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107 Uppsatser om Creep coefficient - Sida 3 av 8

Utveckling av Mätmetoder för Färdmotstånd

The student project Elba at KTH started in 2011 and is a project where a battery driven prototype car is developed. The vehicle competes in Eco Shell Marathon in Rotterdam, Holland. In this competition the vehicle that travels a certain distance including several starts and stops with the lowest energy consumption wins. To minimize the consumption is therefore very important, which requires knowledge of the vehicles energy losses.A vehicle's energy losses depends on several factors and can be divided into the powertrain efficiency and the driving resistance. The driving resistance can then be divided in to rolling and air resistance, if smaller losses like vibrations are ignored.

Populationsstruktur och genetisk analys av exteriöra egenskaper hos svensk ardenner :

The purposes of this study were to estimate genetic and phenotypic parameters for conformation traits in Swedish Ardenner, a heavy draught horse, and to investigate the inbreeding status of the population. Additionally, a breeding scheme proposal was created, based on the results achieved in the study. The data studied were obtained from the Swedish Horse Board and from the Swedish Ardenner Association. The data included 1632 three-year-old horses, mainly mares, and 356 stallions, judged between 1986 and 2005 at conformation shows. The traits studied were type, head-neck-body, legs, walk and trot at hand, total score and height at withers.

Utvärdering av Transportstyrelsens flygtrafiksmodeller

The Swedish Transport Agency has for a long time collected data on a monthly basis for different variables that are used to make predictions, short projections as well as longer projections. They have used SAS for producing statistical models in air transport. The model with the largest value of coefficient of determination is the method that has been used for a long time. The Swedish Transport Agency felt it was time for an evaluation of their models and methods of how projections is estimated, they would also explore the possibilities to use different, completely new models for forecasting air travel. This Bachelor thesis examines how the Holt-Winters method does compare with SARIMA, error terms such as RMSE, MAPE, R2, AIC and BIC  will be compared between the methods. The results which have been produced showing that there may be a risk that the Holt-Winters models adepts a bit too well in a few variables in which Holt-Winters method has been adapted.

CFD simulering av kallras : Undersökning av temperatur- och luftbeteende intill höga glasfasader och i vistelsezon med golvvärme som en värmekälla

Glass has sophisticated front properties and are used as facades in high buildings. During cold periods, these glass facades could cause thermal discomfort, due to cold downdraught. Cold downdraught can be countered by placing heaters under glass surfaces. Nowadays technology offers highly insulating windows, which is why there is an interest to investigate the indoor climate with only underfloor heating. The research in this area is limited, and few empirical methods are available.

Hur en okontrollerad expansion av IT-projekts omfattning undviks

Today there is an even higher demand on IT-projects success rate compared to a few years ago. IT-projects must be handled more efficiently and result in a more profitable investment. In order to make the handling of IT-projects more efficient and create profitability the developers must have a broad understanding of the IT-projects characteristics and which factors that affect the result of the projects. Changes within IT-projects are often carried out through the development of a system. Since this change is more common when it comes to IT-projects it is important to handle risk and change within these kinds of projects in order to prevent and avoid uncontrolled changes.

Lyftkraftsberäkning för vingprofiler: Virvelpanelmetoden

The problem presented in this report is that of finding a method to calculate the lift force from a single-element airfoil of arbitrary shape. A number of restrictions are used in order to simplify calculations while retaining reasonable accuracy. The problem is solved for the two-dimensional case only and no finite-wing effects are taken into account. Furthermore, inviscid and incompressible flow is assumed. The method used to solve the problem is the vortex panel method, with vortex singularities distributed over simplified airfoil geometry.

Effekt av överlast på förstärkt jord : FEM- analys för att visa överlastens verkningsgrad på krypsättningar i kalkcementpelarförstärkt lös jord

Applicering av överlast på kalkcementförstärkta jordar är ofta förekommande idag, forskning indikerar dock på att överlasten här, inte ger samma effekt som på oförstärkta jordar. Med grund i uppmätta värden i fält, visas i denna rapport, sättningsdifferenser mellan att använda överlast jämfört med att endast applicera brukslast. Resultat av analyserna visar på sättningsbeteende observerat i fält. Om erforderlig liggtid för brukslast finns, uppstår endast små sättningsdifferenser mellan att använda överlast eller inte.Genom att utföra sensitivitetsanalys i FEM- programvaran PLAXIS studeras kryputvecklingen i den förstärkta jorden. Effekten av att applicera en överlast visas för krypsättningar över lång tid.Inget resultat från de numeriska FEM- analyserna visade att märkbart gynnsam effekt uppstår på grund av överlastens applicering, med avseende på krypsättningar.De numeriska analyserna utförs i 2 och 3 dimensioner för att belysa effekt av förenkling av ett lastfall som inte uppfyller krav för oförstärkta jordar i plant töjningstillstånd.Utöver detta ges efter en litteraturstudie, förslag på hur vissa indataparametrar kan utvärderas från empiriska relationer.

