We derive the equation linking the Weyl tensor with its Lanczos potential, called the Weyl-Lanczos equation, in 1+3 covariant formalism for perfect fluid Bianchi type I spacetime and find an explicit expression for a Lanczos potential of the Weyl tensor in these spacetimes. To achieve this, we first need to derive the covariant decomposition of the Lanczos potential in this formalism. We also study an example by Novello and Velloso and derive their Lanczos potential in shear-free, irrotational perfect fluid spacetimes from a particular ansatz in 1+3 covariant formalism. The existence of the Lanczos potential is in some ways analogous to the vector potential in electromagnetic theory. Therefore, we also derive the electromagnetic potential equation in 1+3 covariant formalism for a general spacetime.

In this qualitative study the authors explores, by studying several quality-development models what quality in leadership is. The models are: Total Quality Management; SIQ?s model for customer-oriented organizational development; the EFQM excellence model; the ISO 9000:2000 standard; and Six Sigma. These models will be compared from Deming?s list for upper management; the Situational Leadership Theory; and the Contingency Theory.

The purpose of this study was to develop two types of prediction models for Scots Pine and Norway Spruce. The first type for calculation of the stump diameter under bark the year the tree reached breast height (Dstubh130). The second type for calculation of the annual difference, e.g. the number of growth years between stump height (0.2 m) and breast height (1.3 meters above ground level). The primary thought with these prediction models is to obtain the breast height age in the trees on basis of the number of annual rings at stump.

We have by Statistics Sweden (SCB) been given the task of using different dynamic regression models in order to forecast service price index for sea transport. The aim is to see whether these models provide better forecasts than those previously used. This essay aim to identify, estimate and evaluate the selected prediction models. Through our data material we were given access to 28 sightings of sea transport index during the period of 2004 q1 to 2010 q4. We have chosen to evaluate three different transfer function models, one ARIMA model and one naive forecasting model. The input variables we decided to test in our transfer function models were the price of petroleum products, the port activity in Swedish ports and the lending rate of Swedish Central bank. The results of our study suggest that transfer function models generally provide better models than the ARIMA model and the naive forecast model.

The field of work and employment is constantly undergoing changes. In order to help organizations to adjust to new conditions, different models for organizing have been developed. Many of these models are spread worldwide, due to the need for organizations to meet demands of flexibility and efficiency. In this study, a small number of models, which contains solutions of how to organize work in Human Resources, have been selected. The author and scientist Dave Ulrich, who has had a large influence on the development of the work in Human Resources, originally founded these models.The aim of this study was to examine how these models were functioning, in reference to the different departments of Human Resources labor within the township of Uppsala.

Computers together with Internet have been growing enormously, during the last decade and the area of information technology has been growing in the same speed. As long as the surrounding environment evolves, the business models must within the IT-area, keep the same pace. So, how do business corporations handle this change to attract customers? How do the dominant business models look like? In many cases, they are apparently much the same. But what differences can we see and what areas can be improved? We have showed that the IT area isn?t just one, it consist of several segments.

Background: The valuation of Biotechnology companies is difficult in many ways. Patent and human capital are hard to value and also there is a great uncertainty about the success of the compaines research programs. Are traditional valuation models really useful when it comes to research companies or do they result in false values of the companies? Purpose: To study what values different valuation models gives biotechnology companies and how they correspond to the market value. Method:We have studied financial litterature och found the most common used models today.

Computers together with Internet have been growing enormously, during the last decade and the area of information technology has been growing in the same speed. As long as the surrounding environment evolves, the business models must within the IT-area, keep the same pace. So, how do business corporations handle this change to attract customers? How do the dominant business models look like? In many cases, they are apparently much the same. But what differences can we see and what areas can be improved? We have showed that the IT area isn?t just one, it consist of several segments.

