Scipedia: Documents published in 2014

Structural Integrity of Steel Hydrocarbon Pipelines With Local Wall Distortions

Scipedia content — Tue, 02 Feb 2021 02:53:23 +0100

Local distortions on pipeline wall in the form of dents or buckles may constitute a threat for the structural integrity of the steel pipeline. In the present paper, experimental research supported by numerical simulation is reported to investigate the structural integrity of smoothly dented steel pipes. A series of six (6) full-scale experiments on 6-inch X52 pipes has been carried out, and numerical simulations have also been conducted. The dented steel pipes are subjected to cyclic loading (bending or pressure) in order to estimate their residual strength and remaining fatigue life. The finite element analysis simulate the experimental procedure for each type of deformation and loading case, in order to estimate the local stress and strain distributions at the dented region. Based on the numerical results, fatigue life is predicted and compared with the experimental results. The results of the present study are aimed at evaluating existing guidelines and methodologies towards appropriate assessment of local wall distortions in steel pipelines.

Research of air traffic control students proportion concerning their attitude to risk

Scipedia content — Tue, 02 Feb 2021 02:51:19 +0100

Modern air traffic control system consists of entities of different types. Their list includes front line operators, software, hardware, norms and conditions etc. Norms and conditions of air traffic control as part of entire process are changed according to balance in requirements of safety and efficiency. It is important for those changes to take into account many important process properties and parameters. One of those properties is front line operators personal attitude to risky situations. KEYWORD: human factor, flight safety; air traffic control; education; flight norms violation; usefulness functions.

Security overhead and its impact in VANETs

Scipedia content — Tue, 02 Feb 2021 02:49:21 +0100

Vehicular ad hoc networks (VANETs), often called Car2X communication systems, are about to enter the mass market in upcoming years. They are intended to increase traffic safety by enabling new safety critical driver assistance systems. This also means that strong security mechanisms are required to safeguard communication within VANETs. However, standardized security mechanisms lead to significant overhead in terms of data rate requirement and delay. Prior work has focused on reducing the overhead by advanced strategies for pseudonym and authorization authority certificate exchange. However, we find that this is not enough to enable reliable message exchange in VANETs. Various other sources of overhead caused by security mechanisms in VANETs are identified in the provided analysis. Thereby, we find cross layer and cross message dependencies. In combination with the non-fragmentation property of VANET messages, such dependencies are discovered to lead to massive dropping of packets due to maximum size violations at low protocol layers. Thus, we develop a method for cross layer on demand content assembling for VANET messages, which can avoid the size limit violations without preventing individual layers from disseminating their variable length data sets.

Digital image correlation utilization in pipeline oriented residual stress estimation

Scipedia content — Tue, 02 Feb 2021 02:44:48 +0100

The aim of the paper is to present an idea of the utilization of Digital Image Correlation (DIC) method for industrial pipelines residual stress oriented investigation. For this purpose results of tests performed in laboratory and industrial conditions are presented. Obtained results showed that DIC method gives reliable near drilled hole strain/displacement distribution maps which may be used for accurate residual stress calculations.

Operational Evaluation of a Weather-Avoidance Rerouting System

Scipedia content — Tue, 02 Feb 2021 02:42:42 +0100

The Dynamic Weather Routes system, designed to find time-saving corrections to convective weather avoidance routes for airborne flights in en route airspace, has been in operational evaluation at the American Airlines Integrated Operations Center since July 2012. This paper, following an initial study of the first three months of the evaluation, presents the potential time savings for 752 flights for which American Airlines Air Traffic Coordinators accepted weather avoidance advisories during the 2013 calendar year. These advisories are categorized by the proximity of convective weather to both the filed flight plan and the proposed route correction. While the bulk of potential savings came from aircraft receiving direct routes in clear weather, the greatest average savings per advisory (15 minutes per aircraft) resulted from route corrections around convective weather. Measurement of the time spent in analyzing advisories and resulting route corrections indicates that additional time savings can be realized by reducing communication and execution delays. Lastly, survey data validate airline confidence in the system, with an average of one advisory rejected for every seven accepted.

Benefits Analysis of Wind-Optimal Operations For Trans-Atlantic Flights

Scipedia content — Tue, 02 Feb 2021 02:36:56 +0100

North Atlantic Tracks are trans-Atlantic routes across the busiest oceanic airspace in the world. This study analyzes and compares current flight-plan routes to wind-optimal routes for trans-Atlantic flights. The historical flight track data recorded by EUROCONTROL’s Central Flow Management Unit is merged with data from FAA’s Enhanced Traffic Management System to provide an accurate flight movement database containing the highest available flight path resolution in both systems. The combined database is adopted for airspace simulation integrated with aircraft fuel burn to simulate traffic within the Organized Track System (OTS). The fuel burn for the tracks in the OTS are compared with the corresponding quantities for the wind-optimized routes for a month to evaluate the potential benefits of flying wind-optimal routes in North Atlantic Airspace. The potential fuel savings depend on existing inefficiencies in current flight plans, atmospheric conditions and location of the city-pairs. The potential benefits are compared with actual flight tests that have been conducted since 2010 between a few city-pairs in the trans-Atlantic region to improve fuel consumption.

Freeway lab: testing dynamic speed limits

Scipedia content — Tue, 02 Feb 2021 02:32:43 +0100

This paper presents the Dynamic Speed Limit (DSL) experiment that took place in June 2013 on the last 13 km stretch of the B-23 freeway accessing the city of Barcelona (Spain). The DSL system installed on that freeway in addition to the high density of surveillance equipment available makes this stretch a suitable highway lab. The objective of the experiment was to construct a comprehensive database of traffic engineering variables on a freeway site when different speed limits apply. Special attention was paid to ensure similar demand conditions between different scenarios. The experiment included the modification of the speed limits on a freeway segment making use of dynamic signals. Detailed measurements of vehicle counts, speeds, occupancies, lane changing maneuvers and travel times were taken. These simultaneous measurements obtained from very different types of monitoring equipment have been grouped into a single database. These include measurements from inductive loop detectors, radar, ultrasound and passive infrared non-intrusive traffic detectors, TV cameras and license plate recognition devices. The potential of this multi-source database is huge. For instance, a preliminary analysis empirically proves that drivers’ compliance with dynamic speed limits is very limited, unless speed enforcement devices are present. In addition, it is also proved that lane changing rates increase together with the occupancy level of the freeway. This comprehensive DSL database, unique in its nature, is made publicly available to the whole research community [Link], [1] in order to use up all its information. The present paper aims to present in detail this DSL experiment and its preliminary results and to contribute in the dissemination of the resulting database. This will facilitate its analysis to any interested researcher, and would lead to a better understanding of the causes and effects of DSL strategies on freeways.

The changes in airline network configurations (especially temporal configurations) in Europe

Scipedia content — Tue, 02 Feb 2021 02:23:42 +0100

The topic of this article is concerned with the changes of airline network configurations (mainly temporal concentration) in Europe. Air transport in Europe reached significant milestones in 1997, when the air transport became fully liberalized (country from EU 10 in 2004 after their entry to EU). Airline liberalization influenced the configuration of airline networks into hub-andspoke system that is typical by temporal and spatial concentration. The temporal concentration is connected with the adoption or intensification of wave-system structures that considerably influenced overall traffic growth. The wave system structure is the complex of incoming and outgoing flights that are organized such that all incoming flight has connection to all outgoing flights. It is known that airports with wave system perform better due to the number of direct connections via hub. Therefore changes will be observed in transport strategies between years 2005 and 2013, specifically 2005, 2009 and 2013 in the “typical day” – Tuesday in June. The selected area for research is 19 countries in Central and Eastern Europe. The main airports and also the primary airlines (mainly classical airlines) are selected for the counting of wave-system structures in these countries. The main interest should be in the results of differences between airports as a result of their urban hierarchy and also their location in Europe (political and historical differences), which are or are not affected by the liberalization of air transport. It is expected that airports in countries such as Germany or Austria should have more efficient temporal concentration compared with countries such as Czech Republic or Hungary. This is due to the size of city where the airport is located and the liberalization of air transport in Europe.

Evaluation of the Terminal Area Precision Scheduling and Spacing system for Performance-Based Navigation arrivals

Scipedia content — Tue, 02 Feb 2021 02:19:55 +0100

In 2012, NASA and FAA jointly conducted a human-in-the-loop air traffic simulation to evaluate the utility of the Terminal Area Precision Scheduling and Spacing (TAPSS) system for supporting Performance-Based Navigation arrival operations during periods of congestion at a mid-sized airport. The TAPSS system is a trajectory-based strategic planning and tactical control tool that was developed to efficiently manage arrivals. For this study, the TAPSS system was enhanced to handle Required Navigation Performance arrivals. A baseline case, where none of the TAPSS system's advisories were provided, was run along with two different configurations of the TAPSS system with differing sets of controller advisory tools. The engineering data indicate that the TAPSS system has a potential to enable efficient Performance-Based Navigation arrival operations. The participating controllers found the TAPSS system's advisories useful. When controllers were given the full set of TAPSS advisory tools, 90% of Required Navigation Performance arrivals stayed on-path as compared to 87% in the baseline case, the average extra track distance of Area Navigation arrivals decreased by 36%, and the average number of controller voice communications decreased by 13%.

Human Mobility Computing and Privacy: Fad or Reality?

Scipedia content — Tue, 02 Feb 2021 02:09:48 +0100

The advent of mobile computing and sensing technologies, in conjunction with omni-present and high-speed mobile networks, allow nowadays the capture of human mobility data at an extremely high fidelity. Modern mobile computing services not only have the capacity to store spatio-temporal mobile data, these nowadays also have the capability to process incoming data in near-real time. As a result, we have a better chance to develop effective strategies and build intelligent systems that play critical roles in areas like public health, traffic engineering, urban planning and economic forecasting. On the other hand, detailed movement data often poses a threat to the privacy and security of users and companies, given that mobile devices are associated with real human custodians. One fundamental question is whether human mobility computing and privacy can co-exist under the same roof, given different cultural, religious, legal, technological and socio-economic backgrounds of societies. This panel will explore how the academia and industry are tackling human mobility computing and privacy challenges at a global scale. It will also identify and debate the key challenges and opportunities, in terms of applications, queries, architectures, to which the mobile data management community should contribute. © 2015 IEEE. 2 42 43 "p"Sponsors: Aalborg University et al. IEEE Computer Society IEEE Technical Committee on Data Engineering The National Science Foundation University of Pittsburgh Conference code: 118117

Robust H∞ Design of an Automotive Cruise Control System

Scipedia content — Tue, 02 Feb 2021 02:05:29 +0100

dvanced Driver Assistance Systems (ADAS) are in the focus o f the vehicle control research. In the paper, the design method of a controller for a longitudinal ADAS system of a test vehicle is proposed. The cruise control must guaran tee precise velocity tracking at varying vehicle mass and road inclinations. The mass variat ion and road slope changes are formulated as disturbances of the system. A combined robust H ∞ and feedforward control design method is applied, which guarantees the robustness o f the system against disturbances and considers actuator dynamics. The resulting control alg orithm is implemented in CarSim. Simulation scenarios on the Mulhouse-Belfort highway sect ion are performed to illustrate the efficiency of the method.

Priority-based coordination of autonomous and legacy vehicles at intersection

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

Recently, researchers have proposed various autonomous intersection management techniques that enable autonomous vehicles to cross the intersection without traffic lights or stop signs. In particular, a priority-based coordination system with provable collision-free and deadlock-free features has been presented. In this paper, we extend the priority-based approach to support legacy vehicles without compromising above-mentioned features. We make the hypothesis that legacy vehicles are able to keep a safe distance from their leading vehicles. Then we explore some special configurations of system that ensures the safe crossing of legacy vehicles. We implement the extended system in a realistic traffic simulator SUMO. Simulations are performed to demonstrate the safety of the system.

Comment: put in other preprint server

Do Benefits justify Cooperative Systems? A Cost-Benefit-Analysis

Scipedia content — Tue, 02 Feb 2021 01:37:51 +0100

Cooperative systems comprising the V2I and V2V communication, ADAS, and traffic management applications are well-researched, technically sound and nearly ready to be installed in the real world. Their general benefits regarding traffic flow and emission improvements could be proved in simulations and FOTs. What remains underinvestigated is the question whether the costs of installation and operation are outweighed by these benefits from the economical point of view. Therefore Cost-Benefit-Analyses have been conducted in the European research project eCoMove which aimed at reducing fuel consumption and therefore CO2 emission by 20%, as well as in the German research project KOLINE. This paper concentrates on the transformation of the simulation results into monetised benefits, the cost derivation and the resulting Cost-Benefit-Ratios (CBR) of the different scenarios. The most important scenario parameters hereby were the penetration rate of vehicles and traffic light control optimisation. It is shown that very good CBR values can be obtained, when the intersection layout and driver behaviour are regarded carefully.

