Spatial and temporal variation in fish populations and assemblages in coastal waters of the northern Baltic Proper

The distribution and traits of fish are of interest both ecologically and socio-economically. In this thesis, phenotypic and structural variation in fish populations and assemblages was studied on multiple spatial and temporal scales in shallow coastal areas in the archipelago of the northern Baltic Proper. In Lumparn basin in Åland Islands, the fish assemblage displayed significant seasonal variation in depth zone distribution. The results indicate that investigating both spatial and temporal variation in small scale is crucial for understanding patterns in fish distribution and community structure in large scale. The local population of Eurasian perch Perca fluviatilis L displayed habitat-specific morphological and dietary variation. Perch in the pelagic zone were on average deeper in their body shape than the littoral ones and fed on fish and benthic invertebrates. The results differ from previous studies conducted in freshwater habitats, where the pelagic perch typically are streamlined in body shape and zooplanktivorous. Stable isotopes of carbon and nitrogen differed between perch with different stomach contents, suggesting differentiation of individual diet preferences. In the study areas Lumparn and Ivarskärsfjärden in Åland Islands and Galtfjärden in Swedish east coast, the development in fish assemblages during the 2000’s indicated a general shift towards higher abundances of small-bodied lower-order consumers, especially cyprinids. For European pikeperch Sander lucioperca L., recent declines in adult fish abundances and high mortalities (Z = 1.06–1.16) were observed, which suggests unsustainably high fishing pressure on pikeperch. Based on the results it can be hypothesized that fishing has reduced the abundances of large predatory fish, which together with bottom-up forcing by eutrophication has allowed the lower-order consumer species to increase in abundances. This thesis contributes to the scientific understanding of aquatic ecosystems with new descriptions on morphological and dietary adaptations in perch in brackish water, and on the seasonal variation in small-scale spatial fish distribution. The results also demonstrate anthropogenic effects on coastal fish communities and underline the urgency of further reducing nutrient inputs and regulating fisheries in the Baltic Sea region.

Spatiotemporal Features of Coastal Waters in Southwest Finland

In coastal waters, physico-chemical and biological properties and constituents vary at different time scales. In the study area of this thesis, within the Archipelago Sea in the northern Baltic Sea, seasonal cycles of light and temperature set preconditions for intra-annual variations, but developments at other temporal scales occur as well. Weather-induced runoffs and currents may alter water properties over the short term, and the consequences over time of eutrophication and global changes are to a degree unpredictable. The dynamic characteristics of northern Baltic Sea waters are further diversified at the archipelago coasts. Water properties may differ in adjacent basins, which are separated by island and underwater thresholds limiting water exchange, making the area not only a mosaic of islands but also one of water masses. Long-term monitoring and in situ observations provide an essential data reserve for coastal management and research. Since the seasonal amplitudes of water properties are so high, inter-annual comparisons of water-quality variables have to be based on observations sampled at the same time each year. In this thesis I compare areas by their temporal characteristics, using both inter-annual and seasonal data. After comparing spatial differences in seasonal cycles, I conclude that spatial comparisons and temporal generalizations have to be made with caution. In classifying areas by the state of their waters, the results may be biased even if the sampling is annually simultaneous, since the dynamics of water properties may vary according to the area. The most comprehensive view of the spatiotemporal dynamics of water properties would be achieved by means of comparisons with data consisting of multiple annual samples. For practical reasons, this cannot be achieved with conventional in situ sampling. A holistic understanding of the spatiotemporal features of the water properties of the Archipelago Sea will have to be based on the application of multiple methods, complementing each other’s spatial and temporal coverage. The integration of multi-source observational data and time-series analysis may be methodologically challenging, but it will yield new information as to the spatiotemporal regime of the Archipelago Sea.

Vibration analysis of a power take-off line

Gear rattle is a phenomenon that occurs when idling or lightly loaded gears collide due to engine’s torque fluctuations. This behaviour is related to vibration behaviour of the transmission system. Aim of this master’s thesis is to evaluate Adams and Adams/Machinery as a simulation tools for modelling the rattle e ect in a transmission system. A case study of tractor’s power take-o driveline, suspected to be prone to rattle, is performed in this work. Modelling methods used by Adams in this type of study are presented in the theory section while simulation model build with the software during this work is presented in the results. The Machinery toolbox is used to create gears and bearings while other model components are created with standard Adams tool set. Geometries and excitations are exported from other softwares. Results were obtained from multiple variations of a base model. These result sets and literature review suggest that Adams/Machinery may not be the most suitable tool for rattle analysis. While the system behaviour was partially captured, for accurate modelling user-written routines must be used which may be more easily performed with other tools. Further research about this topic is required.

