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  • Järvinen, Ilpo (Helsingin yliopisto, 2006)
    Wireless access is expected to play a crucial role in the future of the Internet. The demands of the wireless environment are not always compatible with the assumptions that were made on the era of the wired links. At the same time, new services that take advantage of the advances in many areas of technology are invented. These services include delivery of mass media like television and radio, Internet phone calls, and video conferencing. The network must be able to deliver these services with acceptable performance and quality to the end user. This thesis presents an experimental study to measure the performance of bulk data TCP transfers, streaming audio flows, and HTTP transfers which compete the limited bandwidth of the GPRS/UMTS-like wireless link. The wireless link characteristics are modeled with a wireless network emulator. We analyze how different competing workload types behave with regular TPC and how the active queue management, the Differentiated services (DiffServ), and a combination of TCP enhancements affect the performance and the quality of service. We test on four link types including an error-free link and the links with different Automatic Repeat reQuest (ARQ) persistency. The analysis consists of comparing the resulting performance in different configurations based on defined metrics. We observed that DiffServ and Random Early Detection (RED) with Explicit Congestion Notification (ECN) are useful, and in some conditions necessary, for quality of service and fairness because a long queuing delay and congestion related packet losses cause problems without DiffServ and RED. However, we observed situations, where there is still room for significant improvements if the link-level is aware of the quality of service. Only very error-prone link diminishes the benefits to nil. The combination of TCP enhancements improves performance. These include initial window of four, Control Block Interdependence (CBI) and Forward RTO recovery (F-RTO). The initial window of four helps a later starting TCP flow to start faster but generates congestion under some conditions. CBI prevents slow-start overshoot and balances slow start in the presence of error drops, and F-RTO reduces unnecessary retransmissions successfully.
  • Luukkainen, Pekka (2003)
    Sydän- ja verisuonitaudit nousivat teollisuusmaissa suurimmaksi julkisen terveydenhuollon ongelmaksi 1940-luvulla, tartuntatautien hävittyä lääketieteen kehityksen seurauksena. Suomi saavutti jopa kyseenalaista kunniaa 1950- ja 1960-luvuilla korkeimmilla mitatuilla sydän- ja verisuonitautikuolleisuusluvuilla maailmassa. Kuolleisuudessa on kuitenkin havaittu selviä alueellisia eroja, ja varsinkin Itä-Suomi on kärsinyt erittäin korkeasta sydän- ja verisuonitautikuolleisuudesta. Useissa tutkimuksissa on todettu kohonneen verenpaineen, korkean kolesterolin, ylipainon ja tupakoinnin olevan tärkeimpiä sydän- ja verisuonitautien riskitekijöitä. Näihin tekijöihin yksilö voi kuitenkin helposti vaikuttaa muokkaamalla elintapojaan ja ruokavaliotaan. Tässä tutkielmassa on seurattu vuodesta 1959 lähtien kahta vuosina 1900-1919 syntyneiden miesten kohorttia Itä- ja Länsi-Suomesta. Tarkoituksena oli selvittää eroja alueiden kuolleisuudessa ja riskitekijöiden kehityksessä kilpailevien kuolinsyiden näkökulmasta käyttäen Coxin verrannollisten hasardien mallia. Tutkimuksen kuluessa huomattiin sydän- ja verisuonitautikuolleisuuden alueellisten erojen vähentyneen, sekä kolesterolin ja tupakoinnin olevan merkittävimpiä riskitekijöitä ikääntyneiden ihmisten joukossa.
  • Luukkainen, Pekka (2003)
    Cardiovascular diseases became the leading public health problem in the developed countries in the late 1940s. Finland has obtained questionable fame for having even the highest coronary heart disease mortality in the world. Previous studies have shown that there are clear regional differencies in mortality due to cardiovascular diseases, especially eastern Finland has suffered from exeptionally high cardiovascular disease mortality. Elevated blood pressure, high total cholesterol, obesity and smoking are suggested to be the main risk factors for the cardiovascular diseases. These factors could be easily affected by making changes in the way of life and dietary habits. In this thesis, we studied two cohorts consisting men born between 1900-1919 from east and west Finland. Cohorts have been examined since year 195$ The aim was to clarify the differensies in the mortality between the cohorts and in the risk factor levels by using competing risks. Data was analysed with Cox's proportional hazards model. During the follow-up study, differensies between the cohorts in mortality due to cardiovascular diseases diminished. According to this study the main risk factors for aging population are high total cholesterol and smoking.
