Software tends to decline in quality over time, causing development and maintenance costs to rise. However, by measuring, tracking, and controlling quality during the lifetime of a software product, its technical debt can be held in check, reducing total cost of ownership. The measurement of quality faces challenges due to disagreement in the meaning of software quality, the inability to directly measure quality factors, and the lack of measurement practice in the software industry. This report addresses these challenges through both a literature survey, a metrics derivation process, and a survey of professional software developers. Definitions of software quality from the literature are presented and evaluated with responses from software professionals. A goal, question, metric process is used to derive quality-targeted metrics tracing back to a set of seven code-quality subgoals, while a survey to software professionals shows that despite agreement that metrics and metric visualizations would be useful for improving software quality, the techniques are underutilized in practice. / text

Το οξείδιο του ψευδαργύρου είναι ένας ημιαγωγός της ομάδας II-VI και έχει μεγάλη ποικιλία σε τεχνολογικές εφαρμογές όπως οι αισθητήρες διαφόρων χημικών αερίων, τα lasers, οι δίοδοι εκπομπής φωτός, οι νανο-γεννήτριες, τα ηλιακά κύτταρα και πολλές άλλες. Το ευρύ του ενεργειακό κενό (3.445 eV) το καθιστά ένα πολλά υποσχόμενο υλικό για φωτονικές εφαρμογές στην περιοχή του UV ή του ιώδους, ενώ ταυτόχρονα η υψηλή ενέργεια συνοχής του εξιτονίου που το χαρακτηρίζει (περίπου στα 60 meV) επιτρέπει την αποτελεσματική εξιτονική εκπομπή σε θερμοκρασία δωματίου. Οι πιο πρόσφατες εξελίξεις στον τομέα του νανοδομημένου ZnO είναι οι νανοδρόμοι, οι νανογέφυρες, οι νανοπροπέλες, οι νανοδακτύλιοι, τα νανονήματα κ.α. Στην παρούσα διπλωματική εργασία μελετώνται οι ηλεκτρονιακές και οπτικές ιδιότητες νανονημάτων οξειδίου του ψευδαργύρου (ZnO) για ένα εύρος διαμέτρων από 2 έως 6 nm και με την βοήθεια της εμπειρικής μεθόδου των ψευδοδυναμικών και της Configuration Interaction (CI). Μια ανασκόπηση των ιδιοτήτων και χαρακτηριστικών του bulk ZnO, όπως η κρυσταλλική και η ενεργειακή του δομή, κάποιες τεχνολογικές εφαρμογές και μέθοδοι ανάπτυξης δίνονται στο πρώτο κεφάλαιο. Το δεύτερο κεφάλαιο περιέχει την περιγραφή διαφόρων υπολογιστικών μεθόδων όπως της προσέγγισης ενεργούς μάζας ( Effective Mass Approximation), της θεωρίας του συναρτησιακού της πυκνότητας (Density Functional Theory) και τέλος, της εμπειρικής μεθόδου των ψευδοδυναμικών που χρησιμοποιείται στους υπολογισμούς των ηλεκτρονιακών και οπτικών ιδιοτήτων των νανοδομών που μελετάμε. Στο τρίτο και τελευταίο κεφάλαιο, παρατίθενται τα αριθμητικά αποτελέσματα . Αυτά, αφορούν στο εξαρτώμενο από το μέγεθος, οπτικό ενεργειακό κενό, το Stokes shift, και το φάσμα φωτοφωταύγειας. Στο τέλος του κεφαλαίου περιγράφονται τα συμπεράσματα. / Zinc oxide (ZnO), a typical group II-VI compound, has a great variety of device applications, such as chemical sensors, lasers, light-emitting diodes, nanogenerators, solar cells and so forth. The wide band gap (3.445 eV) makes it a promising material for photonic applications in the UV or the blue range, while the high exciton binding energy (around 60 meV at room temperature) allows efficient excitonic emission at room temperature. The most recent developments are towards the nanostructured ZnO, such as nanorods, nanobridges, nanopropellers, nanorings, nanowires, et al. In the present master thesis, the electronic and optical properties of ZnO nanowires within the range of 2-6 nm in diameter are studied by means of atomistic empirical pseudopotential method and configuration interaction. A review of the bulk ZnO, such as the crystal and band structures, technological applications and synthesis methods, is presented in chapter one. The second chapter is devoted to the discussion of various types of methods, e.g., effective-mass approximation, density-functional theory (DFT), and especially the empirical pseudopotential method used herein, for the calculations of the electronic and optical properties of nanostructured ZnO. The numerical results, based on the empirical pseudopotential methods and configuration interaction approach, are present in the following chapter. These results cover the size-dependent optical band gap, Stokes shift and photoluminescence spectrum. A summarization of the results is given in the last chapter.

