Scipedia: Documents published in 2014

Developing Walvis Bay Port into a logistics gateway for southern Africa: Issues, challenges and the potential implications for Namibia’s future

Scipedia content — Tue, 23 Mar 2021 07:13:07 +0100

Many developing countries wish to become the ‘gateway’ to a region or part of a continent.One strategy involves encouraging logistics cluster development. These hubs support global supply chains and may enable the economic growth of the host country through the resulting trade, as well as providing direct and indirect employment opportunities during the build and subsequent operation of the hub. Namibia intends to develop the Port of Walvis Bay to be come the preferred gateway to southern Africa and the Southern African Development Community region. This article builds on research on Caribbean cluster potential and Namibian logistics to identify the potential benefits and impact on development, as well as the drawbacks and risks of such a strategy.

Document type: Article

Modeling road accident injury under-reporting in Europe

Scipedia content — Tue, 23 Mar 2021 05:21:13 +0100

In this research, a disaggregate analysis of road accident injury under-reporting in selected European countries is presented. The level of injury under-reporting is expressed by under-reporting coefficients, estimated as the actual estimated number of road accident injuries of a given severity to the number of related injuries recorded by the Police. These coefficients were calculated within national/regional studies in the examined countries, through a specially developed uniform methodology of linking and matching Police road accident records and hospital records. Log-rate models are developed in order to estimate the combined effects of country (CZ, FR, GR, HU, NL, ES and the UK), road user type (car occupant, motorcyclist, pedal cyclist, pedestrian), Police severity score (serious or slight injury) and MAIS score (the maximum Abbreviated Injury Scale score) on under-reporting. The results suggest that the examined characteristics have important combined effect on under-reporting (i.e. third-order interaction). The results of the analysis of lower-order interactions reveal specific particularities of each country/region, indicating areas on which authorities should focus their efforts. For example, it was found that slight injuries are more likely to be under-reported than serious injuries in the Czech Republic, France, and Greece, while the opposite is the case for the Netherlands and the UK. Moreover, although the Netherlands do not present high under-reporting rates overall, a particular issue is identified in this country for pedal cyclists’ slight injuries. Finally, a considerable part of total under-reporting in most countries can be attributed to injury severity mis-reporting.

Document type: Article

Quantifying the Benefits from a Major Infrastructure Improvement: The Case of Thessaloniki Western Ring Road Upgrade to Eliminate at Grade Signalised Intersections

Scipedia content — Tue, 23 Mar 2021 05:16:47 +0100

"jats:p" Thessaloniki is the second largest city in Greece and its transportation system (development and operation) is hampered by the city’s geographical position and surrounding relief. Specifically, the city has been developed and expanded through the years along the coastline, the sea boundary on the southwest, and a second physical boundary, a forest, on the east side. The Thessaloniki Ring Road (divided in western and eastern part) was constructed in the early ‘90s, in order to relief the road network of the city centre from the transit traffic and confront the gradually increasing congestion. The absence of alternatives other than road transport and the increase of car ownership over the years led to an increase of motorized traffic. So even that this Ring Road had been designed to serve 30,000 vehicles daily it became to serve more than triple traffic just before the impacts of the economic crisis on transport and mobility have been made visible. "/jats:p" "jats:p"The Western Internal Ring Road of Thessaloniki ("jats:bold"WIRRT"/jats:bold") has length of 8.4km. It has three lanes per direction separated by a median and no emergency lanes. The traffic increase and moreover the existence of eight at grade intersections along the WIRRT degrade the provided level of service. For the elimination of these intersections an upgrade project is underway for implementation that includes the construction of five grade separated intersections and several interventions on the adjacent road network. This paper presents in brief the methodology and the results of the project’s Cost-Benefit Analysis, which assessed the expected socioeconomic benefits, emerging mainly from minimising the delays for users due to the elimination of the at grade signalised intersections.

Document type: Article

Collision risk-capacity tradeoff analysis of an en-route corridor model

Scipedia content — Tue, 23 Mar 2021 04:58:38 +0100

Flow corridors are a new class of trajectory-based airspace which derives from the next generation air transportation system concept of operations. Reducing the airspace complexity and increasing the capacity are the main purposes of the en-route corridor. This paper analyzes the collision risk-capacity tradeoff using a combined discrete–continuous simulation method. A basic two-dimensional en-route flow corridor with performance rules is designed as the operational environment. A second-order system is established by combining the point mass model and the proportional derivative controller together to simulate the self-separation operations of the aircrafts in the corridor and the operation performance parameters from the User Manual for the Base of Aircraft Data are used in this research in order to improve the reliability. Simulation results indicate that the aircrafts can self-separate from each other efficiently by adjusting their velocities, and rationally setting the values of some variables can improve the rate and stability of the corridor with low risks of loss of separation.

Document type: Article

CYCLE LANES: THEIR EFFECT ON DRIVER PASSING DISTANCES IN URBAN AREAS

Scipedia content — Tue, 23 Mar 2021 03:25:39 +0100

The current literature in the field of cycle lanes has often shown contradictory evidence as to the benefits and risks of cycle lanes and previous work has specifically shown that on higher speed roads, drivers may pass closer to a cyclist when a cycle lane is present. Utilising an instrumented bicycle, we collected information as to the passing distance demonstrated by drivers when overtaking a cyclist within the urban (30 mph/40 mph) environment. The presented analysis shows that when a driver encounters a cyclist mid-block (i.e. not at a junction), there are more significant variables than the presence of a cycle lane that determines the overtaking distance. The three most significant variables identified are: absolute road width, the presence of nearside parking and the presence of an opposing vehicle at the time of an overtaking manoeuvre. The analysis also demonstrated that there is a larger unknown factor when it comes to overtaking distances. We postulate that this unknown variable is the driver himself and will vary by area, site and even time of day (i.e. different driving cultures, congestion, or frustration during peak times, etc.) making it difficult to quantify. First Published Online: 22 Sep 2014

Document type: Article

The Geopolitical Energy Security Evaluation Method and a China Case Application Based on Politics of Scale

Scipedia content — Tue, 23 Mar 2021 03:08:25 +0100

Combining the theories of politics of scale from political geography, security theory from international relations, and energy security theory, and putting the scale conversion of energy contention, geographical relationship and geo-structure in geo-setting, and the three properties of safety in consideration, this paper rebuilds a geo-energy security evaluation model and uses the model to quantitatively evaluate China’s geo-oil energy security in the Russian Pacific oil pipeline construction from 1995 to 2010. Five results could be drawn as follows: (1) from the aspect of time, an up-surging Geo-oil Safety Index of China in the Russian Pacific oil pipeline construction indicated an increasingly disadvantage of China in the geo-oil contention by politics of scale. If the United States and South Korea are involved, the competition would be further intensified

(2) from the aspect of geopolitical relationship, a general decrease occurred in the Sino-Japan Energy Competition Index, but a specific increase appeared in the competition of energy imports from Russia, by China and Japan individually

(3) from the aspect of regional strategy of energy export, an obvious downward tendency in Energy Export Strategy Index showed that Russia has changed its export destination off of Europe

(4) from the aspect of geo-security, a relatively steady proportion of China’s oil consumption, and a friendly comprehensive strategic partnership of cooperation between China and Russia, reduced the worries of China’s geo-oil energy security to some extent

(5) from the aspect of geopolitical structure, the increasing comprehensive national power in China, driven by rapid economic growth, will intensify the geo-oil competition in Northeast Asia.

Document type: Article

SmartPipes: Smart Wireless Sensor Networks for Leak Detection in Water Pipelines

Scipedia content — Tue, 23 Mar 2021 03:01:43 +0100

monitoring, specifically infrastructure monitoring such as water distribution pipelines, is becoming increasingly critical for utility owners who face new challenges due to an aging network. In the UK alone, during the period of 2009–2010, approximately 3281 mega litres (106) of water were wasted due to failure or leaks in water pipelines. Various techniques can be used for the monitoring of water distribution networks. This paper presents the design, development and testing of a smart wireless sensor network for leak detection in water pipelines, based on the measurement of relative indirect pressure changes in plastic pipes. Power consumption of the sensor nodes is minimised to 2.2 mW based on one measurement every 6 h in order to prolong the lifetime of the network and increase the sensor nodes’ compatibility with current levels of power available by energy harvesting methods and long life batteries. A novel pressure sensing method is investigated for its performance and capabilities by both laboratory and field trials. The sensors were capable of measuring pressure changes due to leaks. These pressure profiles can also be used to locate the leaks.

Document type: Article

A new methodology for approaching motorcycle riders’ behavior at curved road sections

Scipedia content — Tue, 23 Mar 2021 00:21:04 +0100

The present paper focuses on the investigation of motorcycle riders’ behavior at curved road sections by introducing a new methodology based on global positioning system (GPS) technology. In the frame of the research, the determination of the optimum regression curve between the curve radius’ and the corresponding velocities, was investigated. Within the context of the paper field measurements were conducted, with the use of appropriate velocity recording equipment in order to confirm the efficiency of the proposed methodology. The measurements were conducted taking into account various factors that potentially influence riders’ behavior such as the different light conditions, the difference on riding experience level, the familiarity of the riders with the routes, the presence of pillion and the different road environments, such as width/condition of the road pavement, roadside land use, right/left hand curves etc. The experimental environment that served the needs of the experiment was mountain Pelion in Magnesia region in Greece and was based upon four primary conditions: the location, the type of the road, the weather conditions and finally, the time and date that the experiment would be conducted. The validation of the proposed methodology was performed by recruiting two motorcyclists. Their selection was based on demographic, psychometric and experience criteria. The research showed among others, that the regression curves could be used as a curve classification mean. Moreover, a significant variation was detected on the riders’ behavior when carrying a pillion related to their experience levels.

Document type: Article

An overview of heavy oil properties and its recovery and transportation methods

Scipedia content — Tue, 23 Mar 2021 00:05:56 +0100

Submitted by Susilene Barbosa da Silva (susilene@unicamp.br) on 2020-07-09T13:35:58Z No. of bitstreams: 0 Made available in DSpace on 2020-07-09T13:35:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2014 Unconventional oils - mainly heavy oils, extra heavy oils and bitumens - represent a significant share of the total oil world reserves. Oil companies have expressed interest in unconventional oil as alternative resources for the energy supply. These resources are composed usually of viscous oils and, for this reason, their use requires additional efforts to guarantee the viability of the oil recovery from the reservoir and its subsequent transportation to production wells and to ports and refineries. This review describes the main properties of high-viscosity crude oils, as well as compares traditional and emergent methods for their recovery and transportation. The main characteristics of viscous oils are discussed to highlight the oil properties that affect their flowability in the processes of recovery and pipeline transportation. Chemical composition is the starting point for the oil characterization and it has major impact on other properties, including key properties for their dynamics, such as density and viscosity. Next, enhanced oil recovery (EOR) methods are presented, followed by a discussion about pipeline and transportation methods. In addition, the main challenges to achieve viable recovery and transportation of unconventional oils are compared for the different alternatives proposed. The work is especially focused on the heavy oils, while other hydrocarbon solid sources, such as oil sands and shale oil, are outside of the scope of this review 31 3 571 590

Document type: Article

Research on Congestion Pricing in Multimode Traffic considering Delay and Emission

Scipedia content — Mon, 22 Mar 2021 23:41:25 +0100

Rapid development of urbanization and automation has resulted in serious urban traffic congestion and air pollution problems in many Chinese cities recently. As a traffic demand management strategy, congestion pricing is acknowledged to be effective in alleviating the traffic congestion and improving the efficiency of traffic system. This paper proposes an urban traffic congestion pricing model based on the consideration of transportation network efficiency and environment effects. First, the congestion pricing problem under multimode (i.e., car mode and bus mode) urban traffic network condition is investigated. Second, a traffic congestion pricing model based on bilevel programming is formulated for a dual-mode urban transportation network, in which the delay and emission of vehicles are considered. Third, an improved mathematical algorithm combining successive average method with the genetic algorithm is proposed to solve the bilevel programming problem. Finally, a numerical experiment based on a hypothetical network is performed to validate the proposed congestion pricing model and algorithm.

Document type: Article

Environmental Factors and Intermodal Freight Transportation: Analysis of the Decision Bases in the Case of Spanish Motorways of the Sea

Scipedia content — Mon, 22 Mar 2021 22:58:20 +0100

Today, there is widespread consensus about the notable, yet simultaneously growing, negative environmental impacts generated by the transportation sector. Experts working in a number of different fields consider the current situation to be unsustainable and possible measures to reduce emissions and foster sustainability are being encouraged. The European Commission has highlighted the need to shift away from unimodal road transport toward a greater use of intermodal transport through, for example, motorways of the sea, in light of the evidence that the former makes a significant contribution to increased CO 2 emissions. However, although there is a general perception that sea transport is environmentally preferable to road transport, recent studies are beginning to question this assumption. Moreover, little research has been conducted to quantify environmental aspects and incorporate them into the decision-making processes involved in the modal shift. This study first reviews the existing literature to examine the extent to which environmental aspects are relevant in the modal choice in the case of short sea shipping and motorways of the sea. Related to this, the study also evaluates the role that different agents may play in making decisions about choice of mode, taking into consideration environmental aspects. Secondly, we use the values the European Commission provides to calculate external costs for the Marco Polo freight transport project proposals (call 2013) to estimate the environmental costs for several routes (a total of 72), comparing the use of road haulage with the intermodal option that incorporates the Spanish motorways of the sea. The results of this comparative analysis show that the intermodal option is not always the best choice in environmental terms. Consequently, the traditional environmental argument to justify this alternative must be used carefully.

