Orientador: Carlos Alberto Canesin / Banca: Falcondes Jose Mendes de Seixas / Banca: Dionizio Paschoareli Junior / Banca: Ernane Antônio Alves Coelho / Banca: José Demisio da Silva / Resumo: Uma das importantes aplicações dos sistemas inversores está associada ao fornecimento de energia elétrica. Com este foco destacam-se o fornecimento para cargas críticas, o fornecimento em áreas desprovidas dos usuais sistemas de transmissão e distribuição e aplicações com multi-fontes primárias de energia, incluindo-se neste caso, as aplicações para geração distribuída, com possibilidade de conectividade com a rede elétrica de distribuição ou, com o paralelismo entre estruturas isoladas. Atualmente, topologias e filosofias de controle que atendam as características das aplicações supracitadas são de interesse técnico e científico. Neste sentido, a possibilidade de paralelismo entre inversores sem interconexão do controle tem se mostrado atrativa à medida que se exigem sistemas distribuídos e adaptáveis às variações paramétricas do circuito. Entretanto, problemas de estabilidade e resposta dinâmica devem ser solucionados para garantir a confiabilidade de tais sistemas. Sendo assim, neste trabalho inicialmente é realizada a modelação em espaço de estados de sistemas compostos por inversores cuja filosofia de controle esteja embasada nas curvas P- e Q-V. Com esta modelação, tornam-se possíveis avaliações de estabilidade e resposta dinâmica através dos autovalores da matriz de estados. Propõe-se assim a busca da estabilidade dos sistemas com melhores respostas dinâmicas através de alterações nos valores da matriz de estados, resultando-se em autovalores que representem parâmetros de desempenho otimizados. Obviamente que alterações na matriz de estados estão associadas a alterações na planta, contudo, alterações em parâmetros físicos não são interessantes, uma vez que não são simples de serem obtidas na prática. Sendo assim, são propostas alterações nas constantes que definem as inclinações das curvas de controle P- e Q-V... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: One of main applications of inverter systems is associated to electrical energy supply. With this focus it emphasizes the supply of energy to critical loads, the supply of energy to areas devoid of the usual transmission and distribution systems of energy and the use of primary energy in multi-fonts applications, including in this case, distributed generation applications with grid connectivity or, parallelism in stand alone applications. Currently, topologies and control philosophies capable to assure the applications characteristics above mentioned are in technical and scientific interests. In this way, the possibility of inverter parallelism with no control interconnection has showed attractive, since distributed systems and adaptable systems to parametric variations are mandatory nowadays. However, stability troubles and inadequate dynamic responses must be solved to ensure reliability of these systems. So, in this work is performed the state space modeling of systems set by inverters whose control philosophy is based on P- and Q-V curves. With this modeling it becomes possible evaluations of stability and dynamic response through state matrix eigenvalues. Thus, it proposes to assure the systems stability and better dynamic responses through changes on state matrix values, resulting in eigenvalues that represent optimized performance parameters. Obviously those variations in state matrix are associated with plant variations, however, physical parameters variations are not interesting, seeing that it is not simple to be obtained in practical situations. In face of this are proposed variations in constants that define the slopes of P- and Q-V curves. These slopes intervene directly on state matrix values and consequently in systems eigenvalues. The variations on constants are not performed randomly, nevertheless based on evolutionary algorithm capable to search values that represent...(Complete abstract click electronic access below) / Doutor

This thesis explores how an Android application that is used in combination with tangible appcessories is capable of facilitating a learning experience for visually impaired students within the specific domain of geometry. This study’s approach illustrates how using an application in combination with a physical appcessory can provide information concerning geometry to the visually impaired. An application, called Invisible Tangible Geometry (ITG), was programmed using Android in conjunction with a 3D printed model. This thesis describes the application, the physical appcessory, as well as early stage user studies. The application enables visually impaired users to explore simple geometric forms displayed on a tablet through sound and vibrotactile feedback. A physical appcessory, that can be manipulated to adopt several forms and is dynamic, is used in addition. Its shape is sensed by the tablet adds an additional tactile layer to the application and experience. Within the thesis a methodological framework, as well as a user-centered design approach was applied. An expert interview and three user engagements with visually impaired individuals serve as early validations of the project and ideas and provide feedback that directs design and development of future work. Current avenues for the future work will include additional interaction modes in the application. For example, the ability to digitize real world forms, and improving the robustness of the tangible appcessory. The plan, for future development, is to establish an autonomous functioning application that enables the visually impaired to be able to explore, participate and interact with geometry smoothly and without the need of aid from others. The correlation of application and appcessory will allow for anything between a quick glance, through feeling the model, and gaining detailed information, by using the application. The application enhances provided information through the use of a model and enriched digital feedback.

