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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.
231

Intrusion Detection of Flooding DoS Attacks on Emulated Smart Meters

Akbar, Yousef M. A. H. 11 May 2020 (has links)
The power grid has changed a great deal from what has been generally viewed as a traditional power grid. The modernization of the power grid has seen an increase in the integration and incorporation of computing and communication elements, creating an interdependence of both physical and cyber assets of the power grid. The fast-increasing connectivity has transformed the grid from what used to be primarily a physical system into a Cyber- Physical System (CPS). The physical elements within a power grid are well understood by power engineers; however, the newly deployed cyber aspects are new to most researchers and operators in this field. The new computing and communications structure brings new vulnerabilities along with all the benefits it provides. Cyber security of the power grid is critical due to the potential impact it can make on the community or society that relies on the critical infrastructure. These vulnerabilities have already been exploited in the attack on the Ukrainian power grid, a highly sophisticated, multi-layered attack which caused large power outages for numerous customers. There is an urgent need to understand the cyber aspects of the modernized power grid and take the necessary precautions such that the security of the CPS can be better achieved. The power grid is dependent on two main cyber infrastructures, i.e., Supervisory Control And Data Acquisition (SCADA) and Advanced Metering Infrastructure (AMI). This thesis investigates the AMI in power grids by developing a testbed environment that can be created and used to better understand and develop security strategies to remove the vulnerabilities that exist within it. The testbed is to be used to conduct and implement security strategies, i.e., an Intrusion Detections Systems (IDS), creating an emulated environment to best resemble the environment of the AMI system. A DoS flooding attack and an IDS are implemented on the emulated testbed to show the effectiveness and validate the performance of the emulated testbed. / M.S. / The power grid is becoming more digitized and is utilizing information and communication technologies more, hence the smart grid. New systems are developed and utilized in the modernized power grid that directly relies on new communication networks. The power grid is becoming more efficient and more effective due to these developments, however, there are some considerations to be made as for the security of the power grid. An important expectation of the power grid is the reliability of power delivery to its customers. New information and communication technology integration brings rise to new cyber vulnerabilities that can inhibit the functionality of the power grid. A coordinated cyber-attack was conducted against the Ukrainian power grid in 2015 that targeted the cyber vulnerabilities of the system. The attackers made sure that the grid operators were unable to observe their system being attacked via Denial of Service attacks. Smart meters are the digitized equivalent of a traditional energy meter, it wirelessly communicates with the grid operators. An increase in deployment of these smart meters makes it such that we are more dependent on them and hence creating a new vulnerability for an attack. The smart meter integration into the power grid needs to be studied and carefully considered for the prevention of attacks. A testbed is created using devices that emulate the smart meters and a network is established between the devices. The network was attacked with a Denial of Service attack to validate the testbed performance, and an Intrusion detection method was developed and applied onto the testbed to prove that the testbed created can be used to study and develop methods to cover the vulnerabilities present.
232

Analýza tréninkového procesu na 800 m u běžce vrcholové úrovně / 800 meters elite runner training analysis

Kužílek, Ondřej January 2011 (has links)
Abstract Title: 800 meters elite runner training analysis Objectives: The main goal of my thesis deals with pedagogical evaluation of 800 meters elite runner training process. It concerns analysis of teoretical background esential for the performance growth of the two annual macrocycles through 2007/2008 and 2008/2009. I mainly focused on the relationship between the volumes of general and specific training indicators and achieved performance indicator in tracked event. The conslusion of the work should provide us with recommendations for the training process improvement in future periods. Methods: The education analysis of training process is based on the values that were obtained by content analysis of training documents and training records of the coach. I used a percentage expression for a quantitative comparison. For the qualitative comparison I used a distribution of training indicators devided into 17 categories, 5 as indicators of general training and 12 as special indicators. Results: The growth of sports performance in 800 meters discipline was primarily achieved by training loads of special training indicators and focus on its main field. The resulting performance was most influenced by changes in speed and special endurance development, which were supported by the growth of tempo and...
233