Document type: Article

Consensus between Pipelines in Structural Brain Networks

Scipedia content — Mon, 22 Mar 2021 22:48:42 +0100

Structural brain networks may be reconstructed from diffusion MRI tractography data and have great potential to further our understanding of the topological organisation of brain structure in health and disease. Network reconstruction is complex and involves a series of processesing methods including anatomical parcellation, registration, fiber orientation estimation and whole-brain fiber tractography. Methodological choices at each stage can affect the anatomical accuracy and graph theoretical properties of the reconstructed networks, meaning applying different combinations in a network reconstruction pipeline may produce substantially different networks. Furthermore, the choice of which connections are considered important is unclear. In this study, we assessed the similarity between structural networks obtained using two independent state-of-the-art reconstruction pipelines. We aimed to quantify network similarity and identify the core connections emerging most robustly in both pipelines. Similarity of network connections was compared between pipelines employing different atlases by merging parcels to a common and equivalent node scale. We found a high agreement between the networks across a range of fiber density thresholds. In addition, we identified a robust core of highly connected regions coinciding with a peak in similarity across network density thresholds, and replicated these results with atlases at different node scales. The binary network properties of these core connections were similar between pipelines but showed some differences in atlases across node scales. This study demonstrates the utility of applying multiple structural network reconstrution pipelines to diffusion data in order to identify the most important connections for further study.

Document type: Article

A Proposed Scalable Design and Simulation of Wireless Sensor Network-Based Long-Distance Water Pipeline Leakage Monitoring System

Scipedia content — Mon, 22 Mar 2021 22:44:46 +0100

nomalies such as leakage and bursts in water pipelines have severe consequences for the environment and the economy. To ensure the reliability of water pipelines, they must be monitored effectively. Wireless Sensor Networks (WSNs) have emerged as an effective technology for monitoring critical infrastructure such as water, oil and gas pipelines. In this paper, we present a scalable design and simulation of a water pipeline leakage monitoring system using Radio Frequency IDentification (RFID) and WSN technology. The proposed design targets long-distance aboveground water pipelines that have special considerations for maintenance, energy consumption and cost. The design is based on deploying a group of mobile wireless sensor nodes inside the pipeline and allowing them to work cooperatively according to a prescheduled order. Under this mechanism, only one node is active at a time, while the other nodes are sleeping. The node whose turn is next wakes up according to one of three wakeup techniques: location-based, time-based and interrupt-driven. In this paper, mathematical models are derived for each technique to estimate the corresponding energy consumption and memory size requirements. The proposed equations are analyzed and the results are validated using simulation.

Document type: Article

Research on Gas Hydrate Plug Formation under Pipeline-Like Conditions

Scipedia content — Mon, 22 Mar 2021 22:32:35 +0100

Hydrates of natural gases like methane have become subject of great interest over the last few decades, mainly because of their potential as energy resource. The exploitation of these natural gases from gas hydrates is seen as a promising mean to solve future energetic problems. Furthermore, gas hydrates play an important role in gas transportation and gas storage: in pipelines, particularly in tubes and valves, gas hydrates are formed and obstruct the gas flow. This phenomenon is called “plugging” and causes high operational expenditure as well as precarious safety conditions. In this work, research on the formation of gas hydrates under pipeline-like conditions, with the aim to predict induction times as a mean to evaluate the plugging potential, is described.

Document type: Article

Innovative Tools of Sustainable Mobility in European Urban Areas: Experience with Evaluation and Role of Political Barriers

Scipedia content — Mon, 22 Mar 2021 22:11:34 +0100

The presented article describes a European initiative for supporting innovative measures in sustainable transport in urban areas Civitas, particularly its latest completed edition Civitas Plus (2008-2012). The article presents the evaluation process of the performed measures and shows an overview of the main obstacles the Civitas Plus cities struggled with (with the emphasis on political barriers). In addition, it mentions drivers which helped to implement the sustainable mobility measures. It concludes with examples from European cities on how to avoid these barriers and prevent their occurrence.

Document type: Article

A Study of Feature Combination for Vehicle Detection Based on Image Processing

Scipedia content — Mon, 22 Mar 2021 21:43:44 +0100

Video analytics play a critical role in most recent traffic monitoring and driver assistance systems. In this context, the correct detection and classification of surrounding vehicles through image analysis has been the focus of extensive research in the last years. Most of the pieces of work reported for image-based vehicle verification make use of supervised classification approaches and resort to techniques, such as histograms of oriented gradients (HOG), principal component analysis (PCA), and Gabor filters, among others. Unfortunately, existing approaches are lacking in two respects: first, comparison between methods using a common body of work has not been addressed; second, no study of the combination potentiality of popular features for vehicle classification has been reported. In this study the performance of the different techniques is first reviewed and compared using a common public database. Then, the combination capabilities of these techniques are explored and a methodology is presented for the fusion of classifiers built upon them, taking into account also the vehicle pose. The study unveils the limitations of single-feature based classification and makes clear that fusion of classifiers is highly beneficial for vehicle verification. This work was partially supported by the Ministerio de Economía y Competitividad of the Spanish Government under Project TEC2010-20412 (Enhanced 3D TV).

Document type: Article

Experimental Correlations with Calculus Parameters for a Dynamic System Equipped with Antiseismic Elastomeric Devices

Scipedia content — Mon, 22 Mar 2021 20:03:12 +0100

Rezumat"/jats:title" "jats:p" Lucrarea prezintă rezultatul încercărilor efectuate la cicluri cinematice cu deplasări instantanee armonice pentru elemente elastomerice cu rol de izolare dinamică în conformitate cu SR EN 1337-3 şi SR EN 15129. Valorile amortizării interne determinate pe standuri de încercare în condiţiile din documentele de referinţă trebuie corelate cu valorile sistemului de dispozitive antiseismice elastomerice ce echipează un sistem dinamic supus acţiunilor seismice exterioare."/jats:p" "jats:p"În acest caz, pentru fiecare situaţie reală, proiectantul trebuie să realizeze corelaţia dintre cele două valori ale amortizării obţinute în laborator cu amortizarea specifică sistemului structural care este supus acţiunilor dinamice exterioare. Din lucrare rezultă echivalenţa necesară astfel încât, valorile experimentale să poată fi corectate în mod riguros şi să poată reprezenta parametrii reali ce trebuie luaţi în calcul.

Document type: Article

The impact of high-speed rail and low-cost carriers on European air passenger traffic

Scipedia content — Mon, 22 Mar 2021 19:51:58 +0100

The expansion of high-speed passenger rail service is often argued as a potentially effective, lower-carbon substitute for intercity air travel. Previous studies on the impact of high-speed rail on air travel in Europe and Asia have primarily examined the impact of travel time and price on market share for a specific city pair (or a handful of city pairs). There has been little focus on the extent to which high-speed rail (HSR) has reduced total short-haul air travel demand (versus market share), or on the potential impacts of high-speed rail on system-wide air travel demand. This paper presents an empirical, econometric analysis of air travel demand in Europe, utilizing an expanded data set to explore: (1) the impact of rail travel times, population density, and market characteristics on air traffic; and (2) the impact of high-speed rail and low-cost-carriers on system-wide air traffic. Although improvements in rail travel times have resulted in reductions in short-haul air travel, variations in city and airport characteristics significantly influence the substitution between air and rail. This paper also finds that HSR substitution has resulted in a modest reduction in system-wide air travel demand, whereas the expansion of low-cost carriers has led to a significant increase in total European air traffic. As concerns about the climate impacts of transportation grow, these results have significant implications for future transport and energy policy.

National Science Foundation (U.S.) (National Academy of Sciences (U.S.). Grant OISE-738129)

Document type: Article

Oil Pollution in the Southeastern Baltic Sea in 2009-2011

Scipedia content — Mon, 22 Mar 2021 19:48:15 +0100

"jats:p"From January 2009 to April 2012 a satellite survey of the central and southeastern parts of the Baltic Sea was carried out by the Space Radar Laboratory at the Space Research Institute of Russian Academy of Sciences (RAS). The main attention was focused on the detection of oil pollution as well as biogenic and anthropogenic surfactant films. The basic data are high resolution radar images obtained by advanced synthetic aperture radar (ASAR) on board of the Envisat satellite of the European Space Agency. Remotely sensed data in visual and infrared (IR) bands acquired by sensors MERIS Envisat, MODIS-Terra and -Aqua, and AVHRR NOAA nearly simultaneously with the ASAR images, were processed and analysed in order to facilitate the discrimination between different types of surface pollutants, to understand a comprehensive features of meteorological and hydrodynamic processes in the sea area of investigation, and to reveal factors determining pollutants spread and drift. The regions of the most intense oil pollution are outlined.

Document type: Article

Assessing driver’s ability to estimate compliance rates to in-car, advisory driver support

Scipedia content — Mon, 22 Mar 2021 19:41:15 +0100

Purpose In-car support systems focus increasingly on improving traffic flow and throughput. Advisory systems allow for fast market penetration, advising drivers how to drive in order to improve general flow. By following the advice, drivers cannot create a beneficial effect by themselves but rely on other road users to comply as well. Drivers who sense a low compliance among other road users may be discouraged to use the system themselves. The present experiment investigated whether drivers are able to distinguish between various compliance rates to Connected Cruise Control (CCC), an advisory driver support system that gives headway, speed and lane advice to improve throughput on motorways. Method Forty-two participants estimated the compliance of other road users to CCC in a driving simulator. Actual system compliance was varied between 10, 50 and 90 %. Half of the participants received detailed information about the advice and the manifestation of compliant behaviour in traffic. Results Compliance estimates showed no effect of actual compliance rates. Overall compliance ratings were higher for participants who had not received additional information about the system. Difference scores between compliance estimate and actual compliance indicate that additional information did not improve estimation accuracy, neither did it increase participants’ confidence with their estimate. Conclusions When actual compliance is low, drivers still show high compliance estimates which can have beneficial effect on system acceptance. Additional information does not improve compliance estimates.

Document type: Article

Towards Life Cycle Sustainability Assessment of Alternative Passenger Vehicles

Scipedia content — Mon, 22 Mar 2021 19:30:45 +0100

Sustainable transportation and mobility are key components and central to sustainable development. This research aims to reveal the macro-level social, economic, and environmental impacts of alternative vehicle technologies in the U.S. The studied vehicle technologies are conventional gasoline, hybrid, plug-in hybrid with four different all-electric ranges, and full battery electric vehicles (BEV). In total, 19 macro level sustainability indicators are quantified for a scenario in which electric vehicles are charged through the existing U.S. power grid with no additional infrastructure, and an extreme scenario in which electric vehicles are fully charged with solar charging stations. The analysis covers all life cycle phases from the material extraction, processing, manufacturing, and operation phases to the end-of-life phases of vehicles and batteries. Results of this analysis revealed that the manufacturing phase is the most influential phase in terms of socio-economic impacts compared to other life cycle phases, whereas operation phase is the most dominant phase in the terms of environmental impacts and some of the socio-economic impacts such as human health and economic cost of emissions. Electric vehicles have less air pollution cost and human health impacts compared to conventional gasoline vehicles. The economic cost of emissions and human health impact reduction potential can be up to 45% and 35%, respectively, if electric vehicles are charged through solar charging stations. Electric vehicles have potential to generate income for low and medium skilled workers in the U.S. In addition to quantified sustainability indicators, some sustainability metrics were developed to compare relative sustainability performance alternative passenger vehicles. BEV has the lowest greenhouse gas emissions and ecological land footprint per $ of its contribution to the U.S. GDP, and has the lowest ecological footprint per unit of its energy consumption. The only sustainability metrics that does not favor the BEV is the water-energy ratio, where the conventional gasoline vehicle performed best.

Document type: Article

Urban Policies On Diversity In Antwerp, Belgium

Scipedia content — Fri, 05 Mar 2021 15:52:17 +0100

Critical analysis of existing urban policy programmes and discourses in Antwerp, Belgium. Includes overview of political systems and governance structures, key shifts in national discourses, and approaches to policy over migration, citizenship, and diversity.

SIMPATO-The safety impact assessment tool of interactive

Scipedia content — Tue, 16 Feb 2021 13:22:39 +0100

One step in the development of safety oriented Advanced Driver Assistance Systems (ADAS) is an ex ante assessment of the expected safety impacts. This requires a careful analysis combining models and data from various sources. This paper describes the Safety IMPact Assessment Tool, called SIMPATO, that was developed in the interactIVe project. This tool performs «what if» analysis for accident scenarios to determine the effect of an ADAS on the outcome. The unique quality of the tool is that it requires very little data on the ADAS itself, and uses in-depth accident data to obtain a representative result.

Quantitative assessment of environmental risk due to accidental spills from onshore pipelines

Scipedia content — Tue, 16 Feb 2021 13:22:14 +0100

The transport of hazardous materials by pipeline is widely used for the transfer of significant quantities of oil and chemicals. Due to the extremely low frequency of spills, pipelines are considered the safest mode for the land transportation of hazardous substances. Accident records, while confirming that Loss of Containment (LOC) events are rare, also point out the major-accident hazard of pipelines, due to the extremely severe potential consequences of spills. Quantitative Risk Analysis (QRA) techniques have been applied to pipelines since many years with the aim of evaluating risk for workers or exposed population. However, releases of liquids, as oil and oil products, also create an hazard to the environment, due to the potential of extensive soil and groundwater contamination. An integrated model was developed for the environmental Risk Analysis of spills from pipelines. Specific environmental risk indexes were defined, expressing the risk of soil and groundwater contamination, both in physical and economic terms. A case-study is presented and discussed to illustrate the features of the methodology. The results confirmed that the proposed model may be considered an important tool within a comprehensive approach to the management of risk related to onshore pipelines.

