506 research outputs found

    Fuzzy cellular model for on-line traffic simulation

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    This paper introduces a fuzzy cellular model of road traffic that was intended for on-line applications in traffic control. The presented model uses fuzzy sets theory to deal with uncertainty of both input data and simulation results. Vehicles are modelled individually, thus various classes of them can be taken into consideration. In the proposed approach, all parameters of vehicles are described by means of fuzzy numbers. The model was implemented in a simulation of vehicles queue discharge process. Changes of the queue length were analysed in this experiment and compared to the results of NaSch cellular automata model.Comment: The original publication is available at http://www.springerlink.co

    Security in Vehicles With IoT by Prioritization Rules, Vehicle Certificates, and Trust Management

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    [EN] The Internet of Vehicles (IoV) provides new opportunities for the coordination of vehicles for enhancing safety and transportation performance. Vehicles can be coordinated for avoiding collisions by communicating their positions when near to each other, in which the information flow is indexed by their geographical positions or the ones in road maps. Vehicles can also be coordinated to ameliorate traffic jams by sharing their locations and destinations. Vehicles can apply optimization algorithms to reduce the overuse of certain streets without excessively enlarging the paths. In this way, traveling time can be reduced. However, IoV also brings security challenges, such as keeping safe from virtual hijacking. In particular, vehicles should detect and isolate the hijacked vehicles ignoring their communications. The current work presents a technique for enhancing security by applying certain prioritization rules, using digital certificates, and applying trust and reputation policies for detecting hijacked vehicles. We tested the proposed approach with a novel agent-based simulator about security in Internet of Things (IoT) for vehicle-to-vehicle communications. The experiments focused on the scenario of avoidance of collisions with hijacked vehicles misinforming other vehicles. The results showed that the current approach increased the average speed of vehicles with a 64.2% when these are giving way to other vehicles in a crossing by means of IoT.This work was supported by Harvard University (stay funded by T49_17R), University of Zaragoza (JIUZ-2017-TEC-03), Foundation Bancaria Ibercaja, Foundation CAI (IT1/18), University Foundation Antonio Gargallo (call 2017), and "Ministerio de Economia y Competitividad" in the "Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia, Subprograma Estatal de Generacion de Conocimiento" (TIN2017-84802-C2-1-P).García-Magariño, I.; Sendra, S.; Lacuesta, R.; Lloret, J. (2019). Security in Vehicles With IoT by Prioritization Rules, Vehicle Certificates, and Trust Management. IEEE Internet of Things. 6(4):5927-5934. https://doi.org/10.1109/JIOT.2018.2871255S592759346

    Trail formation based on directed pheromone deposition

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    We propose an Individual-Based Model of ant-trail formation. The ants are modeled as self-propelled particles which deposit directed pheromones and interact with them through alignment interaction. The directed pheromones intend to model pieces of trails, while the alignment interaction translates the tendency for an ant to follow a trail when it meets it. Thanks to adequate quantitative descriptors of the trail patterns, the existence of a phase transition as the ant-pheromone interaction frequency is increased can be evidenced. Finally, we propose both kinetic and fluid descriptions of this model and analyze the capabilities of the fluid model to develop trail patterns. We observe that the development of patterns by fluid models require extra trail amplification mechanisms that are not needed at the Individual-Based Model level

