Scipedia: Documents published in 2016

The micro-cogeneration and emission control and related utilization field

Scipedia content — Mon, 08 Feb 2021 12:27:04 +0100

Micro-cogeneration is a developed technology aiming to produce electricity and heat close to the final users, with the potential, if designed and operated correctly, to reduce both the primary energy consumption as well as the associated greenhouse gas emissions when compared to traditional energy supply systems based on separate energy production. The distributed nature of this generation technology has the additional advantages of (i) reducing electrical transmission and distribution losses, (ii) alleviating the peak demands on the central power plants, and (iii) diversifying the electrical energy production, thus improving the security of energy supply. Micro-cogeneration devices are used to meet both electrical requirements and heat demands (for space heating and/or hot water production) of a building; they can be also combined with small-scale thermally fed or mechanically/electrically driven cooling systems. Many micro-cogeneration units are already commercialized in different countries (such as Japan, Germany, United Kingdom, etc.) and in recent years several researches have been carried out in order to advance the design, operation, and analysis of this technology. Currently the use of commercial micro-cogeneration units in applications such as hospitals, leisure facilities, hotels, or institutional buildings is well established. The residential cogeneration industry is in a rapid state of development; the market remains not fully mature, but interest in the technology from manufacturers, energy utilities, and government agencies remains strong.

From cooperative to autonomous vehicles

Scipedia content — Mon, 08 Feb 2021 12:26:48 +0100

What defines an autonomous vehicle? In this chapter the authors will try to answer this question and formulate the limitations of driver assistance systems as well as for—conditionally—autonomous vehicles . First a short summary of the levels of automation as provided by the society of automotive engineers (SAE) is given with a consideration on the individual levels and their implication. Following this, an overview of modern-day control techniques for advanced driver assistance systems such as cooperative adaptive cruise control is given and the requirements for automated driving are formulated. The chapter finishes with an outlook on automated driving and a discussion on the requirements and safety of automated driving.

Visualization of Traffic Bottlenecks: Combining Traffic Congestion with Complicated Crossings

Scipedia content — Mon, 08 Feb 2021 12:12:45 +0100

Daily mobility patterns in highly populated urban environments rely on a well-functioning effective road network. Nevertheless, traffic bottlenecks are typical for urban environments with periodic traffic congestion. In this paper, we focus on the investigation of how traffic congestion is related with complicated crossings. First, we select an approach for the classification of the complexity of road partitions and the derivation of complicated crossings based on geodata from OpenStreetMap (OSM). Second, we calculate traffic congestions using Floating Taxi Data (FTD) from Shanghai in 2007. Then, we develop a matching technique to link the congestion and complicated crossings, and subsequently define the concept of traffic bottlenecks represented by polygons. The bottlenecks indicate locations where the transportation infrastructure is complex and traffic congestion appears periodically. Finally, we select suitable cartographic representations of traffic bottlenecks in potential thematic vehicle traffic maps.

Functional resonance analysis method based-decision support tool for urban transport system resilience management

Scipedia content — Mon, 08 Feb 2021 10:25:44 +0100

Today, managing critical infrastructure resilience in smart city is a challenge that can be undertaken by adopting a new class of smart tools, which are able to integrate modeling capability with evidence driven decision support. The Resilience Decision Support tool, as presented in this article, is an innovative and powerful tool that aims at managing critical infrasctructure resilience through a more complex and expressive model based on the Functional Resonance Analysis Method and through the connection of such a model with a system thinking based decision support tool exploiting smart city data. Thanks to ResilienceDS, FRAM model becomes computable and the functional variability that is at the core of the resilience analysis can be quantified. Such quantification allows the decision support tool to compute specific strategies and recommendations for variability dampening at strategic, tactic and operational stage. The solution has been developed in the context of RESOLUTE H2020 project of the European Commission.

Crowd Sensing of Weather Conditions and Traffic Congestion Based on Data Mining in Social Networks

Scipedia content — Mon, 08 Feb 2021 10:24:15 +0100

In recent years, the growing prevalence of social networks makes it possible to utilize human users as sensors to inspect city environment and human activities. Consequently, valuable insights can be gained by applying data mining techniques to the data generated through social networks. In this work, a practical approach to combine data mining techniques with statistical analysis is proposed to implement crowd sensing in a smart city. A case study to analyze the relationship between weather conditions and traffic congestion in Beijing based on tweets posted on Sina Weibo platform is presented to demonstrate the proposed approach. Following the steps of raw dataset pre-processing, target dataset processing and statistical data analysis, analytic corpus containing tweets related to different weather conditions, traffic congestion and human outdoor activity is selected to test causal relationships by Granger Causality Test. The mediation analysis is also implemented to verify human outdoor activity as a mediator variable significantly carrying the influence of good weather to traffic congestion. The result demonstrates that outdoor activity serves as a mediator transmitting the effect of good weather on traffic congestion.

Electromagnetic compatibility (EMC) for integration and use of near field communication (NFC) in aircraft

Scipedia content — Mon, 08 Feb 2021 10:20:26 +0100

For portable electronic devices (PEDs), e.g. smartphones or tablets, near field communication (NFC) enables easy and convenient man-machine interaction by simply tapping a PED to a tangible NFC user interface. Usage of NFC technology in the air transport system is supposed to facilitate travel processes and self-services for passengers and to support digital interaction with other participating stakeholders. One of the potential obstacles to benefit from NFC technology in the aircraft cabin is the lack of an explicit qualification guideline for electromagnetic compatibility (EMC) testing. In this paper, we propose a methodology for EMC testing and for characterizing NFC devices and their emissions according to aircraft industry standards (RTCA DO-160, DO-294, DO-307 and EUROCAE ED-130). A potential back-door coupling scenario of radiated NFC emissions and possible effects to nearby aircraft wiring are discussed. A potential front-door-coupling effect on NAV/COM equipment is not investigated in this paper.

Runtime Modifications of Spark Data Processing Pipelines

Scipedia content — Mon, 08 Feb 2021 10:17:44 +0100

Distributed data processing systems are the standard means for large-scale data analysis in the Big Data field. These systems are based on processing pipelines where the processing is done via a composition of multiple elements or steps. In current distributed data processing systems, the code and parameters that create the pipeline are set at design time, before the application starts processing any data. Any changes that have to be applied to the pipeline after it has been started, require the entire pipeline to be restarted. When a system needs to be operational 24/7 or has to respond in a timely fashion, restarting and having downtime is not acceptable. In this case, computing should be performed autonomously by the processing system that continuously takes the changes from the environment, and adjusts its processing steps, parameters, etc. on-the-fly. In this paper, we try to solve this problem by allowing changes to be made to a processing pipeline without restarting. We focus on two aspects of the problem: switching to another data source that is used as input, and changing the functional code and variables within the elements of a pipeline. Our system is built on top of Apache Spark, a framework widely used for distributed data processing.

An efficient SPIHT algorithm and system architecture for image compression

Scipedia content — Mon, 08 Feb 2021 10:16:09 +0100

25th Signal Processing and Communications Applications Conference (SIU) -- MAY 15-18, 2017 -- Antalya, TURKEY WOS: 000413813100202 In this study, an efficient modified SPIHT algorithm and related architecture design is proposed for image compression. The proposed architecture is designed as a three stage pipeline structure. Different sized images are compressed using the designed architecture for different bpp values. The computed PSNR values of the compressed images using the proposed algorithm and also the original algorithm is compared in order to test the performance of the proposed algorithm and architecture. Turk Telekom, Arcelik A S, Aselsan, ARGENIT, HAVELSAN, NETAS, Adresgezgini, IEEE Turkey Sect, AVCR Informat Technologies, Cisco, i2i Syst, Integrated Syst & Syst Design, ENOVAS, FiGES Engn, MS Spektral, Istanbul Teknik Univ

Scenario tree generation for the optimization model of a parking lot for electric vehicles

Scipedia content — Mon, 08 Feb 2021 10:10:48 +0100

This paper deals with a procedure capable to build the scenario tree associated with a parking lot equipped with several bidirectional charging stations for plug-in electric vehicles (EVs). The scenario tree is conceived to be implemented in multistage stochastic optimization models for day-Ahead energy management systems of microgrids or, more in general, power distribution networks. Specific operating rules relevant to the initial energy available in the cars entering the parking lot are defined, as well as the other typical constraints (such as maximum number of available charging stations, size of the EVs batteries, and power ratings of charging stations). Moreover, the model reproduces also the coupling between the operation of the parking lot with the power production of a photovoltaic unit. The tree generation procedure at first generates a number of equiprobable scenarios by using day-Ahead forecasts and the probability distributions characterizing the expected deviations with respect to the forecasts; then similar scenarios are grouped on the basis of the chosen criteria and of the number of stages. A specific procedure is finally proposed and applied in order to guarantee the existence of feasible solutions.

Assessment of AC interference caused by transmission lines on buried metallic pipelines using F.E.M

Scipedia content — Mon, 08 Feb 2021 10:07:22 +0100

The focus of this paper is on the implementation and subsequent improvement of a technique for computing AC interference on buried metallic pipelines due to nearby power transmission lines. In order to perform this task, the finite element method (F.E.M.) is employed. After performing a description of the implementation of the classic F.E.M. approach, a hybrid technique designed to reduce the size of the mesh and therefore the computational time is presented. The results obtained with the two approaches are finally compared.

Pipeline AER arbitration with event aging

Scipedia content — Mon, 08 Feb 2021 10:03:32 +0100

Paper presented at the 2017 IEEE International Symposium on Circuits and Systems (ISCAS), held in Baltimore, MD, USA, on 28-31 May 2017. We present a simple circuit to handle communication between cells of neuromorphic arrays. It allows cells to operate continuously without waiting for acknowledgement signals back from the AER (Address Event Representation) arbitration circuitry. The module also implements aging of cell petitions i.e., old petitions to access to the AER bus are automatically discarded to give priority to the more recent ones and alleviate the bus congestion. The new arbitration scheme has been implemented and tested. A particular application scenario with an image sensor with spiking pixels that sense light continuously is explained. Experimental data obtained with real visual scenes are provided.

Modeling aeronautical data traffic demand

Scipedia content — Mon, 08 Feb 2021 10:01:56 +0100

Determining the amount of air traffic in an area can help to identify the traffic demands of current and future airborne communication systems. Many mobility models for pedestrians and road vehicles exist, but hardly any for aircraft. Aircraft traces for three exemplary scenarios are analyzed to derive such a model with regard to traffic demand in a certain area, e.g. a cell. The number of aircraft inside the area is considered as state space of a Markov Process. For each state the arrival and departure process is fitted according to the hypothesis to follow a Poisson distribution. The goodness of fit is evaluated by Chi-Squared testing. Results considering all aircraft show predominant Poissonian behavior for areas with low aircraft density and little take-off and landing activities due to airports. In an urban area with high aircraft density and several airports the Chi-Squared Test often rejects the hypotheses. In a second step the problem was limited to only analyze transit traffic since take-off and landing seem to follow a different statistical behavior. The number of states where the Chi-Squared Test passes increases significantly for the scenarios with high aircraft densities. This work shows that aircraft arrivals and departures can be modeled as a Markov Process with state-dependent arrival and departure rates λ(i) and μ(i).

Enhancing sustainable mobility awareness by exploiting multi-sourced data: The case study of the Madeira islands

Scipedia content — Mon, 08 Feb 2021 10:00:05 +0100

In this paper we present a low-cost infrastructure to collect a variety of location-based multi-sourced data with the aim of providing personalized services and raising awareness for sustainable mobility solutions. The gathered data can be used to provide: (i) citizens and tourists with personalized location-based services to increase sustainability awareness; (ii) local authorities and tourism boards with a tool to identify and prevent mobility issues; and (iii) transport companies with an instrument to support urban mobility planning decisions. To collect data, we exploited a low-cost Wi-Fi passive tracking system and we augmented this infrastructure using sensors for detecting environmental conditions. To achieve this, we provided 60 points of interest and 20 buses with our solution, to spread out the sensors over the entire Madeira Island. Using the gathered data, we developed different scenarios to prove that in a world where sensing data is becoming inexpensive, there are opportunities to use our approach to deliver data back to the citizens, empowering local communities, with the goal of promoting sustainable mobility and tourism.