High dynamic range video chains

Scipedia content — Tue, 02 Feb 2021 01:34:19 +0100

Over the last decade, much research experience has been gained in the realm of high dynamic range imaging (HDRI). On account of the significantly improved visual experience that HDRI offers, industry has recently taken a strong interest in this set of technologies. This is evident in the active consideration of HDR by standardization bodies, for instance DVD and EBU in the context of UHDTV, and the emergence of demos at tradeshows. To enable a more engaging/immersive viewing experience in the home or in the cinema, a range of technologies, workflows and processes should be adapted, and HDRI would need to evolve to become HDRV: high dynamic range video. There exists a good number of solutions that each solves part of the problem. However, as a significant number of problems remain open, there is, up to now, no integrated pipeline that includes everything from capture to post-production, archival/storage, compression, transmission, and display. In this paper, we review the requirements for building high dynamic range video pipelines, and discuss how and where HDR components can and should be inserted. This leads to a range of different scenarios, each with their own expected quality levels, associated cost and required effort to implement in practice. In particular, we consider an ideal end-to-end HDR video chain, as well as several variants that involve either legacy content or conventional decoding and rendering devices.

DSS and ITS for intermodal freight transport: some European experiences

Scipedia content — Tue, 02 Feb 2021 01:24:31 +0100

The subject of this paper is the use of ITS (Intelligent Transport System) with the DSS (Decision Support System) for intermodal transport. The types of ITS are classified with attention to specific mobility sequences for freight movements. Referential freight ITS are the CVO (Commercial Vehicle Operations). Then four management tools are presented: SAP-YARD, CroBIT, UirNet and Access. A classification is proposed in which the various types of ITS present in each DSS are highlighted.

Strategic Reactions of Airlines to their Inclusion in the European Trading Scheme

Scipedia content — Tue, 02 Feb 2021 00:56:28 +0100

International audience; The air transport sector entered the European Trading Scheme in 2012 (for the intra-European flights). The regulation of CO2 emissions is costly for airlines and modifies the organization of their market. Our paper proposes an economic analysis in which the regulation but also CO2 emissions of airlines are modeled. We show that, in a perfect competition setting, the difference between passengers carried without regulation and when the regulation is considered is negative for the best-performing planes. However, for the less efficient aircraft, the implementation of the regulation entails a reduction of airlines activity, and therefore a low level of carbon emissions.

An extension of MovSim for Multi-Agent Cooperative Vehicles Modeling

Scipedia content — Tue, 02 Feb 2021 00:54:55 +0100

International audience; We present a multi-agent based extension of a microscopic time continuous lane-based simulator designed to develop cooperative vehicle behaviors within a connected environment.We have chosen to extend the Multi-model Open-source Vehicular-traffic SIMulator (MovSim) which offers a complete traffic simulation platform. By integrating concepts coming from artificial intelligence and related intelligent distributed systems such as multi-agent systems, we aim to model complex individual interactions (including sensors measurements, communication between vehicles and with the infrastructure).

Evolving Traffic Scenarios to Test Driver Assistance Systems in Simulations

Scipedia content — Tue, 02 Feb 2021 00:48:22 +0100

Nowadays, driver assistance systems involve an ever increasing degree of automatization. Costly effort is put into testing the individual components to ensure proper functioning by the vehicle manufacturers. However, problems can also arise on a macroscopic scale, as vehicles and infrastructure are recently equipped with short range radio communication (“Car2X”). These problems caused by interaction are of even greater concern than “normal” bugs, as the final product might already have been deployed when the issues first become apparent. Multi-Agent System (MAS) research refers to such issues as “emergent misbehavior”. The said field also brought up an approach to automatically discover the worst consequences of the malfunctions. Hence, a given system under test can already be revised during development, saving a tremendous amount of resources. The approach from MAS is adapted to the domain of testing driver assistance systems in traffic simulations. A green-light optimal-speed advisory (GLOSA) algorithm is used as an example in which conceptual problems are discovered by the testing system after simpler issues are eliminated.

Harvey H. Hubbard's contributions to aircraft noise control during his NACA-NASA career

Scipedia content — Tue, 02 Feb 2021 00:46:06 +0100

Following his service in the US Army Air Corps during World War ll, Harvey accepted a position at the NACA Langley Memorial Aeronautical Laboratory in 1945. Propeller aircraft dominated the air transport system at that time and he was among the first to perform research on the noise associated with propellers. In the next decade jet engine powered aircraft made their appearance and they became the focus of a rapidly growing acoustics research program at Langley. His pioneering experimental noise studies on propellers and jet engines provided significant insight and understanding of these two areas of concern. Foreseeing that additional research efforts would be required to address the many new aircraft noise issues, including the sonic boom and airport-community noise concerns of the proposed U.S. supersonic transport, he played a key role in getting NASA to expand its acoustic efforts. As a result, Harvey became NASA's technical focal point for all major acoustical activities. In this paper I will present some highlights of his research on propeller noise, jet noise, and sonic boom.

High Speed Railway System and the Tourism Market: Between Accessibility, Image and Coordination Tool

Scipedia content — Tue, 02 Feb 2021 00:45:47 +0100

International audience; The aim of this paper is to propose a state-of-the-art about the interactions between High-Speed Railway systems and the tourism market. Because of changes in accessibility, provided to the territories supplied by these systems, the actors expect a dynamic economy, in general, and of the tourism in particular. Although expectations are important in France as abroad, a literature review of studies carried out ex-post shows that the effects are not systematic, since they depend on the implementation of the High-Speed Railway service and on the characteristics of the territories. It can be noted that, if the high speed rail allows, in some cases, the increase in the number of tourists, a decrease of the stay may follow. To understand the role of High Speed Railway, it is necessary to take into account the changes of accessibility, but also its effects on the image of the destination and on the coordination of the stakeholders.

Arterial traffic signal coordination utilizing vehicular traffic origin-destination information

Scipedia content — Tue, 02 Feb 2021 00:44:57 +0100

Traditional arterial traffic signal coordination methods are focused on providing uninterrupted flow along the arterial direction. This paper proposes a more versatile arterial traffic signal coordination method that can take into consideration of major turning traffic flows from and to cross streets. This new method is formulated as a mixed-integer linear program and solved by CPLEX. A case study based on AIMSUN simulation is conducted to demonstrate the proposed method's superiority compared to Synchro and Transyt-7F.

Implementation of collision warning algorithm based on V2V communications

Scipedia content — Tue, 02 Feb 2021 00:44:08 +0100

One of the major lines of development of intelligent transport systems is ensuring road traffic safety. Recent advances in the field of satellite navigation and wireless data transmission systems have enabled significant expansion of the capabilities of the existing driver assistance systems. The present article provides the pilot test results of the collision warning device for unsignaled road intersections.

Evaluation of Infrastructure Design Solutions Based on Traffic Modelling

Scipedia content — Tue, 02 Feb 2021 00:39:40 +0100

Nowadays the main task remains analysis of traffic flow. It is relevant for designing new roads or interchanges to evaluate the economic and environmental impacts. Foreign experience proves that traffic modelling software is being used before implementing modernization of road network. Traffic simulation models become more and more important tools ensuring traffic control and providing possibility to do the planning process of road network. The main goal of study is to create traffic simulation models using modern software which will enable efficient selection of road design solutions in Lithuania. During the research below studies traffic modelling software packages were analysed, traffic simulation models were designed using traffic modelling tools and calibration of traffic simulation models was made so as their adaptation to Lithuanian conditions. Traffic simulation models adapted to designing of road infrastructure and the process of selection of solutions. The results showed that road design solutions can be compared based on traffic simulation models. Thus a high level of design solutions is being ensured. Two Lithuanian study cases of using traffic modelling in infrastructure design projects are described in the article.

Quality of interaction among path computation elements for trust-aware inter-provider cooperation

Scipedia content — Tue, 02 Feb 2021 00:37:56 +0100

Path Computation Element (PCE) architecture en- ables effective traffic engineering in multi-domain networks while limiting the exposure of intra-domain information. However, re- turned path computations might reveal confidential information if artfully correlated by a malicious PCE. Thus, the selection of domains sequence as the result of PCEs cooperation should depend not only on the capability of providing quality paths but also on factors related to expected revenues or perceived risks. In this scenario, cooperation among PCEs could benefit from a trust model by evaluating the quality of the past interactions. This work introduces the concepts of Quality of Interaction and trust ranking and elaborates a trust management model including effectiveness and security objectives regulating the cooperation among PCEs. Specifically, the proposed trust model aims at stimulating effective interactions among PCEs as a result of a common interest in contributing to successful and profitable path computations while avoiding misuse of path computation services. The simulation results show that our trust model is effective in detecting malicious PCE thereby tuning the amount of information returned in the path computation replies. I. INTRODUCTION

Practical Performance Evaluation of Ethernet Networks with Flow-Level Network Modeling

Scipedia content — Tue, 02 Feb 2021 00:37:35 +0100

Network models for evaluating the behavior of networks are important tools in traffic engineering for dimensioning networks and provisioning bandwidth for different applications. We present in this paper a flow-level network model for the performance evaluation of IP networks with support of long-lived TCP and UDP flows. While flow-level network models for TCP and UDP flows have already been investigated, a vast majority of previous studies often do not take into account the importance of cross-traffic. This paper presents topologies where cross-traffic has a major impact on the performance of TCP flows and shows how previous models are not accurate enough. We consider in our study Ethernet LANs with low latencies and show how to apply our framework to networks with Ethernet switches using priority based scheduling, fair-queuing scheduling, or hierarchical scheduling based on the former algorithms. We assess the accuracy of our approach by comparing the results of our model with results of the discrete event simulator OMNeT++.

Considerations for improving the capacity and performance of AeroMACS

Scipedia content — Tue, 02 Feb 2021 00:34:27 +0100

The Aeronautical Mobile Airport Communications System (AeroMACS) has progressed from concept through prototype development, testing, and standards development and is now poised for the first operational deployments at nine US airports by the Federal Aviation Administration. These initial deployments will support fixed applications. Mobile applications providing connectivity to and from aircraft and ground-based vehicles on the airport surface will occur at some point in the future. Given that many fixed applications are possible for AeroMACS, it is necessary to now consider whether the existing capacity of AeroMACS will be reached even before the mobile applications are ready to be added, since AeroMACS is constrained by both available bandwidth and transmit power limitations. This paper describes some concepts that may be applied to improve the future capacity of AeroMACS, with a particular emphasis on gains that can be derived from the addition of IEEE 802.16j multihop relays to the AeroMACS standard, where a significant analysis effort has been undertaken.

A quantitative approach to behavioural analysis of drivers in highways using particle filtering

Scipedia content — Tue, 02 Feb 2021 00:30:00 +0100

The analysis of driving behaviour is a challenging task in the transport field that has numerous applications, ranging from highway design to micro-simulation and the development of advanced driver assistance systems. There has been evidence suggesting changes in the driving behaviour in response to changes in traffic conditions, and this is known as adaptive driving behaviour. Identifying these changes and the conditions under which they happen, and describing them in a systematic way, contributes greatly to the accuracy of micro-simulation, and more importantly to the understanding of the traffic flow, and therefore paves the way for introducing further improvements with respect to the efficiency of the transport network. In this paper adaptive driving behaviour is linked to changes in the parameters of a given car-following model. These changes are tracked using a dynamic system identification method, called particle filtering. Subsequently, the dynamic parameter estimates are further processed to identify critical points where significant changes in the system take place.

Vehicle detection based on LiDAR and camera fusion

Scipedia content — Tue, 02 Feb 2021 00:29:23 +0100

Vehicle detection is important for advanced driver assistance systems (ADAS). Both LiDAR and cameras are often used. LiDAR provides excellent range information but with limits to object identification; on the other hand, the camera allows for better recognition but with limits to the high resolution range information. This paper presents a sensor fusion based vehicle detection approach by fusing information from both LiDAR and cameras. The proposed approach is based on two components: a hypothesis generation phase to generate positions that potential represent vehicles and a hypothesis verification phase to classify the corresponding objects. Hypothesis generation is achieved using the stereo camera while verification is achieved using the LiDAR. The main contribution is that the complementary advantages of two sensors are utilized, with the goal of vehicle detection. The proposed approach leads to an enhanced detection performance; in addition, maintains tolerable false alarm rates compared to vision based classifiers. Experimental results suggest a performance which is broadly comparable to the current state of the art, albeit with reduced false alarm rate.

A new tool for evaluating road transport fuel consumption and CO2 emissions based on open geographical databases

Scipedia content — Tue, 02 Feb 2021 00:26:03 +0100

The analysis of road transport costs and efficiency relies strongly on the availability of spatial data which in some regions are difficult or expensive to obtain. Open geographical databases seem therefore a promising alternative for these regions. OpenStreetMap©, due to permanent development and improvement by a large number of collaborators, is able to provide reliable data at no cost; as a result, the development and application of specific geographic information tools in most locations becomes possible. In this work we developed routines for forest logistics based on data from OpenStreetMap©, specifically to evaluate fuel consumption and costs as well as CO2 emissions in wood transport in the Northeastern region of Portugal, where the road network is strongly affected by topography that has impact on forest logistics and the viability of alternatives of wood mobilization. We applied our methodology in a real case study of transport of forest biomass to a pellet plant, deriving surface estimates of fuel consumption, fuel costs, CO2 emissions, and accessibility performance to be used as criteria for deciding on support systems for forest management and planning in the Northeastern region. This application demonstrates the importance of available geographic information data and tools in forest mobilization.

