• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 2
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 17
  • 17
  • 17
  • 5
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 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.
1

Road Traffic Safety Problem Based Learning Module

David, Iuliana January 2008 (has links)
Road traffic safety has increasingly become in need of educated road safety professionals, as the number of accidents in the World Health Organization member countries exceeds one million. The profession itself is transitioning from experience based decision making to empirical, theoretical and mathematical based solutions. However, road traffic safety is a multidiscipline, crossing over many fields and requiring a high degree of communication between different institutions. There are very few institutions that provide programs in the field; furthermore, they employ traditional lecture-based teaching methods. The traditional teaching environment does not fulfill the educational needs of future traffic safety professionals due to its rigidity and lack of problem solving exercises. An alternative method, namely problem based learning, is recommended as an alternative teaching method in this paper. The thesis is constructed in such a way as to develop a complete road traffic safety educational module at graduate and post graduate level. The theoretical basis on which a road traffic safety module is later built is presented in the first part of the thesis. Major concepts in road traffic safety, as well as problem based learning methods are investigated. In addition, a literature review SWOT analysis based on literature is conducted.The module development consists of establishing the road traffic safety learning goals for each segment in the module, appropriate assessment criteria and group work format. The module contains gradual difficulty level problems, starting from the easiest topic and easiest format (closed ended problem) and ending with the hardest topic and hardest format (open ended problem). The last section employs the SWOT analysis findings in the theoretical section to develop a SWOT analysis of the road traffic safety module presented in the thesis.
2

Road Traffic Safety Problem Based Learning Module

David, Iuliana January 2008 (has links)
<p>Road traffic safety has increasingly become in need of educated road safety professionals, as the number of accidents in the World Health Organization member countries exceeds one million. The profession itself is transitioning from experience based decision making to empirical, theoretical and mathematical based solutions. However, road traffic safety is a multidiscipline, crossing over many fields and requiring a high degree of communication between different institutions. There are very few institutions that provide programs in the field; furthermore, they employ traditional lecture-based teaching methods. The traditional teaching environment does not fulfill the educational needs of future traffic safety professionals due to its rigidity and lack of problem solving exercises.</p><p>An alternative method, namely problem based learning, is recommended as an alternative teaching method in this paper. The thesis is constructed in such a way as to develop a complete road traffic safety educational module at graduate and post graduate level.</p><p>The theoretical basis on which a road traffic safety module is later built is presented in the first part of the thesis. Major concepts in road traffic safety, as well as problem based learning methods are investigated. In addition, a literature review SWOT analysis based on literature is conducted.The module development consists of establishing the road traffic safety learning goals for each segment in the module, appropriate assessment criteria and group work format. The module contains gradual difficulty level problems, starting from the easiest topic and easiest format (closed ended problem) and ending with the hardest topic and hardest format (open ended problem).</p><p>The last section employs the SWOT analysis findings in the theoretical section to develop a SWOT analysis of the road traffic safety module presented in the thesis.</p>
3

Towards a general optimal model for minimizing nighttime road traffic accidents and road lighting power consumption

Jun, Ma January 2010 (has links)
<p>Nowadays, NRTS (Nighttime Road Traffic Safety) and energy saving are very hot topics in transportation field. This thesis investigates a general optimal model for minimizing NRTAs (nighttime road traffic accidents) and power consumption of the road lighting. To establish this model, the relationship between N/D RTAs (Night to Day Road Traffic Accidents) ratio and road lighting condition and the relationship between power consumption and road lighting condition have been studied and explained. A media variable “economic cost” has been chosen which is used for making a connection between these two relationships. The evaluations of NRTAs and power consumption from cost point of view are introduced as well. The impacts of each internal factor defined by author are explained carefully. The result of the model based on these relationships and internal influencing factors is presented in the paper. Finally, the recommendations for reducing NRTAs and/or power consumption, as well as other interesting areas for further study are presented.</p>
4

Towards a general optimal model for minimizing nighttime road traffic accidents and road lighting power consumption