Automated data extraction from synthetic and real radargrams of district heating pipelines

Scipedia content — Mon, 08 Feb 2021 09:55:44 +0100

The main goal of this paper is to investigate the performance of an algorithm for point extraction from hyperbolic reflections in synthetic and real Ground-Penetrating Radar (GPR) data. The real radargrams that we considered contain hyperbolic reflections due to the presence, in the surveyed area, of district heating pipelines DN250 (250mm inner diameter pipe). These are buried 88 cm deep in a soil trench, and covered by compacted sand and concrete bricks (behaton pavement). The synthetic radargrams result from the simulation of a model representing the real geometry on the location of interest. The simulation was carried out by using gprMax, ver. 3.

Characteristics of Dutch EV drivers

Scipedia content — Mon, 08 Feb 2021 09:53:33 +0100

There has been little research towards the characteristics of Dutch electric vehicle (EV) drivers. This paper describes the result of focus groups and a survey with 286 respondents. Results indicate the current EV driver is predominantly a well-educated middle aged male with a high paying job. We link this to the price of the vehicles and the structure of tax incentives. He is moderately environmentally friendly and likes innovation. He loves the driving experience and promotes EVs towards friends. Most EV drivers are unsatisfied with their all electric range and on average a range of 375 km is desired. Bigger batteries will lead to better use of charging infrastructure. Fast charging is considered important for longer trips but not as a replacement for chargers at parking locations. Smart charging is well received - as long as the user stays in control - which bodes well for the synergy between EVs and the renewable electricity grid.

Micro-simulation of airport taxiing procedures to improve operation sustainability: Application of semi-robotic towing tractor

Scipedia content — Mon, 08 Feb 2021 09:50:27 +0100

Carbon footprint assessment due to airport operations is often required by environmental regulations. Aircraft contribute to local air pollution during the Landing and Take Off cycle. A big portion of the time aircraft spend on the ground is taken by taxi operations. Taxi times also increase at higher rates than traffic demand because of congestion at airports. Several measures are explored in the literature regarding the mitigation of taxi related emissions. These measures are often assessed by means of analytical approaches. In this article, the authors introduce a new micro simulation approach to assess aircraft ground movements with the aim of providing a more realistic estimation of taxi times. The approach is based on the definition of a discrete event model using a generic simulation software, AnyLogic 7. The new model is then used to assess the potential benefits and impacts deriving from the introduction of an environmental friendly taxi procedure at Lisbon International Airport. The simulated procedure envisages the utilization of TaxiBot, a semi-robotic towbarless tractor suitable for dispatch towing at medium to large airports. Results prove the alternative measure would potentially lead to environmental benefits in terms of fuel saved and emissions reduction. Considering an average day, both airports and airlines would gain in terms of, respectively, emitted pollutants and operational costs. Starting from these observations, possibilities for further research are explored.

Forecasting port-level demand for LNG as a ship fuel: the case of the port of Antwerp

Scipedia content — Mon, 08 Feb 2021 09:48:11 +0100

From a European, regional and local perspective, as well as from the point of view of port authorities, it is important that waterborne transport should be sustainable. In this context, liquefied natural gas (LNG) is often put forward as a viable alternative fuel for deep-sea, shortsea and inland navigation. The present paper develops a forecasting method for determining potential LNG bunker volumes at port level. The proposed method is based on a review of the literature, historical data on technological innovation in shipping (i.e. the transitions from sail to steam and marine diesel engines), expert opinions and present-day bunker volumes. The forecast obtained was subsequently validated by shipping companies, bunker companies and fuel suppliers operating in the port of Antwerp. In addition, a sensitivity analysis was conducted to assess the impact of a number of relevant independent variables on the forecast. Overall, it is found that switching to LNG as a ship fuel, like any innovation, exhibits a slow adoption pattern, with sluggish growth initially but picking up some speed with time. At the same time, there is evidence of a chicken-and-egg dilemma, with shipping companies unwilling to invest in LNG-powered ships as long as supply is insufficient or uncertain, and fuel suppliers not willing to provide storage and bunker facilities as long as demand is low. Our analysis points at many uncertainties, which are used as discriminating factors between the different scenarios tested. However, whichever scenario is played out, the indications are that LNG bunkering volumes in Antwerp will not increase sharply between now and 2050. The volume growth under the strong development scenario is about four times greater than that under the weak development scenario, but remains modest. Document type: Article

Leveraging Proximity Sensing to Mine the Behavior of Museum Visitors

Scipedia content — Mon, 08 Feb 2021 09:45:54 +0100

Face-to-face proximity has been successfully leveraged to study the relationships between individuals in various contexts, from a working place, to a conference, a museum, a fair, and a date. We spend time facing the individuals with whom we chat, discuss, work, and play. However, face-to-face proximity is not the realm of solely person-to-person relationships, but it can be used as a proxy to study person-to-object relationships as well. We face the objects with which we interact on a daily basis, like a television, the kitchen appliances, a book, including more complex objects like a stage where a concert is taking place. In this paper, we focus on the relationship between the visitors of an art exhibition and its exhibits. We design, implement, and deploy a sensing infrastructure based on inexpensive mobile proximity sensors and a filtering pipeline that we use to measure face-to-face proximity between individuals and exhibits. Our pipeline produces an improvement in measurement accuracy of up to 64% relative to raw data. We use this data to mine the behavior of the visitors and show that group behavior can be recognized by means of data clustering and visualization.

Development of power converters for electric vehicle charging with photovoltaics interface

Scipedia content — Sun, 07 Feb 2021 13:50:23 +0100

Dissertação de mestrado em Engenharia Eletrónica e de Computadores Currently, an increasing bet in electric mobility has been made, particularly in electric vehicles (EV) and plug-in hybrid vehicles (PHEV). However, in addition to the high initial costs, the EVs feature a very low autonomy when compared with a traditional car. By charging the batteries of the EV using a renewable energy source, it is possible to make the system virtually emissions-free, since the production of electric power, as well as inexhaustible, is made without the use of fossil fuels (e.g. natural gas and coal). In addition, the benefits to the economy of the country are also evident, since we are contributing to the decrease of importing costs of these fossil fuels. As such, the main objective of this dissertation is the development and implementation of an integrated bi-directional converter (DC-DC and DC-AC) in order to connect an array of photovoltaic panels to the battery pack of an EV and to the power grid. In conventional systems, the electrical energy produced by the photovoltaic panels is injected into the grid and the batteries are charged from the grid. The aim is to develop a more efficient charging method which consists in charging the batteries directly from the PV panels. In this way it is possible to avoid the losses associated with the conversion of energy. The converter will allow the charging of the EV’s batteries directly from the PV panel, that is, without making DC-AC and AC-DC conversions, ensuring that the surplus energy is injected into the power grid. On the other hand, if the solar energy absorbed by the PV panel is insufficient to charge the batteries, the rest of the power needed to charge the batteries will be drawn from the grid. Naturally, if the batteries of the EV are already charged or no EV is connected to the system, all of the energy extracted from the PV panel will be injected into the power grid. Finally, the batteries will be able to deliver part of their stored energy to the power grid. Atualmente, tem vindo a ser feita uma aposta crescente na mobilidade elétrica, nomeadamente nos veículos elétricos (VE) e nos veículos híbridos Plug-in (PHEV). Contudo, para além do custo inicial elevado, os VEs apresentam uma autonomia muito baixa quando comparados com um automóvel tradicional. Ao carregar as baterias do VE através de uma fonte de energia renovável, é possível tornar o sistema virtualmente livre de emissões, uma vez que a produção de energia elétrica, para além de inesgotável, é feita sem o uso de combustíveis fósseis (e.g. gás natural e carvão). Para além disso, as vantagens para a economia do País também são evidentes, uma vez que estamos a contribuir para a diminuição dos gastos na importação dos referidos combustíveis fósseis. O objetivo principal desta dissertação é o desenvolvimento e implementação de um conversor integrado bidirecional (CC-CC e CC-CA) de modo a ligar um array de painéis fotovoltaicos ao pack de baterias de um VE e à rede elétrica. Nos sistemas de carregamento convencionais, a energia elétrica produzida pelos painéis fotovoltaicos é injetada na rede elétrica e as baterias são carregadas a partir da rede. Pretende-se desenvolver um método de carregamento mais eficiente que consiste em carregar as baterias do VE diretamente dos painéis fotovoltaicos. Deste modo, evitam-se as perdas associadas à conversão de energia. O conversor permitirá que as baterias do VE sejam carregadas diretamente do painel fotovoltaico, isto é, sem proceder a conversões de CC-CA e CA-CC, assegurando que a energia excedente é injetada na rede elétrica. Caso a energia solar absorvida pelo painel fotovoltaico seja insuficiente para fazer o carregamento das baterias, estas serão carregadas a partir da rede elétrica. Naturalmente, caso as baterias do VE já se encontrem carregadas ou nenhum VE se encontre ligado ao sistema, toda a energia extraída do painel fotovoltaico será injetada na rede elétrica. Finalmente, as baterias serão capazes de devolver parte da sua energia armazenada à rede elétrica.

A feasibility study on the use of smartphone sensors for development of Advanced Driver Assistance Systems

Scipedia content — Sun, 07 Feb 2021 13:50:12 +0100

Dissertação de mestrado integrado em Computer Science Technological evolution is impacting several industries, e.g., by allowing them to deliver higher levels of functionality. The automotive industry is an example of how technology is supporting the development of new solutions in vehicle safety and comfort. Advanced Driver Assistance Systems (ADAS) are cases of solutions that evolved significantly in recent years. This is possible not only due to the progress of electronic solutions but also because of higher quality in software. The smartphone is an example of this evolution with a broad range of applicability since these devices have been used to develop ADAS, making them an interesting cost-effective platform to develop such systems. Previous research has shown smartphones’ ability to output sensors data with the necessary quality for a broad number of applications with special focus in inertial sensors. However, such studies tend to be difficult to reproduce or lack the desired detail levels of their experimental methods. Concerns about how good are smartphone sensors and their use to develop ADAS emerge when reading existing literature, particularly, how the context of collecting data is controlled and which variables impact the collection process. In order to assess the feasibility of using smartphones as sensing devices, questions arise on how different parts of the collection setup affect the quality of data collected. Motivated by those questions, a study considering four different hypotheses is proposed to assess the impact of a controlled set of variables, namely: brands of inertial sensors, car mounts, sensor sampling rates, and vehicles. A set of controlled experiments is performed to assess the impact of each variable in the collection process of inertial sensors, more precisely the vertical acceleration. To perform the experiments, three special-purpose tools were developed. Smartphones used in the experiments feature an application to collect and export their sensors data. A researcher of an experiment operates another smartphone application to annotate road anomalies found while driving. A desktop application automates the computation and statistical validation of the vertical acceleration correlation from different setups. Dynamic Time Warping was used to compute the correlation coefficient of vertical acceleration as measured by different devices. Results show a baseline correlation coefficient of 0.892 with a standard configuration of software and hardware. When one of the independent variables is changed, the resulting coefficients range from 0.827 to 0.848. Randomization tests were executed to statistically validate experiments results, making use of a Random Shuffle algorithm on surrogate data. Such tests rejected all four proposed null hypotheses regarding dissimilarities on vertical acceleration sensed by different setups. From the controlled experiment a deeper understanding of the variables influencing data collection with smartphones was obtained. Results showed that varying the inertial sensors, car mounts, rates of sampling, or vehicles had a low impact on vertical acceleration sensed by smartphones. This is a good indicator that smartphones can be used to develop ADAS without the need to standardize every part of the collection setup. Thus, it possible to foresee the deployment of a system to a wider audience by taking advantage of existing equipment. A evolução tecnológica está a afectar várias indústrias, por exemplo, ao capacitá-las para fornecer níveis mais elevados de funcionalidade. A indústria automóvel é um exemplo da forma como a tecnologia está a apoiar o desenvolvimento de novas soluções de conforto e segurança automóvel. Os Sistemas Avançados de Assistência ao Condutor – Advanced Driver Assistance Systems (ADAS) – são casos de soluções que evoluíram significativamente nos últimos anos. Para tal, não só contribuiu o progresso de soluções electrónicas, mas também o aumento de qualidade do software. Os smartphones são um exemplo desta evolução de ampla aplicabilidade, sendo já utilizados para desenvolver ADAS e uma interessante plataforma para desenvolver tais sistemas com baixo custo. Estudos anteriores demostraram a capacidade dos smartphones para fornecer dados de sensores com a qualidade necessária para um grande número de aplicações, com especial foco nos sensores inerciais. No entanto, tais estudos tendem a ser de difícil reprodução ou não possuem o nível de detalhe desejado nos seus métodos experimentais. Questões sobre a qualidade dos sensores dos smartphones e o seu uso para desenvolver ADAS surgem do estudo da literatura existente, particularmente como a recolha de dados pode ser controlada e que variáveis têm impacto nesse processo. Para avaliar a viabilidade do uso de smartphones como dispositivos sensoriais, nascem questões sobre como as diferentes partes do sistema afetam a qualidade dos dados recolhidos por ele. Motivado por essas questões, é proposto o estudo de quatro hipóteses para medir o impacto de um conjunto de variáveis, a saber: sensores inerciais, suportes de telemóvel, taxas de amostragem dos sensores, e veículos. Experiências controladas são realizadas para estudar o impacto de cada variável no processo de recolha de dados de sensores, mais precisamente a aceleração vertical. Foram desenvolvidas três ferramentas de software para a realização das experiências. Os smartphones usados possuem uma aplicação para recolher e exportar os dados dos seus sensores. Durante a experiência, um investigador utiliza outra aplicação de smartphone para anotar as anomalias da estrada encontradas durante a condução. Uma aplicação de desktop automatiza a computação e validação estatistica da correlação da aceleração vertical medida por diferentes dispositivos. O coeficiente de correlação da aceleração vertical medida por diferentes dispositivos fez-se usando o algoritmo Dynamic Time Warping. Os resultados mostram um coeficiente de 0.892 com uma configuração padrão de software e hardware, que serve como base de análise. Quando uma das variáveis independentes é alterada, os coeficientes resultantes variam entre 0.827 e 0.848. Testes de permutação foram executados para validar estatisticamente os resultados experimentais, usando o algoritmo Random Shuffle sobre dados substitutos. Esses testes rejeitaram as quatro hipóteses nulas relativas à diferença de aceleração vertical detetada por diferentes dispositivos. A partir das experiências obteve-se uma compreensão aprofundada das variáveis que influenciam a coleção de dados com smartphones. Os resultados mostram que variar os sensores inerciais, suportes de telemóvel, taxas de amostragem, e veículos tem baixo impacto na aceleração vertical detetada. Isto indica que estes dispositivos podem ser usados para desenvolver ADAS sem a necessidade de padronizar cada peça da recolha de dados. Assim, é possível antever o desenvolvimento de um sistema para um público mais amplo, tirando partido de equipamentos já existentes.

