954,301 research outputs found

    Two polynomial representations of experimental design

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    In the context of algebraic statistics an experimental design is described by a set of polynomials called the design ideal. This, in turn, is generated by finite sets of polynomials. Two types of generating sets are mostly used in the literature: Groebner bases and indicator functions. We briefly describe them both, how they are used in the analysis and planning of a design and how to switch between them. Examples include fractions of full factorial designs and designs for mixture experiments.Comment: 13 page

    Designing as Construction of Representations: A Dynamic Viewpoint in Cognitive Design Research

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    This article presents a cognitively oriented viewpoint on design. It focuses on cognitive, dynamic aspects of real design, i.e., the actual cognitive activity implemented by designers during their work on professional design projects. Rather than conceiving de-signing as problem solving - Simon's symbolic information processing (SIP) approach - or as a reflective practice or some other form of situated activity - the situativity (SIT) approach - we consider that, from a cognitive viewpoint, designing is most appropriately characterised as a construction of representations. After a critical discussion of the SIP and SIT approaches to design, we present our view-point. This presentation concerns the evolving nature of representations regarding levels of abstraction and degrees of precision, the function of external representations, and specific qualities of representation in collective design. Designing is described at three levels: the organisation of the activity, its strategies, and its design-representation construction activities (different ways to generate, trans-form, and evaluate representations). Even if we adopt a "generic design" stance, we claim that design can take different forms depending on the nature of the artefact, and we propose some candidates for dimensions that allow a distinction to be made between these forms of design. We discuss the potential specificity of HCI design, and the lack of cognitive design research occupied with the quality of design. We close our discussion of representational structures and activities by an outline of some directions regarding their functional linkages

    Developmental changes in information central to artifact representation: evidence from 'functional fluency' tasks.

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    Research suggests that while information about design is a central feature of older children's artifact representations it may be less important in the artifact representations of younger children. Three experiments explore the pattern of responses that 5- and 7-year-old children generate when asked to produce multiple uses for familiar (Experiments 1, 2) and novel (Experiment 3) named objects. Results showed that while older children tended to produce responses based on the known design function of the object, younger children's responses were more flexible, though still constrained by the mechanical structure of the object. Only when ignorant of a novel object's design function did older children produce more varied functions than did younger children. These results suggest that representations supporting object function undergo change across this period of development, with information about design assuming more importance later than it does earlier

    A Graph Rewriting Approach for Transformational Design of Digital Systems

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    Transformational design integrates design and verification. It combines “correctness by construction” and design creativity by the use of pre-proven behaviour preserving transformations as design steps. The formal aspects of this methodology are hidden in the transformations. A constraint is the availability of a design representation with a compositional formal semantics. Graph representations are useful design representations because of their visualisation of design information. In this paper graph rewriting theory, as developed in the last twenty years in mathematics, is shown to be a useful basis for a formal framework for transformational design. The semantic aspects of graphs which are no part of graph rewriting theory are included by the use of attributed graphs. The used attribute algebra, table algebra, is a relation algebra derived from database theory. The combination of graph rewriting, table algebra and transformational design is new

    Building a Common Ground – The Use of Design Representation Cards for Enhancing Collaboration between Industrial Designers and Engineering Designers

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    To achieve success in today’s commercial environment, manufacturers have progressively adopted collaboration strategies. Industrial design has been increasingly used with engineering design to enhance competitiveness. Research between the two fields has been limited and existing collaboration methods have not achieved desired results. This PhD research project investigated the level of collaboration between industrial designers and engineering designers. The aim is to develop an integration tool for enhanced collaboration, where a common language would improve communication and create shared knowledge. An empirical research using questionnaires and observations identified 61 issues between industrial designers and engineering designers. The results were grouped and coded based on recurrence and importance, outlining 3 distinct problem categories in collaborative activity: conflicts in values and principles, differences in design representation, and education differences. A taxonomy further helped categorise design representations into sketches, drawings, models and prototypes. This knowledge was indexed into cards to provide uniform definition of design representations with key information. They should benefit practitioners and educators by serving as a decision-making guide and support a collaborative working environment. A pilot study first refined the layout and improved information access. The final validation involving interviews with practitioners revealed most respondents to be convinced that the tool would provide a common ground in design representations, contributing to enhanced collaboration. Additional interviews were sought from groups of final-year industrial design and engineering design students working together. Following their inter-disciplinary experience, nearly all respondents were certain that the cards would provide mutual understanding for greater product success. Lastly, a case study approach tested the cards in an industry-based project. A design diary captured and analysed the researchers’ activities and observations on a daily basis. It revealed positive feedback, reinforcing the benefits of the cards for successful collaboration in a multi-disciplinary environment. Keywords Industrial Design, Engineering Design, Collaboration, Design Representation, New Product Development.</p

    Non-Direct Encoding Method Based on Cellular Automata to Design Neural Network Architectures

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    Architecture design is a fundamental step in the successful application of Feed forward Neural Networks. In most cases a large number of neural networks architectures suitable to solve a problem exist and the architecture design is, unfortunately, still a human expert’s job. It depends heavily on the expert and on a tedious trial-and-error process. In the last years, many works have been focused on automatic resolution of the design of neural network architectures. Most of the methods are based on evolutionary computation paradigms. Some of the designed methods are based on direct representations of the parameters of the network. These representations do not allow scalability; thus, for representing large architectures very large structures are required. More interesting alternatives are represented by indirect schemes. They codify a compact representation of the neural network. In this work, an indirect constructive encoding scheme is proposed. This scheme is based on cellular automata representations and is inspired by the idea that only a few seeds for the initial configuration of a cellular automaton can produce a wide variety of feed forward neural networks architectures. The cellular approach is experimentally validated in different domains and compared with a direct codification scheme.Publicad
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