Mobiltelefonen är ständigt närvarande i vår vardag. Den är ett kraftfullt verktyg som hjälper oss med allt från att surfa på nätet till att kolla när bussen går eller att betala räkningarna. Den har också gjort att vi kan dela med oss av våra liv och hålla kontakten med våra nära och kära var vi än befinner oss. Kort sagt har den ändrat hur vi beter oss i de flesta situationer. Men alla dessa ändringar är kanske inte lika positiva. Vi tycker oss se ett mönster i samhället där mobilen plockas fram allt oftare i sociala sammanhang och tar bort fokus från mötet med andra människor. Det är detta som vi vill undersöka med denna uppsats och målet är att försöka hitta ett sätt att vända mobilanvändandet till något som främjar den sociala interaktionen mellan människor. The mobile phone is ever present in our daily lives. It is a powerful tool to help us with everything from surfing the net to check when the bus went, or to pay the bills. It has also allowed us to share our lives and stay connected with our loved ones wherever we find ourselves. In short, it has changed the way we behave in most situations. But all of these changes may not be as positive. We think we see a pattern in the community where the mobile is being used more and more often in social settings and removes the focus from meeting with other people. This is what we want to explore with this paper and the objective is to try to find a way to turn mobile usage into something that promotes social interaction among people. / Detta är en reflektionsdel till en digital medieproduktion.

