Scipedia: Documents published in 2013

Moving towards the sustainable city? The role of electric vehicles, renewable energy and energy efficiency

Scipedia content — Wed, 03 Feb 2021 18:29:31 +0100

Integrated energy and urban mobility systems are key components for achieving cities’ sustainability. Several urban metabolism approaches are emerging as leading tools for quantifying energy consumption and use patterns of resources in urban environments. Examples are the mass balance accounting (or energy-materials flux approach) using several quantification methods such as material flow analysis and life cycle assessment and Odum’s emergy methods. In this research we adapt the extended metabolism model of a city developed by Newman (1999) and the material and energy flow accounting by Sheeri (2002) to assess the future role of electric vehicles, renewable energy use for mobility needs and energy efficiency increases for households living in the city of Aveiro, a medium-sized city of 78450 inhabitants in Portugal. The data used comprised an integrated set of energy, transport, socio-economic and solid waste production/treatment collected at the local and National level as part of the research project COST-TRENDS funded by the Portuguese Foundation for Science and Technology. The analysis of the potential energy mix (energy inputs from different sources) and households’ mobility needs refers to the horizon 2010-2020. Several energy sources were considered: hydric, wind, solar (thermic and photovoltaic) and solid waste (incineration and biogas). Potential accessibility indicators were developed to better convergence towards sustainable mobility objectives, measuring the potential for interaction and exchange of services and opportunities. Different household’s profiles were established to represent consumers’ behaviour. It was found that the above integrated energy system could provide a total of 2,61 MWh/household.year, which represents on average around 38,2% of the total energy needs for households’ daily mobility and 1,2 tonnes CO2/household.year avoided. On the other hand, the replacement of conventional internal combustion engine by battery electric vehicles could allow an energy reduction between 4,7 and 6,1 MWh/household.year until 2020 and a reduction of 1,6 tonnes CO2 /household.year. Fundação para a Ciência e Tecnologia, projeto COST-TRENDs 3 4 12 Em 28 de fevereiro de 2013 foram cedidos os direitos de publicação/copyright à WIT Press,para efeitos da sua inserção na publicação no livro/Book da WIT Press - "Sustainable Development and Planning 2013". DT/NPTS 2013 27 a 29 de maio

Assessment of the impact of electric vehicles on iberian day-ahead electricity market

Scipedia content — Wed, 03 Feb 2021 18:21:10 +0100

© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works Electric vehicles (EVs) could become a controllable grid load by using demand side management techniques, but this requires an information and communications technology (ICT) infrastructure and aggregator agents, to coordinate the EV charging process. To determine the opportunity cost of aggregators, it is necessary to analyze the extra charges in the electricity market, due to the EV charging demand. The EV energy consumption is modeled following agent-based techniques, and the data used corresponds to the Iberian day-ahead market and Spanish mobility needs in 2012. The simulation results show that EVs would significantly influence the electricity price on the day-ahead market, depending on the EV charging behavior.

Challenges of implementation of intelligent transportation systems in developing countries: case study – Tehran

Scipedia content — Wed, 03 Feb 2021 18:18:33 +0100

The slope difference of development curves between developed countries and developing ones in IT applications in transportation (ITS) leads to a gap in studies conducted among those countries that will evolve over time. As a result, developing countries usually decide to take advantage of new technologies and the experiences of other countries as soon as possible in order to minimize the costs. While the benefits of ITS applications make the imposed socio-economic costs bearable, and available experiences of similar countries are so helpful; uncoordinated development of infrastructure, cultural differences, lack of law and the inappropriate organizational structure of agencies has led to numerous problems of different nature in the operation of these systems. For example, in some arterial streets of Tehran (which the offending vehicles license plate is recorded by cameras equipped with ANPR technology), many cases of covered license plates by the drivers (in order to become invisible to the cameras), and breaking surveillance cameras and telecommunication equipment of these systems have been reported and new types of offenses are generated. This study illustrates the benefits achieved by the implementation of the ITS new technologies in Tehran as a developing city toward sustainable transportation, numerous prominent problems will be unveiled and several suggestions to improve the situation will be addressed in conclusion.

Combined analysis of local influences and multipath effects for a lane-specific positioning of vehicles in traffic streams

Scipedia content — Wed, 03 Feb 2021 18:18:19 +0100

Future smart traffic environments require very accurate positioning of vehicles to allow for sophisticated traffic flow modeling or autonomous control of cars. To avoid traffic congestion on motorways, a lane-specific localization of vehicles is required to allow for the detection of short-term deviations of traffic flows due to roadwork or accidents. In this paper, we investigate the accuracy of GNSS-based positioning data with consideration of all relevant impairments of the propagation channel, like molecular scattering, ionospheric scintillation and effects caused by the direct receiver surrounding. Taking into account satellite mobility and constellations, position-specific atmospheric influences and the impacts of shadowing and multipath propagation on the determination of TOA values, the accuracy of a lane-specific positioning is investigated for both GPS and GALILEO. The results presented in this paper are based on a dedicated multiscale simulation framework which includes an exact 3D model of the environment of the GNSS receiver. Based on the investigation of a reference scenario, the results demonstrate the feasibility of lane-specific localization enabled by the compensation of both ionospheric as well as multipath fading effects.

Improving the efficiency and environmental safety of gasoline engine operation

Scipedia content — Wed, 03 Feb 2021 18:17:10 +0100

In countries with transition economies a common serious challenge relating to vehicle transport is the increasing shortage of high octane gasoline and its inherent low quality. The aim of this work is to develop a low cost, rapidimplementation method aimed at reducing a vehicle engine's dependency on a gasoline octane rating, the consumption of fuel and the emission of toxic substances in the exhaust gases. The influence of the removal of carbon formation in engines on the improvement of the efficiency of vehicles and the subsequent reduction of their environmental impact was discussed and scientifically substantiated. The technology of coating an engine's working surfaces with ultrafine metal having catalytic activity in redox reactions was developed. A single application of the developed method will provide long-term elimination of carbon deposits on working surfaces. This will reduce the need for high gasoline octane ratings, significantly improve fuel efficiency and also reduce the environmental impact of gasoline engines. © 2013 WIT Press.

ESNEK şebekeli optik ağlarda ip trafiğinin verimli taşınması

Scipedia content — Wed, 03 Feb 2021 18:07:39 +0100

Date of Conference: 23-25 April 2014 Frequency slot width selection in flexi-grid optical networks refers to the process of online update of the slot width of the channel, according to time-varying traffic demands. Since slot width updates are associated with signaling costs, it is common to limit the rate of updates. In this article, we propose a model-free hysteresis-based slot width selection algorithm for flexi-grid optical networks. © 2014 IEEE.

Designing Scenarios for Controller in the Loop Air Traffic Simulations

Scipedia content — Wed, 03 Feb 2021 18:04:59 +0100

Well prepared traffic scenarios contribute greatly to the success of controller-in-the-loop simulations. This paper describes each stage in the design process of realistic scenarios based on real-world traffic, to be used in the Airspace Operations Laboratory for simulations within the Air Traffic Management Technology Demonstration 1 effort. The steps from the initial analysis of real-world traffic, to the editing of individual aircraft records in the scenario file, until the final testing of the scenarios before the simulation conduct, are all described. The iterative nature of the design process and the various efforts necessary to reach the required fidelity, as well as the applied design strategies, challenges, and tools used during this process are also discussed.

Acoustic Resonance Experiments in a Reservoir-Pipeline-Orifice System

Scipedia content — Wed, 03 Feb 2021 18:04:47 +0100

Acoustic resonance in liquid-filled pipe systems is an undesirable phenomenon that cannot always be prevented. It causes noise, vibration, fatigue, instability, and it may lead to damage of hydraulic machinery and pipe supports. If possible, resonance should be anticipated in the design process and be part of the hydraulic-transients analysis."/jats:p" "jats:p"This paper describes acoustic resonance tests carried out at Deltares, Delft, The Netherlands, within the framework of the European Hydralab III programme. The test system is a 49 m long pipeline of 206 mm diameter that is discharging water from a 24 m high reservoir through a 240 mm2 orifice to the open atmosphere. The outflow is partly interrupted by a rotating disc which generates flow disturbances at a fixed frequency in the range 1.5 Hz to 100 Hz. In previous studies [1, 2] a similar system was analysed theoretically. Herein experimental data are presented and interpreted. Steady oscillatory behaviour is inferred from pressures measured at four different positions along the pipeline. Heavy pipe vibration during resonance was observed (visually and audibly) and recorded by a displacement transducer.

Interference coordination in wireless networks: A flow-level perspective

Scipedia content — Wed, 03 Feb 2021 18:03:36 +0100

International audience; In dense wireless networks, inter-cell interference highly limits the capacity and quality of service perceived by users. Previous work has shown that approaches based on frequency reuse provide important capacity gains. We model a wireless network with Inter-Cell Interference Coordination (ICIC) at the flow level where users arrive and depart dy- namically, in order to optimize quality of service indicators perceivable by users such as file transfer time for elastic traffic. We propose an algorithm to tune the parameters of ICIC schemes automatically based on measurements. The convergence of the algorithm to a local optimum is proven, and a heuristic to improve its convergence speed is given. Numerical experiments show that the distance between local optima and the global optimum is very small, and that the algorithm is fast enough to track changes in traffic on the time scale of hours. The proposed algorithm can be implemented in a distributed way with very small signaling load.

Developing a viable electric bus service: The Milton Keynes demonstration project

Scipedia content — Wed, 03 Feb 2021 17:56:57 +0100

Buses can be a serious source of city centre air pollution. Electric buses deliver zero emissions but, because of the time required to recharge, more buses are needed for a given timetable than diesel counterparts, so making mainstream electric bus operations prohibitively expensive.\\ud \\ud Early 2014 saw the implementation in Milton Keynes of an electric bus service designed to overcome this problem. An entire bus route has been converted to electric operation with inductive charging at bus layover points. This permits the use of smaller and less expensive battery packs allowing the electric buses to operate continuously all day. This approach significantly reduces the cost of introducing a pure electric bus fleet.\\ud \\ud This study not only provides an example of how the electric bus problem can be resolved technically. It also addresses the business structures required to deliver sustainable transport, introducing a different commercial model to that which is traditionally used for bus service delivery. This raises important points for regulatory and innovation policy. There is government support for sustainable transport technologies, but successful delivery in the commercial environment requires new institutional structures and business models as well. The Milton Keynes project has sought to develop such a structure.

Water Distribution System Monitoring and Decision Support Using a Wireless Sensor Network

Scipedia content — Wed, 03 Feb 2021 17:52:01 +0100

Water distribution systems comprise labyrinthine networks of pipes, often in poor states of repair, that are buried beneath our city streets and relatively inaccessible. Engineers who manage these systems need reliable data to understand and detect water losses due to leaks or burst events, anomalies in the control of water quality and the impacts of operational activities (such as pipe isolation, maintenance or repair) on water supply to customers. Water Wise is a platform that manages and analyses data from a network of wireless sensor nodes, continuously monitoring hydraulic, acoustic and water quality parameters. Water Wise supports many applications including rolling predictions of water demand and hydraulic state, online detection of events such as pipe bursts, and data mining for identification of longer-term trends. This paper illustrates the advantage of the Water Wise platform in resolving operational decisions.

Document type: Conference object

The analysis of the environmental impact of road traffic in a transport node on the example of the Rondo Rataje roundabout in Poznan

Scipedia content — Wed, 03 Feb 2021 17:47:14 +0100

Road transport is one of the main sources of environment pollution. Transport nodes are a particular challenge for the environment and are related to substantial traffic congestion and slow vehicle flow. One of the main transport nodes in the city of Poznan (Poland) is a roundabout known as Rondo Rataje. Within an hour, up to approximately 5500 vehicles pass through this intersection with an average speed of 10–15 km/h. The paper presents the exhaust emissions and fuel consumption by the vehicles passing through this intersection. These values have been determined based on complex traffic investigations carried out on this intersection, the knowledge of the vehicle structure in Poznan and the use of software for microsimulation of road traffic. The obtained results were subject to further analysis within which the shares of individual vehicle types and emission categories in the total exhaust emissions of individual exhaust components have been identified. The test procedure described in the paper may turn out to be useful in the evaluation of the influence of the traffic parameters on the exhaust emission level generated by vehicles, thus in the evaluation of various traffic control solutions or infrastructural options.

