Scipedia: Documents published in 2019

Simulation and Experimental Study on Cuttings-Carrying for Reverse Circulation Horizontal Directional Drilling with Dual Drill Pipes

Scipedia content — Tue, 23 Mar 2021 04:09:44 +0100

In the past decades, horizontal directional drilling (HDD) has been successfully used to install various pipelines in different strata. However, construction accidents such as drill-burying and drill-sticking occur occasionally when pipelines installed by HDD method in an unstable stratum such as sand cobble stratum. Recently, HDD with dual drill pipes was used to install pipelines in unstable stratum, and the effect is significant. The law of cuttings migration for HDD with dual drill pipes is still unclear. Therefore, it is necessary to study the law of cuttings migration in reverse circulation with dual drill pipes. This study performs numerical simulations and experimental research on the cuttings-carrying process in reverse circulation directional drilling with dual drill pipes. Based on the assumption of dual concentric pipes, simulations of fluid-solid two-phase flows are conducted in different flow channels between the inner and outer drill pipes. An experimental cuttings-carrying model is then established. By combining the results of the numerical simulations and experimental investigation, the hydraulic parameters of the dual drill pipe system are optimized, and the rationalities of the drill tool design and the grading selection are validated. The results of this study provide a reference cuttings-carrying model during reverse circulation HDD with dual drill pipes.

Document type: Article

Route Identification Method for On-Ramp Traffic at Adjacent Intersections of Expressway Entrance

Scipedia content — Tue, 23 Mar 2021 04:00:09 +0100

To determine the control strategy at intersections adjacent to the expressway on-ramp, a route identification method based on empirical mode decomposition (EMD) and dynamic time warping (DTW) is established. First, the de-noise function of EMD method is applied to eliminate disturbances and extract features and trends of traffic data. Then, DTW is used to measure the similarity of traffic volume time series between intersection approaches and expressway on-ramp. Next, a three-dimensional feature vector is built for every intersection approach traffic flow, including DTW distance, space distance between on-ramp and intersection approach, and intersection traffic volume. Fuzzy C-means clustering method is employed to cluster intersection approaches into classifications and identify critical routes carrying the most traffic to the on-ramp. The traffic data are collected by inductive loops at Xujiahui on-ramp of North and South Viaduct Expressway and surrounding intersections in Shanghai, China. The result shows that the proposed method can achieve route classification among intersections for different time periods in one day, and the clustering result is significantly influenced by three dimensions of traffic flow feature vector. As an illustrative example, micro-simulation models are built with different control strategies. The simulation shows that the coordinated control of critical routes identified by the proposed method has a better performance than coordinated control of arterial roads. Conclusions demonstrated that the proposed route identification method could provide a theoretical basis for the coordinated control of traffic signals among intersections and on-ramp.

Document type: Article

Avoiding drunk driving with a push

Scipedia content — Tue, 23 Mar 2021 03:55:41 +0100

The present study explores a novel approach for changing implicit attitudes toward drunk driving with behavioural training. Contrary to explicit attitudes, which people are consciously aware of and therefore can state, implicit attitudes are not necessarily consciously accessible; however, implicit attitudes also direct and affect behaviour. In order to combat problem behaviour such as drunk driving, it is, therefore, crucial to measure and target both types of attitudes. This randomised controlled study first measured implicit drunk driving attitudes. One week later, participants performed a behavioural training procedure, designed to influence implicit drunk driving attitudes, and a subsequent implicit drunk driving attitude test. We randomised young male participants into an experimental group that learned to avoid drunk driving stimuli and a control group performing a neutral version of the training setup. Results showed that behavioural training could change implicit drunk driving attitudes. However, contrary to expectations, the control group’s implicit attitudes also changed. We propose that drivers can hold both positive and negative drunk driving implicit attitudes, and a priming effect may have contributed to the results. We outline and discuss the results.

Document type: Article

Can the Czech Road Tax be considered a Tax on Externalities?

Scipedia content — Tue, 23 Mar 2021 03:48:18 +0100

The transport sector is one of the important components of economic systems. Besides positive effects, it is also a source of external costs transferred to other entities. Through the evaluation of current settings of the tax base and parameters of the road tax rate progressivity it was ascertained that this tax fails to directly or indirectly reflect the external costs of transport. It is through a relatively simple adjustment of the existing road tax rates that indirect reflection of certain items of the road transport external costs may be achieved. Firstly, changes must be made in the definition of the road tax base so as to contain emissions or other parameters of externalities; subsequently, the direct reflection of the road transport external costs in the tax may be achieved.

Document type: Article

Vibration Effect Produced by Raised Pavement Markers on the Exit Ramp of an Expressway

Scipedia content — Tue, 23 Mar 2021 03:34:03 +0100

Driving over raised pavement markers (RPMs) spaced at different spacing, the human body will experience different vibrations. To explore whether RPMs situated at the exit ramp of an expressway induce a good vibration warning effect, this paper determines the spacing of RPMs situated along a deceleration lane and curved ramp. Models of roads, vehicles, and RPMs are first established in the ADAMS software, after which an integrated human-chair model constructed in SolidWorks is imported into ADAMS, and then the complete model is formed so that vibration simulations of different types of vehicle at different spacing and speeds can be carried out. The results show that the vibration warning effects of the spacing proposed by the existing Chinese specifications and this paper are basically between level III and level IV, the driver’s subjective feeling is between less comfortable and uncomfortable, and both induce a good vibration warning effect. For a linear deceleration lane, when considering traffic safety, a spacing of 3 m is recommended; when considering the economy, a spacing of 6 m is recommended. For a curved deceleration lane and curved ramp, according to the actual curve radius, the spacing of RPMs can refer to the spacing recommended in the paper. In addition, the vibration warning effect for cars and semi-trailer trucks initially increases with an increase in the speed; then, after reaching a certain peak speed, the effect decreases with an increase in the speed, and finally, it tends to become gentle at speeds exceeding 100 km/h. The vibration warning effect for a semi-trailer truck is better than that for a car under the same spacing and speed.

Document type: Article

Water Supply Pipeline Risk Index Assessment Based on Cohesive Hierarchical Fuzzy Inference System

Scipedia content — Tue, 23 Mar 2021 03:14:55 +0100

As populations grow, facilities such as roads, bridges, railways lines, commercial and residential buildings, etc., must be expanded and maintained. There are extensive networks of underground facilities to fulfil the demand, such as water supply pipelines, sewage pipelines, metro structures, etc. Hence, a method to regularly assesses the risk of the underground facility failures is needed to decrease the chance of accidental loss of service or accidents that endanger people and facilities. In the proposed work, a cohesive hierarchical fuzzy inference system (CHFIS) was developed. A novel method is proposed for membership function (MF) determination called the heuristic based membership functions determination (HBMFD) method to determine an appropriate MF set for each fuzzy logic method in CHFIS. The proposed model was developed to decrease the number of rules for the full structure fuzzy inference system with all rule implementation. Four very crucial parameters were considered in the proposed work that are inputs to the proposed CHFIS model in order to calculate the risk of water supply pipelines. In order to fully implement the proposed CHFIS just 85 rules are needed while using the traditional Mamdani fuzzy inference system, 900 rules are required. The novel method greatly reduces implementation time and rule design sets that are extremely time consuming to develop and difficult to maintain.

Document type: Article

Evaluation of Transportation Network Reliability under Emergency Based on Reserve Capacity

Scipedia content — Tue, 23 Mar 2021 03:10:34 +0100

There are differences between the requirements for traffic network for traffic demand in daily and emergency situations. In order to evaluate how the network designed for daily needs can meet the surging demand for emergency evacuation, the concept of emergency reliability and corresponding evaluation method is proposed. This paper constructs a bilevel programming model to describe the proposed problem. The upper level problem takes the maximum reserve capacity multiplier as the optimization objective and considers the influence of reversible lane measures taken under emergency conditions. The lower level model adopts the combined traffic distribution/assignment model with capacity limits, to describe evacuees’ path and shelter choice behavior under emergency conditions and take into account the traits of crowded traffic. An iterative optimization method is proposed to solve the upper level model, and the lower level model is transformed into a UE assignment problem with capacity limits over a network of multiple origins and single destination, by adding a dummy node and several dummy links in the network. Then a dynamic penalty function algorithm is used to solve the problem. In the end, numerical studies and results are provided to demonstrate the rationality of the proposed model and feasibility of the proposed solution algorithms.

Document type: Article

The geoecological substantiation of pipelines to collect associated petroleum gas

Scipedia content — Tue, 23 Mar 2021 02:26:26 +0100

Construction and exploitation of the gas pipeline is associated with seriously geoecological risks. The magnitude of risks depends on the kind and value of the impact of influencing factors. The factors of geoecological risk mean to the natural and technical conditions, which influences to probability of occurrence, the value of processes with adverse geoecological consequences, also the size of the expected geoecological damage during the transportation of associated petroleum gas (Gubaidullin and Korobov 2005). Territory near shore of Pechora sea between Bolvanskaya bay and Khaypudyrskaya bay is modern promising center of oil production in region. Ricing of oil production connect with ricing of associated petroleum gas (APG) production and searching of ways of effective utilization APG (instead of burning on torch) is actual challenge. The most promising way is common gathering pipeline system with one center of preparing and utilization of APG. Building and exploitation of pipelines connected with high gejecologilal risks. Evaluation and minimization of geecological risk is actual task."/jats:p" "jats:p"It is necessary to plan steps to minimizing risks (Day et al. 1998) to design stage to reduce the impact on the environment. The factor`s indicators of geoeological risk are distributed unevenly along the gas pipeline. Zoning should help to analyze the distribution of geoecological risk factors and determine territories for activities.

Document type: Article

Planning urban pavement maintenance by a new interactive multiobjective optimization approach

Scipedia content — Tue, 23 Mar 2021 02:24:34 +0100

Pavement maintenance is essential to prevent the deterioration of asset value and to satisfy the expectations of all stakeholders (objectives). However, the budgets are often insufficient to keep the road pavement at optimum levels. Therefore, a decision making process ought to be used for prioritizing different maintenance activities in order to achieve pre-defined goals by optimizing the use of the available budget. One of the biggest difficulties in multiobjective optimization method is the large number of the feasible solutions (Pareto optimal set or its approximation), which makes it hard for the Decision Maker to select the best solution."br/""br/"To support interaction with the decision maker for identifying the best combination of maintenance actions, this paper proposes a new methodology named “Interactive Multiobjective Optimization-Dominance Rough Set Approach” (IMO-DRSA), using a decision-rule preference model."br/""br/"The preference information, obtained by the Decision Maker (DM) during the course of the interaction, is processed using the Dominance-based Rough Set Approach in order to achieve a decision model expressed in terms of easily understandable “if ….then …” decision rules. This approach makes possible an interaction between the analyst and the decision maker and helps the decision maker to classify maintenance options and allocate limited funds according to predefined objectives (quantitative or qualitative). An application of the proposed methodology to road pavements of an Italian urban sub-network is presented.

Document type: Article

Obstacle Avoidance of Semi-Trailers Based on Nonlinear Model Predictive Control

Scipedia content — Tue, 23 Mar 2021 02:09:26 +0100

Obstacle avoidance is a core part of the autonomous driving of off-road vehicles, such as semi-trailers. Due to the long length of semi-trailers, the traditional obstacle avoidance controller based on the circumcircle model can ensure that there is no collision between the semi-trailer and the obstacle, but it also greatly reduces the passable area. To solve this problem, we propose a new obstacle avoidance model. In this model, the distance between the obstacle and the middle line of semi-trailers is used as the indicator of obstacle avoidance. Based on this model, we design a new obstacle avoidance controller for semi-trailers. The simulation results show that the proposed controller can ensure that no collision occurs between the semi-trailer and the obstacle. The minimum distance between the obstacle center and the semi-trailer body trajectory is greater than the sum of the obstacle radius and the safety margin. Compared with the traditional obstacle avoidance controller based on the circumcircle model, the proposed controller greatly reduces the error between the semi-trailer and the reference path during obstacle avoidance.

Document type: Article

Network Analysis of the Multidimensional Symptom Experience of Oncology

Scipedia content — Tue, 23 Mar 2021 01:54:07 +0100

Oncology patients undergoing cancer treatment experience an average of fifteen unrelieved symptoms that are highly variable in both their severity and distress. Recent advances in Network Analysis (NA) provide a novel approach to gain insights into the complex nature of co-occurring symptoms and symptom clusters and identify core symptoms. We present findings from the first study that used NA to examine the relationships among 38 common symptoms in a large sample of oncology patients undergoing chemotherapy. Using two different models of Pairwise Markov Random Fields (PMRF), we examined the nature and structure of interactions for three different dimensions of patients’ symptom experience (i.e., occurrence, severity, distress). Findings from this study provide the first direct evidence that the connections between and among symptoms differ depending on the symptom dimension used to create the network. Based on an evaluation of the centrality indices, nausea appears to be a structurally important node in all three networks. Our findings can be used to guide the development of symptom management interventions based on the identification of core symptoms and symptom clusters within a network.

Document type: Article

Distribution Organization Optimization for Inbound China Railway Express at Alataw Pass Railway Station

Scipedia content — Tue, 23 Mar 2021 01:39:25 +0100

Recently, in the context of &ldquo

The Belt and Road&rdquo

Initiative, the China Railway Express, which has a high volume and spans a long distance has greatly facilitated the construction of international freight transport corridors between developed and developing countries. To ensure sustainable development, this paper introduces an optimization problem of a container distribution organization scheme for the China Railway Express resulting from the major existing problems arising in railway port stations, which is a special and crucial link in transportation organization of the China Railway Express. The problem of a long dwell time of inbound trains is typically concerned with the operation process in railway port stations. Taking various real-world influencing factors of efficiency into account, this paper formulates a distribution organization optimization model to minimize the total container-hours of inbound China Railway Express at Alataw Pass railway station. Subsequently, a solution method based on the main idea of a genetic algorithm is developed to solve the problem, and two examples of different modes of transportation organization are given for validating the effectiveness of the model. Finally, we compare the results between two modes under different orders of magnitude according to the characteristics of sustainability to discuss the possible change and development of the China Railway Express in the future.

Document type: Article

The Effect of Reducing Electric Car Purchase Incentives in the European Union

Scipedia content — Tue, 23 Mar 2021 01:36:22 +0100

The importance of electric car purchase incentives is starting to be questioned. The objective of this paper is to explore the potential effect of reducing or removing electric car purchase public subsidies in the European Union. To this end, the system dynamics Powertrain Technology Transition Market Agent Model is used. The size and timing of purchase incentives for this technology in European countries are investigated under eight scenarios and sensitivity analysis performed. The simulations suggest that, in the short-run, the electric car market share is higher when the subsidies remain in place. In the medium-run, a purchase subsidy scheme granting &euro

3000 for plug-in hybrid electric cars and &euro

4000 for battery electric cars over the period 2020&ndash

2024 yields the fastest electric car market uptake of all the scenarios considered. We conclude that, though the current evolution of the battery price is favorable, electric car purchase subsidies remain an effective policy measure to support electro-mobility in the next years.

