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713 Uppsatser om Dynamic simulations - Sida 20 av 48

Analys av incidenter rörande DP-operationer inom "500-meterzonen" - En studie baserad på incidenter under 2008-2009

Detta examensarbete är en undersökning av The International Marine Contractors Association (IMCA) statistik rörande operationer med dynamisk positionering (DP) inom 500-meterzonen. Statistiken har sedan jämförts med resultaten från en enkät som skickats ut till berörda nautiker och personal i land. I enkäten har deltagarna fått ge sin personliga uppfattning om hur fem övergripande kategorier för orsaker till incidenter, härledda ur IMCAs inrapporterade material, bör rangordnas efter vilken kategori som anses mest trolig att orsaka en incident. Resultatet visar på en skillnad vad gäller operatörens roll i IMCAs statistik och vad som upplevs inom offshore-industrin. Samma resultat återfinns oavsett hur lång arbetslivserfarenhet man har av DP och oavsett om man arbetar till sjöss eller på en säkerhetsavdelning i land..

GPU accelerated SPH simulation of fluids for VFX

Fluids are important to the Visual Effects Industry but extremely hard to control and simulate because of the complexity of the governing equations. Fluid solvers can be divided into two categories, those of the Eulerian point of reference and those of the Lagrangian. Both categories have different advantages and weaknesses and hybrid methods are popular. This thesis examines Smoothed Particle Hydrodynamics, a Lagrangian method for physically based uid simulations. To allow the artist the exibility given by shorter simulation times and increased number of iterations, the performance of the solver is key.

Om värld och bevakning : en studie av en företagslednings omvärldsbild och dess samband med omvärldsbevakningen

Background: Increasing globalization makes companies more influenced than before by actors and factors in their environment. For some this has lead to a more dynamic and complicated business context. Therefore it is of strategic importance to understand what is currently going on as well as to have a general idea of what the future brings. Purpose: To contribute to a deeper understanding of how a corporate management can perceive its business environment and how it affects he gathering of business information from a strategic perspective. Realisation: In-depth interviews were conducted with all four members of the management in the studied company, Volvo Competence Center in Skovde, Sweden.

Datormodellering av en värmelagrande betongväggs inverkan på det termiska klimatet i ett växthus

This report describes the building of a computer model that makes it possible to simulate the thermal climate in a greenhouse. The computer model is built on the physical theory of heat exchange that occur in a greenhouse, such as radiation and convective heat exchange. The model also includes the heat storage that is active in a greenhouse.The computer model is used to simulate the thermal climate in a greenhouse under three periods, winter, spring and summer. It also investigates which effect a concrete wall has on the thermal climate in a greenhouse. The purpose of putting a concrete wall in the greenhouse model is to investigate the possibility to store heat during the day and then use this heat when the temperature drops during the night.The result from the simulations shows that a concrete wall levels the big difference in temperature that normally occurs under a day in a greenhouse.

Framtidens energieffektiva flerbostadshus

The housing sector of today represents for almost 40% of the energy consumption, an energy consumption of which the major part consists of non-renewable energy sources. This is not sustainable and utilization of new energy-efficient technologies in buildings can be a step in the right direction, towards a sustainable energy society.This report has been made on behalf of and in cooperation with Älvstranden Utveckling AB in Gothenburg to examine how future energy-efficient technologies can affect the energy demand in energy-efficient multi-dwelling buildings.The report is based on Älvstrandens passive house, Hamnhuset, a house whose energy consumption is far below the BBR's requirements. The report looks at the opportunities for improvement within windows, insulation, solar energy technologies, as well as white goods. Computer simulations are then made to apply the selected technologies into a reference building. Technologies are selected from an energy efficient perspective and no account has been taken of other aspects such as the economy.

Framtidens elbilar utmanar nutidens elnät : Påverkan av ett ökat antal elbilar på ett halländskt elnät

The challenges facing low voltage grids are rising as an increasing number of domestic houses transition from fossil fueled heating to electricity based heating. Several environmental goals and visions have the same transition from fossil based power to electricity based power in mind for the transportation sector. One of the most important tools for this transformation is widely regarded to be the electric vehicle. With the demands of the electric vehicle pressuring the power grid, several questions arise regarding the growth of the electric vehicle market and what repercussions it may have on the grid. This paper focuses on a typical low voltage grid in southern Sweden and what effects a growing electric vehicle market may have on it. Through computer-assisted simulations based on several future scenarios regarding the EV market, this paper finds that few modifications and reinforcements are needed on this particular grid within the next 10 to 15 years.

Småskalig elproduktion i urban miljö : Fallstudie av elproducerande system på ett handelscentrum

This thesis investigates if a system for small scale electricity production located in anurban environment can be profitable. The work has been divided up into two parts,one extensive literature study and one case study. The purpose of the literature studywas to investigate the area, resulting in a choice of which technology to be studied indepth in a case study.In the case study a system containing small scale wind turbines and photovoltaicsmounted on Gränby Centrums roof was examined. From data containing wind power,wind direction and total irradiation, possible production from a system weresimulated. Three products of each technology were examined in the simulations.From the simulated production an economic analysis was carried out, this toinvestigate if a system is profitable.

