Severe disturbances in a large electrical interconnection cause a large mismatch in generation and load in the network, leading to frequency instability. If the mismatch is not rectified quickly, the system may disintegrate into multiple islands. Though the Automatic Generation Controls (AGC) perform well in correcting frequency deviation over a period of minutes, they are ineffective during a rolling blackout. While traditional Under Frequency Load Shedding Schemes (UFLS) perform quick control actions to arrest frequency decline in an islanded network, they are not designed to prevent unplanned islanding. The proposed Intelligent Load Shedding algorithm combines the effectiveness of AGC Scheme by observing tie line flows and the speed of operation of the UFLS Scheme by shedding loads intelligently, to preserve system integrity in the event of an evolving cascading failure. The proposed scheme detects and estimates the size of an event by monitoring the tie lines of a control area using Wide Area Measurement Systems (WAMS) and initiates load shedding by removing loads whose locations are optimally determined by a sensitivity analysis. The amount and location of the load shedding depends on the location and size of the initiating event, making the proposed algorithm adaptive and selective. Case Studies have been presented to show that control actions of the proposed scheme can directly mitigate a cascading blackout. / Ph. D.

No description available.

No description available.

The vision of the smart grid is predicated upon pervasive use of modern digital communication techniques in today's power system. As wide area measurements and control techniques are being developed and deployed for a more resilient power system, the role of communication networks is becoming prominent. Advanced communication infrastructure provides much wider system observability and enables globally optimal control schemes. Wide area measurement and monitoring with Phasor Measurement Units (PMUs) or Intelligent Electronic Devices (IED) is a growing trend in this context. However, the large amount of data collected by PMUs or IEDs needs to be transferred over the data network to control centers where real-time state estimation, protection, and control decisions are made. The volume and frequency of such data transfers, and real-time delivery requirements mandate that sufficient bandwidth and proper delay characteristics must be ensured for the correct operations. Power system dynamics get influenced by the underlying communication infrastructure. Therefore, extensive integration of power system and communication infrastructure mandates that the two systems be studied as a single distributed cyber-physical system. This dissertation proposes a global event-driven co-simulation framework, which is termed as GECO, for interconnected power system and communication network. GECO can be used as a design pattern for hybrid system simulation with continuous/discrete sub-components. An implementation of GECO is achieved by integrating two software packages: PSLF and NS2 into the framework. Besides, this dissertation proposes and studies a set of power system applications which can be only properly evaluated on a co-simulation framework like GECO, namely communication-based distance relay protection, all-PMU state estimation and PMU-based out-of-step protection. All of them take advantage of interplays between the power grid and the communication infrastructure. The GECO experiments described in this dissertation not only show the efficacy of the GECO framework, but also provide experience on how to go about using GECO in smart grid planning activities. / Ph. D.

