Ausgehend von der Feststellung, dass in Deutschland bislang kein quantitatives Verfahren zur Beurteilung der Sicherheit von Bahnübergängen existiert, wurde in der vorliegenden Arbeit ein Vorschlag für ein solches Verfahren entwickelt. Das zugrunde liegende Risikomodell ermöglicht es, aus den Parametern eines einzelnen Bahnübergangs die individuellen Risiken unterschiedlicher Gruppen von Straßenverkehrsteilnehmern sowie das kollektive Risiko des Bahnübergangs abzuschätzen. Zur Bewertung dieser Risiken wurden Vorschläge für Akzeptanzkriterien hergeleitet. Ein weiterer Teil der Untersuchung beschäftigte sich mit der Ermittlung und Bewertung risikoreduzierender Maßnahmen. Das Verfahren entstand auf Basis umfangreicher Literaturstudien, qualifizierter Schätzungen und ergänzender empirischer Untersuchungen. Der Neuigkeitswert des Modells – auch vor dem Hintergrund der aus dem Ausland bekannten Ansätze – besteht in der differenzierten Betrachtung nicht nur des einzelnen Bahnübergangs, sondern auch der einzelnen Verkehrsarten und insbesondere der einzelnen zum Bahnübergang hin- und vom Bahnübergang wegführenden Verkehrsströme. Dadurch wird der Erkenntnis Rechnung getragen, dass sich die spezifischen Eigenschaften der Straßenverkehrsteilnehmer sowie der von ihnen genutzten Zu- und Abflusswege auf die Sicherheit auswirken können. Aus den erzielten Erkenntnissen wurden Empfehlungen zur Weiterentwicklung der Regelwerke abgeleitet. Hierzu gehört die Forderung nach einer stärkeren Risikoorientierung der Gestaltungsregeln, die insbesondere die aufgezeigten Einflussfaktoren berücksichtigen müssen.

Orientador: Michel Daoud Yacoub / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-06T02:52:07Z (GMT). No. of bitstreams: 1 Fraidenraich_Gustavo_M.pdf: 1838522 bytes, checksum: 4099008fa7bbc89eb2642a891bd64509 (MD5) Previous issue date: 2006 / Resumo: Neste trabalho, uma nova distribuição de probabilidade amplamente geral, a distribuição a-?-?-µ, é proposta. Esta distribuição contempla como casos particulares várias outras distribuições conhecidas na literatura, tais como Rayleigh, Rice, Nakagami-m, Hoyt, Weibull, a-? (Gamma Generalizada) ?-µ e ?-µ. Por conta de sua generalidade, todos os mais importantes ambientes de desvanecimento de curto prazo são modelados por esta distribuição. Além de prover a função densidade de probabilidade para o modelo a-?-?-µ, os momentos e a função cumulativa de probabilidade também são encontrados. Este modelo geral é então especializado para quatro casos particulares, para os quais distribuições mais simples, mas ainda gerais, são encontradas: a a-?-µ, a-?-µ, ?-? Simétrica e ?-? Assimétrica. Para esses casos, estimadores práticos baseados nos momentos são deduzidos. A aplicabilidade destes estimadores é verificada utilizando medidas de campo realizadas na Unicamp com um equipamento construído no laboratório Wisstek para este ?m. Em seguida, estatísticas de ordem superior, em particular a taxa de cruzamento de nível e a duração média de desvanecimento, são encontradas de forma exata para os ambientes Hoyt e Weibull em sistemas de diversidade com M ramos desbalanceados, não idênticos e independentes utilizando os combinadores por ganho igual e por razão máxima. Neste trabalho, o resultado geral é validado através de simulações e redução das expressões gerais para casos em que os resultados já são conhecidos. Além disso, para alguns destes casos particulares, as expressões gerais são simplificadas e reduzidas a fórmulas fechadas. Estendendo esse último campo de investigação e seguindo um pioneiro trabalho da literatura, o qual abordou o caso Rayleigh, a taxa de cruzamento de nível e a duração média de desvanecimento são obtidas para ambientes Hoyt com dois ramos correlacionados. Nesta investigação, reformula-se a metodologia da literatura e obtém-se um procedimento geral para a análise da taxa de cruzamento de nível e duração média de desvanecimento em ambientes com apenas um cluster, com aplicação direta aos canais Rice, Weibull, ?-? Simétrica e ?-? Assimétrica. Finalmente, este trabalho propõe, de forma precursora, uma distribuição para a fase do canal Nakagami-m. Ao contrário do que, convencionalmente e por simplicidade, se postulava, a distribuição de fase é não uniforme e dependente de m, o que torna o modelo compatível com aqueles aproximados por Nakagami-m, nomeadamente Hoyt e Rice / Abstract: In this work, a new, very general probability density function, the a-?-?-µ distribution, is proposed. This distribution comprises, as particular cases, several other well known distributions such as Rayleigh, Rice, Nakagami-m, Hoyt, Weibull, a-? (Generalized Gamma) ?-µ and ?-µ. Due to its generality, all of the most important short fading environments can be modeled by this distribution. Besides providing the probability density function for the a-?-?-µ model, the moments and the cumulative distribution function are also found. This general model is then specialized into four particular cases, for which new simpler, though still general, distributions, are found: the a-?-µ, a-?-µ, Symmetrical ?-?, and Asymmetrical ?-?. For these cases, practical moment-based estimators are derived. The applicability of these estimators is verified using field measurements obtained through an experiment conducted at the University of Campinas (Unicamp) with an equipment specially built for this end in the Wisstek laboratory. Higher order statistics, more specifically the level crossing rates and average fade durations, are then obtained in an exact form for the Hoyt and Weibull fading environments. The results are applicable to M unbalanced, non-identical, and independent channels using equal gain and maximal ratio combining techniques. The general results are thoroughly validated by means of simulation and also by reducing the general solution to some particular cases for which the solutions are known. Moreover, new closed form expressions are also achieved for some of these particular cases. Extending this field of investigation and following a pioneering work in the literature, which approached the Rayleigh case, the level crossing rate and average fade duration are obtained considering two correlated, unbalanced, and non-identical branches in a Hoyt fading environment. In this investigation, the methodology found in the literature is reformulated and generalized so as to comprise several other cases. The general procedure developed for this analysis can now be applied to other fading environment for which one cluster of mutipaths exists, i.e., Rice, Weibull, Symmetrical ?-?, and Asymmetrical ?-?. Finally, this work proposes, in a pioneering way, the phase distribution for the Nakagami-m channel. Contrary to what conventionally, and for simplicity, was usually postulated, the phase distribution is non-uniform and dependent on m, rendering this model compatible with those approximated by Nakagami-m, namely Hoyt and Rice / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

