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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.
11

An Integrated Data Acquisition System for Parachute Development and Qualification Testing

Starbuck, Philip 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / The development and qualification of personnel and cargo aerial delivery parachute systems present unique challenges to the instrumentation and data analysis engineers. Some of the areas that must be addressed include: a) system must be low in cost, b) system often has to be operated on ranges that have limited telemetry or other range instrumentation and support (i.e. commercial skydiving centers), c) system is often rigged and operated by parachute support personnel and test jumpers rather than instrumentation engineers, and d) system must be able to be reconfigured in the field to support a variety of test card requirements during a typical test day, e) data must be available for review and the system be prepared for the next test within a few minutes of parachute recovery, and f) system must withstand ground impact velocities as high as 50 ft/sec (15.24 m/sec) without damage. This paper describes such a system as it is being used for the development and qualification testing of a number of parachute systems for sport skydiving, military personnel, as well as cargo parachute systems. This modular system has been developed as a result of previous experience in other parachute development and qualification projects to address the need for a flexible Data Acquisition System (DAS) system that meets the above requirements. This paper describes some of the tools used to meet these requirements.
12

Evaluating and Improving the Transport Efficiency of Logistics Operations

Fu, Jiali January 2017 (has links)
The thesis focuses on evaluating and improving the transport efficiency of two types of logistics operations in the supply chain. One research area is the production of raw material in construction operations, specifically earthmoving operations. Methods and tools are developed to provide decision support in improving the transport efficiency of earthmoving at the vehicle and the systems levels. Using known road topography and a GPS unit, an optimal control problem is formulated and solved (Paper III) to determine the optimal gear shift sequence and timing in order to improve the transport efficiency at the vehicle level. For decision support at the systems level, a Fleet Performance Simulation (FPS) model is designed (Paper IV) to evaluate the transport efficiency for a given mix of construction vehicles in earthmoving. The FPS system is integrated with an optimization algorithm to solve the optimal fleet composition problem for earthmoving operations (Paper V &amp; VI). Construction operations are dynamic and the environment is changing constantly, which bring difficulties in decision-making. Using GPS data from construction vehicles, a map inference framework (Papers I &amp; II) is developed to automatically extract relevant input to decision support at the vehicle and the systems levels, which include the locations of various workstations, driving time distributions and road networks. The second research area is the transport efficiency of urban distribution system, which is in the final phase of the supply chain. An off-peak delivery pilot project in Stockholm is used as the background, designed to evaluate the potential for commercial vehicles to make use of off-peak hours for goods delivery. The thesis (Paper VII) evaluates the transport efficiency impacts of the off-peak pilot. An evaluation framework is defined where transport efficiency is studied in a number of dimensions. GPS data, fleet management data, and logistic information are used to assess the impacts. / <p>QC 20170323</p>
13

A utilização de dados de GPS de rastreamento de veí­culos para extrair indicadores operacionais do transporte urbano de cargas: estudo de caso no Brasil. / The use of GPS tracking data to extract logistics performance indicators of urban freight: case study in Brazil.