Urban localization with camera and inertial measurement unit

Scipedia content — Wed, 03 Feb 2021 17:45:35 +0100

Next generation driver assistance systems require precise self localization. Common approaches using global navigation satellite systems (GNSSs) suffer from multipath and shadowing effects often rendering this solution insufficient. In urban environments this problem becomes even more pronounced. Herein we present a system for six degrees of freedom (DOF) ego localization using a mono camera and an inertial measurement unit (IMU). The camera image is processed to yield a rough position estimate using a previously computed landmark map. Thereafter IMU measurements are fused with the position estimate for a refined localization update. Moreover, we present the mapping pipeline required for the creation of landmark maps. Finally, we present experiments on real world data. The accuracy of the system is evaluated by computing two independent ego positions of the same trajectory from two distinct cameras and investigating these estimates for consistency. A mean localization accuracy of 10 cm is achieved on a 10 km sequence in an inner city scenario.

Private car and public transportation: dynamics of the modal share

Scipedia content — Wed, 03 Feb 2021 17:42:16 +0100

large proportion of private car modal share and the increasing trend of car use are the main challenges in realising a sustainable urban transportation system. A set of feedback loop models has been developed in this paper to make an attempt to present such challenges. The dynamics of the modal share between the private car and public transportation (PT) have been explained in terms of the model. The model mainly indicates that if the PT travel time is longer, PT availability is sparse, PT station accessibility is difficult, and if PT use does not indicate the social “class” then there will be a strong need to own a private car and it would consequently develop a need-based desire for a car. In such a situation, if the large mass of the population can afford and easily buy a car, then car use would get persistently high. An important issue for transportation policy design would then be how to pull the large mass of an increasing car-dependent population to encourage using the PT.

Corrosion Protection Provided by Mortar Lining in Large Diameter Water Pipelines After Many Years of Service

Scipedia content — Wed, 03 Feb 2021 17:42:05 +0100

Content Based Traffic Engineering in Software Defined Information Centric Networks

Scipedia content — Wed, 03 Feb 2021 17:33:35 +0100

This paper describes a content centric network architecture which uses software defined networking principles to implement efficient metadata driven services by extracting content metadata at the network layer. The ability to access content metadata transparently enables a number of new services in the network. Specific examples discussed here include: a metadata driven traffic engineering scheme which uses prior knowledge of content length to optimize content delivery, a metadata driven content firewall which is more resilient than traditional firewalls and differentiated treatment of content based on the type of content being accessed. A detailed outline of an implementation of the proposed architecture is presented along with some basic evaluation.

Hybrid Simulation of Distributed Large-Scale Critical Infrastructures

Scipedia content — Wed, 03 Feb 2021 17:32:56 +0100

The distributed and complexity nature of modern critical infrastructures that have to provide integrated services through the interoperability of heterogeneous subsystems, even spread among different countries, require new methodologies and tools to dominate overall systems complexity. In particular, in order to get knowledge about their real behavior and define dependability improvement actions, such complex and distributed systems should be reproduced and simulated locally. On the other hand, the extraordinary large number of their components cause a large-scale of the resulting model, limiting its resolution by current simulators. This paper presents a framework to implement hybrid simulation of distributed large-scale critical infrastructures, such as Air Traffic Control (ATC) and Vessel Traffic System (VTS). High Level Architecture (HLA) has been introduced into the engine simulations platform as its design and development foundation, whereas cloud-based virtualization techniques have been exploited in order to reproduce the overall distributed system on a local adaptive testbed. The use of such a framework can result in a considerable reduction of costs in all the system life phases, as well as an increased system dependability level.

A Simulation Based Approach for Evaluating the Impact of Maritime Transport on the Inventory Levels of an Oil Supply Chain

Scipedia content — Wed, 03 Feb 2021 17:32:00 +0100

One of the most important objectives of a manufacturing company is the optimization of the distribution of the produced goods considering the whole value chain. Unfortunately, in many companies the performance of the supply chain depends on many uncertain factors that are difficult to predict. The only way to face them is to adopt innovative solutions and tools that allow a swift response to the market changes. This paper analyzes the distribution processes managed by the logistics department of a large company producing and distributing petroleum products through the following main steps: crude oil's transportation typically from many countries to a refinery; refining process; maritime transportation from the refinery to three costal depots; road transport from depots to gas stations. The analyzed process is the primary supply, consisting in the maritime transport from the refinery to the coastal depots, liable to stochastic activities and events as weather condition. Through simulating the primary supply, we study the effects that the ship traffic generates on the overall variance of inventory levels at the costal depots with respect to specific inventory level targets, and analyze the impact of different tactical decision choices on the variance reduction. Reducing inventory's variance, through a better control of the distribution, allows the company to reduce inventory target levels and hence to reduce inventory costs in term of capital stock, while keeping the same risk level of stock out. The project is made of many phases: map all relevant processes to have a complete vision of transport's structure; conduct a statistical analysis to identify specific statistical distributions of every ships’ process (delay, mooring, loading, etc.); model and simulate the primary supply using simulation software; use the model to make a “what-if” analysis. Within this project, it has been possible to realize a model that presents stochastic elements. All these phases are supported by six-sigma methodology, which focalizes on defects’ process reduction by the control of its mean square deviation and following the stages of the DMAIC (Define Measure Analyze Improve Control). One of the what-if analysis which has been done consists in simulating the opening refinery's jetties h24, because currently these are closed during the night. Opening the jetties, will increase the capacity of some of the bottleneck resources for the oil distribution process, and thanks to the simulation model we can estimate quickly the effects on the oil transport system.

Data mining for understanding and improving decision-making affecting ground delay programs

Scipedia content — Wed, 03 Feb 2021 17:30:54 +0100

Difficulty of deciding on control action depends on the weather and traffic conditions. Weather signature on different days can categorize days into days with little decision difficulty, days with moderate decision difficulty and days with high decision difficulty. This paper examines performance of different data mining methods in the three regions of decision difficulty. Not surprisingly, data mining methods have the best performance in the region of little decision difficulty and have the poorest performance in the region of most decision difficulty. In applications where data mining methods have differing performance in differing regions, it would be more useful to characterize the region specific performance instead of characterizing performance by a single parameter.

Constructive Roof Geometry

Scipedia content — Wed, 03 Feb 2021 17:09:55 +0100

While the growing demand for new building models contained in virtual worlds, games, and movies, makes the easy and fast creation of modifiable models more and more important, 3D modeling of buildings can be a tedious task due to their sometimes complex geometry. For historic buildings, especially the roofs can be challenging. We present a new method of combining simple building solids to form more complex buildings, and give an emphasis on the blending of roof faces. This can be integrated in common pipelines for procedural modeling of buildings and will bring more expressiveness than existing methods.

Multiobjective Tactical Planning under Uncertainty for Air Traffic Flow and Capacity Management

Scipedia content — Wed, 03 Feb 2021 17:06:13 +0100

We investigate a method to deal with congestion of sectors and delays in the tactical phase of air traffic flow and capacity management. It relies on temporal objectives given for every point of the flight plans and shared among the controllers in order to create a collaborative environment. This would enhance the transition from the network view of the flow management to the local view of air traffic control. Uncertainty is modeled at the trajectory level with temporal information on the boundary points of the crossed sectors and then, we infer the probabilistic occupancy count. Therefore, we can model the accuracy of the trajectory prediction in the optimization process in order to fix some safety margins. On the one hand, more accurate is our prediction; more efficient will be the proposed solutions, because of the tighter safety margins. On the other hand, when uncertainty is not negligible, the proposed solutions will be more robust to disruptions. Furthermore, a multiobjective algorithm is used to find the tradeoff between the delays and congestion, which are antagonist in airspace with high traffic density. The flow management position can choose manually, or automatically with a preference-based algorithm, the adequate solution. This method is tested against two instances, one with 10 flights and 5 sectors and one with 300 flights and 16 sectors.

Comment: IEEE Congress on Evolutionary Computation (2013). arXiv admin note: substantial text overlap with arXiv:1309.3917

Creating Data Outputs from Multi Agent Traffic Micro Simulation to Assimilation with Real Traffic Data

Scipedia content — Wed, 03 Feb 2021 17:01:06 +0100

The intensive development of traffic engineering and technologies that are integrated into vehicles, roads and their surroundings, bring opportunities of real time transport mobility modeling. Based on such model it is then possible to establish a predictive layer that is capable of predicting short and long term traffic flow behavior. It is possible to create the real time model of traffic mobility based on generated data. However, data may have different geographical, temporal or other constraints, or failures. It is therefore appropriate to develop tools that artificially create missing data, which can then be assimilated with real data. This paper presents a mechanism describing strategies of generating artificial data using microsimulations. It describes traffic microsimulation based on our solution of multiagent framework over which a system for generating traffic data is built. The system generates data of a structure corresponding to the data acquired in the real world.

On modeling of logistic overnight in airlines

Scipedia content — Wed, 03 Feb 2021 16:58:27 +0100

"The present work shows the results of a study that evaluated the overnight operation, using the modeling of air operations where simulation emerges as a tool, consistent with the objective of the organization to achieve better results. The old paradigms air transport issues have worn the new information systems and the need to compensate for supply capacity with demand. Some aviation sector organizations have felt the need to modify their strategic schemes. It is not enough to be part of the market and wait for the opportunities, now, which runs the changes and is innovative in their practices, achieves superior performance in the market. Because of these constant changes, organizations have had to adapt, as in the case of this particular airline, under higher demand stimulated and most comfortable travel plans and innovative, the operations involved in this value chain become more critical, since in the same chain, feels greater dependence and demand in the various logistics operations related to the provision of air service. When viewing this critical chain, there is a need to assess, innovate and improve the most important aspects in the operation."

Aspiring modal shift by an innovative inland vessel and logistics system

Scipedia content — Wed, 03 Feb 2021 16:58:01 +0100

Central European inland waterways are presently utilized way below their theoretical carrying capacity. The economic situation of companies operating inland waterway fleets is, amongst other factors, characterized by an over aged fleet, eroding profit margins, a high dependency on fuel costs, and/or infrastructural bottlenecks causing delays in running-times. To support an increase of transport flows on inland waterways (especially container transport on the Danube) and to contribute to a significant modal shift, shipping companies and owner-operators have to be enabled to improve their economic position. There are several ways to meet this challenge, of course: One is to develop an innovative inland container vessel and logistics system which allows to meet operator's targeted costs, optimize time-management (reliability), answer to inland shipping-specific bottlenecks (e.g. low bridges, shallow waters), improve carbon footprints and thus successfully interact with road and railway transport.

Reducing carbon emissions by introducing electric vehicle enhanced dedicated bus lanes

Scipedia content — Wed, 03 Feb 2021 16:51:11 +0100

eer-reviewed Most cities have special lanes dedicated to buses, however these lanes are rarely used at full capacity. At the same time governments around the world are encouraging people to buy electric vehicles. This paper proposes the creation of electric vehicle enhanced dedicated bus lanes (E-DBL), by allowing electric vehicles access to bus lanes, in order to improve the use of road capacity. By opening bus lanes to electric vehicles, traffic congestion could be eased, the range of electric vehicles could be extended, and the travel times for electric vehicle owners could be reduced significantly. The paper shows how by introducing EDBLs, the bus journey times are not significantly affected given the current uptake of electric vehicles in most developed countries. This paper presents extensive simulations based on traffic situation in the city of Dublin with regard to the effect of opening up bus lanes to electric vehicles. The results show that even with very high percentages of electric vehicles the bus journey times are not noticeably affected. Opening up bus lanes to electric vehicles can even be beneficial for other road users by reducing congestion on regular lanes, which would further reduce carbon emissions.

Real-time electric vehicle mass identification

Scipedia content — Wed, 03 Feb 2021 16:50:59 +0100

technique capable of identifying electric vehicle (EV) mass in real-time has been a topic of research for several years due to the advantages it presents, such as the ability to dramatically improve range estimates, perform more effective torque vectoring for ABS/ESC, track delivery vehicle weight, etc.. Some crucial issues in mass identification impede an easy implementation of such an algorithm, however, and this work introduces a simple method to calculate EV mass on-the-fly using standard data available on most CAN buses and therefore without the need of additional sensors. The results presented here are achieved using an eight step technique suitable for accurate mass estimations during wide-open-throttle acceleration events. The algorithm’s instantaneous error is less than 10%, and converges to better than 3% absolute accuracy performance with subsequent measurements. A preliminary analysis of trips lacking hard acceleration presented in this paper show an inability to differentiate between loaded and unloaded conditions.