[pt] Hoje no Brasil, o setor de telecomunicações encontra-se em estágio avançado de desenvolvimento, se considerarmos a transição desencadeada há cerca de seis anos com a privatização das empresas do setor, que resultou em uma alteração no modelo institucional, devido à introdução da concorrência na exploração dos serviços e a obrigação da universalização do acesso aos serviços básicos. Neste ambiente, as empresas buscam um novo posicionamento no mercado para serem competitivas e se manterem rentáveis. A fim de lograrem êxito, estas empresas necessitam manter uma gestão estratégica com foco no mercado, e com indicadores que possibilitem o acompanhamento do desempenho financeiro e operacional, assim como da qualidade de seus produtos e serviços e da satisfação de seus clientes. Esta pesquisa tem como objetivo investigar como assegurar a adequação estratégica do sistema de medição de desempenho organizacional na Unidade de Negócios Empresariais da Telemar (UNE). A investigação foi desenvolvida, usando a metodologia de estudo de caso, escolhendo como objeto de pesquisa a UNE - Telemar. Coletados por meio de investigação documental / telematizada, questionários predominantemente estruturados e entrevistas, os dados da pesquisa foram tratados com métodos quantitativos e qualitativos. A interpretação e análise dos dados foram realizadas com base no referencial teórico, fundamentado em revisão de literatura pertinente à área de estudo, com auxílio do modelo genérico integrativo de Macedo - Soares (2001b). Os resultados evidenciaram algumas inconsistências entre o sistema de medição de desempenho organizacional e a estratégia da Unidade. Também, foi possível identificar os fatores organizacionais que contribuem e os que não contribuem para este adequação. Ao final do trabalho, são compartilhadas as lições a respeito do estudo de caso na UNE - Telemar. / [en] The telecommunication industry in Brazil has evolved to an advanced state since the privatization of the sector in 1998. The transition from government controlled segment to public owned institutions, regulated by a government agency, has revamped the structure of the industry, created the foundation for an open market with free and fair competition, and defined the minimum network structure with the so called Universal Plan for Basic Access to Telecommunication Services. In the last six years, the Brazilian telecommunication system has progressed from inefficient and outdated to world class. To succeed in the current highly competitive environment, telecommunication service providers must focus their strategy on their market and clients. These firms must develop metrics that allow them to monitor financial and operational performances, evaluate the quality of their products and services, and assess client satisfaction. The objective of this research is to assess the efficiency and strategic adequacy (fit) of the organizational performance measurement system in the Business Units of Telemar, also known as UNE - Unidade de Negócios Empresariais da Telemar. The investigation was prepared in a case study format, and the object of study defined as the UNE - Telemar. Data was collected through documental/telematic investigations and structured questionnaires. Data compilation and analysis were performed using qualitative and quantitative methods. Information analysis and interpretation were based on academic references, structured through the research of available literature, and in most part rooted on with the support of the systemic and integrative model developed by Macedo-Soares (2001b). The results of the analysis indicate inconsistencies between the method currently used to evaluate the organizational performance in the Business Units of Telemar and the company s strategy. The work also revealed the aspects in the organization that contribute or hinder the implementation of the company s strategies and, ultimately, its success. The lessons captured in the study of the UNE - Telemar case are detailed in the final analysis.

Detta examensarbete har genomförts med syftet att utveckla Inno-x företagets system, som är avsett för vardagsidrottare för att mäta neuromuskulära aktiviteter i underkroppen med hjälp av modern teknologi. Systemet omfattar en tröghetsmätningsenhet (IMU) med accelerometer, gyroskop och en EMG-sensor (elektromyografi). Denna konfiguration möjliggör noggrann övervakning av neuromuskulära aktiviteter genom analys av svar på träning. Studiens mål var att identifiera en effektiv sensor för mätning av horisontella hoppavstånd och att utveckla en algoritm som sedan ska integreras i företagets produkt. Produkten kommer att använda magnetometer och IMU för att tolka mänskliga rörelser och för att förbättra noggrannheten i företagets mätningssystem. Processen inkluderar förbättring av mätningarnas noggrannhet, integration av teknik med biomekaniska principer, utvärdering av kalibreringstekniker för magnetometeravläsningar, kombination av sensorer för rörelseanalys och genomförande av utvärdering med olika åldersgrupper som består av 10 deltagare för att bedöma systemets effektivitet. Även om ingen av metoderna helt uppnådde den önskade noggrannheten inom ±5 cm, visade alla metoder god prestanda för olika tillämpningar. Detta antyder att implementeringen av en kalibrerad magnetometer potentiellt kan förbättra systemets noggrannhet vid bestämning av horisontella hoppavstånd, dock endast med en liten marginal, eftersom studien visade att med kalibrerade magnetometer RMSE (Root Mean Square Error) ökat med 0.99 cm. Ytterligare forskning rekommenderas för att undersöka nya sätt att kalibrera sensorer och integrera dem för mer precisa avläsningar. Dock bör det beaktas att magnetometeravläsningar påverkas av miljöfaktorer. Dessutom är det viktigt att skapa ett användarvänligt gränssnitt som gör det möjligt för idrottare att enkelt spåra och analysera sina prestandadata. / This thesis has been conducted with the objective of developing the Inno-X company's system, which is intended for everyday athletes to measure neuromuscular activities in the lower body using modern technology. The system includes an Inertial Measurement Unit (IMU) with an accelerometer, gyroscope, and an Electromyography (EMG) sensor. This configuration enables accurate monitoring of neuromuscular activities through the analysis of responses to training. The study's goal was to identify an effective sensor for measuring horizontal jump distances and to develop an algorithm that would then be integrated into the company's product. The product will use a magnetometer and IMU to interpret human movements and to improve the accuracy of the company's measurement system. The process includes improving the accuracy of measurements, integrating technology with biomechanical principles, evaluating calibration techniques for magnetometer readings, combining sensors for motion analysis, and conducting evaluations with different age groups consisting of 10 participants to assess the system's effectiveness. Although none of the methods fully achieved the desired accuracy within ±5 cm, all methods showed good performance for various applications. This suggests that the implementation of a calibrated magnetometer could potentially improve the system's accuracy in determining horizontal jump distances, albeit only by a small margin, as the study showed that with calibrated magnetometers, the Root Mean Square Error (RMSE) increased by 0.99 cm. Further research is recommended to explore new ways to calibrate sensors and integrate them for more precise readings. However, it should be considered that magnetometer readings are affected by environmental factors. Additionally, it is important to create a user-friendly interface that enables athletes to easily track and analyze their performance data.