Airport congestion pricing when airlines price discriminate

Scipedia content — Tue, 16 Feb 2021 13:18:29 +0100

This paper extends the literature on airport congestion pricing by allowing carriers to price-discriminate between the business and leisure passengers when operating costs are the same for all passengers. The main results are: First, the second-best discriminating business fare exceeds the first-best uniform fare (which equals the external part of the marginal congestion costs), while the second-best discriminating leisure fare is lower than the first-best uniform fare. Second, the optimal airport charge implements the first-best uniform or second-best discriminating fares. Importantly, this charge can always be higher than what would be expected when all passengers were treated as having the same time valuation. This result provides some support to the finding that the welfare losses associated with an atomistic airport congestion charge may be low. © 2014 Elsevier Ltd.

Determination of the dip angles of Karayaka and Gok double dagger e fault planes in Turkey by seismic reflection method

Scipedia content — Tue, 16 Feb 2021 13:16:20 +0100

WOS: 000360068200081

Along its track between Samsun and Adana, an oil pipeline was planned to cross two active faults among others: Gok double dagger e Fault located at 7 km south of Tokat and Karayaka Fault located at 45 km northeast of Tokat. Geological investigations suggest that both faults reveal reverse fault properties. Determination of the dip angles of the fault planes is crucial in pipeline construction. Fault plane dip angles can be best determined by seismic reflection methods. Although first few metres from the Earth's surface are important in pipeline construction, few hundred metres of penetration depth are required for reliable fault identifications and fault-parameter computations. Two seismic profiles were accomplished on Gok double dagger e and Karayaka faults. Computations based on seismic depth sections obtained in this study reveal that the apparent dip angle of Gok double dagger e Fault is 84.6A degrees, and the apparent dip angle of Karayaka Fault is 72.4A degrees.

ENVY Inc.

This work has been performed within the cooperative work of the Ankara University Geophysics and Energy and Environmental Investments Inc. (ENVY). We acknowledge with gratitude the technical and financial support of ENVY Inc. The authors also give thanks to the stuff of General Directorate of Disaster Affairs Earthquake Research Department for providing seismic recording instruments and their technical support in the field.

Theoretical modeling and experimental investigations for the improvement of the mechanical efficiency in sliding vane rotary compressors

Scipedia content — Tue, 16 Feb 2021 13:14:44 +0100

Positive displacement compressors lead the market of compressed air production for industrial applications. Among them, sliding vane rotary compressors represent an energetically virtuous alternative to the current compression technologies. In the present work, the effects of compressor design parameters were investigated through a comprehensive approach that aimed at addressing more efficient machines to promote sliding vane compressors as the key enabling technology in compressed air systems. A comprehensive mathematical model was developed to study the main phenomena occurring in this kind of compressors. The model provides the cell volume evolution over a whole rotation during which filling, compression and discharge processes occur. The first and latter phases are described by the quasi-propagatory approach that represents the inertial, capacitive and resistive features of one-dimensional unsteady flows. The dynamics of the compressor blades led to four different arrangements inside the rotor slots while an analysis of the hydrodynamic lubrication established between blade tip and stator wall focused on the oil film thickness evolution to prevent dry contacts. An extensive experimental campaign on a mid-size industrial compressor allowed the model validation at different outlet pressure levels and revolution speeds using a direct measurement of mechanical power and the reconstruction of the indicator diagram from piezoelectric pressure transducers. The friction coefficient at the contact points between blades with stator and rotor was estimated in 0.065 and further improvements of the mechanical efficiency were eventually addressed considering the roles of compressor aspect ratio, revolution speed, and blade tilt. The first two theoretical optimizations might lead to an increase of the compressor efficiency of 2 and 9 percentage points respectively. On the other hand, acting on the blade tilt would not produce relevant improvements. The Authors acknowledge Ing. E. Mattei S.p.A. and particularly its CEO, Dr. Giulio Contaldi, for continuous research funding and support. The work has been done also under the FP7 Project ‘‘Complete Vehicle Energy-Saving CONVENIENT’’ founded by the European Commission.

A study of challenges to the success of the safety management system in aircraft maintenance organizations in Turkey

Scipedia content — Tue, 16 Feb 2021 13:11:43 +0100

WOS: 000348088600013

The ICAO is an international regulatory authority put in place, in addition to current prescriptive regulatory approaches based on regulatory compliance that use reactive tools, performance based approaches that focus on, processes, proactivity, productivity and safety performance, to reduce the number of accidents and fatalities irrespective of the volume of air traffic. The safety management system (SMS), a product of this new approach, requires transformations which are likely to create certain challenges to its performance. This study sets out to investigate the challenges to the successful implementation of SMS in aircraft maintenance organizations, the degree of priority of these challenges, the major problems affecting the performance of SMS, the factors causing the problems, and the ensuing results. During a two-day workshop, a problem analysis was conducted with experts using the nominal group technique. At the end of the study, it was identified that 'just culture' problems would be the main challenge to the success of the SMS. It was predicted that, impairing the reporting process, these problems are likely to have an adverse impact on information acquisition within an organization, organizational learning, efficiency of predictive tools and proactivity

Book ‘Moving towards low carbon mobility’ review

Scipedia content — Tue, 16 Feb 2021 13:04:03 +0100

"Book ‘Moving towards low carbon mobility’ review" Transport, 29(3), pp. 342-344 First Published Online: 22 Sep 2014

A real-time multi-sensor fusion platform for automated driving application development

Scipedia content — Tue, 16 Feb 2021 12:59:26 +0100

dvanced Driver Assistance Systems (ADAS) become standard and sometimes mandatory for vehicles, e.g. autonomous emergency braking. Future vehicles will include multiple ADAS that assist with safety-critical operations. For efficiency and effectiveness, these ADAS should share resources, information and functionalities. Additionally, ADAS performing safety-critical functionality require predictability for the execution of their processes. This paper presents the integration of a layer-based multi-sensor fusion and processing platform into a real-time system that also supports non-critical processes, i.e. a mixed-criticality system. A suitable system is selected, the behavior of the platform and its interfaces is described and tests are performed to validate the predictable behavior, by examining the difference in jitter and execution latency. The real-time layer-based platform is suitable for the development and testing of multiple integrated safety-critical ADAS. cop. 2015 IEEE.

Changes in Oil Transportation in the Years 2020 and 2030 – The Case of the Gulf of Finland

Scipedia content — Tue, 16 Feb 2021 12:51:36 +0100

This paper covers the current state of maritime oil transportation in the Baltic Sea and the development of oil transportation in the 2000s, as well as estimations of transported oil volumes in 2020 and 2030 in the Gulf of Finland. The scenarios were formulated on the basis of a current state analysis, energy and transportation strategies and scenarios and expert assessments. The study showed that the volumes of oil transportation in the Gulf of Finland will increase only moderately compared to the current status: 9.5-33.8 %, depending on the scenario. Green energy policy favours renewable energy sources, which can be seen in the smaller volumes of transported oil in the 2030 scenarios compared to the 2020 scenarios. In the Slow development 2020 scenario, oil transport volumes for 2020 are expected to be 170.6 Mt (million tonnes), in the Average development 2020 187.1 Mt and in the Strong development 2020 201.5 Mt. The corresponding oil volumes for the 2030 scenarios were 165 Mt for the Stagnating development 2030 scenario, 177.5 Mt for the Towards a greener society 2030 scenario and 169.5 Mt in the Decarbonising society 2030 scenario.

Reinterpreting EU Air Transport Deregulation: A Disaggregated Analysis of the Spatial Distribution of Traffic in Europe, 1990-2009

Scipedia content — Tue, 16 Feb 2021 12:50:56 +0100

This paper analyses the spatial distribution of seat capacity in the EU from 1990 to 2009 and sheds light on the contrasting results in the literature. It contributes to the debate on the deregulation and whether the rise of hub-and-spoke networks and the success of low-cost carriers lead to concentration or deconcentration. We use the Gini index and its decomposition to evaluate the contribution of airport subgroups and airline networks to the overall concentration of seat capacity. We conclude that, overall, seat capacity follows a spatial deconcentration pattern. While intra-EU seat capacity became more spatially deconcentrated, extra-EU seat capacity concentrated. However, our results do not support the general view that network carriers tend to increase concentration levels and low-cost carriers to decrease them, leading us to a reinterpretation of the impacts of air transport deregulation. The results show the increasing importance of foreign carriers and new strategies such as hub-bypassing.

Understanding mode choice in the Chinese context: the case of Nanjing Metropolitan Area

Scipedia content — Tue, 16 Feb 2021 12:49:33 +0100

In post-reform China, rapid motorisation causes various problems like traffic congestion, diminishing road safety and air pollution. Adequate policies necessitate an understanding of the forces behind changing mode choices, but the rapidly developing literature is not complete yet. This paper aims to help fill that gap with an analysis of mode choice for commuting and shopping-leisure trips in Nanjing. Using the Nanjing Residents Travel Survey, we find that models with the same independent variables explain mode choice in Nanjing better than in other cities in the world. Comparatively, members of ‘adult families’ use public transport and walking more often than the private car and bicycle. And inhabitants of danwei neighbourhoods walk more often than residents in commodity housing estates. These conclusions suggest that ongoing socio-spatial transformations will push mode choice in China further towards private car use.

Leveraging MPLS Backup Paths for Distributed Energy-Aware Traffic Engineering

Scipedia content — Tue, 16 Feb 2021 12:46:41 +0100

Backup paths are usually pre-installed by network operators to protect against single link failures in backbone networks that use multi-protocol label switching. This paper introduces a new scheme called Green Backup Paths (GBP) that intelligently exploits these existing backup paths to perform energy-aware traffic engineering without adversely impacting the primary role of these backup paths of preventing traffic loss upon single link failures. This is in sharp contrast to most existing schemes that tackle energy efficiency and link failure protection separately, resulting in substantially high operational costs. GBP works in an online and distributed fashion, where each router periodically monitors its local traffic conditions and cooperatively determines how to reroute traffic so that the highest number of physical links can go to sleep for energy saving. Furthermore, our approach maintains quality-of-service by restricting the use of long backup paths for failure protection only, and therefore, GBP avoids substantially increased packet delays. GBP was evaluated on the point-of-presence representation of two publicly available network topologies, namely, GÉANT and Abilene, and their real traffic matrices. GBP was able to achieve significant energy saving gains, which are always within 15% of the theoretical upper bound. © 2004-2012 IEEE.

State of charge estimation of high power lithium iron phosphate cells

Scipedia content — Tue, 16 Feb 2021 12:45:47 +0100

This paper describes a state of charge (SOC) evaluation algorithm for high power lithium iron phosphate cells characterized by voltage hysteresis. The algorithm is based on evaluating the parameters of an equivalent electric circuit model of the cell and then using a hybrid technique with adequate treatment of errors, through an additional extended Kalman filter (EKF). The model algorithm has been validated in terms of effectiveness and robustness by several experimental tests.

A modified reinforcement learning algorithm for solving coordinated

Scipedia content — Tue, 16 Feb 2021 12:45:29 +0100

This study proposes Reinforcement Learning (RL) based algorithm for finding optimum signal timings in Coordinated Signalized Networks (CSN) for fixed set of link flows. For this purpose, MOdified REinforcement Learning algorithm with TRANSYT-7F (MORELTRANS) model is proposed by way of combining RL algorithm and TRANSYT-7F. The modified RL differs from other RL algorithms since it takes advantage of the best solution obtained from the previous learning episode by generating a sub-environment at each learning episode as the same size of original environment. On the other hand, TRANSYT-7F traffic model is used in order to determine network performance index, namely disutility index. Numerical application is conducted on medium sized coordinated signalized road network. Results indicated that the MORELTRANS produced slightly better results than the GA in signal timing optimization in terms of objective function value while it outperformed than the HC. In order to show the capability of the proposed model for heavy demand condition, two cases in which link flows are increased by 20% and 50% with respect to the base case are considered. It is found that the MORELTRANS is able to reach good solutions for signal timing optimization even if demand became increased. (C) 2015 Elsevier Ltd. All rights reserved.

Climate Change Adaptation. Challenges and Opportunities for a Smart Urban Growth

Scipedia content — Tue, 16 Feb 2021 12:43:52 +0100

Climate change is one of the main environmental issues challenging cities in the 21th century. At present, more than half of the world population lives in cities and the latter are responsible for 60% to 80% of global energy consumption and greenhouse gas (GHG) emissions, which are the main causes of the change in climate conditions. In the meantime, they are seriously threatened by the heterogeneous climate-related phenomena, very often exacerbated by the features of the cities themselves. In the last decade, international and European efforts have been mainly focused on mitigation rather than on adaptation strategies. Europe is one of the world leaders in global mitigation policies, while the issue of adaptation has gained growing importance in the last years. As underlined by the EU Strategy on adaptation to climate change, even though climate change mitigation still remains a priority for the global community, large room has to be devoted to adaptation measures, in order to effectively face the unavoidable impacts and related economic, environmental and social costs of climate change (EC, 2013). Thus, measures for adaptation to climate change are receiving an increasing financial support and a growing number of European countries are implementing national and urban adaptation strategies to deal with the actual and potential climate change impacts. According to the above considerations, this paper explores strengths and weaknesses of current adaptation strategies in European cities. First the main suggestions of the European Community to improve urban adaptation to climate change are examined; then, some recent Adaptation Plans are analyzed, in order to highlight challenges and opportunities arising from the adaptation processes at urban level and to explore the potential of Adaptation Plans to promote a smart growth in the European cities.

