Changes in the thermal growing season in Nordic countries during the past century and prospects for the future

Selostus: Termisen kasvukauden muutokset Pohjoismaissa viimeisen vuosisadan aikana ja tulevaisuudessa

Yellow-flowered lucerne : properties and influence on performance and reproduction of ewes

Selostus: Sirppimailanen astutettavien uuhien ruokinnassa

Financial Analysis of the Pulp and Paper Industry: Performance and value creation of the world's pulp and paper companies

Tutkimuksen tavoitteena on analysoida 74 sellu- ja paperiyrityksen taloudellista suorituskykyä kannattavuutta, maksuvalmiutta, vakavaraisuutta ja arvonluontikykyä kuvaavilla tunnusluvuilla. Tutkimuksen teoriaosa esittelee liiketoiminta-analyysin välineet, jonka jälkeen esitellään taloudelliset tunnusluvut. Empiriaosassa käydään läpi vuoden 2005 tunnusluvut yritystasolla. Jotta voidaan tarkastella tunnuslukujen muutoksia pitkällä aikavälillä, yritykset ryhmitellään maantieteellisen sijainnin sekä liiketoimintaorientaation mukaan. Tutkimus on kuvaileva. Tunnusluvuista voidaan todeta sellu- ja paperiteollisuudessa meneillään oleva toimialan rakennemuutos. Eteläamerikkalaiset yritykset, jotka hyötyvät uudesta ja kustannustehokkaasta raaka-aineesta, ovat siirtyneet lähemmäs arvonluontia, kun taas suurin osa pohjoisamerikkalaisista yrityksistä, jotka olivat toimialan johtavia arvonluojia, ovat nyt arvon tuhoajia. Toimiala kärsii myös alhaisesta kannattavuudesta, joka vaikuttaa eniten pohjoisamerikkalaisiin yrityksiin. Samaan aikaan eteläamerikkalaiset yritykset ovat nostaneet kannattavuuttaan, mikä puolestaan korostaa meneillään olevaa muutosta.

Digital Audio Broadcasting: Technology and Prospects

The subject of the thesis was the digital audio broadcasting technology developed in the Eureka project 147. The research was based on the literature on the subject. At first, some reasons for the digitisation of broadcasting technology were given. Next, the channel multiplexing and channel coding methods employed by digital radio were discussed. The design of these methods is based on certain phenomena related to the propagation of radio-frequency signals, and these phenomena were also described. After that, audio and data transfer mechanisms as well as the structure of digital radio network were explained. Furthermore, digital audio and data services were considered. Finally, the digital radio was examined from marketing and administrative aspects. From a merely technical point of view, the digital radio technology offers several improvements in comparison with analogue technology. However, the digital radio has not become as widespread as it was perhaps originally expected during its development.

Performance and Methodological Aspects in Positron Emission Tomography

Performance standards for Positron emission tomography (PET) were developed to be able to compare systems from different generations and manufacturers. This resulted in the NEMA methodology in North America and the IEC in Europe. In practices, the NEMA NU 2- 2001 is the method of choice today. These standardized methods allow assessment of the physical performance of new commercial dedicated PET/CT tomographs. The point spread in image formation is one of the factors that blur the image. The phenomenon is often called the partial volume effect. Several methods for correcting for partial volume are under research but no real agreement exists on how to solve it. The influence of the effect varies in different clinical settings and it is likely that new methods are needed to solve this problem. Most of the clinical PET work is done in the field of oncology. The whole body PET combined with a CT is the standard investigation today in oncology. Despite the progress in PET imaging technique visualization, especially quantification of small lesions is a challenge. In addition to partial volume, the movement of the object is a significant source of error. The main causes of movement are respiratory and cardiac motions. Most of the new commercial scanners are in addition to cardiac gating, also capable of respiratory gating and this technique has been used in patients with cancer of the thoracic region and patients being studied for the planning of radiation therapy. For routine cardiac applications such as assessment of viability and perfusion only cardiac gating has been used. However, the new targets such as plaque or molecular imaging of new therapies require better control of the cardiac motion also caused by respiratory motion. To overcome these problems in cardiac work, a dual gating approach has been proposed. In this study we investigated the physical performance of a new whole body PET/CT scanner with NEMA standard, compared methods for partial volume correction in PET studies of the brain and developed and tested a new robust method for dual cardiac-respiratory gated PET with phantom, animal and human data. Results from performance measurements showed the feasibility of the new scanner design in 2D and 3D whole body studies. Partial volume was corrected, but there is no best method among those tested as the correction also depends on the radiotracer and its distribution. New methods need to be developed for proper correction. The dual gating algorithm generated is shown to handle dual-gated data, preserving quantification and clearly eliminating the majority of contraction and respiration movement

The performance and the characteristic field of a centrifugal compressor

Tässä työssä tarkastellaan radiaalikompressorin puristusprosessiin liittyvä peruslaskenta. Ilmankosteuden vaikutukset laskentaan huomioidaan ja kompressorin tunnuskenttä esitellään tässä työssä. Esimerkkinä lasketaan pisteitä kompressorin tunnuskentästä.

