Motion Planning for a Wheeled Robot (Kinematic Approximation)

The motion-planning problem for a wheeled robot is solved in kinematic approximation. The solution is given for robots with one and two steering wheels. The results of solving the problem for a specific system are compared with the results obtained by other authors__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 2, pp. 91–102, February 2005.     

GENERAL SOLUTION OF THE OVERALL BENDING OF FLEXIBLE CIRCULAR RING SHELLS WITH MODERATELY SLENDER RATIO AND APPLICATIONS TO THE BELLOWS (Ⅳ)-CALCULATION FOR U-SHAPED BELLOWS

This is one of the applications of Part (I), in which the angular stiffness, and the corresponding stress distributions of U-shaped bellows were discussed. The bellows was divided into protruding sections, concave sections and ring plates for the calculation that the general solution (I) with its reduced form to ring plates were used respectively, but the continuity of the surface stresses and the meridian rotations at each joint of the sections were entirely satisfied. The resent results were compared with those of the slender ring shell solution proposed earlier by the authors, the standards of the Expansion Joint Manufacturers Association (EJMA), the experiment and the finite element method. It is shown that the governing equation and the general solution (I) are very effective. Contributed by HUANG Qian Biography: ZHU Wei-ping (1962-)     

Triply bridged (1,3,5) cyclophanes from cystine and lanthionine linkers—a comparison

The condensation of benzene 1,3,5-tricarbonylchloride with cystine-di-Me [H₂N-CH(COOMe)-CH₂-S-S-CH₂-CH(COOMe)-NH₂] yielded triply bridged (1,3,5) cyclophane 1, which was shown by detailed spectral studies and molecular orbital calculations to have a D₃ symmetry with conformationally identical linkers and a spherical topology. In sharp contrast, the (1,3,5) cyclophane 2 from the rarely studied lanthionine di-Me [H₂N-CH(COOMe)-CH₂-S-CH₂-CH(COOMe)-NH₂], showed only a equatorial twofold symmetry. This work highlights the special properties of the -S-S- bridge in cystine, which makes it an exceptional synthon in nature and organic synthesis.     

Two Discrete Cu-Complexes Constructed from a Multidentate N-Containing Dinucleating Ligand

Two comparable discrete complexes [CuⅡ(CH3CN)2L2]·2(ClO4) 1 and [CuI2I2L2]·(DMF)2 2 were successfully synthesized by the reaction of CuⅡ and CuⅠ salts with a novel dinucleating ligand 2,5-bis(3-pyridinylmethylthio)-1,3,4-thiadiazole)(L),respectively.Complex 1 presents a single nuclear structure while 2 has a dimeric structure where two CuI ions are doubly bridged by halide ions in a μ2-fashion.Both discrete molecules were outspreaded into a one-dimensional supramolecular chain via aromatic interactions such as C-H…π and π…π interactions.     

Synthesis and Crystal Structure of a New Coordination Polymer: {[AgL]ClO_4}_n(L = 2,5-Bis(3-pyridinylmethylthio)-l,3,4-thiadiazole)

The title complex {[AgL]ClO4}n(L=2,5-bis(3-pyridinylmethylthio)-1,3,4-thiadiazole) was synthesized by the reaction of Ag(I) salt and a novel flexible ligand L.Its structure was determined by X-ray crystallography with the following data:monoclinic,space group P21/n,a=16.5068(13),b=7.6548(4),c=16.5521(13),β=115.119(3)o,V=1893.7(2)3,Z=4,Dc=1.893 g/cm3,μ=1.565 mm-1,F(000)=1072,C14H12AgClN4O4S3,Mr=539.78,T=293(2) K,S=1.067,the final R=0.0342 and wR=0.0870.The silver ion in the complex is in a trigonal coordin...     

大规模伤亡事件应对流程的前摄性调度优化

以死亡人数最少化为目标,研究大规模伤亡事件应对流程的前摄性调度优化问题。首先,使用伤情等级和伤情随机转化的马尔可夫链,建立伤员死亡概率与伤员处置时间的函数关系。随后,将研究问题转化为柔性作业车间静态调度问题,并设计遗传算法求解。最后用一个随机算例对算法进行仿真,结果表明：该算法可行有效;与现有研究中救援时间最短化的调度方法相比,伴随着可接受的救援时间跨度增加,该方法可大幅降低救援过程中的死亡人数。本文研究有助于决策者优化应急救援过程,有效减少死亡人员数量。     

动态联合库存的决策模型及算法

考虑生产商、销售商联合库存的动态优化问题,建立的随机需求下生产-销售运作系统的排队模型,得到了系统的稳态概率分布和队长分布.以成本最小化为目标,模型算法找到了最优的运作策略和机器使用数量.数值模拟的结果表明,依赖于指定机器数量的动态调整策略明显优于静态系统.     

Modelling and control of flexible joint robot based on Takagi–Sugeno fuzzy approach and its stability analysis via sum of squares

This article proposes a Takagi–Sugeno (T-S) fuzzy model of single-link rotary flexible joint robot. The proposed control method is based on parallel distributed control. The parameters of T-S controller are improved by distributed population genetic algorithm (GA) with chaos GA. Using Hermite–Biehler theorem in distributed population, GA is made to have a fast convergence. Dividing search space into several sub-spaces causes a better response, and chaos disturbance helps the whole algorithm to reach a best answer. The stability of the controller is analysed via the sum of squares programming, and finally, it is implemented on the plant.     

A transformed random effects model with applications

This paper proposes a transformed random effects model for analyzing non-normal panel data where both the response and (some of) the covariates are subject to transformations for inducing flexible functional form, normality, homoscedasticity, and simple model structure. We develop a maximum likelihood procedure for model estimation and inference, along with a computational device which makes the estimation procedure feasible in cases of large panels. We provide model specification tests that take into account the fact that parameter values for error components cannot be negative. We illustrate the model and methods with two applications: state production and wage distribution. The empirical results strongly favor the new model to the standard ones where either linear or log-linear functional form is employed. Monte Carlo simulation shows that maximum likelihood inference is quite robust against mild departure from normality. Copyright © 2009 John Wiley & Sons, Ltd.     

Optimal vibration control of flexible spacecraft during a minimum-time maneuver

This paper is concerned with the simultaneous maneuver and vibration control of a flexible spacecraft. The problem is solved by means of a perturbation approach whereby the slewing of the spacecraft regarded as rigid represents the zero-order problem and the control of vibration, as well as of perturbations from the rigid-body maneuver, represents the first-order problem. The zero-order control is to be carried out in minimum time, which implies bang-bang control. On the other hand, the first-order control is a time-dependent linear quadratic regulator including integral feedback and prescribed convergence rate.This research was sponsored by USAF/ASD and AFOSR Research Grant F33615-86-C-3233 monitored by Drs. A. K. Amos and V. B. Venkayya, whose support is greatly appreciated.