[en] STUDY ABOUT MARITIME OIL EXPORTS: METROLOGICAL ASPECT / [pt] ESTUDO SOBRE A EXPORTAÇÃO MARÍTIMA DE PETRÓLEO: ASPECTO METROLÓGICO

ROBERTO DA COSTA CARDOSO 07 January 2015 (has links)
[pt] Por muito tempo, os sistemas de medição dinâmica de petróleo não foram usados para a transferência de custódia. Eles eram utilizados basicamente para fins operacionais, como detectar vazamentos e transferências internas. O aumento progressivo dos preços do barril de petróleo exigiu das medições de petróleo uma incerteza cada vez menor, o que provocou o desenvolvimento de novas tecnologias que resultaram em sistemas dinâmicos de medição de alta precisão a serem utilizados na transferência de custódia. Nesta pesquisa foi avaliada a substituição das medições estáticas por medições dinâmicas no faturamento de exportações marítimas de petróleo, com o objetivo de agilizar as operações de carregamento de navios em píeres diminuindo a indisponibilidade dos recursos logísticos envolvidos, de minimizar a exposição da companhia a perdas financeiras devido a faturamentos errôneos e de verificar que essa diminuição da exposição justifica o investimento em sistemas de medição dinâmica. Foram descritas as medições de tanques de terra, as medições de tanques de navio e os sistemas de medição dinâmica, avaliando procedimentos, equipamentos, além de restrições, problemas e incertezas associadas a cada método. Foi dada atenção especial aos procedimentos de arqueação de tanques para armazenamento de granéis líquidos, comparando procedimentos utilizados no Brasil pelo Inmetro aos requisitos da Norma ISO -7507, e a rastreabilidade metrológica dos equipamentos de medição em relação aos procedimentos utilizados na sua calibração. / [en] For many years, dynamic measurement systems have not been used in the petroleum industry for custody transfer applications, only for operational reasons like detecting leaks and internal transfers. The progressive growth of crude oil prices required measurements with a smaller uncertainty, leading to developing news technologies, resulting in high accuracy flow meters to be used in custody transfer. The main objective of this research was evaluate the replacement of static measurements by dynamic measurements in oil exports sales in order to speed up the loading of vessels, decreasing the unavailability of logistical resources involved, to minimize the company s exposure to economic losses due to erroneous bill of ladings and verify if this justifies the investment in dynamic measurement systems. This research has discussed a number of issues associated with the uncertainty of the shore tanks, vessels tanks and dynamic measurements, evaluating procedures, equipment, and restrictions, problems and accuracy associated with each method. It also included a discussion about the difference between calibration of vertical cylindrical tanks procedures used in Brazil by Inmetro and the requirements of ISO -7507, and about traceability of measuring equipment calibration.
234

The use of steady-state level combinations and signal event edge correlations in the disaggregation of total power measurements

Penn, Joseph J January 2015 (has links)
A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in ful lment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2015 / The work presented extends and contributes to research in Non-Intrusive Load Monitoring (NILM), focussing on steady-state and transient power measurement disaggregation techniques for circuits containing household ap- pliances. Although previous work in this area has produced and evaluated a wide range of NILM approaches, much of it has involved the use of datasets captured from real-world household implementations. In such cases, the lack of accurate ground truth data makes it di cult to assess disaggregation tech- niques. In the research presented, three NILM techniques are comparatively evaluated using measurements from typical household appliances assembled within a laboratory environment, where accurate ground truth data could be compiled to complement the measurements. This allows for the accu- racy of the various disaggregation approaches to be precisely evaluated. It is demonstrated that the correlation of transient event edges in aggregated power measurements to individual appliance transient exemplars performs better than the matching of steady-state power levels against individual ap- pliance state combinations. Furthermore, the transient approach is shown to be the most appropriate technique for further development. / MT2017
235

