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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
451

DEVELOPMENT AND CALIBRATION OF A GLOBAL GEOMETRIC DESIGN CONSISTENCY MODEL FOR TWO-LANE RURAL HIGHWAYS, BASED ON THE USE OF CONTINUOUS OPERATING SPEED PROFILES

Camacho Torregrosa, Francisco Javier 31 March 2015 (has links)
Road safety is one of the most important problems in our society. It causes hundreds of fatalities every year worldwide. A road accident may be caused by several concurrent factors. The most common are human and infrastructure. Their interaction is important too, which has been studied in-depth for years. Therefore, there is a better knowledge about the driving task. In several cases, these advances are still not included in road guidelines. Some of these advances are centered on explaining the underlying cognitive processes of the driving task. Some others are related to the analysis of drivers’ response or a better estimation of road crashes. The concept of design consistency is related to all of them. Road design consistency is the way how road alignment fits drivers’ expectancies. Hence, drivers are surprised at inconsistent roads, presenting a higher crash risk potential. This PhD presents a new, operating speed-based global consistency model. It is based on the analysis of more than 150 two-lane rural homogeneous road segments of the Valencian Region (Spain). The final consistency parameter was selected as the combination of operational parameters that best estimated the number of crashes. Several innovative auxiliary tools were developed for this process. One example is a new tool for recreating the horizontal alignment of two-lane rural roads by means of an analytic-heuristic process. A new procedure for determining road homogeneous segments was also developed, as well as some expressions to accurately determine the most adequate design speed. The consistency model can be integrated into safety performance functions in order to estimate the amount of road crashes. Finally, all innovations are combined into a new road design methodology. This methodology aims to complement the existing guidelines, providing to road safety a continuum approach and giving the engineers tools to estimate how safe are their road designs. / Camacho Torregrosa, FJ. (2015). DEVELOPMENT AND CALIBRATION OF A GLOBAL GEOMETRIC DESIGN CONSISTENCY MODEL FOR TWO-LANE RURAL HIGHWAYS, BASED ON THE USE OF CONTINUOUS OPERATING SPEED PROFILES [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48543 / TESIS
452

Crash recovery with partial amnesia failure model issues

De Juan Marín, Rubén 30 September 2008 (has links)
Replicated systems are a kind of distributed systems whose main goal is to ensure that computer systems are highly available, fault tolerant and provide high performance. One of the last trends in replication techniques managed by replication protocols, make use of Group Communication Sys- tem, and more specifically of the communication primitive atomic broadcast for developing more eficient replication protocols. An important aspect in these systems consists in how they manage the disconnection of nodes {which degrades their service{ and the connec- tion/reconnection of nodes for maintaining their original support. This task is delegated in replicated systems to recovery protocols. How it works de- pends specially on the failure model adopted. A model commonly used for systems managing large state is the crash-recovery with partial amnesia be- cause it implies short recovery periods. But, assuming it implies arising several problems. Most of them have been already solved in the literature: view management, abort of local transactions started in crashed nodes { when referring to transactional environments{ or for example the reinclu- sion of new nodes to the replicated system. Anyway, there is one problem related to the assumption of this second failure model that has not been completely considered: the amnesia phenomenon. Phenomenon that can lead to inconsistencies if it is not correctly managed. This work presents this inconsistency problem due to the amnesia and formalizes it, de ning the properties that must be ful lled for avoiding it and de ning possible solutions. Besides, it also presents and formalizes an inconsistency problem {due to the amnesia{ which appears under a speci c sequence of events allowed by the majority partition progress condition that will imply to stop the system, proposing the properties for overcoming it and proposing di erent solutions. As a consequence it proposes a new majority partition progress condition. In the sequel there is de / De Juan Marín, R. (2008). Crash recovery with partial amnesia failure model issues [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/3302 / Palancia
453

Vliv rychlosti rázového zatěžování na napjatost, deformaci a spolehlivost komponenty palivového systému automobilu / Effect of Velocity of Impact Loading to Stress, Deformation and Durability of Component of Fuel Car System

