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713 Uppsatser om Dynamic simulations - Sida 12 av 48
Motviktsslungans dynamik : En analys av medeltida konstruktionsråd för mekaniskt artilleri
AbstractThis Master?s thesis analyses the dynamics of the medieval counterweight lever engine, ortrebuchet, a type of mechanical artillery. The purpose is to study the differences between different types of these machines, and see if computer simulations can be used to validate preserved advice on construction. Simulations include machines with a fixed counterweight, a hinged counterweight and a combination of both counterweights.Due to the almost complete lack of archaeological finds and insufficient historical source material there are still, after more than a century of research, many unanswered questions concerning the design and performance of these machines.The present study is based on an analysis by Jahsman (2004). A more detailed mathematical model employing Coulomb-friction is used.
Digitalt tidtagningssystem för Agility
We have chosen to write our thesis within a transport company. The work was carried out at DHL activities in Uppsala. DHL is one of the leading transport companies worldwide. Our interest lies in more efficient and advanced transportation and terminals, as globalization and new trends require effective solutions.The aim of our work is to explain the need for information technology applications in road haulage and associated terminal operations. Furthermore, we analyses terminal and applied information technology.
Konstruktionsoptimering av självrensande dysa
We have chosen to write our thesis within a transport company. The work was carried out at DHL activities in Uppsala. DHL is one of the leading transport companies worldwide. Our interest lies in more efficient and advanced transportation and terminals, as globalization and new trends require effective solutions.The aim of our work is to explain the need for information technology applications in road haulage and associated terminal operations. Furthermore, we analyses terminal and applied information technology.
Utvärdering av miljönytta för olika miljöcertifieringssystem för byggnader : En jämförande fallstudie på Swecos kontor i Stockholm, Göteborg och Malmö
This thesis examines the environmental benefits resulting from the choice of environmental certification scheme, with focus on energy. This was carried out by studying the measures that were implemented as a result of the certification of Sweco's three largest office buildings in Stockholm, Gothenburg and Malmö. The office property in Stockholm has been certified with the Swedish Environmental Building, Gothenburg with the British BREEAM and Malmö with the U.S system LEED.The results from the study indicate that an environmental certification can reduce the energy consumption by up to 59 percent and the water consumption by 20 to 66 percent. However; the interviews, literature study and simulations in MATLAB indicate that the size and scope of these environmental benefits depend on several identified factors: the type of building and its conditions, system selection, grade level, the choice of indicators, the ambition of those involved and when in time the certification process begins. The comparison between Environmental Building, LEED and BREEAM showed that Environmental Building for the office property in Stockholm gave the largest environmental benefit in terms of reduced energy consumption thanks to several large measures.
Konvertering från luft till vätskekylning av elektronik
A Swedish electronics company wants to make the cooling of one of their electronic components more efficient. They propose that a retrofit liquid cooler is the way to achieve this goal. The current air cooling has high energy cost due to the high amount of power needed to power fans and heat exchangers. Using high volumes of air for cooling also leads to noise pollution. The conversion from air to liquid cooling would possibly make the operation of the electronics more cost efficient and less noisy.The purpose of this project is to theoretically evaluate different concepts of drawing the heat generated by the electronic component in to a fluid, using numerical calculations in Matlab and FEM simulations in ANSYS.
Förutsättningarna för ett parallellt generation IV system vid svensk nybyggnation av kärnkraft.
A new build in the Swedish nuclear power system would entail increased re-quirements for the proposed repository, which is adapted after the reactors of today. With a fast reactor, capable of burning nuclear waste, operating in parallel with the light water reactors, the increased requirements on the repository could be reduced.In this thesis, simulations of a light water reactor and a fast reactor have been performed by using the Monte Carlo code Serpent to investigate the changes in the fuel inventory. The light water reactor in the study is a boiling water reactor and the fast reactor of the type sodium-cooled fast reactor and they have been used for three different operation scenarios.By studying the fuel composition and the results from the simulations of the three scenarios conclusions can be drawn. Conclusions regarding the change of the fuel inventory and decay heat in Clab as well as the interim storage facility and in the repository. Depending on the operation alternative the changes dif-fered significantly and especially regarding the mass of burned actinides for different fuels in the fast reactor.The lowest increase of fuel assemblies was meet when using 50 years old fuel with 20MWd/kg U burnout and 2,0 % enrichment for start up of the fast reactor and 30 years old fuel assemblies with 50MWd/kg U burnout and 4,7 % enrichment for the further operation of the reactor.The increase of the number of fuel assemblies was 3174, which is equivalent to 641tons of heavy metal.
IT system för vägtransporter och tillhörande terminalverksamhet
We have chosen to write our thesis within a transport company. The work was carried out at DHL activities in Uppsala. DHL is one of the leading transport companies worldwide. Our interest lies in more efficient and advanced transportation and terminals, as globalization and new trends require effective solutions.The aim of our work is to explain the need for information technology applications in road haulage and associated terminal operations. Furthermore, we analyses terminal and applied information technology.