Andrade, Patricia Faias Laranjeiro de 20 March 2019 (has links)
Esta pesquisa propõe uma abordagem genérica de processamento de dados de rastreamento de veículos de carga com a finalidade de extrair indicadores de desempenho logístico no contexto urbano. Tais indicadores são importantes para caracterizar como as operações logísticas se desenvolvem nas cidades e subsidiar o processo de tomada de decisão dentro do âmbito do planejamento urbano de cargas, por parte do poder público. Esta abordagem é aplicada a três bases de dados - para a Região Metropolitana de São Paulo (RMSP) - obtidas junto a empresas privadas distintas, sendo duas grandes redes varejistas e a terceira uma provedora de serviços de mapas. Apesar de algumas limitações nos dados disponíveis, foi possível identificar paradas dos caminhões e analisar suas características, como: distribuição espacial e temporal, frequência de paradas por veículo, a localização de clusters de paradas etc. Além disso, foi possível classificar do os veículos que circulam na cidade distinguindo a parcela que corresponde ao \'fluxo de passagem\", veículos que estão apenas cruzando a cidade (São Paulo) e, por fim, apresentou-se também um estudo do perfil de velocidades - por hora e dia da semana - em uma importante via arterial de São Paulo. Os resultados e análises desta pesquisa reforçam que há grande potencial na utilização de dados de rastreamento de veículos de carga no contexto do planejamento de transporte urbano de cargas, embora este dependa em parte de algumas especificidades dos dados, como a frequência dos registros, a precisão da posição geográfica coletada, além da necessidade de um processamento otimizado devido ao grande volume de dados. / The purpose of this research is a general approach for processing tracking data of cargo vehicles in order to extract logistic performance indicators in the urban scenario, essential to characterize how logistic operations are developed and support the decision-making process within the scope of urban freight planning by the public sector. This approach is applied to three data bases - for the São Paulo Metropolitan Region (SPMR) - acquired from different private companies, being two large retailers and the third a great mapping services provider. In spite of available data limitations, it was possible to identity truck stops and analyze its particulars, such as: spatial and temporal distribution, stop frequency per vehicle, the location of stop clusters, etc. Apart from that, it was possible to classify among the flow of vehicles in the city, the ones that are just passing, crossing the city, and ultimately, it was presented a speed profile analysis - per day and week day - of an important arterial way of São Paulo. The results and analysis of this research reinforce that there is great potential in the use of cargo vehicle tracking data for urban freight planning, even though it partially depends on some data specifics, such as frequency of records, location accuracy, besides the need of an optimized data processing due to their great volume.
14

A contemporary machine learning approach to detect transportation mode - A case study of Borlänge, Sweden

Golshan, Arman January 2020 (has links)
Understanding travel behavior and identifying the mode of transportation are essential for adequate urban devising and transportation planning. Global positioning systems (GPS) tracking data is mainly used to find human mobility patterns in cities. Some travel information, such as most visited location, temporal changes, and the trip speed, can be easily extracted from GPS raw tracking data. GPS trajectories can be used as a method to indicate the mobility modes of commuters. Most previous studies have applied traditional machine learning algorithms and manually computed data features, making the model error-prone. Thus, there is a demand for developing a new model to resolve these methods' weaknesses. The primary purpose of this study is to propose a semi-supervised model to identify transportation mode by using a contemporary machine learning algorithm and GPS tracking data. The model can accept GPS trajectory with adjustable length and extracts their latent information with LSTM Autoencoder. This study adopts a deep neural network architecture with three hidden layers to map the latent information to detect transportation mode. Moreover, different case studies are performed to evaluate the proposed model's efficiency. The model results in an accuracy of 93.6%, which significantly outperforms similar studies.
15

Road Estimation Using GPS Traces and Real Time Kinematic Data

Ghanbarynamin, Samira 29 April 2022 (has links)
Advance Driver Assistance System (ADAS) are becoming the main issue in today’s automotive industry. The new generation of ADAS aims at focusing on more details and obtaining more accuracy. To achieve this objective, the research and development parts of the automobile industry intend to utilize Global Positioning System (GPS) by integrating it with other existing tools in ADAS. There are several driving assistance systems which are served by a digital map as a primary or a secondary sensor. The traditional techniques of digital map generation are expensive and time consuming and require extensive manual effort. Therefore, having frequently updated maps is an issue. Furthermore, the existing commercial digital maps are not highly accurate. This Master thesis presents several algorithms for automatically converting raw Universal Serial Bus (USB)-GPS and Real Time Kinematic (RTK) GPS traces into a routable road network. The traces are gathered by driving 20 times on a highway. This work begins by pruning raw GPS traces using four different algorithms. The first step tries to minimize the number of outliers. After the traces are smoothed, they tend to consolidate into smooth paths. So in order to merge all 20 trips together and estimate the road network a Trace Merging algorithm is applied. Finally, a Non-Uniform Rational B-Spline (NURBS) curve is implemented as an approximation curve to smooth the road shape and decrease the effect of noisy data further. Since the RTK-GPS receiver provides highly accurate data, the curve resulted from its GPS data is the most sufficient road shape. Therefore, it is used as a ground truth to compare the result of each pruning algorithm based on data from USB-GPS. Lastly, the results of this work are demonstrated and a quality evaluation is done for all methods.
16