Dobeš, Martin January 2018 (has links)
Passive safety is a well-known term. This term can be further categorized into different topics of the car passive safety, restraint systems, safety assistants (ABS, ESP, ASR, etc.). One of these topics is passive safety of the fuel system. Safety and tightness of the fuel system must be guaranteed even under non-standard conditions, for example a collision against a fixed obstacle. This issue is not often mentioned in the field of car safety. It is considered a standard. Passive safety of the fuel system is often ensured using various interesting technical solutions and devices, usually patented ones. The development of these solutions is supported by numerical simulations in different stages of development process. The doctoral thesis deals with impact loading of the plastic components of the fuel system, in particular Fuel Supply Module (FSM), which is mounted inside the fuel tank. The flange is the most important part of the fuel supply module from the car safety point of view. The flange closes FSM on the external side of the fuel tank. The thesis focuses on the finite element analysis of the complete or partial FSM, and the flange itself during impact loading. The main objective of this thesis are numerical material models, taking into account important aspects of the mechanical behavior of polymer materials during impact loading. There are a lot of ad hoc invented or standardized experiments described in this thesis. These experiments are used for estimation of the material parameters or comparison of numerical analysis vs real conditions, or tests. The solver LS-DYNA was mainly used for numerical simulations. The final results of this thesis brings new quantified knowledge about behavior of the Typical Semi-Crystal Polymer (TSCP), not only for impact loading. The practical part of this thesis defines new methodology for the numerical simulation approach of impact loading for FSM. This methodology is directly usable for new product development. A lot of numerical material models were developed and tested. The best results were achieved using numerical material model *MAT_24 with combination of *MAT_ADD_EROSION card. The limits and parameters for this numerical material model was estimated empirically during conducting experiments. The numerical material model SAMP-1 was partly solved in this doctoral thesis, but more detail study will be given in future works.
454

Podnikatelský záměr - Help one, s. r. o. / Business plan - Help one, s. r. o.

Oberreiterová, Dana January 2008 (has links)
The aim of this work is to invent a business plan for beginning company HELP ONE, s. r. o., which offers complete services to the people who have been damaged by a car crash. On the other hand, this work also shows all possible problems that can appear from the middle position between insurance company and ordinary people and eventually to find a suitable investor.
455

Analýza jízdy osobního vozidla s přívěsem / Analysis of Driving a Passenger Vehicle with a Trailer

Šujan, Tomáš January 2013 (has links)
The subject of this thesis is the analysis of the negative effects associated with the operation of a trailer for a personal vehicle with respect to the design speed, technical checks and analysis related legislation. Its work is drawn from the measurement, cooperation with leading Czech production plant trailers Vezeko s.r.o., an organization engaged in the implementation of engineering controls DEKRA Automobil a.s. and available literature, including electronic resources. Results of the work end with proposals for specific measures to minimize the identified adverse effects.
456

Vývoj "Indie Game" / Indie Game Development

Zachariáš, Michal January 2011 (has links)
This master's thesis deals with development of indie game - independently-developed game. It describes important moments in computer games history. It clarifies terms like golden age of video arcade games and video game crash of 1983. Further it explains history and origin of indie game phenomenon. It describes some of the differences between independent and commercial game development. In next chapter it presents some game engines which are suitable for independent game development. And in the last chapter it describes the design and implementation of game engine and game running on it.
457

La sécurité aérienne en Afrique : la communication autistique au sein du collectif sécuritaire de l'aéronautique civile congolaise / The aeronautic african security : the autistic communication in the Congolese DRC collective civil aeronautical security

