Recentemente um efeito piezoelétrico foi encontrado quando um filme polimérico, separando duas soluções de eletrólitos em diferentes concentrações, foi deformado. Este efeito foi atribuído à modulação da mobilidade dos íons no polímero. Foi observado que o efeito diminui com o aumento da concentração de eletrólitos. Para entender mais profundamente este último efeito, foram realizados estudos sobre o transporte de água e sal através do polímero, com e sem deformação, e os resultados podem ser resumidos como segue: a) O aumento da hidratação acarreta um aumento na porosidade e um decréscimo na cristalinidade do polímero. b) O aumento da concentração de sal, no interior do polímero acarreta um aumento na permeabilidade, sendo mais pronunciado na presença de deformação. Esses efeitos tornam mais difícil a modulação dos íons, diminuindo o sinal piezoelétrico observado. / Recently a piezoelectric effect was found when a polymeric film, separating two electrolyte solutions at different concentrations, was deformed. This effect was attributed to the modulation of the mobility of the íons in the polymer. It was observed that the effect decreases as the electrolyte concentrations increases. In order to understand more deeply this last effect a study on water and salt transport through the polymer with and without deformation was carried out, and the results may be summarized as follows: a) An increase in hydration of the polymer leads to an increase in porosity and a decrease in cristallinity. b) An increase in the concentration of the salt leads to an increase in permeability, which is more pronounced in the presence of deformation. The effects make more difficult the modulation of the íons, so lower piezoelectric signals are observed.

Pair trading is a well-known strategy based on statistical arbitrage. This strategy uses a short-term deviation from the mean value of the price ratio of two highly correlated stocks from the same sector as the opportunity to open a position. When ratio returns to its mean value again, the position closes. This strategy has been used for many years and the main outcome of this thesis was to test whether this strategy can be profitable even in current market conditions. For that purpose, data ranging from 2010 to April 2017 on all stocks included in the S&P 500 index were used. It was subsequently found that a pair trading strategy generated 25x higher absolute profit in comparison to random agent. Thus, it can still be considered as a profitable strategy.

I have in this case study evaluated advantages and disadvantages with mob programming, at a IT-company called CGM (CompuGroup Medical LAB AB), in Borlänge, Sweden. Mob programming is new way to work with computer code creation or system maintenance. A group of developers works together to solve problems, like computer bugs. Only one person sits at the keyboard at one time. Like an evolution of pair programming. I have interviewed a selected number of staffs at CGM. What are the pros and cons with mob programming for information systems engineers? I have also conducted a test, with university students that study information systems science at Dalarna University. The students tested to solve a problem with mob programming, and then evaluated the test in a questionnaire. / Jag har i denna fallstudie utvärderat för- och nackdelar med mobprogrammering, vid företaget CGM (CompuGroup Medical LAB AB), Borlänge, Sverige. Mobprogrammering är ett nytt sätt att arbeta med systemutveckling där flera personer arbetar tillsammans i en för att lösa problem, som ex. buggar i datorprogram. Endast en person sitter vid tangentbordet åt gången. Det är en vidareutveckling av parprogrammering. I studien så jag intervjuat personal vid CGM. Vilka för- och nackdelar finns det med mobprogrammering för systemutvecklare? Jag har fått fram flertal fördelar samt nackdelar med mobprogrammering. Jag har även för att få fler synvinklar genomfört ett test med systemvetenskapsstudenter vid Högskolan Dalarna. Studenterna har testat mobprogrammering för att lösa ett problem och analyserade sedan testet med frågeformulär.