The aim of the diploma thesis is design of the Vsetín railway station reconstruction according to the current operation and the requirements for persons with reduced mobility. The two new double face island platforms with the height of 550 mm above the top of rail is designed. Further, the speed in passing running lines and also the curves in front of Polanka throat of the station is increased.

The aim of thesis is to design a reconstruction of railway station Studenec, so it would suit current and future traffic. The main purpose of reconstruction is increasing the line speed. The reconstruction reflects on requirements for persons with reduced mobility under applicable legislation.

This thesis focuses on the reconstruction design of Uničov railway station. The aim was to create a solution which would satisfy both traffic and passenger requirements. The design puts an emphasis on a compliance with applicable laws and standards, simplicity and usefulness. New constructions were designed for maximum safety. Railway station accessibility for disabled persons played an important role in the design. In comparison with the original state, the permissible line speed was increased and new platforms and drainage system were designed.

The master’s thesis deals with upgrading of the Holešov railway station. The goal is to design a solution suitable for the capacity for a current traffic and valid legislation. Required are two boarding edges in the length of 130 meters enabling access to persons with reduced mobility and orientation, adjustments or renovation of a station throat triggered by insertion of platforms, maximizing line speed and design of railway superstructure and substructure design including drainage.

Level crossings are a dangerous part of railways, causing several deaths every year. While the safest solution is to remove crossings altogether using bridges or tunnels, this is complicated and cannot be done on a large scale. Many level crossings will therefore continue to exist. To enhance the safety of those crossings, they are equipped with automatic barriers, preventing crossing traffic from entering the track when trains are approaching. Partly due to outdated systems, the Swedish Transport Administration procured a fully integrated and automatic level crossing system aimed to make safety systems more cost efficient. However, it has been stated that the cost of such a system is still high in relation to the number of crossings in the Swedish railway infrastructure. To enhance the scalability of safety systems in level crossings, this research aims to explore the potential of modular systems. Applications of the concept within the railway industry are limited. In addition, previous research perceives the power of modular designs differently. This research was conducted as a case study on level crossings in the Swedish railway infrastructure that is managed by the Swedish Transport Administration. Opportunities with modular systems were identified within the three themes of reducing groundwork costs, improving maintenanc eactivities, and enhancing the replaceability of parts. The study proposes that scalability can be increased by a standardised foundational structure, standardised communication protocols, convenient replacements of modules rather than repairs on-site, shared maintenance activities across systems, and customised testing procedures based on the individual requirements of modules. Different conditions, such as being able to oversee the state of inherent modules and regulations regarding data usage, were also determined to be important for a successful implementation. / Plankorsningar är en farlig del av järnvägar som orsakar flera dödsfall varje år. Även om den säkraste lösningen är att bygga bort dessa helt och hållet genom broar och tunnlar, så är detta ofta komplicerat och inte möjligt i många fall. Många plankorsningar kommer därför att finnas kvar. För att säkerställa säkerheten förses dessa med automatiskt fällande bommar, som hindrar korsande trafik att passera spåret när tåg närmar sig. Till följd av bland annat utdaterade system, har Trafikverket upphandlat ett fullt integrerat och automatiskt bomsystem som ska vara mer kostnadseffektivt än tidigare lösningar. Det har däremot konstaterats att kostnaden för ett sådant system fortfarande är hög i relation till antalet korsningar i den svenska järnvägsinfrastrukturen. För att öka skalbarheten av säkerhetssystem i plankorsningar syftar denna forskning till att undersöka potentialen av modulärt designade system. Tidigare studier är oense om möjligheterna med modulsystem. Därutöver är forskning som applicerar konceptet inom järnvägsbranschen begränsad. Denna undersökning utfördes som en fallstudie inom plankorsningar i den svenska järnvägsinfrastrukturen som hanteras av Trafikverket. Möjligheter med modulsystemidentifierades inom de tre temana minskade kostnader för markarbete, förbättratunderhållsarbete, och ökad utbytbarhet av delar. Studien föreslår att skalbarheten kan ökas genom ett standardiserat fundament, standardiserade kommunikationsprotokoll, smidigt utbytbara moduler istället för reparationer i anläggningen, gemensamma underhållsaktiviteter mellan system, och anpassade tester baserat på kraven i enskilda moduler. Samtidigt framträdde vissa villkor, såsom möjligheten att kunna överse tillståndet i de inneboende modulerna och regleringar gällande dataanvändning, som viktiga faktorer för en lyckad implementation.

