986 resultados para Wind tunnel testing.


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Control on regional government budgets is important in a monetary union as lower tiers of government have fewer incentives to consolidate debt. According to the Fiscal Theory of the Price Level; unsustainable non-Ricardian fiscal policies eventually force monetary policy to adjust. Hence, uncoordinated and non-regulated regional fiscal policies would therefore threaten price stability for the monetary union as a whole. However, the union central bank is not without defense. A federal government that internalises the spillover effect of non-Ricardian fiscal policies on the price level can offset non-Ricardian regional fiscal policies. A federal government, which taxes and transfers resources between regions, may compensate for unsustainable regional fiscal policies so as to keep fiscal policy Ricardian on aggregate. Following Canzoneri et al. (2001), we test the validity of the Fiscal Theory of the Price Level for both federal and regional governments in Germany. We find evidence of a spillover effect of unsustainable policies on the price level for other Länder. However, the German federal government offsets this effect on the price level by running Ricardian policies. These results have implications for the regulation of fiscal policies in the EMU.

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Advancements in power electronic semiconductor switching devices have lead to significantly faster switching times. In motor and generator applications, the fast switching times of pulse width modulated (PWM) inverters lead to overvoltages caused by voltage reflections with shorter and shorter cables. These excessive overvoltages may lead to a failure of the electrical machine in a matter of months. In this thesis, the causes behind the overvoltage phenomenon as well as its different mitigation techniques are studied. The most suitable techniques for mitigating the overvoltage phenomenon in wind power generator applications are chosen based on both simulations and actual measurements performed on a prototype. An RC filter at the terminals of the electrical machine and an inverter output filter designed to reduce the rise and fall times of voltage pulses are presented as a solution to the overvoltage problem. The performance and losses of both filter types are analysed.

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This Master's thesis deals with a Micro Scale Wind Wind Turbine application. The thesis consists of nine chapters. The first chapter is an introduction to the philosophy of a small scale wind turbine application. The second defines concepts, and lists the requirements. The third presents the whole application for an On-Grid , and for an Off-Grid arrangement, with main concentration on lighting, heating, and energy storage. The fourth deals with the Inverter's technology, which are used for the conversion of the produced power. The fifth chapter presents the available storage technology and it's possibilities. The sixth deals with the system, and the technological means used for the implementation. The seventh presents the PLC device, which was used as the controller for the management of the whole application. The eighth deals with the concept and the control application philosophy that the PLC involves. And the final chapter presents conclusions and ideas for further considerations.

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The goal of the master's thesis is a detailed research of the technical wind energy potential in Russian Federation: the distribution of the potential all over the territory of the country and the possibility of the application of the potential for power supply of various objects. The main attention of the thesis is devoted to the assessment of wind energy resources (potential) of Russian Federation, both for the territory of country in whole and for every region. Theoretical basic wind energy concepts and the scheme of transformation of kinetic energy of a wind into electric energy by modern wind turbines are given in the work. Also the costs of energy, stimuli of development of wind-engineering and obstacles which impact the industry development are analyzed. The review of existent and projected wind power plants in Russia is carried out.

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The strategic group theory provides an intermediate level of analysis between a single company and the whole industry for identifying issues about the company's competitive position and strategic choices. Strategic groups are companies within an industry with similar strategic characteristics or competing on similar bases. Strategic choices are aligned with the firms’ resources. The purpose of this study was to identify the strategic groups in the wind energy industry in Europe, and study, whether a certain group membership results in financial performance differences. Altogether 80 European wind energy companies were included in the study, which were clustered into four strategic groups according to their age and growth rate. Each group corresponds to a different strategy. The results show that the wind energy companies can be clustered according to the chosen strategic characteristics. Strategic decisions were investigated with characteristic variables. Performance variables were used in the analysis measuring profitability, liquidity and solvency of the groups. These strategic choices of the companies did not have a significant influence on the firms’ performance. The more mature and slower growing group proved to be the most successful. However, the differences between groups were generally not statistically significant. The only statistically significant difference found was in the solvency ratio between Mature Slow and Young Rapid groups. Measured with these variables, more mature and slower growing companies performed better. Therefore, a certain strategic group membership results in performance differences.

