Scipedia: Documents published in 2018

Effect of capsule shape on hydrodynamic characteristics and optimal design of hydraulic capsule pipelines

Scipedia content — Mon, 15 Feb 2021 09:55:21 +0100

Hydraulic capsule pipelines (HCPs) are the third generation pipelines transporting hollow containers, known as capsules. These capsules are filled with material/cargo to be transported. The shape of these capsules has a significant effect on the hydrodynamic flow characteristics within HCPs. As the variations in the pressure distribution within HCPs are directly linked to and the flow characteristics within pipelines, it is essential to critically evaluate the effect of capsule shape on the pressure drop across the pipeline. Published literature is severely limited in terms of establishing the effects of the shape of the capsules on the flow characteristics within pipelines. Hence, the present study focuses on using a well-validated Computational Fluid Dynamics tool to numerically simulate the flow of capsules of various shapes quantified in form of a novel shape factor in hydraulic capsule pipelines. Both on-shore and off-shore applications of such pipelines have been investigated in the present study, along-with pipe fittings, such as bends. Variations in flow related parameters within these pipelines have been discussed in detail for a wide range of geometrical parameters associated with the capsules and the pipelines. Pressure drop values have been used to develop novel semi-empirical prediction models as a function of the shape factor and other flow and geometric variables of the capsules. These prediction models have been embedded into a pipeline optimisation methodology, which has been developed based on Least-Cost Principle. The resulting novel optimisation methodology can be used for hydraulic capsule pipeline design. Performance charts for practical applications have been developed for easy implementation of the design methodology for the designers of hydraulic capsule pipelines transporting capsule of different shapes.

Document type: Article

User Response – Based Sustainable Solutions to Traffic Congestion Problem using Public Transport: The Case of Uttara, Dhaka

Scipedia content — Mon, 15 Feb 2021 09:52:03 +0100

For a country of millions, traffic congestion significantly reduces the economic productivity. This statement holds true for most urban areas of the world, especially Dhaka, the mega-city of Bangladesh. An area of Dhaka which has a lot of potential in terms of both as a residential and commercial region, is undoubtedly the suburb of Uttara. Along with being adjacent to the airport on one side and having a link to industrial areas like Gazipur and Savar on the other, it also has residential amenities in its numerous blocks, making it a colony for traffic congestion. Unfortunately, no sustainable solution has come about to successfully reduce this problem. Hence, this paper tries to understand where the problems lie from the perspectives of the most important stakeholders – the residents and commuters of the area. It supports the use of their simple thinking to reach solutions through suasive instruments, like training and awareness-building campaigns, instead of spending millions on building lengths of roads and investing in technology. A survey of 150 bus passengers and 150 private car owners, coupled with literature review were conducted to accumulate, identify and address the traffic congestion reasons and associated issues. These problems were later used to propose recommendations. Responses revealed that the satisfaction levels of the commuters fell mostly under the ‘dissatisfied’ category (78%), based on parameters like fitness of the bus and driver, behavior of drivers and conductors, etc. Unsurprisingly, most respondents showed interest to pay an extra bit of fare for better bus service and believed that these would greatly help to mitigate the issue of running this sector with ‘unskilled’ and ‘unprofessional’ drivers/conductors (92%). Additionally, the large presence of private cars seemed to cause higher amounts of traffic congestion, but 56% of these users believed that the public buses had poor service and hence, their decision to avoid it as a regular commuting option. Hence, it was clear from the responses and their analysis that only a reliable, comfortable, and safe bus service system (including good drivers, conductors and buses themselves) is what will encourage more people to travel in public buses, leaving behind their private cars. This would in turn, greatly reduce the traffic congestion problem as people will be able/want to follow the traffic regulations better.

Document type: Article

Steam and Oxyhydrogen Addition Influence on Energy Usage by Range Extender—Battery Electric Vehicles

Scipedia content — Mon, 15 Feb 2021 09:50:32 +0100

The objective of this paper is to illustrate the benefits of the influence of the steam and oxyhydrogen gas (HHO) on the composition of emitted exhaust gases and energy usage of operating the internal combustion engine (ICE) that drives a generator-powered battery electric vehicle (BEV). The employed internal combustion generating sets can be used as trailer mounted electric energy sources allowing one to increase the range of BEV vehicles, mainly during long distance travel between cities. The basic configurations of hybrid and electric propulsion systems used in a given Electric Vehicles (xEV) includes all types of Hybrid Electric Vehicles (xHEV) and Battery Electric Vehicles (xBEV), which are discussed. Using the data collected during traction tests in real road traffic (an electric car with a trailer range extender (RE) fitted with ICE generators (5 kW petrol, 6.5 kW diesel), a mathematical model was developed in the Modelica package. The elaborated mathematical model takes into account the dynamic loads acting on the set of vehicles in motion and the electric drive system assisted by the work of RE. Conducted tests with steam and HHO additives for ICE have shown reduced (5&ndash

10%) fuel consumption and emissions (3&ndash

19%) of harmful gases into the atmosphere.

Document type: Article

Corrosion and Wear Analysis in Marine Transport Constructions

Scipedia content — Mon, 15 Feb 2021 09:49:01 +0100

"jats:p" Corrosion is one of the most common naturally occurring processes studied by thermodynamics, which includes oxidation process, metal disruption, and its chemical and electrochemical effects under environmental influence. Corrosion of metal and equipment accounts for a considerable proportion of total corrosion losses, thus providing the impetus for further investigation and developments related to corrosion protection in order to provide transport systems and industry with corrosion preventive materials and tools.

Document type: Article

Short sea shipping: a statistical analysis of influencing factors on SSS in European countries

Scipedia content — Mon, 15 Feb 2021 09:45:25 +0100

Short sea shipping (SSS) is the maritime transport of goods over relatively short distances, as opposed to the intercontinental cross-ocean deep sea shipping. The goal of the current paper is to identify SSS growth potential and the univariate regression analysis indicates that the following variables influence total SSS volume in European countries: land area, coastline, total number of SSS ports, number of small SSS ports, number of large SSS ports, number of inhabitants, Gross Domestic Product (GDP), GDP per head, road length and rail length. An additional multivariate regression analysis indicates that more than 78% of the variance in the total SSS volume per country can be explained by variations in the number of large SSS ports and the GDP per head. Finally, future prospects for SSS indicate that most countries show (theoretical) potential to further increase their SSS volume calling for tailor-made policies to utilize this potential.

Document type: Article

Smart Automation, Customer Experience and Customer Engagement in Electric Vehicles

Scipedia content — Mon, 15 Feb 2021 09:44:42 +0100

major challenge to cleaner and more sustainable transportation is the lack of adoptability of electric vehicles (EVs) by customers. Therefore, most of the vehicles we see on the road use fossil fuel instead of sustainable green energy sources. One way to improve customer acceptance is to market EVs as a socially desirable product, rather than only environmentally friendly. The silver lining to promote is the potential of information and communications technology (ICT) features in EVs, which can lead to a deeper connection between the EVs and their users. These engaging technologies can bring customers closer to the company, resulting in generating big data, which can lead to even deeper insights into customer preferences. Because the technology of vehicle connectivity and automation is just taking off, it is important to understand how these technologies in EVs can enhance customer experiences and result in sustainable customer engagement. Unfortunately, this important research area remains neglected. This research, therefore, is focused on building a conceptual framework for understanding the influence of electric vehicle (EV) automation and connectivity on customer experience, and ultimately, customer engagement.

Document type: Article

Destruction mechanisms and methods of laboratory autoclave tests of internal coatings of oil pipes

Scipedia content — Mon, 15 Feb 2021 09:44:09 +0100

The main mechanisms of destruction of internal anticorrosive polymer coatings (IACPC) of the inner surface of tubing and fielding pipes are review in the article. They are divide into decompression peeling, substrate destruction under the corrosion of and natural aging of the polymeric basis. A critical analysis of the existing standards for the testing of internal anticorrosive coatings was made. The carrying out test on these documents does not allow obtaining the destructions identical to those found during the exploitation of pipelines. Investigations on the selection of optimal regimes of autoclave tests and the methodology for conduct research are describe. A comparison for the results of laboratory and experimental field tests of the coatings presented.

Document type: Article

The influence of changes in the project on the reliability of heat power systems during construction and installation works

Scipedia content — Mon, 15 Feb 2021 09:43:41 +0100

However, during the construction and reconstruction of existing heat networks, cases that lead to unstable operation of newly laid or replaced areas arise. An important task is to minimize the reasons that can cause damage to replaced areas. Factors that negatively affect the reliability include: laying pipelines without design documentation, non-compliance of the regulatory requirements for their laying by installation organizations. The assumptions of design engineers developing the project and installers laying the heating main can lead to negative consequences, including a decrease in the reliability of the facilities functioning. Physical deterioration, coupled with the above factors, leads to a large number of failures of heat networks. Breakthroughs reduce the reliability of the entire heat supply system, worsen the quality of the supplied coolant and lead to an increase in the cost of maintenance of heat networks by operating organizations. The paper considers the influence of changes in the project during the construction and installation works on the reliability of the heat supply system.

Document type: Article

A Reliability-Based Network Equilibrium Model with Adaptive Risk-Averse Travelers

Scipedia content — Mon, 15 Feb 2021 09:43:07 +0100

In this paper, route free-flow travel time is taken as the lower bound of route travel time to examine its impacts on budget time and reliability for degradable transportation networks. A truncated probability density distribution with respect to route travel time is proposed and the corresponding travel time budget (TTB) model is derived. The budget time and reliability are compared between TTB models with and without truncated travel time distribution. Under truncated travel time distribution, the risk-averse levels of travelers are adaptive, which are affected by the characteristics of the used routes besides the confidence level of travelers. Then, a TTB-based stochastic user equilibrium (SUE) is developed to model travelers’ route choice behavior. Moreover, its equivalent variational inequality (VI) problem is formulated and a route-based algorithm is used to solve the proposed model. Numerical results indicate that route travel time boundary produces a great influence on decision cost and route choice behavior of travelers.

Document type: Article

Vehicle trajectory at curved sections of two-lane mountain roads: a field study under natural driving conditions

Scipedia content — Fri, 12 Feb 2021 16:23:24 +0100

Purpose The trajectory of a vehicle is comprehensively affected by the interactions between the vehicle, the driving behavior, and the road environment. High-risk driving behaviors and accident-prone road sections can be identified based on the relationship between the trajectory and road geometry. Previous related studies mostly focused on the trajectory deviation at a few points on the road, which cannot capture the continuous variation of the trajectory in an entire curve, and seldom considered the trajectory characteristics along curves with large deflection angles. The aim of this study is to investigate the trajectories passenger cars take on two-lane mountain roads and thus to determine the track patterns and its relevant risks. Methods Field driving experiments were performed on four two-lane mountain highways, and vehicle trajectories under natural driving conditions were acquired. The continuous change in the lateral deviation rate of the trajectory was also determined by putting the measured trajectories into the coordinate frame together with the edge line of roadway. Further, the morphological features of the vehicle trajectory and how it is affected by the highway geometry were analyzed. Results and conclusions The following were observed: i) Typical track patterns were determined according to features of LDRT profiles, four patterns for left-hand bends and five patterns for right-hand bends, which can be used to identify crash prone position and reveal the mechanism of crash. ii) Inertia may cause the vehicle to move too close to the outer side of the curve after a cut, for which reason the driver has to correct the trajectory, although overcorrection may move the vehicle into the oncoming lane. iii) A higher speed at curve entry adopt by the driver could result in a larger encroachment into opposite lane or shoulder. iv) The smaller the radius of the horizontal curve, the more frequently the trajectory entered the oncoming lane. These findings could provide a better understanding of the track behavior of passenger cars, judge the safety implications of driver behavior, and thus identify crash prone positioning and the potential mechanisms of head-on crashes, run-off-road and guardrail collisions.

Document type: Article

Underwater Optical Imaging for Automotive Wading

Scipedia content — Fri, 12 Feb 2021 16:21:23 +0100

n underwater imaging system was investigated for automotive use in highly scattered underwater environments. The purpose of the system is the driver&rsquo

s information about hidden obstacles, such as stones, driftwood, open sewer hatches. A comparison of various underwater vision methods was presented by the way they are implemented, the range reached, and the cost of implementation. It has been experimentally shown that a conventional active system can provide a maximum visibility range of up to three light attenuation lengths. In most practical cases of turbid waters during floods, this corresponds to distances of about 1 meter. From the presented analysis it follows that advanced extended range imaging methods allow increasing of the visibility range up to 2 meters.

Document type: Article

Uniform Market Conditions in Road Freight Transport

Scipedia content — Fri, 12 Feb 2021 16:19:21 +0100

International road transport is a specific service within the frame of services provided in the European Union. It is because the conditions of being active on the market are influenced by the states where businessmen operate, but services can be provided throughout the whole year in other member states of the European Union. The aim of the contribution is to highlight the existing problems in international road freight transport sector. These problems persist despite the fact that market access was exempted from the national law of individual member states and regulated directly by EU regulations. The contribution identifies the factors that deform the equal operating conditions in single market.

Document type: Article

Compliance with ecological safety requirements in air transport organizations

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

The relevance of the article is determined by the fact that air transport in general and the infrastructure of the airports in particular have strong negative impact on the environment. Some factors influencing the solution of this problem are considered in article, including the human factor. The quality management system in civil aviation organizations and the ecological strategy in the organizations of air transport are analysed. The examples of some Russian airports are studied. According to the authors, in addition to special technical measures, it is possible to use the incentive mechanism for employees of the air transport organization to form their responsible attitude to the accomplishment of their functional responsibilities regarding the potential impact on the ecological situation in the region.

Document type: Article

Random Regret-Minimization Model for Emergency Resource Preallocation at Freeway Accident Black Spots

Scipedia content — Fri, 12 Feb 2021 16:15:03 +0100

The preallocation of emergency resources is a mechanism increasing preparedness for uncertain traffic accidents under different weather conditions. This paper introduces the concept of accident probability of black spots and an improved accident frequency method to identify accident black spots and obtain the accident probability. At the same time, we propose a three-stage random regret-minimization (RRM) model to minimize the regret value of the attribute of overall response time, cost, and demand, which allocates limited emergency resources to more likely to happen accident spots. Due to the computational complexity of our model, a genetic algorithm is developed to solve a large-scale instance of the problem. A case study focuses on three-year rainy accidents’ data in Weifang, Linyi, and Rizhao of China to test the correctness and validity of the application of the model.

Document type: Article

Analysis of the Strapdown Inertial Navigation System (SINS) Error Genesis

Scipedia content — Fri, 12 Feb 2021 16:13:04 +0100

"jats:p"Analysis and simulation of the Strapdown Inertial Navigation System (SINS) error genesis revealed that the East Feedback Contour has the greatest influence on the development of an error in this model, and angular velocity sensor Δωð is the critical element. In order to prevent the development of an error, structural correction in the East Feedback Contour, and elements that are more critical, namely in angular velocity measurement sensors is the best option.

