This paper proposes a system for dynamic speed adaptation in adverse conditions, such as wet/slippery roads, decreased visibility, darkness and sharp curves. Accident risks increase drastically in such conditions, especially since drivers often do not adapt speeds to lower friction or impaired visibility. Thus, the discussion is centred around a method for calculating the appropriate highest speeds and a system to influence driver’s speed-choice in these conditions via an in-vehicle device. The safety effect of the proposed system is estimated to result in a 19% - 42% reduction of injury accidents in Sweden. The paper concludes by making suggestions for further research into alternative technological solutions, effects on driver behaviour and workload and implementation of the system for other reasons than weather and road-dependent adverse conditions. (Less) Document type: Article
Abstract
This paper proposes a system for dynamic speed adaptation in adverse conditions, such as wet/slippery roads, decreased visibility, darkness and sharp curves. Accident risks [...]
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SPEED REGULATION BY IN-CAR ACTIVE ACCELERATOR PEDAL
S. Almqvist, A. Varhelyi, M. Hjälmdahl

Collection of open articles in transport research (2002). Vol. 2002, 3

Abstract
The effects on speeds and speed distribution were studied in a large scale field trial with an in car system for speed adaptation in the city of Lund, Sweden. In the trial 290 vehicles were equipped with an "active accelerator pedal" and data logger for a period of 3-11 months. Data was logged in each test vehicle during the whole trial and was analyzed for 3 one-month periods: Before activating the system, after short time use and after long time use. The results showed significant reductions in the speed level. Speeds on stretches decreased statistically significantly (p"0.05) at 60 out of 69 observed sections. The effects were largest on arterial roads, at mid-block sections, where the prevailing traffic conditions and street design allows higher speeds. The standard deviation decreased on all arterial roads, mainly due to the decrease in speed of the fastest vehicles but there is also an effect from an increase in speed of the slowest vehicles. On streets with mixed traffic no differences in speed or speed distribution could be shown. This is most likely due to the fact that speeds were already controlled by the prevailing traffic conditions and they already were so low that the system never had to interfere. Further research is needed in order to investigate possible behavioral adaptation effects when the system is active as well as inactive and how driver behavior would be influenced in a situation where a large part of the vehicle fleet equipped with an active accelerator pedal. (Less) Document type: Article
Abstract
The effects on speeds and speed distribution were studied in a large scale field trial with an in car system for speed adaptation in the city of Lund, Sweden. In the trial [...]
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SHARING ELECTRIC VEHICLES IN KYOTO: KYOTO PUBLIC CAR SYSTEM
R. Kitamura

Collection of open articles in transport research (2002). Vol. 2002, 2

Abstract
This paper describes a survey of the Kyoto Public Car System project, which is comprised of a shared fleet of electric vehicles using advanced fleet management systems on a rental basis. It started operation in December 2000 with 180 subscribers, five stations and 19 two-seaters. A simulation model was developed to represent the system and help design its configuration. A small number of frequent users accounted for most of the activity. High user satisfaction was recorded. In September 2001, membership was extended to non-residents of Kyoto. Users were also assessed fees to cover the costs of charging the vehicles after they used them. The system continued to be operated in the hope of striking the right balance between the need to raise revenues without pricing the cars higher than alternatives. Document type: Article
Abstract
This paper describes a survey of the Kyoto Public Car System project, which is comprised of a shared fleet of electric vehicles using advanced fleet management systems on [...]
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Encasement pressurization after leaks in primary piping
L. JULYK, R. Schlosser

Collection of restricted reports in transport research (2021). Vol. 2001, 2

Abstract
Preliminary evaluations of existing tank farm waste transfer system encasement piping pressure response to flowing waste supernate following a large primary line leak indicate the potential to exceed current design conditions for the encasement piping system. The potential impact to design of the encasement piping systems is assessed in this paper. Based on the encasement pressure conditions reported, the existing encasement piping systems can perform their safety functions and are capable of withstanding the worst predicted pressure conditions for a large leak in the primary system. Testing is being conducted to validate parameters used in the completed preliminary supernate evaluations and to establish a basis for evaluation of slurry transfer leaks. The results of these tests will be incorporated into the evaluations after results become available. This report provides the current status of encasement pressure analyses to determine suitable conditions for design of encasement piping within the tank farms waste transfer systems. This report provides results of preliminary evaluations, activities necessary to complete the evaluations, potential impacts on existing piping systems, and demonstration of adequacy of the existing encasement piping for withstanding higher pressure than the current design pressure without jeopardizing the safety function of the encasement piping systems tomore » direct the flow of leaked waste from the primary line to a waste transfer-associated structure for detection (i.e., the encasement will direct waste to a pit leak detector before there is any significant release of waste to the environment).
Abstract
Preliminary evaluations of existing tank farm waste transfer system encasement piping pressure response to flowing waste supernate following a large primary line leak indicate [...]
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Effectiveness of Bus Signal Priority
R. Newland, S. Chada

Collection of restricted reports in transport research (2021). Vol. 2002, 2

Abstract
Effectiveness of bus signal priority (BSP) study evaluates bBSP's impact on traffic operations. The goal was to examine how different situations such as the level of congestion, placement of bus stops, presence of express bus service, and number of transit vehicles on route, require different techniques of BSP such as real time or fixed time based control. those techniques also utilize a variety of different control strategies such as phase suppression, synchronization, compensation, and green recall. Five agencies utilizing BSP around the country were studied to determine which types of priority are used in certain conditions and what technology is being implemented.
Abstract
Effectiveness of bus signal priority (BSP) study evaluates bBSP's impact on traffic operations. The goal was to examine how different situations such as the level of congestion, [...]
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Worlds apart: Exclusion-processes in DDS
E. Rommes, M. Tanabe, P. van der Besselaar, T. Ishida

Collection of closed chapters of books in transport research (2021). Vol. 2002, 4

Abstract
More and more interfaces are designed for ‘everybody’, instead of with a specific user-group in mind. In practice, most of them are still used by the ‘typical Internet-user’, the highly educated, white young male with extensive computer and Internet-experience. Amsterdam-based digital city DDS is no exception to this rule. In this article, the interface of DDS is studied with the help of ten first-time users with a more diverse background. Did they face any barriers in using DDS? And what kind of work did they need to perform to use the interface? This study shows that the most serious problems the first-time users faced were not caused by a lack of skill, but by the different technological frame they had. Thus, a script-analysis with the help of ‘outsiders’ seems to be an effective way to uncover some exclusion-processes of a digital city.
Abstract
More and more interfaces are designed for ‘everybody’, instead of with a specific user-group in mind. In practice, most of them are still used by the ‘typical [...]
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IEA implementing agreement for hybrid and electric vehicle technologies and programmes, Annex VII hybrid vehicles : Topic 13, assessment of the energy consumption of hybrid trucks using ADVISOR
J. Eelkema, R. Winkel, R. Geraets, M. Verbakel

Collection of closed reports in transport research (2021). Vol. 2002, 2

Abstract
This topic report focuses on the possible benefits of the application of a hybrid powertrain in heavy-duty vehicles. The main objective is to assess whether a significant reduction in fuel consumption is feasible. An average Dutch distribution truck with a conventional driveline will be compared to a truck with a series hybrid driveline and a truck with a parallel hybrid driveline. Both hybrids will only use diesel fuel as their source of energy: i.e. the batteries are only charged through the on-board generator, not by an external source. The dimensioning of the hybrid powertrains is done on the bases of comparable acceleration times and top speed. An auxiliary power demand of 8 kW is taken into account. Assessment of the energy consumption of the trucks is done through the use of the simulation tool ADVISOR (ADvanced VehIcle SimulatOR), version 3.1, developed by the National Renewable Energy Laboratory (NREL), USA.
Abstract
This topic report focuses on the possible benefits of the application of a hybrid powertrain in heavy-duty vehicles. The main objective is to assess whether a significant [...]
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Dealing With Low-Frequency-Welded ERW Pipe and Flash-Welded Pipe With Respect to HCA-Related Integrity Assessments
J. Kiefner

Collection of open conferences in research transport (2002). Vol. 2002, 96

Abstract
The new regulations, Part 195 Section 195.452, require that special integrity assessments be made to address potential seam-defect problems in low-frequency-welded ERW (electric-resistance-welded) pipe materials where a failure of such materials could have an impact on a high-consequence area (HCA). The spirit of this requirement appears to require action if, and only if, significant seam-related deficiencies are in evidence or if they can be reasonably anticipated. This leaves open the option of categorizing these types of pipelines by performance such that potentially problematic pipeline segments can be subjected to special (i.e., seam-quality) inspections while those that show little or no propensity for such problems can be subjected to metal loss and deformation inspections only. This document is intended to establish a systematic procedure to permit an operator to characterize the relevant ERW pipe segments as to the likelihood of significant seam-related deficiencies. The author is particularly grateful to Rich Turley of Marathon Ashland Pipe Line LLC for helping to formulate the essential steps in deciding when an integrity assessment is needed. Rich made significant inputs to Figure 1 of this document.Copyright © 2002 by ASME
Abstract
The new regulations, Part 195 Section 195.452, require that special integrity assessments be made to address potential seam-defect problems in low-frequency-welded ERW (electric-resistance-welded) [...]
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A Justification for Designing and Operating Pipelines Up to Stresses of 80% SMYS
M. Marley, M. Nessim, P. Hopkins, M. McLamb

Collection of open conferences in research transport (2002). Vol. 2002, 94

Abstract
Oil and gas majors are interested in several projects worldwide involving large diameter, long distance gas pipelines that pass through remote locations. Consequently, the majors are investigating the feasibility of operating pipelines of this type at stress levels up to and including 80% of the specified minimum yield strength (SMYS) of the pipe material. This paper summarises a study to investigate the impact upon safety, reliability and integrity of designing and operating pipelines to stresses up to 80% SMYS.
Abstract
Oil and gas majors are interested in several projects worldwide involving large diameter, long distance gas pipelines that pass through remote locations. Consequently, the [...]
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InfoPAE: An Emergency Plan Deployment System
M. Carvalho, M. Casanova, F. Torres, A. Santos

Collection of open conferences in research transport (2002). Vol. 2002, 91

Abstract
InfoPAE is an automated system designed to improve the response to emergency situations. The system offers sophisticated action plans, easy access to vital information and tight control over the resources allocated to face an emergency. The system is currently in use at Petrobras and its subsidiaries, incorporating the company’s technical experience. The system is applicable to pipelines, oils terminals, oil refineries and offshore installations, and it also proved to be a valuable training tool.Copyright © 2002 by ASME
Abstract
InfoPAE is an automated system designed to improve the response to emergency situations. The system offers sophisticated action plans, easy access to vital information and [...]
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TransCanada PipeLines: An Expert Advisory System for Pipeline Operations
L. Williams, J. Kmet, K. Mah, J. Kerkhof

Collection of open conferences in research transport (2002). Vol. 2002, 88

Abstract
This paper describes a new approach to provide advanced advisory information intended to complement the systems used by Gas Controllers operating the TransCanada gas pipeline. The “Advisory System” is based upon Gas Controller knowledge and experience captured into an expert system and integrated with signal processing of SCADA in real-time. The Advisory System continuously applies its knowledge seeking and identifying deviations from normal and efficient operation, determining whether these deviations are significant, and presenting warnings and possible causes through a web-enabled user interface. The technology monitors both steady-state variations from normal operation and the transient effects of unintentional or abnormal conditions. Discussed are system requirements, and the unique approach taken to monitor, tune, evaluate and communicate conclusions. The results achieved, Gas Controller feedback, and future directions are presented, including the successful rapid detection of a linebreak incident.Copyright © 2002 by ASME
Abstract
This paper describes a new approach to provide advanced advisory information intended to complement the systems used by Gas Controllers operating the TransCanada gas pipeline. [...]
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A statistical analysis of the influence of vertical and ground speed errors on conflict probe
J. Alliot, N. Durand, G. Granger

Collection of open conferences in research transport (2001). Vol. 2001, 34

Abstract
International audience; Conflict probes will be important components of air traffic control tools in the next years. They appear in almost every project (CINCAT, ERATO, HIPS, PHARE, and so on). To be useful, they have to fulfill two goals : reliability (they have to detect all conflicts) and efficiency (they must minimize the number of false alarms). Conflict probes rely on trajectory prediction, and their reliability and efficiency highly depend on the accuracy of trajectory prediction. In this paper, we present a quick mathematical insight of the influence of ground speed errors on trajectory prediction, results of arithmetic simulations on real traffic both on ground and vertical speed errors, and a statistical analysis of these results to model the influence of vertical and ground speed errors on conflict probe.
Abstract
International audience; Conflict probes will be important components of air traffic control tools in the next years. They appear in almost every project (CINCAT, ERATO, HIPS, [...]
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Airport Remote Tower Sensor Systems
C. Leidich, D. Maluf, P. Tran, R. Papasin, Y. Gawdiak