This Master’s Degree project has been performed on behalf of Vanuatu Renewable Energy and Power Association. The purpose of the project was to suggest the design of stand-alone renewable power supply systems on Futuna Island in the Republic of Vanuatu. Futuna is the easternmost island in Vanuatu with a population of about 400 people. The island covers an area of just 13 km2. The proposed sites for power production were the villages of Mission Bay, Matangi, Herald Bay and Iahsoa. In Mission Bay and Matangi the power should be produced by wind turbines and in Herald Bay and Iahsoa, solar modules are proposed. The results of the study showed that some parts of Futuna Island can be suitable for wind power production and wind speeds in the order of 5-7 m/s are suggested. However, wind monitoring on the sites are required to estimate the exact potential. Furthermore, the study showed that there is less uncertainty involved with estimating the power output from the solar modules. In addition, solar power proved to be more reliable and less vulnerable to local variations in weather and topography. Solar modules are therefore considered more appropriate for small scale power production on the island, at least until the wind climate is better known. The results of the study also showed that proper sizing of battery banks and cables are essential to increase the efficiency and lifetime of the systems. If there are insufficient financial resources in the project, it is therefore recommended in the report to use all resources available to properly size the systems in 1-2 villages rather than to inadequately size the systems in all the villages. / Ögruppen Vanuatu är en självständig nation som består av mer än 83 bebodda öar av varierande storlek. Landet ligger mellan Fiji och Australien i Stilla havet och tillhör enligt FN världens fattigaste länder. Av landets befolkning på ungefär 200 000 människor är minst 80 procent självförsörjande bönder. Förutom på några av de större öarna där man byggt ut elnät till viss del finns det i princip ingen produktion av elektrisk energi i landet. Undantaget är några enstaka dieselaggregatsystem och solcellssystem som installerats med hjälp av privata medel och bistånd. Dock är många av dessa mikrosystem beroende av fossilt bränsle som måste importeras och därför är både dyrt och ofta en bristvara då transporten mellan öarna kan vara oberäknelig. Öarnas geografiska isolation och bristen på infrastruktur hindrar utvecklingen av storskalig energiproduktion i landet. För att förbättra denna situation initierade frivilligorganisationen Vanuatu Renewable Energy and Power Association (VANREPA) år 2005 ett projekt med syftet att producera elektrisk energi på öarna Futuna och Aneityum med hjälp av förnybara energikällor. Landet har gott om förnybara energiresurser i form av hög solinstrålning, passadvindar, biobränslen och höga vulkanberg som även möjliggör produktion av vattenkraft. Landet har därför potential att producera relativt billig och miljövänlig energi med hjälp av lokala resurser. Projektet leds av VANREPA’s grundare David Stein, ursprungligen från USA, och finansieras med hjälp av bidrag från EU. Det här examensarbetet har utförts i samarbete med VANREPA, och med David Stein som handledare. Ämnesgranskare på Uppsala universitet har varit Marcus Berg och examinator har varit Kjell Pernestål. Examensarbetet har även utförts som en Minor Field Study i samarbete med Arbetsgruppen för tropisk ekologi (ATE) på Uppsala universitet och med stipendium från Styrelsen för internationellt utvecklingssamarbete (Sida). I tillägg har examensarbetet finansierats med hjälp av ett resestipendium ur Jacob A. Letterstedts resestipendiefond som förvaltas av Kungl. Vetenskapsakademien (KVA). Syftet med examensarbetet har varit att föreslå lämplig design av de fyra förnybara kraftproduktionssystem som planeras i byarna Mission Bay, Matangi, Herald Bay och Iahsoa på Futuna. Den totala befolkningen på ön består av ungefär 400 människor. Det var önskvärt att kraftproduktionssystemen utformades så enkelt som möjligt. Detta för att underlätta att drift och underhåll ska kunna skötas av den lokala befolkningen på ön men även för att minimera projektets kostnader. Eftersom både efterfrågan och produktion av energi kommer att vara relativt låga var det även önskvärt att minimera alla förluster så mycket som möjligt. Dessutom var det önskvärt att systemen designades med möjlighet för expansion då detta endast anses vara ett första steg i att försörja Futuna med elektrisk energi. Komponenter som inkluderades i designen var vindturbiner, solpaneler, batterier och kablar. Ett antal givna förutsättningar begränsade utförandet av examensarbetet. Dels var vindturbinerna och solpanelerna redan införskaffade vid den tidpunkt då författaren påbörjade examensarbetet. Detta innebar att det inte fanns möjlighet att påverka vare sig val av produktionsmetod eller antal produktionsenheter. Dessutom hade byggnaderna för batteribankerna i de fyra byarna redan byggts. Eftersom det var viktigt att hålla förlusterna och kostnaderna på en minimal nivå kunde därför inte heller placeringen av solpanelerna eller vindturbinerna påverkas, då dessa måste placeras så nära batteribankerna och konsumenterna som möjligt. Utförandet av examensarbetet delades in i tre delar. I den första delen gjordes förberedande litteraturstudier i Sverige om småskaliga energisystem i allmänhet och förutsättningarna i Vanuatu i synnerhet. I den andra delen utfördes under sex veckor fältstudier på plats i Vanuatu. Under denna period genomfördes bland annat en fältresa till Futuna, där de fyra platserna föreslagna för kraftproduktion besöktes. Under fältresan samlades relevanta data in, såsom koordinater för platserna i behov av elektrisk energi och topografiska förutsättningarna för sol- och vindkraft på de fyra platserna. Dessutom intervjuades representanter för de fyra byarna för att kartlägga var och till vad elektrisk energi var önskvärd. Under den sista delen av examensarbetet analyserades materialet som samlats in under fältstudierna tillsammans med ämnesgranskaren på Uppsala universitet. Den förväntade kraftproduktionen från solpanelen och vindturbinerna uppskattades med hjälp av data från NASA, då inga vind- eller solmätningar gjorts på plats per idag. På grund av den stora osäkerheten med att använda dessa data är den beräknade kraftproduktionen inte lika exakt som den annars kunnat vara. När den förväntade kraftproduktionen uppskattats beräknades den nödvändiga storleken på batteribankar och kablar. För att inte underdimensionera systemen inkluderades ett visst antal dagar som batteribanken skulle kunna försörja den givna lasten med elektrisk energi om vind eller sol skulle utebli. Dessutom dimensionerades batteribankerna för ett maximalt urladdningsdjup, detta för att förlänga batteriernas liv. Kablarna dimensionerades för att minimera spänningsfall och i gränsfall valdes därför alltid den större kabelstorleken. Både batteribankarna och kablarna dimensionerades även med hänsyn till övriga förluster i systemet. Studien visade att vissa områden på Futuna kan vara lämpade för vindkraftsproduktion. Dock krävs vindmätningar på plats för att kunna uppskatta den exakta potentialen. Osäkerheten med kraftproduktion från solceller är mindre än för vindturbiner. Denna energikälla är också mindre känslig för lokala variationer och kräver mindre kunskap hos lokalbefolkningen för drift och underhåll. Solenergi anses därför vara en bättre lämpad energikälla för småskalig kraftproduktion på ön, åtminstone tills man fått en bättre uppfattning om det rådande vindklimatet. Kostnaden för batterier är en känslig del av energisystemen som tyvärr inte går att komma undan, då kraftproduktionen är för instabil för att försörja lasten direkt. Det är mycket viktigt att batteribankernas kapacitet dimensioneras korrekt, för att undvika kortlivade system. Underdimensionerade batteribanker leder även till mindre effektiva system då en mindre andel av den producerade energin kan användas. Detsamma gäller för dimensioneringen av kablar, eftersom för högt spänningsfall kan leda till att den producerade energin inte når fram till konsumenten. Om tillräckliga finansiella resurser saknas för att slutföra projektet är det därför rekommenderat att snarare satsa på korrekt dimensionerade system i 1-2 byar än ofullständigt dimensionerade system i alla fyra byarna.