Jun, Ma January 2010 (has links)
Nowadays, NRTS (Nighttime Road Traffic Safety) and energy saving are very hot topics in transportation field. This thesis investigates a general optimal model for minimizing NRTAs (nighttime road traffic accidents) and power consumption of the road lighting. To establish this model, the relationship between N/D RTAs (Night to Day Road Traffic Accidents) ratio and road lighting condition and the relationship between power consumption and road lighting condition have been studied and explained. A media variable “economic cost” has been chosen which is used for making a connection between these two relationships. The evaluations of NRTAs and power consumption from cost point of view are introduced as well. The impacts of each internal factor defined by author are explained carefully. The result of the model based on these relationships and internal influencing factors is presented in the paper. Finally, the recommendations for reducing NRTAs and/or power consumption, as well as other interesting areas for further study are presented.
5

Der Einfluss von Cloud-Computing auf die Sicherheit im Straßenverkehr

Augele, Vivian 28 July 2023 (has links)
Jährlich sterben weltweit 1,35 Millionen Menschen durch Verkehrsunfälle. Ob Cloud-Computing zu einer Reduzierung dieser Zahl beitragen wird, wird in der vorliegenden Arbeit untersucht. Zunächst werden Cloud-Anwendungen ermittelt, welche im Straßenverkehr verwendet werden und Einfluss auf die Straßenverkehrssicherheit haben. Anschließend wird deren genauer Einfluss auf die Straßenverkehrssicherheit durch die Betrachtung von Stu-dienergebnissen, Herstellerangaben sowie eigenen Kalkulationen untersucht. Zudem werden die Gefahren von Cyberangriffen und Netzausfällen für die ermittelten Anwendungen analysiert. Es folgt eine kritische Diskussion sowie die Zusammenfassung des Erarbeiteten: Cloud-Computing ermöglicht durch den einfachen, risikoarmen Zugang zu unlimitierten Rechenressourcen die Entwicklung und den Betrieb von Anwendungen, die Einfluss auf die Verkehrssicherheit nehmen. Es ist davon auszugehen, dass die Anwendungen bei einer weiter voranschreitenden Felddurchdringungsrate positiven Einfluss auf die Straßenverkehrssicherheit in Deutschland und anderen Industriestaaten nehmen und damit aktiv zur Reduzierung der Anzahl Verkehrstoter und -verletzter beitragen werden. Cloud-Computing wird somit ein indirekt positiver Einfluss auf die Straßenverkehrssicherheit zugeschrieben. / 1.35 million people die in traffic accidents worldwide every year. Whether cloud computing contributes to a reduction of this number is examined in the present work. First, cloud com-puting applications are identified, which are used in road traffic and have an impact on traffic safety. The exact influence on traffic safety is then examined by considering study results, manufacturer information and through own calculations. In addition, the dangers of cyber-attacks and network failures are examined in the context of the identified applications. This is followed by a critical discussion and a summary of what has been worked out: Cloud computing enables the development and operation of applications that affect traffic safety through simple, low-risk access to unlimited computing resources. It can be assumed that the applica-tions will have a positive influence on traffic safety in Germany and other industrialized countries and will thus actively contribute to reducing the number of deaths and injuries, given that the penetration rate is further increasing. Cloud computing is thus attributed an indirect positive influence on road safety.
6

Развој модела динамичких параметара кретања мотоцикла са аспекта безбедности саобраћаја / Razvoj modela dinamičkih parametara kretanja motocikla sa aspekta bezbednosti saobraćaja / DEVELOPMENT OF MOTORCYCLE'S DYNAMIC PARAMETERMODELS FROM THE ASPECTS OF TRAFFIC SAFETY

