• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 137
  • 62
  • 30
  • 29
  • 6
  • 6
  • 4
  • 4
  • 4
  • 2
  • 2
  • 1
  • Tagged with
  • 344
  • 52
  • 52
  • 46
  • 38
  • 34
  • 34
  • 33
  • 33
  • 30
  • 28
  • 25
  • 24
  • 24
  • 24
  • 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.
61

Lane-Based Front Vehicle Detection and Its Acceleration

Chen, Jie-Qi 02 January 2013 (has links)
Based on .Net Framework4.0 development platform and Visual C# language, this thesis presents various methods of performing lane detection and preceding vehicle detection/tracking with code optimization and acceleration to reduce the execution time. The thesis consists of two major parts: vehicle detection and tracking. In the part of detection, driving lanes are identified first and then the preceding vehicles between the left lane and right lane are detected using the shadow information beneath vehicles. In vehicle tracking, three-pass search method is used to find the matched vehicles based on the detection results in the previous frames. According to our experiments, the preprocessing (including color-intensity conversion) takes a significant portion of total execution time. We propose different methods to optimize the code and speed up the software execution using pure C # pointers, OPENCV, and OPENCL etc. Experimental results show that the fastest detection/tracking speed can reach more than 30 frames per second (fps) using PC with i7-2600 3.4Ghz CPU. Except for OPENCV with execution rate of 18 fps, the rest of methods have up to 28 fps processing rate of almost the real-time speed. We also add the auxiliary vehicle information, such as preceding vehicle distance and vehicle offset warning.
62

Development of a Control Systems Platform for an Autonomous Soft-Car

Ray, Pratish January 2015 (has links)
Balloon Cars (Soft Cars) used for active-system testing are presently statically following one specific path. Autonomous GPS driven balloon cars can be extremely useful if made to be accurate.Volvo group’s long term plan involves usage of such cars to improve active-safety systems. Thisreport presents comprehensive details about the development of the control system of the soft-car.Software development was preceded by purchase of parts. Detailed descriptions of the ballooncar hardware components are presented. Various hardware components were interconnected toform a CAN Bus network. This thesis work describes CAN networks in general and with referenceto the developed Linux based software system.The navigation system is presented in the thesis report using a ‘bottom up’ approach. First theLow-level functions and variables are described that directly control the hardware component.They are called by high level functions that are subsequently explained. The high level functionsinclude accurate turning and an automated lane change process.The high level functions may be sequentially called and to accurately follow a specific path. Various lines and points may be used in a user defined Cartesian coordinate system. Details about theperformance of various high level functions as well as of a demonstration of a pattern are presented along with the limitations of the overall system.
63

Entry-lane capacity analysis of roundabouts in Texas using VISSIM, SIDRA, and the highway capacity manual

Mills, Alison Fayre 29 September 2011 (has links)
Road safety and traffic congestion are two of the critical issues facing the transportation profession today. As a means to promote safety and efficiency at United States intersections modern roundabouts are becoming more and more common. Over the last ten years, roundabouts implementation methodologies have been developed using data collected at U.S. roundabouts. These methodologies were first published in National Cooperative Highway Report 572: Roundabouts in the United States and more recently in the second edition of the national roundabout guidelines. This work attempts to validate the use of these methodologies for roundabouts in the state of Texas and also enhance guidelines for evaluating roundabout operations by exploring the effects of exiting flow, origin-destination patterns, and mean speed on roundabout entry-lane capacity. Capacity results from VISSIM are compared to the Highway Capacity Manual entry-lane capacity curve and results from SIDRA. / text
64

Development of a Driver Model for Vehicle Testing / Framtagning av förarmodell för fordonstester