  • Döhla, Julia Maria (2013)
    Peroxisome proliferator activated receptor γ coactivator 1α (PGC-1α) is a transcriptional coactivator involved in mitochondrial biogenesis, oxidative stress response, and energy metabolism. PGC-1α is part of an energy sensing network that translates environmental influences into alterations in gene expression of mainly mitochondrial molecular pathways. A role in neuroprotection has been implicated for PGC-1α in the context of mitochondrial expression networks. Our research group has previously established a transgenic mouse line with stable overexpression of PGC-1α in brain neurons. Transgenic overexpression of PGC-1α is associated with an enhanced functional state of mitochondrial energy production. In the context of neurodegenerative processes, brain neurons of PGC-1α transgenic mice are protected against oxidative stressors in the MPTP mouse model of Parkinson’s Disease. To further characterize the transcriptional activity of PGC-1α regulated gene networks in brains of transgenic mice, a quantitative real-time PCR based system was established. Gene expression was measured for a subset of genes found to be differentially regulated in a microarray based screening of RNA obtained from hippocampus and cortex of PGC-1α transgenic mice. Increased PGC-1α gene expression was found in hippocampus and cortex of PGC-1α transgenic mice, and their translation into protein was confirmed immunohistochemically. Expression analysis revealed significant changes in mRNA levels of PGC-1α controlled molecular pathways involved in mitochondrial energy production and antioxidant responses. Furthermore, alterations in the expression of some non-mitochondrial genes with established links to neurodegeneration were observed. Furthermore, a change in GABAA receptor subunit expression was detected. In accordance with previous studies on the PGC-1α transgenic mouse line, these findings suggest that differential gene expression associated with PGC-1α overexpression contributes to an enhanced functional state of neurons in hippocampus and cortex of PGC-1α transgenic mice. Increased knowledge about the transcriptional modulation of neuronal genes regulated by PGC-1α can lead to better insights into mechanisms governing neurodegeneration and neuroprotective pathways. Pharmacological modulation of PGC-1α activity may be a feasible approach for neuroprotective treatments in neurodegenerative diseases, such as Parkinson’s Disease.
  • Selin, Markus (2012)
    This thesis is constructed as a part of a larger research project aiming to increase understanding of polyketone reductases (PKR) and develop applications from them. PKRs are enzymes in biosynthetic pathways leading to several aromatic secondary metabolites in plants. The previous work in the research group has led to establishment of several callus cultures from plants belonging to the genus Rubus in the family Rosaceae. The aim in the experimental part of this thesis is the identification and semi-quantitation of raspberry ketone (RK) and related aromatics in the cell suspension cultures initiated from the previously established callus cultures. RK is biosynthetically produced by reduction of p-hydroxybenzalacetone (p-OH-BA) by benzalacetone reductase (BAR). As a part of the experimental work, p-OH-BA has to be chemically synthetized and analysed. Special emphasis is placed to experiment, develop and validate an extraction method for phenolic compounds using ASE 200 working station. In the review part of this thesis, the basic procedures of chemical analysis are described, optimization and validation of analytical methods are discussed, and lastly studies related to raspberry ketone (RK) are summarized. The detection limit is 0.73 μg/ml for RK with the established UPLC-UV method, and the quantitation limit (QL) is 2.22 μg/ml. At the QL, the standard deviation of the extraction method is 8.9 % and the results are 6.4 % higher than expected. At the high end of the standard curve the extraction results are 18.7 % higher than expected. Some changes are proposed to optimize the method. Analysis of the cell line extracts with the established UPLC-UV method did not readily reveal any of the studied compounds. Although the interpretation of the results of the MS experiment is still underway, RK was detected from the arctic bramble cell line Ra15. Also, a possible derivative of zingerone was detected from cloudberry cell line extract even without the corresponding standard compound. This shows the power of the MS in metabolite profiling, and gives a course for future studies.
  • Islam, Hasan Mahmood Aminul (2013)
    The Web has introduced a new technology in a more distributed and collaborative form of communication, where the browser and the user replace the web server as the nexus of communications in a way that after the call establishment through web servers, the communication is performed directly between browsers as peer to peer fashion without intervention of the web servers. The goal of Real Time Collaboration on the World Wide Web (RTCWeb) project is to allow browsers to natively support voice, video, and gaming in interactive peer to peer communications and real time data collaboration. Several transport protocols such as TCP, UDP, RTP, SRTP, SCTP, DCCP presently exist for communication of media and non-media data. However, a single protocol alone can not meet all the requirements of RTCWeb. Moreover, the deployment of a new transport protocol experiences problems traversing middle boxes such as Network Address Translation (NAT) box, firewall. Nevertheless, the current implementation for transportation of non-media in the very first versions of RTCWeb data does not include any congestion control on the end-points. With media (i.e., audio, video) the amount of traffic can be determined and limited by the codec and profile used during communication, whereas RTCWeb user could generate as much as non-media data to create congestion on the networks. Therefore, a suitable transport protocol stack is required that will provide congestion control, NAT traversal solution, and authentication, integrity, and privacy of user data. This master’s thesis will give emphasis on the analysis of transport protocol stack for data channel in RTCWeb and selects Stream Control Transmission Protocol (SCTP), which is a reliable, message oriented general-purpose transport layer protocol, operating on top of both IPv4 and IPv6, providing congestion control similar to TCP and additionally, some new functionalities regarding security, multihoming, multistreaming, mobility, and partial reliability. However, due to the lack of universal availability of SCTP within the OS(s), it has been decided to use the SCTP userland implementation. WebKit is an open source web browser engine for rendering web pages used by Safari, Dashboard, Mail, and many other OS X applications. In WebKit RTCWeb implementation using GStreamer multimedia framework, RTP/UDP is utilized for the communication of media data and UDP tunnelling for non-media data. Therefore, in order to allow a smooth integration of the implementation within WebKit, we have decided to implement GStreamer plugins using SCTP userland stack.. This thesis work also investigates the way Mozilla has integrated those protocols in the browser’s network stack and how the Data Channel has been designed and implemented using SCTP userland stack.
