Sökresultat:
1264 Uppsatser om Search engine - Sida 8 av 85
CFD simulering av en fyrtakts Otto motorcykel motor
This thesis deals with the numerical 3D simulation of a four stroke, spark-ignited, internalcombustion engine, which is mounted on a high performance motorcycle. The work, carried outin collaboration with Politecnico di Milano and MV Agusta, focuses on the simulation of theintake, compression and expansion stroke, including combustion simulation, using an opensource CFD code.Simulation of internal combustion engines offers a great challenge in the field of CFD research.Moving boundaries of the solution domain, caused by the motion of the piston and valves, leadsto deformation of the computational grid, with decreasing quality of the solution as result. Basedon this, a previously developed mesh motion strategy was employed where a number of meshesare used to cover the whole simulation cycle. Within each mesh interval the internal cell pointsof the mesh are moved to account for the boundary motion of the piston and valves. This strategywas previously applied to simplified geometries as well as real engine geometries.
Söktjänster för akademiskt bruk. En jämförande undersökning mellan Google, Google Scholar och Scirus.
This paper is a comparing study of the retrieval effectiveness of the Search engines Google, Google Scholar and Scirus. The aim is to find out how good they are at retrieving relevant academic material in the research-field of Library and Information science. The thirty search questions where based on actual information needs collected from exams within the field of Library and Information Science. This method was used to prevent that none of the Search engines were given an advantage because of construction of the information needs. The first twenty retrieved documents on the retrieval lists are examined for academic content and relevance.
VVA-strategier för avgastemperaturhöjning på en HD-Dieselmotor
Regulations on the exhaust emissions of HD-diesel engines are becoming more and more stringent, and therefore, emission after-treatment systems are commonly used. These systems rely on catalytic conversion of NOx,CO , and HC emissions, and are thus dependant on temperature. At low load of the engine, exhaust temperatures are not sufficient for the after-treatment components. Therefore, means to increase the exhaust temperature while maintaining low emissions and fuel consumption are needed.The focus of this project has been to develop strategies for the lift profiles of exhaust and intake valves in the engine, with the goal to raise exhaust temperature in combination with low emissions and fuel consumption. The strategies have been tested in a single-cylinder reSearch engine equipped with a hydraulic variable valve actuation system.
Utnyttjar konsumenter möjligheten att agera rationellt? : En uppsats om konsumenters sökbeteende inför ett köp med avseende på irrationella köpbeslut eller möjliggörandet av rationella köpbeslut genom informationssökningsprocessen
The buying decision process describes how the consumer makes a purchase decision through a rational process (Markin, 1979) and an understanding for how consumers make a purchase decision can according to Sands et al. (2010) be obtained by increased knowledge for the information search process (the second part of the buying decision process) before a purchase. Today?s society offers great opportunity to obtain information (Rahim & Clemens, 2012; Bawden & Robinson, 2009) and by that there are in other words good opportunities for a rational acting by the consumers. However, there are factors working against that consumers act rationally and seek information prior to their purchases primarily in the form of the concept of information overload (Bawden & Robinson, 2009) which claims that consumers are limited in their information search because there is too much information but also other factors such as lack of time (Wood & Neal, 2009) and ability to find information (Slegers et al.
Grönare på andra sidan Mediebilden av cannabis i tre skandinaviska länder
Authors: Patrik Jäverbo & Jon LindheTitle: Greener on the other sideLevel: Bachelor of JournalismLocation: University of GothenburgLanguage: SwedishIn later years the strict laws and policies surrounding cannabis use have been questioned around the world by several influential leaders, among them US president Barack Obama and former UN secretary general Kofi Annan. It has been argued that the ?War on Drugs? has done more harm than good and in some American states and a number of European countries the drug have been legalized or decriminalized. Everybody does not agree however, that legalization is the best course of action and in Sweden the emotions have sometimes run high in the discussions taking place in television shows and newspapers.The purpose of this study is to examine the image media portrays of cannabis; based on the theory that mass media is an important influence on the individual and the way in which he or she views the world. To put the result into a context the Swedish media image will be compared with the one in Denmark and Norway.
Reglerstrategi för fria ventiler : ? Utveckling av en fyrtakts förbränningsmodell för att prediktera optimala ventilinställningar
As emission legislations across the world continuously pushes engine development forward,engineers constantly need to come up with and implement fuel saving technologies. During thelast decade, variable cam phasing has become a popular solution to increase gas exchangeefficiency. This configuration is typically mechanically constrained by camshaft limitations, anda solution to circumvent this problem would be to use a different valve actuation principle.One example of this is to use pressurized air controlled by electrical solenoids. Such a systemhas been developed byCargine Engineering and this provides the starting point for this work. Tobe able to operate the valvetrain on an actual engine, a control system is needed.
Man irrar runt i katakomberna: Studenters informationssökning och relevansbedömning under rapportskrivande.
The main object for this thesis is to study how students in library and information science at Högskolan i Borås search and valuate documents in the process of writing a paper. The study is based on a series of interviews with 12 students. Our methodology is also based on studies of their final product. The goal of the study was to map out how the students make their decisions during their search process. We studied the students use of search words, relevance judgements and how their need for information changed trough out the writing of their paper.