Document type: Article

Study on Behavior of Ductile Iron Pipelines with Earthquake-Resistant Joints Buried across a Fault

Scipedia content — Wed, 03 Feb 2021 16:48:58 +0100

This study is focusing on behavior of ductile iron pipelines with earthquake-resistant joints buried across a fault used widely for water pipelines in Japan. It is necessary to design a pipeline carefully in case of crossing a fault, because the partially large displacement occurs on the pipelines when a fault moves by an earthquake. Although there is some research on behavior of steel pipelines which cross a fault, there are few studies of ductile iron pipelines. In this study, we investigated the behavior of pipeline buried across a fault by simulation analysis and verification experiment. As a result, we clarified that the earthquake resistant joint nearest to a fault began to move when a fault began to move, and then the joints in line began to move when the expansion, contraction and deflection angle in the joint nearest to a fault reached its capacity. In addition, we confirmed that we could evaluate the safety of pipeline against the fault movement by deflection angle in each joint. As a result, using colors with large bending performance rather than straight pipe sockets of shortening the pipe length was effective to increase the safety of pipeline near a fault.

Optimizing transportation infrastructure planning: Koya city as a case study

Scipedia content — Wed, 03 Feb 2021 16:47:33 +0100

In this article the feasibility of using a multi-objective genetic algorithm model to optimize land use, infrastructure, social, and financial variables has been investigated using multi-objective algorithm model. The model used in this article considered three primary objective functions which are minimizing travel time, minimizing per capita cost, and minimizing land use change. Genetic programming is a further extension to the complexity of evolving structures within the genetic programming system the structures hierarchical computer programs. The size, shape and structure of the solution as a genetic program are left unspecified and are found by using genetic programming operators. Solving a problem therefore becomes a search through all the possible combinations of symbolic expressions defined by the programmer. The model was applied on the Koya region in Erbil; a medium sized region experiencing rapid growth. The current population is 90,000 and projected to grow to 250,000 by the year 2030. Residents are becoming progressively more upset with new land development and increasing traffic congestion.

Design and testing of an integrated ground handler working position

Scipedia content — Wed, 03 Feb 2021 16:14:40 +0100

fter air traffic controllers and pilots had been supplied with new surveillance and planning support tools in the airport environment the last decade, airport ground handlers are still suffering out-of-date technology and thus, nowadays, frequently cause bottlenecks for efficient surface operations. The dispatcher and luggage drivers lack a full traffic pictures, have to compile needed information from difficultly accessible sources and are bound to a sequential radio communication. By that reason a human-centered concept for ground handlers was designed, implemented and tested at Hamburg Airport. Dispatcher and driver were provided with the complete traffic situation in real time, data link communication and an integrated human- machine interface (HMI) providing all needed information at one gaze and intuitive interactions to assign tasks to the driver by one click only. The concept design was much appreciated by the dispatchers.

Parallel Computing on the Preheating and Commissioning of Hot Oil Pipelines

Scipedia content — Wed, 03 Feb 2021 15:59:20 +0100

In recent years, the numerical simulation method has been widely applied in hydraulic and thermal calculations for hot oil pipelines. Based on the governing equations of fluid flow in hot oil pipelines, a new parallel numerical simulation method for the preheating and commissioning of hot oil pipelines is put forward. From the heat transfer mechanism of hot oil pipelines, a mathematical model on the preheating and commissioning processes of the pipelines is developed. The pipelines and their surrounding soil are discredited by a two-level model, which are the pipeline discretization and the cross-section spatial discretization, then the thermodynamic characteristic line method and the finite volume method were used respectively to discrete the governing equations. Compared with the traditional numerical method, this method can better cope with the sharp thermal transient, during the preheating and commissioning of hot oil pipelines. To improve the computational efficiency of the numerical simulation method, a parallel computing method and the matrix method are applied. Index Terms - parallel computing, numerical simulation, oil pipeline, preheating, commissioning

Incentivizing Aircraft Equipment Upgrade Through Preferential Merging: A Phoenix Case Study

Scipedia content — Wed, 03 Feb 2021 15:59:09 +0100

Preferential Merging is a best-equipped best-served air traffic management concept meant to accelerate the adoption of Automatic Dependent Surveillance-Broadcast Out (ADS-B Out) in the national airspace by giving an operational incentive to airlines who invest in upgrading their fleet. The concept relies on re-sequencing aircraft arrival order at en-route arrival merge-fixes favoring high-equipped aircraft (such as ADS-B Out) over lowequipped aircraft. This in turn reduces flight-time for high-equipped aircraft and moves them ahead in the arrival queue. In this study Preferential Merging was simulated using historical flight traffic into Phoenix Sky Harbor International Airport, focusing on a benefit analysis from an airline’s perspective. A second set of Monte Carlo simulations randomizing aircraft equipage were run to determine the effectiveness of Preferential Merging as the percent of ADS-B Out equipped Aircraft increases. Results show that the policy creates a 4.5 minute reduction in total flight time for aircraft equipped with ADS-B Out, and that the incentive provided by the policy remains effective over a broad range of ratios of high- to low-equipage aircraft in the US airspace.

Optimized simulation architecture for multimodal radar modeling: Application to automotive driving assistance system

Scipedia content — Wed, 03 Feb 2021 15:50:12 +0100

International audience; This paper presents a new radar sensor modeling for Advanced Driver Assistance Systems (ADAS) prototyping. This virtual model is embedded in the SiVIC platform dedicated to the simulation of vehicles, infrastructure and sensors. Lots of simulators already exist addressing radar simulation, but none of them is designed to address in the same time the following objectives: real-time computation, highly sampled signal generation, multiple radar technologies, and, hardware and software platform integration for ADAS prototyping. In this paper, we proposed such a solution solving this issue and a focus will be done on the radar sensor modeling, from material modeling to implemented technology and associated signal processing. First results of this radar sensor modeling is carried out in motorway scenario.

Analysis of Excess Wake Vortex Separation on Arrival Delay

Scipedia content — Wed, 03 Feb 2021 15:48:50 +0100

n analysis is performed to estimate the delay in the terminal area due to excess leading/trailing aircraft wake vortex spacing. This analysis makes use of a large database of recorded traffic from early 2010 at several of the busiest Terminal Radar Approach Control Facilities (TRACONs) in the United States. To facilitate delay estimates, two arrival compression models are developed and applied to the recorded arrival traffic. A key feature of the compression modeling is the use of just two discrete points in the trajectory: TRACON entry and runway threshold crossing, eliminating the need for the resource intensive procedure of trajectory reconstruction. The analysis has two parts and each part focuses on two runways that are dedicated entirely to arrivals: KATL 27L and KDEN 35R. The first part is a sensitivity study exploring two strategies for compressing the arrivals: path reduction with original average true airspeeds and path reduction with (often times) faster average true airspeeds. This sensitivity study results in a range of delay savings on the order of tens of seconds per flight. The rest of the analysis uses the path compression model (original average true airspeeds), showing the uneven variation of daily delay savings at KATL 27L. Cumulative distribution functions capture the excess spacing reductions. They show a 10% increase (relative to the observed excess spacing) in arrivals landing with an excess spacing of 0.5 nmi or less at KATL 27L and a 25% increase at KDEN 35R.

Automated Probabilistic Analysis of Air Traffic Control Communications

Scipedia content — Wed, 03 Feb 2021 15:48:16 +0100

: Initiatives to integrate autonomous Unmanned Aerial Vehicles (UAVs) with regular airport operations require automated onboard situational awareness to maintain safety at all times. More specifically, this requires the capability to sense, interpret, and predict what other aircraft are doing, based on the same incoming data that are available to a human pilot. This includes not only baseline knowledge of the airport layout, operational practices and landmarks, but also an ability to interpret radio communications with Air Traffic Control (ATC) and correlate them with observable movements and positions of other aircraft. This analysis informs an autonomous UAV's control mechanisms which ultimately regulate its kinetic behavior at the airport. As with any operational domain governed by human actions and control, there are many inherent challenges in interpreting ATC communications -- a noisy data stream not only in terms of signal quality, but more significantly in the range of human deviations from the strictest procedures. This makes the analysis a natural application for Artificial Intelligence techniques, where the goal is to support automated reasoning that mimics a human pilot's decision processes. This paper provides a detailed discussion of a probabilistic reasoning approach using Bayesian Networks to classify ATC communications and synthesize them with baseline knowledge of an airport and produce real-time hypotheses about the states and trajectories of other aircraft. This provides a key component for automated situational awareness, which also requires correlation with sensor data, and ultimately a functional set of behaviors to act accordingly, although these latter capabilities are beyond the scope of this paper. The probabilistic communications analysis methodology is described, along with testing results using a real-world sample data set annotated for ground truth, to evaluate performance.

Optimal control approaches for aircraft conflict avoidance using speed regulation : a numerical study

Scipedia content — Wed, 03 Feb 2021 15:45:40 +0100

International audience; In this paper a numerical study is provided to solve the aircraft conflict avoidance problem through velocity regulation maneuvers. Starting from optimal controlbased model and approaches in which aircraft accelerations are the controls, and by applying the direct shooting technique, we propose to study two different largescale nonlinear optimization problems. In order to compare different possibilities of implementation, two environments (AMPL and MATLAB) and deterministic local optimization solvers are used. Numerical results are discussed. They show that the considered problem is really difficult to solve to global optimality, as different local minima are found using different methods.

The discovery and quantification of risk in high dimensional search spaces

Scipedia content — Wed, 03 Feb 2021 15:43:06 +0100

We describe a technique used by the ASHiCS project (Automating the Search for Hazards in Complex Systems) to discover high risk air traffic control (ATC) scenarios. We use a fast time ATC simulation of an en-route sector containing multiple flight paths and aircraft types, and into this we inject a serious incident (cabin pressure loss) which forces one aircraft to make an emergency descent. In order to create additional workload for the air traffic controller (ATCo), we also introduce a storm moving across the sector. We measure the associated levels of risk by analyzing the simulation outputs, selecting scenarios on basis of most risk and mutating aircraft entry times to see if the search can discover variant scenarios of even greater risk. The search space is extremely large and cannot be exhaustively searched for the worst case; this is a problem for safety engineers who require a context to search results so that event probabilities can be determined. While providing context cannot demonstrate that the worst case scenario has been found over all input permutations, it can indicate the expected frequency of that result in its near neighborhood, allowing analysts to focus on a much reduced parameter range when investigating those aircraft in conflict.

Analysis of Voltage Support by Electric Vehicles and Photovoltaic in a Real Danish Low Voltage Network

Scipedia content — Wed, 03 Feb 2021 15:41:27 +0100

With conventional generating units being replaced by renewable sources which are not required to provide same high level of ancillary services, there is an increasing need for additional resources to achieve certain standards regarding frequency and voltage. This paper investigates the potential of incorporating electric vehicles (EVs) in a low voltage distribution network with high penetration of photovoltaic installations (PVs), and focuses on analysing potential voltage support functions from EVs and PVs. In addition, the paper evaluates the benefits that reactive power control may provide with addressing the issues regarding voltage control at the expense of increased loading. Analysed real Danish low voltage network has been modelled in Matlab SimPowerSystems and is based on consumption and PV production data measured individually for number of households."br

Understanding the automotive industry: German OEM behaviour during the last 20 years and its implications

Scipedia content — Wed, 03 Feb 2021 15:33:59 +0100

This work presents a study of how the automotive industry has responded in the last 20 years to pressures driven by economic and environmental issues, and by the transition towards electric mobility. Timelines for the major German automotive OEMs are presented to understand the industry’s behaviour in the past in order to design suitable policies that are appropriate to reach future goals around the electrification of road transport. Based upon a comparison of the pressures arising in the automotive sector and the companies’ behaviour with regard to technology choice and R&

D, a set of hypotheses concerning this behaviour is then presented.

