Functional reliability analysis of Safety Grade Decay Heat Removal System of Indian 500 MWe PFBR

Passive systems are increasingly deployed in nuclear industry with an objective of increasing reliability and safety of operations with reduced cost. Methods for assessing the reliability of thermal-hydraulic passive systems, that is systems with moving working fluid, address the issues in natural buoyancy-driven flow that could result in a failure to meet the design safety limits under accident scenarios. This is referred as design functional reliability. This paper presents the results of functional reliability analysis carried out for the passive Safety Grade Decay Heat Removal System (SGDHRS) of Indian Prototype Fast Breeder Reactor (PFBR). The analysis is carried out based on the overall approach reported in the Reliability Methods for Passive System (RMPS, European Commission) project. Functional failure probability is calculated using Monte-Carlo method and also with method of moments.     

基于数学形态学的二维条码边缘检测算法

边缘模糊会导致二维条码识别率下降,提出了一种基于数学形态学边缘检测的二维条码识别算法,该算法最大的特点是用具有特定形态的结构元素去度量和提取图像中的对应形状以达到对图像分析和识别的目的,从而有效地降低边缘模糊对条码识别的影响。选取PDF417二维条码为应用对象,采用基于数学形态学对二维条码的识别算法选择合适的结构元素。实验结果表明与传统的几种边缘检测算法相比,基于数学形态学对二维条码的识别算法能够更有效地识别条码边界,显著地提高了条码的识别率。     

An improved mixing model providing joint statistics of scalar and scalar dissipation

For the calculation of nonpremixed turbulent flames with thin reaction zones the joint probability density function (PDF) of the mixture fraction and its dissipation rate plays an important role. The corresponding PDF transport equation involves a mixing model for the closure of the molecular mixing term. Here, the parameterized scalar profile (PSP) mixing model is extended to provide the required joint statistics. Model predictions are validated using direct numerical simulation (DNS) data of a passive scalar mixing in a statistically homogeneous turbulent flow. Comparisons between the DNS and the model predictions are provided, which involve different initial scalar-field lengthscales.     

一种新的蜂窝网NLOS误差抑制算法

非视距传播(NLOS)误差是目前基于蜂窝网络的移动台定位系统提高定位精度必须解决的关键问题,该文提出一种基于概率密度估计和偏差Kalman滤波器的NLOS误差无偏估计算法。仿真结果表明,该算法在性能上优于现有同类算法,并且算法对环境先验知识的需求更少,具有更广泛的适用性。     

SAR多视图像的Stokes参数的统计分布

该文首先应用散射矩阵的Wishart 联合分布推导了高斯分布散射矩阵的Stokes参数分布,利用极化不变量思想得到了全部4个Stokes参数分布相当理想的理论结果,并与前人的结果进行了对比,体现了此分析算法的简洁性与统一性,他们可以具体描述Stokes参数的起伏性。在此基础上,求出了SAR多视情况下标准化Stokes参数分布的概率密度函数,从另一方面描述了SAR多视图像的随机状态特性,这些结果对于降低斑点噪声、地表分类与背景中的目标识别具有重要的指导意义。     

Preliminary analysis of compatibility with low activation martensitic steel blanket for the fusion experimental breeder: Impact of ferromagnetic behavior on plasma burning cycle

The reduced activation ferritic martensitic steels is considered a candidate for the first wall (FW) blanket structural material because of its safety environmental advantages [R.L. Klueh, D.S. Geiles, et al., Ferritic/martensitic steels overview of recent results, J. Nucl. Mater. 307-312 (2002) 455-465; T. Muroga, M. Gasparotto, S.J. Zinkle, Overview of materials research for fusion reactors, Fusion Eng. Des. 61-62 (2002) 3-25]. An engineering design analysis concerning the electromagnetic issues is performed. Preliminary analysis results show that design effort of the fusion reactor can cope with the effect of the ferromagnetic FW blanket on the electromagnetic forces, which increases by 28-38% during a major plasma disruption and overcome the influence of the poloidal field, which reduces by 10-20%, comparing with the austenitic steel blanket. Both the effect and influence depend on the saturation magnetic susceptibility and blanket configurations.     

TFPI-1抑制作用的模型化研究

TFPI-1在凝血动力系统中起着重要的调节作用,主要对FV∏α-TF的抑制过程作用显著.根据生物学实验建立一个关于TFPI-1,FV∏α-TF和FXα等因子的凝血动力数学模型.通过对模型的分析和数值模拟得到了一些与临床医学及实验相吻合的结论,展现出模型化方法的重要作用及预测能力.     

数字印刷外行人入侵

<正>我们无法预见未来,又得为将来打算,于是大家都跑去德鲁巴(drupa)展览会,希望能一窥印刷产业的未来。本届展会,有3万多人从中国到德国杜塞尔多夫市,占所有参观人数39.1万的将近十分之一。     

Statistical appraisal of economic design strategies of LV distribution networks

This paper presents a statistical approach for assessing general LV distribution network design strategies based on a large set of realistic test networks and optimal economic circuit design. The test networks are generated using a fractal-based algorithm that allows creation of generic networks with various topological features (e.g., typical of rural/urban/mixed areas) and characterised by different numbers of substations, numbers of customers, load densities, and so forth. In comparison to standards derived from a traditional approach, that is, case studies on a small number of specific real or test networks, the proposed approach facilitates the derivation of more robust conclusions on optimal network design policies and can thus be used as a valuable tool for decision support. The methodology is exemplified through numerical applications for both urban and rural areas.