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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.
1

A Secured Data Protocol for the Trusted Truck(R) System

Bulusu, Srinivasa Anuradha 01 December 2010 (has links)
Security has become one of the major concerns in the Intelligent Transportation Systems (ITS). The Trusted Truck(R) System, provides an efficient wireless communication mechanism for safe exchange of messages between the moving vehicles (trucks) and the roadside inspection stations. The vehicles and the station are equipped with processing units but with different computational capabilities. To make this Trusted Truck(R) system more secure, this thesis proposes a secured data protocol which ensures data integrity, message authentication and non-repudiation. The uniqueness of the protocol is: it is cost-effective, resource-efficient and embeds itself into the Trusted Truck (R) environment without demanding any additional infrastructure. The protocol also balances the computational load between the vehicle and station by incorporating an innovative key transport mechanism. Digital signatures and encryption techniques are used for authentication and data con dentiality. Cryptography algorithms along with optimization methods are used for the digital signatures. The computational time for the algorithms are analyzed. Combining all these techniques, an efficient secured data protocol is developed and implemented successfully.
2

An Extensible Computing Architecture Design for Connected Autonomous Vehicle System

Hochstetler, Jacob Daniel 05 1900 (has links)
Autonomous vehicles have made milestone strides within the past decade. Advances up the autonomy ladder have come lock-step with the advances in machine learning, namely deep-learning algorithms and huge, open training sets. And while advances in CPUs have slowed, GPUs have edged into the previous decade's TOP 500 supercomputer territory. This new class of GPUs include novel deep-learning hardware that has essentially side-stepped Moore's law, outpacing the doubling observation by a factor of ten. While GPUs have make record progress, networks do not follow Moore's law and are restricted by several bottlenecks, from protocol-based latency lower bounds to the very laws of physics. In a way, the bottlenecks that plague modern networks gave rise to Edge computing, a key component of the Connected Autonomous Vehicle system, as the need for low-latency in some domains eclipsed the need for massive processing farms. The Connected Autonomous Vehicle ecosystem is one of the most complicated environments in all of computing. Not only is the hardware scaled all the way from 16 and 32-bit microcontrollers, to multi-CPU Edge nodes, and multi-GPU Cloud servers, but the networking also encompasses the gamut of modern communication transports. I propose a framework for negotiating, encapsulating and transferring data between vehicles ensuring efficient bandwidth utilization and respecting real-time privacy levels.
3

Protocolo de roteamento de dados para redes de sensores sem fio com nó coletor móvel para controle da deriva em pulverização agrícola. / Routing data protocol for wireless sensor networks with mobile sink to spray drift control in crop spraying.

Santos, Ivairton Monteiro 17 December 2013 (has links)
A aplicação eficiente de agrotóxicos é um desafio na produção agrícola, mesmo considerando os avanços com a agricultura de precisão. O efeito deriva é o principal responsável pela ineficiência no controle das pragas ou doenças, pelo desperdício de recursos e pela contaminação ambiental. Para minimizar a deriva é essencial conhecer as condições ambientais como vento, temperatura e umidade. Esta pesquisa propõe o uso das redes de sensores sem fio como sistema de monitoramento ambiental e de suporte ao processo de pulverização agrícola, especialmente a pulverização executada por aeronave. São propostas três funcionalidades para o sistema: avaliação das condições ambientais, verificando se as condições estão apropriadas para a pulverização, buscando minimizar a ocorrência da deriva; suporte na definição e manutenção da rota do veículo pulverizador por meio dos dados do vento, de modo a efetuar ajustes na rota de pulverização e manter a aplicação do defensivo agrícola na área alvo; e a avaliação da eficácia da pulverização por meio dos dados da deposição do produto pulverizado coletados pela rede de sensores. Para viabilizar a utilização das redes de sensores sem fio no controle da deriva é proposto um protocolo de roteamento de dados que visa garantir a coleta dos dados pelos nós e a entrega para o veículo pulverizador, mesmo sendo ele um avião e se deslocando em alta velocidade. Para demonstrar a viabilidade do sistema proposto, foi desenvolvido um sistema de simulação computacional que considera os aspectos das redes de sensores sem fio e as características do protocolo de roteamento proposto. Os resultados demonstraram sua viabilidade, demonstrando que as redes de sensores sem fio podem ser utilizadas como suporte em um sistema de controle da deriva, incrementando a qualidade da pulverização, reduzindo custos e a contaminação ambiental. / The efficient application of low cost pesticides is a challenge for agricultural production. Pesticide drift is the major cause of money loss, inefficiency in crop disease control, and environmental contamination in the crop spraying process. At the time of application, it is essential to know the environmental conditions, such as wind, temperature and humidity to minimize contamination by pesticide drift. This study proposes the use of wireless sensor networks in a support and control system for crop spraying, especially in aircraft application methods. Three system functionalities are proposed: In the first case, the sensor network evaluates environmental data at the time of application to notify the user if the environmental conditions are suitable for continuing with the application. The second case evaluates the wind speed and its direction to suggest corrections in the path of a spray vehicle. Due to this alteration in the vehicle path, the pesticide will be applied only in the appropriate area. The final case involves collecting data samples and analyzing the quality of the spraying operation by evaluating the deposition of pesticide over the crop. This work proposes a new routing data protocol to make possible the use of wireless sensor networks in aerial crop spraying. It ensures that the sensor node data will be delivered to the sink node. Through computer simulations, wireless sensor networks are shown to be useful in crop spraying to minimize and to control pesticide drift, to improve the quality of application, to reduce environmental contamination and to reduce costs and the duration of the application operation.
4

