10,705 research outputs found

    Design and Development of the Space Shuttle Tail Service Masts

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    The successful launch of a space shuttle vehicle depends on the proper operation of two tail service masts (TSMs). Reliable TSM operation is assured through a comprehensive design, development, and testing program. The results of the concept verification test (CVT) and the resulting impact on prototype TSM design are presented. The design criteria are outlined, and the proposed prototype TSM tests are described

    Spectrum Analysis of Speech Recognition via Discrete Tchebichef Transform

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    Speech recognition is still a growing field. It carries strong potential in the near future as computing power grows. Spectrum analysis is an elementary operation in speech recognition. Fast Fourier Transform (FFT) is the traditional technique to analyze frequency spectrum of the signal in speech recognition. Speech recognition operation requires heavy computation due to large samples per window. In addition, FFT consists of complex field computing. This paper proposes an approach based on discrete orthonormal Tchebichef polynomials to analyze a vowel and a consonant in spectral frequency for speech recognition. The Discrete Tchebichef Transform (DTT) is used instead of popular FFT. The preliminary experimental results show that DTT has the potential to be a simpler and faster transformation for speech recognition

    Building of the Enabled Web-Based GIS Participation System: A Tool to Enhance Community Participation in City Development Plan

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    This research has been conducted under the frame work of GIS interoperability infrastructure financed by the Malaysian Ministry of Science and Technology. In this paper, we discuss the development and analyze the potential application of the Geographical Information System (GIS) and Internet computing to enhance community participation in the decision making processes i.e. in Local Plan of Block 3, Melaka Tengah district as a model. The focus of this paper is on the designing and development of the enabled Web-based GIS Participation System called, GISPSS. It is considered to be similar to a Real Time Resources Discovery Server but it comprises four main complimentary components: the Map Viewer, the Objection Support, the Planning Process Documentation, and the Web Content Management. The functional features of these components are highlighted. The multi-tiered architecture forms the basis of the Enabled Webbased GIS system has been adopted in this research

    Practical Database Design for Industrial Maintenance System

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    This paper describes how a database design can play an important role for developing practical industrial maintenance system. The good database design will in return give a better information sharing and good system in term of data accessibility. The design of the database are presented and illustrated by a case. The preliminary result presented to show that is possible to access a more correct view of the situation in the system development and thereby obtain a better base for making maintenance decisions. The database supports the development of applications e.g. for monitoring the performance of a maintenance in the production, for deciding the most appropriate maintenance policy or for simulating possible maintenance solutions

    Differential inhibition of polymorphonuclear leukocyte recruitment in vivo by dextran sulphate and fucoidan

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    The selectin-mediated rolling of leukocytes along the endothelial cells is a prerequisite step followed by firm adhesion and extravasation into the inflamed tissue. This initial contact can be suppressed by sulphated polysaccharides. We have studied the effect of sulphated polysaccharides on the ultimate polymorphonuclear leukocyte (PMN) recruitment and plasma leakage in rabbit skin in response to intradermal injection of various inflammatory mediators. PMN infiltration evoked by various PMN chemoattractants (FMLP, C5a desArg, LTB4 and IL-8) was significantly inhibited after intravenous injection of dextran sulphate (25 mg/kg), heparin (2 × 90 mg/kg) or fucoidan (1 mg/kg). PMN-dependent plasma leakage was equally well reduced by the different sulphated polymers. Vascular permeability induced by histamine or thrombin acting via a PMN-independent mechanism was not reduced. Fucoidan was the only polysaccharide able to suppress IL-1-induced PMN infiltration for 60–70%. Local administration of dextran sulphate had no effect on PMN-dependent plasma leakage. Differential inhibition of PMN recruitment was determined after injection of dextran sulphate or fucoidan depending on the type of insult. Therefore, these results suggest that different adhesion pathways are utilized during PMN recruitment in vivo in response to chemoattractants and IL-1

    Moir\'e patterns in quantum images

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    We observed moir\'e fringes in spatial quantum correlations between twin photons generated by parametric down-conversion. Spatially periodic structures were nonlocally superposed giving rise to beat frequencies typical of moir\'e patterns. This result brings interesting perspectives regarding metrological applications of such a quantum optical setup.Comment: 4 pages, 5 figure

    Impact of ultrafast electronic damage in single particle x-ray imaging experiments

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    In single particle coherent x-ray diffraction imaging experiments, performed at x-ray free-electron lasers (XFELs), samples are exposed to intense x-ray pulses to obtain single-shot diffraction patterns. The high intensity induces electronic dynamics on the femtosecond time scale in the system, which can reduce the contrast of the obtained diffraction patterns and adds an isotropic background. We quantify the degradation of the diffraction pattern from ultrafast electronic damage by performing simulations on a biological sample exposed to x-ray pulses with different parameters. We find that the contrast is substantially reduced and the background is considerably strong only if almost all electrons are removed from their parent atoms. This happens at fluences of at least one order of magnitude larger than provided at currently available XFEL sources.Comment: 15 pages, 3 figures submitted to PR
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