基于本征间隙与正交特征向量的自动谱聚类

 针对经典谱聚类算法无法自动确定数据类个数的问题,本文提出了一种基于本征间隙与正交特征向量的自动谱聚类算法.该方法利用样本数据构建亲和度矩阵,然后进行谱分解得到相应的特征值和特征向量,对特征值从大至小依次排序,用本征间隙来刻画相邻特征值之间的差,通过第一个极大本征间隙出现的位置来自动确定类个数,最后以特征向量之间的夹角作为相似度和已获得的类个数相结合来实现数据分类.本文算法的正确性在人造数据库上得到了验证,并在UCI数据库上与k-means、FCM、 Jordan算法进行了分类准确性比较实验,结果表明本文方法比其他三种方法的分类准确率更高.     

如何筹建符合国际标准的实验室

随着中国加入WTO,企业面临的全球技术壁垒日趋森严,作为产品进入市场的准入证,安规认证已成为企业不可或缺的一个环节,以‘最低成本,最高效率’完成世界各国认证的申请和检测工作以满足不同市场的准入规则,其有效途径之一就是建立符合国际标准的实验室。好的实验室是企业产品自行设计、自主创新的基础,是企业核心竞争力的体现,可以提升企业的形象和创造企业价值。本文详述了企业如何筹建符合IEC/ISO17025国际标准的实验室,以及实验室设计规划中应注意的问题,并阐述了欧美知名安规机构对其认可实验室的分类及要求。     

Level of Internet use by Chinese businesses: A preliminary study

A preliminary study of the level of Internet use by Chinese firms was carried out. Data were collected by a questionnaire survey of a convenience sample of Chinese managers. The major finding is that firm size plays a role only in influencing a firm’s decision regarding whether or not to have Internet access. Within the Internet-using sub-sample, firm size is not significantly related to the overall level of Internet use, or to the use of individual Internet features. In addition, the data reveal that there are a high proportion of Chinese businesses that have Internet access. Chinese Internet using firms use an average of three features, with e-mail and buying and selling online being the two most widely used features. The results are also compared to similar studies in other countries. The limitations of this study and future research are discussed.     

一种用于天然气调压系统的自动识别选路装置

介绍了一种用于天然气场站调压系统的自动识别选路装置,包括了它的结构、工作原理及创新点。采用这种系统,当运行路发生故障或不能满足下游用气时,备用路能自动启动供气,同时能够确保备用路安全切断阀与运行路安全切断阀在切断点设定一致的情况下不同时动作。     

谈民用建筑外墙涂料的过程控制

对民用建筑外墙涂料的施工管理方法作了介绍,分析了建筑外墙涂料常见的涂层表面污染、涂层粉化、涂层起皮脱落及墙面变色和退色的原因,提出了相应的解决方法,并从质量验收准备、验收标准、成品保护方面确立了具体的质量控制措施。     

约束地震反演中测井数据的标准化及储层的精细标定

约束地震反演结果是否合理、准确，很大程度上取决于基础工作。测井数据标准化处理和储层精细标定是约束地震反演基础工作的核心。文中通过实例说明了测井数据做标准化编辑处理与不做标准化编辑处理对反演结果的影响，前者储层精细标定的结果准确，后者效果很差。文中简要地介绍了参与约束地震反演的测井数据标准化编辑处理和储层精细标定的方法。     

Bispectra-based impact acoustic non-destructive evaluation

This paper presents a novel cost-effective non-destructive evaluation (NDE) method for detecting defects in tiled-walls of high-rise buildings. The method is based on impact acoustic technique which identifies the bonding quality of tiles by analyzing the acoustic vibration signals generated by tapping a structure with an impacting device. However, the basic impact acoustic method, which uses a single impacting device, can only provide a single-point inspection and will take time to inspect a large high-rise building. To speedup the evaluation process, impacting the structure simultaneously with multiple impacting devices are being developed to increase the coverage area of the inspection. However, the sound signals generated by multiple impacting devices are more complicated than those from a single impacting device. Through the analysis of the raw sound data, this paper proposes a regional integrated bispectra method to extract the feature vector and a threshold method for classifying the bonding quality of tiles for multiple impacting devices. The experimental results confirm the validity of the proposed method.     

相同氧含量醇类混合燃料燃烧和排放特性差异研究

对一台4缸发动机燃用相同氧浓度的不同醇类混合燃料进行了试验研究,以对比不同三元燃料柴油机在相同转速不同负荷情况下的燃烧特性和常规排放的差异。试验结果表明:甲醇混合燃料在醇类混合燃料中获得最高的燃烧压力,而丁醇混合燃料的热释放率最高。与普通柴油相比,戊醇混合燃料在不同混合物中具有相对最佳的CO和未燃碳氢排放,甲醇混合燃料可获得最优的氮氧化物排放;乙醇混合燃料减小颗粒物效果明显,最大可以减少22.4%～55.6%的颗粒物数量浓度和3.4%～12.8%的颗粒物粒径,其中乙醇混合燃料的核态颗粒物和聚集态颗粒物排放量也最低,戊醇混合燃料达到最高(除高负荷外)。     

Cu2O半导体薄膜在酸性条件下的电化学沉积

在酸性溶液中在透明导电玻璃(ITO)基体上电化学沉积Cu2O薄膜.通过实验研究了电沉积工艺条件对电沉积Cu2O薄膜的影响.X射线衍射(XRD)和扫描电镜(SEM)对薄膜的微观结构和表面形貌进行了分析.结果表明,水浴温度较高时,酸性镀液中Ac-HAc共轭缓冲体系的反应速率提高,可以有效抑制铜单质的生长;镀液中铜离子的浓度...