    OPTIMIZATION OF TERMINAL LAYOUTS: AN ANALYTICAL AND SIMULATIVE APPROACH BASED ON GENETIC ALGORITHMS

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    2012/2013Every day millions of pedestrian move with different needs and objectives through spaces each of them with its functional specifications. An accurate design or revisiting of transport terminals, as for example railway stations, underway stations, airports, as well as complex buildings, open spaces and a deep analysis of public events with relevant pedestrian flows, would improve its usability at users benefit. To reach this goal is necessary a careful integration among architecture, engineering needs and transport disciplines, that, starting from the study of users behavior and pedestrian dynamics, provides the fundamental elements to be considered during design stage to ensure a major level of service. In literature nothing much is known about the optimal dimension of pedestrian transportation terminals. The aim of this study is to develop a methodology to size the functional terminal layouts, by the integration of analytical and simulative models submitted to generic algorithms, taking into account the dynamics and flows generated inside the terminals. In order to obviate the lack of requisite data for models calibration, validation and verification, as well as testing the process developed, an algorithm for data acquisition has been elaborated. It has a dedicated graphic interface, which allows to reveal the pedestrian dynamics and consequently to generate database; with these data is possible to obtain statistical and behavioral indicators about pedestrians detected. The use of analytical models, both to define the sizing of facilities inside the terminals and to model the user behavior during their paths, allows to define an objective function able to represent the performances of the terminal functional layout. Defined the dimensional ranges of each functional element inside the layout according a specific Level of Service, performed a design of experiments methodology and applied genetic algorithms to minimize the objective function, it is possible to obtain a set of optimal solutions for the terminal configuration sizing, in coherence with flows and dynamics generated inside the terminals itself. A further simulative approach, based on the application of the social force algorithm, allows, through quantitative and qualitative parameters, to identify the best solution(s) inside the domain previously identified with genetic algorithm application. Starting from the motivation that inspired this work, analyzed the existing literature and the main methods for data acquisition, it will be introduced the algorithm for the automatic acquisition of data and pedestrian database generation. The application of this tool will be illustrated in order to manifest the potentiality of the instrument same. Subsequently introduced the tool developed for the definition of the characteristic elements sizing and the model chosen for the correct estimation of pedestrian travel times, it will be explored the structure of the objective function aimed to identify the right trade-off between infrastructure and pedestrian costs. Finally, the application of genetic algorithms, resulting in the identification of Pareto front, generates the domain of optimal solutions to sift through the simulation approach. The developed methodology reveals a flexible and simple instruments, but, at the same time, accurate in the resolution of the problems for which has been structured. The potential of the developed methodology is highlighted in the course of the work thanks to a case of study.Ogni giorno milioni di pedoni si muovono con esigenze ed obbiettivi diversi in contesti differenti, ognuno dei quali con le sue caratteristiche tecniche funzionali. Un’attenta progettazione o rivisitazione dei terminali di trasporto, quali stazioni ferroviarie, metropolitane, aeroporti, così come degli edifici complessi, degli spazi aperti ed una corretta disamina degli eventi pubblici con flussi pedonali rilevanti, consentirebbe di migliorarne la fruibilità a beneficio dell’utenza. Per raggiungere tale obiettivo risulta necessaria un’attenta integrazione tra esigenze architettoniche, ingegneristiche e le discipline trasportistiche, le quali, partendo dallo studio comportamentale degli utenti e dalle dinamiche pedonali, forniscano gli elementi fondamentali da tenersi in considerazione nella fase di progettazione per garantire un maggiore livello di servizio. Riscontrata in letteratura una carenza di approcci finalizzata alla determinazione del miglior layout funzionale dei terminali, attraverso l’integrazione di modelli analitici e simulativi sottoposti ad algoritmi genetici, è stata sviluppata una metodologia che, coerentemente con le dinamiche e i flussi che all’interno dei terminali stessi si generano, mirasse al dimensionamento ottimo dei terminali di trasporto pedonale. Per ovviare alla mancanza di dati necessari per i processi di calibrazione, validazione e verifica dei modelli così come per testare il metodo sviluppato è stato innanzitutto elaborato un algoritmo per l’acquisizione di dati, con interfaccia grafica dedicata, che consente di rilevare le dinamiche pedonali, generare database e conseguentemente ricavare dati statistici e comportamentali dei pedoni. L’utilizzo di modelli analitici, sia per l’identificazione dei range dimensionali degli elementi caratteristici presenti all’interno dei terminali che per la modellizzazione del comportamento degli utenti, permette di definire una funzione obbiettivo che rappresenti le performances dei layout funzionali dei terminali. Attraverso design of experiments calibrati sui range dimensionali dei singoli elementi funzionali presenti all’interno dei terminali e la successiva applicazione degli algoritmi genetici finalizzati alla minimizzazione della funzione obiettivo, è possibile definire un insieme di soluzioni ottime per il dimensionamento dei terminali, in coerenza con i flussi e le dinamiche che in esso si generano. Un’ulteriore approccio simulativo, basato sull’applicazione dell’algoritmo delle forze sociali, consente, attraverso la valutazione di parametri quantitativi e qualitativi, di identificare la/e miglior soluzione/i all’interno del dominio di soluzioni precedentemente identificate con l’applicazione degli algoritmi genetici. A partire dall’esplicitazione delle motivazioni che hanno alimentato questo lavoro, analizzata la letteratura esistente e le principali metodologie per l’acquisizione dati, verrà introdotto l’algoritmo per l’acquisizione automatica dei dati pedonali e la generazione di database contenenti i profili degli utenti rilevati. A seguire troverà spazio l’applicazione di questo strumento per manifestarne le potenzialità. Successivamente, introdotto il tool sviluppato per la definizione dei range dimensionali degli elementi caratteristici e il modello scelto per la corretta stima dei tempi di percorrenza pedonali, verrà esplorata la strutturazione della funzione obiettivo finalizzata alla ricerca del giusto trade off tra costi infrastrutturali e pedonali. Infine, l’applicazione degli algoritmi genetici, risultanti nell’identificazione del fronte paretiano, genererà il dominio di soluzioni ottime da vagliare attraverso l’approccio simulativo. La metodologia sviluppata si è rivelata uno strumento flessibile ed agevole, ma, allo stesso tempo, puntuale nel risolvere i problemi per cui è stata ideata. Le potenzialità della metodologia sviluppata vengono messe in risalto nel corso dell’elaborato grazie ad un caso di studio condotto.XXVI Ciclo198