Itabu Issa Sadiki, Michel 10 March 2017 (has links)
La République Démocratique du Congo (RDC) fut l'un des meilleurs modèles de l'exploitation aéronautique en Afrique pendant la colonisation et plus d'une vingtaine d'années après l'indépendance au point d'en être félicitée par l'Association Internationale des Transporteurs Aériens (IATA). Aujourd'hui, par contre, ce vaste pays situé au cœur de l'Afrique passe pour le mauvais élève de l'aviation civile mondiale sur le plan sécuritaire et le pire dans l'enregistrement des accidents et des catastrophes aériens depuis la libéralisation de ce secteur en 1978. Conséquence: la DOC est blacklistée par l'Union européenne depuis 2005 jusqu'à ce jour. Dans la mémoire collective et les médias, la RDC est ainsi assimilée aux crashes et aux catastrophes aériennes et le commentaire l'égratigne chaque fois que survient un accident aérien dans n'importe quel pays au monde. Cette étude s'inscrit dans la problématisation de la communication au sein des organisations. Elle questionne les nouveaux paradigmes de l'accident aérien dans le but de sa prévention en amont dans le transport aérien. La question principale concerne donc la communication en aéronautique civile. En effet, malgré l'imputabilité des occurrences comptabilisées en RDC soit à l'erreur humaine, soit à la technique, soit à l'environnement, soit à la conjonction de ces trois facteurs causaux, cette thèse doctorale démontre, dans une approche généalogico­processuelle, socio-anthropologique et macro systémique-technique aéronautique, que l'avalanche des accidents et des catastrophes aériens en RDC est consécutive à « la communication autistique», c'est-à-dire à « la normalisation de l'anormal, des dysfonctionnements, des déviances, des transgressions normatives», donc de « l'anormal normalisé» ou à un échange ou une communication procédant par les écarts aux normes de l'Organisation de !'Aviation Civile Internationale (OACI) dans un domaine très réglementé et très normalisé. Ainsi, l'étude décrit l'évolution de l'aéronautique civile congolaise des origines coloniales à ce jour. Elle fait une immersion dans les organisations ou les structures de son « collectif sécuritaire», en esquisse les types de communications, d'interactions, de relations et d'interrelations y entretenus, à savoir les incommunications, les communications paradoxales, ambigües, confuses, incompatibles, absurdes, l'aveuglement communicationnel ou déni de communication, les dialogues de sourds, communication de défense transpersonnelle, silences en tant que langue de bois. Enfin, cette recherche doctorale analyse sans complaisance les accidents et les catastrophes aériens survenus de 1990 à 2011 en ROC pour le démontrer et propose une théorie systémique du collectif sécuritaire de l'aéronautique civile comme « frein » aux pratiques communicationnelles autistiques en aviation civile. / The Democratic Republic of Congo (DRC) was one of the best models of aeronautical exploitation in Africa during colonization and over a couple of decades after independence to the extent of being congratulated by the International Air Transport Association (IATA). Today, in contrast, this huge central African country (DRC) is the bad student in world civil aviation in terms of security and the worst in terms of air accidents and disasters since the sector was liberalized in 1978. The consequence is that ORC has been blacklisted by the European Union since 2005. In the collective memory and the media, DRC is associated with crashes and air disasters so that every lime there is a plane crash anywhere in the world, reference is made to ORC. This research questions the issue of communication within organizations. New paradigms of air accidents are questioned with the aim of their prevention upstream in air transport. The main research question is about communication in civil aeronautics. As a matter of tact, even though registered occurrences in ORC have been attributed either to human error or to technology, or to the environment, or sometimes to the combination of these three factors, results of this study conducted in a genealogic-process, socio-anthropological and macro aeronautical technically-systemic approach indicate that the avalanche of air accidents and disasters in ORC is due to "autistic communication", that is, "the normalization of the abnormal, dysfunction, deviances and infringement of standards", thus 'the abnormal standardized" or through communication that proceeds by discrepancies to standards of the International Civil Aviation Organization (ICAO) in a highly regulated and standardized field. The study depicts the evolution of Congolese civil aeronautics since its colonial origins until the present, it immerses itself in the organizations or structures of its "security sector", and outlines the types of communications, interactions, relations and interrelations that occur in there including paradoxical, ambiguous, confusing, incompatible, absurd communications, non-communications, communicational blindness or denial of communication, dialog of the deaf, transpersonal defense communication, silence as waffle. Finally, the research analyzes air accidents and disasters that occurred in DRC between 1990 and 2011 without leniency to demonstrate this and suggests a systemic theory of civil aeronautics security sector as "a brake" to autistic communicational practices in civil aviation.
458

