The Inverse Problem of Analytic Interpolation With Degree Constraint and Weight Selection for Control Synthesis

The minimizers of certain weighted entropy functionals are the solutions to an analytic interpolation problem with a degree constraint, and all solutions to this interpolation problem arise in this way by a suitable choice of weights. Selecting appropriate weights is pertinent to feedback control synthesis, where interpolants represent closed-loop transfer functions. In this paper we consider the correspondence between weights and interpolants in order to systematize feedback control synthesis with a constraint on the degree. There are two basic issues that we address: we first characterize admissible shapes of minimizers by studying the corresponding inverse problem, and then we develop effective ways of shaping minimizers via suitable choices of weights. This leads to a new procedure for feedback control synthesis.      

具有极点约束的输出反馈完整性控制器设计

基于LMI理论,给出了线性连续时不变系统具有极点约束的输出反馈完整性控制器存在的充分条件,并在此基础上提出一种输出反馈完整性控制器的设计方法。使得当传感器或执行器发生故障时。闭环系统渐近稳定,且闭环极点位于左半复平面的指定区域。数值示例说明了该方法的有效性。     

Certainty-Equivalence Feedback Design With Polynomial-Type Feedbacks Which Guarantee ISS

The purpose of this note is to establish a certainty-equivalence feedback design for inverse optimally controlled affine systems. In particular, it is shown that a class of polynomial-type state feedbacks in conjunction with a globally asymptotically convergent observer leads to a globally asymptotically stable closed-loop. A key step in the proposed certainty-equivalence feedback design procedure is the identification of a new class of polynomial-type inverse optimal feedbacks which guarantees input-to-state stability (ISS) with respect to measurement errors. As a consequence, the proposed certainty-equivalence feedback design has the important feature that the state feedback is allowed to contain polynomial nonlinearities of arbitrarily high degree in the unmeasured states. This feature is illustrated on an example     

Gaze Interaction With Vibrotactile Feedback: Review and Design Guidelines

Vibrotactile feedback is widely used in mobile devices because it provides a discreet and private feedback channel. Gaze-based interaction, on the other hand, is useful in various applications due to its unique capability to convey the focus of interest. Gaze input is naturally available as people typically look at things they operate, but feedback from eye movements is primarily visual. Gaze interaction and the use of vibrotactile feedback have been two parallel fields of human–computer interaction research with a limited connection. Our aim was to build this connection by studying the temporal and spatial mechanisms of supporting gaze input with vibrotactile feedback. The results of a series of experiments showed that the temporal distance between a gaze event and vibrotactile feedback should be less than 250 ms to ensure that the input and output are perceived as connected. The effectiveness of vibrotactile feedback was largely independent of the spatial body location of vibrotactile actuators. In comparison to other modalities, vibrotactile feedback performed equally to auditory and visual feedback. Vibrotactile feedback can be especially beneficial when other modalities are unavailable or difficult to perceive. Based on the findings, we present design guidelines for supporting gaze interaction with vibrotactile feedback.     

Space-Time Adaptive Decision Feedback Neural Receivers With Data Selection for High-Data-Rate Users in DS-CDMA Systems

A space-time adaptive decision feedback (DF) receiver using recurrent neural networks (RNNs) is proposed for joint equalization and interference suppression in direct-sequence code-division multiple-access (DS-CDMA) systems equipped with antenna arrays. The proposed receiver structure employs dynamically driven RNNs in the feedforward section for equalization and multiaccess interference (MAI) suppression and a finite impulse response (FIR) linear filter in the feedback section for performing interference cancellation. A data selective gradient algorithm, based upon the set-membership (SM) design framework, is proposed for the estimation of the coefficients of RNN structures and is applied to the estimation of the parameters of the proposed neural receiver structure. Simulation results show that the proposed techniques achieve significant performance gains over existing schemes.      

指定圆形极点配置区域输出无偏的输出反馈协方差控制器设计

系统输出无偏性及稳态状态协方差是随机系统的两个重要稳态性能指标，系统的动态品质主要决定于系统的闭环极点位置。本文给出的输出反馈协方差控制器能确保系统：１）闭环极点位于指定圆形配置区域；２）稳态协方差满足既定的上限约束；３）稳态输出无偏。     

具非对称状态和控制约束的离散系统状态反馈设计

利用正不变集的概念,讨论了具有非对称状态和控制约束的线性状态反馈控制器的设计;建立了LCRP可解的代数条件,并化为线性规划问题来求解;最后讨论了分段线性反馈阵的可行性及计算。     

基于类间分散度和类内集中度的文本特征选择。

特征选择是文本分类的关键步骤之一,所选特征子集的优劣直接影响文本分类的结果。论文首先定义了两种特征分类能力：一种是特征对类间文档的分散程度,该分散度越大越好;另一种是特征对类内文档的聚集程度,该集中度越大越好。然后把这两种特征影响度有机地结合起来设计了一个新的特征选择方法,该方法能够对所选特征进行综合考虑,从而使获得的特征集具有较好的代表性。仿真实验表明所提特征选择方法在一定程度上能够提高文本分类性能。     

Mean-VaR Portfolio Selection Under Real Constraints

This paper is concerned with asset allocation under real constraints when VaR is the risk measure to minimize. Our paper makes a contribution in several ways, we use a risk measure that is not linear programming solvable, we introduce real constraints, such as minimum transaction units and non-linear cost structure and, finally, we avoid the use of smoothing techniques. The approach we propose is based on multi-objective genetic algorithms. The results presented show the adequacy of the method for the portfolio optimization problem and emphasize the importance of dealing with real constraints during the optimization process.     