The present essay set out to investigate the work methodology of closing level crossings and chart the process from the initial need to close the level crossing up to completed closing of level crossing, furthermore; to investigate which factors affect the projects efficiency and progress both in terms of planning and implementation. This essay sets out to answer the following questions: “What is the current way of dealing with closing off level crossings and when would the implementation of a railway plan be useful?” and “How does project-implementation look like when dealing with the project of removal of level crossings in regard to time and cost?”. When it comes to repealing an overpass easement in order to be able to close a level crossing, a railway plan can be established to facilitate such easement measures. Although it does not directly imply "construction of the railway", if it is to be cancelled without support in a railway plan, the conditions of protection in Chapter 5 and Chapter 7 of the FBL must be fully applied. The method used was partly interview and partly study of railway plans and cadastral dossier. Twelve interviews were conducted, of which seven represented the Swedish Transport Agency and five persons who represented the National Land Survey, who were considered to fulfil the response required to answer the questions to an enough extent. There were only a limited number of railway plans which included only the closure of level crossings. However, there were a number of railway plans that dealt with the closure of level crossings, but then in connection with other measures which by law are the construction or rebuilding of railways. The united nations global sustainable objective strive to reach 17 objectives before the year 2030 wereof objective 11 is as follows: “Sustainable cities and societies”, which was considered to be connected with this essays problem formulation. It has emerged from the result that there are both pros and cons of applying railway plan in connection with the closure of level crossings. What can be stated after the implementation of the study is that the Swedish Transport Administration has a desire to implement more railway plans at complicated level crossings and the National Land Survey Office sees certain advantages from a handling perspective to applying a railway plan. / Trafikverket strävar efter att effektivisera, öka kapaciteten och säkra tillgängligheten för landets vägar och järnvägar genom att bland annat ta bort järnvägsövergångar. Ökad kapacitet i form av högre hastigheter ställer högre krav på säkerheten vid järnvägsövergångar och stängning av plankorsningar mellan enskilda vägar och statliga järnvägar är en angelägen åtgärd nationellt. Målet med examensarbetet var att efterforska arbetsmetodiken kring stängning av plankorsningar samt att utreda vilka faktorer som påverkar effektiviteten och framdriften i projekt vid dels planläggningen dels genomförande av åtgärden. De frågeställningar som behandlades i denna uppsats var: ”Hur ser den nuvarande hanteringen ut vid stängning av plankorsningar och i vilka situationer skulle det vara användbart att tillämpa järnvägsplan?” och ”Hur ser projektgenomförandet ut i projekt som berör borttagande av plankorsningar med avseende på tid och kostnader?”. När det gäller upphävande av överfartsservitut i syfte att kunna stänga en plankorsning kan en järnvägsplan upprättas för att underlätta sådana servitutsåtgärder även om det inte direkt innebär "byggande av järnväg". Om det däremot ska upphävas utan stöd i järnvägsplan ska skyddsvillkoren i 5 kap och 7 kap FBL tillämpas fullt ut. Metoderna som användes var intervjuer och studie av järnvägsplaner och förrättningsakter. Det genomfördes tolv intervjuer, där sju personer representerade Trafikverket och fem förrättningslantmätare representerade Lantmäterimyndigheten, vilket bedömdes uppfylla den svarsmättnad som krävdes för att få frågeställningen besvarad med tillräcklig räckvidd. Det fanns ett begränsat antal järnvägsplaner som endast behandlade stängning av en plankorsning. Det fanns däremot ett flertal järnvägsplaner som behandlade stängning av plankorsningar, men då i samband med andra åtgärder som enligt lag är byggande eller ombyggnad av järnväg. Förenta nationernas globala hållbara mål består av 17 mål som syftar till att utrota fattigdom, stoppa klimatförändringar och skapa fredliga och trygga samhällen innan 2030. Varav mål 11 lyder: ”Hållbara städer och samhällen”, vilket ansågs berör denna uppsats problemformulering. Resultaten visade både för- och nackdelar med att tillämpa järnvägsplan vid stängning av plankorsningar. Det som kan konstateras efter den genomföra studien är att Trafikverket har en vilja att genomföra fler järnvägsplaner vid komplicerade plankorsningar och Lantmäterimyndigheten ser vissa fördelar från ett handläggningsperspektiv att tillämpa järnvägsplan.

