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NUMERICAL DETERMINATION OF A PERFORMANCE INDEX FOR IMPROVED SYSTEM RESPONSE

PROCEEDINGS OF THE INSTITUTION OF ELECTRICAL ENGINEERS-LONDON 1978年第7期125卷 698-700页

作者： SMITH, JR STRINGFELLOW, DC VICKERS LTD DIV DESIGN & PROJECT SWINDON WILTSHIRE ENGLAND

The paper describes a computer program for the systematic numerical predetermination of a performance indexJ=∫∞0(xtQx+u2)dtsuch that the synthesised feedback controller that minimisesJresults in a controlled system with satisfactory eigenvalues that all lie to the left of the set {s|s=α, α≤0} in the complex plane. The computer algorithm, which is based on the derivatives of the eigenvalues with respect to the coefficients ofQ, may be used in isolation or can be included in an overall synthesis procedure. Examples illustrating the method are included.

关键词： performance index optimal control Control system analysis and synthesis methods Other topics in systems theory eigenvalues control system analysis computing FORTRAN IV Optimal control computer algorithm synthesised feedback controller numerical determination Control engineering computing computer program

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THEODORSENS IDEAL PROPELLER PERFORMANCE WITH AMBIENT PRESSURE IN THE SLIPSTREAM

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JOURNAL OF AIRCRAFT 1993年第3期30卷 417-419页

作者： SCHOUTEN, G Delft University of Technology 2629 HS Delft The Netherlands

Theodorsen's propeller theory provides a rational estimation of the highest efficiency attainable for specified operating conditions. However, the theory suffers from the deficiency that it yields a static pressure in the slipstream which is too high. As a consequence of the high pressure in the slipstream, Theodorsen's theory leads to the optimistic result that the required power is less than what one would roughly expect from the product of thrust T and axial velocity (V + w/2) at the propeller blades. The remedy proposed for both the deficiencies, the high pressure in the slipstream, and the low required power, is to allow the outer parts of the helicoidal sheets to roll up in helical vortices wrapped around an inhomogeneous slipstream. It is not our aim to rephrase Theodorsen's theory, only the effects on the expressions for the thrust coefficient cs, the power coefficient cp, and the efficiency η will be discussed in detail.

关键词： Propeller Performance Vortex Sheet Incompressible Flow Power Coefficient Static Pressure Conservation of Mass Reynolds Transport Theorem computer algorithm Lift Coefficient Aircraft Design

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Predicting and analyzing X-rays to measure propellant crack propagation speed

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JOURNAL OF PROPULSION AND POWER 1996年第2期12卷 310-314页

作者： Frederick, RA Williams, BM Farmer, SB SVERDRUP TECHNOL INC ENGN SUPPORT DEPTARNOLD AFBTN 37389 SVERDRUP TECHNOL INC PLUME DATA CTRARNOLD AFBTN 37389

Real-time radioscopy (RTR) of solid rocket motors has revealed information about the propellant burning and cracking. This theoretical study evaluated the viability of real-time radioscopy for measuring propellant crack propagation speed. The scope included the quantitative interpretation of crack tip velocity from simulated radiographic images of a burning, center-perforated motor. The simplified motor simulation portrayed a bore crack that moved radially at a speed that was 10 times the propellant burning rate. Comparing the image interpretation with the simulation input quantified the accuracy of the crack velocity measurement under favorable, first-order assumptions. The simulation included the effects of system configuration, finite spatial resolution (from video pixels), and (8-bit) intensity digitization. The image digitization and interpretation introduced a +/-20% measurement uncertainty in the crack tip speed for the nominal condition. A +/-10% uncertainty resulted from doubling the camera gain. Using curve-fitting techniques, the result was a constant 2% bias in the crack tip velocity measurement. This best case analysis shows that RTR has the potential for making acceptable measurements under the conditions studied.

关键词： Crack Propagation Propellant Burn Rate Solid Rocket Motor Image Processing Los Alamos National Laboratories Solid Propellant Rocket Automatic Gain Control computer algorithm Real Time System Energy Intensity

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AN ANNEALING algorithm FOR SEARCHING OPTIMAL BLOCK-DESIGNS

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BIOMETRICAL JOURNAL 1992年第5期34卷 529-538页

作者： JANSEN, J DOUVEN, RCMH VANBERKUM, EEM CTR PLANT BREEDING & REPRODUCT RES 6700 AA WAGENINGENNETHERLANDS UNIV EINDHOVEN EINDHOVENNETHERLANDS

This paper is concerned with a computer algorithm for searching optimal block designs. Thc algorithm uses a technique called simulated annealing. Exchange and interchange steps are defined in a way similar to JONES an... 详细信息

关键词： computer algorithm CRITERION FOR DESIGN OPTIMALITY INTERCHANGE STEP EXCHANGE STEP OPTIMAL BLOCK DESIGN