Aleksandrović Branislav 28 September 2017 (has links)
<p>Основни предмет истраживања докторске дисертације<br />представљали су рачунарски модели за анализу динамичких<br />карактеристика кретања мотоцикла у функцији повећања безбедности<br />саобраћаја. Значајан удео чине и оргиналана експериментална<br />истраживања са опремом која је прилагођена испитивањима, како у<br />статичко-динамичким лабораторијским условима, тако и у сложеним<br />условима путних испитивања.<br />У oквиру циља дефинисања страдања мотоциклиста дат је<br />осврт на проблематику безбедности мотоциклиста у саобраћају,<br />стања и тенденције, гледано и анализирано на глобалном нивоу,<br />преко специфичности у појединим ширим географским регионима,<br />закључно са стањем у Републици Србији.<br />Као значајан аспект је наведена и приказана конструкција<br />мотоцикла у целини, при чему указано на значај сваког система, са<br />посебним освртом на рам мотоцикла и његову интеракцију са<br />системима ослањања и управљања.<br />На бази добијених резултата динамичких параметара кретања<br />мотоцикла, идентификовани су показатељи динамичког понашања<br />мотоцикла за следеће режиме: кочења, залета, кретања константном<br />брзином, режима осциловања, као и за режиме изражене интеракције<br />динамичких равни.</p> / <p>Osnovni predmet istraživanja doktorske disertacije<br />predstavljali su računarski modeli za analizu dinamičkih<br />karakteristika kretanja motocikla u funkciji povećanja bezbednosti<br />saobraćaja. Značajan udeo čine i orginalana eksperimentalna<br />istraživanja sa opremom koja je prilagođena ispitivanjima, kako u<br />statičko-dinamičkim laboratorijskim uslovima, tako i u složenim<br />uslovima putnih ispitivanja.<br />U okviru cilja definisanja stradanja motociklista dat je<br />osvrt na problematiku bezbednosti motociklista u saobraćaju,<br />stanja i tendencije, gledano i analizirano na globalnom nivou,<br />preko specifičnosti u pojedinim širim geografskim regionima,<br />zaključno sa stanjem u Republici Srbiji.<br />Kao značajan aspekt je navedena i prikazana konstrukcija<br />motocikla u celini, pri čemu ukazano na značaj svakog sistema, sa<br />posebnim osvrtom na ram motocikla i njegovu interakciju sa<br />sistemima oslanjanja i upravljanja.<br />Na bazi dobijenih rezultata dinamičkih parametara kretanja<br />motocikla, identifikovani su pokazatelji dinamičkog ponašanja<br />motocikla za sledeće režime: kočenja, zaleta, kretanja konstantnom<br />brzinom, režima oscilovanja, kao i za režime izražene interakcije<br />dinamičkih ravni.</p> / <p>The basic researching subject of this dissertation were computer<br />models used for the analysis, of motorcycle motion dynamic characteristics,<br />in the function of traffic safety increasement. Significant share also have<br />had the original experimental researching, by implementing equipment<br />which was specifically adjusted for thе researching both in static and<br />dynamic laboratory conditions and also in complex conditions of road<br />examinations.<br />With the aim to define fatal injuries of drivers of the motorcycles a<br />specific attention was given to driver&#39;s safety in traffic, driver&rsquo;s conditions<br />and tendencies, which were examined and analysed on global level,<br />considering specific factors in the wide geographic regions, concluding with<br />the actual state in the Republic of Serbia.<br />As one of significant aspects herein is quoted and presented entire<br />design of motorcycle, indicated a significance of each system, with the<br />special remarks on motorcycle&rsquo;s frame and it&rsquo;s interaction with suspension<br />and steering system.<br />On the basis of obtained results of motorcycle motion dynamic<br />parameters, a key indicators of dynamic behaviour of motorcycle were<br />identified for the following working regimes: braking, accelerating, constant<br />speed motion, oscillation regimes, and also for the regimes of exposed<br />interaction of dynamic planes.</p>
7

Korrelationen mellan fotgängares skador i verkliga olyckor och Euro NCAPs testresultat för fotgängarskydd / The Correlation Between Pedestrian Injury Severity in Real-Life Crashes and Euro NCAP Pedestrian Test Results

