Nickel-black solar absorber coatings

A new electrolyte has been proposed for the deposition of nickel-black selective coatings for use in flat-plate solar collectors. The authors have studied the influence of various ingredients and operating parameters on the appearance of the black coatings so obtained with special reference to their optical values (, ε). The coating exhibits better corrsion resistance than the well known black-nickel coatings (which contains nickel, zinc and sulphur) apart from having thermal stability upto 380°C. With no zinc in the deposit, this can be used in place of black nickel coatings with less corrosion problems.     

基于RBR—CBR的数控刀具材料选择专家系统

针对数控车削加工中刀具材料选取困难等问题,提出了一个基于规则推理（RBR）和基于实例推理（CBR）相结合的专家系统,详细阐述了该系统的知识表达、推理机制以及功能模块等。在此基础上,以VisualC＋＋为开发平台,SQLServer作为数据库管理工具,并结合ado技术实现了数控刀具材料选择专家系统。实验表明,该系统能够根据车削加工的要求正确合理地选取刀具材料,具有广泛的应用价值。     

裂解气阀和清焦阀的选型及使用

常见的裂解气阀和清焦阀的阀型有软密封平板闸阀、金属密封平板闸阀、双闸板平行式闸阀和金属密封蝶阀4种,文中分别论述了其原理和特点,简单介绍了这4种阀门在国内的应用概况,总结了裂解气阀和清焦阀的选型及使用应该注意的事项。     

基于免疫克隆高斯过程隐变量模型的SAR目标特征提取与识别

作为一种非线性维数约减算法,高斯过程隐变量模型(Gaussian process latent variable model,GPLVM)由于其适合处理小样本、高维数据,因而在模式识别、计算机视觉等领域得到了广泛应用.基于此,提出一种基于改进GPLVM的SAR图像目标特征提取及自动识别方法,其中利用改进的GPLVM进行特征提取,高斯过程分类进行目标识别.传统GPLVM使用共轭梯度法对似然函数进行优化,为避免梯度估值易受噪声干扰、步长对算法影响严重等缺点,提出基于免疫克隆选择算法的GPLVM,利用其具有快速收敛到全局最优的特性提高算法性能.实验结果表明,该算法不仅降低了特征维数,且提高了识别精度,从而验证了算法用于SAR图像目标识别的有效性.     

气田缓蚀剂的筛选及评价

针对土库曼斯坦某天然气田中酸性气体组成,以静态试验和动态试验对不同缓蚀剂进行筛选,用挂片失重法评价了缓蚀剂的缓蚀性能,并对温度及加药量进行了考察。缓蚀效果评价结果表明,新研制的缓蚀剂KO具有很好的防腐效果,可适用于酸性腐蚀介质。     

基于建筑工程空间要素规划许可条件的规划验线验测点选取规则

解析法建筑工程规划验线必须合理选取验测点。基于建筑工程建设位置、建设形状、建筑间距、建筑面宽和建筑退让用地红线等规划许可条件的规划验线验测点选取规则,是一个经济、合理、有效的规则。依据该规则选取规划验线验测点,是确保建筑工程规划验线成果能够如实反映被检验建筑物的相关现状空间要素与其规划许可条件符合情况的前提。     

基于间隔损失和L1范数调节的特征选择方法研究

特征评价和选择是机器学习和模式识别的重要步骤。为了获得稀疏特征子集,结合间隔损失评估策略和L1范数调节技术来获得一种有效的特征选择方法(MLFWL-L1),并将其应用到RBFSVM分类器。实验中,在UCI数据集上将提出的算法与Simba和ReliefF对比表明,验证所提出的算法是一种有效的特征选择方法。     

Performance analysis of multiple-antenna cooperative networks under Weibull fading

In wireless communications, cooperative relaying is well-known to enhance the overall system performance, but implementation and cost constraints stand against its wide deployment. This paper investigates the performance of cooperative relays with and without multiple antennas under independent and identically distributed (i.i.d.) Weibull faded channels in a two-hop wireless network. We consider the Weibull fading channel model due to its flexibility in describing the radio propagation environment more than the classical Rayleigh model. Our study relies on applying selection combining (SC) along with threshold decode and forward (TDF) protocol at the cooperative relays as a good compromise between cost and performance. In addition, maximal ratio combining (MRC) is used at the destination. We derive analytical expressions for the end-to-end (E2E) error performance of the network under such scenario and provide simulation results to confirm the validity of the obtained analytical expressions.     

Efficient Calculation of All Possible Regressions

When the number of contemplated independent variables in a regression analysis is reasonably small, an alternative to the use of step-wise procedures for selecting variables is to base the selection on the calculation of all possible regressions.

This paper describes efficient computational procedures for calculating all possible 2 ^{k ? 1} regressions of a dependentv ariable upon subsets of k independent variables, and provides efficiency comparisons among five different procedures.     

The Distribution of a Variate Based on Independent Ranges from a Uniform Population

The statistic of interest in this article is W = R ₁/min_{1 ≤ j ≤ k} R _j where R _i , i = 1, …, k, denote k independent sample ranges from a standard uniform distribution each based on a common sample size n. Expressions are derived for the distribution function and moments of W, and a table of percentage points is included for selected valrles of k and n. The role of the statistic W in the construction of a subset selection procedure is indicated and operating characteristics of the proceduce are derived under a slippage configuration. A numerical example is provided.