  • Lizcano, Raymundo (2013)
    In the literature part an introduction to emerging organic contaminants is presented as well as the subcategory of endocrine disrupting chemicals, which includes steroid hormones. An overview of liquid chromatography trends in environmental analysis as well as mass spectrometry operational conditions are discussed. Review is focused on ionization techniques and tandem mass spectrometry functionalities reported on state of the art studies of steroidal compounds in environmental samples. Experimental part presents an extensive sample preparation method and a liquid chromatography – mass spectrometry (HPLC-MS) method that were developed for the determination of concentration of eleven steroidal compounds: 4-androstene-3,17-dione (A1), trans-androsterone (A2), Corticosterone (C1), Cortisone (C2), Estrone (E1), 17-β-estradiol (E2), Estriol (E3), 17-α-ethynil estradiol (EE2), Progesterone (P), 17-hydroxy progesterone (HP) and Testosterone (T). Separation efficiency and analysis time were compared for three HPLC columns with different stationary phase: Pentafluorophenyl (PFP), C8 and C18 monolithic. Three atmospheric pressure ionization (API) techniques were tested to compare their performance: Electrospray ionization (ESI), Atmospheric Pressure Chemical Ionization (APCI) and Atmospheric Pressure Photoionization (APPI). The proposed method included the best column choice coupled with the API technique, which presented an efficient ionization for most of the target analytes. Best methodology was applied to the analysis of effluent and influent samples from the wastewater treatment plant in Viikinmäki, Helsinki.
  • Kamlang-ek, Pimwalee (2012)
    The literature survey reviewed principles of oxidation of edible oils, adverse effects of lipid oxidation and analysis of volatile oxidation products by SPME-GC-MS. The main aim of the experimental research was to study the influence of relative humidity (RH) on the release of volatile oxidation products from spray-dried emulsions with natural and cross-linked casein as emulsifier. The release of volatiles was determined by SPME-GC-MS. The sub aims were to study the effects of stabilization time at specific RHs, of temperature and agitation speed during the SPME extraction. The spray-dried emulsions were oxidised at 40oC in order to reach a certain level of oxidation. Next, the powders were stabilised under five RHs (0%, 11%, 33%, 54% and 75%) for one or two weeks in order to observe the effect of the RH and the stabilisation time on the release of volatiles. After adjusting the RHs, volatile compounds were analysed by SPME-GC-MS. The following SPME extraction conditions were tested: C1: temperature 40oC, agitation speed 250 rpm, C2: 50oC, 250 rpm, C3: 40oC, 500 rpm and C4: 50oC, 500 rpm. Identification of the compounds was carried out by matching their MS spectra with the NIST database. Altogether 45 volatiles released from the powders could be identified, and 18 of them were found in most samples. RH had an important effect on the release of volatiles from the encapsulated samples. The highest release was always observed at 11% and 33% RH, whereas the lowest release was found at 0% and/or 75% RH, depending on the SPME extraction conditions. The stabilisation time did not have a significant effect on the release of volatiles in most RHs. During the SPME extraction step, elevation of the temperature from 40oC to 50oC, as well as the agitation speed from 250 rpm to 500 rpm, facilitated higher release. However, the effect of temperature was greater than that of agitation speed. Although it was suspected that cross-linking of sodium-caseinate would enhance retention of volatiles, our experiment showed greater peak areas of most volatiles from the cross-linked samples than from the natural ones. By controlling the SPME parameters, it was possible to obtain repeatable volatile compound results. The SPME-GC-MS method applied in this study can be reliably used to analyse volatile oxidation products from spray-dried emulsions. Only at very low or high RH the release of volatiles may differ from samples stored at 11% -54% RH.
  • Javanainen, Timo (2007)
    Market risk is among the most important sources of risk for companies in the financial and commodity markets. Proper estimation of market risk has become very important in the electricity market, where volatility is very high and trading volumes continue to increase. Value at Risk (VaR) is the most widely used approach to quantify market risk. The aim of this thesis is to study how well analytical VaR methods can be applied to trading portfolios of electricity derivatives. The objectives of the thesis are: 1. To study how the financial electricity market differs from the financial markets and other commodity markets, and what are the implications of these differences to the estimation of market risk 2. To study which analytical VaR methods provide the best results in the financial and commodity markets 3. To study how well these analytical VaR methods perform in estimating the daily market risk for portfolios of electricity derivatives and conclude the implications of this performance to the Nordic electricity market 4. To give recommendations on how the market risk of portfolios of electricity derivatives should be measured in the financial electricity market. Several studies show that due to the non-storability of electricity, the dynamics of the forward curve in financial electricity market differ from other commodity markets. Both the literature study and statistical analysis done in this thesis reveal that the return distributions of Nord Pool traded electricity forwards exhibit fat tails and are skewed. The non-normality of risk factor returns causes some challenges for VaR estimation. In this thesis, the most prominent analytical VaR methods are identified based on the literature study and assessed with a thorough backtesting procedure. The statistical analysis and backtesting conducted in this thesis are unique in terms of focus and scope. The results show that using the studied VaR methods in the Nordic electricity market underestimates market risk. Practical recommendations on using VaR methods are given to market participants. The MATLAB implementation done in connection to this thesis is of considerable extent and could be used by a small or medium size company to estimate its market risk.