Modeling of ev (electric vehicles) charging station locations

Scipedia content — Sun, 07 Feb 2021 13:49:03 +0100

[EN] In this thesis, an “Anxiety Model” is developed, by simulating EV driver´s charging decision under different degrees of anxiety, to give a more accurate prediction of where charging events are most likely to happen. [ES] En esta tesis se desarrolla un Modelo de Ansiedad, mediante la simulación de la decisión de carga del conductor del vehículo electrónico, EV. Se proponen diferentes grados de ansiedad, para hacer una predicción más exacta de donde se produjeron los eventos de carga con mayor probabilidad. Zhou, L. (2014). Modeling of ev (electric vehicles) charging station locations. http://hdl.handle.net/10251/59789 Archivo delegado

A machine-learned ranking algorithm for dynamic and personalised car pooling services

Scipedia content — Wed, 03 Feb 2021 21:55:57 +0100

Car pooling is expected to significantly help in reducing traffic congestion and pollution in cities by enabling drivers to share their cars with travellers with similar itineraries and time schedules. A number of car pooling matching services have been designed in order to efficiently find successful ride matches in a given pool of drivers and potential passengers. However, it is now recognised that many non-monetary aspects and social considerations, besides simple mobility needs, may influence the individual willingness of sharing a ride, which are difficult to predict. To address this problem, in this study we propose GoTogether, a recommender system for car pooling services that leverages on learning-to-rank techniques to automatically derive the personalised ranking model of each user from the history of her choices (i.e., the type of accepted or rejected shared rides). Then, GoTogether builds the list of recommended rides in order to maximise the success rate of the offered matches. To test the performance of our scheme we use real data from Twitter and Foursquare sources in order to generate a dataset of plausible mobility patterns and ride requests in a metropolitan area. The results show that the proposed solution quickly obtain an accurate prediction of the personalised user's choice model both in static and dynamic conditions.

Building a Driving Simulator with Parallax Barrier Displays

Scipedia content — Wed, 03 Feb 2021 21:51:08 +0100

In this paper, we present an optimized 3D stereoscopic display based on parallax barriers for a driving simulator. The overall purpose of the simulator is to enable user studies in a reproducible environment under controlled conditions to test and evaluate advanced driver assistance systems. Our contribution and the focus of this article is a visualization based on parallax barriers with (I) a-priori optimized barrier patterns and (II) an iterative calibration algorithm to further reduce visualization errors introduced by production inaccuracies. The result is an optimized 3D stereoscopic display perfectly integrated into its environment such that a single user in the simulator environment sees a stereoscopic image without having to wear specialized eye-wear.

Coupled Operational Optimization of Smart Valve System Subject to Different Approach Angles of a Pipe Contraction

Scipedia content — Wed, 03 Feb 2021 21:50:04 +0100

In this paper, we focus on interconnected trajectory optimization of two sets of solenoid actuated butterfly valves dynamically coupled in series. The system undergoes different approach angles of a pipe contraction as a typical profile of the so-called “Smart Valves” network containing tens of actuated valves. A high fidelity interconnected mathematical modeling process is derived to reveal the expected complexity of such a multiphysics system dealing with electromagnetics, fluid mechanics, and nonlinear dynamic effects. A coupled operational optimization scheme is formulated in order to seek the most efficient trajectories of the interconnected valves minimizing the energy consumed enforcing stability and physical constraints. We examine various global optimization methods including Particle Swarm, Simulated Annealing, Genetic, and Gradient based algorithms to avoid being trapped in several possible local minima. The effect of the approach angles of the pipeline contraction on the amount of energy saved is discussed in detail. The results indicate that a substantial amount of energy can be saved by an intelligent operation that uses flow torques to augment the closing efforts.

A Hierarchical Model Predictive Control Framework for On-road Formation Control of Autonomous Vehicles

Scipedia content — Wed, 03 Feb 2021 21:45:41 +0100

International audience; This paper presents an approach for formation control of autonomous vehicles traversing along a multi-lane road with obstacles and traffic. A major challenge in this problem is a requirement for integrating individual vehicle behaviors such as lane-keeping and collision avoidance with a global formation maintenance behavior. We propose a hierarchical Model Predictive Control (MPC) approach. The desired formation is modeled as a virtual structure evolving curvilinearly along a centerline, and vehicle configurations are expressed as curvilinear relative longitudinal and lateral offsets from the virtual center. At high-level, the trajectory generation of the virtual center is achieved through an MPC framework, which allows various on-road driving constraints to be considered in the optimization. At low-level, a local MPC controller computes the vehicle inputs in order to track the desired trajectory, taking into account more personalized driving constraints. High-fidelity simulations show that the proposed approach drives vehicles to the desired formation while retains some freedom for individual vehicle behaviors.

Numerical simulation of scour below pipelines using flexible mesh methods

Scipedia content — Wed, 03 Feb 2021 21:40:00 +0100

Evaluating bed morphological structure and evolution (specifically the scoured bed level) accurately using numerical models is critical for analyses of the stability of many marine structures. This paper discusses the performance of an implementation within Fluidity, an open source, general purpose, computational fluid dynamics (CFD) code, capable of handling arbitrary multi-scale unstructured tetrahedral meshes and including algorithms to perform dynamic anisotropic mesh adaptivity. The flexibility over mesh structure and resolution that these capabilities provide makes it potentially highly suitable for coupling the structural scale with larger scale ocean dynamics. In this very preliminary study the solver approach is demonstrated for an idealised scenario. Discontinuous Galerkin finite-element (DG-FEM) based discretisation methods have been used for the hydrodynamics and morphological calculations, and automatic mesh deformation has been utilised to account for bed evolution changes while preserving the validity and quality of the mesh. In future work, the solver will be used in three-dimensional impinging jet and other industrial and environmental scour studies.

A Neuromorphic Approach for Tracking using Dynamic Neural Fields on a Programmable Vision-chip

Scipedia content — Wed, 03 Feb 2021 21:24:50 +0100

In artificial vision applications, such as tracking, a large amount of data captured by sensors is transferred to processors to extract information relevant for the task at hand. Smart vision sensors offer a means to reduce the computational burden of visual processing pipelines by placing more processing capabilities next to the sensor. In this work, we use a vision-chip in which a small processor with memory is located next to each photosensitive element. The architecture of this device is optimized to perform local operations. To perform a task like tracking, we implement a neuromorphic approach using a Dynamic Neural Field, which allows to segregate, memorize, and track objects. Our system, consisting of the vision-chip running the DNF, outputs only the activity that corresponds to the tracked objects. These outputs reduce the bandwidth needed to transfer information as well as further post-processing, since computation happens at the pixel level.

TRENCHLESS LAYING USING CURVED PIPELINES FOR UNDERWATER CROSSINGS

Scipedia content — Wed, 03 Feb 2021 21:22:11 +0100

Traffic Aware Planner for Cockpit-based Trajectory Optimization

Scipedia content — Wed, 03 Feb 2021 21:21:59 +0100

The Traffic Aware Planner (TAP) software application is a cockpit-based advisory tool designed to be hosted on an Electronic Flight Bag and to enable and test the NASA concept of Traffic Aware Strategic Aircrew Requests (TASAR). The TASAR concept provides pilots with optimized route changes (including altitude) that reduce fuel burn and/or flight time, avoid interactions with known traffic, weather and restricted airspace, and may be used by the pilots to request a route and/or altitude change from Air Traffic Control. Developed using an iterative process, TAP's latest improvements include human-machine interface design upgrades and added functionality based on the results of human-in-the-loop simulation experiments and flight trials. Architectural improvements have been implemented to prepare the system for operational-use trials with partner commercial airlines. Future iterations will enhance coordination with airline dispatch and add functionality to improve the acceptability of TAP-generated route-change requests to pilots, dispatchers, and air traffic controllers.

Terminal airspace modelling for unmanned aircraft systems integration

Scipedia content — Wed, 03 Feb 2021 21:21:47 +0100

This paper considers the problem of integrating unmanned aircraft into low altitude airspace above urban environments, including major terminal areas and helicopter landing sites. A simple set of data-driven modelling techniques are used to explore, visualise and assess existing air traffic in a manner more informative to the unmanned aircraft community. First, low altitude air traffic data sets (position reports) are analysed with respect to existing exclusion/no-fly zones. Second, an alternative geometric approach to defining and comparing various exclusion zones is derived based on set theory. The analysis is applied to a region of south-east Queensland, Australia including Brisbane International Airport and three helicopter landing areas. The results challenge some of the current unmanned aircraft regulations, and should help to motivate a more rigorous scientific approach to safely integrate unmanned aircraft.

Driver behavior and workload in an on-road automated vehicle

Scipedia content — Wed, 03 Feb 2021 21:15:15 +0100

Driver mental underload is an important concern in the operational safety of automated driving. In this study, workload was evaluated subjectively (NASA RTLX) and objectively (auditory detection-response task) on Dutch public highways (~150km) in a Tesla Model S comparing manual and supervised automated driving with moderators automation experience and traffic complexity. Participants (N=16) were either automationinexperienced drivers or automation-experienced Tesla owners. Complexity ranged from an engaging environment with a road geometry stimulating continuous traffic interaction, and a monotonic environment with lower traffic density and a simple road geometry. Perceived and objective workload increased with traffic complexity. Automation use reduced perceived workload in both environments for automation-experienced drivers, but not for inexperienced drivers. However, the DRT did not reveal a reduced attentional demand with automation. This suggests that attentive monitoring requires a similar attentional demand as manual driving. The findings highlight the relevance of using system-experienced participants and the relevance of on-road testing for behavioral validity.