Protocolo de roteamento de dados para redes de sensores sem fio com nó coletor móvel para controle da deriva em pulverização agrícola. / Routing data protocol for wireless sensor networks with mobile sink to spray drift control in crop spraying.

Ivairton Monteiro Santos 17 December 2013 (has links)
A aplicação eficiente de agrotóxicos é um desafio na produção agrícola, mesmo considerando os avanços com a agricultura de precisão. O efeito deriva é o principal responsável pela ineficiência no controle das pragas ou doenças, pelo desperdício de recursos e pela contaminação ambiental. Para minimizar a deriva é essencial conhecer as condições ambientais como vento, temperatura e umidade. Esta pesquisa propõe o uso das redes de sensores sem fio como sistema de monitoramento ambiental e de suporte ao processo de pulverização agrícola, especialmente a pulverização executada por aeronave. São propostas três funcionalidades para o sistema: avaliação das condições ambientais, verificando se as condições estão apropriadas para a pulverização, buscando minimizar a ocorrência da deriva; suporte na definição e manutenção da rota do veículo pulverizador por meio dos dados do vento, de modo a efetuar ajustes na rota de pulverização e manter a aplicação do defensivo agrícola na área alvo; e a avaliação da eficácia da pulverização por meio dos dados da deposição do produto pulverizado coletados pela rede de sensores. Para viabilizar a utilização das redes de sensores sem fio no controle da deriva é proposto um protocolo de roteamento de dados que visa garantir a coleta dos dados pelos nós e a entrega para o veículo pulverizador, mesmo sendo ele um avião e se deslocando em alta velocidade. Para demonstrar a viabilidade do sistema proposto, foi desenvolvido um sistema de simulação computacional que considera os aspectos das redes de sensores sem fio e as características do protocolo de roteamento proposto. Os resultados demonstraram sua viabilidade, demonstrando que as redes de sensores sem fio podem ser utilizadas como suporte em um sistema de controle da deriva, incrementando a qualidade da pulverização, reduzindo custos e a contaminação ambiental. / The efficient application of low cost pesticides is a challenge for agricultural production. Pesticide drift is the major cause of money loss, inefficiency in crop disease control, and environmental contamination in the crop spraying process. At the time of application, it is essential to know the environmental conditions, such as wind, temperature and humidity to minimize contamination by pesticide drift. This study proposes the use of wireless sensor networks in a support and control system for crop spraying, especially in aircraft application methods. Three system functionalities are proposed: In the first case, the sensor network evaluates environmental data at the time of application to notify the user if the environmental conditions are suitable for continuing with the application. The second case evaluates the wind speed and its direction to suggest corrections in the path of a spray vehicle. Due to this alteration in the vehicle path, the pesticide will be applied only in the appropriate area. The final case involves collecting data samples and analyzing the quality of the spraying operation by evaluating the deposition of pesticide over the crop. This work proposes a new routing data protocol to make possible the use of wireless sensor networks in aerial crop spraying. It ensures that the sensor node data will be delivered to the sink node. Through computer simulations, wireless sensor networks are shown to be useful in crop spraying to minimize and to control pesticide drift, to improve the quality of application, to reduce environmental contamination and to reduce costs and the duration of the application operation.
5