Pruning and ranking the Pareto optimal set, application for the dynamic multi-objective network design problem

Scipedia content — Tue, 16 Feb 2021 12:42:44 +0100

Solving the multi-objective network design problem (MONDP) resorts to a Pareto optimal set. This set can provide additional information like trade-offs between objectives for the decision making process, which is not available if the compensation principle would be chosen in advance. However, the Pareto optimal set of solutions can become large, especially if the objectives are mainly opposed. As a consequence, the Pareto optimal set may become difficult to analyze and to comprehend. In this case, pruning and ranking becomes attractive to reduce the Pareto optimal set and to rank the solutions to assist the decision maker. Because the method used, may influence the eventual decisions taken, it is important to choose a method that corresponds best with the underlying decision process and is in accordance with the qualities of the data used. We provided a review of some methods to prune and rank the Pareto optimal set to illustrate the advantages and disadvantages of these methods. The methods are applied using the outcome of solving the dynamic MONDP in which minimizing externalities of traffic are the objectives, and dynamic traffic management measures are the decision variables. For this, we solved the dynamic MONDP for a realistic network of the city Almelo in the Netherlands using the non-dominated sorting genetic algorithm II. For ranking, we propose to use a fuzzy outranking method that can take uncertainties regarding the data quality and the perception of decision makers into account; and for pruning, a method that explicitly reckons with significant trade-offs has been identified as the more suitable method to assist the decision making process.

Determination of the economical optimum insulation thickness for VRF (variable refrigerant flow) systems

Scipedia content — Tue, 16 Feb 2021 12:38:03 +0100

This study deals with the investigation into optimum insulation thickness of installed inside building pipe network of VRF (variable refrigerant flow) systems. Optimum insulation thickness, energy savings over a lifetime of 10 years and payback periods are determined for high pressure gas pipelines, low pressure gas pipelines and low pressure liquid pipelines under the heating-only and cooling-only modes of the three-pipe VRF system using R-410A as refrigerant. By using the P1-P2 method, the value of the amount of the net energy savings is calculated. Under heating mode of VRF system, while the optimum insulation thickness varies between 16 and 20 mm depending on the pipe sections of high pressure gas pipeline, it varies from 11 to 13 mm for the pipe sections of low pressure liquid pipeline. Under cooling mode of VRF system, the optimum insulation thickness varies between 7 and 8 mm for pipe sections of low pressure gas pipeline and low pressure liquid pipeline. © 2015 Elsevier Ltd.

Ranking Links in a Road Transport Network: A Practical Method for the Calculation of Link Importance

Scipedia content — Tue, 16 Feb 2021 12:35:22 +0100

This paper deals with the issue of road network vulnerability and describes the implementation of a methodology which ranks the links of a network according to their importance for maintaining a proper connectivity between all origin-destination pairs. Such a ranking can be easily used by practitioners and decision-makers for prioritising maintenance investments along the links of a road transport network. In this regard, following a conceptual approach well consolidated in transport literature, vulnerability is assumed to be related to the concept of importance, i.e. a measure of the consequences of the collapse of a network's element. In the present study, the definition of importance – with respect to a given link –simultaneously includes two aspects: the level of usage, i.e. how many people typically use the link for their trips, and the impact that the closure of the link itself can have on the general functionality of the network as a whole. These two aspects are considered in the link importance index formulation, as two different functions that can be properly weighted by means of different coefficients. The methodology proposed has been implemented in the framework of Paramount EU project, to obtain a ranking of importance for the links of a real-scale network, i.e. the road network of Bolzano, a highly mountainous province located in the Italian Alps. The application of the methodology led to satisfactory results represented by a ranking of links, in decreasing order importance scores. Furthermore, Spearman's rank correlation coefficient has been used to quantify the variation of the importance ranking caused by the variation of its coefficients.

Applying complexity science to air traffic management

Scipedia content — Tue, 16 Feb 2021 12:31:48 +0100

Complexity science is the multidisciplinary study of complex systems. Its marked network orientation lends itself well to transport contexts. Key features of complexity science are introduced and defined, with a specific focus on the application to air traffic management. An overview of complex network theory is presented, with examples of its corresponding metrics and multiple scales. Complexity science is starting to make important contributions to performance assessment and system design: selected, applied air traffic management case studies are explored. The important contexts of uncertainty, resilience and emergent behaviour are discussed, with future research priorities summarised.

Security Economics: an adversarial risk analysis approach to airport security

Scipedia content — Tue, 16 Feb 2021 12:28:48 +0100

WOS: 000385425300018

We analyze the case of protecting an airport, in which there is concern with terrorist threats against the Air Traffic Control Tower. To deter terrorist actions, airport authorities rely on various protective measures, which entail multiple consequences. By deploying them, airport authorities expect to reduce the probabilities and potential impacts of terrorist actions. We aim at giving advice to the airport authorities by devising a security resource allocation plan. We use the framework of adversarial risk analysis to deal with the problem.

European Union [285223]; Spanish Ministry of Economy and Innovation program [MTM2011-28983-C03-01]; Government of Madrid RIESGOS-CM program [S2009/ESP-1685]; AXA-ICMAT Chair on Adversarial Risk Analysis; URJC's postdoctoral program

This project has received funding from the European Union's Seventh Framework Programme for Research, Technological Development and Demonstration under grant agreement no 285223. Work has been also supported by the Spanish Ministry of Economy and Innovation program MTM2011-28983-C03-01, the Government of Madrid RIESGOS-CM program S2009/ESP-1685 and the AXA-ICMAT Chair on Adversarial Risk Analysis. We are grateful to airport experts and stakeholders for fruitful discussions about modeling issues. This work was completed while the first author was visiting Uppsala University, supported by a grant from URJC's postdoctoral program.

Estimation of the damage in a natural gas flow line caused by the motion of methane hydrates

Scipedia content — Tue, 16 Feb 2021 12:27:16 +0100

Gas storage and petroleum Companies invest every year large sums of money to prevent the formation of gas hydrates plugs in flow lines as the safety requirements and the costs related to the blocking of pipelines suggest to invest in research studies to avoid the hydrate formation or to detect its presence. Gas hydrates are aggregates where hydrocarbons gas such as methane are embedded in a crystalline cage of water molecules: they can develop abruptly and block pipelines. The nucleation of hydrates and their growth occurs when methane comes in contact with water under suitable thermodynamic conditions, such as high pressures and low temperatures. Methane hydrates induce the most relevant troubles as they form with no warning and can produce partial or even full obstructions in a pipeline thus reducing flow, increasing both back- and differential pressures. If a line section is obstructed the differential pressure across the hydrate can set the plug in motion and accelerate it quickly up to a speed approaching that of sound. In that case, the moving mass can cause serious mechanical damages at locations where the plug meets such constrictions or obstacles as valves, elbows or tees. In this paper a gas pipeline failure case due to the presence of a moving hydrate plug has been investigated by using appropriate analytical and numerical models to analyse the motion of a hydrate plug as well as its impact against the pipe wall.

Car2x with software defined networks, network functions virtualization and supercomputers technical and scientific preparations for the Amsterdam Arena telecoms fieldlab

Scipedia content — Tue, 16 Feb 2021 12:22:50 +0100

In the invited talk 'Car2x with SDN, NFV and supercomputers' we report about how our past work with SDN [1, 2] allows the design of a smart mobility fieldlab in the huge parking lot the Amsterdam Arena. We explain how we can engineer and test software that handle the complex conditions of the Car2X case. The talk starts by describing the engineering challenges that developers of smart car telecommunications and computing infrastructures face. We concentrate on the development of software defined networks (SDN) that support smart cars optimally and securely over a heterogeneous, dynamic and developing ICT infrastructure. The goal here is to enable smart cars to profit maximally from any bit of information available from fixed and moving objects as well as persons. For example, in a low tech situation, the lack of other options makes that one has to fall back to GPRS to download only traffic jam locations. As a contrast, in an advanced telecom environment video streams from multiple cars are transmitted via 5G pico cells to computers a few millisecond nearby. These computers fuse the video information to generate a local traffic model. In an ultimate situation, cars use all the communications infrastructures that are available including the numerous WiFi hotspots, all generations of mobile telecommunications, the developing car-to-car communications technologies and even the smart phone of a passing person. SDN technologies deal with the complexities of such communication environment. © 2015 IEEE.

Optimising data placement and traffic routing for energy saving in Backbone Networks

Scipedia content — Tue, 16 Feb 2021 12:19:36 +0100

The energy consumption of network elements has become a big concern due to the exponential traffic growth and the rapid expansion of communication infrastructures. To deal with this problem, we propose a new approach called Backbone network Energy Saving based on Traffic engineering (BEST), which reduces the power consumption of network elements at the backbone level through jointly optimising data placement and traffic routing. Based on analysis on traffic characteristics, BEST firstly optimises the placement of data services such that the pairwise traffic demands can be better coordinated with the pairwise network costs, in order to minimise the traffic burden imposed on the network elements. Then, BEST optimises the routing of traffic flows and tries to find the minimum-power network subset that must remain active to fulfill the traffic requirements. Efficient heuristics are given by BEST to find an admissible solution when the problem size is very large. The simulation results illustrate the efficacy and efficiency of BEST in energy conservation on backbone networks This work was supported in part by the National Science Foundation of China (grant nos. 61202430, 61303245 and 61103185), the Science and Technology Foundation of Beijing Jiaotong University (grant no. 2012RC040). Fang, W.; Wang, Z.; Lloret, J.; Zhang, D.; Yang, Z. (2014). Optimising data placement and traffic routing for energy saving in Backbone Networks. Transactions on Emerging Telecommunications Technologies. 25(9):914-925. doi:10.1002/ett.2774 S 914 925 25 9

State of science: mental workload in ergonomics

Scipedia content — Tue, 16 Feb 2021 12:07:20 +0100

Mental workload (MWL) is one of the most widely used concepts in ergonomics and human factors and represents a topic of increasing importance. Since modern technology in many working environments imposes ever more cognitive demands upon operators while physical demands diminish, understanding how MWL impinges on performance is increasingly critical. Yet, MWL is also one of the most nebulous concepts, with numerous definitions and dimensions associated with it. Moreover, MWL research has had a tendency to focus on complex, often safety-critical systems (e.g. transport, process control). Here we provide a general overview of the current state of affairs regarding the understanding, measurement and application of MWL in the design of complex systems over the last three decades. We conclude by discussing contemporary challenges for applied research, such as the interaction between cognitive workload and physical workload, and the quantification of workload ‘redlines’ which specify when operators are approaching or exceeding their performance tolerances.

Key research themes on travel behavior, lifestyle, and sustainable urban mobility

Scipedia content — Tue, 16 Feb 2021 12:06:26 +0100

The concept of lifestyle adds a behavioral component to travel models that used to be dominated by engineering and econometric traditions. This article presents an overview of how lifestyle is defined and measured in transport studies, and how travel behavior is influenced by lifestyles. Lifestyles are often used pragmatically rather than theoretically in the behavior studies. Nevertheless, some important theoretical contributions have been made, especially in sociology by scholars such as Weber, Bourdieu, Ganzeboom, and Schulze who agree on the communicative character of lifestyles: individuals express their social position through specific patterns of behavior, consumption, and leisure. These behavioral patterns are shaped by underlying opinions and orientations, including beliefs, interests, and attitudes. Thus, travel behavior is not simply determined by price, speed, and comfort but is also related to attitudes, status, and preferences. Because lifestyle has many different dimensions, a variety of measurement approaches exists. Nevertheless, most studies suggest that travel behavior is conditioned by specific lifestyles. How lifestyles themselves can be modified to promote more sustainable patterns of transport has not received much attention to date. This article argues that lifestyles need to be considered as dynamic rather than as static and given, and that future research could delve more deeply into this area.

Aircraft routing with minimal climate impact: the REACT4C climate cost function modelling approach (V1.0)

Scipedia content — Tue, 16 Feb 2021 12:05:24 +0100

Abstract. In addition to CO2, the climate impact of aviation is strongly influenced by non-CO2 emissions, such as nitrogen oxides, influencing ozone and methane, and water vapour, which can lead to the formation of persistent contrails in ice-supersaturated regions. Because these non-CO2 emission effects are characterised by a short lifetime, their climate impact largely depends on emission location and time; that is to say, emissions in certain locations (or times) can lead to a greater climate impact (even on the global average) than the same emission in other locations (or times). Avoiding these climate-sensitive regions might thus be beneficial to climate. Here, we describe a modelling chain for investigating this climate impact mitigation option. This modelling chain forms a multi-step modelling approach, starting with the simulation of the fate of emissions released at a certain location and time (time-region grid points). This is performed with the chemistry–climate model EMAC, extended via the two submodels AIRTRAC (V1.0) and CONTRAIL (V1.0), which describe the contribution of emissions to the composition of the atmosphere and to contrail formation, respectively. The impact of emissions from the large number of time-region grid points is efficiently calculated by applying a Lagrangian scheme. EMAC also includes the calculation of radiative impacts, which are, in a second step, the input to climate metric formulas describing the global climate impact of the emission at each time-region grid point. The result of the modelling chain comprises a four-dimensional data set in space and time, which we call climate cost functions and which describes the global climate impact of an emission at each grid point and each point in time. In a third step, these climate cost functions are used in an air traffic simulator (SAAM) coupled to an emission tool (AEM) to optimise aircraft trajectories for the North Atlantic region. Here, we describe the details of this new modelling approach and show some example results. A number of sensitivity analyses are performed to motivate the settings of individual parameters. A stepwise sanity check of the results of the modelling chain is undertaken to demonstrate the plausibility of the climate cost functions.

