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computer-PREDICTION OF IDMT RELAY SETTINGS AND PERFORMANCE FOR INTERCONNECTED POWER-SYSTEMS

IEE PROCEEDINGS-C GENERATION TRANSMISSION AND DISTRIBUTION 1983年第3期130卷 139-147页

作者： WHITING, JP LIDGATE, D UNIV MANCHESTER INST SCI & TECHNOLDEPT ELECT ENGN & ELECTRMANCHESTER M60 1QDLANCSENGLAND

The application of the inverse definite minimum time (IDMT) overcurrent relay to power system protection is reviewed, and the present methods for determining its settings are briefly described. A computer program to calculate relay settings based on a generalised procedure, and therefore suitable for both radial and interconnected ring systems, is then proposed. Its application to a specific interconnected system is explained. Two further programs have been developed to be used in conjunction with the first one. These assess, by a simulated circuit breaker tripping facility, how the IDMT protection would perform on an interconnected ring power system when there occurs either a failure of the main protection or a circuit breaker on the faulted section.

关键词： Protection apparatus Power system protection relay settings overcurrent relay IDMT electrical engineering computing power system protection performance power system interconnection overcurrent protection inverse definite minimum time interconnected power systems computer program Power engineering computing relay protection radial and interconnected ring systems Power system management, operation and economics

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Resolution of overlapping peaks and the determination of kinetic parameters for the crystallization of multicomponent system from DTA or DSC curves .1. Non-isothermal kinetics

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THERMOCHIMICA ACTA 1996年第1-2期288卷 123-135页

作者： Kurajica, S Bezjak, A Tkalcec, E Faculty of Chemical Engineering and Technology University of Zagreb 20 Marculićev trg 10 000 Zagreb Croatia

A new computer program has been created to separate overlapping exothermic and endothermic DTA (DSC) effects, obtained under non-isothermal conditions, occurring due to simultaneous nucleation and growth or more growth processes, and also to calculate the kinetic parameters of the processes represented by each peak. A new graphical method for the initialization of the required parameters and the refinement of the initial values by the least squares method is presented. The procedure for the determination of the kinetic parameters from DTA data is demonstrated on a model system and on a kinetic analysis of mullite formation from diphasic gel.

关键词： computer program crystallization kinetics differential thermal analysis mullite overlapping

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AN EXPERT-SYSTEM UTILITY FOR ENVIRONMENTAL-IMPACT ASSESSMENT IN ENGINEERING

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JOURNAL OF ENVIRONMENTAL MANAGEMENT 1995年第1期45卷 1-23页

作者： MERCER, KG UNIV CAPE TOWN DEPT CIVIL ENGN CAPE TOWN SOUTH AFRICA

The idea of this project was to create a prototype primary environmental impact assessment computer program for use in the planning of engineering projects by engineers. The idea is that this system will be used early in the planning phase of projects, to identify potential negative environmental impacts and thereby iteratively modify proposals before further work on them is undertaken. The result would be a saving in time and money to clients by minimizing abortive work. The problem is highly complex in that there are almost limitless combinations of environmental characteristics available for selection for the evaluation of a project proposal. Each characteristic, in turn, is able to assume a varying level of importance. The structure of the system developed to solve this problem uses a combination of an expert system shell and conventional computer programs. The trend in modern environmental impact assessment methods is towards qualitative methods of assessment. As a result, the expert system shell SYNAPSE was chosen to provide a decision-making facility for each environmental characteristic using heuristic techniques. Due to certain limitations of SYNAPSE, a number of computer programs were developed to enable other supporting capabilities to be available to users. These programs were written using Turbo Pascal features such as windowing and event-driven regimens. The concept of using expert systems in environmental management is not new, with several papers published to date. The writer proposes a method whereby a set of rulebases (each specializing in a specific environmental characteristic) can be assembled for the specific problem at hand, and each environmental characteristic assigned a weighting according to the importance of that characteristic to the problem. The results of the SYNAPSE consultation are in the form of real-value logic, and are finally combined and presented to the user in a graphical qualitative form. The programs were developed using cer

关键词： computer program Environmental impact assessment Expert system

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Preliminary studies on fitting experimental differential capacitance to theoretical curves

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JOURNAL OF ELECTROANALYTICAL CHEMISTRY 1996年第1-2期402卷 37-46页

作者： Karolczak, M Faculty of Chemistry Adam Mickiewicz University Ul. Grunwaldzka 6 Pozna? 60-780 Poland