Collection of open conferences in research transport (2001). Vol. 2001, 33

Abstract
Networks of video cameras, meteorological sensors, and ancillary electronic equipment are under development in collaboration among NASA Ames Research Center, the Federal Aviation Administration (FAA), and the National Oceanic Atmospheric Administration (NOAA). These networks are to be established at and near airports to provide real-time information on local weather conditions that affect aircraft approaches and landings. The prototype network is an airport-approach-zone camera system (AAZCS), which has been deployed at San Francisco International Airport (SFO) and San Carlos Airport (SQL). The AAZCS includes remotely controlled color video cameras located on top of SFO and SQL air-traffic control towers. The cameras are controlled by the NOAA Center Weather Service Unit located at the Oakland Air Route Traffic Control Center and are accessible via a secure Web site. The AAZCS cameras can be zoomed and can be panned and tilted to cover a field of view 220 wide. The NOAA observer can see the sky condition as it is changing, thereby making possible a real-time evaluation of the conditions along the approach zones of SFO and SQL. The next-generation network, denoted a remote tower sensor system (RTSS), will soon be deployed at the Half Moon Bay Airport and a version of it will eventually be deployed at Los Angeles International Airport. In addition to remote control of video cameras via secure Web links, the RTSS offers realtime weather observations, remote sensing, portability, and a capability for deployment at remote and uninhabited sites. The RTSS can be used at airports that lack control towers, as well as at major airport hubs, to provide synthetic augmentation of vision for both local and remote operations under what would otherwise be conditions of low or even zero visibility.
Abstract
Networks of video cameras, meteorological sensors, and ancillary electronic equipment are under development in collaboration among NASA Ames Research Center, the Federal Aviation [...]
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A Model for Sizing High Consequence Areas Associated With Natural Gas Pipelines
D. Moore, M. Stephens, K. Leewis

Collection of open conferences in research transport (2002). Vol. 2002, 82

Abstract
The failure of a high-pressure natural gas pipeline can lead to various outcomes, some of which can pose a significant threat to people and property in the immediate vicinity of the failure location. The dominant hazard is thermal radiation from a sustained jet or trench fire. An estimate of the ground area affected by a credible worst-case failure event can be obtained from a model that characterizes the heat intensity associated with rupture failure of the pipe where the escaping gas is assumed to feed a sustained trench fire that ignites very soon after line failure. An equation has been developed that relates the diameter and operating pressure of a pipeline to the size of the area likely to experience high consequences in the event of an ignited rupture failure. The model upon which the hazard area equation is based consists of three parts: 1) a fire model that relates the rate of gas release to the heat intensity of the fire as a function of distance from the fire source; 2) an effective release rate model that provides a representative steady-state approximation to the actual transient release rate; and 3) a heat intensity threshold that establishes the sustained heat intensity level above which the effects on people and property are consistent with the adopted definition of a so-called High Consequence Area. The validity of the proposed model is established by a comparison between the predicted extent of the damage area and the actual extent of damage for significant gas pipeline failure incidents reported in the public domain.Copyright © 2002 by ASME
Abstract
The failure of a high-pressure natural gas pipeline can lead to various outcomes, some of which can pose a significant threat to people and property in the immediate vicinity [...]
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Performance Guarantees for Hazard Based Lateral Vehicle Control
J. Gerdes, E. Rossetter

Collection of open conferences in research transport (2002). Vol. 2002, 81

Abstract
Today’s vehicles are incorporating many advanced driver assistance systems and in the near future it will be likely to have increased capabilities such as lanekeeping assist systems. These systems will be an integral part of the driving experience, aiding the driver in avoiding hazardous obstacles. One approach for these systems is to represent the hazards as artificial potential fields that add control inputs to move the vehicle towards safe regions on the road. This paper focuses on bounding the lateral motion of a vehicle for a lanekeeping system. A Lyapunov approach is used where the bounding function consists of the artificial potential energy associated with the controller, the kinetic energy in the lateral and yaw modes, and energy terms that are dependent on vehicle heading. In order to achieve this bound, a condition has to be met for the lookahead distance and the location of the control force (which can also be interpreted as a condition on the decoupling of lateral and yaw modes). Using this bound, a potential field gain can be chosen to guarantee collision avoidance with fixed lateral obstacles.Copyright © 2002 by ASME
Abstract
Today’s vehicles are incorporating many advanced driver assistance systems and in the near future it will be likely to have increased capabilities such as lanekeeping assist [...]
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Leak Detection Systems for Multiphase Flow: Moving Forward
C. Moura, R. Baptista

Collection of open conferences in research transport (2002). Vol. 2002, 80

Abstract
Multiphase flow is one of the most difficult situations for leak detection in pipelines, due to several reasons: the existence of two different and independent flow rates at each phase, five or more possible flow patterns, different fluid velocities at the phases, and sometimes a non-Newtonian associated behavior, due to the formation of an oil-water emulsion. There are two main groups for leak detection techniques: the models (or CPM, as stated in [API_1130]) which monitor the flow in real time (CVB, RTTM, PPA, etc.) from inside the pipeline (the instrument sensor is actually in physical contact with the fluid), and try to model the flow using a state estimator; and those based on dedicated external sensors (thermal, mass dispersion, etc) along the pipeline. Most of the technologies at the first group rely entirely on volumetric flow rate measurements, which turn them quite ineffective for multiphase flow. It is also relevant to consider that in some multiphase flow pipelines, the flow pattern changes quite random and intensively, allowing from a bubble pattern, to a slug pattern. There is sometimes the situation where a gas slug is big enough to fill entirely a short line and allow it to behave similarly to a gas pipeline, during a certain time (in fact, this was the case of one of the field tests this work will describe). This will bring unpredictability to those lines, in opposition to a regular single-phase line. Within this frame, the systems based on prediction approaches (hydraulic, statistical, etc, i. e., CPM’s), will show a good probability to be unreliable, inaccurate and not sensitive. The acoustic system is an exception to those two groups of technologies previously mentioned. It has, on one hand, a sensor that really touches the fluid (which would suggest it to be within the first group), but there’s no flow model behind it, on the other hand, but an acoustic sign analysis algorithm, acting somewhat like a piece of hardware. This paper will describe, discuss and report data for tests using an acoustic leak detection system at three different multiphase flow pipelines in Brazil, managed by PETROBRAS Production & Exploration Department.Copyright © 2002 by ASME
Abstract
Multiphase flow is one of the most difficult situations for leak detection in pipelines, due to several reasons: the existence of two different and independent flow rates [...]
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"title"Traffic engineering for Internet applications"/title"
A. Popescu, A. Jena

Collection of open conferences in research transport (2001). Vol. 2001, 32

Abstract
The focus of the paper is on resource engineering for supporting Service Level Agreements (SLAs) in IP networks. SLA at both link level and application level are considered. Using an object-oriented simulation model a case study is presented for client-server interactions generated by mixed traffic conditions in a Frame Relay (FR) WAN. Performance issues of Short Range Dependence (SRD) and Long Range Dependence (LRD) traffic under different resource control regimes are compared. The results show that major portion of the end-to-end delay comes from the queueing delay at the WAN ingress points, which is due to the significant bandwidth differences that may exist between LAN and WAN link layers. The results also highlight the role TCP window size and FR PVC control mechanisms play in the provision of delay performance for Internet services.
Abstract
The focus of the paper is on resource engineering for supporting Service Level Agreements (SLAs) in IP networks. SLA at both link level and application level are considered. [...]
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A Proposal for Sustainable Mobility Indicators as Urban Transport Policy Tools
J. Nicolas, P. Pochet, H. Poimboeuf

Collection of open conferences in research transport (2002). Vol. 2002, 74

Abstract
This research was funded by Renault automobile manufacturers.; This paper applied the theme of sustainable development to the case of urban transport. A series of indicators which simultaneously take account of environmental matters and the daily economic and social mobility of the inhabitants of a city is offered. The objective is to furnish a tool which will help in decision making, allowing the comparison of different urban transport alternatives within an urban area. We present here a research carried out to verify the possibility and the usefulness of elaborating these sustainable mobility indicators. It is applied to the French conurbation of Greater Lyon.
Abstract
This research was funded by Renault automobile manufacturers.; This paper applied the theme of sustainable development to the case of urban transport. A series of indicators [...]
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Evaluation and Application of MIDAS v2.0
D. Dahn, K. Dalal, A. Atencio, S. Hart

Collection of open conferences in research transport (2001). Vol. 2001, 29

Abstract
Version 2.0 of the Man-Machine Design and Analysis System (MIDAS) was released in 2001. It provides tools to describe an operating environment, mission, and equipment. User-defined goals, procedures, and knowledge interact with and are modified by models of perception, memory, situation awareness, and attention and constrained by the environment. Output of simulations that demonstrate or evaluate new capabilities or answer questions posed by customers are presented graphically and visually. MIDAS has been used to model different professions (soldiers in protective gear, air traffic controllers, astronauts, nuclear power plant operators, pilots), missions (e.g., flying, target designation, underwater exploration, police dispatch) and environments (e.g., battlefields, civil airspace, ocean floor, control rooms, low earth orbit). A recent independent evaluation of MIDAS V2.0 is reviewed.
Abstract
Version 2.0 of the Man-Machine Design and Analysis System (MIDAS) was released in 2001. It provides tools to describe an operating environment, mission, and equipment. User-defined [...]
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The use of discourse analysis to enhance ESP teacher knowledge: an example using aviation English
H. Girginer, P. Sullivan

Collection of open conferences in research transport (2002). Vol. 2002, 60

Abstract
Effective ESP programs require relevant materials, knowledgeable instructors, and teamwork with subject matter professionals. This report provides an example of one process used by a teacher–researcher to increase and expand each of these aspects. The process of data collection and data analysis, as described here, results in greater knowledge on the part of an instructor and leads to the development of enhanced course materials. The study was conducted for an ESP program in a Civil Aviation School in Turkey where students were in training to become pilots and air traffic controllers. Primary data included tape-recorded communication between pilots and air traffic controllers, observation in the airport tower, and questionnaires and interviews with Turkish pilots and air traffic controllers. The results, which comprised a basis for materials writers, indicate that even in such a restricted and globally monitored language as Airspeak, local variations exist in the use of greetings, the pronunciation of numbers, and the extended use of Turkish.
Abstract
Effective ESP programs require relevant materials, knowledgeable instructors, and teamwork with subject matter professionals. This report provides an example of one process [...]
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Conflict resolution by negotiation
K. Leblebicioğlu, U. Halici, M. Erden

Collection of open conferences in research transport (2002). Vol. 2002, 59

Abstract
Copyright © 2002 IFAC.The increase in air traffic, forces the current centralized air traffic control systems to be replaced with more decentralized control systems. The idea of free flight is developed with this consideration. In free flight aircrafts communicate and cooperate with each other to solve the conflicts. Each aircraft has its own separate optimization criteria, and aircrafts have to modify their paths considering these criteria. There should be a compromise in the amount of concession that aircrafts make in order to solve the conflict. In this research negotiation is introduced to achieve an agreement on the deviations from the optimal paths. Aircrafts negotiate on the amount of deviations they will perform to modify their paths. A frame for negotiation is developed, negotiation principles are determined, and simulations are performed.
Abstract
Copyright © 2002 IFAC.The increase in air traffic, forces the current centralized air traffic control systems to be replaced with more decentralized control systems. The [...]
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Radar-based analysis of the efficiency of runway use
J. Robinson, J. Andrews

Collection of open conferences in research transport (2001). Vol. 2001, 28

Abstract
The air transportation system faces a challenge in accommodating growing air traffic despite an inability to build new runways at most major airports. One approach to alleviating congestion is to find ways of using each available runway to the maximum extent possible without violating safety standards. Some decision support tools, such as the Final Approach Spacing Tool (FAST) that is a part of the Center TRACON Automation System (CTAS), are specifically targeted toward achieving greater runway throughput by reducing the average landing time interval (LTI) between arrivals at a given runway. In order to understand the potential benefits of such innovations, techniques for detecting spacing inefficiencies and estimating potential throughput improvements are needed. This paper demonstrates techniques for analyzing radar data from actual airport operations and using it to validate, calibrate, and extend analyzes of the FAST benefits mechanisms. The emphasis is upon robust statistical measures that can be produced through automated analysis of radar data, thus enabling large amounts of data to be analyzed.
Abstract
The air transportation system faces a challenge in accommodating growing air traffic despite an inability to build new runways at most major airports. One approach to alleviating [...]
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Pipeline Girth Weld Inspections Using Ultrasonic Phased Arrays
E. Ginzel, N. Dube´, M. Moles

Collection of open conferences in research transport (2002). Vol. 2002, 57

Abstract
Mechanized ultrasonics is rapidly replacing radiography worldwide for gas pipeline girth weld inspections. Compared with radiography, mechanized ultrasonics is more reliable, faster, has better detectability for critical Lack of Fusion defects, and poses no safety hazard. Phased arrays present major improvements over conventional multiprobe ultrasonics, both for onshore and for offshore use. Probe pans are lighter and smaller, permitting less cutback; scans are quicker due to the smaller probe pan; phased arrays are considerably more flexible for changes in pipe dimensions or weld profiles, and for different scan patterns; phased arrays have great potential for the future, such as compensating for variations in pipe wall thickness or temperature. This paper describes the evaluation of the PipeWIZARD ultrasonic phased array system for girth weld inspections, using standard ASTM E-1961 Mechanized Ultrasonics set-ups. Some typical results will be shown. The paper will describe the latest phased array UT results, plus developments like automated set-ups and improved imaging using an increased number of zones. A brief comparison of E-1961 and the recent API 1104 19th Edition codes will be made, plus a summary of approvals and track record to date.
Abstract
Mechanized ultrasonics is rapidly replacing radiography worldwide for gas pipeline girth weld inspections. Compared with radiography, mechanized ultrasonics is more reliable, [...]
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Managing the Design and Construction of the World's Largest Airport People Mover Project
D. Brown, P. Solis