Document type: Article

A Bi-Objective Fuzzy Credibilistic Chance-Constrained Programming Approach for the Hazardous Materials Road-Rail Multimodal Routing Problem under Uncertainty and Sustainability

Scipedia content — Tue, 23 Mar 2021 01:20:13 +0100

Hazardous materials transportation involves extensive risk and cannot be avoided in practice. An advanced routing, however, can help to reduce the risk by planning the best transportation routes for hazardous materials that can make effective tradeoffs between the risk objective and the economic objective. In this study, we explore the hazardous materials routing problem in the road-rail multimodal transportation network with a hub-and-spoke structure, in which the risk is measured by the multiplication of population exposure and the associated volume of hazardous materials, and minimizing the total risk of all the transportation orders of hazardous materials is set as the risk objective. It is difficult to estimate the population exposure exactly during the routing decision-making process, which results in its uncertainty. In this study, we formulate the uncertain population exposure from a fuzzy programming perspective by using triangular fuzzy numbers. Moreover, the carbon dioxide emission constraint is formulated to realize the sustainable transportation of hazardous materials. To optimize the problem under the above framework, we first establish a bi-objective fuzzy mixed integer nonlinear programming model, and then develop a three-stage exact solution strategy that the combines fuzzy credibilistic chance constraint, linearization technique, and the normalized weighting method. Finally, a computational experiment is carried out to verify the feasibility of the proposed method in dealing with the problem. The experimental results indicate that tradeoffs between the two conflicting objectives can be effectively made by using the Pareto frontier to the hazardous materials routing problem. Furthermore, the credibility level and carbon dioxide emission cap significantly influence the hazardous materials routing optimization. Their effects on the optimization result are quantified by using sensitivity analysis, which can draw some useful insights to help decision makers to better organize the hazardous materials road-rail multimodal transportation under uncertainty and sustainability.

Document type: Article

FCG-ASpredictor: An Approach for the Prediction of Average Speed of Road Segments with Floating Car GPS Data

Scipedia content — Tue, 23 Mar 2021 01:17:17 +0100

The average speed (AS) of a road segment is an important factor for predicting traffic congestion, because the accuracy of AS can directly affect the implementation of traffic management. The traffic environment, spatiotemporal information, and the dynamic interaction between these two factors impact the predictive accuracy of AS in the existing literature, and floating car data comprehensively reflect the operation of urban road vehicles. In this paper, we proposed a novel road segment AS predictive model, which is based on floating car data. First, the impact of historical AS, weather, and date attributes on AS prediction has been analyzed. Then, through spatiotemporal correlations calculation based on the data from Global Positioning System (GPS), the predictive method utilizes the recursive least squares method to fuse the historical AS with other factors (such as weather, date attributes, etc.) and adopts an extended Kalman filter algorithm to accurately predict the AS of the target segment. Finally, we applied our approach on the traffic congestion prediction on four road segments in Chengdu, China. The results showed that the proposed predictive model is highly feasible and accurate.

Document type: Article

External Human–Machine Interfaces: The Effect of Display Location on Crossing Intentions and Eye Movements

Scipedia content — Tue, 23 Mar 2021 01:03:35 +0100

In the future, automated cars may feature external human&ndash

machine interfaces (eHMIs) to communicate relevant information to other road users. However, it is currently unknown where on the car the eHMI should be placed. In this study, 61 participants each viewed 36 animations of cars with eHMIs on either the roof, windscreen, grill, above the wheels, or a projection on the road. The eHMI showed &lsquo

Waiting&rsquo

combined with a walking symbol 1.2 s before the car started to slow down, or &lsquo

Driving&rsquo

while the car continued driving. Participants had to press and hold the spacebar when they felt it safe to cross. Results showed that, averaged over the period when the car approached and slowed down, the roof, windscreen, and grill eHMIs yielded the best performance (i.e., the highest spacebar press time). The projection and wheels eHMIs scored relatively poorly, yet still better than no eHMI. The wheels eHMI received a relatively high percentage of spacebar presses when the car appeared from a corner, a situation in which the roof, windscreen, and grill eHMIs were out of view. Eye-tracking analyses showed that the projection yielded dispersed eye movements, as participants scanned back and forth between the projection and the car. It is concluded that eHMIs should be presented on multiple sides of the car. A projection on the road is visually effortful for pedestrians, as it causes them to divide their attention between the projection and the car itself.

Document type: Article

Lifetime Analysis of Energy Storage Systems for Sustainable Transportation

Scipedia content — Tue, 23 Mar 2021 00:55:59 +0100

On the path to a low-carbon future, advancements in energy storage seem to be achieved on a nearly daily basis. However, for the use-case of sustainable transportation, only a handful of technologies can be considered, as these technologies must be reliable, economical, and suitable for transportation applications. This paper describes the characteristics and aging process of two well-established and commercially available technologies, namely Lithium-Ion batteries and supercaps, and one less known system, flywheel energy storage, in the context of public transit buses. Beyond the obvious use-case of onboard energy storage, stationary buffer storage inside the required fast-charging stations for the electric vehicles is also discussed. Calculations and considerations are based on actual zero-emission buses operating in Graz, Austria. The main influencing parameters and effects related to energy storage aging are analyzed in detail.Based on the discussed aging behavior, advantages, disadvantages, and a techno-economic analysis for both use-cases is presented. A final suitability assessment of each energy storage technology concludes the use-case analysis.

Document type: Article

Influence Mechanism of Geometric Characteristics of Water Conveyance System on Extreme Water Hammer during Load Rejection in Pumped Storage Plants

Scipedia content — Tue, 23 Mar 2021 00:44:13 +0100

Pumped storage plants (PSPs) have achieved rapid development and deployment worldwide since the penetration of intermittent renewable energy sources (RES). Hydraulic transient analysis in the PSP, to obtain the control parameters such as extreme water hammer pressure, is vital to the safe design of water conveyance system. Empirically, simultaneous load rejection (SLR) is commonly accepted as the control condition for extreme water hammer, while it is not completely true for the PSP. Employing theoretical analysis and numerical simulation, this study systematically investigates the effects of geometric characteristics on the extreme water hammer, and reveals the mechanism leading to the maximum spiral case pressure (SCP) during a two-stage load rejection (TLR) process. The results indicate that the extreme water hammer pressure is closely related to geometric characteristics of the water conveyance system, performing the allocation of the water inertia time constant of the main and branch pipelines. When the water inertia time constant in the branch pipe is dominant (&eta

1 >

0.24 for example), the maximum SCP will occur in TLR conditions rather than SLR. Moreover, the maximum SCP is almost the same, providing the water inertia time constants of both the main and branch pipelines are kept constant.

Document type: Article

The open diffusion data derivatives, brain data upcycling via integrated publishing of derivatives and reproducible open cloud services

Scipedia content — Tue, 23 Mar 2021 00:42:21 +0100

We describe the Open Diffusion Data Derivatives (O3D) repository: an integrated collection of preserved brain data derivatives and processing pipelines, published together using a single digital-object-identifier. The data derivatives were generated using modern diffusion-weighted magnetic resonance imaging data (dMRI) with diverse properties of resolution and signal-to-noise ratio. In addition to the data, we publish all processing pipelines (also referred to as open cloud services). The pipelines utilize modern methods for neuroimaging data processing (diffusion-signal modelling, fiber tracking, tractography evaluation, white matter segmentation, and structural connectome construction). The O3D open services can allow cognitive and clinical neuroscientists to run the connectome mapping algorithms on new, user-uploaded, data. Open source code implementing all O3D services is also provided to allow computational and computer scientists to reuse and extend the processing methods. Publishing both data-derivatives and integrated processing pipeline promotes practices for scientific reproducibility and data upcycling by providing open access to the research assets for utilization by multiple scientific communities.

Design Type(s)data integration objective • database creation objectiveMeasurement Type(s)brainTechnology Type(s)magnetic resonance imagingFactor Type(s)Voxel SizeSample Characteristic(s)Homo sapiens • brain Machine-accessible metadata file describing the reported data (ISA-Tab format)

Document type: Preprint

The Parker Project: Cross-Brand Service Testing Using V2G

Scipedia content — Tue, 23 Mar 2021 00:22:43 +0100

The Parker project sought to experimentally validate that contemporary series-produced electric vehicles (EVs), capable of V2G, are ready to participate in a number of advanced grid services. In such services, the timing, size and direction of power and energy exchanged between the EV battery and grid is controlled as to support either a single building, the local neighborhood or the regional power system. Vehicles purposely designed for such services are referred to as grid integrated electric vehicles (GIVs). The field of research, describing how GIVs may be used to actively support the power system, is called Vehicle&ndash

Grid Integration (VGI).The purpose of this paper is to present how the Danish Parker project has systematically categorized a range of grid services, collected in a service catalog, and then illustrate state-of-the-art EVs ability to support such services through experimental validation. Results are presented for three different tests performed in Parker

marginal emission factor charging, frequency containment reserves and a performance test for controlling power setpoints. The ultimate aim of this paper, and the Parker project, is to promote the GIV concept so that it may inform the design and capabilities of present and future EVs, EV supply equipment (EVSE) and communication standards.

Document type: Article

Cost-Effective, Time-Efficient Passenger Rail System for the Eastern United States

Scipedia content — Tue, 23 Mar 2021 00:17:22 +0100

A program was developed using a genetic algorithm and automated lookup features to design an efficient passenger rail system for the eastern-half of the United States connecting large cities, metropolitan populations greater than two million, with overnight rail service. The results of the program predicted a passenger starting at the farthest point of the system boards the train at 16:02 on average and arrives at a different point of the system at 07:57 on average the following day, assuming the train travels an average speed of 70 mph. The design used actual distances by train track where possible. The system was modeled with six trains that meet at a hub and exchange passengers and continue on to their destination. The optimal solution had a total one-way minimum distance of 4334 km (2693 miles). Assuming the same ridership that currently exists on a popular train route, ticket prices would average $62 (USD) for a one-way ticket. For this system to be feasible, the government would need to own or lease one set of tracks for all the routes determined, build a hub for passengers to transfer trains near Charleston, WV, and ensure the trains are unimpeded by other trains. Installing tracks that go around cities that the trains do not stop at would be a great benefit also. With advances in communication, GPS, and train control technology, this article points out the benefits of publically available tracks to form a transportation network similar to that found in road, air, and water traffic.

Document type: Article

Framework for Assessing Public Transportation Sustainability in Planning and Policy-Making

Scipedia content — Tue, 23 Mar 2021 00:14:20 +0100

Transportation plays a key role in urban sustainability planning and urban greenhouse gas emission reductions. Globally, cities have established sustainability agendas and policies to guide the shift from traditional private automobile dependent transportation systems towards an increased use of public transportation, cycling, and walking. While the surrounding physical urban form and governance structures condition public transportation services, there are also many other factors to consider when discussing sustainability. As such, comprehensive planning and policy-oriented assessment frameworks that are independent of local conditions are still largely missing in literature. This paper presents a Public Transportation Sustainability Indicator List (PTSIL) that provides a platform for an integrated assessment of environmental, economic, and social dimensions of sustainability through an indicator-based approach. To demonstrate its use, the PTSIL is applied to analyze the policy documents of public transportation agencies in Helsinki, Finland, and Toronto, Canada. The results show that while both cities achieve relatively high scores in all dimensions, there is still high variability among individual indicators. The PTSIL presents a missed stepping stone between descriptive definitions of transportation sustainability and case specific sustainability performance assessments, offering an opportunity within the planning and policy-making sectors to review, assess, and develop public transportation services comprehensively.

Document type: Article

Queue-Based Modeling of the Aircraft Arrival Process at a Single Airport

Scipedia content — Tue, 23 Mar 2021 00:11:10 +0100

This paper proposes data-driven queuing models and solutions to reduce arrival time delays originating from aircraft arrival processing bottlenecks at Tokyo International Airport. A data-driven analysis was conducted using two years of radar tracks and flight plans from 2016 and 2017. This analysis helps not only to understand the bottlenecks and operational strategies of air traffic controllers, but also to develop mathematical models to predict arrival delays resulting from increased, future aircraft traffic. The queue-based modeling approach suggests that one potential solution is to expand the realization of time-based operations, efficiently shifting from traffic flow control to time-based arrival management. Furthermore, the proposed approach estimates the most effective range of transition points, which is a key requirement for designing extended arrival management systems while offering automation support to air traffic controllers.

Document type: Article

Effects of Smart City Policies on Green Total Factor Productivity: Evidence from a Quasi-Natural Experiment in China

Scipedia content — Tue, 23 Mar 2021 00:02:06 +0100

When cities develop rapidly, there are negative effects such as population expansion, traffic congestion, resource shortages, and pollution. It has become essential to explore new types of urban development patterns, and thus, the concept of the &ldquo

smart city&rdquo

has emerged. The purpose of this paper is to investigate the links between smart city policies and urban green total factor productivity (GTFP) in the context of China. Based on panel data of 200 cities in China from 2007&ndash

2016 and treating smart city policy as a quasi-natural experiment, the paper uses a difference-in-differences propensity score matching (PSM-DID) approach to prevent selection bias. The results show: (a) Smart city policies can significantly increase urban GTFP by 16% to 18%

(b) the larger the city, the stronger and more significant this promotion.

Document type: Article

The Relationship Between People’s Environmental Considerations and Pro-environmental Behavior in Lithuania

Scipedia content — Mon, 22 Mar 2021 23:57:25 +0100

Given the need for global action on climate change, it is crucial to comprehend which factors motivate people in different countries to act more pro-environmentally. Lithuania is a post-socialist country that has recently increased commitment to foster pro-environmental behavior of individuals, by implementing interventions that target mainly the personal costs and benefits of relevant behaviors. Yet, research suggests that people’s general environmental considerations, namely biospheric values and environmental self-identity, can drive people’ pro-environmental behavior and may be important targets for interventions. These studies, however, have been mostly conducted in Western Europe and the United States, with limited evidence of relationship between people’s biospheric values, environmental self-identity and pro-environmental behaviors across different countries and cultures. We performed a correlational study with a convenience sample in Lithuania (n = 334). Consistent with previous studies and the theory, our study revealed that people’s general environmental considerations were positively related with recycling and environmental activism, but not with fuel-efficient driving and the use of sustainable transportation in Lithuania. We conclude that general environmental considerations are related to pro-environmental behaviors beyond Western Europe and the United States. Yet, future studies need to examine the boundary conditions of this relationship and test whether interventions targeting environmental consideration can be effective to promote pro-environmental behavior.