Study of Slug Control Techniques in Pipeline Systems

Scipedia content — Tue, 02 Feb 2021 00:24:16 +0100

Severe slugging may occur at low flow rate conditions when a downward inclined pipeline is followed by a vertical riser. This phenomenon is undesirable for offshore oil and gas production due to large pressure and flow rate fluctuations. It is of great technological relevance to develop reliable and economical means of severe slugging mitigation. This study aims to develop an automated control system to detect and mitigate the formation of severe slugging through a choke valve and a series of sensors. As a first step, an overall flow map is generated to indicate the region within which severe slugging may occur based on Boe’s criterion [1] and Taitel’s model [2, 3]. It was possible to obtain different flow patterns by controlling the rate of water and gas injection."/jats:p" "jats:p"The aim of this paper is, however, the formation of severe slugs and study of mitigation techniques. In the control part, we used a choke valve controlled by software which is in feedback with data from a system with pressure, temperature, flow, which are able to measure even small changes in the relevant parameters to the model. A two-phase flow loop was built for the study of severe slugging in pipeline-riser system with air and water as work fluids. The inner diameter of riser and flowline is 76.2 mm. The riser is 20 meters high and the flowline is 15 meters long and could be inclined upward or downward up to 8-degree. It has been shown by experiments how riser slugging can be controlled by automated control system.

State Space Reduced Dynamic Programming for the Aircraft Sequencing Problem with Constrained Position Shifting

Scipedia content — Tue, 02 Feb 2021 00:23:39 +0100

LNCS, Vol. 8596; International audience; In this paper we present state space reduction techniques for a dynamic programming algorithm applied to the Aircraft Sequencing Problem (ASP) with Constrained Position Shifting (CPS). We consider the classical version of the ASP, which calls for determining the order in which a given set of aircraft should be assigned to a runway at an airport, subject to minimum separations in time between consecutive aircraft, in order to minimize the sum of the weighted deviations from the scheduled arrival/departure times of the aircraft. The focus of the paper is on a number of ways of improving the computation times of the dynamic programming algorithm proposed. This is achieved by using heuristic upper bounds and a completion lower bound in order to reduce the state space in the dynamic programming algorithm. We compare our algorithm to an approach based on mixed integer linear programming, which was adapted from the literature for the case of CPS. We show using real-world air traffic instances from the Milan Linate Airport that the dynamic programming algorithm significantly outperforms the MILP. Furthermore, we show that the proposed algorithm is capable of solving very large instances in short computation times, and that it is suitable for use in a real-time setting.

Enabling autonomous flight capabilities onboard commercial aircraft to improve safety

Scipedia content — Tue, 02 Feb 2021 00:15:10 +0100

This paper presents the development and implementation of a novel Flight Management System (FMS) to ensure onboard passenger safety of commercial aircraft in the event of an emergency scenario where the pilot must relinquish control of the aircraft (e.g. hijacking or loss of cabin pressure). In such situations, the flight management system autonomously pilots the aircraft to a predefined destination whilst taking into account potential hazards such as terrain (in low altitude scenarios), aircraft dynamic constraints, and flight objectives with real-time constraints present. Furthermore, the FMS must ensure that the Human Decision Maker (HDM) (e.g. Air Traffic Control or ATC) has sufficient time to intervene if they do not agree with automated onboard decisions. The proposed FMS shows that the inclusion of intelligent planning capabilities onboard commercial aircraft can assist in improving safety for the aircraft and onboard passengers in the event of emergencies by allowing the aircraft to continue operating autonomously in a management by exception paradigm. This approach has been demonstrated in this paper through simulation using a commercial aircraft model operating in low altitude partially known environments.

Novel quantum NMR magnetometer non-contact defectoscopy and monitoring technique for the safe exploitation of gas pipelines

Scipedia content — Tue, 02 Feb 2021 00:11:10 +0100

Pipeline transportation has already proved to be a high-performance tool of resources transportation for the efficient functioning of modern society. However, an aggressive environment, the modernization of existing pipelines and the building of new pipelines pose a number of problems to be solved for secure exploitation. Such problems include mapping, systems certification, technical inspection and monitoring. Recently much attention has being paid to the effective solution of these problems, with no interference into the functioning of the existing systems (non-contact methods), and the magnetometric technique is one such method. The method presented in this paper is based on the interpretation of the absolute value of the magnetic field of an object, which allows us to carry out measurements more accurately compared to other approaches. This paper presents the preliminary results of the usage of high-precision absolute quantum Overhauser “POS” (proton Overhauser sensor) magnetometers in the oil-and-gas field. The field work conducted in the summer of 2013 showed that this equipment has great potential for safe exploitation of oil-and-gas pipelines. The efficiency of the geophysical equipment for gas pipelines of a large diameter (1400 mm) was also confirmed under actual operating conditions. © 2014 WIT Press. International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

Economic Impact of Distribution Grid Operation Scenarios for the Integration of Electric Vehicles

Scipedia content — Tue, 02 Feb 2021 00:08:30 +0100

The paper lists the drivers and the barriers for a widespread adoption of electric vehicles (EVs), describes the different stakeholders involved in the electro-mobility ecosystem and summarises the main issues for the integration of EVs in distribution grids. Then, it presents some outcomes of the PlanGridEV Project, including the proposed new grid planning criteria, the envisaged future scenarios for EV integration, the expected services to be provided by EVs to distribution system operators and the ICT requirements linked to those services. Electric Vehicles (EVs) will become an important part of the transport system in Europe and can thus create a number of benefits in term of oil dependence reduction, air quality improvement and trade balance enhancement. However, they can also become a burden for distribution system operator (DSOs) if they charge in an uncontrolled way. In addition, the increasing deployment of renewable energy sources (RES) and other distributed energy resources (DER) are making the distribution grid planning more complicated than in the past, when consumers were considered to be passive elements and grid was dimensioned to meet peak demand. PlanGridEV project proposes new planning procedures, which take into account the possibility to manage consumers’ electricity demand, including the charging process of EVs, both to better integrate DER and to more efficiently plan the investments in the distribution grid. The planning rules will be validated by carrying out four test beds, which will serve as an input for assessing the economic performance of four scenarios, representing four theoretical alternatives for distribution grid planning. Different services that EVs can provide to DSOs and other actors in the e-mobility ecosystem will be analysed in each scenario. Then, a grid planning tool will be developed to help DSOs consider EVs and demand and other demand response (DR) capabilities when planning distribution grid extension. European Commission's FP7

The results of the implementation of SAS technology for the renovation and life extension of district heating systems

Scipedia content — Tue, 02 Feb 2021 00:08:09 +0100

The analysis of the results of large-scale work on the introduction of the facilities of complex technology, based on changing the functional surface properties of pipelines and heat power equipment using surface-active substances (SAS) technology is carried out. The volume of SAS technology realization has been specified in the heating supply systems of the Russian Federation’s cities since 2003. An evaluation of the technical and economic efficiency of SAS technology, as an example of the typical elements of district heating systems based on hot water heating plants, including their boilers, heating networks, heating stations and buildings heating systems, is presented.

The Impact of RNA-seq Alignment Pipeline on Detection of Differentially Expressed Genes

Scipedia content — Tue, 02 Feb 2021 00:05:10 +0100

RNA-seq data analysis pipelines are generally composed of sequence alignment, expression quantification, expression normalization, and differentially expressed gene (DEG) detection. Each step has numerous specific tools or algorithms, so we cannot explore all combinatorial pipelines and provide a comprehensive comparison of pipeline performance. To understand the mechanism of RNA-seq data analysis pipelines and provide some useful information for pipeline selection, we believe it is necessary to analyze the interactions among pipeline components. In this paper, by combining different alignment algorithms with the same quantification, normalization, and DEG detection tools, we construct nine RNA-seq pipelines to analyze the impact of RNA-seq alignment on downstream applications of gene expression estimates. Specifically, we find moderate linear correlation between the number of DEGs detected and the percentage of reads aligned with zero mismatch.

Inserting bus rapid transit into an existing transportation system: the Mexico City experience

Scipedia content — Mon, 01 Feb 2021 23:55:13 +0100

A green fleet planning framework: assessment and improvement strategies

Scipedia content — Mon, 01 Feb 2021 23:50:51 +0100

Under the enforcement of stringent regulations to preserve environment, airlines encounter increasing financial burden particularly in paying pollution fines. This could be avoided if airlines could improve their environmental (green) performance. This paper proposes a novel methodology to quantify airline’s green performance. A ‘Green Fleet Index (GFI)’ framework is formulated by capturing three major environmental factors, namely aircraft emission, noise and fuel efficiency. The proposed framework also allows the evaluation of various improvement strategies to yield a greener performance. A realistic case study, with 38 international routes, is presented to examine the applicability of the developed framework. The findings show that aircraft emission, noise and fuel efficiency could affect the green performance of airlines to a great extent. Furthermore, the results point out the effectiveness of a particular mitigation strategy that performs differently on specific environmental factors (emission, noise and fuel efficiency). It is anticipated that this study may reveal some beneficial insights for airlines to operate in a sustainable and environmental manner, which would benefit air travellers as well as the community in return.

Characterization of the portuguese SSS into the Europe: a contribution

Scipedia content — Mon, 01 Feb 2021 23:43:03 +0100

Nowadays, Short Sea Shipping (SSS) is an essential part in European multi-modal transport system, representing approximately thirty-seven per cent of intra-Community transactions in tonnes per kilometre (tkm). Since 2001, the European Shortsea Network (ESN) in partnership with the short-sea Promotion Centres (SPC) of each Member State of the European Union (EU) have managed to make significant progress in the promotion and development of this mode of transport.This paper aims to assess and analyse the SSS of containerised goods in Portugal and its articulation with other EU routes and also other transport modes. The current SSS infrastructure, how the sector is organized, as well as the future perspectives for the sector are also analysed for the case of Portugal.The analyses are based on a survey that was carried out on the logistics operators, navigation agents, freight forwarders, and the leading imports and exports manufacturers in Portugal. This research was funding by BInt-ICD/IPP-BST/CIEFGEI/02/2014 under Santander Totta funding. info:eu-repo/semantics/publishedVersion

Phase Balancing by Means of Electric Vehicles Single-Phase Connection Shifting in a Low Voltage Danish Grid

Scipedia content — Mon, 01 Feb 2021 23:41:54 +0100

In Denmark, household consumers are supplied with three phase with neutral cable. In addition, the distribution service operator cannot decide to which phase electrical appliance are connected. The technician who realizes the installation connects the loads according to his technical expertise. This may results in heavy imbalances. This paper uses a real Danish distribution system with household consumers, photovoltaic in- stallation and electrical vehicles (EV). In this paper the possibility to use EVs' charging spots in order to reduce grid's imbalances will be investigated. Usually, charging stations are equipped with single-phase converters. According to the designed control strategy, the charging spot can select the phase to be used for the charge. The selection is done according to a phase voltage measurement.

Leak detection and location based on improved pipe model and nonlinear observer

Scipedia content — Mon, 01 Feb 2021 23:39:41 +0100

International audience; This paper proposes a new contribution to observer-based approaches for detection and location of leaks in pipelines. In previous studies for such approaches, the observer is most of the time designed for a model obtained from hydraulic dynamical equations and finite difference techniques, using pressures at both ends of the pipe as boundary conditions; in the present work, the finite difference model is modified by using other boundary conditions, which are the pressure in the inlet pump and the pressure at the end of the pipe system. This modification provides a better representation of the pipeline dynamics, as illustrated by comparing the behavior simulated in this way with real data. It is then emphasized that this improved model may be used for an observer-based direct estimation of a possible leak flow in the pipe - together with its position, only using two measured variables (instead of four in former studies): one pressure at one end of the pipe, and one flow at the other pipe side. The other two variables, to be known by the observer - related to the boundary conditions, can indeed be taken here as constant values, since they correspond to the inlet pump pressure and the atmospheric pressure respectively. Results obtained with an Extended Kalman observer designed on this basis are finally presented, both in simulation and with real data.

Autonomous System for Air Traffic Control in Terminal Airspace

Scipedia content — Mon, 01 Feb 2021 23:38:23 +0100

In this article we present recent work towards the development of an autonomous system that performs conflict resolution and arrival scheduling for aircraft in the terminal airspace around an airport. An autonomous air traffic control system is defined as a system that can safely solve the major traffic management problems currently handled by human controllers. It has the potential to handle higher traffic levels and a mix of conventional and unmanned aerial vehicles with reduced dependency on controllers. The main objective of this paper is to describe the fundamental trajectory algorithms that must be incorporated in such a system. These algorithms generate arrival trajectories that are free of conflicts with other traffic, and meet scheduled times of arrival for landing with specified in-trail spacings. The maneuvers the system employs to resolve separation and spacing conflicts include speed control, horizontal maneuvers, and altitude changes. Furthermore, the system can reassign arrival aircraft to a different runway in order to reduce delays. Examples of problems solved and performance statistics from a fast-time simulation using simulated traffic of arrivals and departures at the Dallas/Fort Worth International Airport and Dallas Love Field Airport are also provided.