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Tämä diplomityö käsittelee teollisen yrityksen tuotannonohjauksen kehittämistä piensarjatuotannossa. Työn kohteena on ABB Oy:n Tuulivoimageneraattorit-tulosyksikkö, joka valmistaa vakiotuotteita asiakasohjautuvasti. Työssä esitellään aluksi tuotannon ja tuotannonohjauksen teoriaa. Lävitse käydään perusasioiden kuten määritelmien, tavoitteiden ja tehtävien lisäksi tuotannonohjausprosessia sekä tuotannonohjauksen tietotekniikkaa. Teorian jälkeisessä empiriaosuudessa esitellään työssä kehitettyjä keinoja tuotannonohjauksen parantamiseksi. Tutkimus on toteutettu teoreettisen ja empiirisen tutkimustyön avulla. Teoreettiseen tutkimustyöhön sisältyi suomalaisiin ja ulkomaalaisiin kirjallisuuslähteisiin perehtyminen. Empiirinen tutkimustyö suoritettiin itsenäisen ongelman ratkaisutyön avulla. Tämä sisälsi kehittämiskohteiden analysoinnin, tarkempien kehittämistarpeiden määrityksen sekä kokeilujen kautta tapahtuneen kehittämistyön. Tutkimuksen päätavoitteena oli selvittää, miten tuotannonohjauksen kehittämisellä voidaan parantaa kohteena olevan tulosyksikön tuottavuutta ja kannattavuutta. Päätavoitteen pohjalta muodostettiin kuusi osatavoitetta: toimitusvarmuuden parantaminen, kapasiteetin kuormitusasteen nostaminen, kapasiteetin suunnittelun kehittäminen, läpäisyaikojen lyhentäminen, uuden ERP-järjestelmän vaatimusmäärittely sekä tuotannonohjausprosessin määrittäminen. Työssä rakennettiin neljään ensiksi mainittuun osatavoitteeseen tietotekniset sovellukset, jotka mahdollistavat osatavoitteiden suunnittelun ja ohjaamisen. Sovelluksia varten kullekin tuotteelle määriteltiin esimerkiksi työnvaiheketjut läpäisyaikoineen, kuormitusryhmät, kuormitusryhmien kapasiteetit, tuotteiden kuormittavuudet sekä kriittiset työvälineet. Työ osoitti, että tietotekniikka auttaa suuresti tuotannonohjauksessa. Lisääntynyt läpinäkyvyys, parantunut tiedonkulku, simulointimahdollisuudet sekä graafinen esitystapa helpottavat erilaisten suunnitelmien teossa ja parantavat siten päätöksenteon laatua. Tietotekniikan hyväksikäytön pohjana toimii tuotannon perus- ja tapahtumatietojen kurinalainen päivitys. Tämän vuoksi tietojärjestelmistä kannattaa rakentaa mahdollisimman yksinkertaisia.

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Master thesis represents the literature overview of small wind energy. I have given the description of principles of work wind turbines, the description of the types of wind turbines, their advantages and disadvantages, the characteristics of small wind turbines, have shown how to count the payback period, have given an overview of currently market wind turbines and the future forecast.

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In the last few years, the Ukrainian investment market has constantly shown strong performance and significant growth. This is primarily due to the investment attractiveness of Ukraine. From the perspective of investments in energy sector, Ukraine can be described as a country providing significant number of opportunities to multiply invested funds. But there are numbers of risks which hamper large investments. The work objective was to discover opportunities in small-scale hydropower and wind power sectors of Ukraine and more importantly to prove economic expediency of such investments. Thesis covers major of issues, concerning entering the Ukrainian power market as a foreign investor. It provides basic information about the structure of power market, the state of renewables sector in Ukraine, development of power sector in the regions, functioning of Wholesale Electricity Market, formation of electricity prices, possibilities for implementing joint Implementation mechanism, while the most attention, nevertheless, is concentrated on the opportunities in small-scale hydro and wind power sectors. Theoretical part of the study disclosed that Crimea peninsula has perfect wind conditions and could be a prospective area for wind project development. Investment analysis revealed that project profits will be excellent if green tariff for renewable energy is adopted. By the moment uncertainties about green law adoption bring additional risk to the projects and complicate any investment decision.

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Mimicry is a central plank of the emotional contagion theory; however, it was only tested with facial and postural emotional stimuli. This study explores the existence of mimicry in voice-to-voice communication by analyzing 8,747 sequences of emotional displays between customers and employees in a call-center context. We listened live to 967 telephone inter-actions, registered the sequences of emotional displays, and analyzed them with a Markov chain. We also explored other propositions of emotional contagion theory that were yet to be tested in vocal contexts. Results supported that mimicry is significantly present at all levels. Our findings fill an important gap in the emotional contagion theory; have practical implications regarding voice-to-voice interactions; and open doors for future vocal mimicry research.