A localização de faltas em um sistema de distribuição radial baseada na aplicação de árvores de decisão e redes neurais artificiais / Fault location in a radial distribution system based on the application of decision trees and artificial neural networks

Pessoa, André Luís da Silva 02 August 2017 (has links)
Os Sistemas de Distribuição (SDs), devido as suas topologias e configurações, dentre outros fatores, apresentam um desafio para a localização física das situações de faltas passíveis de ocorrência. Como fato, tem-se que uma localização de faltas, rápida e precisa, possibilita atenuar os transtornos que os usuários finais dos SDs viriam a ter em relação à qualidade do serviço prestado pelas distribuidoras. No contexto das redes elétricas inteligentes, e considerando medidores de qualidade da energia elétrica previamente alocados de forma otimizada, esta pesquisa propõe uma metodologia baseada em árvores de decisão e redes neurais artificiais para a localização de faltas em SDs radiais e aéreos. Foram realizados testes da metodologia proposta considerando variações no tipo, na impedância e no ângulo de incidência da falta aplicadas sobre o SD de 34 barras do IEEE (Institute of Electrical and Electronics Engineers). Para os testes de sensibilidade da metodologia desenvolvida, foram consideradas variações no carregamento do sistema, os erros inerentes ao sistema de medição, a variação no número de medidores disponível, o impacto de uma alocação não otimizada dos medidores e uma redução na taxa amostral. Os resultados encontrados foram promissores e indicam que a metodologia como desenvolvida poderá ser aplicada para SDs diferentes do caso teste utilizado. / Due to the distribution systems (DS) topologies, configurations and among other factors, it is a challenge to physically locate situations of faults. As a matter of fact, a fast and accurate fault location will make it possible to mitigate the inconvenience that the end users of DS would have due to the quality of the service provided by the distributors. In the context of intelligent electric grids, and considering the electric power quality meters optimally alocated, this research proposes a methodology based in decision trees and artificial neural networks for a fault location in radial and aerial DS. The proposed methodology was tested considering variations on the type, impedance and angle of incidence of the fault applied on the DS of 34 bars of the IEEE (Institute of Electrical and Electronic Engineers). For a sensitivity test of the developed methodology, it were considered the variations in system loading, the errors inherent to the measurement system, a variation in number of meters available, the impact of the non-optimized allocation of the meters and a redution on the sampling rate. The results were promising and indicated that the methodology developed can be applied to different DS from the test case used.
236

Diagnóstico de curtos-circuitos a partir da alocação otimizada de medidores em um sistema de distribuição subterrâneo / Diagnostic short-circuits from the optimized allocation meters in a underground distribution system

Festa, Alexandre Vinícius 12 February 2015 (has links)
O monitoramento e diagnóstico, com a consequente localização dos curtos-circuitos em Sistemas de Distribuição (SD), fazem parte de um processo complexo, exigindo esforços e agilidade das equipes técnicas de manutenção das concessionárias de energia elétrica. Quando se trata de um SD Subterrâneo (SDS), a complexidade de localização das faltas aumenta, pois não é possível realizar a inspeção visual. Por este motivo, desenvolver e aprimorar métodos para monitorar, classificar e localizar as situações de faltas em SD tem sido de relevante interesse para a comunidade técnico-científica nos últimos anos. Neste contexto, apresenta-se nesta pesquisa um método para processar as informações necessárias para classificar e localizar a ocorrência de um curto-circuito (monofásico, bifásico e/ou trifásico, com e/ou sem o envolvimento da terra) em um SDS. O processamento das informações foi realizado por meio da observação da propagação dos afundamentos de tensão, decorrentes de curtos-circuitos passíveis de ocorrência no SDS, e pela alocação de um número reduzido de medidores, permitindo a classificação e localização precisa da falta. Um dos diferenciais da metodologia proposta é que esta utiliza somente os valores eficazes das tensões trifásicas, registradas em medidores estrategicamente alocados, para indicação da área afetada e classificação das fases envolvidas. A metodologia é baseada no emprego de redes neurais artificiais. Os resultados encontrados são promissores, indicando a aplicabilidade da metodologia proposta. / The monitoring and diagnostics, with the consequent localization of short circuits in Distribution Systems (DS), are part of a complex process, requiring efforts and agility of the technical teams of maintenance of electric utilities. In the case of an underground DS (UDS), the location of faults complexity increases, because it is not possible to perform visual inspection. For this reason, develop and improve methods to monitor, sort and locate the fault situations in DS has been of relevant interest to the technical-scientific community in recent years. In this context, this study presents a method for processing the information required to classify and locate the occurrence of a short circuit (single phase, biphasic and / or phase with and / or without the involvement of the earth) on a UDS. The information processing was carried out by observing the propagation of voltage sags, caused by short circuits that may occur in the UDS, and the allocation of a few meters, allowing classification and precise location of the fault. One of the proposed methodology differentials is that it uses only the RMS values of the three-phase voltages, registered in strategically located meters, for indicating the affected area and classification of the phases involved. The methodology is based on the use of artificial neural networks. The results found are promising, indicating the applicability of the proposed methodology.
237

