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  • 期刊名称:

    Journal of Computer and Systems Sciences International

  • 中文名称: 国际计算机与系统科学学报
  • 刊频: 0.168
  • ISSN: 1064-2307
  • 出版社: -
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2029条结果
  • 机译 具有复杂成本函数的约束路由问题中的插入优化
    摘要:An iterative method for solving routing problems subject to constraints and possible dependence of the cost functions on the list of tasks that have not been accomplished is considered. Such statements occur in some problems of nuclear power engineering and in developing optimizing programs for sheet cutting on programmable numerically controlled machines (in the first case, the dependence on the list of tasks can occur due to sequential dismantling of radiation sources, and in the second case it can be due to taking into account technological constraints using penalties). It is assumed that the problems under examination are large, which calls for the use of heuristic methods. The approach proposed in the paper makes it possible to design an iterative procedure based on optimizing insertions that use widely interpreted dynamic programming. The proposed algorithm is implemented on a multicore personal computer.
  • 机译 具有控制和测量的特殊形式的线性时变系统的可约性
    摘要:This paper considers some classes of linear time-varying systems with control and output vectors that can be reduced to time-invarint systems using a constructive transformation with state-space extension. As an illustrative example, the calibration problem of a gimballess inertial navigation system on a single degree-of-freedom turn table is solved.
  • 机译 分布泊松流模型中对象的顺序并行搜索优化
    • 作者:Khutortsev, V. V.;
    • 刊名:Journal of Computer and Systems Sciences International
    • 2019年第1期
    摘要:Mathematical models of the optimized fictitious dynamical systems for the probabilities that there are undetected observation objects in various sectors of the search area are formed. The invariance condition of the search control that allows combining the current and terminal quality criteria is stated. The procedure for synthesizing the optimal control law for the sequential-parallel search is specified and its properties analyzed. An example is given.
  • 机译 在最恶劣的干扰下使用预期控制对可移动基础上的对象进行保护
    • 作者:Korneev, V. A.;
    • 刊名:Journal of Computer and Systems Sciences International
    • 2019年第1期
    摘要:The problem of constructing a guaranteeing anticipating control for a shock isolator that protects an object on a movable base from impacts acting on this base is considered. It is assumed that the shape of the impact is not known but its duration is given and the base acceleration is described by a sign definite function of time the integral of which over time is also given. The anticipating control acts between the base and the object to be protected, it has one switching, is bounded, and the absolute acceleration of the base may exceed this bound only on one time interval. The performance index to be minimized is the peak displacement of the object relative to the base for various disturbances from the class of impacts under consideration. Optimal and near-optimal solutions are obtained. These solutions are compared with each other and with the solutions obtained based on the controls designed in previous studies.
  • 机译 摄动条件下带有耗散振荡器的刚体的控制
    摘要:This paper considers a system consisting of a carrier body and two linear dissipative oscillators attached to it. The body moves in a straight horizontal line under the action of a bounded control force and a small unknown perturbation. It is assumed that the coordinate and velocity of the body are known at all times and the phase states of the oscillators cannot be measured. A control law which stops the carrier body at the origin of coordinates in finite time is proposed. The effectiveness of the proposed control law is illustrated by numerical modeling.
  • 机译 在多种处理过的物品中寻找多阳极电镀工艺中对当前状态的最佳控制
    摘要:Methods of controlling electroplating processes are considered, and the shortcomings in the use of basic engineering and structural configurations for this purpose are revealed. An original approach consisting of controlling current regimes in a multianode bath is proposed. In implementing this approach, the problem of the optimal control over electroplating processes in compliance with the criteria of the coating's nonuniformity and process duration is formulated. The electroplating process in a bath with multi anodes is considered as an object of control, for which the input and output vectors of the process are specified, together with the external disturbances and the control vector. The control vector is related with the optimality criterion by composing a mathematical model with the distributed coordinates based on an elliptic partial differential equation with different ways of correcting the corresponding current in every anodic section. A series of experiments with a complicatedly shaped article are performed to prove the adequacy of this mathematical model and the efficiency of the proposed approach and demonstrate a ravine character of the target criterion function. A three-level architecture is selected for the control system to implement the optimal control. The procedure of the preliminary search for the optimal control with the formation of a corresponding matrix is proposed due to the very time-consuming character of the solution of the formulated problem. The actions to be performed in the cases when the control matrix contains or does not contain the found solution for an incoming lot of articles are considered.
  • 机译 由二维波动方程控制的系统的边界可控性问题
    摘要:The boundary controllability of oscillations of a plane membrane is studied. The magnitude of the control is bounded. The controllability problem of driving the membrane to rest is considered. The method of proof proposed in this paper can be applied to any dimension but only the two-dimensional case is considered for simplicity.