Optimal deployment of stations for a car sharing system with stochastic demands: A queueing theoretical perspective

Scipedia content — Wed, 03 Feb 2021 21:12:32 +0100

Car sharing holds a promise of reducing traffic congestion and pollution in cities as well as of boosting the use of public transport when used as a last-mile solution in a multimodal transportation scenario. Despite this huge potential, several problems related to the deployment and operations of car sharing systems have yet to be fully addressed. In this work, we focus on station-based car sharing and we define an optimization problem for the deployment of its stations. The goal of this problem is to find the minimum cost deployment (in terms of number of stations and their capacity) that can guarantee a pre-defined level of service to the customers (in terms of probability of finding an available car/parking space). This problem combines insights from queueing theory (used to model the stochastic demand for cars/parking spaces at the stations) with a variant of the classical set covering problem. For its evaluation, we use a trace of more than 100,000 pickup and drop-off events at a free-floating car sharing service in The Netherlands, which are used to model the input demand of the car sharing system. Our results show that the proposed solution is able to strike the right balance between cost minimisation and quality of service, outperforming three alternative schemes used as benchmarks.

Origami

Scipedia content — Wed, 03 Feb 2021 21:11:18 +0100

Graphical processing units (GPUs) are increasingly used to run a wide range of general purpose applications. Due to wide variation in application parallelism and inherent application level inefficiencies, GPUs experience significant idle periods. In this work, we first show that significant fine-grain pipeline bubbles exist regardless of warp scheduling policies or workloads. We propose to convert these bubbles into energy saving opportunities using Origami. Origami consists of two components: Warp Folding and the Origami scheduler. With Warp Folding, warps are split into two half-warps which are issued in succession. Warp Folding leaves half of the execution lanes idle, which is then exploited to improve energy efficiency through power gating. Origami scheduler is a new warp scheduler that is cognizant of the Warp Folding process and tries to further extend the sleep times of idle execution lanes. By combining the two techniques Origami can save 49% and 46% of the leakage energy in the integer and floating point pipelines, respectively. These savings are better than or at least on-par with Warped-Gates, a prior power gating technique that power gates the entire cluster of execution lanes. But Origami achieves these energy savings without relying on forcing idleness on execution lanes, which leads to performance losses, as has been proposed in Warped-Gates. Hence, Origami is able to achieve these energy savings with virtually no performance overhead.

Probabilistic Modeling of Aircraft Trajectories for Dynamic Separation Volumes

Scipedia content — Wed, 03 Feb 2021 21:05:14 +0100

With a proliferation of new and unconventional vehicles and operations expected in the future, the ab initio airspace design will require new approaches to trajectory prediction for separation assurance and other air traffic management functions. This paper presents an approach to probabilistic modeling of the trajectory of an aircraft when its intent is unknown. The approach uses a set of feature functions to constrain a maximum entropy probability distribution based on a set of observed aircraft trajectories. This model can be used to sample new aircraft trajectories to form an ensemble reflecting the variability in an aircraft's intent. The model learning process ensures that the variability in this ensemble reflects the behavior observed in the original data set. Computational examples are presented.

Urban Emissions in Canada: The Impact of the Electric Car

Scipedia content — Wed, 03 Feb 2021 21:01:30 +0100

Presented during the McMaster University Big Ideas Better Cities Conference on April 20, 2016 in Hamilton, Ontario, Canada. "div""br""/div""div"This work is part of the Environmental Component for the McMaster Institute for Transportation & Logistics' project: Social Costs and Benefits of Electric Mobility in Canada."/div

Characterising demand and usage patterns in a large station-based car sharing system

Scipedia content — Wed, 03 Feb 2021 20:55:17 +0100

Car sharing is a new mode of transportation that is gaining increasing popularity with its promise to reduce traffic congestion, parking demands and pollution in our cities. Despite this potential, the properties of car sharing systems, e.g., in terms of spatiotemporal characterisation of how customers use the service, remain largely unexplored in the research literature. In order to fill this gap, in this work we analyse one month of online car-sharing map data from a large station-based carsharing operator in France, which has 960 stations and more than 2700 electric cars. First, we study the spatial and temporal patterns of station utilisation, uncovering a dichotomy in station usage (stations that attract cars mostly in the morning vs. stations attracting cars mostly in the evening). We also find that this dichotomy is linked to the destination (residential or business) of the zone in which the station is located. In addition, we statistically model the users' demand in terms of drop-off and pickup rates, and the parking times of vehicles. Finally, we propose a classifier that exploits simple average statistics (average pickup rate and car availability of a station) in order to understand whether the station is profitable or not for the operator.

Request Patterns and Caching for VoD Services with Recommendation Systems

Scipedia content — Wed, 03 Feb 2021 20:54:14 +0100

Video on Demand (VoD) services like Netflix and YouTube account for ever increasing fractions of Internet traffic. It is estimated that this fraction will cross 80% in the next three years. Most popular VoD services have recommendation engines which recommend videos to users based on their viewing history, thus introducing time-correlation in user requests. Understanding and modeling this time-correlation in user requests is critical for network traffic engineering. The primary goal of this work is to use empirically observed properties of user requests to model the effect of recommendation engines on the request patterns in VoD services. We propose a Markovian request model to capture the time-correlation in user requests and show that our model is consistent with the observations of existing empirical studies. Most large-scale VoD services deliver content to users via a distributed network of servers as serving users requests via geographically co-located servers reduces latency and network bandwidth consumption. The content replication policy, i.e., determining which contents to cache on the servers is a key resource allocation problem for VoD services. Recent studies show that low start-up delay is a key Quality of Service (QoS) requirement of users of VoD services. This motivates the need to pre-fetch (fetch before contents are requested) and cache content likely to be request in the near future. Since pre-fetching leads to an increase in the network bandwidth usage, we use our Markovian model to explore the trade-offs and feasibility of implementing recommendation based pre-fetching.

A power and time efficient radio architecture for LDACS1 air-to-ground communication

Scipedia content — Wed, 03 Feb 2021 20:53:59 +0100

—L-band Digital Aeronautical Communication System (LDACS) is an emerging standard that aims at enhancing air traffic management by transitioning the traditional analog aeronautical communication systems to the superior and highly efficient digital domain. The standard places stringent requirements on the communication channels to allow them to coexist with critical L-band systems, requiring complex processing and filters in baseband. Approaches based on cognitive radio are also proposed since this allows tremendous increase in communication capacity and spectral efficiency. This requires high computational capability in airborne vehicles that can perform the complex filtering and masking, along with tasks associated with cognitive radio systems like spectrum sensing and baseband adaptation, while consuming very less power. This paper proposes a radio architecture based on new generation FPGAs that offers advanced capabilities like partial reconfiguration. The proposed architecture allows non-concurrent baseband modules to be dynamically loaded only when they are required, resulting in improved energy efficiency, without sacrificing performance. We evaluate the case of non-concurrent spectrum sensing logic and transmission filters on our cognitive radio platform based on Xilinx Zynq, and show that our approach results in 28.3% reduction in DSP utilisation leading to lower energy consumption at run-time.\\ud

An efficient algorithm for detecting traffic congestion and a framework for smart traffic control system

Scipedia content — Wed, 03 Feb 2021 20:50:37 +0100

Since the number of vehicles is increasing day by day, traffic jams are becoming a common scenario in large cities like Dhaka. These frequent traffic jams at major junctions kill a lot of man hours. Thus it creates a need for an efficient traffic management system. This paper proposes to implement a smart traffic control system which is based on the measurement of traffic density using real time video processing technique. The video sequences from a camera are analyzed using object detection and counting methods to obtain the most effective way. The computed vehicle density is compared with other parts of the traffic in order to control the traffic signal brilliantly. The system has an advantage of using RFID sensors to ensure law enforcement. Therefore, any car or vehicle which breaks the traffic rules can be easily caught. Through this paper we tried to present a progress in the existing manual traffic control system.

Investigation of modified asphalt concrete

Scipedia content — Wed, 03 Feb 2021 20:46:38 +0100

Currently the problem of improving the asphalt quality is very urgent. It is used primarily as topcoats exposed to the greatest relative to the other layers of the road, dynamic load – impact and shear. The number of cars on the road, the speed of their movement, as well as the traffic intensity increase day by day. We have to upgrade motor roads, which entails a huge cost. World experience shows that the issue is urgent not only in Russia, but also in many countries in Europe, USA and Asia. Thus, the subject of research is the resistance of asphalt concrete to water and its influence on the strength of the material at different temperatures, and resistance of pavement to deformation. It is appropriate to search for new modifiers for asphaltic binder and mineral additives for asphalt mix to form in complex the skeleton of the future asphalt concrete, resistant to atmospheric condensation, soil characteristics of the road construction area, as well as the growing road transport load. The important task of ...

Decentralized control of inland navigation networks with distributaries: Application to navigation canals in the north of France

Scipedia content — Wed, 03 Feb 2021 20:45:05 +0100

@2017 Personal use of these materials is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating news collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

Inland navigation networks are large-scale systems with large dead times, nonlinearities and variable time delays. They are composed of interconnected reaches. The management goal is to maintain the water level of each reach around a certain value. In this paper, a decentralized control approach is addressed to fulfill this objective. It is based on IDZ models by considering connected reaches with distributaries. A real navigation sub-network in the north of France serves as the case study for this work.

Peer Reviewed

Green energy based inductive Self-Healing highways of the future

Scipedia content — Wed, 03 Feb 2021 20:43:56 +0100

This paper deals with a green energy highway in the Netherlands. Here, the development of electric mobility and self- driving cars is introduced. The ideas of wireless power integration with green energy technologies - solar and wind is considered. In case of wind energy, conventional turbines and bladeless vortex are considered as options. Solaroads along the emergency lanes are also investigated. A Dutch highway A12 is considered as a case study and sizing of these energy sources for electric mobility is considered. A grid power demand profile is considered and number of EVs that can be charged hourly is calculated. A preliminary investigation of the combination of IPT and Self-Healing roads is considered in this study.

Data requirements for urban logistics decision support: Case of loading and unloading operations in Bogotá, Colombia

Scipedia content — Wed, 03 Feb 2021 20:32:42 +0100

International audience; The aim of this paper is to analyze, via a case study, the main issues related to data production in a preliminary step of defining and designing a Decision Support System (DSS) for urban logistics. The case study is that of Bogotá City, Colombia. We present in a first time a literature review concerning with the relevance of developments and application of DSS in urban areas, focusing on megacities. Then, the case study is presented, by identifying the context, the main stakeholders and the needs in information that would be used in a DSS for urban logistics. Finally, a discussion of those results and a set of practical implication are proposed.

Line integrated traffic operation assistance system

Scipedia content — Wed, 03 Feb 2021 20:28:40 +0100

The Cerema pedestrian database: A specific database in adverse weather conditions to evaluate computer vision pedestrian detectors

Scipedia content — Wed, 03 Feb 2021 20:26:19 +0100

Nowadays, many pedestrians are victims of road accidents. Several artificial vision solutions, based on pedestrian detection, have therefore been developed to assist drivers and reduce the accident rate. But most of the proposed pedestrian databases make it possible to test detection only in favorable conditions. The main goal of this research is to provide a learning and testing environment for the development of pedestrian detectors able to function under all weather conditions by day and even by night. This paper presents a new database, called Cerema, composed of 10 sets which include normal and degraded conditions (day, night, fog, rain). Image data will include detailed annotations for each set. Two common detectors are used to show the usefulness of our database, which are HOG and Haar. Finally, the results obtained on this new database will be presented to show the impact of adverse weather conditions on these two different detectors.

Analysis of optimal solutions to robot coordination problems to improve autonomous intersection management policies

Scipedia content — Wed, 03 Feb 2021 20:23:43 +0100

International audience; The deployment of Cooperative Intelligent Transportation Systems (C-ITS) raises the question of future traffic management systems, which will be operating with an increasing amount of information and control over the infrastructure and the vehicles. This topic of research shares some similarities with robot coordination problems, inspiring our research on autonomous intersection management. In this article, we use a mixed-integer linear programming formulation for time-optimal robots coordination along specified paths and apply it to intersection management for autonomous vehicles. Our formulation allows to simultaneously solve a discrete optimal vehicle ordering problem, and a (discretized) continuous optimal velocity planning problem taking into account kinodynamics constraints. This allows faster pruning of the decision tree for the discrete problem, thus reducing computation time. A possible application for ITS is to evaluate the efficiency loss from a given vehicle ordering policy, or dynamically adapt policies to improve their efficiency. Moreover, any intermediary solution found by the solver can be used as a heuristically good policy, with proved bounds on sub-optimality.