Document type: Article

Sequanix: a dynamic graphical interface for Snakemake workflows

Scipedia content — Fri, 12 Feb 2021 16:11:23 +0100

Summary"/jats:title""jats:p"We designed a PyQt graphical user interface – Sequanix – aiming at democratizing the use of Snakemake pipelines. Although the primary goal of Sequanix was to facilitate the execution of NGS Snakemake pipelines available in the Sequana project ("jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://sequana.readthedocs.io""http://sequana.readthedocs.io"/jats:ext-link"), it can also handle any Snakemake pipelines. Therefore, Sequanix should be useful to all Snakemake developers willing to expose their pipelines to a wider audience."/jats:p""/jats:sec""jats:sec""jats:title"Availability"/jats:title""jats:p"Source code available on "jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://github.com/sequana/sequana""http://github.com/sequana/sequana"/jats:ext-link" and standalone on "jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://bioconda.github.io""http://bioconda.github.io"/jats:ext-link" (sequana package)."/jats:p""/jats:sec

Document type: Article

A Comparison Framework for Conflict Detection and Resolution Multi Agent Modeling Methods in Air Traffic Management

Scipedia content — Fri, 12 Feb 2021 16:09:49 +0100

Nowadays air traffic density increased, thus existing air traffic management systems are not able to manage the massive capacities of air traffic perfectly. To solve problems in current air traffic management systems, the aviation industry focused on a new concept called Free flight. Nonetheless, the most important challenge in current air traffic management and especially in free flight is conflict detection and resolution between different aircrafts. So far a number of methods have been presented in order to automate air traffic management using multi agent systems technology. However, there has been a little discussion about the efficiency of these methods. Also, there has not been created a comprehensive comparison of these methods. In this paper, we presented a clear framework to categorization and comparing different multi agent models for conflict detection and resolution in air traffic management. Then, using this framework, we evaluated various proposed models. Our comparison framework is based on characteristic such as: agent selection (the entity which selected as Agent), agent’s actions, agents’ interaction method in the process of conflict detection and resolution, the strategy used in agents’ implementation, type of the multi agent system (pure multi agent system or combined), conflict detection method, conflict resolution method, Plan Dimensions, Maneuvers, and management the multiple aircrafts’ conflict.

Document type: Article

Calculation of pressure loss and critical velocity for slurry flows with additive agents in vertical polyethylene pipelines

Scipedia content — Fri, 12 Feb 2021 16:03:05 +0100

The method of determination of parameters of hydrotransport of solid polydisperse materials in vertical pipelines is offered. The reasons of discrepancy between estimated and observed data when using A. Smoldyrev’s method for calculation of hydraulic gradient and critical velocity in vertical steel pipelines are analysed. Particularly non-applicability of Velicanov principle to hydrotransport of solid materials in vertical pipelines is proved and contribution of particles fall velocity to the value of complementary hydraulic gradient in vertical pipelines is estimated. Suggested formulas for calculation of hydraulic gradient and critical velocity in vertical pipelines are multipurpose because they may be used for calculation of hydrotransport parameters in steel and polymeric vertical pipelines with using of friction reducing agents and without it. The method for parameters calculation of solid materials hydrotransport in vertical polymeric pipelines is first offered. Elaborated formulas ensure also increasing of accuracy of calculations.

Document type: Article

Ecological aspects of economical development: issues of forecast greenhouse gas emissions in road transport in Europe and regions of Russia

Scipedia content — Fri, 12 Feb 2021 16:01:51 +0100

Environmental aspects are an essential part of economic development. Improvement of the environmental situation can have a significant impact on the pace and structure of economic development. For environmental component, it is important to analyze the current state and predict greenhouse gas emissions. The development of methodological approaches in this area will allow for more detailed forecasting of the situation. In order to reduce the emission of greenhouse gases, European countries have set targets for efficiency of energy consumption and widespread use of renewable energy sources, which they have achieved and become world leaders in using them. By 2020, the goal is set for energy consumption to be at least 20% from renewable sources. According to the forecast on average, in 2040 the share of oil products in the structure of fuel consumption in road transport in Europe will be reduced to 80%. Nevertheless, in the countries of Europe, various trends in the field of greenhouse gas emissions are expected. Most countries have a high potential for reducing greenhouse gas emissions from fuel combustion on road vehicles. In Russia, emissions from vehicles are projected to reduce by 8% by 2040.

Document type: Article

Understanding the Spatial Structure of Urban Commuting Using Mobile Phone Location Data: A Case Study of Shenzhen, China

Scipedia content — Fri, 12 Feb 2021 16:01:35 +0100

Understanding commuting patterns has been a classic research topic in the fields of geography, transportation and urban planning, and it is significant for handling the increasingly serious urban traffic congestion and air pollution and their impacts on the quality of life. Traditional studies have used travel survey data to investigate commuting from the aspects of commuting mode, efficiency and influence factors. Due to the limited sample size of these data, it is difficult to examine the large-scale commuting patterns of urban citizens, especially when exploring the spatial structure of commuting. This study attempts to understand the spatial structure characteristics generated by human commutes to work by using massive mobile phone datasets. A three-step workflow was proposed to accomplish this goal, which includes extracting the home and work locations of phone users, detecting the communities from the commuting network, and identifying the commuting convergence and divergence areas for each community. A case study of Shenzhen, China was implemented to determine the commuting structure. We found that there are thirteen communities detected from the commuting network and that some of the communities are in accordance with urban planning; moreover, spatial polycentric polygons exist in each community. These findings can be referenced by urban planners or policy-makers to optimize the spatial layout of the urban functional zones.

Document type: Article

Construction Prototyping, Flight Dynamics Modeling, and Aerodynamic Analysis of Hybrid VTOL Unmanned Aircraft

Scipedia content — Fri, 12 Feb 2021 16:00:55 +0100

A challenging issue associated with fixed-wing Unmanned Aerial Vehicles (UAVs) is that these vehicles are often not appropriate for operating effectively in limited airspace. This problem emerges especially in urban environment where the usage of a runway is not possible, and UAVs usually have to fly at a relatively low speed and altitude. The development of a vertical take-off and landing (VTOL) fixed-wing plane is a promising trend which hopefully will solve this issue. This paper presents the design process of an unmanned vertical take-off and landing aircraft including prototyping of the airframe construction and mathematical modeling as well as computational fluid dynamics (CFD) simulations. The designed system is to be a hybrid platform, for which different operating modes correspond to the vertical flight, transition, and spatial flight in the airframe system. The paper discusses an iterative design process of the platform with emphasis on CAD design and aerodynamic analysis for particular flight modes. The operating prototype is presented and future plans for platform improvement are discussed.

Document type: Article

Selection of ports, tariffs, service frequency, and ship size for a SSS Route in Java Island

Scipedia content — Fri, 12 Feb 2021 16:00:37 +0100

Short Sea Shipping (SSS) is one of modes to reduce the dominance of trucking mode of freight transportation in Indonesia. It concerns to multimodal freight transportation network system through sea mode transportation line. As a maritime nation, it is possible to develop SSS lines in Indonesia. The development of the SSS lines is expected to improve the continuity of goods which supporting the efficiency and effectiveness of the national logistics system. It develops integrated connectivity in local, inter-island and national scale. The objective of this study is to obtain optimum SSS route with objective function to maximize the difference of total transportation cost by designing SSS operating system model. Several factors are considered in SSS operating system model as policy measures, such as transit ports selection, tariffs, services, and ship sizes. This SSS model is approached by Incremental Assignment method. SSS operating system model will be applied to the freight mobility in Java.

Document type: Article

A Review of the Self-Adaptive Traffic Signal Control System Based on Future Traffic Environment

Scipedia content — Fri, 12 Feb 2021 15:13:23 +0100

The self-adaptive traffic signal control system serves as an effective measure for relieving urban traffic congestion. The system is capable of adjusting the signal timing parameters in real time according to the seasonal changes and short-term fluctuation of traffic demand, resulting in improvement of the efficiency of traffic operation on urban road networks. The development of information technologies on computing science, autonomous driving, vehicle-to-vehicle, and mobile Internet has created a sufficient abundance of acquisition means for traffic data. Great improvements for data acquisition include the increase of available amount of holographic data, available data types, and accuracy. The article investigates the development of commonly used self-adaptive signal control systems in the world, their technical characteristics, the current research status of self-adaptive control methods, and the signal control methods for heterogeneous traffic flow composed of connected vehicles and autonomous vehicles. Finally, the article concluded that signal control based on multiagent reinforcement learning is a kind of closed-loop feedback adaptive control method, which outperforms many counterparts in terms of real-time characteristic, accuracy, and self-learning and therefore will be an important research focus of control method in future due to the property of “model-free” and “self-learning” that well accommodates the abundance of traffic information data. Besides, it will also provide an entry point and technical support for the development of Vehicle-to-X systems, Internet of vehicles, and autonomous driving industries. Therefore, the related achievements of the adaptive control system for the future traffic environment have extremely broad application prospects.

Document type: Article

Sensitivity-Based Fault Detection and Isolation Algorithm for Road Vehicle Chassis Sensors

Scipedia content — Fri, 12 Feb 2021 15:11:40 +0100

Vehicle control systems such as ESC (electronic stability control), MDPS (motor-driven power steering), and ECS (electronically controlled suspension) improve vehicle stability, driver comfort, and safety. Vehicle control systems such as ACC (adaptive cruise control), LKA (lane-keeping assistance), and AEB (autonomous emergency braking) have also been actively studied in recent years as functions that assist drivers to a higher level. These DASs (driver assistance systems) are implemented using vehicle sensors that observe vehicle status and send signals to the ECU (electronic control unit). Therefore, the failure of each system sensor affects the function of the system, which not only causes discomfort to the driver but also increases the risk of accidents. In this paper, we propose a new method to detect and isolate faults in a vehicle control system. The proposed method calculates the constraints and residuals of 12 systems by applying the model-based fault diagnosis method to the sensor of the chassis system. To solve the inaccuracy in detecting and isolating sensor failure, we applied residual sensitivity to a threshold that determines whether faults occur. Moreover, we applied a sensitivity analysis to the parameters semi-correlation table to derive a fault isolation table. To validate the FDI (fault detection and isolation) algorithm developed in this study, fault signals were injected and verified in the HILS (hardware-in-the-loop simulation) environment using an RCP (rapid control prototyping) device.

Document type: Article

Potential economic benefits of using a weather ship routing system at Short Sea Shipping

Scipedia content — Fri, 12 Feb 2021 15:10:11 +0100

The final publication is available at Springer via http://dx.doi.org/10.1007/s13437-018-0143-6

This contribution investigates the economic benefits of using weather ship routing on Short Sea Shipping (SSS) activities. The investigation is supported with the development of a ship routing system based on pathfinding algorithm, the parametrization of the wave effect on navigation, and the use of high-resolution meteo-oceanographic predictions. The optimal ship routing analysis is investigated in a European SSS system: the link between Spanish and Italian ports. The results show the economic benefits using ship routing in SSS during energetic wave episodes. The rate of cost savings may reach 18% of the total costs under particular bad weather conditions in the navigation area. The work establishes the basis of further developments in optimal route applied in relatively short distances and its systematic use in the SSS maritime industry.

Peer Reviewed

Document type: Article

Internet of Energy Approach for Sustainable Use of Electric Vehicles as Energy Storage of Prosumer Buildings

Scipedia content — Fri, 12 Feb 2021 15:09:54 +0100

Vehicle-to-building (V2B) technology permits bypassing the power grid in order to supply power to a building from electric vehicle (EV) batteries in the parking lot. This paper investigates the hypothesis stating that the increasing number of EVs on our roads can be also beneficial for making buildings sustainably greener on account of using V2B technology in conjunction with local photovoltaic (PV) generation. It is assumed that there is no local battery storage other than EVs and that the EV batteries are fully available for driving, so that the EVs batteries must be at the intended state of charge at the departure time announced by the EV driver. Our goal is to exploit the potential of the EV batteries capacity as much as possible in order to permit a large area of solar panels, so that even on sunny days all PV power can be used to supply the building needs or the EV charging at the parking lot. A system architecture and collaboration protocols that account for uncertainties in EV behaviour are proposed. The proposed approach is proven in simulation covering one year period for three locations in different climatic regions of the US, resulting in the electricity bill reductions of 15.8%, 9.1% and 4.9% for California, New Jersey and Alaska, respectively. These results are compared to state-of-the-art research in combining V2B with PV or wind power generation. It is concluded that the achieved electricity bill reductions are superior to the state-of-the-art, because previous work is based on problem formulations that exploit only a part of the potential EV battery capacity.

Document type: Article

Sustainable Accessibility and the Implementation of Automated Vehicles: Identifying Critical Decisions

Scipedia content — Fri, 12 Feb 2021 15:08:21 +0100

The emergence of fully Automated Vehicles (AVs) is expected to occur in the next 10 to 30 years. The uncertainties related to AVs pose a series of questions about what the societal consequences of such technology are. Mainly, what are the consequences of AVs regarding accessibility? This paper uses Geurs and Van Wee’s definition of accessibility to give an exploratory answer to this question. Using a scenario-based approach which allows identifying critical decisions that will emerge shortly (or are already emerging) concerning automated travelling, this paper proposes that AVs have great potential to both seriously aggravate and considerably alleviate accessibility problems. A great deal will depend on how these critical decisions will be approached and the choices that will be made. This debate is most needed because existing research on AVs tends to focus on how to make them a commercially viable and safe technological enterprise, and on what their benefits and drawbacks are regarding variables such as carbon emissions, energy consumption, and total miles travelled. Narratives of this nature can be problematic, as they are unlikely to promote sufficient awareness about the real disruptive potential of AVs. It is crucial that stakeholders realise the extent to which—if the governance of AVs implementation processes is not taken very seriously, and the identified critical decisions are not carefully approached—these machines can materialise a dystopian mobility future.

Document type: Article

Induced electromagnetic field on underground metal pipelines running parallel to nearby high voltage AC power lines

Scipedia content — Fri, 12 Feb 2021 15:07:35 +0100

High voltage AC (HVAC) power lines can induce significant amount of voltages on underground gas/oil metal pipelines in areas where they share similar Right of Way (RoW), the situation becoming serious particularly in case of fault conditions. Electromagnetic field generated by the HVAC power lines on these pipelines, generate unwanted voltages which present threats to the pipeline and its associated protective equipment such as cathodic systems. The aim of this research is to compute induced voltage on pipeline running parallel to HVAC power lines. The study was conducted using CDEGS software package and revealed that under steady state condition, results were in agreement with GB 6830-1986 standard. However, high currents are generated under single phase to ground short circuit rising the potential of adjacent soil including the underground pipeline beyond limits. Therefore, the gradient control wire mitigation technique is proposed to reduce these voltages to safe limits.