Several theoretical forms of the dependence of the electrode differential capacitance on the electrode potential (capacitance curves) have been examined in the context of their effectiveness in fitting experimental data. Each curve has been derived from a rigorously defined physical model. The link between the capacitance curve and the model has been clearly indicated. The goodness of fit and the curvature measures of non-linearity (maximum intrinsic and maximum parameter effects non-linearity, defined in the paper) served as a criterion for the acceptance or rejection of a particular curve and the related model. A new computer program that facilitates the fitting is briefly described. This user-interactive program enables non-linear fitting of an arbitrary capacitance curve, provides fitted data, together with residuals and the dependence of surface coverage on the electrode potential, and calculates the standard deviations for the parameter estimates, their Student t values and the matrix of parameter correlation coefficients, Additionally, the program provides Box's bias of the parameters and both maximum intrinsic and maximum parameter effects curvature measures. If required, the program output can be arranged to deliver simultaneously the dependence of surface charge density on electrode potential or surface coverage, the theoretical electrocapillary curves and other related information. The two-dimensional grids of the non-linear least-squares solution locus for some parameters are presented. The quality of fit is demonstrated for a few examples. The two-, three- and four-parameter models considered in this paper were unable to fit the experimental data within accepted experimental errors although they did not show any other extraordinary deficiencies. No definite conclusions were reached regarding the six-parameter models considered. Some of them can fit the data within experimental error but more work is required on reparametrization. Some six-parameter mode

关键词： curve fitting computer program differential capacitance

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THEORETICAL-STUDY OF THE INTERFEROMETRIC BRAGG-CELL SPECTRUM ANALYZER

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IEE PROCEEDINGS-J OPTOELECTRONICS 1986年第1期133卷 47-59页

作者： WILBY, WA GATENBY, PV Marconi Defence Systems Ltd. Stanmore UK

The paper reports on a theoretical study of the two-Bragg-cell interferometric spectrum analyser system. This architecture offers an improvement in radio frequency (RF) dynamic range compared to that of the conventional power spectrum analyser. Bulkwave shear mode lithium niobate Bragg cells are assumed for the study together with shot noise limited detection by avalanche photodiodes. A theoretical model is presented which enables the temporal history of the intermediate frequency (IF) output on each channel of the detector array to be predicted. A time-domain model is employed in which the instantaneous Fourier transforms of the (Gaussian weighted) signal and reference waveforms are evaluated at intervals much less than theIFperiod. These are then coherently combined to simulate the heterodyne detection. A computer program based on this theory provides a realistic simulation of pulse responses, ringing and delay effects in theIFfilter, image and sidelobe levels, andIFbreakthrough due to the reference waveform. Results are presented for chirp, pseudonoise and Gaussian noise reference waveforms. It is concluded that for the detection ofRFpulses with durations as short as 100 ns, an instantaneous dynamic range of 50–55 dBrelative to rms noise should be achievable, for simultaneous signals.

关键词： delay effects optical information processing interferometric Bragg-cell spectrum analyser radio frequency dynamic range filter sidelobe levels image levels intermediate frequency output LiNbO3 ringing effects signal detection avalanche photodiodes time-domain model pulse responses computer program Optical information, image and video signal processing spectral analysers pulse duration instantaneous Fourier transforms detector array Other instrumentation and measurement systems dynamic range

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A time-domain finite element method for dynamic viscoelastic solution of layered-half-space responses under loading pulses

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computerS & STRUCTURES 2015年第Nov.期160卷 20-39页

作者： Xu, Qinwu Prozzi, Jorge A. Univ Texas Austin Civil Architectural & Environm Engn Austin TX 78734 USA

This research develops a dynamic viscoelastic model, a Galerkin based time-domain finite element method, and computer program for simulating layered half-space responses under loading pulses. A combined Houbolt, central finite-difference (FD) and forward FD method is proposed for time discretization of acceleration and velocity to reduce time-step lengths. Compared to existing methods, the developed approach has advantages that it: (1) captures the coupled effects of material viscoelasticity, dynamics and system damping, which fosters understanding structural responses and material deformations: (2) is able to model temperature and space-dependent material properties. The model is implemented and validated for a multilayer pavement-soil structure. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Layered half-space Dynamic response Viscoelasticity FE method computer program

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Shading performance of polygonal courtyard forms

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BUILDING AND ENVIRONMENT 2006年第8期41卷 1050-1059页

作者： Muhaisen, AS Gadi, MB Univ Nottingham Sch Built Environm Nottingham NG7 2RD England

This paper examines the shading performance of polygonal courtyard forms with pentagonal, hexagonal, heptagonal and octagonal plans. In order to carry out the investigation, a computer program was developed to calculate the shaded and sunlit areas generated in any of the examined geometries with any dimensions. The computer model is based on a set of equations, which were derived through analysing the relationship between the sun location at any time and the courtyard form. A parametrical study, carried out by the designed model, showed that the courtyard proportions and geometry have a considerable influence on the shading performance of courtyard forms. (C) 2005 Elsevier Ltd. All rights reserved.