Vehicle Detection and Classification Using Passive Infrared Sensing

Scipedia content — Wed, 03 Feb 2021 20:20:57 +0100

We propose a new sensing device that can simultaneously monitor urban traffic congestion and another phenomenon of interest (flash floods on the present case). This sensing device is based on the combination of an ultrasonic rangefinder with one or multiple remote temperature sensors. We show an implementation of this device, and illustrate its performance in both traffic flow sensing. Field data shows that the sensor can detect vehicles with a 99% accuracy, in addition to estimating their speed and classifying them in function of their length. The same sensor can also monitor urban water levels with an accuracy of less than 2 cm.

Identification of conflicts between transmission and distribution system operators when acquiring ancillary services from electric vehicles

Scipedia content — Wed, 03 Feb 2021 20:17:45 +0100

Distributed energy resources are able to provide services to grid operators, possibly with competing objectives. With the development of active distribution grid management, various market designs arise. Here, a reference market framework is considered, which allocates the available flexibility products according to requests coming from both distribution and transmission system operators. The goal of this paper is to provide an identification procedure that is able to detect,"br/"identify and catalogue possible conflicts among the involved stakeholders that take place when requesting and/or acquiring ancillary services from flexible units. The investigation is carried out considering a 3-area power system which allows to take into account local constraints as well as system-wide needs. As outcome, this paper identifies the conflicts from both a theoretical and a practical point of view, by means of descriptions/identification procedure and by visual examples, respectively.

3D SPAD camera for Advanced Driver Assistance

Scipedia content — Wed, 03 Feb 2021 20:15:27 +0100

We present a 3D-ranging camera based on the optical indirect Time-of-Flight technique, suitable for automotive applications. The camera is based on a 64×32-pixel chip, integrating a Single-Photon Avalanche Diode (SPAD) in each pixel, fabricated in an automotive-certified CMOS technology, and on an 808 nm active illuminator, emitting 1.5 W average optical power. Thanks to the SPAD single-photon sensitivity and the in-pixel processing, the camera provides a precision better than 1 m over a 40° × 20° field-of-view, at 45 m distance.

Building scalable digital library ingestion pipelines using microservices

Scipedia content — Wed, 03 Feb 2021 20:11:33 +0100

CORE, a harvesting service offering access to millions of open access research papers from around the world, has shifted its harvesting process from following a monolithic approach to the adoption of a microservices infrastructure. In this paper, we explain how we rearranged and re-scheduled our old ingestion pipeline, present CORE's move to managing microservices and outline the tools we use in a new and optimised ingestion system. In addition, we discuss the ineffciencies of our old harvesting process, the advantages, and challenges of our new ingestion system and our future plans. We conclude that via the adoption of microservices architecture we managed to achieve a scalable and distributed system that would assist with CORE's future performance\\ud and evolution.

Exploratory Study with Eye Tracking Devices to Build Interactive Systems for Air Traffic Controllers

Scipedia content — Wed, 03 Feb 2021 20:09:58 +0100

International audience; While the mouse is the main input device for interacting with different screens, many alternatives do exist. In this article, we report our exploratory study with the usage of eyes as a new input device for Air Traffic Control systems. Our investigations, based on a user - centered design, include a study of the activity, a classification of interaction techniques based on eye tracking systems, and finally a working prototype with the evaluations of the developed interaction techniques. Our goal is to investigate gaze usages as a means of interaction, and give recommendations for future development of Air Traffic Control systems.

Towards hybrid driver state monitoring: Review, future perspectives and the role of consumer electronics

Scipedia content — Wed, 03 Feb 2021 20:09:47 +0100

The purpose of this paper is to bring together multiple literature sources which present innovative methodologies for the assessment of driver state, driving context and performance by means of technology within a vehicle and consumer electronic devices. It also provides an overview of ongoing research and trends in the area of driver state monitoring. As part of this review a model of a hybrid driver state monitoring system is proposed. The model incorporates technology within a vehicle and multiple brought-in devices for enhanced validity and reliability of recorded data. Additionally, the model draws upon requirement of data fusion in order to generate unified driver state indicator(-s) that could be used to modify in-vehicle information and safety systems hence, make them driver state adaptable. Such modification could help to reach optimal driving performance in a particular driving situation. To conclude, we discuss the advantages of integrating hybrid driver state monitoring system into a vehicle and suggest future areas of research.

Safety awareness of roadside traders in Osogbo Township, Osun State, Nigeria

Scipedia content — Wed, 03 Feb 2021 20:07:54 +0100

The study focuses on evaluating the safety awareness of roadside traders along the major axis of Osogbo, Osun state, Nigeria. The objectives include to identify the location where street traders operate, assess their socio-economic characteristics, identify the risks involved and determine the traders’ awareness of the risks involved in their activity. A total of 278 roadside traders were selected from six clusters on the basis of streets using stratified random sampling techniques. Findings reveal that road-side trading within the central business district (CBD) of Osogbo was influenced by low level of education, poverty, need for survival and by high rent value within the CBD among other factors. The study reveals a significantly high level of awareness of the risks involved such as exposure to high concentration of pollutants, exposure to hot sun and inclement weather and being hit by vehicles among others. It is recommended that a comprehensive planned alternative retail location with high connectivity and visibility be put in place, and the protection of the traders in the form government sponsored safety regulations for their operations as well as the enforcement of the existing traffic safety measures.

Improving Quality Management Systems (QMS) for Pipeline Construction Activities

Scipedia content — Wed, 03 Feb 2021 20:07:21 +0100

Since 2007, the pipeline industry has experienced a large increase in pipeline construction. Construction inspections performed by the Department of Transportation (DOT) Pipeline Hazardous Materials Safety Administration (PHMSA) have revealed numerous quality issues. These inspections, coupled with several pre-commissioning pressure test failures, first year in-service failures, and other material and construction problems, brought construction quality to the attention of the oil and gas pipeline industry."/jats:p" "jats:p"A proven method for improving quality in other industries is through the implementation of a quality management system (QMS). One widely accepted QMS used across industries is ISO 9001. Additionally, several QMS standards specific to the oil and gas industry have been developed. Due to the uniqueness of pipeline construction projects, PHMSA solicited proposals in 2013 for a research and development project titled, “Improving Quality Management Systems for Pipeline Construction Activities” which was awarded to and co-funded by DNV GL."/jats:p" "jats:p"This paper describes the QMS framework for pipeline construction activities and an accompanying guidance document developed by DNV GL. The framework and guidance document are intended to assist pipeline operating companies and contractors in the development and implementation of a company-specific QMS, with a goal of elevating the focus on quality to the level of safety."/jats:p" "jats:p"The framework adopts a risk-based, process approach, as defined in other QMS and management system documents, and follows the plan-do-act-check methodology. The QMS framework is designed to be scalable for a wide range of pipeline construction projects, including liquid and gas transmission pipelines and gas distribution lines. The framework includes the general management system components, as well as specific sections on implementation of a QMS for a pipeline construction project. The QMS framework and guidance document developed are intended to be used either as a stand-alone management system or as the quality component in a company’s corporate management system.

NextGen Far-Term Concept Exploration for Integrated Gate-to-Gate Trajectory-Based Operations

Scipedia content — Wed, 03 Feb 2021 20:00:50 +0100

NASA is currently conducting concept exploration studies toward the definition of a far-term, gate-to-gate concept for Trajectory-Based Operations. This paper presents a basic architectural framework for the far-term concept and discusses some observations about implementation of trajectory-based operations in the National Airspace System. Within the concept, operators and service providers collaboratively negotiate aircraft trajectories, providing agile, optimized, aircraft-specific routing to meet service provider gate-to-gate flow-management constraints and increasing capacity by smoothly and effectively combining flight-deck-based and ground-based metering, merging, and spacing in a mixed-equipage environment. The far-term TBO concept is intended to influence the direction of mid-term TBO research and to inform the definition of stable requirements and standards for TBO communications infrastructure and user equipage.

A Life-Cycle Approach to the Assessment of Pipeline Dents

Scipedia content — Wed, 03 Feb 2021 19:52:00 +0100

The application of in-line inspection (ILI) to assess pipelines for various anomalies is standard practice in the pipeline industry. When ILI data identifies the presence of anomalies such as denting or ovalization, current convention is to perform either a depth-based or strain-based assessment to assess the severity. Although a strain-based methodology is generally accepted in the pipeline industry, this approach does not address all of the primary damage mechanisms associated with pipeline dents. Assessment based upon either depth or strain alone may not only provide non-conservative results but also fail to properly rank dents in order of their true severity. A life-cycle assessment approach that considers the damage caused by the dent formation, the stress intensification effect of the dent profile, and the severity of future pressure cycling provides an improved understanding of the probability of failure, allowing for more informed integrity management decision making."/jats:p" "jats:p"Strain-based assessment of dents in pipelines is typically performed by calculating the local curvatures in the dent geometry as measured by ILI. Local strains are then calculated based on these local curvatures. However, this approach does not address that once a dent has been formed, continued pressure cycling at that location is what will ultimately cause a failure. The current strain-based methodology does not account for the severity of the pressure cycling at the dent."/jats:p" "jats:p"A new and innovative methodology has been developed which takes a life-cycle approach to the assessment of pipeline dents. This approach estimates the remaining life of a dent based on fatigue damage accumulation. Finite element analysis (FEA) is used to calculate various stress concentration factors (SCFs) based on the geometry of the dent. These SCFs are used to calculate an equivalent alternating stress for a unit pressure cycle event. Past representative pressure cycling data is gathered using a rainflow counting approach. The amount of damage accumulated during each pressure cycle is calculated using stress or strain based (S-N) fatigue curves; this allows for a damage rate to be calculated based on past operational history. A remaining life can be estimated based on this damage rate and an estimation of the initial fatigue damage accumulated during formation of the dent. This estimation is made based on previous elastic-plastic FEA of various scenarios which simulate the formation and shakedown of a pipeline dent."/jats:p" "jats:p"Case studies which explore the use of different assessment methods to analyze dents will be presented. A comparison of different assessment methodologies will illustrate the improved understanding of the probability of failure of dents based upon the life-cycle assessment.

Fault management strategies and architecture design for turboelectric distributed propulsion

Scipedia content — Wed, 03 Feb 2021 19:47:20 +0100

The TeDP concept has been presented as a possible solution to reduce aircraft emissions despite the continuing trend for increased air traffic. However, much of the benefit of this concept hinges on the reliable transfer of electrical power from the generators to the electrical motor driven propulsors. Protection and fault management of the electrical transmission and distribution network is crucial to ensure flight safety and to maintain the integrity of the electrical components on board. Therefore a robust fault management strategy is required. With consideration of the aerospace-specific application, the fault management strategy must be efficient, of minimal weight and be capable of a quick response to off-nominal conditions. This paper investigates how the TeDP architecture designs are likely to be driven by the development of appropriate fault management strategies.

Evaluation of traffic control systems as ITS infrastructure for automated driving: Paper presented at INTSYS 2017, Intelligent Transport Systems. From research and development to the market uptake, November 29-30, 2017, Helsinki, Finland

Scipedia content — Wed, 03 Feb 2021 19:45:46 +0100

Vehicles with automated driving systems require more sensor information about their environment than non-automated vehicles. Detection with camera, lidar or other sensors is already state of the art in newer vehicles. As of today though, they only work in close proximity and lack the incorporation of existing traffic information from local authorities. In this paper, we present a novel way of providing traffic management information to vehicles, sent directly from Road Authorities. We use existing ITS (Intelligent Transport Systems) infrastructure and assess how information on traffic control and reroutes, displayed on variable message signs, can be used as sensory input for vehicles. We examine real world data from a South German Road Authority. The evaluation of latency, reliability and integrity of traffic information has been conducted end-to-end as well as between the six stations that are involved. We show the general feasibility of our proposal and discuss which obstacles need to be overcome for a wider use in other road systems.

