一种基于Web文本聚类的用户兴趣发现模型的研究

研究了一种基于Web文本聚类的用户兴趣发现方法．他通过Web文档信息获取，文本的形式表示，以及Web文本聚类方法最终提取用户兴趣知识，并给出了一个设计模型。     

主题搜索引擎中爬虫搜索策略的研究

为了解决传统主题爬虫效率偏低的问题,传统主题爬虫会选择最有价值的链接进行访问,仅简单地计算链接的相关性,却忽视待分析URL之间的相关性关系,致使主题爬虫爬取效率较低。提出一种基于链接模型的相关性判别算法,综合利用有标种子URL和无标的待判别URL实现对无标URL的相关性判别,并推导出迭代初值选取对结果的不敏感性。实验结果表明,与传统的网络爬虫算法相关性判别方法相比,提出的方法效率更高。     

Organometallic L-Alanine Cadmium Iodide Crystals for Optical Device Fabrication

Single crystals of L-alanine cadmium iodide (LACI) were grown by the slow evaporation technique at room temperature. A single-crystal X-ray diffraction (SXRD) model was used to evaluate the crystal structure of the as-grown LACI crystal. The energy dispersive X-ray (EDX) analysis and ultraviolet-visible-near infrared (UV-vis-NIR) transmittance studies were carried out, and the results reveal the presence of elements in the title compound. From the transmittance data, the optical bandgap as a function of photon energy was estimated, and the different optical constants were calculated. A fluorescence study was performed for the LACI crystal. Thermogravimetric and differential thermal analyses have also been studied to investigate the thermal property of the LACI crystal. The efficiency of the second harmonic generation (SHG) of the title crystal was investigated. The magnetic and electrical properties were estimated by the vibrating sample magnetometer (VSM) analysis and impedance study, respectively.     

Structural and magnetic properties of nano-sized Cu-Cr ferrites prepared through a simple method using egg white

CuFe_2 − xCr_xO₄ (0 ≤ x ≤ 1) nanopowders were successfully synthesized by a simple method using metal nitrates and freshly extracted egg white. The resultant powders annealed at 550 °C for 2 h and were investigated by X-ray diffractometer (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). The results revealed the formation of cubic spinel structure at Cr concentrations ≥ 0.2. In spite of the lattice constant is hardly changed with increasing of Cr content, the magnetic properties of Cr-substituted copper ferrite are strongly affected. The saturation magnetization, remanent magnetization, and coercive force were found to decrease monotonously with increasing of Cr content.     

振动样品磁强计在磁记录介质中的应用

采用7407型振动样品磁强计(VibratingSampleMagnetometer)对(FePt/C)10磁记录多层膜的磁学性质进行了测量,包括磁滞回线、直流退磁曲线(DCD)、等温剩磁曲线(IRM)及磁化强度与时间(M-t)的关系。通过磁滞回线可直接得到Hc、Mr、Ms、S*、Mr/Ms、SFD等宏观磁学性能参数;由DCD和IRM得到的δM曲线可用来研究晶粒间交换耦合作用;磁反转体积(Va)的计算通过DCD、M-t实验可实现,由此可以确定磁记录介质的热稳定性。     

Development of a Thin Film Magnetic Moment Reference Material

In this paper we present the development of a magnetic moment reference material for low moment magnetic samples. We first conducted an inter-laboratory comparison to determine the most useful sample dimensions and magnetic properties for common instruments such as vibrating sample magnetometers (VSM), SQUIDs, and alternating gradient field magnetometers. The samples were fabricated and then measured using a vibrating sample magnetometer. Their magnetic moments were calibrated by tracing back to the NIST YIG sphere, SRM 2853.     

Processing and characterization of nano-magnetic Co0.5Ni0.5Fe2O4 system

Various techniques such as X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron micrographs (SEM), energy dispersive X-ray (EDX) and a vibrating sample magnetometer (VSM) were used to investigate the structural, morphological, and magnetic properties of spinel Co_0.5Ni_0.5Fe₂O₄ system. XRD and IR analyses enabled us to determine the functional group and structural parameters of Co_0.5Ni_0.5Fe₂O₄. EDX measurements showed the concentrations of O, Ni, Fe, and Co species involved in Co_0.5Ni_0.5Fe₂O₄ specimen from the uppermost surface to the bulk layers. The magnetization and coercivity of the as synthesized composite were 77 emu/g and 128 Oe, respectively.     

精益生产实践中提前期绩效的改进与实证——以3M中国工厂为例

为了在推行精益生产实践中缩短生产提前期,提出了一种按单制造（MTO）模式下的提前期绩效改进模型.针对3M中国工厂HH系列显示屏（LCD HH）产品的业务流程,通过因果矩阵和失效模式与结果分析（FMEA）,找出影响提前期绩效的关键因素,并采用价值流分析、统计检验等方法来进一步论证.研究发现,通过业务过程优化（如业务流程重组）和信息技术整合（如看板管理）,3M中国工厂生产率从原来的平均1 505件/h提高到1 600件/h,产品可获得性水平从89.7%提高到90%以上,明显缩短了生产提前期,从原来的5.88d缩短到3d,最终提高了公司的客户满意度和竞争能力.     

基于免疫算法的文本特征选择方法

文本的特征选择可以被看成是组合优化问题,而遗传算法是求解此类问题的较好方法。在遗传算法的基础上,提出了一种新的算法-免疫算法,用于文本的特征选择,通过免疫算子的构造,减轻了遗传算法后期的波动现象,提高了收敛速度。     

基于价值流图的车用组合电线组装流程优化

针对连续型生产过程中存在的生产线不平衡、资源管控粗放等问题,文章利用价值流图分析技术和流程程序图以某车用组合电线组装流程为例进行研究。采用"5W1H"技术和"ECRS四原则"并结合精益思想,从信息流、供应链、工艺流3个方面对生产流程全生命周期进行了改进。Flexsim软件仿真证明,改善后生产线的平衡率和增值比提高显著,生产周期时间和作业人数明显减少,极大地削减了生产浪费,有效地提高了生产线的生产效率,降低了生产成本。