Document type: Article

Case Study of Holistic Energy Management Using Genetic Algorithms in a Sliding Window Approach

Scipedia content — Mon, 22 Mar 2021 23:45:34 +0100

Energy management systems are used to find a compromise between conflicting goals that can be identified for battery electric vehicles. Typically, these are the powertrain efficiency, the comfort of the driver, the driving dynamics, and the component aging. This paper introduces an optimization-based holistic energy management system for a battery electric vehicle. The energy management system can adapt the vehicle velocity and the power used for cabin heating, in order to minimize the overall energy consumption, while keeping the total driving time and the cabin temperature within predefined limits. A genetic algorithm is implemented in this paper. The approach is applied to different driving cycles, which are optimized by dividing them into distinctive time frames. This approach is referred to as the sliding window approach. The optimization is conducted with two separate driving cycles, the New European Driving Cycle (NEDC) and a recorded real-world drive. These are analyzed with regard to the aspects relevant to the energy management system, and the optimization results for the two cycles are compared. The results presented in this paper demonstrate the feasibility of the sliding window approach. Moreover, they reveal the differences in fundamental parameters between the NEDC and the recorded drive and how they affect the optimization results. The optimization leads to an overall reduction in energy consumption of "inline-formula" "math display="inline"" "semantics" "mrow" "mn"3.37"/mn" "mo"%"/mo" "/mrow" "/semantics" "/math" "/inline-formula" for the NEDC and "inline-formula" "math display="inline"" "semantics" "mrow" "mn"3.27"/mn" "mo"%"/mo" "/mrow" "/semantics" "/math" "/inline-formula" for the recorded drive, without extending the travel time.

Document type: Article

Research into a Multi-Variate Surveillance Data Fusion Processing Algorithm

Scipedia content — Mon, 22 Mar 2021 23:32:50 +0100

Targeted information sources include radar and ADS (Automatic Dependent Surveillance) for civil ATM (Air Traffic Management) systems, and the new navigation system based on satellites has the capability of global coverage. In order to solve the surveillance problem in mid-and-high altitude airspace and approaching airspace, this paper proposes a filter-based covariance matrix weighting method, measurement variance weighting method, and measurement-first weighted fusion method weighting integration algorithm to improve the efficiency of data integration calculation under fixed accuracy. Besides this, this paper focuses on the technology of the integration of a multi-radar surveillance system and automated related surveillance system in the ATM system and analyzes the constructional method of a multigeneration surveillance data integration system, as well as establishing the targeted model of sensors and the target track and designing the logical structure of multi-radar and ADS data integration.

Document type: Article

Study of Pipeline Penetration Based on CEL in Clay

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

In deep water, pipelines are usually laid directly on the seabed. During the laying process, the pipe typically penetrates into the seabed by a fraction of a diameter. The vertical embedment of pipeline and formation of berm during penetration have a significant effect on the pipeline stability. This study aims to investigate the vertical pipeline penetration at uniform and normal consolidated clay, by carrying out a series of numerical analyses, in which the coupled Eulerian-Lagrangian method (CEL) is incorporated to enable large deformation simulation. These analyses have been compared with collapse loads calculated using the theory solution. The results show that the CEL method is very suitable for simulating large-deformation pipesoil interaction.

Document type: Article

Unpacking the Smart Mobility Concept in the Dutch Context Based on a Text Mining Approach

Scipedia content — Mon, 22 Mar 2021 23:22:46 +0100

Existing mobility solutions are criticized for falling short of effectively addressing transport issues and sustainability challenges. In this light, smart mobility has received increasing attention. In the Netherlands, the smart mobility concept triggered various developments, leading to the uptake of initiatives for real-life experimentation, accompanied by an increase in media attention. While the concept is making its way through Dutch society, its meaning for practice remains unspecified. Therefore, this paper aims to unpack the meaning of the smart mobility concept, by analyzing Dutch news articles and initiatives&rsquo

websites using text mining and qualitative content analysis. The analyses reveal some ambiguous meanings for the smart mobility concept, demonstrating on the one hand a focus on incremental technological innovations that bring forward car-based solutions for short-term fixes, while on the other hand promising to address car-related issues and fundamentally change the mobility system by taking long-term challenges into account. In general, smart mobility seems to be about optimizations and maintaining the status quo rather than challenging it, although there are a few deviating and more critical voices. The smart mobility concept mobilizes actors and resources, but considering the ambiguities, these developments should be critically evaluated when proposed as solutions to transport issues and sustainability challenges.

Document type: Article

Battery Models for Battery Powered Applications: A Comparative Study

Scipedia content — Mon, 22 Mar 2021 23:09:06 +0100

Battery models have gained great importance in recent years, thanks to the increasingly massive penetration of electric vehicles in the transport market. Accurate battery models are needed to evaluate battery performances and design an efficient battery management system. Different modeling approaches are available in literature, each one with its own advantages and disadvantages. In general, more complex models give accurate results, at the cost of higher computational efforts and time-consuming and costly laboratory testing for parametrization. For these reasons, for early stage evaluation and design of battery management systems, models with simple parameter identification procedures are the most appropriate and feasible solutions. In this article, three different battery modeling approaches are considered, and their parameters’ identification are described. Two of the chosen models require no laboratory tests for parametrization, and most of the information are derived from the manufacturer’s datasheet, while the last battery model requires some laboratory assessments. The models are then validated at steady state, comparing the simulation results with the datasheet discharge curves, and in transient operation, comparing the simulation results with experimental results. The three modeling and parametrization approaches are systematically applied to the LG 18650HG2 lithium-ion cell, and results are presented, compared and discussed.

Document type: Article

An Overview of, and a Definition, Ecosystem and System Architecture for Electric Mobility as a Service (eMaaS)

Scipedia content — Mon, 22 Mar 2021 22:54:15 +0100

Mobility as a Service (MaaS) is a concept that aligns with both current and future mobility demands of users, namely intermodal, personalized, on-demand and seamless. Although the number of shared mobility, electric mobility and multimodal passenger transport users is rapidly growing, until now, the list of MaaS and electric Mobility as Service (eMaaS) providers is quite short. This could partly be explained by the lack of a common architecture that facilitates the complex integration of all actors involved in the (e)MaaS ecosystem. The goal of this publication is to give an overview of the state of the art regarding (e)MaaS&rsquo

ecosystems and architectures. Moreover, it aims to support the further development of eMaaS by proposing a definition and a novel system architecture for eMaaS. Firstly, the state of the art of the MaaS ecosystem is reviewed. Secondly, the eMaaS ecosystem that builds upon our definition of eMaaS is described and the MaaS system- and technical- architectures found in literature are reviewed. Finally, an eMaaS architecture that focuses on the integration of MaaS and electric mobility systems is presented. With the definition, ecosystem and system architecture presented in this work, the aim is to support the further development of the eMaaS concept.

Document type: Article

Key factors for the implementation and integration of innovative ICT solutions in SMEs and large companies involved in the multimodal transport of dangerous goods

Scipedia content — Mon, 22 Mar 2021 22:46:03 +0100

The increased number of transports with dangerous goods (TDG) increases the risk of both accidents and terrorist attacks. Digitalisation is crucial in order to avoid human errors and to increase safety, security and efficiency, however there are few research studies that analyse digitalisation for the TDG, this being the first time, to the author’s knowledge, that barriers to the implementation of information and communication technology (ICT) solutions for the transport of dangerous goods has been analysed. A new elicitation methodology called the ‘implementation acceleration methodology for ICT (IAM-ICT)’ has been created, with the aim of identifying and hierarchizing potential barriers to the implementation and integration of ICT solutions involved in the multimodal TDG, and with a view to overcoming the most relevant problems at an early stage. This methodology combines user-driven innovation (UDI), the analytic hierarchy process (AHP) and Bayesian networks. The application of this methodology, which is easily replicable in other fields, will enable a better design of ICT solutions so that they can be implemented and integrated in SMEs and large companies. The results show a hierarchy of potential barriers for a multi-modular ICT solution used as use case study, in two different co-designed schemes for a small and medium enterprise (SME) and for a large company.

Document type: Article

Speed profile optimization of catenary-free electric trains with lithium-ion batteries

Scipedia content — Mon, 22 Mar 2021 22:28:34 +0100

Catenary-free operated electric trains, as one of the recent technologies in railway transportation, has opened a new field of research: speed profile optimization and energy optimal operation of catenary-free operated electric trains. A well-formulated solution for this problem should consider the characteristics of the energy storage device using validated models and methods. This paper discusses the consideration of the lithium-ion battery behavior in the problem of speed profile optimization of catenary-free operated electric trains. We combine the single mass point train model with an electrical battery model and apply a dynamic programming approach to minimize the charge taken from the battery during the catenary-free operation. The models and the method are validated and evaluated against experimental data gathered from the test runs of an actual battery-driven train tested in Essex, UK. The results show a significant potential in energy saving. Moreover, we show that the optimum speed profiles generated using our approach consume less charge from the battery compared to the previous approaches.

Document type: Article

Principal Component Analysis of the Potential for Increased Rail Competitiveness in East-Central Europe

Scipedia content — Mon, 22 Mar 2021 22:27:17 +0100

Increased rail competitiveness has been the objective of many countries around the world, including member states of the EU. Although railway market liberalization has always been accompanied by high expectations of increased efficiency and competitiveness, the overall impact of such decisions can be considered controversial. This paper aims to contribute to the scientific debate by conducting a factor analysis of some East-Central European countries from the aspect of rail freight competitiveness. Since many highly correlated factors influence competitiveness, its mathematical&ndash

statistical representation and analysis is difficult due to the high number of dimensions of the factor space. Moreover, competitiveness cannot be measured directly only as a latent variable which is a feature of Principal Component Analysis (PCA). The introduced PCA, model by way of reducing the number of dimensions, can highlight the relations among the attributes and determine the most crucial issues capable of increasing rail competitiveness in the given countries and also of clustering those national railway markets. Recommendations for structural changes in national rail freight markets of the region are also supplied. Our results show that international rail competitiveness depends rather on market efficiency than on market liberalization due to the fact that the Global Competitiveness Index and Export/Import attributes did not significantly correlate with market concentration. As for the larger domestic rail freight sectors, small freight forwarders&mdash

spawned by liberalization&mdash

are shown to play a significant role in increasing competitiveness.

Document type: Article

Slow Steaming as Part of SECA Compliance Strategies among RoRo and RoPax Shipping Companies

Scipedia content — Mon, 22 Mar 2021 22:26:00 +0100

Many geographically peripheral member states of the EU are critically dependent on short sea Roll-on/Roll-off (RoRo) and mixed freight&ndash

passenger (RoPax) shipping services for intra-European trade. The implementation of the Sulfur Emission Control Area (SECA) regulation was expected to raise the operating cost for RoRo and RoPax shipping, and slow steaming was proposed as an immediate solution to save the increased cost. Previous research has investigated the issue of slow steaming and SECA using a quantitative approach. However, the reaction of the RoRo and RoPax shipping firms toward slow steaming as a mitigating factor in the face of expected additional SECA compliance costs using qualitative methodology has not been explored yet. In addition, the knowledge regarding the impact of slow steaming on the competitiveness of short sea RoRo and RoPax with respect to service quality is limited. This article has addressed these issues through the analysis of multiple cases focusing on RoRo and RoPax firms operating in the North and Baltic Seas. Overall, our findings suggest that the 0.1% SECA regulation of 2015 requiring the use of higher-priced MGO has not caused slow steaming in the RoRo and RoPax segments to a large extent. The increased bunker prices are partially transferred to the customers via increased Bunker Adjustment Factor and partly borne by the shipowners. We have found that out of 11 case firms in our study only one RoRo and one RoPax firm have reduced vessel speeds to compensate for the additional SECA compliance costs. We conclude that for RoPax and RoRo segment bunker prices, rigorous competition and, most important, different service quality requirements have significantly restricted the potential implementation of slow steaming.

Document type: Article

A fully coupled fluid-structure interaction simulation of three-dimensional dynamic ductile fracture in a steel pipeline

Scipedia content — Mon, 22 Mar 2021 22:24:42 +0100

Long running fractures in high-pressure pipelines transporting hazardous fluid are catastrophic events resulting in pipeline damage and posing safety and environmental risks. Therefore, the ductile fracture propagation control is an essential element of the pipeline design. In this study, a coupled fluid-structure interaction modelling is used to simulate the dynamic ductile fractures in steel pipelines. The proposed model couples a fluid dynamics model describing the pipeline decompression and the fracture mechanics of the deforming pipeline exposed to internal and back-fill pressures. To simulate the state of the flow in a rupturing pipeline, a compressible one-dimensional computational fluid dynamics model is applied, where the fluid properties are evaluated using a rigorous thermodynamic model. The ductile failure of the steel pipeline is described as an extension of the modified Bai-Wierzbicki model implemented in a finite element code. The proposed methodology has successfully been applied to simulate a full-scale pipeline burst test performed by British Gas Company, which involved rupture of a buried X70 steel pipeline, initially filled with rich natural gas at 11.6 MPa and −5 °C.

Document type: Article

The Color of Health: Residential Segregation, Light Rail Transit Developments, and Gentrification in the United States

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

the modern urban−suburban context becomes increasingly problematic with traffic congestion, air pollution, and increased cost of living, city planners are turning their attention to transit-oriented development as a strategy to promote healthy communities. Transit-oriented developments bring valuable resources and improvements in infrastructure, but they also may be reinforcing decades-old processes of residential segregation, gentrification, and displacement of low-income residents and communities of color. Careful consideration of zoning, neighborhood design, and affordability is vital to mitigating the impacts of transit-induced gentrification, a socioeconomic by-product of transit-oriented development whereby the provision of transit service “upscales” nearby neighborhood(s) and displaces existing community members with more affluent and often White residents. To date, the available research and, thus, overall understanding of transit-induced gentrification and the related social determinants of health are limited and mixed. In this review, an overview of racial residential segregation, light rail transit developments, and gentrification in the United States has been provided. Implications for future transit-oriented developments are also presented along with a discussion of possible solutions.

