701,435 research outputs found

    Principles for the definition of design structures

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    Different kinds of design structure are created and used in engineering design and development processes. Function structures, design grammars and bills of materials are common examples. However, there is a lack of clarity regarding distinctions and similarities between different kinds of structure and systematic ways to articulate them. This paper brings together research on product structuring and shape computation to inform the specification of principles for the definition of design structures. The principles draw together findings reported in the computational geometry and product definition literature with research from a range of companies and industry sectors that encompasses enterprise and process structures. The potential value of the principles to computer integrated manufacturing and through-life support is demonstrated through application to four case studies

    Sustainable Urban Habitats: The Contributory Components of Viable Eco-Diverse Landscapes

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    This study examines the conceptual, ecological and structural elements that contribute to the development of sustainable urban habitats. It is argued that the establishment of genuinely sustainable urban environments has been hampered by the lack of a clear and agreed definition of sustainable practices amongst building professions. Whilst this militates against the synthesis of sustainable architectural and landscaping design methodologies, it also highlights the piecemeal adoption of sustainable design pedagogy within university design departments. With a few exceptions the embedding of sustainable design principles within design departments has been pedestrian. As a consequence this has contributed to the maintenance of fuzzy ideology and practices regarding sustainability within built environment professions. One of the more obvious manifestations of this phenomenon is the absence of creativity when amalgamating relevant native species, ecological diversity and landscaping materials within UK city centers. This can be traced directly to inconsistent pedagogical approaches when addressing ecological applications within the built environment. The paper reviews the threads that connect genuine aspirations for sustainable habitats within built environment professions and university design departments to their inevitable erratic outcomes. The fundamental association of the concepts of place and ownership and the creative application of pertinent eco-diversification are intrinsic to genuine sustainable cityscapes. This matter will not be resolved by tweaking the relevant frameworks and organizations. The ‘play it safe’ orthodoxies of existing professional anatomies and educational structures are not an option, what is needed is the fundamental re-design of the existing modes of practice. The paper will discuss how this is possible, cite institutional and commercial innovation, good practice and outline the potential for genuine sustainable urban habitats

    Current trends and developments in progressive collapse research on reinforced concrete flat plate structures

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    Progressive collapse of structures caused by extreme or accidental loads may lead to significant loss of life and property. Considerable research efforts have been made to date to mitigate the probability of progressive collapse and its consequences. This study summarises the fundamentals of progressive collapse in relation to the existing theoretical concepts and understanding. Specifically the existing theories pertinent to progressive collapse of building structures, in particular reinforced concrete (RC) flat plates, are examined from the following four key aspects: (1) definition of progressive collapse from deformation and/or strength perspectives with respect to the failure criteria of structural members and the entire structural system; (2) failure mechanisms of load-bearing systems undergoing progressive collapse with respect to the structural ultimate capacity, which has not been considered in the design process; (3) research methodologies for investigating collapse mechanisms, with emphases on experimental and numerical approaches; and (4) collapse-resistant design principles as covered in several international design standards in which a number of robustness requirements have been recognised. Based on the schematic review of the current trends and developments, gaps and limitations in progressive collapse research are identified and a new research direction is established to advance the progressive collapse study of RC flat plate structures

    Paleomimetics: A Conceptual Framework for a Biomimetic Design Inspired by Fossils and Evolutionary Processes

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    In biomimetic design, functional systems, principles, and processes observed in nature are used for the development of innovative technical systems. The research on functional features is often carried out without giving importance to the generative mechanism behind them: evolution. To deeply understand and evaluate the meaning of functional morphologies, integrative structures, and processes, it is imperative to not only describe, analyse, and test their behaviour, but also to understand the evolutionary history, constraints, and interactions that led to these features. The discipline of palaeontology and its approach can considerably improve the efficiency of biomimetic transfer by analogy of function; additionally, this discipline, as well as biology, can contribute to the development of new shapes, textures, structures, and functional models for productive and generative processes useful in the improvement of designs. Based on the available literature, the present review aims to exhibit the potential contribution that palaeontology can offer to biomimetic processes, integrating specific methodologies and knowledge in a typical biomimetic design approach, as well as laying the foundation for a biomimetic design inspired by extinct species and evolutionary processes: Paleomimetics. A state of the art, definition, method, and tools are provided, and fossil entities are presented as potential role models for technical transfer solutions