The peculiarities of fatigue failure for pipe steels of different strength classes (pipes with welds)

Scipedia content — Mon, 01 Feb 2021 23:37:50 +0100

Variable loads, as compared with static loads, have a greater impact on the condition of pipelines. They lead to the degradation of metal and significantly reduce the service life of pipelines. This paper considers the mechanism of fatigue crack development in steels of different strength classes (K50, K60 and K62), which helps to specify the fracture mechanism and evaluate the residual life of a pipeline material. Fatigue tests were carried out until the complete failure of specimens at a maximum tensile load below the yield strength of the steels. The number of cycles to failure of specimens with no visible weld defects was reduced by more than 40%, as compared with seamless specimens. If there were allowable defects of up to 0.4 mm in size, then the number of cycles was reduced by 5–12 times. Photographs of the fractures are provided. The tests allowed the authors to establish the peculiarities of K60 steel failure and to calculate regression equations of the second order between the number of cycles to failure of the specimen, the maximum tensile stress and the stress range during fatigue tests. An essential effect of the stress range (in the range of 18–44 MPa) on the number of cycles to failure of the specimen has been established. After its reduction to 6–8% of the maximum tensile stress, the stress range ceases to affect the number of cycles. Since the appearance of the first visually perceptible cracks, the specimens endured from 4,000 to 10,000 cycles to failure. This makes it possible to detect the initiation of a failure and take steps to repair the defective part. Knowing the number of pressure fluctuations in the pipeline, which are registered in the control room, one can use the equations to predict the residual life of a particular section of the pipeline.

Failure mechanism of cutting submerged frozen clay in an arctic trenching process

Scipedia content — Mon, 01 Feb 2021 23:37:17 +0100

This version of the thesis only covers the literature study. The results analysis and conclusion of the thesis are confidential. Pipelines in arctic waters are at risk of being damaged by gouging ice masses. To protect these pipelines, they can be buried in trenches. When trenching in arctic clayey soil, sub sea permafrost can be encountered. The main objective of this research is to study the failure mechanism of frozen clay as encountered in permafrost regions. Knowledge of the cutting mechanism leads to the ability to calculate cutting forces and the specific energy required to excavate material. To find the failure mechanism and answer the research question, a cutting setup was designed and built and cutting experiments were conducted. The setup was designed, based on requirements that result from studied literature on frozen clay and cutting theories. A series of cutting experiments were conducted where a slab of frozen clay was pressed against a transparent wall and the top layer was cut off while filming the process with a high speed camera. The results are measurements of the cutting forces and observations of the failure mechanism.

Personal air vehicle (PAVE) application in Malaysia

Scipedia content — Mon, 01 Feb 2021 23:35:17 +0100

Transportation has become a huge necessity in our life today, which is instrumental to create greater socioeconomic opportunities. As the world progresses, transportation systems will undergo paradigm shifts to suit with changing requirements. Personal transportation is often preferred to the public transport and to date, most of them have been made on the ground through roads. However, with the increasing traffic volume, the average time spent travelling on roads has significantly increased for the same amount of distance travelled. It has already been proposed that utilization of the possible third dimension of transportation system, which is the air transport, can facilitate in supporting the personal transportation and subsequently alleviate this problem. This notion gives birth to the design concepts of the personal air vehicle (PAVE) that is envisioned to operate synergistically with ground and air infrastructures. This paper aims to preliminarily study and analyze the potential benefits of having PAVE option in Malaysia for domestic travel and how its performance will fare in comparison to the existing ground transportation options. The results of travel time and cost comparisons highlight the potential of PAVE application for the domestic transportation in Malaysia, particularly for personal travel need.

Design of pipeline composite repairs : from lab scale tests to FEA and full scale testing

Scipedia content — Mon, 01 Feb 2021 23:29:54 +0100

Composite repair systems are used for many years to restore locally the pipe strength where it has been affected by damage such as wall thickness reduction due to corrosion, dent, lamination or cracks."/jats:p" "jats:p"Composite repair systems are commonly qualified, designed and installed according to ASME PCC2 code or ISO 24817 standard requirements. In both of these codes, the Maximum Allowable Working Pressure (MAWP) of the damaged section must be determined to design the composite repair. To do so, codes such as ASME B31G for example for corrosion, are used. The composite repair systems is designed to “bridge the gap” between the MAWP of the damaged pipe and the original design pressure."/jats:p" "jats:p"The main weakness of available approaches is their applicability to combined loading conditions and various types of defects. The objective of this work is to set-up a “universal” methodology to design the composite repair by finite element calculations with directly taking into consideration the loading conditions and the influence of the defect on pipe strength (whatever its geometry and type)."/jats:p" "jats:p"First a program of mechanical tests is defined to allow determining all the composite properties necessary to run the finite elements calculations. It consists in compression and tensile tests in various directions to account for the composite anisotropy and of Arcan tests to determine steel to composite interface behaviors in tension and shear. In parallel, a full scale burst test is performed on a repaired pipe section where a local wall thinning is previously machined. For this test, the composite repair was designed according to ISO 24817."/jats:p" "jats:p"Then, a finite element model integrating damaged pipe and composite repair system is built. It allowed simulating the test, comparing the results with experiments and validating damage models implemented to capture the various possible types of failures. In addition, sensitivity analysis considering composite properties variations evidenced by experiments are run."/jats:p" "jats:p"The composite behavior considered in this study is not time dependent. No degradation of the composite material strength due to ageing is taking into account. The roadmap for the next steps of this work is to clearly identify the ageing mechanisms, to perform tests in relevant conditions and to introduce ageing effects in the design process (and in particular in the composite constitutive laws).

Socio-cyberphysical system for proactive driver support: Approach and case study

Scipedia content — Mon, 01 Feb 2021 23:29:39 +0100

Recent developments in the areas of decision support, data and decision mining, on-board infotainment systems have produced valuable results that can be used to support people in different aspects of their lives. Infomobile driver support is one of the possible applications of these, what can significant increase the quality of the user experience. The paper presents a developed approach and enabling technologies for implementation of an intelligent driver support system that takes advantages provided by such modern developing technologies as context-based collaborative recommendation systems, proactive information support, smart space, and V2V communication. The developed concept is illustrated via a parking assistance scenario.

RFLP Approach in the Designing of Power-Trains for Road Electric Vehicles

Scipedia content — Mon, 01 Feb 2021 23:28:52 +0100

International audience; This paper is focused on the designing process of propulsion systems for road electric vehicles, by means of the RFLP approach for System Engineering. The process starts from the analysis of the main requirements for the vehicle considered, in relation to its specific mission. The vehicle behavior is then simulated on standard driving cycles, evaluating the performance figures of different power-train configurations, under different operative conditions. The presented designing procedure reaches the 3D CAD model of the identified propulsion system, coupled with a specific laboratory test bench, based on an eddy current brake and flywheel for the simulation of the vehicle inertia. The obtained simulation results show the good performance of the power-train in terms of vehicle speed following its reference on driving cycle and vehicle autonomy.

Theoretical Model for the Power Recovery Optimization in Natural Gas Distribution Networks: Colombian Case

Scipedia content — Mon, 01 Feb 2021 23:19:35 +0100

LNG production used in passenger transport systems obtained trough natural gas expansion in city networks is a novel process and it has been demonstrated its small energy consumption. This process has made in two stages: first one consist of a pressure reduction and the second one in a cryogenic liquefaction. This paper is focused in the first stage and in a second paper the author will present the simulation result of LNG production optimization for urban transportation systems. This research has been supported by Colombian Science and Technology National Agency (Colciencias, in Spanish) and the company Terpel. As before mention, in natural gas distribution networks, this fuel is transported at high pressures through long length pipelines between the source and final consumers. In every place of consumption or at passing into a lower pressure pipeline the gas pressure must be reduced. Commonly, high pressure is achieved by using a number of compressors, each one attached to a natural gas combustion turbine, consuming energy, and gas pressure reduction is accomplished in mechanical letdown-valves, where an isenthalpic expansion takes place without any energy production. A few amount of the energy consumed could be recovered taking advantage of the enthalpy drop in delivery sites or in pressure reduction stations by the

Traffic sign detection for U.S. roads:Remaining challenges and a case for tracking

Scipedia content — Mon, 01 Feb 2021 23:16:09 +0100

Traffic sign detection is crucial in intelligent vehi- cles, no matter if one's objective is to develop Advanced Driver Assistance Systems or autonomous cars. Recent advances in traffic sign detection, especially the great effort put into the competition German Traffic Sign Detection Benchmark, have given rise to very reliable detection systems when tested on European signs. The U.S., however, has a rather different approach to traffic sign design. This paper evaluates whether a current state-of-the-art traffic sign detector is useful for American signs. We find that for colorful, distinctively shaped signs, Integral Channel Features work well, but it fails on the large superclass of speed limit signs and similar designs. We also introduce an extension to the largest public dataset of American signs, the LISA Traffic Sign Dataset, and present an evaluation of tracking in the context of sign detection. We show that tracking essentially suppresses all false positives in our test set, and argue that in order to be useful for higher level analysis, any traffic sign detection system should contain tracking.

Measurement and Modelling of the Near-field Structure of Large-scale Sonic CO2 Releases from Pipelines

Scipedia content — Mon, 01 Feb 2021 23:13:57 +0100

The work presented in this paper describes a novel multi-phase discharge and dispersion model capable of predicting the near-field fluid dynamics and phase-transition phenomena associated with accidental CO2 releases. Also presented in this paper are previously unpublished data describing the near-field structure of a number of largescale CO2 experimental releases, obtained through the EU-FP7 CO2PipeHaz (2009) project. The calculations employed an adaptive finite-volume grid algorithm to solve the Favre-averaged fluid-flow equations. This equation set was closed with the inclusion of both a two-equation k-e model and a second-moment Reynolds stress model to represent turbulent fluctuations. Results demonstrate the superior performance of the Reynolds stress transport model when compared to its compressibility-corrected counterpart.

The Role of Composite Repair Technology in Rehabilitating Piping and Pipelines

Scipedia content — Mon, 01 Feb 2021 23:08:33 +0100

Composite materials have been used to repair high pressure pipelines and piping for the better part of 20 years. The initial aim of composite repair technology was focused on reinforcing corrosion. However, composite materials are now used to reinforce a wide array of anomalies and features including dents, mechanical damage, vintage girth and seam welds, wrinkle bends, elbows, tees, branch connections, and even cracks."/jats:p" "jats:p"In this paper the author provides an industry overview including results and insights from multiple research programs sponsored by composite repair manufacturers, pipeline operators, and the Pipeline Research Council International, Inc. Discussions will also be included regarding the important role that the ASME PCC-2 and ISO 24817 composite repair standards have in ensuring that quality control measures are in place. The ongoing focus of these efforts has been to demonstrate to industry the capabilities that composite repair systems have to provide long-term solutions for reinforcing damaged equipment.

UAS Contingency Management: The Effect of Different Procedures on ATC in Civil Airspace Operations

Scipedia content — Mon, 01 Feb 2021 23:07:25 +0100

UAS currently lack key capabilities required to routinely integrate with the current Air Traffic Management (ATM) system, including standardized and predictable procedures for managing off nominal or contingency events, especially those that are specifically related to UAS and their unique communications architecture [i.e., loss of the command and control communications link(s). A simulation experiment was conducted to examine the effects of a variety of currently-employed UAS contingency procedures on sector safety and efficiency, and Air Traffic Controller (ATC) workload. ATC participants were tasked with maintaining safe separation standards in a busy Terminal Radar Approach Control (TRACON) sector that included a single UAS. During different trials, the UAS would execute one of five contingency types, including one trial with no contingency (i.e., baseline), three different contingency procedures for the loss of command and control link, and one emergency landing procedure. Objective aircraft separation and sector throughput data, workload ratings, situation awareness ratings, and subjective ratings regarding the safety and efficiency of UAS operations in the NAS were collected. Results indicated that the simulated UAS contingency procedures had no significant impact on objective measures of safety and efficiency compared to the baseline. Further, there were no significant differences in subjective workload and situation awareness ratings between the baseline and any of the contingency procedures.

SmartRoad: A New Approach to Law Enforcement in Dense Traffic Environments

Scipedia content — Mon, 01 Feb 2021 23:01:46 +0100

Road transport law enforcement is facing new challenges against the background of increasingly congested traffic conditions. An ideal law enforcement system must enable authorities to detect, identify and act against illegal road users with minimum disruption of normal traffic flows. This paper presents a new concept for in-traffic law enforcement that overcomes many of the limitations of existing approaches. The SmartRoad system combines the best abilities of imaging, automated identification, radio communications and artificial intelligence technologies to identify not only vehicles with anomalous identities but also anomalous behavior displayed by legal vehicles. The proposed system utilizes the combined abilities of traffic cameras and RFID to firstly detect vehicles and subsequently verify their true identity. Such information is passed downstream to enable the removal of such vehicles from the road with minimal disruption to other road users. As more historical statistics representing normal and abnormal road usage are collected the system will learn from such data in order to improve its ability to reduce both false positives and negatives. Successful deployment of the SmartRoad concept should therefore result in a self-regulating traffic system that discourages unacceptable road use and that adapts itself to new forms of road behavior.

