On the cost-complexity of multi-context systems

Multi-context systems provide a powerful framework for modelling information-aggregation systems featuring heterogeneous reasoning components. Their execution can, however, incur non-negligible cost. Here, we focus on cost-complexity of such systems. To that end, we introduce cost-aware multi-context systems, an extension of non-monotonic multi-context systems framework taking into account costs incurred by execution of semantic operators of the individual contexts. We formulate the notion of cost-complexity for consistency and reasoning problems in MCSs. Subsequently, we provide a series of results related to gradually more and more constrained classes of MCSs and finally introduce an incremental cost-reducing algorithm solving the reasoning problem for definite MCSs

Levelable Sets and the Algebraic Structure of Parameterizations

Asking which sets are fixed-parameter tractable for a given parameterization constitutes much of the current research in parameterized complexity theory. This approach faces some of the core difficulties in complexity theory. By focussing instead on the parameterizations that make a given set fixed-parameter tractable, we circumvent these difficulties. We isolate parameterizations as independent measures of complexity and study their underlying algebraic structure. Thus we are able to compare parameterizations, which establishes a hierarchy of complexity that is much stronger than that present in typical parameterized algorithms races. Among other results, we find that no practically fixed-parameter tractable sets have optimal parameterizations

The Volatility of Private Capital Flows to the Developing Countries: Lessons from the Asian Crisis

Summary Eurodollar markets have a decisive role in creating liquidity, which contributed to overinvestment in emerging economies. IMF responses to the situation failed to prevent currency crises but there may be some benefit from structural adjustment in the long run. The short?term debt/reserve ratio is important as a crisis indicator, though disaster myopia is a persistent aspect of international currency markets. One should contemplate internationally coordinated restrictions on high?risk, short?term investment covering source and recipient countries. For crisis management, standardised rescheduling measures could be helpful

Fuzzy argumentation for trust

In an open Multi-Agent System, the goals of agents acting on behalf of their owners often conflict with each other. Therefore, a personal agent protecting the interest of a single user cannot always rely on them. Consequently, such a personal agent needs to be able to reason about trusting (information or services provided by) other agents. Existing algorithms that perform such reasoning mainly focus on the immediate utility of a trusting decision, but do not provide an explanation of their actions to the user. This may hinder the acceptance of agent-based technologies in sensitive applications where users need to rely on their personal agents. Against this background, we propose a new approach to trust based on argumentation that aims to expose the rationale behind such trusting decisions. Our solution features a separation of opponent modeling and decision making. It uses possibilistic logic to model behavior of opponents, and we propose an extension of the argumentation framework by Amgoud and Prade to use the fuzzy rules within these models for well-supported decisions

Signal processing techniques for efficient compilation of controlled rotations in trapped ions

Quantum logic gates with many control qubits are essential in many quantum algorithms, but remain challenging to perform in current experiments. Trapped ion quantum computers natively feature a different type of entangling operation, namely the Molmer-Sorensen (MS) gate which effectively applies an Ising interaction to all qubits at the same time. We consider a sequence of equal all-to-all MS operations, interleaved with single qubit gates that act only on one special qubit. Using a connection with quantum signal processing techniques, we find that it is possible to perform an arbitray SU(2) rotation on the special qubit if and only if all other qubits are in the state |1>. Such controlled rotation gates with N-1 control qubits require 2N applications of the MS gate, and can be mapped to a conventional Toffoli gate by demoting a single qubit to ancilla.Comment: 14 pages, 3 figures, comments welcome. v3 includes several fixes and adds an appendix with explicit angle

The voice of the visual : visual learning strategies for problem analysis, social dialogue and mediated participation

