Models based on various types of automata are ubiquitous in modern science. These models allow reasoning about deep theoretical questions and provide a basis for the development of efficient algorithms to solve related computational problems. This work discusses several types of automata used in such models, including cellular automata and mandatory results automata. The first part of this work is dedicated to cellular automata. These automata form an important class of discrete dynamical systems widely used to model physical, biological, and chemical processes. Here we discuss a way to study the dynamics of one-dimensional cellular automata through the theory of two-dimensional picture languages. The connection between cellular automata and picture languages stems from the fact that the set of all space-time diagrams of a cellular automaton defines a picture language. We will discuss a hierarchy of cellular automata based on the complexity of the picture languages that they define. In addition to this, we present a characterization of cellular automata that can be described by finite-state transducers. The second part of this work presents a theory of runtime enforcement based on mech- anism models called Mandatory Results Automata (MRAs). MRAs can monitor and trans- form security-relevant actions and their results. Because previous work could not model general security monitors transforming results, MRAs capture realistic behaviors outside the scope of previous models. MRAs also have a simple but realistic operational seman- tics that makes it straightforward to define concrete MRAs. Moreover, the definitions of policies and enforcement with MRAs are significantly simpler and more expressive than those of previous models. Putting all these features together, we argue that MRAs make good general models of (synchronous) runtime mechanisms, upon which a theory of run- time enforcement can be based. We develop some enforceability theory by characterizing the policies deterministic and nondeterministic MRAs enforce.

As software systems are growing in complexity and size, reliability becomes a major concern. A large degree of industrial and academic efforts for increasing software reliability are directed towards design, testing and validation—activities performed before the software is deployed. While such activities are fundamental for achieving high levels of confidence in software systems, bugs still occur after deployment resulting in costly software failures. This dissertation presents assertion-based repair, a novel approach for error recovery from insidious bugs that occur after the system is deployed. It describes the design and implementation of a repair framework for Java programs and evaluates the efficiency and effectiveness of the approach on repairing data structure errors in both software libraries and open-source stand-alone applications. Our approach introduces a new form of assertions, assertAndRepair, for developers to use when checking the consistency of the data structures manipulated by their programs with respect to a set of desired structural and data properties. The developer provides the properties in a Java boolean method, repOk, which returns a truth value based on whether a given data structure satisfies these properties. Upon an assertion violation due to a faulty structure, instead of terminating the execution, the structure is repaired, i.e., its fields are mutated such that the resulting structure satisfies the desired properties, and the program proceeds with its execution. To aid developers in detecting the causes of the fault, repair-logs are generated which provide useful information about the performed mutations. The repair process is performed using a novel algorithm that uses a systematic search based on symbolic execution to determine valuations for the structures’ fields that result in a valid structure. Our experiments on repairing both library data structures, as well as, stand-alone applications demonstrate the utility and efficiency of the approach in repairing large structures, enabling programs to recover from crippling errors and proceed with their executions. Assertion-based repair presents a novel post-deployment mechanism that integrates with existing and newly developed software, providing them with the defensive ability to recover from unexpected runtime errors. Programmers already understand the advantages of using assertions and are comfortable with writing them. Providing new analyses and powerful extensions for them presents an attractive direction towards building more reliable software. / text

The last few years have seen a resurgence of interest in the use of symbolic execution--program analysis technique developed more than three decades ago to analyze program execution paths. However, symbolic execution remains an expensive technique and scaling it remains a key technical challenge. There are two key factors that contribute to its cost: (1) the number of paths that need to be explored and (2) the cost of constraint solving, which is typically required for each path explored. Our insight is that the cost of symbolic execution can be reduced by an incremental approach, which uses static analysis and dynamic analysis to focus on relevant parts of code and reuse previous analysis results, thereby addressing both the key cost factors of symbolic execution. This dissertation presents Memoized Incremental Symbolic Execution, a novel approach that embodies our insight. Using symbolic execution in practice often requires several successive runs of the technique on largely similar underlying problems where successive problems differ due to some change, which may be to code, e.g., to fix a bug, to analysis parameters, e.g., to increase the path exploration depth, or to correctness properties, e.g., to check against stronger specifications that are written as assertions in code. Memoized Incremental Symbolic Execution, a three-fold approach, leverages the similarities in the successive problems to reduce the total cost of applying the technique. Our prototype tool-set is based on the Symbolic PathFinder. Experimental results show that Memoized Incremental Symbolic Execution enhances the efficacy of symbolic execution. / text