Sternlund, Simon January 2011 (has links)
The aim of the present study was to estimate the correlation between Euro NCAP pedestrian rating scores and injury outcome in real-life car to pedestrian crashes, with special focus on long-term disability. The study also surveyed most frequently injured body regions and risk differences for specific elements of pedestrians hit by cars. Another aim was to determine whether Brake Assist systems affect the injury outcome in real-life car to pedestrian crashes and to estimate the effect in injury reduction of a high Euro NCAP ranking score combined with Brake Assist. In the current study, the Euro NCAP pedestrian scoring was compared with the real-life outcome in pedestrian crashes that occurred in Sweden 2003-2010. The real-life crash data was obtained from the data acquisition system STRADA, which combines police records and hospital admission data. The medical data consisted of International Statistical Classification of Diseases and Related Health Problems (ICD) diagnoses and Abbreviated Injury Scale (AIS) scoring. In all approximately 500 pedestrians submitted to hospital were included in the study. Each car model was coded according to Euro NCAP pedestrian scores. In addition, the presence or absence of Brake Assist (BA) was coded for each car involved. Pedestrians were grouped according to associated car scoring. Injury outcomes were analyzed with AIS and, at victim level, with permanent medical impairment. This was done by translating the injury scores for each individual to Risk of Serious Consequences (RSC) at 1, 5 and 10% level of medical disability or more. This indicates the total risk of a medical disability for each victim, given the severity and location of injuries. The mean RSC (mrsc) was then calculated for each pedestrian group and t-tests were conducted to ensure statistically significant differences in mrsc between groups. The results showed a significant reduction of injury severity for pedestrians hit by cars with better pedestrian scoring, although pedestrians hit by cars with a high score (three or four stars) could not be studied, due to lack of cases. The reduction of RSC for pedestrians hit by medium performing (two-star) cars in comparison with pedestrians hit by low performing (one-star) cars was 12, 19 and 28% for 1 ,5 and 10% of medical impairment or more, respectively. These results applied to speed limits up to 90 km/h. In urban areas with speed limits up to 50 km/h the reduction of RSC was 17, 26 and 38% for 1, 5 and 10% of medical impairment or more, respectively. Car to pedestrian crashes was most common at speed limits up to 50 km/h and leg, arm and head were the most frequently injured body regions. RSC for pedestrians hit by cars with Brake Assist was not statistically significant lower than for pedestrians hit by cars without Brake Assist. RSC for pedestrians hit by two-star cars with Brake Assist was 19, 31 and 46% lower for 1, 5 and 10% of medical impairment or more, respectively, compared to pedestrians hit by one-star cars without Brake Assist. A significant correlation between Euro NCAP pedestrian score and injury outcome in real-life car to pedestrian crashes was found. The injury reduction was found to be larger for higher severity and level of permanent medical impairment. Car to pedestrian crashes was most common at lower speed zones. Leg, arm and head were the most frequently injured body regions. Brake Assist had no statistically significant effect measured in RSC on car to pedestrian crashes in this material. A high Euro NCAP scoring combined with Brake Assist was shown to give a high effect in reduction of RSC for pedestrians. / Syftet med denna studie var att uppskatta korrelationen mellan Euro NCAPs testresultat för fotgängarskydd och skadeutfall i