  • 机译 固定时间段内飞行器的受限二次最优控制
    • 作者:Levskii, M. V.;
    • 刊名:Journal of Computer and Systems Sciences International
    • 2019年第1期
    摘要:A dynamic problem of a spacecraft (SC) turning from an arbitrary initial position to the required terminal angular position with restricted control is considered and solved. The termination time of the maneuver is known. The control program is optimized using the quadratic criterion of quality; the minimized functional characterizes the energy consumed in the turn. The construction of the optimal control of the turn is based on quaternion variables and Pontryagin's maximum principle. It is shown that during the optimal turn, the moment of force is parallel to the straight line fixed in the inertial space, and the direction of the angular momentum in the process of the SC's rotation is constant relative to the inertial coordinate system. The formalized equations and computational expressions for determining the optimal turning program are obtained. A special mode of control is studied in detail, and the conditions of the impossibility of occurrence of this mode are formulated. The control algorithms allow performing turns over a fixed time period with the minimum angular kinetic energy. A comprehensive solution to the control problem is given for a dynamically symmetric SC: the dependences as explicit functions of time for the control variables and relations for calculating the key parameters of the turn maneuver's control law are obtained. A numerical example and the results of the mathematical modeling of the SC's motion with the optimal control are given, which demonstrate the practical feasibility of the method for controlling the attitude of the SC.
  • 机译 可控的马尔可夫跳跃过程。 Ⅱ。监视和优化TCP连接
    摘要:The article considers the practical application of the analysis and estimation of the controlled Markov jump process states by continuous, discrete, and counting observations in the development of state monitoring algorithms for network connections operating under the Transmission Control Protocol (TCP). A specific feature of the applied problem is the physical heterogeneity of the channel providing the TCP connection under study: along with the wired section, there is a wireless last mile of the channel. The current state of the entire connection cannot be directly observed, and there is just indirect statistical information in the form of a flow of acknowledgements of successful packet transmission, as well as packet loss counting processes and timeouts. In this part of the work, not only the controlled stochastic dynamic observation system was used for the mathematical description of the TCP New Reno connection but also the developed high-precision algorithm for tracking this connection state according to the available statistical information. The numerical examples make it possible to define causes of channel losses, such as congestion in the wired section or signal attenuation in the wireless section, and as a result modify the TCP algorithm so as to significantly increase the bandwidth.
  • 机译 给定离散不精确测量值的确定性可切换系统的平均控制中的最优
    摘要:We consider the problem of the optimal-in-the-mean control of a switchable system whose continuous change of state is described by differential equations, whereas instantaneous discrete changes of the state (switches) are described by recurrent equations. Discrete changes in the control process simulate the operation of an automaton (with a memory) that switches modes of the continuous motion of a control plant. Switching moments and their number are not set in advance. The quality of the control is characterized by a functional that takes into account the cost of each switch. The state of the control plant is not known exactly; however, this state is refined as a result of discrete inexact measurements. Therefore, in addition to the problem of the optimal control, the problem of the optimal-in-the-mean control of bundles of trajectories is also studied. Sufficient conditions for the optimality of control are obtained; based on them, algorithms for constructing the suboptimal control of bundles of trajectories of switchable systems given discrete inexact measurements are proposed. The use of the algorithms is demonstrated by academic examples.
  • 机译 一组无人机的在线二维路线规划
    摘要:This paper suggests a novel approach to online two-dimensional route planning for a coordinated flight of a group of unmanned aerial vehicles (UAVs) that complexifies the modified heuristic and integer matrix algorithms using a new nearness criterion of analyzed points to each route. Asdemonstrated below, this approach guarantees the maximal speed of coordinated flight planning. The modified Dijkstra algorithm that considers the consequences of choosing the nearest point on all future segments of a flight plan is proposed as the heuristic algorithm. For avoiding mistakes in the case of conflict (i.e., assigning a proper route for an analyzed point among the existing options), a modified integer branch-and-bound method is developed that includes the following operations: an alternating analysis of two distance matrices for each UAV; route choice for adding an assigned minimal-length element in each of the matrices. In case of conflict, this method removes short cross connections between paths and their intersections from the flight plan.
  • 机译 非线性顺序交会问题的最优控制
    • 作者:Berdyshev, Yu. I.;
    • 刊名:Journal of computer & systems sciences international
    • 2019年第1期
    摘要:An algorithm for constructing the time optimal control of a nonlinear fourth-order system that must visit two fixed points in the prescribed order is proposed. This system describes the motion of a car or an aircraft in the horizontal plane with a variable controllable speed and controllable steering angle.
