Mutation testing and adequacy testing are two major technologies to assure the quality of software. In this thesis, we present the first work that alleviates the high cost of mutation testing and ineffectiveness of adequacy testing for context-aware applications. We also present large-scale multi-subject case studies to evaluate how our work successfully alleviates these problems. Mutation testing incurs a high execution cost if randomly selected test inputs kill a small percentage of remaining live mutants. To address this problem, we formulate the notion of context diversity to measure the context changes inherent in test inputs, and propose three context-aware strategies in the selection of test inputs. The empirical results show that the use of test inputs with higher context diversity can significantly benefit mutation testing in terms of resulting in fewer test runs, fewer test case trials, and smaller resultant test suites that achieve a high mutation score level. The case study also shows that at the test case level, the context diversity of test inputs positively and strongly correlates with multiple types of adequacy metrics, which provide a foundation on why context diversity contributes to the effectiveness of test cases in revealing faults in context-aware applications. In adequacy testing, many strategies randomly select test cases to construct adequate test suites with respect to program-based adequacy criteria. They usually exclude redundant test cases that are unable to improve the coverage of the test requirements of an adequacy criterion achieved by constructing test suites. These strategies have not explored in the diversity in test inputs to improve the test effectiveness of test suites. To address this problem, we propose three context-aware refined strategies to check whether redundant test cases can replace previously selected test cases to achieve the same coverage level but with different context diversity levels. The empirical study shows that context diversity can be significantly injected into adequate test suites, and favoring test cases with higher context diversity can significantly improve the fault detection rates of adequate test suites for testing context-aware applications. In conclusion, this thesis makes the significant contributions to the research in testing context-aware applications: (1) It has formulated context diversity, a novel metric to measure context changes inherent in test inputs. (2) It has proposed three context-aware strategies to select test cases with different levels of context diversity. Compared with the baseline strategy, the strategy CAS-H that uses test cases with higher context diversity can significantly reduce the cost of mutation testing over context-aware applications in terms of less number of test runs, smaller adequate test suites, and less number of test inputs used to construct test suites. (3) It has defined three context-aware refined strategies to construct adequate test suites with different context diversity levels. Compared with the baseline strategy, the strategy CARS-H that favors test cases with higher context diversity can significantly improve the effectiveness of adequacy testing in terms of higher fault detection rates. / published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy

The allocation of resources to tasks in a computationally efficient manner is a key problem in computer science. One important application domain for solutions to this class of problem is the allocation of sensing resources for environmental monitoring, surveillance, or similar sensing tasks. Within this domain, however, the complexity of the problem is compounded by a number of factors: new tasks may arrive at any time, resources may be shared between tasks under some conditions, tasks may be composed of inter-dependent sub-tasks, and tasks may compete for sensor resources. These factors combined with the dynamic nature of the topology of sensor networks (e.g. sensors may move out of range or become damaged) mean that it is extremely difficult or impossible to have a solution using existing techniques. In this thesis, we propose an efficient, agent-based solution (FAST for Flexible Allocation for Sensing Tasks) to this complex dynamic problem. The sensing resources in FAST can be either static or mobile or a mixture of both. Particularly, each resource is managed by a task leader agent (i.e. the actual sensor that is closest to the task central point). The problem is then modelled as a coordination problem where the task agents employ a novel multi-round Knapsack-based algorithm (GAP-E) to obtain a solution. If there are dependencies between sub-tasks, such relationships are solved prior to the actual allocation. At execution time, if there is any environment change that affects the task sensing type requirements, the previously determined sensor types for tasks are revised. When applicable, the agents are cooperative through exchanging and sharing resources to maximise their profits. In addition, FAST addresses the situation where sensor resource sharing is not possible and there is no incentive for sensor resources to be exchanged. In such situations, an additional post-process step underpinned by mechanism for exchanging resources through negotiation were introduced. Through those mechanisms, agents may, in a decentralized manner, decide the means to deliver on a sensing task given local conditions, and to alleviate the impact of task arrival time on the quality of the global solution. Via empirical evaluation, these steps significantly improved the number of sensing tasks that can be successfully completed with only a minor impact on execution time.

Teams have become increasingly popular in organizations (Devine, Clayton, Philips, Dunford, & Melner, 1999), and the issue of process loss in teams presents a persistent challenge to teamwork and team effectiveness (Karau & Williams, 1993). The present study addresses a basic issue in process loss; namely, team member motivation to contribute personal resources toward individual and team-level goals. This study identified three sources of motivation in teams: Task demands, team attributes, and member traits. Individual motivation increased with task difficulty, increased as deadlines approached, and declined overall with time on task. Team efficacy was positively associated with episodic increases in motivation over time, while cohesion was unrelated to motivation. Trait motivation was positively related, and psychological collectivism negatively related to individual motivation. This relationship persisted over the lifespan of the team. The results of this study have implications for understanding the unique and joint role of individual and contextual influences on team member motivation over time and experience.

