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82 Uppsatser om Mean-variance - Sida 3 av 6
Reagera och agera: Styrka och snabbhet i den manuella responsen för emotionella stimuli
In this study I investigated whether the strength in the manual response for emotional and neutral stimulus search arrays can explain some of the difference in reaction times (RT:s) for emotional stimuli, or not. Earlier, perceptual, cognitive and attentional processes has mostly been used to explain the variance in RT:s. Thirtythree individuals were asked to, as fast as possible, detect a target picture among distractor pictures in 3 rows x 4 columns arranged search arrays. The pictures were categorized in fear relevant animals (snake, spider) and neutral animals (cat). The results showed, more correct responses for cat target.
Fonders avkastning - en variabelanalys av fonders avkastning under ekonomisk upp- och nedgång
Vårt syfte är att ta reda på mer om vad som påverkar fonders avkastning och om detta skiljer sig åt i ekonomisk uppgångs- respektive nedgångsperiod. För att uppfylla vårt syfte har vi valt att genomföra regressionsanalys med avkastning som beroende variabel och variablerna: standardavvikelse, beta, storlek, TKA och omsättningshastighet som förklarande variabler. Detta har genomförts i en ekonomisk uppgångs- och en ekonomisk nedgångsperiod. Vi har använt portföljvalsteori med dess ingående variabler avkastning och risk. Även begrepp som kovarians, korrelation, effektiva fronten, mean variance, CAPM och beta gås igenom.
Biologisk behandling av oljeförorenad jord : Abiotiska faktorers inverkan och effekter av olika uppläggningssätt på nedbrytningshastigheten.
The purpose of this report was to investigate how the abiotic factors (temperature, pH, nutrients, oxygen levels and water content) would affect the decomposition of oil-contaminated soil and how a variance in structured soil would affect the decomposition-rate. A minor field-study was made and soil where structured in five different ways (one was a default pile and was used as a reference). The study took place over 137 days and three samples were taken (start, middle, end) and analyzed for aromatic and aliphatic compounds. The result of this study shows that there is a significant difference between all methods for the aliphatic compounds and no significant difference for the aromatic compounds. The abiotic factors that affect decomposition vary from organism to organism, depending on what type of environment it will function the best.
Föredraget ledarbeteende - en jämförelse mellan män och kvinnor, samt mellan lagidrottare och individuella idrottare
The aim of the study was to a) examine what leader behaviors individual and team athletes prefer and b) examine what leader behaviors men and women prefer. A questionnaire (The Leadership Scale for Sports) was distributed to 168 individuals, from which 130 were included in the study. The data was analyzed in SPSS, in which a three-way and a two-way variance analysis were performed. The results showed that individual athletes preferred the behavior dimensions ?Training and instruction?, ?Positive feedback? and ?Democratic behavior? to a higher degree than did team athletes.
Tidsperspektiv som prediktor för individuella skillnader i upplevd stress : En tvärsnittsstudie av äldre vuxna
Time Perspective is related to mental and physical health. This study examines the relationship between Time Perspective and perceived stress where Time Perspective was expected to predict the level of perceived stress. Past-negative, Future-negative, Future-positive and present-fatalistic were expected to be positively associated with perceived stress while Past-positive and present-hedonistic were expected to be negatively associated. Measures from the self-assessment forms S-ZTPI, PSQ-recent and CES-D from 445 participants (242 women, 203 men) between 60-90 years were used to examine the hypothesis of the study. Two hierarchical multiple regression analysis confirmed that Time Perspective is associated with perceived stress and in part 2 explains it's variance, one when adjusting for demographic data (.R = .37) and the 2 other when adjusting for demographic data and depressive symptoms (.R = .13).
Analys och produktionsförbättring på monteringslinan Vensafe
This study is preformed at Westbaltic Components placed in Töcksfors Sweden. Themain target in this study is to make one of the company?s assembly lines better andmore effective. The assembly line constructs vending machines for different stores allover Europe.It will contain tobacco, snuff, cigarettes and shaving blades and many more similarproducts.The first step in our study is to locate the daily problems and find out a good way toreduce them and make them disappear. A good way to do this job easier was toconstruct a visualizing board.
Välbefinnande, psykosocial arbetsmiljö och deltagande i friskvårdsaktiviteter bland anställda på ett tillverkningsföretag
Work environment activities, such as work health promotion, can take place at different levels - though the best result is obtained when all levels can interact. The overall aim with this study was to examine the impact of health promotion on work related well-being and stress in an industrial company. The focus was on employee experience of and participation in company initiated wellness activities. A quantitative cross-sectional study was conducted in which parts of the Copenhagen Psychosocial Questionnaire (COPSOQ II) were used to examine factors in the psychosocial work environment, and well-being was examined with the Satisfaction with Life Scale (SWLS). In all 303 employees (50 %) responded to the survey.