Collection of open conferences in research transport (2001). Vol. 2001, 27

Abstract
Dallas / Fort Worth (DFW) International Airport has experienced significant increases in air traffic demand that supports the need for an overall airport expansion program. Expansion of existing Terminals has caused the current Airport's Train network to operate at a level very close to maximum practical capacity. The addition of a secure Automated People Mover System to transfer passengers between all the Airport Terminals is critical to support the Airport's projected future growth. The APM Program is a multifaceted organization made up of the owner, designers, contractors, train consultant, and the train supplier. All design and construction resources are co-located at the Airport's CDP Satellite Office Complex.
Abstract
Dallas / Fort Worth (DFW) International Airport has experienced significant increases in air traffic demand that supports the need for an overall airport expansion program. [...]
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Real Time Statistical Leak Detection on the RRP Crude Oil Network, Holland
J. Hoeijmakers, J. Lewis

Collection of open conferences in research transport (2002). Vol. 2002, 53

Abstract
Prior to the year 2000, the RRP crude oil pipeline network in Holland and Germany was monitored using a dynamic leak detection system based on a dynamic model. The system produced some false alarms during normal operation; prompting RRP to investigate what advances had been made in the leak detection field before committing to upgrade the existing system for Y2K compliance. RRP studied the available leak detection systems and decided to install a statistics-based system. This paper examines the field application of the statistics based leak detection system on the three crude oil pipelines operated by RRP. They are the 177 km Dutch line, the 103 km South line, and the 86 km North line. The results of actual field leak trials are reported. Leak detection systems should maintain high sensitivity with the minimum of false alarms over the long term; thus this paper also outlines the performance of the statistical leak detection system over the last year from the User’s perspective. The leak detection experiences documented on this crude oil pipeline network demonstrate that it is possible to have a reliable real-time leak detection system with minimal maintenance costs and without the costs and inconvenience of false alarms.
Abstract
Prior to the year 2000, the RRP crude oil pipeline network in Holland and Germany was monitored using a dynamic leak detection system based on a dynamic model. The system [...]
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Road curb and intersection detection using a 2D LMS
A. Balasuriya, W. Wijesoma, K. Kodagoda

Collection of open conferences in research transport (2002). Vol. 2002, 51

Abstract
In most urban roads and similar environments, such as in theme parks, campus sites, industrial estates, science parks and the like, the painted lane markings that exist may not be easily discernible by CCD cameras due to poor lighting, bad weather conditions, and inadequate maintenance. An important feature of roads in such environments is the existence of pavements or curbs on either side defining the road boundaries. These curbs, which are mostly parallel to the road, can be harnessed to extract useful features of the road for implementing autonomous navigation or driver assistance systems. However, extraction of the curb or road edge feature using vision image data is a very formidable task as the curb is not conspicuous in the vision image. To extract the curb using vision data requires extensive image processing, heuristics and very favorable ambient lighting. In our approach, road curbs are extracted speedily using the range data provided by a 2D laser range measurement system (LMS). Experimental results are presented to demonstrate the viability and effectiveness of the proposed methodology and its robustness to different road configurations including road intersections.
Abstract
In most urban roads and similar environments, such as in theme parks, campus sites, industrial estates, science parks and the like, the painted lane markings that exist may [...]
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Influence of Capacity Constraints on Airline Fleet Mix
M. Hansen, W. Wei, G. Gosling, J. Margulici

Collection of open conferences in research transport (2001). Vol. 2001, 26

Abstract
This report documents the findings of research sponsored by the Los Angeles World Airports to examine the influence of airport capacity constraints on airline fleet mix and to explore the potential effects of policy options to influence airlines to use larger aircraft types and thereby accommodate growth in passenger or cargo demand without a corresponding increase in the number of aircraft operations. This issue is of growing importance at many major airports in the United States and indeed around the world, as a steadily increasing demand for air transportation has resulted in volumes of air traffic that are approaching the capacity of the existing airport infrastructure, resulting in the prospect of significantly greater levels of aircraft delay in the future. At the same time, environmental and other concerns are limiting the ability of airports to construct additional runways to increase their airside capacity.
Abstract
This report documents the findings of research sponsored by the Los Angeles World Airports to examine the influence of airport capacity constraints on airline fleet mix and [...]
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A knowledge-based conflict resolution algorithm for terminal area air traffic control advisory generation
D. Isaacson, J. Robinson

Collection of open conferences in research transport (2001). Vol. 2001, 24

Abstract
NASA researchers, working under the Aviation System Capacity Program and in conjunction with the FAA Free Flight Program Office, have developed a set of decision support tools to assist terminal area air traffic controllers with control of arrival and departure traffic. Two of these tools, the Final Approach Spacing Tool (FAST) and the Expedite Departure Path (EDP) tool, provide air traffic controllers with heading, speed and altitude advisories to assist in spacing aircraft. This paper describes the conflict prediction and resolution algorithm shared by aFAST and EDP to produce conflict-free aircraft trajectories with realistic conflict resolution maneuvers. The process is accomplished in three stages: prediction, classification and resolution. A conflict prediction scheme is documented which incorporates all applicable FAA separation requirements, including automatic detection of separation during transition from staggered to simultaneous parallel approach operations. A method of classifying predicted conflicts with a limited set of criteria is detailed. Finally, a knowledge-based conflict resolution process is presented which allows for resolution of predicted conflicts in a manner consistent with controller practice: including prioritization of resolution tactics and mixture of multiple degrees of freedom to achieve separation. The scheme has been employed in both closed-loop simulations to determine solution stability and controller-in-the-loop simulations to begin development of the resolution tactics knowledge base.
Abstract
NASA researchers, working under the Aviation System Capacity Program and in conjunction with the FAA Free Flight Program Office, have developed a set of decision support tools [...]
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Integrated, Feed-Forward Hybrid Electric Vehicle Simulation in SIMULINK and its Use for Power Management Studies
C. Lin, Z. Filipi, Y. Wang, L. Louca, H. Peng, D. Assanis, J. Stein

Collection of open conferences in research transport (2001). Vol. 2001, 23

Abstract
hybrid electric vehicle simulation tool (HE-VESIM) has been developed at the Automotive Research Center of the University of Michigan to study the fuel economy potential of hybrid military/civilian trucks. In this paper, the fundamental architecture of the feed-forward parallel hybrid-electric vehicle system is described, together with dynamic equations and basic features of sub-system modules. Two vehicle-level power management control algorithms are assessed, a rule-based algorithm, which mainly explores engine efficiency in an intuitive manner, and a dynamic-programming optimization algorithm. Simulation results over the urban driving cycle demonstrate the potential of the selected hybrid system to significantly improve vehicle fuel economy, the improvement being greater when the dynamic-programming power management algorithm is applied. Copyright © 2001 Society of Automotive Engineers, Inc.
Abstract
hybrid electric vehicle simulation tool (HE-VESIM) has been developed at the Automotive Research Center of the University of Michigan to study the fuel economy potential of [...]
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Assessing delay benefits of the Final Approach Spacing Tool (FAST)
J. Robinson, J. Welch, J. Andrews

Collection of open conferences in research transport (2001). Vol. 2001, 20

Abstract
traffic delay grows each year. NASA is developing the Final Approach Spacing Tool (FAST) to help reduce airport arrival delays. FAST is intended to increase throughput and reduce delays. Analysis and field trials have suggested that FAST can help controllers increase arrival throughput on busy runways by several aircraft per hour. Published simulation studies have predicted that delay reductions from such throughput increases would save several hundred million dollars annually. However, these predictions disagree on delay savings for some airports and omit other airports of interest. Their predicted delay savings for some airports are higher than actual reported delays for those airports. They do not consider hazardous weather disruptions to arrival routes, and they do not address downstream delays caused by schedule disruption. This paper focuses on simple statistical and analytical measures of delay to resolve these problems. It develops a rule for ranking benefits and compares delay reduction predictions against actual reported delays. It relates delay to ceiling and visibility and thunderstorms. It examines the correlation of delay between airports and estimates the impact of downstream delay on FAST benefits.
Abstract
traffic delay grows each year. NASA is developing the Final Approach Spacing Tool (FAST) to help reduce airport arrival delays. FAST is intended to increase throughput and [...]
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Frequency and Time Domain Analysis of Vortex Induced Vibrations for Free Span Pipelines
C. Larsen, K. Koushan, E. Passano

Collection of open conferences in research transport (2002). Vol. 2002, 35

Abstract
The present paper will discuss various models for calculation of vortex induced vibrations (VIV) of free span pipelines, and present a new strategy for such analyses. Applications of traditional models are presented and their limitations discussed. The new approach is based on the combination of an empirical linear frequency domain model, and a non-linear time domain structural model. The first step is to carry out the VIV analysis according to linear response theory, and next introduce the calculated hydrodynamic forces to the non-linear structural model. The benefit from using the non-linear model is to describe stresses at the shoulders more accurately, which is important since fatigue damage in many cases will be largest in this area. The conclusion is that the interaction between pipe and seafloor is crucial for accurate stress prediction, and that a non-linear time domain model will give the most accurate result.
Abstract
The present paper will discuss various models for calculation of vortex induced vibrations (VIV) of free span pipelines, and present a new strategy for such analyses. Applications [...]
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Development and assessment of problem resolution capabilities for the en route sector controller
N. Rozen, K. Viets, K. Bowen, D. Kirk, W. Heagy

Collection of open conferences in research transport (2001). Vol. 2001, 19

Abstract
This paper provides an overview of problem resolution capabilities being developed to assist en route air traffic controllers. This function is termed Problem Analysis, Resolution and Ranking (PARR). PARR is envisioned as an enhancement to the User Request Evaluation Tool (URET) Free Flight Phase 1 (FFP1) capability, and has been designated as Priority Research for the follow-on Free Flight Phase 2 (FFP2) effort. PARR is being developed as a series of incremental enhancements to URET, with the first step focusing on providing additional support to the Radar Associate (D) controller for the resolution of aircraft-to-a ircraft and aircraft-to-airspace problems. Subsequent enhancements address the avoidance of severe weather areas, the implementation of Traffic Flow Management (TFM) flow initiatives, and the integration into a common en route Sector Team Computer-Human Interface (CHI). This paper provides an overview of the initial PARR capabilities and a summary of results from ongoing evaluations with active field controllers. An overview of the techniques being developed for the PARR functional performance and benefits assessment are given, along with initial results. Finally, concepts are described for the enhancement of URET and PARR to assist in the avoidance of severe weather areas and implementation of TFM flow initiatives.
Abstract
This paper provides an overview of problem resolution capabilities being developed to assist en route air traffic controllers. This function is termed Problem Analysis, Resolution [...]
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VIV Response of Long Free Spanning Pipelines
F. Nielsen, S. Kvarme, T. So̸reide

Collection of open conferences in research transport (2002). Vol. 2002, 30

Abstract
Vortex induced vibration (VIV) of free spanning pipelines in current is considered. In standard VIV estimation, one mode of oscillation is considered only. Increasing the length of the span, several modal shapes may be excited. Further, due to the sag effect of a long free span, the dynamic properties in vertical and horizontal direction of the span are different. This causes a much more complex VIV response pattern for long free spans than for short spans. The observed VIV response of long free spans during model testing is discussed. Hypotheses that may explain the observed behaviour are presented. Also a format of new design principles for long free spans is outlined.Copyright © 2002 by ASME
Abstract
Vortex induced vibration (VIV) of free spanning pipelines in current is considered. In standard VIV estimation, one mode of oscillation is considered only. Increasing the [...]
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Development of a tool for comparing conflict detection algorithms for air traffic management
E. Hoffman, T. Loureiro, K. Zeghal, K. Blin

Collection of open conferences in research transport (2001). Vol. 2001, 18

Abstract
One possible option to cope with increasing air traffic while maintaining or improving safety is the use of advanced decision support tools. The objective of the study presented here is to develop an evaluation environment together with an evaluation methodology to compare different conflict detection algorithms. The motivation is to estimate the benefits" of the conflict detection enhancements proposed in a previous work An environment to quantitatively evaluate and compare conflict detection algorithms has been developed. A geometric, and of two probabilistic approaches were evaluated using radar data.. While the use of a simple trajectory prediction precludes an operational evaluation, relative comparisons are still relevant. It was found that the modified probabilistic error model, approximating better the measured error, shows a decrease of the missed alert rate, while maintaining the false alert rate. The comparison of the geometric and probabilistic algorithms highlighted the sensitivity of the latter to parameters like the conflict probability threshold and the error model
Abstract
One possible option to cope with increasing air traffic while maintaining or improving safety is the use of advanced decision support tools. The objective of the study presented [...]
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The Application of 3D and Interference Detection in Construction Engineering
Y. Shiau, M. Wang, C. Yang

Collection of open conferences in research transport (2001). Vol. 2001, 17

Abstract
Skyscrapers and Hi-tech factories are a hot topic among construction industry nowadays. As the function of buildings become more sophisticated, subcontractors of a project are more closely related. It is difficult task for designers to present a 3D construction project at a 2D level especially when the building is full of equipments and pipelines. Lots of cost and time will have to waste on resolving inadequacy of the original design. In this research we transform a 2D design into 3D drawing by means of Virtual Reality technology. Users can use functions such as zoom, pan, and scale and penetrate to present the drawing and preview the project in planning stage; therefore, designing mistakes can be eliminated. Not only does our application execute interference detection to review structure, appliances and piping system at a 3D level, but it also lists the raw material for cost analysis. Through the assist of this research, engineers can exam all data at designing stage. Thus, human negligence can be reduced and budget and schedule can be controlled better.
Abstract
Skyscrapers and Hi-tech factories are a hot topic among construction industry nowadays. As the function of buildings become more sophisticated, subcontractors of a project [...]
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Accessibility by air passenger transport related to Switzerland: conference paper STRC 2002, session (1) travel, 2nd Swiss Transport Research Conference, Monte Verità, Ascona, March 20-22, 2002
J. Widmer