This thesis investigates how disparity estimation may be used to visualize an object on a 3D-screen. The first part looks into different methods of disparity estimation, and the second part examines different ways to visualize an object from one or several stereo pairs and a disparity map. Input to the system is one or several stereo pairs, and output is a sequence of images of the input scene but from more angles. This sequence of images can be shown on Setred AB's 3D-screen. The system has high real time demands and the goal is to do the disparity estimation and visualization in real time. In the first part of the thesis, three different ways to calculate disparity maps are implemented and compared. The three methods are correlation-based, local structure-based and phase-based techniques. The correlation-based methods cannot satisfy the real-time demands due to the large number of 2D-convolutions required per pixel. The local structure-based methods have too much noise and cannot satisfy the quality requirements. Therefore, the best method by far is the phase-based method. This method has been implemented in Matlab and C and comparisons between the different implementations are presented. The quality of the disparity maps is satisfying, but the real-time demands cannot yet be fulfilled. The future work is therefore to optimize the C code and move some functions to a GPU, because a GPU can perform calculations in parallel with the CPU. Another reason is that many of the calculations are related to resizing and warping, which are well-suited to implementation on a GPU.

Pair programming is a programming technique in which two programmers sit literally side by side working on the same task at the same computer. One member of a pair called “driver” is in charge of writing the code. The other member plays a role of “navigator”, working on the more strategic tasks, such as looking for tactical error, thinking about overall structure, and finding better alternatives. Pair programming is claimed to improve product quality, reduce defects, and shorten time to market. On the other hand, it has been criticized on cost efficiency. To increase a body of evidence regarding the real benefits of pair programming, this thesis investigates its effect on software defects and efficiency of defect correction. The analysis bases on 14-month data of project artifacts and developers' activities collected from a large Italian manufacturing company. The team of 16 developers adopts a customized version of extreme programming and practices pair programming on a daily basis. We investigate sources of defects and defect correction activities of approximately 8% of defects discovered during that time, and enhancement activities of approximately 9% of new requirements. Then we analyze whether there exists an effect of pair programming on defect rate, duration and effort of defect correction, and precision of localizing defects. The result shows that pair programming reduces the introduction of new defects when the code needs to be modified for defect corrections and enhancements.

Extreme programming is an agile software development process, which has gained a lot of publicity the last couple of years. It has also brought Pair Programming into new light. Research and experiments have shown that the usage of Pair Programming can increase the quality in software development. People who used Pair Programming are usually satisfied using it and they are also more confident in their solutions. Having a pair colleague is not redundancy, people bring the best out of each other and they produce better solutions. Wages for employees are today heavy costs for companies but quality and time aspects in software development become more and more important. A quantitative survey has been conducted among professionals and students, both with and without Pair Programming experience. People surveyed have very low resistance from the start when using Pair Programming. They actually find benefits from it compared to being singles, but they think it should not be used on every task and at every time. This report investigates if Pair Programming is a technique to increase quality and productivity within software development. We also address business related aspects compared to the usage of Pair Programming as well as management aspects to see if we can find other synergy effects from the use of Pair Programming. / Denna rapport undersöker om Parprogrammering är en teknik för att höja kvalitén och produktiviteten inom mjukvaruutvecklingen. Vi belyser även relaterade areor och jämför dessa med Parprogrammering för att se om vi kan finna synergieffekter från användandet av Parprogrammering. Vi har gjort en undersökning både bland professionella och studenter, både med och utan Parprogrammeringserfarenhet. De som svarat har väldigt lågt motstånd till att använda Parprogrammering. De anser att det finns fördelar med att använda Parprogrammering jämfört med att arbeta själv, men de anser att tekniken inte kan användas hela tiden på alla delmoment. / Nöjesv 6 294 77 Sölvesborg 0708-422240

