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14305 Uppsatser om Difference- in- difference analys - Sida 3 av 954
Kan förändringar i bottenfaunan påvisas två år efter en bäckrestaurering?
The aim of this work is to analyze if a change in the benthic community can be detected two years after a restoration of a small stream. The samples were taken in a small stream at Tinnerö Eklandskap just south of Linköping. In addition to the restored area, two reference sites upstream and downstream of the restored area were sampled to compare to the restored site. The method used for sampling of benthic fauna in the stream was kick sampling. ASPT, Berger-Parker and Renkonen-indices were used to find out if there was any difference between the reference areas and the restored area.
Skatt eller skräp? En studie av fältarkeologisk dokumentation.
This thesis deals with the documentation of non-prioritised material during archaeological fieldwork. The main questions are whether there is a difference in the documentation of the non- prioritised material, between rescue archaeology and research archaeology and what the reasons for such a difference may be related to. Furthermore, the thesis deals with what arch-aeologists write say and do about the subject. To answer these questions, I analyse three different projects; Two research projects, Zvejnieki (Latvia) and Monte da Igreja (Portugal), and one rescue archaeological project, Gyllins Trädgård (Sweden).The most important result is that there is as great a difference between the two research projects as there is between the research projects and the rescue archaeological project. Many similarities can be seen in the projects conducted at Monte da Igreja and Gyllins Trädgård.
Enhetschefer : En studie om ledarskap inom äldreomsorgen
My purpose is to describe and analyse how care managers experience their position as middle managers in the public sector. I have used a qualitative interview method to answer this question and also to capture my six interview persons opinion and understanding of their own position as middle managers. From my six interviews I noticed some difference in their opinions about how it is being a care manger. The results show that the role as care managers have challenges such as to intertwine their own notion how the caring of the elder should be with strict politic decisions. Other challenges are the limitation of economic recourses and reorganisations.
Flickors och pojkars användning av adjektiv i berättande texter utifrån ett genusperspektiv.
The purpose of this study was to examine six girls and boys in grade 4 use of adjectives in narrative texts and examine students' perception and experience of writing from a gender perspective. The methods used were text analysis and an interview. The results showed that girls write more adjectives than boys, but no further significant difference in their use of adjectives was found. There was a certain stereotypical difference in which adjectives they wrote and their attitudes toward writing. Girls are more positive to writing and see writing primarily important for school, while boys think writing is important to succeed in life..
En jämförelsestudie av koldioxidsläpp för en byggnad med trä- respektive betongstomme ur ett livscykelperspektiv
The goal with this examination thesis is to investigate the difference in carbon dioxide emissions between a building with a wooden versus concrete carcassing from a life cycle perspective. The huge amounts of carbon dioxide released into air from human activities must be reduced to prevent serious consequences. A way to limit this issue is through performing a comparative study where the result shows which of two products with the same function has the lowest emission of carbon dioxide, whereof the product with the lowest carbon dioxide pollution can be chosen.To be able to perform a study like this an object has been chosen and studies about life cycle analyses have been done. The rental square meter, the thermal conductivity value, the energy requirements and the placement of the building has been set equal in both framework types. There were solely dissimilarities of the two buildings taken into account when this comparison study was performed.The result of the study is that a building constructed with a wooden carcassing has the lowest amount of carbon dioxide emissions.
Sänkt restaurangmoms : Hur många jobb skapades?
År 2012 sänktes momsen på restaurang- och cateringverksamhet från 25 % till 12 %.Huvudsyftet med denna sänkning var att öka sysselsättningen i restaurangbranschen.Liknande momssänkningar har tidigare gjort på flera håll i övriga Europa. Denna studies syfteär att utvärdera om denna momssänkning har ökat sysselsättningen och så fall i hur stor grad.För att skatta denna effekt har en difference-in-difference modell använts. Studien kommerfram till att det troligtvis har skett en ökning av sysselsättningen i restaurangbranschen menhar svårt att vissa precis hur stor denna ökning har varit..
Utveckling och implementering av ett audiopejlsystem baserat på tidsdifferensmätning
The use of spread spectrum signals has increased dramatically in military applications. Finding methods for detecting and positioning of these signals have become interesting research areas for signal intelligence purposes. One method is to measure the time difference of arrival (TDOA) that occurs when two receivers are synchronous and spatially separated. Based on the TDOA-technique an audio-demonstrator has been developed and implemented. This report describes the theory for how sound received in microphones can be used to extract information about the transmitter?s position from the measured time difference.
Anställningsotrygghetens effekt på självskattad hälsa, i hög respektive lågkonjunktur
The subject of this study was to research whether or not the effect of job insecurity on self reported health differs between good and bad times in the economic climate. Two different years of a national health survey from the Swedish institute of health (FHI) served as data, with 2007 representing good economic climate and 2009 doing the opposite. Both years consisted of data from a national health survey distributed to 20 000 random individuals in Sweden, where 2007 had 5738 valid cases and 2009 had 10 373. A quantitative method was used to determine the difference, consisting of a three variable cross tabulation with chi2-analysis as well as a model of binary logistic regression for each of the two years.The cross tabulation found a significant difference between the two years, with those reporting job insecurity having less of a chance to report bad health during the year representing bad economic climate. While the logistic regression showed the same tendency, the two years could not be significantly differed from each other in that part of the analyzes.With this in mind, the conclusion from the whole test was that no significant difference could be found between the years regarding the health effect of job insecurity..