    Paleomimetics: A Conceptual Framework for a Biomimetic Design Inspired by Fossils and Evolutionary Processes

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    In biomimetic design, functional systems, principles, and processes observed in nature are used for the development of innovative technical systems. The research on functional features is often carried out without giving importance to the generative mechanism behind them: evolution. To deeply understand and evaluate the meaning of functional morphologies, integrative structures, and processes, it is imperative to not only describe, analyse, and test their behaviour, but also to understand the evolutionary history, constraints, and interactions that led to these features. The discipline of palaeontology and its approach can considerably improve the efficiency of biomimetic transfer by analogy of function; additionally, this discipline, as well as biology, can contribute to the development of new shapes, textures, structures, and functional models for productive and generative processes useful in the improvement of designs. Based on the available literature, the present review aims to exhibit the potential contribution that palaeontology can offer to biomimetic processes, integrating specific methodologies and knowledge in a typical biomimetic design approach, as well as laying the foundation for a biomimetic design inspired by extinct species and evolutionary processes: Paleomimetics. A state of the art, definition, method, and tools are provided, and fossil entities are presented as potential role models for technical transfer solutions

    Probabilistic-based structural safety analysis of concrete gravity dams

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    The construction and operation of dams, associated with the use of water resources, aims generically at water supplying, the energy producing and, in many cases, flow regulating and flood controlling. Considering the dam dimensions and the potential risks associated with its structural failure, due to the occupation of the downstream valley, and to the costs of the construction, maintenance and rehabilitation, the use of probabilistic principles in its design, as it is already performed for other type of structures, is justified considering adequate levels of safety. The objections shared throughout the dam engineering community, regarding the difficulty in estimating the probability of failure for concrete dams, are expectedly overcome by the failure mode and uncertainty modeling, allowing the application of probabilistic principles for their safety analysis, based on conservative simplifications regarding the structural behavior, namely: (i) the definition of the failure surface (dam-foundation interface); (ii) the consideration of rigid body failure mechanisms; and (iii) the consideration of the residual shear strength, given only by the frictional component, corresponding to a limit analysis valid for ultimate limit states. For that purpose, the failure modes are derived from the current construction and design practice by comparing analytical and numerical models of a generic, though representative, case study. The uncertainties involved in the safety of concrete dams are statistically quantified, through the definition of probabilistic distributions for loads and material properties, using, in addition to the elements found in the literature, the information available at LNEC about those features, resulting from the monitoring of the concrete dam behavior during the construction, first filling and operation periods. This work explores the required tasks for the adoption of the partial safety factor method for the safety analysis of concrete gravity dams, at the design phase. Two representative studies regarding the reliability-based design of concrete gravity dams and partial safety factor calibration are presented, intending to stimulate the discussion on the applicability of probabilistic principles for the design of concrete dams, as well as, to influence the safety criteria to be considered in a future revision of the dam safety regulation. The obtained results confirm that the seismic load combination and the sliding failure modes are the most conditioning situations. It is also observed that cross-sections profiles flatter than currently used may be needed for high intensity seismic zones. Partial safety factors that approximate reasonably the reliability-based results could be derived