Document type: Article

The development of low-emission public urban transport in Poland

Scipedia content — Fri, 12 Feb 2021 15:04:52 +0100

"jats:p"The aim of the paper is to identify the main factors and mechanisms behind the development of low-emission public transport vehicles in Polish cities. This innovation is primarily connected with growing environmental requirements for transport, with the EU environmental and transport policies being the key factors. However, strategies of local governments and municipal transport companies as well as the organization of urban transport - which differs significantly between cities - also play an important role. Three basic types of approach towards low-emission buses can be observed in Polish cities: tests of electric and hybrid vehicles, purchases of small quantities of buses in order to implement new solutions, and finally attempts to replace the majority or even the entire transport fleet with low-emission vehicles. It should be emphasised that an important element which affects the development of low emission public urban transport in Poland is the fact that the country has become one of the main bus producers in Europe - a fact which is a result of both large-scale foreign investments and the success of Polish manufacturers.

Document type: Article

On the modal shift from motorway to high-speed rail: evidence from Italy

Scipedia content — Fri, 12 Feb 2021 15:04:37 +0100

The development of high-speed rail (HSR) has had a notable impact on modal market shares on the routes on which its services have been implemented. The aim of this study is to analyse whether the HSR expansion in Italy has led to a modal shift from motorway to HSR. We empirically test i) whether HSR openings adjacent to motorway sectors have reduced the total km travelled by light vehicles on these sectors during the period 2001-2017; and ii) whether this reduction has been persistent or even more evident after the opening of on-track competition between two HSR operators. To do so, we carried out a generalized difference-in-differences estimation, using a unique panel dataset that exploits the heterogeneous traffic data within all tolled motorway sectors in a quasi-experimental setting. Our findings reveal that neither HSR openings nor the opening of on-track competition led to a modal shift from motorway to HSR services, as the two transport modes are non-competing. Conversely, both phenomena had a slightly positive impact on motorway traffic. The extent to which HSR demand could be the result of a modal shift from motorways is a relevant issue in any cost-benefit analysis of HSR investments.

Document type: Article

Application of vapor phase corrosion inhibitors for contaminated environments

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

Availability and accessibility to clean water for industrial applications such as hydrotesting and hydrostatic testing of pipelines, vessels, and plumbing distribution systems has been a challenging task especially when the job sites are in remote locations. When contaminated water is used in these tests, corrosion of the metallic components of the systems, during and after testing become a major concern. Vapor-phase corrosion inhibitors (VCI), can be added to water in small concentrations to prevent corrosion during testing, during wet storage and after testing. These inhibitors are to prevent corrosion of metallic components in three phases, within the solution, at the water line, and above the water line. Three commercially available corrosion inhibitors were evaluated in this investigation. Laboratory studies are presented in this paper, showed the effectiveness of VCI products in both fresh and salt water applications. Average corrosion rate dropped from ~10 mpy for salt solution to less than 1-1.6 mpy when various inhibitors was added. The effectiveness of these inhibitors is remarkable in the fresh water (less than 0.4 mpy). Exposure of the steel samples to these inhibitors did not show any loss in mechanical properties. Both strength and ductility of the low carbon steel samples was maintained.

Document type: Article

Driving Risk Detection Model of Deceleration Zone in Expressway Based on Generalized Regression Neural Network

Scipedia content — Fri, 12 Feb 2021 15:01:14 +0100

Drivers’ mistakes may cause some traffic accidents, and such accidents can be avoided if prompt advice could be given to drivers. So, how to detect driving risk is the key factor. Firstly, the selected parameters of vehicle movement are reaction time, acceleration, initial speed, final speed, and velocity difference. The ANOVA results show that the velocity difference is not significant in different driving states, and the other four parameters can be used as input variables of neural network models in deceleration zone of expressway, which have fifteen different combinations. Then, the detection model results indicate that the prediction accuracy rate of testing set is up to 86.4%. An interesting finding is that the number of input variables is positively correlated with the prediction accuracy rate. By applying the method, the dangerous state of vehicles could be released through mobile internet as well as drivers' start of risky behaviors, such as fatigue driving, drunk driving, speeding driving, and distracted driving. Numerical analyses have been conducted to determine the conditions required for implementing this detection method. Furthermore, the empirical results of the present study have important implications for the reduction of crashes.

Document type: Article

Numerical Modeling of pipes conveying gas-liquid two-phase flow

Scipedia content — Fri, 12 Feb 2021 15:00:45 +0100

Results of studies of the oscillations of pipelines conveying a two-phase slug flow are presented in the paper. A viscoelastic model of the theory of beams and the Winkler base model are used in the study of pipeline oscillations with a gas-containing slug flowing inside. The Boltzmann-Volterra hereditary theory of the viscoelasticity is used to describe the viscoelastic properties of the pipeline material and earth bases. The effect of gas and liquid phases flow rates, influence of tensile forces in the longitudinal direction of the pipeline, parameters of Winkler bases, parameters of singularity in the heredity kernels and geometric parameters of the pipeline on the oscillations of structures with viscoelastic properties are numerically studied. It is revealed that an increase in the length of the gas bubble zone leads to a decrease in the amplitude and oscillation frequency of the pipeline. The critical rates for a two-phase slug flow are determined. It is revealed that an increase in the soil density of the bases leads to an increase in the critical rate of gas flow. It is shown that an account of viscoelastic properties of structure material and earth bases leads to a decrease in the critical flow rate.

Document type: Article

Joint Operating Revenue and Passenger Travel Cost Optimization in Urban Rail Transit

Scipedia content — Fri, 12 Feb 2021 14:59:36 +0100

Urban rail transit (URT) scheduling requires designing efficient timetables that can meet passengers’ expectations about the lower travel cost while attaining revenue management objectives of the train operators. This paper presents a biobjective timetable optimization model that seeks maximizing the operating revenue of the railway company while lowering passengers’ average travel cost. We apply a fuzzy multiobjective optimization and a nondominated sorting genetic algorithm II to solve the optimization problem and characterize the trade-off between the conflicting objective functions under different types of distances. To illustrate the model and solution methodology, the proposed model and solution algorithms are validated against train operation record from a URT line of Chengdu metro in China. The results show that significant improvements can be achieved in terms of the travel cost and revenue return criteria when implementing the solutions obtained by the proposed model.

Document type: Article

Wave Equation of Suppressed Traffic Flow Instabilities

Scipedia content — Fri, 12 Feb 2021 14:55:35 +0100

Traffic congestion wastes fuel and commuters' time, and adds to CO₂ emissions. Stop-and-go traffic instabilities can be suppresses using bilateral control - which differs from 'car following' and adaptive cruise control in that, counter-intuitively, it uses information about the following vehicle (as well as about the leading vehicle). Stability can be proven mathematically, and can be demonstrated in simulation. A physical analog of a sequence of vehicles using bilateral control is a chain of masses connected by springs and dampers - a system which is inherently stable, since it lacks an external energy source. Here, in order to further understand bilateral control and its capacity to suppress instabilities, we move from a microscopic view (interaction of individual vehicles) to a macroscopic view (densities and flow rates). This leads us to the damped wave equation governing traffic under bilateral control. That equation allows us to determine the speed of propagation of disturbances, as well as their rate of decay. The equation is also useful in fine tuning parameters of bilateral control systems.

Document type: Article

Highway Project Value of Money Assessment under PPP Mode and Its Application

Scipedia content — Fri, 12 Feb 2021 14:53:04 +0100

The application of Public-Private Partnership (PPP) mode in transportation infrastructure construction has achieved more progress worldwide; now this mode has been adopted in highway projects of China from 2015. In the application of PPP mode, there are three main facts in China, which include whether the government is responsible for land acquisition and resettlement (LAR), the discount rate changes, and the replacement of business tax by value-added tax (VAT) in 2016. So this paper discusses Value for Money (VFM) quantitative assessment of highway projects under PPP mode in China, which considers currently three actual issues in China. A case study of Heda freeway in China has shown that "mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"""mml:mo stretchy="false""("/mml:mo""mml:mn fontstyle="italic""1"/mml:mn""mml:mo stretchy="false"")"/mml:mo""/mml:math" the government’s responsibility for LAR compensation may attract social capital investor and reduce the risk of social instability, "mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"""mml:mo stretchy="false""("/mml:mo""mml:mn fontstyle="italic""2"/mml:mn""mml:mo stretchy="false"")"/mml:mo""/mml:math" a reasonable range of a low discount rate can greatly reduce government expenditure, and "mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"""mml:mo stretchy="false""("/mml:mo""mml:mn fontstyle="italic""3"/mml:mn""mml:mo stretchy="false"")"/mml:mo""/mml:math" the replacement of business tax by VAT will increase the highway project company’s burden. The research results will be helpful for value of money assessment of highway projects under PPP mode in China and may offer the reference for other countries’ highway projects under PPP mode.

Document type: Article

Impact of a Lower Conservation Budget on Road Safety Indices

Scipedia content — Fri, 12 Feb 2021 14:47:57 +0100

Over the past few years, several countries, including Spain, have been experiencing a period of economic recession. As a result, these governments have reduced their budgets for transport infrastructures (both construction and maintenance operations). The main objective of this study is to analyze whether these budget reductions have an effect on increased accident rates and to perform an assessment of their real economic benefit. Thus, we analyze whether significant changes over recent years are perceptible in the road safety indexes in Spain, in terms of risk, accident fatality, and accident severity. The relation between lower budgets and higher road safety indices is analyzed through linear regression techniques. The results show a strong relation between the Risk Index and the maintenance budget, measured as an average of the last years. In addition, a final economic assessment demonstrates that this reduction in investment had no real economic benefits, especially as the costs of the accidents exceeded the savings in the conservation plans.

Document type: Article

An Experimental Setup with Alternating Current Capability for Evaluating Large Lithium-Ion Battery Cells

Scipedia content — Fri, 12 Feb 2021 14:47:41 +0100

In the majority of applications using lithium-ion batteries, batteries are exposed to some harmonic content apart from the main charging/discharging current. The understanding of the effects that alternating currents have on batteries requires specific characterization methods and accurate measurement equipment. The lack of commercial battery testers with high alternating current capability simultaneously to the ability of operating at frequencies above 200 Hz, led to the design of the presented experimental setup. Additionally, the experimental setup expands the state-of-the-art of lithium-ion batteries testers by incorporating relevant lithium-ion battery cell characterization routines, namely hybrid pulse power current, incremental capacity analysis and galvanic intermittent titration technique. In this paper the hardware and the measurement capabilities of the experimental setup are presented. Moreover, the measurements errors due to the setup&rsquo

s instruments were analysed to ensure lithium-ion batteries cell characterization quality. Finally, this paper presents preliminary results of capacity fade tests where 28 Ah cells were cycled with and without the injection of 21 A alternating at 1 kHz. Up to 300 cycles, no significant fade in cell capacity may be measured, meaning that alternating currents may not be as harmful for lithium-ion batteries as considered so far.

Document type: Article

Air traffic management based on 4D-trajectories: requirements and practical implementation

Scipedia content — Fri, 12 Feb 2021 14:44:42 +0100

The current Air Traffic Management (ATM) functional approach is changing: ‘time’ is now integrated as an additional fourth dimension on trajectories. This notion will impose on aircraft the compliance of accurately arrival times over designated checkpoints, called Time Windows (TWs). In this context, we review the operational concept of 4D-trajectories, by initially developing an analysis of basic requirements for their implementation in the Communications, Navigation and Surveillance (CNS) systems and then by investigating their management in the future ATM context. We focus on defining the relationships between 4D-trajectories and other concepts and systems of the future ATM framework, and the needs that it will require for its application, detailing the main tools, programs and ATM/CNS systems that must be deployed. We appraise how 4D-trajectories must be managed and planned (negotiation, synchronization, modification and verification processes). Then, based on the degradation of a 4D-trajectory, we define and introduce the necessary corrective measures by evaluating the degradation tolerances and conditions.

Document type: Article

Ridesharing Problem with Flexible Pickup and Delivery Locations for App-Based Transportation Service: Mathematical Modeling and Decomposition Methods

Scipedia content — Fri, 12 Feb 2021 14:43:22 +0100

App-based transportation service system, such as Uber and Didi, has brought a new transportation mode to users, who are able to make reservations using mobile apps conveniently. However, one of the fundamental challenges in app-based transportation system is the inefficiency and unreliability of the vehicle routing plans caused by complex topology of urban road network and unpredictable traffic conditions. A common way to tackle this problem is repositioning pickup or delivery locations via the coordination between drivers and passengers. This paper studies an on-demand ridesharing problem that determines the optimal ride-share matching strategy and vehicle routing plan with respect to flexible pickup and delivery locations. By introducing the concept of space-time windows, the problem is formulated as the pickup and delivery problem with space-time windows (PDPSW) in space-time network. To solve the model efficiently and accurately, we particularly develop a customized solution approach based on Lagrangian relaxation. Numerical examples are conducted to demonstrate the performance of the proposed framework and draw some managerial insights into the optimal system operation. The results indicate that adopting the serving strategy of flexible pickup and delivery locations will evidently reduce the system cost and improve the service quality in app-based transportation service systems.

Document type: Article

Challenges in Governing the Digital Transportation Ecosystem in Jakarta: A Research Direction in Smart City Frameworks

Scipedia content — Fri, 12 Feb 2021 14:42:43 +0100

Mobility is one of the most difficult domains of the smart city to face. In fact, most large cities in the world are still facing urban mobility problems, especially traffic congestion. Particularly, in Jakarta, Indonesia, traffic congestion is a major issue that negatively affects productivity and the overall living quality of the citizens. Along with the development of the information communication and technology (ICT), the transportation domain in Jakarta has formed a digital transportation ecosystem, shown by the emergence of innovative digital-based transportation services. In line with this current condition, this paper hopes to contribute to the improvement of urban traffic in Jakarta by proposing research directions to govern the digital transportation ecosystem within a smart city framework. The significance of the research directions is reviewed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology in a systematic review of previous studies. Ultimately, the research directions proposed in this paper lead to the necessity for an architectural perspective and relevant big data analytical tools to improve the digital transportation ecosystem in Jakarta.

Document type: Article

Changes in Trust after Driving Level 2 Automated Cars

Scipedia content — Fri, 12 Feb 2021 14:40:49 +0100

Overtrust and undertrust are major issues with partially automated vehicles. Ideally, trust should be"jats:italic" calibrated"/jats:italic" ensuring that drivers’ subjective feelings of safety match the objective reliability of the vehicle. In the present study, we examined if drivers’ trust toward Level 2 cars changed after on-road experience. Drivers’ self-reported trust was assessed three times: before having experience with these vehicles, immediately after driving two types of vehicles, and two weeks after the driving experience. Analysis of the results showed major changes in trust scores after the on-road driving experience. Before experiencing the vehicles, participants tended to overestimate the vehicle capabilities. Afterwards they had a better understanding of vehicles’ limitations, resulting in better calibrated trust.