This study is based upon the idea that foreign language (FL) classrooms exist apart from their target language communities. While historically, this has been a geographic truth, divides between FL learners and native speakers may also reflect symbolic social distance. Given the symbolic, if not geographic, isolation of the FL classroom from the real world, this study presumes that a challenge inherent to the endeavor of FL education is that the authentic, real-world language and culture under study are, by definition, not naturally present in the FL classroom. This study considers how this challenge, referred to as the challenge of authenticity, is managed in one FL classroom. Seven eighth-grade students and their teacher comprise Classroom 204, a beginning Spanish FL classroom at a private school in the southwest U.S. This qualitative case study uses classroom observations, audio-recordings, classroom artifacts, and participant interviews as data to consider not only how authenticity is imported, imagined, and conjured by participants in Classroom 204, but how authenticity is assigned value therein. Data is analyzed largely with discourse analysis of transcripts of classroom talk about (and classroom talk that constituted) various facets of authenticity, value, and the real world. Ecology theory serves as a broad theoretical lens through which to understand (and accept) the complexity inherent to the social phenomena being researched. Benedict Anderson's (1991) theory of imagined communities is adopted to understand the boundaries that delineate the inside of the FL classroom from the outside, and Bourdieu's (1992) notion of symbolic capital is used to understand the ways by which authenticity becomes valuable (and, conversely, how that which is valuable becomes authentic). Findings suggest that, while participants are largely oriented to real-world manifestations of Spanish language and culture, authenticity is not most present in Classroom 204 in the form of stuff imported from elsewhere. Rather, authenticity emerges out of the highly local, socially-immediate interactions and value systems unique to Classroom 204. Suggestions for both pedagogy and future research focus on approaches that acknowledge and capitalize on the power of local authenticity in the FL classroom, as cultivated by local social actors. / text

Today's mobile student population follows diverse paths. This research presents findings from a qualitative study investigating the perceptions of transfer students while they were actively engaged in the transfer process. Fifty-seven incoming community college transfer students (n=57) were interviewed, in a large metropolitan area, through e-journaling during fall 2006 (while students were still attending community colleges) and during spring 2007 (students' first semester of admission to the university). The following research questions guided the study: What do transfer students perceive as a successful transfer process? From the transfer student's perspective, what supports are needed to accommodate a successful transfer process? From the transfer student's perspective, what barriers inhibit successful transfer? The study sought to identify transfer student retention policies and practices that offer the most promising outcomes, as substantiated by the transfer students. Their experiences and perceptions might have implications for improving programs and policies at either the sending or receiving institution. The necessity to determine the challenges faced by students when entering a four-year institution is key to understanding student persistence and success in attaining the baccalaureate. The Urban Transfer Research Network (UTRN) is a project funded through Lumina Foundation for Education. The purpose of this collaborative project is to chart the pathways and success of transfer students who begin their college careers at community colleges. The research conducted in this study served as the pilot study for UTRN's qualitative research. The findings suggest three first stage transfer adjustment themes. The first stage includes: students' expectations prior to entering the university, students' initial experiences of marginality, complications from the need for guidance combined with feelings of entitlement, and students learning to navigate the university system. The second stage of the transfer students' adjustment identified the support systems needed by students: personal attention, academic integration, social interaction, and technology. Barriers to successful transfer involved the lack of communication students perceived among and within the community college and the university. The third and final stage of the transfer adjustment process offered student recommendations for change supporting reflections of self-reliance, and balance of academic rigor and personal identity.