    Informational laws of genome structures

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    In recent years, the analysis of genomes by means of strings of length k occurring in the genomes, called k-mers, has provided important insights into the basic mechanisms and design principles of genome structures. In the present study, we focus on the proper choice of the value of k for applying information theoretic concepts that express intrinsic aspects of genomes. The value k\u2009=\u2009lg2(n), where n is the genome length, is determined to be the best choice in the definition of some genomic informational indexes that are studied and computed for seventy genomes. These indexes, which are based on information entropies and on suitable comparisons with random genomes, suggest five informational laws, to which all of the considered genomes obey. Moreover, an informational genome complexity measure is proposed, which is a generalized logistic map that balances entropic and anti-entropic components of genomes and is related to their evolutionary dynamics. Finally, applications to computational synthetic biology are briefly outlined

    Digital Tectonics as a Morphogenetic Process

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    p. 938-948Tectonics is a seminal concept that defines the nature of the relationship between architecture and its structural properties. The changing definition of the symbiotic relationship between structural engineering and architectural design may be considered one of the formative influences on the conceptual evolution of tectonics in different historical periods. Recent developments in the field of morphogenesis, digital media, theories techniques and methods of digital design have contributed a new models of integration between structure, material and form in digital tectonics. The objective of this paper is to propose and define tectonics as a model of morphogenetic process. The paper identifies and presents the manner in which theory and emerging concepts of morphogenesis as well as digital models of design are contributing to this new model. The paper first analyzes the historical evolution of tectonics as a concept and characterizes the emergence of theoretical framework reflected in concepts and terms related to morphogenesis.Oxman, R. (2010). Digital Tectonics as a Morphogenetic Process. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/695

    Managing multimedia content databases

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    The Internet provides an effective means of dissemination of information in the Humanities, and so in many cases the Internet is becoming the primary or even only form for dissemination of information. In this context, the effective management of published resources becomes essential. Management of published multimedia content on the internet must deal with not only the Content Management but issues of technological obsolescence, effective management and reuse of the digital assets, and version control of information. Sites must address the established disciplines of effective description, classification and preservation to be more than just transient sources of information. Content Management systems on their own address only one part of the problem: the workflow management of publication and separation of content from presentation. The theory toward a Content Management System design that incorporates elements of digital asset management and version control will be described and a working system that implements these principles through internal XML definition of content structures and use of relational database techniques to provide database content management.Hosted by the Scholarly Text and Imaging Service (SETIS), the University of Sydney Library, and the Research Institute for Humanities and Social Sciences (RIHSS), the University of Sydney

    Organismic Supercategories: I. Proposals for a General Unified Theory of Systems- Classical, Quantum, and Complex Biological Systems.\ud \ud \ud

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    The representation of physical and complex biological systems in terms of organismic supercategories was introduced in 1968 by Baianu and Marinescu in the attached paper which was published in the Bulletin of Mathematical Biophysics, edited by Nicolas Rashevsky. The different approaches to relational biology, developed by Rashevsky, Rosen and by Baianu et al.(1968,1969,1973,1974,1987,2004)were later discussed. \ud The present paper is an attempt to outline an abstract unitary theory of systems. In the introduction some of the previous abstract representations of systems are discussed. Also a possible connection of abstract representations of systems with a general theory of measure is proposed. Then follow some necessary definitions and authors' proposals for an axiomatic theory of systems. Finally some concrete examples are analyzed in the light of the proposed theory.\ud \ud An abstract representation of biological systems from the standpoint of the theory of supercategories is presented. The relevance of such representations forG-relational biologies is suggested. In section A the basic concepts of our representation, that is class, system, supercategory and measure are introduced. Section B is concerned with the mathematical representation starting with some axioms and principles which are natural extensions of the current abstract representations in biology. Likewise, some extensions of the principle of adequate design are introduced in section C. Two theorems which present the connection between categories and supercategories are proved. Two other theorems concerning the dynamical behavior of biological and biophysical systems are derived on the basis of the previous considerations. Section D is devoted to a general study of oscillatory behavior in enzymic systems, some general quantitative relations being derived from our representation. Finally, the relevance of these results for a quantum theoretic approach to biology is discussed.\ud \ud http://www.springerlink.com/content/141l35843506596h
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