2,202 research outputs found
Computability of Homology for Compact Absolute Neighbourhood Retracts
Full text linkIn this note we discuss the information needed to compute the homology groups of a topological space. We argue that the natural class of spaces to consider are the compact absolute neighbourhood retracts, since for these spaces the homology groups are finite. We show that we need to specify both a function which defines a retraction from a neighbourhood of the space in the Hilbert cube to the space itself, and a sufficiently fine over-approximation of the set. However, neither the retraction itself, nor a description of an approximation of the set in the Hausdorff metric, is sufficient to compute the homology groups. We express the conditions in the language of computable analysis, which is a powerful framework for studying computability in topology and geometry, and use cubical homology to perform the computations
Usurping architecture : sculptural resistance to the built environment
No full textIncludes bibliographical references (p. 70-71).Usurping Architecture is a study in three parts. Part One explores the historical and theoretical basis that has informed my body of work. In this section, I explore the perfection of the depiction of the three-dimensional structure on a two-dimensional plane. This is specifically related to architecture. I then examine the role of geometric abstraction, as developed on the two-dimensional format, in sculptural strategies and their insertion in the lived, everyday environment.The role of geometric formalism is expanded on in the chapters on minimal art, where I explore the role of Gestalt psychology in creating a phenomenological response in the viewer. In the following chapters I indicate how the strategies employed by the minimal artists were used in subsequent decades as a response to the architectural environment. Part Two deals with the methodology related to my art-making processes. The first chapter of this section informs the reader about the general use of concrete as a material. The second chapter explains how I use this material in the construction of cast concrete sculptures. It describes the technical aspects of the process in detail. Part Three comprises a list of each work submitted for examination. The works are represented photographically and are accompanied by a short explanatory text
Constraint-driven nonlinear reachability analysis with automated tuning of tool properties
No full textThe effectiveness of reachability analysis often depends on choosing appropriate values for a set of tool-specific properties which need to be manually tailored to the specific system involved and the reachable set to be evolved. Such property tuning is a time-consuming task, especially when dealing with nonlinear systems. In this paper, we propose, instead, a methodology to automatically and dynamically choose property values for reachability analysis along the system evolution, based on the actual verification objective, i.e., the verification or falsification of a set of constraints. By leveraging an initial solution to the reachable set, we estimate bounds on the numerical accuracy required from each integration step to provide a definite answer to the satisfaction of the constraints. Based on these accuracy bounds, we design a cost function which we use, after mapping the property space to an integer space, to search for locally optimal property values that yield the desired accuracy. Results from the application of our methodology to the nonlinear reachability analysis tool ARIADNE show that the frequency of correct answers to constraint satisfaction problems increases significantly with respect to a manual approach
Entertainer: Pieter-Dirk Uys
No full textThis booklet celebrates the life and work of Pieter-Dirk Uys, internationally acclaimed playwright, author, role-model and one of South Africa's living treasures
Entertainer: Pieter-Dirk Uys
No full textThis booklet celebrates the life and work of Pieter-Dirk Uys, internationally acclaimed playwright, author, role-model and one of South Africa's living treasures
Entertainer: Pieter-Dirk Uys
No full textThis booklet celebrates the life and work of Pieter-Dirk Uys, internationally acclaimed playwright, author, role-model and one of South Africa's living treasures
Mood Regulation as a Design Topic: Interview with Pieter Desmet
Full text linkPieter Desmet is the founding co-director of the Delft Institute of Positive Design, chair of the TU Delft Department of Human Centered Design, and Director of the Delft Design Labs. After introducing cognitive emotion theory to the field of design research, he established the Design and Emotion Society. Full professor of Design for Experience at TU Delft, Desmet is also co-editor of Design and Emotion Moves (Cambridge Scholars, 2008) and co-author of Positive Design: An Introduction to Design for Subjective Well-Being (IJDesign, 2013). Pieter Desmet, who holds a PhD in the domain of Emotion Psychology, has been recently awarded a five-year personal grant to research about the nuances of human mood in human-product interactions. Besides his academic activities, he also contributes to local community projects, such as a recently developed sensory wellness neighborhood park, and a cultural ‘House of Happiness’ located in Rotterdam. In this interview, Desmet discusses the background to positive design, as well as the practical and ethical challenges that arise from using such an approach. He also refers to his latest research initiative: Design for Mood Regulation. Finally, Desmet explains how he transfers the knowledge he develops to companies
Mood Regulation as a Design Topic: Interview with Pieter Desmet
Full text linkPieter Desmet is the founding co-director of the Delft Institute of Positive Design, chair of the TU Delft Department of Human Centered Design, and Director of the Delft Design Labs. After introducing cognitive emotion theory to the field of design research, he established the Design and Emotion Society. Full professor of Design for Experience at TU Delft, Desmet is also co-editor of Design and Emotion Moves (Cambridge Scholars, 2008) and co-author of Positive Design: An Introduction to Design for Subjective Well-Being (IJDesign, 2013). Pieter Desmet, who holds a PhD in the domain of Emotion Psychology, has been recently awarded a five-year personal grant to research about the nuances of human mood in human-product interactions. Besides his academic activities, he also contributes to local community projects, such as a recently developed sensory wellness neighborhood park, and a cultural ‘House of Happiness’ located in Rotterdam. In this interview, Desmet discusses the background to positive design, as well as the practical and ethical challenges that arise from using such an approach. He also refers to his latest research initiative: Design for Mood Regulation. Finally, Desmet explains how he transfers the knowledge he develops to companies
Mood Regulation as a Design Topic: Interview with Pieter Desmet
No full textPieter Desmet is the founding co-director of the Delft Institute of Positive Design, chair of the TU Delft Department of Human Centered Design, and Director of the Delft Design Labs. After introducing cognitive emotion theory to the field of design research, he established the Design and Emotion Society. Full professor of Design for Experience at TU Delft, Desmet is also co-editor of Design and Emotion Moves (Cambridge Scholars, 2008) and co-author of Positive Design: An Introduction to Design for Subjective Well-Being (IJDesign, 2013). Pieter Desmet, who holds a PhD in the domain of Emotion Psychology, has been recently awarded a five-year personal grant to research about the nuances of human mood in human-product interactions. Besides his academic activities, he also contributes to local community projects, such as a recently developed sensory wellness neighborhood park, and a cultural ‘House of Happiness’ located in Rotterdam. In this interview, Desmet discusses the background to positive design, as well as the practical and ethical challenges that arise from using such an approach. He also refers to his latest research initiative: Design for Mood Regulation. Finally, Desmet explains how he transfers the knowledge he develops to companies
A computable and compositional semantics for hybrid systems
Full text linkHybrid Systems are systems having a mixed discrete and continuous behaviour that cannot be characterised faithfully using either discrete or continuous models only.
Due to the intrinsic complexity of hybrid systems, it is highly desirable to describe them compositionally, where large systems are seen as the composition of several simpler subparts that are studied independently. Furthermore, since several problems, including reachability, are undecidable for hybrid systems, the availability of approximate decision procedures is another important feature.
In this paper, we propose a purely behavioural formalism for hybrid systems that is compositional and supports approximate decision procedures. The formalism is abstract and sufficiently general to subsume or be a semantic framework for most of the concrete formalisms or languages proposed in the literature
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