Document type: Article

Control of a Multiphase Buck Converter, Based on Sliding Mode and Disturbance Estimation, Capable of Linear Large Signal Operation

Scipedia content — Mon, 22 Mar 2021 22:21:02 +0100

Power-hardware-in-the-loop systems enable testing of power converters for electric vehicles (EV) without the use of real physical components. Battery emulation is one example of such a system, demanding the use of bidirectional power flow, a wide output voltage range and high current swings. A multiphase synchronous DC-DC converter is appropriate to handle all of these requirements. The control of the multiphase converter needs to make sure that the current is shared equally between phases. It is preferred that the closed-loop dynamic model is linear in a wide range of output currents and voltages, where parameter variations, control signal limits, dead time effects, and so on, are compensated for. In the case presented in this paper, a cascade control structure was used with inner sliding mode control for phase currents. For the outer voltage loop, a proportional controller with output current feedforward compensation was used. Disturbance observers were used in current loops and in the voltage loop to compensate mismatches between the model and the real circuit. The tuning rules are proposed for all loops and observers, to simplify the design and assure operation without saturation of control signals, that is, duty cycle and inductor current reference. By using the proposed control algorithms and tuning rules, a linear reduced order system model was devised, which is valid for the entire operational range of the converter. The operation was verified on a prototype 4-phase synchronous DC-DC converter.

Document type: Article

The Impact of Different Incentive Policies on Hybrid Electric Vehicle Demand and Price: An International Comparison

Scipedia content — Mon, 22 Mar 2021 22:12:51 +0100

Significant efforts to incentivize the uptake of energy efficient vehicles (EEVs) are evident across the globe. Given EEV markets are dynamic, and consumer demand may fluctuate in response to incentives, this may also lead to other market forces influencing prices. An analysis of EEV incentives, therefore, must account for the possible endogeneity between demand and pricing. Here we estimate the effects of different types of incentives on the demand and price premiums of a specific group of EEVs: plug-in and conventional hybrid electric vehicles (HEVs). For the first time we dis-entangle the endogeneity between HEV demand and price, using error components three-stage least squares (EC3SLS) regression, and establish that increased HEV price premiums lead to reduced demand. In turn, we also establish that increased HEV demand leads to lower price premiums. Additionally, we find that one-off subsidies are associated with higher consumer demand, however, unlike other types of incentives, are also associated with higher HEV price premiums. This finding suggests that HEV manufacturers and/or dealers are absorbing a significant monetary benefit from one-off subsidies, raising a question regarding the appropriateness of HEV subsidies, particularly in non-HEV manufacturing nations. We also find that higher fuel prices are associated with higher HEV demand and price premiums.

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A Brief Analysis of the Current Situation and Development Trend on Green Transportation Standard System

Scipedia content — Mon, 22 Mar 2021 22:06:16 +0100

It is great significance to improve green transportation standards system for promoting the construction of ecological civilization and the sustainable development of recycling and low carbon of transportation. This paper summarizes the status of green transportation standards system and the progress of standard publication and revision. According to the key areas and links of green transportation development, the development trends of green transportation and the requirement of green transportation standards were analysed, and policy recommendations for improving the construction of green transportation standards system was proposed. The paper is trying to provide decisive support for the industry to promote the development of green transportation standardization.

Document type: Article

Road transport infrastructure: a longitudinal case study (2009-2017)

Scipedia content — Mon, 22 Mar 2021 22:02:23 +0100

This article investigates the economic gains with the reduction of logistic costs after the asphalt pavement of the highway MT 235 for a Brazilian crystal sugar and alcohol industry. Investment in infrastructure is an attribute that increases economic growth and increases the competitiveness of companies. As far as road transport infrastructure is concerned, the problems are not limited to a specific area, but stretches of highways, which link urban transportation and ports to the generation and transmission of electricity, among others. Only 12.2% of Brazilian highways are paved. This work is the result of a longitudinal case study with participant observation, in a time line from 2009 to 2017. It was possible to identify that, after improvements in road transport infrastructure, the asphalt pavement of the highway MT 235 made possible a gain in travel time and a decrease in logistics costs, which led to the closure of the activities of one of the subsidiaries of the company studied, located in Manaus (Amazonas), in 2009. With the benefits of the asphalt pavement of the MT 235, in 2017 we found that sales volume increased 650% in relation to 2011, logistics costs have been significantly reduced in relation to gross revenues, maintaining an average of 11.58%. In 2017, the logistic costs of the company studied were 12.61% versus 20.7% from the group of Brazilian agribusiness companies. The findings show that investments in road transport infrastructure are crucial when it comes to fostering trade and competitiveness of domestic products in international markets, by reducing logistics costs.

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Effects of Highway Landscapes on Drivers’ Eye Movement Behavior and Emergency Reaction Time: A Driving Simulator Study

Scipedia content — Mon, 22 Mar 2021 21:48:31 +0100

This study aims at investigating the effects of highway landscapes and alignments on drivers’ eye movement behavior and emergency reaction time, based on a driving simulator experiment. In this study, four simulation scenarios are evaluated including open space, semiopen space, semiclosed space, and enclosed space landscapes on highways in Yunnan Province, China. Twenty-four experienced drivers participated in a 6-kilometer driving experiment in each landscape scenario. Each subject was required to drive at 80 km/h in the scenarios and the driving behavior data were collected. Three different data analysis methods were employed: (1) descriptive analysis of the characteristics of drivers’ visual fixation area; (2) statistical tests of emergency reaction time with drivers’ demographic characteristics, highway landscapes, and alignments; and (3) multiple linear regression analysis of emergency reaction time, highway landscapes, and alignments. The results show that emergency reaction time is significantly influenced by highway landscapes and alignments, and the multiple linear regression model built in this experiment could accurately predict drivers’ emergency reaction time in different highway landscapes and alignments.

Document type: Article

Modeling Spatio-Temporal Evolution of Urban Crowd Flows

Scipedia content — Mon, 22 Mar 2021 21:45:07 +0100

Metropolitan cities are facing many socio-economic problems (e.g., frequent traffic congestion, unexpected emergency events, and even human-made disasters) related to urban crowd flows, which can be described in terms of the gathering process of a flock of moving objects (e.g., vehicles, pedestrians) towards specific destinations during a given time period via different travel routes. Understanding the spatio-temporal characteristics of urban crowd flows is therefore of critical importance to traffic management and public safety, yet it is very challenging as it is affected by many complex factors, including spatial dependencies, temporal dependencies, and environmental conditions. In this research, we propose a novel matrix-computation-based method for modeling the morphological evolutionary patterns of urban crowd flows. The proposed methodology consists of four connected steps: (1) defining urban crowd levels, (2) deriving urban crowd regions, (3) quantifying their morphological changes, and (4) delineating the morphological evolution patterns. The proposed methodology integrates urban crowd visualization, identification, and correlation into a unified and efficient analytical framework. We validated the proposed methodology under both synthetic and real-world data scenarios using taxi mobility data in Wuhan, China as an example. Results confirm that the proposed methodology can enable city planners, municipal managers, and other stakeholders to identify and understand the gathering process of urban crowd flows in an informative and intuitive manner. Limitations and further directions with regard to data representativeness, data sparseness, pattern sensitivity, and spatial constraint are also discussed.

Document type: Article

Operational Aspects of Electric Vehicles from Car-Sharing Systems

Scipedia content — Mon, 22 Mar 2021 21:40:28 +0100

The article was dedicated to the topic of energy consumption of driving cars equipped with an electric motor. Due to the emerging demands for the excessive use of energy by vehicles (including car-sharing system vehicles), the authors carried out research to determine factors that affect the energy consumption. Due to the occurrence of a research gap related to the lack of reliable scientific information regarding real electricity consumption by vehicles used in car-sharing systems, the authors attempted to determine these values based on the proposed research experiment. The purpose of the research was to identify factors that increase energy consumption while driving in the case of car-sharing systems and developing recommendations for users of car-sharing systems and system operators in relation to energy consumption. Based on data received from car-sharing system operators and to their demands that users move cars uneconomically and use too much energy, the authors performed a scientific experiment based on Hartley&rsquo

s plan. The authors made journeys with electric cars from car-sharing (measurements) in order to compare real consumption with data obtained from operators. As a result, the authors developed a list of factors that negatively affect the energy consumption of electric vehicles from car-sharing systems. As conclusion, a number of recommendations were developed for car-sharing system operators on how to manage their systems to reduce excessive energy consumption in electric vehicles.

Document type: Article

Meshfree Model for Wave-Seabed Interactions Around Offshore Pipelines

Scipedia content — Mon, 22 Mar 2021 21:36:09 +0100

The evaluation of the wave-induced seabed instability around a submarine pipeline is particularly important for coastal engineers involved in the design of pipelines protection. Unlike previous studies, a meshfree model is developed to investigate the wave-induced soil response in the vicinity of a submarine pipeline. In the present model, Reynolds-Averaged Navier-Stokes (RANS) equations are employed to simulate the wave loading, while Biot&rsquo

s consolidation equations are adopted to investigate the wave-induced soil response. Momentary liquefaction around an offshore pipeline in a trench is examined. Validation of the present seabed model was conducted by comparing with the analytical solution, experimental data, and numerical models available in the literature, which demonstrates the capacity of the present model. Based on the newly proposed model, a parametric study is carried out to investigate the influence of soil properties and wave characteristics for the soil response around the pipeline. The numerical results conclude that the liquefaction depth at the bottom of the pipeline increases with increasing water period (T) and wave height (H), but decreases as backfilled depth ( H b ), degree of saturation ( S r ) and soil permeability (K) increase.

Document type: Article

Minimization Problems in Signalized Road Networks

Scipedia content — Mon, 22 Mar 2021 21:31:45 +0100

In this study, we present a bilevel programming model in which upper level is defined as a biobjective problem and the lower level is considered as a stochastic user equilibrium assignment problem. It is clear that the biobjective problem has two objectives: the first maximizes the reserve capacity whereas the second minimizes performance index of a road network. We use a weighted-sum method to determine the Pareto optimal solutions of the biobjective problem by applying normalization approach for making the objective functions dimensionless. Following, a differential evolution based heuristic solution algorithm is introduced to overcome the problem presented by use of biobjective bilevel programming model. The first numerical test is conducted on two-junction network in order to represent the effect of the weighting on the solution of combined reserve capacity maximization and delay minimization problem. Allsop & Charlesworth's network, which is a widely preferred road network in the literature, is selected for the second numerical application in order to present the applicability of the proposed model on a medium-sized signalized road network. Results support authorities who should usually make a choice between two conflicting issues, namely, reserve capacity maximization and delay minimization. C1 [Baskan, Ozgur; Ceylan, Huseyin] Pamukkale Univ, Dept Civil Engn, Fac Engn, TR-20160 Denizli, Turkey. [Ozan, Cenk] Adnan Menderes Univ, Dept Civil Engn, Fac Engn, TR-09100 Aydin, Turkey.

Document type: Article

Population-based simulation optimization for urban mass rapid transit networks

Scipedia content — Mon, 22 Mar 2021 21:28:22 +0100

In this paper, we present a simulation-based headway optimization for urban mass rapid transit networks. The underlying discrete event simulation model contains several stochastic elements, including time-dependent demand and turning maneuver times as well as direction-dependent vehicle travel and passenger transfer times. Passenger creation is a Poisson process that uses hourly origin–destination-matrices based on anonymous mobile phone and infrared count data. The numbers of passengers on platforms and within vehicles are subject to capacity restrictions. As a microscopic element, passenger distribution along platforms and within vehicles is considered. The bi-objective problem, involving cost reduction and service level improvement, is transformed into a single-objective optimization problem by normalization and scalarization. Population-based evolutionary algorithms and different solution encoding variants are applied. Computational experience is gained from test instances based on real-world data (i.e., the Viennese subway network). A covariance matrix adaptation evolution strategy performs best in most cases, and a newly developed encoding helps accelerate the optimization process by producing better short-term results.

Document type: Article

Containerisation in the Baltic Sea region: development, characteristics and contemporary organisation

Scipedia content — Mon, 22 Mar 2021 21:27:20 +0100

The main focus of the paper is on the container system development in the Baltic Sea Region studying cotemporary changes and organisation, as well as explaining the main driving forces of this situation.
The Baltic Sea is a transport corridor between Eastern and Western Europe. Over the last decade maritime transport in the Baltic Sea area has changed significantly. The disintegration of the Soviet Union forced Russia to start developing its own Baltic ports and terminals and to find new routes to export its oil and gas. The Baltic ports have welcomed a remarkable growth, especially in oil transportation and containerised flows.
The geographical configuration of the region naturally places it away from major global shipping lines. This situation is accentuated by the organisation of maritime regular lines, centred in Northern European ports. For this reason, the regional container network is mainly made up of feeder services.

Document type: Article

Heterogeneity of logistics facilities: an issue for a better understanding and planning of the location of logistics facilities

Scipedia content — Mon, 22 Mar 2021 21:24:19 +0100

International audience; In the last few years, the issue of the location of logistics activities emerged in the literature, in Europe and in the United States, especially from the perspective of logistics spatial dynamics as logistics sprawl. These issues of spatial dynamics question urban policies, because they underline the lack of interest in freight in the planning process. Indeed, one of the major issues in planning logistics facilities is the lack of a good understanding of the logistics sector: it is difficult to guide public action in the absence of detailed and precise data. The great heterogeneity of logistics facilities is often underestimated by public policies. The visibility of some sectors in public policies or academic literature, as parcel industry or e-commerce, hides other sides of logistics as an industry sector. With this paper we underline differences in the location of facilities, which translates into a difficult implementation of public policies to regulate logistics sprawl in the case of the Paris region. This paper studies precisely the location of the warehouses and terminals, and their place in the spatial organization of logistics facilities in the Paris Region. In particular, we compare the location of mass retail and wholesale trade facilities, logistics provider's facilities and parcel's industry facilities.

Document type: Article

INTEGRATING NETWORK CONCEPT INTO MULTI CRITERIA ANALYSIS FOR SUGGESTING BUS RAPID TRANSIT ROUTES

Scipedia content — Mon, 22 Mar 2021 21:22:49 +0100

Abstract. Population explosion in the city of Johor Bahru has led to traffic congestions, which hitherto to that there were better movements and flow of vehicles in and around the city. Road transportation in particular has played a gargantuan role in creating and maintaining easy and quick access to various destinations. Increases in the number of vehicle indicate a higher economic prosperity that contributes to traffic congestion within the city. This can be seen in a number of developments such as increased population density and creation of alternative routes over several years, which has still not totally eradicated the traffic congestion problems of the city. Ideally, a good public transport service would carry the passenger directly from their origin to their destination without having to face traffic congestion. The buses may not be available and accessible from certain origins or destinations of residents or they may need to walk some distances from their residents to the bus stops resulting into discouragement for most of the people using public transport services. This paper aims to utilise geospatial analysis approach to suggest effective bus routing that would be able to increase connectivity to rural areas and boost commercial activities through better transportation. Route selection is the process of finding locations that meet the selection criteria for each parameter using Geographic Information System (GIS). The process employs applied multi-criteria decision analysis and network analysis to generate thpsye highest score areas for bus rapid transit (BRT) route by maximising network and mobility and ensuring the newly suggested routes are connected to the existing networks of BRT to serve the community.