Document type: Article

Urban Cycling as an Indicator of Socio-Economic Innovation and Sustainable Transport

Scipedia content — Fri, 12 Feb 2021 14:40:35 +0100

"jats:p"Environmental pollution in cities is an increasingly popular issue tackled in research. One of the elements with a significant impact on the state of urban ecosystems is transport with its pressure on individual components of the environment. Sustainable urban transport is gaining prominence as a postulate expressed in cities’ strategic documents, constituting an element alleviating the negative effects of anthropopressure. In the light of the need to introduce innovative solutions for clean forms of transport, numerous papers indicate the bicycle as an answer to some of those problems. The article presents a review of literature referring to the socio-economic aspects of using the bicycle in cities as a means of transport for daily commuting. The analysis is based on publications on cyclist safety in road traffic, the perception of the bicycle as a means of transport in cities, and the introduction of innovative solutions, such as bicycle-sharing systems.

Document type: Article

The Analysis of Spatial Pattern and Hotspots of Aviation Accident and Ranking the Potential Risk Airports Based on GIS Platform

Scipedia content — Fri, 12 Feb 2021 14:39:51 +0100

Aviation accident analysis is an important task to ensure aviation safety. The existing researches mainly focus on the analysis of aviation accident time characteristics and accident causes and less analysis of the spatial characteristics of aviation accidents. The spatial characteristics analysis of aviation accidents can identify hot spots of aviation accidents, improve the accuracy of aviation accident emergency management, and provide decision support for airport route planning. This study established the severity index of aviation accident based on aviation accident data, using GIS spatial analysis methods to study the spatial distribution characteristics of aviation accidents. The hot spots were identified in the aviation accidents. Finally, airports around the accident hot spots were ranked to obtain the airports with high potential aviation risks based on RI, taking Florida as an example. It was found that in the Florida aviation accident, general aviation accidents accounted for the majority, but the aviation accident severity index for air route flight was far greater than general aviation accidents. From the spatial distribution point of view, accidents with high severity index were distributed around large international airports. The Density Center for Aviation Accidents was located in Tampa, Miami, and some airports link areas in Florida. In terms of the Moran’s I index, the distribution of aviation accidents tended to aggregate in the region as a whole. However, aviation accident severity index was randomly distributed for each year separately. At the level of significance of 0.01, there were a total of 75 accident hotspots in the Florida region, mainly in the north and southwest. Airports with high RI in the Florida area were mainly concentrated in the Miami area and the Tampa Bay area, and Orlando Airport was ranked outside the top 10.

Document type: Article

Impact on Network Performance of Probe Vehicle Data Usage: An Experimental Design for Simulation Assessment

Scipedia content — Fri, 12 Feb 2021 14:35:21 +0100

Probe-based technologies are proliferating as a means of inferring traffic states. Technological companies are interested in traffic data for computing the best routes in a traffic-aware manner and they also provide real-time traffic information with certain temporal accuracy. This paper analyses and evaluates how data provided by a fleet of probe cars can be used to develop a navigation service and how the penetration rate of this service affects a set of city-scale KPIs (Key Performance Indicators) and driver KPIs. The case study adopts a model-driven approach in which microscopic simulation emulates real-size fleets of probe vehicles that provide positions and speed data. What is noteworthy about the modelling behaviour is that drivers are segmented according to their knowledge of network conditions for selected trips: experts, regular drivers, and tourists. The paper presents and discusses the modelling approach and the results obtained from an experimental Barcelona CBD model designed to evaluate the penetration rates of probe vehicles and route guidance. An analysis of the simulation experiments reveals remarkable links among city-scale KPIs, which—from a multivariate point of view—is a novelty. A simulation-based framework for results analysis and visualization is also introduced in order to simplify the simulation results analysis and easily visualize OD paths for driver segments.

Throughout this work, the authors have benefited from the support of inLab FIB team at UPC and the suggestions of Jaume Barceló (Emeritus Professor at UPC). This research was funded by Spanish R+D Programs, TRA2016-76914-C3-1-P, and by Secretaria d’Universitats-i-Recerca-Generalitat de Catalunya, 2017-SGR-1749.

Peer Reviewed

Document type: Article

Optimization of Base Location and Patrol Routes for Unmanned Aerial Vehicles in Border Intelligence, Surveillance, and Reconnaissance

Scipedia content — Fri, 12 Feb 2021 14:29:16 +0100

The location-routing problem (LRP) of unmanned aerial vehicles (UAV) in border patrol for Intelligence, Surveillance, and Reconnaissance is investigated, where the locations of UAV base stations and the UAV flying routes for visiting the targets in border area are jointly optimized. The capacity of the base station and the endurance of the UAV are considered. A binary integer programming model is developed to formulate the problem, and two heuristic algorithms combined with local search strategies are designed for solving the problem. The experiment design for simulating the distribution of stations and targets in border is proposed for generating random test instances. Also, an example based on the practical border in Guangxi is presented to illustrate the problem and the solution approach. The performance of the two algorithms is analysed and compared through randomly generated instances.

Document type: Article

Core and critical cities of global region airport networks

Scipedia content — Fri, 12 Feb 2021 14:28:40 +0100

transport is one of the key infrastructures of today’s global economy. Connections between airports define airport networks, where nodes are cities served by airports, connected by edges if there is at least one direct flight connecting them. The aims of this research are to relate structural properties of airport networks which explain how these networks respond to isolation of critical nodes, and to gain insight into relevant socio-economic factors that influence the development of airport networks. We split the world airport network (WAN) into seven global region airport networks (GRANs), using the divisions established by OAG database. We gather information about structural properties of each GRAN determining core cities through k-core decomposition, and critical cities through robustness analysis. We find that differences of robustness across GRANs can be explained by the fraction of core cities relative to total cities. Furthermore, analysis of multilevel structure reveal relevant differences between GRANs, rooted on geographical and socio-economic factors, and give insight about how network robustness in airport networks can be enhanced

Peer Reviewed

Document type: Article

OSM Data Import as an Outreach Tool to Trigger Community Growth? A Case Study in Miami

Scipedia content — Fri, 12 Feb 2021 14:28:28 +0100

This paper presents the results of a study that explored if and how an OpenStreetMap (OSM) data import task can contribute to OSM community growth. Different outreach techniques were used to introduce a building import task to three targeted OSM user groups. First, existing OSM members were contacted and asked to join the data import project. Second, several local community events were organized with Maptime Miami to engage local mappers in OSM contribution activities. Third, the import task was introduced as an extra credit assignment in two GIS courses at the University of Florida. The paper analyzes spatio-temporal user contributions of these target groups to assess the effectiveness of the different outreach techniques for recruitment and retention of OSM contributors. Results suggest that the type of prospective users that were contacted through our outreach efforts, and their different motivations play a major role in their editing activity. Results also revealed differences in editing patterns between newly recruited users and already established mappers. More specifically, long-term engagement of newly registered OSM mappers did not succeed, whereas already established contributors continued to import and improve data. In general, we found that an OSM data import project can add valuable data to the map, but also that encouraging long-term engagement of new users, whether it be within the academic environment or outside, proved to be challenging.

Document type: Article

Additional Stress on a Buried Pipeline under the Influence of Coal Mining Subsidence

Scipedia content — Fri, 12 Feb 2021 14:27:48 +0100

Buried pipelines influenced by coal mining subsidence will deform and generate additional stress during surface deformation. On the basis of the coordinating deformation relationship between buried pipeline and its surrounding soils, a stress analysis method of a buried pipeline induced by mining was proposed. The buried pipeline additional stresses were analyzed; meanwhile, a corresponding analysis process of the pipeline stresses was also presented during mining subsidence. Furthermore, based on the ground subsidence along the pipeline predicted in advance by the probability integral method, the additional stresses and Von Mises equivalent stresses and their distributions along the buried pipeline induced by the exploitation of a coal mining working face named 14101 were obtained. Meanwhile, a comparative analysis of additional stresses between simulation and analytical calculation was performed for the deep analysis and reliability of the results presented by the proposed methodology in this paper. The proposed method provides references for analysis of the additional stress and safety of buried pipelines under the influence of mining subsidence.

Document type: Article

A Torque Vectoring Control for Enhancing Vehicle Performance in Drifting

Scipedia content — Fri, 12 Feb 2021 14:27:32 +0100

When dealing with electric vehicles, different powertrain layouts can be exploited. Among them, the most interesting one in terms of vehicle lateral dynamics is represented by the one with independent electric motors: two or four electric motors. This allows torque-vectoring control strategies to be applied for increasing vehicle lateral performance and stability. In this paper, a novel control strategy based on torque-vectoring is used to design a drifting control that helps the driver in controlling the vehicle in such a condition. Drift is a particular cornering condition in which high values of sideslip angle are obtained and maintained during the turn. The controller is applied to a rear-wheel drive race car prototype with two independent electric motors on the rear axle. The controller relies only on lateral acceleration, yaw rate, and vehicle speed measurement. This makes it independent from state estimators, which can affect its performance and robustness.

Document type: Article

Automatic detection of traffic lights, street crossings and urban roundabouts combining outlier detection and deep learning classification techniques based on GPS traces while driving

Scipedia content — Fri, 12 Feb 2021 14:26:50 +0100

The automatic generation of street networks is attracting the attention of research and industry communities in areas such as routable map generation. This paper presents a novel mechanism that focuses on the automatic detection of street elements such as traffic lights, street crossings and roundabouts which could be used to generate street maps and populate them with traffic influencing infrastructural elements such as traffic lights. In order to minimize the system requirements and simplify the data collection from many users with minimal impact for them, only traces of GPS data from a mobile device while driving are used. Speed and acceleration time series are derived from the GPS data. An outlier detection algorithm is used first in order to detect abnormal driving locations (which can be due to infrastructural elements or particular traffic conditions). Using deep learning, speed and acceleration patterns are automatically analyzed at each outlier in order to extract relevant features which are then classified into a traffic light, street crossing, urban roundabout or other element. The classification results are enhanced by adding the degree of atypicity for each point calculated as the percentage of times that a particular location is detected as an outlier in several drives. The proposed algorithm achieves a combined recall of 0.89 and a combined precision of 0.88 for classification. The research leading to these results has received funding from the “HERMES-SMART DRIVER” project TIN2013-46801-C4-2-R (MINECO), funded by the Spanish Agencia Estatal de Investigación (AEI), and the “ANALYTICS USING SENSOR DATA FOR FLATCITY” project TIN2016-77158-C4-1-R (MINECO/ ERDF, EU) funded by the Spanish Agencia Estatal de Investigación (AEI) and the European Regional Development Fund (ERDF).

Document type: Article

An Overview of Problems and Solutions for Urban Freight Transport in Brazilian Cities

Scipedia content — Fri, 12 Feb 2021 14:23:15 +0100

Urban freight transport is a challenge for Brazilian cities due to the lack of adequate planning for freight flow movement. Public managers also show negligence and a lack of awareness when dealing with urban logistics. Decision-support data on urban freight transport are still scarce, despite being of fundamental value to economic development. With this in mind, this paper presents problems and solutions regarding urban freight transport in Brazilian cities. Data were obtained through a survey conducted in nine cities and analysed by means of descriptive statistics and the successive intervals method. Additionally, a cluster analysis was performed to identify patterns regarding the typical characteristics of each city in order to compare and generalise the perception of retailers regarding problems and solutions at the national level. The results indicate divergent opinions among retailers from different cities, even from cities with similar socioeconomic profiles and urban dynamics. The municipalities which demonstrated the most similarities were (i) Betim and Niteroi, in the Southeast of Brazil; (ii) Palmas and Quixada, in the North and Northeast, respectively; and (iii) Palmas and Caruaru, also in the North and Northeast. The results reinforce the importance of studying the local context and involving stakeholders in the process of planning urban logistics solutions.

Document type: Article

Analysis of high-speed rail and airline transport cooperation in presence of non-purchase option

Scipedia content — Fri, 12 Feb 2021 14:21:44 +0100

We study cooperation between the airline and high-speed rail (HSR) sectors by formulating their joint profit as a maximization problem using a multinomial logit choice model in a three-node setting. We allow the non-purchase option as an outside option available to consumers. The demand for each choice is not only a function of the price but also the service quality, such as the total trip time, frequency of service, and ease of connecting from the hub to a nearby HSR station. As a result, the following findings are presented. First, regardless of the service quality of either sector and the non-purchase option, cooperation decreases the total volume of the domestic market of a country. Second, when the attractiveness of the outside option is high, the HSR and air sectors can prevent a large reduction in the total volume by cooperation in the connecting market. However, this is not the case in the domestic market. Third, if the non-purchase quality in the domestic market is high, then cooperation increases the social welfare of the whole market. If the non-purchase quality is low, then cooperation increases the welfare of the whole market only in cases where the number of potential customers in the connecting market is relatively large. We also show the effect of improving air–rail service quality on each market share and on the total profit.

Document type: Article

Estimation of Urban Link Travel Time Distribution Using Markov Chains and Bayesian Approaches

Scipedia content — Fri, 12 Feb 2021 14:19:52 +0100

Despite the wide application of Floating Car Data (FCD) in urban link travel time and congestion estimation, the sparsity of observations from a low penetration rate of GPS-equipped floating cars make it difficult to estimate travel time distribution (TTD), especially when the travel times may have multimodal distributions that are associated with the underlying traffic states. In this case, the study develops a Bayesian approach based on particle filter framework for link TTD estimation using real-time and historical travel time observations from FCD. First, link travel times are classified by different traffic states according to the levels of vehicle delays. Then, a state-transition function is represented as a Transition Probability Matrix of the Markov chain between upstream and current links with historical observations. Using the state-transition function, an importance distribution is constructed as the summation of historical link TTDs conditional on states weighted by the current link state probabilities. Further, a sampling strategy is developed to address the sparsity problem of observations by selecting the particles with larger weights in terms of the importance distribution and a Gaussian likelihood function. Finally, the current link TTD can be reconstructed by a generic Markov Chain Monte Carlo algorithm incorporating high weighted particles. The proposed approach is evaluated using real-world FCD. The results indicate that the proposed approach provides good accurate estimations, which are very close to the empirical distributions. In addition, the approach with different percentage of floating cars is tested. The results are encouraging, even when multimodal distributions and very few or no observations exist.

Document type: Article

Technology and Instrument Constituencies as Agents of Innovation: Sustainability Transitions and the Governance of Urban Transport

Scipedia content — Fri, 12 Feb 2021 14:19:35 +0100

Sustainable urban transport is a complex challenge requiring innovation in technologies, culture, and policies. Given the systemic nature of the issues involved, numerous studies have applied the transitions approach to urban transport. However, relatively weak conceptualization of agency in the transitions literature limits the usefulness of this approach for the governance of urban transport. The objective of this study is to contribute to the conceptualization of agency in the multilevel perspective to sustainability transitions. We propose that two types of actors exercise agency to foster innovation: technology constituencies, who promote the adoption of specific technologies by citizens, businesses, or governments; and instrument constituencies, who promote the adoption of specific policy instruments. In focusing predominantly on technological innovation, the transitions literature has generally juxtaposed these constituencies or considered them to be the same. We posit that the two constitute distinct, albeit possibly overlapping, actors and that their relationship(s) help better understand and explain how transitions evolve. We discuss the implications of this distinction for the governance of urban transport and argue that the presence of instrument and technology constituencies, and their relationship(s), should be examined empirically in future research.