Att ha grafiska applikationer i webben har blivit allt mer vanligt sedan World Wide Web kom till i slutet på 80-talet. Till en början handlade det om effektfulla interaktiva element så som reklamskyltar, logotyper och menyknappar. Idag år 2015 har webbläsarna utvecklats så pass långt att inga tredjepartsprogram krävs för att interaktiv grafik ska fungera, vilket tidigare var fallet. Grafiska funktioner och bibliotek finns nu istället inbyggda i webbläsaren. De tekniker som denna rapport/arbete ska behandla är Canvas och WebGL. Dessa är tekniker som används för att presentera interaktiv grafik på webben. WebGL är ett grafiskt bibliotek som bygger på ett känt grafiskt bibliotek vid namnet OpenGL, men konstruerat för webben. Grafiken är hårdvaruaccelererad precis som OpenGL, vilket innebär att tekniken kan åstadkomma relativt kraftfull grafik för att vara en webbapplikation. För en utbildad webbutvecklare kan WebGL upplevas som en svårare värld jämfört med Canvas som ligger närmare en webbutvecklares kunskapsområde. Canvas har även en större tillgänglighet bland webbläsare än WebGL. Detta arbete ska redovisa hur dessa två tekniker förhåller sig till varandra i utritningshastighet tillsammans med en bildteknik kallad Atlas. Atlas teknik är enkelt förklarat när ett bildobjekt är som en atlas med flertal bildobjekt där i som hade kunnat motsvara separata bildobjekt. Detta examensarbete kommer jämföra alla fallen i ett experiment för att kunna ge svar på hur prestanda i utritningshastighet står sig mellan teknikerna Canvas och WebGL med eller utan Atlas teknik.

Today’s software systems are becoming increasingly integrated into the lives of their end-users and their ever-changing environments and needs. These demands lead to a growing complexity of systems. The development of adaptive systems is a promising way to manage this complexity. Adaptive systems are able to adapt their behavior at operation time while considering the changing operational environment to maximize the satisfaction of end-user needs. However, adaptive systems have their own challenges to overcome. Especially, requirements engineering for adaptive systems is challenging given the fact that requirements are active runtime entities and can change at runtime. Requirements engineering activities have not only to take place at design but also at runtime. Requirements engineering for adaptive systems is an emerging research area that has so far received little attention, compared to other research areas (e.g., architecture) for adaptive systems. Adaptive systems need to have a full understanding of the context in order to handle the complexity and satisfy end-user needs. Therefore, a new trend in require- ments engineering for adaptive systems emerged to document requirements with the context in which the requirements are valid. Such contextual requirements necessi- tate adaptive systems to consider and define context in order to fully understand the requirements at operation time. Further, adaptive systems must be able to cope with uncertainty inherent in a changing runtime environment. Otherwise, adaptive sys- tems will not be able to satisfy end-user needs. Therefore, after the system has been deployed, support for the evolution of contextual requirements is needed, too. The trend of considering context as part of a contextual requirement poses new challenges in the field of requirements engineering. This dissertation investigates the capture and evolution of contextual requirements for adaptive systems, which leads to three contributions: First, this dissertation presents a framework that differentiates between context and requirements as two separate entities in contextual requirements that can be captured and can be evolved independently. It is especially necessary to capture and evolve the essential context to support the ability of a system to adapt to fulfilling the needs of its end-users, whose requirements and context are constantly changing. The framework is then applied in two case studies. The first case study investi- gates the usefulness of existing requirements elicitation techniques for the elicitation of contextual requirements. This dissertation’s second contribution is the empirical evidence that existing requirement elicitation techniques can be used for the capture of contextual requirements at design time. We propose a combination of interviews, focus groups and prototyping that we found useful in eliciting contextual requirements in our case study. The second study develops and evaluates techniques to support the evolution of context when contextual requirements are validated at runtime. For this purpose we propose an approach which uses machine learning and feedback loops to support the evolution of contextual requirements and which represents the third contribution of this dissertation. / Graduate

Sport participation in the United States is often characterized as a unitary experience that naturally instills a standardized set of values. In this work, however, I challenge the mythology of a unitary conceptualization of sport participation and examine how the experiences and outcomes of playing sports change depending on the setting in which the participation occurs. Specifically, I undertake an investigation into the differences between playing sports in an organized setting and playing them in an informal, unstructured setting. Drawing from the findings of three distinct studies, I first demonstrate through a mixed-method historical study how the field of sport management has narrowed its focus over time to exclude the more playful forms of sport and physical activity. In the second and third studies, I show the experiential and developmental outcomes that are potentially overlooked by maintaining a narrow definition of sport that excludes sport played in unstructured settings. In the second study, a phenomenological examination of pre-teen youth sport participants reveals that the meaning of the experience of playing youth sports derives not from playing in one setting alone, but emerges through the synthesis of experiences accrued in both organized and unstructured settings. In the third study, the relative influences of time spent participating in organized sports and informal sports during childhood are assessed with respect to the development of participant creativity. Like the phenomenological study, the results of this quantitative analysis again point to the importance of balancing participation in both organized and unstructured settings. The most creative individuals are those who split their sport participation time across both settings, as opposed to individuals with below-average creativity, who spent the majority of their sport participation time in organized settings. Combined, the results of these three studies demonstrate the historical shift (in both research and practice) away from unstructured sport settings, and highlight the potentially transformative sport development implications of reincorporating unstructured sport settings on the overall experiences and outcomes of sport participation. / text

