Concurrent Blind Channel Equalization in Impulsive Noise Environments

In some communication systems the trans- mitted signal is contaminated by impulsive noise with a non-Gaussian distribution. Non-Gaussian noise caused significant performance degradation to communication re- ceivers. The new constant modulus blind equalizer based on Fractional lower-order statistics of the equalizer input, which is defined as FLOS_CMA, is able to mitigate impul- sive channel noise while restoring the constant modulus character of the transmitted communication signal. How- ever, like the Constant modulus algorithm （CMA）, the steady-state Mean square error （]VISE） of the FLOS_CMA algorithm may not be sufficient low for the system to ob- tain adequate performance. This paper proposes a con- current equalizer, in which a Decision-directed least mean p norm （DD_LMP） equalizer operates cooperatively with a FLOS_CMA equalizer, controlled through a non-linear link. Simulation results using M-QAM and 8-PSK signal- ing have shown that besides the capability of compensating the phase offset, the proposed concurrent FLOS_CMA and DD_LMP blind equalizer has faster convergence rate and lower steady-state MSE than the FLOS_CMA approach.     

建筑的复杂性和简单性——建筑空间与形式丰富性设计方法探讨

建筑的空间与形式有复杂和简单之分。在设计的过程中应该获得耐人寻味,富有层次的复杂空间与形式,规避下意识的,不假思索的简单性。本文试图通过理性的分析,从哲学和意识形态、过程和发展、技术、社会历史因素的演变等不同层面寻求创造丰富建筑空间与形式的方法和途径。     

一栋未能建成的住宅隐含的空间理念——勒·柯布西耶的昌迪加尔总督府项目研究

昌迪加尔的总督府项目在柯布西耶住宅项目中占据着一个独特的位置。本文从功能、形式、秩序和理念四个方面层层深入的对这个形式奇特而且结构庞大的建筑进行解读,以揭示该建筑与其理念原型——印度法特普尔·西克里城(Fatehpur Sikri)宫殿建筑群的枢密殿(Diwan-i-khas)之间的关联,这就为理解柯布西耶晚期作品(主要是昌迪加尔首府广场建筑群)的设计手法和意图提供了一条线索。     

An Introduction to Multivariate Statistical Analysis

A permutation test is proposed for examining the significance of effects in unreplicated factorial experiments. The procedure tests each effect with a separate sampling distribution using a test statistic that is equivalent to the optimal invariant decision rule of Birnbaum. The proposed test is more flexible than other methods proposed for the same situation because it requires no a priori assumptions regarding the underlying distribution of the data nor does it impose any practical restriction on the number of potentially significant effects present.     

Production and set-up control of a failure-prone manufacturing system

The present paper considers a stochastic optimal control problem for a one-machine two-parts manufacturing system, subject to random breakdowns and repairs. The machine under consideration is not completely flexible and hence requires set-up time and cost in order to switch the production from a part type to another. The objective is to find the production plan and sequence of set-ups that minimize the cost function that penalizes inventory/backlog and set-up costs. A continuous dynamic programming formulation of the problem is presented. A numerical scheme is then adopted to solve the obtained optimality conditions equations. The optimal set-up policy. is shown numerically, to be described by a modified hedging corridor strategy. A complete heuristic policy, based on the determination of the boundaries of the corridors that describe the optimal policy in positive and negative areas of the state variables, is developed. The usefulness of such a policy is iJlustrated through experimentation and sensitivity analysis. Extensions to more complex systems are also discussed.     

A decision-support system for the design and management of warehousing systems

The issue of material handling involves the design and operative control of warehousing systems (i.e., distribution centres), which allow matching vendors and demands, smoothing with seasonality, consolidating products and arranging distribution activities. Warehousing systems play a crucial role in providing efficiency and customer satisfaction. The warehouse design entails a wide set of decisions, which involve layout constraints and operative issues that seriously affect the performances and the overall logistics costs.     

Elementary Statistics

Fractional two-level factorial designs are often used in the early stages of an investigation to screen for important factors. Traditionally, 2 ^n-k fractional factorial designs of resolution III, IV, or V have been used for this purpose. When the investigator is able to specify the set of nonnegligible factorial effects, it is sometimes possible to obtain an orthogonal design with fewer runs than a standard textbook design by searching within a wider class of designs called parallel-flats designs. The run sizes in this class of designs do not necessarily need to be powers of 2. We discuss an algorithm for constructing orthogonal parallel-flats designs to meet user specifications. Several examples illustrate the use of the algorithm.     

Lot scheduling on a single machine

In a practical situation, a manufacturer receives different orders from its customers. Different orders may contain different quantities of the product. Therefore, the manufacturer has to decide how to group these orders into different lots based on the capacity of the lot processing machine (such as integrated circuit tester, heated container, etc.) and then decides the sequence of these lots. In this paper, we study a lot scheduling problem with orders which can be split. The objective is to minimize the total completion time of all orders. We show that this problem can be solved in polynomial time.     

Robust stability and stabilization of fractional order linear systems with positive real uncertainty

This paper investigates the robust stability and stabilization of fractional order linear systems with positive real uncertainty. Firstly, sufficient conditions for the asymptotical stability of such uncertain fractional order systems are presented. Secondly, the existence conditions and design methods of the state feedback controller, static output feedback controller and observer-based controller for asymptotically stabilizing such uncertain fractional order systems are derived. The results are obtained in terms of linear matrix inequalities. Finally, some numerical examples are given to validate the proposed theoretical results.     

Performance analysis of fractional order fuzzy PID controllers applied to a robotic manipulator

A two-link robotic manipulator is a Multi-Input Multi-Output (MIMO), highly nonlinear and coupled system. Therefore, designing an efficient controller for this system is a challenging task for the control engineers. In this paper, the Fractional Order Fuzzy Proportional-Integral-Derivative (FOFPID) controller for a two-link planar rigid robotic manipulator for trajectory tracking problem is investigated. Robustness testing of FOFPID controller for model uncertainties, disturbance rejection and noise suppression is also investigated. To study the effectiveness of FOFPID controller, its performance is compared with other three controllers namely Fuzzy PID (FPID), Fractional Order PID (FOPID) and conventional PID. For tuning of parameters of all the controllers, Cuckoo Search Algorithm (CSA) optimization technique was used. Two performance indices namely Integral of Absolute Error (IAE) and Integral of Absolute Change in Controller Output (IACCO) having equal weightage for both the links are considered for minimization. Numerical simulation results clearly indicate the superiority of FOFPID controller over the other controllers for trajectory tracking, model uncertainties, disturbance rejection and noise suppression.