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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Recruitment strategies in transition economies

Nerjovaj, Valmir, Solovev, Egor January 2014 (has links)
This study is concentrated in recruitment strategies and finding the right competence for firms establishing in transition economies. The study is conducted with six Swedish companies operating in Russia and the Baltic States. Thus, this is a qualitative study in order to identify the different strategies used by the companies and why or why not they have been successful. Furthermore this study is based on in-depth interviews that give us the dimensions we need to solve the issue of recruitment in transition economies.  In conclusion the study shows us that major companies have issues when recruiting personnel in Russia and also a guidance what should be done in order to be as successful as possible in process of recruitment.
2

Development of a methodology to simulate simple mismatching in photovoltaic systems

Frid, Gustav January 2015 (has links)
The currently available tools to simulate solar photovoltaic (PV) systems do not offer a reliable solution to simulate string or module level inverter systems with partial shading and modules with mismatching electrical characteristics. The available methodologies to simulate this satisfying require computational power that is not commonly available. To make it possible to simulate these kinds of systems a methodology based around the software “System Advisory Model” (SAM) is proposed. The methodology assumes that shading is binary, meaning a module can either be fully shaded or not shaded at all. Two different global IV curve models are presented and evaluated in comparison with a more detailed Matlab global IV model based on the one diode equivalent circuit. All these methodologies disregards the impact of the bypass diodes in the PV module and this is considered a significant error, which has to be quantified. It is proposed that this should be done by using the two-diode equivalent circuit instead of the one diode model. Finally the methodology is not concluded to be reliable until verified in comparison with real world data. / De för närvarande tillgängliga simuleringsverktygen för solcellssystem erbjuder inte en tillförlitlig metod för simulering av delvis skuggade system eller system med moduler med olika elektriska egenskaper. De metoder som är tillgängliga för att simulera detta tillförlitligt kräver datorkraft som inte är allmäntillgänglig. För att göra det möjligt att simulera dessa typer av system föreslås en metod baserad kring programvaran "System Advisory Model" (SAM). Metoden utgår från antagandet att skuggning är binärt, vilket innebär att en modul kan antingen vara helt skuggad eller inte skuggad alls. Två olika globala IV-modeller presenteras och utvärderas i jämförelse med en detaljerad Matlab global IV-modell baserad på enkel-diods ekvivalenta kretsen. Denna metod bortser dock från effekterna av bypass-dioderna i PV-modulen och detta antas medföra betydande fel som måste kvantifieras, detta bör då göras med hjälp av två-diods ekvivalenta kretsen. Slutligen så kan metoden inte anses pålitlig förrän den har blivit verifierad med verkliga data.
3

Evaluating the Economic Feasibility for utilizing PV Power Optimizers in Large-scale PV Plants for The Cases of Soiling, Mismatching, and Degradation

Alhamwi, MHD Mouaz January 2018 (has links)
The solar PV modules are influenced by a variety of loss mechanisms by which the energy yield is affected. A PV system is the sum of individual PV modules which should ideally operate similarly, however, inhomogeneous soiling, mismatching, and degradation, which are the main focus in this study, lead to dissimilarities in PV modules operating behavior and thus, lead to losses which will be assessed intensively in terms of energy yield. The dissimilarities in PV modules are referred to the ambient conditions or the PV modules characteristics which result in different modules’ maximum power point (MPP) and thus, different currents generated by each PV modules which cause the mismatching. However, the weakest PV module current governs the string current, and the weakest string voltage governs the voltage. Power optimizers are electronic devices connected to the PV modules which adjust the voltages of the PV modules in order to obtain the same current as the weakest module and thus, extract the modules’ MPP. Hence, the overall performance of the PV plant is enhanced. On the other hand, the power optimizers add additional cost to the plant’s investment cost and thus, the extra energy yield achieved by utilizing the power optimizers must be sufficient to compensate the additional cost of the power optimizers. This is assessed by designing three systems, a reference system with SMA inverters, a system utilizes Tigo power optimizers and SMA inverters, and a system utilizes SolarEdge power optimizers and inverters. The study considers four different locations which are Borlänge, Madrid, Abu Dhabi, and New Delhi. An Excel model is created and validated to emulate the inhomogeneous soiling and to evaluate the economic feasibility of the power optimiz ers. The model’s inputs are obtained from PVsyst and the precipitation data is obtained from Meteoblue and SMHI database. The economic model is based on the relation between Levelized Cost of Electricity (LCOE) which will be used to derive the discount rate. Graphs representing the discounted payback period as a function of the feed-in tariff for different discount rates is created in order to obtain the discounted payback period. The amount of extra energy yielded by the Tigo and the SolarEdge systems is dependent on the soiling accumulated on the PV modules. Relative to the reference system, 6.5 % annual energy gain by the systems utilizing the power optimizers in soiling conditions, up to 2.1 % in the degradation conditions, and up to 9.7 % annual energy gain at 10 % mismatching rate. The extra energy yield is dependent on the location, however, the Tigo and the SolarEdge systems have yielded more energy than the reference system in all cases except one case when the mismatch losses is set to zero. The precipitation pattern is very influential, and a scare precipitation leads to a reduction in the energy yield, in this case, the Tigo and the SolarEdge systems overall performance is enhanced and the extra energy gain becomes greater. The Tigo system yield slightly more energy than the SolarEdge system in most cases, however, during the plant’s lifetime, the SolarEdge system could become more efficient than the Tigo system which is referred to the system’s sizing ratio. The degradation of the system or the soiling accumulation decreases the irradiation and thus, a slightly oversized PV array become suitable and deliver an optimal power to the inverters. The SolarEdge system is feasible in all scenarios in terms of LCOE and discounted payback period, although its slightly lower performance relative to the Tigo system, this is referred to its low initial cost in comparison to the other systems. The Tigo system is mostly infeasible although it yields more energy than the reference and the SolarEdge systems, this is referred iii to its relatively high initial cost. However, feed- in tariffs higher than 20 € cent / kWh make all systems payback within less than 10 years. The results have overall uncertainty within ± 6.5 % including PVsyst, Excel model, and the precipitation uncertainties. The uncertainty in the degradation and the mismatching calculations is limited to PVsyst uncertainty which is ± 5 %. The uncertainties in LCOE in the location of New Delhi, since it is the worst-case scenario, are 5.1 % and 4 % for the reference and the systems utilizing power optimizers, respectively. Consequently, accommodating the uncertainties to the benefits gained by utilizing power optimizers indicates that the energy gain would oscillate in the range of 6 % - 6.9 % for the soiling calculations, 2 % - 2.2 % for the degradation simulations, and 9.2 % - 10.2 % for the mismatching simulations at 10 % mismatchrate.
4