La qualité de communication dans un réseau sans fil est déterminée par la qualité du signal, et plus précisément par le rapport signal à interférence et bruit. Cela pousse chaque récepteur à se connecter à l'émetteur qui lui donne la meilleure qualité du signal. Nous utilisons la géométrie stochastique et la théorie des extrêmes pour obtenir la distribution de la meilleure qualité du signal, ainsi que celles de l'interférence et du maximum des puissances reçues. Nous mettons en évidence comment la singularité de la fonction d'affaiblissement modifie leurs comportements. Nous nous intéressons ensuite au comportement temporel des signaux radios en étudiant le franchissement de seuils par un processus stationnaire $X(t)$. Nous démontrons que l'intervalle de temps que $X(t)$ passe au-dessus d'un seuil $\gamma \to -\infty$ suit une distribution exponentielle, et obtenons également des résultats caractérisant des franchissements par $X(t)$ de plusieurs seuils adjacents. Ces résultats sont ensuite appliqués à la gestion de mobilité dans les réseaux cellulaires. Notre travail se concentre sur la fonction de 'handover measurement'. Nous identifions la meilleure cellule voisine lors d'un handover. Cette fonction joue un rôle central sur l'expérience perçue par l'utilisateur. Mais reste une question ouverte à cause des difficultés posées par la coopération entre plusieurs mécanismes de contrôle qu'elle nécessite. Nous traitons ce problème en proposant des approches analytiques pour les réseaux émergents de types macro et pico cellulaires, ainsi qu'une approche d'auto-optimisation pour les listes de voisinage utilisées dans les réseaux cellulaires actuels.

Made available in DSpace on 2015-05-08T14:57:18Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3795959 bytes, checksum: 7a11a6cf0b41c67297d55642c2b80df3 (MD5) Previous issue date: 2014-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work, we analyse different architectures of analog-to-digital converters (ADC) and propose an architecture based on sampling by crossing levels and adaptive quantization step, aiming at reducing the energy required to convert and process specific signals. The proposed architecture has parameters which can be dynamically configured by the user, as to adapt the conversion process to the signal being sampled and to the requirements of power consumption of the target application. The architecture was modeled and simulated using Matlab, and used to convert several test signals, of which an ECG signal. The use of the proposed architecture resulted in SNR improvements of up to 10dB if compared against uniform (periodic) sampling. The digital logic was implemented in FPGA from a SystemVerilog description functionally compatible with the Matlab model, and the analog part was implemented with discrete components. / Neste trabalho, faz-se uma análise de diferentes arquiteturas de conversores analógico-digitais, e propõe-se uma arquitetura de conversor analógico-digital baseado em amostragem por cruzamento de níveis (não-uniforme) com adaptação do passo de quantização, com o objetivo de reduzir o consumo de energia requerido pela conversão analógica-digital e processamento de sinais com características específicas. A arquitetura proposta possui parâmetros que podem ser configurados dinamicamente pelo usuário, a fim de que o processo de conversão se adeque às características do sinal a ser amostrado e aos requerimentos de consumo de energia da aplicação. A arquitetura foi modelada e simulada em MatLab, tendo sido utilizada na conversão de diversos sinais de teste, dentre os quais um sinal típico de eletrocardiograma. Verificou-se que a amostragem não-uniforme com adaptação do passo de quantização proposta resultou em um aumento da relação sinal-ruído do sinal amostrado de até 10dB quando comparado com a amostragem uniforme. A implementação da parte digital foi feita em FPGA a partir de uma descrição em SystemVerilog funcionalmente compatível com o modelo em Matlab, e a parte analógica foi implementada com componentes discretos.