Hydrogen Effects on Fatigue Crack Growth Rates in Pipeline Steel Welds

Scipedia content — Wed, 03 Feb 2021 19:44:59 +0100

Fatigue crack growth rate (da/dN) versus stress intensity factor range (ΔK) relationships were measured for various grades of pipeline steel along with their respective welds in high pressure hydrogen. Tests were conducted in both 21 MPa hydrogen gas and a reference environment (e.g. air) at room temperature. Girth welds fabricated by arc welding and friction stir welding processes were examined in X65 and X52 pipeline grades, respectively. Results showed accelerated fatigue crack growth rates for all tests in hydrogen as compared to tests in air. Modestly higher hydrogen-assisted crack growth rates were observed in the welds as compared to their respective base metals. The arc weld and friction stir weld exhibited similar fatigue crack growth behavior suggesting similar sensitivity to hydrogen. A detailed study of microstructure and fractography was performed to identify relationships between microstructure constituents and hydrogen accelerated fatigue crack growth.

Data Blocks: hybrid OLTP and OLAP on compressed storage using both vectorization and compilation

Scipedia content — Wed, 03 Feb 2021 19:43:08 +0100

htmlabstractThis work aims at reducing the main-memory footprint in high performance hybrid OLTP & OLAP databases, while retaining high query performance and transactional throughput. For this purpose, an innovative compressed columnar storage format for cold data, called Data Blocks is introduced. Data Blocks further incorporate a new light-weight index structure called Positional SMA that narrows scan ranges within Data Blocks even if the entire block cannot be ruled out. To achieve highest OLTP performance, the compression schemes of Data Blocks are very light-weight, such that OLTP transactions can still quickly access individual tuples. This sets our storage scheme apart from those used in specialized analytical databases where data must usually be bit-unpacked. Up to now, high-performance analytical systems use either vectorized query execution or “just-in-time” (JIT) query compilation. The fine-grained adaptivity of Data Blocks necessitates the integration of the best features of each approach by an interpreted vectorized scan subsystem feeding into JIT-compiled query pipelines. Experimental evaluation of HyPer, our full-fledged hybrid OLTP & OLAP database system, shows that Data Blocks accelerate performance on a variety of query workloads while retaining high transaction throughput.

Human reliability analysis for railway operations: a framework for integration of human factors in risk analysis

Scipedia content — Wed, 03 Feb 2021 19:41:15 +0100

International audience

A congestion-free vehicle route reservation architecture

Scipedia content — Wed, 03 Feb 2021 19:35:10 +0100

Transportation research is mainly focused on answering the question of how to eliminate traffic congestion over large scale areas. Inasmuch as a large portion of big cities suffers from traffic congestion with severe (in many cases) consequences on personal mobility. Drawbacks of congestion include driver delay and frustration, higher fuel consumption, air pollution and financial losses (in terms of man-hours lost on working days). Congestion has, traditionally, been a difficult problem to tackle since traffic demand fluctuates dynamically. The major cause of congestion is that a portion of the network is conferred to accommodate higher number of vehicles than its actual capacity. Nonetheless, congestion usually occurs due to lack of an efficient management of transport network utilization and not because demand exceeds network's capacity [1]. Therefore, it is possible to alleviate congestion if vehicles are more effectively distributed over the entire network achieving better load balancing. • "© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, in-cluding reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to serv-ers or lists, or reuse of any copyrighted component of this work in other works. C. Menelaou, P. Kolios, S. Timotheou and C. G. Panayiotou, "A congestion-free vehicle route reservation architecture," 2016 18th Mediterranean Electrotechnical Conference (MELECON), Lemesos, 2016, pp. 1-6. doi: 10.1109/MELCON.2016.7495458 • https://www.ieee.org/publications_standards/publications/rights/rights_policies.html

Document type: Conference object

Mining Traffic Congestion Correlation between Road Segments on GPS Trajectories

Scipedia content — Wed, 03 Feb 2021 19:31:49 +0100

Traffic congestion is a major concern in many cities around the world. Previous work mainly focuses on the prediction of congestion and analysis of traffic flows, while the congestion correlation between road segments has not been studied yet. In this paper, we propose a three-phase framework to study the congestion correlation between road segments from multiple real world data. In the first phase, we extract congestion information on each road segment from GPS trajectories of over 10,000 taxis, define congestion correlation and propose a corresponding mining algorithm to find out all the existing correlations. In the second phase, we extract various features on each pair of road segments from road network and POI data. In the last phase, the results of the first two phases are input into several classifiers to predict congestion correlation. We further analyze the important features and evaluate the results of the trained classifiers. We found some important patterns that lead to a high/low congestion correlation, and they can facilitate building various transportation applications. The proposed techniques in our framework are general, and can be applied to other pairwise correlation analysis.

Modelling and solving the multi-day container drayage problem

Scipedia content — Wed, 03 Feb 2021 19:30:31 +0100

This paper deals with a general Multi-Day Container Drayage Problem (MDCDP) that consists in assigning trucks to container transportation orders during several days. To this aim, a Mixed Integer Linear Programming problem is formulated: the model describes real problems taking into account the orders to be planned for several days, the types of the containers and the rest periods of drivers. In order to address real scenarios, a heuristic algorithm based on the rolling horizon approach is proposed. Some randomly generated MDCDP instances validate the heuristic algorithm and a case study of real dimensions shows the effectiveness of the proposed solution technique.

Benefits of multi-layer application-aware resource allocation and optimization

Scipedia content — Wed, 03 Feb 2021 19:30:06 +0100

Internet traffic is generated by a multitude of applications, each one with diverse service requirements in terms of bandwidth, latency, reliability, etc. Today traffic engineering techniques can provide service differentiation at the IP/MPLS layer, but not at the optical layer. In this paper we propose a framework where application service requirements drive a dynamic multi-layer (IP/MPLS and optical) resource allocation and optimization. We compare by means of simulations such application-aware algorithmic framework with a multi-layer but application-unaware strategy. Results show that the application-aware approach, unlike the application-unaware one, is always able to guarantee the specified service requirements to those applications whose generated traffic is accepted by the network. In addition, the application-aware strategy does not consume more network resources than the application-unaware one, but only requires a network that is more dynamic and responsive.

Landmark based localization: LBA refinement using MCMC-optimized projections of RJMCMC-extracted road marks

Scipedia content — Wed, 03 Feb 2021 19:22:31 +0100

International audience; Precise localization in dense urban areas is a challenging task for both mobile mapping and driver assistance systems. This paper proposes a strategy to use road markings as localization landmarks for vision based systems. First step consists in reconstructing a map of road marks. A mobile mapping system equipped with precise georeferencing devices is applied to scan the scene in 3D and to generate an ortho-image of the road surface. A RJMCMC sampler that is coupled with a simulated annealing method is applied to detect occurrences of road marking templates instanced from an extensible database of road mark patterns. The detected objects are reconstructed in 3D using the height information obtained from 3D points. A calibrated camera and a low cost GPS receiver are embedded on a vehicle and used as localization devices. Local bundle adjustment (LBA) is applied to estimate the trajectory of the vehicle. In order to reduce the drift of the trajectory, images are matched with the reconstructed road marks frequently. The matching is initialized by the initial poses that are estimated by LBA and optimized by a MCMC algorithm. The matching provides ground control points that are integrated in the LBA in order to refine the pose parameters. The method is evaluated on a set of images acquired in a real urban area and is compared with a precise ground-truth.

Minimizing DSP block usage through multi-pumping

Scipedia content — Wed, 03 Feb 2021 19:22:18 +0100

Resource sharing in the mapping of an algorithm to an architecture allows the same resource to be scheduled for different uses in different cycles, generally at the cost of increased schedule length. Multi-pumping is a method whereby a resource is clocked at a frequency that is a multiple of the surrounding circuit, thereby offering multiple executions per global clock, and therefore sharing in the same clock cycle. This concept maps well to FPGA architectures, where hard macro blocks are typically capable of running at higher frequencies than standard logic. While this technique has been demonstrated for multipliers, modern DSP blocks are more complex with multiple computational nodes. In this paper, we apply multi-pumping to minimise DSP block usage, while taking advantage of the multiple nodes they support. The proposed approach uses, on average, 39% fewer DSP blocks, at a cost of 19% more LUTs and 7% more registers.

Will fleet managers really help vehicle fleets to become electric?

Scipedia content — Wed, 03 Feb 2021 19:21:04 +0100

International audience; Over the last few years, obligations to reduce carbon dioxide emissions have led European States to propose ambitious targets concerning electrifying car fleets. In France for instance, electric vehicles are required to cover a quarter of all new car purchases in big companies and public administrations. In these organizations, departments that are traditionally in charge of company vehicles have thus been tasked to implement these policy decisions. General Resources have become de facto responsible for testing and managing these new EVs. Illustrating our results through five case-studies that took place in France in 2012-2015, we will show how these departments, and notably fleet managers, carry out the numerous tasks accompanying the spreading of EVs in their organizations: acquiring these vehicles (and the charging infrastructure), allocating them and managing the charging of the cars. The allocation, whether as fleet cars or executive ones, is an important step for the success of their implementation in these companies. We will also point out the contradictory significations and powerful constraints that complicate the performance of these tasks. Their achievement strengthens the role of the fleet managers, who turn out to be crucial but unexpected players in electricity demand.

Strategic Planning of Aircraft Trajectories in North Atlantic Oceanic Airspace Based on Flocking Behaviour

Scipedia content — Wed, 03 Feb 2021 19:20:50 +0100

The North Atlantic Airspace (NAT) accommodates traffic between Europe and North America. This area is considered as the most congested oceanic airspace in the world. Radar-Based surveillance is not applied in the most of the oceanic area due to its limited coverage. So, aircraft become obliged to follow predefined routes called Organized Track System (OTS). These routes require very restrictive separation standards which limit the traffic of aircraft. Thus, a new kind of communication system, called Automated Dependence Surveillance Broadcast (ADS-B), has been introduced in order to afford the aircraft a reliable communication with both controllers and surrounding traffic. Hence, aircraft crossing the NAT will be able to follow more flexible routes, which will improve significantly the air traffic situation over this area. In this paper, we propose a strategic planning 1 model that overcomes the constraints of the OTS system in order to produce the closest routes to the direct ones of aircraft. This method is based on flocking boid model. It provides us with satisfying results on a portion of one day traffic over the NAT airspace.

Study of the lane change maneuver: automated driving use case

Scipedia content — Wed, 03 Feb 2021 19:19:59 +0100

Nowadays, the idea of a completely interconnected city with infrastructure, vehicles and even the humans on a connectivity loop is a reality. This work is partly supported by the H2020 project UnCoVerCPS with grant number 643921.

Assessment of Harmonic Distortion on Distribution Feeders with Electric Vehicles and Residential PVs

Scipedia content — Wed, 03 Feb 2021 19:19:47 +0100

Power-electronic interfacing based devices such as photovoltaic (PV) panels and electric vehicles (EVs) cause voltage/current harmonic distortions on the power grid. The harmonic current profiles from EVs and PVs depend on the design of the controllers integrated to the PV inverters and EV chargers. Similarly the voltage and current harmonic distortions on a grid change throughout the day as the PV output power number of grid connected EVs and the other load pattern change. In this context we present harmonic assessment to demonstrate cumulative effect of large number of EVs and PVs on a medium voltage distribution grid. We will demonstrate the case studies on the IEEE 123-node distribution feeder with 20% 50% and 100% PV and EV penetrations based on time series simulations carried out for an entire day.

Studying the Factors Affecting Sales of New Energy Vehicles from Supply Side

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

Flight Test Overview for UAS Integration in the NAS Project

Scipedia content — Wed, 03 Feb 2021 19:13:23 +0100

The National Aeronautics and Space Administration is conducting a series of flight tests intended to support the reduction of barriers that prevent unmanned aircraft from flying without the required waivers from the Federal Aviation Administration. The most recent testing supported two separate test configurations. The first investigated the timing of Detect and Avoid (DAA) alerting thresholds using a radar-equipped unmanned vehicle and multiple live intruders flown at varying encounter geometries. The second configuration included a surrogate unmanned vehicle (flown from a ground control station, with a safety pilot on board) flying a mission in a virtual air traffic control airspace sector using research pilot displays and DAA advisories to maintain separation from live and virtual aircraft. The test was conducted over a seven-week span in the summer of 2015. The data from over 100 encounter sorties will be used to inform the RTCA Phase 1 Detect and Avoid and Command and Control Minimum Operating Performance Standards (MOPS) intended to be completed by the summer of 2016. Follow-on flight-testing is planned for the spring of 2016 to capture remaining encounters and support validation of the MOPS.