A considerable body of research shows that network structure can either assist or hinder one's access to social capital. Though the effects of particular structural arrangements of relationships are well known, there is comparatively little research on how a person might come to have one structural arrangement of ties over another. This study asks: What structures network structure? What cultural templates guide persons in their practice of friendship and in managing, maintaining, and adapting their personal communities over time? What contextual factors influence the duration and intensity of social relationships? Respondents were asked to make a list of "people who are important to you" and to describe the relationships individually while labeling each person on a social map. Interviews were coded using content analysis software in order to assess emergent cultural themes and the settings from which social relationships were drawn. Interview data confirmed respondents' use of cultural templates in the practice of friendship, which may affect one's ability to acquire and/or lose social capital. Interview data demonstrated how material resources may impact the vigor with which persons engage with social settings. Finally, some respondents reported important voluntary relationships that are at once high-commitment and low-contact. Frequently this type of tie arose when a relationship had outlived its original social context. This finding challenges the idea that contact and commitment usually go together in voluntary relationships.

Current research on network use in the labor market focuses primarily on network morphology. In this dissertation, I use hierarchical regression to examine the influence of macro-level context on network use in job search.This study relies on a unique data set that combines individual job history data for years 1985 through 2001 collected by the Survey of Social Dynamics and Migration in Russia (SSMDR) in 40 regions in 2001-2002 and corresponding regional macro-economic data published by Goskomstat, the State Statistical Committee of the Russian Federation.The first question of this study focuses on what accounts for the temporal and regional variation in personal network use in the Russian labor market. I find that, for the post-Soviet period, increase in network use in job search can be attributed to the growth of the private sector: Russian employers are becoming "social capitalists" who take advantage of the resources personal connections can offer. I also find that the chances of finding a new job through personal ties are higher in the regions with larger small business sectors and in the regions with lower economic performance.Next I examine how regional economic performance and unemployment affect workers' chances of getting new jobs in the private sector and in smaller size organizations by means of personal networks. The analysis shows that social networks do lead to employment in the private sector and that this relationship is positively affected by regional economic performance, but not by unemployment rate. I also find here that social ties are likely to lead to new jobs in small organizations, but that this relationship does not vary by region.Finally, I investigate how regional economic performance and unemployment rates affect wages for jobs found through personal networks in the private sector and in small organizations. I find that while the private sector rewards network use, small organizations do not. The relationship between network use and wages does not vary by region. That is, regional economic performance does not have an effect on this relationship.

Reproductive traits are often thought of as fixed, genetically determined properties. However, such traits are often dynamic, exhibiting different expression patterns depending on context. Both internal state and external environment can have a strong effect on how traits are expressed. Variation in these factors across the lifetime of an individual should select for flexibility in trait expression, rather than fixation.My dissertation work examines how mating behavior and testes size respond to several previously unexplored contextual factors, using Rhagoletis juglandis, the walnut fly, as a model system. For mating behavior, I predicted that differences in female reproductive state (egg load) and experience with host resource would impact mating decisions. For testes size, I predicted that social environment (sex ratio) and changes in resource environment would determine testes size.Behavioral observations of flies showed that a large egg load increased the likelihood of copulation, while prior experience with host fruit decreased copulation time. These results are the first to distinguish effects of experience on physiological state from other effects of experience in the context of mating behavior.Manipulation of the sex ratio revealed that males develop larger testes when reared in an environment with many potential competitors. This is the first study to show that that allocation to a male reproductive organ can change depending on the sex ratio. My studies showed that resource environment is also important in determining testes investment patterns. When adult males are deprived of protein, they develop smaller testes. A stable isotope analysis of testes further confirms that resource environment is important for testes development. Males rely more on nitrogen derived at the larval stage than at the adult stage, but adult carbon sources are a large component of testes mass.In sum, this dissertation demonstrates the importance of context in the expression of reproductive traits. Recent research has shown that such traits can respond more dynamically to context than previously thought, but this area of research is young. My results help provide a greater understanding of the processes shaping the evolution of reproductive traits.

Changes in breastfeeding practices have been accompanied by profound changes in the daily context within which women make infant-feeding decisions. The availability and promotion of breast milk alternatives, the transmission of breastfeeding knowledge and skills, and the individual and societal value placed on breastfeeding and breast milk are all issues that need to be considered. In this seminar, Aleck will provide a brief history of breastfeeding trends and policies. He will suggest that a historical understanding of the relationship between socio-cultural trends and breastfeeding patterns is essential to informing current policy development and advocacy in the area of infant feeding. Finally, he will examine the context of policy development in the twenty-first century, including the possible challenges presented by international free trade agreements, questions about federal/provincial responsibility for breastfeeding promotion, the relationship between women’s productive and reproductive work, and the need to redefine breastfeeding success at a policy level.