Jansson, Andreas, Olsson, Erik January 2013 (has links)
The safety requirements for vehicles are today high and they will become more stringent in the future. The car companies test their products every day to ensure that safety requirements are met. These tests are often done by professional drivers. If the car is tested in an everyday traffic situation, a normal experienced driver is desired. A drawback is that a human will eventually learn the manoeuvre he/she is told to do. An artificial driver is therefore to prefer to make the test repeatable. This thesis’ purpose is to develop and implement an artificial driver as a controller in order to follow a predefined trajectory. The driver model’s performance driving a double lane change manoeuvre should be as close to a real driver’s as possible. Data was gathered by inviting people to drive in a simulator. The results from the simulator tests were used to implement three different drivers with different experiences. The gathered data was used to categorize the test drivers into different driver types for each specific velocity by using the vehicle position from thetest results. This thesis studies the driver from a controller’s perspective and it resulted in two implemented controllers for reference tracking. The first approach was a Model Predictive Controller with reference tracking and the other approach was to use a FIR-filter in order to describe the drivers’ characteristics. A vehicle model was implemented in order to do the double lane change manoeuvre in a simulation environment together with the implemented driver model. The results show that the two approaches can be used for reference tracking. The MPC showed good results with the recreation of the test runs that were made by the categorized drivers. The FIR-filter had problems to mimic the drivers’ test runs and their characteristics. The advantage with MPC is its robustness, while the advantages with the FIR-filter are its, in comparison, simplicity in the implementation and the algorithm’s low computational cost. In order to make the FIR-filter more robust, some improvements have to be made. One improvement is to use gain scheduling in order to adjust the filter coefficients depending on thevelocity. / De säkerhetskraven som idag ställs på fordon är höga och det kommer bli mer strikt i framtiden. Bilföretag testar sina bilar varje dag för att se om komponenterna och bilen klarar säkerhetskraven som ställs. Till dessa tester används professionella testförare. I en vardaglig trafiksituation är det önskvärt att en normalt erfaren bilförare utför testen. En mänsklig förare kommer använda sin inlärningsförmåga vid repeterande manöver, vilket inte är önskvärt. En artificiell förare är därför att föredra. Den artificiella föraren ska köra så likt en verklig förare som möjligt vid en "double lane change"- (DLC) manöver. Detta examensarbete har som avsikt att implementera en förare som en regulator för att kunna följa en förutbestämd trajektoria på samma sätt som en verklig förare. I detta examensarbete har "DLC"-manövern studerats. I examensarbetet har insamlad data från testförare använts för att kunna implementera tre olika förartyper med olika erfarenheter. Den insamlade datan användes till att kategorisera testförarna för varje särskild hastighet. Två tillvägagångssätt har gjorts med föraren, en där föraren är en modellbaserad prediktionsregulator med referensignalsföljning (MPC) och en där föraren implementeras som ett ändligt impulssvarsfilter (FIR-filter). En fordonsmodell har implementerats för att en "DLC"-manöver ska kunna testas i en simuleringsmiljö. Resultaten blev att de två metoderna klarade av referensföljningen. MPC:n var bra på att återskapa testförararnas körningar. FIR-filtret hade problem med att härma förarnas körningar och deras karaktäristik. Fördelen med MPC är dessrobusthet och fördelen med FIR-filtret är dess, i jämförelse, simplicitet vid implementering samt den låga beräkningskostnaden för algoritmen. För att göra FIR-filtret mer robust måste förbättringar göras. En förbättring är att använda gain scheduling för att anpassa filterkoefficienterna beroende på hastigheten.
65

Improvements for Waran-patients in Finspång / Förbättringsarbete för Waran-patienter i Finspång