Document type: Article

Measuring the effects of aborted takeoffs and landings on traffic flow at JFK

Scipedia content — Wed, 03 Feb 2021 15:32:12 +0100

The FAA Office of Accident Investigation and Prevention (AVP) supports research, analysis and demonstration of quantitative air traffic analyses to estimate safety performance and benefits of the Next Generation Air Transportation System (NextGen). This paper describes research for AVP, developing a unique capability to support safety cases for NextGen Operational Improvements (OIs) across FAA lines of business, by the U.S. DOT Volpe Center and government contractors: The Boeing Company (Boeing), and Saab Sensis Corporation (Saab Sensis). Analysis of eight weeks Airport Surface Detection Equipment — Model X (ASDE-X) surveillance of KFJK terminal area traffic that characterized missed departures and missed arrivals is described first. The paper concludes with simulation studies of these events' impact on traffic flow.

Runtime architecture adaptation for energy management in embedded real-time systems

Scipedia content — Wed, 03 Feb 2021 15:31:24 +0100

Energy consumption has long been recognized as an important performance metric for many real-time and embedded systems. The traditional approach to energy-aware computing is to dynamically scale the voltage: this results in a significant drop in the energy consumed at the cost of a slowdown of the computation. In this paper, we explore a complementary approach to energy-aware real-time computing: that of runtime architecture configuration. As embedded real-time systems become ever more complex, the processors used will no longer be the bare-bones pipelines traditionally used, but rather high-end processors capable of meeting the timing needs of increasingly demanding applications. Also, the price of superscalar processors continues to fall, which allows them to be considered even for relatively cost-sensitive applications. Such high-end processors lend themselves to dynamic architecture adaptation. We describe how to exploit such adaptation and show that architecture adaptation when combined with dynamic voltage scaling, provides significant advantages over dynamic voltage scaling alone.

Supercapacitor characterization for electric vehicle applications

Scipedia content — Wed, 03 Feb 2021 15:29:06 +0100

International audience; This study deals with the dynamic and thermal behaviors of supercapacitors. Characterization is performed using the Electrochemical Impedance Spectroscopy (EIS) method to determine by experiment the supercapacitor's series resistance (ESR) and capacitance according to the frequency. The study deals also the particular case of the supercapacitor's spectra and the thermal shock. Finally, life test at constant temperature and the impact of the vibration on the supercapacitor's parameters are illustrated.

Optimisation of a multimodal public transport network

Scipedia content — Tue, 02 Feb 2021 08:45:06 +0100

Troisième Conférence Anniversaire de la Chaire socio-économie et modélisation des transports collectifs de voyageurs en milieu urbain, CHAMPS-SUR-MARNE, FRANCE, 17-/04/2013 - 17/04/2013; Presentation of an aggregate model of optimisation of a multimodal hierarchised public transport network. Application to Ile-de-France.

How to reduce the carbon footprint of road freight on supply chains?

Scipedia content — Tue, 02 Feb 2021 08:44:01 +0100

International audience; Rendering the supply chain more carbon-friendly is an innovative idea progressively adopted by industry. Transport accounts for one-fifth of the carbon emissions that are generated on French territory. Among the different transport modes, road transport is the one responsible for the majority of transport emissions. Our research focuses on the CO2 emissions along the supply chain due to road freight transport. Accordingly, we conduct a greenhouse gas (GHG) emissions assessment of a transport company. The main objectives of the study are twofold: identifying the main emission sources and improving green supply chains.

A driver assistance system based on multilayer iconic classifiers: Model and assessment on adverse conditions

Scipedia content — Tue, 02 Feb 2021 08:30:05 +0100

Recent work demonstrates that iconic classifiers are good candidates for the development of effective driver assistance systems, exploiting on-board micro cameras and embedded architectures. Following this line of research, in this paper the combined use of multilayer classifiers and iconic data reduction, based on Sanger neural networks, is investigated. It is shown that by this affordable approach it is possible to capture the essential information of the images, making worthless much more structured and time-consuming feature-based techniques. In particular, the applicability of a simplified learning stage, based on a small dictionary of poses, is considered; this peculiarity makes the system almost independent from the actual user. A detailed model of a simple driver assistance system, based on iconic classifiers, is presented and a comparative assessment, focused on the specific task of monitoring the car driver, is performed on adverse driving conditions. Three well known classification techniques are applied, demonstrating that the iconic approach, though can be certainly improved, is characterized by robustness, accuracy and real-time response; these features prove this technology to be an ideal tool for embedded automotive applications.

Merge recommendations for driver assistance: A cross-modal, cost-sensitive approach

Scipedia content — Tue, 02 Feb 2021 08:28:09 +0100

In this study, we present novel work focused on assisting the driver during merge maneuvers. We use an automotive testbed instrumented with sensors for monitoring critical regions in the vehicle's surround. Fusing information from multiple sensor modalities, we integrate measurements into a contextually relevant, intuitive, general representation, which we term the Dynamic Probabilistic Drivability Map [DPDM]. We formulate the DPDM for driver assistance as a compact representation of the surround environment, integrating vehicle tracking information, lane information, road geometry, obstacle detection, and ego-vehicle dynamics. Given a robust understanding of the ego-vehicle's dynamics, other vehicles, and the on-road environment, our system recommends merge maneuvers to the driver, formulating the maneuver as a dynamic programming problem over the DPDM, searching for the minimum cost solution for merging. Based on the configuration of the road, lanes, and other vehicles on the road, the system recommends the appropriate acceleration or deceleration for merging into the adjacent lane, specifying when and how to merge.

Knowledge-based trajectory control for engine-out aircraft

Scipedia content — Tue, 02 Feb 2021 08:21:40 +0100

International audience; Aircraft total failure of engines or engine-out, is a dramatic situation which may end by a crash unless a flyable descent trajectory towards a safe landing place is adopted. Although it is now a rare event, there are many different reasons for engine-out. Since with engine-out any wrong decision taken by the pilot may lead to catastrophic consequences, it appears useful to develop an automatic emergency guidance mode for this situation. This new functionality could be integrated in a Flight Guidance System which should be able to select a proper landing site while proposing tactical decisions to fly a feasible trajectory towards this site. In this study, a proposal for the design of such guidance system is developed. First, considering space-indexed glide dynamics for a transportation aircraft, reverse dynamic programming is used to generate, starting from safe landing conditions, a full safe glide domain up to cruise conditions and composed of quasi steady trajectories. Then a neural network structure is designed to produce for any glide situation within the safe glide domain, a reference pitch angle proposed to the pilot in manual mode. Total energy is then considered to distinguish between over range, on range and out of range glide situations and provide directives for the use of air brakes when necessary. Finally, a tentative integration of the produced information within the primary flight display is proposed. Numerical simulations are performed using data from a wide body transportation aircraft.

Methodology for development of a seaport: the case study of Kozhikode seaport (India)

Scipedia content — Tue, 02 Feb 2021 08:16:08 +0100

present, bigger vessels anchor in the outer sea at Beypore seaport, Kozhikode due to inadequate draught. Smaller vessels transport the freight from these bigger vessels to the harbor resulting in unnecessary expenditure. Thus, many commodities are diverted to the nearby major ports resulting in needless traffic on the highways connecting these ports increasing traffic congestion and accidents. Hence the development of Kozhikode seaport is essential in order to enable bigger vessels to berth. Stated preference surveys conducted to estimate the future traffic after development estimated that the freight traffic will multiply 15 fold, resulting in a tremendous increase in seaport revenue, huge profits for the shippers and massive benefits to society. The facilities needed at the seaport were estimated by queuing theory. The cost benefit analysis revealed that the project is viable and results in a sustainable future.

Vehicle and pedestrian collision prevention system based on smart video surveillance and C2I communication

Scipedia content — Tue, 02 Feb 2021 08:10:33 +0100

Hundreds of thousands of pedestrians are involved in severe traffic accidents every year world-wide. Reasons for these accidents include complex and highly dynamic traffic situations where views are obstructed or unexpected movement occurs. Driver assistance systems are a valid option for increasing pedestrian safety by enhancing the awareness of complex traffic situations and identifying potential dangers. In this work, the authors present a collision avoidance system based on smart video surveillance and car-to-infrastructure communication. They use a distributed system of monocular cameras to determine the position of both vehicles and pedestrians in real time. In addition, the authors utilize standard car-2-x communication technology (ETSI ITS G5) to provide all position detections to the vehicles, thus enabling complex use cases such as warning cascades to drivers in case of oncoming dangers. A detailed evaluation of the proposed system and collision warning use case demonstrates the suitability as assistance system for human drivers. The authors also show that automatic braking systems would lead to drastic performance improvements due to a significant reduction of reaction times.

Determining seasonal delay curves

Scipedia content — Tue, 02 Feb 2021 08:00:11 +0100

This paper presents an approach to expand on the Annual Service Volume (ASV) method for estimating air traffic delays. The ASV approach is a direct and intuitive method to estimate air traffic delays at an airport based on airline scheduled demand levels at that particular airport. The Seasonal Delay Curve (SDC) approach attempts to build on the ASV delay estimates by accounting for seasonal capacity variations. The result is an equally intuitive method that sheds light on the impact that seasons can have on delays at specific airports. This improvement helps explain why a particular scheduled level of demand can produce different amounts of delay in January than in July. This paper demonstrates how delay estimates can differ by season at airports like SFO and ORD that have noticeable seasonality in their arrival and departure rates.

Empirical assessment of urban traffic congestion

Scipedia content — Tue, 02 Feb 2021 07:55:23 +0100

This paper presents an empirical assessment of urban traffic congestion in Central London, UK. Compared with freeways or motorways, urban networks are relatively less studied because of its complexity and availability of required traffic data. This paper introduces the use of automatic number plate recognition technology to analyze the characteristic of urban traffic congestion in Central London. We also present the use of linear regression to diagnose the observed congestion and attribute them to different causes. In particular, we distinguish the observed congestion into two main components: one due to recurrent factors and the other due to nonrecurrent factors. The methodologies are illustrated through a case study of Central London Area. It is found that about 15% of the observed congestion in the region is due to nonrecurrent factors such as accidents, roadwork, special events, and strikes. Given the significance of London, the study will be valuable for transport policy evaluation and appraisal in other global cities. Copyright © 2013 John Wiley & Sons, Ltd. Language: en

Towards efficient methodologies for rapid-prototyping of communication technologies and cooperative ITS applications: Presentation held at the Tenth International Conference on Wireless and Mobile Communications (ICWMC), Expert Panel Mobility: Achievements and Challenges, 26 June, Seville, Spain

Scipedia content — Tue, 02 Feb 2021 07:50:23 +0100

Knowledge-Based Approach for 3D Reconstruction of As-Built Industrial Plant Models from Laser-Scan Data

Scipedia content — Tue, 02 Feb 2021 07:48:50 +0100

The three-dimensional (3D) reconstruction of as-built industrial plant models plays an important role in revamping planning, maintenance planning, and preparation for dismantling during the lifecycle of industrial plants. Recently, the 3D reconstruction of existing industrial plants was conducted using laserscan data to make surveying processes more efficient. However, the current 3D reconstruction process from laser-scan data is still limited due to the need for significant human assistance. Although a great deal of effort has been made to efficiently reconstruct 3D as-built industrial plant models, the presence of objects—such as equipment, pipelines, and valves of different sizes and shapes—in existing industrial plants significantly increases the complexity of laser-scan data and makes automating the reconstruction process more challenging in practice. The purpose of this study is to propose a knowledge-based approach for the 3D reconstruction of as-built industrial plant models from unstructured laser-scan data. First, pipelines were extracted from laser-scan data based on surface curvature information and knowledge about pipelines' sizes from existing piping and instrumentation diagrams (P&ID). Once entire pipelines were extracted, they were modeled based on skeleton features. Then, the remaining objects were clustered and grouped separately via the region grouping process. Afterward, clustered objects were retrieved and modeled based on global feature-based matching from the 3D database. Finally, the resulting model was checked to ensure that it was well-reconstructed according to the information regarding the relationships among objects abstracted from the existing P&ID. The preliminary results on actual industrial plants show that integrating knowledge into the reconstruction steps played an important role in the proposed approach and that this approach obtained accurate as-built industrial plant models from unstructured laser-scan data. The proposed approach could be successfully utilized to assist in many applications during the lifecycle of industrial plants.