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The mapping and reconstitution of a conformational discontinuous B-cell epitope of HIV-1

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JOURNAL OF MOLECULAR BIOLOGY 2003年第1期334卷 87-101页

作者： Enshell-Seijffers, D Denisov, D Groisman, B Smelyanski, L Meyuhas, R Gross, G Denisova, G Gershoni, JM Tel Aviv Univ George S Wise Fac Life Sci Dept Cell Res & Immunol Tel Aviv Israel Galilee Technol Ctr MIGAL Kiryat Shmona Israel

A method for the discovery of the structure of conformational discontinuous epitopes of monoclonal antibodies (mAbs) is described. The mAb is used to select specific phages from combinatorial phage-display peptide libraries that in turn are used as an epitope-defining database that is applied via a novel computer algorithm to analyze the crystalline structure of the original antigen. The algorithm is based on the following: (1) Most contacts between a mAb and an antigen are through side-chain atoms of the residues. (2) In the three-dimensional structure of a protein, amino acid residues remote in linear sequence can juxtapose to one another through folding. (3) Tandem amino acid residues of the selected phage-displayed peptides can represent pairs of juxtaposed amino acid residues of the antigen. (4) Contact residues of the epitope are accessible to the antigen surface. (5) The most frequent tandem pairs of amino acid residues in the selected phage-displayed peptides can reflect pairs of juxtaposed amino acid residues of the epitope. Application of the algorithm enabled prediction of epitopes. On the basis of these predictions, segments of an antigen were used to reconstitute an antigenic epitope mimetic that was recognized by its original mAb. (C) 2003 Elsevier Ltd. All rights reserved.

关键词： monoclonal antibody epitope phage display computer algorithm protein conformation

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Development and validation of a computerized South Asian Names and Group Recognition algorithm (SANGRA) for use in British health-related studies

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JOURNAL OF PUBLIC HEALTH MEDICINE 2001年第4期23卷 278-285页

作者： Nanchahal, K Mangtani, P Alston, M Silva, ID Univ London London Sch Hyg & Trop Med Dept Epidemiol & Populat Sci London WC1E 7HT England

Background Studies on ethnic variations in health have played an important role in aetiological and health services research. Most routine datasets, however, do not include information on ethnicity. South Asians, one of the largest minority ethnic groups in Britain, have distinctive names that also allow differentiation of the main sub-groups with their important differences in health-related exposures and disease risks. Methods A computerized name recognition algorithm (SANGRA) was developed incorporating directories of South Asian first names and surnames together with their religious and linguistic origin. SANGRA was validated using health-related data with self-ascribed information on ethnicity. Results SANGRA was successful in recognizing South Asian origin in reference datasets, with sensitivity of 89-96 per cent, specificity of 94-98 per cent, positive predictive value (PPV) of 80-89 per cent and negative predictive value (NPV) of 98-99 per cent. Religious origin was correctly assigned in the majority of cases: sensitivity, specificity and PPV were 94 per cent, 91 per cent and 90 per cent for Hindus;90 per cent, 99 per cent and 98 per cent for Muslims;and 76 per cent, 99 per cent and 94 per cent for Sikhs. SANGRA correctly identified 76 per cent Gujerati and 70 per cent Punjabi names, although only 62 per cent of Gujerati names were sufficiently distinct to be allocated to the Gujerati-only category and only 53 per cent Punjabi names were allocated to the Punjabi-only category. However, specificity and PPV were high for both languages (respectively 97 per cent and 93 per cent for Gujerati, and 99 per cent and 97 per cent for Punjabi). Conclusions SANGRA provides a practical and valid method of ascertaining South Asian origin by name and, to a lesser degree of accuracy, of differentiating between the main religious and linguistic subgroups living in Britain. This algorithm will be useful in health-related studies where information on self-ascribed ethnicity is

关键词： South Asian ethnicity computer algorithm

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Automated detection of the phase III slope during inert gas washout testing

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JOURNAL OF APPLIED PHYSIOLOGY 2012年第6期112卷 1073-1081页

作者： Stuart-Andrews, Christopher R. Kelly, Vanessa J. Sands, Scott A. Lewis, Angela J. Ellis, Matthew J. Thompson, Bruce R. Alfred Hosp Dept Allergy Immunol & Resp Med Serv Physiol Melbourne Vic Australia Monash Univ Dept Med Nursing & Hlth Sci Clayton Vic Australia Cooperat Res Council Asthma & Airways Glebe NSW Australia Massachusetts Gen Hosp Dept Med Pulm & Crit Care Unit Boston MA 02114 USA Harvard Univ Sch Med Boston MA USA Monash Univ Ritchie Ctr Baby Hlth Res Monash Inst Med Res Clayton Vic Australia Brigham & Womens Hosp Div Sleep Med Boston MA 02115 USA

