A Delay-Dependent Approach to Robust H ∞ Control for Uncertain Stochastic Systems with State and Input Delays

In this paper, the problem of delay-dependent robust H _∞ control for uncertain stochastic systems with state and input delays is investigated. The time delays are assumed to be bounded and time varying and the uncertainties are assumed to be norm bounded. By using the Lyapunov functional method, a new delay-dependent robust H _∞ control scheme is presented in terms of linear matrix inequalities (LMIs). Some numerical examples are given to illustrate the effectiveness of the proposed approach. This work is partially supported by the Natural Science Foundation of China (60674055, 60774047), and the Taishan Scholar Programme of Shandong Province. An erratum to this article can be found at     

加筋土挡墙有限元分析材料模型综述

对20世纪60年代以来国内外加筋土挡墙有限单元分析中采用的几种方法进行了简单介绍,并分别指出它们的优缺点。对加筋土结构有限元计算时经常采用的一些本构模型进行了详细介绍,并着重描述了一种可用于模拟接触面的结构性模型———复合体模型。目前加筋土挡墙的有限元模型基本上均是二维平面模型,建议计算工作者建立三维模型,并考虑筋———土、面板———土、基础———墙体之间相互作用。指出将基于微观理论的结构性模型用于模拟加筋土体,特别是筋———土接触面,是一个新的研究方向。     

OPTIMIZING LAYOUT OF URBAN STREET CANYON USING NUMERICAL SIMULATION COUPLING WITH MATHEMATICAL OPTIMIZATION

1. INTRODUCTION Vehicular emissions have become one of thmain sources of urban atmospheric pollution in Chinwith the development of the urban construction andthe increase in the number of vehicles. There are lots of factors influencing the transport and dispersion of vehicular exhausted pollutants and further influencing the local air quality, among which the gas dynamical effect due to the mechanical turbulence from huge buildings and street canyons is especially remarkable. Previous stu…     

Multifinality in implicit choice.

This research examines the possibility that people's choices in the service of an explicit focal goal may also reflect their tendency to fulfill implicit background goals and in that sense are multifinal. We carried out 5 experimental studies to investigate this notion. In Experiment 1, a primed implicit goal affected individuals' choices even when those avowedly served an explicit “focal” goal. Experiment 2 replicated this finding with a different type of implicit goals. Experiment 3 found that primed implicit goals had no effect on choices where the options that served them undermined the explicit goal. Experiment 4 found that a primed implicit goal served by a multifinal option does not privilege it over a unifinal option if that goal had been already attained by a different means. Finally, Experiment 5, via 3 types of control groups, showed that choices were affected by both the explicit and implicit goals in isolation, and they shifted toward multifinality when these goals were conjointly present. The discussion considers the integrative potential of the multifinality framework and its implications for a variety of phenomena in the domain of motivated cognition. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Optimisation of location and dimension of SMC precharge in compression moulding process

The main goal of the present study is to optimise the precharge conditions such as the precharge location and dimensions that give significant effects on the mechanical performance of composite structures manufactured by the compression moulding process. As preliminary step of optimisation, we developed a manufacturing simulation program to predict the fibre volume fraction and fibre orientation. And coupled with this simulation program and a structural analysis program, a genetic algorithm (GA) is implemented to optimise the precharge conditions. The penalty function method and the repair algorithm are modified for handling constraints. The repair algorithm is applied to a symmetric structure and an arbitrary shape structure to find optimal precharge conditions.     

Fabrication of Al matrix composite reinforced with submicrometer-sized Al<Subscript>2</Subscript>O<Subscript>3</Subscript> particles formed by combustion reaction between HEMM Al and V<Subscript>2</Subscript>O<Subscript>5</Subscript> composite particles during sintering

To fabricate an Al-V matrix composite reinforced with submicron-sized Al₂O₃ and Al_xV_y (Al₃V, Al₁₀V) phases, high energy mechanical milling (HEMM) and sintering were employed. By increasing the milling time, the size of mechanically milled powder was significantly reduced. In this study, the average powder size of 59 μm for Al, and 178 μm for V₂O₅ decreased with the formation of a new product, Al-Al₂O₃-Al_xV_y, with a size range from 1.3 μm to 2.6 μm formed by the in-situ combustion reaction during sintering of HEM milled Al and V₂O₅ composite powders. The in-situ reaction between Al and V₂O₅ during the HEMM and sintering transformed the Al₂O₃ and Al_xV_y (Al₃V, Al₁₀V) phases. Most of the reduced V reacted with excess the Al to form Al_xV_y (Al₃V, Al₁₀V) with very little V dissolved into Al matrix. By increasing the milling time and weight percentage of V₂O₅, the hardness of the Al-Al₂O₃-Al_xV_y composite sintered at 1173 K increased. The composite fabricated with the HEMM Al-20wt.%V₂O₅ composite powder and sintering at 1173 K for 2 h had the highest hardness.     

Two-dimensional linear-combination model fitting of magnetic resonance spectra to define the macromolecule baseline using FiTAID,a Fitting Tool for Arrays of Interrelated Datasets

Object  

To propose the determination of the macromolecular baseline (MMBL) in clinical 1H MR spectra based on T₁ and T₂ differentiation using 2D fitting in FiTAID, a general Fitting Tool for Arrays of Interrelated Datasets.     

Performance of Reuse Partitioning in Cellular Systems with Mobile Users

Reuse partitioning (RP) is a simple technique that can be used to increase the traffic capacity in a cellular system. With RP, a cell is divided into several concentric regions, each associated with a different cluster size. In this article, a traffic model is developed to analyze the impact of mobile users on a two-region RP system using fixed channel assignment. The influence of user speed and cell size on the new call blocking probability, P_b, and the call dropping probability, P_d, is investigated. A simpler model that can be used to estimate P_b and P_d in some cases is described. The effect on system capacity of reserving some channels for handoff calls is also studied. It is found that even though prioritized handoff can reduce P_d, it may also degrade the capacity. The accuracy of the analysis is verified using simulation for three mobility models.