Le design critique et les nouveaux enjeux de conception : un territoire historico-géopolitique de 1960 à nos jours / Critical design and new challenges of conception : a historico-geopolitical domain from 1960 up to the present day

Bertrand, Gwenaëlle 07 November 2016 (has links)
Ce travail de recherche contribue au questionnement sur les nouveaux enjeux de conception soulevés par le design critique. À plusieurs égards, le corpus de cette thèse repose sur une histoire de la contre-histoire. Une manière de faire et de penser dont l’historicité la plus évidente se situe à la fin des années 1960, lorsque certains designers ont souhaité porter le projet vers la mise en œuvre d’un écart afin d’interroger la société par les moyens du design. Une attitude qui instaure la conception à l’instar d’une logique de la désadaptation des habitudes et des manières conventionnelles de penser. La notion de critique, du grec krinein, qui signifie «séparer», «distinguer», prend ici tout son sens en instaurant, non pas une rupture, mais un déplacement, qui aménage des entre-deux et ménage des porosités de la pensée et de la conception. De l’individu augmenté à l’individu modifié, cette thèse révèle de surcroît, l’inquiétude d’une mainmise au delà de l’invention de l’artificiel et aux abords du biologique. Au gré d’un épuisement de la question du critique en design, nous décelons des moyens de déconstruire les systèmes de la discipline et ses réinventions. / This research work aims to contribute to the study of the new challenges of conception raised by critical design. In several respects the corpus of this thesis is based on a history of coun¬ter history, a way of doing and thinking whose conspicuous historicity takes place in the late sixties when a few designers decided to reconsider the notion of project and stray from the straight and narrow in order to question society through the means of design. The notion of criticism - from the Greek krinein meaning «separate», «discriminate» - takes on its full meaning by introducing a shift (not a break) which makes room for inter¬vals and allows sensitive thinking and conception. From human enhancement to human modification, this thesis also reveals a number of concerns which go beyond the invention of artificial means and touch upon biological aspects. Considering that the critical dimen¬sion in the field of design has been exhausted, this research highlights a few ways to deconstruct the operating principles of this discipline as well as its reinventions.
5

東日本大震災と福島第一原子力発電所事故に伴う"風評被害":買い控えを引き起こす心理的メカニズムの解明と買い控え低減を目標とした応用的戦略の検討 / ヒガシニホン ダイシンサイ ト フクシマ ダイイチ ゲンシリョク ハツデンショ ジコ ニトモナウ"フウヒョウ ヒガイ" : カイビカエ オ ヒキオコス シンリテキ メカニズム ノ カイメイ ト カイビカエ テイゲン オ モクヒョウ トシタ オウヨウテキ センリャク ノ ケントウ / 東日本大震災と福島第一原子力発電所事故に伴う風評被害:買い控えを引き起こす心理的メカニズムの解明と買い控え低減を目標とした応用的戦略の検討

工藤 大介, Daisuke Kudo 31 March 2017 (has links)
博士(心理学) / Doctor of Philosophy in Psychology / 同志社大学 / Doshisha University

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