Hur går sökmotoroptimering till? -teori och praktik
Idag finns omkring 625 miljoner webbsidor på internet. Rapporten betonar vikten av att synas bland dessa samt hur man gör för att bli sedd, detta samlingsnamn kallas sökmotoroptimering.I den här studien behandlar vi ämnet sökmotoroptimering med inriktning mot Google, vad det är och hur det används i praktiken. Vårt syfte är att fördjupa oss i detta ämne och bilda oss en uppfattning om vad det handlar om. I resultatet har vi utifrån Googles riktlinjer listat flera begrepp som hjälper dig att optimera din webbsida. Vi har även i resultatet intervjuat flera verksamheter eftersom vi vill veta hur sökmotoroptimering används hos dem.I analysen har vi sedan jämfört Googles riktlinjer med teori och resultat för att ta reda på vad som utmärker sig mest.Vi har kommit fram till att en lättillgänglig sida med bra innehåll är det som utmärker sökmotoroptimering och det som gör att webbsidan blir synligare i träfflistan.
Självkänsla och bekräftelse på sociala medier : En kvantitativ enkätundersökning om självkänsla, bekräftelse på Instagram och skillnaden mellan män och kvinnor
This study aimed to investigate whether there was a correlation between an individual?s selfesteem and search for confirmation on social media. The study also sought to answer whether there were differences in self-esteem and search for confirmation from a gender perspective. In this study social media was defined as Instagram. The choice was founded on the basis that Instagram in the current situation is one of the world's largest social media that allows users to share their everydaylife in pictures, which are commented and ?liked? by other users.
Beslutsmodell för inköp och lagerhållning av motorer i ett produktionssystem : En fallstudie på Sandvik
AbstractIt is important to choose which spare parts to keep in stock. With the right spareparts in stock the costs for inventory and production loss will decrease. Cavalieri et al. (2008) highlights that the balance between inventory cost and production loss is underestimated. It affects the company and must be considered before decision on purchase.The problem with spare engines is that they are all more or less critical for the production. That can be a reason for why no previous research targeting engines and classification of with engine should be kept in stock has been found.
Proxyserver för passiv informationssökning
In today?s society the average person is flooded by information from everywhere. This is in particular the case when using the Internet; consider for a moment the fact that a decent Search engine at this moment scans 8 058 million homepages. For a user that repeatedly comes back to the same site, the case is often that they know what they are looking for. The problem is to isolate the important information from all the other information embedding it.We would like to state that we have found one possible solution to this problem, where the user himself can define what information he is looking for at a specific server, then scan the server when visiting it with his browser.
?Jag tycker bara att jag gör vad jag vet att jag kan göra? : en undersökning av en webbaserad bibliotekskatalogs användarvänlighet utifrån användarnas perspektiv
The purpose of this Master's thesis is to examine whether a web-based library catalogue is to be considered user-friendly. We have examined this from a user-perspective by interviewing users of a web-based catalogue at a public library. In order to get a picture of the user-friendliness of a catalogue, the thesis is centred upon the following questions: How is a web-based catalogue used? What problems do the users experience? How is the catalogue perceived by its users? Since the producers of these catalogues now are taking into account the research upon human-computer interaction, we are also interested in finding out whether a web-based catalogue is more user-friendly than a more traditional OPAC. We do this by comparing the results of our examination with earlier studies of OPAC use.
En utvärdering av två pearl growing-metoder i ISI Web of Science
The purpose of this thesis is to evaluate two pearl growing methods in ISI Web of Science. The methods tested are Find Related Records FRR, an automatic service that uses bibliographic coupling, and Author Keywords AK, where searches are performed using the two first keywords from this field. Both search methods were used on twenty initial documents and the first twenty hits were evaluated for relevance using a binary scale 0,1. The relevance criteria were based on specific information needs connected to every initial document. The measures used to evaluate the effectiveness of the search methods were Precision at DCV=10, P10, and Uninterpolated Average Precision AP.
En studie av evalueringar av webbaserade söktjänsters återvinningseffektivitet
The aim of this thesis is to describe and critically investigate eight different evaluations of the retrieval effectiveness of webbased Search engines. The questions to be answered in this investigation are: - What kind of relevance judgements have been used? - Which criteria have been used when judging the relevance of a document? - Which measures have been used? - How many queries have been used? - How were the queries constructed? - What document cut-off value has been used? - Has hypothes testing been applied? - What kind of webbased Search engines have been included in the evaluations? The study showed that although the evaluations investigate the same phenomena, they are very different from each other in certain aspects. Generally the study showed that precision is the preferred measure in comparison to recall in the chosen evaluation even though all the included evaluations have constructed unique formulas for calculating precision. Some attempts to measure relative recall have been performed but they all suffer from different defects.
GSM-baserat larm
The ability to tackle NP-hard problems has been greatly extended by the introduction of Metaheuristics (see Blum & Roli (2003)) for a summary of most Metaheuristics, general problem-independent optimisation algorithms extending the hill-climbing local search approach to escape local minima. One of these algorithms is Iterated Local Search (ILS) (Lourenco et al., 2002; Stützle, 1999a, p. 25ff), a recent easy to implement but powerful algorithm with results comparable or superior to other state-of-the-art methods for many combinatorial optimisation problems, among them the Traveling Salesman (TSP) and Quadratic Assignment Problem (QAP). ILS iteratively samples local minima by modifying the current local minimum and restartinga local search porcedure on this modified solution. This thesis will show how ILS can be implemented for MSA.