High frequency link power converters for DC – 3Φ AC applications are investigated. Low cost, reduced size, galvanic isolation and efficient large boosting of voltage level are the key motivations behind the selection of such topologies. This thesis proposes high frequency link 3Φ inverters for three wire and four wire systems. The proposed topologies have the simplest power circuit configuration and commutation requirements among all high frequency link topologies reported in the literature. A full load efficiency greater than 90% is achieved with a passive snubber. The effect of various circuit non-idealities are common and important for desirable performances of these topologies. A few such issues are highlighted. Firstly, the special commutation requirement of the power circuit causes a non-linear distortion in the output voltages and thus makes the gain of the power converter time varying. A simple compensation technique is adopted to mitigate the problem. Secondly, the high frequency transformer should operate with only switching frequency component. However, in the practical situations a significant amount of low frequency component gets injected into the transformer and results in peaky transformer magnetizing current unless it is over designed. A suitable measure is incorporated in the proposed topologies to achieve a magnetic protection. The power circuit topology is used as stand-by AC power supply. These are of interest for Uninterruptible Power Supply (UPS) and Micro-grid applications. One of the main objectives of such supplies is to provide a high quality and highly reliable power to the connected loads. A voltage regulation loop based on proportional + multiresonant controller is proposed to achieve excellent quality of the output voltage with unbalanced and nonlinear loadings. The factors influencing regulation and stability of the voltage waveform are identified and necessary modifications are carried out to improve the performance. The potential of this voltage regulation loop along with P/Q droop technique and a simple resistive virtual output impedance loop is exploited to achieve decentralized paralleling of inverters. A trade off between the output voltage power quality and the sharing accuracy is examined. The total harmonic distortion and degree of unbalance in the output voltage waveform are experimentally measured well below the specified limit for stand alone AC supplies with an excellent sharing accuracy. Some of the grid interactive modes are addressed for the completeness of the work. A shunt compensator system and a double conversion system based on the same high frequency link converter are experimentally evaluated. These systems can find their application in UPS systems. A few important observations on the power circuit performances are indicated.

To enable wireless control of factories, such that sensor measurements can be sent wirelessly to an actuator, the probability to receive data correctly must be very high and the time it takes to the deliver the data from the sensor to the actuator must be very low. Earlier, these requirements have only been met by cables, but in the fifth generation mobile network this is one of the imagined use cases and work is undergoing to create a system capable of wireless control of factories. One of the problems in this scenario is when all data in a packet cannot be sent in one transmission while ensuring the very high probability of reception of the transmission. This thesis studies this problem in detail by proposing methods to cope with the problem and evaluating these methods in a simulator. The thesis shows that splitting the data into multiple segments and transmitting each at an even higher probability of reception is a good candidate, especially when there is time for a retransmission. When there is only one transmission available, a better candidate is to send the same packet twice. Even if the first packet cannot achieve the very high probability of reception, the combination of the first and second packet might be able to. / För att möjliggöra trådlös kontroll av fabriker, till exempel trådlös sändning av data uppmätt av en sensor till ett ställdon som agerar på den emottagna signalen, så måste sannolikheten att ta emot datan korrekt vara väldigt hög och tiden det tar att leverera data från sensorn till ställdonet vara mycket kort. Tidigare har endast kablar klarat av dessa krav men i den femte generationens mobila nätverk är trådlös kontroll av fabriker ett av användningsområdena och arbete pågår för att skapa ett system som klarar av det. Ett av problemen i detta användningsområde är när all data i ett paket inte kan skickas i en sändning och klara av den väldigt höga sannolikheten för mottagning. Denna uppsats studerar detta problem i detalj och föreslår metoder för att hantera problemet samt utvärderar dessa metoder i en simulator. Uppsatsen visar att delning av ett paket i flera segment och sändning av varje segment med en ännu högre sannolikhet för mottagning är en bra kandidat, speciellt när det finns tid för en omsändning. När det endast finns tid för en sändning verkar det bättre att skicka samma paket två gånger. Även om det första paketet inte kan uppnå den höga sannolikheten för mottagning så kan kanske kombinationen av det första och andra paketet göra det.

The purpose of this paper is to show the integration of the transmission gain values of a telemetry transmission antenna according to its relative position and integrate them in the C band link budget, in order to obtain an accuracy vision of the link. Once our C band link budget was fully performed to model our link and ready to work in real time with several received values (GPS position, roll, pitch and yaw) from the aircraft and other values from the Ground System (azimuth and elevation of the reception telemetry antenna), it was necessary to avoid a constant value of the transmitter antenna and estimate its values with better accuracy depending of the relative beam angles between the transmitter antenna and receiver antenna. Keeping in mind an aircraft is not a static telecommunication system it was necessary to have a real time value of the transmission gain. In this paper, we will show how to perform a real time link budget (C band).