Collection of open conferences in research transport (2002). Vol. 2002, 28
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MATE: MPLS adaptive traffic engineering
I. Widjaja, A. Elwalid, C. Jin, S. Low

Collection of open conferences in research transport (2001). Vol. 2001, 16

Abstract
Destination-based forwarding in traditional IP routers has not been able to take full advantage of multiple paths that frequently exist in Internet service provider networks. As a result, the networks may not operate efficiently, especially when the traffic patterns are dynamic. This paper describes a multipath adaptive traffic engineering mechanism, called MATE, which is targeted for switched networks such as multiprotocol label switching (MPLS) networks. The main goal of MATE is to avoid network congestion by adaptively balancing the load among multiple paths based on measurement and analysis of path congestion. MATE adopts a minimalist approach in that intermediate nodes are not required to perform traffic engineering or measurements besides normal packet forwarding. Moreover MATE does not impose any particular scheduling, buffer management, or a priori traffic characterization on the nodes. This paper presents an analytical model, derives a class of MATE algorithms, and proves their convergence. Several practical design techniques to implement MATE are described. Simulation results are provided to illustrate the efficacy of MATE under various network scenarios.
Abstract
Destination-based forwarding in traditional IP routers has not been able to take full advantage of multiple paths that frequently exist in Internet service provider networks. [...]
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"title"Avoiding congestion through dynamic load control"/title"
A. Sethi, V. Hnatyshin

Collection of open conferences in research transport (2001). Vol. 2001, 15

Abstract
The current best effort approach to quality of service in the Internet can no longer satisfy a diverse variety of customer service requirements, and that is why there is a need for alternative strategies. In order to solve this problem a number of service differentiation models have been proposed. Unfortunately, these schemes often fail to provide proper service differentiation during periods of congestion. To deal with the issue of congestion, we introduce a new load control mechanism that eliminates congestion based on the feedback from the network core by dynamically adjusting traffic load at the network boundary. We introduce four methods for calculating load distribution among the ingress routers and among different flows in each ingress router, and we evaluate these proposed methods through simulation.
Abstract
The current best effort approach to quality of service in the Internet can no longer satisfy a diverse variety of customer service requirements, and that is why there is a [...]
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From cars towards dual-mode personal transport systems
S. Clement, E. Ekner, M. Taylor

Collection of open conferences in research transport (2002). Vol. 2002, 23

Abstract
Dual-mode transport systems can be regarded as a hybrid of today's road transport system, some elements of the current crop of ITS technologies and personal rapid transit (PRT) systems. In this paper we compare the personal transport characteristics of today's system with an example-the simple platoon advancement (SPA) model-of future ITS deployment, and with PRT systems. Then we present dual-mode systems-for example the rapid urban flexible (RUF) system-as possessing characteristics of the above three systems.
Abstract
Dual-mode transport systems can be regarded as a hybrid of today's road transport system, some elements of the current crop of ITS technologies and personal rapid transit [...]
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Intelligent agent for aircraft collision avoidance
S. Shandy, J. Valasek

Collection of open conferences in research transport (2001). Vol. 2001, 14

Abstract
way to obtain optimal traffic avoidance trajectory. The trend of air traffic system is heading towards a free flight environment. Free flight offers greater flexibility in planning for flights than the current air traffic control and management system. In free flight, operators are allowed to fly under Instrument Flight Rules and choose their own flight path and speed at real time. Some of the requirements to make free flight environment feasible include aircraft collision avoidance agent, also known as the traffic agent. One widely accepted concept of aircraft to aircraft communication for free flight environment is Automatic Dependent Surveillance Broadcast. In this paper, the focus is on constructing a traffic agent, utilizing aircraft to aircraft information, for an autonomous flight management system. The agent includes a traffic conflict detection module and collision avoidance module. The method used by the modules is a combination of knowledge base expert system and optimal control. The expert system is the primary decision maker and determines the appropriate actions required for conflict detection and avoidance. Optimal control is used to generate the optimum avoidance trajectory that adheres to the criteria assigned by the expert system. Results of a test case presented in the paper demonstrate that the combination of the two methods provides an efficient and effective
Abstract
way to obtain optimal traffic avoidance trajectory. The trend of air traffic system is heading towards a free flight environment. Free flight offers greater flexibility in [...]
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"title"Achieving fair and predictable service differentiation through traffic degradation policies"/title"
V. Hnatyshin, A. Sethi

Collection of open conferences in research transport (2001). Vol. 2001, 13

Abstract
Recently a large number of approaches to service differentiation have appeared in the literature. Most of these approaches are based on the Differentiated Services (DiffServ) Architecture proposed by IETF and they have been evaluated in a number of independent studies. It is widely acknowledged that the Differentiated Services approach provides proper service differentiation in well-provisioned networks under normal traffic conditions. However DiffServ may fail to provide proper service differentiation in the presence of extreme network conditions such as congestion or in under-provisioned networks, resulting in unfair service degradation and unpredictable traffic behavior. We believe that the main reasons for the failure of service differentiation under extreme network conditions are static per-aggregate resource allocation and the lack of the specification of traffic behavior during the congestion. We propose to explicitly define traffic behavior through so called degradation policies. Degradation policies would specify how much of the network resources each traffic class could receive under different levels of congestion. In particular, the degradation policy would specify traffic behavior in terms of the performance parameters like delay, loss, or throughput. Such an approach to service differentiation allows dynamic allocation of traffic resources while maintaining fairness and predictability of the traffic behavior under all network conditions.
Abstract
Recently a large number of approaches to service differentiation have appeared in the literature. Most of these approaches are based on the Differentiated Services (DiffServ) [...]
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Optimal resolution of en route conflicts
O. Chansou, J. Alliot, N. Durand

Collection of open conferences in research transport (2001). Vol. 2001, 12

Abstract
utomatic Control has been a subject of studies for the last twenty years. It involves many difficult problems that have to be solved: conflict detection, modelling of uncertainties on trajectories, clustering of 1-to-1 conflict to find unconnected n-aircraft problems, etc. . . Moreover, the n-aircraft conflict resolution problem is highly combinatorial and cannot be optimally solved using classical mathematical optimization techniques. The set of admissible solutions is made of many unconnected subsets enclosing different local optima, but the subset enclosing the optimum cannot be found a priori. In this paper, we present an automatic conflict solver and its implementation in an Air Traffic simulator, with statistical results on real traffic over France. This solver, which takes into account speed uncertainties and allows aircraft to fly on direct routes, solves every conflict on a loaded day, and gives each aircraft its requested flight level and departure time.
Abstract
utomatic Control has been a subject of studies for the last twenty years. It involves many difficult problems that have to be solved: conflict detection, modelling of uncertainties [...]
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Dynamic Congestion Avoidance using Multi-Agents Systems
N. Rouhana, E. Horlait

Collection of open conferences in research transport (2001). Vol. 2001, 10

Abstract
International audience; In this paper, we present a mechanism called DWRED (Dynamic Weighted RED) that uses communicating agents in a Multi-Agents Systems to enhance the basic Random Early Detection (RED) congestion management algorithm. Our proposition provides different levels of service for multiple classes of traffic, and adds cooperation between the network nodes that allows dynamic modification of the running algorithm’s parameters in response to different network congestion states. We show preliminary results of a simple DWRED prototype implemented using the Multi-Agents Systems platform MADKIT.
Abstract
International audience; In this paper, we present a mechanism called DWRED (Dynamic Weighted RED) that uses communicating agents in a Multi-Agents Systems to enhance the basic [...]
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Secure Large-Scale Airport Simulations Using Distributed Computational Resources
D. Maluf, Y. Gawdiak, P. Tran, W. McDermott

Collection of open conferences in research transport (2001). Vol. 2001, 9

Abstract
To fully conduct research that will support the far-term concepts, technologies and methods required to improve the safety of Air Transportation a simulation environment of the requisite degree of fidelity must first be in place. The Virtual National Airspace Simulation (VNAS) will provide the underlying infrastructure necessary for such a simulation system. Aerospacespecific knowledge management services such as intelligent data-integration middleware will support the management of information associated with this complex and critically important operational environment. This simulation environment, in conjunction with a distributed network of super-computers, and high-speed network connections to aircraft, and to Federal Aviation Administration (FAA), airline and other data-sources will provide the capability to continuously monitor and measure operational performance against expected performance. The VNAS will also provide the tools to use this performance baseline to obtain a perspective of what is happening today and of the potential impact of proposed changes before they are introduced into the system.
Abstract
To fully conduct research that will support the far-term concepts, technologies and methods required to improve the safety of Air Transportation a simulation environment of [...]
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Evaluation of car traffic reduction potential in urban area, Paris and Lyon case-studies
M. Massot, J. ARMOOGUM, P. Bonnel, D. Caubel, L. Hivert, D. Mignot

Collection of open conferences in research transport (2002). Vol. 2002, 16

Abstract
Proceedings on CD-ROM.; International audience; The private car currently dominates travel in large metropolitan areas and its use is on the increase, in spite of the fact that public opinion is generally in favour of the development of public transport and political statements which reflect this opinion. Furthermore, the available projections and an analysis of the potential effect of conventional policies indicate that although such policies are able to exert some control, it is limited."br /""br /"Then, the question, that this research directed by INRETS will attempt to answer, is: could a major metropolitan area operate with a radically different transport system that is based principally on the use of modes other than the automobile? By "radically different", we mean a system in which use of the conventional automobile would be reduced in a non-marginal manner, by, say, between a third and a half of all private car vehicle-kilometres."br /""br /"This research does not attempt to justify a move towards a radically different system a lot as already been said on it. Instead, the project will perform different transport simulations and assess on based-rules the effect on the use of modes."br /""br /"Transport scenarios have been designed to incorporate a progressive improvement in public transport supply in the following respects: increase in speeds on the roads, increase in service frequencies during off-peak periods, creation of exclusive public transport lanes, reserving radial roads for public transport, extension of metro and regional express rail and reorganisation of bus routes in response to this. We have also devised and simulated a set of appropriate accompanying strategies that are intended to improve the effectiveness of public transport supply, for example policies to encourage the use of the bicycle or park and ride schemes. "br /""br /"The methodology, developed by INRETS has been applied on Paris and Lyon region based on the last household travel survey conducted in each area. For each transport scenario, Paris and Lyon models are used to calculate public transport time for all trips whatever is the actual mode of transport. We then applied the procedure of mode transfer to assess the effect of each of these scenario on mode choice. The procedure is based on automatic rules. Trips, or more precisely round trips, are assigned to one or other of the alternative modes on the basis of elimination rules (no walking for distances over 2 kilometres, no cycling over 8 kilometres, no modal transfer if the purpose of the round trip is for escorting purposes...) and on the basis of constraints (individual travel-time budgets, the length of each trip and round trips, the existence of transport supply...). This system of rules and constraints constitutes the core of the modal transfer procedure."br /""br /"The paper will present both the methodology and results obtain from Paris and Lyon case studies.
Abstract
Proceedings on CD-ROM.; International audience; The private car currently dominates travel in large metropolitan areas and its use is on the increase, in spite of the fact [...]
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Evaluation of Eta model forecasts as a backup weather source for CTAS
R. Hogaboom, H. Vandevenne, R. Lloyd

Collection of open conferences in research transport (2001). Vol. 2001, 7

Abstract
Knowledge of present and future winds and temperature is important for air traffic operations in general, but is crucial for Decision Support Tools (DSTs) that rely heavily on accurately predicting trajectories of aircraft. One such tool is the CenterTRACON Automation System (CTAS) developed by NASA Ames Research Center. The Rapid Update Cycle (RUC) system is presently the principal source of weather information for CTAS.' RUC provides weather updates on an hourly basis on a nationwide grid with horizontal resolution of 40 km and vertical resolution of 25 mb in pressure. However, a recent study of RUC data availability showed that the NWS and NOAA servers are subject to frequent service interruptions. Over a 210 day period (4/19/0011/11/00), the availability of two NOAA and one NWS RUC server was monitored automatically. It was found that 60 days (29%) had periods of one hour or more where at least one server was out, with the longest outage lasting 13 hours on 9/21/00. In addition, there were 9 days (4%) for which all three servers were simultaneously unavailable, with the longest outage lasting 6 hours on 5/7/00. Moreover, even longer outages have been experienced with the RUC servers over the past several years. RUC forecasts are provided for up to 12 hours, but these are not currently used in CTAS as back up sources (except that the 1 or 2 hour forecasts are used for the current winds to compensate for transmission delays in obtaining the RUC data). Since RUC outages have been experienced for longer than 12 hours, it is therefore necessary to back RUC up with another weather source providing long-range forecasts. This paper examines the use of the Eta model forecasts as a back-up weather source for CTAS. A specific *This work was performed for the Federal Aviation Administration under Air Force Contract No. F19628-00-C-0002. tCopyright © 2001 by M.I.T. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. output of the Eta 32 km model, namely Grid 104, was selected for evaluation because its horizontal and vertical resolution, spatial extent and output parameters match most closely those of RUC. While RUC forecasts for a maximum of 12 hours into the future, Eta does so for up to 60 hours. In the event that a RUC outage would occur, Eta data could be substituted. If Eta data also became unavailable, the last issued forecasts could allow CTAS to continue to function properly for up to 60 hours. The approach used for evaluating the suitability of the Eta model and RUC forecasts was to compare them with the RUC analysis output or 0 hour forecast file, at the forecast time. Not surprisingly, it was found that the RUC model forecasts had lower wind magnitude errors out to 12 hours (the limit of the RUC forecasts) than the Eta model had. However, the wind magnitude error for the Eta model grew only from 9 ft/s at 12 hours (comparable with RUC) to 11 ft/s at 48 hours. We therefore conclude that RUC forecasts should be used for outages up to 12 hours and Eta model forecasts should be used for outages up to 60 hours.
Abstract
Knowledge of present and future winds and temperature is important for air traffic operations in general, but is crucial for Decision Support Tools (DSTs) that rely heavily [...]
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Design of an Advanced Heavy Tactical Truck: A Target Cascading Case Study
N. Michelena, L. Louca, M. Kokkolaras, C. Lin, D. Jung, Z. Filipi, D. Assanis, P. Papalambros, H. Peng, J. Stein, M. Feury