Document type: Article

Machine Learning and Cognitive Ergonomics in Air Traffic Management: Recent Developments and Considerations for Certification

Scipedia content — Fri, 12 Feb 2021 14:15:55 +0100

Resurgent interest in artificial intelligence (AI) techniques focused research attention on their application in aviation systems including air traffic management (ATM), air traffic flow management (ATFM), and unmanned aerial systems traffic management (UTM). By considering a novel cognitive human&ndash

machine interface (HMI), configured via machine learning, we examined the requirements for such techniques to be deployed operationally in an ATM system, exploring aspects of vendor verification, regulatory certification, and end-user acceptance. We conclude that research into related fields such as explainable AI (XAI) and computer-aided verification needs to keep pace with applied AI research in order to close the research gaps that could hinder operational deployment. Furthermore, we postulate that the increasing levels of automation and autonomy introduced by AI techniques will eventually subject ATM systems to certification requirements, and we propose a means by which ground-based ATM systems can be accommodated into the existing certification framework for aviation systems.

Document type: Article

Decarbonization Pathways for International Maritime Transport: A Model-Based Policy Impact Assessment

Scipedia content — Fri, 12 Feb 2021 14:15:07 +0100

International shipping has finally set a target to reduce its CO2 emission by at least 50% by 2050. Despite this positive progress, this target is still not sufficient to reach Paris Agreement goals since CO2 emissions from international shipping could reach 17% of global emissions by 2050 if no measures are taken. A key factor that hampers the achievement of Paris goals is the knowledge gap in terms of what level of decarbonization it is possible to achieve using all the available technologies. This paper examines the technical possibility of achieving the 1.5°

goal of the Paris Agreement and the required supporting policy measures. We project the transport demand for 6 ship types (dry bulk, container, oil tanker, gas, wet product and chemical, and general cargo) based on the Organization for Economic Co-operation and Development&rsquo

s (OECD&rsquo

s) global trade projection of 25 commodities. Subsequently, we test the impact of mitigation measures on CO2 emissions until 2035 using an international freight transport and emission model. We present four possible decarbonization pathways which combine all the technologies available today. We found that an 82&ndash

95% reduction in CO2 emissions could be possible by 2035. Finally, we examine the barriers and the relevant policy measures to advance the decarbonization of international maritime transport.

Document type: Article

A Robust Longitudinal Control Strategy of Platoons under Model Uncertainties and Time Delays

Scipedia content — Fri, 12 Feb 2021 14:12:30 +0100

Automated vehicles are designed to free drivers from driving tasks and are expected to improve traffic safety and efficiency when connected via vehicle-to-vehicle communication, that is, connected automated vehicles (CAVs). The time delays and model uncertainties in vehicle control systems pose challenges for automated driving in real world. Ignoring them may render the performance of cooperative driving systems unsatisfactory or even unstable. This paper aims to design a robust and flexible platooning control strategy for CAVs. A centralized control method is presented, where the leader of a CAV platoon collects information from followers, computes the desired accelerations of all controlled vehicles, and broadcasts the desired accelerations to followers. The robust platooning is formulated as a Min-Max Model Predictive Control (MM-MPC) problem, where optimal accelerations are generated to minimize the cost function under the"jats:italic" worst case"/jats:italic", where the worst case is taken over the possible models. The proposed method is flexible in such a way that it can be applied to both homogeneous platoon and heterogeneous platoon with mixed human-driven and automated controlled vehicles. A third-order linear vehicle model with fixed feedback delay and stochastic actuator lag is used to predict the platoon behavior. Actuator lag is assumed to vary randomly with unknown distributions but a known upper bound. The controller regulates platoon accelerations over a time horizon to minimize a cost function representing driving safety, efficiency, and ride comfort, subject to speed limits, plausible acceleration range, and minimal net spacing. The designed strategy is tested by simulating homogeneous and heterogeneous platoons in a number of typical and extreme scenarios to assess the system stability and performance. The test results demonstrate that the designed control strategy for CAV can ensure the robustness of stability and performance against model uncertainties and feedback delay and outperforms the deterministic MPC based platooning control.

Document type: Article

Experimental Data-Driven Parameter Identification and State of Charge Estimation for a Li-Ion Battery Equivalent Circuit Model

Scipedia content — Fri, 12 Feb 2021 14:11:35 +0100

It is well known that accurate identification of the key state parameters and State of Charge (SOC) estimation method for a Li-ion battery cell is of great significance for advanced battery management system (BMS) of electric vehicles (EVs), which further facilitates the commercialization of EVs. This study proposed a systematic experimental data-driven parameter identification scheme and an adaptive extended Kalman Filter (AEKF)-based SOC estimation algorithm for a Li-Ion battery equivalent circuit model in EV applications. The key state parameters of Li-ion battery cell were identified based on the second-order resistor capacitor (RC) equivalent circuit model and the experimental battery test data using genetic algorithm (GA). Meanwhile, the proposed parameter identification procedure was validated by carrying out a comparative study of the simulated and experimental output voltage under the same input current profile. Then, SOC estimation was performed based on the AEKF algorithm. Finally, the effectiveness and feasibility of the proposed SOC estimator was verified by loading different operating profiles.

Document type: Article

Travelling wave solutions of the perturbed mKdV equation that represent traffic congestion

Scipedia content — Fri, 12 Feb 2021 14:09:50 +0100

A well-known optimal velocity (OV) model describes vehicle motion along a single lane road, which reduces to a perturbed modified Korteweg–de Vries (mKdV) equation within the unstable regime. Steady travelling wave solutions to this equation are then derived with a multi-scale perturbation technique, where the travelling wave propagation coordinate depends upon slow and fast variables. The leading order solution in the hierarchy is then written in terms of these multi-scaled variables. At the following order, a system of differential equations is highlighted that govern the slowly evolving properties of the leading solution. Next, it is shown that the critical points of this system signify travelling waves without slow variation. As a result, a family of steady waves with constant amplitude and period are identified. When periodic boundary conditions are satisfied, these solutions’ parameters, including the wave speed, are associated with the driver’s sensitivity, a ˆ , which appears in the OV model. For some given a ˆ , solutions of both an upward and downward form exist, with the downward type corresponding to traffic congestion. Numerical simulations are used to validate the asymptotic analysis and also to examine the long-time behaviour of our solutions.

Document type: Article

Improving Bus Operations through Integrated Dynamic Holding Control and Schedule Optimization

Scipedia content — Fri, 12 Feb 2021 14:09:31 +0100

Bus bunching can lead to unreliable bus services if not controlled properly. Passengers will suffer from the uncertainty of travel time and the excessive waiting time. Existing dynamic holding strategies to address bus bunching have two major limitations. First, existing models often rely on large slack time to ensure the validity of the underlying model. Such large slack time can significantly reduce the bus operation efficiency by increasing the overall route travel times. Second, the existing holding strategies rarely consider the impact on the schedule planning. Undesirable results such as bus overloading issues arise when the bus fleet size is limited. This paper explores analytically the relationship between the slack time and the effect of holding control. The optimal slack time determined based on the derived relationship is found to be ten times smaller than in previous models based on numerical simulation results. An optimization model is developed with passenger-orient objective function in terms of travel cost and constraints such as fleet size limit, layover time at terminals, and other schedule planning factors. The optimal choice of control stops, control parameters, and slack time can be achieved by solving the optimization. The proposed model is validated with a case study established based on field data collected from Chengdu, China. The numerical simulation uses the field passenger demand, bus average travel time, travel time variance of road segments, and signal timings. Results show that the proposed model significantly reduce passengers average travel time compared with existing methods.

Document type: Article

Cloud-Based Behavioral Monitoring in Smart Homes

Scipedia content — Fri, 12 Feb 2021 14:08:29 +0100

Environmental sensors are exploited in smart homes for many purposes. Sensor data inherently carries behavioral information, possibly useful to infer wellness and health-related insights in an indirect fashion. In order to exploit such features, however, powerful analytics are needed to convert raw sensor output into meaningful and accessible knowledge. In this paper, a complete monitoring architecture is presented, including home sensors and cloud-based back-end services. Unsupervised techniques for behavioral data analysis are presented, including: (i) regression and outlier detection models (also used as feature extractors for more complex models)

(ii) statistical hypothesis testing frameworks for detecting changes in sensor-detected activities

and (iii) a clustering process, leveraging deep learning techniques, for extracting complex, multivariate patterns from daily sensor data. Such methods are discussed and evaluated on real-life data, collected within several EU-funded projects. Overall, the presented methods may prove very useful to build effective monitoring services, suitable for practical exploitation in caregiving activities, complementing conventional telemedicine techniques.

Document type: Article

Comparative Life Cycle Analysis of Conventional and Hybrid Heavy-Duty Trucks

Scipedia content — Fri, 12 Feb 2021 14:06:43 +0100

Heavy-duty trucks are one of the main contributors to greenhouse gas emissions in German traffic. Drivetrain electrification is an option to reduce tailpipe emissions by increasing energy conversion efficiency. To evaluate the vehicle&rsquo

s environmental impacts, it is necessary to consider the entire life cycle. In addition to the daily use, it is also necessary to include the impact of production and disposal. This study presents the comparative life cycle analysis of a parallel hybrid and a conventional heavy-duty truck in long-haul operation. Assuming a uniform vehicle glider, only the differing parts of both drivetrains are taken into account to calculate the environmental burdens of the production. The use phase is modeled by a backward simulation in MATLAB/Simulink considering a characteristic driving cycle. A break-even analysis is conducted to show at what mileage the larger CO2eq emissions due to the production of the electric drivetrain are compensated. The effect of parameter variation on the break-even mileage is investigated by a sensitivity analysis. The results of this analysis show the difference in CO2eq/t km is negative, indicating that the hybrid vehicle releases 4.34 g CO2eq/t km over a lifetime fewer emissions compared to the diesel truck. The break-even analysis also emphasizes the advantages of the electrified drivetrain, compensating the larger emissions generated during production after already a distance of 15,800 km (approx. 1.5 months of operation time). The intersection coordinates, distance, and CO2eq, strongly depend on fuel, emissions for battery production and the driving profile, which lead to nearly all parameter variations showing an increase in break-even distance.

Document type: Article

Urban Rail Transit Present Situation and Future Development Trends in China: Overall Analysis Based on National Policies and Strategic Plans in 2016–2020

Scipedia content — Fri, 12 Feb 2021 14:04:35 +0100

This study analyzes the development of the urban rail transit industry in China from an overall and macroscopic perspective. Multiple factors were considered, such as the degree of urbanization, non-public vehicle ownership, road capacity, and modal share of public transport in international metropolises, as well as planning and construction of urban rail transit systems in China’s large and extra-large cities. Through extensive investigations and research, this paper presents a comprehensive, systematic, and in-depth analysis and explanation of the domestic social demands and environmental background for the development of urban rail transit in China. Based on national development policies and strategic plans, information on current cutting-edge technologies, the adaptability of various urban rail transit modes, industrial technologies, local finances as well as investment and financing models, this study analyzes the opportunities and challenges that the development of urban rail transit in China faces over the 2016–2020 period aligned with China’s 13th Five-Year Plan. This paper aims to provide a forecast and outlook on the period’s ten major trends. The predicted trends include expanded scale, differentiated development, networked structure, multimodal transit systems, industrial standardization, intelligent systems, self-developed technology, diversified funding, international markets, and strategic planning. This article presents a comprehensive analysis of the current situation, development prospects, and future trends of urban rail transit in China and proposes corresponding measures and strategies. The findings can serve as an important and valuable reference for the development of urban rail transit in China and other countries.

Document type: Article

Influence of railway loading on the performance of soil-filled masonry arch bridges

Scipedia content — Fri, 12 Feb 2021 13:58:13 +0100

Masonry arch bridges are found in large numbers on the rail networks of Europe and other parts of the world. However, the mode of response of masonry arch structures subjected to railway loading is little understood. To address this, an experimental study involving large-scale physical models of backfilled masonry arch bridges subjected to railway loading conditions has recently been conducted. This has explored the influence of the rail track bed system on bridge behaviour and on load carrying capacity. Tests indicate that the track bed system fundamentally alters the mode of response of the bridge system, and significantly increases load carrying capacity. Using the same test facility, load tests have also been used to explore and characterise the behaviour and performance of damaged arch bridges, with the test results obtained suggesting that although there is likely to be a reduction in overall capacity, even a significantly damaged arch bridge can still perform adequately under loading. This has important implications for bridge owners and assessment engineers."br/"\\ud "br/"\\ud "strong"Keywords:"/strong" masonry arch bridges, physical modelling, cyclic loading, rail track system, backfill.

Document type: Article

Air Traffic Efficiency Analysis of Airliner Scheduled Flights Using Collaborative Actions for Renovation of Air Traffic Systems Open Data

Scipedia content — Fri, 12 Feb 2021 13:56:41 +0100

The increase in air traffic worldwide requires improvement of flight operational efficiency. This study aims to reveal the potential benefits, namely, savings on fuel consumption and flight time, which are expected for Japanese airspace, by statistically evaluating the operational efficiency defined by average differences of fuel consumption, flight time, and flight distance between the original and the optimized flight of domestic flights in Japan. The aircraft position and time data used in this study were obtained from Collaborative Actions for Renovation of Air Traffic Systems Open Data—the radar data released by the Japan Civil Aviation Bureau. Flight information, such as air data and fuel flow, is estimated by applying meteorological data and aircraft performance model to the position information of radar data. Each reconstructed trajectory is optimized in terms of flight fuel consumption and flight time with an assumed cost index (CI). Dynamic programming is used as the trajectory optimization method. The flight fuel consumption and flight time of the optimized flight are compared with the original values to evaluate the operational efficiency. Herein, approximately one-third of 1-day data, i.e., 1087 cases of four aircraft types, are analyzed with reasonable CI settings. Our research findings suggest that flight fuel consumption and flight distance can be saved by 312 kg and 19.7 km, respectively, on average for the object flights. Following a statistical comparison between the original and the optimized flights, it was observed that two types of features, namely, flying on a detoured path and flying with nonoptimal altitude and speed in the cruise phase, are major factors which deteriorate the total operational efficiency in terms of fuel consumption, flight time, and flight distance.