verkliga olyckor med fotgängare och personbilar, med särskilt fokus på skador som ger medicinsk invaliditet. I studien kartlades även de mest frekvent skadade kroppsregionerna och riskskillnader för särskilda faktorer för fotgängare påkörda av personbilar. Studien syftar dessutom till att undersöka bromsassistanssystems påverkan av skadeutfallet för fotgängare i verkliga olyckor med personbil och att uppskatta den skadereducerande effekten av en hög Euro NCAP-poäng kombinerat med en bromsassistansutrustning. I denna studie var Euro NCAPs fotgängarskyddspoäng jämförd mot skadeutfallet i verkliga olyckor som skett i Sverige 2003-2010. Data från verkliga olyckor inhämtades från databasen STRADA (Swedish Traffic Accident Data Acquisition) som kombinerar polis- och sjukvårdsrapporterad data. De medicinska data innehåller diagnoser av typen ICD (International Statistical Classification of Diseases and Related Health Problems) och värden för AIS (Abbreviated Injury Scale). I helhet var omkring 500 fotgängare inkluderade i studien. Varje enskild personbilmodell kodades enligt Euro NCAPs fotgängarskyddspoäng. Dessutom kodades förekomst eller avsaknad av bromsassistansutrustning för varje enskild personbil inkluderad i studien. Fotgängarna grupperades enligt påkörande personbils fotgängarskyddspoäng. Skadeutfallet analyserades med AIS, på individnivå och med medicinsk invaliditet. Detta gjordes genom översättning av skadeutfall för varje fotgängare till risk för allvarliga konsekvenser (RSC, Risk of Serious Consequences) på 1, 5 och 10 % medicinsk invaliditet eller mer. Detta påvisar den totala risken för medicinsk invaliditet med hänsyn till skadegrad och -lokalisering. Medelvärdet av RSC (mrsc) beräknades sedan för varje fotgängargrupp och t-test utfördes för att säkerställa statistiskt signifikanta skillnader mellan gruppernas mrsc. Resultaten visade en signifikant skadereduktion för fotgängare påkörda av personbilar med en högre fotgängarskyddspoäng, trots att fotgängarolyckor med personbilar som har hög poäng (stjärnbetyg tre och fyra) inte kunde studeras på grund av fåtaligt antal olycksfall. Reduktionen av RCS för fotgängare påkörda av medelpresterande (stjärnbetyg två) personbilar i jämförelse med fotgängare påkörda av lågpresterande (stjärnbetyg ett) personbilar var 12, 19 och 28 % för 1, 5 respektive 10 % medicinsk invaliditet eller mer. Dessa resultat gäller olyckor på vägar med hastighetsgräns upp till 90 km/h. I stadsmiljö med hastighetsgräns upp till 50 km/h var reduktionen av RSC 17, 26 och 38 % för 1, 5 respektive 10 % medicinsk invaliditet eller mer. Fotgängarolyckor med personbil var vanligast på vägar med hastighetsgräns upp till 50 km/h och ben, arm och huvud var de mest frekvent skadade kroppsregionerna. RSC för fotgängare påkörda av personbilar utrustade med bromsassistans var inte statistiskt signifikant lägre än för fotgängare påkörda av personbilar utan bromsassistansutrustning. RSC för fotgängare påkörda av tvåstjärniga personbilar utrustade med bromsassistans var 19, 31 och 46 % lägre för 1, 5 respektive 10 % medicinsk invaliditet eller mer jämfört med fotgängare påkörda av enstjärniga personbilar utan bromsassistansutrustning. En signifikant korrelation mellan Euro NCAPs fotgängarpoäng och skadeutfall i verkliga fotgängarolyckor med personbil påträffades. Skadereduktionen visade sig vara högre för högre skadegrad och nivå av medicinsk invaliditet. Det var vanligare att personbilar kör på fotgängare på vägar med lägre hastighetsgräns. Ben, arm och huvud var de mest frekvent skadade kroppsregionerna. Bromsassistans hade inte en statistiskt signifikant effekt mätt i RSC för fotgängarolyckor i detta material. En hög Euro NCAP poäng kombinerat med bromsassistansutrustning visade sig ge en hög effekt av att reducera fotgängares RSC.
8

