1,720,956 research outputs found
Möjligheter till energigemenskap för ett fritidshusområde : En utvärdering av förutsättningar till effektdelning och energilagring vid ett framtida mikronät i Härnösand
No full textPlaner finns till att bygga ett mikronät på Hemsön, i Härnösand. Denna studie syftar till att utreda möjligheter till detta och om möjligt identifiera var kostnadsbesparingar kan göras inför byggnationen och implementeringen av denna energigemenskap. Mikronätet kommer innefatta 18 tomter varvid sommarstugor förväntas byggas och enligt kontrakt även ska inkludera en produktionsanläggning för egenproducerad el, vilka förväntas bli solceller. En utredning har även gjorts för att finna svar på om energilagring via elfordon kan utnyttjas i stället för ett batterilager. Studien har funnit att denna typ av energilagring har potential att eliminera behovet av inköpt el under sommarmånader då solel produceras. Vidare har studien tydliggjort att implementering av detta mikronät ej tillåter en högre total produktion än 44,1 kW, vilket är betydligt lägre än först var väntat. Studiens resultat visar på att kabelskåpets impedans bör reduceras om högre produktion är önskat. Detta kräver vidare dialog med elnätsföretaget och en fortsatt utredning för detta är rekommenderat i framtiden.Plans have arisen to build a micro grid in Hemsön, Härnösand. The purpose of this study is to evaluate possibilities for solutions and identify ways to save on costs during the building and implementation of the micro grid. The grid will contain 18 building plots where vacation homes may be built, which by contract shall include energy production assumingly solar panels. An investigation has also been conducted regarding if electric vehicles can be used for energy storage instead of batteries. During the study it has been found that energy storage through electric vehicles has the potential to eliminate the need to buy electricity during the summer months when solar power is produced. Furthermore, the study has shown that the maximum total production of solar power for the micro grid is 44,1 kW which is less than first expected. It has been found that the impedance needs to be reduced if a higher production is wanted. To resolute this, a dialogue needs to be held with the power supplier which is recommended going forward
Power architecture analysis : Design and evaluation of DC-DC converter systems
No full textUnder denna studie har topologier och switchstrategier för omvandlare utretts. Målet var att finna en passande lösning för ett specifikt system, med ett övergripande syfte att utvärdera fördelar som även kan appliceras på likströmsomvandlare generellt, eller möjligtvis framtida system. Den rekommenderade lösningen inkluderade en boostregulator, en boostregulator med bypass och en buckregulator. Den sistnämnda hade en skalbar design där en andra fas kunde appliceras vid system med hög effekt, medan den enfasiga lösningen användes vid mindre effektkrävande implementationer för att spara onödiga kostnader. Experimentella resultat visade att genom implementering av en sekundär fas för högströmsmoduler ökade effektiviteten med upp till 9,1% varpå även störningar förbättrades. Med en sammanlagd verkningsgrad på 92,97% var den skalbara designen fördelaktig för systemet och slutsatsen var att även andra system kan dra nytta av en sådan lösning, både sett till kostnad, effektivitet, och prestanda. During this study, converter topologies and switching strategies have been investigated. The goal was to find a suitable solution for a specific power supply system, with an overall aim to further evaluate benefits applicable to DC-DC converter systems in general, or any possible future system. The recommended solution included a boost converter, a boost converter with bypass, and a buck converter. The latter of which had a modular design, where a second phase could be applied for high power systems, whereas the single-phase solution was utilized for less power demanding implementations to cut unnecessary costs. Experimental results showed that implementing a second phase to a high current module increased the efficiency by up to 9.1% while also improving effects of interference. With a combined efficiency of 92.97%, the system greatly benefitted from the scalable design and the conclusion was that other converter systems could improve by such a solution, both regarding cost, efficiency and performance
Möjligheter till energigemenskap för ett fritidshusområde : En utvärdering av förutsättningar till effektdelning och energilagring vid ett framtida mikronät i Härnösand
No full textPlaner finns till att bygga ett mikronät på Hemsön, i Härnösand. Denna studie syftar till att utreda möjligheter till detta och om möjligt identifiera var kostnadsbesparingar kan göras inför byggnationen och implementeringen av denna energigemenskap. Mikronätet kommer innefatta 18 tomter varvid sommarstugor förväntas byggas och enligt kontrakt även ska inkludera en produktionsanläggning för egenproducerad el, vilka förväntas bli solceller. En utredning har även gjorts för att finna svar på om energilagring via elfordon kan utnyttjas i stället för ett batterilager. Studien har funnit att denna typ av energilagring har potential att eliminera behovet av inköpt el under sommarmånader då solel produceras. Vidare har studien tydliggjort att implementering av detta mikronät ej tillåter en högre total produktion än 44,1 kW, vilket är betydligt lägre än först var väntat. Studiens resultat visar på att kabelskåpets impedans bör reduceras om högre produktion är önskat. Detta kräver vidare dialog med elnätsföretaget och en fortsatt utredning för detta är rekommenderat i framtiden.Plans have arisen to build a micro grid in Hemsön, Härnösand. The purpose of this study is to evaluate possibilities for solutions and identify ways to save on costs during the building and implementation of the micro grid. The grid will contain 18 building plots where vacation homes may be built, which by contract shall include energy production assumingly solar panels. An investigation has also been conducted regarding if electric vehicles can be used for energy storage instead of batteries. During the study it has been found that energy storage through electric vehicles has the potential to eliminate the need to buy electricity during the summer months when solar power is produced. Furthermore, the study has shown that the maximum total production of solar power for the micro grid is 44,1 kW which is less than first expected. It has been found that the impedance needs to be reduced if a higher production is wanted. To resolute this, a dialogue needs to be held with the power supplier which is recommended going forward
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Power architecture analysis : Design and evaluation of DC-DC converter systems
No full textUnder denna studie har topologier och switchstrategier för omvandlare utretts. Målet var att finna en passande lösning för ett specifikt system, med ett övergripande syfte att utvärdera fördelar som även kan appliceras på likströmsomvandlare generellt, eller möjligtvis framtida system. Den rekommenderade lösningen inkluderade en boostregulator, en boostregulator med bypass och en buckregulator. Den sistnämnda hade en skalbar design där en andra fas kunde appliceras vid system med hög effekt, medan den enfasiga lösningen användes vid mindre effektkrävande implementationer för att spara onödiga kostnader. Experimentella resultat visade att genom implementering av en sekundär fas för högströmsmoduler ökade effektiviteten med upp till 9,1% varpå även störningar förbättrades. Med en sammanlagd verkningsgrad på 92,97% var den skalbara designen fördelaktig för systemet och slutsatsen var att även andra system kan dra nytta av en sådan lösning, både sett till kostnad, effektivitet, och prestanda. During this study, converter topologies and switching strategies have been investigated. The goal was to find a suitable solution for a specific power supply system, with an overall aim to further evaluate benefits applicable to DC-DC converter systems in general, or any possible future system. The recommended solution included a boost converter, a boost converter with bypass, and a buck converter. The latter of which had a modular design, where a second phase could be applied for high power systems, whereas the single-phase solution was utilized for less power demanding implementations to cut unnecessary costs. Experimental results showed that implementing a second phase to a high current module increased the efficiency by up to 9.1% while also improving effects of interference. With a combined efficiency of 92.97%, the system greatly benefitted from the scalable design and the conclusion was that other converter systems could improve by such a solution, both regarding cost, efficiency and performance
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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