Collection of open conferences in research transport (2001). Vol. 2001, 6

Abstract
The target cascading methodology is applied to the conceptual design of an advanced heavy tactical truck. Two levels are defined: an integrated truck model is represented at the top (vehicle) level and four independent suspension arms are represented at the lower (system) level. Necessary analysis models are developed, and design problems are formulated and solved iteratively at both levels. Hence, vehicle design variables and system specifications are determined in a consistent manner. Two different target sets and two different propulsion systems are considered. Trade-offs between conflicting targets are identified. It is demonstrated that target cascading can be useful in avoiding costly design iterations late in the product development process. Copyright © 2001 Society of Automotive Engineers, Inc.
Abstract
The target cascading methodology is applied to the conceptual design of an advanced heavy tactical truck. Two levels are defined: an integrated truck model is represented [...]
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Smart PIG “Fingerprint” Inspections Can Lead to Fitness for Purpose Assessments and Contractual Disputes
R. Palmer-Jones, G. Wintle, P. Hopkins, P. Nafis

Collection of open conferences in research transport (2002). Vol. 2002, 13

Abstract
recent ‘fingerprint’ smart pigging inspection recorded over 40,000 metal loss (corrosion) features in a 57km 42” diameter, dry gas pipeline supplying a major LNG facility in Indonesia. The pipeline had been in operation for less than 6 months. Assessment of these results by the inspection company identified 10 sections of pipe that required repair according to ASME B31.G, indicating that the pipeline was not ‘fit for purpose’. The pipeline operator immediately cut out these 10 sections to ensure the continued safe operation of the new pipeline. A detailed pipeline corrosion study subsequently identified the features as corrosion that had occurred during transport and storage of the line pipe. In addition, the corrosion was found to be less severe than initially thought and the same work assessed the remaining defects and, calculations using DNV Guideline RP F101, showed that the features were all acceptable. It was concluded that the high sensitivity of the smart pigging tool, combined with the failure to identify the cause of the features and the simple initial feature assessment overestimated the significance of the corrosion defects. This demonstrates the need for good care and inspection of line pipe during transport storage and construction. It also highlights the need to conduct engineering assessments to determine the inspection philosophy and to quantify the ‘workmanship’ level of metal loss features acceptable on a fingerprint run, before the run takes place. Otherwise new pipelines containing ‘custom and practice’ defects could be the subject of lengthy and costly disputes between operator and constructor. This paper proposes a method for assessing baseline survey data that provides an acceptance level for pre-existing defects. This methodology will assist operators in assessing smart pigging data from new pipelines.Copyright © 2002 by ASME
Abstract
recent ‘fingerprint’ smart pigging inspection recorded over 40,000 metal loss (corrosion) features in a 57km 42” diameter, dry gas pipeline supplying a major LNG facility [...]
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Stress Analysis of Pipelines With Composite Repairs
J. Freire, R. Vieira, J. Diniz, L. Meniconi

Collection of open conferences in research transport (2002). Vol. 2002, 12

Abstract
The repair of corroded pipelines with fiber reinforced composite materials is a well-developed practice in the oil and gas transportation industry. Laboratory hydrostatic burst tests and field practice of several years have shown that these repairs are effective for pipelines with external corrosion defects. This paper deals with laboratory tests carried out to compare the behavior of fiber reinforced composite repairs applied to defects machined in pipeline test specimens. The experimental results were compared to results from Finite Element Analysis (FEA) of the tubes tested. The parameters of FEA were calibrated to this specific problem, beforehand. Some hipotheses were tested during FEA trials to better explain the experimental results. The results indicated that, up to the starting of yielding of the pipe defected region, practically only the elastic pipe stresses equilibrate the pressure loading, due to the steel high Young modulus. After yielding, the composite material starts to work, carrying an important part of the pressure loading increments. Experimental results also showed that the repair systems tested allowed the pipes to achieve the original design pressure before bursting. However, only one of the repair systems was approved in all strength verification tests for both internal and external defects. This system operated for four hours under a hydrostatic pressure test associated to the specified minimum yield strength (SMYS) of the steel and was also able to support ten pressure cycles of the design pressure afterwards, without showing any visual damage.
Abstract
The repair of corroded pipelines with fiber reinforced composite materials is a well-developed practice in the oil and gas transportation industry. Laboratory hydrostatic [...]
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Conflict resolution in presence of uncertainty - A case study of decision making with dynamic programming
F. Bonnans, K. Blin, K. Zeghal, E. Hoffman

Collection of open conferences in research transport (2001). Vol. 2001, 5

Abstract
From a system perspective, one important characteristic of the air traffic system, is the uncertainty or even the lack of knowledge of future states (aircraft trajectories). In a such context, deciding when an action (to solve a conflict) has to be performed is an open issue. However, since the knowledge of future states (aircraft trajectories) is dynamically refined and updated, the air traffic system can be considered as a dynamic system. In this context, attempting to identify an "optimal" time to manoeuvre (and the manoeuvre itself) can be formulated as a problem of optimal control of a dynamic system. It has been shown that this class of problem can be modelled by the Hamilton-Jacobi-Bellman equation. The dynamic programming approach could be used to solve this equation for a dynamic system. As a first attempt to take advantage of this perspective, the paper proposes an initial problem statement (including the HJB equation and a cost function), along with a possible dynamic programming algorithm to solve it. Some simulations have been conducted to stress the impact of different cost functions and level of knowledge about surrounding aircraft.
Abstract
From a system perspective, one important characteristic of the air traffic system, is the uncertainty or even the lack of knowledge of future states (aircraft trajectories). [...]
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Multi-Sensor Data Fusion Using Bayesian Programming : an Automotive Application
T. Fraichard, P. Bessière, C. Coué, E. Mazer

Collection of open conferences in research transport (2002). Vol. 2002, 8

Abstract
International audience; A prerequisite to the design of future Advanced Driver Assistance Systems for cars is a sensing system providing all the information required for high-level driving assistance tasks. Carsense is a European project whose purpose is to develop such a new sensing system. It will combine different sensors (laser, radar and video) and will rely on the fusion of the information coming from these sensors in order to achieve better accuracy, robustness and an increase of the information content. This paper demonstrates the interest of using probabilistic reasoning techniques to address this challenging multi-sensor data fusion problem. The approach used is called Bayesian Programming. It is a general approach based on an implementation of the Bayesian theory. It was introduced first to design robot control programs but its scope of application is much broader and it can be used whenever one has to deal with problems involving uncertain or incomplete knowledge.
Abstract
International audience; A prerequisite to the design of future Advanced Driver Assistance Systems for cars is a sensing system providing all the information required for high-level [...]
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The design and implementation of the new center/TRACON automation system (CTAS) weather distribution system
R. Hogaboom, H. Vandevenne, S. Campbell, J. Murphy, R. Lloyd

Collection of open conferences in research transport (2001). Vol. 2001, 4

Abstract
The National Aeronautics and Space Administration (NASA), working with the Federal Aviation Administration (FAA), is developing a suite of decision support tools, called the Center/TRACON Automation System (CTAS). CTAS tools such as the Traffic Management Advisor (TMA) and Final Approach Spacing Tool (FAST) are designed to increase the efficiency of the air traffic flow into and through Terminal airspace. A core capability of CTAS is the Trajectory Synthesis (TS) software for accurately predicting an aircraft's trajectory. In order to compute these trajectories, TS needs an efficient access mechanism for obtaining the most up-to-date and accurate winds. The current CTAS weather access mechanism suffers from several major drawbacks.1 First, the mechanism can only handle a winds at a single resolution (presently 40-80 km). This prevents CTAS from taking advantage of high resolution wind from sources such as the Integrated Terminal Weather System (ITWS). Second, the present weather access mechanism is memory intensive and does not extend well to higher grid resolutions. This potentially limits CTAS in taking advantage of improvements in wind resolution from sources such as the Rapid Update Cycle (RUC). Third, the present method is processing intensive and limits the ability of CTAS to handle higher traffic loads. This potentially could impact the ability of new tools such as Direct-To and Multi-Center TMA (McTMA) to deal with increased traffic loads associated with adjacent Centers.
Abstract
The National Aeronautics and Space Administration (NASA), working with the Federal Aviation Administration (FAA), is developing a suite of decision support tools, called the [...]
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Immersion reality: Combining microsimulation modelling and probe vehicles in traffic studies
M. Taylor, J. Woolley, R. Zito, R. Cheu, D. Srinivasan, D. Lee

Collection of open conferences in research transport (2002). Vol. 2002, 7

Abstract
Paramics micro-simulation model of an Adelaide radial road corridor has been constructed. The corridor includes a novel one-way reversible direction expressway equipped with an advanced traffic management system (ATMS). The modelled area included two alternative radial routes: an arterial road and the expressway. The model was used to analyse the performance of the corridor when an incident occurred on the expressway, in terms of traffic conditions and greenhouse gas emissions. Real world data was collected on both routes using an instrumented vehicle which records vehicle engine, positional and emissions data in real time. Paramics allows a representation of the probe vehicle to be introduced into the simulations. The paper describes the modelled results when this vehicle was immersed in the simulation modelling on incidents and the responses of the corridor's ATMS, with particular regard to the estimation of the emission impacts of ATIS and INMS.
Abstract
Paramics micro-simulation model of an Adelaide radial road corridor has been constructed. The corridor includes a novel one-way reversible direction expressway equipped with [...]
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Mechanics of Offshore Pipelines in Several Operating States and Analyzing Software
C. Liu, J. Xing, X. Zeng

Collection of open conferences in research transport (2002). Vol. 2002, 6

Abstract
Offshore pipelines are indispensable structures during the marine petroleum exploitation. There are manifold operation states having to do with pipelines such as in situ operation, span, trenching, pipelaying, lifting of pipe/riser, etc. The behavior of pipelines in one state differs greatly from the others. In addition, the structure configuration, the sea severity, and the seabed soil conditions are complex. Therefore, strength analysis of offshore pipelines becomes a rather difficult and onerous task. Presently, there is a lot of technological difficulty in the course of analysis, among which are not only theoretical problems such as geometric non-linearity and moveable boundary, but also practical problems. To tackle the problems, analytical methods, numerical methods such as FEM and shooting method are adopted respectively and jointly. Based on the theoretical research, integrated software named ‘Offshore Pipelines Strength Analysis’ is developed. This software can carry through strength analysis of pipelines in different operating state, being up to the requirement of engineers. The theoretical background and interface of the software are presented.Copyright © 2002 by ASME
Abstract
Offshore pipelines are indispensable structures during the marine petroleum exploitation. There are manifold operation states having to do with pipelines such as in situ operation, [...]
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Evaluation of Pipe Whip Impacts on Neighboring Piping and Walls of the Ignalina Nuclear Power Plant
E. Uspuras, R. Kulak, M. Petry, E. Narvydas, G. Dundulis, A. Marchertas

Collection of open conferences in research transport (2002). Vol. 2002, 3

Abstract
Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. Therefore, two cases are investigated: • GDH impact on an adjacent GDH and its attached piping; • GDH impact on an adjacent reinforced concrete wall. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large displacements and nonlinear material characteristics. The results of the study indicate that a whipping GDH pipe would not significantly damage adjacent walls or piping and would not result in a propagation of pipe failures.Copyright © 2002 by ASME
Abstract
Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important [...]
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Traffic Engineering in a Bluetooth Piconet
A. Dahlberg

Collection of open thesis in transport research (2002). Vol. 2002, 7

Abstract
The Bluetooth technology is still in an early stage of development. Much more research can and will be done before the performance of Bluetooth reaches its peak. During the recent years, ideas to integrate Bluetooth units in larger networks have arose, with the Bluetooth unit in the role as access point to the network. This behavior opens up for new possibilities but also increases the requirements on performance. In this thesis the main topic is improvement of piconet performance. The piconet, with the Master unit as access point, is studied from a teletraffic engineering point of view. Different performance attributes and behaviors have been found and investigated. With the outcome of these investigations in mind, new and more efficient policies and algorithms are proposed for both data and voice. A policy increasing the utilization of available bandwidth in a piconet is presented. Furthermore, a proposal is presented where multiple Bluetooth units are used in an efficient manner to support voice calls. The proposed solution does also enable creation of simple teletraffic models to be used for dimensioning. Phone: +46709138850
Abstract
The Bluetooth technology is still in an early stage of development. Much more research can and will be done before the performance of Bluetooth reaches its peak. During the [...]
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Designing for safety: The free flight air traffic management concept
J. Hoekstra

