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81.
This paper presents a structural application of a shape optimization method based on a Genetic Algorithm (GA). The method
produces a sequence of fixed-distance step-wise movements of the boundary nodes of a finite element model to derive optimal
shapes from an arbitrary initial design space. The GA is used to find the optimal or near-optimal combination of boundary
nodes to be moved for a given step movement. The GA uses both basic and advanced operators. For illustrative purposes, the
method has been applied to structural shape-optimization. The shape-optimization methodology presented allows local optimization,
where only crucial parts of a structure are optimized as well as global shape-optimization which involves finding the optimal
shape of the structure as a whole for a given environment as described by its loading and freedom conditions. Material can
be removed or added to reach the optimal shape. Two examples of structural shape optimization are included showing local and
global optimization through material removal and addition.
Received October 14, 1999 相似文献
82.
We describe a system which supports dynamic user interaction with multimedia information using content-based hypermedia navigation
techniques, specialising in a technique for navigation of musical content. The model combines the principles of open hypermedia, whereby hypermedia link information is maintained by a link service, with content-based retrieval techniques in which a database is queried based on a feature of the multimedia content; our approach could be described as
‘content-based retrieval of hypermedia links’. The experimental system focuses on temporal media and consists of a set of
component-based navigational hypermedia tools. We propose the use of melodic pitch contours in this context and we present
techniques for storing and querying contours, together with experimental results. Techniques for integrating the contour database
with open hypermedia systems are also discussed. 相似文献
83.
As a research paradigm, pattern analysis has been shown to be an effective tool for analyzing complex game situations in
both chess and go. We extend the prior pattern analysis research in chess to the domain of shogi. Shogi is computationally
more complex than chess and should realize greater benefits than the chess domain from pattern recognition and pattern exploitation
research. The IAM program, which has accurately predicted up to 28% of the moves for a specific chess player, is redesigned
to operate in the domain of shogi. Results similar to those achieved for the domain of chess are achieved in shogi.
Received 25 February 1999 / Revised 1 October 1999 / Accepted in revised form 2 February 2000 相似文献
84.
Koop D Scheidegger CE Callahan SP Freire J Silva CT 《IEEE transactions on visualization and computer graphics》2008,14(6):1691-1698
Building visualization and analysis pipelines is a large hurdle in the adoption of visualization and workflow systems by domain scientists. In this paper, we propose techniques to help users construct pipelines by consensus--automatically suggesting completions based on a database of previously created pipelines. In particular, we compute correspondences between existing pipeline subgraphs from the database, and use these to predict sets of likely pipeline additions to a given partial pipeline. By presenting these predictions in a carefully designed interface, users can create visualizations and other data products more efficiently because they can augment their normal work patterns with the suggested completions. We present an implementation of our technique in a publicly-available, open-source scientific workflow system and demonstrate efficiency gains in real-world situations. 相似文献
85.
86.
David-A. Mendels Emmelyn M. Graham Steven W. Magennis Anita C. Jones François Mendels 《Microfluidics and nanofluidics》2008,5(5):603-617
The development and adoption of lab-on-a-chip and micro-TAS (total analysis system) techniques requires not only the solving
of design and manufacturing issues, but also the introduction of reliable and quantitative methods of analysis. In this work,
two complementary tools are applied to the study of thermal and solutal transport in liquids. The experimental determination
of the concentration of water in a water–methanol mixture and of the temperature of water in a microfluidic T-mixer are achieved
by means of fluorescence lifetime imaging microscopy (FLIM). The results are compared to those of finite volume simulations
based on tabulated properties and well-established correlations for the fluid properties. The good correlation between experimental
and modelled results demonstrate without ambiguity that (1) the T-mixer is an adiabatic system within the conditions, fluids
and flow rates used in this study, (2) buoyancy effects influence the mixing of liquids of different densities at moderate
flow rates (Reynolds number Re ≪ 10−2), and (3) the combination of FLIM and computational fluid dynamics has the potential to be used to measure the thermal and
solutal diffusion coefficients of fluids for a range of temperatures and concentrations in one single experiment. As such,
it represents a first step towards the full-field monitoring of both the extent and the kinetics of a chemical reaction.
