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4044 Uppsatser om Hypothesis testing and t-test - Sida 14 av 270
Lärares kunskaper om dyslexi
Dyslexia is a functional problem, affecting the ability to read and write. As future teachers, we will meet students with dyslexia. The purpose with this exam study has therefore been to describe dyslexia and its causes. Another purpose was to find out ? from the perspective of a teacher ? what experienced teachers know about the problem and how they in practical work can enhance the learning process for students with dyslexia, both individually and in class.
Termomekanisk utmattning av Sanicro 25 : Materialmodellering med finita elementmetoden
The report aims to describe the austenitic stainless steel Sanicro 25 from a thermomechanical point of view. The thermal and mechanical properties of the material make it suitable for use in coal ? and thermal power plants. By the use of Sanicro 25 it would be possible to bring the efficiency of these plants up while bringing the carbon emissions down.A material model is created from material testing and validated through simulation in the finite element software Abaqus. The model that has been derived describes the material behavior during loading and stress relaxation for the first cycle in a thermomechanical fatigue test well.
Överföring av elektrisk signal och effekt med magnetisk induktion.
This report tested the possibility of using induction as a mean for transferring data and power so that it can be implemented as a communication medium between a terminal and measuring head mounted in a measuring frame. This would eliminate the need for the cable bunches that are used today. For testing, signal generators were used to generateFSK-signals and were transferred with the help of inductors to the oscilloscope for signal detection, this to see how the coils used in the tests behaved. Simulations of a PLL were performed to see how good it could handle FSK-demodulation. With the help of a PLL IC and the simulations a working FSK-demodulator could be assembled.
Öppna test ja?mfo?rt med blindtest : Hur pa?verkas lyssnarens bedo?mning?
Denna underso?kning so?ker ett svar pa? hur den relativt vana lyssnarens bedo?mning av ljudkvalitet pa?verkas av ett sa? kallat o?ppet test, da?r det som bedo?ms a?r ka?nd fo?r lyssnaren, ja?mfo?rt med ett blindtest, da?r detta objekt a?r oka?nt. Fra?gan appliceras pa? kvalitetsbedo?mningen av digitala kodningstekniker, d.v.s. hur lyssnaren pa?verkas av att valet av kodningsteknik som avlyssnas a?r ka?nd eller inte.
Validation of Steins/Arla Foods method for lactate fermenting clostridia in milk
One of the most serious and economically important defects caused by clostridia in milk products is the late blowing of semi-hard cheeses.Clostridia occur naturally in soil and can contaminate milk through crops contaminated by dung and soil followed by a less successful silage process, that give them opportunity to grow unaerobically. When anaerobic conditions occur, such as storage of semi-hard cheese, they ferment lactic acid to butyric acid and the gases CO2 and H2.At the fusion of Arla and MD Foods, a series of changes were conducted on the MPN method for lactic acid fermentation for clostridia in milk. These changes resulted in an increased accuracy due to an increased number of test tubes and the change of media from MRCM to BBB, Bryant & Burkey Broth, that was thought to be more selective for Cl. tyrobutyricum, the organism mostly found in hard cheese. When the number of dairy farmers that were given quality reduction fines increased, the new method was suspected and a validation was conducted.The validation included inoculation of different clostridia and bacillus strains into BBB substrate and enzymatic testing of positive samples with Rapid ID 32A.
Vilken roll spelar chefer på mellannivå i en omorganisation : En fallstudie av Teliasonera
The economic development and industrialization that has taken place in many parts of the world during the past century has brought about a huge increase in economic welfare. During this process, it has repeatedly been debated whether the gains from economic development are shared by everyone or just a few. In the field of economics, vast research has been conducted on this particular subject ever since the 1950?s. The most famous contribution might be said to be Simon Kuznets article, Growth and Income Inequality from 1955 and the ?inverted U?-hypothesis that was formulated on the basis of that article.
Metodik för utmattningsberäkning av svets i vibrationsmiljö
In this work, a method was developed and evaluated for calculating the life of welds under the influence of fatigue loads from a vibration environment. Typically, a shaker table is used for testing a component against vibration loads. The shaker table creates a vibration environment that is defined in the frequency domain by a power spectrum.Similarly, a virtual vibration table can be used to calculate the same type of load environment, which can then be used to calculate the expected lifetime. The benefit of this method is that it can be used in design, as well as in simulation of tests before physical verification tests are carried out.Today there are methods for calculating fatigue life of non-welded base material, but since many components contain welded joints, there is a need to apply this method to those types as well. To achieve this, the thesis combines two different areas, which together provide a method for fatigue assessment of welds using a virtual shaker table.The methodology is carried out by modeling the component, and its welded joints, in a finite element program.
Utveckling av en ytmonterad fördelningsmätare som underlag för individuell debitering av vattenförbrukning i fastigheter
The master thesis, conducted at Metrima AB, concerns the development of a non-intrusivedistribution meter as a basis for individual tap water billing in apartments.The project is conducted in response to the market interest in individual tap water billing inapartments as an answer to environmental concerns regarding water consumption. Due to thehigh installation cost of traditional water meters, a new method of determining waterconsumption, without having to cut water pipes, is proposed.The proposed method distributes the total water consumption for an apartment complex toindividual apartments according to distribution meters, measuring water run-time, in eachapartment. The water run-time is estimated by measuring the water pipe?s outward vibrationsand temperature changes.A test environment was established and a prototype built, using a tilt- and vibration sensor forvibration sensing and a precision temperature sensor to measure temperature changes. As bothsensors work well in the test environment, further testing was done in 3 apartments for aduration of 5 days.