If Aristotle was right in claiming that the aim of moral philosophy is to help us determine how we ought to live, then part of the aim of moral philosophy must be to help us improve our prescriptive accounts of moral decision making--our accounts of how we should make moral decisions. In my dissertation I examine implications of empirical research in cognitive science, social psychology, and decision theory for issues in moral decision making. I argue that empirical evidence suggests that principled guidance is in fact beneficial for decision making, which calls into question particularist prescriptive accounts. I also argue that contrary to the prevailing view, research suggests that taking a first-person perspective when making judgments about what we ought to do might actually help us make better moral judgments. Additionally, I argue that jurors will be more likely to make fairer and more accurate judgments by taking the perspective of the defendant than by trying to maintain a detached and 'objective' point of view.

The present study sought to investigate the extent to which masked semantic priming is an automatic process and whether its effects vary depending upon the type of stimuli used. Recent studies have shown that there is a differential priming effect for prime-target pairs with different types of semantic relationships. Here, using a semantic categorization task with masked priming, we compared the effects of synonym, antonym,and associatively related non-exemplar prime-target pairs when presented at different stimulus onset asynchronies (SOAs). Participants took a prime visibility posttest in conjunction with the categorization task which served as a measure of "partial awareness" of the prime. The results here indicate that differences in perceptual awareness may produce differential semantic priming patterns across the semantic relationships and SOAs considered. Potential mechanisms for this divergence are proposed.

This dissertation consists of four articles and a summary. The main focus of the studies is students' explorations in upper secondary school mathematics. In the first study the central research question was to find out if the students could learn something difficult by using the graphing calculator. The students were working with questions connected to factorisation of quadratic polynomials, and the factor theorem. The results indicate that the students got a better understanding for the factor theorem, and for the connection between graphical and algebraical representations. The second study focused on a the last part of an investigation, the verification of an idea or a conjecture. Students were given three conjectures and asked to decide if they were true or false, and also to explain why the conjectures were true or false. In this study I found that the students wanted to use rather abstract mathematics in order to verify the conjectures. Since the results from the second study disagreed with other research in similar situations, I wanted to see what Swedish teachers had to say of the students' ways to verify the conjectures. The third study is an interview study where some teachers were asked what expectations they had on students who were supposed to verify the three conjectures from the second study. The teachers were also confronted with examples from my second study, and asked to comment on how the students performed. The results indicate that teachers tend to underestimate students' mathematical reasoning. A central focus to all my three studies is explorations in mathematics. My fourth study, a revised version of a pilot study performed 1998, concerns exactly that: how students in upper secondary school explore a mathematical concept. The results indicate that the students are able to perform explorations in mathematics, and that the graphing calculator has a potential as a pedagogical aid, it can be a support for the students' mathematical reasoning.

The estimation of low income proportions plays an important role in comparisons of poverty in different countries. In most countries, the stability of the society and the development of economics depend on the estimation of low income proportions. An accurate estimation of a low income proportion has a crucial role for the development of the natural economy and the improvement of people's living standards. In this thesis, the Jackknife empirical likelihood method is employed to construct confidence intervals for a low income proportion when the observed data had missing values. Comprehensive simulation studies are conducted to compare the relative performances of two Jackknife empirical likelihood based confidence intervals for low income proportions in terms of coverage probability. A real data example is used to illustrate the application of the proposed methods.

