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Tilting modules for classical groups and howe duality in positive characteristics


We use the theory of tilting modules for algebraic groups to propose a characteristic free approach to "Howe duality" in the exterior algebra.


In our paper [KR] we began a systematic study of representations of the universal central extension[InlineEquation not available: see fulltext.] of the Lie algebra of differential operators on the circle.


This study was continued in the paper [FKRW] in the framework of vertex algebra theory.


In the present paper we study the remaing nontrivial case, that of a negative central chargeN.

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 In ordinary sampleddata control systems the system response to a step input can reach its equilibrium state only within n or more sampling intervals (n is the order of the controlled plant). In this paper multipleimpulses are used, instead of ordinary simple impulses, to speed up the system response. In such sampled data systems the system response to step input can reach its equilibrium state within less than n, even one, sampling intervals. Methods of design of such kind of sampleddata... In ordinary sampleddata control systems the system response to a step input can reach its equilibrium state only within n or more sampling intervals (n is the order of the controlled plant). In this paper multipleimpulses are used, instead of ordinary simple impulses, to speed up the system response. In such sampled data systems the system response to step input can reach its equilibrium state within less than n, even one, sampling intervals. Methods of design of such kind of sampleddata systems and their components are discussed. In the last part of the paper methods of compensating sampled data systems with dead time elements is also considered.  在通常的脉冲控制系统中,当输入信号是阶跃函数时,系统的过渡过程至少在n个采样周期内才能完全结束(n是控制对象的阶数).文中考虑了采用宽度不等的多拍脉冲代替通常的单拍脉冲以加快系统的过渡过程.在采用多拍脉冲以后,系统的过渡过程可以在少于n个采样周期内,甚至在一个采样周期内完全结束.文中叙述了这种脉冲系统的综合方法,也讨论了系统中有关组成部分——脉冲组成器和校正装置——的构成方案及其参数的计算方法.最后并考虑了由于时滞引起的对系统动态特性有害影响的补偿问题.文中举有例题,对文中各节内容作必要的说明.  In this paper the general synthesis problem of optimal control systems with the criterion of transient responses as a positive integral functional (3) is discussed.In the first part it is assumed that the motion of controlled object is described by a system of ordinary differential equations and that the final states of the system form a bounded and closed convex region in ndimentional euclidian phase space. A method is proposed for finding all optimal control functions which lead any starting... In this paper the general synthesis problem of optimal control systems with the criterion of transient responses as a positive integral functional (3) is discussed.In the first part it is assumed that the motion of controlled object is described by a system of ordinary differential equations and that the final states of the system form a bounded and closed convex region in ndimentional euclidian phase space. A method is proposed for finding all optimal control functions which lead any starting state into the given final region of states. Some conclusions are obtained from the maximum principle by using transversal conditions of optimal trajectories in terminal points, and the particular properties of the stated problem are pointed out. The case of linear differential equations with integral quadratic functional criterion is investigated in detail.Further, in the second part the fundamental properties of isoloss regions, the relations between the isoloss region and optimal control functions are indicated. As a direct result a partial differential equation determining the optimal lossfunction J (x) is found and the connection between function J (x)and optimal vector control function u (x) is also stated. The methods proposed are practically the extension of the methods used by us for designing time optimal control systems as seen in [5, 6 ,7].Finally, an example is illustrated with optimal trajectories shown in phase plane.The necessary numerical data is calculated by an analog computer with high accuracy.  文中研究了具有公式(3)表示的一般正积分泛函的最优控制系统的综合问题.在第一部分中研究了具有控制参数的一阶微分方程组.控制系统的终点状态为n维相空间内的某一逐段光滑边界的闭性区域Ω.文中指出了根据极大值原理和轨道终点的横截条件寻找引到Ω的所有最优轨迹的方法.这里详细地研究了具有二次泛函和被积函数中不明显含有控制参数的质量指标泛函的线性方程情况.在文中第二部分研究了等损耗区的主要特性.指出了等损耗区与最优控制函数之间的关系.导出了求算最优损耗函数J(x)的偏微分方程,以及这一函数与最优控制函数u(x)的关系.上述方法是我们曾在文献[5,6,7]中用过的最优快速系统的综合方法的推广.文章最后举有例证.  This paper presents an investigation of the"Automatic Operator" of Diesel Locomotive based on the principle of compound programming control. According to the surrounding conditions of locomotive, the"Automatic Operator"can change its structure automatically in order to obtain better quality of control.In this paper, the principle scheme, the characteristics of"Automatic Operator" and the experimental results of automatic control of Diesel locomotive with "Automatic Operator"are presented, the principle... This paper presents an investigation of the"Automatic Operator" of Diesel Locomotive based on the principle of compound programming control. According to the surrounding conditions of locomotive, the"Automatic Operator"can change its structure automatically in order to obtain better quality of control.In this paper, the principle scheme, the characteristics of"Automatic Operator" and the experimental results of automatic control of Diesel locomotive with "Automatic Operator"are presented, the principle and the design of logical circuit for changing the characteristics of"Automatic Operator"is emphasized. The latter part of the paper includes a discussion of quality of control; and finally, formulas for determining the parameters of the control system are derived.  文内介绍了采用复合控制原理和根据机车所处客观条件自动切换系统结构的内燃机车程序控制方案,介绍了按此方案制成的(自动司机)总体线路及其性能.介绍了利用这台控制机进行内燃机车自动驾驶的全面试验结果.文中着重讨论了自动切换系统结构的逻辑装置的设计计算.给出了综合这类系统参数的计算公式.此外,对系统的控制质量进行了详细讨论.   << 更多相关文摘 
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