    Improvements in the acoustical modelling of traffic noise prediction: theoretical and experimental results

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    2009 - 2010Traffic acoustical noise is one of the most important component of the urban environmental pollution in densely populated areas all over the world. A very recent ACI-Censis study [1] on Italian urban areas shows that car is the favorite mean of transportation for 90% of population. In particular, this study shows that during years ranging from 2000 to 2007, the number of circulating vehicles is grown of 14.5%. To this growth did not always correspond an improvement of national street network. This problem can be evidenced by the high growth of the traffic charge on urban, sub-urban and extra-urban roads, with a clear impact on costs, security and environment, even in term of acoustical noise. A similar tendency can be observed in the framework of many european countries. Traffic noise affects areas surrounding roads especially when high traffic load and high speed conditions occur and can lead to a degradation of the quality of life in residential areas. The impact of noise on mental and physical health and on daily activities has been widely documented in the scientific literature [2, 3, 4]. In particular a continuous exposure to acoustical noise may affect sleep and/or conversation, may lead to perception of annoyance, may cause hearing loss, cardiovascular problems etc. As a consequence, during last years, a large number of anti-noise laws, ordinances and regulations were decreed by many national governments and international institutions. Looking to Italy, it is the D.P.C.M. 01.03.1991 [5] which regulates noise pollution matters, giving the main acoustical elements definitions such as maximum limit of noise exposure in inner and external environment, acoustic zoning criteria, etc. Then the Framework Law n. 447/1995 has defined a general policy on the noise pollution that has been implemented in different decrees and regulations. Among these, one of the most interesting is the D.M.A. 16.03.1998 ”Noise pollution detection and measurement method” (Tecniche di rilevamento e di misurazione dell’inquinamento acustico) which deals with the vehicular and railway noise detection procedure. Moreover the D.Lgs 194/2005 (Attuazione della direttiva 2002/49/CE relativa alla determinazione e alla gestione del rumore ambientale) establishes the method to set the acoustic indicator for the different kind of noise sources such as vehicular traffic. In this Ph.D. thesis our aim is to improve the current prediction tools for traffic noise prediction in non trivial situations such as traffic lights, traffic jam, intersections etc., accounting some aspects of traffic dynamics by the use of traffic models (TM), i.e. following the leader model and Cellular Automata. This thesis is organized as follows. In the first chapter we briefly discuss the main features of sound and noise propagation. In the second chapter we focus our attention on vehicle noise emission and existing traffic noise models (TNM) while in the third we present a new noise prediction procedure: GERIAN2009. In chapter four some general features of physics of road traffic and transportation are discussed. In the last three chapters we propose an integration of traffic noise model and traffic dynamic model in the ”following the leader” and Cellular Automata (CA) framework, with a particular attention on road’s intersection issue. [edited by author]IX n.s

    Urban Informatics

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    This open access book is the first to systematically introduce the principles of urban informatics and its application to every aspect of the city that involves its functioning, control, management, and future planning. It introduces new models and tools being developed to understand and implement these technologies that enable cities to function more efficiently – to become ‘smart’ and ‘sustainable’. The smart city has quickly emerged as computers have become ever smaller to the point where they can be embedded into the very fabric of the city, as well as being central to new ways in which the population can communicate and act. When cities are wired in this way, they have the potential to become sentient and responsive, generating massive streams of ‘big’ data in real time as well as providing immense opportunities for extracting new forms of urban data through crowdsourcing. This book offers a comprehensive review of the methods that form the core of urban informatics from various kinds of urban remote sensing to new approaches to machine learning and statistical modelling. It provides a detailed technical introduction to the wide array of tools information scientists need to develop the key urban analytics that are fundamental to learning about the smart city, and it outlines ways in which these tools can be used to inform design and policy so that cities can become more efficient with a greater concern for environment and equity