Document type: Article

Electric Trolley Trucks—A Techno-Economic Assessment for Germany

Scipedia content — Mon, 22 Mar 2021 21:13:02 +0100

Road freight transport is responsible for about one-third of road transport emissions and it is still growing. One solution to decarbonize this sector are electric trolley trucks powered by overhead lines. We compare electric trolley trucks to conventional diesel vehicles from a techno-economic perspective in Germany up to 2030. We find that an infrastructure set-up ordered by utilization of roads can be financed up to 2700 km with higher savings than cost. The impact on the energy system is lower than expected and the largest impacts are found in rural areas with highway intersections. Further fields of research are discussed.

Document type: Article

Filling OpenStreetMap data gaps in rural Nepal: a digital youth internship and leadership Programme

Scipedia content — Mon, 22 Mar 2021 21:12:01 +0100

"jats:p"Crowdsourced, open geospatial data such as the data compiled through OpenStreetMap have proven useful in addressing humanitarian, disaster and development needs. However, the existing ways in which volunteers engage in OpenStreetMap have inherent limitations that lead to critical data gaps in economically underdeveloped countries and regions. Various initiatives that target specific geospatial data gaps and engage volunteers for longer periods have emerged to overcome these limitations, yet there has been limited in-depth study of such targeted mapping initiatives. This article reports the findings from Digital Internship and Leadership (DIAL), a programme designed to fill data gaps in rural Nepal by engaging young people in mapping rural Nepal by integrating targeted mapping, a virtual internship strategy and youth leadership development. The findings suggest the potential benefits of targeted mapping initiatives embedded in youth leadership internship programmes to address those critical data gaps.

Document type: Article

Including negative externalities during transport infrastructure construction in assessment of investment projects

Scipedia content — Mon, 22 Mar 2021 21:11:02 +0100

The paper presents a method for optimizing the financing option for transport infrastructure project. The execution time for large project is substantial and the social costs generated during the construction phase are insufficient included in the assessment models. These are the main reasons for starting the research to extend the project evaluation methods with procedures that consider also social costs during the implementation of the project, besides the social costs after work completion. The proposed method aims to enhance the solution given by the current applied methods for investment assessment. Starting from the results of the present procedures of transport investment assessment, two approaches are presented. The first one assumes that the work starts at the reference year and different construction schemes can be applied. The optimal time of project implementation is determined considering the social costs during construction and after project implementation. In the second approach, the purpose is to determine the moments of the starting and the completion of the works for minimum of the losses caused by the social costs before and during the project implementation. The paper emphasizes that social cost during transport infrastructure work must be considered in investment timing. In this regard, supplementary procedures can be added to the current method used for ranking of the transport infrastructure investments. For an investment measure identified as opportune, the proposed method aim to minimize the total social cost.

Document type: Article

Centralized simulated annealing for alleviating vehicular congestion in smart cities

Scipedia content — Mon, 22 Mar 2021 21:09:05 +0100

Vehicular traffic congestion is a serious problem arising in many cities around the world, due to the increasing number of vehicles utilizing roads of a limited capacity. Often the congestion has a considerable influence on the travel time, travel distance, fuel consumption and air pollution. This paper proposes a novel dynamic centralized simulated annealing based approach for finding optimal vehicle routes using a VIKOR type of cost function. Five attributes: the average travel speed of the traffic, vehicles density, roads width, road traffic signals and the roads' length are utilized by the proposed approach to find the optimal paths. The average travel speed and vehicles density values can be obtained from the sensors deployed in smart cities and communicated to vehicles and roadside communication units via vehicular ad hoc networks. The performance of the proposed algorithm is compared with four other algorithms, over two test scenarios: Birmingham and Turin city centres. These show the proposed method improves traffic efficiency in the presence of congestion by an overall average of 24.05%, 48.88% and 36.89% in terms of travel time, fuel consumption and CO2 emission, respectively, for a test scenario from Birmingham city in the UK. Additionally, similar performance patterns are achieved for the a test with data from Turin, Italy.

Document type: Article

A Hybrid Method for Predicting Traffic Congestion during Peak Hours in the Subway System of Shenzhen

Scipedia content — Mon, 22 Mar 2021 21:03:58 +0100

Traffic congestion, especially during peak hours, has become a challenge for transportation systems in many metropolitan areas, and such congestion causes delays and negative effects for passengers. Many studies have examined the prediction of congestion

however, these studies focus mainly on road traffic, and subway transit, which is the main form of transportation in densely populated cities, such as Tokyo, Paris, and Beijing and Shenzhen in China, has seldom been examined. This study takes Shenzhen as a case study for predicting congestion in a subway system during peak hours and proposes a hybrid method that combines a static traffic assignment model with an agent-based dynamic traffic simulation model to estimate recurrent congestion in this subway system. The homes and work places of the residents in this city are collected and taken to represent the traffic demand for the subway system of Shenzhen. An origin-destination (OD) matrix derived from the data is used as an input in this method of predicting traffic, and the traffic congestion is presented in simulations. To evaluate the predictions, data on the congestion condition of subway segments that are released daily by the Shenzhen metro operation microblog are used as a reference, and a comparative analysis indicates the appropriateness of the proposed method. This study could be taken as an example for similar studies that model subway traffic in other cities.

Document type: Article

Aplicación del modelo SERVQUAL para evaluar la calidad del servicio de transporte público en Morelia, Mexico

Scipedia content — Mon, 22 Mar 2021 20:58:57 +0100

Purpose: The objective of this paper is to evaluate the quality of the public transportation system service in the city of Morelia, Mexico. Methodology: According to the needs of the study, the expectation-perception SERVQUAL model was adapted, which consists of 5 variables: Tangibility, Reliability, Responsiveness, Security and Empathy, and 25 items. The subjects of the study were users over 15 years old who regularly use the system. Users answered the expectations questionnaire the before getting on the transport vehicle and for the perceptions questionnaire, users answered it after getting off the vehicles. For each questionnaire, the sample was 392, a total of 784 people participated in the study, and their answers where measured using a five-point Likert-type scale. Results: The mean comparison shows that respondents have a high expectation level, with 4 points or above, whereas their perception level is 3, with gaps between 0.5 and 1 points. Resumen Propósito: El objetivo de este trabajo es evaluar la calidad en el servicio del sistema de transporte público en la ciudad de Morelia, México. Metodología: Se adaptó el modelo SERVQUAL que evalúa las percepciones y expectativas de los usuarios de un servicio mediante una escala de 5 puntos tipo Likert, consta de 5 variables: Tangibilidad, Fiabilidad, Capacidad de Respuesta, Seguridad y Empatía, consta de 25 ítems. El sujeto de estudio fueron usuarios mayores de 15 años que utilizan el servicio. Para medir las expectativas, los usuarios fueron cuestionados antes de utilizar el servicio, para las percepciones, fueron cuestionados después de utilizarlo. La muestra fue de 392 casos, con un total de 784 participantes. Resultados: La comparación de medias muestra que los individuos tienen expectativas muy altas, con 4 o más puntos, contrario a las percepciones que presentan resultados de 3 puntos, además de brechas entre 0.5 y 1 puntos.

Document type: Article

Assessment of the Applicability of Failure Frequency Models for Dense Phase Carbon Dioxide Pipelines

Scipedia content — Mon, 22 Mar 2021 20:56:20 +0100

In Carbon Capture, Usage and Storage (CCUS) schemes, Carbon Dioxide (CO2) is captured from large scale industrial emitters and transported to geological sites for storage. The most efficient method for the transportation of CO2 is via pipeline in the dense phase. CO2 is a hazardous substance which, in the unlikely event of an accidental release, could cause people harm. To correspond with United Kingdom (UK) safety legislation, the design and construction of proposed CO2 pipelines requires compliance with recognised pipeline codes. The UK code PD-8010-1 defines the separation distance between a hazardous pipeline and a nearby population as the minimum distance to occupied buildings using a substance factor. The value of the substance factor should be supported by the results of a Quantitative Risk Assessment (QRA) approach to ensure the safe design, construction and operation of a dense phase CO2 pipeline. Failure frequency models are a major part of this QRA approach and the focus of this paper is a review of existing oil and gas pipeline third-party external interference failure frequency models to assess whether they could be applied to dense phase CO2 pipelines. It was found that the high design pressure requirement for a dense phase CO2 pipeline typically necessitates the use of high wall thickness linepipe in pipeline construction; and that the wall thickness of typical dense phase CO2 pipelines is beyond the known range of applicability for the pipeline failure equations used within existing failure frequency models. Furthermore, even though third party external interference failure frequency is not sensitive to the product that a pipeline transports, there is however a limitation to the application of existing UK fault databases with to onshore CO2 pipelines as there are currently no dense phase CO2 pipelines operating in the UK. Further work needs to be conducted to confirm the most appropriate approach for calculating failure frequency for dense phase CO2 pipelines, and it is recommended that a new failure frequency model suitable for dense phase CO2 pipelines is developed that can be readily updated to the latest version of the fault database.

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Understanding the Thermal Runaway of Ni-Rich Lithium-Ion Batteries

Scipedia content — Mon, 22 Mar 2021 20:53:37 +0100

The main safety issue pertaining to operating lithium-ion batteries (LIBs) relates to their sensitivity to thermal runaway. This complex multiphysics phenomenon was observed in two commercial 18650 Ni-rich LIBs, namely a Panasonic NCR GA and a LG HG2, which were based on L i ( N i 0.8 C o 0.15 A l 0.05 ) O 2 (NCA) and L i ( N i 0.8 M n 0.1 C o 0.1 ) O 2 (NMC811), respectively, for positive electrodes, in combination with graphite-SiOx composite negative electrodes. At pristine state, the batteries were charged to different levels of state of charge (SOC) (100% and 50%) and were investigated through thermal abuse tests in quasi-adiabatic conditions of accelerating rate calorimetry (ARC). The results confirmed the proposed complete thermal runaway of exothermic chain reactions. The different factors impacting the thermal runaway kinetics were also studied by considering the intertwined impacts of SOC and the related properties of these highly reactive Ni-rich technologies. All tested cells started their accelerated thermal runaway stage at the same self-heating temperature rate of ~48 °

C/min. Regardless of technology, cells at reduced SOC are less reactive. Regardless of SOC levels, the Panasonic NCR GA battery technology had a wider safe region than that of the LG HG2 battery. This technology also delayed the hard internal short circuit and shifted the final venting to a higher temperature. However, above this critical temperature, it exhibited the most severe irreversible self-heating stage, with the highest self-heating temperature rate over the longest duration.

Document type: Article

Fuzzy Model for Quantitative Assessment of Environmental Start-up Projects in Air Transport

Scipedia content — Mon, 22 Mar 2021 20:45:39 +0100

The purpose of this paper is to develop an applied fuzzy model of information technology to obtain quantitative estimates of environmental start-up projects in air transport. The developed model will become a useful tool for venture funds, business angels, or crowdfunding platforms for the development of innovative air transport businesses. Obtaining a quantitative estimate of the environmental start-up projects will increase the sustainability of the decision making on the security of financing of such projects by investors. This article develops a fuzzy evaluation model of project start-ups in air transport as an application of our neuro-fuzzy model in a specific air transport environment. The applied model provides output ranking of start-up project teams in air transport based on a four-layer neuro-fuzzy network. The presented model declares the possibilities of the application to solve these economic problems and offers the space for subsequent research focused on its usability in several areas of start-up development, in sectors and processes differentiated. The benefits are also visible for several types of policies, with an emphasis on decision-making processes in regulatory mechanisms to support the state funding in Slovakia, the EU etc.

Document type: Article

Identifying Road Traffic Accidents Hotspots Areas Using GIS in Ethiopia: A Case Study of Hosanna Town

Scipedia content — Mon, 22 Mar 2021 20:41:23 +0100

"jats:p"Due to increasing human population and the number of vehicles, road traffic accident has significant influence on human life and economic development. In the present study, road traffic accident data of three years (2015-2017) were obtained from Hosanna Town Traffic Police Department, and Hosanna Town Transport Authority in Ethiopia. The Global Position System was used to know X, Y coordinates of the accident locations. Global Position System point data and accident data were added to road network data using the ‘Joins and relates’ function in ArcGIS. The results of the study showed a total of 241 Road traffic accidents (RTAs) were occurred in the town from which about 208 victims occurred on people and 33 damaged properties. Based on severity and frequencies of RTAs top nine hot spot areas were identified which requires high attention to protect people and property from damage and loss. Thus, the government and other concerned stakeholders should provide public education and awareness creation to reduce risk of fatalities and property damage due to RTAs in Hosanna town.

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34th Annual Meeting & Pre-Conference Programs of the Society for Immunotherapy of Cancer (SITC 2019): part 2

Scipedia content — Mon, 22 Mar 2021 20:38:00 +0100

Document type: Article

How to Mitigate Traffic Congestion Based on Improved Ant Colony Algorithm: A Case Study of a Congested Old Area of a Metropolis

Scipedia content — Mon, 22 Mar 2021 20:32:23 +0100

Old areas of metropolises play a crucial role in their development. The main factors restricting further progress are primitive road transportation planning, limited space, and dense population, among others. Mass transit systems and public transportation policies are thus being adopted to make an old area livable, achieve sustainable development, and solve transportation problems. Identifying old areas of metropolises as a research object, this paper puts forth an improved ant colony algorithm and combines it with virtual reality. This paper predicts traffic flow in Yangpu area on the basis of data obtained through Python, a programming language. On comparing the simulation outputs with reality, the results show that the improved model has a better simulation effect, and can take advantage of the allocation of traffic resources, enabling the transport system to achieve comprehensive optimization of time, cost, and accident rates. Subsequently, this paper conducted a robustness test, the results of which show that virtual traffic simulation based on the improved ant colony algorithm can effectively simulate real traffic flow, use vehicle road and signal resources, and alleviate overall traffic congestion. This paper offers suggestions to alleviate traffic congestion in old parts of metropolises.