Simulation and Analysis for Electric Bicycle Traffic Flow

Scipedia content — Wed, 03 Feb 2021 19:05:51 +0100

Keywords: traffic engineering, electric bicycle flow, lane changing rule, cellular automaton model. Abstract. The electric bicycle has become the main part of non motor vehicles in small and medium-sized cities. Research on the traffic flow characteristic of the electric bicycle has important practical significance. Based on NaSch model, this paper models electric bicycle traffic flow with CA model and improves the lane changing model. Then the electric bicycle lanes change into general lane change and whistle change, and corresponding lane changing rules are set up. Simulation analysis of the model is carried out. The results show that when the traffic density is small, whistling behavior to raise the road utilization rate has some effect, but in the high density, whistle behavior can not improve road traffic capacity.

Assessment of impacts of Electric Vehicles on LV distribution networks in Turkey

Scipedia content — Wed, 03 Feb 2021 18:56:12 +0100

This study proposes a methodology to analyze the impacts of Electric Vehicles (EVs) on Low Voltage (LV) distribution networks based on probabilistic models developed for the charging process of EVs. In addition to the battery charging characteristics, Gaussian distribution function for EV plug-in times and Weibull distribution function for daily travel times are utilized in simulations. Monte Carlo based load flow simulations are performed in order to evaluate the response of the LV networks to various EV and load scenarios and different multi-tariff mechanisms. The sample networks are investigated for branch overloads, excessive voltage drops and losses using a systematic reporting approach developed. This method guides the utilities to determine the necessary investments on LV networks and their associated time frames. The expected consumer reaction to different multi tariff systems can also be modeled to assess the economic feasibility of a new multi tariff system against necessary investments in the LV network.

Semantic data containers for realizing the full potential of system wide information management

Scipedia content — Wed, 03 Feb 2021 18:50:46 +0100

In order to unleash the full potential of System Wide Information Management (SWIM), the BEST project(Achieving the Benefits of SWIM by Making Smart Use of Semantic Technologies) proposes the semantic container approach which shields service and application developers from the complexities of data provisioning in Air Traffic Management(ATM). In combination with SWIM, semantic containers facilitate the emergence of a marketplace of value-added information services, and allow for complex derivation chains of data sets. Along these derivation chains, existing data are intelligently filtered and prioritized as well as combined and annotated with additional information. Refereed/Peer-reviewed

Challenging the Car Norm

Scipedia content — Wed, 03 Feb 2021 18:37:37 +0100

The use of practices as a unit of analysis has been suggested in order to scale up efforts within sustainable HCI and to shift the focus from changing individual behaviours to supporting transitions at a societal level. In this paper, we take a practice approach to the case of sustainable transportation, and more specifically to car-free transportation. Car use is intertwined in many practices and managing life without a car is difficult, particularly for people in contexts where owning at least one car per family is the norm. We studied three families in Stockholm who replaced their cars with different combinations of light electric vehicles during one year. From the families' experiences, we identified a number of opportunities for designers of interactive technologies to support environmental pioneers in the particular case of car-free living, as well as to support transitions towards sustainable practices in general.

Convex Optimization for Joint Expansion Planning of Natural Gas and Power Systems

Scipedia content — Wed, 03 Feb 2021 18:37:25 +0100

Within the energy sector, two of the most tightly coupled systems are natural gas and electric power. The recent advent of cheap gas extraction technologies have only driven these systems more tightly together. Despite their interconnections, in many areas of the world these systems are operated and managed in isolation. This separation is due to a number of reasons and challenges, ranging from technological (problems involving connected systems are difficult to solve) to political and commercial (prevention of monopolies, lack of communication, market forces, etc.). However, this separation can lead to a number of undesirable outcomes, such as what the northeastern United States experienced during the winter of 2013/2014. In this paper, we develop approaches to address the technological reasons for separation. We consider the problem of expanding and designing coupled natural gas and electric power systems to meet increased coincident demand on both systems. Our approach utilizes recent advances in convex modeling of gas and power systems to develop a computationally tractable optimization formulation.

Risk-Hedged Approach for Re-routing Air Traffic Under Weather Uncertainty

Scipedia content — Wed, 03 Feb 2021 18:35:58 +0100

This presentation corresponds to: our paper explores a new risk-hedged approach for re-routing air traffic around forecast convective weather. In this work, flying through a more likely weather instantiation is considered to pose a higher level of risk. Current operational practice strategically plans re-routes to avoid only the most likely (highest risk) weather instantiation, and then tactically makes any necessary adjustments as the weather evolves. The risk-hedged approach strategically plans re-routes by minimizing the risk-adjusted path length, incorporating multiple possible weather instantiations with associated likelihoods (risks). The resulting model is transparent and is readily analyzed for realism and treated with well-understood shortest-path algorithms. Risk-hedged re-routes are computed for some example weather instantiations. The main result is that in some scenarios, relative to an operational-practice proxy solution, the risk-hedged solution provides the benefits of lower risk as well as shorter path length. In other scenarios, the benefits of the risk-hedged solution are ambiguous, because the solution is characterized by a tradeoff between risk and path length. The risk-hedged solution can be executed in those scenarios where it provides a clear benefit over current operational practice.

The MIRI Medium Resolution Spectrometer calibration pipeline

Scipedia content — Wed, 03 Feb 2021 18:28:05 +0100

The Mid-Infrared Instrument (MIRI) Medium Resolution Spectrometer (MRS) is the only mid-IR Integral Field Spectrometer on board James Webb Space Telescope. The complexity of the MRS requires a very specialized pipeline, with some specific steps not present in other pipelines of JWST instruments, such as fringe corrections and wavelength offsets, with different algorithms for point source or extended source data. The MRS pipeline has also two different variants: the baseline pipeline, optimized for most foreseen science cases, and the optimal pipeline, where extra steps will be needed for specific science cases. This paper provides a comprehensive description of the MRS Calibration Pipeline from uncalibrated slope images to final scientific products, with brief descriptions of its algorithms, input and output data, and the accessory data and calibration data products necessary to run the pipeline.

Comment: 10 pages, 8 figure

Fast CNN surveillance pipeline for fine-grained vessel classification and detection in maritime scenarios

Scipedia content — Wed, 03 Feb 2021 18:24:51 +0100

Deep convolutional neural networks (CNNs) have proven very effective for many vision benchmarks in object detection and classification tasks. However, the computational complexity and object resolution requirements of CNNs limit their applicability in wide-view video surveillance settings where objects are small. This paper presents a CNN surveillance pipeline for vessel localization and classification in maritime video. The proposed pipeline is build upon the GPU implementation of Fast-R-CNN with three main steps:(1) Vessel filtering and regions proposal using low-cost weak object detectors based on hand-engineered features. (2) Deep CNN features of the candidates regions are computed with one feed-forward pass from the high-level layer of a fine-tuned VGG16 network. (3) Fine-grained classification is performed using CNN features and a support vector machine classifier with linear kernel for object verification. The performance of the proposed pipeline is compared with other popular CNN architectures with respect to detection accuracy and evaluation speed. The proposed approach mAP of 61.10% was the comparable with Fast-R-CNN but with a 10× speed up (on the order of Faster-R-CNN) on the new Annapolis Maritime Surveillance Dataset.

Scour below marine pipelines due to random waves on mild slopes

Scipedia content — Wed, 03 Feb 2021 18:13:11 +0100

This paper provides a practical stochastic method by which the maximum equilibrium scour depth beneath a marine pipeline exposed to random waves on mild slopes can be derived. The approach is based on assuming the waves to be a stationary narrow-band random process, adopting the Battjes and Groenendijk (2000) wave height distribution for mild slopes including the effect of breaking waves, and using the empirical formulas for the scour depth on the horizontal seabed by Sumer and Fredsoe (1996). Results will be presented and discussed by varying the seabed slope and water depth. An approximate method is also proposed, and comparisons are made with the present stochastic method. Generally, it appears that the approximate method can replace the stochastic method.

An automated methodology for converting OSM data into a Land Use/Cover map

Scipedia content — Wed, 03 Feb 2021 18:07:10 +0100

Land Use/Land Cover Maps (LULCM), fundamental for many areas of application, are usually generated through the classification of satellite imagery. However, their creation is time consuming and therefore updated LULCM are seldom available. The OpenStreetMap (OSM) collaborative project collects a rich set of vector data provided by volunteers at a global scale. It has already been shown that OSM data may be converted into LULCM, but data quality issues in OSM raise some challenges for this conversion, such as overlapping features that should be assigned to different classes. Thus, the creation of LULCM using OSM requires a solution for handling these inconsistencies. In this article an automated methodology is proposed using rules of decision and spatial analysis in a GIS environment to convert OSM features into LULCM, which automatically solves the inconsistencies mentioned above. The methodology is applied to two areas in Europe and the results are compared to available LULCM.

Investigation of scour onset under seabed pipelines with geometric irregularities

Scipedia content — Wed, 03 Feb 2021 18:06:00 +0100

Based on previous studies, it is well understood that the hydrodynamic pressure difference across the pipeline is responsible for initiation of piping and the onset of scour. However, the influence of geometric irregularities such as field joints on the onset of scour has not previously been investigated. This new study has been stimulated by field observations of subsea pipelines that have indicated that scour holes tend to occur at field joint locations. This paper summarizes a series of experimental results using The University of Western Australia’s (UWA)’s unique O-tube test facilities investigating onset of scour underneath scaled model pipelines with a field joint in steady currents. The results of this work are benchmarked against experimental tests and published results for prismatic / uniform pipes. It is demonstrated that periodic geometric irregularities such as field joints have a significant influence on the onset of scour underneath a pipeline. KEY WORDS: Scour, piping, subsea pipeline, field joint, anode, STABLEpipe JIP.

Methods for Determining Aircraft Surface State at Lesser-Equipped Airports

Scipedia content — Wed, 03 Feb 2021 18:04:23 +0100

Tactical departure scheduling within a terminal airspace must accommodate a wide spectrum of surveillance and communication capabilities at multiple airports. The success of such a scheduler is highly dependent upon the knowledge of a departure's state while it is still on the surface. Airports within a common Terminal RAdar CONtrol (TRACON) airspace possess varying levels of surface surveillance infrastructure which directly impacts uncertainties in wheels-off times. Large airports have access to surface surveillance data, which is shared with the TRACON, while lesser-equipped airports still rely solely on controllers in Air Traffic Control Towers (Towers). Coordination between TRACON and Towers can be greatly enhanced when the TRACON controller has access to the surface surveillance and the associated decision-support tools at well-equipped airports. Similar coordination at lesser-equipped airports is still based on verbal communications. This paper investigates possible methods to reduce the uncertainty in wheels-off time predictions at the lesser-equipped airports through the novel use of Over-the-Air (OTA) data transmissions. We also discuss the methods and equipment used to collect sample data at lesser-equipped airports within a large US TRACON, as well as the data evaluation to determine if meaningful information can be extracted from it.

Exploiting Fitness Apps for Sustainable Mobility - Challenges Deploying the GoEco! App

Scipedia content — Wed, 03 Feb 2021 17:58:31 +0100

The large interest in analyzing one’s own fitness led to the development of more and more powerful smartphone applications. Most are capable of tracking a user’s position and mode of locomotion, data that do not only reflect personal health, but also mobility choices. A large field of research is concerned with mobility analysis and planning for a variety of reasons, including sustainable transport. Collecting data on mobility behavior using fitness tracker apps is a tempting choice, because they include many of the desired functions, most people own a smartphone and installing a fitness tracker is quick and convenient. However, as their original focus is on measuring fitness behavior, there are a number of difficulties in their usage for mobility tracking. In this paper we denote the various challenges we faced when deploying GoEco! Tracker (an app using the Moves fitness tracker to collect mobility measurements), and provide an analysis on how to best overcome them. Finally, we summarize findings after one month of large scale testing with a few hundred users within the GoEco! living lab performed in Switzerland.

