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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.
891

Autoconfiguración de redes ad hoc basadas en confianza.

Sorribes Díaz, José Vicente 17 January 2022 (has links)
[ES] En la presente tesis se aborda el problema del descubrimiento de vecinos en redes estáticas inalámbricas ad hoc, redes sin infraestructura. En estas redes los nodos deben descubrir los vecinos como un primer paso tras el despliegue. Además se aborda el problema de creación de redes espontáneas basadas en la confianza, y el de selección de vecinos. Se han presentado distintos algoritmos que solucionan el problema siguiendo unas premisas que se irán relajando a lo largo de la tesis. Se han implementado esos algoritmos en Castalia 3.2 para su validación y comparación con otros protocolos de referencia. Los protocolos determinísticos presentan mejores resultados de simulación, aunque requieren que sigan una planificación en la transmisión. En cuanto al protocolo aleatorio CDPRR (Collision Detection Probabilistic Round Robin) no sigue una planificación pero requiere el conocimiento del número de nodos de la red. El protocolo CDH (Collision Detection Hello) permite el desconocimiento del número de nodos. Ambos logran el descubrimiento de los vecinos con probabilidad 1 mediante la detección de colisiones. Ambas propuestas obtienen mejores prestaciones que los protocolos usados como referencia. Tanto para CDH como para CDPRR se ha realizado un modelo analítico de determinadas métricas. Se ha propuesto un protocolo aleatorio basado en líder que permite obtener buenas prestaciones y se puede usar de forma asíncrona aunque solo permite su uso en entornos one-hop. Finalmente, se presenta un protocolo aleatorio consciente de la energía que permite buenos resultados para altos duty cycles y redes compuestas de pocos nodos. En cuanto a la creación de redes espontáneas basadas en la confianza, se ha propuesto un modelo que usa el protocolo CDPRR como base. Este protocolo de creación de redes espontáneas basadas en la confianza permite premisas más realistas y mejora un protocolo determinístico de referencia. Finalmente, se propone un protocolo que combina el descubrimiento y la selección de vecinos con el objetivo de proporcionar nodos favoritos. Estos nodos permiten el envío de información al exterior de la red o en futuras operaciones como el encaminamiento. / [CA] En la present tesi s'aborda el problema del descobriment de veïns en xarxes estàtiques sense fil ad hoc, xarxes sense infraestructura. En estes xarxes els nodes han de descobrir els veïns com un primer pas després del desplegament. A més s'aborda el problema de creació de xarxes espontànies basades en la confiança, i el de selecció de veïns. S'han presentat distints algoritmes que solucionen el problema seguint unes premisses que se n'aniran relaxant al llarg de la tesi. S'han implementat eixos algoritmes en Castalia 3.2 per a la seua validació i comparació amb altres protocols de referència. Els protocols determinístics presenten millors resultats de simulació, encara que requerixen que seguisquen una planificació en la transmissió. Quant al protocol aleatori CDPRR (Collision Detection Probabilistic Round Robin) no seguix una planificació però requerix el coneixement del nombre de nodes de la xarxa. El protocol CDH (Collision Detection Hello) permet el desconeixement del nombre de nodes. Ambdós aconseguixen el descobriment dels veïns amb probabilitat 1 per mitjà de la detecció de col·lisions. Ambdós propostes obtenen millors prestacions que els protocols usats com a referència. Tant per a CDH com per a CDPRR s'ha realitzat un model analític de determinades mètriques. S'ha proposat un protocol aleatori basat en líder que permet obtindre bones prestacions i es pot usar de forma asíncrona encara que només permet el seu ús en entorns onehop. Finalment, es presenta un protocol aleatori conscient de l'energia que permet bons resultats per a alts duty cycles i xarxes compostes de pocs nodes. Quant a la creació de xarxes espontànies basades en la confiança, s'ha proposat un model que usa el protocol CDPRR com a base. Este protocol de creació de xarxes espontànies basades en la confiança permet premisses més realistes i millora un protocol determinístic de referència. Finalment, es proposa un protocol que combina el descobriment i la selecció de veïns amb l'objectiu de proporcionar nodes favorits. Estos nodes permeten l'enviament d'informació a l'exterior de la xarxa o en futures operacions com l'encaminament. / [EN] This thesis addresses the neighbor discovery problem in static wireless ad hoc networks, infrastructure-less networks. In these networks the nodes must discover the neighbors as a first step after the deployment. Furthermore, the thesis addresses the problem of creation of spontaneous networks based on trust, and the neighbor selection. Several algorithms have been presented that solve the problem following some assumptions that will be relaxed throughout the thesis. Those algorithms have been implemented in Castalia 3.2 for validation and comparison with other reference protocolos. The deterministic protocols provide better simulation results, although they require a transmission schedule. As for the randomized protocol CDPRR (Collision Detection Probabilistic Round Robin), it does not follow a schedule but it requires the knowledge of the number of nodes in the network. The CDH (Collision Detection Hello) protocol allows the ignorance of the number of nodes. They both achieve the discovery of the neighbors with probability 1 by detecting collisions. Both proposals achieve better performance than the protocols used as reference. For CDH and CDPRR an analytical model has been carried out regarding several metrics. A randomized protocol based on leader has been proposed that achieves a good performance and it can be used in an asynchronous way although it can only be used in one-hop environments. Finally, an energy-aware randomized protocol is proposed, which achieves good results for high duty cycles and networks composed of a small number of nodes. As for the creation of spontaneous networks based on trust, a model has been proposed which is based on the CDPRR protocol. This protocol for the creation of spontaneous networks based on trust allows more realistic assumptions and outperforms a determinsitic protocol used as reference. Finally, a protocol is proposed which combines the discovery and selection of neighbors aiming at providing favourite nodes. These nodes allow sending information towards outside the network or in future operations such as routing. / Sorribes Díaz, JV. (2021). Autoconfiguración de redes ad hoc basadas en confianza [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/180283 / TESIS
892