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In recent years the number of bicycles with e-motors has been increased steadily. Within the pedelec – bikes where an e-motor supports the pedaling – a special group of transportation bikes has developed. These bikes have storage boxes in addition to the basic parts of a bike. Due to the space available on top of those boxes it is possible to install a PV system to generate electricity which could be used to recharge the battery of the pedelec. Such a system would lead to grid independent charging of the battery and to the possibility of an increased range of motor support. The feasibility of such a PV system is investigated for a three wheeled pedelec delivered by the company BABBOE NORDIC.The measured data of the electricity generation of this mobile system is compared to the possible electricity generation of a stationary system.To measure the consumption of the pedelec different tracks are covered, and the energy which is necessary to recharge the bike battery is measured using an energy logger. This recharge energy is used as an indirect measure of the electricity consumption. A PV prototype system is installed on the bike. It is a simple PV stand alone system consisting of PV panel, charge controller with MPP tracker and a solar battery. This system has the task to generate as much electricity as possible. The produced PV current and voltage aremeasured and documented using a data logger. Afterwards the average PV power is calculated. To compare the produced electricity of the on-bike system to that of a stationary system, the irradiance on the latter is measured simultaneously. Due to partial shadings on the on-bike PV panel, which are caused by the driver and some other bike parts, the average power output during riding the bike is very low. It is too low to support the motor directly. In case of a similar installation as the PV prototype system and the intention always to park the bike on a sunny spot an on-bike system could generate electricity to at least partly recharge a bike battery during one day. The stationary PV system using the same PV panel could have produced between 1.25 and 8.1 times as much as the on-bike PV system. Even though the investigation is done for a very specific case it can be concluded that anon-bike PV system, using similar components as in the investigation, is not feasible to recharge the battery of a pedelec in an appropriate manner. The biggest barrier is that partial shadings on the PV panel, which can be hardly avoided during operation and parking, result in a significant reduction of generated electricity. Also the installation of the on-bike PV system would lead to increased weight of the whole bike and the need for space which is reducing the storage capacity. To use solar energy for recharging a bike battery an indirect way is giving better results. In this case a stationary PV stand alone system is used which is located in a sunny spot without shadings and adjusted to use the maximum available solar energy. The battery of the bike is charged using the corresponding charger and an inverter which provides AC power using the captured solar energy.

How might we through emotional service design investigate how to support people in coping with social isolation by enabling for opportunities to be alone together? This is the research question this interaction design bachelor thesis, through applying theories of emotional and service design, has been aiming towards investigating. What is presented in the work is a merge of the terms, emotional service design. In addition to this, a service to help improve its user’s well-being and ability to cope with the effects of an isolated stay-at-home life is proposed.The conducted research has taken a qualitative approach, using methods of semi-structured interviews, affinity-diagramming, cultural probes, co-creative workshops and prototype testing, insights indicating that loneliness can be combated through two main ways: by finding an activity-based escape or by connecting with people or others. What is argued for is the importance of keeping emotional reactions in mind when designing for experiences.

The beneficial effects obtained from the application of farmyard manure to the soil have long been known in Utah, but now the point has apparently been reached where it becomes evident that the supply of manure is hardly adequate in some sections where intensive cropping is predicted. The use of commercial fertilizers to increase crop yields is a new practice in Utah agriculture as is shown in Table 1 from an estimate made from data kindly furnished by the Columbia Steel Company, and Porter Walden Company.

The purpose of the study is to make a netnographic comparison between the groups of Incels and Forever Alone Women in a way that has not been done before. With the study, we want to shine new light on how online interactions take place and how these affect people. The study uses Collins' theory of interaction rituals to highlight how people create bonds and feelings for each other through written language and how these affect them even when the computer is turned off. The study was carried out through a non-participation in the forums Incels.is and Reddit.com, where the focus has been on the use of language and repetitions of the language. The collected material has then been analyzed through a thematic analysis to then carry out a comparison between the groups to demonstrate similarities and differences. The results and analysis demonstrate how the interactions that take place online have a major impact on the participants' self-images and the ways in which conversations take place in the forums. The study has been able to show how the groups discuss similar topics but how the conversations look completely different between the forums. Collins' theory was helpful in creating an understanding of causality, that is, the cause and effect of why the interactions look the way they do in the specific groups. The response participants receive to their posts has proven to be of great importance in understanding why they continue to participate and reproduce what is written in the forums. The closeness that is created in the forums gives rise to an emotional energy and a feeling of similarity to the other participants, which has proven to be of great importance in order to stay in the forums. The conclusion is that two groups that suffer from the same kind of exclusion deal with it in different ways.

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