The Impact of Trajectory Prediction Uncertainty on Air Traffic Controller Performance and Acceptability

Scipedia content — Tue, 02 Feb 2021 07:39:28 +0100

Human-In-The-Loop air traffic control simulation investigated the impact of uncertainties in trajectory predictions on NextGen Trajectory-Based Operations concepts, seeking to understand when the automation would become unacceptable to controllers or when performance targets could no longer be met. Retired air traffic controllers staffed two en route transition sectors, delivering arrival traffic to the northwest corner-post of Atlanta approach control under time-based metering operations. Using trajectory-based decision-support tools, the participants worked the traffic under varying levels of wind forecast error and aircraft performance model error, impacting the ground automations ability to make accurate predictions. Results suggest that the controllers were able to maintain high levels of performance, despite even the highest levels of trajectory prediction errors.

Assessing vehicular density estimation using vehicle-to-infrastructure communications

Scipedia content — Tue, 02 Feb 2021 07:34:16 +0100

©2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Vehicle density is one of the main metrics used for assessing the road traffic conditions. In this paper, we present a solution to estimate the density of vehicles that has been specially designed for Vehicular Networks. Our proposal allows Intelligent Transportation Systems to continuously estimate the vehicular density by accounting for the number of beacons received per Road Side Unit, as well as the roadmap topology. Simulation results indicate that our approach accurately estimates the vehicular density, and therefore automatic traffic controlling systems may use it to predict traffic jams and introduce countermeasures. Index Terms—Vehicular Networks, vehicular density estimation, Road Side Unit, VANETs. This work was partially supported by the Ministerio de Ciencia e Innovación, Spain, under Grant TIN2011-27543-C03-01. Barrachina Villalba, J.; Fogue, M.; Garrido, P.; Martínez, FJ.; Cano Escribá, JC.; Tavares De Araujo Cesariny Calafate, CM.; Manzoni, P. (2013). Assessing Vehicular Density Estimation Using Vehicle-to-Infrastructure Communications. IEEE. doi:10.1109/WoWMoM.2013.6583416 S

Boundary between air entrainment and air transport downstream of a hydraulic jump in circular conduits

Scipedia content — Tue, 02 Feb 2021 07:31:11 +0100

The transition from partially full to full flow in downward sloping pipes often occurs with a hydraulic jump that entrains air bubbles downstream in a filled conduit that makes it difficult to define the boundary between the air entrainment and air transport behind the jump in circular conduits. With the aim of addressing this issue, an experimental investigation that included the measurement of air bubble velocities with a high speed camera at distances of 1, 5 and 10 diameters downstream of the jump was carried out. The analysis results showed that when the distance beyond the jump was less than 10 diameters, the velocity profiles were irregular and influenced by the eddying action of the jump; however, when it was greater than 10 diameters, the velocity distribution was very similar to that of a typical fully developed velocity profile in a circular conduit.The work concentrated on a mild downward slope S = 0.087 (theta = 5 degrees) and small Froude numbers ranged from 0.045 to 2.04.

An Aggregate Air Traffic Forecasting Model subject to Stochastic Inputs

Scipedia content — Tue, 02 Feb 2021 07:30:30 +0100

This paper introduces an aggregate air traffic model that calculates the number of aircraft in each Air Route Traffic Center in the United States at any time iteration. The algorithm has the feature of being able to compute the shortest path of an aircraft using future previsions. Weather perturbations and available resources are two main types of input that have a stochastic nature due to their uncertainties. Too often they result in last minute delays or flight cancellations. Thus when predictions are available, their integrations in the path computation modify the aircraft trajectories accordingly, generating robust flight plans. More importantly, this algorithm handles different aircraft types which fly at different cruising speeds, making the scenarios being tested more realistic. Three simple scenarios were tested to validate this aggregate model. A large scale example using historical traffic data of a typical day in the National Airspace System is also presented. The results in comparison with uncontrolled simulations performed in the Future Automation Concepts Evaluation tool show that the model constitutes a potential Traffic Flow Management strategy. Nomenclature

Airport surface gridlock analysis: A case study of Chicago O'Hare 2007

Scipedia content — Tue, 02 Feb 2021 07:27:20 +0100

The evolution of Air Traffic Control (ATC) and Traffic Flow Management (TFM) over the last decade has resulted in improved coordination of departures and enroute trajectories to minimize airborne congestion and airborne holding. Since the system is a “closed-system,” the effect of these changes has been to shift airborne holding, to holding flights on the airport surface at the origin. This has placed increased emphasis on the coordination of gates, remote stands, airport parking, and surface trajectories. Previous research in this area has evaluated surface operations at specific airports through manual observation and/or surface track data, and through aggregate airport data and air traffic control logs. The purpose of this research is to develop a tool to systematically measure airport surface gridlock using publicly available data over extended periods of time (e.g. one year). The tool uses ASPM and AOTP data to count the number of aircraft on the surface but not at the gates (m i ). A measure of surface gridlock for a day is determined by identifying the number of flights on the surface (but not at the gates) for each 15-minute period in a 24 hour day. The maximum, mean, and median 15 minute flight count for a day is used to characterize the airport performance for a 24 hour period. A case study analysis of flight operations at Chicago O'Hare airport in 2007 identified the number of flights on the surface (but not at a gate) for each 15-minute period. ORD experienced an average in maximum 15-minute surface flight count of 97 flights with a standard deviation of 18 flights. Twenty-four days in the year experienced a maximum surface flight count in excess of 1.5 times the standard deviation (≈ 125 flights). Fifteen days in the year experienced a maximum surface flight count in excess of 2 times the standard deviation (≈ 134 flights). Eight days in the year experienced a maximum surface flight count in excess of 3 times the standard deviation (≈ 150 flights). The maximum surface flight count in excess of twice the standard deviation is concentrated in the summer convective season, and the winter snow season. Detailed analysis of the operations when the maximum surface flight count was in excess of three times the standard deviation identifies irregular operations with significant reductions in operations due to cancellations. However the coordination between arrivals, gates, and departures results in surface congestion. These results suggest that modernization initiatives that address normal operations are unlikely to affect these irregular operations.

Systematic Analysis on Pipeline Leak Detection and Location

Scipedia content — Tue, 02 Feb 2021 07:22:19 +0100

Because pipeline has large pipe diameter, large throughout and high pressure, once pipeline leakage accident happens, the damage is quite serious. In addition, pipeline leakage accident caused by man-made drilling oil stolen every year results in huge economic losses on oilfield. Therefore, a real-time and accurate pipeline leak detection and location system not only can effectively decrease leakage loss and reduce the waste of manpower and material resources in patrolling work, but also is conductive to the management of oil pipeline and improvement of economic efficiency of enterprise. The paper determines leak detection and location project giving priority to negative pressure wave and supplemented by flow parameter analysis. The method not only can judge the accidence of leakage timely and accurately, but also can effectively avoid leakage false alarm caused by start or stop pumps in pipeline. Negative pressure wave method is the method which is used widely on pipeline leakage detection and location internationally at present. It is based on signal processing. And the method doesn't need to establish hydraulic and mathematical model of pipeline, and most only use pressure signal. So the method adapts to the application of pipeline in China(1). Because oil pipeline has the function of guiding wave, the negative pressure wave caused by leakage can transmit more than tens of kilometers along the pipeline. Its propagation velocity is equal to the propagation velocity of sound wave transferring fluid in pipeline. And the propagation velocity of negative pressure wave in the original oil pipeline is between 1000meters and 1200 meters. As negative pressure wave has the characteristics of remote transmission, pressure transducer installed at the end and first of the pipeline can be used to capture negative pressure wave containing leakage information and to detect the leakage. After identifying leakage happens, leakage location can be made according to time difference of negative pressure wave caused by leakage transmitting to the head and end of the pipeline and negative pressure wave velocity(2).

Searching for sustainable urban transport solutions for Africa: a case study of the Greater Johannesburg region in South Africa

Scipedia content — Tue, 02 Feb 2021 07:21:32 +0100

The purpose of this paper is to undertake a critical review of existing urban transport interventions and innovations in Africa. The success factor that such measures have attained in seeking to reverse the trend of worsening and declining urban public transport services and infrastructure performance is assessed. Making use of the Greater Johannesburg region of South Africa as a case study, the urban transport hierarchy issues that make closing the loop difficult are identified and options for overcoming such obstacles discussed. The findings are based from a desktop analysis which is completed by an empirical research study in the Greater Johannesburg region carried consistently from 2007 up to 2011. These insights are complemented by key informants and transport stakeholder inputs. The aim of this longitudinal research is to seek to understand the complex and deeper issues that inform urban transport, policy, infrastructure and services dimensions. Overall, results confirm the consistent application of a mix of transport technology and non-technology solutions in the quest to solve urban transport problems in Africa. The tension and mismatch between transport infrastructure requirements and service gaps as contrasted with transport infrastructure and services budgeting and investment gap is an obvious weakness. Beyond transport plans and strategies, simultaneous application of transformative technology and related solutions is important if transport problems have to be reversed or significantly reduced. The need to implement more intelligent transport solutions today may serve developing countries from a worse transport situation in the future. Some of these transport technology innovations requiring serious consideration include a light rail; tram as well scope for underground train systems in the Greater Johannesburg region.

Effectiveness of link and path information on simultaneous adjustment of dynamic O-D demand matrix

Scipedia content — Tue, 02 Feb 2021 07:18:18 +0100

Introduction The paper deals with the adjustment of time-dependent Origin–destination (O-D) demand matrix, which is the fundamental input of ITS application for traffic predictions. The usual problem is to search for temporal O-D matrices that are “near” an a priori estimate (seed matrices) and that best fit traffic counts. However information on link flows is not fully effective in describing the state of the network; recent technologies for tracking vehicles provide a new kind of information on route travel times that can integrate usual information on traffic flows at count sections.

Document type: Article

Short paper: Distributed vehicular traffic congestion detection algorithm for urban environments

Scipedia content — Tue, 02 Feb 2021 07:08:26 +0100

Vehicular traffic congestion is a well-known economic and social problem generating significant costs and safety challenges, and increasing pollution in the cities. Current intelligent transport systems and vehicular networking technologies rely heavily on the supporting network infrastructure which is still not widely available. This paper contributes towards the development of distributed and cooperative vehicular traffic congestion detection by proposing a new vehicle-to-vehicle (V2V) congestion detection algorithm based on the IEEE 802.11p standard. The new algorithm allows vehicles to be self-aware of the traffic in the street, performing congestion detection based on speed monitoring and cooperation with the surrounding vehicles. Cooperation is achieved using adaptive single-hop broadcasting which depends on the level of congestion. The paper presents the congestion detection algorithm and the cooperative communication in detail, and presents performance evaluation using large-scale simulation in Veins framework based on OMNeT++ network simulator and SUMO vehicular mobility simulator. Results show that precise congestion detection and quantification can be achieved using a significantly decreased number of exchanged packets.

Recover 3D Information of the Moving Object from Video Streams

Scipedia content — Tue, 02 Feb 2021 06:59:38 +0100

Perception of the moving object in 3D from video streams has been one hot topic in computer vision. We present a fast method to reconstruct 3D information of the moving object from binocular video streams. System is assembled as two pipelines, technica are used to excavate the potential parallelism. With the corresponding points searching confined to very limited and credible region, the mismatching errors and time-consumed computation are reduced considerably. At the last, sparse depth map is calculated and then 3D contours and location of the object are estimated. The system is implemented and tested with outdoor and indoor moving object perception on 640×480 frame. Results show that the proposed method is improved in speed and stability. It can be used as a reference for autonomous navigation of mobile robot and object tracking.

Protection of Subsea Pipelines Against Ice Ridge Gouging in Conditions of Substantial Surface Ice

Scipedia content — Tue, 02 Feb 2021 06:55:52 +0100

The development of Arctic offshore hydrocarbon fields involves transportation systems for oil and gas, which comprise their shipping by tankers or pipeline systems. The later have sustained behavior with respect to hydrocarbons delivery and relatively non-sophisticated operational requirements."/jats:p" "jats:p"However, some important challenges regarding Arctic conditions have to be assessed before the pipeline is constructed. Attention is given to the conditions of a specific hydrocarbon field off the Sakhalin Island, and the design of an offshore pipeline. The issue of the pipelines’ interaction with first year ice ridges is described, a design ridge is selected and two theoretical models for evaluation of the maximum scour depth produced by the ridge ploughing the seabed are introduced."/jats:p" "jats:p"Thereafter a beam model of a pipeline exposed to bending and tension in terms of combined transverse and lateral loadings is established and analyzed. Based on the limit state design criteria the required trench features for different soil conditions for the safety of the pipeline are specified. Following the required pipeline failure probability, it is documented that the pipeline might be buried just below the probable scour depth if certain conditions of a “sandwich” backfilling with a weak soil layer on the bottom are met."/jats:p" "jats:p"Conclusions summarizing the acquired findings provide reasonable recommendations for offshore pipeline design in the Arctic regions and suggest a scope for future works and studies.