Collection of open thesis in transport research (2001). Vol. 2001, 3

Abstract
This paper describes the conceptual design and validation of an air traffic management (ATM) concept and the role the safety and human factors played in this design and validation process. The free flight (FF) concept is characterised by being a direct route concept where the pilots, instead of the air traffic controller, are responsible for the separation assurance. Moving this task to the cockpit has consequences for the man machine interface in the cockpit, which needs to be modified to accommodate this new task (micro level design). On top of that, a set of rules and procedures are required to ensure an efficient and safe traffic flow (macro level design). Both the micro and macro aspect of this design are intertwined and require an accurate tuning to arrive at an overall acceptable solution. Both micro-level (flight simulator) experiments and macro-level (traffic simulations) experiments have been conducted to investigate the feasibility of this concept after optimising the initial conceptual design.
Abstract
This paper describes the conceptual design and validation of an air traffic management (ATM) concept and the role the safety and human factors played in this design and validation [...]
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Encouraging Environmentally Sustainable Growth in the United States
P. O'Brien

Collection of open reports in transport research (2001). Vol. 2001, 14

Abstract
This paper analyses aspects of US environmental policy, including, among others, policy on air and water quality, water supply in certain areas, climate change and greenhouse gas emissions. Particular attention is paid to certain policies in agriculture and road transport, sectors with an important influence on the environment, as well as to the use of cost-benefit analysis (and in some cases specific prohibitions on its use) and the role of the courts in designing and implementing policy. While “command and control” style regulations have produced significant improvements in environmental standards since the 1970s, increasing attention has been paid to the use of economic incentives - permit trading arrangements have been preferred to environmental taxes - and more flexibility in some regulatory policies. These trends towards more cost-effective policies should be extended to such areas as fuel economy, where increased fuel taxes would be more cost-effective than the “CAFE” ... Ce document analyse quelques aspects de la politique environnementale des Etats-Unis, concernant en particulaier la qualite de l'air et de l'eau, la gestion de l'offre de l'eau dans certaines regions, le changement climatique et les emissions de gas a effet de serre. Une attention particuliere est portee sur certaines politiques dans les secteurs de l'agriculture et du transport routier, qui ont une influence importante sur l'environnement, ainsi que sur l'utilisation de l'analyse cout-benefice (ou dans certains cas son interdiction) et le role des cours de justice dans le developpement et la mise en oeuvre des politiques. Tandis que les politiques de type "obligations et reglementations" ont permis une amelioration notable des standards environnementaux depuis les annees 70, On a porte une attention croissante a l'utilisation d'incitations economiques - des marches de permis plutot que des taxes-, et a l'introduction de plus de flexibilite dans certaines reglementations. Ces ...
Abstract
This paper analyses aspects of US environmental policy, including, among others, policy on air and water quality, water supply in certain areas, climate change and greenhouse [...]
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Improving Efficiency of INDOT Traffic Data Collection Using GPS Devices
C. Tuttle, J. Nagle, K. Zhu, S. Li, B. Gelder

Collection of open reports in transport research (2002). Vol. 2002, 18

Abstract
INDOT has utilized many new technologies to reduce travel delay, mitigate traffic congestion, and enhance public and employees’ safety. Many projects are underway, including re-timing of most existing traffic signals and pavement maintenance and rehabilitation. To evaluate signal system performance, prioritize alternatives of improvement, conduct before and after studies and investigate work zone safety, it requires a large amount of traffic data such as travel time, speed and delay. Issues, such as safety, efficiency and cost, may arise associated with the current methods. For the current manual or automatic data collection, it usually requires two operators, a driver and a recorder. The current methods also require much time for data processing and the resulting data files may not be reusable. With the global positioning system (GPS) technologies, it appears that traffic data collection can be performed more safely and efficiently. The objective of this study is to investigate use of the GPS technologies to improve efficiency of INDOT traffic data collection, to enhance field operation safety, and to reduce potential human errors. Primary emphasis is given to utilization of GPS receivers to acquire traffic data so as to generate a reusable data file. This kind of data files is essential for providing INDOT traffic engineers with consistent information for assessing the performance of signal systems. Secondary emphasis is given to use of the GPS data in specific transportation studies, such as travel time and delay studies, work zone studies, and congestion management. In this study, the GPS techniques were examined and the Trimble AgGPS 132 devices were tested using the precisely known geographic points. A computer program, GPS-Trek, was developed for data collection and data processing. A huge amount of data was collected over the selected routes. Based on the results of analysis and field tests, a summary of the major findings are presented below: The proposed GPS data collection system is inexpensive and cost-effective. It can improve the efficiency of traffic data collection, save manpower and enhance field operation safety. The AgGPS 132 receiver can provide traffic data of high accuracy and consistency. The field data may exhibit gaps in “deep” urban canyons. However, through interpolation and proper data screening these disadvantages may be limited. The removal of Selective Availability from the GPS signals further improves the accuracy of GPS data. It was shown that the relative positional accuracy using a DGPS service is well below the 0.5 meter level. The GPS-Trek consists of two components, one for data collection and the other for data processing. The program is free of personal interpretation during data collection and provides a consistent system of analysis. The resulting data files are reusable. The data file can be easily exported to Microsoft® Excel, allowing traffic engineers to utilize their own experience and judgment for data analysis and specific transportation studies. A modified equation is presented to estimate the sample size requirements for field data collection using GPS devices. It was shown that in the filed tests, the modified equation produced a realistic estimate of the minimum sample size. Generally, a minimum of three initial test runs should be performed. If possible, five initial test runs for 90% confidence or six for 95% confidence are required to reduce the potential errors. The proposed system can be readily used for various transportation studies. This system bases its procedures on the existing INDOT highway digital map, resulting in a great saving in terms of manpower and time for creating a high resolution base map. The system also allows us to mark any critical points during data collection or data processing. As a result, it is possible for us to provide graphical reports, such as vehicle trajectory and speed profile that are required in the Manual of Transportation Engineering Studies and get a full picture of traveling situation on the test route. Also, this system can be used for measuring congestion on a system level.
Abstract
INDOT has utilized many new technologies to reduce travel delay, mitigate traffic congestion, and enhance public and employees’ safety. Many projects are underway, including [...]
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Material Balance Assessment for Double-Shell Tank Waste Pipeline Transfer
S. Hartley, Y. Onishi, C. Enderlin, B. Wells

Collection of open reports in transport research (2001). Vol. 2001, 13

Abstract
PNNL developed a material balance assessment methodology based on conservation of mass for detecting leaks and mis-routings in pipeline transfer of double-shell tank waste at Hanford. The main factors causing uncertainty in these transfers are variable property and tank conditions of density, existence of crust, and surface disturbance due to mixer pump operation during the waste transfer. The methodology was applied to three waste transfers from Tanks AN-105 and AZ-102.
Abstract
PNNL developed a material balance assessment methodology based on conservation of mass for detecting leaks and mis-routings in pipeline transfer of double-shell tank waste [...]
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Waste Preparation and Transport Chemistry: Results of the FY 2000 Studies
R. Hunt

Collection of open reports in transport research (2001). Vol. 2001, 12

Abstract
Problems with pipeline plugs at Hanford have occurred throughout its tank farm system. Most cross-site transfer lines at Hanford are no longer functional due to these plugs. Waste transfers frequently led to partial line plugs, resulting in substantial amounts of water being added to the tank system in an attempt to free the lines. In response to these plugs, the Hanford tank farm developed waste acceptance criteria that a waste must pass before it can be transferred (Shekarriz et al., 1997). The criteria, which include physical properties such as viscosity, specific gravity, and percent solids, are based primarily on past operational experience. Unfortunately, the chemistry of the waste solutions was not included in the criteria even though the tank farm operators are fully aware of its importance. Pipeline plugs have also occurred during relatively short waste transfers at Hanford. In FY 2000, the effort to saltwell pump 50,000 gal of filtered waste from tank U-103 to tank SY-102 was delayed for several weeks due to a plugged pipeline. Attempts to locate the plug(s) determined that it had occurred in the 02-A flex and that other plugs were possible in each of the SY-farm flexes. Modifications such as larger flex jumpers and additional heat tracing were made to the transfer system. The plug was probably attributable to a reduction in the temperature of the waste in the pipeline. The waste in tank U-103 was approximately 30 C prior to the transfer. During tests on actual waste from tank U-103 (Herting, 1999), trisodium phosphate solids were observed at temperatures as high as 20 C after a 50% dilution with water. Therefore, the following precautions (Herting, 1999) were recommended during the saltwell pumping of tank U-103. First, the tank waste should not be heated prior to the transfer. Second, the waste should not be permitted to cool during the transfer. Third, the waste should be kept moving during the transfer. A previous Tanks Focus Area (TFA) study (Hunt et al., 1999) clearly demonstrated the need to maintain the temperature of the waste in this range. Even small reductions in the temperature of simulated wastes from 35 to 30 C and from 30 to 25 C led to high-viscosity solids that could easily plug a pipeline.
Abstract
Problems with pipeline plugs at Hanford have occurred throughout its tank farm system. Most cross-site transfer lines at Hanford are no longer functional due to these plugs. [...]
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A Strategy for Slovakia's Transport Sector
W. Bank

Collection of open reports in transport research (2001). Vol. 2001, 11

Abstract
Slovakia’s transport sector has not suffered from the dramatic reductions in demand and neglect of its infrastructure that have afflicted many of its neighbors. However, current under-maintenance is eating away at the stock of transport infrastructure and is unsustainable in anything more than the very short term. In addition, despite good intentions, progress on commercializing its transport operations has not progressed far enough to put them in a strong position to confront the pressures they will face when Slovakia enters the European Union, hopefully at the beginning of 2004. There is now a short window of opportunity to make good on deferred maintenance, establish a more sustainable maintenance regime and make good on the previous good intentions for commercialization. The opportunity exists also for the institutional structure of the sector to be revised so as to better reflect the interests of transport users, reform the way that infrastructure is financed and to systematically eliminate the remaining regulatory protections given to existing operators. The Strategy presented here shows how these objectives can best be reached, and how the World Bank can help bring them about. If the Strategy is implemented, action will have been taken before there is a problem and order will have been introduced before disorder takes over.
Abstract
Slovakia’s transport sector has not suffered from the dramatic reductions in demand and neglect of its infrastructure that have afflicted many of [...]
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Reflections on Transportation and Mobility
S. Polzin, X. Chu

Collection of open reports in transport research (2001). Vol. 2001, 10

Abstract
The 14 essays in this collection are short pieces authored to share perspectives and encourage reflective thinking about the state of transportation planning and mobility in the United States. These essays are based on personal observations and derive much of their essence from a series of research projects and observations of contemporary issues in transportation planning and policy. Intended to be informative, insightful, and provocative, the author is solely responsible for the accuracy and opinions expressed in the essays. They do not reflect opinions of CUTR, USF, or our clients and sponsors.
Abstract
The 14 essays in this collection are short pieces authored to share perspectives and encourage reflective thinking about the state of transportation planning and mobility [...]
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Hose in Hose Transfer Line Qualification and Acceptance Test Plan and Procedure
K. Witwer

Collection of open reports in transport research (2001). Vol. 2001, 9

Abstract
This Test Plan and Procedure outlines the methodology used to test the performance of several Hose-in-Hose Transfer Lines used by the River Protection Project's Interim Stabilization Group.
Abstract
This Test Plan and Procedure outlines the methodology used to test the performance of several Hose-in-Hose Transfer Lines used by the River Protection Project's Interim Stabilization [...]
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Waste transfer encasement pressure capability
R. Schlosser

Collection of open reports in transport research (2001). Vol. 2001, 8

Abstract
This report provides calculation of the pressure retention capability of waste transfer piping encasement system components based on ASME B31.1 requirements.
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Advanced Driver Assistance Systems
R. Kala

Collection of open reports in transport research (2001). Vol. 2001, 7

Abstract
dvanced Driver Assistance Systems are intelligent systems that reside inside the vehicle and assist the main driver in a variety of ways. These systems may be used to provide vital information about traffic, closure and blockage of roads ahead, congestion levels, suggested routes to avoid congestion etc. These systems may also be used to judge the fatigue and distraction of the human driver and thus make precautionary alerts or to assess the driving performance and make suggestions regarding the same. These systems can take over the control from the human on assessing any threat, perform easy tasks (like cruise control) or difficult manoeuvres (like overtaking and parking). The greatest advantage of using the assistance systems is that they enable communication between different vehicles, vehicle infrastructure systems and transportation management centres. This enables exchange of information for better vision, localization, planning and decision making of the vehicles.
Abstract
dvanced Driver Assistance Systems are intelligent systems that reside inside the vehicle and assist the main driver in a variety of ways. These systems may be used to provide [...]
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Development of a Density Sensor for In-Line Real-Time Process Control and Monitoring of Slurries during Radioactive Waste Retrieval and Transport Operations at DOE Sites
J. Bamberger, M. Greenwood