Dexametasons effekt på trombocytaggregering och syreradikalproduktion
Platelets are important for the healing of damaged blood vessels since they have an importantpart to play in the coagulation process. At the same time, the blood must be kept fluid and notcoagulate at the wrong time. Therefore there are factors that effect the aggregation of plateletsin a positive or a negative way.Previous investigations have shown that platelets during stirring conditions produce reactiveoxygen species (ROS) that weaken the inhibiting effect of nitric oxides (NO) on platelets andthat the drug Dexamethasone (Dex) can reduce the ROS-production.The aim of this project was to investigate if glucocorticoids, in this case Dexamethasone,could restore the inhibiting effect of NO on platelets and if there was any decrease in ROS-production.The result of the ROS-measurements showed a great variance and it was difficult to draw anyconclusions from them, but a clear decrease in ROS, as previous reported, was not shown. In the aggregation experiments the inhibiting effect of NO was observed through the drug S-nitroso-N-acetylpenicillamine (SNAP), a NO-donator.From the aggregation experiments, the result seemed to be that SNAP during longerincubation time lost its inhibiting effect, probably because the cells become desensitized.With superoxid dismutase (SOD), the effect of SNAP increased, both in the experiment withlonger and shorter incubation times. Dex seemed to reinforce the aggregation in relation toboth SOD and SNAP.
Analys av systemfaktorers påverkan på tillförlitligheten i distributionsnät
In this master thesis outage statistics covering tree years from two distribution grids are analyzed with the purpose to deduce which factors yield outages. The statistics are extensive therefore allowing in-depth analysis of both customer and system related factors. From this starting point and as a model of explanation energy not supplied is studied as the consequence and the measurement of the inconvenience caused by outages. Different methods for calculating energy not supplied are developed and studied and put in comparison to the method used in Network Performance Assessment Model, which is the Swedish frame work for regulating electricity distribution.Analysis of the outage statistics show a relation between the type category of customer and outages that can be deduced to the variance and the density associated with that customer category. Prioritization of different customer categories is elevated also in this aspect.
Hedgefund strategies - En studie där hedgestrategier utvärderas och jämförs med traditionell förvaltning
Hedgefonder är en relativt ny investeringsform på den svenska marknaden. Dessa fonder karakteriseras av att oavsett marknadsutvecklingen uppnå en positiv absolut avkastning med låg risk. Hedgefonder är en förvaltningsform med stor variation vilket medför att de kan karakteriseras som en heterogen grupp av fonder, dock med vissa gemensamma drag. I denna studie har jag valt att jämföra fyra olika hedgestrategier med traditionell förvaltning i riskjusterad avkastning. Då hedgefonders avkastningsmönster ofta inte är normalfördelade tappar Mean-variance måtten sin exakthet.
Skillnader mellan manligt och kvinnligt? : Ett genusperspektiv på ledaregenskaper
AimThe purpose of this study is to investigate if there is any variance between masculine and feminine physical education teachers leadership.Are men more authoritarian than woman in their education? Do the influence of pupils have something to do with the gender of the teacher?s? Do the pupils respect masculine physical education teachers any different compound to feminine teachers?MethodWe have studied relevant literature that consider masculine and feminine leadership. The choice was to work with senior compulsory school. We choose the community of Botkyrka, through comfort choice. The criterion for the teachers were that they would have a swedish physical education and have been working at least for 4 years.
På väg mot den inre marknaden? - en studie om sammanlänkningar mellan börserna i det nya EU
Det primära syftet med uppsatsen är att studera relationerna mellan de nya och de etablerade börsmarknaderna i EU för att se om det ha skett någon förändring under perioden 1996-2005. Ett sekundärt syfte är att undersöka huruvida den finansiella integrationen inom unionen har blivit starkare under den studerade tidsperioden. I syfte att kunna besvara de frågor som vi är intresserade av använder vi oss av VAR-metoden. Med hjälp av "impulse response" beräknade vi hur snabbt en händelse sprider sig mellan de undersökta börsmarknaderna samt hur lång tid det tar innan dessa åter är i jämvikt. "Variance decomposition" talar om för oss i vilken utsträckning de olika börsmarknaderna påverkar varandra.
International transmission of stock market movements - a Scandinavian focus -
Previous research has found an increased transmission of stock movements in Europe, partly caused by the establishment of institutions as the EU and the EMU. The purpose of this paper is to find the possible impact from the EU and the EMU concerning the evolution of international transmission of stock market movements, on four Scandinavian markets, Denmark, Finland, Norway and Sweden. The research is based on primary data, existing theories and earlier studies regarding international transmission of stock market movements. The examined method is a VAR (Vector autoregressive model) including a 10x1 vector of variables. Furthermore the tests considered are correlation, granger-causality, variance decomposition and impulse response.
Automatisk bedömning av reglerkretsarsprestanda
In this thesis, a computer program that in a simple way can calculate the performance of control loops at the refinery Preemraff Lysekil has been created. The computer program has been adapted to the environment at Preemraff Lysekil. Theories for evaluation has been studied in aspect of reliability and of automatic implementation. The evaluation has been carried out from data collected directly from control loops at the refinery and from simulated control loops with implemented errors. Among the studied methods are Harris index and Stattin´s oscillation index.
Från Skiss till Diss
Over the past decade, the fashion industry has experienced a relatively high rate of consumption with material and clothing becoming increasingly subject to waste and disposal. As a result of the increased awareness within the industry the interest in CSR (Corporate Social Responsibility) amongst retailers has increased substantially in an attempt to shy away from the critically amplified media attention. In addition the underlying demand from external stakeholders has forced companies to ensure they focus and act upon each stage of the product life cycle.This study provides a further in depth analysis of the fashion industry and conveys the key messages and steps that firms are taking in response to the external pressures and requirements based on four different merged process areas. This research paper examines the impact of CSR on two Swedish fashion retailers Åhléns and JC and shows how accountability relates to the external expectations and norms that prevail in society. The result shows that the firms do meet the demands within each sub category as a response to market demands.