DS/CDMA通信系统盲差分自适应接收器

针对标准MMSE自适应接收器在频率非选择性衰落信道中的相位滑动和失锁问题，提出了一种无需进行训练和信道参数估计的盲差分自适应接收器，为自适应地实现该接收器，同时提出了一种基于正交分解的盲平均随机梯度（Orthogonal Decomposition-based Blind Averaged stochastic Gradient,ODBAG)算法，仿真结果，这种以ODBAG算法实现的盲差分自适应接收器的瑞利（Rayleigh)衰落信道中，误码率性能比传统匹配滤波器（Matched Filter,MF)接收器有显著的提高，并接近改进的MMSE自适应接收器的性能。     

数据挖掘与建模进展

数据挖掘与数据模型化是两个热门的课题，它们都在快速地发展。由于其广泛的应用和丰富的研究内容，引起许多专业人员和学术界人士的极大兴趣。2002年6月27～28日在香港举行了“数据挖掘与数据建模研究讨论会”。这个讨论会得到了香港大学数学研究所和香港数学学会的支持。本书是这次讨论会的论文集，会议的主题有两个：数据挖掘与数据建模，数据挖掘涉及了模式的发现、群集算法、     

Anthropometric Study of the Physique of Hong Kong-Chinese Fire Services Recruits to Streamline the Sizing System

This research applies the principles of anthropometrics to improve existing size charts together with somatotyping techniques to define the physique of the Hong Kong-Chinese Fire Services recruits. The research results proved that age does not correspond with either body measurements or somatotype components. The results of the study demonstrates that the somatotype component (i. e., endomorphy, mesomorphy and ectomorphy) has low to moderate correlation with body girth and body length measurements.     

Golgi biogenesis in Toxoplasma gondii

Two models have been put forward to explain the growth of new Golgi during the cell cycle. The first suggests that a new Golgi grows out of the endoplasmic reticulum by de novo synthesis. The second suggests that a pre-existing Golgi is needed for the growth of a new one, that is, the Golgi is an autonomously replicating organelle. To resolve this issue, we have exploited the simplicity of the apicomplexan parasite Toxoplasma gondii, which has only a single Golgi stack. Here we show, by using video fluorescence microscopy and three-dimensional reconstructions of serial thin sections, that the Golgi grows by a process of lateral extension followed by medial fission. Further fission leads to the inheritance by each daughter of a pair of Golgi structures, which then coalesce to re-form a single Golgi. Our results indicate that new Golgi grow by autonomous duplication and raise the possibility that the Golgi is a paired structure that is analogous to centrioles.     

Ethanol preference in rats with a prior history of acetaldehyde self-administration

Summary Peripherally self-injected acetaldehyde in interaction with environmental and nutritional variables significantly enhances alcohol drinking in rats and suggests an involvement of acetaldehyde in voluntary alcohol intake.     

Microscopic electronic inhomogeneity in the high-Tc superconductor Bi2Sr2CaCu2O8+x

The parent compounds of the copper oxide high-transition-temperature (high-Tc) superconductors are unusual insulators (so-called Mott insulators). Superconductivity arises when they are 'doped' away from stoichiometry. For the compound Bi2Sr2CaCu2O8+x, doping is achieved by adding extra oxygen atoms, which introduce positive charge carriers ('holes') into the CuO2 planes where the superconductivity is believed to originate. Aside from providing the charge carriers, the role of the oxygen dopants is not well understood, nor is it clear how the charge carriers are distributed on the planes. Many models of high-Tc superconductivity accordingly assume that the introduced carriers are distributed uniformly, leading to an electronically homogeneous system as in ordinary metals. Here we report the presence of an electronic inhomogeneity in Bi2Sr2CaCu2O8+x, on the basis of observations using scanning tunnelling microscopy and spectroscopy. The inhomogeneity is manifested as spatial variations in both the local density of states spectrum and the superconducting energy gap. These variations are correlated spatially and vary on the surprisingly short length scale of approximately 14 A. Our analysis suggests that this inhomogeneity is a consequence of proximity to a Mott insulator resulting in poor screening of the charge potentials associated with the oxygen ions left in the BiO plane after doping, and is indicative of the local nature of the superconducting state.     

Ethanol preference in rats with a prior history of acetaldehyde self-administration

Peripherally self-injected acetaldehyde in interaction with environmental and nutritional variables significantly enhances alcohol drinking in rats and suggests an involvement of acetaldehyde in voluntary alcohol intake.     

Variance intervention

Variance intervention is a simple state-space approach to handling sharp discontinuities of level or slope in the states or parameters of models for non-stationary time-series. It derives from earlier procedures used in the 1960s for the design of self-adaptive, state variable feedback control systems. In the alternative state-space forecasting context considered in the present paper, it is particularly useful when applied to structural time series models. The paper compares the variance intervention procedure with the related ‘subjective intervention’ approach proposed by West and Harrison in a recent issue of the Journal of Forecasting, and demonstrates it efficacy by application to various time-series data, including those used by West and Harrison.