  • 机译 通过并行顺序结构的操纵器驱动器执行设备的程序位移跟踪
    摘要:Synthesis methods for program displacements are developed for executive cylinders of the manipulator of a parallel-sequential structure, that ensure implementation of the required trajectories of the executive device of a manipulator. Program displacements of executive cylinders are interpolated by a finite collection of third-order and fourth-order splines. At each point of the trajectory of the executive device, the manipulator configuration is determined by resolving an optimization problem with the minimum condition of the generalized energy criterion.
  • 机译 最优控制位移对拟线性扩散型随机系统镇定问题的影响
    摘要:A displacement effect of a linear optimal control in stabilization problems for diffusion-type stochastic systems that operate on an unbounded time interval is studied. Hidden asymmetry of perturbations is shown to exist in systems without deterministic drift, where the equilibrium state of the open-loop system is zero. A displaced linear controller helps improve stabilization quality despite the asymmetry of the oscillations of the system.
  • 机译 合成用于中断和执行间隔调度的多处理器系统
    • 作者:Furugyan, M. G.;
    • 刊名:Journal of Computer and Systems Sciences International
    • 2019年第2期
    摘要:A problem of finding processor performances in a multiprocessor system is studied such that an admissible schedule with interruptions exists for the given set of jobs with execution intervals. Cases are considered when (1) the amounts of jobs are fixed and (2) linearly depend on the amount of extra resources allocated for them; (3) processor performances are bounded above and below. In all three cases, the original problem is reduced to the system of linear inequalities. The algorithm for finding Pareto optimal solutions is described.
  • 机译 稳定低轨道电动系链系统的运动
    摘要:This paper considers the motion of a low-orbit electrodynamic tether system designed to raise the orbit of a small spacecraft or nanosatellites. The system operates in the thrust generation mode. The orbit is raised by the Ampere force resulting from the interaction of the conducting tether with the Earth's magnetic field. The mathematical model of motion is constructed using the Lagrange method taking into account the effect of the distributed loads from the Ampere force and the aerodynamic forces on the tether. It is shown that the motion of the system relative to the center of mass is unstable if the current is constant. It is proposed to use a linear regulator to stabilize the motion of the system with respect to the local vertical. Bellman's dynamic programming principle is used to synthesize the regulator.
  • 机译 关系数据库中推断功能依赖项的代数化
    摘要:The paper considers a closed automaton with six not more than two-address instructions called inference axioms. Its purpose is to transform the so-called functional dependences over an arbitrary finite set R called a scheme. We establish the possibility of a functionally equivalent replacement of algorithms for inferring functional dependences by algebraic expressions with one of the binary algebraic operations ? and ? with the addition of very simple nullary and unary operations (instructions) to them, which together comprise the universal D-algebra.
  • 机译 主动隔振系统的动态阻滞和功效边界
    摘要:Miscellaneous active vibration isolation systems designed for laboratory (workshop), transport, and space applications with the decoupled control of six vibration modes of the bearing plate are studied. Using the electric circuit method, a compact mathematical description of the dynamic behavior of individual mechanical and electrical units and of the control of active vibration isolators is obtained. It is shown how, given the basic parameters of a vibration isolation system (the active frequency range and maximal vibration attenuation factor, which are together called efficacy bounds), the parameters of the dynamic blocks of the device and its design characteristics can be determined. The factors that limit the active frequency range and the maximal vibration attenuation factor of vibration isolators are analyzed.
  • 机译 将布尔函数系统分解为连接函数的子系统
    • 作者:Bibilo, P. N.;
    • 刊名:Journal of computer & systems sciences international
    • 2019年第2期
    摘要:This paper suggests some algorithms for decomposing a system of Boolean functions into subsystems of connected functions for representations such as truth tables (TTs), systems of disjunctive normal forms (DNFs), and binary decision diagrams (BDDs). The connectivity of functions consists of the presence of identical parts in the domains of functions from a given system. The algorithms are heuristic and can be used in computer-aided synthesis systems for real-dimension problems with several hundred functions, each having several tens of arguments. The experiments described below prove the efficiency of this decomposition approach in the logic optimization of a system of Boolean functions based on Shannon's decomposition with the possible use of subfunction inversions.
  • 机译 带偏置位置传感器的倒立摆的观测器设计
    摘要:Inverted pendulums can be considered as an approximation for the stabilization problem for legged robots. In this paper we design a linear observer for a reaction wheel inverted pendulum under biased angle measurements. The reaction wheel is a flywheel that allows the free spinning motor to apply the control torque on the pendulum. In this paper we consider the stabilization problem in the presence of a constant unknown bias in the pendulum angle measurements; this problem has important practical implications, allowing for less precise sensor placement as well as a closer approximation for the control of legged robots. This paper provides a theoretical and experimental basis for the estimation of the velocities and the bias in the system.
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