Today’s electrical grid companies understand that better knowledge of and information about their grid can help realize a smart grid network. One way to gain better knowledge and information about the low voltage network is to install measuring equipment on the substation transformer´s secondary low voltage side that measures the low voltage network losses for that specific substation. By doing so, grid companies can, due to the calculation of the low voltage network losses, identify and address issues such as illegal power dissipation, unmeasured power outtakes, and unsatisfied technical documentation for the substations low voltage network. During 2012, Mälarenergi Elnät AB had a total electrical network loss (both medium and low voltage network losses included) of three to four percent of their total distributed electrical volume. Converting this energy volume into a monetary figure this accounts for a loss of around 30 million Swedish crowns. To address Mälarenergi Elnät AB’s issue about their low voltage network losses, Mälarenergi Elnät AB asked me to perform my civil engineering master thesis around this subject. Mälarenergi Elnät AB wanted me to perform measurements in five pre-existingsubstations. I had seven EDMI MK10A CT electrical meters for substation measurements installed in five pre-existing substations in the surrounding area of Västerås in order to investigate the potential costs and benefits of increased measurement in the low voltage network system. The total cost of my substation measurement installation reached 35 000 SEK or around 5 000 SEK per installed electrical meter. The calculated low voltage network losses from my measurements in the selected pre-existing substations showed that 75 % of the studied low voltage networks had losses in the range of zero to five percent. From the calculated results I also identified several benefits of measurements in pre-existing substations, including improved calculation of low voltage network losses, increased awareness of load levels so that maintenance could be more efficiently scheduled, and more accurate technical documentation, all of which can lead to increased customer satisfaction. The disadvantages of measurement in pre-existing substations that I identified during my master thesis study were the high installation cost of the meters and the increased demand on human resources during the implementation phase. Overall, my economic evaluation of the project showed that the investment was not cost effective, despite the acknowledged benefits of these substation measurements. The overall results suggest that Mälarenergi Elnät AB could benefit from installing meters in new substations, and in some existing substations where specific information about the low voltage network loss is needed for issues such as identifying suspicious illegal power dissipation or unmeasured power outtakes. The high installation cost for substation measurements are, in those cases, motivated by the fact that the substation measuring equipment costs are low compared to a whole new substation or compared to the fact of finding unmeasured outtakes, illegal powerdissipations etc.

We consider linear perturbations of the background type IIB SUGRA solutions and find the equations of motion for the moduli. In particular, we allow for spacetime fluctuations of the positions of D3-branes in the compact dimensions. We postulate an ansatz for the 5-form flux due to the motion of the D3-branes, and a corresponding first-order part of the metric. The movement of the D3-branes is then shown to affect the warp factor at linear order. Using the equations of motion for the D3-branes, the universal volume modulus, and the universal axion, we construct a second-order, effective action. Finally, based on the form of the effective action, we examine a Kahler potential for the moduli space.

On presente une generalisation d'un resultat de Wallin ainsi qu'une caracterisation des ensembles compacts polaires dans un espace de Brelot. Ces resultats se generalisent a un produit de n espaces de Brelot en demontrant la continuite des fonctions multireduites. On en deduit qu'un ensemble localement n polaire est un ensemble in polaire. Des resultats semblebles ont lieu pour une sous-classe des ensembles pluripolaires dans un domaine hyperconvexe et borne de C('n).

国立情報学研究所で電子化したコンテンツを使用している。

国立情報学研究所で電子化したコンテンツを使用している。

The restrictions of micro-scale systems are approaching rapidly. In anticipation of this development, nano-scale electronics has become the focus of many researchers and engineers in academia and industry since early 1990s. The basic building blocks of modern integrated circuits have been diodes and transistors with their current-voltage I-V characteristics being of prime significance for the design of complex signal processing and shaping devices and systems. Classical and semi-classical physical principles are no longer powerful enough or even valid to describe the phenomena involved. The application of rich and powerful concepts in quantum theory has become indispensable. These facts have been influential in undertaking this research project. This research is built upon the determination of the Eigenpairs of one and two dimensional positive differential operators with periodic boundary conditions. The Schrödinger equation was solved for positive operators in both one and two dimensions. Fourier series were used to express the derivatives as the summation of Fourier terms. This led to a novel approach for the calculation of the eigenmodels of a perturbed potential well. The perturbation can be done via an electric field applied to the potential well. The research in this thesis includes a thorough understanding of quantum mechanics fundamentals, mastering of different approximation techniques such as the variational technique and results that have been generated and published using the novel techniques.

Recently, task-based research motivated by a Vygotskian theoretical perspective has led to studies that demonstrate how the task-as-workplan is interpreted and reshaped by learners in actual performance (Coughlan and Duff, 1994). The ability of learners to set their own ‘tasks’ suggests that researchers need to investigate how individual students react to the tasks they have been asked to perform (Ellis, 2003). To date, there have been very few systematic studies on learner and teacher perceptions in this particular field. Four studies conducted by Kumaravadivelu (1989, 1991), Slimani (1989, 1992), Block (1994, 1996), and Barkhuizhen (1998) have shed light on the learner and teacher perception of classroom events. This study has continued the investigation into how individual students react to the tasks they have been asked to perform. In particular, it has focussed on four potential mismatches between teacher intention and learners’ interpretation of task, previously identified in a study by Kumaravadivelu (2003): instructional, pedagogic, procedural and strategic. The study aimed to look at teacher and learners’ perceptions and therefore a qualitative approach was used to gather information. The study was triangulated on two levels, using a variety of data (data triangulation) and different methods (questionnaires and interviews) to collect the data (methodological triangulation). Sixteen students studying for a Certificate in English at the School of Languages and Social Sciences at Auckland University of Technology were asked to perform a task and then complete a questionnaire which was designed to elicit information regarding the four potential mismatches, between teacher intention and learner interpretation, referred to above. Four pairs of students participated in each of the two tasks. Four students, one from each pair was then interviewed in order to elicit more in-depth information regarding the four mismatches referred to above. The teacher was also interviewed after the task had been completed. The student answers from the questionnaires were compared with the data gathered from the student and teacher interviews. The findings seem to show that two mismatches between teacher intention and learners’ interpretation were evident, namely instructional and pedagogic. There was no clear evidence of a strategic or procedural mismatch. Despite the small sample size, the study seems to show that mismatches are identifiable. Given the importance of perceptual mismatches and the fact that they are part of the practice of everyday teaching, it is important that we try to identify as many mismatches as possible in future research. It is reasonable to assume that the narrower the gap between teacher intention and learner interpretation, the greater the chances of achieving learning and teaching objectives (Kumaravadivelu, 2003).

Thesis (Ph.D.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references.

Thesis (M.S.)--Ohio University, June, 1999. / Title from PDF t.p.

Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [114]-119).