最大距离分割码误比特率的精确计算

基于最大距离分割(MDS)码的码重分布，得到了不完全译码器中发生译码错误和译码失败的概率．根据译码错误和译码失败对MDS码误比特率的影响，推导出精确的误比特率公式．利用该公式可计算出不同长度的MDS码在加性白高斯噪声(AWGN)信道中的误比特率．仿真结果表明，该公式比传统的误比特率上限公式具有更高的精度．     

面向虚拟产品设计的专家协同评审系统

利用计算机支持的协同工作（CSCW）技术，开发一个面向虚拟产品设计的专家协同评审系统，建造了一个三级体系结构的分布式协同开发环境，对系统的主要功能及工作流程作了介绍；并就实现专家协同工作的几个关键技术进行了探讨，实践证明，本系统对提高产品开发效率具有极为重要的意义。     

围压对旋转射流破岩钻孔效率的影响

根据现场径向水平钻井技术的需要 ,在前期常压条件下研究的基础上 ,对围压条件下旋转射流的破岩钻孔效率进行了试验研究。结果表明 ,在围压条件下 ,随着射流压力的增加 ,旋转射流破岩效率呈现出线性增加的趋势。随着喷距的增加 ,破碎效率呈现出先增加后减小的趋势 ,即存在最优喷距。在围压低于 5MPa时 ,破碎红砂岩的最优无因次喷距为 2～ 2 .5 ;随着围压的增加 ,破岩效率呈指数下降趋势 ,最优喷距随围压的增加而减小。在同压差条件下 ,围压比射流压力对破碎效果的影响更大。     

Adelfa： a futuristic biodiesel fuel for DI diesel engines： a comparative experimental investigation

Biodiesel fuel is found to be a promising alter- native for the petroleum diesel based on the results published by the researchers for a decade. Biodiesel fuel is renewable and non degradable fuel. Many countries use biodiesel fuel for automotives to meet the crisis due to the depletion of the petroleum fuel and to meet the stringent emission norms. Various researches have been carried out with different bio- diesel fuels with vegetable oil as the source and appreciable results were reported. Few biodiesel fuels which have been already tested are Jatropha, Pongamia, Mahua, neem, cotton seed, etc. In this experimental work, Adelfa biodiesel blend is used as the test fuel. The emission and performance charac- teristics were compared with three other different biodiesel fuel blends. Appreciable results imply that Adelfa biodiesel （Nerium oil methyl ester） can be a futuristic biodiesel fuel, which has a good compatibility with the direct injection （DI） diesel engine without any major modification. Moreover, Adelfa can be cultivated in a non agricultural land with fewer sources of water. It is widely spread over all major countries of Asia. Experimental investigations have been carried out on a single cylinder DI diesel engine with standard engine speci- fications. In this experimental work, various Adelfa biodiesel blends is compared with reference fuel （diesel） to choose the best blend which gives a closer performance to diesel. The comparative analysis with other biodiesel fuels has also been done and results have been discussed.     

多缸柴油机冷起动过程的模型研究

为了研究多缸柴油机冷起动瞬态过程的特点和影响因素，在原有的包括准维燃烧模型的单缸直喷式柴油机冷起动过程预测模型基础上，分析多缸机冷起动过程特点，建立了多缸直喷式柴油机冷起动过程的瞬态模型，在详细分析多缸柴油机冷起动特点的基础上，介绍了冷起动模型的主要构成和计算公式．     

函数再现机构的可靠性综合

以曲柄滑块机构为例，提出了函数再现机构的可靠性综合方法．首先由机构的允许输出误差应用可靠性概念确定各构件尺寸，然后用概率法分配各构件的尺寸公差．从而使机构具有预定的可靠度．     

Rough集-神经网络系统在信息融合目标识别中的应用

研究了Rough集和神经网络方法在信息融合目标识别中的应用 .提出将神经网络学习机制引入到Rough集系统 ,同时通过Rough集的条件和决策属性构造神经网络结构 ,并针对三种不同谱段下的三种不同目标图像进行了实验 ,试验表明 ,Rough集 神经网络相结合的识别算法的识别率要明显高于单独使用一种融合算法的识别率 ,训练时间也大大缩短 .     

初始排污权拍卖的博弈分析

基于一级密封价格拍卖方式,建立了排污权交易制度中初始排污权分配的不完全信息静态博弈模型,对模型进行了分析,认为况标拍卖方式是初始排污权的一种合理的分配方式,并得到投标人越多,政府管理机构所得收益越高的结论。     

用GPS输出反馈实现大角度姿态状态跟踪控制

本文首次讨论并给出了利用星上GPS输出反馈,来实现卫星大角度姿态机动的自主非线性状态跟踪控制系统的设计.其中包括非线性状态反馈控制器的设计以及利用星上GPS伪距测量输出信息,采用修改的罗格里德参数描述姿态状态方程,实现星上实时状态跟踪控制的非线性估计器的设计.文中以EO-1/LandSat7卫星编队飞行为背景,给出了姿态测量信息的获取、姿态状态估计和实时跟踪控制的数学仿真结果,验证了控制系统设计的可行性和正确性,精度指标满足要求.     

Undoped semi-insulating indium phosphide (InP) and its applications

During the past several years, the research and development of InP material has made great progress due to serving as the substrate for most optoelectronic devices operating at the communications wavelength of 1.31 and 1.55 μm. At present, InP has become an important semiconductor material together with Si and GaAs. When compared to GaAs, InP has higher electron velocity, higher radiation hardness and better heat-conducting property. The advantage of InP crystal material allows higher frequency operation and lower power requirements. Therefore, InP is widely being used for the manufacture of microwave devices, high-frequency devices and optoelectronic integrated circuits (OEICs) which are indispensable for wireless technology, satellite communications^[1—3]. Although n-type and p-type InP can meet actual needs, semi-insulating InP substrates remain to be improved due to their poor uniformity and consistency. For this reason, several possible approaches have been reported to the preparation of SI InP by wafer annealing under different conditions^[4—9].