  • Javanainen, Timo (2007)
    Markkinariski on merkittävä riskilähde finanssi- ja hyödykemarkkinoilla toimivilla yrityksillä. Markkinariskin estimoiminen riittävällä tarkkuudella on erittäin tärkeä asia sähkön johdannaismarkkinalla, jossa volatiliteetti on muihin markkinoihin verrattuna hyvin korkea ja kaupankäyntivolyymit jatkavat kasvamistaan. Value at Risk (VaR) on yleisimmin käytetty lähestymistapa markkinariskin kvantifioimiseksi. Tämän Pro gradu -työn tavoitteena on tutkia, kuinka hyvin ns. analyyttiset Value at Risk -menetelmät toimivat sähkön johdannaissalkkujen markkinariskin estimoimisessa. Työn tarkemmat tavoitteet ovat: 1. Tutkia, miten sähkön johdannaismarkkina eroaa finanssimarkkinoista ja muista hyödykemarkkinoista ja miten nämä eroavaisuudet vaikuttavat markkinariskin estimointiin sähkön johdannaismarkkinalla 2. Tutkia, mitkä analyyttiset VaR-menetelmät toimivat parhaiten finanssimarkkinoilla ja muilla hyödykemarkkinoilla markkinariskin estimoimisessa 3. Tutkia, kuinka hyvin analyyttiset VaR-menetelmät toimivat sähkön johdannaissalkun päivittäisen markkinariskin estimoimisessa, ja päätellä tulosten seuraamukset pohjoismaiselle sähkön johdannaismarkkinalle. 4. Antaa suosituksia siitä, miten markkinariskiä tulisi sähkön johdannaismarkkinalla estimoida. Sähkö eroaa muista hyödykkeistä siinä, että sähköä ei pystytä taloudellisesti järkevästi varastoimaan pitkiä aikoja. Useat aiemmat tutkimukset ovat osoittaneet, että todennäköisesti juuri sähkön varastoimattomuus on muovannut sähkön johdannaismarkkinan dynamiikan erilaiseksi kuin muiden hyödykemarkkinoiden dynamiikan. Tämän työn kirjallisuuskatsaus ja empiirinen osa osoittavat, että pohjoismaisen sähköpörssin finanssijohdannaisten tuottojakaumat ovat paksuhäntäisiä ja vinoja. Tämä riskifaktoreiden ei-normaalisuus aiheuttaa tiettyjä haasteita VaR-lukujen estimointiin. Tässä työssä identifioidaan kirjallisuuskatsauksen avulla lupaavimmat analyyttiset VaR-menetelmät ja menetelmiä verrataan toisiinsa ns. backtestauksella. Tässä työssä esitetyt backtesting-tulokset ja tilastollinen analyysi ovat sähkön johdannaismarkkinalla sekä toteutustavaltaan että laajuudeltaan uusia. Työn tulokset osoittavat, että käyttämällä työssä käsiteltyjä VaR-menetelmiä markkinatoimijat aliarvioivat markkinariskiä sähkön johdannaismarkkinalla. Tätä työtä varten rakennettu MATLAB-toteutus on laajuudeltaan mittava ja kelpaisi sinällään pienen- tai keskisuuren yrityksen markkinariskin estimoimiseen.
  • Saikku, Laura (Helsingin yliopisto, 2010)
    Industrial ecology is an important field of sustainability science. It can be applied to study environmental problems in a policy relevant manner. Industrial ecology uses ecosystem analogy; it aims at closing the loop of materials and substances and at the same time reducing resource consumption and environmental emissions. Emissions from human activities are related to human interference in material cycles. Carbon (C), nitrogen (N) and phosphorus (P) are essential elements for all living organisms, but in excess have negative environmental impacts, such as climate change (CO2, CH4 N2O), acidification (NOx) and eutrophication (N, P). Several indirect macro-level drivers affect emissions change. Population and affluence (GDP/capita) often act as upward drivers for emissions. Technology, as emissions per service used, and consumption, as economic intensity of use, may act as drivers resulting in a reduction in emissions. In addition, the development of country-specific emissions is affected by international trade. The aim of this study was to analyse changes in emissions as affected by macro-level drivers in different European case studies. ImPACT decomposition analysis (IPAT identity) was applied as a method in papers I III. The macro-level perspective was applied to evaluate CO2 emission reduction targets (paper II) and the sharing of greenhouse gas emission reduction targets (paper IV) in the European Union (EU27) up to the year 2020. Data for the study were mainly gathered from official statistics. In all cases, the results were discussed from an environmental policy perspective. The development of nitrogen oxide (NOx) emissions was analysed in the Finnish energy sector during a long time period, 1950 2003 (paper I). Finnish emissions of NOx began to decrease in the 1980s as the progress in technology in terms of NOx/energy curbed the impact of the growth in affluence and population. Carbon dioxide (CO2) emissions related to energy use during 1993 2004 (paper II) were analysed by country and region within the European Union. Considering energy-based CO2 emissions in the European Union, dematerialization and decarbonisation did occur, but not sufficiently to offset population growth and the rapidly increasing affluence during 1993 2004. The development of nitrogen and phosphorus load from aquaculture in relation to salmonid consumption in Finland during 1980 2007 was examined, including international trade in the analysis (paper III). A regional environmental issue, eutrophication of the Baltic Sea, and a marginal, yet locally important source of nutrients was used as a case. Nutrient emissions from Finnish aquaculture decreased from the 1990s onwards: although population, affluence and salmonid consumption steadily increased, aquaculture technology improved and the relative share of imported salmonids increased. According to the sustainability challenge in industrial ecology, the environmental impact of the growing population size and affluence should be compensated by improvements in technology (emissions/service used) and with dematerialisation. In the studied cases, the emission intensity of energy production could be lowered for NOx by cleaning the exhaust gases. Reorganization of the structure of energy production as well as technological innovations will be essential in lowering the emissions of both CO2 and NOx. Regarding the intensity of energy use, making the combustion of fuels more efficient and reducing energy use are essential. In reducing