The Hampton Roads Bridge-Tunnel is one of the oldest prestressed concrete structures in the United States. The 3.5 mile long twin structure includes the world's first underwater tunnel between two man-made islands. Throughout its 60 years in service, the harsh environment along the Virginia coast has taken its toll on the main load carrying girders. Concrete spalling has exposed prestressing strands within the girders allowing corrosion to spread. Some of the more damaged girders have prestressing strands that have completely severed due to the extensive corrosion. The deterioration has caused select girders to fail the necessary load ratings. The structure acts as an evacuation route for the coast and is a main link for the local Norfolk Naval Base and surrounding industry. Because of these constraints, load posting is not a viable option. Live load testing of five spans was performed to investigate the behavior of the damaged spans. Innovative techniques were used during the load test including a wireless system to measure strains. Two different deflection systems were implemented on the spans, which were located about one mile offshore. The deflection data was later compared head to head. From the load test results, live load distribution factors were developed for both damaged and undamaged girders. The data was also used by the local Department of Transportation to validate computer models in an effort to help pass the load rating. Overall, this research was at the forefront of the residual strength of prestressed concrete girders and the testing of in-service bridges. / Master of Science / According to Federal law, each bridge across the United States must be inspected by a licensed engineer on a biennial cycle – meaning every two years. Roughly every ten years, or when major work is performed such as a bridge widening, a load rating must be performed. During a load rating, licensed structural engineers analyze every structural component of a bridge under various loads. These loads include general traffic loads, heavy design loads, as well as special permit truck loads. For each of these loadings, it is proven whether each structural component has enough strength to withstand the load entering the member. Inspection reports are incorporated into the load rating analysis to account for any deterioration in the members which will lower its strength. Recently, a load rating was performed on the Hampton Roads Bridge-Tunnel. The Bridge-Tunnel is a 3.5 mile long twin structure located in Southeastern Virginia. Throughout its 60 years in service, the harsh coastal environment has caused extensive deterioration to some of its main load carrying girders. The deterioration has caused the Bridge-Tunnel to fail its load ratings meaning load posting may have to be imposed. This means signs, and possibly security guards, would have to be implemented before the approach ramps preventing trucks over a certain weight limit from entering. The structure acts as an evacuation route for the coast and is a main link for the local Norfolk Naval Base and surrounding industry. Because of these constraints, load posting is not a viable option. The Bridge-Tunnel is one of the oldest structures of its type so the effects of the deterioration are not well understood causing conservative assumptions to be used within the load rating. This research describes load testing that was performed on the structure to understand the performance and deterioration effects of the bridge. The results and recommendations from this research were used by the load rating engineers to justify assumptions made and help pass the load rating.

Thesis (MBA (Business Management))--Stellenbosch University, 2008. / Traditionally, organisational performance and efficiency measurements have been focused on cost containment. Today, however, performance measurement systems of world-class organisations are tailored to drive manufacturing and service business excellence. Quality is crucial for gaining a competitive advantage internationally. Quality award programmes promote quality awareness, recognise the quality achievements of companies and provide a platform for sharing successful quality management initiatives. Quality award frameworks form the foundation for developing business excellence models. Business excellence models are based on the premise that customer satisfaction, people (employee) satisfaction and impact on society are all achieved through leadership driving the policy and strategy, the people management, resources and processes, leading ultimately to excellence in business results. In this paper five of the most prominent international business excellence models are discussed. The success stories of companies that have implemented these models are looked at and the South African Excellence Model is compared with these five international models. The aim of the study is to analyse the South African Business Excellence Model as compared to international models such as the Deming Prize, the MBNQA, the EFQM, the AQA and the SQA. Case studies of two companies, Combine Cargo and Daimler Chrysler, are analysed with the aim of determining the shortcomings of the SAEM and the effects of the SAEM on business practices. Conclusions are drawn based on the experiences of these businesses, in order to verify the shortcomings and the effects of the SAEM. Lastly, the reasons for the failure of the SAEF and the SAEM are investigated and recommendations and guidelines are given for the revival of the SAEM and the promotion of quality in South Africa.