Lennartsson, Emma January 2014 (has links)
Närsjukvården i Finspång har idag 540 patienter som är i behov av, och behandlas med det blodförtunnande läkemedlet Waran. Läkemedlet ges till de som drabbats av blodpropp (bentrombos/lungemboli), förmaksflimmer eller har klaffproteser. Patienterna besöker i stor del den mottagning som finns på Finspångs Lasarett men det finns de som av olika anledningar inte kan ta sig till mottagningen, främst beroende på att de lider av andra sjukdomar som gör att de har svårt att förflytta sig längre sträckor. Därför besöks de i hemmet och där tar DS de prover som behövs. Grunden till projektet Närsjukvården i Finspång-Förbättringsarbete för Waran-patienter i Finspång, är att hitta andra lösningar på hur situation kan förändras och därigenom också förbättras för de patienter där provtagningen måste ske i hemmet. Projektet har resulterat i en analys kring fyra olika scenarier som alla medförde förbättringar både vad gäller kostnader, transporter och tid. För att få en inblick i vilka scenarier som användes beskrivs de nedan. Scenario 1a visar en bild över situationen som den såg ut när fösta kartläggningen skedde i och med det första besöket på Närsjukvården i Finspång. Scenario 1b visar en bild över hur hanteringen av patienterna fungerar vid andra kartläggningen på Närsjukvården i Finspång. Här har vissa patientbesök redan ersatts med att patienterna själva, med hjälp av CoaguChek, genomför kontroll av sitt INR-värde. Scenario 2 liknar scenario 1a men istället för en distriktssköterska (DS) är det en biomedicinsk analytiker (BMA) som besöker patienterna och genomför provtagningen. Scenario 3 ger en bild över hur det ser ut när det är en DS som gör hembesöken men att provtagningen nu sker med hjälp av CoaguChek. Scenarier har därefter analyserats sinsemellan med fördelar och nackdelar och projektet har kommit fram till den lösning som projektet anser vara den bäst lämpade för hanteringen av Waran patienterna.
66

Piety, politics, and pedagogy : an Evangelical Protestant tradition in higher education at Lane, Oberlin, and Berea, 1834-1904.

Warford, Malcolm Lyle. January 1973 (has links)
Thesis (Ed.D.)--Teachers College, Columbia University, 1973. / Typescript; issued also on microfilm. Sponsor: Robert W. Lynn. Dissertation Committee: Douglas M. Sloan. Includes bibliographical references.
67

The Theatre-Royal in Drury Lane, 1711-1716, under Colley Cibber, Barton Booth, and Robert Wilks

Ashley, Leonard R. N. January 1962 (has links)
Thesis (Ph. D.)--Princeton University. / Reprint of 1957 microfilm ed., published by University Microfilms, Ann Arbor. Includes bibliographical references (leaves 539-545) and index.
68

The diplomatic career of Henry Lane Wilson in Latin America

Masingill, Eugene Frank, January 1957 (has links)
Thesis (Ph. D.)--Louisiana State University and Agricultural and Mechanical College, 1957. / Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 246-257).
69

The Public Career of Joseph Lane

Forsyth, Marjorie Phyllis 01 January 1942 (has links)
No description available.
70

Proposição de um método de codificação de rodovia de pista simples em região montanhosa a partir dos dados do Google Earth no microssimulador VISSIM : estudo de caso da rodovia ERS-115

