Equivalent Time-Domain Representation and Uplink Channel Estimator for Multicarrier CDMA Systems

Many blind channel estimation methods have been proposed for direct sequence (DS) code-division multiple access (CDMA) systems, so we can certainly use them to estimate the finite impulse response (FIR) channel for the multi-carrier (MC-) CDMA system. In this paper, the MC-CDMA system is interpreted as an equivalent time-domain DS-CD-MA system with specific spreading codes. Then, an equivalently time-domain blind channel estimator is derived for the     

Performance Analysis of the Dynamic CSMA/CD Protocol in a Wireless Channel

In wireless networks, packet access is a popular mode, and the key problem is how to improve throughput and access delay performance, especially the throughput for wireless channels. These results will be a reference for not only a wireless channel but also a common MAC protocol.     

Face Recognition Based on Support Vector Machine and Nearest Neighbor Classifier

Support vector machine (SVM), as a novel approach in pattern recognition, has demonstrated a success in face detection and face recognition. In this paper, a face recognition approach based on the SVM classifier with the nearest neighbor classifier (NNC) is proposed. The principal component analysis (PCA) is used to reduce the dimension and extract features. Then one-against-all stratedy is used to train the SVM classifiers. At the testing stage, we propose an al-     

Dynamic Characteristics of Inter-Satellite Links in LEO Networks

To establish an efficient inter-satellite link (ISL) in an LEO network, the effect of geometric characteristics of ISL on the ISLs and the devices on the LEO satellite should be examined. Because of the continuous movement of the LEO satellite, the time-varying behaviours of the ISL's geometric charactersistics continuously change with the changes of the satellite's position on the orbit. These dynamic geometric characteristics of the ISLs are important for ISL's performance analyzing and the design of the devices on the LEO satellite. This paper describes dynamic geometric characteristics of ISL, analyzes the impact of these regulations on the tracking system of the satellite's antenna and the power adjusting system of the satellite's transmitter, with the Iridium system as an example.     

Study on the Medical Image Distributed Dynamic Processing Method

To meet the challenge of implementing rapidly advanced, time-consuming medical image processing algorithms, it is necessary to develop a medical image processing technology to process a 2D or 3D medical image dynamically on the web. But in a premier system, only static image processing can be provided with the limitation of web technology. The development of Java and CORBA (common object request broker architecture) overcomes the shortcoming of the web static application and makes the dynamic processing of medical images on the web available. To develop an open solution of distributed computing, we integrate the Java, and web with the CORBA and present a web-based medical image dynamic processing methed, which adopts Java technology as the language to program application and components of the web and utilies the CORBA architecture to cope with heterogeneous property of a complex distributed system. The method also provides a platform-independent, transparent processing architecture to implement the adva     

基于模拟退火算法的VaR-GARCH模型

针对GARCH模型中的参数估计问题，提出了一种基于模拟退火算法（simulated annealing algorithm)的估计方法，并将其应用于VaR估计中，道琼斯指数和汇率的算例表明，基于模拟退火的VaR-GARCH模型在计算鲁棒性和估算精度方面优于传统的数值方法。     

A kind of Generalized Learning Model

1　IntroductionSymboliclearning,connectivelearning,fuzzylearningandevolutionarylearningarethepresentfundamentalmethodsformachinelearning[1～3].Eachofthemhascharacteristicsandadvantages,andcancarryoutmachinelearningtasksincertainregioneffectively.Howe...     

基于频散特性的杆中超声波传播仿真

针对超声实时在线检测中缓冲杆应用的局限性,以无限长杆的频散特性为理论基础,利用有限长杆的端面边界条件,分别以应力关系和应变关系为系统函数,建立了超声波在有限长杆中传播的系统模型。通过在杆端面施加激励,借助系统传输模型,获取回波信号,并与实验进行对比,验证该方法的正确性。同时得出了超声波在有限长杆中传播产生的多次回波的重复周期与杆半径之间成正比的关系。     

Decentralized Bezout Identity and a Parametrization of Decentralized Controllers for Singular Systems

1　 IntroductionConsider a singular decentralized control system of the formEx(t) =Ax(t) ∑Ni=1Biui(t)yi =Cix(t) ,i∈ N ={ 1 ,2 ,… ,N}(1 )where x(t)∈ Rn is the state vector,ui(t)∈ Rmi and yi(t)∈ Rpi are respectively the localcontrol input and measure outputvectors of the ith control channel.The matrix E may besingular,i.e.,rank(E) 相似文献