This thesis treats the subject of a complete steady state and dynamic model of the VSC-HVDC covering both the AC and DC system-side of the converter. The topology of the model is recreated after the scheduled transmission line in the south of Sweden, called SydVa?stla?nken. The topology covers both a simple two terminal connection as well as a multi-terminal one. This model is to be implemented in the power system simulation program ARISTO.

Detta arbete var beställt av Sjöfartshögskolan i Kalmar. Skolan ville ha en enhet som kunde mäta aktiv-, reaktiv- och skenbar effekt, ström, spänning, frekvens och cos? på en generator och som kommunicerade vidare dessa värden till en PLC. Detta för att kunna lastfördela lasten mellan ett antal generatorer i kursen Tillämpad elteknik 15 hp där studenterna bygger en generatorinstallation med tre generatorer. Ett funktionsblock för lastfördelning skulle också programmeras.

I detta arbete behandlas transient simulering i ett 1D-simuleringsprogram, i dettafall Gamma technologies GT-Power. Vad som behöver ändras i en modell för attden skall kunna simulera en motor under transienta driftsfall med godnoggrannhet har undersökts. När detta är gjort, skall det undersökas hur väl dentransient kalibrerade modellen kan simulera en motor med förändrad rörgeometripå insugs- eller avgassidan, och vad som måste omkalibreras om detta inte ärfallet.Den viktigaste slutsatsen av detta arbete är vikten av att ha en korrekt framtagenkompressormapp i modellen. Den som fanns tillgänglig under arbetet hade baramätdata ned till 70000 rpm. Detta resulterade i en överskattning av massflödet iden lägre regionen i den av GT-Power framställda kompressormappen.

A large number of rivers in northern Sweden have hydropower developments that cause negative effects on both up- and downstream migrations of anadromous species like Atlantic salmon. So far, most attention has focused on the hindrances of adult fish during their upstream spawning migration. However, since turbines in power stations cause losses on downstream passing fish, the focus on negative effects on smolts has increased. The aim of this study was to compare three different causes of losses of salmon smolts passing downstream through a power station area in the flow-controlled River Åbyälven in northern Sweden.A total of 61 wild salmon smolts were caught and radio-tagged in the River Åbyälven during their downstream migration in June 2009. The salmon smolts were released at three locations, 1.1 km upstream from the power station, in the turbine intake and in the upper part of a fishway, acting both for up- and downstream fish passage.

Modern forest owners are very familiar with forest management and forest economics. Therefore they have high demands for quality in forest operations. Guarantee of quality in the shape of self-checking activities is an important tool to guarantee a well managed forestry operation. To meet the forest owners? demands on guarantee of quality and the entrepreneurs wish of an easy method for self-checking, the forest owners association, Södra skogsägarna, has developed a new method for thinning inventory. The purpose of this study is to evaluate the method that is used for self-checking and to find ways to develop and improve of the method. The data has been collected by inventory in a number of stands with circle-area survey and with strip survey, which is method that is used for self-checking. The results show that the strip survey does not diverge more than ±10 % in measuring values of basal area, number of stems, roads share, thinning quotient, outtake of basal area and total volume compared to circle-area survey.

The purpose of this essay is to do an ecocritical reading of Vilhelm Moberg?s The Emi-grants from 1949. By asking and answering the three following questions; How does a system present itself, What are the different reasons for emigration; Why does differentsystem fit some well and some not.By using two articles from Green Planets - Ecology and Science Fiction to illus-trate two different views; Different parts value in an ekosystem and The Ship as an ecosystem. I have also created, based on the literary text four different terms concern-ing the dynamic system; Stable, Static, Unstable and Collapsing systems. I have found that all system goes through changes, some drastic, that changes the way the parts of the systems fit with in it.

By using univariate analysis, tobit and logit regressions, this thesis investigates determinants of asset writedowns. After controlling for variables indicating reductions in asset values, the results show that changes in senior management are significant in explaining the writedown decision and magnitude, which is in line with previous research. The explanatory power of changes in senior management has not increased with the transition to IFRS in 2005. No evidence is found supporting the hypothesis that the explanatory power of management incentives is higher for more discretionary types of asset writedowns..

This Thesis aims to explore how to integrate an IT-system for facilitating anorganizations work with Continous Impprovements.This is done here by examining and analyzing the process within a handful ofcompanies who seem to have been successful with their own implementations. Thestudy is focused on the implementation of one particular system, "System C2".Simliarities and differences between the companies, and the established rule of thumbfor these kind of activities are focused upon. This to emphasis how another actormight emulate some of the apparent success.Part of the core question is found in the title, since Continous Improvement is oftenseen as a relativly low-risk activity, is it then also possible to take a low-risk slow pathto the implementation of such a system in the entire organization?.