Post-transaction brand and model line-up integration in the automotive industry: Case studies of European companies as target of acquisitions by Chinese and Indian multinational corporations

Corporations practice company acquisitions in order to create shareholder’s value. During the last few decades, the companies in emerging markets have become active in the acquisition business. During the last decade, large and significant acquisitions have occurred especially in automotive industry. While domestic markets have become too competitive and companies are lacking required capabilities, they seek possibilities to expand into Western markets by attaining valuable assets through acquisitions of developed country corporations. This study discusses the issues and characteristics of these acquisitions through case studies. The purpose of this study was to identify the acquisition motives and strategies for post-transaction brand and product integration as well as analyze the effect of the motives to the integration strategy. The cases chosen for the research were Chinese Geely acquiring Swedish Volvo in 2010 and Indian Tata Motors buying British Jaguar Land Rover in 2008. The main topics were chosen according to their significance for companies in automotive industry as well as those are most visible parts for consumers. The study is based on qualitative case study methods, analyzing secondary data from academic papers and news articles as well as companies’ own announcements e.g. stock exchange and press releases. The study finds that the companies in the cases mainly possessed asset-seeking and market-seeking motives. In addition, the findings refer to rather minimal post-acquisition brand and product integration strategies. Mainly the parent companies left the target company autonomous to make their own business strategies and decisions. The most noticeable integrations were in the product development and production processes. Through restructuring the product architectures, the companies were able to share components and technology between product families and brands, which results in cutting down costs and in increase of profitability and efficiency. In the Geely- Volvo case, the strategy focused more on component sharing and product development know-how, whereas in Tata Motors-Jaguar Land Rover case, the main actions were to cut down costs through component sharing and combine production and distribution networks especially in Asian markets. However, it was evident that in both cases the integration and technology sharing were executed cautiously to prevent on harming the valuable image of the luxury brand. This study has concluded that the asset-seeking motives have significant influence on the posttransaction brand and model line-up integration strategies. By taking a cautious approach in acquiring assets, such as luxury brand, the companies in the cases have implemented a successful post-acquisition strategy and managed to create value for the shareholders at least in short-term. Yritykset harjoittavat yritysostoja luodakseen osakkeenomistajille lisäarvoa. Viimeisten muutamien vuosikymmenien aikana yritykset kehittyvissä maissa ovat myös aktivoituneet yritysostoissa. Viimeisen vuosikymmenen aikana erityisesti autoteollisuudessa on esiintynyt suuria ja merkittäviä yritysostoja. Koska kilpailu kotimaan markkinoilla on kiristynyt ja yritykset ovat vailla vaadittavia valmiuksia, ne etsivät mahdollisuuksiaan laajentaa länsimaisiin markkinoihin hankkimalla arvokkaita etuja kehittyneiden maiden yrityksistä yritysostojen avulla. Tämä tutkimus pohtii näiden yritysostojen olennaisia kysymyksiä ja ominaisuuksia casetutkimuksien kautta. Tutkimuksen tarkoitus oli tunnistaa sekä yritysostojen motiiveja ja brändi- ja mallisto-integraation strategioita että analysoida kyseisten motiivien vaikutusta integraatiostrategiaan. Tapaus-tutkimuksiksi valittiin kiinalaisen Geelyn yritysosto ruotsalaisesta Volvosta vuonna 2010 ja intialaisen Tata Motorsin yritysosto englantilaisesta Jaguar Land Roverista vuonna 2008. Tutkimus on kvalitatiivinen case-tutkimus ja siinä analysoidaan toissijaista tietoa sekä akateemisten ja uutisartikkeleiden että yritysten omien ilmoitusten, kuten pörssi- ja lehdistötiedotteiden, kautta. Tutkimuksen tulokset osoittavat, että tutkittujen yritysten toiminnat perustuivat motiiveihin, joita ajoivat etujen and uusien markkinoiden tarve. Sen lisäksi tutkimustulokset osoittivat, että yritysoston jälkeinen brändi- ja mallisto-integraatio pidettiin minimaalisena. Pääasiallisesti kohdeyrityksille jätettiin autonomia tehdä omat liikkeenjohdolliset päätökset yritysstrategioihin liittyen. Huomattavimmat integraatiot koskivat tuotekehityksellisiä ja tuotannollisia prosesseja. Kehittämällä uudelleen tuotearkkitehtuureja, yritykset pystyivät jakamaan komponentteja ja teknologiaa tuoteperheiden ja brändien välillä. Tämä mahdollisti kustannusleikkauksia sekä kannattavuuden ja tehokkuuden parantamista. Geely-Volvo –tapauksessa integraatiostrategia keskittyi komponenttien jakamiseen yhteisten tuotearkkitehtuurien avulla ja tuotekehityksen ammattitaitoon, kun taas Tata Motors-JLR –tapauksessa päätoiminnat olivat kustannuksien leikkaus sekä tuotannon ja jakeluverkoston yhdistäminen erityisesti Aasian maissa. Yhteistä yrityskaupoissa oli, että brändi- ja mallisto-integraatio sekä teknologian jakaminen suoritettiin varoen ehkäistäkseen arvokkaiden luksus-brändien tuotekuvan vahingoittamista. Tutkimuksen lopputulokset osoittavat, että yrityskaupan motiiveilla on huomattava vaikutus brändija mallisto-integraation strategiaan. Toteuttamalla varovaista lähestymistapaa luksus-brändin hankinnassa ja integraatiossa, yritykset ovat onnistuneet luomaan lisäarvoa osakkeenomistajille vähintään lyhyellä aikavälillä.