Logan's run: Lane optimisation using genetic algorithms based on nsga-ii

Scipedia content — Mon, 01 Feb 2021 22:56:26 +0100

Whilst bus lanes are an important tool to ensure bus time reliability their presence can be detrimental to urban traffic. In this paper a Non-dominated Sorting Genetic Algorithm (NSGA-II) has been adopted to study the effect of bus lanes on urban traffic in terms of location and time of operation. Due to the complex nature of this problem traditional search would not be feasible. An artificial arterial route has been modelled from real data to evaluate candidate solutions. The results confirm this methodology for the purpose of studying and identifying bus lane locations and times of operation. Additionally it is shown that bus lanes can exist on an arterial link without exclusively occupying a continuous lane for large periods of time. Furthermore results indicate a use for this methodology over a larger scale and potential near real-time operation.

Compiling path queries in software-defined networks

Scipedia content — Mon, 01 Feb 2021 22:51:34 +0100

Monitoring the flow of traffic along network paths is essential for SDN programming and troubleshooting. For example, traffic engineering requires measuring the ingress-egress traffic matrix; debugging a congested link requires determining the set of sources sending traffic through that link; and locating a faulty device might involve detecting how far along a path the traffic makes progress. Past path-based monitoring systems operate by diverting packets to collectors that perform "after-the-fact" analysis, at the expense of large data-collection overhead. In this paper, we show how to do more efficient "during-the-fact" analysis. We introduce a query language that allows each SDN application to specify queries independently of the forwarding state or the queries of other applications. The queries use a regular-expression-based path language that includes SQL-like "groupby" constructs for count aggregation. We track the packet trajectory directly on the data plane by converting the regular expressions into an automaton, and tagging the automaton state (i.e., the path prefix) in each packet as it progresses through the network. The SDN policies that implement the path queries can be combined with arbitrary packet-forwarding policies supplied by other elements of the SDN platform. A preliminary evaluation of our prototype shows that our "during-the-fact" strategy reduces data-collection overhead over "after-the-fact" strategies.

Aircraft Trajectory Design Based on Reducing the Combined Effects of Carbon-Di-Oxide, Oxides of Nitrogen and Contrails

Scipedia content — Mon, 01 Feb 2021 22:49:47 +0100

ft operations need to meet the combined requirements of safety, efficiency, capacity and reduced environmental impact. Aircraft routes can be made efficient by flying wind optimal routes. However, the desire to reduce the impact of aviation emissions and contrails may result in trajectories, which deviate from wind optimal trajectories leading to extra fuel use. The lifetime associated with different emissions and contrails varies from a few hours to several hundred years. The impact of certain gases depends on the amount and location of the emission, and the decision-making horizon, in years, when the impact is estimated. The Absolute Global Temperature Potential (AGTP) is used as a metric to measure the combined effects of emissions and contrails. This paper extends earlier work by the authors to include the effect of oxides of nitrogen in the development of aircraft trajectories to reduce the combined effects of carbon dioxide, oxides of nitrogen (NOX) and contrails. The methodology is applied to air traffic in the continental US. The paper shows the trade-offs between reducing emissions and the cost of extra fuel using a fuel sensitivity index, defined as the reduction in AGTP per kg of fuel. The paper shows the performance of the optimization strategy for decision intervals of 10, 25 and 100 years. Based on the simplified models, the inclusion of NOX emissions has a slight influence on the minimal climate impact trajectories when the decision horizons are around 25 years.

A closer look at automation behavior during a human-in-the-loop simulation

Scipedia content — Mon, 01 Feb 2021 22:48:44 +0100

2012 Human-In-The-Loop air traffic control simulation investigated a gradual paradigm-shift in the allocation of functions between operators and automation. Air traffic controllers staffed five adjacent high-altitude en route sectors, and during the course of a two-week experiment, worked traffic under four different function allocation concepts aligned with increasingly mature NextGen operational environments. These NextGen ‘timeframes’ ranged from near current-day operations to nearly fully-automated control, in which the ground system’s automation was responsible for detecting conflicts, issuing strategic and tactical resolutions, and alerting controllers to exceptional circumstances. This paper continues the investigations reported in previous publications. Analyses of data surrounding the conflict-resolution task serve as the context in which we investigate the interactions between controllers and the automation.

A health impact assessment of proposed public transportation service cuts and fare increases in Boston, Massachusetts (U.S.A.).

Scipedia content — Mon, 01 Feb 2021 22:48:25 +0100

Transportation decisions have health consequences that are often not incorporated into policy-making processes. Health Impact Assessment (HIA) is a process that can be used to evaluate health effects of transportation policy. We present a rapid HIA, conducted over eight weeks, evaluating health and economic effects of proposed fare increases and service cuts to Boston, Massachusetts’ public transportation system. We used transportation modeling in concert with tools allowing for quantification and monetization of multiple pathways. We estimated health and economic costs of proposed public transportation system changes to be hundreds of millions of dollars per year, exceeding the budget gap the public transportation authority was required to close. Significant health pathways included crashes, air pollution, and physical activity. The HIA enabled stakeholders to advocate for more modest fare increases and service cuts, which were eventually adopted by decision makers. This HIA was among the first to quantify and monetize multiple pathways linking transportation decisions with health and economic outcomes, using approaches that could be applied in different settings. Including health costs in transportation decisions can lead to policy choices with both economic and public health benefits.

Document type: Article

CO2PipeHaz : quantitative hazard assessment for next generation CO2 pipelines

Scipedia content — Mon, 01 Feb 2021 22:44:07 +0100

International audience; Without a clear understanding of the hazards associated with the failure of CO2 pipelines, carbon capture and storage (CCS) cannot be considered as a viable proposition for tackling the effects of global warming. Given that CO2 is an asphyxiant at high concentrations, the development of reliable validated pipeline outflow and dispersion models are central to addressing this challenge. This information is pivotal to quantifying all the hazard consequences associated with the failure of CO2 transportation pipelines, which forms the basis for emergency response planning and determining minimum safe distances to populated areas. This paper presents an overview of the main findings of the recently completed CO(2)PipeHaz project [1] which focussed on the hazard assessment of CO2 pipelines to be employed as an integral part of CCS. Funded by the European Commission FP7 Energy programme, the project's main objective was to address this fundamentally important issue.

Document type: Conference object

Characterization of Hazardous Ice using Spaceborne SAR and Ice Profiling Sonar: Preliminary Results

Scipedia content — Mon, 01 Feb 2021 22:40:38 +0100

Ice can pose hazard for operations (e.g., transportation, shipping, offshore oil and gas exploration) and for infrastructure (e.g., ports, pipelines, offshore structures). There is an increasing need for fine scale characterization of hazardous ice conditions. This information is of interest to many stakeholders including government departments and agencies, and the oil and gas industry. Spaceborne Synthetic Aperture Radar (SAR) sensors have demonstrated the viability and cost-effectiveness of near-real-time monitoring of the regional ice conditions. Satellite derived ice information products typically rely on the interpretation of ice analysts or in some cases semi-automated techniques, and cover relatively large areas at coarse resolution. Development of improved data products using high spatial resolution polarimetric RADARSAT-2 datasets (e.g., Fine Quad) is desired for detailed characterization of potentially hazardous ice conditions. Although validation of ice data products is challenging due to limited ground truth data, there are numerous sites throughout the Arctic with many years of continuous measurements of ice conditions obtained using bottom mounted Upward Looking Sonar (ULS) instruments. Using ULS data we have recently developed analytical methods to characterize highly deformed sea ice features including large individual keels, segments of hummocky ice, multi-year ice, and episodes of internal ice stress, which can also serve as validation data for SAR-based analysis. This paper presents an overview of our ongoing work and very preliminary results on hazardous ice characterization using SAR and ULS data. ULS data view from below and SAR data view from above are complementary information sources, and utilizing both is expected to result in better characterization of the ice conditions. During this work, paired SAR and ULS datasets will be generated to allow calibration and validation of algorithms, and methodologies will be developed to utilize these complementary data sources. This project is expected to (1) develop improved methods for fine scale analysis of RADARSAT-2 data; (2) develop enhanced information products generated in the hindcast mode when ULS and RADARSAT-2 are both available; (3) demonstrate potential for RCM (compact polarimetry). Calibrated and validated information products of hazardous ice will be extremely valuable for users who require such information for engineering design, to make management and policy decisions, and to safely perform operations.

Efficient power-electronic converters for electric vehicle applications

Scipedia content — Mon, 01 Feb 2021 22:38:23 +0100

This paper introduces advanced power-electronic converter topologies for Electric Vehicles (EVs) using a four-phase DC/DC interleaved boost converter (FP-IBC) and a five-level T-type DC/AC multilevel converter. A comparison between the proposed topologies and other converter topologies is performed and discussed. The simulation results are analysed to evaluate the converters based on power loss calculations and harmonic analysis. The converters are studied at different switching frequencies and various loading conditions to reflect their effects on the converter losses. The results highlight the proposed converters' higher efficiency compared to other studied converter topologies in electric vehicle applications.

Investigating the role of High Speed Rail in shaping metro-regions

Scipedia content — Mon, 01 Feb 2021 22:23:03 +0100

In the literature many definitions of megacities and mega-regions are proposed (Urena et al., 2009; Pagliara et al., 2011). For example, Hall (2009) defines a mega city region as a ?series of cities physically separated but functionally networked clustered around one or more larger central cities and are connected with dense flows of people and information using important transport infrastructures?. Transport infrastructures and services are fundamental either for the emergence or the proper functioning of mega cities and regions. High Speed Rail systems are definitely today considered as important infrastructures. By impacting strongly on accessibility patterns, they have revolutionized users? life style together with their mobility behavior thanks to their power of shrinking spaces and shaping places. This contribution is based on the recognition that commuting flows are not enough to justify the formation of a megacity or a mega-region. Even if they can contribute to it, they don?t justify the development of a megapolis. A theoretical model should be specified in order to explain the mechanisms through which metro areas integrate into mega-regions and to understand what is the real role of HSR systems as a variable of this model. This paper attempts to fill this gap, present in the literature, and identify some European corridors having high potential for mega-region formation as supported by High Speed Rail. Examples can be found in France, in Spain and in Italy as well. To achieve this objective, this paper will rely on a thorough literature review aimed at the identification of the possible causal relations between changes in accessibility induced by HSR and the emergence of megacities and megaregions. Moreover a first attempt of specifying the model is proposed. Indeed regression models are defined, where the dependent variables are described in terms of commuting flows, travel time and travel cost of the competing transport modes between metro areas, variables connected with HSR, i.e. comfort, speed, low environmental impact, etc. will be considered as well. Other factors influencing the formation of megacities and megaregions will be introduced and tested. Among them economic variables like the number of jobs, the GDP, etc. Further perspectives should consider that this construct should be tested and synthesized in mathematical terms and then calibrated with the collection of real data.

Encouraging Elegant Solutions by Applying Choice Architecture to Infrastructure Project Delivery

Scipedia content — Mon, 01 Feb 2021 22:20:41 +0100

Meeting the national infrastructure challenges will require that an answer to the question posed by the National Academy of Engineering (NAE): "How can the processes be more effective, more quality conscious, more flexible, simpler, and less expensive?" In this paper, the authors share one approach to identify solutions meeting the "simpler" characteristic of NAE's question. Through an interdisciplinary literature review, the authors characterize "elegant" solutions—those that meet user needs with minimal complexity. Whereas elegance can appear simple in hindsight, it represents a deeper understanding of the actual problem. As with other project outcomes, elegance is dependent on infrastructure project delivery processes: an owner who contracts with a designer to provide a reduction in traffic is encouraging a more elegant solution than an owner who specifies that the designer must add an additional lane. Behavioral scientists have developed choice architecture theory, which is being applied to improve decision processes in fields from medicine to law to finance. The authors believe choice architecture also could be used to arrange infrastructure delivery processes to encourage elegance. The authors describe the reasoning by connecting behavioral science theory and common infrastructure project delivery scenarios. The authors hope this paper begins a discussion to identify and motivate future research in this area.