Quantification du biais de sélection en sécurité routière : apport de l’inférence causale / Causal inference to quantify selection bias in road traffic safety

Dufournet, Marine 01 December 2017 (has links)
Les principaux facteurs de l'insécurité routière sont connus, et l'enjeu réside aujourd'hui dans la mesure de l'effet d'un facteur, et la hiérarchisation de l'ensemble des causes intervenant dans la survenue de l'accident. Toutefois, les données disponibles concernent généralement que des accidentés. En l'absence de non-accidentés, l'épidémiologiste du risque routier se heurte à une sélection extrême. Une des solutions classiques est d'utiliser des analyses en responsabilité, et de mesurer l'effet causal d'un facteur sur le risque d'être responsable d'un accident. Néanmoins, la validité des analyses en responsabilité repose sur l'hypothèse, discutable, que les non-responsables sont représentatifs des circulants. L'objectif de cette thèse est donc de déterminer si les données disponibles d'accidentés permettent de fournir, via les analyses en responsabilité, des estimations des effets causaux sans biais, et notamment sans un biais de sélection résiduel. Nous montrons dans cette thèse que, dès lors que l'inclusion dépend de la gravité de l'accident, et que le facteur étudié a un impact sur la vitesse, il est impossible d'estimer l'effet causal du facteur sur le risque d'être responsable de l'accident grave sans un biais de sélection résiduel. Ce résultat est tout d'abord démontré de manière formelle, grâce à l'utilisation des modèles causaux structuraux. Ces modèles sont fondés sur une structure graphique, le DAG, qui représente les différentes relations entre les variables. Ce DAG permet la description des variables réellement observées, mais également des variables contrefactuelles, variables observables dans un monde contrefactuel où l'on aurait fixé l'exposition à une certaine valeur. L'effet causal étant défini à partir de ces variables contrefactuelles partiellement observées, c'est la structure du DAG qui permet de déterminer si l'effet causal peut être estimé en fonction des variables observées. Or, la structure du DAG conduisant à la survenue d'un accident grave ne permet pas d'exprimer l'effet causal du facteur étudié sur la responsabilité de l'accident grave en fonction des distributions observées sur les accidentés graves. Conditionner les estimations sur les accidentés graves correspond à ajuster sur une variable du DAG appelée « collider », et ainsi à introduire un biais dit de collision. En générant un modèle relativement simple, nous donnons à nos résultats théoriques une illustration numérique. En effet, lorsque les données ne dépendent pas de la gravité de l'accident, ou que le facteur étudié n'a pas d'effet sur la vitesse, la mesure estimable à partir des analyses en responsabilité est une mesure sans biais de l'effet causal, sous certaines hypothèses de prévalences faibles. Lorsque l'inclusion dépend de la gravité de l'accident, il existe un biais et ce biais induit par les analyses en responsabilité est d'autant plus grand que l'intensité de la relation entre le facteur et la vitesse, et celle entre la vitesse et l'accident est grand. Les schémas d'étude présentés permettent d'approcher des situations où le facteur étudié serait l'alcool ou le cannabis. Dans le cas de l'alcool, il apparait que sous le modèle simple considéré, la mesure d'association estimable serait une sous-estimation de l'effet causal. En revanche, dans le cas du cannabis, la mesure d'association correspondrait à une sur-estimation de l'effet causal. D'autre part, les outils de l'inférence causale nous ont permis de fournir une description formelle de la validité externe et interne, ainsi qu'une description formelle de la mesure d'association estimable via les analyses en responsabilité. Cette question de la validité interne d'une mesure se pose dans d'autres champs d'application que la sécurité routière. Elle se pose notamment dans le cas du paradoxe de l'obésité [etc...] / Many factors associated with the risk and severity of road accidents are now widely considered as causal : alcohol, speed, usage of a mobile phone... Therefore, questions asked by decision-makers now mostly concern the magnitude of their causal effects, as well as the burden of deaths or victims attributable to these various causes of accident. One particularity of road safety epidemiology is that available data generally describe drivers and vehicles involved in road accidents only, or even severe road accidents only. This extreme selection precludes the estimation of causal effects. To circumvent this absence of « control » population of non-crash involved drivers, it is common to use responsibility analysis and to assess the causal effect of a given factor on the risk of being responsible for an accident among involved drivers. The underlying assumption is that non-responsible drivers represent a random sample of the general driving population that was « selected » to crash by circumstances beyond their control and therefore have the same risk factor profile as other drivers on the road at the same time. However, this randomness assumption is questionable. The objective of this thesis is to determine whether available data in road safety allow us to assess causal effects on responsibility without a residual selection bias. We show that a good approximation of causal effect of a given factor on the risk of being responsible is possible only if the inclusion into the dataset does not depend on the severity of the accident, or if the given factor has no effect on speed. This result is shown by using the Structural Causal Model (SCM) framework. The SCM framework is based on a causal graph : the DAG (directed acyclic graph), which represents the relationships among variables. The DAG allows the description of what we observe in the actual world, but also what we would have observed in counterfactual worlds, if we could have intervened and forced the exposure to be set to a given level. Causal effects are then defined by using counterfactual variables, and it is the DAG’s structure which determines whether causal effects are identifiable, or recoverable, and estimable from the distribution of observed variables. However, the assumptions embedded in the DAG which describes the occurence of a severe accident does not ensure that a causal odds ratios is expressible in terms of the observable distribution. Conditioning the estimations on involved drivers in a severe crash correspond to conditioning on a variable in the DAG called « collider », and to create a « collider bias ». We present numerical results to illustrate our theoretical arguments and the magnitude of the bias between the estimable association measure and some causal effects. Under the simple generative model considered, we show that, when the inclusion depends on the severity of the accident, the bias between the estimable association measure and causal effect is larger than the relation between the exposure and speed, or speed and the occurrence of a severe accident is strong. Moreover, the presented designs allow us to describe some situations where the exposure could be alcohol or cannabis intoxication. In the case of alcohol, where alcohol and speed are positively correlated, the estimable associational effect underestimates the causal effect. In the case of cannabis, where cannabis and speed are negatively correlated, the estimable associational effect overestimates the causal effect. On the other hand, we provide a formal definition of internal and external validity, and a counterfactual interpretation of the estimable quantity in the presence of selection bias, when causal effects are not recoverable. This formal interpretation of the estimable quantity in the presence of selection bias is not only useful in the context of responsibility analyses. It is for instance useful to explain the obesity paradox
9

Bodový systém jako nástroj silniční bezpečnosti / The Point System as a Road Safety Tool

Habásko, Jakub January 2011 (has links)
HABÁSKO Jakub: The Point System as a Road Safety Tool. The Master´s thesis of Master degree, second grade, school year 2010/2011, Brno University of Technology, Institute of Forensic Engineering, May 2011, pages 198, pictures 12, tables 6, supplements 21. The thesis is elaborated in frame of the Master degree, study branch Expert Engineering in Transport. In this diploma thesis is in detail introduced Penalty Point System in our country and in other selected european countries. The thesis further contains the part about comparing Road Safety in our country and in other selected countries from the point of view of statistics. Most frequented offences and criminal offences in our country were analyzed. In the final part of this thesis is the suggestion of changes in point system. In the last chapter is introduced actual amendment of the Road Safety Act.
10

Markering av dolda objekt på väg genom användning av förstärkt verklighet.