Control of a line robot system with Embedded Linux

Many, if not all, aspects of our everyday lives are related to computers and control. Microprocessors and wireless communications are involved in our lives. Embedded systems are an attracting field because they combine three key factors, small size, low power consumption and high computing capabilities. The aim of this thesis is to study how Linux communicates with the hardware, to answer the question if it is possible to use an operating system like Debian for embedded systems and finally, to build a Mechatronic real time application. In the thesis a presentation of Linux and the Xenomai real time patch is given, the bootloader and communication with the hardware is analyzed. BeagleBone the evaluation board is presented along with the application project consisted of a robot cart with a driver circuit, a line sensor reading a black line and two Xbee antennas. It makes use of Xenomai threads, the real time kernel. According to the obtained results, Linux is able to operate as a real time operating system. The issue of future research is the area of embedded Linux is also discussed.

Evaluation of the Efficiency of Line-Start Permanent-Magnet Machines as a Function of the Operating Temperature

The standard squirrel-cage induction machine has nearly reached its maximum efficiency. In order to further increase the energy efficiency of electrical machines, the use of permanent magnets in combination with the robust design and the line start capability of the induction machine is extensively investigated. Many experimental designs have been suggested in literature, but recently, these line-start permanent-magnet machines (LSPMMs) have become off-the-shelf products available in a power range up to 7.5 kW. The permanent magnet flux density is a function of the operating temperature. Consequently, the temperature will affect almost every electrical quantity of the machine, including current, torque, and efficiency. In this paper, the efficiency of an off-the-shelf 4-kW three-phase LSPMM is evaluated as a function of the temperature by both finite-element modeling and by practical measurements. In order to obtain stator, rotor, and permanent magnet temperatures, lumped thermal modeling is used.

Efficient Algorithms for Coastal Geographic Problems

The increasing performance of computers has made it possible to solve algorithmically problems for which manual and possibly inaccurate methods have been previously used. Nevertheless, one must still pay attention to the performance of an algorithm if huge datasets are used or if the problem iscomputationally difficult. Two geographic problems are studied in the articles included in this thesis. In the first problem the goal is to determine distances from points, called study points, to shorelines in predefined directions. Together with other in-formation, mainly related to wind, these distances can be used to estimate wave exposure at different areas. In the second problem the input consists of a set of sites where water quality observations have been made and of the results of the measurements at the different sites. The goal is to select a subset of the observational sites in such a manner that water quality is still measured in a sufficient accuracy when monitoring at the other sites is stopped to reduce economic cost. Most of the thesis concentrates on the first problem, known as the fetch length problem. The main challenge is that the two-dimensional map is represented as a set of polygons with millions of vertices in total and the distances may also be computed for millions of study points in several directions. Efficient algorithms are developed for the problem, one of them approximate and the others exact except for rounding errors. The solutions also differ in that three of them are targeted for serial operation or for a small number of CPU cores whereas one, together with its further developments, is suitable also for parallel machines such as GPUs.

Geographical Studies of Underwater Light Dynamics in the Coastal Archipelago of SW Finland, Baltic Sea

The underwater light field is an important environmental variable as it, among other things, enables aquatic primary production. Although the portion of solar radiation that is referred to as visible light penetrates water, it is restricted to a limited surface water layer because of efficient absorption and scattering processes. Based on the varying content of optical constituents in the water, the efficiency of light attenuation changes in many dimensions and over various spatial and temporal scales. This thesis discusses the underwater light dynamics of a transitional coastal archipelago in south-western Finland, in the Baltic Sea. While the area has long been known to have a highly variable underwater light field, quantified knowledge on the phenomenon has been scarce, patchy, or non-existent. This thesis focuses on the variability in the underwater light field through euphotic depths (1% irradiance remaining), which were derived from in situ measurements of vertical profiles of photosynthetically active radiation (PAR). Spot samples were conducted in the archipelago of south-western Finland, mainly during the ice-free growing seasons of 2010 and 2011. In addition to quantifying both the seasonal and geographical patterns of euphotic depth development, the need and usability of underwater light information are also discussed. Light availability was found to fluctuate in multiple dimensions and scales. The euphotic depth was shown to have combined spatio-temporal dynamics rather than separate changes in spatial and temporal dimensions. Such complexity in the underwater light field creates challenges in data collection, as well as in its utilisation. Although local information is needed, in highly variable conditions spot sampled information may only poorly represent its surroundings. Moreover, either temporally or spatially limited sampling may cause biases in understanding underwater light dynamics. Consequently, the application of light availability data, for example in ecological modelling, should be made with great caution.