Air Route Clustering for a Queuing Network Model of the National Airspace System

Scipedia content — Mon, 01 Feb 2021 22:19:37 +0100

network queuing model of the National Airspace System has been developed to support research into a strategic air traffic flow management capability. One of the challenges in the execution of the model is the size of the network – the computing resources required when modeling the entire United States are immense. As a way to reduce the network size, we investigate route clustering, i.e., grouping similar routes to reduce the number of paths between two airports. Clustering routes comes at a cost: as the number of clusters falls, the with-in cluster variability rises, and the solution quality is diminished. A trade-off curve for solution quality vs. cluster variability is developed for a sample problem involving seven major airports. I. Introduction/Background A prototype capability for strategic air traffic flow management is undergoing research and development. The capability, called Flow Contingency Management (FCM), will supply automated decision support for what currently is a mostly manual process. 1 It is recognized that strategic decisions made with a 2- to 24-hour time horizon will likely improve air traffic flows in the National Airspace System (NAS) by averting large-scale traffic congestion due to weather. The Next-Generation Air Transportation System (NextGen) mid-term concept reflects the need for this type of capability. Basic functionality has been developed for the prototype, including the representation of weather and traffic forecasts, and the integration of the two forecasts for predictions of significant impact. At the operative look-ahead times, there is significant uncertainty in the forecasts of both weather and traffic and, therefore, it is not appropriate to represent traffic at the level of individual flights. Rather, an aggregate model has been developed whereby traffic is represented as flows (an undifferentiated count of flights progressing in quarter-hour steps) in a queuing network. An initial formulation of such a model uses historical aircraft routings, one-day-prior filed flight routes, and “dayof” filed and predicted counts as input to a regression model to create the demand on a network of routes between airports. In the network, routes are represented by sequences of airspace sectors, 5 demand is expressed as the fraction per route of total flow between airports, and airports are represented as source and sink nodes. The queuing network model operates by associating air traffic demand with a sequence of sectors, and advancing time in quarterhour increments. Sectors have a finite capacity, and flights may queue before transiting a sector, if demand would exceed capacity. In prior work, it was found that clustering airports reduced the network size and complexity, as well as the model’s run-time. 2 In this paper, we explore another means of reducing network size: route clustering, i.e., grouping of similar routes between airports. Assessing similarity of routes requires a similarity/difference measure and we propose the use of a specialized algorithm called “edit distance,” appropriate for lexical string representation, i.e., the sequence of sectors in a route. The paper is organized as follows. The next section describes the clustering algorithm: edit distance, similarity/difference assessment, and selection of a clustering method. Subsequent sections examine initial results, selection of a similarity threshold, and trading-off regression model error and resultant network size. A final section summarizes findings and suggests a next step in the analysis.

The impact of public transport expansions on informality: The case of the São Paulo Metropolitan Region

Scipedia content — Mon, 01 Feb 2021 22:17:26 +0100

Submitted by Isabele Garcia (isabele.garcia@fgv.br) on 2018-01-03T16:48:40Z No. of bitstreams: 1 CEPESP_Moreno-Moroy; Posada. The impact of public transport expansions on informality.pdf: 3096163 bytes, checksum: ab616acbd943d66a959dad54ebd1c5fb (MD5) Approved for entry into archive by Isabele Garcia (isabele.garcia@fgv.br) on 2018-01-03T16:49:55Z (GMT) No. of bitstreams: 1 CEPESP_Moreno-Moroy; Posada. The impact of public transport expansions on informality.pdf: 3096163 bytes, checksum: ab616acbd943d66a959dad54ebd1c5fb (MD5) Made available in DSpace on 2018-01-03T16:49:55Z (GMT). No. of bitstreams: 1 CEPESP_Moreno-Moroy; Posada. The impact of public transport expansions on informality.pdf: 3096163 bytes, checksum: ab616acbd943d66a959dad54ebd1c5fb (MD5) Previous issue date: 2015 The São Paulo Metropolitan Region (SPMR) displays a strong core-periphery divide. Central areas concentrate the bulk of formal jobs while peripheral areas display high incidence of informal employment. This pattern is reinforced by a large deficit in urban transport provision. Against this background, we estimate the impact of expansions of the public transport system on local informality rates for the SPMR between 2000 and 2010. We compare the average changes in informality in areas which received new public transport infrastructure with the average changes in areas which were supposed to receive infrastructure according to official plans, but did not because of delays. After controlling for endogenous selection, we find that informality decreased on average 16 percent faster in areas receiving new public transport infrastructure compared to areas that faced project delays.

Towards STAMP Based Dynamic Safety Management of Eco-Socio-Technical Maritime Transport System

Scipedia content — Mon, 01 Feb 2021 22:12:23 +0100

Under an increasing maritime transport in the Baltic Sea, and especially in the Gulf of Finland, the possibility of environmental harm and accidents due to shipping pressure is growing. To counteract increasing risks, adequate measures for accident prevention and mitigation of environmental consequences are critically important. The Gulf of Finland Mandatory Ship Reporting System (GOFREP) is a the complex socio-technical maritime transport safety management system that has been in efficient operation since 2004 and it is open to further improvement and development. However, environmental safety is not explicitly covered by the GOFREP so far. According to our working hypothesis, the Systems Theoretic Accident Models and Processes (STAMP) can be extended beyond the area of socio-technical system safety into realm of complex eco-socio-technical systems safety. This paper attempts to demonstrate the conceptual potential of STAMP based on adaptive management of the Maritime Spatial Planning processes and integrated safety management of eco-socio-technical maritime transport system.

Development of a Cell-based Simulation Model for Earthmoving Operation using Real-time Location Data

Scipedia content — Mon, 01 Feb 2021 22:08:08 +0100

Simulation is a proven technique for effective construction site layout planning and resource optimization. Historical data is used as input for task durations in traditional simulation approaches. This data is fed into activity cycle diagrams which do not consider spatial constraints. Cell-based simulation with real-time location data can be implemented for more realistic modeling and incorporating spatial changes on the site during project execution. Despite the potential, very little research has been done towards it. The objective of this research is to develop a framework of utilizing real-time data for spatial simulation of cyclic activities on a construction site. Continuous data was collected using Global Positioning System and cell-based simulation model was developed for spatial consideration of earthmoving cycles. The potential of analyzing and visualizing the effects of varying resource combinations on productivity and traffic congestion on site were explored. The approach will aid in increasing insight and awareness for decision making in resource management, site layout and internal traffic control plan. It will also serve as an education and training tool for project managers.

Biofuels : their emergence and implications for sustainability in aviation

Scipedia content — Mon, 01 Feb 2021 21:59:53 +0100

The global aviation industry is facing complex and unpredictable market conditions with fluctuating oil prices and the adverse environmental impact of aircraft operations. Since the regulatory approval for biofuels, the first biojet fuel flight test in 2007, using a blend fuel, was a remarkable step towards having more test and schedule flights up to the year of 2014. The purpose of this paper is to engage this new alternative energy with the issues that airlines associate with sustainability, mainly focusing on aircraft operations and profitability. The key findings suggest that the uses of alternative energy need to be in parallel to the reliability and maintainability of the aircraft system, so that the adoption of biofuels can be effective.

MITC: An Intention-Based Model for Cooperative Resolution of Traffic Conflicts

Scipedia content — Mon, 01 Feb 2021 21:58:04 +0100

Urban traffic problems have become a quotidian problem that affects many cities in the world. This problem, caused by the exponential increase of vehicles, leads to the appearance of different complications such as environmental pollution, accidents and slow mobility. This work formulates MITC, a model of cooperation focused to conflict resolution for the traffic agents, considering explicit communication of their intentions, allowing them to adjust their decisions intelligently, so as to reduce the conflicts and mitigate traffic congestion.

ADS-B signals reception: A Software Defined Radio approach

Scipedia content — Mon, 01 Feb 2021 21:50:11 +0100

In Air Traffic Control, ADS-B (Automatic Dependent Surveillance - Broadcast) systems provide surveillance information as obtained by the cooperating airplanes. This usage of air-derived data and of a common link opens various issues: performance in dense traffic area, signals validation and security. A Software Defined Radio (SDR) permits the needed flexibility and modularity in order to easily develop prototypal devices for evaluation and test of novel enhancements of ADS-B receivers. In this frame, a multi-channel receiver for 1090 MHz ADS-B signals was implemented, using an array antenna, a specific designed analog front-end and a software defined receiver. The device is useful to test signal processing algorithms and to analyse the channel traffic. The receiver is also jointly used with another SDR device capable to generate 1090 MHz traffic. With this configuration it is possible to generate specific traffic scenarios characterized by interferences from multiple sources and/or by jammer. This paper deals with the hardware and set-up description, the presentation of the developed software receiver and its functions, and, finally, the results achieved using the system.

Anticipatory Coordination of Electric Vehicle Allocation to Fast Charging Infrastructure

Scipedia content — Mon, 01 Feb 2021 21:48:30 +0100

The limited range of electric vehicles (EVs) in combination with the limited capacity of current fast charging infrastructure are both causes for a limited adoption of EVs. In order to reduce the general inconvenience that EV users experience when having to wait for available fast charging stations and to lessen the danger of damaging the infra- structure by overloading it, an efficient coordination strategy is needed. This paper proposes an anticipatory, decentralised coordination strategy for on-route charging of EVs during lengthy trips in a fast-charging infra- structure. This strategy is compared to a reference strategy that uses global real-time knowledge of charging station occupation. Simulation results using a realistic scenario with real-world traffic data demonstrate that the anticipatory strategy is able to reduce the waiting times for EV users by up to 50% while at the same time decreasing the peak loads of the electricity grid caused by charging EVs by 21%. The limited range of electric vehicles (EVs) in combination with the limited capacity of current fast charging infrastructure are both causes for a limited adoption of EVs. In order to reduce the general inconvenience that EV users experience when having to wait for available fast charging stations and to lessen the danger of damaging the infra- structure by overloading it, an efficient coordination strategy is needed. This paper proposes an anticipatory, decentralised coordination strategy for on-route charging of EVs during lengthy trips in a fast-charging infra- structure. This strategy is compared to a reference strategy that uses global real-time knowledge of charging station occupation. Simulation results using a realistic scenario with real-world traffic data demonstrate that the anticipatory strategy is able to reduce the waiting times for EV users by up to 50% while at the same time decreasing the peak loads of the electricity grid caused by charging EVs by 21%. ispartof: pages:74-85 ispartof: Advances in Practical Applications of Heterogeneous Multi-Agent Systems. The PAAMS Collection vol:8473 pages:74-85 ispartof: PAAMS'14 location:Salamanca (Spain) date:4 Jun - 6 Jun 2014 status: published

Conditions for the preparation of the complex transport infrastructure investment illustrated by the Lower Vistula River revitalization

Scipedia content — Mon, 01 Feb 2021 21:46:19 +0100

The article presents results of research dedicated to the project of development of the logistics function in the river ports of the Lower Vistula River. Project has a strategic and complex character and aims to create an effective network of river logistics centres along the Lower Vistula River. The analysis includes the identification of investment tasks and the sources of their funding. The authors’ present original investment benefits and risks analysis that identifies the most important efficiency factors for the project. The article ends with conclusions and recommendations of a general nature to be addressed to other such large infrastructure projects. Bogusz Wisnicki

The impact of heritage investment on public attitudes to place: evidence from the Townscape Heritage Initiative (THI)

Scipedia content — Mon, 01 Feb 2021 21:40:34 +0100

Planning for future energy-efficient and energy-producing buildings requires specific knowledge during the design process. Many design decisions taken by urban planners –form, density, roof type and orientation – have a significant effect on the conditions of such buildings, although urban planners might not always be aware of the effect of their design. This study examines the effects of important design decisions on the solar energy potential of net zero energy solar buildings. Typical Swedish building blocks with varying form, density, roof type and orientation were used to simulate the annual solar irradiation and energy production, and to calculate the load match for heating and electricity under Swedish conditions. Results of this study show that the urban density is the most influential parameter on the solar potential of building blocks. Furthermore, flat roofs often returned the highest load match value, while the effect of orientation on the solar potential turned out not to be that straightforward. With the results of this study, urban planners can make better informed decisions, while it also provides a ground for the net zero energy solar buildings discussion by exposing the boundaries of such buildings in the urban environment.

Pipeline Repair of Corrosion and Dents: A Comparison of Composite Repairs and Steel Sleeves

Scipedia content — Mon, 01 Feb 2021 21:35:17 +0100

When pipeline repairs are made on high pressure onshore transmission pipelines, in modern times repairs typically involve steel sleeves or composite repair systems. A comprehensive testing program was conducted to evaluate the repair of severe corrosion and dents using composite materials, as well as Type A and B steel sleeves. Full-scale destructive testing was performed including cyclic pressure loading and burst testing. Along with testing to failure, strain gages installed beneath the repairs were used to quantify the level of reinforcement provided by the respective repair systems."/jats:p" "jats:p"In this seminal body of work, operators are given information that provides a direct comparison between these competing repair technologies. The fundamental objective in testing was to determine the service life of the competing repair technologies, although of specific interest in this study was an effort to qualify the relative performance of the composite repairs and steel sleeves. The authors also utilized the test results to quantify the service lives of the repaired anomalies based on the operating conditions of actual pipeline systems.

Research on the Regional Logistics Index System of Sustainable Development

Scipedia content — Mon, 01 Feb 2021 21:34:34 +0100

The development of logistics has experienced from the enterprise internal management to integrated enterprise internal departments and then to the external integration among enterprises of the three stage. In this development process, people focus on the factors of productivity, efficiency and cost associated with economic benefits, while ignoring the logistics activities cause the ecological environment destruction caused by the "external negative effect", such as waste gas pollution, noise pollution, waste of resources, traffic congestion and waste, carbon dioxide emissions, etc. Thus, it caused the people from simply considering logistics economic benefit factors to comprehensive consideration of economic, social and environmental factors, and then formed the sustainable development of the logistics mode. Through the logistics index we can more effectively analyze regional macroeconomic trends and regional economic ties outside. It is also an important indicator of regional economic development. Keywords-sustainable development; regional logistics; index system

AMITRAN methodology for CBA and CEA of ITS measures

Scipedia content — Mon, 01 Feb 2021 21:29:34 +0100

The Amitran project provides a methodology for evaluating the effects of ICT measures in traffic and transport on energy efficiency and CO2 emissions. Last step of the methodology is the possibility to carry out a CBA or CEA of the ITS measures which are investigated. This paper presents the Amitran quick-scan CBA: the results will give the user an overview of the relevant effects in monetary terms that will give him or her a first indication to determine whether or not the ITS implementation is profitable for society.