Winner-Loser Performance and Macroeconomic Effects during three last Economic Crises in Finnish Stock Market

The main purpose of this thesis is to investigate winner-loser performance when financial markets are facing crisis. This is examined through the idea that does the prior loser portfolios outperform the prior winner portfolios during the three major crises: The depression of the 1990s, the IT-Bubble and the Subprime -crisis. Firstly, the winner and loser portfolios superiority is counted by using the cumulative excess returns from the examination period. The portfolios were formed by counting the excess returns and locating them in to the order of superiority. The excess returns are counted by using one year pre-data before the actual examination period. The results of this part did not support the results of De Bondt & Thaler’s (1985) paper. Secondly, it is investigated how the Finnish and the US macroeconomic factors are seen to be affecting the stock market valuation in Finnish Stock Markets during economic crises. This is done to explain better the changes in the successes of the winner-loser performance. The crises included different amount of selected macro factors. Two latest crises involved as well few selected US macro factors. Exclusively the IT-Bubble -crisis had the most statistically significant results with the US factors. Two other crises did not receive statistically significant results. An extra research was produced to study do the US macro factors impact more significantly on Finnish stock exchange after lags. The selected lags were three, six, nine and twelve months. Three and six month lagged US macro factors during the IT-Bubble -crisis improved the results. The extra research did not improve the results of the Subprime -crisis.

Centralized Motion Control of a Linear Tooth Belt Drive: Analysis of the Performance and Limitations

A centralized robust position control for an electrical driven tooth belt drive is designed in this doctoral thesis. Both a cascaded control structure and a PID based position controller are discussed. The performance and the limitations of the system are analyzed and design principles for the mechanical structure and the control design are given. These design principles are also suitable for most of the motion control applications, where mechanical resonance frequencies and control loop delays are present. One of the major challenges in the design of a controller for machinery applications is that the values of the parameters in the system model (parameter uncertainty) or the system model it self (non-parametric uncertainty) are seldom known accurately in advance. In this thesis a systematic analysis of the parameter uncertainty of the linear tooth beltdrive model is presented and the effect of the variation of a single parameter on the performance of the total system is shown. The total variation of the model parameters is taken into account in the control design phase using a Quantitative Feedback Theory (QFT). The thesis also introduces a new method to analyze reference feedforward controllers applying the QFT. The performance of the designed controllers is verified by experimentalmeasurements. The measurements confirm the control design principles that are given in this thesis.

Mutual Fund Performance and the Market Timing Ability - Finnish Evidence

The purpose of this thesis is to examine the performance of Finnish equity funds and their market timing ability. Fund performance is evaluated by using annual returns and various risk-adjusted measures, including Sharpe ratio, DDSR, SKASR, Treynor ratio and Jensen’s alpha, whereas portfolio manager’s timing ability is examined with Treynor-Mazuy model and Henriksson-Merton model. The data is collected from the Finnish fund market during the sample period from January 1997 to February 2010. Results show that Finnish equity funds have been able to outperform the market return on a risk-adjusted basis, but these results are influenced heavily by the exceptionally good performance during the IT-bubble. Market timing models show that fund managers have been, to some degree, able to time the market but not a single fund have been able to possess security selection ability and market timing ability simultaneously.

Performance and scalability of isolated DC-DC converter topologies in low voltage, high current applications