Document type: Article

Lane Marking Detection and Reconstruction with Line-Scan Imaging Data

Scipedia content — Fri, 12 Feb 2021 13:55:58 +0100

Lane marking detection and localization are crucial for autonomous driving and lane-based pavement surveys. Numerous studies have been done to detect and locate lane markings with the purpose of advanced driver assistance systems, in which image data are usually captured by vision-based cameras. However, a limited number of studies have been done to identify lane markings using high-resolution laser images for road condition evaluation. In this study, the laser images are acquired with a digital highway data vehicle (DHDV). Subsequently, a novel methodology is presented for the automated lane marking identification and reconstruction, and is implemented in four phases: (1) binarization of the laser images with a new threshold method (multi-box segmentation based threshold method); (2) determination of candidate lane markings with closing operations and a marching square algorithm; (3) identification of true lane marking by eliminating false positives (FPs) using a linear support vector machine method; and (4) reconstruction of the damaged and dash lane marking segments to form a continuous lane marking based on the geometry features such as adjacent lane marking location and lane width. Finally, a case study is given to validate effects of the novel methodology. The findings indicate the new strategy is robust in image binarization and lane marking localization. This study would be beneficial in road lane-based pavement condition evaluation such as lane-based rutting measurement and crack classification.

Document type: Article

Self-reporting traffic crashes – a systematic literature review

Scipedia content — Fri, 12 Feb 2021 13:54:26 +0100

Purpose A traffic safety analysis that is based on registered crashes often suffers from underreporting, which may result in biased conclusions and lead to misguided crash-prevention strategies. Self-reporting traffic crashes is a complementary method to obtain crash information that is often not available in official databases. By surveying studies from around the world, this paper aims to map the current practices in the collection of data from self-reporting traffic crashes. Method A systematic literature search was carried out in three databases, ScienceDirect, Scopus and Transport Research International Documentation (TRID), resulting in 134 reviewed studies. Results Self-reported crash studies were found to be more common in Europe, North America and Australasia, but there are few studies in developing countries. The reviewed studies mostly focused on adult road users (i.e. legal age of obtaining driving license and with no upper limit) and car users. Questionnaires (either paper based or online) were the most often used method, and 1 year was the most common recall period used. Regardless of its drawbacks, the reviewed studies showed that researchers ‘trust’ self-reports. Conclusion More studies should be conducted, especially targeting adolescent and young adults (age of 15–30 years) and vulnerable road users (VRUs). Developing countries should increase their efforts when it comes to using self-reporting to better assess the actual traffic safety situation and produce knowledge-based appropriate safety measures. Utilisation of smartphone application to assist data collection in self-reporting study for in-depth crash analysis should be explored further.

Document type: Article

Pengembangan Bandar Udara Fatmawati Dalam Mendukung Visit Wonderful Bengkulu 2020

Scipedia content — Fri, 12 Feb 2021 13:54:08 +0100

The Development of Fatmawati Airport in Supporting Visit Wonderful Bengkulu 2020: This research is conducted with regard to the strategy of Fatmawati Airport Bengkulu development in supporting Visit Bengkulu 2020. The purpose of this research is not only related to the development strategy of Fatmawati Airport Bengkulu in supporting Visit Bengkulu 2020 but also to determine the accessibility of the airport to the tourism sites. Primary and secondary data was used in this study. Data analysis was exercised using SWOT method and qualitative descriptive. The results of research indicate four Strength Opportunity (SO) strategies for the development of Fatmawati Airport Bengkulu, namely the need for increased investment cooperation and partnership with other agencies as the impact of the establishment of Fatmawati Airport Bengkulu as a BLU, airport development to serve the increase of air transport through the operation of wide body aircraft, increased commitment of excellent service by Fatmawati Airport Bengkulu with the support from the Ministry of Transportation and Local Government in the construction of airport facilities and increased accessibility from and to the tourist attraction sites due to its strategic location in the city center while has also become the main node of transportation, and availability of connecting transportation modes to support the accessibility to and from the airport among others two BRT corridors of “Trans Rafflesia” which is planned to cross the tourism sites in Bengkulu City where corridor 1 will getting passengers to Panjang Beach and Marlborought Port and corridor 2 to Dendam Lake. Penelitian ini dilakukan terkait dengan strategi pengembangan Bandar Udara Fatmawati Bengkulu dalam mendukung program Visit Wonderful Bengkulu 2020. Tujuan penelitian ini adalah untuk mengetahui strategi pengembangan Bandar Udara Fatmawati Bengkulu dalam mendukungan visit Bengkulu 2020, dan untuk mengetahui ketersediaan aksesibilitas (moda lanjutan) dari bandar udara Fatmawati Bengkulu ke obyek wisata dan sebaliknya. Penelitian menggunakan data primer dan sekunder. Analisis data dengan metode analisis SWOT dan deskriptif kualitatif. Hasil penelitian menunjukkan terdapat 4 (empat) Strength Opportunity (SO) strategi dalam pengembangan Bandar Udara Fatmawati Bengkulu, yaitu perlunya peningkatan kerjasama investasi dan kemitraan dengan instansi lain sebagai dampak dari penetapan Bandar udara Fatmawati sebagai BLU, pengembangan bandar udara untuk dapat melayani peningkatan angkutan udara melalui pengoperasian pesawat berbadan besar (wide body), peningkatan komitmen pelayanan prima bandar udara Fatmawati dengan dukungan Kementerian Perhubungan dan Pemerintah Daerah dalam pembangunan fasilitas bandar udara dan peningkatan aksesibilitas dari dan ke objek wisata karena letak bandar udara yang strategis di pusat kota dan menjadi simpul utama transportasi. Ketersedian moda lanjutan untuk mendukung aksesibilitas dari dan ke bandar udara antara lain 2 (dua) koridor BRT “Trans Rafflesia” yang direncanakan akan melintasi obyek wisata di Kota Bengkulu yaitu koridor 1 melewati pantai Panjang dan benteng Marlborough serta koridor 2 yang melewati obyek wisata danau Dendam.

Document type: Article

Traffic prediction using a self-adjusted evolutionary neural network

Scipedia content — Fri, 12 Feb 2021 13:51:16 +0100

Short-term prediction of traffic flow is one of the most essential elements of all proactive traffic control systems. The aim of this paper is to provide a model based on neural networks (NNs) for multi-step-ahead traffic prediction. NNs’ dependency on parameter setting is the major challenge in using them as a predictor. Given the fact that the best combination of NN parameters results in the minimum error of predicted output, the main problem is NN optimization. So, it is viable to set the best combination of the parameters according to a specific traffic behavior. On the other hand, an automatic method—which is applicable in general cases—is strongly desired to set appropriate parameters for neural networks. This paper defines a self-adjusted NN using the non-dominated sorting genetic algorithm II (NSGA-II) as a multi-objective optimizer for short-term prediction. NSGA-II is used to optimize the number of neurons in the first and second layers of the NN, learning ratio and slope of the activation function. This model addresses the challenge of optimizing a multi-output NN in a self-adjusted way. Performance of the developed network is evaluated by application to both univariate and multivariate traffic flow data from an urban highway. Results are analyzed based on the performance measures, showing that the genetic algorithm tunes the NN as well without any manually pre-adjustment. The achieved prediction accuracy is calculated with multiple measures such as the root mean square error (RMSE), and the RMSE value is 10 and 12 in the best configuration of the proposed model for single and multi-step-ahead traffic flow prediction, respectively.

Document type: Article

On the variation of the crash risk with the total number of bicyclists

Scipedia content — Fri, 12 Feb 2021 13:50:38 +0100

Introduction A prominent policy, which has been proposed in many European municipalities over the last years is the promotion of cycling to decrease pollution and to increase public health. One important part of the assessment of this policy is the estimation of the induced change in bicycle crash numbers. Several recent works supported the ideas by reporting that cycling becomes safer if the number of cyclists increases, i.e., there seems to be a safety-in-numbers effect (SiN). Methods The problems related to the interpretation of bicycle crash and volume data are discussed and an approach aiming at a better understanding of the SiN-phenomenon is presented. In particular it is proposed to adopt models with memory to pursue causal relations and to study SiN at different time scales. To estimate daily cyclist volumes from irregular counts, a weather based model for bicycle volumes is developed. Results We provide a proof of concept for the proposed memory model by testing it on synthesized data and apply the proposed techniques on data provided by Berlin authorities. The application on synthetic data shows that improved fits with memory models can indicate temporal correlations within data and, thus, can give hints for causal relations. Although such a temporal correlation could not be substantiated in the real data, a surprising ambiguity was found to exist on different time scales. Over the long term, individual risks decline with increased bicycle volumes, while on shorter terms the opposite seems to be present: The more bicyclists are on the roads, the more unsafe cycling becomes. Conclusions The paper concludes by considering possible interpretations for the observed ambiguity. Further, a discussion of the developed methodology and some thoughts for a role that the SiN effect can play for transportation planning are included.

Document type: Article

Exploring the effectiveness of demand management policy in reducing traffic congestion and environmental pollution: Car-free day and odd-even plate measures for Bandung city in Indonesia

Scipedia content — Fri, 12 Feb 2021 13:43:34 +0100

Traffic congestion has been a major problem in big cities around the world, not to mention several large cities in Indonesia. Bandung is the second largest metropolitan area after Jakarta in Indonesia which suffers from extreme levels of congestion. With a high number of motorcycles and large private car population, congestion in this city is ever growing worsening the environment. While the local authorities struggle to find resources to fund capital intensive capacity expansion projects, this research explores the use of cost effective demand management policy measures to reduce the congestion and pollution. This study aims at assessing two relatively under-researched demand management policy measures that restrict vehicle flows viz., car-free day and odd-even plate schemes to investigate the effect on traffic congestion and the environment. SATURN traffic network modelling software has been used to predict the route choices of vehicles. Bandung city road network and origin destination matrix have been adapted to simulate the two measures during the peak hour. As well as providing the necessary inputs to a pollutant emission estimation model, traffic network modelling output forms the basis for assessing the congestion levels. Results show that both car-free day and odd-even plate measures have unintended consequences that undermine their effectiveness which if addressed could make them highly beneficial solutions. Car-free day scheme reduces the traffic flow levels in the vicinity of scheme but diverts the vehicle flow elsewhere to other routes which may adversely affect the congestion/pollution. Odd-even plate scheme is very effective at the beginning of its implementation but the performance gradually diminishes as drivers start to adapt by buying a second vehicle or even using fake number plates.

Document type: Article

Optimizing High-Speed Railroad Timetable with Passenger and Station Service Demands: A Case Study in the Wuhan-Guangzhou Corridor

Scipedia content — Fri, 12 Feb 2021 13:43:13 +0100

This paper aims to optimize high-speed railroad timetables for a corridor. We propose an integer programming model using a time-space network-based approach to consider passenger service demands, train scheduling, and station service demands simultaneously. A modified branch-and-price algorithm is used for the computation. This algorithm solves the linear relaxation of all nodes in a branch-and-bound tree using a column generation algorithm to derive a lower-bound value (LB) and derive an upper-bound value (UB) using a rapid branching strategy. The optimal solution is derived by iteratively updating the upper- and lower-bound values. Three acceleration strategies, namely, initial solution iteration, delayed constraints, and column removal, were designed to accelerate the computation. The effectiveness and efficiency of the proposed model and algorithm were tested using Wuhan-Guangzhou high-speed railroad data. The results show that the proposed model and algorithm can quickly reduce the defined cost function by 38.2% and improve the average travel speed by 10.7 km/h, which indicates that our proposed model and algorithm can effectively improve the quality of a constructed train timetable and the travel efficiency for passengers.

Document type: Article

Evaluation of wave propagation effects for detection of vulnerable road users

Scipedia content — Fri, 12 Feb 2021 13:42:08 +0100

Abstract. The protection of vulnerable road users (VRU) is a key issue of future driver assistance systems. An important point is to determine whether a VRU is visually hidden to the driver. This additional information is essential for the driver to prevent an accident or to reduce its severity. We show that by using a transponder attached at the VRU, wavelength dependent diffraction effects can be utilized to distinguish between visible and hidden VRUs. Several diffraction measurements were carried out taking place in open space areas with simple big scattering objects and in different road traffic scenarios demonstrating a reliability of nearly 100%. If future driver assistance systems for detecting VRUs are complemented with automotive electronics which enable distinction between visible and hidden VRUs, accidents can be avoided.

Document type: Article

Enhancing Freeway Safety through Intervening in Traffic Flow Dynamics Based on Variable Speed Limit Control

Scipedia content — Fri, 12 Feb 2021 13:40:15 +0100

New technologies and traffic data sources provide great potential to extend advanced strategies in freeway safety research. The High Definition Monitoring System (HDMS) data contribute comprehensive and precise individual vehicle information. This paper proposes an innovative Variable Speed Limit (VSL) based approach to manage crash risks by intervening in traffic flow dynamics on freeways using HDMS data. We first conducted an empirical analysis on real-time crash risk estimation using a binary logistic regression model. Then, intensive microscopic simulations based on AIMSUN were carried out to explore the effects of various intervention strategies with respect to a 3-lane freeway stretch in China. Different speed limits with distinct compliance rates under specified traffic conditions have been simulated. By taking into account the trade-off between safety benefits and delay in travel time, the speed limit strategies were optimized under various traffic conditions and the model with gradient feedback produces more satisfactory performance in controlling real-time crash risks. Last, the results were integrated into lane management strategies. This research can provide new ideas and methods to reveal the freeway crash risk evolution and active traffic management.

Document type: Article

The Destination Experience Through Stopover Tourism – Bucharest Case Study

Scipedia content — Fri, 12 Feb 2021 13:39:34 +0100

Over the years, the evolution of the air transport sector has determined important changes in the tourism industry. One of the consequences of the liberalization of air transport has been the development of the “hub-and-spoke” system, used by traditional airlines in order to be more efficient in a highly competitive environment. As air traffic significantly developed worldwide, “hubs” became highly connected places concentrating an increasing number of transit passengers. At the same time, the liberalization of the airline industry has stimulated both airline and airport competition, therefore, vertical partnerships have become an interesting option for airlines, as well as airports. Moreover, considering that transiting traffic represents a potential tourism market, tourism organizations have also started to get involved in the process. “Stopover tourism” is a new type of tourism based on the partnership between airlines, airports and tourism organizations, with the purpose to turn transiting passengers into stayover tourists. This paper focuses on building a better understanding of how “stopover tourism” type programs can enhance tourism development, identifying the characteristics of this form of tourism and the measures that need to be taken by the authorities in order to encourage its development and investigates the possibility of implementing it in Romania. In order to achieve these objectives, the research was conducted using analysis of secondary data included in several scientific journals and publication, as well as primary data collection, through qualitative research, having as interviewees, experts from the airline industry and from tourism organizations in Romania.