Feedback Stabilization of Singularly Perturbed Systems Under Information Constraints

The quantized feedback control for a class of singularly perturbed systems is addressed, in which the controlled system and the controller are connected via a limited capacity communication channel. First, a proper coder–decoder pair is presented such that the transmission error decays to zero exponentially under information constraints. Then, a control law in terms of linear matrix inequalities is constructed to render the resulting closed‐loop system input‐to‐state stable with regard to the transmission error. Thus the asymptotic stability of the closed‐loop system is guaranteed. It is shown that the proposed method is simple and easy to operate. Moreover, an upper bound of the small perturbation parameter for the stability of systems can be explicitly estimated with a workable computational way. Finally, two examples are presented to show the effectiveness of the proposed method.     

Memoryless State Feedback Controller Design for Time Delay Systems With Matched Uncertain Nonlinearities

The robust control problem for a class of uncertain time-delay systems is investigated. The systems include multiple time delays and uncertain nonlinear functions. To our best knowledge, no controller design method for the systems is reported in the literature except for sliding mode control (SMC). However, the sliding mode controller must use the delayed state of the system, so that the precise time delays have to be known, and also a large memory is needed for controller implementation. To overcome the shortcomings, we employ the backstepping method to design a memoryless state feedback controller. By constructing a novel Lyapunov-Krasovskii functional, we show that the resulting closed-loop system is asymptotically stable. Simulations are done to verify the effectiveness of the proposed method.     

一种基于约束条件的服务选择方法

照明控制系统的服务选择为工作流的研究提供了新的契机与挑战,基于约束条件的服务选择问题是一个典型的 NP 问题.利用遗传算法所具有的全局解空间搜索的特点,针对照明服务选择问题,提出基于遗传算法的照明系统服务选择方法,并根据照明系统的特点,改进了遗传算法的收敛性,通过分析实验结果证明该算法优于传统的服务选择算法.     

基于权重的反馈优先IP流量控制算法

针对因特网上对收发双方数据信息的高速率、高质量的要求,提出基于权重的反馈优先流量控制算法.此算法将不同类型的报文分组给予不同的权重,在每一个分组中保留一位域以标志拥塞,同一分组的报文队列根据接收方的信用值和等待时间设置优先级,对于高权重高优先级的反馈报文实行优先强占的策略,综合考虑数据信息的传输速率和传输质量,以提高网络的资源利用率.实验证明这种流量控制算法可以有效地防止网络的拥塞崩溃现象,从而达到了高效地利用网络资源的目的.     

Feedback Relevance Spaces: Interactional Constraints on Processing Contexts in Dynamic Syntax

Journal of Logic, Language and Information - Feedback such as backchannels and clarification requests often occurs subsententially, demonstrating the incremental nature of grounding in dialogue....     

Two Job Cyclic Scheduling With Incompatibility Constraints

The present paper deals with the problem of scheduling several repeated occurrences of two jobs over a finite or infinite time horizon in order to maximize the yielded profit. The constraints of the problem are the incompatibilities between some pairs of tasks which require a same resource.     

Enforcing Service-Level Constraints in Supply Chains With Assembly Operations

We study a feedforward supply network that involves assembly operations. We compute optimal stock levels which minimize inventory costs and maintain stockout probabilities below given desirable levels (service-level constraints). To that end, we develop large deviations approximations for inventory costs and service level constraints and formulate the stock level selection problem as a nonlinear programming problem which can be solved using standard techniques. This results in significant computational savings when compared to exhaustive search using simulation. Our distributional assumptions are general enough to include temporal dependencies in the demand and production processes. We leverage the solution of the inventory control problem in the design of supply contracts under explicit service-level constraints     

升力反馈减摇鳍及其鲁棒控制器的研究

减摇鳍是一种非常重要的船舶减摇装置，但传统的鳍角反馈减摇鳍在没计中存存着很多问题。升力反馈减摇鳍通过测量直接得到鳍上产生的升力克服了角度反馈减摇鳍的缺点，是最为有效的新型减摇设备本文介绍了升力反馈减摇鳍的构成和减摇原理。同时由于减摇鳍特殊的工作环境，系统控制器的设计应尽可能满足随时出现的不确定因素，鲁棒控制器是解决这一问题可行的办法，本文针对实验室中国内第一套升力减摇鳍系统设计了鲁捧H∞控制器，仿真研究表明，所设计的系统能够得到很好的减摇效果。     

输入饱和及输出受限的纯反馈非线性系统控制

针对具有输入饱和和输出受限的纯反馈非线性系统,设计了神经网络自适应控制器.首先利用隐函数定理和中值定理将非仿射形式的纯反馈非线性系统转换成有显式输入的非线性系统,基于李雅普诺夫第二方法以及反推法并采用障碍型李雅普诺夫函数进行控制器的设计,最后通过稳定性分析证明了闭环控制系统是半全局一致最终有界的,利用仿真例子验证了控制...     

Constructing Plane Spanners of Bounded Degree and Low Weight

Given a set S of n points in the plane, we give an O(n log n)-time algorithm that constructs a plane t-spanner for S, with t ≈ 10, such that the degree of each point of S is bounded from above by 27, and the total edge length is proportional to the weight of a minimum spanning tree of S. Previously, no algorithms were known for constructing plane t-spanners of bounded degree.     

构件库用户反馈子系统的客观反馈的设计

随着分布式构件技术的日趋成熟和Internet技术的发展,出现了新的复用形式的构件——在线构件。由于在线构件数量的大量增长,用户反馈子系统除了收集离线构件的静态信息对软件复用者提供辅助以外,还要考虑如何获得和利用在线构件的动态运行信息。文中以国家863计划“基于Internet以构件库为核心的软件开发平台”的开发为背景,着重于从客观反馈方面阐述用户反馈子系统的设计。