Use of the general transit feed specification (GTFS) in transit performance measurement

Wong, James C. 13 January 2014 (has links)
Until recently, transit data lacked a common data format that could be used to share and integrate information among multiple agencies. In 2005, however, Google worked with Tri-Met in Oregon to create the General Transit Feed Specification (GTFS), an open data format now used by all transit agencies that participate in Google Maps. GTFS feeds contain data for scheduled transit service including stop and route locations, schedules and fare information. The broad adoption of GTFS by transit agencies has made it a de facto standard. Those agencies using it are able to participate in a host of traveler services designed for GTFS, most notably transit trip planners. Still, analysts have not widely used GTFS as a data source for transit planning because of the newness of the technology. The objectives of this project are to demonstrate that GTFS feeds are an efficient data source for calculating key transit service metrics and to evaluate the validity of GTFS feeds as a data source. To demonstrate GTFS feeds’ analytic potential, the author created a tool called GTFS Reader, which imports GTFS feeds into a database using open-source products. GTFS Reader also includes a series of queries that calculate metrics like headways, route lengths and stop-spacing. To evaluate the validity of GTFS feeds, annual vehicle revenue miles and hours from the National Transit Database (NTD) are compared to the calculated values from agencies whose GTFS feeds are available. The key finding of this work is that well-formed GTFS feeds are an accurate representation of transit networks and that the method of aggregation presented in this research can be used to effectively and efficiently calculate metrics for transit agencies. The daily aggregation method is more accurate than the weekly aggregation method, both introduced in this thesis, but practical limitations on processing time favor the weekly method. The reliability of GTFS feed data for smaller agencies is less conclusive than that of larger agencies because of discrepancies found in smaller agencies when their GTFS-generated metrics were compared to those in the NTD. This research will be of particular interest to transit and policy analysts, researchers and transit planners.
6

Integrating XML and RDF concepts to achieve automation within a tactical knowledge management environment

McCarty, George E., Jr. 03 1900 (has links)
Approved for public release, distribution is unlimited / Since the advent of Naval Warfare, Tactical Knowledge Management (KM) has been critical to the success of the On Scene Commander. Today's Tactical Knowledge Manager typically operates in a high stressed environment with a multitude of knowledge sources including detailed sensor deployment plans, rules of engagement contingencies, and weapon delivery assignments. However the WarFighter has placed a heavy reliance on delivering this data with traditional messaging processes while focusing on information organization vice knowledge management. This information oriented paradigm results in a continuation of data overload due to the manual intervention of human resources. Focusing on the data archiving aspect of information management overlooks the advantages of computational processing while delaying the empowerment of the processor as an automated decision making tool. Resource Description Framework (RDF) and XML provide the potential of increased machine reasoning within a KM design allowing the WarFighter to migrate from the dependency on manual information systems to a more computational intensive Knowledge Management environment. However the unique environment of a tactical platform requires innovative solutions to automate the existing naval message architecture while improving the knowledge management process. This thesis captures the key aspects for building a prototype Knowledge Management Model and provides an implementation example for evaluation. The model developed for this analysis was instantiated to evaluate the use of RDF and XML technologies in the Knowledge Management domain. The goal for the prototype included: 1. Processing required technical links in RDF/XML for feeding the KM model from multiple information sources. 2. Experiment with the visualization of Knowledge Management processing vice traditional Information Resource Display techniques. The results from working with the prototype KM Model demonstrated the flexibility of processing all information data under an XML context. Furthermore the RDF attribute format provided a convenient structure for automated decision making based on multiple information sources. Additional research utilizing RDF/XML technologies will eventually enable the WarFighter to effectively make decisions under a Knowledge Management Environment. / Civilian, SPAWAR System Center San Diego

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