Restspänningar i arc-förångade (Ti(1-x)Al(x))N ytskikt

This report is the written documentation of a project work carried out at the Division of Engineering Materials at Luleå University of Technology in cooperation with Seco Tools AB. The project deals with the analysis of residual stresses in Ti-Al-N thin film grown on WC/Co cutting inserts. The composition of Al varied from 0% up to 75%. Increasing the Al content in the Ti(1-x)Alx N compound improves the compressive residual stresses even after annealing of the material. The experiments have been performed in a high temperature x-ray diffractometer (HTXRD) where the interplanar atomic spacing was determined in-situ and subsequent converted into stresses.

Evaluating the effects of a tax increase : how the Swedish demand for snus will react to the new tax increase proposed by the government

This thesis deals with the concept of how price affects demand for a good by estimating various price elasticities of demand for snu sold in Sweden. Information was gathered on price development for snus and cigarettes as well as sales data from Swedish Match, the largest supplier of snus in Sweden. Income-, price- and cross-price elasticities were estimated based on log-log regression. Results show that snus is an inelastic good since the coefficient for price of snus was -0.536. This proved that a 1% increase in price causes a 0.536% decrease in quantity demanded.

Eurokoder : en jämförelse mot BKR

In Sweden there are currently two separate guidelines you may use whenperforming calculations on frameworks, BKR and the Eurocodes. Although at theend of 2010 you are not allowed to use BKR any longer and only the Eurocodeswill be viable. The aim of this thesis is to explain how the Eurocodes and EKS work and alsohow they compare to the current guideline BKR. Similarities and differencesbetween these guidelines are also discussed so that the reader will get a betterunderstanding of how the Eurocodes are applied. The areas discussed are asfollows:Principles and adviceSafety ClassesSymbols and IndexesLifespanLoads and partial coefficientThe thesis also deals with the impact that this transition into a new guideline willhave on corporations, guideline costs, education and computer software. As anexample a rough estimate on what costs this transition will create on a companywith 20 employees is also included. Calculations have been performed in order to investigate how the design valuesdiffer between the two guidelines, the Eurocodes and BKR.

DCF-modellering vid multipelvärdering: En empirisk studie av hybrida värderingsmodellers prediktionsförmåga

Today, there are a number of different models and methods used to estimate the equity value of a company. A common tool for valuating stock prices is the usage of different multiples. This is a method used to determine the value of a company, by examining and comparing the financial ratios of relevant peer groups. The disadvantage with this method is that it does not take all the important aspects, such as risk, investments and capital structure, into consideration. However, this study investigates if the key value, called discounted cash flow (DCF), can be integrated with the valuation of the multiples.

Double integrating spheres: A method for assessment of optical properties of biological tissues

The determination of the optical properties of biological tissue is an important issue in laser medicine. The optical properties define the tissue´s absorption and scattering behaviour, and can be expressed by quantities such as the albedo, the optical thickness and the anisotropy coefficient. During this project, a measurement system for the determination of the optical properties was built up. The system consists of a double integrating sphere set-up to perform the necessary reflection and transmission measurements, and a computer algorithm to calculate the optical properties from the measured data. This algorithm is called Inverse Adding Doubling method, and is based on a one-dimensional transport model.

Marksättningar i Uppsala : En jämförelse mellan beräknat och verkligt utfall

Delar av marken i Uppsala består av mäktiga lerlager. Naturliga krypsättningar pågår ständigt i området, en process som i litteraturen benämns geologisk åldring. Ökad belastning i form av uppfyllnad kring byggnader och sänkt grundvattenyta till följd av pumpning av färskvatten bidrar också till sättningar. I ett nybyggt bostadsområde på Kapellgärdet har marksättningarna intill de pålade husen på vissa platser uppgått till 0.3 m på 10 år.Med geotekniska data för området har en jordprofil tolkats. Analys har gjorts utifrån den klassiska sättningsteorin för primärsättningar till av ökade effektivspänningar från fyllnadsmassor och grundvattensänkning.

Har analytikernas roll på aktiemarknaden blivit mindre relevant: En studie av analytikernas påverkan på aktiers avkastning

The purpose of this thesis is to investigate if the stock market reacts differently to accounting information, depending on the stock market climate. The study focuses solely on stocks listed on the OMX Stockholm 30 during each year from 2005 to 2009. By applying the concept of Earnings Response Coefficient we can estimate how the market reacts to accounting information. The dependent variable in the equation is the market reaction on unexpected earnings, in the study described as the abnormal return on stock. For quality purposes we measure this on a ±1,5,10 and 20 days basis.

Deltid och kön: En undersökning av deltidsarbetets utveckling under åren 1987-2005

This paper aims at assessing the relationship between female and male part-time employment and the business cycle in Sweden during the years 1987?2005 using quarterly time-series data and two alternative indicators of the business cycle. It further aims at determining whether the share of women working part-time has changed over time. Key results include that the relationship between the business cycle and female part-time employment is found to be significant and countercyclical. No significant effect is however found for men.

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