Document type: Article

Differences between HCM Procedures and Fundamental Diagram Calibration for Operational LOS Assessment on Italian Freeways

Scipedia content — Tue, 16 Feb 2021 12:04:10 +0100

A not clear national framework and the uncertainty as to the transferability of the U.S. HCM require an assessment of standard methodologies more calibrated on Italian freeways. The study is aimed at testing the Levels of Service assessment for a sample freeway segment on the basis of a calibrated Fundamental Diagram, and at evaluating its consistency with respect to the most recent methodologies from HCM2010. The research shows a test calibration of the Fundamental Diagram according to the Longitudinal Control Model and Van Aerde Model. The comparative analysis shows how standard procedures and ranges could underestimate operational congestion levels on the test section. Therefore, the results suggest that operators should to use carefully HCM standard procedures and that transferability issues should be further analyzed.

Color enhanced pipelines for reality-based 3D modeling of on site medium sized archeological artifacts

Scipedia content — Tue, 16 Feb 2021 12:03:09 +0100

The paper describes a color enhanced processing system - applied as case study on an artifact of the Pompeii archaeological area - developed in order to enhance different techniques for reality-based 3D models construction and visualization of archaeological artifacts. This processing allows rendering reflectance properties with perceptual fidelity on a consumer display and presents two main improvements over existing techniques: a. the color definition of the archaeological artifacts; b. the comparison between the range-based and photogrammetry-based pipelines to understand the limits of use and suitability to specific objects.

Document type: Article

Business models for sustainable technologies: Exploring business model evolution in the case of electric vehicles

Scipedia content — Tue, 16 Feb 2021 12:00:52 +0100

International audience; Sustainable technologies challenge prevailing business practices, especially in industries that depend heavily on the use of fossil fuels. Firms are therefore in need of business models that transform the specific characteristics of sustainable technologies into new ways to create economic value and overcome the barriers that stand in the way of their market penetration. A key issue is the respective impact of incumbent and entrepreneurial firms' path-dependent behaviour on the development of such new business models. Embedded in the literature on business models, this paper explores how incumbent and entrepreneurial firms' path dependencies have affected the evolution of business models for electric vehicles. Based on a qualitative analysis of electric vehicle projects of key industry players over a five-year period (2006-2010), the paper identifies four business model archetypes and traces their evolution over time. Findings suggest that incumbent and entrepreneurial firms approach business model innovation in distinctive ways. Business model evolution shows a series of incremental changes that introduce service-based components, which were initially developed by entrepreneurial firms, to the product. Over time there seems to be some convergence in the business models of incumbents and entrepreneurs in the direction of delivering economy multi-purpose vehicles.

Queue Profile Estimation in Congested Urban Networks with Probe Data

Scipedia content — Tue, 16 Feb 2021 11:58:27 +0100

Queues at signalized intersections are the main cause of traffic delays and travel time variability in urban networks. In this article, we propose a method to estimate queue profiles that are traffic shockwave polygons in the time-space plane describing the spatiotemporal formation and dissipation of queues. The method integrates the collective effect of dispersed probe vehicle data with traffic flow shockwave analysis and data mining techniques. The proposed queue profile estimation method requires position and velocity data of probe vehicles; however, any explicit information of signal settings and arrival distribution is indispensable. Moreover, the method captures interdependencies in queue evolutions of successive intersections. The significance of the proposed method is that it is applicable in oversaturated conditions and includes queue spillover identification. Numerical results of simulation experiments and tests on NGSIM field data, with various penetration rates and sampling intervals, reveal the promising and robust performance of the proposed method compared with a uniform arrival queue estimation procedure. The method provides a thorough understanding of urban traffic flow dynamics and has direct applications for delay analysis, queue length estimation, signal settings estimation, and vehicle trajectory reconstruction.

Planning Pharmacies: An Operational Method to Find the Best Location

Scipedia content — Tue, 16 Feb 2021 11:55:32 +0100

The theme of the spatial distribution of the pharmacies on the territory is closely connected to urban planning and to services supply. In Italy, the regulatory change that took place in 2012, triggered partly by the need to adhere more to a constantly changing economic system, has led to a revision of the existing situation, consisting both on the method to quantify the pharmacies distribution and on the efficiency of the service. If Law 27/2012 has effectively allowed municipalities to increase the number of pharmacies that they can settle on the municipal territory, it has also started a process of rethinking the logic of pharmacies location and of their catchment areas. In this framework, the present paper aims to discuss the merits of a regulatory evolutions that sparked the process of liberalization of locations, integrating the law guidelines and goals with an operating logic process, usable and useful to translate goals into planning actions in a continuous dialogue between law and territory, constraints and opportunities, equity and accessibility of the care services. Following this logic operations, we have investigated the urban context of Castelfranco Emilia, assuming the location of new offices on the basis of pharmaceutical analyzes.

Airport traffic complexity and environment efficiency metrics for evaluation of ATM measures

Scipedia content — Tue, 16 Feb 2021 11:54:13 +0100

For a given (current or planned) traffic demand, different air traffic management measures could result in different airport traffic complexity and efficiency. This paper presents the research on the relationship between airport traffic complexity and time and environmental efficiency for different air traffic control (ATC) tactics applied to the given or planned airport layout. Emphasis is placed on the evaluation of airport traffic complexity, aircraft fuel consumption, gas emissions and time efficiency for different ATC tactics and/or airport airfield layouts. For busy airports during peak hours, arrival queuing delays, taxi-in, taxi-out times and departure queuing delays increase, which induces additional unnecessary fuel consumption, gas emission and time inefficiency. In order to find a tool which could indicate potential delay generators, a measure of airport traffic complexity – called Dynamic Complexity is proposed. Experiments were performed for airports with different airfield layouts, for different traffic demands and ATC applied tactics using SIMMOD simulation model. Traffic situations were analyzed and delays were measured. The values of airport traffic complexity, fuel consumption and gas emissions were also determined. A comparative analysis of the results show: first, the proposed airport traffic complexity metric quite satisfactorily reflects the influence of traffic characteristics upon the environmental state of the system, and second, different ATM strategic and tactical measures (airport airfield infrastructure development and applied ATC tactics) could significantly reduce traffic complexity and increase time and environmental efficiency at the airport.

Location of logistics companies : a stated preference study to disentangle the impact of accessibility

Scipedia content — Tue, 16 Feb 2021 11:51:27 +0100

© 2014 Elsevier Ltd. Due to the globalization and the fragmentation of industrial production processes, the logistics sector, organizing the linkages between different production plants and the market, is growing fast. This results in an increasing demand for suitable new business locations. Previous research has indicated that accessibility is a key factor in the location decision making process. Though the literature on this subject is extensive, little research has been done to quantify the impact of the different dimensions of accessibility on the location decision process of logistics companies. This paper aims to fill this void in the literature by means of a revealed preference study (using a Geographic Information System (GIS) analysis) and a stated preference study (using a designed discrete choice experiment) in Flanders (Belgium). The results of the revealed preference study served as input to the design of the choice situations in the stated preference study. In the stated preference study, the respondents were confronted with a series of choice situations described by means of accessibility variables as well as land rent information. An analysis of the resulting data by means of discrete choice modeling revealed that land rent is the most important factor in the location choice of logistics companies in Flanders. Access to a port is the second most important factor, followed by access to a motorway, the location in a business park and an inland navigation terminal, which are all about equally important. Access to a rail terminal plays no significant role in the location choice of logistics companies in Flanders. ispartof: Journal of Transport Geography vol:42 pages:110-121 status: published

Development of an internal air cooling sprayed oil injection technique for the energy saving in sliding vane rotary compressors through theoretical and experimental methodologies

Scipedia content — Tue, 16 Feb 2021 11:50:24 +0100

The present work highlights the energy saving potential of the lubricant fluid supplied in Sliding Vane Rotary air Compressors. A Lagrangian theoretical model of a sprayed oil injection technology assessed the cooling effect of the lubricant due to the high surface to volume ratio of the oil droplets and predicted a reduction of the indicated power. The model validation was carried out through a test campaign on a mid-size sliding vane compressor equipped with a series of pressure swirl atomizers. The oil injections took place along the axial length of the compressor. The reconstruction of the indicator diagram and the direct measurement of the mechanical power revealed a reduction of the energy consumption close to 7% using an injection pressure of 20 bar. A parametric analysis on the injection pressure and temperature and on the cone spray angle was eventually carried out to identify an optimal set of operative injection parameters. The work has been done under the FP7 Project “Complete Vehicle Energy-Saving CONVENIENT” founded by the European Commission.

Investigation of a method for real time quantification of gas bubbles in pipelines

Scipedia content — Tue, 16 Feb 2021 11:47:51 +0100

The need to measure the dynamic void fraction (the proportion of flowing bubbly liquid that is gas) is common across many power, processing and manufacturing industries. Many such pipelines and liquids are optically opaque, and work on margins that require a low cost solution that is not commensurate with the size of the challenge. Such a solution will therefore be a compromise, and in this paper costs are reduced by using a narrowband acoustic solution that cannot, on its own, contain enough information to characterise the void fraction in real time unambiguously. The ambiguity is reduced using likely estimates of the general shape of the bubble size distribution so that, with a single source-receiver pair attached to the outside of the pipe, the absolute gas content can be estimated. Whilst the data that are required a priori (the general shape of the bubble size distribution) are not identical to the output of the inversion (the absolute void fraction of gas entrained as bubbles in the flow), the requirement for such a priori information could limit the usefulness of the technique in industry.

Urban sustainable mobility. Part 1: Rationality in transport planning

Scipedia content — Tue, 16 Feb 2021 11:45:18 +0100

The impact of the transport sector is in the range of 20%-40% in terms of consumption of fossil fuels and emissions of greenhouse gases and particulate matter. In this context, policies aimed at reducing these effects are very important. Many urban areas are trying to adopt planning strategies aimed to a sustainable use of resources often referred to as sustainable mobility. These policies are very different in terms of costs and expected benefits, and the effects of these policies and their combinations are difficult to anticipate on a purely intuitive basis and sometimes the end effect could be contrary to intuitive expectations (e.g. policies aimed to reduce pollution, ending up in increasing it). In this context, the concept of eco-rational planning assumes a central role. This means identifying the right mixture of interventions to be implemented on the transport system that is: rational for the transport system (e.g. reduction in terms of congestion, traffic accidents, travel time) and sustainable for people's health and for the environmental (e.g. emissions reduction) and requires minimal economic resources (e.g. lower monetary cost per unit of CO2 saved). The paper discusses the importance of rational decisions in transport planning.

Improved cost models for optimizing CO2 pipeline configuration for point-to-point pipelines and simple networks

Scipedia content — Tue, 16 Feb 2021 11:42:07 +0100

In this study, a new cost model is developed for CO2 pipeline transport, which starts with the physical properties of CO2 transport and includes different kinds of steel grades and up-to-date material and construction costs. This pipeline cost model is used for a new developed tool to determine the configuration leading to the lowest levelized costs for CO2 transport, for point-to-point pipelines as well as for simple networks on different types of terrain and for different time frames. The model optimizes inlet pressure, diameter, steel grade and number of pumping stations. Results show that gaseous CO2 transport can give lower levelized costs than liquid CO2 transport for point-to-point pipelines and for simple networks, if the CO2 is stored in a reservoir with a low required injection pressure, like depleted natural gas fields. However, for storage fields with a required injection pressure of 8 MPa or higher (like aquifers), CO2 can be better transported in a liquid form. For onshore pipelines transporting liquid CO2, the optimal inlet pressure is 9-13 MPa and pumping stations are installed roughly every 50-100 km. For offshore pipelines, pumping stations are not an option and the inlet pressure is determined by the length of the pipeline. The maximum inlet pressure is about 25 MPa and for even longer pipelines, a larger diameter is selected. The levelized costs (excluding initial compression) for transporting 100 kg/s (about 3 Mt/y) over 100 km are between 1.8 and 33 (sic)/t for liquid and 4.0-6.4 (sic)/t for gaseous CO2 transport. For larger mass flows the costs are decreasing, for instance transporting 200 kg/s (about 6 Mt/y) over 100 km are 1.2-1.8 (sic)/t for liquid and 3.0-3.8 (sic)/t for gaseous CO2 transport. Furthermore, results show that higher steel grades lead to lower investment costs for onshore pipelines transporting liquid CO2. Using X120 in the long term reduces the pipeline costs up to 17%. For gaseous CO2 transport, lower steel grades (like X42 and X52) are the best option. Also offshore pipelines do not benefit from the development of higher steel grades over time because the thickness should be at least 2.5% of the outer diameter. The results indicate that oversizing the pipeline, to transport CO2 from an additional source that is coming available later, is not always cost-attractive. This strongly depends on the time span of which further CO2 sources are available and on the mass flows. Oversizing appears earlier cost-attractive compared to two point-to-point pipelines if the source with the largest mass flow becomes available first. (C) 2014 Elsevier Ltd. All rights reserved.

