安徽省水资源宏观经济优化模型研究

以水资源可持续发展为出发点,探讨了一种可以同时兼顾经济发展、水资源利用和社会效益的多目标水资源宏观经济模型的建立方法,通过引入带权2-模评价函数,将多目标优化问题转变成单目标优化问题。以2002年为现状水平年,对安徽省2010年的产业结构及产业规模进行优化分析。结果表明,多目标模型求得的总用水量较单目标模型明显降低,而两模型优化的产业规模与结构差别不大,体现了高用水效率行业优先发展的要求。     

应用PIMS选油模型实施进口原油优化选购

应用AspenTech公司PIMS软件，模拟炼油企业生产经营过程，综合考虑原油成本、产品价格以及长岭分公司炼油厂加工流程特点和产品质量等要求，建立了适用于该厂的原油选购模型。利用该模型对该企业2002年第三季度进口原油品种进行优化选择，对综合效益好的原油实施采购。实际生产数据表明，该模型比较准确。     

DESIGN AND IMPLEMENTATION OF STATE OBSERVERS IN REACTIVE DISTILLATION

This study demonstrates that state observers can be developed and applied to infer the composition profiles of reactive distillation columns from noise-contaminated temperature measurements. The design and implementation of a Kalman filter (KF) and a Luenberger observer (LO) are carried out, and their performances are quantitatively assessed. The reliability, accuracy, and robustness of the two designs method are examined and compared quantitatively. The design and implementation of a Luenberger observer are simpler and easier to carry out than those of a Kalman filter. On the other hand, a Kalman filter is found to be more robust to a noisy measurements, erroneous initial estimates, and model uncertainties. A Luenberger observer could be used for composition estimation of reactive distillation when an ideal model of the system can reasonably approximate the real system; otherwise, a Kalman filter is recommended to be applied in more practical situations.     

济钢高炉喷煤数学模型的研究与应用

基于湍流两相流理论建立了高炉喷煤两相流动及传质三维数学模型。采用该模型指导高炉生产 ,高炉利用系数由2 .7t/(m3.d)提高到 3 .0 t/(m3.d)以上 ,焦比由 460 kg/t降到 40 0 kg/t,煤比达到 10 0 kg/t,提高了高炉的各项经济技术指标。     

单层开采的圆形定压边界两层油藏压力动态分析

为更好地分析具有越流的多层油藏的压力动态，采用有效井径的概念，在半透壁模型的基础上建立了圆形定压边界、两层越流油藏单层开采时的渗流数学模型。通过拉氏变换得到了拉氏空间中以Bessel函数表示的精确解。数值反演计算结果表明，单层开采的两层油藏与全部打开的两层油藏的压力动态基本相同，都表现为3个阶段：早期是介于两个渗透层之间的均质流动；中间为过渡段，导数曲线出现下凹特征；晚期表现为整个油藏的均质特征。随着边界距离的增加，压力导数值趋近于0．5。半透率越大过渡段出现得越早。导数曲线下凹程度越小；储容比越大导数曲线峰值越小，导数曲线下凹程度越小；随着两层渗透率比值变小。过渡段变短，导数曲线下凹程度变小。图1参9     

Estimation for the number of components in a mixture model using stepwise split-and-merge EM algorithm

The main difficulty with EM algorithm for mixture model concerns the number of components, say g. This is the question of model selection, and the EM algorithm itself could not estimate g. On the contrary, the algorithm requires g to be specified before the remaining parameters can be estimated. To solve this problem, a new algorithm, which is called stepwise split-and-merge EM (SSMEM) algorithm, is proposed. The SSMEM algorithm alternately splits and merges components, estimating g and other parameters of components simultaneously. Also, two novel criteria are introduced to efficiently select the components for split or merge. Experimental results on simulated and real data demonstrate the effectivity of the proposed algorithm.     

Pedestrian detection and tracking at crossroads

This paper presents a system that can perform pedestrian detection and tracking using vision-based techniques. A very important issue in the field of intelligent transportation system is to prevent pedestrians from being hit by vehicles. Recently, a great number of vision-based techniques have been proposed for this purpose. In this paper, we propose a vision-based method, which combines the use of a pedestrian model as well as the walking rhythm of pedestrians to detect and track walking pedestrians. Through integrating some spatial and temporal information grabbed by a vision system, we are able to develop a reliable system that can be used to prevent traffic accidents happened at crossroads. In addition, the proposed system can deal with the occlusion problem. Experimental results obtained by executing some real world cases have demonstrated that the proposed system is indeed superb.     

关于海面无线传播模型的探讨

现有文献中一般都认为海面环境的无线传播模型近似于自由空间传播模型，但在实际测试中发现，自由空间模型预测值与实测值差别较大，不能很好地解释此类环境的信号传播。笔者根据多次海面覆盖测试的数据，分析并拟合出了新的海面传播模型。