Interchange: Bidding for green lights

Scipedia content — Tue, 02 Feb 2021 06:47:00 +0100

In urban environments great effort is directed toward alleviating traffic including the design and implementation of complex software and hardware infrastructure. We introduce the idea of an auction-based mechanism for resolving vehicle intersections using a multi-way group auction mechanism. We propose a supporting infrastructure that has promise for increasing performance and responsiveness to dynamic traffic conditions. In order to evaluate new intersections, we propose new metrics that attempt to capture a more human aspect of vehicular transportation. We demonstrate that Interchange intersections perform well in single and multi-grid configurations, are self-adapting and are responsive to a variety of traffic loads.

Low Speed Automation: technical feasibility of the driving sharing in urban areas

Scipedia content — Tue, 02 Feb 2021 06:32:58 +0100

International audience; This article presents the technical feasibility of fully automated driving at speeds below 50 km/h in urban and suburban areas with an adequate infrastructure quality (no intersections, known road geometry and lane markings available) focusing on congested and heavy traffic. This requires implementation of several systems: lane keeping system, Adaptive Cruise Control (ACC), lane changing,\\ldots Feasibility has been demonstrated through a complex scenario during the final ABV project event.

A novel policy making proposition for EV charging infrastructure management at HEI's

Scipedia content — Tue, 02 Feb 2021 05:55:00 +0100

This paper is based on real time EV charging infrastructure development that took place at Brunel University, which is located in west of London, UK. The aim of this paper is to establish the policy making process that has stages of an initial student-staff interest survey, records of the consultation process with EV owners, results of competitive benchmarking with other HEI's and the discussion on Type 2 Mode 3 charging stations which are 240V, 32A, 7kW, 50Hz compliant with IEC 62196 and ISO 14443 Mifare standards. The first time ever PAYG concept of POD Point Ltd is explained. Benefits of using PAYG concept for charging EV are mentioned. Various other factors that played major role were also considered as follows: deciding the tariff of the electricity used by the EV owners, charging cable compatibility with charging station, hours of operation, creation of new enforcement rules and recommendations to provide incentives that recognise and motivate EV community.

Improved automotive self learning system using hypothesis test triggered forgetting to adapt to change points

Scipedia content — Tue, 02 Feb 2021 05:40:03 +0100

Current advanced driver assistance systems (ADAS) measure and evaluate every environment scenario in each trip from scratch. They are not able to draw on information of previous trips because currently a memory function in production vehicles does not exist. Learning systems for vehicles were proposed to aggregate information gathered by driving routes multiple times. This information can be used to create a learning map and enable highly automated driving. Learned information can represent a certain state of the environment captured by sensors like speed limits or geo-positions of roadworks. Changes in the vehicle relevant environment will affect vehicle perception and may affect the distribution of measured variables over time. The instant where the underlying distribution of a variable changes is denoted as change point. This can invalidate parts of the acquired knowledge and was not sufficiently dealt with in previous publications in the automotive field. The ability to detect the mentioned change points is essential for the necessary ongoing update of the learning map by devaluing or removing any invalidated knowledge from memory. For this purpose we propose a statistical hypothesis test and investigate its application for a prototypic ADAS: a Curve Warning Assistance System. The formulated test is able to detect change points faster and more robust than previously proposed algorithms. The ability to aggregate information in a learning map and to handle information actualization and devaluation represents a major building block for future highly automated driver assistance systems.

RACE: A Centralized Platform Computer Based Architecture for Automotive Applications

Scipedia content — Tue, 02 Feb 2021 05:34:41 +0100

In the last couple of years software functionality of modern cars increased dramatically. This growing functionality leads directly to a higher complexity of development and configuration. Current studies show that the amount of software will continue to grow. Additionally, advanced driver assistance systems (ADAS) and autonomous functionality, such as highly and fully automated driving or parking, will be introduced. Many of these new functions require access to different communication domains within the car, which increases system complexity. AUTOSAR, the software architecture established as a standard in the automotive domain, provides no methodologies to reduce this kind of complexity and to master new challenges. One solution for these evolving systems is developed in the RACE project. Here, a centralized platform computer (CPC) is introduced, which is inspired by the well-established approach used in other domains like avionics and automation. The CPC establishes a generic safety-critical execution environment for applications, providing interfaces for test and verification as well as a reliable communication infrastructure to smart sensors and actuators. A centralized platform also significantly reduces the complexity of integration and verification of new applications, and enables the support for Plug&Play.

A permanent-magnet machine with improved torque density based on a single layer winding layout for electric vehicle applications

Scipedia content — Tue, 02 Feb 2021 05:26:16 +0100

This paper proposes a novel single layer winding layout for a permanent magnet machine with improved torque density for electric vehicle applications. In this paper, two permanent-magnet (PM) machines with outer rotors and single layer fractional slot concentrated windings are compared based on two different slot/pole combinations, namely 20 slots/18 poles and 20 slots/22 poles. The two machines are inherently five-phase machines; however, a winding layout is employed to create three-phase stator terminals. Hence, the proposed machines exploit the advantages of multiphase machines while providing three phase terminals allowing for standard three-phase converters. Two machines are designed with same rotor and stator dimensions and same stator winding layout but with different number of rotor poles. The comparison is carried out using finite element analysis. NPRP grant NPRP (4-941-2-356) from the Qatar National Research Fund (a member of Qatar Foundation). Scopu

Keeping or not a BRT line on the route of a new subway?

Scipedia content — Tue, 02 Feb 2021 05:07:58 +0100

International audience; Line 1 of BRT, the first line of BRT system in Iran, and line 4 of Subway, designed as a sustainable transport system and constructed afterwards, have common path of 10 km length in the most congested area of the capital. This pioneer BRT line has the maximum record among all BRT lines in Tehran. Its success caused lower funds allocation and less attention to the planning and implementation of the line 4 of Subway. As a result currently line 4 of Subway works at 35% of its capacity with only 13 car-trains and the headway of 7-10 min. Construction investment in the subway line 4 was about 11 times more than in the line 1 of BRT. Thus, postponing of investments to the line 4 of Subway causes 65% of its infrastructure capacity to be unused. However, the elimination for BRT line appears logical, it’s important to avoid negative social impact, as this is a fact that the citizens of Tehran usually have fractal character, so that little changes in their behavior needs long time and enough desirability. Additional funds should also be found for the line 4 of Subway while budgets are saturated and other lines, considering existing demand, are in priority. Therefore, Tehran nowadays is brought to find remedial solutions to transport challenges: to align short-term and long-term sustainable solutions in order to achieve its economic, social and environmental goals.

Begin boulevard in Tel Aviv – from a suburban highway to an urban boulevard

Scipedia content — Tue, 02 Feb 2021 04:49:30 +0100

This paper describes how Tel Aviv’s Central Business District (CBD) is centered around Begin Road. By 2020, this area is expected to increase 50% in employment and 40% in housing. Initial proposals for Begin Road sought to meet the increased demand for travel by increasing road capacity. In response, the Israel Ministry of transport mandated an alternative design, which would give priority to public transit and pedestrians. The requirements of the alternative plan were: create a street with positive and clear urban identity, provide accessibility and safety for pedestrians and bicycles, give real priority for public transportation, allow through-traffic and provide access to street frontages, including short term parking. Five alternatives were developed by the planning team. All of them were different versions of the “multi-way boulevard”. The “multi-way boulevard” creates a clear separation between a slow moving “pedestrian realm”, and fast movement in the “through-traffic realm.” A multi-disciplinary evaluation process, involving professionals from several disciplines, was used to select two alternatives for further study. Evaluators first ranked the different road uses. Then each design was evaluated to provide a score on the overall integration and performance for the road design. Despite differences in priority schemes given to bus transit, both of the preferred alternatives provide a good balance between through traffic, vehicular access to adjacent uses, public transportation, and pedestrian and bicycle movement. They also create a strong, memorable street attractive to its users, which will encourage new development in the area.

Estimation of airline benefits from avionics upgrade under preferential merge re-sequence scheduling

Scipedia content — Tue, 02 Feb 2021 04:38:40 +0100

Modernization of the airline fleet avionics is essential to fully enable future technologies and procedures for increasing national airspace system capacity. However in the current national airspace system, system-wide benefits gained by avionics upgrade are not fully directed to aircraft/airlines that upgrade, resulting in slow fleet modernization rate. Preferential merge re-sequence scheduling is a best-equipped-best-served concept designed to incentivize avionics upgrade among airlines by allowing aircraft with new avionics (high-equipped) to be re-sequenced ahead of aircraft without the upgrades (low-equipped) at enroute merge waypoints. The goal of this study is to investigate the potential benefits gained or lost by airlines under a high or low-equipped fleet scenario if preferential merge resequence scheduling is implemented.

Control of Aircraft in the Terminal Manoeuvring Area using Parallelised Sequential Monte Carlo

Scipedia content — Tue, 02 Feb 2021 04:32:16 +0100

This paper reports on the use of a parallelised Model Predictive Control, Sequential Monte Carlo algorithm for solving the problem of conflict resolution and aircraft trajectory control in air traffic management specifically around the terminal manoeuvring area of an airport. The target problem is nonlinear, highly constrained, non-convex and uses a single decision-maker with multiple aircraft. The implementation includes a spatio-temporal wind model and rolling window simulations for realistic ongoing scenarios. The method is capable of handling arriving and departing aircraft simultaneously including some with very low fuel remaining. A novel flow field is proposed to smooth the approach trajectories for arriving aircraft and all trajectories are planned in three dimensions. Massive parallelisation of the algorithm allows solution speeds to approach those required for real-time use. This work was supported by EPSRC (Engineering and Physical Sciences Research Council - UK) Grant No. EP/G066477/1 AIAA Conference on Guidance, Navigation and Control 2013

A Multi-Agent based vehicles re-routing system for unexpected traffic congestion avoidance

Scipedia content — Tue, 02 Feb 2021 04:18:09 +0100

urbanization has been spreading across the world for decades, the traffic congestion problem becomes increasingly serious in most of the major cities. Among the root causes of urban traffic congestion, en route events are the main source of the sudden increase of the road traffic load, especially during peak hours. The current solutions, such as on-board navigation systems for individual vehicles, can only provide optimal routes using current traffic data without considering any traffic changes in the future. Those solutions are thus unable to provide a better alternative route quickly enough if an unexpected congestion occurs. Moreover, using the same alternative routes may lead to new bottlenecks that cannot be avoided. Thus a global traffic load balance cannot be achieved. To deal with these problems, we propose a Multi Agent System (MAS) that can achieve a trade-off between the individual and global benefits by giving the vehicles optimal turn suggestions to bypass a blocked road ahead. The simulation results show that our strategy achieves a substantial gain in average trip time reduction under realistic scenarios. Moreover, the negative impact of selfish re-routing is investigated to show the importance of altruistic re-routing applied in our strategy.

Security procedures and devices for road transportation of high consequence dangerous goods

Scipedia content — Tue, 02 Feb 2021 04:15:13 +0100

Road tankers transporting high consequences dangerous goods (HCDG) may represent an attractive target for terrorists, travelling practically anywhere, without escort, and presenting the potential to give rise to catastrophic incidents with a number of fatalities. Different kinds of security devices are available, ensuring a number of useful functions (localization of the vehicle, communication, etc.): their cost may represent a problem, even if prices are progressively decreasing, but additional concern may be workers’ privacy, which should be safeguarded. The operating procedures should be carefully tuned to provide the needed protection level without bothering the driver with a number of time consuming tasks to be fulfilled. The driver may be taken as hostage by terrorists, and forced to obey to their orders, this eventuality should be assessed without endangering the worker’s life. The present work outlines some basic arrangements of security devices and proposes some procedures to prevent threats to security posed by road transportation of HCDG.