Collection of open reports in transport research (2001). Vol. 2001, 6

Abstract
density sensor (densimeter) to monitor and control slurries in-line real-time during radioactive waste retrieval and transport and detect conditions leading to degraded transport and line plugging is described. Benefits over baseline grab samples and off line analysis include: early detection and prevention of pipeline plugging, real-time density through the transfer process, elimination of grab sampling and off-line analysis, and reduced worker radiation exposure. The sensor is small, robust and could be retrofitted into existing pump pit manifolds and transfer lines. The probe uses ultrasonic signal reflection at the fluid-pipe wall interface to quantify density and features include: a non-intrusive sensing surface located flush with the pipeline wall; performance that is not affected by entrained air or by electromagnetic noise from nearby pumps and other equipment and is compact. Components were tested for chemical and radiation resistance and the spool piece was pressure tested in accordance with ASME Process Piping Code B31.3 and approved by the Hanford Site Flammable Gas Equipment Advisory Board for installation. During pipeline tests, the sensor predicted density within + 2% oriented in vertical and horizontal position. The densimeter is installed in the modified process manifold that is installed in the prefabricated pump pit at Hanfordmore » tank SY-101 site. In FY-2002 the density sensor performance will be evaluated during transfers of both water and waste through the pipeline. A separate project developed an ultrasonic sensor that: 1) can be attached permanently to a pipeline wall, possibly as a spool piece inserted into the line or 2) can clamp onto an existing pipeline wall and be movable to another location. This method is attractive for radioactive fluids transport applications because the sensors could be applied to existing equipment without the need to penetrate the pipe pressure boundary or to open the system to install new equipment.« le
Abstract
density sensor (densimeter) to monitor and control slurries in-line real-time during radioactive waste retrieval and transport and detect conditions leading to degraded transport [...]
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Interpreting ODP Viewpoint Specification: Observations from a Case Study
C. Taylor, E. Boiten, J. Derrick

Collection of open chapters of books in transport research (2001). Vol. 2001, 26

Abstract
Open Distributed Processing (ODP) is a framework for specifying open distributed systems, under development by the International Standards Organisation (ISO). It is based on the general idea of viewpoints - i.e. partial specifications of an overall system, from different perspectives - but assumes five specific, named viewpoints, which are described informally in the ODP Reference Model (RM-ODP). This paper summarises some observations regarding an attempt to use ODP to specify a complex air traffic control system. Some of the key issues that arise are discussed further in the context of the formal specification of a simpler, idealised model, involving two formalised viewpoints - the Information Viewpoint (a high-level, abstract specification, in Z), and the Computational Viewpoint (a specification of distributed components and objects, in Object-Z).
Abstract
Open Distributed Processing (ODP) is a framework for specifying open distributed systems, under development by the International Standards Organisation (ISO). It is based [...]
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Low-Weight Congestion Control for Multi-sender Applications
P. Parnes, J. Scholl

Collection of open chapters of books in transport research (2002). Vol. 2002, 21

Abstract
This paper presents a prototype for single-rate reliable multicast congestion control, which has been built into an existing commercial whiteboard. The prototype was developed using a novel scheme that was engineered around conflicting industry provided requirements for collaborative workspaces. This required the scheme to be both low-weight when used with many senders and compatible with NAT, firewalls and reflectors. The key to overcome this conflict was to combine congestion control and recovery feedback. This differs from many current solutions in that they are often designed for use with a wide variety of protocols and thus operate independent of the recovery mechanism. This paper does not go into the detail required to specify a protocol but instead discusses a few important design requirements for multi-sender applications, which are generally not considered by current research, and describes an approach towards meeting these requirements.
Abstract
This paper presents a prototype for single-rate reliable multicast congestion control, which has been built into an existing commercial whiteboard. The prototype was developed [...]
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Tank waste transport pipeline plugging and the prospects for reducing the risk of waste transfers
T. Welch, T. Welch

Collection of open reports in transport research (2001). Vol. 2001, 4

Abstract
This report provides an overview of the capabilities and limitations of some current models being applied to the analysis of waste transfers; identifies the modeling capabilities needed to reduce the risk of pipeline plugging during tank waste transfers; and summarizes ongoing, planned, and future work needed to add these capabilities. Development of improved waste transport modeling tools with these capabilities will also help with waste transfer planning and evaluation, process control, and diagnosis of plugging events. Other potential applications include evaluation of waste-mixing scenarios, analysis of waste transfer stability, analysis of waste-unplugging alternatives, minimization of water addition, maximization of system availability, evaluation of risk-reduction strategies, and evaluation of cost-reduction strategies. Document type: Report
Abstract
This report provides an overview of the capabilities and limitations of some current models being applied to the analysis of waste transfers; identifies the modeling capabilities [...]
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Wax point determinations using acoustic resonance spectroscopy
D. Bostick, R. Jubin, T. Schmidt

Collection of open reports in transport research (2001). Vol. 2001, 3

Abstract
The thermodynamic characterization of the wax point of a given crude is essential in order to maintain flow conditions that prevent plugging of undersea pipelines. This report summarizes the efforts made towards applying an Acoustic Cavity Resonance Spectrometer (ACRS) to the determination of pressures and temperatures at which wax precipitates from crude. Phillips Petroleum Company, Inc., the CRADA participant, supplied the ACRS. The instrumentation was shipped to Dr. Thomas Schmidt of ORNL, the CRADA contractor, in May 2000 after preliminary software development performed under the guidance of Dr. Samuel Colgate and Dr. Evan House of the University of Florida, Gainesville, FL. Upon receipt it became apparent that a number of modifications still needed to be made before the ACRS could be precisely and safely used for wax point measurements. This report reviews the sequence of alterations made to the ACRS, as well as defines the possible applications of the instrumentation once the modifications have been completed. Document type: Report
Abstract
The thermodynamic characterization of the wax point of a given crude is essential in order to maintain flow conditions that prevent plugging of undersea pipelines. This report [...]
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Material balance assessment for double shell tank waste pipeline transfer
Y. Onishi, B. Wells, S. Hartley, C. Enderlin, M. White

Collection of open reports in transport research (2001). Vol. 2001, 2

Abstract
PNNL developed a material balance assessment methodology based on conservation of mass for detecting leaks and mis-routings in pipeline transfer of double-shell tank waste at Hanford. The main factors causing uncertainty in these transfers are variable property and tank conditions of density, existence of crust, and surface disturbance due to mixer pump operation during the waste transfer. The methodology was applied to three waste transfers from Tanks AN-105 and AZ-102. Document type: Report
Abstract
PNNL developed a material balance assessment methodology based on conservation of mass for detecting leaks and mis-routings in pipeline transfer of double-shell tank waste [...]
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Interpreting ODP Viewpoint Specification: Observations from a Case Study
C. Taylor, E. Boiten, J. Derrick

Collection of open chapters of books in transport research (2001). Vol. 2001, 22

Abstract
Open Distributed Processing (ODP) is a framework for specifying open distributed systems, under development by the International Standards Organisation (ISO). It is based on the general idea of viewpoints - i.e. partial specifications of an overall system, from different perspectives - but assumes five specific, named viewpoints, which are described informally in the ODP Reference Model (RM-ODP). This paper summarises some observations regarding an attempt to use ODP to specify a complex air traffic control system. Some of the key issues that arise are discussed further in the context of the formal specification of a simpler, idealised model, involving two formalised viewpoints - the Information Viewpoint (a high-level, abstract specification, in Z), and the Computational Viewpoint (a specification of distributed components and objects, in Object-Z). Document type: Book
Abstract
Open Distributed Processing (ODP) is a framework for specifying open distributed systems, under development by the International Standards Organisation (ISO). It is based [...]
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On Detecting Unsteady Demand in Mobile Networking Environment
V. Shakhov, H. Choo, H. Youn

Collection of open chapters of books in transport research (2002). Vol. 2002, 20

Abstract
One of the key issues in mobile communication system is how to predict the number of calls per each cell. It is an important parameter and usually assumed as random Poisson value. For effective management of cellular network, the average number of calls should be traced and the changes in the numbers need to be promptly detected. In this paper we propose an algorithm detecting the changes in the behavior of the users using the technique proposed for point-of-change problem based only on the number of call arrivals. Computer simulation reveals that the proposed method can effectively detect the discord, and the developed model is very accurate as showing mostly less than 1% differences. Document type: Part of book or chapter of book
Abstract
One of the key issues in mobile communication system is how to predict the number of calls per each cell. It is an important parameter and usually assumed as random Poisson [...]
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Circumstance and Choice: The Role of Initial Conditions and Policies in Transition Economies
M. de Melo, C. Denizer, A. Gelb, S. Tenev

Collection of open chapters of books in transport research (2001). Vol. 2001, 18

Abstract
The experience of countries in transition from a planned to a market-oriented economy has varied greatly. The clearest differences are between the East Asian countries, China and Vietnam, and the countries of Central and Eastern Europe (CEE) and the former Soviet Union (FSU). China and Vietnam have contained inflation and benefited from continued high growth in GDP since the beginning of their reforms, while all CEE and FSU countries have experienced large declines in output, and most have experienced hyperinflation. But even in CEE and the FSU, differences are marked. Some countries have lost over half of their GDP, and growth performance in a number of countries is still poor, while others are growing strongly. Some are still suffering from high inflation while others have successfully reduced annual inflation. What determines this divergence of outcomes across transition countries? No study so far has analyzed the interaction of all factors, including initial conditions, political change, and reforms, in a unified framework including CEE, the FSU, China, and Vietnam. The authors examine these broader interactions, but focus first on the role of initial conditions, such as initial macroeconomic distortions and differences in economic structure and institutions, which have been emphasized less in the literature. They find that initial conditions and economic policy jointly determine the large differences in economic performance among the 28 transition economies in the sample. Initial conditions dominate in explaining inflation, but economic liberalization is the most important factor determining differences in growth. But reform policy choices are not exogenous. They depend, in turn, on both initial conditions and political reform, with political reform the most important determinant of the speed and comprehensiveness of economic liberalization. Other findings provide additional insight into these relationships. Results show that liberalization has a negative contemporaneous impact, but a stronger positive effect on performance over time. The results also show that macroeconomic and structural distortions are negatively related to both policy and performance. Regarding the former, unfavorable initial conditions discourage policy reforms but do not diminish their effectiveness once they are implemented. The authors find some evidence that the influence of initial conditions diminishes over time. This is in part because many of the initial conditions are themselves modified in the course of transition. Monetary overhangs are dissipated through inflation, industrial overhang is eroded as plants shut down, and market memory returns through experience. Document type: Book
Abstract
The experience of countries in transition from a planned to a market-oriented economy has varied greatly. The clearest differences are between the East Asian countries, China [...]
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MobileWork - Arbeit in Bewegung: Internetbasierte Technologien und ihre Auswirkungen auf Arbeit und Organisation am Beispiel Teleservice
S. Pfeiffer

Collection of open chapters of books in transport research (2002). Vol. 2002, 14

Abstract
"Mobil agil - flexibel! Seit Jahren wird der Ruf nach mobilen, flexiblen Arbeitskräften laut und lauter - spätestens seit die Dauerhaftigkeit großer Arbeitslosenzahlen nicht mehr zu leugnen ist, gilt (individualisierte) Mobilität als bislang offensichtlich nicht sehr erfolgreiches - Allheilmittel zur Bekämpfung der Arbeitslosigkeit. Um den Jahrtausendwechsel schließlich entwickelt sich der Begriff Mobilität im Rahmen der Debatten rund um Globalisierung und Informationsgesellschaft endgültig zum Synonym für einen zeitgemäßen Arbeitsund Lebensstil. Mobilität wird zum gesellschaftlichen und kaum kritisch hinterfragten Leitbild, zu einem Wert an sich. Alles scheint mobil zu werden: Organisationen, Kapitalflüsse, soziale Beziehungen und: die Arbeit. Technologien, die e-mobility technisch ermöglichen, stehen damit vor anderen Bewertungskriterien und Gestaltungsanforderungen als bisherige Technologien. Vor dem Hintergrund einer Fülle sich neu stellender und zukünftig zu beantwortender Fragen werden hier zum einen klassische Gestaltungsbereiche humanorientierter Arbeitsorganisation (Arbeitszeit, Arbeits-/Aufgabenteilung und Kooperation) auf ihre Aktualität unter e-mobility-Bedingungen diskutiert und als neue Gestaltungsprinzipien Vertrauen und Transparenz vorgestellt." (Autorenreferat) Document type: Part of book or chapter of book
Abstract
"Mobil agil - flexibel! Seit Jahren wird der Ruf nach mobilen, flexiblen Arbeitskräften laut und lauter - spätestens seit die Dauerhaftigkeit großer Arbeitslosenzahlen [...]
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Trade in International Maritime Services: How Much Does Policy Matter?
I. Neagu, A. Mattoo, C. Fink, C. Fink, I. Neagu, C. Mattoo

Collection of open chapters of books in transport research (2001). Vol. 1999, 12

Abstract
Maritime transport costs significantly impede international trade. This article examines why these costs are so high in some countries and quantifies the importance of two explanations: restrictive trade policies and private anticompetitive practices. It finds that both matter, but the latter have a greater impact. Trade liberalization and the breakup of private carrier agreements would lead to an average of one-third lower liner transport prices and to cost savings of up to US dollar 3 billion on goods carried to the United States alone. The policy implications are clear: there is a need not only for further liberalization of government policy but also for strengthened international disciplines on restrictive business practices. The authors propose an approach to developing such disciplines in the current round of services negotiations at the World Trade Organization (WTO). Document type: Book
Abstract
Maritime transport costs significantly impede international trade. This article examines why these costs are so high in some countries and quantifies the importance of two [...]
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Agglomeration and market interaction
M. Fujita, J. Thisse