A Multi-Criteria Decision-Making Scheme for Multi-Aircraft Conflict Resolution

Scipedia content — Wed, 03 Feb 2021 17:57:10 +0100

Multi-Aircraft Conflict Resolution (MACR) is a Multi-Criteria Decision-Making (MCDM) problem, which involves multiple stakeholders (airline, air traffic controller, and aircraft) with competing and incommensurable objectives. This paper proposes a two-step MCDM scheme to the solution of MACR. In the first step, a second order cone program is adopted to generate a set of candidate resolution strategies with different minimum separations between trajectories. Each candidate strategy is then evaluated via three criteria modeling the interests of the stakeholders. In the second step, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) approach is used to determine the best strategy that realizes an adequate tradeoff among the competing interests while coping with their incommensurability. Some numerical results are presented to show the efficacy of the proposed scheme. Interestingly, the minimum separations associated with the best resolution strategies according to either the interest of the airline or that of the aircraft both differ from the one adopted in the current air traffic control operation.

Optimization of Support Stiffness at a Railway Crossing Panel

Scipedia content — Wed, 03 Feb 2021 17:56:30 +0100

Turnouts are a key element of the railway system. They are also one part of the railway system with the highest number of degradation modes and failures for a number of reasons, including dynamic loads generated from non-linearities in the rail geometry and track support stiffness. It is therefore necessary to optimise the performance of the system in terms of its dynamic behaviour taking into account effects on long-term term damage evolution. The main aim of this study is to optimise the rail-pad stiffness in the crossing panel in order to achieve a decrease in the main indicator for ballast settlement, which is ballast pressure. A three-dimensional vehicle/track interaction model has been established, considering a detailed description of the crossing panel support structure. Genetic algorithm has been applied to find the optimum rail-pad combination for a specific case where variation in travelling speed and support conditions have been considered.

Comparative design space exploration of dense and semi-dense SLAM

Scipedia content — Wed, 03 Feb 2021 17:49:38 +0100

SLAM has matured significantly over the past few years, and is beginning to appear in serious commercial products. While new SLAM systems are being proposed at every conference, evaluation is often restricted to qualitative visualizations or accuracy estimation against a ground truth. This is due to the lack of benchmarking methodologies which can holistically and quantitatively evaluate these systems. Further investigation at the level of individual kernels and parameter spaces of SLAM pipelines is non-existent, which is absolutely essential for systems research and integration. We extend the recently introduced SLAMBench framework to allow comparing two state-of-the-art SLAM pipelines, namely KinectFusion and LSD-SLAM, along the metrics of accuracy, energy consumption, and processing frame rate on two different hardware platforms, namely a desktop and an embedded device. We also analyze the pipelines at the level of individual kernels and explore their algorithmic and hardware design spaces for the first time, yielding valuable insights.

Comment: IEEE International Conference on Robotics and Automation 2016

Towards flexible and dependable E/E-architectures for future vehicles

Scipedia content — Wed, 03 Feb 2021 17:39:11 +0100

International audience; Future vehicles are expected to evolve towards enabling fully electric and autonomous driving. However, technically this evolution requires fundamental changes of traditional automotive engineering principles. Specifically, challenges arise for the Electric/Electronic (E/E) vehicle architectures as underlying basis for almost all car functionalities. Higher demands on vehicle system's flexibility and dependability have to be incorporated. We present a novel approach for such future E/E-architectures which considers these requirements as first principles by exploiting runtime adaptation capabilities. Based on use cases, a generic hardware and software architecture is presented which enables technology-independent realization of the provided concepts. Additionally, the incorporated generic failure management and design support are introduced. The approach has been evaluated in different prototype demonstrators, including an e-vehicle prototype compromising enhanced driving functionality. Thereby, the advantages of the concepts for future vehicle E/E-architectural development could be highlighted.

The discovery of “relevant” data-sources in a Smart City environment

Scipedia content — Wed, 03 Feb 2021 17:38:58 +0100

International audience; Among all the Internet of Things (IoT) applications, the Smart City concept has received significant attention in the last few years. The main motivation behind this interest is attributable to population growth and urbanization trend. Cities need, indeed, to be ready to face new challenges - e.g., traffic congestion, wast management, etc. - caused by this new amount of citizens. To address those issues, many IoT solutions have already been proposed and many others are still under investigation; anyway, those initiatives are all based on different standards and protocols, while the Smart City concept requires integration among all the stakeholders. In this paper, we present the VITAL architecture, which aims to integrate Internet-Connected Objects (ICOs) among multiple IoT platforms and ecosystems. In particular, we introduce the “ICOs and Services Discovery” module, which makes completely transparent, for users, the exploration of data-sources that are appropriate for his/her business context. This mechanism is at the basis of the Cloud of Things paradigm and a key feature as the platform agnostic property is an essential goal for VITAL.

Traffic Flow Forecasting Model Based on Data Mining

Scipedia content — Wed, 03 Feb 2021 17:35:14 +0100

The research and application of Intelligent Transportation System has developed rapidly due to the demand on safe , convenient , comfortable and information-based modern transportation. It is important part of the research of Intelligent Transportation System to study different forms and operation rules on traffic flow and establish rapid, stable and effective traffic flow model. With the development of Intelligent Transportation System, mass traffic flow data have been accumulated in Intelligent Transportation System. More and more researchers have started to analyze the information of traffic flow by use of advanced data-mining technique, and discover hidden transportation mode and regulation amongst the information of traffic flow. Data mining technology provides a powerful analysis and processing function of mass traffic data. This paper analyzes the characteristics of traffic data in intelligent transportation system, and puts forward the system model and the hierarchical architecture of traffic data mining system.

Super-resolution pipeline for fast adjudication in watchlist screening

Scipedia content — Wed, 03 Feb 2021 17:34:05 +0100

hough still-to-video face recognition is an important function in watchlist screening, state-of-the-art systems often yield limited performance due to camera inter-operability and to variations in capture conditions. Therefore, the visual comparison of faces captured in unconstrained low-quality videos against a matching high-quality reference facial still image captured under controlled conditions is required in many surveillance applications to limit the number of costly false matches. To improve the visual appearance of faces captured in videos, this paper presents a new super-resolution (SR) pipeline that is suitable for fast adjudication of face-matches produced by an automated system. In this pipeline, face quality measures are used to rank and select face captures belonging to a facial trajectory, and multi-image SR iteratively enhances the appearance of a super-resolved face image. Face selection is optimized and registered using graphical models. Experiments with the Chokepoint dataset show that the proposed pipeline efficiently produces super-resolved face images by ranking best quality ROIs in a trajectory. To select the best face captures for SR, this pipeline exploits a strong correlation existing between pose and sharpness quality measurements.

Accurate 3D head pose estimation under real-world driving conditions: A pilot study

Scipedia content — Wed, 03 Feb 2021 17:32:27 +0100

Reliable and accurate car driver head pose estimation is an important function for the next generation of Advanced Driver Assistance Systems that need to consider the driver state in their analysis. For optimal performance, head pose estimation needs to be non-invasive, calibration-free and accurate for varying driving and illumination conditions. In this pilot study we investigate a 3D head pose estimation system that automatically fits a statistical 3D face model to measurements of a driver's face, acquired with a low-cost depth sensor on challenging real-world data. We evaluate the results of our sensor-independent, driver-adaptive approach to those of a state-of-the-art camera-based 2D face tracking system as well as a non-adaptive 3D model relative to own ground-truth data, and compare to other 3D benchmarks. We find large accuracy benefits of the adaptive 3D approach. Our system shows a median error of 5.99 mm for position and 2.12° for rotation while delivering a full 6-DOF pose with very little degradation from strong illumination changes or out-of-plane rotations of more than 50°. In terms of accuracy, 95% of all our results have a position error of less than 9.50 mm, and a rotation error of less than 4.41°. Compared to the 2D method, this represents a 59.7% reduction of the 95% rotation accuracy threshold, and a 56.1% reduction of the median rotation error.

Ways to Increase Population Mobility through the Transition to Sustainable Transport

Scipedia content — Wed, 03 Feb 2021 17:32:13 +0100

© 2017 The Authors. Published by Elsevier Ltd. Ways to increase sustainability of the city transport system and, particularly, measures to promote safe public transport and non-motorized means of transport are considered in the article. Analysis of the existing positive experience shows that complex decisions for a sustainable development of the urban transport system are necessary. Technical and organizational ways to increase sustainability and safety of the transport system are studied. The results of solution for separate tasks, which are aimed to meet the goal, are presented: they include definition of transport preferences for the citizens of Naberezhnye Chelny and a model of an adaptive smart-bicycle. It is shown that the reasonable combination of public transport and non-motorized transport systems for strategic and operational management will help to enhance efficiency and safety of transport system.

Practical Way Halting by Speculatively Accessing Halt Tags

Scipedia content — Wed, 03 Feb 2021 17:23:31 +0100

Conventional set-associative data cache accesses waste energy since tag and data arrays of several ways are simultaneously accessed to sustain pipeline speed. Different access techniques to avoid activating all cache ways have been previously proposed in an effort to reduce energy usage. However, a problem that many of these access techniques have in common is that they need to access different cache memory portions in a sequential manner, which is difficult to support with standard synchronous SRAM memory.We propose the speculative halt-tag access (SHA) approach, which accesses low-order tag bits, i.e., the halt tag, in the address generation stage instead of the SRAM access stage to eliminate accesses to cache ways that cannot possibly contain the data. The key feature of our SHA approach is that it determines which tag and data arrays need to be accessed early enough for conventional SRAMs to be used. We evaluate the SHA approach using a 65-nm processor implementation running MiBench benchmarks and find that it on average reduces data access energy by 25.6%.

From Discourse Representation Structure to Event Semantics: A Simple Conversion?

Scipedia content — Wed, 03 Feb 2021 17:19:17 +0100

Many applications in Natural Language Processing require a semantic analysis of sentences in terms of truth-conditional representations, often with specific desiderata in terms of which information needs to be included in the semantic analysis. However, there are only very few tools that allow such an analysis. We investigate the representations of an automatic analysis pipeline of the C&C parser and Boxer to determine whether Boxer's analyses in form of Discourse Representation Structure can be successfully converted into a more surface oriented event semantic representation, which will serve as input for a fusion algorithm for fusing hard and soft information. We use a data set of synthetic counter intelligence messages for our investigation. We provide a basic pipeline for conversion and subsequently discuss areas in which ambiguities and differences between the semantic representations present challenges in the conversion process.

Initial Assessment of the Impact of Modern Taxiing Techniques on Airport Ground Control

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

International audience; Project Modern Taxiing (MoTa) studies the impact of future taxiing technologies such as Datalink and autonomous taxiing tugs on airport taxiing operations and air traffic controller workload. Seven air traffic controllers were asked to manage ground traffic in two scenarios that imposed medium and high levels of workload with three different degrees of automated technology assistance: paper strips; Datalink and path suggestion; Datalink, path suggestion, and tugs. Initial results indicate that participants were able to manage more traffic when using either just the interface or interface and tugs, but the inclusion of tugs also resulted in an increase in self-reported workload. Participants were divided on technology acceptance with no one rejecting completely the new technology.

Route networks within the air transport system:A comparative study of two European low-cost airlines using network metrics

Scipedia content — Wed, 03 Feb 2021 17:11:00 +0100

This paper presents a comparative analysis of the route networks of two European low-cost airlines in 2015. A case study is presented which highlights the key differences and similarities of their route network characteristics that they operate, aimed toward improving understanding of the current Air Transport System (ATS) for modeling and simulation purposes.

How to interact with a Cybercar? – Attitudes and expectations on the interaction and communication with fully automated vehicles

Scipedia content — Wed, 03 Feb 2021 17:10:19 +0100

In this paper we are addressing the question how driverless vehicles (Cybercars) driving fully automated could interact with surrounding traffic participants. Cybercars present a new mobility approach and are dedicated to provide a new way of transportation for short to medium distances especially in city centres or on campus areas. As Cybercars are operated in non-dedicated environments the interaction with other either motorized or non-motorized, vulnerable road users becomes a crucial factor. We conducted a face-to-face interview study (N=14, structured interview, 25-53 minutes) at the German Aerospace Center (DLR) to investigate the expectations people have towards the concept of Cybercar and the interaction with Cybercars. On the one hand, results show that people prefer quite conservative interaction elements as known from conventional vehicles such as braking lights or indicators to predict the future behaviour of Cybercars. On the other hand, 53% of the participants wish additional information like a stopping announcement of the Cybercar or whether pedestrians were detected or not. Based on the results we discuss how Cybercars could be designed to optimize the interaction and communication with other traffic participants.