There are numerous studies that address the issue of discipline practices in schools. Within the last decade there have been an increasing number of scholars and school district personnel who have written about discipline, and more specifically, the discipline of specific populations of students such as African Americans. Although many of these studies address the disparate disciplinary practices that occur in many school districts, little attention is devoted to how students understand these practices in the larger context of their general school experiences. This research intends to fill the void in the literature that utilizes the experiences of students to understand inequitable discipline practices. The primary purpose of this study is to examine a selected group of "at-risk" African American male students' experiences and beliefs about disciplinary practices used in school.

Följande studie behandlar delaktighet för brukarrepresentanter från olika sociala företag. Det övergripande syftet med studien är att undersöka hur delaktighet kan påverkas genom social interaktion mellan blivande socionomer och representanter från sociala företag. En kvalitativ studie har genomförts genom en deltagande observation under två dagar i en framtidsverkstad mellan socionomstudenter, lärare och brukarrepresentanter. Empirin har analyserats med hjälp av symbolisk interaktionism och Goffmans dramaturgiska teaterscen. Åldersspannet på deltagarna i studien ligger på 22 - 70 år, och det var en övervägande kvinnlig deltagarskara. Studiens resultat visar att delaktighet med ett reellt inflytande är något som eftersträvas både från politiskt håll bl.a. av socialstyrelsens riktlinjer och från samhällsmedborgarna, i den här studien i form av studenter och brukarrepresentanter. Detta är dock inget som visar sig i praktiken utan det handlar snarare om en pseudodelaktighet, som innefattar "mycket snack och lite verkstad", där delaktigheten inte leder till något reellt inflytande. Det krävs en jämn maktfördelning mellan olika grupprepresentanter för att ge rätt förutsättningar i skapandet av delaktighet på lika villkor. Tidsbrist är en förhindrande faktor. Det visas att en framgångsfaktor för delaktighet är att vi delar samma verklighetsförståelse och eftersträvar en maktutjämning för bekämpning av stigmatisering. För detta krävs gemensamma mötesplatser. Studien visar att det krävs en långsiktighet för en lyckad implementering i alla led från utbildning till arbetsplats till medborgare. Det är en lång kedja där mycket kan gå fel på vägen. Detta kan förklara den tröghet som påvisas i denna studie. / The following study deals with the participation of user-representatives from various social enterprises. The overall aim of the study is to examine how participation can be influenced by social interactions between future social workers and user-representatives from social enterprises. A qualified study has been carried out through a participant observation for two days in a future-workshop between social work students, teachers and user-representatives. Empirical data has been analyzed by means of symbolic interactionsm and Goffman's dramaturgical theater analysis. The age range of study participants is at 22-70 years and it was predominately female group of participants. The study-results show that the inclusion of real influence is something pursued both from the policies of the National board and from community citizens, in this study in terms of students and user representatives. However, this is nothing that shows in practice, it is rather a pseudoparticipation which includes a lot of talk and little action, where participation does not lead to any real influence. It requires an even division of power between different group representatives to provide the right conditions in the making of participation on equal terms. Lack of time is a preventing factor. It appears that the success of participation is that we share the same understanding of reality and pursue a power leveling to fight stigmatization. This requires common meeting places. The study shows that a long term approach for a successful implementation at all stages from education to the workplace to the citizen is required. There is at long chain where much can go wrong along the way. This may explain the inertia detected in this study.