Muitos links entre páginas na Web podem ser vistos como indicadores de qualidade e importância para as páginas que eles apontam. A partir desta ideia, vários estudos propuseram métricas baseadas na estrutura de links para inferir qualidade de conteúdo em páginas da web. Contudo, até onde sabemos, o único trabalho que examinou a correlação entre tais métricas e qualidade de conteúdo consistiu de um estudo limitado que deixou várias questões em aberto. Embora tais métricas sejam muito bem sucedidas na tarefa de ranquear páginas que foram fornecidas como respostas para consultas submetidas para máquinas de busca, não é possível determinar a contribuição específica de fatores como qualidade, popularidade e importância para os resultados. Esta dificuldade se deve em parte ao fato de que a informação sobre qualidade, popularidade e importância é difícil de obter para páginas da web em geral. Ao contrário de páginas da web, estas informações podem ser obtidas para artigos da Wikipédia, uma vez que qualidade e importância são avaliadas por especialistas humanos, enquanto a popularidade pode ser estimada com base nas visualizações dos artigos. Isso torna possível a verificação da relação existente entre estes fatores e métricas de análise de links, nosso objetivo neste trabalho. Para fazer isto, nós implementamos vários algoritmos de análise de links e comparamos os rankings obtidos com eles com os obtidos considerando a avaliação humana feita na Wikipédia com relação aos fatores qualidade, popularidade e importância. Nós observamos que métricas de análise de links são mais relacionadas com qualidade e popularidade que com importância e a correlação é moderada / Many links between Web pages can be viewed as indicative of the quality and importance of the pages pointed to. Accordingly, several studies have proposed metrics based on links to infer web page content quality. However, as far as we know, the only work that has examined the correlation between such metrics and content quality consisted of a limited study that left many open questions. In spite of these metrics having been shown successful in the task of ranking pages which were provided as answers to queries submitted to search machines, it is not possible to determine the specific contribution of factors such as quality, popularity, and importance to the results. This difficulty is partially due to the fact that such information is hard to obtain for Web pages in general. Unlike ordinary Web pages, the content quality of Wikipedia articles is evaluated by human experts, which makes it feasible to verify the relation between such link analysis metrics and the quality of Wikipedia articles, our goal in this work. To accomplish that, we implemented several link analysis algorithms and compared their resulting rankings with the ones created by human evaluators regarding factors such as quality, popularity and importance. We found that the metrics are more correlated to quality and popularity than to importance, and the correlation is moderate

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This diploma thesis first handles the general issues concerning free space optics in the~atmosphere. The aim is to design and implementation of optical wireless equipment, which would serve in the laboratories of optical networks. Ronja was used as the basis for a~wireless link, which is already widespread in the world. Students will work with the device, which they may come into contact in the future. It consists several separate modules: transmitter, receiver and inteface. Each module have a separate chapter describing the~functional blocks and circuit realization. Ronja was adjusted for the needs of~laboratory tasks, where additional voltmeters measures received signal strength (RSSI) at~both ends of the link. Measuring device provides adjustment of power the transmitting LED via~computer, measures and sends RSSI values to a PC via~USB or RS232, turn off Ronja with computer. For targeting the pipes of Ronja was developed the mechanical design. In the last part of thesis the device was undergone a series of tests.

This thesis deals with articulated robots for special applications for confined spaces. Introduction work includes the distribution and development in the field of handling technology. It also deals with the handlers chain structure. Following the described types of articulated robot kinematic model was developed and subsequently implemented the 3D design in SolidWorks. The conclusion is drawn visualizations made-handling arm.

Women and children who turn to domestic violence shelters for help witness about the violence they and their companion animal have experienced. There are strong emotional bonds between humans and animals, which domestic violence perpetrators can use to hurt or control their partner. In fear that the domestic violence perpetrators will harm the animal if the victim tries to leave the relationship, thus she remains in the relationship to protect the animals. The aim of this study was to investigate how animal welfare officers work to discover the link between animal abuse and human violence. Moreover, how animal welfare officers help the victims in such relationships. The study was conducted using an inquiry and telephone interviews. The result of this study showed that the majority of animal welfare officers in Sweden work to discover the link during animal welfare inspection. With education, guidelines and cooperation with other authorities, they have the possibility to help abused animals and humans. In conclusion, animal welfare officers have an important role in dealing with abused animals and humans. They might be the first ones to discover violence and can thereby help the victims away from the domestic violence perpetrator.

Pyrrolizidine alkaloids (PAs) are natural plant compounds found in hundreds of plant species worldwide and are reported to have cytotoxic, carcinogenic, antimitotic, and gentotoxic activity. PAs are metabolized by the cytochrome P450 (CYP) sytem to the pyrrole or the N-oxide form. They pyrroles are bifunctional electrophillic alkylators that bind cellular nucleophiles such as DNA and proteins and disrupt normal cell processes, including DNA replication and gene transcription, and can cause megalocytosis. The pyrroles dehyrosenecionine (DHSN) and dehydromoncrotaline (DHMO) are among the most potent PA cross-linkers and inducers of megalocytosis. DHSN and DHMO-induced cross-links in cultured normal (MDBK) and neoplastic (MCF7) cells were nalyzed by SDS-PAGE and Western blot and both were found to contain the protein actin. Actin is crucial to DNA replication and is known to be involved in cross-links induced by cis-dichlorodiammine platinum II (cistplatin), a well known cross-linking drug used for the treatment of cancer. Actin cross-linking may explain the antimitotic, megalocytotic, and anticarcinogenic effects of PAs. Since protein cross-linking is an important mode of action for PAs, we were interested in what characteristics of the protein might make it a good nucleophilic target. Thus, further research was undertaken based on the hypothesis that cysteine residues, and specifically free sulfhydryl groups, are attractive targets for the bifunctional electrophilic alkylators DHSN and DHMO. Nucleophiles were selected for their abundance in the cell, their cysteine content, and their relationship to the documented side effects of PAs. Actin, glutathione (GSH), metallothionein, topoisomerase II, and cysteine were all found to cross-link with DHSN and DHMO in vitro while methionine, with no free sulfhydryl groups, did not cross-link. Our results support the hypothesis that cysteine residues are a key characteristic of proteins that are cross-linked by PAs. The cross-links could have negative effects to the cell as in the case of binding actin or topoisomerase II to alter normal DNA processes and replication, or beneficial effects such as binding to electrophillic scavengers like GSH or metallothionine as a detoxifying mechanism. the nucleophiles we tested in vitro and found to form cross-links with DHSN and DHMO may help to explain the antimitotic carcinogenic, and anticarcinogenic effects of PAs.

No description available.