The changing needs for innovative learning strategies in the life sciences results from the growing complexity of societal issues. Nowadays, complex societal issues are also called ‘wicked problems.’ Wicked problems are problems that do not have one single solution that is right or wrong, good or bad or true or false. These are problems in which many stakeholders are involved, all of them framing the problems and issues in a different way. Reflecting on the consequent changing role of scientists and the way they need to be trained, it is realized that innovative learning strategies are needed to enhance problem analysis. This PhD project explored visual learning strategies for problem analysis. In exploring these strategies, the project emphasized dialogue and participation by social actors, (future) practitioners and decision makers involved in wicked problem settings. The project had the twofold aim of exploring the potential of visual learning and defining the design and production of visual learning strategies. The project materialized in a design and research perspective on the production and use of visual learning strategies. The design track resulted in the development of the Visual Problem Appraisal (VPA) and Embedded Filming strategies. At the start of the project these strategies were used in settings of international master course work and adult education. As the project advanced, the attention also focused on using the strategies in the public domain, with a focus on public participation by silenced or overlooked social actors. The VPA design developed with the production and use of the ‘VPA Kerala’s Coast’ (2003 – 2008) and the ‘VPA AIDS & Rural Development in Sub-Saharan Africa’ (2005-2009). Core of the VPA design are filmed stakeholder narratives and a well elaborated methodological approach that creates a learning space where the VPA user meets with these stakeholders as part of a decision making process. The wicked problems addressed in these VPAs focus on integrated coastal zone management in Kerala, India, and on AIDS and rural development in Sub-Saharan Africa. Embedded Filming, designed and produced between 2003 and 2007, also focuses on HIV/AIDS and rural development professionalism in Sub-Saharan Africa and Asia. Embedded Filming involves participation in the production phase by combining action research with a learning process. The film crew, facilitators and participants form an integrated whole. The shared focus of VPA and Embedded Filming is reflected in similarities in the general production and use. The filming process of both strategies focuses on social actors, their perspectives and reflections on reality. This consideration for multiple realities and societal complexity in the films is further underlined in the absence of a voice over or otherwise a steering ‘outsider.’ Although VPA and Embedded Filming have strong similarities, they are also characterized by differences. VPA filming activities are not embedded in a wider activity as is the case for Embedded Filming. Editing in Embedded Filming differs from the editing style of the VPA interviews as it adheres more to conventional documentary editing. The distinctive visual language of each film style was highlighted in the found footage experiment. This experiment showed that the footage of the Embedded Filming series could not be used for the production of VPA narratives because of the film styles not being congruent. The visual learning strategies have been used in an array of situations and with a variety of audiences. They have shown the ability to bring complex realities and a diversity of stakeholders together in spaces of learning, reflection and change. The experiences obtained with Visual Problem Appraisal and Embedded Filming provided the empirical evidence that it is possible to design, produce and use specific visual learning strategies to achieve strategic learning objectives that enhance complex competences for action and change. Research on these experiences is documented in the various chapters of this dissertation. The first chapter provides the background to the study and elaborates on the research design. The second chapter gives a broad introduction to the design, production and use of the ‘VPA Kerala’s Coast.’ It describes the educational design of VPA and the operationalisation during the filming process in Kerala, India. The analysis of the production experiences led to a series of workshops to research the impact of the VPA in the public domain. The evaluation of these workshops provided indications for social learning and stakeholder dialogue. The third chapter elaborates on the effects of the VPA in higher professional education. The study is based on experiences with the ‘VPA Kerala’s Coast,’ lectured in 2007/08 and 2008/09. The VPA design deliberately incorporates a rich variety of instruction strategies to anticipate the diverse learning styles of students in the international and intercultural classroom with a prominent role for visual learning. Students are confronted with a variety of learning activities that provides a challenging environment. They are immersed in the reality of complex multi stakeholder settings and they are stimulated to learn about wicked problems that are not easy to solve. Facilitator’s instructions and precise feedback options stimulate students to reflect on their work and that of their peers. It makes students almost immediately aware