Det svenska konsumtionsbeteendet-En ekonometrisk analys av den permanenta inkomsthypotesen
Abstract Titel: Det svenska konsumtionsbeteendet ? En ekonometrisk analys av den permanenta inkomsthypotesenTopic/course: NEKK01, Bachelor thesisWriters: Ida Hedlund, Anna Persdotter Supervisor: Fredrik NG Andersson Keywords: Permanent income hypothesis, Milton Friedman, Consumption smoothing, Sweden Purpose: The purpose of this thesis is to examine whether the permanent income hypothesis can be applied on the consumption pattern of Sweden during the time period 1950-2006. Method: To do the observation an econometric regression analysis has been made. The variables tested are consumption, real GDP, stock- and real estate market prices. In the model three different time periods have been investigated to facilitate the origin of different patterns.
Kommunal självstyrelse - en myt? : En lokalhistorisk studie av Borgviks kommun 1861-1924
The hypothesis of this study is that the local government act in Sweden 1862 was an instrument for the state to keep its´ political influence on the local level. It did not open for local self-government. The swedish historians Dahlkvist and Strandberg description of the Swedish local government act support this hypothesis, as does the analysis of political scientists Pettersson and Söderlind. The general opinion that the local government act opened for local self-government does still exist among many swedish historians.This study had two aims. The first was to investigate the actual extent of self-government in Borgvik, a small municipality in Sweden during the period 1861-1924.
Varierad kaliumgödsling i potatis : en fältstudie i Hedemora
Variation in tuber quality within a single field was one of the motives for a pilot study
in Halland, in south-western Sweden conducted during 2002. Quality problems in potatoes have been increasing due to the aggregation of several small fields with different land use history into larger farm units, which are heterogeneous in soil properties and fertility. The study in Halland indicated that both the uniformity and the mean size of tubers may increase from site-specific K fertilization, whereas total yields may be unaffected. The results from this pilot-study with site-specific fertilization showed that tubers reached a more uniform quality and gave a more uniform mean size, while the total yield wasn't affected at all.
Site-specific K-fertilization has been applied for some years in Halland with good
results. The aim of this study was to test this technique in another potato growing
area.
Server Message Block : En undersökning av potentiella prestandavinster mellan SMB 2.1 och SMB 3.0 i ett befintligt nätverk
Examensarbetet behandlar en jämförelse av Server Message Block 3.0 och föregångaren 2.1 i ett befintligt nätverk. Jämförelsen utfördes i fyra laborationsmiljöer bestående av fyra operativsystem: Windows Server 2008 R2, Windows Server 2012, Windows 7 ochWindows 8. Sammanlagt har fyra tester utförts: Förstudie, Test 1, Test 2 och Test 3. Förstudien utfördes för att testa nätverksprestanda mellan två datorer. De andra testerna satte SMB 2.1 och SMB 3.0 på prov.I Test 1 ansågs SMB 3.0 prestera sämre än SMB 2.1, för att bekräfta resultaten kontaktades Jose Barreto på Microsoft.
Grand Hotel i Lund en fallstudie om ett fristående hotell på en marknad dominerad av kedjor
Abstract: Purpose: The purpose of this study is to describe the situation for independent hotels. With a thorough case study of ?The Grand Hotel in Lund? ,our intentions is to gain knowledge about the demands a hotel must keep up with in order to be a successful independent hotel, in a market dominated by chain-constellations. Methodology: An abductive method is used as the study form the basis for hypothesis. The first part of the thesis, which describes the line of business, is based primary on secondary data.
Utdragshållfasthet hos limmade och olimmade gängstänger i limträ
This essay examines pull-out strength of threaded rods fixed into glulam timber. The technology is intended to be used in hidden joints between glulam components. The work began with a study of literature focusing on current research within the topic, mainly to create a base of knowledge before the testing was initiated. Studies of scientific articles reveals a lack of research within this area, which makes it difficult to develop standards and calculation models for these joints. The drill holes in the tests have a diameter of 7 mm.
Test och verifiering av en ny inkapslingsmetod för SiC BJT och MOSFET
The use of silicon carbide (SiC) as a base material in power electronics has manyadvantages, including high breakdown voltage and excellent temperature endurance.However, the packaging of such electronics presents major challenges and there is aneed for packaging that can operate in higher temperature. The purpose of this thesishas been to develop a test method and verify the functionality of SiC powertransistors prototypes with a new packaging technique developed by Swerea IVF AB.It includes setting up an electrical test-bed for power and high temperature cyclingand analysis of the results. Even though test confirmed functionality after thepackaging process, (at room temperature) the performance seemed to have been reduced. This could be a result of the measurement setup and the packaging process.In higher temperature the transistors failed to operate longer than a couple ofminutes which showed the weaknesses in the design and the challenges with this typeof packaging..