Die Eurokrise: Konsequenzen der defizitären Institutionalisierung der gemeinsamen Währung

Preunkert, Jenny, Vobruba, Georg January 2011 (has links)
Ziel des Artikels ist, die Entwicklung der Eurokrise im Spannungsfeld von Institutionen und Handeln zu erklären. Dazu rekonstruieren wir im ersten Schritt die Krise in zwei Perspektiven, zum einen als Verkettung ökonomischer und politischer Funktionszusammenhänge, zum anderen als Arena von Verteilungskonflikten. Darauf aufbauend analysieren wir den Verlauf der Eurokrise, den wir in fünf Phasen unterteilen. Im Zentrum stehen dabei folgende Fragen: 1. Welche Akteure werden jeweils in die Problemkonstellation „Eurokrise“ hineingezogen? 2. Welche Relevanz haben die unterschiedlichen Akteure für das Funktionieren der gemeinsamen Währung und wie setzen sie diese Relevanz in den Verteilungskonflikten, die sich aus der Eurokrise ergeben, ein? Es geht also um die Entwicklung der Akteurskonstellation im Zuge der Eurokrise und um die Funktionsrelevanz dieser Akteure als Handlungsressource in den Konflikten um die Verteilung der Kosten der Krise. Im dritten Schritt der Untersuchung fassen wir unsere empirische Rekonstruktion der Eurokrise zusammen. Unser Fazit ist, dass die Eurokrise die defizitäre Institutionalisierung der gemeinsamen Währung manifest macht. Weiter gehende Regulierung, also zusätzliche Institutionenbildung steht aber vor dem schwierig auflösbaren Widerspruch zwischen funktionalen Erfordernissen und Interessen, bzw. zwischen Erwartungsstabilisierung und Interessenverfolgung.:Krise?; Ein institutionen- und handlungstheoretischer Rahmen; Folgen der Finanzkrise für die Eurozone; Konsequenz: Ergänzung der defizitären Institutionalisierung
459

IDENTIFICATION OF FAILURE-CAUSED TRAFFIC CONFLICTS IN TRACKING SYSTEMS: A GENERAL FRAMEWORK

Cristhian Lizarazo Jimenez (9375209) 16 December 2020 (has links)
<p><a>Proactive evaluation of road safety is one of the most important objectives of transportation engineers. While current practice typically relies on crash-based analysis after the fact to diagnose safety problems and provide corrective countermeasures on roads, surrogate measures of safety are emerging as a complementary evaluation that can allow engineers to proactively respond to safety issues. These surrogate measures attempt to address the primary limitations of crash data, which include underreporting, lack of reliable insight into the events leading to the crash, and long data collection times. </a></p> <p>Traffic conflicts are one of the most widely adopted surrogate measures of safety because they meet the following two conditions for crash surrogacy: (1) they are non-crash events that can be physically related in a predictable and reliable way to crashes, and (2) there is a potential for bridging crash frequency and severity with traffic conflicts. However, three primary issues were identified in the literature that need to be resolved for the practical application of conflicts: (1) the lack of consistency in the definition of traffic conflict, (2) the predictive validity from such events, and (3) the adequacy of traffic conflict observations.</p> <p>Tarko (2018) developed a theoretical framework in response to the first two issues and defined traffic conflicts using counterfactual theory as events where the lack of timely responses from drivers or road users can produce crashes if there is no evasive action. The author further introduced a failure-based definition to emphasize conflicts as an undesirable condition that needs to be corrected to avoid a crash. In this case, the probability of a crash, given failure, depends on the response delay. The distribution of this delay is adjusted, and the probability is estimated using the fitted distribution. As this formal theory addresses the first two issues, a complete framework for the proper identification of conflicts needs to be investigated in line with the failure mechanism proposed in this theory.</p> <p>The objective of this dissertation, in response to the third issue, is to provide a generalized framework for proper identification of traffic conflicts by considering the failure-based definition of traffic conflicts. The framework introduced in this dissertation is built upon an empirical evaluation of the methods applied to identify traffic conflicts from naturalistic driving studies and video-based tracking systems. This dissertation aimed to prove the practicality of the framework for proactive safety evaluation using emerging technologies from in-vehicle and roadside instrumentation.</p> <p>Two conditions must be met to properly claim observed traffic events as traffic conflicts: (1) analysis of longitudinal and lateral acceleration profiles for identification of response due to failure and (2) estimation of the time-to-collision as the period between the end of the evasion and the hypothetical collision. Extrapolating user behavior in the counterfactual scenario of no evasion is applied for identifying the hypothetical collision point.</p> <p>The results from the SHRP2 study were particularly encouraging, where the appropriate identification of traffic conflicts resulted in the estimation of an expected number of crashes similar to the number reported in the study. The results also met the theoretical postulates including stabilization of the estimated crashes at lower proximity values and Lomax-distributed response delays. In terms of area-wide tracking systems, the framework was successful in identifying and removing failure-free encounters from the In-Depth understanding of accident causation for Vulnerable road users (InDeV) program.</p> <p>This dissertation also extended the application of traffic conflicts technique by considering estimation of the severity of a hypothetical crash given that a conflict occurs. This component is important in order for conflicts to resemble the practical applications of crashes, including the diagnostics of hazardous locations and evaluating the effectiveness of the countermeasures. Countermeasures should not only reduce the number of conflicts but also the risk of crash given the conflict. Severity analysis identifies the environmental, road, driver, and pre-crash conditions that increase the likelihood of severe impacts. Using dynamic characterization of crash events, this dissertation structured a probability model to evaluate crash reporting and its associated severity. Multinomial logistic models were applied in the estimation; and quasi-complete separation in logistic regression was addressed by providing a Bayesian estimation of these models.</p>
460