Document type: Article

Mitigating Air Delay: An analysis of the Collaborative Trajectory Options Program

Scipedia content — Mon, 22 Mar 2021 20:21:43 +0100

Congestion is a problem at major airports in the world. Airports, especially high-traffic ones, tend to be the bottleneck in the air traffic control system. The problem that arises for the airspace planner is how to mitigate air congestion and its consequent delay, which causes increased cost for airlines and discomfort for passengers. Most congestion problems are fixed on the day of operations in a tactically manner using operational enhancements measures. Collaborative Trajectory Options Program (CTOP) aims to improve air traffic management (ATM) considering National Airspace System (NAS) users business goals, particularities faced by each flight and airspace restrictions, making this process more flexible and financially stable for those involved. In CTOP, airlines share their route preferences with the air control authority, combining delay and reroute. When CTOP is created, each airline might decide its strategy without knowledge of other airline’s flights. Current solutions for this problem are based on greedy methods and game theory. There is potential space to improve. This paper examines CTOP and identifies important strategic changes to ATM adopting this philosophy, particularly in Brazil.

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Conceptualization of CO"sub"2"/sub" Terminal for Offshore CCS Using System Engineering Process

Scipedia content — Mon, 22 Mar 2021 20:20:57 +0100

In this study, the basic configuration and operation concept of a CO"sub"2"/sub" terminal were identified by conducting a system engineering process. The performance goal of a CO"sub"2"/sub" terminal was determined by requirement analysis. Then, functions and timelines were derived by functional analysis to meet the performance goal. Equipment to perform the functions were defined and finally, a process flow block diagram of the CO"sub"2"/sub" terminal was acquired. The CO"sub"2"/sub" terminal in this study consisted of three parts. First, the CO"sub"2"/sub" loading/unloading part is responsible for liquid CO"sub"2"/sub" unloading from the carrier and loading vapor CO"sub"2"/sub" onto the carrier. Secondly, the liquid CO"sub"2"/sub" transmission part extracts liquid CO"sub"2"/sub" from the storage tanks and increases the pressure until it satisfies the offshore pipeline transportation condition. The vapor-treatment part collects boil-off gas, generates vapor CO"sub"2"/sub", and charges the storage tanks with vapor CO"sub"2"/sub" to control the pressure of the storage tanks that discharge liquid CO"sub"2"/sub". Finally, the study results were compared with a liquefied natural gas (LNG) terminal. The biggest difference between the CO"sub"2"/sub" terminal in this study and the LNG terminal is that a vaporizer is essential in the CO"sub"2"/sub" terminal due to the smaller storage capacity of the CO"sub"2"/sub" terminal and, therefore, the lower amount of boil-off gas.

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Machine Learning and Embedded Computing in Advanced Driver Assistance Systems (ADAS)

Scipedia content — Mon, 22 Mar 2021 20:14:26 +0100

Advanced driver assistance systems (ADAS) are rapidly being developed for autonomous vehicles [...]

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Internet of Energy Training through Remote Laboratory Demonstrator

Scipedia content — Mon, 22 Mar 2021 20:13:43 +0100

In this paper, a new learning tool is proposed to train professional figures, such as entrepreneurs, engineers, and technicians, who need to improve their skills in the field of Internet of Energy. The proposed tool aims to cover the lack of experimental knowledge on new energy systems and to layer proper skills, which are useful to deal with challenges required by smart energy management in the new complex distributed configuration of the electric power systems, characterized by demand response services. This tool is based on a small-scale laboratory demonstrator, representative of a smart rural house, equipped with a measurement and control system. This demonstrator can be remotely accessed, through web server applications based on a low cost single-board computer. Trainers can have direct experience on the main concepts related to smart grids, renewable energy sources, electrochemical storage systems, and electric vehicles, through the use of the proposed tool managed by the web software interface.

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Electrical Steels and Their Evaluation for Automobile Motors

Scipedia content — Mon, 22 Mar 2021 20:09:29 +0100

Achieving high efficiency and high torque is an important target in EV motors. This paper describes the effect of the magnetic properties of electrical steels used as core materials for synchronous motors with permanent magnets, which are commonly used as the EV traction motors. It was confirmed that electrical steels, which have high flux density and low iron loss properties can realize high motor efficiency and torque. When PWM excitation is considered, thinner electrical steels are advantageous to suppress increased loss due to higher harmonics. Based on these results, electrical steels having high flux densities and low iron losses at high frequencies were developed.

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EV Idle Time Estimation on Charging Infrastructure, Comparing Supervised Machine Learning Regressions

Scipedia content — Mon, 22 Mar 2021 19:59:52 +0100

The adoption of electric vehicles (EV) has to be complemented with the right charging infrastructure roll-out. This infrastructure is already in place in many cities throughout the main markets of China, EU and USA. Public policies are both taken at regional and/or at a city level targeting both EV adoption, but also charging infrastructure management. A growing trend is the increasing idle time over the years (time an EV is connected without charging), which directly impacts on the sizing of the infrastructure, hence its cost or availability. Such a phenomenon can be regarded as an opportunity but may very well undermine the same initiatives being taken to promote adoption

in any case it must be measured, studied, and managed. The time an EV takes to charge depends on its initial/final state of charge (SOC) and the power being supplied to it. The problem however is to estimate the time the EV remains parked after charging (idle time), as it depends on many factors which simple statistical analysis cannot tackle. In this study we apply supervised machine learning to a dataset from the Netherlands and analyze three regression algorithms, Random Forest, Gradient Boosting and XGBoost, identifying the most accurate one and main influencing parameters. The model can provide useful information for EV users, policy maker and network owners to better manage the network, targeting specific variables. The best performing model is XGBoost with an R2 score of 60.32% and mean absolute error of 1.11. The parameters influencing the model the most are: The time of day in which the charging sessions start and the total energy supplied with 22.35%, 15.57% contribution respectively. Partial dependencies of variables and model performances are presented and implications on public policies discussed.

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Optimal Signal Control Algorithm for Signalized Intersections under a V2I Communication Environment

Scipedia content — Mon, 22 Mar 2021 19:57:53 +0100

This study aims to develop an optimal signal control algorithm for signalized intersections using individual vehicle’s trajectory data under the vehicle-to-infrastructure (V2I) communication environment. The optimal signal control algorithm developed in this study consists of three modules, namely, a phase group length computation module, a split distribution module, and a phase sequence assignment module. A set of analyses using a microscopic simulation model, VISSIM, was conducted for evaluating the effectiveness of the V2I-based optimal signal control algorithm proposed in this study. The analysis results show that the performance of the V2I-based optimal signal control algorithm is superior to the actuated as well as the fixed signal control methods in an isolated intersection and a 2X3 signalized intersection network. In addition, this study investigated the minimum market penetration rate of V2I equipped vehicles for which the V2I-based optimal signal control algorithm is applicable.

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Humans Use Predictive Gaze Strategies to Target Waypoints for Steering

Scipedia content — Mon, 22 Mar 2021 19:57:15 +0100

major unresolved question in understanding visually guided locomotion in humans is whether actions are driven solely by the immediately available optical information (model-free online control mechanisms), or whether internal models have a role in anticipating the future path. We designed two experiments to investigate this issue, measuring spontaneous gaze behaviour while steering, and predictive gaze behaviour when future path information was withheld. In Experiment 1 participants (N = 15) steered along a winding path with rich optic flow: gaze patterns were consistent with tracking waypoints on the future path 1–3 s ahead. In Experiment 2, participants (N = 12) followed a path presented only in the form of visual waypoints located on an otherwise featureless ground plane. New waypoints appeared periodically every 0.75 s and predictably 2 s ahead, except in 25% of the cases the waypoint at the expected location was not displayed. In these cases, there were always other visible waypoints for the participant to fixate, yet participants continued to make saccades to the empty, but predictable, waypoint locations (in line with internal models of the future path guiding gaze fixations). This would not be expected based upon existing model-free online steering control models, and strongly points to a need for models of steering control to include mechanisms for predictive gaze control that support anticipatory path following behaviours. Peer reviewed

Document type: Article

Pedestrian perception-based level-of-service model at signalized intersection crosswalks

Scipedia content — Mon, 22 Mar 2021 19:54:17 +0100

"jats:p"Pedestrian level of service (PLOS) is an important measure of performance in the analysis of existing pedestrian crosswalk conditions. Many researchers have developed PLOS models based on pedestrian delay, turning vehicle effect, etc., using the conventional regression method. However, these factors may not effectively reflect the pedestrians’ perception of safety while crossing the crosswalk. The conventional regression method has failed to estimate accurate PLOS because of the primary assumption of an arbitrary probability distribution and vagueness in the input data. Moreover, PLOS categories in existing studies are based on rigid threshold values and the boundaries that are not well defined. Therefore, it is an important attempt to develop a PLOS model with respect to pedestrian safety, convenience, and efficiency at signalized intersections. For this purpose, a video-graphic and user perception surveys were conducted at selected nine signalized intersections in Mumbai, India. The data such as pedestrian, traffic, and geometric characteristics were extracted, and significant variables were identified using Pearson correlation analysis. A consistent and statistically calibrated PLOS model was developed using fuzzy linear regression analysis. PLOS was categorized into six levels ("jats:italic"A"/jats:italic"–"jats:italic"F"/jats:italic") based on the predicted user perception score, and threshold values for each level were estimated using the fuzzy "jats:italic"c"/jats:italic"-means clustering technique. The developed PLOS model and threshold values were validated with the field-observed data. Statistical performance tests were conducted and the results provided more accurate and reliable solutions. In conclusion, this study provides a feasible alternative to measure pedestrian perception-based level of service at signalized intersections. The developed PLOS model and threshold values would be useful for planning and designing pedestrian facilities and also in evaluating and improving the existing conditions of pedestrian facilities at signalized intersections.

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Economic Routing of Electric Vehicles using Dynamic Pricing in Consideration of System Voltage

Scipedia content — Mon, 22 Mar 2021 19:50:15 +0100

There is a growing market for electric vehicles (EVs) in recent years. Due to this, many studies on electric vehicles are in progress and research on charging operations for EVs are especially active. Recent research trends on electric vehicle routes rely on the stochastic modelling of various factors such as convenience of a user&rsquo

s point of view, charging station (CS), location, destination, and so on. In this paper, a charging control scheme for electric vehicles is proposed from the point of view of the system operators rather than the user. From a user&rsquo

s point of view, the EV route can be set up directly, but it is difficult for the system operator to directly participate in the route of the EV. In this paper, a method is proposed to indirectly change the route of the EV by changing the charging cost through real-time dynamic pricing, in order to prevent risks in the system operation due to voltage fluctuations in the system. With dynamic pricing, the voltage of the system is kept within a stable range, and the EV user sets the route with an economic benefit. The proposed scheme is verified through Dijkstra&rsquo

s algorithm and a control strategy via a simulation model using MATLAB.

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Growing Cities and Mass Participant Sport Events: Traveling Behaviors and Carbon Dioxide Emissions

Scipedia content — Mon, 22 Mar 2021 19:48:49 +0100

Fast-growing cities are expected to become a key contributor to the global climate crisis. A key characteristic of those urban districts is the accommodation of mass participant sport events. Sport entities, in collaboration with city governments, plan annually active participation sport events to promote their cities as tourism destinations. Mass participant sport events aim to attract more visitors to the cities and to establish a successful social and economically sustainable future to those places. Given the fact that transportation is a critical factor of the residents and the visitors&rsquo

behavior, it is crucial to research the quantity of CO2 emissions generated to those places in association with the travel behaviors of the active sport event participants. Data collected from an annual mass participant running event in a highly ranked growing city in the United States. Findings showed that most of the active sport event participants traveled more than 150 miles to participate in the race and they used their vehicles. The largest quantity of CO2 emissions derived from those participants who traveled a round trip of, on average, 500 miles. The long-distance travelers alone generated 338 million kg of CO2 emissions. The conclusions recommend that growing cities and sport events should target long-distance travelers for promotions concerning sustainable transportation. Consequently, mass participant sport events could play a crucial role in the development of growing cities, and, in turn, growing cities that control long-distance traveling behaviors can reduce the global amount of greenhouse gas emissions and their impact on the global environmental destruction.

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Analyzing Stakeholders' Perceptions of the Critical Risk Factors in Oil and Gas Pipeline Projects

Scipedia content — Mon, 22 Mar 2021 19:45:07 +0100

Currently, there are enormous Risk Factors (RFs) threating the safety of Oil and Gas Pipelines (OGPs) at all stages of projects. However, there is a lack of information about the root causes of pipeline failures and an absence of trusted data about the "probability and severity" levels of the RFs; this hinders the risk management in such projects. To improve the safety level of OGPs, this paper aims to explore stakeholders' perceptions about pipeline failures issues to analyze the RFs and recommend effective Risk Mitigation Methods (RMMs). Due to the lack of trusted data about the RFs and RMMs, this paper started with extensive investigations to identify the critical RFs and the applied RMMs in OGP projects in different circumstances. The findings of these investigations were used to design a questionnaire survey, which was distributed to analyze the "probability and severity" levels of the RFs and evaluate the "usability and effectiveness" degrees of the suggested RMMs. The survey results revealed that RFs related to Third-Party Disruption (TPD) including sabotage and terrorism, corruption and insecure areas are the most severe RFs. Additionally, based on the survey some RMMs such as anti-corrosion efforts, laying the pipelines underground and using technologically advanced risk-monitoring systems were found to be effective RMMs. These results were found to be varied based on the stakeholders' occupation in the projects; for example, the overall survey results indicated that terrorism and sabotage is the most critical RF, while the planners and the researchers identified corruption as the most critical one. It was also observed that using anti-corrosion measures such as isolation and cathodic protection would be the most effective RMM, while the other stakeholders have different perceptions like moving the pipelines underground an advanced risk-monitoring system are the most effective RMMs as indicated by the consultant, planner or designer and researches respectively.

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Role of Customized Bus Services in the Transportation System: Insight from Actual Performance

Scipedia content — Mon, 22 Mar 2021 19:42:55 +0100

After attaining great prevalence from the end of 2013, customized bus (CB) transit services have experienced a huge decline in China. The feasibility of this new bus sharing system is thus being questioned. Therefore, it is imperative to investigate the actual role of CB services in the overall transportation system based on successful cases, as the role of the CB service determines its primary service object, system construction, marketing orientation, and even government function. To examine the role of CB services, this study investigates the practical performance, advantages, and spatial and temporal coverage of a successful CB system based on practical subscription data for more than two years. The results illustrate that the CB service is an eclectic choice that can balance service quality and cost between traveling by traditional public transportation (PT) and private cars/taxis. Even though the travel cost increased to a limited extent, the CB service significantly improved the travel experience in terms of the travel time, travel speed, number of stations, and difference arrival time compared to PT services. The multinomial logit model and regression models demonstrate a significant positive relationship between the relative advantage and amount of demand for the CB services. Furthermore, the CB service primarily serves trips generated during the peak traffic hours of the city and supplements traditional PT service in areas with poor coverage levels.