Document type: Article

Advancing E-Roaming in Europe: Towards a Single “Language” for the European Charging Infrastructure

Scipedia content — Fri, 12 Feb 2021 13:39:13 +0100

The E.U. market for electric vehicles (EVs) is growing significantly, but the absence of widely adopted protocols and interoperability standards for charging hinders the development of cross-border EV travel (“e-roaming”). In this paper, we present our vision on what should be the basic functionalities of e-roaming. Furthermore, we describe the best practices of 6 years of e-roaming in the Netherlands, and analyze what can be learned from other sectors that were successful in introducing roaming mechanisms in the past. We translate these into proposed next steps, such as the need for piloting e-roaming on a European level using open standards, such as Open Charge Point Interface (OCPI). We conclude with a proposal for a comparative study of protocols to pave the way for future convergence, and, thus, facilitate a European market for EV products and services.

Document type: Article

Inland Shipping to Serve the Hinterland: The Challenge for Seaport Authorities

Scipedia content — Fri, 12 Feb 2021 13:38:26 +0100

The competitiveness of seaports is predominantly affected by factors external to the ports themselves, connected mainly with the quality of the hinterland and foreland infrastructure. Measures taken in these areas are reflected in the main objectives of the port strategies. Concurrently, the measures may have adverse environmental impacts (pollutant emissions, noise, land occupancy, etc.) and deteriorate the life quality of the port city&rsquo

s communities. Therefore, measures taken by seaport authorities to improve their competitiveness must also heed the idea of sustainable development (sustainable port strategy). The answer to this challenge is the idea of green ports, being an element of the corporate social responsibility (CSR) strategies of seaports. One of the elements of this concept is promoting more environmentally friendly transport modes/transport chains in serving the hinterland as an alternative to road transport. Inland shipping is the most environmentally friendly and also cost-competitive mode of transport. Therefore, a modal shift from road to inland waterways is one of the elements of the European Union sustainable transport policy, as well as also gaining importance in the development policies of seaport authorities as an element of a green port strategy. However, this issue has been relatively rarely addressed in the seaport economics literature. In particular, there has been a lack of studies that would make it possible to answer the question of what kind of action should be taken by seaport authorities in order to increase the share of inland shipping in hinterland transport. This article aimed to develop a concept of a promotion policy to be applied by seaport authorities to increase the share of inland shipping in hinterland transport. The study used the elements of a multiple case study design method which included the following seaports: Antwerp, Rotterdam, Hamburg, and the Marseilles&ndash

Fos port complex. This article was dedicated to identifying, analyzing, and classifying the policies implemented by these European seaports to promote inland waterway transportation. The research showed that these actions were quite similar in terms of their scope. The actions were classified as external and internal initiatives. The most common external actions included initiatives that improved the quality of inland waterways and the quality of shipping connections with the hinterland. Internal initiatives focused on improving the port&rsquo

s infrastructure for barges and on implementing an appropriate information policy. The presented concept of a promotion policy can be a road map for all port authorities aiming to improve the quality of inland shipping as a mode of hinterland transport.

Document type: Article

Analysis of the Determinant Factors of the Historical Development of Air Transport: An Empirical Application to Turkey

Scipedia content — Fri, 12 Feb 2021 13:36:31 +0100

WOS: 000456465200006

Emerging Sources Citation Index

The aim of this study was to empirically examine the development of air transport in Turkey in the period between 1980 and 2015. The study intended, within its scope, to determine the developments experienced in air transport in Turkey and the probable causes of the structural changes. Moreover, it was aimed at highlighting the years in which the structural changes in air transport were realized. In line with this objective, the one-break Zivot Anderews (1992) unit root test, the two-break Clemente-MontatiOs-Reyes (1998) unit root test, and the one-break and two-break LM were applied to the domestic and international air transport data of the 1980-2015 period. The results of the study show that there were substantial economic and political developments both at home and abroad in the years that the significant structural breaks that affect air transport took place.

Document type: Article

Pipeline Inspection Gauge’s Velocity Simulation Based on Pressure Differential Using Artificial Neural Networks

Scipedia content — Fri, 12 Feb 2021 13:34:45 +0100

Industrial pipelines must be inspected to detect typical failures, such as obstructions and deformations, during their lifetime. In the petroleum industry, the most used non-destructive technique to inspect buried pipelines is pigging. This technique consists of launching a Pipeline Inspection Gauge (PIG) inside the pipeline, which is driven by the pressure differential produced by fluid flow. The purpose of this work is to study the application of artificial neural networks to calculate the PIG&rsquo

s velocity based on the pressure differential. We launch a prototype PIG inside a testing pipeline, where this PIG gathers velocity data from an odometer-based system, while a supervisory system gathers pressure data from the testing pipeline. Then we train a Multilayer Perceptron (MLP) and a Nonlinear Autoregressive Network with eXogenous Inputs (NARX) network with the gathered data to predict velocity. The results suggest it is possible to use a neural network to model the PIG&rsquo

s velocity from pressure differential measurements. Our method is a new approach to the typical speed measurements based only on odometer, since the odometer is prone to fail and present poor results under some circumstances. Moreover, it can be used to provide redundancy, improving reliability of data obtained during the test.

Document type: Article

Critical factors in organisational effectiveness: The case of Saudi Arabian seaports

Scipedia content — Fri, 12 Feb 2021 13:34:02 +0100

Seaport management environment has continually changed over the last few decades due to increasing external pressure for seaports to be more competitive, active, dynamic and growing sustainably. These changes have created the need to manage organisational effectiveness in order to monitor port performance and achieve organisational objectives. While organisational effectiveness has been well known in organisational management and important in port management, its application to the seaport sector is limited. This paper presents exploratory research into critical factors of Saudi Arabian seaports’ organisational effectiveness. A Delphi method was applied. Data were collected from a two-round survey of the Saudi Arabian seaports, and interviews of 43 senior staff from Saudi Arabian seaports. A mixed method combining quantitative and qualitative analysis was conducted. A total of thirty-one (31) factors from six different dimensions, namely human resource management, customer service, finance, operation, marketing, research & development, were identified to be influential to OE. The gathered data are no doubt important to seaports because only limited research has been conducted on the application of the organisational effectiveness concept to the seaport sector. Findings of this research regarding selecting and evaluating the most influential factors of OE are relevant to decision makers in managing seaport organisations.

Document type: Article

Road Maintenance Optimization Model Based on Dynamic Programming in Urban Traffic Network

Scipedia content — Fri, 12 Feb 2021 13:30:22 +0100

Urban road maintenance is an important part of urban traffic management. However, in modern cities, road maintenance work needs to occupy some traffic resources; therefore, unreasonable road maintenance schemes often lead traffic networks to unexpected large-scale congestion. In this paper, a dynamic programming model is proposed in order to minimize the delay caused by road maintenance scheme. This model can obtain a globally optimal maintenance scheme which contains the decisions and sequence for every stage of maintenance. Each stage of this model can be boiled down to a discrete network design problem. This model helps make suggestions for the traffic managers with the request of minimizing the delay caused by the maintenance scheme. This paper uses two examples to illustrate this method, one is a small-scale Nguyen-Dupuis network, and the other one is a larger scale Sioux-Falls network.

Document type: Article

Analisa Sentimen Menggunakan Data Twitter, Flume, Hive Pada Hadoop dan Java Untuk Deteksi Kemacetan di Jakarta

Scipedia content — Fri, 12 Feb 2021 13:24:25 +0100

Traffic congestion big cities in Indonesia is unavoidable, especially in Jakarta. The increasing number of vehicle and the lack of public transportation is the main cause of traffic congestion in Jakarta. It disturb people activities. Government already did various efforts to resolve congestion problem, however it needs high installation, maintenance cost and need time to be implemented. Peoples often complained about traffic congestion in Jakarta by posting in Twitter which called tweets. Every tweets post are saved in API Twitter and used for sentiment analysis. It analyzed emotion of the user. Based of problems we do research how to detect traffic congestion in Jakarta. Therefore, we try to makes Congestion Detection App. We design the app using UML diagrams. Congestion Detection App is connected with Hadoop, Flume, Hive and Derby. The app stream twitters data to colected by connecting with API Twitter. This app is Java-based application which can makes and view data tables. It performance searching tweets data by ID and analyze traffic condition on a certain region in Jakarta. The perform sentiment analysis to a certain tweet and display the result based on the data table. The result of research is comparing Data from Congestion Detection App with data from Google Maps. We make three valus categories which consist of three colors: green for less traffic congestion have a value of 1. Orange for medium-scale traffic congestion has value of 2 and Red for heavily traffic congestion has a value of 3. Based on three categories and value we use 4 regions for sample and comparing the values with value from Google Maps Data to get the accuracy. We got 81% average accuracy from the four samples. The result of Data from tweet sample compared with Google Maps Data. It have big detected congestion with Congestion Detection App.

Document type: Article

Network Analysis of the Tel Aviv Mass Transit Plan

Scipedia content — Fri, 12 Feb 2021 13:23:28 +0100

This paper analyzes the strategic transit network plan for the Tel Aviv metropolitan area, using graph theory and other recently developed transit network measures. The different transit modes included in the strategic plan are emphasized by adding weights to distinguish metro lines from light rail lines (LRT). This approach can help compare the combined metro or LRT alternatives of the new Tel Aviv plan to the metro-only alternatives as well as measure the performance relative to the metro systems in other cities around the world. The analysis of the alternative plans in Tel Aviv showed that when metro and LRT lines were treated as homogeneous modes, in which all were considered as metro, the alternatives resembled medium developed metro systems, such as in Barcelona and Washington DC. In contrast, when the distinguished weights were included, the combined metro/LRT alternatives resembled less developed systems, such as in Lyon and Lisbon, and only the metro-only alterative score remained high. The results also showed that the alternatives have regional coverage, and the alternatives with more LRT lines score lower in coverage. The network structure analysis showed that the metro-oriented networks score higher in both directness and connectivity. When using the weighted measures, the existing plan (LRT-only) scores low on both directness and connectivity. The analysis of the results emphasizes the need for more metro lines in the Tel Aviv metropolitan area. The results also suggest that the analysis of the complex mass transit networks based on graph theory should consider differences in line technology reflected in the line speed and coverage.

Document type: Article

Marine Spatial Planning – Prospects for the Arctic

Scipedia content — Fri, 12 Feb 2021 13:22:52 +0100

Marine Spatial Planning (MSP) is defined as an integrated and comprehensive approach to ocean governance. Planning has the potential to ensure ecosystem and biodiversity conservation and establish rational use of marine space, combining activities relating to extraction industries, maritime transport, fisheries and related services and infrastructure. This article looks at what part transnational and national marine spatial planning can play in the Arctic. There is no international convention on marine spatial planning, and there are no requirements under international law that marine plans, as such, should be prescribed by law. MSP-regulation in different jurisdictions is diversified. It is difficult to claim that the international rights and obligations of a state under UNCLOS, CBD or regional instruments such as OSPAR, need to be fulfilled through the instrument of marine spatial planning. The comprehensive EU approach to marine planning is thus of particular interest. The EU members Denmark, Finland and Sweden do not have coastlines bordering the Arctic. EU has no direct influence over the regulation of marine spatial planning in Arctic marine areas through its relationship to Greenland or Norway, states with a close connection to the EU. The status of marine spatial planning in the European Arctic is thus dependent on the policies of Norway, Greenland and Russia. It is an open question whether spatial planning will be used for preventive and precautionary purposes in the Arctic, before the area is overwhelmed by marine activities and spatial conflicts. publishedVersion

Document type: Article

Combination of LiCs and EDLCs with Batteries: A New Paradigm of Hybrid Energy Storage for Application in EVs

Scipedia content — Fri, 12 Feb 2021 13:20:56 +0100

The research presented in this paper proposes a hybrid energy storage system that combines both electrolytic double-layer capacitors (EDLCs) also known as supercapacitors (SCs) and lithium-ion capacitors (LiCs) also known as hybrid capacitors (HCs) with a battery through a multiple input converter. The proposal was verified in simulation and validated by implementing a laboratory prototype. A new hybridisation topology, which reduces the amount of resource requirement when compared to the conventional hybridisation topology, is introduced. An electric vehicle (EV) current profile from previous research was used to test the performance of the proposed topology. From the results obtained, the hybridisation topology proposed in this research had the lowest cost per unit power at 14.81 $/kW, the lowest cost per unit power to energy, and available power to energy ratio, both at 1:1.3, thus making it a more attractive hybridisation topology than the two conventional alternatives. The multiple input converter built had efficiency values in excess of 80%. The key take away from this paper is that using the proposed hybridisation topology, the battery is less often required to supply energy to the electric vehicle, and so, its cycle life is preserved. Furthermore, since the battery is not used for the repeated acceleration and deceleration in the entire driving cycle, the battery’s cycle life is further preserved. Furthermore, since the battery is not the only storage device in the energy storage system, it can be further downsized to best fit the required base load

therefore, leading to a more optimized energy storage system by reducing the weight and volume of space occupied by the energy storage system, while also achieving better efficiencies.

Document type: Article

URBAN TRAFFIC FLOW ANALYSIS BASED ON DEEP LEARNING CAR DETECTION FROM CCTV IMAGE SERIES

Scipedia content — Fri, 12 Feb 2021 13:17:06 +0100

Abstract. Traffic flow analysis is fundamental for urban planning and management of road traffic infrastructure. Automatic number plate recognition (ANPR) systems are conventional methods for vehicle detection and travel times estimation. However, such systems are specifically focused on car plates, providing a limited extent of road users. The advance of open-source deep learning convolutional neural networks (CNN) in combination with freely-available closed-circuit television (CCTV) datasets have offered the opportunities for detection and classification of various road users. The research, presented here, aims to analyse traffic flow patterns through fine-tuning pre-trained CNN models on domain-specific low quality imagery, as captured in various weather conditions and seasons of the year 2018. Such imagery is collected from the North East Combined Authority (NECA) Travel and Transport Data, Newcastle upon Tyne, UK. Results show that the fine-tuned MobileNet model with 98.2% precision, 58.5% recall and 73.4% harmonic mean could potentially be used for a real time traffic monitoring application with big data, due to its fast performance. Compared to MobileNet, the fine-tuned Faster region proposal R-CNN model, providing a better harmonic mean (80.4%), recall (68.8%) and more accurate estimations of car units, could be used for traffic analysis applications that demand higher accuracy than speed. This research ultimately exploits machine learning alogrithms for a wider understanding of traffic congestion and disruption under social events and extreme weather conditions.