Retail image has received considerable attention in the academic literature in recent years, its influence on consumer behaviour demonstrated extensively in contexts such as stores, brands, shopping malls and tourist destinations. It is therefore surprising that the study of retail image in a town centre has been neglected. Town centres, since time immemorial existing as markets facilitating the exchange of goods, have throughout history been of significant importance to local and national economies. Yet academic interest in consumers choice of town centres, and particularly their image perceptions of these locations, has only been stimulated in response to competition from the development of purpose-built shopping malls. Research into town centres as distinct locations has been extremely limited. The research reported in this thesis has studied town centre image as a specific retail location. In doing so, the research has also addressed a further limitation in the retail image literature. Researchers have pointed to the limited theoretical development in retail image studies, and particularly to the discrepancy between image conceptualisation and its operationalisation. Image is conceptualised as having both tangible qualities and an aura of psychological attributes (Martineau, 1958), but its measurement has focussed almost exclusively on its physical properties, ignoring the less tangible elements which it is hypothesised to contain. As a consequence of adopting a theoretical approach to town centre image, this research has for the first time developed a model of town centre image which addresses both its tangible and intangible qualities, and which comprises three dimensions: functional, experiential and symbolic. The model was tested using Structural Equation Modelling based on a survey of 816 consumers in three town centres. Analysis of the results suggests that consumers perceive town centre image as a higher order construct consisting of these three dimensions, and that their image perceptions focus on top-level salient aspects of the retail provision, together with feelings, emotions, and subjective attitudes towards the town centre. It is suggested that this conceptualisation provides a more accurate measure of consumer perceptions of town centre image for future academic researchers and for practitioners, particularly as town centres are currently the focus of government policy to support their continuing preservation as important local and national economic drivers.

Enacted as part of the 1996 Welfare Reform bill, the faith-based initiative was intended to ensure that small religious groups were not discriminated against in the awarding of government funding. While there has been a great deal of attention paid to changes at the federal level, little attention has been paid to how and why states are implementing the faith-based initiative. Currently, states are not required to implement any part of the initiative, other than guaranteeing that faith-based organizations (FBOs) will not be discriminated against in funding decisions. Nevertheless, states have been acting on the initiative in a variety of ways in the hope of increasing the number of faith-based organizations performing social services.Although religious groups have been receiving government funds to provide social services for much of American history, the faith-based initiative represents a new effort from both state and federal governments to encourage even greater participation. To understand the state-level faith-based implementation I focus on two research questions: Why are states creating faith-based policies and practices? What are these new policies and practices? Data collected from multiple sources reveal three key aspects of faith-based policy implementation: appointment of state actors known as Faith-Based Liaisons (FBLs), legislation, and presentation of state Faith-Based Policy conferences.While supporters argue that the faith-based initiative is about solving problems of poverty and an over-burdened welfare system, I find that these policies and practices do not respond to problems of poverty or welfare, and do not offer the substantial new help to the poor and needy that was promised by supporters. Instead, I find that state faith-based practices are more likely to be implemented in states with a strong evangelical movement presence. My data also shows that these practices are actually a series of symbolic policies that further the goals of the evangelical movement in two ways. First, state faith-based policies and practices enable the evangelical movement's greater goal of chipping away at church/state separation. Second, because these policies and practices reframe and reshape the church/state relationship in ways that appeal to deeply held ideological views by many in the United States, they have the potential to create new political allies for the evangelical movement.

Research establishes, that clothes constantly communicate something about its wearer. You send out different messages depending on what sort of clothes you are wearing. For example, a suit can project social status and power, while, a pair of jeans usually conveys a more casual impression. Either way, research state that clothes are symbolic expressions. This essay focuses on the theme clothes and pupils within the school world. Do pupils today experience clothes as symbolic values? By using qualitative interviews, I have examined how four senior high school pupils talk about clothes and its potential symbolic value in school. Together with, in what ways the participants experience clothes functions as status markers in school. The French sociologist Pierre Bourdieu´s theory of the judgment of taste, is the theoretical starting point of this paper. Bourdieu claims that trivial things, such as clothes, reveal the social belonging of the individual. Because, clothes can project differences in taste, and taste is connected with social class, according to the Bourdieu. The conclusion of the essay is that all participants, more or less, experience that clothes project symbolic values within school; however, what it projects varies in different social spaces. That is, clothes do not have the same symbolic meaning in all schools. For the second research assignment, I have come to the conclusion that quite often clothes actually do functions as status markers in school. But, what sort of clothing that is synonymous with status also varies within different social spaces. That is, a piece of clothing that is symbolic with high social status in one school does not necessarily project the same status value at another school.