    Urban Informatics

    Get PDF
    This open access book is the first to systematically introduce the principles of urban informatics and its application to every aspect of the city that involves its functioning, control, management, and future planning. It introduces new models and tools being developed to understand and implement these technologies that enable cities to function more efficiently – to become ‘smart’ and ‘sustainable’. The smart city has quickly emerged as computers have become ever smaller to the point where they can be embedded into the very fabric of the city, as well as being central to new ways in which the population can communicate and act. When cities are wired in this way, they have the potential to become sentient and responsive, generating massive streams of ‘big’ data in real time as well as providing immense opportunities for extracting new forms of urban data through crowdsourcing. This book offers a comprehensive review of the methods that form the core of urban informatics from various kinds of urban remote sensing to new approaches to machine learning and statistical modelling. It provides a detailed technical introduction to the wide array of tools information scientists need to develop the key urban analytics that are fundamental to learning about the smart city, and it outlines ways in which these tools can be used to inform design and policy so that cities can become more efficient with a greater concern for environment and equity

    A systematic literature review on the relationship between autonomous vehicle technology and traffic-related mortality.

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    학위논문(석사) -- 서울대학교대학원 : 행정대학원 글로벌행정전공, 2023. 2. 최태현.The society is anticipated to gain a lot from Autonomous Vehicles (AV), such as improved traffic flow and a decrease in accidents. They heavily rely on improvements in various Artificial Intelligence (AI) processes and strategies. Though some researchers in this field believe AV is the key to enhancing safety, others believe AV creates new challenges when it comes to ensuring the security of these new technology/systems and applications. The article conducts a systematic literature review on the relationship between autonomous vehicle technology and traffic-related mortality. According to inclusion and exclusion criteria, articles from EBSCO, ProQuest, IEEE Explorer, Web of Science were chosen, and they were then sorted. The findings reveal that the most of these publications have been published in advanced transport-related journals. Future improvements in the automobile industry and the development of intelligent transportation systems could help reduce the number of fatal traffic accidents. Technologies for autonomous cars provide effective ways to enhance the driving experience and reduce the number of traffic accidents. A multitude of driving-related problems, such as crashes, traffic, energy usage, and environmental pollution, will be helped by autonomous driving technology. More research is needed for the significant majority of the studies that were assessed. They need to be expanded so that they can be tested in real-world or computer-simulated scenarios, in better and more realistic scenarios, with better and more data, and in experimental designs where the results of the proposed strategy are compared to those of industry standards and competing strategies. Therefore, additional study with improved methods is needed. Another major area that requires additional research is the moral and ethical choices made by AVs. Government, policy makers, manufacturers, and designers all need to do many actions in order to deploy autonomous vehicles on the road effectively. The government should develop laws, rules, and an action plan in particular. It is important to create more effective programs that might encourage the adoption of emerging technology in transportation systems, such as driverless vehicles. In this regard, user perception becomes essential since it may inform designers about current issues and observations made by people. The perceptions of autonomous car users in developing countries like Azerbaijan haven't been thoroughly studied up to this point. The manufacturer has to fix the system flaw and needs a good data set for efficient operation. In the not-too-distant future, the widespread use of highly automated vehicles (AVs) may open up intriguing new possibilities for resolving persistent issues in current safety-related research. Further research is required to better understand and quantify the significant policy implications of Avs, taking into consideration factors like penetration rate, public adoption, technological advancements, traffic patterns, and business models. It only needs to take into account peer-reviewed, full-text journal papers for the investigation, but it's clear that a larger database and more documents would provide more results and a more thorough analysis.