Local online kernel ridge regression for forecasting of urban travel times

Scipedia content — Mon, 01 Feb 2021 21:28:34 +0100

urate and reliable forecasting of traffic variables is one of the primary functions of Intelligent Transportation Systems. Reliable systems that are able to forecast traffic conditions accurately, multiple time steps into the future, are required for advanced traveller information systems. However, traffic forecasting is a difficult task because of the nonlinear and nonstationary properties of traffic series. Traditional linear models are incapable of modelling such properties, and typically perform poorly, particularly when conditions differ from the norm. Machine learning approaches such as artificial neural networks, nonparametric regression and kernel methods (KMs) have often been shown to outperform linear models in the literature. A bottleneck of the latter approach is that the information pertaining to all previous traffic states must be contained within the kernel, but the computational complexity of KMs usually scales cubically with the number of data points in the kernel. In this paper, a novel kernel-based machine learning (ML) algorithm is developed, namely the local online kernel ridge regression (LOKRR) model. Exploiting the observation that traffic data exhibits strong cyclic patterns characterised by rush hour traffic, LOKRR makes use of local kernels with varying parameters that are defined around each time point. This approach has 3 advantages over the standard single kernel approach: (1) It allows parameters to vary by time of day, capturing the time varying distribution of traffic data; (2) It allows smaller kernels to be defined that contain only the relevant traffic patterns, and; (3) It is online, allowing new traffic data to be incorporated as it arrives. The model is applied to the forecasting of travel times on London's road network, and is found to outperform three benchmark models in forecasting up to 1. h ahead. © 2014 The Authors.

Document type: Article

Using the General Link Transmission Model in a Dynamic Traffic Assignment to Simulate Congestion on Urban Networks

Scipedia content — Mon, 01 Feb 2021 21:26:53 +0100

This article presents two new models of Dynamic User Equilibrium that are particularly suited for ITS applications, where the evolution of vehicle flows and travel times must be simulated on large road networks, possibly in real-time. The key feature of the proposed models is the detail representation of the main congestion phenomena occurring at nodes of urban networks, such as vehicle queues and their spillback, as well as flow conflicts in mergins and diversions. Compared to the simple word of static assignment, where only the congestion along the arc is typically reproduced through a separable relation between vehicle flow and travel time, this type of DTA models are much more complex, as the above relation becomes non-separable, both in time and space. Traffic simulation is here attained through a macroscopic flow model, that extends the theory of kinematic waves to urban networks and non-linear fundamental diagrams: the General Link Transmission Model. The sub-models of the GLTM, namely the Node Intersection Model, the Forward Propagation Model of vehicles and the Backward Propagation Model of spaces, can be combined in two different ways to produce arc travel times starting from turn flows. The first approach is to consider short time intervals of a few seconds and process all nodes for each temporal layer in chronological order. The second approach allows to consider long time intervals of a few minutes and for each sub-model requires to process the whole temporal profile of involved variables. The two resulting DTA models are here analyzed and compared with the aim of identifying their possible use cases. A rigorous mathematical formulation is out of the scope of this paper, as well as a detailed explanation of the solution algorithm. The dynamic equilibrium is anyhow sought through a new method based on Gradient Projection, which is capable to solve both proposed models with any desired precision in a reasonable number of iterations. Its fast convergence is essential to show that the two proposed models for network congestion actually converge at equilibrium to nearly identical solutions in terms of arc flows and travel times, despite their two diametrical approaches wrt the dynamic nature of the problem, as shown in the numerical tests presented here.

The impact of transport management on the local activities system: the role of limited traffic zones

Scipedia content — Mon, 01 Feb 2021 21:20:26 +0100

The impacts of transportation in planning land use and activities are not always intended and can have unforeseen or unintended consequences such as congestion or evident impacts on the local economy where the interventions are conceived. This is the case for Limited Traffic Zones (LTZs), i.e. areas where cars are not allowed in them. In this paper, the impact of these measures on the local economy is analyzed, considering as a case study the town of Napoli in the south of Italy, where two Limited Traffic Zones, in two different boroughs and years, named Vomero and Chiaia, have been introduced. Moreover, the impacts due to changes involving one of the LTZ’s areas are also observed and analyzed through a before-after survey. The direct impact on traffic congestion has not been taken into account. More than 30% of all activities have been interviewed in the two restricted areas and some key points have been assessed for the successful or unsuccessful of car restriction measure. Retailers were also asked about their decrease in turnover in order to evaluate the effects of the LTZ’s area after taking into account the actual economic crisis. The survey showed how much the retailers require: efficient public transport; parking places as close as possible; residential and activity density and typology. Those are the main reasons for the success of the Vomero LTZ zone and of the failure of the Chaia restricted zone. Other revealed indicators gathered in the survey confirmed the results underlying the attractiveness of the subzone of Chiaia that is a string of restaurants close to the seafront.

Using exit time predictions to optimize self automated parking lots

Scipedia content — Mon, 01 Feb 2021 21:20:09 +0100

Private car commuting is heavily dependent on the subsidisation that exists in the form of available free parking. However, the public funding policy of such free parking has been changing over the last years, with a substantial increase of meter-charged parking areas in many cities. To help to increase the sustainability of car transportation, a novel concept of a self-automated parking lot has been recently proposed, which leverages on a collaborative mobility of parked cars to achieve the goal of parking twice as many cars in the same area, as compared to a conventional parking lot. This concept, known as self-automated parking lots, can be improved if a reasonable prediction of the exit time of each car that enters the parking lot is used to try to optimize its initial placement, in order to reduce the mobility necessary to extract blocked cars. In this paper we show that the exit time prediction can be done with a relatively small error, and that this prediction can be used to reduce the collaborative mobility in a self-automated parking lot. I. INTRODUCTION Parking is a major problem of car transportation, with important implications in traffic congestion and urban land- scape. It has been shown that parking represents 75% of the variable costs of automobile commuting (1), supported by a major public subsidisation of the space devoted to car parking, where the user does not pay in more than 95% of the occasions (2). The sustainability of car transportation is nowadays facing several challenges. The number of cars in many cities has reached a level where the road infrastructure is unable to avoid systematic traffic congestions. In addition, the high cost of fossil fuels and pollutant emission levels are creating significant challenges for the sustainability of private car commuting in major cities. Tolls and prohibition of circu- lation in one or two week days for a given vehicle are already in place in some of our cities. Technology is trying to mitigate these challenges faced by car transportation. Zero- emissions electric propulsion and connected navigation are two examples of technologies that can help making car transportation more sustainable. Technology has been focusing however in moving cars, disregarding the parked period of these cars, which represen

Non-invasive application for domestic pipeline monitoring and corrosion detection

Scipedia content — Mon, 01 Feb 2021 21:19:51 +0100

In this paper a method of assessment and control of condition for domestic pipelines is proposed and been tested for a pair. Most of the previous works has been designed for long range pipes as they may carry valuable liquids. But having a system to monitor domestic's pipes also can help to save so much time and energy in future as leaking itself can be destructive in structures. This system is applying much lower frequency (40 kHz) in compare to other similar systems (above hundreds megahertz) which leads to lower power consumption. This ultrasonic wave is applied to short distance pipes to observe the changes and detect the leakage base on adjusted thresholds amplitude. It is able to detect smallest changes as the matter of difference in acoustic waves for healthy and damaged pipes. The alarming system works by analyzing output signals from receivers. Ultrasonic sensors are having 40 kHz central frequency for both transmitter and receiver with best responsibility at face to face condition. Acoustic sensors are working independently in pair and by dismissing one pair others will not affect continuity of data acquisition. For this paper a couple of transducer (a transmitter and receiver) operation has been investigated. By understanding the functionality of a pair can analyses how they are working in more numbers. This system is a cheap, easy to assemble, install and maintain for homes and most of public facilities such as schools, hospitals, parks, offices and business buildings. It doesn't need any particular constriction or changes in pipeline structures.

Inland waterways transport for city logistics: a review of experiences and the role of local public authorities

Scipedia content — Mon, 01 Feb 2021 21:13:37 +0100

Urban freight transport is increasingly difficult to organize and manage: the demographic expansion of cities, the environmental issues, new logistical trends, scarcity of space and the evolving consumer habits are just some of the challenges. In most cities, road transportation is essentially the only mode used for performing urban distribution of goods. Inland navigation is used solely for transport of bulk materials over long distances bulk material (e.g. construction material and agricultural products). However, experiences in several European cities have demonstrated that the use of inland waterways can be a viable alternative for smaller-scale freight transport in urban areas. This present article aims at reviewing current experiences in the field of inland navigation for city logistics. Through the analysis of several implementation cases in Europe, the authors demonstrate that inland navigation can be used for various segments of the urban freight transport, including transportation of palletized goods (e.g. construction and industrial material), transportation of containerized goods (e.g. for the supply of the supermarkets), deliveries to local shops and restaurants, deliveries of parcels, transport of waste and recycled material and service trips. Furthermore, the article analyses the conditions in which these transport schemes were developed, highlights their key success factors, and investigates the particular role of local public authorities in organizing and managing these innovative transport schemes.

GPU-based Parallelization for Schedule Optimization with Uncertainty

Scipedia content — Mon, 01 Feb 2021 21:12:03 +0100

This paper presents an application of Graphics Processing Units (GPU) technology for speeding up a schedule optimization problem under uncertainty and provides a fast decision support algorithm to solve an air traffic management problem. In terminal airspace, integrated departure and arrival operations using shared resources have the potential to increase operations efficiency. However, results and benefits from integrated operations might be sensitive to flight time uncertainty. In previous work, a scheduling algorithm was proposed for a model of the Los Angeles terminal airspace. Uncertainty was introduced in the flight times and the uncertainty cost computation was handled by Monte Carlo simulations. The original implementation was carried out on sequential processors, but a 30-minute scenario ran in 6.5 hours, which prohibits applying the algorithm in real-time. This paper presents a GPU-based implementation of the scheduling optimization with uncertainty achieving a 637x speedup in Monte Carlo simulations and a 154x speedup for the entire algorithm compared to a sequential implementation. The runtime of the GPU-based code for the same 30-minute scenario is about 2.5 minutes. This significant speedup allows a large range of experiments to be explored and hundreds of simulations to be run. Two types of experiments are designed and they explore different values of traffic densities and arrival-to-departure ratios. The results demonstrate that there exist trade-off solutions between computed delays and number of controller interventions. The variation of total number of aircraft showed a larger impact on the controller’s workload than the variation of arrival-to-departure ratios. When the traffic density is increased, compromise solutions can be identified to reduce the number of controller interventions and achieve low delays.

Analysis of parking usage at the park and ride facility in Klang Valley, Malaysia

Scipedia content — Mon, 01 Feb 2021 21:11:06 +0100

parking utilization survey was administered to examine the parking usage at three selected park and ride facilities along the Kelana Jaya LRT Line and Putrajaya Public transportation terminal (Putrajaya Sentral). This study also analyzes the existing parking supply and its physical conditions through a parking space inventory survey at the three selected facilities. Parking characteristics such as parking occupancy, parking accumulation, parking turnover and parking duration at each facility were also examined. Findings showed that the overall parking utilization pattern was generally high with an occupancy rate of more than 85% (Terminal Putra station) and more than 92% (Kelana Jaya station). However, the Putrajaya Sentral park and ride facility recorded a low occupancy rate at multi-storey parking (below 50%) but a high occupancy rate at surface parking (85%). Additionally, all park and ride stations were used by long-term parkers (more than 7 hours). The results from this study were found to be comparable with park and ride studies at Shah Alam and Seremban KTM stations and Washington. A high parking demand at the park and ride facility will, eventually, help to achieve the benefits of sustainable transportation. Finally, recommendations to improve the parking supply to meet an increase in parking demand and conclusions are also drawn.

Modeling pipeline projects using computer simulation

Scipedia content — Mon, 01 Feb 2021 20:52:19 +0100

Due to The increasing demand on fossil fuel, Pipelines have become an essential element in today's world economy. Thus, any delays in pipeline construction projects have become highly intolerable. The construction process has many activities that involve various resources and each activity relies strongly on its predecessors. This paper presents a tool for planning pipelines projects using computer simulation. The proposed tool aids contractors in planning pipelines projects by estimating their associated time and cost of construction. The tool breaks down pipeline projects into a number of activities along with their resources. An application example is presented to demonstrate the features of the proposed tool.