Diagnóstico de curtos-circuitos a partir da alocação otimizada de medidores em um sistema de distribuição subterrâneo / Diagnostic short-circuits from the optimized allocation meters in a underground distribution system

Alexandre Vinícius Festa 12 February 2015 (has links)
O monitoramento e diagnóstico, com a consequente localização dos curtos-circuitos em Sistemas de Distribuição (SD), fazem parte de um processo complexo, exigindo esforços e agilidade das equipes técnicas de manutenção das concessionárias de energia elétrica. Quando se trata de um SD Subterrâneo (SDS), a complexidade de localização das faltas aumenta, pois não é possível realizar a inspeção visual. Por este motivo, desenvolver e aprimorar métodos para monitorar, classificar e localizar as situações de faltas em SD tem sido de relevante interesse para a comunidade técnico-científica nos últimos anos. Neste contexto, apresenta-se nesta pesquisa um método para processar as informações necessárias para classificar e localizar a ocorrência de um curto-circuito (monofásico, bifásico e/ou trifásico, com e/ou sem o envolvimento da terra) em um SDS. O processamento das informações foi realizado por meio da observação da propagação dos afundamentos de tensão, decorrentes de curtos-circuitos passíveis de ocorrência no SDS, e pela alocação de um número reduzido de medidores, permitindo a classificação e localização precisa da falta. Um dos diferenciais da metodologia proposta é que esta utiliza somente os valores eficazes das tensões trifásicas, registradas em medidores estrategicamente alocados, para indicação da área afetada e classificação das fases envolvidas. A metodologia é baseada no emprego de redes neurais artificiais. Os resultados encontrados são promissores, indicando a aplicabilidade da metodologia proposta. / The monitoring and diagnostics, with the consequent localization of short circuits in Distribution Systems (DS), are part of a complex process, requiring efforts and agility of the technical teams of maintenance of electric utilities. In the case of an underground DS (UDS), the location of faults complexity increases, because it is not possible to perform visual inspection. For this reason, develop and improve methods to monitor, sort and locate the fault situations in DS has been of relevant interest to the technical-scientific community in recent years. In this context, this study presents a method for processing the information required to classify and locate the occurrence of a short circuit (single phase, biphasic and / or phase with and / or without the involvement of the earth) on a UDS. The information processing was carried out by observing the propagation of voltage sags, caused by short circuits that may occur in the UDS, and the allocation of a few meters, allowing classification and precise location of the fault. One of the proposed methodology differentials is that it uses only the RMS values of the three-phase voltages, registered in strategically located meters, for indicating the affected area and classification of the phases involved. The methodology is based on the use of artificial neural networks. The results found are promising, indicating the applicability of the proposed methodology.
238

A localização de faltas em um sistema de distribuição radial baseada na aplicação de árvores de decisão e redes neurais artificiais / Fault location in a radial distribution system based on the application of decision trees and artificial neural networks