Soient g une algèbre de Lie simple complexe et e un élément nilpotent de g. Nous nous intéressons dans ce mémoire à la question (soulevée par Premet) d'isomorphisme entre les W-algèbres finies construites à partir de certaines sous-algèbres nilpotentes de g dites e-admissibles. Nous introduisons les notions de paire et graduation e-admissibles. Nous montrons ensuite que la W-algèbre associée à une paire e-admissible possède des propriétés similaires à celle introduite par Gan et Ginzburg. De plus, nous définissons une relation d'équivalence sur l'ensemble des paires admissibles. Nous montrons alors que si deux paires sont équivalentes, alors les W-algèbres associées sont isomorphes. Nous introduisons enfin les notions de graduation et paire admissibles b-maximales et nous montrons que les paires admissibles b-maximales sont équivalentes entre elles. Comme conséquence de ce résultat, nous retrouvons un résultat de Brundan et Goodwin sur les bonnes graduations. Dans une dernière partie, nous considérons des cas particuliers pour lesquels nous pouvons apporter une réponse complète à la question d'isomorphisme. / Let g be a complex simple Lie algebra and e a nilpotent element of g. We are interested to answer the isomorphism question (raised by Premet) between the finite W-algebras constructed from some nilpotent subalgebras of g called e-admissible. We introduce the concept of e-admissible pair and e-admissible grading. We show then that the W-algebra associated to an e-admissible pair admits similar properties to that introduced by Gan and Ginzburg. Moreover, we define an equivalence relation on the set of admissible pairs and we show that if two admissible pairs are equivalent, it follows that the associated W-algebras are isomorphic. We introduce later the concepts of b-maximal admissible pair and b-maximal admissible grading and show that b-maximal admissible pairs are equivalent. As a consequence to this result, we recover a result of Brundan and Goodwin on the good gradings. In a final part, we consider some particular cases where we may find a complete answer to the isomorphism question.

The goal of this work was to prove the fact, that definable closure of any subclass of cotorsion modules closed under direct sums consists of $\Sigma$-cotorsion modules. The only known proof uses substantially the calculus of derived category, in this work we tried to prove the same, but only by means of a given category of all right $R$-modules and set-theoretic properties of partial orders indexing direct systems of $R$-modules. The main results of this work are proved under additional assumptions on the ring $R$, in particular $\vert R\vert\leq\aleph_{\omega}$ or $\text{dim}(R)<\aleph_{\omega}$. Attempts to give s proof in the same general situation, where the fact is known to hold, was not successful. Powered by TCPDF (www.tcpdf.org)

The University of ManchesterSandra TaylorDoctor of PhilosophyThe Reciprocal Influence Of Person Centred Counselling Students And Trainers2013This research has explored the reciprocal influence of counselling students and trainers in the UK, through the researcher’s lens of being a Person Centred trainer. The methodology evolved into relational heuristic research, an adaptation of heuristic research which is itself a contribution to knowledge. It is a qualitative approach that holds the researcher/trainer’s heuristic experience as its core whilst including and valuing the experience of others. Six pairs of former counselling students and trainers were interviewed together, followed by eight interviews between the researcher and her former students. The interviews provided the opportunity for the co-creation of a coherent story of their reciprocal influence and enabled clarification, corroboration, disagreement, memory jogging, and the emergence of surprises. Participants in the six interviews were gained through the researcher’s professional networks and so were convenience sampling. The eight former students were from the 22 invited whom the researcher had worked with two years previously. As is typical of heuristic research the analysis was a long, iterative and creative process of incubation and illumination.The main finding, available only because of the former students and trainers being interviewed together, is the uniqueness, complexity and richness of counselling student-trainer relationships. The three other substantial findings are: the huge impact of the transferential/countertransferential relationship between students and trainers; the nuances of liking and favouritism between students and trainers; and an invaluable insight into challenges and difficulties within the student-trainer relationship and their impact.In addition to the findings and discussion the researcher also offers a creative synthesis and a summary of learning, not to be turned into general principles and procedures but for each reader to resonate with their own experiences and see what does and doesn’t fit. This is in keeping with the complexity and uniqueness of experience found in the research. Specific contributions of this research for past, present and future counselling students and trainers as well as for course development are also discussed.

Many children are exposed to excessively technology. Such use of technology may lead to health issues including obesity, attention deficits, and sleep disorders. Research has shown that parameters of reinforcement, such as quality and delay, may influence how children allocate their preferences. One way to drive preference away from high-tech toys may be to arrange delays to reinforcement following such selections and immediate reinforcement for an alternative response. In Experiment 1, four subjects who preferred high-tech leisure items over low-tech leisure items were identified through the pair-stimulus preference assessments. The results of Experiment 2 indicated that all subjects were sensitive to delay to reinforcement. When delays were implemented following selection of high-tech items, preference shifted from high-tech to low-tech leisure items at different delays.