nutrient emissions from Finnish aquaculture to the Baltic Sea (paper III) through technology, limits of biological and physical properties of cultured fish, among others, will eventually be faced. Regarding consumption, salmonids are preferred to many other protein sources. Regarding trade, increasing the proportion of imports will outsource the impacts. Besides improving technology and dematerialization, other viewpoints may also be needed. Reducing the total amount of nutrients cycling in energy systems and eventually contributing to NOx emissions needs to be emphasized. Considering aquaculture emissions, nutrient cycles can be partly closed through using local fish as feed replacing imported feed. In particular, the reduction of CO2 emissions in the future is a very challenging task when considering the necessary rates of dematerialisation and decarbonisation (paper II). Climate change mitigation may have to focus on other greenhouse gases than CO2 and on the potential role of biomass as a carbon sink, among others. The global population is growing and scaling up the environmental impact. Population issues and growing affluence must be considered when discussing emission reductions. Climate policy has only very recently had an influence on emissions, and strong actions are now called for climate change mitigation. Environmental policies in general must cover all the regions related to production and impacts in order to avoid outsourcing of emissions and leakage effects. The macro-level drivers affecting changes in emissions can be identified with the ImPACT framework. Statistics for generally known macro-indicators are currently relatively well available for different countries, and the method is transparent. In the papers included in this study, a similar method was successfully applied in different types of case studies. Using transparent macro-level figures and a simple top-down approach are also appropriate in evaluating and setting international emission reduction targets, as demonstrated in papers II and IV. The projected rates of population and affluence growth are especially worth consideration in setting targets. However, sensitivities in calculations must be carefully acknowledged. In the basic form of the ImPACT model, the economic intensity of consumption and emission intensity of use are included. In seeking to examine consumption but also international trade in more detail, imports were included in paper III. This example demonstrates well how outsourcing of production influences domestic emissions. Country-specific production-based emissions have often been used in similar decomposition analyses. Nevertheless, trade-related issues must not be ignored.
  • Iija, Veera (2012)
    The thesis aims at analyzing concept of citizenship in political philosophy. The concept of citizenship is a complex one: it does not have a definitive explication, but it nevertheless is a very important category in contemporary world. Citizenship is a powerful ideal, and often the way a person is treated depends on whether he or she has the status of a citizen. Citizenship includes protection of a person’s rights both at home and abroad. It entails legal, political and social dimension: the legal status as a full member of society, the recognition of that status by fellow citizens and acting as a member of society. The thesis discusses these three dimensions. Its objective is to show how all of them, despite being insufficient in some aspects, reach something important about the concept. The main sources of the thesis are Civic Republicanism by Iseult Honohan (Routledge 2002), Republicanism by Philip Pettit (Clarendon Press 1997), and Taking Rights Seriously by Ronald Dworkin (1997). In addition, the historical part of the thesis relies mainly on the works of Aristotle, Immanuel Kant, Adam Smith, Quentin Skinner, James Pocock and James Tully. The writings of Will Kymlicka, John Rawls, Chantal Mouffe, and Shane Phelan are referred to in the presentation and critique of the liberal tradition of thought. Hannah Arendt and Seyla Benhabib’s analysis of Arendt’s philosophy both address the problematic relations between human rights and nation-states as the main guarantors of rights. The chapter on group rights relies on Peter Jones’ account of corporate and collective rights, after which I continue to Seumas Miller’s essay on the (liberal) account of group rights and their relation to the concept of citizenship. Republicanism and Political Theory (2002) edited by Cécile Laborde and John Maynor is also references. David Miller and Maurizio Viroli represent the more “rooted” version of republicanism. The thesis argues that the full concept of citizenship should be seen as containing legal, political and social dimensions. The concept can be viewed from all of these three angles. The first means that citizenship is connected with certain rights, like the right to vote or stand for election, the right to property and so on. In most societies, the law guarantees these rights to every citizen. Then there is also the social dimension, which can be said to be as important as the legal one: the recognition of equality and identities of others. Finally, there is the political dimension, meaning the importance of citizens’ participation in the society, which is discussed in connection with the contemporary account of republicanism. All these issues are discussed from the point of view of groups demanding for group-specific rights and equal recognition. The challenge with these three aspects of citizenship is, however, that they are difficult to discuss under one heading. Different theories or discourses of citizenship each approach the subject from different starting points, which make reconciling them sometimes hard. The fundamental questions theories try to answer may differ radically depending on the theory. Nevertheless, in order to get the whole image of what the citizenship discourses are about all the aspects deserve to be taken into account.