Maman, Lucas Paim De January 2018 (has links)
A malha rodoviária brasileira é constituída predominantemente de rodovias de pista simples e boa parte delas encontra-se em regiões montanhosas. Rodovias de pista simples em regiões montanhosas possuem dificuldades de modelagem, porque as rampas elevadas e os raios de curvatura pequenos possuem impacto significativo no desempenho do tráfego. Adicionalmente, existem poucos estudos de simulação de tráfego de veículos em rodovias de pista simples, sobretudo em regiões montanhosas. Sendo assim, a combinação de rodovias de pista simples com região montanhosa é ainda mais restrita para codificação dessas redes em microssimuladores de tráfego. Dados de geometria de rodovias são comumente obtidos por meio de plataformas como o Google Earth, contudo sua precisão pode ser insuficiente para uma boa representação em regiões montanhosas, devido à influência significativa dos perfis planialtimétricos no desempenho do tráfego em rodovias de pistas simples. O presente trabalho desenvolveu uma metodologia para a codificação de rodovias de pista simples em região montanhosa. Esta metodologia foi aplicada em um estudo de simulação de tráfego através do microssimulador de tráfego VISSIM. O trecho de estudo de caso corresponde à 16 km de extensão da ERS-115 entre as cidades de Três Coroas e Gramado na Serra Gaúcha. A partir de dois bancos de dados (Google Earth e levantamento veicular a Laser), foram desenvolvidos três modelos: (i) modelo baseado nos dados originais do Google (Google original), (ii) modelo com perfil altimétrico suavizado (LOESS) e (iii) modelo com perfil planialtimétrico baseado em levantamento de campo a Laser (Laser). A comparação do perfil altimétrico dos três modelos revelou diferenças significativas entre o modelo do Google original em relação aos demais. O perfil altimétrico decorrente dos dados originais do Google Earth apresentou grandes declividades, na prática, incompatíveis com a classe da rodovia. O método proposto de suavização (LOESS) resultou em um modelo bem mais próximo do perfil real da rodovia, representado pelo modelo construído a partir do levantamento a laser. Com o objetivo de avaliar o desempenho através da simulação de tráfego nos 3 modelos foram executados 11 cenários de simulação. Os cenários envolveram 2 níveis de demanda: demanda baixa, compatível com condições de fluxo livre e uma demanda representativa das condições típicas de tráfego verificadas no trecho. Em relação à demanda em fluxo livre, veículos nos modelos Laser e LOESS apresentaram velocidades similares ao longo do estaqueamento, enquanto que o modelo Google original revelou diferenças significativas de velocidades. A análise do desempenho do tráfego nos cenários de demanda típica foi baseada nos tempos de viagem. Cenários nesta análise envolveram a segmentação da rodovia em trechos homogêneos e variações na proporção de veículos por sentido (split direcional). A comparação entre os tempos de viagem dos modelos LOESS e Laser resultou em R²=0,99, enquanto que R² obtidos entre os modelos Google original e Laser variaram no intervalo de 0,04 a 0,99. Os resultados obtidos apontam a importância da metodologia desenvolvida pelo presente trabalho na modelagem de rodovias de pista simples, sobretudo em região montanhosa. / The Brazilian road network consists predominantly of two-lane highways and great part of them are in mountainous regions. Two-lane highways in mountainous regions have modeling difficulties because high slopes and small bend radii have a significant impact on traffic performance. Additionally, there are few simulation studies of vehicle traffic on two-lane highways, especially in mountainous regions. Thus, the combination of two-lane highways and mountainous region is even more restricted for coding these networks into traffic microsimulators. Road geometry data are commonly obtained through platforms such as Google Earth, but their accuracy may be insufficient for good representation in mountainous regions due to significant influence of planialtimetric profiles on traffic performance on two-lane highways. The present work developed a methodology for the codification of two-lane highways in mountainous region. This methodology was applied in a simulation study of traffic through the VISSIM traffic microsymulator. The case study section corresponds to the 16 km extension of the ERS-115 between the cities of Três Coroas and Gramado in the Serra Gaúcha. From two databases (Google Earth and Laser Vehicle Survey), three models were developed: (i) model based on original Google data (Google original), (ii) model with smoothed altimetric profile (LOESS) and (iii) model with planialtimetric profile based on laser field survey (Laser). The comparison of altimetric profiles of the three models revealed significant differences between the Google original model in relation to the others. The altimetric profile derived from the original data of Google Earth presented great slopes, in practice, incompatible with the highway class. The proposed smoothing method (LOESS) resulted in a model that is closer to the actual road profile, represented by the model constructed from the laser survey. In order to evaluate the performance through the simulation of traffic in the three models, 11 simulation scenarios were executed. The scenarios involved two levels of demand: low demand, compatible with free flow conditions and a representative demand of the typical traffic conditions verified in the road segment. Regarding the free-flow demand, vehicles in Laser and LOESS models presented similar speeds along the road, while the Google original model revealed significant differences in speeds. The analysis of traffic performance in typical demand scenarios was based on travel times. Scenarios in this analysis involved the segmentation of the highway in homogeneous segments and variations in the proportion of vehicles by direction (directional split). The comparison of travel times of the LOESS and Laser models resulted in R² = 0.99, while R² obtained between the Google original and Laser models varied in the range of 0.04 to 0.99. The results obtained point out the importance of the methodology developed by the present work in the modeling of two-lane highways, especially in the mountainous region.

Page generated in 0.0419 seconds