André Luís da Silva Pessoa 02 August 2017 (has links)
Os Sistemas de Distribuição (SDs), devido as suas topologias e configurações, dentre outros fatores, apresentam um desafio para a localização física das situações de faltas passíveis de ocorrência. Como fato, tem-se que uma localização de faltas, rápida e precisa, possibilita atenuar os transtornos que os usuários finais dos SDs viriam a ter em relação à qualidade do serviço prestado pelas distribuidoras. No contexto das redes elétricas inteligentes, e considerando medidores de qualidade da energia elétrica previamente alocados de forma otimizada, esta pesquisa propõe uma metodologia baseada em árvores de decisão e redes neurais artificiais para a localização de faltas em SDs radiais e aéreos. Foram realizados testes da metodologia proposta considerando variações no tipo, na impedância e no ângulo de incidência da falta aplicadas sobre o SD de 34 barras do IEEE (Institute of Electrical and Electronics Engineers). Para os testes de sensibilidade da metodologia desenvolvida, foram consideradas variações no carregamento do sistema, os erros inerentes ao sistema de medição, a variação no número de medidores disponível, o impacto de uma alocação não otimizada dos medidores e uma redução na taxa amostral. Os resultados encontrados foram promissores e indicam que a metodologia como desenvolvida poderá ser aplicada para SDs diferentes do caso teste utilizado. / Due to the distribution systems (DS) topologies, configurations and among other factors, it is a challenge to physically locate situations of faults. As a matter of fact, a fast and accurate fault location will make it possible to mitigate the inconvenience that the end users of DS would have due to the quality of the service provided by the distributors. In the context of intelligent electric grids, and considering the electric power quality meters optimally alocated, this research proposes a methodology based in decision trees and artificial neural networks for a fault location in radial and aerial DS. The proposed methodology was tested considering variations on the type, impedance and angle of incidence of the fault applied on the DS of 34 bars of the IEEE (Institute of Electrical and Electronic Engineers). For a sensitivity test of the developed methodology, it were considered the variations in system loading, the errors inherent to the measurement system, a variation in number of meters available, the impact of the non-optimized allocation of the meters and a redution on the sampling rate. The results were promising and indicated that the methodology developed can be applied to different DS from the test case used.
239

Assessing Soil Moisture Remotely

Reginato, Robert J., Idso, Sherwood B., Jackson, Ray D. 12 April 1975 (has links)
From the Proceedings of the 1975 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 11-12, 1975, Tempe, Arizona / Space-age technology has produced tools which when turned to earthly pursuits can provide information on food and fiber production. Soil moisture has the potential for being remotely assessed, and three techniques for accomplishing this are under study. Two of the methods, reflectance and thermal, are sensitive to the conditions of the bare soil surface. The third technique, microwave emission, appears to have a good potential for assessing soil moisture with depth, because of its greater wavelength.
240

A Microroughness Meter for Evaluating Rainwater Infiltration

Simanton, J. R., Dixon, R. M., McGowan, I. 15 April 1978 (has links)
From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / Described is a microroughness meter developed to obtain numerous and accurate measurements of rangeland surface microroughness and characteristics. The meter, which consists of four basic parts: (1) meter base and pin guide, (2) pin lifting support bar and lifting mechanism, (3) 100 vertically moving pins, and (4) stripchart support guide and winding mechanism, was designed to measure soil surface evaluations and characteristics of a 1m2 plot. Performance tests on multi-plot sprinkler infiltrometer studies conducted on the Santa Rita Experimental Range in southeastern Arizona indicated that the meter was accurate and relatively precise in repeating soil surface roughness measurements but was not precise in defining the theoretical characteristics of constructed surfaces. It was concluded, however, that these errors in precision were insignificant and due partly to surface geometry construction errors and that the meter is a convenient, quick, simple and accurate means of measuring surface roughness in studies requiring many plots and data points.

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