  • Kuukka, Antti Oskari (2013)
    Työn päätavoitteena on todistaa eräs versio informaatioteorian kuuluisasta tuloksesta, Shannon- McMillan-Breiman -teoreemasta. Koska tämä lause liittyy ergodisiin stokastisiin prosesseihin ja sen todistuksessa tarvitaan ergoditeorian tuloksia, olen ottanut ergoditeorian toiseksi tasavertaiseksi pääaiheeksi Shannon-McMillan-Breiman -teoreeman rinnalle. Lukijalta ei oleteta esitietovaatimuksena ergoditeoriasta tai informaatioteorista mitään. Vaikka mittateoreettisen todennäköisyysteorian ja Markovin ketjujen perusteet oletetaan tunnetuiksi, kappaleessa 0 käydään läpi tiettyjä todennäköisyysteorian osa-alueita, jotka eivät alan peruskursseille mahdu. Näitä ovat esimerkiksi ääretönulotteisiin jonoavaruuksiin konstruoitavat sigma-algebrat, diskreettiaikainen martingaalikonvergenssiteoria, Radon-Nikodym - lauseeseen perustuva ehdollinen todennäköisyys, sekä tasainen integroituvuus. Kappale 1 käsittelee ergoditeoriaa. Koska ergoditeoria on hyvin laaja matematiikan osa-alue, tämä kappale on aiheeseen vain lyhyt johdatus. Eräs alan tärkeimmistä tuloksista, Birkhoffin ergodilause kuitenkin esitetään kappaleessa todistuksineen. Ergoditeorian voidaan ajatella olevan matematiikan osa-alue, joka tutkii ilmiöiden keskimääräistä käyttäytymistä. Birkhoffin ergodilauseesta esimerkiksi seuraa lähes välittömästi vahva suurten lukujen laki sekä se, että pelkistymättömän ja jaksottoman Markovin ketjun tietyssä tilassa viettämä suhteellinen aika on asymptoottisesti sama kuin tasapainojakauman kyseistä tilaa koskeva pistetodennäköisyys. Kappaleen lopuksi määritellään käsite ergodinen stokastinen prosessi, joita Shannon-McMillan-Breiman -lauseen väite koskee. Kappaleen 2 aiheena on informaatioteoria ja Shannon-McMillan-Breiman -lause. Koska lukijalta ei oleteta minkäänlaista etukäteistietoa informaatioteoriasta, kappale alkaa johdatuksella informaatioteoriaan. Johdatuksessa keskitytään ennen kaikkea diskreettien satunnaismuuttujien entropiaan, jota koskevia lauseita ja aputuloksia esitetään runsaasti. Tämän jälkeen satunnaismuuttujien entropiasta siirrytään stokastisten prosessien entropian tutkimiseen, jonka jälkeen on mahdollista esittää käsite asymptoottinen tasapartitiointiominaisuus. Karkeasti ottaen voidaan sanoa, että diskreetillä stokastisella prosessilla on asymptoottinen tasapartitiointiominaisuus, mikäli melkein kaikki sen realisaatiot kuuluvat alkioiden lukumäärältään pieneen, mutta todennäköisyysmassaltaan suureen tyypillisten jonojen joukkoon, joka käsitteenä määritellään kappaleessa tarkasti. Esimerkiksi tasapainoista kolikkoa heitettäessä tyypillisiä jonoja ovat sellaiset realisaatiot, joissa noin puolet heitoista on klaavoja. Paljastuu, että realisaatioiden jakamisella tyypillisiin ja ei-tyypillisiin jonoihin on mielenkiintoisia sovelluksia kuten tiedon tiivistäminen. Shannon-McMillan-Breiman -lause sanoo, että stationaarisella, ergodisella stokastisella prosessilla, jolla on äärellinen tila-avaruus, on asymptoottinen tasapartitiointiominaisuus. Kappaleen 2 pituudesta huomattava osuus liittyy tämän tuloksen todistamiseen. Todistus on monivaiheinen, ja se hyödyntää runsaasti erilaisia tuloksia informaatioteorian ulkopuolelta sekä punoo yhteen työssä aiemmin johdetut tulokset. Birkhoffin ergodilause ja kappaleessa 0 esitettävä Levyn martingaalikonvergenssilause ovat erityisen tärkeässsä roolissa.
  • Tang, Tiantian (2009)
    The objective of this thesis is to assess the recreational value (access value) provided by Yuelu Mountain Park in China applying travel cost method (TCM) which is commonly used to estimate non-market benefits. Also, a fee that would maximize the entrance fee income is tentatively calculated. The potential trips to be lost next year are estimated based on local respondents visiting intentions among different age groups. The travel cost demand function is estimated by using basic count data travel cost model-Poisson regression, and survey data collected on-site. Average access values per trip were estimated to be € 0.75 for local and € 64.52 for non-local individuals producing aggregate annual access value of € 20.43 million. Based on the travel cost demand function, an entrance fee of € 5.43 would maximize the revenue collected from the visitors. This would mean more than doubling of the present entrance fee. The result could potentially be utilized when deciding on the entrance fees. It is also suggested that the park management could further study visitors' intentions and reasons either to visit or not to visit the park in the future. Estimated consumer surpluses as well as suggested entrance fee must however, be considered with caution because truncation of the on-site survey data is not accounted for in the Poisson model estimations of this study.
