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Application of the piecewise linear polynomial functions expansion is extended to linear time-varying systems. With the treatment of the product of two time functions, two types of operational matrix are developed. By applying these operational matrices, the dynamic equations are transformed into a set of algebraic equations. A recursive algorithm is derived and the system equations can be solved with very low dimensional matrix inversions. This represents a considerable saving of computer memory capacity and computing time. 相似文献
23.
This paper investigates the control and state observation problem for periodic linear controllable and observable multimodal systems. For a controllable periodic linear multimodal system, this paper proposes an alternative minimum-norm dynamic state feedback control scheme for state transition matrix assignment. Also presented is a new design of state observers for an observable periodic linear multimodal system. Finally, an analysis of closed-loop behaviour of controlled periodic linear multimodal systems using a state-estimate is given 相似文献
24.
LU-PING TSAO CHING-LAIN CHOU CHUEN-MING CHEN CHI-TEH CHEN 《International journal of systems science》2013,44(2):95-102
A new aiming point guidance (APG) law is presented which generates a missile turn rate command proportional to the heading error, that is defined as the angle between the current missile heading and predicted aiming point. The target under consideration is assumed to be manoeuvring with constant longitudinal and/or lateral accelerations, and the missile dynamics are modelled as an acceleration-limited first-order lag point mass. The aiming point is calculated based on current intercept geometry and target velocity and position. Time-to-go, a key factor for successful interception, is estimated by a time-to-go predictor. With the heading error defined as stated above, the guidance law can guide the missile into the collision course in the early stage of the engagement. As a consequence, the later part of the missile trajectory tends to be a straight line, provided that the target maintains its current status. The performance of the proposed APG is evaluated by simulation and is compared with the proportional navigation guidance (PNG) and Kim's prediction guidance (PRG) law (Kim 1985). Numerical simulations show that APG is superior to PNG and PRG in both intercept time and miss distance 相似文献
25.
Double-shifted Chebyshev polynomials are developed in this study to approximate the solutions of the convolution integral, Volterra integral equation, and Fredholm integral equation. This method simplifies the computations of integral equations to the successive solutions of a linear algebraic equation in matrix form. In addition, the computational complexity can be reduced remarkably. Three examples are illustrated. It is seen that the proposed approach is straightforward and convenient, and converges faster in finding approximations than other existing orthogonal function methods. 相似文献
26.
The piecewise linear polynomial function approach to the minimum energy control of linear systems with time delay, is presented in this paper. The concepts of a delay shift matrix and an operational matrix for integration are employed in solving the related state and costate equations containing terms with advanced and delayed arguments. An attractive feature of the present method is its ultimate simplicity and convenience. The differential equations with delay and advance terms are converted into a set of linear algebraic equations using a recurrence algorithm. An example demonstrates the accuracy of the method. 相似文献
27.
锅炉对流管束快速腐蚀的原因分析 总被引:1,自引:1,他引:1
分析了一台燃煤改燃油锅炉运行中产生对流管腐蚀的原因,提出了改进建议。 相似文献
28.
J.G. CHUNG J.H. LEE C.C. HO J.M. LAI Y.C. CHOU H.H. TENG C.F. HUNG S.C. HUANG 《Journal of Food Biochemistry》1996,20(4):481-490
The N-acetyltransferase activity was determined in 58 common fruits and vegetables. The assay was based on acetylation of 2-aminofluorene or p-amino-benzoic acid, followed by high pressure liquid chromatographic analysis of products and remaining nonacetylated substrate. The highest specific activities were observed in Balsam pear which contained 17.37 ± 1.45 N-acetyl aminofluorene nmole/min/mg protein and 46.27 ± 6.87 N-acetyl p-aminobenzoic acid nmole/min/mg protein. N-acetyltransferase activities within the remaining 57 foodstuffs analyzed ranged from none detected to 3.39 ± 0.72 N-acetyl aminofluorene nmole/min/mg protein and none detected to 32.45 ± 6.55 N-acetyl p-aminobenzoic acid nmole/min/mg protein. This is the first demonstration of acetyl CoA: arylamine N-acetyltransferase activity in common foodstuffs. 相似文献
29.
聚氨酯改性TDE-85/E-51环氧树脂的固化反应 总被引:3,自引:0,他引:3
以混合芳胺为固化剂,通过聚氨酯(PU)对4,5-环氧环己烷-1,2-二甲酸二缩水甘油酯(TDE-85)与二酚基丙烷缩水甘油醚(E-51)环氧树脂的混合树脂体系的改性,制备了高性能聚氨酯改性环氧树脂(PU/EP)。通过差示扫描量热法(DSC),确定了PU/EP体系的最佳固化条件,并探讨了PU/EP体系的固化反应动力学特征。研究结果表明,PU/EP体系的最佳固化条件为:25℃12h+150℃2h。PU/EP体系的固化反应活化能为69.18kJ/mol,反应级数为0.901。 相似文献
30.