矿井中频感应通信系统研究

分析与研究矿井中频感应通信系统 ,并提出了一种新型的矿井中频数字感应通信系统。这种系统采用连续可变斜率增量调制 (CVSD)来实现语音信号的编码、GFM调制解调方式、FDMA、PLL频率合成器技术。本系统具有通话质量好、设备简单、抗衰减能力强等特点 ,适于矿井通信。     

Further remarks for the matrix type-B codes

Different philosophies lie behind the detecting and correcting error patterns in a real communication channel. The sceptic points in choosing an efficient code, specifically the matrix type-B code, were pointed out in Refs. 1 and 2.Some more points are shown here. As a result the matrix type-B code is found to be a best choice. Some more theoretical aspects for this code are also given. These are useful for the realization and testing of an encoding-decoding algorithm with IC's used in a unique way for its implementation.     

Application of multi-layer perceptron neural networks to vision problems

This paper discusses the application of a class of feed-forward Artificial Neural Networks (ANNs) known as Multi-Layer Perceptrons(MLPs) to two vision problems: recognition and pose estimation of 3D objects from a single 2D perspective view; and handwritten digit recognition. In both cases, a multi-MLP classification scheme is developed that combines the decisions of several classifiers. These classifiers operate on the same feature set for the 3D recognition problem whereas different feature types are used for the handwritten digit recognition. The backpropagationlearning rule is used to train the MLPs. Application of the MLP architecture to other vision problems is also briefly discussed.     

基于CPLD的信号相关器设计

针对单向发射被动测距的应用需求，提出了一种基于巴克码变换码型的脉压编码方案——对称替换码。分析表明该种编码方案可以在连续发送调幅信号进行测距的同时还可以传输二元信息。针对该编码方案，用VHDL在CPLD上完成了在倍采细分条件下的时域卷积结构的优化与具体实现。为提高信噪比，利用EAB单元设计了双RAM块，采用切换方式同时完成视频积分处理与数据输出，并设计了相应的与嵌入式处理器ARM之间的数据硬件接口以及工作时序分析。结果表明基于CPLD的相关器设计性能良好且易于实现。     

多用户检测技术的发展与应用

CDMA系统是一个自干扰系统，多址干扰是限制其容量和性能的主要原因之一，传统的相干接收机不能从根本上解决消除多址干扰的问题，因此如何抑制多址干扰引起了通信界学者们的关注．多用户检测技术能从根本上消除多址干扰，提高系统的性能。文中主要介绍了多用户检测的思想和检测器的分类，以及衡量多用户检测器性能的三个重要指标，还阐述了多用户检测技术的新发展和该技术在几个具体系统中的应用。     

基于TETRA的低速ACELP语音编码算法及其仿真

描述了TETRA中的低速率语音编码算法实现过程，并在CCS2．0中对其进行了软件仿真．由于这种低速率(4．567Kbps)ACELP算法与应用于多媒体通信的变速率G．723标准、应用于未来个人通信的8Kbps的G．729标准、第三代移动通信的语音压缩编码有许多相似之处，因此对其算法仿真的研究和实时实现对第三代移动通信的语音压缩编码算法有比较重要的意义．     

带梁式转换层的超限高层建筑结构设计

介绍了广州某带主次梁式转换层的超限高层建筑结构设计，详细介绍了其结构转换层的方案选择、结构布置、结构分析与构造处理，并结合此工程总结了带梁式转换层的高层建筑结构设计关键问题．     

使用MCNP程序调整和优化启明星实验装置设计方案

用蒙特卡罗程序(MCNP)对验证ADS系统的启明星实验装置的设计方案进行了有效增殖因数(Keff)计算,并对与Keff密切相关的热区燃料元件栅距和热区厚度进行了最优参数的计算。结果表明,启明星实验装置的Keff能够达到设计的目标。     

Analysis of NEA C5MOX benchmark with computer code “cohint” based on interface current approach

Interface current approach to solution of neutron transport equation has been earlier used for LWR lattice problems. The analysis of the C5MOX benchmark is a opportunity to test its applicability to heterogeneous reactor problem. Computer code COHINT, which incorporates a routine for solution of neutron transport equation in X-Y geometry by interface current approach was used for this analysis by representing the fuel rod as a square one. Region interface angular fluxes are represented by a four-term expansion. It is found that the average pin power error is about 2.28 % (peak pin error 4.1 %) relative to reference calculations. Further improvement is possible by introduction of the capability to represent circular rods with in a square cell in COHINT.     

Axial offset control of PWR nuclear reactor core using intelligent techniques

Improved load following capability is one of the main technical performances of advanced PWR (APWR). Controlling the nuclear reactor core during load following operation encounters some difficulties. These difficulties mainly arise from nuclear reactor core limitations in local power peaking, while the core is subject to large and sharp variation of local power density during transients. Axial offset (AO) is the parameter usually used to represent of core power peaking, in form of a practical parameter. This paper, proposes a new intelligent approach to AO control of PWR nuclear reactors core during load following operation. This method uses a neural network model of the core to predict the dynamic behavior of the core and a fuzzy critic based on the operator knowledge and experience for the purpose of decision-making during load following operations. Simulation results show that this method can use optimum control rod groups maneuver with variable overlapping and may improve the reactor load following capability.