  • Peltonen, Ella (2013)
    Cloud computing offers important resources, performance, and services nowadays when it has became popular to collect, store and analyze large data sets. This thesis builds on Berkeley Data Analysis Stack (BDAS) as a cloud computing environment designed for Big Data handling and analysis. Especially two parts of the BDAS, the cluster resource manager Mesos and the distribution manager Spark will be introduced. They offer important features, such as efficiency, multi-tenancy, and fault tolerance, for cloud computing. The Spark system expands MapReduce, the well-known cloud computing paradigm. Machine learning algorithms can predict trends and anomalies of large data sets. This thesis will present one of them, a distributed decision tree algorithm, implemented on the Spark system. As an example case, the decision tree will be used on the versatile energy consumption data from mobile devices, such as smart phones and tablets, of the Carat project. The data consists of information about the usage of the device, such as which applications have been running, network connections, battery temperatures, and screen brightness, for example. The decision tree aims to find chains of data features that might lead to energy consumption anomalies. Results of the analysis can be used to advise users on how to improve their battery life. This thesis will present selected analysis results together with advantages and disadvantages of the decision tree analysis.
  • Hutri, Kaisa-Leena (Säteilyturvakeskus (STUK), 2007)
    Olkiluoto Island is situated in the northern Baltic Sea, near the southwestern coast of Finland, and is the proposed location of a spent nuclear fuel repository. This study examined Holocene palaeoseismicity in the Olkiluoto area and in the surrounding sea areas by computer simulations together with acoustic-seismic, sedimentological and dating methods. The most abundant rock type on the island is migmatic mica gneiss, intruded by tonalites, granodiorites and granites. The surrounding Baltic Sea seabed consists of Palaeoproterozoic crystalline bedrock, which is to a great extent covered by younger Mesoproterozoic sedimentary rocks. The area contains several ancient deep-seated fracture zones that divide it into bedrock blocks. The response of bedrock at the Olkiluoto site was modelled considering four future ice-age scenarios. Each scenario produced shear displacements of fractures with different times of occurrence and varying recovery rates. Generally, the larger the maximum ice load, the larger were the permanent shear displacements. For a basic case, the maximum shear displacements were a few centimetres at the proposed nuclear waste repository level, at proximately 500 m b.s.l. High-resolution, low-frequency echo-sounding was used to examine the Holocene submarine sedimentary structures and possible direct and indirect indicators of palaeoseismic activity in the northern Baltic Sea. Echo-sounding profiles of Holocene submarine sediments revealed slides and slumps, normal faults, debris flows and turbidite-type structures. The profiles also showed pockmarks and other structures related to gas or groundwater seepages, which might be related to fracture zone activation. Evidence of postglacial reactivation in the study area was derived from the spatial occurrence of some of the structures, especial the faults and the seepages, in the vicinity of some old bedrock fracture zones. Palaeoseismic event(s) (a single or several events) in the Olkiluoto area were dated and the palaeoenvironment was characterized using palaeomagnetic, biostratigraphical and lithostratigraphical methods, enhancing the reliability of the chronology. Combined lithostratigraphy, biostratigraphy and palaeomagnetic stratigraphy revealed an age estimation of 10 650 to 10 200 cal. years BP for the palaeoseismic event(s). All Holocene sediment faults in the northern Baltic Sea occur at the same stratigraphical level, the age of which is estimated at 10 700 cal. years BP (9500 radiocarbon years BP). Their movement is suggested to have been triggered by palaeoseismic event(s) when the Late Weichselian ice sheet was retreating from the site and bedrock stresses were released along the bedrock fracture zones. Since no younger or repeated traces of seismic events were found, it corroborates the suggestion that the major seismic activity occurred within a short time during and after the last deglaciation. The origin of the gas/groundwater seepages remains unclear. Their reflections in the echo-sounding profiles imply that part of the gas is derived from the organic-bearing Litorina and modern gyttja clays. However, at least some of the gas is derived from the bedrock. Additional information could be gained by pore water analysis from the pockmarks. Information on postglacial fault activation and possible gas and/or fluid discharges under high hydraulic heads has relevance in evaluating the safety assessment of a planned spent nuclear fuel repository in the region.
