Backstepping tracking control for nonlinear time-delay systems

1. INTRODUCTION The presence of time delay has a significant effect on system performance and destroys the stability of closed-loop system[1]. Therefore, the study on time-delay systems has important practical significance. Recen- tly,considerable progress has been made in this field[1~10]. According to the dependency of the designed contr-oller depends on the time delay, the control approa-ches for time-delay systems can be classified into two categories: delay-dependent[2~3,10] and dela…     

Research on development of in situ titanium matrix composites and in situ reaction thermodynamics of the reaction systems

The in situ synthesis method for titanium matrix composites (TMCs) has obvious technical and economical advantages over other traditional methods. Ultrafine reinforcement particles were formed in situ by chemical reaction between elements or between elements and compounds. Using the approach, contamination at the composite matrix/reinforcement particle interface did not occur,interface bonding was good, and the reinforcement particle was the rmodynamically stable. The stage of development of the preparation process for in situ TMCs as well as the thermodynamic analysis of the possible in situ reaction systems was described.     

Electrochemical behaviors of silicon wafers in silica slurry

The electrochemical behaviors of n-type silicon wafers pH value and solid content of the slurry on the corrosion of silicon in silica-based slurry were investigated, and the influences of the wafers were studied by using electrochemical DC polarization and AC impedance techniques. The results revealed that these factors affected the corrosion behaviors of silicon wafers to different degrees and had their suitable parameters that made the maximum corrosion rate of the wafers. The corrosion potential of (100) sttrface was lower than that of(111), whereas the current density of (100) was much higher than that of(111).     

Micro-particle deposition and lobar distribution of mass flow in human upper respiratory tract model

A representative human upper respiratory tract model consisting of oropharyngeal and asymmetric tracheobronchial(TB) airways from the trachea(G0) to the main lobar bronchi(G2) was constructed. Laminar-to-turbulent airflow for typical inhalation modes as well as micro-particle transportation,wall deposition and mass flow to lobes was simulated using the CFX10.0 software from Ansys Inc. The numerical particle deposition efficiency of the oropharynx region and two generations(G1 and G2) of TB airways shows gre...     

Characteristics and realization of the second generation surface acoustic wave’s wavelet device

1.INTRODUCTIONDue to the process and characteristics of the non-stationary signals both in ti me and frequency do-mains,wavelet technology has been widely em-ployedin scientific research and engineering appli-cation fields[1~3].To date,wavelet algorithmthatneeds a larger number of mathematic operationsand complicated program is mainly realized bycomputer,whichis quite difficult and expensive toapplyit to engineeringfields and portable electron-ic systems.To solve these problems,we proposed…     

Study on RS- and GIS-based ecological capital assessment in arid areas

Ecological capital assessment is currently one of the important research contents in the interdisciplinary field of ecology, resources economics, environmental economics and ecological economics. To scientifically assess ecological capital redounds to decision-makers to consider the ecological cost in economic development, and is also necessary for sustainable economic development in arid areas. Based on the theory of landscape ecology in this paper the per unit area ecological capital values in arid areas are researched by using the Landsat TM data, CBERS satellite data, meteorological data, MODIS satellite data and other ecological data, and the RS- and GIS-based models of assessing ecological capital values in arid areas are developed. Moreover, based on the field-measured data, a case study on ecological capital assessment in the Manas River basin, Xinjiang in 2003 is carried out. The basin is divided into 4 ecological capital areas so as to quantitatively calculate the ecological capital values of the ecosystems, analyze the spatial distribution of ecological capital, and chart the maps of spatial distribution of ecological capital. The results show that the total ecological capital value of the ecosystems in the Manas River basin in 2003 was 1.49454×10^11 yuan RMB. In spatial distribution, the ecological capital decreases from the alpine zones to the plains and from the oases to the deserts, which accords with the distribution of vegetation zonality in this arid area. The assessed results can objectively reflect the ecological capital and its spatial distribution in the aridbasin, and can also provide reference for roundly carrying out the assessment of ecological capital in arid areas.     

Target distribution in cooperative combat based on Bayesian optimization algorithm

1 .INTRODUCTIONThe target distributionis one of difficult content incooperation air combat . The missionis fully exertsthe whole advantage of all firepower units . Thedistributionis finding the best schedule which ac-cord with distribution principles at the moment ofgiven conditions .It can make finitely weapons gainthe best effective through opti mizing method. Theresult is that the effective of weaponis best andthewhole benefits are highest .But the target distribu-tionis restricted wi…     

Novel satellite transport protocol with on-board spoofing proxy

1 .INTRODUCTIONTCP has been designed and tuned for wired net-works with low bit-error rate (BER) on the orderof less than 10-8,in which TCP segment lossesand corruptions are mainly due to network conges-tion . However ,this assumptionis not validin sat-ellite networks[1]. Satellite channel has severalcharacteristics that may degrade the performance ofTCP. These characteristics include large propaga-tion delay (i .e .,approxi mately 250 ms over a geo-synchronous satellite channel) ,lar…     

战争分析仿真实验综合分析系统研究

战争分析仿真实验是一种运用战争分析与仿真实验结合的面向高层的分析方法.针对战争分析仿真实验对仿真实验数据进行综合分析的需求,在分析系统功能特征的基础上,提出了仿真实验综合分析系统的体系结构,对内部组成和功能进行了分析,并针对探索性数据分析中存在的问题和解决方案进行了讨论,最后结合实例,对系统应用进行了介绍.     

High-resolution algorithm based on temporal-spatial extrapolation

To enhance the resolution of parameter estimation with limited samples received by a short passive array, an iterative nonparametric algorithm for estimating the frequencies and direction-of-arrivals (DOAs) of signals is proposed. The cost function is constructed using l2-norm Gaussian entropy combined with an additional constraint, l2-norm constraint or linear constraint. By minimizing the cost functions in the temporal and the spatial dimensions using corresponding iteration algorithms respectively, the s...