Sjödin, Filip January 2019 (has links)
Enligt en rapport från trafikverket förekommer kollisioner vid väghållningsarbeten mellan väghållningsfordon och objekt täckta av väglag. Dessa trafikolyckor kan leda till personskador, skador på infrastruktur och skador på de inblandade väghållnings-fordonen. Som lösning på detta problem har möjligheten att visuellt markera de dolda objekten med förstärkt verklighet undersökts. Olika implementationer och metoder för användning av förstärkt verklighet studerades först för att få en bra upp-fattning om ämnet. En applikation utvecklades därefter till mobiltelefon med opera-tivsystemet Android i utvecklingsmiljön Unity. För förstärkt verklighet i applikat-ionen användes en natural feature tracking implementation av ARCore. Positioner-ingstester utfördes med Mobiltelefonens inbyggda GPS vilket visade en stor felmar-ginal. Applikationen utgår därför från en fast startpunkt inmätt med geodetisk mät-utrustning för ökad positioneringsnoggrannhet. För markering av de dolda objekten användes en lösning med cirkelbaserat skapande av tredimensionella objektmarkörer där cirklarnas radie utgick från startpositionen. Användning av applikationen gav va-rierande resultat beroende på den trafiksituation den används i och avståndet från startpositionen. Objektens position markeras tydligast i situationer där mobiltelefo-nen närmar sig det objekt som ska markeras på en väg i en riktning parallellt med cirkelns radie. Sämre tydlighet uppnåddes i situationer där mobiltelefonen närmar sig på en väg med en riktning parallell med cirkelns tangent eller på öppna ytor likt parkeringsplatser. Positioner för olika testobjekt mättes också med geodetisk mätut-rustning för hög precision för att få tillgång till en testmiljö där pålitligt data kunde hämtas upprepade gånger. Resultaten visar att den implementation av ARCore som finns i applikationen är känslig för avbrott i spårning av omgivningen och kan leda till fel i positionering. Ett fel i avståndsberäkningen finns också i programmet. Där-för är vidareutveckling och mer tester ett krav innan applikationen kan fungera i skarpt läge. / According to a report from Trafikverket collisions occur in road maintenance work with road maintenance vehicles and objects hidden by road conditions. These traffic accidents can lead to personal injury, damage to infrastructure and damage to the road maintenance vehicles involved. As a solution to this problem the possibility of visually marking the hidden objects with the use of augmented reality has been ex-amined. Different implementations and methods for use of augmented reality were first studied to get a good understanding of the subject. An application for mobile telephone was developed with the development platform Unity. The targeted oper-ating system for the mobile telephone was Android. A natural feature tracking imple-mentation of ARCore was used to bring features of augmented reality to the applica-tion. Tests were done to measure the precision of the mobile telephone’s GPS which showed a large margin for error. The application therefore uses a fixed start-ing location which has been measured with geodetic-measuring equipment for in-creased positioning accuracy. To visualize the position of the hidden objects a solu-tion with circle based creation of three-dimensional object markers was used where the radius of the circles originated from the starting position. Use of the application led to varied results which depended on the traffic situation and distance from the start position. The positions of the objects are marked more clearly in situations where the mobile phone is approaching the objects on a road and in a direction par-allel to the circle’s radius. Lower accuracy was generally achieved in situations where the mobile phone was approaching the objects on a road in a direction paral-lel to the circle’s tangent or in open areas like a parking lot. Positions for different test objects were also measured to achieve a test-environment where reliable data could be extracted repeatedly. The results of this study showed that the implemen-tation of ARCore used in this application is sensitive to disruption in the real-world registration of the mobile telephone’s position, which can lead to errors in position-ing. An error in calculating the distance to the objects also exists in the application. Therefore, before the application can be used in a real-life situations further devel-opment and tests are required.

Page generated in 0.0811 seconds