  • Hermunen, Taneli (2010)
    Käyn Pro gradu –tutkielmassani läpi ongelmia, joita Robert Nozickin (1938–2002) Anarchy, State and Utopiassa (1974) kehittelemään valtionmuodostusteoriaan sisältyy. Työni tavoite on esittää Nozickin teoria nimenomaan libertaristisesta, ja Nozickin teorian sisäisiin epäjohdonmukaisuuksiin keskittyvästä, näkökulmasta. Esittelen työssäni ensiksi tämän hänen teoriansa pääpiirteet, sekä hänen ajatuksensa utopian kehyksestä (framework for utopia). Nozickin tavoitteena on muodostaa valtio, John Locken (1632¬–1704) määrittelemästä luonnontilasta, ilman kenenkään sitä yrittämättä ja ilman että kenenkään oikeuksia rikotaan sitä muodostettaessa. Valtio on tässä määritelty Max Weberin (1864– 1920) mukaan. Valtion kriteeri täyttyy, kun tietyllä maantieteellisellä alueella, vain yhdellä taholla on hallussaan väkivallan monopoli. Nozickin valtionmuodostusteoriassa valtio muodostuu kahdessa osassa. Ensin dominoivan turva-agentuurin saavuttaessa monopolin turvamarkkinoilla. Tätä kutsutaan ultraminimaaliseksi valtioksi. Sitten dominoiva turva-agentuuri saavuttaa valtion määritelmän liittämällä itsenäiset (independent) itseensä kompensaation periaatteen avulla. Tätä kutsutaan minimaaliseksi valtioksi. Työssäni ongelmalliseksi muodostuvat, niin ultaminimaalinen–, kuin minimaalinenkin valtion. Ultraminimaalisen valtion ongelma on sen kenekään tarkoittamattomuudella muodostuminen. Minimaalisen valtion ongelma on puolestaan sen oikeutus. Väitteeni on, ettei Nozickin valtionmuodostusteoria välttämättä johda valtioon. Hänen käyttämänsä näkymättömän käden (invisible hand) selitykset voivat johtaa myös toisiin lopputuloksiin. Väitän myös, ettei Nozickin valtionmuodostaminen ole moraalisesti hyväksyttävä, koska se ei kunnioita itsenäisten oikeuksia. Esittelen työni lopuksi Murray Rothbardin teksteihin perustuen vaihtoehtoisen loppu tuleman Locken luonnontilasta muodostuvasta yhteisöstä. Esitän myös, että tämä markkina-anarkistinen vaihtoehto voisi myös olla yhteensopiva Nozickin ajatukseen utopian kehyksestä.
  • Lyytinen, Heli (Helsingin yliopisto, 2009)
    Since national differences exist in genes, environment, diet and life habits and also in the use of postmenopausal hormone therapy (HT), the associations between different hormone therapies and the risk for breast cancer were studied among Finnish postmenopausal women. All Finnish women over 50 years of age who used HT were identified from the national medical reimbursement register, established in 1994, and followed up for breast cancer incidence (n= 8,382 cases) until 2005 with the aid of the Finnish Cancer Registry. The risk for breast cancer in HT users was compared to that in the general female population of the same age. Among women using oral or transdermal estradiol alone (ET) (n = 110,984) during the study period 1994-2002 the standardized incidence ratio (SIR) for breast cancer in users for < 5 years was 0.93 (95% confidence interval (CI) 0.80–1.04), and in users for ≥ 5 years 1.44 (1.29–1.59). This therapy was associated with similar rises in ductal and lobular types of breast cancer. Both localized stage (1.45; 1.26–1.66) and cancers spread to regional nodes (1.35; 1.09–1.65) were associated with the use of systemic ET. Oral estriol or vaginal estrogens were not accompanied with a risk for breast cancer. The use of estrogen-progestagen therapy (EPT) in the study period 1994-2005 (n= 221,551) was accompanied with an increased incidence of breast cancer (1.31;1.20-1.42) among women using oral or transdermal EPT for 3-5 years, and the incidence increased along with the increasing duration of exposure (≥10 years, 2.07;1.84-2.30). Continuous EPT entailed a significantly higher (2.44; 2.17-2.72) breast cancer incidence compared to sequential EPT (1.78; 1.64-1.90) after 5 years of use. The use of norethisterone acetate (NETA) as a supplement to estradiol was accompanied with a higher incidence of breast cancer after 5 years of use (2.03; 1.88-2.18) than that of medroxyprogesterone acetate (MPA) (1.64; 1.49-1.79). The SIR for the lobular type of breast cancer was increased within 3 years of EPT exposure (1.35; 1.18-1.53), and the incidence of the lobular type of breast cancer (2.93; 2.33-3.64) was significantly higher than that of the ductal type (1.92; 1.67-2.18) after 10 years of exposure. To control for some confounding factors, two case control studies were performed. All Finnish women between the ages of 50-62 in 1995-2007 and diagnosed with a first invasive breast cancer (n= 9,956) were identified from the Finnish Cancer Registry, and 3 controls of similar age (n=29,868) without breast cancer were retrieved from the Finnish national population registry. Subjects were linked to the medical reimbursement register for defining the HT use. The use of ET was not associated with an increased risk for breast cancer (1.00; 0.92-1.08). Neither was progestagen-only therapy used less than 3 years. However, the use of tibolone was associated with an elevated risk for breast cancer (1.39; 1.07-1.81). The case-control study confirmed the results of EPT regarding sequential vs. continuous use of progestagen, including progestagen released continuously by an intrauterine device; the increased risk was seen already within 3 years of use (1.65;1.32-2.07). The dose of NETA was not a determinant as regards the breast cancer risk. Both systemic ET, and EPT are associated with an elevation in the risk for breast cancer. These risks resemble to a large extent those seen in several other countries. The use of an intrauterine system alone or as a complement to systemic estradiol is also associated with a breast cancer risk. These data emphasize the need for detailed information to women who are considering starting the use of HT.