In-Order Delivery Approach for 2D and 3D NoCs

Scipedia content — Tue, 16 Feb 2021 11:41:53 +0100

In many applications, it is critical to guarantee the in-order delivery of requests from the master cores to the slave cores, so that the requests can be executed in the correct order without requiring buffers. Since in NoCs packets may use different paths and on the other hand traffic congestion varies on different routes, the in-order delivery constraint cannot be met without support. To guarantee the in-order delivery, traditional approaches either use dimension-order routing or employ reordering buffers at network interfaces. Dimension-order routing degrades the performance considerably while the usage of reordering buffers imposes large area overhead. In this paper, we present a mechanism allowing packets to be routed through multiple paths in the network, helping to balance the traffic load while guaranteeing the in-order delivery. The proposed method combines the advantages of both deterministic and adaptive routing algorithms. The simple idea is to use different deterministic algorithms for independent flows. This approach neither requires reordering buffers nor limits packets to use a single path. The algorithm is simple and practical with negligible area overhead over dimension-order routing. The concept is investigated in both 2D and 3D mesh networks.

Application of new human factors tool in an air traffic management organization

Scipedia content — Tue, 16 Feb 2021 11:36:44 +0100

m: An easy-to-use human factors (HF) tool for air traffic control (ATC) operators was applied in an air traffic management (ATM) organization to ensure ATC operators' learning and commitment to HF, which is seen as a critical factor in improving safety. Methods: ATC operators analyzed the positive and negative causal factors of 3163 incident reports in 2008-2010 using the HF tool in 27 ATC units. We studied the active usage of the HF tool and causal factors of incidents. Users' experiences of the HF tool were assessed using questionnaires with open questions. Results: Although the usage of the tool varied from year to year and across units, it helped ATC units analyze both positive and negative HF-related causal factors of incidents. It also enabled ATC operators to learn about the new field of HF. Discussion: The target ATM organization accepted the new HF tool. The benefits of the tool were its visuality, user-friendliness and the congruence of its contents with existing HF tools. The lessons learnt revealed the need for more extensive training, clearer instructions for the users of the HF tool, and publicizing the actions based on the findings. Conclusions: The application of a new HF tool in the target ATM organization was supported by the fact that it could be included as one of the core processes of ATC work (reporting system). Improving HF competence in the organization is recommended, to further improve ATC work and the safety of ATC operations. The HF tool would support this.

Sustainability as a Change Agent? Lessons From the European Airspace Regulation

Scipedia content — Tue, 16 Feb 2021 11:35:25 +0100

The contribution at hand follows the sociologist Niklas Luhmann in framing ecological problems as communicative ones. This approach offers valuable insights for the difficulties in finding society-wide accepted solutions. Reflexive steering (RS) as well as reflexive governance (RG) took up basic assumptions but also added proposals for working towards solutions. Because actors from different contexts cannot escape from a “vicious circle of first-order reflexivity”, they have to be forced to take into account the big picture (claim 1). In the RG literature it is argued that notions such as “sustainable development” may ease triggering communication across different societal domains by working as a “change agent” (claim 2). Both of these claims are examined by introducing a case study on European airspace regulation (“Single European Sky”). It shows that economy – usually the system that is intended to be changed – makes use of sustainability as a change agent in order to redirect the pressure to reflect and adapt towards others. It is concluded that, on the one hand, public credibility is a powerful means to induce changes within idiosyncratic societal entities. On the other hand, terms such as “sustainable development” are so widely diffused that they allow for being used by almost any societal actor able to communicate publicly. This multi-directionality has been neglected in the literature so far which calls for thinking of new communicative solutions – especially beyond procedural proposals which are favored by many approaches from RS to RG.

A dendrochronological reassessment of three Roman boats from Utrecht (the Netherlands) : evidence of inland navigation between the lower-Scheldt region in Gallia Belgica and the limes of Germania inferior

Scipedia content — Tue, 16 Feb 2021 11:31:32 +0100

This study addresses the provenance of two Roman river barges and a Roman punt excavated along the limes of Germania inferior near the Dutch city of Utrecht ( De Meern 1 , 4 and 6 ). To establish the geographical origin of these vessels, their tree-ring series are compared to 1452 dated oak ( Quercus robur/petraea ) growth patterns from Roman-period sites in the current Netherlands and Belgium. The strong resemblance to patterns of oak used in the civitas Menapiorum and the bordering region of civitas Nerviorum in Gallia Belgica indicates that the ships were built with oak from the lower-Scheldt region in present-day Flanders (north-western Belgium). Given the absence of Flemish oak in Roman land-based constructions along the Dutch limes , this provenance implies that the vessels were constructed in the lower-Scheldt region. The geographical location of the final wreck sites of De Meern 1 , 4 and 6 points at inland-navigation between this region and the Rhine-based limes of Germania inferior .

Threat-based sensor management for target tracking

Scipedia content — Tue, 16 Feb 2021 11:30:02 +0100

sensor management scheme that focuses on managing the uncertainty in the threat level of targets is proposed. The scheme selects the best sensing mode such that the uncertainty in the threat level of targets is minimized. The main advantage of the proposed scheme is that it opens the possibility for incorporation of the operational context when performing Bayes-optimal sensor management. Different aspects of threat can be meaningfully aggregated making this flexible approach a favorite choice for multifunctional systems. The proposed scheme is demonstrated in simulated scenarios, both simple and advanced, where the data association problem is taken into account. In the multitarget example, the proposed scheme outperforms the other schemes considered in this manuscript, both naive and adaptive. The proposed scheme can be used in target tracking applications, such as air traffic management or area surveillance.

The Modal Split of Cities: A Workplace-Based Mixed Modelling Perspective

Scipedia content — Tue, 16 Feb 2021 11:29:10 +0100

Many transport planners and policy-makers compare cities on the basis of travel behaviour or transport system characteristics. These comparisons are then used to promote cities as cycling capitals or public transport paradises. However, data-related and methodological issues make comparisons across cities difficult. This paper presents an alternative to the dominant atomistic-residential perspective which takes a random sample of residents in a city as input. We conceptualise cities as concentrations of workplaces and compare the commuting behaviour of employees active in a selection of sectors. This paper presents a new indicator to measure the modal split of cities and explains the level of car use in Belgian cities using mixed models. The presence of a railway station is associated with lower levels of car use, while highway access increases the share of the car. The car is also less popular in city centres, subcentres and in more dense urban areas.

Decentralized Signal Control for Urban Road Networks

Scipedia content — Tue, 16 Feb 2021 11:28:43 +0100

We propose in this paper a decentralized traffic signal control policy for urban road networks. Our policy is an adaptation of a so-called BackPressure scheme which has been widely recognized in data network as an optimal throughput control policy. We have formally proved that our proposed BackPressure scheme, with fixed cycle time and cyclic phases, stabilizes the network for any feasible traffic demands. Simulation has been conducted to compare our BackPressure policy against other existing distributed control policies in various traffic and network scenarios. Numerical results suggest that the proposed policy can surpass other policies both in terms of network throughput and congestion.

Comment: Public technical repor

A GIS-based tool for the management of industrial accidents triggered by volcanic ash fallouts

Scipedia content — Tue, 16 Feb 2021 11:25:40 +0100

In this last decade, worldwide attention has been focused on the hazards derived from the interaction between extreme natural phenomena and critical infrastructures and/or chemical and process industry (natural–technological hazards or Na-Tech). Due to the recent occurrence of significant events, great attention has also been given to Na-Tech hazards triggered by volcanic eruptions; in particular, the eruption of the Icelandic volcano alarmed the European community due to the ash fallout over the continent, which caused significant problems for the population, road, rail and air traffic and production activities. This study aims at defining a procedure for the representation of the vulnerability of industrial facilities to potential volcanic ash fallouts. Its implementation on a Geographical Information System has also been executed and a semi-automatic procedure for the vulnerability mapping has been constructed. © 2014 Taylor & Franci

In the wake of liberalisation: long-term developments in the EU air transport market

Scipedia content — Tue, 16 Feb 2021 11:23:03 +0100

Using a 24-year analysis period (1990-2013), a new perspective is offered on long-term first- and second-order developments following liberalisation of the intra-EU air transport market. The focus of the analysis is on supply-side issues, such as airline output, structure of supply, yields, business models, and the position of (former) flag carriers. We find that air transport liberalisation in the EU internal market has facilitated significant growth in both the number and frequency of routes. Greater competition and lower fares at the route level went hand in hand with ongoing consolidation. The first and second liberalisation packages have enabled former flag carriers to develop into full-service hub-and-spoke carriers. It was only after the third package (1993-1997) that low-cost carriers were able to fully develop Europe-wide, point-to-point networks. They rapidly achieved a substantial market share after 2000. Following the adoption of the third package of liberalisation measures, charter operators launched scheduled operations as leisure airlines and adopted in part the new low-cost business model. Until 2013, direct competition between low-cost carriers and former flag carriers was limited due to different route development strategies. This picture has changed in recent years since more low-cost carriers have begun to focus on primary hubs. The competitive impact of the rapidly expanding new generation of hub carriers from Turkey and the Gulf has further increased competitive pressure on the former European flag carriers. Consequently, consolidation of the European airline industry is likely to continue, as well as the ongoing effort to reduce costs. Finally, rising competitive pressure may incentivise EU member states to develop a more protective national aviation policy.

New environmental demands and the future of the Helsinki−Tallinn freight route

Scipedia content — Tue, 16 Feb 2021 11:16:37 +0100

The environmental friendliness of short sea shipping has been justified in Europe by the ensuing lower congestion at hinterlands and unneeded large-scale infrastructure investments on roads and railways. However, the attractiveness of short sea shipping is about to change. This is because of increasing environmental regulations (International Maritime Organization (IMO) sulfur regulation in the Baltic Sea and planned CO2 emissions trading) and increased world market oil prices. In this research, we analyze this potential change using data envelopment analysis on the existing transportation chain alternatives in the Helsinki (Finland)−Tallinn (Estonia) short sea route (chains using either roro, ropax or container ships). The analysis also includes the planned railway tunnel between the two cities. On the basis of our findings, the current truck and semi-trailer-based transportation is challenged by containers, irrespective of how they are carried (ship type). In the long term, for reasons of emissions and oil independency, the possibility of tunnel construction would make it vital to have container ship operations available along this route. The forthcoming change is not radical, but rather evolutionary and long term oriented.

Classification for Safety-Critical Car-Cyclist Scenarios Using Machine Learning

Scipedia content — Tue, 16 Feb 2021 11:16:20 +0100

The number of fatal car-cyclist accidents is increasing. Advanced Driver Assistance Systems (ADAS) can improve the safety of cyclists, but they need to be tested with realistic safety-critical car-cyclist scenarios. In order to store only relevant scenarios, an online classification algorithm is needed. We demonstrate that machine learning techniques can be used to detect and classify those scenarios based on their trajectory data. A dataset consisting of 99 realistic car-cyclist scenarios is gathered using an instrumented vehicle. We achieved a classification accuracy of the gathered data of 87.9%. The execution time of only 45.8 us shows that the algorithm is suitable for online purposes. cop. 2015 IEEE.

On certain anisotropic elliptic equations arising in congested optimal transport: local gradient bounds

Scipedia content — Tue, 16 Feb 2021 11:16:05 +0100

Motivated by applications to congested optimal transport problems, we prove higher integrability results for the gradient of solutions to some anisotropic elliptic equations, exhibiting a wide range of degeneracy. The model case we have in mind is the following: \\[ \\partial_x \\left[(|u_{x}|-\\delta_1)_+^{q-1}\\, \\frac{u_{x}}{|u_{x}|}\\right]+\\partial_y \\left[(|u_{y}|-\\delta_2)_+^{q-1}\\, \\frac{u_{y}}{|u_{y}|}\\right]=f, \\] for $2\\le q"\\infty$ and some non negative parameters $\\delta_1,\\delta_2$. Here $(\\,\\cdot\\,)_+$ stands for the positive part. We prove that if $f\\in L^\\infty_{loc}$, then $\ abla u\\in L^r_{loc}$ for every $r\\ge 1$.

The Potential Impact of Vehicle-to-Vehicle and Sensor-to-Vehicle Communication in Urban Parking

Scipedia content — Tue, 16 Feb 2021 11:10:56 +0100

Studies have shown that up to thirty percent of all traffic in crowded urban areas can be cruising for parking. Information provision to drivers can potentially decrease cruising time for individual drivers and subsequently improve the performance of the overall system. While most cities provide drivers with information on the occupancy rates of off-street parking facilities, information on single on-street parking places was non-existing until recently. Recent technological advances have made it possible to provide such information.

Marine spatial planning and Good Environmental Status: : a perspective on spatial and temporal dimensions

Scipedia content — Tue, 16 Feb 2021 11:07:52 +0100

Accident risk and factors regarding non-motorised road users - a central road safety challenge with deficient data

Scipedia content — Tue, 16 Feb 2021 11:06:38 +0100

most half of all traffic fatalities worldwide are non-motorised road users (NMRUs). In Denmark, the number has increased with about 30%. NMRUs consist of about 63% of the injured in the Danish traffic. Much has been done to reduce the number of injured NMRUs with counterparts, while little effort is put into the reduction of the vast majority of the accidents, NMRU single accidents, which are about 90% of all injured NMRUs. There are no efficient tools available to reduce this number. A significantly better designed, maintained, and illuminated road network would most likely help. However, that is expensive and not possible for most road authorities. Despite this, the challenges with NMRUs in single accidents need more attention, if road safety is to be improved. The situation in Denmark is more than likely the case in many other countries as well; although the documentation is scarce. Almost half of all traffic fatalities worldwide are non-motorised road users (NMRUs). In Denmark, the number has increased with about 30%. NMRUs consist of about 63% of the injured in the Danish traffic. Much has been done to reduce the number of injured NMRUs with counterparts, while little effort is put into the reduction of the vast majority of the accidents, NMRU single accidents, which are about 90% of all injured NMRUs. There are no efficient tools available to reduce this number. A significantly better designed, maintained, and illuminated road network would most likely help. However, that is expensive and not possible for most road authorities. Despite this, the challenges with NMRUs in single accidents need more attention, if road safety is to be improved. The situation in Denmark is more than likely the case in many other countries as well; although the documentation is scarce.