GIS-Based Roughness Derivation for Flood Simulations: A Comparison of Orthophotos, LiDAR and Crowdsourced Geodata

Scipedia content — Mon, 01 Feb 2021 20:48:35 +0100

Natural disasters like floods are a worldwide phenomenon and a serious threat to mankind. Flood simulations are applications of disaster control, which are used for the development of appropriate flood protection. Adequate simulations require not only the geometry but also the roughness of the Earth’s surface, as well as the roughness of the objects hereon. Usually, the floodplain roughness is based on land use/land cover maps derived from orthophotos. This study analyses the applicability of roughness map derivation approaches for flood simulations based on different datasets: orthophotos, LiDAR data, official land use data, OpenStreetMap data and CORINE Land Cover data. Object-based image analysis is applied to orthophotos and LiDAR raster data in order to generate land cover maps, which enable a roughness parameterization. The vertical vegetation structure within the LiDAR point cloud is used to derive an additional floodplain roughness map. Further roughness maps are derived from official land use data, OpenStreetMap and CORINE Land Cover datasets. Six different flood simulations are applied based on one elevation data but with the different roughness maps. The results of the hydrodynamic–numerical models include information on flow velocity and water depth from which the additional attribute flood intensity is calculated of. The results based on roughness maps derived from LiDAR data and OpenStreetMap data are comparable, whereas the results of the other datasets differ significantly.

Document type: Article

Segment Routing based Traffic Engineering for Energy Efficient Backbone Networks

Scipedia content — Mon, 01 Feb 2021 20:40:43 +0100

International audience; Energy consumption has become a limiting factor for deploying large-scale distributed infrastructures. This work 1 seeks to improve the energy efficiency of backbone networks by providing an intra-domain Software Defined Network (SDN) approach to selectively turn off a subset of links. We propose the STREETE framework (SegmenT Routing based Energy Efficient Traffic Engineering) that dynamically adapts the number of powered-on links to the traffic load. The core of the solution relies on SPRING, a novel protocol being standardized by IETF. It is also known under the name of Segment Routing. The algorithms have been implemented and evaluated using the OMNET++ simulator. Experimental results show that the consumption of 44% of links can be reduced while preserving good quality of service.

Reducing the negative impact of motor transport on the environment: Prospects for the use of fiscal instruments in Russia

Scipedia content — Mon, 01 Feb 2021 20:38:36 +0100

The study focuses on the fact that, in major Russian cities, up to 80% of the negative impact on the environment is formed by motor transport emissions. The authors analyze the indicators of the negative impact due to the forced increase in the Russian fleet and the age pattern of the Russian fleet is researched. The proposed paper argues the conclusion that fleet capacity leads to an increase in its quantitative indicators, but does not lead to a rapid displacement of cars with the environmental classes 1 and 2. In Russia, the share of these vehicle classes continues to be very high. The presented research analyzes the reasons for the conservation of the unsatisfactory environmental Russian fleet structure. The conclusion is proved that one of the significant reasons for the continued manufacturing and consumption of low environmental class vehicles is the lack of real tax incentives. The authors analyze the fiscal payment’s system in the production and consumption of vehicles. It is concluded that these payments do not depend now on the environmental performance of the vehicle. The research paper introduces the renewed combination of tax instruments, the implementation of which will encourage producers and consumers to produce and purchase cars of a higher environmental class. The presented paper provides producers to make the excise tax on the car sale and disposal charge to be dependent on engine power and environmental class. The authors argue that the higher costs will be made up by the manufacturers’ lower tax payments. As a result, it will not lead to a sharp increase in car prices. For consumers it is proposed to modify the transport tax, the value of which should be dependent on the environmental class of the car. Environmentally-orientedtransport tax will stimulate consumers to purchase cars of a higher environmental class with the expectation that their higher costs will be paid off later with lower tax payments. © 2014 WIT Press. International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

Integrating Advanced Technology into Air Traffic Controller Training

Scipedia content — Mon, 01 Feb 2021 20:18:51 +0100

Effective training for air traffic controllers is a critical component of the Federal Aviation Administration’s (FAA’s) mission of providing a safe and efficient national aerospace system. The Air Traffic Control (ATC) training program must address the training needs of newly hired controllers (students), ongoing refresher and skill enhancement training for Certified Professional Controllers (CPCs), and new technology and procedures training for students and CPCs. The current ATC training practices and methods have not kept pace with advancements in training technology and design. As a result, training for students and CPCs is costly, inefficient, subjective, and inconsistent. The current training system also does not have the flexibility or adaptability necessary to meet the need for training new technologies which may reduce the expected benefit of acquisitions. Since 2004, The MITRE Corporation’s Center for Advanced Aviation System Development has been analyzing the FAA’s training processes and capabilities and exploring the application of advanced training technology to air traffic controller training. This research has demonstrated that training quality, standardization, efficiency, and availability can all be improved throught the use of advanced training technology.

A Frequency Analysis Approach for Categorizing Air Traffic Behavior

Scipedia content — Mon, 01 Feb 2021 20:16:46 +0100

method of analyzing National Air Space (NAS) air traffic thatuses the Discrete Fourier Transform (DFT) is presented. The DFT is used to transform time domain traffic count data into the frequency domain where the sourcesof traffic in air spaces can be identified and characterized more easily. It is shown in simulation that individual traffic flows within Air Route Traffic Control Centers can be dist inguished by their periodicity in the DFT plot. Next, three Traffic Management Initiatives (playbook rerouting, metered flows, and Ground Delay Programs) are implemented in simulations and their signature effects on the traffic are identified using t DFT. Finally, historical flight data is studied and the DFT is applied to sector traffic count data. It is found that in many cases, variations in traffic due to rerouting and convective weather disturbances are better highlighted in the frequency domain than in the original time domain data. Initial results of the DFT show it has potential as a tool for measuring and/or predicting NAS behavior for daily tactical planning and control purposes.

Design Characteristics of a Terminal Departure Scheduler

Scipedia content — Mon, 01 Feb 2021 20:16:16 +0100

terminal departure scheduler designed to work with varying degree of precision across many airports is required to operate with high levels of uncertainty, multiple disparate departure constraints and substantial volatility. This paper describes fast time simulation modeling of terminal departure traffic to assess performance of a terminal departure scheduler. A prototype terminal departure scheduler is developed and exposed to a range of air traffic constraints, departure time uncertainty and terminal transit time uncertainty. Terminal transit error and surface error are varied to assess the robustness of scheduler design to these variations. Current day manual terminal departure scheduling practices are simulated and compared against performance of a prototype terminal departure scheduler. Simulation is used to assess the tradeoffs of sequence and schedule freeze methodologies in the terminal departure environment. Sequence freeze capability demonstrates lower average delay than schedule freeze capability for expected levels of OFF time compliance in future automation. Dallas/Fort Worth TRACON simulation results indicate the possibility of a delay reduction of 35 percent and increased departure throughput of 17 percent for commonly used terminal departures constraints. The results of this study are used to inform the design of a terminal departure scheduler which will undergo evaluation at NASA’s North Texas Research station.

(Un)planned mixed neighbourhoods in Milan: integrationist discourse and the threat of the ghetto

Scipedia content — Mon, 01 Feb 2021 20:11:19 +0100

In the city of Milan, Italy, via Padova and Sarpi-Canonica are two neighbourhoods were cultural diversity became visible and caused concern in the local political and media debate. Via Padova, a working-class area with one of the highest share of immigrant residents, has been subject to a stigmatization process after clashes between groups put a strain on in it in 2009. Sarpi-Canonica – simplisticly defined as the Chinatown of Milan – is a middle-class neighbourhood which saw the growth of Chinese wholesale; after conflicts raised over the functions of the neighbourhood, a renovation project was started. Drawing from these two cases, in this paper we explore the discourse about diversity and mixed communities according to neighbourhood and city key informants: the representations provided by policy-makers and social partners are insightful on the Italian discourse about the “ideal” model of interaction and living together between diverse residents. A quite shared integrationist/intercultural approach shows that diversity is accepted but not encouraged, while pluralism should be tempered by an attention to social cohesion and minority specificity should blend into the majority. So, social faults are seen as due a) on the one hand, to an inadequate diversity management by public institutions; b) in a more blaming way, to the (self-)isolation of some minorities. Drawing from interviews, policy documents, and literature, we will show how the fear for ghettoisation is related to the ethnicisation of public space: a visible and “separated” diversity is somehow considered more dangerous than socio-economic inequality, and this grounds local policies and initiatives that may compress diversity.

Safe platooning in the event of communication loss using the flatbed tow truck model

Scipedia content — Mon, 01 Feb 2021 20:10:24 +0100

International audience; Optimizing inter-vehicle distances is very important to reduce traffic congestion on highways. A modification of the constant time headway policy (CTH) has been proposed in [1]. This modification significantly reduces inter-vehicle distances, but this reduction in the inter-distance may increase the risks of collisions. In this paper, the safety of the modified CTH applied to a homogeneous platoon is addressed. Many critical scenarios are discussed, including hard braking of the leader and followers in the event of communication loss. Safety conditions are presented. In addition, a method to find the maximum allowed delay to inform all the vehicles about communication loss, is also presented. Simulations have been run with 10 vehicles to check safety in the proposed scenarios.

ICT development and productivity of transport infrastructure

Scipedia content — Mon, 01 Feb 2021 20:07:13 +0100

This paper examines the impact of ICT network on productivity contribution of transportation infrastructure. Using dynamic panel data of OECD member countries, the paper finds that there exists significant complementarity between ICT network and transportation infrastructure. The network effect of motorway infrastructure in OECD countries tends to accelerate when the ICT network grows beyond a certain threshold level.

The role of railway transport in designing a proecological transport system

Scipedia content — Mon, 01 Feb 2021 19:58:06 +0100

This paper is prepared as a part of the scientific project “Proecological transport system designing” (EMITRANSYS). It presents the selected aspects and roles of railway transport in realization of the tasks set out by the national transport system. Particular attention is paid to the ecological aspects of railway transport, especially to the emission of pollutants in comparison to road transport. The ecological aspects are crucial for a systemic approach to the designing of transport and are important in developing a sustainable economy. One of the criteria for designing a large scale transport system is the external cost of environmental degradation. Two partial criteria considering external costs related to harmful emissions resulting from cargo and passenger streams distribution onto a network are discussed in the paper. These criteria are implemented into the PTV Visum environment for simulation experiments.

Estensione del'approccio "Atlante" all'Adriatico nel progetto Adriplan

Scipedia content — Mon, 01 Feb 2021 19:40:43 +0100

Presentation given at the workshop "L'Atlante della laguna di Venezia: l'interoperabilità dei dati per la gestione e la pianificazione, Venezia, July 9th 2014", in the context of the event Digital Venice 2014 (http://www.digitalvenice.eu/)."/p" "p"Here the web page with the specific event detalis: http://www.corila.it/digitalvenice

Ground Delay Program Analytics with Behavioral Cloning and Inverse Reinforcement Learning

Scipedia content — Mon, 01 Feb 2021 19:25:27 +0100

Historical data are used to build two types of models that predict Ground Delay Program implementation decisions and produce insights into how and why those decisions are made. More specifically, behavioral cloning and inverse reinforcement learning models are built that predict hourly Ground Delay Program implementation at Newark Liberty International and San Francisco International airports. Data available to the models include actual and scheduled air traffic metrics and observed and forecasted weather conditions. The developed random forest models are substantially better at predicting hourly Ground Delay Program implementation for these airports than the developed inverse reinforcement learning models. However, all of the models struggle to predict the initialization and cancellation of Ground Delay Programs. The structure of the models are also investigated in order to gain insights into Ground Delay Program implementation decision making. Notably, characteristics of both types of model suggest that...

ADS-B over satellite: Global air traffic surveillance from space

Scipedia content — Mon, 01 Feb 2021 16:24:07 +0100

The steadily increasing air traffic in particular on transoceanic routes requires extending controlled airspace to those regions not yet covered by ground based surveillance. In this paper the authors present the world's first in-orbit demonstration of a space based ADS-B system, hosted on the ESA satellite PROBA-V.

Architecture and capabilities of a data warehouse for ATM research

Scipedia content — Mon, 01 Feb 2021 16:19:19 +0100

This paper describes the design, implementation, and use of a data warehouse that supports air traffic management (ATM) research at NASA’s Ames Research Center. The data warehouse, dubbed Sherlock, has been in development since 2009 and is a crucial piece of the ATM research infrastructure used by Ames and its partners. Sherlock comprises several components, including a database, a webbased user interface, and supplementary services for query and visualization. The information stored includes raw data collected from the National Airspace System (NAS), parsed and processed data, derived data, and reports derived from pre-defined queries. The raw data include a variety of flight information from live streams of FAA operational systems, weather observations and forecasts, and NAS advisories and statistics. The modified data comprise parsed and merged data sources and metadata, enabling parameterized searches for data of interest. The derived data represent the results of research analyses deemed to be of significant interest to a wide cross-section of users. Sherlock is implemented on an Oracle 11g database, with supplemental services built on open-source packages and custom software. It contains over 20 TB of data spanning several years, and more data are added daily. It has supported several research studies, such as finding similar days in the NAS and predicting imposition of traffic flow management restrictions. Planned enhancements include integrated search across data sources and the capability for large-scale analytics.