자율주행차(AV)를 통해 교통 흐름이 개선되고 사고가 줄어드는 등 사회가 얻는 것이 많을 것으로 예상된다. 그들은 다양한 인공지능(AI) 프로세스와 전략의 개선에 크게 의존한다. 이 분야의 일부 연구자들은 AV가 안전성을 향상시키는 열쇠라고 믿지만, 다른 연구자들은 AV가 이러한 새로운 기술/시스템 및 애플리케이션의 보안을 보장하는 것과 관련하여 새로운 문제를 야기한다고 믿는다. 이 논문은 자율주행차 기술과 교통 관련 사망률 사이의 관계에 대한 체계적인 문헌 검토를 수행한다. 포함 및 제외 기준에 따라 EBSCO, ProQuest, IEEE Explorer 및 Web of Science의 기사를 선택하고 분류했다.연구 결과는 이러한 출판물의 대부분이 고급 운송 관련 저널에 게재되었음을 보여준다. 미래의 자동차 산업의 개선과 지능형 교통 시스템의 개발은 치명적인 교통 사고의 수를 줄이는 데 도움이 될 수 있다. 자율주행 자동차 기술은 운전 경험을 향상시키고 교통 사고의 수를 줄일 수 있는 효과적인 방법을 제공한다. 충돌, 교통, 에너지 사용, 환경 오염과 같은 수많은 운전 관련 문제들은 자율 주행 기술에 의해 도움을 받을 것이다. 평가된 대부분의 연구에 대해 더 많은 연구가 필요하다. 실제 또는 컴퓨터 시뮬레이션 시나리오, 더 좋고 현실적인 시나리오, 더 좋고 더 많은 데이터, 그리고 제안된 전략 결과가 산업 표준 및 경쟁 전략의 결과와 비교되는 실험 설계에서 테스트될 수 있도록 확장되어야 한다. 따라서 개선된 방법에 대한 추가 연구가 필요하다. 추가 연구가 필요한 또 다른 주요 분야는 AV의 도덕적, 윤리적 선택이다. 정부, 정책 입안자, 제조업체 및 설계자는 모두 자율 주행 차량을 효과적으로 도로에 배치하기 위해 많은 조치를 취해야 한다. 정부는 특히 법, 규칙, 실행 계획을 개발해야 한다. 운전자 없는 차량과 같은 운송 시스템에서 새로운 기술의 채택을 장려할 수 있는 보다 효과적인 프로그램을 만드는 것이 중요하다. 이와 관련하여, 설계자에게 현재 이슈와 사람에 의한 관찰을 알려줄 수 있기 때문에 사용자 인식이 필수적이 된다.제조업체는 시스템 결함을 수정해야 하며 효율적인 작동을 위해 좋은 데이터 세트가 필요하다. 멀지 않은 미래에, 고도로 자동화된 차량(AV)의 광범위한 사용은 현재의 안전 관련 연구에서 지속적인 문제를 해결하기 위한 흥미로운 새로운 가능성을 열어줄 수 있다. 보급률, 공공 채택, 기술 발전, 교통 패턴 및 비즈니스 모델과 같은 요소를 고려하여 Avs의 중요한 정책 영향을 더 잘 이해하고 정량화하기 위한 추가 연구가 필요하다. 조사를 위해 동료 검토를 거친 전문 저널 논문만 고려하면 되지만, 데이터베이스가 커지고 문서가 많아지면 더 많은 결과와 더 철저한 분석이 제공될 것이 분명하다.Abstract 3 Table of Contents 6 List of Tables 7 List of Figures 7 List of Appendix 7 CHAPTER 1: INTRODUCTION 8 1.1. Background 8 1.2. Purpose of Research 13 CHAPTER 2: AUTONOMOUS VEHICLES 21 2.1. Intelligent Traffic Systems 21 2.2. System Architecture for Autonomous Vehicles 22 2.3. Key components in AV classification 27 CHAPTER 3: METHODOLOGY AND DATA COLLECTION PROCEDURE 35 CHAPTER 4: FINDINGS AND DISCUSSION 39 4.1. RQ1: Do autonomous vehicles reduce traffic-related deaths 40 4.2. RQ2: Are there any challenges to using autonomous vehicles 63 4.3. RQ3: As a developing country, how effective is the use of autonomous vehicles for reducing traffic mortality 72 CHAPTER 5: CONCLUSION 76 5.1. Summary 76 5.2. Implications and Recommendations 80 5.3. Limitation of the study 91 Bibliography 93 List of Tables Table 1: The 6 Levels of Autonomous Vehicles Table 2: Search strings Table 3: Inclusion and exclusion criteria List of Figures Figure 1: Traffic Death Comparison with Europe Figure 2: Research strategy and study selection process List of Appendix Appendix 1: List of selected articles석

    Modelling the impact of land subsidence on urban pluvial flooding: a case study of downtown Shanghai, China.

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    This paper presents a numerical analysis of pluvial flooding to evaluate the impact of land subsidence on flood risks in urban contexts using a hydraulic model (FloodMap-HydroInundation2D). The pluvial flood event of August 2011 in Shanghai, China is used for model calibration and simulation. Evolving patterns of inundation (area and depth) are assessed over four time periods (1991, 1996, 2001 and 2011) for the downtown area, given local changes in topography and rates of land subsidence of up to 27mm/yr. The results show that land subsidence can lead to non-linear response of flood characteristics. However, the impact on flood depths is generally minor (<5cm) and limited to areas with lowest-lying topographies because of relatively uniform patterns of subsidence and micro-topographic variations at the local scale. Nonetheless, the modelling approach tested here may be applied to other cities where there are more marked rates of subsidence and/or greater heterogeneity in the depressed urban surface. In these cases, any identified hot-spots of subsidence and focusing of pluvial flooding may be targeted for adaptation interventions
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