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Design Criteria for Improving Safety Performance of Rural Intersections

Scipedia content — Mon, 22 Mar 2021 19:40:19 +0100

This paper, on the one hand, aims to identify significant crash risk factors at unsignalized three-leg intersections connecting rural two-lane two-way roads and minor roads with a STOP control on the approaches (3ST) and, on the other, to make adjustments to the Highway Safety Manual (HSM) procedure, fine-tuning its Safety Performance Function (SPF) based on observation of the local context. Over an 8-year period of study, a total of 240 crashes on 35 3ST intersections were observed, with no geometric-infrastructure adjustments or changes in the Annual Average Daily Traffic (AADT) and surrounding context noted at the intersections investigated. To obtain reliable results, the study period was divided into two groups: (a) 5 years to calibrate a new SPF, and (b) the remaining 3, not included in the first dataset, were used to validate the results. A negative binomial regression model was adopted to calibrate the new SPF. It was found that the AADT on the major and minor roads, the intersection skew angle, the co-occurrence of left and right-turn lanes on the major roads, and lighting seriously affect the crash scenario.

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Vehicle Scheduling Optimization considering the Passenger Waiting Cost

Scipedia content — Mon, 22 Mar 2021 19:35:52 +0100

In the operational planning process of public transport, the time a passenger spends on waiting is a very critical element for judging passenger service. Schedule synchronization is a useful strategy for reducing bus waiting time and improving service connectivity. This paper develops an extended vehicle scheduling model, taking into account the interests of passengers and operators in attaining optimization of timetable synchronization integrated with vehicle scheduling and considering the passenger waiting cost. Deficit functions at terminals are formulated. Deadheading (DH), shifting departure time (SDT), and network flow technique are used for vehicle scheduling with the consideration of passenger waiting times. An experimental study in Beijing is conducted and three important bus lines are selected as a regional bus network to demonstrate the methodology developed. Results show that both the fleet size of bus operators and the waiting cost of passengers are minimized. For example, the minimum fleet size can be reduced from 28 vehicles to 24 ones while the passenger times are less than 20 minutes in this multidepot network.

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Research on Safety Lane Change Warning Method Based on Potential Angle Collision Point

Scipedia content — Mon, 22 Mar 2021 19:34:55 +0100

In order to ensure safe lane change and avoid traffic accidents, an effective lane change assist system is required. In a lane change assist system, it is very important to obtain the following elements in time, such as actual distance between vehicles, minimum safety distance, and warning signal. To this end, this paper analyzed four kinds of lane change angle collision scenes. Initial position, initial velocity, acceleration, heading angle, and kinematics of vehicles were used to calculate the position of potential angle collision points between lane change vehicle and obstacle vehicles. Then, actual distance model was constructed based on potential angular collision points. The minimum safety distance model was also established under the two most unfavorable conditions. In order to achieve the lane change warning, three early warning rules were formulated. We verified the validity of models and early warning rules using vehicle driving video data of Interstate 80 in California. Models and early warning rules constructed in our research can be applied to the advanced active safety systems of vehicle, such as vehicle lane change assist system and active collision early warning system, which can improve the active safety and reduce traffic accidents.

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Single-Phase 13-Level Power Conditioning System for Peak Power Reduction of a High-Speed Railway Substation

Scipedia content — Mon, 22 Mar 2021 19:33:11 +0100

The control and operation of a single-phase 13-level power conditioning system (PCS) for peak power reduction of a high-speed railway substation (HSRS) are proposed. This PCS is a single-phase 3100 V, 2 MVA 13-level H-bridge multi-level inverter structure. It has excellent power quality. It is easy to serialize by voltage. In addition, the DC bus power of each cell inverter is supplied by lithium-ion batteries. The generalized reduction gradient optimization algorithm based on past load pattern is applied to the power management system for peak power reduction of HSRS. The phase detector and power controller for the control of a single-phase PCS based on virtually coordinated axes using an all-pass filter are expected to be robust to external disturbances with fast response characteristics. This study also proposes an adapted select switch (ASS) method that can change the switching depending on the operation state of PCS and the state of charge (SOC) of the battery to minimize battery imbalance by controlling each cell inverter of the H-bridge. The validity of the proposed system was confirmed by PSiM simulation and experiments using a demonstration system of 6 MW PCS and 2.68 MWh batteries at one of Gyeongbu high-speed line substations in Korea.

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Event management architecture for the monitoring and diagnosis of a fleet of trains: a case study

Scipedia content — Mon, 22 Mar 2021 19:31:40 +0100

In recent years, more and more manufacturers and operators of fleets of mobile systems have been focusing their efforts on studying and developing conditional maintenance, monitoring, and diagnostic strategies to cope with an increasingly competitive, unstable, costly, and unpredictable environment. This paper proposes a case study concerning the application of a novel event management architecture, called EMH2, to a fleet of trains. This EMH2 architecture, which applies the holonic paradigm, aims to facilitate the monitoring and diagnosis of a fleet of mobile systems. It is based on a recursive decomposition of cooperative monitoring holons. The definition of a generic event modeling, called SurfEvent, is the second key element of the contribution. EMH2 has been designed to be applicable to any kind of system or equipment up to fleet level. The edge computing paradigm has been adopted for implementation purpose. The EMH2 architecture is designed to facilitate asynchronous and progressive onboard and off-board deployments. A real-world application of EMH2 to a fleet of ten trains currently in use, in collaboration with our industrial partner, Bombardier Transport, is presented. Three key performances indicators have been estimated by comparing EMH2 with the current industrial situation. These indicators are (1) the number of fleet maintenance visits, (2) the time needed by a maintenance operator to investigate and diagnose, and (3) the time needed by the system to update data regarding the health status and monitoring of trains. Results obtained outperformed industrial expectations. The paper finally discusses feedbacks from experience and limitations of the work.

Document type: Article

Quantitative Correlation between Thermal Cycling and the Microstructures of X100 Pipeline Steel Laser-Welded Joints

Scipedia content — Mon, 22 Mar 2021 19:29:36 +0100

Due to the limitations of the energy density and penetration ability of arc welding technology for long-distance pipelines, the deterioration of the microstructures in the coarse-grained heat-affected zone (HAZ) in welded joints in large-diameter, thick-walled pipeline steel leads to insufficient strength and toughness in these joints, which strongly affect the service reliability and durability of oil and gas pipelines. Therefore, high-energy-beam welding is introduced for pipeline steel welding to reduce pipeline construction costs and improve the efficiency and safety of oil and gas transportation. In the present work, two pieces of X100 pipeline steel plates with thicknesses of 12.8 mm were welded by a high-power robot laser-welding platform. The quantitative correlation between thermal cycling and the microstructure of the welded joint was studied using numerical simulation of the welding temperature field, optical microscopy (OM), and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). The results show that the heat-source model of a Gaussian-distributed rotating body and the austenitization degree parameters are highly accurate in simulating the welding temperature field and characterizing the austenitization degree. The effects of austenitization are more significant than those of the cooling rate on the final microstructures of the laser-welded joint. The microstructure of the X100 pipeline steel in the HAZ is mainly composed of acicular ferrite (AF), granular bainite (GB), and bainitic ferrite (BF). However, small amounts of lath martensite (LM), upper bainite (UB), and the bulk microstructure are found in the columnar zone of the weld. The aim of this paper is to provide scientific guidance and a reference for the simulation of the temperature field during high-energy-beam laser welding and to study and formulate the laser-welding process for X100 pipeline steel.

Document type: Article

Electrical Vehicles: Current State of the Art, Future Challenges, and Perspectives

Scipedia content — Mon, 22 Mar 2021 19:27:48 +0100

The goal of the study presented in this article is to provide a general overview of the various aspects related to electric vehicles (EVs), along with all associated emerging challenges and perspectives. In this context, the basic types of EVs and the corresponding charging technologies are analyzed. Since EVs are expected to be a key component of future smart electrical grids (SEG), connection to the grid issues, along with advanced charging techniques (i.e., wireless power transfer), are analyzed as well. To this end, the main features, the requirements of vehicle to grid (V2G) communications, as well as future developments and scenarios of electrification, are also presented and analyzed. Moreover, integration issues with currently deployed fifth generation (5G) mobile wireless networks are also outlined, in order to ensure optimum transmission and reception quality in V2G communications and improved user experience. This integration is also expanded in autonomous vehicles (AVs) technology (self-driving objects), since optimized information processing from various diverse sources is required in order to ensure advanced traffic management aspects.

Document type: Article

Dynamic Duty-Cycle MAC Protocol for IoT Environments and Wireless Sensor Networks

Scipedia content — Mon, 22 Mar 2021 19:27:23 +0100

This paper proposes a new protocol that can be used to reduce transmission delay and energy consumption effectively. This will be done by adjusting the duty-cycle (DC) ratio of the receiver node and the contention window size of the sender node according to the traffic congestion for various devices in the Internet of Things (IoT). In the conventional duty-cycle MAC protocol, the data transmission delay latency and unnecessary energy consumption are caused by a high collision rate. This is because the receiver node cannot sufficiently process the data of the transmitting node during the traffic peak time when the transmission and reception have the same duty-cycle ratio. To solve this problem, this paper proposes an algorithm that changes the duty-cycle ratio of the receiver and broadcasts the contention window size of the senders through Early Acknowledgment (E-ACK) at peak time and off/peak time. The proposed algorithm, according to peak and off/peak time, can transmit data with fewer delays and minimizes energy consumption.

Document type: Article

Analytical Model for the Structural Behavior of Pipelines During Lowering-In

Scipedia content — Mon, 22 Mar 2021 19:25:46 +0100

Since pipelines experience the largest deformation during lowering-in, structural analysis for this construction sequence should be performed to ensure structural safety. In this study, a new analytical model named the &ldquo

segmental pipeline model&rdquo

was developed to predict the structural behavior of the pipeline. This analytical model consists of several segmental elements to represent various boundary and contact conditions. Therefore, the segmental pipeline model can consider the geometric configuration and characteristics of pipelines that appear during lowering-in. Adopting the Euler-Bernoulli beam and two-parameter beam on elastic foundation theory, the new model takes the effect of the soil and axial forces acting on the pipelines into account. This paper compares the displacements, sectional bending moments and shear forces of the pipeline obtained from the analytical model and finite element (FE) analysis, where good agreement was demonstrated. Also, the paper presents three examples to demonstrate the applicability of the analytical model.

Document type: Article

A Hybrid Simulated Annealing Heuristic for Multistage Heterogeneous Fleet Scheduling with Fleet Sizing Decisions

Scipedia content — Mon, 22 Mar 2021 19:23:20 +0100

This paper deals with multistage heterogeneous fleet scheduling with fleet sizing decisions (MHFS-FSD). This MHFS-FSD attempts to integrate vehicles allocation and fleet sizing decisions considering the vehicle routing of multiple vehicle types. The problem is formulated as mixed integer programming model. The matrix formulation denoting vehicle allocation scheme is explored according to the characteristic of this problem. Generating vehicle allocation scheme with greedy heuristic procedure (VA-GHP) as initial solution of problem is presented. The USP-IVA method to update the initial solution generated by VA-GHP approach is developed. And then, incorporating VA-GHP and USP-IVA into simulated annealing algorithm, a novel heuristic called HSAH-GHP&IVA is proposed. Finally, some experiments are designed to test the proposed heuristic and the results show that the heuristic can generate reasonably good solutions in short CPU times.

Document type: Article

Crash-Prone Section Identification for Mountainous Highways Considering Multi-Risk Factors Coupling Effect

Scipedia content — Mon, 22 Mar 2021 19:21:44 +0100

In order to identify crash-prone sections of the highways in mountainous areas professionally and exclusively, the common phenomena of “sharp turns”, “continuous long downhill”, “multiple tunnels”, “dangerous roadside environment”, and complex and changeable meteorological environment, which all imply risk factors of the mountainous highways, are comprehensively considered. Utilizing the improved classical coupling model, the coupling mechanism of the risk factors is revealed, and the coupling model of the traffic risk factors is constructed, by which the coupling degrees of multi-risk factors couplings are calculated respectively. Based on the coupling degrees of the above factors, the concept of vehicle operation risk index ("jats:italic"VORI"/jats:italic") of the mountainous highway is introduced and its numerical value is quantified as the basis for identifying the crash-prone sections. The 21 km of Songming to Huize section of the Songdai Highway in the Yunnan Province of China is selected as an example, and the good applicability of the identification model is verified.

Document type: Article

Developing Train Station Parking Algorithms: New Frameworks Based on Fuzzy Reinforcement Learning

Scipedia content — Mon, 22 Mar 2021 19:21:01 +0100

Train station parking (TSP) accuracy is important to enhance the efficiency of train operation and the safety of passengers for urban rail transit. However, TSP is always subject to a series of uncertain factors such as extreme weather and uncertain conditions of rail track resistances. To increase the parking accuracy, robustness, and self-learning ability, we propose new train station parking frameworks by using the reinforcement learning (RL) theory combined with the information of balises. Three algorithms were developed, involving a stochastic optimal selection algorithm (SOSA), a Q-learning algorithm (QLA), and a fuzzy function based Q-learning algorithm (FQLA) in order to reduce the parking error in urban rail transit. Meanwhile, five braking rates are adopted as the action vector of the three algorithms and some statistical indices are developed to evaluate parking errors. Simulation results based on real-world data show that the parking errors of the three algorithms are all within the "mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"""mml:mrow""mml:mo"±"/mml:mo""/mml:mrow""/mml:math"30cm, which meet the requirement of urban rail transit.

Document type: Article

Flexible Mobility On-Demand: An Environmental Scan

Scipedia content — Mon, 22 Mar 2021 19:20:19 +0100

On-demand shared mobility is increasingly being promoted as an influential strategy to address urban transport challenges in large and fast-growing cities. The appeal of this form of transport is largely attributed to its convenience, ease of use, and affordability made possible through digital platforms and innovations. The convergence of the shared economy with a number of established and emerging technologies—such as artificial intelligence (AI), Internet of Things (IoT), and Cloud and Fog computing—is helping to expedite their deployment as a new form of public transport. Recently, this has manifested itself in the form of Flexible Mobility on Demand (FMoD) solutions, aimed at meeting personal travel demands through flexible routing and scheduling. Increasingly, these shared mobility solutions are blurring the boundaries with existing forms of public transport, particularly bus operations. This paper presents an environmental scan and analysis of the technological, social, and economic impacts surrounding disruptive technology-driven shared mobility trends. Specifically, the paper includes an examination of current and anticipated external factors that are of direct relevance to collaborative and low carbon mobility. The paper also outlines how these trends are likely to influence the mobility industries now and into the future. The paper collates information from a wide body of literature and reports on findings from actual ‘use cases’ that exist today which have used these disruptive mobility solutions to deliver substantial benefits to travellers around the world. Finally, the paper provides stakeholders with insight into identifying and responding to the likely needs and impacts of FMoD and informs their policy and strategy positions on the implementation of smart mobility systems in their cities and jurisdictions.