of the effects of their actions and the way they learn. The assessment presented indicates that the VPA strategy is effective as a strong and attractive simulation. The created safe space provides students an opportunity to learn from their interaction with un-familiar stakeholders and the VPA enhances critical reflection on learning procedures and patterns. Besides elaborating on the impact in education the chapter also provides insight in the design process of this learning strategy. The fourth chapter presents the process of producing and testing the ‘VPA Kerala’s Coast’ as a complex and intriguing multidisciplinary and multicultural project. We wondered what made the project a success. Framing the project as a space of intercultural communication gave guidance to the questions that articulated our search to understand the process we had been immersed in. In this chapter the events are described and critical incidents are analyzed that occurred during the production and the use of the VPA. The outcome leads to valuable recommendations for international and intercultural teams working on similar production and research projects. The fifth chapter reports on Embedded Filming. The filming and the films of a series of workshops and courses for Rural Development Professionals in Ghana, India, Tanzania and Zambia are analyzed as tools for learning and social change for different audiences. Analyzing the production and consumption processes shows the interconnectedness of the filming and learning during the courses. The results indicate that the films contribute to improved rural development professionalism in the context of HIV/AIDS. Chapter six highlights the potential of ‘mediated participation’ as compared to live participation, especially regarding the inclusion of vulnerable and distanced stakeholders. Mediated participation was explored by studying the production and use of the ‘VPA AIDS & Rural Development in Sub-Saharan Africa’ in workshops in Congo DRC, Ghana, Tanzania, the Netherlands and Zambia. The qualitative assessment was based on production experiences, evaluations of participants, and debriefings of workshops. The results indicate that mediated participation is not just a second-best option to live participation. Mediated participation as operationalized in VPA-methodology offers an alternative to learning in face-to-face interactions. The concept of mediated participation that resulted from the study is perceived as a promising concept. This term is used to contrast live presence of silenced and overlooked stakeholders in processes of public participation with participation or representation of these stakeholders’ concerns through the use of media (film). Mediated participation refers in this study to the filmed narrative (or mediated presence) of direct stakeholders who otherwise wouldn’t be present in public policy making processes. Mediated participation enhances social inclusion and equity in problem analysis and decision making by other means than through live participation. The experiences in this study with the design, production and use of VPA and Embedded Filming indicate the relevancy of designing and producing specific visual learning strategies in the context of wicked problems in multi stakeholder settings and sustainable development. It was learned that a specific visual learning strategy requires a particular film style or visual language. It is not film in general that defines the outcome of a learning process; it is the conceptual design, grounded in specific learning and film theories and film making expertise that lays foundations for the process that can be induced by the film. The discussed visual learning strategies overcome physical, cultural and social barriers between vulnerable stakeholders and decision makers. The mediated encounters with ‘the Other’ and ‘meeting’ other realities in social dialogues turned out to contribute to problem analysis. Designing, producing and using visual learning strategies requires due attention, expertise and resources. <br/

The effects of undergraduate financing on advanced degree attainment

This study examines the effects of undergraduate financing on subsequent advanced degree attainment in a context characterized by a shift away from traditional grant aid programs and toward widespread student loans. Using data from the National Survey of College Graduates, 2SLS Lewbel method regressions estimate the effects of having received undergraduate grant aid and having student loan debt on the chances of attaining an advanced degree during the next ten years. Results suggest a large positive influence of receiving undergraduate grant aid on advanced degree attainment (+8.5%), thus boosting higher education attainment far beyond only an undergraduate degree across college graduation cohorts between 1986 and 2007. Conversely, having loan debt upon college graduation affected the chances of advanced degree attainment negatively. The increased reliance on loans during undergraduate studies coincided with its long-term (or “spillover”) effect on advanced degree attainment being null in the late 1980s to a substantive deficit of more than 4 percentage—points from the 2000s onward. Counterfactual projection models suggest that loan-taking after the 1992 Higher Education Act suppressed the number of advanced degree holders in the US labor market and will continue to do so given current undergraduate financing patterns