78,256 research outputs found
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Development of raised access floor panel by optimisation techniques
Raised access floor panels currently have a chipboard core and are encapsulated within thin layer of galvanised steel. Two key problems with these raised access floor panels are that they are heavy because of the chipboard and expensive, as the cost of steel has increased significantly over the past few years. The consequence of the raised access floor panel’s mass is that they are difficult to handle, they are expensive to transport and they add considerably to the load on a structures foundation. Glass fibre filled epoxy of floor panels were designed and optimised to achieve lighter weights without compromising their strength using Altair Hypermesh software. A material weight reduction of the glass fibre filled epoxy floor panel was achieved by optimised design of the panes using an evolutionary structural optimisation (ESO) method and the introduction of panel ribs. The lighter weight of new raised floors panel would have a significant impact on the loadings of buildings foundation and allow architects to reduce the carbon footprint of a building resulting in reduced construction costs. In addition, a reduction in the weight of the new raised access floor panels would reduce the transportation costs of the panels
Experiences Migrating Microcosm Learning Materials
Microcosm was an open hypertext system that evolved in the early 1990s, before the advent of the Web. Apart from its success as a research platform it was widely used for presenting interactive educational materials. Since the commercial version of the product ceased to be supported it became necessary for users to migrate their educational materials, generally to the Web. However, the SToMP consortium chose to implement their own environment copying parts of the functionality of Microcosm in order to achieve their educational objectives. This paper examines the motivations of this work in order to understand whether there were features that were available in Microcosm that were not replicated in current Web based solutions
An approximation method for the solution of nonlinear integral equations
A Chebyshev collocation method has been presented to solve nonlinear integral equations in terms of Chebyshev polynomials. This method transforms the integral equation to a matrix equation which corresponds to a system of nonlinear algebraic equations with unknown Chebyshev coefficients. Finally, some examples are presented to illustrate the method and results discussed. (c) 2005 Elsevier Inc. All rights reserved
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Weather, climate, and hydrologic forecasting for the US Southwest: A survey
As part of a regional integrated assessment of climate vulnerability, a survey was conducted from June 1998 to May 2000 of weather, climate, and hydrologic forecasts with coverage of the US Southwest and an emphasis on the Colorado River Basin. The survey addresses the types of forecasts that were issued, the organizations that provided them, and techniques used in their generation. It reflects discussions with key personnel from organizations involved in producing or issuing forecasts, providing data for making forecasts, or serving as a link for communicating forecasts. During the survey period, users faced a complex and constantly changing mix of forecast products available from a variety of sources. The abundance of forecasts was not matched in the provision of corresponding interpretive materials, documentation about how the forecasts were generated, or reviews of past performance. Potential existed for confusing experimental and research products with others that had undergone a thorough review process, including official products issued by the National Weather Service. Contrasts between the state of meteorologic and hydrologic forecasting were notable, especially in the former's greater operational flexibility and more rapid incorporation of new observations and research products. Greater attention should be given to forecast content and communication, including visualization, expression of probabilistic forecasts and presentation of ancillary information. Regional climate models and use of climate forecasts in water supply forecasting offer rapid improvements in predictive capabilities for the Southwest. Forecasts and production details should be archived, and publicly available forecasts should be accompanied by performance evaluations that are relevant to users
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Matrix formulation of fuzzy rule-based systems
In this paper, a matrix formulation of fuzzy rule based systems is introduced. A gradient descent training algorithm for the determination of the unknown parameters can also be expressed in a matrix form for various adaptive fuzzy networks. When converting a rule-based system to the proposed matrix formulation, only three sets of linear/nonlinear equations are required instead of set of rules and an inference mechanism. There are a number of advantages which the matrix formulation has compared with the linguistic approach. Firstly, it obviates the differences among the various architectures; and secondly, it is much easier to organize data in the implementation or simulation of the fuzzy system. The formulation will be illustrated by a number of examples
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Factors affecting seasonal forecast use in Arizona water management: A case study of the 1997-98 El Niño
The 1997-98 El Niño was exceptional, not only because of its magnitude, but also because of the visibility and use of its forecasts. The 3 to 9 mo advance warning of a wet winter with potential flooding in the US Southwest, easily accessible by water management agencies, was unprecedented. Insights about use of this information in operational water management decision processes were developed through a series of semi-structured in-depth interviews with key personnel from a broad array of agencies responsible for emergency management and water supply, with jurisdictions ranging from urban to rural and local to regional. Interviews investigated where information was acquired, how it was interpreted and how it was incorporated into specific decisions and actions. In addition, technical and institutional barriers to forecast use are explored. Study findings emphasize (1) the need for special handling of tailored forecast products on a regional scale, (2) the need for systematic regional forecast evaluation and (3) the potential for climate information to directly affect water management decisions through integrating climate forecasts into water supply outlooks where appropriate
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Relationships between human auditory cortical structure and function
The human auditory cortex comprises multiple areas, largely distributed across the supratemporal plane, but the precise number and configuration of auditory areas and their functional significance have not yet been clearly established. In this paper, we discuss recent research concerning architectonic and functional organisation within the human auditory cortex, as well as architectonic and neurophysiological studies in non-human species, which can provide a broad conceptual framework for interpreting functional specialisation in humans. We review the pattern in human auditory cortex of the functional responses to various acoustic cues, such as frequency, pitch, sound level, temporal variation, motion and spatial location, and we discuss their correspondence to what is known about the organisation of the auditory cortex in other primates. There is some neuroimaging evidence of multiple tonotopically organised fields in humans and of functional specialisations of the fields in the processing of different sound features. It is thought that the primary area, on Heschl's gyrus, may have a larger involvement in processing basic sound features, such as frequency and level, and that posterior non-primary areas on the planum temporale may play a larger role in processing more spectrotemporally complex sounds. Ways in which current knowledge of auditory cortical organisation and different data analysis approaches may benefit future functional neuroimaging studies which seek to link auditory cortical structure and function are discussed
Eccrine spiradenoma: an uncommon breast tumour
Eccrine spiradenoma is a benign tumour of the sweat gland. Eccrine glands can be found almost everywhere but are mostly concentrated on the palms, soles and the axillae. Lesions involving the breast are rare. We present a case of a 13-years-old Malay girl with eccrine spiradenoma of the breast. The clinical presentation and histological features are being described
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A new approach to adaptive fuzzy control: the controller output error method
The controller output error method (COEM) is introduced and applied to the design of adaptive fuzzy control systems. The method employs a gradient descent algorithm to minimize a cost function which is based on the error at the controller output. This contrasts with more conventional methods which use the error at the plant output. The cost function is minimized by adapting some or all of the parameters of the fuzzy controller. The proposed adaptive fuzzy controller is applied to the adaptive control of a nonlinear plant and is shown to be capable of providing good overall system performance
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