8,626 research outputs found

    Beam scanning by liquid-crystal biasing in a modified SIW structure

    Get PDF
    A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium

    Learning to Collaborate by Grouping: a Consensus-oriented Strategy for Multi-agent Reinforcement Learning

    Full text link
    Multi-agent systems require effective coordination between groups and individuals to achieve common goals. However, current multi-agent reinforcement learning (MARL) methods primarily focus on improving individual policies and do not adequately address group-level policies, which leads to weak cooperation. To address this issue, we propose a novel Consensus-oriented Strategy (CoS) that emphasizes group and individual policies simultaneously. Specifically, CoS comprises two main components: (a) the vector quantized group consensus module, which extracts discrete latent embeddings that represent the stable and discriminative group consensus, and (b) the group consensus-oriented strategy, which integrates the group policy using a hypernet and the individual policies using the group consensus, thereby promoting coordination at both the group and individual levels. Through empirical experiments on cooperative navigation tasks with both discrete and continuous spaces, as well as Google research football, we demonstrate that CoS outperforms state-of-the-art MARL algorithms and achieves better collaboration, thus providing a promising solution for achieving effective coordination in multi-agent systems

    Constitutions of Value

    Get PDF
    Gathering an interdisciplinary range of cutting-edge scholars, this book addresses legal constitutions of value. Global value production and transnational value practices that rely on exploitation and extraction have left us with toxic commons and a damaged planet. Against this situation, the book examines law’s fundamental role in institutions of value production and valuation. Utilising pathbreaking theoretical approaches, it problematizes mainstream efforts to redeem institutions of value production by recoupling them with progressive values. Aiming beyond radical critique, the book opens up the possibility of imagining and enacting new and different value practices. This wide-ranging and accessible book will appeal to international lawyers, socio-legal scholars, those working at the intersections of law and economy and others, in politics, economics, environmental studies and elsewhere, who are concerned with rethinking our current ideas of what has value, what does not, and whether and how value may be revalued

    Belief Revision in Expressive Knowledge Representation Formalisms

    Get PDF
    We live in an era of data and information, where an immeasurable amount of discoveries, findings, events, news, and transactions are generated every second. Governments, companies, or individuals have to employ and process all that data for knowledge-based decision-making (i.e. a decision-making process that uses predetermined criteria to measure and ensure the optimal outcome for a specific topic), which then prompt them to view the knowledge as valuable resource. In this knowledge-based view, the capability to create and utilize knowledge is the key source of an organization or individual’s competitive advantage. This dynamic nature of knowledge leads us to the study of belief revision (or belief change), an area which emerged from work in philosophy and then impacted further developments in computer science and artificial intelligence. In belief revision area, the AGM postulates by AlchourrĂłn, GĂ€rdenfors, and Makinson continue to represent a cornerstone in research related to belief change. Katsuno and Mendelzon (K&M) adopted the AGM postulates for changing belief bases and characterized AGM belief base revision in propositional logic over finite signatures. In this thesis, two research directions are considered. In the first, by considering the semantic point of view, we generalize K&M’s approach to the setting of (multiple) base revision in arbitrary Tarskian logics, covering all logics with a classical model-theoretic semantics and hence a wide variety of logics used in knowledge representation and beyond. Our generic formulation applies to various notions of “base”, such as belief sets, arbitrary or finite sets of sentences, or single sentences. The core result is a representation theorem showing a two-way correspondence between AGM base revision operators and certain “assignments”: functions mapping belief bases to total — yet not transitive — “preference” relations between interpretations. Alongside, we present a companion result for the case when the AGM postulate of syntax-independence is abandoned. We also provide a characterization of all logics for which our result can be strengthened to assignments producing transitive preference relations (as in K&M’s original work), giving rise to two more representation theorems for such logics, according to syntax dependence vs. independence. The second research direction in this thesis explores two approaches for revising description logic knowledge bases under fixed-domain semantics, namely model-based approach and individual-based approach. In this logical setting, models of the knowledge bases can be enumerated and can be computed to produce the revision result, semantically. We show a characterization of the AGM revision operator for this logic and present a concrete model-based revision approach via distance between interpretations. In addition, by weakening the KB based on certain domain elements, a novel individual-based revision operator is provided as an alternative approach

    Cornwall's Border: Celtic Frontier or Anglicised Territory?

    Get PDF
    Cornwall has had a long history of difference compared to the experience of other English counties. As landscape and identity have interwoven, the river Tamar has represented a clear divide between Cornwall and the rest of the United Kingdom undoubtedly, an important facet of the Cornish identity. Whilst it has functioned as a historic and symbolic break in the landscape, the ‘borderlands’ of the Tamar have begun to emerge in the Civic Society of the South-West in their own right as part of the evolution of living close to the border has changed and opportunities for investment, protection and prosperity have emerged. This thesis therefore seeks to explore the impact of the bordering and re-bordering process of Cornwall and more specifically, East Cornwall. Thus, though this thesis we can explore the sub-national border, an area of border studies that is far less developed, but in Reflecting on their daily interactions with neighbouring Plymouth and Devon, built on historic connections, we see how life differs in East Cornwall compared to the rest of the county. An interdisciplinary approach considering the political, cultural, and socio-economic history of these communities, particularly focused on post-19th century life, but also drawing on precedence from earlier examples, sees how divergence has grown across parts of the borders. There is the struggle of the voice of local communities on both banks of the River Tamar, some advocated, others challenging the construction and re-organisation of cultural and political borders. Cornish studies has traditionally focused on Cornwall as a whole, defining its distinctive sense of place and identity as a Celtic nation and a constitutional part of the Celtic fringe in the context of the British State. This thesis, building on the growing body of more micro-historical, localised histories within Cornwall, seeks to challenge the orthodox narrative that has found West Cornwall, which has been the subject of most of these intra-Cornwall studies, to be ‘more Cornish’. Unearthing new narratives about the ‘forgotten Corner’ of Cornwall amongst other parts of East Cornwall not only disputes the homogeneity of Cornwall and Cornish identity, but also the brings to light the shared heritage amongst these more rural communities. Through Border studies, we can explore how competitive territory, overlapping jurisdictions and implications of social mobility have changed over time and in doing so reshaped perceptions of the border. The field also recognizes that border politics will continue to be reshaped, and in doing so, alter the relationships and territories they define. Looking towards Cornwall’s future, this thesis reflects as to how it is evolving amidst a backdrop of devolution, de-centralization, and threats to the British constitution. This has implications for Cornish identity, which may be multiple identities, in a more globalized world, changing rapidly for those living near borders.Awarded degree of Master of Philosophy (MPhil

    Year of the Golden Jubilee: Culture Change in the Past, Present and Future

    Get PDF
    Part 1 of the IACCP Proceedings contains the abstracts and links to the recordings of the XXVI Congress of the International Association for Cross-Cultural Psychology, 2022. (c) 2023, International Association for Cross-Cultural Psychologyhttps://scholarworks.gvsu.edu/iaccp_proceedings/1011/thumbnail.jp

    University of Windsor Graduate Calendar 2023 Winter

    Get PDF
    https://scholar.uwindsor.ca/universitywindsorgraduatecalendars/1026/thumbnail.jp

    Procedural Constraint-based Generation for Game Development

    Get PDF
    • 

    corecore