重视熵权的供应商选择DEA/TOPSIS联合方法

通过分析和总结供应链环境下战略供应商评价选择的准则、指标和方法,以供应链核心企业选择战略性供应商为目标,提出了战略性供应商评价的指标体系.研究了一种新的DEA模型,首先利用熵权法为各指标确定一个权重,然后利用线性加权方法将其与C2R模型的自由权重合成生成综合权重,并使用DEA/TOPSIS联合方法解决供应商选择问题,克服了DEA法与TOPSIS法单独应用时各自存在的不足.实证分析证明了该模型及方法的有效性,并为重视熵权的DEA/TOPSIS联合法在多目标规划中的运用提供了依据与参考.     

线性分配法及Bernardo方法的改进研究

线性分配法是一种单人多属性生决策方法,Bernardo方法是在线性分配法基础上的群决策方法.通过引入模糊大于关系与权重的思想对两种方法进行了改进,进一步细化了方案排序的优劣程度,避免了一些模棱两可的情况甚至错误情况出现,提高了两种方法的准确性.另外在Bernardo方法中引入加权重的γis,使之更加合理.从改进线性分配法谈起.讨论了改进多人多准则的Bernardo方法,并对两种改进方法分别进行示例研究,最后进行了总结.     

多目标决策分析在暖通空调方案决策中的应用研究

将现代决策理论中的多目标分析应用于暖通空调工程的决策尤其是方案决策。介绍了多目标决策的方法,讨论了暖通空调决策问题的多目标特征,针对我国北京地区供热方案的选择这一多目标问题,采用线性加权法进行求解,获得了与工程实际相符的优化方案结果。     

最佳组合赋权的供应商选择方法及其应用

提出了一种最佳组合赋权方法,利用加权偏差平方和最小化准则给出了最佳组合权重的线性表达形式,并用广义一致性准则和TOPSIS法来求解最优组合权重系数,给出了相应的供应商评价方案并给出了一个应用案例.最佳组合赋权法的事后检验准则表明了本文所给方法的有效性.     

排除系统误差的若干方法

文章中主要阐述了系统误差的来源及分类，并提出了系统误差的排除的几种方法。针对系统误差的线性规律和非线性规律分别进行了叙述。文中的代替法、补偿法、对称法等几种方法又分别列举了实例进行了论证。     

小样本采样数据的预处理

一般情况下数据处理大多采用数理统计方法，该方法对于数据较少情况下处理和判别粗大误差不适用．提出了运用线性均方估计法和熵值判别法来处理和判别粗大误差．线性均方估计消除粗大误差是一种采用软化的方法处理粗大误差；熵值判别法是根据熵的上界对应最大的不确定度，利用所得数据的熵信息量判别数据是否含有粗大误差．这两种方法经过多个实例计算，结果表明，它们在处理小样本采样数据时更有效．     

线性相位有限冲激响应滤波器的实现

介绍线性相位滤波器的一种实现方法,即采用有限冲激响应（FIR）滤波器的窗函数法设计线性相位的数字滤波器。     

语音信号的线性预测分析原理及算法分析

通过对LPC(线性预测编码)的研究,介绍语音信号的线性预测分析原理,详细分析用来求解线性预测方程的自相关法、协方差法的原理和计算方法,对算法进行比较,并用Matlab对实际语音信号进行线性预测编码实验。     

基于舍一交叉验证优化最小二乘支持向量机的故障诊断模型

提出一种基于舍一交叉验证优化最小二乘支持向量机(LS-SVM)的旋转机械故障诊断模型。首先将故障信号EMD分解为平稳IMF分量，再选择表征故障调制特征的IMF分量并构造瞬时幅值欧式范数作为故障特征矢量输入到舍一交叉验证(leave-one-outcross-validation, LOO-CV)优化线性核LS-SVM中进行故障识别。EMD分解可自适应分离故障调制信号；瞬时幅值欧式范数矢量的不同表征各类故障的差异；舍一交叉验证优化惩罚因子可以使线性核LS-SVM克服对故障类型与模式编号映射关系先验知识的依赖，提高LS-SVM的故障预测精度和自适应诊断能力。一个深沟球轴承故障诊断实例说明该模型的有效性。     

基于加权线性响应面法的支持向量机可靠性分析方法

针对估算非线性隐式极限状态函数的失效概率问题,提出了一种基于加权线性响应面法的支持向量机可靠性分析方法。首先采用加权线性响应面确定设计点,在线性响应面迭代的同时获得一定数量的样本,然后在这些样本和设计点附近补充抽取样本的基础上,采用具有良好小样本学习能力的支持向量机方法来训练样本,保证了在设计点周围获得更好的非线性极限状态函数的替代。这种方法既保证了对设计点的精确近似,又保证了对设计点附近非线性极限状态函数的良好近似,大大提高了失效概率的计算精度,为非线性隐式极限状态的可靠性分析提供了一种合理可行的方法。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.