Attitydproblem : Om attityduttryck och deras retoriska funktioner

This thesis explores how verbal and nonverbal signs communicate attitudes and the rhetorical functions of such attitudinal signs. Attitudes are regarded as rationalized evaluations of attitudinal objects, and through their manifestation in signs an attitudinal gestalt is communicated. This gestalt is regarded as the audiences perception of the rhetors attitude. It is shown that the attitudinal signs function as ethical, logical and pathetic proofs and that they can create identification between the audience and the rhetor. The signs can have effects on the audiences perception of the attitudinal objects, their perception of the rhetor and influence the social dynamic of the discourse.

Visualization of Particle In Cell Simulations

A numerical simulation case involving space plasma and the evolution of instabilities that generates very fast electrons, i.e. approximately at half of the speed of light, is used as a test bed for scientific visualisation techniques. A visualisation system was developed to provide interactive real-time animation and visualisation of the simulation results. The work focuses on two themes and the integration of them. The first theme is the storage and management of the large data sets produced.

Identifiering av synkronmaskinsmodell genom SSFR-test

At the Division of Electricity at Uppsala University there is an experimental rig forhydroelectric generators. The experimental rig?s vital part is a 12-pole synchronousmachine, whose electrical characterizing parameters (resistances, inductances andtime constants) are unknown. The aim of this thesis is to characterize the machine inits current state by perform a Standstill Frequency Response (SSFR) test. From theanalysis of the measurement data, which is a part of the test, a set of basic parametershave been received.

Robotstyrning med metoden Sliding Mode Control

The task in this thesis is the steering of one of Saab Bofors Dynamics robots using Sliding Mode Control, a method they never used before. The robot constitutes a system which in addition to perturbations and uncertainties due to modeling imprecision, hold the difficulty of being highly time variant. In order to be able to keep required performance with uncertainties and modeling imprecision present, the use of robust control methods like Sliding Mode Control is necessary. SMC is based on the states of the system being forced to stay on or in the direct vicinity of a hyper plane in the state space which is chosen in a way that gives the system dynamics desired properties. Other advantages with sliding mode are reduced order dynamics on the switching surface and total insensitivity to some uncertainties and perturbations.

Supermarket Strategies : Kvalitativ studie av Ica Maxi, Coop Forum och Citygross konkurrensstrategier

This thesis investigates if a system for small scale electricity production located in anurban environment can be profitable. The work has been divided up into two parts,one extensive literature study and one case study. The purpose of the literature studywas to investigate the area, resulting in a choice of which technology to be studied indepth in a case study.In the case study a system containing small scale wind turbines and photovoltaicsmounted on Gränby Centrums roof was examined. From data containing wind power,wind direction and total irradiation, possible production from a system weresimulated. Three products of each technology were examined in the simulations.From the simulated production an economic analysis was carried out, this toinvestigate if a system is profitable.

Dagens Nyheters tryckeri: En jämförande tvåfallsstudie av företaget och makten

This study is an institutional analysis of the firm both as it is theoretically conceptualized and how it takes shape and changes. The role of power relations between manage¬ment and employees is especially examined with the aim of evaluating pos¬sible connections between the firm as an institution and power relations within it. Based on a comparison of two cases (two selected periods of the same organization) it asks ?How closely does each case match the conceptual characteristics of the firm??; ?What are the power relations between management and employees in each case??; and finally ?What factors account for the resulting differences??. It is found that there is a negative correlation between employee power and proximity to the firm as a concept.

Energianvändning i badhus : Simulering och jämförelse av gamla och nya system

Every year new premises are built in Sweden, and even if they are made as energy efficient as possible, this will not reduce the energy demands, but the rate of the increase of the energy use will be reduced. One type of facility in Sweden that is a major energy user is public baths, and this makes public baths an interesting facility to study more closely. There are around 500 public baths in Sweden and about 75 % of those can be seen as older baths with large need of renovation, and they all require a high level of energy efficiency measures. To show how the energy demand increase or decrease depending on the changes chosen to be made, the simulation application IDA Indoor Climate and Energy was used. Simulations were made and compared for several cases, with two extreme cases as starting points.

On-line uppdragsplanering baserad på prediktionsreglering

Modern air battles are very dynamic and fast, and put extreme pressure on pilots. In some unpredictable situations, like new discovered threats or mission plan deviation because of enemy aircraft, the pilots might need to replan their predefined flight route. This is very difficult, if not impossible, to do since numerous factors affect it. A system that can help the pilots to do such a thing is needed. Previous work in this field has involved methods from artificial intelligence like A*-search.

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