Modeling of low illuminance road lighting condition using road temporal profile

Dong, Libo 05 October 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Pedestrian Automatic Emergency Braking (PAEB) system for avoiding/mitigating pedestrian crashes have been equipped on some passenger vehicles. At present, there are many e orts for the development of common standard for the performance evaluation of PAEB. The Transportation Active Safety Institute (TASI) at Indiana University-Purdue University-Indianapolis has been studying the problems and ad- dressing the concerns related to the establishment of such a standard with support from Toyota Collaborative Safety Research Center (CSRC). One of the important components in the PAEB evaluation is the development of standard testing facili- ties at night, in which 70% pedestrian crash social costs occurs [1]. The test facility should include representative low-illuminance environment to enable the examination of sensing and control functions of di erent PAEB systems. This thesis work focuses on modeling low-illuminance driving environment and describes an approach to recon- struct the lighting conditions. The goal of this research is to characterize and model light sources at a potential collision case at low-illuminance environment and deter- mine possible recreation of such environment for PAEB evaluation. This research is conducted in ve steps. The rst step is to identify lighting components that ap- pear frequently on a low-illuminance environment that a ect the performance of the PAEB. The identi ed lighting components include ambient light, same side/opposite side light poles, opposite side car headlight. Next step is to collect all potential pedes- trian collision cases at night with GPS coordinate information from TASI 110 CAR naturalistic driving study video database. Thirdly, since ambient lighting is relatively random and lack of a certain pattern, ambient light intensity for each potential col- lision case is de ned and processed as the average value of a region of interest on all video frames in this case. Fourth step is to classify interested light sources from the selected videos. The temporal pro le method, which compressing region of interest in video data (x,y,t) to image data (x,y), is introduced to scan certain prede ned region on the video. Due to the fact that light sources (except ambient light) impose distinct light patterns on the road, image patterns corresponding to speci c light sources can be recognized and classi ed. All light sources obtained are stamped with GPS coordinates and time information which are provided in corresponding data les along with the video. Lastly, by grouping all light source information of each repre- sentative street category, representative light description of each street category can be generated. Such light description can be used for lighting construction of PAEB test facility.
893

3D Autoškola / 3D Driving School

Pernica, Lukáš January 2009 (has links)
This study was created to describe and to design the 3D simulator for a driving schools. In the study there are gathered the basic definitions of available simulators and possibilities of their application in real life. This new simulator is designed on a basis of detailed study of available simulators. In study are described the issues with simulation of traffic system, monitoring compliance with the traffic rules as well as a new user interface model. The whole concept and procedure during implementation of the simulator are described at the end of the work.
894

INVESTIGATION OF NUCLEAR COMPRESSION IN THE AMPT MODELOF NUCLEUS-NUCLEUS COLLISIONS

Alalawi, Huda 28 November 2018 (has links)
No description available.
895

A Novel Approach to Assessing Abundance and Behavior in Summer Populations of Little Brown Myotis in Yellowstone National Park

Waag, Austin G. January 2018 (has links)
No description available.
896

Mass Spectrometry Methods For Macromolecules: Polymer Architectures, Cross-Linking, and Surface Imaging

Endres, Kevin J. 20 June 2019 (has links)
No description available.
897

Azimuthal anisotropy in gold-gold collisions at 4.5 GeV center-of-mass energy per nucleon pair using fixed-target mode at the Relativistic Heavy-Ion Collider

Wu, Yang 09 July 2019 (has links)
No description available.
898

Handoff of Advanced Driver Assistance Systems (ADAS) using a Driver-in-the-Loop Simulator and Model Predictive Control (MPC)

Wilkerson, Jaxon 01 December 2020 (has links)
No description available.
899

二体衝突近似にもとづいた粒子 : 物質相互作用の数値シミュレーション / ニタイ ショウトツ キンジ ニ モトズイタ リュウシ : ブッシツ ソウゴ サヨウ ノ スウチ シミュレーション

加藤 周一, Shuichi Kato 22 March 2016 (has links)
二体衝突近似法を、粒子-物質相互作用に関する様々な現象に応用した。特に二体衝突近似法と動的モンテカルロ法の接続によるBCA-kMCハイブリッドシミュレーションにより、従来の二体衝突近似法と拡散方程式を合わせた手法が抱える問題を克服することで、材料内での不純物拡散挙動をより詳細に解析することに成功した。本論文は将来的な二体衝突近似法の幅広い分野への応用の足がかりになることが期待される。 / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University
900

Safe Controller Design for Intelligent Transportation System Applications using Reachability Analysis

Park, Jaeyong 17 October 2013 (has links)
No description available.

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