相似文献
David-A. MendelsEmail: |
87.
O'Riordan E Orlova TN Mendelev N Patschan D Kemp R Chander PN Hu R Hao G Gross SS Iozzo RV Delaney V Goligorsky MS 《Proteomics. Clinical applications》2008,2(7-8):1025-1035
The pathogenesis of progressive renal allograft injury, which is termed chronic allograft nephropathy (CAN), remains obscure and is currently defined by histology. Prospective protocol-biopsy trials have demonstrated that clinical and standard laboratory tests are insufficiently sensitive indicators of the development and progression of CAN. The study aim was to determine if CAN could be characterized by urinary proteomic data and identify the proteins associated with disease. The urinary proteome of 75 renal transplant recipients and 20 healthy volunteers was analyzed using surface enhanced laser desorption and ionization MS. Patients could be classified into subgroups with normal histology and Banff CAN grades 2-3 with a sensitivity of 86% and a specificity of 92% by applying the classification algorithm Adaboost to urinary proteomic data. Several urinary proteins associated with advanced CAN were identified including α1-microglobulin, β2-microglobulin, prealbumin, and endorepellin, the antiangiogenic C-terminal fragment of perlecan. Increased urinary endorepellin was confirmed by ELISA and increased tissue expression of the endorepellin/perlecan ratio by immunofluoresence analysis of renal biopsies. In conclusion, analysis of urinary proteomic data has further characterized the more severe CAN grades and identified urinary endorepellin, as a potential biomarker of advanced CAN. 相似文献
88.
We demonstrate that a near-field microwave microscope based on a transmission line resonator allows imaging in a substantially wide range of frequencies, so that the microscope properties approach those of a spatially resolved impedance analyzer. In the case of an electric probe, the broadband imaging can be used in a direct fashion to separate contributions from capacitive and resistive properties of a sample at length scales on the order of one micron. Using a microwave near-field microscope based on a transmission line resonator we imaged the local dielectric properties of a focused ion beam milled structure on a high-dielectric-constant Ba(0.6)Sr(0.4)TiO(3) thin film in the frequency range from 1.3 to 17.4 GHz. The electrostatic approximation breaks down already at frequencies above approximately 10 GHz for the probe geometry used, and a full-wave analysis is necessary to obtain qualitative information from the images. 相似文献
89.
The paper addresses a notion of configuring systems, constructing them from specified component parts with specified sharing.
This notion is independent of any underlying specification language and has been abstractly identified with the taking of
colimits in category theory. Mathematically it is known that these can be expressed by presheaves and the present paper applies
this idea to configuration.
We interpret the category theory informally as follows. Suppose ? is a category whose objects are interpreted as specifications,
and for which each morphism u : X→Y is interpreted as contravariant ‘instance reduction’, reducing instances of specification Y to instances of X. Then a presheaf P: Set ?op represents a collection of instances that is closed under reduction. We develop an algebraic account of presheaves in which
we present configurations by generators (for components) and relations (for shared reducts), and we outline a proposed configuration
language based on the techniques. Oriat uses diagrams to express colimits of specifications, and we show that Oriat's category
Diag(?) of finite diagrams is equivalent to the category of finitely presented presheaves over ?.
Received May 1998 / Accepted in revised form August 2000 相似文献
90.
Shapiro Steven; Lesperance Yves; Levesque Hector J. 《Journal of Logic and Computation》2007,17(5):983-1018
Although there has been much discussion of belief change (e.g.[4, 21]), goal change has not received much attention. In thispaper, we propose a method for goal change in the frameworkof Reiter's; [12] theory of action in the situation calculus[8, 10], and investigate its properties. We extend the frameworkdeveloped by Shapiro et al. [17] and Shapiro and Lespérance[16], where goals and goal expansion were modelled, but goalcontraction was not. 相似文献