基于模糊数学的高维稀疏数据聚类统计方法设计

传统的数据聚类统计方法仅适用于低维数据聚类问题,为此,本研究设计了基于模糊数据的高维稀疏数据聚类统计方法,以期提升高维稀疏数据的聚类统计效果。以模糊C均值聚类算法为基础,通过优化初始聚类中心解决局部最优问题,缩短聚类统计时间;然后引入权重机制,令该方法适用于高维稀疏数据聚类统计。基于此,以余弦距离替换原有的欧几里德距离,提高高维稀疏数据聚类统计效果。实验证明：在数据维度不同时,该方法均有较优的聚类统计效果。当数据维度较低时,分块比例为10%时聚类统计效果最优;当数据维度较高时,分块比例为40%时聚类统计效果最优。在不同稀疏度等级时,该方法的命中率和聚类统计效率均较高。     

一种基于语料库的日语动词格框架自动构造技术*

结合一个基于格语法的日汉机器翻译系统,针对现有系统日语动词格框架缺乏的现状,提出一种日语动词格框架自动构造方法.该方法基于类比与统计思想,从现有的少量人工构造的动词格框架和大量生语料出发,自动构造日语动词格框架.     

Influences of mullite fibers on mechanical and thermal properties of silica-based ceramic cores

Mullite fibers composite silica-based ceramic cores were successfully prepared by injection molding. The effects of mullite fibers on the mechanical and thermal properties of ceramic cores were investigated. The results indicated that the linear shrinkage was significantly decreased and the porosity was gradually increased with the increase of mullite fibers. In addition, the flexural strength for the room temperature and the simulated casting temperature of 1500°C was increased to a maximum value when the content of mullite fibers was about 1 wt.%, and then decreased with the increase of mullite fibers. The mullite fibers of 1 wt.% presented excellent mechanical properties with a linear shrinkage of .65%, a porosity of 6.96%, and a flexural strength of 17 MPa at room temperature and 34.83 MPa at the simulated casting temperature of 1500°C. Besides, the change in microstructure and properties in various contents of mullite fibers were analyzed.     

Varnish layer hardness of oriental beech (fagus orientalist L.) wood as affected by impregnation and bleaching

The impacts of impregnation and bleaching on the varnish layer hardness of Oriental beech (Fagus orientalist L.) wood were investigated. A number of bleaching combinations {[NaOH−H₂O₂], [NaOH−Ca(OH)₂−H₂O₂], [NaOH−MgSO₄−H₂O₂] [NaHSO₃−H₂C₂O₄], [NaSiO₃−H₂O₂], [KMnO₄+NaHSO₃+H₂O₃]} were applied at 18% concentration for bleaching to both impregnated and unimpregnated specimens of Oriental beech wood. Subsequently, water-based (WB) varnish was coated over the samples and the varnish layer hardness values were determined in accordance with ASTM D 4366-95. All of the chemicals used for bleaching reduced the surface hardness. However, after varnish coating, the hardness of most samples was similar to that of the varnish-coated natural (control) samples.     

N-氧化吡啶-2-甲醛类Schiff碱配合物的情报分析

通过对N-氧化吡啶-2-甲醛类Schiff碱配合物研究论文的研究内容、发表年代、期刊和作者等方面进行统计分析,探讨了N-氧化吡啶-2-甲醛类Schiff碱配合物研究进展、现状和发展趋势,以推动对N-氧化吡啶-2-甲醛类Schiff碱配合物的进一步探索和研究。     

基于改进卡方统计的微博特征提取方法

通过对微博文本特征信息的分析与研究,提出一种基于改进卡方统计的微博特征提取方法。扩充微博信息分类特征,在传统的卡方统计量的基础上,引入了频度等因素,改进特征选择方法;在传统的特征项权值计算的基础上,提出了新的改进卡方统计量的方法,改进权重计算效果。对上述方法利用经典KNN和SVM算法进行了测试,实验结果表明该方法提高了微博信息分类的准确率。     

运用数理统计方法提高循环水质量控制能力

介绍了对循环水质量控制的必要性和直方图法、过程能力计算等数理统计方法。绘制了直方图,并计算过程能力指数,对循环水质量控制水平作出评价。通过实际应用控制图,有效地提高循环水质量控制能力。     

A multivariate study of the correlation between tocopherol content and fatty acid composition in vegetable oils

The main biochemical function of the tocopherols is believed to be the protection of polyunsaturated fatty acids (PUFA) against peroxidation. A critical question that must be asked in reference to this is whether there is a biochemical link between the tocopherol levels and the degree of unsaturation in vegetable oils, the main source of dietary PUFA and vitamin E. We used a mathematical approach in an effort to highlight some facts that might help address this question. Literature data on the relative composition of fatty acids (16:0, 16:1, 18:0, 18:1, 18:2, and 18:3) and the contents of tocopherols (α-, β-, δ-, and γ-tocopherol) in 101 oil samples, including 14 different botanical species, were analyzed by principal-component analysis and linear regression. There was a negative correlation between α- and γ-tocopherols (r=0.633, P<0.05). Results also showed a positive correlation between linoleic acid (18:2) and α-tocopherol (r=0.549, P<0.05) and suggested a positive correlation between linolenic acid (18:3) and γ-tocopherol.     

A review of the current status of small-scale seawater reverse osmosis desalination

The current status of small-scale desalination (produced water capacity 100 m³/day or less) is reviewed to provide an overview of the market segment. The use of energy-recovery devices in this market segment is also reviewed. We find that the Middle East accounts for the largest market share worldwide at present, and reverse osmosis is overwhelmingly dominant among the desalination technologies adopted. Implementation of energy-recovery devices at small scale is rare, which leads to relatively high energy consumption for small-scale seawater reverse osmosis desalination systems.