Stuart-Andrews CR, Kelly VJ, Sands SA, Lewis AJ, Ellis MJ, Thompson BR. Automated detection of the phase III slope during inert gas washout testing. J Appl Physiol 112: 1073-1081, 2012. First published December 15, 2011;doi:10.1152/japplphysiol.00372.2011.-We describe a method to determine the phase III slope for the purpose of calculating indexes of ventilation heterogeneity, S-acin and S-cond, from the multiple breath nitrogen washout test (MBNW). Our automated method applies a recursive, segmented linear regression technique to each breath of the MBNW test and determines the best point of transition, or breakpoint, between each phase of the washout. A sample set of 50 MBNW tests (controls, asthma, and COPD) was used to establish the conditions in which the phase III slope obtained from the automated technique best matched that obtained by two manual interpreters. We then applied our technique to a test set of 30 subjects (with an even number of subjects in each of the above groups) and compared these results against the manual analysis of a third independent manual interpreter. Indexes of ventilation heterogeneity were determined using both methods and compared. The phase III slopes determined by the automatic technique best matched the manual interpreter when the phase III slope was calculated from the phase II-III transition point plus the addition of 50% of the phase II volume to the end of the expiration. Calculation of the indexes S-acin and S-cond showed no overall difference between analysis methods in either S-acin (P = 0.14) or S-cond (P = 0.59) when the set threshold was applied to our automated analysis. Our analysis method provides an alternate means for rapid quantification of the MBNW test, removing operator dependence without alteration in either S-acin or S-cond.

关键词： inert gas washout computer algorithm alveolar slope

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CHARACTERIZATION OF THE INTERACTION CONSTANTS FOR THE BINDING OF 2 UNLABELED LIGANDS TO THE SITES OF A RECEPTOR - AN EXPERIMENTAL STRATEGY

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NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY 1989年第5期339卷 487-495页

作者： SWILLENS, S GOURDIN, A DELAHAUT, O 1.Institut de Recherche Interdisciplinaire Université Libre de Bruxelles Campus Erasme route de Lennik 808 B-1070 Brussels Belgium

The model describing the binding of three ligands to the sites of a receptor is theoretically studied in order to characterize the binding interaction between two unlabelled ligands. For this, the binding of a third labelled ligand, the affinity of which is dependent on the presence of the unlabelled ligands, must be measured in different conditions. This paper describes an experimental strategy leading to an accurate determination of the equilibrium parameters of the model. This strategy, which assumes that the model is compatible with the data, rests on the determination of the optimal experimental conditions, i.e. the choice of the ligand concentrations which minimize the error of the parameter estimates. For this purpose, a computer program which runs on a microcomputer under the MS-DOS operating system has been elaborated on the basis of the D-optimization criterion. This work shows that such a computer analysis is essential to the determination of the optimal experimental design, even when very simple biochemical systems are considered.

关键词： Ligand binding computer algorithm D-optimization criterion

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AN algorithm FOR FINDING ALL FUNCTIONS EMBEDDED IN A RELATION

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INTERNATIONAL JOURNAL OF GENERAL SYSTEMS 1985年第2-3期10卷 187-195页

作者： SNELL, JL SUNY BINGHAMTON THOMAS J WATSON SCH ENGN APPL SCI & TECHNOLDEPT SYST SCIBINGHAMTONNY 13901 USA

The problem is posed: find an algorithm which for any givenn-dimensional relationR⊂ A1× A2× ⃛ × An, defined on a set familyA= { A1, A2, ⃛, Anrcub;,n= 1,2, ⃛, determines all functional dependences between disjoint subsets ofAwhich are embedded inR. A solution algorithm is presented, a theorem is proved that allows a simplification in the algorithm, and an efficient computer implementation (available through the General Systems Depository) is demonstrated.

关键词： algorithm computer algorithm relation function embedded function.

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A COMPUTATIONAL algorithm FOR THE POLYNOMIAL-APPROXIMATION METHOD OF SENSITIVITY ANALYSIS IN CHEMICAL-KINETICS

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JOURNAL OF THE CHINESE CHEMICAL SOCIETY 1985年第3期32卷 253-261页

作者： HWANG, JT Department of Chemistry National Tsing Hua University Hsinchu Taiwan 300 R.O.C. The author formerly a chemistry student of the National Taiwan University from 1966 to 1970 and presently a professor of Chemistry at the National Tsinghua University wishes to dedicate this paper to Dr. Chien.

AbstractThis paper describes the logic for a program developed by the author to implement the polynomial approximation method (PAM) of sensitivity analysis for general kinetic purposes. The relevant equations and numerical details of the algorithm are outlined, a flow chart is provided, and some programming considerations are discussed in detail. A listing of the PAM code is given in the appendix. The paper also gives a few suggestions for possible improvements and extensions of the present algorithm.

关键词： Sensitivity analysis chemical kinetics computer algorithm polynomial approximation method

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