Collision Avoidance System Optimization for Closely Spaced Parallel Operations through Surrogate Modeling

Scipedia content — Tue, 02 Feb 2021 04:14:55 +0100

The Traffic Alert and Collision Avoidance System (TCAS) has been mandated worldwide to protect against aircraft mid-air collisions. One drawback of the current TCAS design is limited support for certain closely spaced parallel runway operations. TCAS alerts too frequently, leading pilots to often inhibit Resolution Advisories during approach. Research is underway on ACAS X, a next-generation collision avoidance system that will support new surveillance systems and air traffic control procedures. ACAS X has been shown to outperform TCAS for en route encounter scenarios. However, the design parameters that are tuned for the en route environment are not appropriate for closely spaced parallel operations. One concept to allow for closely spaced parallel operations is a procedure-specific mode of the logic that reduces the nuisance alert rate while still providing collision protection. This paper describes the application of surrogate modeling for the purpose of tuning ACAS X for parallel operations. The performance of the tuned system is assessed using a data-driven blunder model and an operational performance model. The tuned ACAS X logic is found to outperform TCAS for each model in terms of both safety and operational suitability.

A Randomized Approach to Space Debris Footprint Characterization

Scipedia content — Tue, 02 Feb 2021 04:08:19 +0100

This paper studies the problem of characterizing the 4D (space cross time) region of the airspace that will be occupied by a space debris during an uncontrolled reentry, with the final goal of supporting the air traffic controllers in re-routing the air traffic when such an event occurs. The problem is formulated in terms of a chance-constrained optimization program, which is solved via a simulation-based method. The approach is comparatively evaluated against the so-called covariance propagation method recently proposed in the literature, emphasizing how some of the limitations of the latter method are overcome.

Potential of ITS to Improve Safety and Mobility of VRUs

Scipedia content — Tue, 02 Feb 2021 04:07:57 +0100

ITS Applications have in recent years assisted in reducing the number of fatalities in Europe. However, Vulnerable Road Users (VRUs) have not benefited as much as vehicle users. The EU-sponsored VRUITS project assesses the safety and mobility impacts of ITS applications for VRUs, assesses the impacts of current and upcoming ITS applications on the safety and mobility of VRUs, identifies how the usability and efficiency of ITS applications can be improved, and recommends which actions have to be taken at a policy level to improve ITS"br/"safety and mobility. This paper describes the results of the first phase of the project, in which the critical scenarios for VRUs are identified starting from accident data analysis, and following a user needs based on focus groups and expert interviews. From this basis, the most promising ITS applications for VRUs are selected according to their potential to address the specific needs of VRUs.

From Visualization to Association Rules : an automatic approach

Scipedia content — Tue, 02 Feb 2021 04:02:39 +0100

International audience; The main goal of Data Mining is the research of relevant information from a huge volume of data. It is generally achieved either by automatic algorithms or by the visual exploration of data. Thanks to algorithms, an exhaustive set of patterns matching specific measures can be found. But the volume of extracted information can be greater than the volume of initial data. Visual Data Mining allows the specialist to focus on a specific area of data that may describe interesting patterns. However, it is often limited by the difficulty to deal with a great number of multi dimensional data. In this paper, we propose to mix an automatic and a manual method, by driving the automatic extraction using a data scatter plot visualization. This visualization affects the number of rules found and their construction. We illustrate our method on two databases. The first describes one month French air traffic and the second stems from 2012 KDD Cup database.

Considering sustainability in the planning of transit systems: Istanbul case

Scipedia content — Tue, 02 Feb 2021 03:58:18 +0100

Traditionally, minimization of the total travel time spent by the passenger in the system is the most preferred objective while planning transit systems. To satisfy this objective, forecasted travel demands between zones and characteristics of the available fleet are taken into account, and at the end of the planning process, optimum frequencies of each of the transit lines are identified. Unfortunately, this planning approach is not sufficient as the negative effects of the global warming are growing each day. Fossil fuels are the primary energy sources for transport systems and accordingly, the emission of the greenhouse gases especially carbon dioxide is accredited to this industry. Hence, it is impossible to ignore environmental requirements in the transit planning phase. In this study, the authors developed a bi-level and bi-objective optimization model to identify the optimum line frequencies. One of the objectives is to minimize the mean travel time of the passengers. The other objective is to minimize the total emission. A genetic algorithm is developed to solve this mathematical programming problem. A large instance related to Istanbul transit system involving 39 zones and 463 bus lines is solved with this solution method and results are elaborated.

Toward a verifiable software dataplane

Scipedia content — Tue, 02 Feb 2021 03:56:27 +0100

Software dataplanes are emerging as an alternative to traditional hardware switches and routers, promising programmability and short time to market. These advantages are set against the concern of introducing buggy or under-performing code into the network. We explore whether it is practical to formally prove that a software dataplane satisfies key properties that would ensure smooth network operation. In general, proving properties of real programs remains an elusive goal, but we argue that dataplanes are different: they typically follow a pipeline structure that enables our proposed approach, in which we verify pieces of the code in isolation, then compose the results to reason about the entire dataplane. We preliminarily demonstrate the potential of our approach by applying it on simple Click pipelines and proving that they are crash-free and execute a bounded number of instructions. This takes on the order of minutes, whereas a general-purpose state-of-the-art verifier fails to complete the same task within 12 hours.

Combined numerical-experimental framework for strain based design and flaw assessment of girth welds

Scipedia content — Tue, 02 Feb 2021 03:55:56 +0100

An increasing number of transmission pipelines have to be installed and operated in harsh conditions, due to the diminishing reserves of exploited fossil fuel sources. Under certain environment related circumstances, longitudinal plastic strains are imposed. When tensile, these may induce failure in girth welds in conjunction with the inevitable presence of weld defects. A large number of factors related to environment, material, geometry and operating conditions influence the tensile strain capacity and, hence, the acceptability of girth weld flaws. Therefore, a project specific development of guidelines in this strain based context is recommended. This paper provides systematic frameworks on (a) how to design pipelines under strain based conditions, and (b) how to assess girth weld flaws that were detected using non destructive testing. Attention is given to several technical and economical aspects related to the selection and qualification of pipe and weld metals, and to the evaluation of flaw acceptability. Both frameworks comprise a combined experimental-numerical approach, collecting project development reports from literature with research carried out at Soete Laboratory. Concretely, four in-house realizations are adopted: the UGent equation for strain capacity, the curved wide plate tension test, the UGent stress-strain equation and a finite element model of full scale pressurized pipe tension testing. The proposed frameworks aim to facilitate in performing thorough and economically justifiable strain based design and assessment processes.

Design of a High Voltage Bidirectional DC-DC Converter for Driving Capacitive Incremental Actuators usable in Electric Vehicles (EVs)

Scipedia content — Tue, 02 Feb 2021 03:41:41 +0100

This paper presents the design of a low input (24 V) and variable high output voltage (0–2.5 kV) bidirectional dc-dc converter for driving a capacitive actuator. The topology is a digitally controlled bidirectional flyback converter with a variable frequency control. The objective is, to design the converter for efficiently charging and discharging the capacitive actuator from 0 V to 2.5 kV and vice versa, respectively. The converter is used to drive a dielectric electro active polymer (DEAP) based capacitive incremental actuator, which has the potential to be used in automotive (e.g., EVs), space and medical industries. The design of the bidirectional flyback converter to charge and discharge a 400 nF capacitive actuator is presented, when 4 kV and 4.5 kV high voltage MOSFETs are used on the secondary high voltage side. The experimental results and efficiency measurements of the converter with the proposed design are provided.

Fog Regime in Latvia and Factors Affecting it: Case Study-Riga Airport

Scipedia content — Tue, 02 Feb 2021 03:38:51 +0100

Fog is a hazardous weather phenomenon, which can impact traffic (especially air traffic) and air quality. The aim of this study is to analyse fog climatology, the trends of long-term changes of fog events and factors affecting them in general, in Latvia, but especially in Riga airport. For a 50-year period of observations, the analysis of the fog frequencies, long-term changes and atmospheric conditions favourable for the occurrence of fog events in Latvia has been studied. During the analysis two inter-annual maxima of fog frequency were found in spring and autumn, and the seasonal differences in the formation of fog were also approved by the satellite data on low cloud cover.

Limits and opportunities of risk analysis application in railway systems

Scipedia content — Tue, 02 Feb 2021 03:35:54 +0100

Risk analysis is a collection of methods widely used in many industrial sectors. In the transport sector it has been particularly used for air transport applications. The reasons for this wide use are well-known; risk analysis allows one to approach the safety theme in a stochastic – rather than deterministic – way; it forces one to break down the system in sub-components. Last, but not least, it allows a comparison between solutions with different costs, introducing de facto an element of economic feasibility of the project alternatives in the safety field. Apart from the United Kingdom, in Europe, the application of this tool in the railway sector is relatively recent. In particular, Directive 2004/49/EC (the “railway safety directive”) provides for compulsory risk assessment in relation to the activities of railway Infrastructure Managers (IMs) and of Railway Undertakings (RUs). Nevertheless, the peculiarity of the railway system – in which human, procedural, environmental and technological components have a continuous interchange and in which human responsibilities and technological functions often overlap – induced the EC to allow wide margins of subjectivity in the interpretation of risk assessment. When enacting Commission Regulation (EC) No 352/2009 which further regulates this subject, a risk assessment is considered positive also if the IM or RU declare to take safety measures widely used in normal practice. The paper shows the results of a structured comparative analysis of the rail sector and other industrial sectors, which illustrate the difficulties but also the opportunities of a transfer towards the railway system of the risk analysis methods currently in use for the other systems.

The impact of ITS on CO2 emissions – An analysis of effect chains

Scipedia content — Tue, 02 Feb 2021 03:29:26 +0100

Information and communication technologies (ICT) applied to the transport sector are expected to play a significant role in reducing the carbon dioxide (CO2) emissions emitted by the transport sector. To foster the development and deployment of these technologies, known as “intelligent transport systems” (ITS), and direct the development into promising tracks their potential impact on CO2 emissions needs to be known in advance. Therefore a methodology for a reliable environmental evaluation is crucial, which is outline in this technical paper.

The Research on Road Congestion Of Pre-diversion Method

Scipedia content — Tue, 02 Feb 2021 03:26:01 +0100

An Enhancement to the Linear Dynamic System Model for Air Traffic Forecasting

Scipedia content — Tue, 02 Feb 2021 03:25:25 +0100

traffic forecast is among the most important functionalities of air traffic controls. The Linear Dynamic System Model that predicts the traffic demand within the Air Route Traffic Control Centers serves well for this purpose. This model formulates inflows and outflows between Centers’ boundaries by assuming that the boundary crossings between Centers are in conformance with Poisson distribution and that the traffic patterns do not change too much over multiple days. As a result, the traffic in the near future can be predicted based on knowledge of historical traffic patterns and anticipated departures. As a predictive model, its prediction accuracy relies heavily on parameter estimation. In the earlier implementations of this model, the traffic patterns are obtained by averaging estimations of multiple days. However, given the uncertainties in the traffic system and the deficiencies inherent in the radar track data, using observed traffic data of a few days to train the parameters is likely to result in bias due to limited samples. A large training set on the other hand contains a lot of noise, to which the mean is susceptible. This paper introduces the Kernel Density Estimation into the Linear Dynamic System Model. This non-parametric method serves as an enhancement to the model in that it is able to capture the major transition patterns from a large data set in the presence of outliers and data deficiencies regardless of the actual distribution of data. Therefore, this statistical approach is useful in extracting normal traffic patterns that are representative of major behavior of the traffic flows. An one-month traffic simulation shows that, by incorporating with the Kernel Density Estimation, the Linear Dynamic System Model reduces the estimation errors by 20% on average.

Student satisfaction with the campus bus services at UiTM Shah Alam, Malaysia

Scipedia content — Tue, 02 Feb 2021 03:23:59 +0100

Campus traffic congestion is a common occurrence because of the factorial increase in enrolment every year. Universities in the Klang Valley, Selangor, Malaysia have to adjust to the situation to appease the stakeholders, in particular the students. With affluent times, many students have their own private vehicle which they drive or ride to school. However, most public universities bar students' vehicles from campus if they were given on-campus housing and on-campus transport is available. In the case of Universiti Teknologi MARA, due to the limited number of dormitories, many students rent out. Consequently, they drive their own vehicles to class or for lesser-affluent ones, the buses and taxis are the popular choice to commute. Thus, the influx of these vehicles is the main cause of traffic congestion. This issue continues to be debatable between the university administrators, the staff and the students. Also, the limited number of parking spaces aggravates the situation, hence, the need to plan for an efficient and effective bus system - the campus hybrid transportation system. In doing so, it is important to get the bus passenger's feedbacks on the current transport services provided. In this case, the units of analysis are the students which form the majority of the bus passengers. Thus, this paper reports the pilot survey on student satisfaction with the campus bus service at the main campus. Through a cross-sectional design, 78 completed responses were analyzed where 28.2% indicated dissatisfaction with the current bus service. Furthermore, the comments from the respondents provided further evidence that the transportation system on campus has to be reformed. The paper concludes with suggestions for a hybrid transportation system planning, implementation and policy that would guide the success of the project for all stakeholders.