Understanding social and community dynamics from taxi GPS data

Chen, Chao 04 July 2014 (has links) (PDF)
Taxis equipped with GPS sensors are an important sensory device for examining people's movements and activities. They are not constrained to a pre-defined schedule/route. Big taxi GPS data recording the spatio-temporal traces left by taxis provides rich and detailed glimpse into the motivations, behaviours, and resulting dynamics of a city's mobile population through the road network. In this dissertation, we aim to uncover the "hidden facets" regarding social and community dynamics encoded in the taxi GPS data to better understand how urban population behaves and the resulting dynamics in the city. As some "hidden facets" are with regard to similar aspect of social and community dynamics, we further formally define three categories for study (i.e. social dynamics, traffic dynamics, and operational dynamics), and explore them to fill the wide gaps between the raw taxi GPS data and innovative applications and smart urban services. Specifically, 1. To enable applications of real-time taxi fraud alerts, we propose iBOAT algorithm which is capable of detecting anomalous trajectories "on-the-fly" and identifying which parts of the trajectory are responsible for its anomalousness, by comparing them against historically trajectories having the same origin and destination. 2. To introduce cost-effective and environment-friendly transport services to citizens, we propose B-Planner which is a two-phase approach, to plan bi-directional night bus routes leveraging big taxi GPS data. 3. To offer a personalized, interactive, and traffic-aware trip route planning system to users, we propose TripPlanner system which contains both offline and online procedures, leveraging a combination of Location-based Social Network (i.e. LBSN) and taxi GPS data sets. Finally, some promising research directions for future work are pointed out, which mainly attempt to fuse taxi GPS data with other data sets to provide smarter and personalized urban services for citizens
17

Travel Time Estimation Using Sparsely Sampled Probe GPS Data in Urban Road Networks Context

Hadachi, Amnir 31 January 2013 (has links) (PDF)
This dissertation is concerned with the problem of estimating travel time per links in urban context using sparsely sampled GPS data. One of the challenges in this thesis is use the sparsely sampled data. A part of this research work, i developed a digital map with its new geographic information system (GIS), dealing with map-matching problem, where we come out with an enhancement tecnique, and also the shortest path problem.The thesis research work was conduct within the project PUMAS, which is an avantage for our research regarding the collection process of our data from the real world field and also in making our tests. The project PUMAS (Plate-forme Urbaine de Mobilité Avancée et Soutenable / Urban Platform for Sustainable and Advanced Mobility) is a preindustrial project that has the objective to inform about the traffic situation and also to develop an implement a platform for sustainable mobility in order to evaluate it in the region, specifically Rouen, France. The result is a framework for any traffic controller or manager and also estimation researcher to access vast stores of data about the traffic estimation, forecasting and status.
18

Sběr a vyhodnocení dat z GPS pro letecký průmysl / Acquirement and Interpretation of GPS Data for Aerospace Industry

Rejman, Lukáš January 2011 (has links)
This thesis deals with design and implementation of collecting data from GPS device. The proposed solution provides storage of the current GPS information in NMEA standard, where each sentence of this standard are stored in XML le. Record performs GPS device based on Windows Mobile 6.1 system, which communicates with built-in module and the data are stored in XML format. Thus, stored data is interpreted using Interpret GPS data, which uses Google Maps to display information about the track.
19

Určení přetvoření železničního svršku / Deformation Surveying of Railway Track

Štrba, Peter January 2014 (has links)
The aim of this diploma thesis is to specify the displacement and deformations of the railway tracks axis on bridge structures in cities of Zábřeh na Moravě and Břeclav. The bridge structures covered have great dilatation distances, therefore it is necessary to monitor the movements of the railway tracks depending on climatic conditions. GPS methods have been used throughout the whole measurement and data processing. The result includes also a comparison of GPS and conventional methods. The result of the thesis is a detection of proven displacements. One of the goals of the thesis is the comparison of the displacements and the accuracy using the method chosen by author of the thesis and using classical geodetic methods.
20

Analyse des Routenwahlverhaltens von Radfahrenden auf Grundlage GPS basierter Daten zum real beobachteten Verkehrsverhalten

