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125 Uppsatser om Variance Decomposition - Sida 1 av 9

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.

Konsumentprisindex för kläder och skor 1986-2005 - Dekomponering och prognostisering

The essay initially intends to find adequate models to describe and forecast monthly data for the Swedish Consumer Price Index sub group Clothes and Shoes 1986-2005. The time series observations during 2006 are considered ?out of sample period? which is used to evaluate the forecasts. The purpose is to perform time series decomposition and to investigate and analyzethe seasonal pattern. The Box-Jenkins approach is used to find adequate ARIMA models.

Effekten på nedbrytningen av rötter vid tillförsel av ammonium sulfat i en granskog i sydvästra Sverige

Decomposition of organic matter is a critical process in the ecosystem, which involves many essential biotic and physical parts. Decomposition is therefore an important process both above and below ground. The rate of decomposition is dependent of many environmental factors for example: pH, moisture and supply of oxygen. The decomposition can therefore be affected by large scaled environmental influences, such as acidification and climatic changes. The root litter in the forest is in different ways affected by acidification, liming and manuering.

Portföljteorier en jämförelse

The purpose of this paper is to find out which portfolio theory one should use during a financial crisis. We will examine two different portfolio theorys, the Minimum Variance portfolio and the beta portfolio.We have chosen to study two different portfolios, and followed their development during the financial crisis with its start in 2008 and the IT bubble with its start in the middle of 2000.The data has been collected from OMX internet database making it quantitative study. The beta portfolio's objective is to follow the index and the Minumim Variance portfolio´s objective is to spread the risk by investing in stocks with low volatility. By following the two different portfolios, and compare the development to the index, we will be able to determine which theory is most suitable to use during a recession. The studyperiods we chose were both in a recession and it turned out that the most appropriate portfolio to use was the Minimum Variance portfolio because stock in this portfolio tends to be less sensitive to economic fluctuations..

En jämförelse av stickprovsmetoder vid mätning av radioaktivetet på en yta

This study compares the sample variance of the mean in a simple random sample (SRS) and a systematic sample from a surface. The study also compares the prediction error variance in a SRS and systematic sample from a random field. Recommendations are presented on which method to use in the clearance and exemption process in the nuclear industry. The results indicate that quadratic systematic sampling outperformed SRS in most instances and proved to be especially efficient in the presence of a long-ranged covariance function and high sampling intensity (i.e. short distances between observations).

Makroekonomiska variablers påverkan på Dow Jones och OMXS30

Syftet med studien är att undersöka makroekonomiska variablers effekt på Dow Jones och OMXS30, med hjälp av en lämplig ekonometrisk modell. Vidare är syftet att analysera möjligheten för börsprognostisering och analysera om denna möjlighet är lika stor för Dow Jones som för OMXS30. Detta kommer att ske genom att undersöka motsvarande variabler för respektive lands aktieindex. Variablerna arbetslöshet, ränta och oljepris visade sig inte ha någon signifikant påverkan på varken Dow Jones eller OMXS30. Det visade sig dock att aktieindexen reagerade på samma sätt, för respektive lands variabler..

Temperaturens och den fotosyntetiskt aktiva strålningens effekt på avgång och inlagring av kol på en dikad torvjord

The decomposition of organic carbon in drained peat soils is a major source of carbon di-oxide in Sweden. A big part of these drained peat soils are used in agriculture and it is a big challenge to slow down their decomposition. It has earlier been thought that less tilling and higher water table levels would decrease the activity of soil microbes and thereby the decomposition, but recent experiments has showed that this has little or no effect. In this bachelor thesis a field experiment was made on drained peat soil with ley, outside Björklinge, Uppsala municipality, Sweden. The experiment was carried out in May 2011. The objective was to develop a method to examine how the net exchange of carbon diox-ide from plant covered peat soil is affected by temperature and photosynthetically active radiation (PAR).

Portföljoptimering med courtageavgifter

Ever since it was first introduced in an article in the Journal of Finance 1952, Harry Markowitz? mean - variance model for portfolio selection has become one of the best known models in finance. The model was one of the first in the world to deal with portfolio optimization mathematically and have directly or indirectly inspired the rest of the world to develop new portfolio optimization methods. Although the model is one of the greatest contributions to modern portfolio theory, critics claim that it may have practical difficulties. Partly because the Markowitz model is based on various assumptions which do not necessarily coincide with the reality.

Ett träd och dess liv : Förskolebarns uppfattningar om träd

The aim of this study was to investigate preschool children's perceptions of trees in and it was done through qualitative interviews. The children were drawing trees and told me what the tree needs to grow and what happens to the leaves in autumn. In a playful way, they learned more about trees and the purpose was also to examine whether they had acquired new experiences and thoughts on the trees, photosynthesis and decomposition. Then the children were interviewed again to see if their answers were different. The results showed that the children gave different answers at the second interview.

Systemidentifiering och reglering av en luftningsbassäng på ett reningsverk

A wastewater treatment plant has the task to refine the wastewater from substances that should not be released into the environment. The decomposition process can, in a simple way, be described as follows: micro-organisms breathe oxygen and eat unwanted substances. The environment in which the micro-organism lives is known as sludge and the correct amount of oxygen available in the sludge is important for the decomposition to be effective. The oxygenation of the sludge alone stands for about 30% of the plant?s energy consumption.

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.

Framtagning av analysmetodik för uppslutning av kemiska produkter

The purpose of this thesis was to develop and optimize a method of analysis for combustion of organic chemical products, followed by an ion chromatographic quantitative analysis. This was to be achieved with the decomposition equipment IKA AOD 1. The aim was to receive a precise and repeatable method that would be able to be applied to the process of qualification and technical marking of chemical products at the company, OKG AB in Oskarshamn. A complete instruction for the decomposition equipment and the method of analysis was written. A number of parameters were chosen from the general method of the combustion equipment, which then was tested parallel with a simultaneous development of an appropriate ion chromatographic method.

Förstudie för skapandet av ett miljöövervakningsprogram : en styrkeanalys angående vattendrag i västerhavets vattendistrikt för fastställandet av provantal i tid och rum för ett effektivt omdrevsprogram

The environmental monitoring in Sweden has been developed by several different parties and is now being coordinated and made more effective in order to meet the current demands on high quality information regarding the state of the environment. Sweden has been divided into five different water districts based on watershed areas because of requirements in the Water Directive of the EU. In Sweden there are two common types of environmental monitoring programs used to gather information on changes in time and in space. Currently both these two types are used for lakes in the water district of the western sea but only one is used for watersheds. The purpose of this report is to supply basic information regarding the possible need for a second environmental monitoring program for watersheds in order to better describe the spatial variation within the district as well as to determine the number of samples necessary in order to describe the district over time and space.

Stubblyftningens initiala effekt på emissioner av växthusgaser från en granmark i Småland :

In order to reduce greenhouse gas emissions from human activities fossil fuels will have to be replaced with renewable energy alternatives, such as bioenergy. Sweden has a great potential to produce bioenergy derived from forest products and there is currently a great interest within Sweden in using stumps for bioenergy production. However, the environmental consequences of the method need to be investigated before stump removal can be performed on a large scale. Swedish forest soils contain large carbon pools and a different land use may change conditions so that soils that presently act as sinks of carbon could potentially turn into sources of carbon release instead. This study investigates the initial effects of stump harvesting on the emissions of three greenhouse gases, carbon dioxide, methane and nitrous oxide. The emissions were measured from the soil surface in a Norway spruce forest located in the southern part of Sweden.

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