Flow–structure–seabed interactions in coastal and marine environments

Scipedia content — Tue, 16 Feb 2021 11:04:24 +0100

Flow–structure–seabed interaction in coastal and marine environments is a rapidly growing area of research and applications. In this vision paper, this area is discussed with a view of identifying its state of the art and current research challenges. The discussion draws attention to key issues related to structures such as marine pipelines, offshore windfarms, and multiuse offshore platforms. Tsunamis, which received considerable attention after two recent extreme events (2004 Indonesia tsunami and 2011 Japan tsunami) are also included in the discussion. Marine hydro-geomechanics is highlighted, among other areas, as an emerging branch of Marine Civil Engineering. Predictions of the field development for the forthcoming years are also briefly outlined."br

Roads to Nowhere:The Accuracy of Travel Demand Forecasts for Do-nothing Alternatives

Scipedia content — Tue, 16 Feb 2021 11:01:12 +0100

Impact appraisals of major transport infrastructure projects rely extensively on the accuracy of forecasts for the expected construction costs and aggregate travel time savings. The latter of these further depend on the accuracy of forecasts for the expected travel demand in both the do-something and do-nothing alternatives, in order to assess the impact of implementing new projects compared to doing nothing or postponing the decision. Previous research on the accuracy of travel demand forecasts has focused exclusively on the do-something alternatives, where inaccuracies have been revealed in the form of large imprecision as well as systematic biases. However, little or no attention has been given to the accuracy of demand forecasts for the do-nothing alternatives, which are equally important for impact appraisals. This paper presents the first ex-post evaluation of demand forecast accuracy for do-nothing alternatives, based on an empirical study of 35 road projects in Denmark and England. The results show a tendency for systematic overestimation of travel demand in the do-nothing alternatives, which is in contrast to the systematic underestimation of travel demand observed in previous studies of do-something alternatives. The main implication for planning practice is that the severity of future congestion problems is systematically overestimated. As a consequence, impact appraisals of road construction as a means of congestion relief appear overly beneficial.

Towards smart grids: Identifying the risks that arise from the integration of energy and transport supply chains

Scipedia content — Tue, 16 Feb 2021 10:54:20 +0100

This paper identifies the risks for the functionality and reliability of the grid that arise from the integration of the transport and supply chain. The electrification of transport is a promising option for the transition to a low carbon energy and transport system. But on the short term, the electrification of transport also creates risks. More specifically, when promising technological such as vehicle-to-grid and smart-grids are not yet available on a large scale, the rapid diffusion of electric vehicles and the recharging behaviour of consumers can create risks for grid functioning. In order to assess these risks, this paper present a GIS-based simulation method that assesses electricity demand and supply on the neighbourhood level. The paper combines local level electric vehicle diffusion forecasts, with neighbourhood level data about the grid additional capacity. Application of the model to the Netherlands shows that risks for grid functioning already appear as early as 2015. More specifically, the diffusion of electric vehicles is found to compromise the functioning of the grid on the short term in densely populated areas such as Amsterdam. In these neighbourhoods early and fast adoption of electric vehicles coincides with the presence of an older grid with less additional capacity. The model provides insights for grid operators as well as for policy makers that seek to stimulate the transition to sustainable energy and transport systems, and can be used as a strategic tool to plan (smart) grid investments.

A three-dimensional macroscopic fundamental diagram for mixed bi-modal urban networks

Scipedia content — Tue, 16 Feb 2021 10:52:43 +0100

Recent research has studied the existence and the properties of a macroscopic fundamental diagram (MFD) for large urban networks. The MFD should not be universally expected as high scatter or hysteresis might appear for some type of networks, like heterogeneous networks or freeways. In this paper, we investigate if aggregated relationships can describe the performance of urban bi-modal networks with buses and cars sharing the same road infrastructure and identify how this performance is influenced by the interactions between modes and the effect of bus stops. Based on simulation data, we develop a three-dimensional vehicle MFD (3D-nu MFD) relating the accumulation of cars and buses, and the total circulating vehicle flow in the network. This relation experiences low scatter and can be approximated by an exponential-family function. We also propose a parsimonious model to estimate a three-dimensional passenger MFD (3D-pMFD), which provides a different perspective of the flow characteristics in hi-modal networks, by considering that buses carry more passengers. We also show that a constant Bus-Car Unit (BCU) equivalent value cannot describe the influence of buses in the system as congestion develops. We then integrate a partitioning algorithm to cluster the network into a small number of regions with similar mode composition and level of congestion. Our results show that partitioning unveils important traffic properties of flow heterogeneity in the studied network. Interactions between buses and cars are different in the partitioned regions due to higher density of buses. Building on these results, various traffic management strategies in hi-modal multi-region urban networks can then be integrated, such as redistribution of urban space among different modes, perimeter signal control with preferential treatment of buses and bus priority. (C) 2014 Elsevier Ltd. All rights reserved.

Comparison of Electric Vehicles Charging Strategies and their Impact on Network Capacity

Scipedia content — Tue, 16 Feb 2021 10:49:36 +0100

Identification of effective visual problem solving strategies in a complex visual domain

Scipedia content — Tue, 16 Feb 2021 10:40:21 +0100

Students in complex visual domains must acquire visual problem solving strategies that allow them to make fast decisions and come up with good solutions to real-time problems. In this study, 31 air traffic controllers at different levels of expertise (novice, intermediate, expert) were confronted with 9 problem situations depicted on a radar screen. Participants were asked to provide the optimal order of arrival of all depicted aircrafts. Eye-movements, time-on-task, perceived mental effort, and task performance were recorded. Eye-tracking data revealed that novices use inefficient means-end visual problem solving strategies in which they primarily focus on the destination of aircraft. Higher levels of expertise yield visual problem solving strategies characterized by more efficient retrieval of relevant information and more efficient scan paths. Furthermore, experts’ solutions were more similar than intermediates’ solutions and intermediates’ solutions were more similar than novices’ solutions. Performance measures showed that experts and intermediates reached better solutions than novices, and that experts were faster and invested less mental effort than intermediates and novices. These findings may help creating eye-movement modeling examples for the teaching of visual problem solving strategies in complex visual domains.

Reference architecture for interoperability testing of Electric Vehicle charging

Scipedia content — Tue, 16 Feb 2021 10:36:21 +0100

This paper presents a reference architecture for interoperability testing of electric vehicles as well as their support equipment with the smart grid and the e-Mobility environment. Pan-European Electric Vehicle (EV)-charging is currently problematic as there are compliance and interoperability issues on different communication levels and among the different domains comprising the eMobility system. The discussed reference architecture is composed out of three layers that enable addressing a direct mapping of interfaces, functions and services, as well as real world actors and/or laboratory equipment. Utilizing this architecture enables cross-domain co-simulation for interoperability within the electric mobility and the smart grid environment. Given the future challenges that rise to interoperability testing and the fact that certain aspects are yet unknown or rarely defined, the discussed architecture presents a very modular and extendable approach. © 2015 IEEE.

Seismic vulnerability of gas and liquid buried pipelines

Scipedia content — Tue, 16 Feb 2021 10:35:08 +0100

Lifelines play a crucial and essential role in human life and in economic development. The resilience of those systems under extreme events as earthquakes is a primary requirement, especially when large amount of toxic and flammable material are transported. In this work, the seismic vulnerability of buried gas and liquid pipelines has been analyzed, starting from a large number of damage data to pipelines collected from post-earthquake reconnaissance reports.Seismic fragility formulations and threshold values for the earthquake intensity with respect to the release of content from different types of pipelines have been derived. The main outcome of the work is therefore a novel seismic assessment tool which is able to cover the needs of industrial risk assessment procedures and land use planning requirements. © 2013 Elsevier Ltd.

Prices, prices and prices: A study in the airline sector

Scipedia content — Tue, 16 Feb 2021 10:29:04 +0100

[EN] This article creates and empirically analyzes a dynamic pricing framework. The model includes the main theories on prices in the literature, and dynamically analyzes how companies change their pricing policies according to different circumstances. Through the use of regressions, the article shows the relative long and short-term impact on pricing equations (strategic versus operational matters), and on production conditions versus demand perspectives in the setting of operational prices. In addition, it highlights how the proportions of these pricing perspectives change in the airline sector according to the effect of the environment on the configuration of the strategy (determined by monthly and hourly seasonality), and also according to the nature of this competitive strategy (determined by the characteristics of the company and the destination airport). The results confirm our framework, and show how firms combine the different perspectives in their pricing strategies. We acknowledge financial support from the Valencian Economic Research Institute (IVIE, Valencian Government), and the Universitat Politècnica de València. Narangajavana, Y.; Garrigós Simón, FJ.; Sánchez García, J.; Forgas-Coll, S. (2014). Prices, prices and prices: A study in the airline sector. Tourism Management. 41:28-42. doi:10.1016/j.tourman.2013.08.008 S 28 42 41

Friction power modeling and measurements in sliding vane rotary compressors

Scipedia content — Tue, 16 Feb 2021 10:24:11 +0100

In compressed air systems, mechanical and organic losses account for 15% of compressor energy consumption. In the current research, the energy saving potential achievable through friction power reduction in sliding vane rotary compressors was investigated using experimental and modeling approaches. Tests on a new mid-size industrial compressor operating at different steady conditions (outlet pressure 9, 12.5, 14.5 bar at 1000 and 1500 RPM) assessed the machine performance through measurement of mechanical power and the reconstruction of the pressure-volume diagram. An experimental methodology was also developed to quantify the power lost by friction and its measurement uncertainty using the concept of indicated mean effective pressure. Modeling the compressor blade dynamics allowed a friction power decomposition while an analysis of the hydrodynamic lubrication at the most severe friction location, namely between blade tip and stator wall, additionally provided the oil film thickness evolution along the contact surface. The agreement between modeling and experimental data identified a value for the friction coefficient of 0.065. Design suggestions on existing machines and new design solutions were eventually outlined varying blade mass, revolution speed and compressor aspect ratio. These improved configurations predicted an efficiency increase up to 6%. The authors acknowledge Ing. Enea Mattei S.p.A. and particularly its CEO, Dr. Giulio Contaldi, for continuous research funding and support. The work has been done also under the FP7 Project “Complete Vehicle Energy-Saving CONVENIENT” funded by the European Commission.

A comparative analysis of the effects of economic policy instruments in promoting environmentally sustainable transport

Scipedia content — Tue, 16 Feb 2021 10:19:03 +0100

This paper presents a comparative analysis of the effects of economic policy instruments in promoting environmentally sustainable transport. Promoting environmentally sustainable transport is defined as follows: (1) Reducing the volume of motorised travel; (2) Transferring travel to modes generating less external effects, and (3) Modifying road user behaviour in a way that will reduce external effects of transport. External effects include accidents, congestion, traffic noise and emissions to air. Four economic policy instruments are compared: (1) Prices of motor fuel; (2) Congestion charges; (3) Toll schemes; (4) Reward systems giving incentives to reduce driving or change driver behaviour. The effects of these policy instruments are stated in terms of elasticities. All four economic policy instruments have negative elasticities, which means that they do promote environmentally sustainable transport. Long-term elasticities tend to be larger than short term elasticities. The long-term elasticities of reward systems are unknown. (C) 2014 Elsevier Ltd. All rights reserved.

Trade-offs between mobility and equity maximization under environmental capacity constraints: A case study of an integrated multi-objective model

Scipedia content — Tue, 16 Feb 2021 10:15:01 +0100

This paper investigates the performance of a policy decision tool proposed for multi-objective decision under different policy interventions. This tool deals with the trade-off between mobility and equity maximization under environmental capacity constraints. Two system objectives, maximization of mobility and equity, are formulated in terms of the sum of total car ownership and number of trips, and the differences in accessibility between zones. Environmental capacities are based on production efficiency theory in which the frontier emission under maximum system efficiency is taken as environmental capacity. To examine the performance of the proposed model, three types of hypothetical policies (network improvement, population increase and urban sprawl) are formulated. Effects are simulated using data pertaining to Dalian City, China. Results show that the proposed model is capable of representing the trade-offs between mobility and equity based on different policy interventions. Compared with two extreme cases with the single objective of mobility maximization or equity maximization, the Pareto-optimal solutions provide more interesting practical options for decision makers. Taking the solution based on the maximum equity as an example, the policy of urban sprawl yields the most significant improvement in both emission and accessibility of the three scenarios.

To Fuel or Not to Fuel? Is that the Question?

Scipedia content — Tue, 16 Feb 2021 10:14:27 +0100

ording to the International Air Transport Association, the industry fuel bill accounts for more than 25% of the annual airline operating costs. In times of severe economic constraints and increasing fuel costs, air carriers are looking for ways to reduce costs and improve fuel efficiency without putting flight safety into jeopardy. In particular, this is inducing discussions on how much additional fuel to put in a planned route to avoid diverting to an alternate airport due to Air Traffic Flow Management delays. We provide here a general model to support such decisions. We illustrate it with a case study and provide comparison with the current practice, showing the relevance of our approach.