Decision-making In Mutual Funds During the COVID-19 Pandemic / Beslutsfattande i svenska aktiefonder underpandemin COVID-19

Galijasevic, Amar, Tegbaru, Josef January 2021 (has links)
During the beginning of 2020, the world was struck by the vicious virus COVID­19, forcing societies into lockdown. Demand froze across the board and this was quickly reflected on stockmarkets worldwide. The Swedish stock market index, OMXS30, plummeted around 30% in a matter of weeks. As an investor, it can be difficult to navigate the financial market and make investment decisions during such turbulent periods. The goal of this study is to analyze the decision-making made by Swedish mutual fund managers during the turbulent market period of 2020, to identify common behavior. This is done through interviewing fund managers of major Swedish mutual funds. The results of the study imply that a specific template for decision-­making amongst fund managers is difficult to create. Yet, a common and early decision during market corrections is to reduce positions in assets performing well in order to maintain fund liquidity and capture new investment opportunities created by the correction. Making decisions during market volatility is a difficult process that is dependant on factors such as investment mandates, internal resources, investment ­horizon and preferred valuation methods. / Under början av 2020 spreds viruset COVID­19 över stora delar av världen, vilket tvingade samhällen att stänga ner och införa restriktioner för att minska smittospridningen. Efterfrågan föll på bred front och detta återspeglades snabbt på aktiemarknaderna världen över. Det svenska aktieindexet OMXS30 rasade runt 30% på ett par veckor. Under sådanna turbulentaperioder på börsen kan det vara svårt som investerare att navigera och göra rätt beslut kring investeringar. Målet med denna studie är att analysera beslutsprocessen vid investeringar hos svenska fondförvaltare under den volatila marknadsperioden 2020, för att försöka identifiera likheter. En rad intervjuer har utförts för att samla in information om förvaltarnas beslutsprocesser. Resultaten från studien visar att det är svårt att hitta en gemensam metod som fondförvaltare använder vid beslutsfattande i turbulenta marknadsperioder. Trots det, är det vanligaste och tidigaste beslutet att minska positioner i tillgångar som klarat sig väl tidigt i nedgången för att upprätthålla fondens likviditet och kunna investera i nya möjligheter skapade av börsnedgången. Att fatta beslut i fonder under marknadsvolatilitet är en svår process som är beroende av faktorer som investeringsmandat, interna resurser, placeringshorisont och värderingsmetod.

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