This study is made on assignment by the local board of forestry in Skåne, Blekinge and Halland. The change of the forest law 1994 brought a new type of management plan. A more active planning was introduced in order to equate the environment goal with the production goal. The purpose with this study is to give a better picture of how planning for nature conservation in production forest is made and to develop support for selection of silviculture methods for stands with combined goals. With combined goals means production forestry with a reinforced consideration to both nature and culture, called PF-classified stands. This was done by: ? Describing silviculture models from the literature that are possible to use for stands with combined goals. ? Describing silviculture models that is used in practice in stands with combined goals. ? Describing how the classification of stands with combined goals is used. Which means, were in the terrain, with which frequency and in which type of forest PF-classification is used. ? Comparing differences and similarities of theoretical and practical used models. The study was done partly as a literature study and partly as an interview study of forest planners.

Background: Diabetes mellitus is one of today's major public health problems, affecting up to 347 million people worldwide. Several studies have shown a correlation between hearing loss and diabetes mellitus. However, it is still unclear whether this correlation differs between type 1-diabetes and type 2-diabetes.Purpose: The purpose of this study is to investigate whether there is any difference in prevalence of hearing loss in type 1-diabetics versus type 2-diabetics.Method: A meta-analysis was performed based on ten studies that were identified through the database PubMed and through manual searching of references. Odds ratios for the risk of developing hearing loss were calculated in each study. Pooled odds ratios were calculated using a random effects model.Results: Pooled odds ratios indicates that both type 1-diabetics and type 2-diabetics are more likely to develope hearing loss compared to non-diabetic controls.

Value-at-Risk (VaR) is among financial institutions a commonly used tool for measuring market risk. Several methods to calculate VaR exists and different implementations often results in different VaR forecasts. An interesting implementation is historical simulation, and the purpose of this thesis is to examine whether historical simulation with dynamic volatility updating is useful as a model to calculate VaR and how this differs in regard to type of asset or instrument. To carry out the investigation six different models are implemented, which then are tested for statistical accuracy through Christoffersens test. We find that incorporation of volatility updating into the historical simulation method in many cases improves the model.

This study tests two financial valuation models empirically by valuing three stocks from three industries, with the purpose of studying how well valuation models work empirically and to make a forecast. The models which will be tested are residual income valuation and discounted cash flow. Nine stocks will be picked strategically from the Swedish stock market and additional analysis will follow in the analysis chapter.Based on analysis and valuation, the commodities industry has decent valuation as the healthcare industry is undervalued thanks to the high valuation of AZN. The energy industry has low value due to the capital intensive nature of the industry. When it comes to the models and their practical implementation, DCF has been the most problematic to apply empirically whereas RIV was better but it still shows extreme values, which teaches the student the clear difference between theory and empiri..

This master thesis was made to validate hydropower models of a turbine governor,Kaplan turbine and a Francis turbine in the power system simulator ARISTO atSvenska Kraftnät. The validation was made in three steps. The first step was to makesure the models was implement correctly in the simulator. The second was tocompare the simulation results from the Kaplan turbine model to data from a realhydropower plant. The comparison was made to see how the models could generatesimulation result that was similar to the reference power station.

Certain types of waste, e.g. bottom ash originating from municipal solid waste incineration (MSWI bottom ash) can be used as road construction materials. A potential problem is the possibility of substances leaching out of the road and spreading in the surrounding groundwater.The aim of this master?s thesis is to conclude whether hydrogeological type settings can be employed to, based on local conditions, provide an estimate of the probable spreading of these substances in the surrounding groundwater, and whether certain types of soils can be identified as being less suitable for the localization of a MSWI bottom ash road. A hydrogeological type setting is defined as a mappable unit with similar hydrogeological properties.

The formulation of visions into practical projects is an important part of the professional expertise of landscape architects. This expertise includes the gathering, structuring, improvement and utilization of knowledge. Project models have been developed to provide tools for the implementation and governance of projects, as well as means of learning, reflection and survey of individual projects. The aim of this thesis is to describe some general project models and their theory, and to describe practical, real-life examples of project models used within landscape architecture. Questions asked are: ? How do the processes of idea to construction in landscape architectural projects lool like? Do project models have a relevance for the mission of landscape architects? ? Is a common project model used within such projects, or is the project model varying depending on e.g.