关键词： shading courtyard building form computer program

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Evaluation of mechanical face seals operating with hydrocarbon mixtures

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TRIBOLOGY INTERNATIONAL 2003年第3期36卷 199-204页

作者： Peng, XD Xie, YB Gu, YQ Univ Petr Sch Mechatron Engn Shandong 257061 Peoples R China Xian Jiaotong Univ Theory Lubricat & Bearing Inst Xian 710049 Peoples R China

Methods are introduced for calculating thermophysical properties of the common volatile media, such as hydrocarbon mixtures in a petrochemical plant. Using a suitable equation of state for simulating thermodynamic equilibrium of the media and taking parallel face seals as geometrical models, a computer program for predicting seal performance of various phase states mechanical face seals (MFS) operating with the mixtures is presented. Based on theoretical analysis and experimental results, a criterion named fluid film pressure coefficient K-m for identifying phase states and phase states stability of MFS is put forward. An appropriate model for determining mean face temperature is set up and compared to the test results. It is shown that the predicted results are in excellent agreement with the test results. It is proved that the methods and program may be useful in practice. It is concluded that performance of MFS can be predicted only if thermophysical properties of a sealed medium could be expressed in suitable expressions. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： mechanical face seals film pressure coefficient hydrocarbon mixtures phase states (stability) criterion computer program

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OptiRNAi, an RNAi design tool

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computer METHODS AND programS IN BIOMEDICINE 2004年第1期75卷 67-73页

作者： Cui, WW Ning, JC Naik, UP Duncan, MK Univ Delaware Dept Sci Biol Newark DE 19716 USA Univ Delaware Delaware Biotechnol Inst Newark DE 19716 USA

RNA interference (RNAi), a recently developed reverse genetics toot, has many advantages compared to traditional gene knockout methods. Appropriate selection of double stranded RNAs identical to a specific region(s) of the target gene is critical for the successful implementation of this technology. Recently, Elbashir et at. [Methods 26 (2002) 199] has established empirical criteria for siRNA sequence selection that significantly improved the success rate for RNAi attempts. We have developed OptiRNAi, a computational tool, which uses the Elbashir et at. criteria to predict appropriate target sequences for siRNA production. Specificity of these siRNAs for the target of interest can then be assessed by the investigator using the embedded Blast search engine optimized for RNAi design. Thus, OptiRNAi is an efficient and user friendly toot for RNAi design based on criteria that are more stringent than other available tools. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

关键词： RNAi design computer program siRNA

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Toward a predictive model for estimating dew point pressure in gas condensate systems

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FUEL PROCESSING TECHNOLOGY 2013年 116卷 317-324页

作者： Arabloo, Milad Shokrollahi, Amin Gharagheizi, Farhad Mohammadi, Amir H. Sharif Univ Technol Dept Chem & Petr Engn Tehran Iran Univ KwaZulu Natal Sch Chem Engn Thermodynam Res Unit ZA-4041 Durban South Africa Islamic Azad Univ Dept Chem Engn Buinzahra Branch Buinzahra Iran IRGCP Paris France

Dew-point pressure is one of the most important quantities for characterizing and successful prediction of the future performance of gas condensate reservoirs. The objective of this study is to present a reliable, computer-based predictive model for prediction of dew-point pressure in gas condensate reservoirs. An intelligent approach based on least square support vector machine (LSSVM) modeling was developed for this purpose. To this end, the model was developed and tested using a total set of 562 experimental data points from different retrograde gas condensate fluids covering a wide range of variables. Coupled simulated annealing (CSA) was employed for optimization of hyper-parameters of the model. The results showed that the developed model significantly outperforms all the existing methods and provide predictions in acceptable agreement with experimental data. In addition, it is shown that the proposed model is capable of simulating the actual physical trend of the dew-point pressure versus temperature for a constant composition fluid on the phase envelope. (C) 2013 Elsevier B.V. All rights reserved.

关键词： Dew-point pressure Gas condensate Support vector machine Empirical correlations computer program

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