The goal with this master thesis has been to evaluate and to examine the stationary resistance bridge. The resistance bridge uses a 4-point measuring to determinate the resistance, which is used in the manufacturing of the conductor. It is then used when the resistance is to be decided for coarser aluminium conductors. A conductor has to fulfil certain demands to be able to move forward in the process. One of these demands is the resistance in ohm/km, which has demands that the measure values of the resistance bridge are as true and precise as possible. The stationary resistance bridge had been examined through various kinds of measurements to be able to see how stable the system is and how to obtain a measure value as optimized as possible.

This thesis is an evaluation of a new design concept for statorfeets in Gallejaur hydro power plant. Founder of the work is Vattenfall AB Vattenkraft. During the 70- and 80´s nuclear power began to be phased in to the Swedish grid, which meant that hydropower became an important source of rules. The generators began running in so called intermittent operations instead of basic operations, which meant 300-600 start/stop per year instead of one-ten numbers start/stop per year. In order to deal with the thermal forces that arise at every start and stop suppliers began to mount so called sliding joints, which is to take advantage of these forces and maintain the stator shape.

Overdue cleanings have for a long time been an important topic of discussion within the forestry sector. When stands that have not been pre-commercially thinned are reaching the level of commercial thinning, many problems occur in terms of decision-making and economical outcomes. These types of stands are commonly known as conflict-stands. The work was carried out partly as an interview survey towards representatives from the forest sector and the energy sector, partly as a case study of conflict-stands situated in Böksholm, north of Växjö and in Tönnersjö east of Halmstad. The criteria for the studied stands were that they had to be dominated by Norway spruce and be in a severe status of ?conflict?. The aim of the interview was to get an overview of the situation today, and also analyse trends in terms of conflict stands.

This thesis aims to develop a control system for measuring electromagnetic compability (EMC). This has meant that a controller designed around an ATmega8 microcontroller has been manufactured and programmed. It has also meant the development of a comprehensive control software in the program MATLAB. The control system has been tested with satisfactory results and can now, monitor and control measurements of the EMC-type..

Syfte och frågeställning: Syftet med denna studie är att undersöka de eventuella fördelar styrketräning med yttre belastning kan ge kvinnliga truppgymnaster på juniornivå. Frågeställningar: Vilken effekt på explosivitet i nedre extremitet har sex veckors powerträning med yttre belastning på truppgymnaster? Skiljer resultaten sig från de som uppnås vid traditionell gymnastisk styrketräning?Metod: Två lag som representerar Sverige-eliten på damsidan i juniorklassen delades in i test- (n=7) och kontrollgrupp (n=8). Testgruppen genomförde under sex veckor ett specialdesignat träningsprogram riktat mot power medan kontrollgruppen genomförde traditionell gymnastisk styrketräning. För- och eftertester genomfördes för att utvärdera effekterna av programmen.

Construction of an autonomous wind station was a project with the goal of creating a product that could collect wind data from a sensor and then transfer this data to a server wirelessly over the GSM network. The device would be powered by batteries and solar cells and function fully without requiring external power supply. This required that a small computer was constructed and programmed to store and send data at predetermined cycle times and programming of a server that received the sent data. The project also required optimization of power consumption and dimensioning of solar cells and batteries based on this. The construction of this station demanded research both for the selection of hardware and programming software. The computer was based on a microcontroller and a GSM module that sent the data over the 2G network.

Voice over IP (VoIP) is a relatively new technology that enables voice calls over data networks.With VoIP it is possible to lower expenses, and increase functionality and flexibility. FromSwedish Armed Forces point of view, the security issue is of great importance, why the focus inthis report is on the security aspect of the two most common open-source VoIP-protocols H.323and SIP, some of the most common attacks, and counter-measures for those attacks.Because of the level of complexity with a network running H.323 or SIP, and the fact that it hasyet to stand the same level of trial as of traditional telephony, a VoIP-system includes manyknown security-issues, and probably at present many unknown security flaws.The conclusion is that it takes great knowledge and insight about a VoIP-network based onH.323 or SIP to make the network satisfyingly safe as it is today, and is therefore perhaps not asuitable solution for the Swedish Armed Forces today for their more sensitive communications..