Integration of land use and transportation within the CBD of an intermediate city: a case study of Tlokwe local municipality, South Africa

Scipedia content — Tue, 02 Feb 2021 03:21:05 +0100

The Tlokwe Local Municipality (Potchefstroom) (secondary node) is located on the N12 corridor between Johannesburg as (primary node) through Kimberley (secondary node) to Cape Town (primary). This location reality implies that some 65% of the inter traffic consists of heavy motor vehicles transporting freight that is passing through the Central Business District (CBD) of Potchefstroom based on origin and destination movement patterns between the high order nodes within the national spatial system. These traffic movement patterns result in traffic congestion that impacts negatively on the intra-traffic flows within the CBD of Potchefstroom and its spatial land use development, consolidation, growth, urban renewal, internal movement patterns and local accessibility. The research includes a literature overview of land use and transportation integration; study of inter-traffic movement patterns (regional) and traffic volumes for intra-traffic movements in terms of modal split; detailed land use and parking surveys within the study area. Inclusive in the research methodology is a quantitative research approach supported by a qualitative research survey as to identify local experience, patterns and perceptions related to the research problem. This elementary modeling and simulation output is supported in the demarcation of the CBD boundary based on land use and transportation integration considerations and related tendencies within the study area. The devised elementary technique will be used to project the future land use patterns.

Research and Development of Gas and Pipeline Technical Standard Content Reveal Technology and System

Scipedia content — Tue, 02 Feb 2021 03:17:58 +0100

Traditional standard retrieval methods and systems presented in various papers are widely used based on the standard titles and the keywords. However, these methods may be inapposite to modern pipeline engineers, especially for the ones who want find the requirements details of pipeline standards as fast as possible. In recent years, a number of projects have been funded to develop a Gas and Pipeline Standard Content Reveals System in PetroChina. This paper covers the development process of the system. The development of Gas and Pipeline Standard Content Reveals System involves ontology knowledge, technical details picking up and reveals system, and the process is as follows. Firstly, standard retrieval methods are reviewed. Then pipeline ontology knowledge is built as standardization objects. So the gas and pipeline standard content reveals system can be designed and developed with powerful database. It is believed that the approach to show the standard content presented in this paper may lay the initial basis for the important assist system for pipelines engineers.

The integration of intelligent transport systems in urban transport

Scipedia content — Tue, 02 Feb 2021 03:13:22 +0100

The global increase of mobility – especially in cities – and continuing climate change necessitates the decarbonisation of the transport system, the enhancement of the energy efficiency of transport and the implementation of innovative transport solutions. But the continuously growing volume of traffic can also result in congestion, air pollution and collapsed traffic systems, caused by fast growing populations, the lack of city planning and low financial budgets. An approach for managing traffic in urban areas is an intelligent transport system (ITS); especially large cities are forerunners for such solutions. At the same time, large events provide an opportunity to develop, implement and evaluate innovative transport solutions. The growing interest in international events like football championships, the Olympic Games or exhibitions require high-performance transport solutions and traffic concepts due to the large number of participants. In consequence of the international attention, for prestige purposes and not least the financial background, large events are drivers of sustainable developments in transport. The focus of the current paper lies on new ITS solutions in the cities of Cape Town, Delhi and London. All three cities are part of the EU-funded project STADIUM (Smart Transport Applications Designed for large events with Impacts on Urban Mobility) which aims at improving the performance of transport services and systems made available for large events hosted by big cities. The project demonstrates ITS applications at three events: the FIFA Soccer World Cup (2010) in South Africa, the Commonwealth Games (2010) in India and the Summer Olympics (2012) in London.

How to anticipate the level of activity of a sustainable collaborative network: the case of urban freight delivery through logistics platforms

Scipedia content — Tue, 02 Feb 2021 03:07:46 +0100

International audience; In this paper, we elaborate a methodology to study a particular case of collaborative network: city logistics. We identify that many solutions for urban logistics are, most of time, badly evaluated. Indeed, the theory often predicts a positive effect but the reality is most of time counterbalanced. We tried to fill this gap by making use of innovative methods. To do so, we mobilize several domains of knowledge: operational research, game theory and transportation studies on real cases. We suggest a solution to anticipate the level of activity of an Urban Consolidation Center and determine the condition under which it generates benefit for a carrier using or not, the collaborative network. We present the result obtained by application of our method on the real case of the city of Saint-Etienne.

Fiber Optic based Pipeline Oil and Gas Leak and Intruder Detection System with Security Intervention Plan

Scipedia content — Tue, 02 Feb 2021 03:00:00 +0100

The accurate and timely localization of the vandalization and leak point on an oil pipeline provides operators with information to aid with the development of robust security response and intervention plans. These plans have the potential of reducing the impact of leaks on the environment by enabling operators to take actions to mitigate their effect. A major challenge with current leak and vandalization detection systems is the generation of spurious signals which in time slows down the response to these alerts. This paper presents results of the field trial of a Fiber Optic Cable based Oil/ Gas leak and intruder detection system. Oil and Gas leaks were simulated on a pipeline section buried in a swamp location with 1mm and 2mm Orifices located at the 0o, 90o and 180o positions on the pipe with a section of the pipe exposed for third party intruder detection tests. The orifices were connected to compressed air and water used in place of Oil and gas. The fiber optic cable was buried on both sides of the pipeline and hooked up to the Helios Integrator. The system was able to detect and localize leaks from the orifices with the signal intensity proportional to the leak intensity. It was able to detect third party activities such as cutting and the use of hammers on the pipeline and also walking near the pipeline. The results coupled with the security intervention plan which is developed to provide varying levels of response will eliminate response to spurious signals thus providing a robust response and intervention plan to oil and gas leak and intruder detection.

A TCAS-II Resolution Advisory Detection Algorithm

Scipedia content — Tue, 02 Feb 2021 02:54:14 +0100

The Traffic Alert and Collision Avoidance System (TCAS) is a family of airborne systems designed to reduce the risk of mid-air collisions between aircraft. TCAS II, the current generation of TCAS devices, provides resolution advisories that direct pilots to maintain or increase vertical separation when aircraft distance and time parameters are beyond designed system thresholds. This paper presents a mathematical model of the TCAS II Resolution Advisory (RA) logic that assumes accurate aircraft state information. Based on this model, an algorithm for RA detection is also presented. This algorithm is analogous to a conflict detection algorithm, but instead of predicting loss of separation, it predicts resolution advisories. It has been formally verified that for a kinematic model of aircraft trajectories, this algorithm completely and correctly characterizes all encounter geometries between two aircraft that lead to a resolution advisory within a given lookahead time interval. The RA detection algorithm proposed in this paper is a fundamental component of a National Aeronautics and Space Administration (NASA) sense and avoid concept for the integration of Unmanned Aircraft Systems in civil airspace.

Climatological influences on inland waterway transport capacity

Scipedia content — Tue, 02 Feb 2021 02:53:57 +0100

Climate change may affect inland waterway transport through disturbances in waterway hydrology: longer periods with strong water swells and drops. To allow fully loaded barges, the water level must be neither too high (limited air draught) nor too low (limited draught). Therefore, the water level impacts the load factor of barges and thus the transportation costs. Moreover, in winter, ice jams can paralyze inland waterway traffic on the river. In this paper, the effect of various climatological changes on the capacity of inland waterway in terms of barge transport is examined. The paper focusses on the development of a methodology for assessing the sensitivity of inland waterway systems to climatological changes and takes into account an experts' opinion survey that provides insight into the perceived likelihood of the different scenarios that are investigated. The analysis focusses on the inland waterway systems in Belgium, which has the second highest density of European inland waterways. It enables the integration of inland waterway transport in the intermodal supply chain. The results are related to investment planning and management in inland waterways transport. They are intended to be interesting to researchers and to inland waterways actors developing intermodal transport as well. Peer reviewed

A decomposition-based optimal control approach for aircraft conflict avoidance performed by velocity regulation

Scipedia content — Tue, 02 Feb 2021 02:48:54 +0100

International audience; One of the decisive tasks within the air traffic management is the resolution of aircraft conflict avoidance problems. To avoid conflict, aircraft have to preserve a minimal safety distance between them. In this paper, we present optimal control models and approaches based on speed regulation to perform aircraft conflict avoidance. We consider some aircraft configurations with separable trajectories, i.e., such that trajectories of aircraft pairs exhibit conflict zones which are each other separated in terms of time and/or space. We propose a decomposition of the problem in such a way to solve independently subproblems of the original one.

Automating Trajectory Prediction Performance Analyses for the FAA Traffic Management Advisor

Scipedia content — Tue, 02 Feb 2021 02:35:10 +0100

This paper presents a new approach for analyzing the trajectory prediction performance of the FAA’s Traffic Management Advisor (TMA). TMA is a deployed system that generates scheduled time-of-arrival constraints for en-route air traffic controllers in the US. The new automated analysis provides a repeatable evaluation of the current trajectory performance metrics, for new releases of TMA, in different traffic and airspace environments, and for current traffic situations. Using a wider set of data, it provides also a higher level of understanding on the causes of possible degradation of the trajectory prediction performance of TMA. The bulk of the work consisted of the development of the ability to filter flights not impacted by controller intervention. Identifying interrupted flights from recorded data is challenging but necessary for a fair and accurate performance test. Currently, no method for identification of flights exists other than a manual review of voice communications. The automated approach was tested with two data sets, from 2006 and 2013. The 2013 data consisted of 24 hours of traffic arriving into Dallas Forth Worth Airport. The results of the testing on this data set showed that the approach selected a statistically significant number of flights to validate the TMA trajectory predictor’s performance against the system requirements. New metrics for the evaluation of the TMA trajectory predictor’s performance are introduced and compared with the current set of metrics used by the FAA.

Estimated Fuel Burn Performance for MDW Arrivals

Scipedia content — Tue, 02 Feb 2021 02:24:50 +0100

The Terminal Radar Approach Control (TRACON) arrival flows are an important component of overall NAS efficiency and airline costs of operation. The efficiency of TRACON arrival flows is a function of the relative position of the final waypoint on the Standard Terminal Arrival Route (STAR) to the runway threshold, the type of approach (ILS, RNP, VFR), and the arrival vertical and longitudinal profile. A previous research established the presence of 16 unique arrival flows for the main runways (31C, 4R, 22L and 13C) at Midway International Airport (MDW), using 43 days of National Offload Program (NOP) radar track data. This paper uses an aerodynamic fuel burn model to estimate the fuel burn for these flows.

Applying Mathematical Model to Simplify the Procession of Pipeline Route Selection

Scipedia content — Tue, 02 Feb 2021 02:06:40 +0100

Now there are many pipelines to deliver liquid-like water diversions in the world. Optimal route for pipeline transportation is a major concern for engineers, economists, and decision makers. Pipeline route selection is governed by many factors such as the shortest distance between supply and demand points, constructability, affordability, environmental impacts, and approachability. There are many methods developed for the pipeline route selection like Gestalt method, land suitability mapping techniques, geographic information systems (GIS), imaging technologies for pipeline mapping with the use of airborne lidar, etc. But these methods, though robust in translating physical constraints into feasible alternatives for route location, have their own pros and cons for applications, which are weak in incorporating the decision maker's preferences. This paper presents an easy approach to route selection with the goal of saving energy and having the shortest distance. The method in this paper makes an attempt to establish a method for the route with minimum energy required with the aid of mathematics computing and GIS or the data coming from Google Earth. This method is demonstrated here through two different case studies of pipe route selection, the Los Angeles aquaduct, the second Los Angeles aquaduct in USA, and water diversion from Palmer to Millbrook Reservoir in Australia. The calculated results are shown and analyzed.