Document type: Article

A Machine Learning Method for Predicting Driving Range of Battery Electric Vehicles

Scipedia content — Mon, 22 Mar 2021 19:18:52 +0100

It is of great significance to improve the driving range prediction accuracy to provide battery electric vehicle users with reliable information. A model built by the conventional multiple linear regression method is feasible to predict the driving range, but the residual errors between -3.6975 km and 3.3865 km are relatively unfaithful for real-world driving. The study is innovative in its application of machine learning method, the gradient boosting decision tree algorithm, on the driving range prediction which includes a very large number of factors that cannot be considered by conventional regression methods. The result of the machine learning method shows that the maximum prediction error is 1.58 km, the minimum prediction error is -1.41 km, and the average prediction error is about 0.7 km. The predictive accuracy of the gradient boosting decision tree is compared against that of the conventional approaches.

Document type: Article

Optimum Resilient Operation and Control DC Microgrid Based Electric Vehicles Charging Station Powered by Renewable Energy Sources

Scipedia content — Mon, 22 Mar 2021 19:16:47 +0100

This paper introduces an energy management and control method for DC microgrid supplying electric vehicles (EV) charging station. An Energy Management System (EMS) is developed to manage and control power flow from renewable energy sources to EVs through DC microgrid. An integrated approach for controlling DC microgrid based charging station powered by intermittent renewable energies. A wind turbine (WT) and solar photovoltaic (PV) arrays are integrated into the studied DC microgrid to replace energy from fossil fuel and decrease pollution from carbon emissions. Due to the intermittency of solar and wind generation, the output powers of PV and WT are not guaranteed. For this reason, the capacities of WT, solar PV panels, and the battery system are considered decision parameters to be optimized. The optimized design of the renewable energy system is done to ensure sufficient electricity supply to the EV charging station. Moreover, various renewable energy technologies for supplying EV charging stations to improve their performance are investigated. To evaluate the performance of the used control strategies, simulation is carried out in MATLAB/SIMULINK.

Document type: Article

Expanding airport capacity of cities under uncertainty: Strategies to mitigate congestion

Scipedia content — Tue, 16 Feb 2021 13:46:16 +0100

Airport capacity constraints are increasingly challenging the growth of air traffic. At the same time, decision-making about airport capacity investments is extremely complex, involving trade-offs. This paper’s objective is to optimise a privately owned airport system’s capacity investment decision in a city under demand uncertainty. Next to the investment size, our real options model incorporates the timing of the investment, as well as the cost of congestion. The results reveal that the larger a city’s initial airport capacity, the smaller its investment will relatively be and the lower the occupancy rate threshold at which investment will take place. We also show that, in case of a higher demand growth combined with more demand uncertainty, the city will benefit from a significantly larger investment, but made later at a higher occupancy rate. In this case, cities with a small initial capacity will sometimes even more than double current capacity. Higher airport charges and an increase in non-aeronautical revenues both lead to a later investment in more capacity, due to the increased project attractiveness. An increase in congestion costs results in a larger investment made earlier, in order to eliminate delays. Airport operational cost and capacity holding cost increases both lead to smaller investments.

Reused second life batteries for aggregated demand response services

Scipedia content — Tue, 16 Feb 2021 13:44:56 +0100

The electric vehicle is presented as an environmental friendly alternative to common vehicles and as the future of transportation. However, car manufacturers consider that electric vehicle batteries are not useful for traction purposes when they reach a state of health of 80%. Thus, as a matter of fact, these batteries are sold knowing that they have a premature obsolescence, as they still have 80% of useful capacity that could be used elsewhere. This study analyzes economically and in terms of ageing performance the possibility to provide a second life to these batteries in buildings. The study presents several scenarios depending on the battery use, considering independent buildings or getting closer to the concept of smart grid with demand response services where buildings could participate in secondary electricity markets by means of an energy aggregator. Moreover, the study analyzes the existing European markets that allow aggregated demand response services. Results show that, effectively, the reuse of batteries for residential purposes might not be the best economical option even though their lifespan is enlarged four years more. Nonetheless, if they are able to participate in secondary electricity markets in addition to their normal use in buildings, the business becomes juicy enough having a relatively low impact on ageing. The promotion of electric vehicle battery reuse is necessary, as there is a large amount of batteries with a huge useful potential in stationary applications coming in the nearby future from the electric vehicles that have been sold during the last five years. If possible, car manufacturers should consider eco-design in order to facilitate this battery repurposing and lifespan enlargement.

Peer Reviewed

Sustainability assessment of trenches including the new eco-trench: a multi-criteria decision-making tool

Scipedia content — Tue, 16 Feb 2021 13:43:59 +0100

Narrow trenches are a common technique for the installation of utility pipelines of small diameter. Theexcavated soil is not always appropriate as landfill and, in those cases, an appropriate soil from some-where else (ex. a borrow pit or another construction site) should be used instead (classical solution, CS).Another common solution is to use a controlled low-strength (cementitious) material (CLSM) as backfillinstead of compacted soil. However, both solutions lead to increased raw material consumption, wastegeneration, need for transportation, and CO2emissions. In an attempt to address these issues, researchersdeveloped an eco-trench (ECO) that reuses the excavated soil of narrow trenches to produce a controlledlow-strength material to be used as landfill. Although technically viable, the sustainability of this solutionversus the traditional solution has not been properly addressed. Hence, this paper aims to develop amethod for the sustainability assessment of trenches. The Sustainability Index of Trenches (SIT), based onthe MIVES decision-making method, enables the assessment and prioritisation of different types oftrenches according to sustainability criteria. Criteria, indicators, weights and value functions were spe-cifically defined based on seminars with experts in thefield of utility services and construction. A casestudy was performed in which four types of trenches (CS, CS with recycling CSþR, CLSM and ECO) wereassessed and prioritised according to SIT. ECO resulted in the most sustainable alternative with a SIT of0.80 out of 1 followed by CSþR, CS and CLSM with SITs of 0.63, 0.40 and 0.38 respectively. The sensitivityanalysis showed consistent results in different scenarios. Thesefindings demonstrate the capability andreliability of SIT as a decision-making tool for the evaluation of the sustainability of different constructionprocesses for trenches and the prioritisation of the most suitable solution for different situations

Peer Reviewed

Document type: Article

An experimental study of the drag reducing surfactant for district heating and cooling

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

Drag reducing surfactants can be applied to decrease pressure losses in closed circulation pipelines systems like district heating and cooling. This article represents empirical lab scale study of the two drag reducing products developed by AkzoNobel (Sweden) specifically for aqueous solutions for different temperature ranges. Two main issues stopped previous researches of drag reducing agents: heat transfer reduction in shell and tube heat exchanger and environmental concerns. Current shift to heat supply based on renewable energy sources and small-scale biogas CHP plants will no longer require such kind of heat exchangers. It opens opportunities for new surfactants and its application in district heating. This research outlines environmental properties of the two surfactants including its biodegradability rates.

Are electric vehicles masculinized? Gender, identity, and environmental values in Nordic transport practices and vehicle-to-grid (V2G) preferences

Scipedia content — Tue, 16 Feb 2021 13:42:57 +0100

In this paper, we provide a comparative and mixed methods assessment of the gendered dimensions of electric mobility and stated preferences for electric vehicles in the Nordic region. This includes the potential for such vehicles to be configured in a vehicle-to-grid (V2G) manner, where they can store energy and offer services to the grid, generating revenue and accelerating decarbonisation. Based primarily on a survey distributed to a mix of more than 5000 respondents across five countries, research interviews, and focus groups, and supplemented with a comprehensive literature review, we examine how perceptions, attitudes, values and identities towards electric mobility differ by gender. We use this data to test, and largely confirm, with some exceptions, three hypotheses: H1: Men use cars (conventional and electric) more than women, more often own a car or EV, drive further than women, and use less public transport. H2: Women have stronger preferences for the environmentally friendly or safety attributes of vehicles (such as EVs and V2G), reflecting higher levels of environmental awareness. H3: Women attach less importance to acceleration, power, or sound, whereas men will emphasize range, sex appeal, and acceleration. In examining these hypotheses about gender, we reveal the more complex social dynamics behind how potential adopters in Denmark, Finland, Iceland, Norway, and Sweden consider and calculate various aspects of conventional mobility, electric mobility, and V2G.

A universal middleware streaming framework and data analytics: Analysing their economic feasibility in road transport planning

Scipedia content — Tue, 16 Feb 2021 13:42:42 +0100

The individual paths followed by road transport operators in adopting and using information and communication technologies (ICT) result in heterogeneous planning practices. This includes working with multiple IT systems, data sources and applications. There is no coordination or standardisation that ensures a straightforward approach to develop and implement cross-sector IT solutions. Different integrative state-of-the-art solutions are sub-optimal, not flexible and relatively expensive to maintain. The proposed methodology starts by investigating the current working practices of a road transport operator. It reports on an own exploration initiative conducted by researchers in logistics and computer science, and brings together their complementary expertise. It identifies firstly the ICT solutions used at an operational level and points out the necessities for further integration, functionalities or application development. Secondly, it develops a theoretical model that assists road transport operators in checking whether using a uniform integration layer and data analytics tools is economically feasible. The model shows the fleet size from which significant costs reductions are made. These costs reductions are enabled by implementing a middleware framework and data analytics algorithm that assists human operators in operational planning.

Semi-autonomous vehicles: Usage-based data evidences of what could be expected from eliminating speed limit violations

Scipedia content — Tue, 16 Feb 2021 13:42:21 +0100

The use of advanced driver assistance systems and the transition towards semi-autonomous vehicles are expected to contribute to a lower frequency of motor accidents and to have a significant impact for the automobile insurance industry, as rating methods must be revised to ensure that risks are correctly measured. Telematics information and usage-based insurance research are analyzed to identify the effect of driving patterns on the risk of accident. This is used as a starting point for addressing risk quantification and safety for vehicles that can control speed. The effect of excess speed on the risk of accidents is estimated with a real telematics data set. Scenarios for a reduction of speed limit violations and the consequent decrease in the expected number of accident claims are shown. If excess speed could be eliminated, then the expected number of accident claims could be reduced to half of its initial value, applying the average conditions of the data used in this study. As a consequence, insurance premiums also diminish.

Development and application of an updated geospatial distribution model for gridding 2015 global mercury emissions

Scipedia content — Tue, 16 Feb 2021 13:41:45 +0100

Mercury is a global pollutant that poses threats to ecosystems and to human health. Due to its global transport, mercury contamination is found in regions of the Earth that are remote from major emissions areas, including the Polar regions. Global anthropogenic emission inventories identify important sectors and industries responsible for emissions at a national level; however, to be useful for air transport modelling, more precise information on the locations of emission is required. This paper describes the methodology applied, and the results of work that was conducted to geospatially distribute anthropogenic mercury emissions as part of the global anthropogenic mercury emissions inventory for 2015 prepared by AMAP/UNEP for the Global Mercury Assessment (GMA) 2018 (UN Environment, 2019). This work includes the identification and use of emission point sources as well as distributing diffuse emissions for 21 emission (industry) sectors. The basic approach involves assigning emission estimates to geo-located point sources, using reported emissions information where available, and otherwise assigning a modelled emission to the point. Emissions which cannot be assigned to point sources are distributed using sector-specific proxies. Mercury speciation highly depends on industry processes and air pollution control technology. Different Hg speciation ratios are therefore applied per sector and country technology level. The resulting global emission datasets include total mercury (HgT), gaseous elemental mercury (Hg0), divalent mercury (Hg2+) and particulate mercury (HgP) in kg per year per raster cell (kg/a). The spatial resolution is flexible and the vertical resolution of the data is based on a set of predefined height classes. The resolution of the GMA2018 emission data is 0.25° × 0.25° with three (physical emission) height classes (0–50, 50–150 and " 150m). A comparison with the EMEP European mercury emission was made based on spatial correlation between the two datasets. Suggested improvements for future work include the further development of proxy data and the implementation of a more structured reporting of emissions by countries.

Voltage fluctuation smoothing in distribution systems with RES considering degradation and charging plan of EV batteries

Scipedia content — Tue, 16 Feb 2021 13:41:32 +0100

Recently, the use of renewable energy sources (RES) and electric vehicles (EVs) has been rapidly increased worldwide. As a result of the highly fluctuating nature of RES, the charging and discharging rates of EVs significantly have to be increased, and so the lifespan of EV batteries decreases. In this paper, an optimization-based method is proposed to smooth voltage fluctuations due to various RES types by optimally controlling the charging and discharging power of EVs and the reactive power of the RES inverters. To extend the lifespan of the EV battery, EV power fluctuations and their minimum preset state of charge (SOC) are considered in the proposed optimization model. For this purpose, a new multi-objective function is formulated, including (1) voltage fluctuations, (2) EV power fluctuations, and (3) the deviation of SOC of EVs from their minimum desired level. The use of the hull moving average (HMA) is proposed to mitigate voltage fluctuations, which eliminates the lag problem of the widely used movingaverage methods. The gravitational search algorithm (GSA) is utilized to accurately solve the optimization model. The simulation results demonstrate the effectiveness of the proposed method to smooth voltage fluctuations while considering degradation and charging plan of EV batteries. Peer reviewed

Modeling Hydrogen Networks for Future Energy Systems: A Comparison of Linear and Nonlinear Approaches

Scipedia content — Tue, 16 Feb 2021 13:39:30 +0100

Common energy system models that integrate hydrogen transport in pipelines typically simplify fluid flow models and reduce the network size in order to achieve solutions quickly. This contribution analyzes two different types of pipeline network topologies (namely, star and tree networks) and two different fluid flow models (linear and nonlinear) for a given hydrogen capacity scenario of electrical reconversion in Germany to analyze the impact of these simplifications. For each network topology, robust demand and supply scenarios are generated. The results show that a simplified topology, as well as the consideration of detailed fluid flow, could heavily influence the total pipeline investment costs. For the given capacity scenario, an overall cost reduction of the pipeline costs of 37% is observed for the star network with linear cost compared to the tree network with nonlinear fluid flow. The impact of these improvements regarding the total electricity reconversion costs has led to a cost reduction of 1.4%, which is fairly small. Therefore, the integration of nonlinearities into energy system optimization models is not recommended due to their high computational burden. However, the applied method for generating robust demand and supply scenarios improved the credibility and robustness of the network topology, while the simplified fluid flow consideration can lead to infeasibilities. Thus, we suggest the utilization of the nonlinear model for post-processing to prove the feasibility of the results and strengthen their credibility, while retaining the computational performance of linear modeling.

Document type: Article