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The purpose of the thesis is to analyze whether the returns of general stock market indices of Estonia, Latvia and Lithuania follow the random walk hypothesis (RWH), and in addition, whether they are consistent with the weak-form efficiency criterion. Also the existence of the day-of-the-week anomaly is examined in the same regional markets. The data consists of daily closing quotes of the OMX Tallinn, Riga and Vilnius total return indices for the sample period from January 3, 2000 to August 28, 2009. Moreover, the full sample period is also divided into two sub-periods. The RWH is tested by applying three quantitative methods (i.e. the Augmented Dickey-Fuller unit root test, serial correlation test and non-parametric runs test). Ordinary Least Squares (OLS) regression with dummy variables is employed to detect the day-of-the-week anomalies. The random walk hypothesis (RWH) is rejected in the Estonian and Lithuanian stock markets. The Latvian stock market exhibits more efficient behaviour, although some evidence of inefficiency is also found, mostly during the first sub-period from 2000 to 2004. Day-of-the-week anomalies are detected on every stock market examined, though no longer during the later sub-period.

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Web application performance testing is an emerging and important field of software engineering. As web applications become more commonplace and complex, the need for performance testing will only increase. This paper discusses common concepts, practices and tools that lie at the heart of web application performance testing. A pragmatic, hands-on approach is assumed where applicable; real-life examples of test tooling, execution and analysis are presented right next to the underpinning theory. At the client-side, web application performance is primarily driven by the amount of data transmitted over the wire. At the server-side, selection of programming language and platform, implementation complexity and configuration are the primary contributors to web application performance. Web application performance testing is an activity that requires delicate coordination between project stakeholders, developers, system administrators and testers in order to produce reliable and useful results. Proper test definition, execution, reporting and repeatable test results are of utmost importance. Open-source performance analysis tools such as Apache JMeter, Firebug and YSlow can be used to realise effective web application performance tests. A sample case study using these tools is presented in this paper. The sample application was found to perform poorly even under the moderate load incurred by the sample tests.

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During recent years, mobile phone markets have changed significantly. Asian markets have become vital for the manufacturers with their millions of end users and multiple major mobile network operators. This has resulted in software development as global companies have research and development sites running in multiple locations, including Asia. The reasons behind this are not only in reducing labor costs but also in capitalizing on the local knowledge and knowhow. A ramp-up site has multiple effects in the software development and software release activities. This thesis focuses on representing the importance of software testing as part of software development process and highlighting issues that need to be considered during ramp-up activities. In addition this work tries to emphasize the importance of communication between parties and information gathering prior to setting up the ramp-up site. The output of this thesis was successful software testing site ramp-up within the set time limits. The quality of software testing work was assured and the ramp-up -project requirements were achieved.

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Software testing is one of the essential parts in software engineering process. The objective of the study was to describe software testing tools and the corresponding use. The thesis contains examples of software testing tools usage. The study was conducted as a literature study, with focus on current software testing practices and quality assurance standards. In the paper a tool classifier was employed, and testing tools presented in study were classified according to it. We found that it is difficult to distinguish current available tools by certain testing activities as many of them contain functionality that exceeds scopes of a single testing type.

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The main purpose of this study was to analyze how stress tests are used in risk management in the Finnish banking and insurance sectors. In order to enhance understanding of the topic, stress testing was explored in the context of corporate governance and regulato-ry implications of Basel II and Solvency II on stress testing were examined. In addition, the effects of the global financial crisis on stress testing were mapped and the differences in stress testing practices between the banking and insurance sector were discussed. The research method was qualitative case study and it was conducted by interviewing risk managers from ten institutions and a representative from FIN-FSA. Findings pointed out that stress testing practices vary significantly between different institutions. Interesting observations were made in terms of stress testing practices in the banking and insurance sectors. The increasing importance and use of stress tests were recognized as a result of the financial crisis. Stress testing was even considered more like art than science given the amount of challenges it involves. In general, improvements in stress tests were suggested, with an emphasis on stress concentration between different types of risks.

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During the past decades testing has matured from ad-hoc activity into being an integral part of the development process. The benefits of testing are obvious for modern communication systems, which operate in heterogeneous environments amongst devices from various manufacturers. The increased demand for testing also creates demand for tools and technologies that support and automate testing activities. This thesis discusses applicability of visualization techniques in the result analysis part of the testing process. Particularly, the primary focus of this work is visualization of test execution logs produced by a TTCN-3 test system. TTCN-3 is an internationally standardized test specification and implementation language. The TTCN-3 standard suite includes specification of a test logging interface and a graphical presentation format, but no immediate relationship between them. This thesis presents a technique for mapping the log events to the graphical presentation format along with a concrete implementation, which is integrated with the Eclipse Platform and the OpenTTCN Tester toolchain. Results of this work indicate that for majority of the log events, a visual representation may be derived from the TTCN-3 standard suite. The remaining events were analysed and three categories relevant in either log analysis or implementation of the visualization tool were identified: events indicating insertion of something into the incoming queue of a port, events indicating a mismatch and events describing the control flow during the execution. Applicability of the results is limited into the domain of TTCN-3, but the developed mapping and the implementation may be utilized with any TTCN-3 tool that is able to produce the execution log in the standardized XML format.