Collection of open chapters of books in transport research (2002). Vol. 2002, 11

Abstract
Despite the drop in transport and commuting costs since the mid-19th century, sizable and lasting differences across locations at very different spatial scales remain the most striking feature of the space-economy. The main challenges of the economics of agglomeration are therefore (a) to explain why people and economic activities are agglomerated in a few places and (b) to understand why some places fare better than others."/p" "p"To meet these challenges, the usual route is to appeal to the fundamental trade-off between (internal and external) increasing returns and various mobility costs. This trade-off has a major implication for the organization of the space-economy: High transport and commuting costs foster the dispersion of economic activities, while strong increasing returns act as a strong agglomeration force."/p" "p"The first issue is to explain the existence of large and persistent regional disparities within nations or continents. At that spatial scale, the mobility of commodities and production factors is critical. By combining new trade theories with the mobility of firms and workers, economic geography shows that a core periphery structure can emerge as a stable market outcome."/p" "p"Second, at the urban scale, cities stem from the interplay between agglomeration and dispersion forces: The former explain why firms and consumers want to be close to each other whereas the latter put an upper limit on city sizes. Housing and commuting costs, which increase with population size, are the most natural candidates for the dispersion force. What generates agglomeration forces is less obvious. The literature on urban economics has highlighted the fact that urban size is the source of various benefits, which increase firm productivity and consumer welfare."/p" "p"Within cities, agglomeration also occurs in the form of shopping districts where firms selling differentiated products congregate. Strategic location considerations and product differentiation play a central role in the emergence of commercial districts because firms compete with a small number of close retailers. Document type: Book
Abstract
Despite the drop in transport and commuting costs since the mid-19th century, sizable and lasting differences across locations at very different spatial scales remain the [...]
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Dynamic Online Routing Algorithm for MPLS Traffic Engineering
R. Boutaba, W. Szeto, Y. Iraqi, R. Boutaba, W. Szeto

Collection of open chapters of books in transport research (2002). Vol. 2002, 8

Abstract
The main contribution of this paper is a new online routing algorithm, called Dynamic Online Routing Algorithm (DORA), for dynamic setup of bandwidth guaranteed paths in MPLS networks. The goal of DORA is to accept as many network path setup requests as possible by carefully mapping paths with reserved bandwidth evenly across the network. The key operation behind DORA is to avoid routing over links that: 1) have high potential to be part of any other paths, and 2) have less residual bandwidth available. We compare DORA against other existing constraint-based routing algorithms based on two performance metrics: path setup rejection ratio and percentage of successful reroutes. Our result shows that DORA performs better than the other algorithms in both metrics. Document type: Part of book or chapter of book
Abstract
The main contribution of this paper is a new online routing algorithm, called Dynamic Online Routing Algorithm (DORA), for dynamic setup of bandwidth guaranteed paths in MPLS [...]
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A realistic simulation for Highway Traffic by the use of Cellular Automata
E. Campari, G. Levi, G. Levi, E. Campari

Collection of open chapters of books in transport research (2002). Vol. 2002, 2

Abstract
A two lane, non-periodic highway with on-ramps and off-ramps is simulated using a simple cellular automata model. The main experimental features of highway traffic are reproduced, indicating the usefulness of this approach for the study of traffic and it is shown the need of ramps to produce congested traffic. A fractal dimension for the variables used for traffic analysis, that is car density, car speed and flow has been measured with a Box Counting algorithm. Finally, it is suggested how to perform real-time traffic forecasts. Document type: Part of book or chapter of book
Abstract
A two lane, non-periodic highway with on-ramps and off-ramps is simulated using a simple cellular automata model. The main experimental features of highway traffic are reproduced, [...]
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A large strain plasticity model for anisotropic materials - composite material application
E. Car, S. Oller, E. Oñate

International Journal of Plasticity (2001). Vol. 17 (11), pp. 1437-1463

Abstract
In this work a generalized anisotropic model in large strains based on the classical isotropic plasticity theory is presented. The anisotropic theory is based on the concept of mapped tensors from the anisotropic real space to the isotropic fictitious one. In classical orthotropy theories it is necessary to use a special constitutive law for each material. The proposed theory is a generalization of classical theories and allows the use of models and algorithms developed for isotropic materials. It is based on establishing a one-to-one relationship between the behavior of an anisotropic real material and that of an isotropic fictitious one. Therefore, the problem is solved in the isotropic fictious space and the results are transported to the real field. This theory is applied to simulate the behavior of each material in the composite. The whole behavior of the composite is modeled by incorporating the anisotropic model within a model based on a modified mixing theory.
Abstract
In this work a generalized anisotropic model in large strains based on the classical isotropic plasticity theory is presented. The anisotropic theory is based on the concept [...]
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Optimización de embarcaciones de recreo mediante la utilización de un código CFD
M. López-Rodríguez, J. García-Espinosa, E. Oñate

Ingeniería Naval (2001). Vol. 784, pp. 122-130

Abstract
En la actualidad las más avanzadas técnicas para diseño naval ya no se restringen sólo a proyectos de alto coste; si no que también ahora son de aplicación en el campo de las embarcaciones de recreo y turísticas, dando con ello un valor añadido al proyecto final. La utilización de un código CFD para el mayor conocimiento del comportamiento hidrodinámico de las embarcaciones de recreo y turísticas es de una gran utilidad debido a las complejidades que en el diseño de estas se presentan. Estas herramientas nos van a proporcionar una serie de datos como sustentación lateral en las embarcaciones de vela o interacción entre cascos en catamaranes con deriva lateral, que de otra forma nunca pudieran conocerse. Los resultados hidrodinámicos obtenidos nos sirven para comparar las diferentes alternativas, y para además obtener unos valores que directamente son usados para la predicción de velocidad de la embarcación, que más tarde se verán refrendadas por las pruebas de mar. La utilización de técnicas CFD, basadas en el método de los elementos finitos, para la resolución de las ecuaciones de Reynolds (RANSE), incluyendo efectos de superficie libre, hace que todo esto sea posible. En este trabajo se presentan diversos resultados de aplicación del código CFD SHYNE a varias embarcaciones deportivas y de recreo. SHYNE está basado en la técnica del Cálculo Finitesimal para la integración de las ecuaciones de Reynolds.
Abstract
En la actualidad las más avanzadas técnicas para diseño naval ya no se restringen sólo a proyectos de alto coste; si no que también ahora [...]
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Probabilistic analysis of an a posteriori error estimator for Finite Elements
P. Diez, J. Egozcue

Mathematical Models and Methods in Applied Sciences (2001). Vol. 11 (5), pp. 841-854

Abstract
A residual type a posteriori error estimator for finite elements is analyzed using a new technique. In this case, the error estimate is the result of two consecutive projections of the exact error on two finite-dimensional subspaces. The analysis introduced in this paper is based on a probabilistic approach, that is, the idea is to assess the average value of the effectivity index (the ratio estimated error over exact error) by assuming the randomness of the exact error. The average value characterizes the mean behavior of the estimator and it is found to be related with some geometric properties of the subspaces. These geometric properties are obtained from the standard matrices of the linear systems arising in the formulation of the finite element method.
Abstract
A residual type a posteriori error estimator for finite elements is analyzed using a new technique. In this case, the error estimate is the result of two consecutive [...]
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CBS versus GLS stabilization of the incompressible Navier–Stokes equations and the role of the time step as stabilization parameter
R. Codina, O. Zienkiewicz

Commun. Numer. Meth. Engng (2001). Vol 18 (2), pp. 99-112

Abstract
In this work we compare two apparently different stabilization procedures for the finite element approximation of the incompressible Navier–Stokes equations. The first is the characteristic‐based split (CBS). It combines the characteristic Galerkin method to deal with convection dominated flows with a classical splitting technique, which in some cases allows us to use equal velocity–pressure interpolations. The second approach is the Galerkin‐least‐squares (GLS) method, in which a least‐squares form of the element residual is added to the basic Galerkin equations. It is shown that both formulations display similar stabilization mechanisms, provided the stabilization parameter of the GLS method is identified with the time step of the CBS approach. This identification can be understood from a formal Fourier analysis of the linearized problem.
Abstract
In this work we compare two apparently different stabilization procedures for the finite element approximation of the incompressible Navier–Stokes equations. The first [...]
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Implementation of a stabilized finite element formulation for the incompressible Navier-Stokes equations based on a pressure gradient projection
R. Codina, J. Blasco, G. Buscaglia, A. Huerta

Int. J. Numer. Meth. Fluids (2001). Vol. 37 (4), pp. 419-444

Abstract
We discuss in this paper some implementation aspects of a finite element formulation for the incompressible Navier-Stokes which allows the use of equal order velocity-pressure interpolations. The method consists in introducing the project of the pressure gradient and adding the difference between the pressure Laplacian and divergence of this new field to the incompressibility equations, both multiplied by suitable algorithmic parameters. The main purpose of this paper is to discuss how to deal with the new variable in the implementation of the algorithm. Obviously, it could be treated as one extra unknown, either explicitly or as a condensed variable. However, we take for granted that the only way or another. Here we discuss some iterative schemes to perform this uncoupling of the pressure gradient projection (PGP) from the calculation of the velocity and the pressure, both for stationary and the transient of the linearization loop and the iterative segregation of the PGP, whereas in the second the main dilemma concerns the explicit or implicit treatment of the PGP.
Abstract
We discuss in this paper some implementation aspects of a finite element formulation for the incompressible Navier-Stokes which allows the use of equal order velocity-pressure [...]
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Numerical modeling of magma withdrawal during explosive caldera-forming eruptions
A. Folch, J. Martí i Castell, R. Codina

Journal of Geophysical Research (2001). Vol. 106 (B8), pp. 16 163-16 175

Abstract
We propose a simple physical model to characterize the dynamics of magma withdrawal during the course of caldera-forming eruptions. Simplification involves considering such eruptions as a piston-like system in which the host rock is assumed to subside as a coherent rigid solid. Magma behaves as a Newtonian incompressible fluid below the exsolution level and as a compressible gas-liquid mixture above this level. We consider caldera-forming eruptions within the frame of fluid-structure interaction problems, in which the flow-governing equations are written using an arbitrary Lagrangian-Eulerian (ALE) formulation. We propose a numerical procedure to solve the ALE governing equations in the context of a finite element method. The numerical methodology is based on a staggered algorithm in which the flow and the structural equations are alternatively integrated in time by using separate solvers. The procedure also involves the use of the quasi-Laplacian method to compute the ALE mesh of the fluid and a new conservative remeshing strategy. Despite the fact that we focus the application of the procedure toward modeling caldera-forming eruptions, the numerical procedure is of general applicability. The numerical results have important geological implications in terms of magma chamber dynamics during explosive caldera-forming eruptions. Simulations predict a nearly constant velocity of caldera subsidence that strongly depends on magma viscosity. They also reproduce the characteristic eruption rates of the different phases of an explosive calderaforming eruption. Numerical results indicate that the formation of vortices beneath the ring fault, which may allow mingling and mixing of parcels of magma initially located at different depths in the chamber, is likely to occur for low-viscosity magmas. Numerical results confirm that exsolution of volatiles is an efficient mechanism to sustain explosive caldera-forming eruptions and to explain the formation of large volumes of ignimbrites.
Abstract
We propose a simple physical model to characterize the dynamics of magma withdrawal during the course of caldera-forming eruptions. Simplification involves considering such [...]
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Space and time error estimates for a first order, pressure stabilized finite element method for the incompressible Navier–Stokes equations
J. Blasco, R. Codina

Applied Numerical Mathematics (2001). Vol. 38 (4), pp. 475-497

Abstract
In this paper we analyze a pressure stabilized, finite element method for the unsteady, incompressible Navier–Stokes equations in primitive variables; for the time discretization we focus on a fully implicit, monolithic scheme. We provide some error estimates for the fully discrete solution which show that the velocity is first order accurate in the time step and attains optimal order accuracy in the mesh size for the given spatial interpolation, both in the spaces L2(Ω) and H10(Ω); the pressure solution is shown to be order 12 accurate in the time step and also optimal in the mesh size. These estimates are proved assuming only a weak compatibility condition on the approximating spaces of velocity and pressure, which is satisfied by equal order interpolations.
Abstract
In this paper we analyze a pressure stabilized, finite element method for the unsteady, incompressible Navier–Stokes equations in primitive variables; for the [...]
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Pressure stability in fractional step finite element methods for incompressible flows
R. Codina

Journal of Computational Physics (2001). Vol. 170 (1), pp. 112-140

Abstract
The objective of this paper is to analyze the pressure stability of fractional step finite element methods for incompressible flows. For the classical first order projection method, it is shown that there is a pressure control which depends on the time step size, and therefore there is a lower bound for this time step for stability reasons. The situation is much worse for a second order scheme in which part of the extremely weak. To overcome these shortcomings, a stabilized fractional step finite element method is also considered, and its stability is analyzed. Some simple numerical examples are presented to support the theoretical results.
Abstract
The objective of this paper is to analyze the pressure stability of fractional step finite element methods for incompressible flows. For the classical first order projection [...]
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