Kontorsanställdas psykiska välmående i relation till deras fysiska aktivitetsnivå
Background: There have been doping usage as far back as as ancient Greece and around the early 1900s started the doping we have today. In 2008 it was 22,000 men aged 15-54 years old who had any kind of experience with doping in Sweden. The problem of doping use are all over the world and to overcome this problem, we need to work across borders.Objectives: The purpose of this study is to investigate whether there is any connection between the use of supplements and attitude to doping. The study is based on the questions: is there any connection between the use of supplements and positive attitude to doping? is there any connection between the use of supplements/doping substances and high training frequency? and is there different use of supplement/doping substances between girls and boys?Method: A survey in form of a cross-sectional study and a waiting room survey was conducted with 63 respondents of whom 57,1% were women.
Incitamentsstrukturer i socialbidragssystemet : Leder hårdare krav till ett minskat socialbidragstagande?
I denna uppsats studeras hur förändrade incitament i form av hårdare aktiveringskrav för arbetslösa socialbidragstagare i Sveriges kommuner inverkar på andelen socialbidragstagare och socialbidragskostnaderna i kommunerna. Studien möjliggörs av att de svenska kommunerna i varierande utsträckning har infört hårdare aktiveringskrav för arbetslösa socialbidragstagare, varför en difference in differences-analys som renodlar effekten av hårdare krav kan genomföras. Kommunerna klassificeras utifrån graden av aktivitet vad gäller att få socialbidragstagare i aktivering. Väldigt aktiva kommuner jämförs med icke alls aktiva, och en betydande uppsättning kontrollvariabler som kontrollerar för andra skillnader mellan kommungrupperna inkluderas. Resultaten visar att ett införande av hårda aktiveringskrav för arbetslösa socialbidragstagare ger tydliga negativa effekter på andelen socialbidragstagare i kommunerna, i synnerhet för unga socialbidragstagare, men mer begränsade effekter på kommunernas socialbidragskostnader..
Betydelsen av tidig hantering av nyanlända försökshundar till en försöksdjursavdelning :
AstraZeneca in Mölndal (AZRDM) uses beagles bred at Rååhöjdens kennel in Örkelljunga for their research purposes. The staff wishes to have mentally stable dogs to work with, sine stress can effect the research results.
The purpose of this study was to put together the testresults from dogs delivered 2003 and 2004, to see if there is a connection between delivery age and testresult. We have also worked out a method to test if early planned handling of the dogs makes a difference on how the dogs later respond in a testsituation, and tried this method in a pilotstudy.
The data that we have based our calculations on is 172 dogs, divided into 108 males and 64 females.
We found a significant connection between the age at delivery and the testresult in contactability for female dogs delivered in 2003, where increasing age led to decreasing grades in the test at AZRDM. When looking at the difference in testresults between test number two at the kennel and the test at AZRDM we found a significant connection for female dogs delivered during 2003, ie the difference takes on a more negative value with increasing age at delivery.
We found a difference between the two sexes in our calculations.
Får elever bättre uppmärksamhetsförmåga efter fysisk aktivitet? : En experimentell studie om fysisk aktivitets påverkan på uppmärksamhet
The aim of this study is to find out whether there is any difference to be found in the attention ability before and after physical activity. The method used in this study was made of an experimental design. The participants were chosen through a cluster sampling and thereafter divided into a control group and an experimental group. A total of 64 pupils from upper secondary school participated in the study, 25 of them in the experimental group and 39 of them in the control group. Since the measure was repeated, both in respect of time and the comparison between the groups, a mixed design was used.
"Fallbacks" - betydelsen av vandringstid för Atlantlax (Salmo salar L.) som faller nedströms vandringshinder
In Lake Vänern, Sweden, there is an endemic population of Atlantic salmon (Salmo salar L.) that lives its entire life in fresh water. The salmon is hindered from migrating to its natural spawning sites in the northern part of the River Klarälven by nine hydro-electric power plants. None of the hydro-electric power plants have fishways so that salmon migrating upstream or downstream may pass. In the current situation, the upward migrating salmon are caught in a fish trap at the most downstream located power plant in Forshaga. From there, the salmon are driven in a truck, past eight power plants and released a few kilometers upstream of the eighth power plant at Edsforsen.
Kvinnligt eller manligt - En studie av könsbedömningsmetodernas utveckling för humant material
This study focuses on the development of methods for sexual determination of human skeletal remains, mainly between the years 1981 to 2007. By comparing an older analysis from 1983 (Persson and Persson) with my own on the same material, a difference of 40% was shown, which indicates that the methods has changed through time, and that these should not be used for newer conclusions about a population if the method is not throughoutly described.The main cause of the difference was identified as a change in the reliability of the sexual indicators, rather than a total change of method. Any general tendencies did not show, it is however considered that the pelvic bones are able to make a better conformity between the analyses as opposed to using the cranium..
Vad har en AD/HD-diagnos för betydelse för barnet i skolan? : Sett ur pedagogens, specialpedagogens, läkarens och förälderns perspektiv
The purpose of this research has been to study and find out if a diagnose AD/HD is of importance. Does a diagnostic significance matter for how to support and respond to children in school? Are diagnosed children with signs of AD/HD treated differently than children without diagnosis? My study is based on input from teachers, special educators, from two different schools and also one doctor and one parent.I have interviewed teachers, special educators, one physician and one parent. I have been using qualitative interviews with tape recorders and emailed them with open questions. I have been using literature; see bibliography.