Huber, Stefan 03 May 2022 (has links)
Eine an den Bedürfnissen von Radfahrer*innen orientierte Planung ist für die Förde-rung des Radverkehrs unumgänglich. Um den Ausbau der Radverkehrsinfrastruktur ent-sprechend zu planen, sind jedoch Informationen zum Routenwahlverhalten der Radfah-renden und dessen Einflussfaktoren notwendig. Mit diesen Informationen können z.B. Wirkungen von Maßnahmen oder die zukünftige Nutzung von geplanter Radverkehrsinf-rastruktur abgeschätzt werden. Aus diesem Grund wurden vor allem in der letzten Dekade zahlreiche internationale Arbeiten vorangetrieben, die die Routenwahl auf Basis von GPS-basierten Daten zum real beobachteten Routenwahlverhalten untersuchten. Da die Studien meist für einzelne und nichtdeutsche Städte durchgeführt wurden, lassen sich die Ergebnisse jedoch nicht direkt auf den deutschen Raum übertragen. Um die Einflussfaktoren der Routenwahl für den deutschen Raum zu untersuchen, wird in dieser Arbeit die Routenwahl von Radfahrenden im Raum Dresden analysiert. Ba-sis der Untersuchung stellt ein während der Aktion STADTRADELN erhobener GPS-Daten-satz dar, der 18.459 Radfahrten von 1.361 Radfahrer*innen enthält und Auskunft über deren real beobachtetes Routenwahlverhalten gibt. Die erhobenen Routendaten wurden mit unterschiedlichen Verfahren aufbereitet und über ein Verkehrsnetz mit Sekundärda-ten angereichert, sodass die Eigenschaften der gewählten Routen berechnet und den je-weils erzeugten und nicht gewählten Routenalternativen gegenübergestellt werden konn-ten. Der Einfluss der unterschiedlichen Faktoren wurde anschließend mittels logistischer Regressionsanalyse untersucht. Das Ergebnis der Untersuchung zeigt auf, dass sich die folgenden Einflussfaktoren positiv auf die Routenwahl auswirken: + Existenz von Radverkehrsinfrastruktur + Geringe Längsneigungen + Gute Oberflächenbeschaffenheit (z.B. Asphalt) + Vorhandensein anderer Radfahrender entlang einer Route + Geringe zulässige Maximalgeschwindigkeit des motorisierten Verkehrs + Geringe Fahrstreifenanzahl des Kfz-Verkehrs + Durch Lichtsignalanlagen geregelte Knotenpunkte + Grün- und Wohngebietsflächen Demgegenüber üben die folgenden Einflussfaktoren einen negativen Einfluss auf die Wahl einer Route aus: – Zunehmende Distanz – Hohe Streckenanteile mit großer Längsneigung – Eine hohe maximale Längsneigung der Route – Geringe Breite der Radverkehrsführung – Höhere Unfallhäufigkeit entlang der Route Für einige Einflussfaktoren konnte kein (signifikanter) Einfluss auf die Routenwahl nachgewiesen werden. Dazu gehören bspw. die durchschnittlich tägliche Verkehrsstärke des Kfz-Verkehrs, der ruhende Verkehr oder die Häufigkeit von „rechts-vor-links“ geregel-ten Knotenpunkten. Die vorliegende Arbeit konnte dazu beitragen, die Wirkung der Einflussfaktoren auf die Routenwahl im Radverkehr einer deutschen Stadt zu quantifizieren. Eine Stärke der Untersuchung liegt in der Erhebung und Nutzung des umfangreichen GPS-Datensatzes zum real beobachteten Routenwahlverhalten der Radfahrer*innen. Das resultierende Routenwahlmodell kann für die Abschätzung von Maßnahmenwirkungen genutzt werden (z.B. im Rahmen der Verkehrsnachfragemodellierung). Eine kritische Reflexion der Ergebnisse und Methoden zeigt, dass die Qualität der Ana-lyse und ihrer Ergebnisse durch die Nutzung weiterer Sekundär- und Primärdaten sowie anderer Methoden weiter verbessert werden kann. Die Ergebnisse der Untersuchung geben einen Einblick in die Routenwahl der Radfah-renden des Untersuchungsgebiets. Im Rahmen der Arbeit konnte nicht geprüft werden, ob die Routenwahl der Radfahrer*innen in Dresden vergleichbar mit der Routenwahl in anderen deutschen Städten ist. Das entwickelte Verfahren kann jedoch auch für Analysen in anderen Städten angewendet werden, sodass verlässliche Aussagen zur Routenwahl deutscher Radfahrender in anderen deutschen Kommunen erarbeitet werden können. Es lassen sich insgesamt folgende Schlussfolgerungen ziehen: Um den Radfahrenden eine möglichst attraktive Radverkehrsinfrastruktur zu bieten und damit die Nutzung des Fahrrads zu fördern, sollte der Radverkehr auf eigener Radverkehrsinfrastruktur geführt werden, die möglichst breit ist und eine gute Oberflächenqualität besitzt. Entlang der Rad-routen