层序地层学研究现状,方法与前景

本文总结了层序地层学的研究现状，讨论了层序地层学的研究方法，评述了层序地层学研究中存在的有争议的问题及研究前景。     

油气层序地层学研究的若干问题

油气层序地层学是在地震地层学、层序地层学、石油地质学基础上发展起来的一门综合性新型边缘学科。它实质上是一种含油气层序分析学，在等时地层格架内对油气层序进行成因单元分析。它应用地震层序地层、测井层序地层、露头层序地层分析方法，采用计算机技术和模拟技术研究含油气盆地的地层层序，进行地层对比、盆地生储盖组合和含油气系统分析，进而指出有利的油气勘探方向，特别是非构造油气藏的勘探方向。源于海相含油气盆地的油气层序地层学的基本原理和研究方法，同样也适用于过渡相和陆相含油气盆地。     

Successive beamforming,multiuser detection and diversity reception for multicarrier DS-CDMA system with antenna array

Code-Division Multiple-Access (CDMA) systems are interference limited,and therefore efficient interference management is necessary to enhance the performance of a CDMA system.In this paper,a successive beamforming (spatial filtering),linear decorrelating MultiUser Detection (MUD, temporal filtering) and diversity reception structure for uplink multicarrier Direct Sequence CDMA (DS-CDMA) system with antenna array are proposed.By beamforming,the antenna array suppresses interference according to the distinct array signature.Subsequently,linear decorrelating MUD is ap- plied to separate the signals of different users and eliminate Multiple Access Interference (MAI).Finally, the decorrelated signals at different subcarriers that belong to the same user are combined to achieve frequency diversity.Simulation results show that the proposed structure offers significant Bit Error Rate (BER) performance improvement by successively exploiting the space-time-frequency processing.     

A class of band-limited chip waveforms for DS-CDMA systems

In Direct Sequence Code Division Multiple Access （DS-CDMA） systems, the chip waveform affects the implementation, system bandwidth, envelope uniformity, eye pattern and Multiple user Access Interference （MAI）. In this paper, based on an elementary density function of a second order polynomial, a class of second order continuity pulses is proposed. From this class of pulses, we can find some members having faster decaying rate, bigger eye opening, more uniform envelope and stronger anti-MAI capability than the Nyquist waveform. The normalized-bandwidth-pulseshape-factor product, the decaying rate of the tail of the time waveform, the opening of the eye diagram, and the envelope uniformity of the second order continuity pulses are addressed in the paper that provide the basic information for the selection of the chip pulse for CDMA systems.     

扩频通信中伪随机序列编解码器的FPGA实现

提出一种基于FPGA技术的伪随机序列编解码器的设计方案,用以模拟扩频通信的过程,可用于现今高校的扩频通信技术教学工作。     

CPM中相关同步技术的研究

针对连续相位调制系统,提出了一种利用相关器来辅助实现同步的方法,分为差分相关、绝对相位相关两种方法.通过MATLAB仿真,分析了两种相关方法的性能.在性能最佳的基础上,提出了一种利用FPGA实现的简化算法,节省了FPGA芯片的逻辑资源,使相关器的FPGA有效实现变为可能.     

Sequence Algebra, Sequence Decision Diagrams and Dynamic Fault Trees

A large attention has been focused on the Dynamic Fault Trees in the past few years. By adding new gates to static (regular) Fault Trees, Dynamic Fault Trees aim to take into account dependencies among events. Merle et al. proposed recently an algebraic framework to give a formal interpretation to these gates.In this article, we extend Merle et al.'s work by adopting a slightly different perspective. We introduce Sequence Algebras that can be seen as Algebras of Basic Events, representing failures of non-repairable components. We show how to interpret Dynamic Fault Trees within this framework. Finally, we propose a new data structure to encode sets of sequences of Basic Events: Sequence Decision Diagrams. Sequence Decision Diagrams are very much inspired from Minato's Zero-Suppressed Binary Decision Diagrams. We show that all operations of Sequence Algebras can be performed on this data structure.     

Sequence of linear programming for transmission of fine-scalable coded content in bandwidth-limited environments

In this paper, we propose an optimal peer assignment algorithm on peer-to-peer networks. This algorithm is designed to maximize the quality of transmitting fine-scalable coded content by exploiting the embedding property of scalable coding. To be more realistic, we assume that the requesting peer has a delay constraint to display the content within a certain delay bound, and it also has limited incoming bandwidth. We first use a simple example to illustrate the peer assignment problem, and then formulate this problem as a linear programming problem, followed by a nonlinear programming problem. To efficiently solve the second nonlinear problem, we transform it into a sequence of linear programming problems. Finally, we apply our proposed algorithm to both image and video transmissions in bandwidth-limited environments. Extensive experiments have been carried out to evaluate the complexity and performance of our approach by comparing it with both nonlinear formulation and two heuristic schemes. The results have verified the superior performance of our proposed algorithm.     

集散控制系统中控制方案实现与研究

文中应用集散控制系统分析设计了PH值控制应用系统、流量应用系统。对顺序面板功能块进行了设计分析和实现。文中综合运用了连续控制、顺序控制和运算编程等功能。编写了顺控表和运算块的程序。文中的研究对集散控制系统的设计应用具有一定的实用价值。