Assessment of finger range of motion (ROM) is often required for monitoring the effectiveness of rehabilitative treatments and for evaluating patients' functional impairment. There are several devices which are used to measure this motion, such as wire tracing, tracing onto paper and mechanical and electronic goniometry. These devices are quite cheap, excluding electronic goniometry; however the drawbacks of these devices are their lack of accuracy and the time- consuming nature of the measurement process. The work described in this thesis considers the design, implementation and validation of a new medical measurement system utilized in the evaluation of the range of motion of the human finger joints instead of the current measurement tools. The proposed system is a non-contact measurement device based on computer vision technology and has many advantages over the existing measurement devices. In terms of accuracy, better results are achieved by this system, it can be operated by semi-skilled person, and is time saving for the evaluator. The computer vision system in this study consists of CCD cameras to capture the images, a frame-grabber to change the analogue signal from the cameras to digital signals which can be manipulated by a computer, Ultra Violet light (UV) to illuminate the measurement space, software to process the images and perform the required computation, a darkened enclosure to accommodate the cameras and UV light and to shield the working area from any undesirable ambient light. Two calibration techniques were used to calibrate the cameras, Direct Linear Transformation and Tsai. A calibration piece that suits this application was designed and manufactured. A steel hand model was used to measure the fingers joint angles. The average error from measuring the finger angles using this system was around 1 degree compared with 5 degrees for the existing used techniques.

Examensarbetets syfte var att skapa ett generellt mät- och styrsystem som är möjligt att fjärrstyra över Internet. Systemet består av en kontrolldator och ett antal separata moduler, vilka var och en realiserar någon typ av mät- eller styrfunktion. Användningsområdet för ett sådant system är brett; det kan exempelvis användas inom automation av bostäder, för process-övervakning och styrning inom tillverkningsindustrin, eller inom under-hållningsbranschen.Eftersom ett fullt utbyggt system kan bestå av ett drygt 100-tal olika mo-duler, är det här examensarbetet av praktiska skäl begränsat till att rea-lisera en handfull av dessa. Då systemet är enkelt att skala upp, är den be-gränsningen i antalet realiserade moduler i prototypsystemet inget som påverkar de erhållna resultaten. Exempel på storheter som kan övervakas är temperatur, avstånd, lufttryck och ljusstyrka. Styrning kan ske av bland annat servomotorer, lampor och allmänna digitala utgångar.På kontrolldatorn körs en webbserver och styrning och avläsning av de anslutna modulerna sker från en ansluten webbklient. På webbservern finns även en webbkamera, vilken kan visa resultaten av de kommandon som ges från webbklienten.Resultaten från användningen av prototypsystemet visar att konstruk-tionerna fungerar och att systemets fördröjningar är relativt små. Att styra snabba realtidsförlopp är dock inte möjligt, men processer och system med blygsammare hastighetskrav är högst lämpade kandidater att styras och kontrolleras av detta system. / The purpose of this thesis work was to create a general measurement and control system, which is remotely controlled using Internet. The system comprises a controlling computer and several separate modules, each one realizing one or more measurement and control tasks. The possibilities of such a system are wide. It could be used for home automation, industrial process control or by the entertainment business. For example, the system can implement measurement of temperature, distance, pressure and light and control servos, lamps and general digital outputs.A fully implemented system comprises over 100 separate modules, so for practical reasons this thesis work was restricted to only implementing and demonstrating a few of those modules. Since the system is easily scalable, this was a minor restriction, which did not negatively affect the results.The results show that the system works and in general the latency is low. Fast real time processes will not work, but most applications with more moderate timing demands are ideally suited for this system.