sollten die Geschwindigkeiten des fließenden motorisierten Verkehrs möglichst reduziert werden. Die Bündelung von Radverkehrsströmen sowie die Führung durch Grünflächen kann zudem Fahrtkomfort und Sicherheitsempfinden erhöhen. / User-oriented bicycle planning is essential for the promotion of cycling in cities. In order to adequately plan and build cycling infrastructure, information on route choice be-haviour of cyclists and its influencing factors is essential. The knowledge about influencing factors of bicycle route choice can help to assess the effect of measures as well as future or potential utilisation of planned cycling infrastructure. Several international studies – particularly carried out in the last decade – examined route choice based on GPS-based revealed preference data. As the studies were mostly conducted for few and non-German cities the results, however, cannot be directly trans-ferred to the German area. In order to investigate bicycle route choice for the German area, the route choice of cyclists in the city of Dresden is analysed in this study. The basis of the investigation is a GPS data set collected during the CITY CYCLING campaign. It contains 18,459 bicycle trips by 1,361 cyclists and provides detailed information about the observed route choice be-haviour of cyclists. The collected route data were processed by using different methods. Linking the routes to a traffic supply network allowed enriching them with secondary data so that characteristics of the selected routes and the non-selected generated alternatives were determined. The influence of the different factors was investigated using logistic re-gression analysis. The results of the study reveal that the following influencing factors positively affect bicycle route choice: + Existence of cycling infrastructure + Low slopes + Good surface conditions (e.g. asphalt) + Presence of other cyclists along a route + Low maximum speed of motorised traffic + Few number of lanes for motorised traffic + Intersections controlled by traffic signals + Green and residential areas In contrast, the following factors show a negative influence on bicycle route choice: – Increasing distance – High proportion of routes with steep longitudinal gradients – A high maximum gradient along the route – Narrow width of the cycle lane – Higher accident frequency along the route For some influencing factors, no (significant) influence on route choice was found (e.g. for the average daily traffic volume of motorized traffic, stationary traffic or the frequency of right-of-way regulated intersections). The present study contributes to the quantification of influencing factors or rather their effect on bicycle route choice in a German city. Furthermore, the resulting route choice model can be used to estimate the effects of different measures (e.g. in the context of traffic demand modelling). A strength of the study is the extensive data set on revealed preferences of cyclists that has been used to analyse route choice behaviour. A critical reflection of the results and methods shows that the quality of the analysis and its results could further be improved by using more secondary and primary data as well as other models for analysis. The results of the study provide an insight into route choices of cyclists in the study area. However, it could not be determined whether route choice of cyclists in Dresden is similar to route choice of cyclists in other German cities. Nevertheless, the developed method could also be used to analyse route choice in other cities, so that reliable state-ments on route choice of German cyclists can be compiled. Overall, the following conclusions can be drawn: in order to provide cyclists the most attractive cycling infrastructure possible and, thus, promote the use of cycling in cities, bicycle traffic should be guided on dedicated and wide cycling infrastructure with good surface quality. Furthermore, the speed of moving motorised traffic should be reduced along the route segments if possible. Bundling of cycling traffic flows and routing cyclists through green spaces can furthermore increase riding comfort and the perception of safety.

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