Pavement damage due to heavy loads on thaw weakened flexible pavements is a major concern for road agencies in Western Canada. To protect weaker, low volume roads, agencies impose spring weight restrictions (SWR) during the spring thaw to reduce pavement damage. While SWR may be cost effective for highway agencies, reducing the spring weight allowances can have a major impact on truck productivity and shipping costs. Therefore an improved process that links SWR loads to pavement damage, and based on limiting failure strain, is required. This thesis developed Local mechanistic-empirical damage models to predict fatigue and rutting failure on two spring weight restricted (SWR) flexible pavements in Manitoba. The Local damage models were used to assess the SWR loads that regulate commercial vehicle weights in Manitoba based on a limiting strain relationship between truck loads and damage. The Local damage models and a calibrated Finite Element Model (FEM) were used to predict the equivalent single axle load (ESAL) repetitions to fatigue and rutting failure at varying B-Train axle loads at the Manitoba sites. The Local model predictions were compared to predictions from the Asphalt Institute (AI) and Mechanistic Empirical Design Guide (MEPDG) damage models. The results of the analysis showed that for each 1% increase in load, there was a corresponding 1% increase in strain, and up to 3% decrease in ESAL repetitions to failure, depending on the Local, AI, or MEPDG damage models. The limiting failure strains, computed from the Local model for design ESALs of 100,000, were 483μm/m and 1,008μm/m for fatigue and rutting failure, respectively. For the Manitoba sites, the predicted FEM strains at B-Train normal and SWR loads were higher than the Local model limiting strains. Therefore the Manitoba ii SWR loads regulating B-Train operations on the two pavements during the spring period appeared to be reasonable. It is recommended that the research findings be verified with further calibration and validation of the Local damage model using a larger data set of low volume flexible pavements. A strain-based concept on how to manage the SWR regime in Manitoba based on the limiting strains was developed and presented.

In this thesis, we apply smoothed empirical likelihood method to investigate confidence intervals for the receiver operating characteristic (ROC) curve with right censoring. As a particular application of comparison of distributions from two populations, the ROC curve is constructed by the combination of cumulative distribution function and quantile function. Under mild conditions, the smoothed empirical likelihood ratio converges to chi-square distribution, which is the well-known Wilks's theorem. Furthermore, the performances of the empirical likelihood method are also illustrated by simulation studies in terms of coverage probability and average length of confidence intervals. Finally, a primary biliary cirrhosis data is used to illustrate the proposed empirical likelihood procedure.

Compare the accuracy of two continuous-scale tests is increasing important when a new test is developed. The traditional approach that compares the entire areas under two Receiver Operating Characteristic (ROC) curves is not sensitive when two ROC curves cross each other. A better approach to compare the accuracy of two diagnostic tests is to compare the areas under two ROC curves (AUCs) in the interested specificity interval. In this thesis, we have proposed bootstrap and empirical likelihood (EL) approach for inference of the difference between two partial AUCs. The empirical likelihood ratio for the difference between two partial AUCs is defined and its limiting distribution is shown to be a scaled chi-square distribution. The EL based confidence intervals for the difference between two partial AUCs are obtained. Additionally we have conducted simulation studies to compare four proposed EL and bootstrap based intervals.

This paper uses Maximum likelihood estimation method to estimate the common correlation coefficients for multivariate datasets. We discuss a graphical tool, Q-Q plot, to test equality of the common intraclass correlation coefficients. Kolmogorov-Smirnov test and Cramér-von Mises test are used to check if the intraclass correlation coefficients are the same among populations. Bootstrap and empirical likelihood methods are applied to construct the confidence interval of the common intraclass correlation coefficients.