Datahantering vid dynamiska webbteknologier : PHP eller ASP?
The last couple of years the use of Internet has changed in the way that the web pages can be affected of the person that uses them. Because of this dynamic Internet technology has emerged that makes it possible for a web page to receive information from a web browser. This information can then be used to affect the appearance of the page. PHP and ASP are two dynamic Internet technologies. They are integrated in HTML and are executed on the web server.
Den olfaktoriska l?sningen. Lukt i Sara Stridsbergs Happy Sally
This essay examines the olfactory reading as a possible way to make sense of a fragmented novel, in this case Sara Stridsberg?s debut Happy Sally (2004). Through close reading, the essay identifies the source of the smells, who perceives it, and how this is portrayed in the text. The smell?s position in the text is understood in relation to Maurice Merleau-Ponty?s phenomenology, where the body, as created in the literary text, is considered as a source of knowledge.
Maximerande av ekosystemtj?nster i urbana kulturmilj?er: En fallstudie om tr?dval i Pommerska tomten i Mariestad
The purpose of this work has been to explore what ecosystem services a small green area in an urban
environment can offer and whether specific trees can be used to maximize regulatory ecosystem
services in a cultural-historical environment. Additionally, it investigates whether there is any
difference in ecosystem services depending on whether these trees, or trees that better fit into the
cultural-historical environment, are used. Through simulations and comparisons with existing trees in
Pommerska tomten, Mariestad, Sweden, a pocket park within a national interest area, different
hypothetical tree planting options are analyzed and evaluated. To measure ecosystem services, the
website My-Tree, developed by the US equivalent of the Department of Agriculture, was used. By
inputting data about the tree, such as location, species, vitality, stem diameter, and solar exposure,
My-Tree calculates some of the ecosystem services the tree provides.
Modularisering : Modulbaserad arkitektur ? flexibel motormodulline
We have chosen to write our thesis within a transport company. The work was carried out at DHL activities in Uppsala. DHL is one of the leading transport companies worldwide. Our interest lies in more efficient and advanced transportation and terminals, as globalization and new trends require effective solutions.The aim of our work is to explain the need for information technology applications in road haulage and associated terminal operations. Furthermore, we analyses terminal and applied information technology.
Lagerstyrning vid Frigoscandia Freezer AB
Frigoscandia Freezer AB have seen themselves as an entrepreneur company for a long time, but have lately begun to realise that they have to go against a more administrative era. With that insight they have begun to examine their enterprise in order to achieve this. The division Team Spare Parts has started a project with the intention of checking-up the inventory management, and improving it for the future. To get support for this and other point of views, they decided to let us do our exam thesis as a part of the project.The first part of the thesis deals with the appropriate inventory theory. All calculations in the other parts of the thesis have been based upon this.
Kinematisk och dynamisk modellering av den haptiska enheten TAU i sex frihetsgrader
The thesis presents an optimally designed kinematic structure for a new 6-DOF haptic devicebased on TAU configuration. The configuration of the TAU-2 proposed by Suleman Khan andKjell Andersson [1] was modified and its mobility was verified by using Grübler criterion tohave a 6 DOF. Analytical kinematic models for the inverse and forward kinematics weredeveloped for the haptic TAU configuration to determine a set of optimal design parameters.Kinematic performance indices such as volume of the workspace, kinematic isotropy and payload index, were defined based on the singular values of the Jacobian matrix. The Jacobianmatrix was scaled to homogenize the physical units. The Jacobian matrix dependent on theposition and orientation of the end-effector gives local isotropy and pay load index, so globaldesign indices were defined, which represent the performance of the mechanism in the wholeworkspace.
Hantering av QoS i Distribuerade MPEG-videosystem
With the advance in computer and network technologies, multimedia systems and Internet applications are becoming more popular. As broadband network is prevailing, more clients are able to watch streaming videos or to play multimedia data over the Internet in real-time. Consequently, there is an increasing demand in the Internet for streaming video systems. As the run-time environment of such applications tends to be dynamic, it is imperative to handle transient overloads effectively. The goal of this work is to develop an algorithm that would provide a robust and controlled behavior of the video system so that important data is delivered on time to the video clients.
Akustisk mätning av U-värde
This pre-study investigates the possibility of U-value measurements through an acoustic method. A hypothesis about an acoustic model built on acoustic theories combined with U-value theories is presented to answer the questions:
? Can U-value theory be combined with acoustic theories?
? Can the coefficient of heat be affirmed trough an acoustic measurement?
The idea for this dissertation begun with a logical idea in mathematical similarity, between the coefficient of heat transmission units and sound intensity units.
The U-value theory is based on assumptions such as initial resistance for inner walls and initial resistance for outer walls. The resistance in the material is interpreted through sound intensity theory.
The argument is built upon mass law theory, which means if the frequency or thickness of the material layer doubles it implies an increase of sound reduction by 6 dB.