Peer Reviewed

Seismic damage to pipelines in the framework of Na-Tech risk assessment

Scipedia content — Tue, 16 Feb 2021 10:10:18 +0100

The structural integrity of pipelines undergone seismic waves is crucial for industrial installation and for the distributed transportation networks of gaseous and liquid fluids. However, it is nowadays proved that the definition of seismic vulnerability based on purely, structural-derived limit states or on return-to-service or even on the purely economic repair rate indications, is not sufficient for the holistic analysis of risks. On the other hand, detailed numerical studies based on full analyses (including fluid/soil/structure interaction) are too expensive for the aims of risk assessment and simplified methodologies are still needed.In this paper, a large database of earthquake-induced damage for steel and non-steel pipelines is presented. Each case was analyzed and collected from post-earthquake reconnaissance, seismic engineering reports and technical papers. The database may be adopted for the definition of specific vulnerability function (fragility curves), which are commonly implemented in multi-hazard analyses, and more in general for the assessment of Na-Tech risks (Natural events triggering Technological disasters). © 2014 Elsevier Ltd.

The adoption of sustainable innovations: Driven by symbolic and environmental motives

Scipedia content — Tue, 16 Feb 2021 10:07:47 +0100

Critical to the environmental success of sustainable innovations is the adoption by consumers. The consensus is that instrumental shortcomings of sustainable innovations inhibit their adoption. However, we argue that the adoption of sustainable innovations does not exclusively depend on their instrumental attributes. In addition, people may be motivated to adopt sustainable innovations because of their positive environmental and symbolic attributes, that is, they benefit the environment and can be used to signal positive characteristics to oneself and others. We studied the significance of instrumental, environmental and symbolic attributes for the adoption of two sustainable innovations: electric cars (Study 1) and local renewable energy systems (Study 2), following two methods. Results showed that when asked directly, participants claimed that instrumental and environmental attributes are most important for their decision to adopt sustainable innovations, while symbolic attributes were rated as less important. Interestingly, evaluations of the symbolic and environmental attributes of sustainable innovations, but not evaluations of their instrumental attributes, predicted different indicators of adoption (i.e., interest in, the acceptability of, and intention to adopt these sustainable innovations), suggesting that the significance of symbolic motives for adopting sustainable innovations may not be recognized by consumers. Moreover, favorable evaluations of symbolic attributes particularly enhanced interest in and acceptability of sustainable innovation when participants evaluated the instrumental attributes more negatively, but not when instrumental attributes were evaluated relatively positively. This suggests that the instrumental drawbacks of sustainable innovations may sometimes strengthen their positive signal, which can promote interest in sustainable innovations. (c) 2014 Elsevier Ltd. All rights reserved.

Personalised feedback and eco-driving: An explorative study

Scipedia content — Tue, 16 Feb 2021 10:06:12 +0100

Conventional road transport has negative impact on the environment. Stimulating eco-driving through feedback to the driver about his/her energy conservation performance has the potential to reduce CO"inf"2"/inf" emissions and promote fuel cost savings. Not all drivers respond well to the same type of feedback. Research has shown that different drivers are attracted to different types of information and feedback. The goal of this paper is to explore which different driver segments with specific psychographic characteristics can be distinguished, how these characteristics can be used in the development of an ecodriving support system and whether tailoring eco-driving feedback technology to these different driver segments will lead to increased acceptance and thus effectiveness of the eco feedback technology. The driver segments are based on the value orientation theory and learning orientation theory. Different possibilities for feedback were tested in an exploratory study in a driving simulator. An explorative study was selected since the choice of the display (how and when the information is presented) may have a strong impact on the results. This makes testing of the selected driver segments very difficult. The results of the study nevertheless suggest that adapting the display to a driver segment showed an increase in acceptance in certain cases. The results showed small differences for ratings on acceptation, ease of use, favouritism and a lower general rating between matched (e.g., learning display with learning oriented drivers) and mismatched displays (e.g., learning display with performance oriented drivers). Using a display that gives historical feedback and incorporates learning elements suggested a non-verifiable increase in acceptance for learning oriented drivers. However historical feedback and learning elements may be less effective for performance oriented drivers, who may need comparative feedback and game elements to improve energy conserving driving behaviour. © 2015.

Frequency modelling and solution of fluid–structure interaction in complex pipelines

Scipedia content — Tue, 16 Feb 2021 10:05:11 +0100

Complex pipelines may have various structural supports and boundary conditions, as well as branches. To analyse the vibrational characteristics of piping systems, frequency modelling and solution methods considering complex constraints are developed here. A fourteen-equation model and Transfer Matrix Method (TMM) are employed to describe Fluid–Structure Interaction (FSI) in liquid-filled pipes. A general solution for the multi-branch pipe is proposed in this paper, offering a methodology to predict frequency responses of the complex piping system. Some branched pipe systems are built for the purpose of validation, indicating good agreement with calculated results.

European Cities Dealing with Climate Issues: Ideas and Tools for a Better Framing of Current Practices.

Scipedia content — Tue, 16 Feb 2021 10:00:10 +0100

Contemporary cities have to deal with numerous challenges, from the growth and aging of urban populations to the scarcity of resources; from environmental degradation to climate change. The latter, also due to the increasing severity of climate-related impacts on urban areas, is widely considered one of the most urgent challenges for urban development in the near future: cities are the main contributors to energy consumption and GHG emissions, paying, at the same time, the highest price for the climate impacts. Thus, climate issues have gained increasing importance in the last decades, both in terms of the metaphors coined by scholars relative to urban future (low-carbon cities, transition cities, smart cities, resilient cities, etc.) and in terms of the initiatives undertaken on different institutional levels. Unfortunately, mitigation and adaptation are generally regarded as two different approaches, neglecting the potential synergies and trade-offs between the related strategies. Hence, based on the growing awareness of the need for mainstreaming mitigation and adaptation policies at city level, this study will provide an overview of the state of the art of the mitigation and adaptation initiatives in Italian metropolitan cities. Then, focusing on the concepts of the “smart” and the “resilient” city – recognized as key concepts for reducing CO2 emissions and improving the ability of cities to respond to climate impacts – and with reference to a conceptual framework for building up a smart and resilient urban system carried out in previous research works (Papa et al., 2015), the study will examine case studies of the cities of Rotterdam and Barcelona, highlighting how this framework may improve our understanding and, above all, contribute to better integration of the fragmented on-going strategies and initiatives.

Temporal Performance of Advanced Driver Assistance Systems vis-á-vis Human Driving Behavior in Dense Traffic

Scipedia content — Tue, 16 Feb 2021 09:56:51 +0100

dvanced Driver Assistance Systems (ADAS) are becoming ubiquitous, and gradually take over the role of human drivers in the vision of the automotive sector. Humans are different from most systems: while in general humans exhibit a much higher error rate when performing specific functions, they are also unmatched in their adaptability, and their ability to recognize patterns and anticipate on these. In this paper we derive temporal requirements on future ADAS operation, needed to at least match human driving behavior in dense traffic. We examine Adaptive Cruise Control and Automated Emergency Braking systems at highway speeds, derive temporal requirements, and show that in dense traffic situations intent communication has a significant benefit to improve systems operation. The resulting requirements will challenge ADAS developments in the coming years. cop. 2015 IEEE.

Impacts of a green-driving application in city buses on fuel consumption, speeding and passenger comfort

Scipedia content — Tue, 16 Feb 2021 09:56:39 +0100

The impacts of a green-driving application on fuel consumption, speeding and passenger comfort were assessed on a frequently operated bus route in the Helsinki metropolitan area. The main results of the study show that use of a green-driving application in buses significantly reduces fuel consumption and speeding and increases passenger comfort. Novel users of the system drove more economically than those who had used the system longer, but the impact was smaller than found in previous studies. In addition to savings on fuel, the application encouraged driving within the speed limit. A transfer effect on journeys without the system was found for long-term users but not for novel users. Furthermore, passengers of drivers who used the green-driving application gave better grades for decelerations and the driver’s service attitude in peak traffic. The authors main conclusion is that use of a green-driving application is beneficial even after years of use for reducing both fuel consumption and speeding. The authors recommended that drivers be regularly encouraged to use the system and that green driving be included in driver training.

Design of lightweight magnesium car body structure under crash and vibration constraints

Scipedia content — Mon, 15 Feb 2021 12:30:44 +0100

Car body design in view of structural performance and lightweighting is a challenging task due to all the performance targets that must be satisfied such as vehicle safety and ride quality. In this paper, material replacement along with multidisciplinary design optimization strategy is proposed to develop a lightweight car body structure that satisfies the crash and vibration criteria while minimizing weight. Through finite element simulations, full frontal, offset frontal, and side crashes of a full car model are evaluated for peak acceleration, intrusion distance, and the internal energy absorbed by the structural parts. In addition, the first three fundamental natural frequencies are combined with the crash metrics to form the design constraints. The wall thicknesses of twenty-two parts are considered as the design variables. Latin Hypercube Sampling is used to sample the design space, while Radial Basis Function methodology is used to develop surrogate models for the selected crash responses at multiple sites as well as the first three fundamental natural frequencies. A nonlinear surrogate-based optimization problem is formulated for mass minimization under crash and vibration constraints. Using Sequential Quadratic Programming, the design optimization problem is solved with the results verified by finite element simulations. The performance of the optimum design with magnesium parts shows significant weight reduction and better performance compared to the baseline design.

Document type: Article

Evaluation of Strain Distribution for the P91 Steel under Static Load Using Espi System

Scipedia content — Mon, 15 Feb 2021 11:29:27 +0100

The goal of the research was to evaluate the change of displacement/strain phases in the P91 steel under static load conditions. Undertaken tests were aimed at estimation and analysis of the impact of the material state, which was subjected to loading conditions, on the distribution of stress pattern using ESPI system. Specimen made of high temperature creep resistant steel X10CrMoVNb9-1 (P91) used as a construction material for boiler steam feed heaters, vapor tanks, pressure vessels and vapor pipelines, is used in the service conditions of temperature range up of 650°C. Test samples were taken from two P91 steel pipes. One sample came from a segment of a pipeline transporting fresh vapor in time 80 000 h, under the pressure of 8.4 MPa and temperature 540 °C. The second sample was the same material but in the delivery state.

Document type: Article

Traffic Information Interface Development in Route Choice Decision

Scipedia content — Mon, 15 Feb 2021 10:56:40 +0100

"jats:p"In this paper, a method has been developed based on historic traffic data (vehicle speed), which helps the commuters to choose routes by their intelligence knowing the traffic conditions in Google maps. Data has been collected on basis of video analysis from several segments between Tuker Bazar and Bandar Bazar route. For each of the video footage, a reference length has been recorded with measurement tape for use in video analysis. Software has been also developed based on Java language to get the traffic information from historic data, which shows the output as images consisting of traffic speed details on the available routes by giving day and time limit as inputs. The developed models provide useful insights and helpful for the policy makers that can lead to the reduction of traffic congestion and increase the scope of intelligence of the road users, at least for the underdeveloped or developing country where navigation is still unavailable.

Document type: Article

Reduced carbon and energy footprint in highway operations: the Highway Energy Assessment (HERA) methodology

Scipedia content — Mon, 15 Feb 2021 10:54:24 +0100

Global demand for mobility is increasing and the environmental impact of transport has become an important issue in transportation network planning and decision-making, as well as in the operational management phase. Suitable methods are required to assess emissions and fuel consumption reduction strategies that seek to improve energy efficiency and furthering decarbonization. This study describes the development and application of an improved modeling framework – the HERA (Highway EneRgy Assessment) methodology – that enables to assess the energy and carbon footprint of different highways and traffic flow scenarios and their comparison. HERA incorporates an average speed consumption model adjusted with a correction factor which takes into account the road gradient. It provides a more comprehensive method for estimating the footprint of particular highway segments under specific traffic conditions. It includes the application of the methodology to the Spanish highway network to validate it. Finally, a case study shows the benefits from using this methodology and how to integrate the objective of carbon footprint reductions into highway design, operation and scenario comparison.

Document type: Article

Event Detection and Localization in Urban Water Distribution Network

Scipedia content — Mon, 15 Feb 2021 10:32:02 +0100

Urban water supply and distribution infrastructure is aging rapidly and the frequency of pipe burst increases. These events can be very expensive due to water supply disruptions, and damage to surrounding properties and infrastructures. Therefore, methods of detecting and localizing underground burst events in real time can be very helpful in mitigating these impacts. This paper is a part of the WaterWiSe@SG project in Singapore. In this paper, a cost-effective wireless sensor network was developed for a real-time monitoring, analyzing, and modeling of urban water distribution systems. This paper presents an application of joint time-frequency analysis (JTFA) for detecting events in water distribution pipelines. The idea behind this method is based on the detection of pressure fluctuations induced by the burst. This proposed approach for event detection employs a spectrogram, one of the JTFA approaches. The feasibility of the proposed method is tested through emulated leak-off experiments and validated with monitoring data in an operational system. The results demonstrate that the proposed method has the potential to assist in the management of water infrastructure by monitoring existing conditions and providing real-time feedback in case of the failure.

Document type: Article

Numerical approach to a low pressure gas-injection scroll compressor

Scipedia content — Mon, 15 Feb 2021 10:14:25 +0100

In order to solve problems arising in ordinary heat pump system for pure electric vehicles at ultra-low temperature, a low pressure gas-injection scroll compressor is designed, and a mathematical model is established. Comparison with the experimental results shows good accuracy of the theoretical prediction.

Document type: Article