Document type: Article

Supervised Classification of Built-Up Areas in Sub-Saharan African Cities Using Landsat Imagery and OpenStreetMap

Scipedia content — Fri, 12 Feb 2021 13:16:47 +0100

The Landsat archives have been made freely available in 2008, allowing the production of high resolution built-up maps at the regional or global scale. In this context, most of the classification algorithms rely on supervised learning to tackle the heterogeneity of the urban environments. However, at a large scale, the process of collecting training samples becomes a huge project in itself. This leads to a growing interest from the remote sensing community toward Volunteered Geographic Information (VGI) projects such as OpenStreetMap (OSM). Despite the spatial heterogeneity of its contribution patterns, OSM provides an increasing amount of information on the earth’s surface. More interestingly, the community has moved beyond street mapping to collect a wider range of spatial data such as building footprints, land use, or points of interest. In this paper, we propose a classification method that makes use of OSM to automatically collect training samples for supervised learning of built-up areas. To take into account a wide range of potential issues, the approach is assessed in ten Sub-Saharan African urban areas from various demographic profiles and climates. The obtained results are compared with: (1) existing high resolution global urban maps such as the Global Human Settlement Layer (GHSL) or the Human Built-up and Settlements Extent (HBASE); and (2) a supervised classification based on manually digitized training samples. The results suggest that automated supervised classifications based on OSM can provide performances similar to manual approaches, provided that OSM training samples are sufficiently available and correctly pre-processed. Moreover, the proposed method could reach better results in the near future, given the increasing amount and variety of information in the OSM database.

SCOPUS: ar.j

info:eu-repo/semantics/published

Document type: Article

Lost in Optimisation of Water Distribution Systems? A Literature Review of System Design

Scipedia content — Fri, 12 Feb 2021 13:15:18 +0100

Optimisation of water distribution system design is a well-established research field, which has been extremely productive since the end of the 1980s. Its primary focus is to minimise the cost of a proposed pipe network infrastructure. This paper reviews in a systematic manner articles published over the past three decades, which are relevant to the design of new water distribution systems, and the strengthening, expansion and rehabilitation of existing water distribution systems, inclusive of design timing, parameter uncertainty, water quality, and operational considerations. It identifies trends and limits in the field, and provides future research directions. Exclusively, this review paper also contains comprehensive information from over one hundred and twenty publications in a tabular form, including optimisation model formulations, solution methodologies used, and other important details.

Document type: Article

Development of an assessment model for predicting public electric vehicle charging stations

Scipedia content — Fri, 12 Feb 2021 13:10:00 +0100

Deploying an adequate electric vehicle (EV) charging infrastructure to support the increasing EV market is one of the major strategic goals of the U.S. government. This requires a well-designed EV charging network. The distribution and capability of the existing charging networks in terms of EV population, location, charging rate, and time of charging in San Diego is examined. A mathematical model to calculate the demand number of public Level 2 chargers universally applicable is developed. The study showed that although San Diego has sufficient chargers to accommodate the existing EV’s charging demand, the current public charging distribution network is neither well designed nor effectively used. To eliminate the waste resulting from the inefficiently designed charging infrastructure and maximize the usage rate of each charger, it is recommended that the designed optimal model to be utilized and the charging location priority be implemented to improve the availability and accessibility of charging network in the City of San Diego. Introduction: The purpose of this study is to identify current problems with the existing electric vehicle public charging stations and come up with solutions to improve the availability and accessibility of public charging stations in the City of San Diego. The objective of this research project is also to develop a mathematical model to predict the demand of EV chargers in any city including in the City of San Diego. Methods: A mix of quantitative and qualitative research methods are used to analyze the problem. The first phase of this project is to determine the study area by identifying the existing problems and issues from existing sources, and formulating hypothesis. Results: The distribution and capability of the existing charging networks in terms of EV population, location, charging rate, and time of charging in San Diego was examined. A mathematical model to calculate the demand number of public Level 2 chargers for the City of San Diego and for each zip code was developed. Among 361 tested public Level 2 chargers distributed in 34 communities, 66 chargers located at 37 charging stations distributed in 22 communities were found to be nonoperational or damaged but still operational. They accounted for 18% of the total number of tested EV charging stations and 12.7% of the total public Level 2 in San Diego. The model tested using data from San Francisco Bay Area, and Los Angeles County matched well to the predictions. Conclusions: The conclusion is that although San Diego has sufficient chargers to accommodate the existing EV’s charging demand, the current public charging distribution network is neither well designed nor effectively used. To eliminate the waste resulting from the inefficiently designed charging infrastructure and maximize the usage rate of each charger, it is recommended that the designed optimal model to be utilized and the charging location priority be implemented to improve the availability and accessibility of charging network in the City of San Diego. This model is easily applicable in the European environment since all the five significant independent variables (B/E - Battery capacity to EV Range Ratio, D-Driver Traveling Distance, β - Ratio of EV driver charges away from home, PrefL2 - percentage that EV driver prefers to charge on Level 2 stations, and TL2- duration of public Level 2 chargers’ work per day) are easy to obtain. Hence this proposed model has universal applicability.

Document type: Article

Noise Costs from Road Transport

Scipedia content — Fri, 12 Feb 2021 13:09:04 +0100

Building and improving road infrastructure in Slovakia is currently influenced by the amount of state funding. Therefore, it is necessary to determine the effectiveness of each proposed solution of road project, which is based on life-cycle costs. Besides capital costs, social costs are also important, which valued the negative impacts due to road construction and operation on road users, the environment, and the population living in the affected area. Some components of social costs have shortcomings in quantifying and valuating, which need to be resolved. The one of important components which affects human health and the value of an area, and have some shortcomings are noise costs. Improvement of this component will lead to more accurate valuation of economic efficiency of roads.

Document type: Article

Enhanced primary frequency control from EVs: a fleet management strategy to mitigate effects of response discreteness

Scipedia content — Fri, 12 Feb 2021 13:08:09 +0100

Electric vehicle (EV) chargers can be controlled to support the grid frequency by implementing a standard-compliant fast primary frequency control (PFC). This study addresses potential effects on power systems due to control discreteness in aggregated EVs when providing frequency regulation. Possible consequences of a discrete response, as reserve provision error and induced grid frequency oscillations, are first identified by a theoretical analysis both for large power systems and for microgrids. Thus, an EV fleet management solution relying on shifting the droop characteristic for the individual EVs is proposed. The PFC is implemented in a microgrid with a power-hardware-in-the-loop approach to complement the investigation with experimental validation. Both the analytical and the experimental results demonstrate how the controller performance is influenced by the response granularity, and that related oscillations can be prevented either by reducing the response granularity or by applying appropriate shifts on the droop characteristics for individual EVs. This is an open access article published by the IET under the Creative Commons Attribution -NonCommercial License (http://creativecommons.org/licenses/by-nc/3.0/)

Document type: Article

“Howya gettin’ on?” Investigating Public Transport Satisfaction Levels in Galway, Ireland

Scipedia content — Fri, 12 Feb 2021 13:07:24 +0100

Public transport transforms urban communities and the lives of citizens living in them by stimulating economic growth, promoting sustainable lifestyles and providing a greater quality of life. Globally, the healthiest cities have one thing in common, a public and active transport network that does not depend on each person owning a personal motorised vehicle. Growing dependence on the automobile has created a multitude of problems, some of which public transport can help solve. Adverse social, environmental and health effects related to automobile emissions and car-dependency suggest that using public transport will result in a decrease in an individual&rsquo

s carbon footprint, will lessen overall CO2 emissions, and will help to ease urban traffic congestion as well as encourage more effective and efficient land use. With many urban areas experiencing ongoing traffic problems, it is acknowledged that any sustainable long-term solution must entail a significant public transport element. The aim of this research study, conducted in November and December 2017, was to obtain essential baseline information on service user satisfaction levels with the existing public bus services in Galway City, Ireland. By measuring levels of satisfaction, it is possible to build our overall knowledge of the public transport network and thus identify improvements in the service that would lead to an increase in bus passenger numbers and result in reductions in the amount of cars on the roads. Results suggest deficiencies in public transport infrastructure, such as Dedicated Bus Lanes, and the lack of attention to customer services are hindering improvements in the public bus service.

Document type: Article

Pressure Transient Model of Water-Hydraulic Pipelines with Cavitation

Scipedia content — Fri, 12 Feb 2021 13:05:38 +0100

Transient pressure investigation of water-hydraulic pipelines is a challenge in the fluid transmission field, since the flow continuity equation and momentum equation are partial differential, and the vaporous cavitation has high dynamics; the frictional force caused by fluid viscosity is especially uncertain. In this study, due to the different transient pressure dynamics in upstream and downstream pipelines, the finite difference method (FDM) is adopted to handle pressure transients with and without cavitation, as well as steady friction and frequency-dependent unsteady friction. Different from the traditional method of characteristics (MOC), the FDM is advantageous in terms of the simple and convenient computation. Furthermore, the mechanism of cavitation growth and collapse are captured both upstream and downstream of the water-hydraulic pipeline, i.e., the cavitation start time, the end time, the duration, the maximum volume, and the corresponding time points. By referring to the experimental results of two previous works, the comparative simulation results of two computation methods are verified in experimental water-hydraulic pipelines, which indicates that the finite difference method shows better data consistency than the MOC.

Document type: Article

Use of Shared-Mobility Services to Accomplish Emergency Evacuation in Urban Areas via Reduction in Intermediate Trips—Case Study in Xi’an, China

Scipedia content — Fri, 12 Feb 2021 12:59:05 +0100

Under no-notice evacuation scenarios with limited time horizons, the effectiveness of evacuation can be negatively impacted by intermediate trips that are made by family members and the identification of vulnerable populations. The emergence of shared-mobility companies, such as Uber and DiDi, can be considered as a potential means to address above-mentioned concerns. The proposed study explores the utility of shared-mobility services under emergency-evacuation scenarios and makes recommendations to relevant bodies that are based on the obtained and they are discussed herein. The study investigates attitudes of the public, experts, and drivers towards the use of shared-mobility resources during emergency evacuations based on a stated preference survey. Results of questionnaires, driver interviews, and face-to-face expert interviews have been analyzed to validate the feasibility and identify potential problems of leveraging shared-mobility services during evacuation response, especially in metropolitan areas wherein such services are already ubiquitous. Numerical simulations have been performed to quantify potential improvements in the total trip distance and number of evacuees after incorporating the use of shared mobility into emergency-response operations. However, despite the observed improvement in emergency efficiency, certain realistic roadblocks must be overcome. Realization of the proposed objective heavily depends on actionable policy recommendations, provided herein as a reference for the government, emergency management agencies, and shared-mobility companies.

Document type: Article

Impact of Air Transport on the Noise Level in the City of Burgas

Scipedia content — Fri, 12 Feb 2021 12:58:39 +0100

Aviation, as every type of transport, is responsible for a number of negative external effects to the environment. The main goal of this study is to reveal the relation between the noise level in the urban areas near to the Burgas airport and the air traffic. Our main research tasks are: to make a literature review of the problem; to gather data for the noise levels; to gather data for the air traffic; to choose relevant statistical methods and models for the revealing of the relation between the noise level and air traffic; to draw conclusions and to make recommendations about the noise pollution in the vicinity of Burgas Airport. The data are on monthly basis and cover the period from January 2015 to December 2017, i.e. 36 months. In our regression model we use three traffic indicators as independent variables: aircraft movements; passengers and freight. In the established regression model we introduce ‘the time’ as an additional factor, which provides concrete practical advantages. Our results show that two independent variables (aircraft movements and freight) affect the Twenty-four hours average equivalent level of noise due to flights. Aircraft movements are the most important factor and we expect their increasing in the future. This will lead to increased noise levels.

Document type: Article

A Dynamic Approach to Rebalancing Bike-Sharing Systems

Scipedia content — Fri, 12 Feb 2021 12:54:53 +0100

Bike-sharing services are flourishing in Smart Cities worldwide. They provide a low-cost and environment-friendly transportation alternative and help reduce traffic congestion. However, these new services are still under development, and several challenges need to be solved. A major problem is the management of rebalancing trucks in order to ensure that bikes and stalls in the docking stations are always available when needed, despite the fluctuations in the service demand. In this work, we propose a dynamic rebalancing strategy that exploits historical data to predict the network conditions and promptly act in case of necessity. We use Birth-Death Processes to model the stations’ occupancy and decide when to redistribute bikes, and graph theory to select the rebalancing path and the stations involved. We validate the proposed framework on the data provided by New York City’s bike-sharing system. The numerical simulations show that a dynamic strategy able to adapt to the fluctuating nature of the network outperforms rebalancing schemes based on a static schedule.

Document type: Article

A decision-support framework to optimize border control for global outbreak mitigation

Scipedia content — Fri, 12 Feb 2021 12:54:33 +0100

The introduction and spread of emerging infectious diseases is increasing in both prevalence and scale. Whether naturally, accidentally or maliciously introduced, the substantial uncertainty surrounding the emergence of novel viruses, specifically where they may come from and how they will spread, demands robust and quantifiably validated outbreak control policies that can be implemented in real time. This work presents a novel mathematical modeling framework that integrates both outbreak dynamics and outbreak control into a decision support tool for mitigating infectious disease pandemics that spread through passenger air travel. An ensemble of border control strategies that exploit properties of the air traffic network structure and expected outbreak behavior are proposed. A stochastic metapopulation epidemic model is developed to evaluate and rank the control strategies based on their effectiveness in reducing the spread of outbreaks. Sensitivity analyses are conducted to illustrate the robustness of the proposed control strategies across a range of outbreak scenarios, and a case study is presented for the 2009 H1N1 influenza pandemic. This study highlights the importance of strategically allocating outbreak control resources, and the results can be used to identify the most robust border control policy that can be implemented in the early stages of an outbreak.

Document type: Preprint

PWM Carrier Displacement in Multi-N-Phase Drives: An Additional Degree of Freedom to Reduce the DC-Link Stress

Scipedia content — Fri, 12 Feb 2021 12:54:11 +0100

The paper presents a particular Pulse Width Modulation (PWM) strategy to reduce the (Direct Current) DC-link capacitor stress for multi-n-phase drives. A multi-n-phase drive is composed of multiple independent systems of n inverter supplying a multi-n-phase electric machine. The paper focused on the investigation of the best phase shifting between carriers for a triple-3-phase drive compared to the 3-phase counterpart in order to reduce the capacitor bench design point. Simulation and experimental results show as the control technique proposed is able to reduce the value of the DC-link capacitor current in any operating condition including fault case. In this sense, the PWM carrier displacement appears like an additional degree of freedom that can be exploited in multi-n-phase drives but also in multi-motor application.

Document type: Article

Bus-OLAP: A Data Management Model for Non-on-Time Events Query Over Bus Journey Data

Scipedia content — Fri, 12 Feb 2021 12:53:44 +0100

Increasing the on-time rate of bus service can prompt the people’s willingness to travel by bus, which is an effective measure to mitigate the city traffic congestion. Performing queries on the bus arrival can be used to identify and analyze various kinds of non-on-time events that happened during the bus journey, which is helpful for detecting the factors of delaying events, and providing decision support for optimizing the bus schedules. We propose a data management model, called Bus-OLAP, for querying bus journey data, considering the characteristics of bus running and the scenarios of non-on-time analysis. While fulfilling typical requirements of bus journey data queries, Bus-OLAP not only provides a flexible way to manage the data and to implement multiple granularity data query and update, but it also supports distributed queries and computation. The experiments on real-world bus journey data verify that Bus-OLAP is effective and efficient.

Document type: Article