Fuel cells are a promising alternative for clean and efficient energy production. A fuel cell is probably the most demanding of all distributed generation power sources. It resembles a solar cell in many ways, but sets strict limits to current ripple, common mode voltages and load variations. The typically low output voltage from the fuel cell stack needs to be boosted to a higher voltage level for grid interfacing. Due to the high electrical efficiency of the fuel cell, there is a need for high efficiency power converters, and in the case of low voltage, high current and galvanic isolation, the implementation of such converters is not a trivial task. This thesis presents galvanically isolated DC-DC converter topologies that have favorable characteristics for fuel cell usage and reviews the topologies from the viewpoint of electrical efficiency and cost efficiency. The focus is on evaluating the design issues when considering a single converter module having large current stresses. The dominating loss mechanism in low voltage, high current applications is conduction losses. In the case of MOSFETs, the conduction losses can be efficiently reduced by paralleling, but in the case of diodes, the effectiveness of paralleling depends strongly on the semiconductor material, diode parameters and output configuration. The transformer winding losses can be a major source of losses if the windings are not optimized according to the topology and the operating conditions. Transformer prototyping can be expensive and time consuming, and thus it is preferable to utilize various calculation methods during the design process in order to evaluate the performance of the transformer. This thesis reviews calculation methods for solid wire, litz wire and copper foil winding losses, and in order to evaluate the applicability of the methods, the calculations are compared against measurements and FEM simulations. By selecting a proper calculation method for each winding type, the winding losses can be predicted quite accurately before actually constructing the transformer. The transformer leakage inductance, the amount of which can also be calculated with reasonable accuracy, has a significant impact on the semiconductor switching losses. Therefore, the leakage inductance effects should also be taken into account when considering the overall efficiency of the converter. It is demonstrated in this thesis that although there are some distinctive differences in the loss distributions between the converter topologies, the differences in the overall efficiency can remain within a range of a few percentage points. However, the optimization effort required in order to achieve the high efficiencies is quite different in each topology. In the presence of practical constraints such as manufacturing complexity or cost, the question of topology selection can become crucial.

Analysis of corporate social responsibility (CSR) performance and financial performance of selected mining companies

The global concern about sustainability has been growing and the mining industry is questioned about its environmental and social performance. Corporate social responsibility (CSR) is an important issue for the extractive industries. The main objective of this study was to investigate the relationship between CSR performance and financial performance of selected mining companies. The study was conducted by identifying and comparing a selection of available CSR performance indicators with financial performance indicators. Based on the result of the study, the relationship between CSR performance and financial performance is unclear for the selected group of companies. The result is mixed and no industry specific realistic way to measure CSR performance uniformly is available. The result as a whole is contradictory and varies at company level as well as based on the selected indicators. The result of this study confirms that the relationship between CSR performance and financial performance is complicated and difficult to determine. As an outcome, evaluation of benefits of CSR in the mining sector could better be analyzed based on different attributes.

Railways, Airports and Sea Container Operators as Publicly Listed Companies – Financial Performance and Shareholder Value Creation Perspective

Logistics infrastructure and transportation services have been the liability of countries and governments for decades, or these have been under strict regulation policies. One of the first branches opened for competition in EU as well as in other continents, has been air transports (operators, like passenger and freight) and road transports. These have resulted on lower costs, better connectivity and in most of the cases higher service quality. However, quite large amount of other logistics related activities are still directly (or indirectly) under governmental influence, e.g. railway infrastructure, road infrastructure, railway operations, airports, and sea ports. Due to the globalization, governmental influence is not that necessary in this sector, since transportation needs have increased with much more significant phase as compared to economic growth. Also freight transportation needs do not correlate with passenger side, due to the reason that only small number of areas in the world have specialized in the production of particular goods. Therefore, in number of cases public-private partnership, or even privately owned companies operating in these sub-branches have been identified as beneficial for countries, customers and further economic growth. The objective of this research work is to shed more light on these kinds of experiments, especially in the relatively unknown sub-branches of logistics like railways, airports and sea container transports. In this research work we have selected companies having public listed status in some stock exchange, and have needed amount of financial scale to be considered as serious company rather than start-up phase venture. Our research results show that railways and airports usually need high fixed investments, but have showed in the last five years generally good financial performance, both in terms of profitability and cash flow. In contrary to common belief of prosperity in globally growing container transports, sea vessel operators of containers have not shown that impressive financial performance. Generally margins in this business are thin, and profitability has been sacrificed in front of high growth – this also concerns cash flow performance, which has been lower too. However, as we examine these three logistics sub-branches through shareholder value development angle during time period of 2002-2007, we were surprised to find out that all of these three have outperformed general stock market indexes in this period. More surprising is the result that financially a bit less performing sea container transportation sector shows highest shareholder value gain in the examination period. Thus, it should be remembered that provided analysis shows only limited picture, since e.g. dividends were not taken into consideration in this research work. Therefore, e.g. US railway operators have disadvantage to other in the analysis, since they have been able to provide dividends for shareholders in long period of time. Based on this research work we argue that investment on transportation/logistics sector seems to be safe alternative, which yields with relatively low risk high gain. Although global economy would face smaller growth period, this sector seems to provide opportunities in more demanding situation as well.