构建高可用校园网

校园网的高可用性一直是网络管理人员追求的目标之一,本文针对作者所在学校校园网运行的特点,结合长期的校园网管理经验,以用户管理为切入点采取对应的措施来构建高可用校园网,获得了较好的效果.     

超大直径钢筋混凝土顶管在排水工程中的应用

本文叙述了国内外顶管技术的发展历史,简要介绍了国内大直径钢筋混凝土顶管在排水工程中的应用与实践,详细分析和归纳了上海南线污水输送管线两条DN4000钢筋混凝土顶管平行顶进的设计和施工技术,为今后同类工程的推广应用和发展提供参考和借鉴。     

MODEL OF OPERATING AND BALANCING ASSEMBLY LINE IN A MASS CUSTOMIZATION ENVIRONMENT

The successful implementation of mass customization lies on reengineering technology andmanagement methods to organize the production. Especially in assembly phase, various product con-figurations, due-time penalties and order-driven strategy challenge the traditional operation and man-agement of assembly lines. The business features and the operation pattern of assembly line based onmass customization are analyzed. And the research emphatically studies various technologic factors toimprove customer satisfaction and their corresponding implement methods in operating assembly line.     

一种基于复合混沌序列的图像加密方法

针对低维度混沌系统的密钥空间小、加密系统安全性较低的不足。提出一种由sine混沌改变均匀分布logistic混沌排列次序形成复合混沌序列的图像加密方法。首先,产生服从均匀分布的logistic混沌序列,用sine混沌序列重排该序列整数化后的重复部分,以此无重复数值的复合混沌序列进行像素位置置乱;之后,由于仅进行位置置乱不能改变图像的灰度统计直方图特征,用sine混沌重排整个logistic混沌序列形成复合混沌序列,以此进行像素扩散完成图像加密。对方法安全性从密钥空间、密钥敏感性、差分分析、统计直方图、相邻像素相关性、信息熵方面进行了测量。实验结果表明该方法密钥空间大、敏感性高,能有效地抵抗穷举分析、差分分析和统计分析。     

青奥会对南京城市空间发展影响研究

2014年第二届青年奥林匹克运动会将在南京举办,这是南京首次举办全球性质的大型综合性体育赛事。从城市事件与城市空间形态入手,分析青奥会场馆选址、布局及其与南京城市空间规划的契合,着重探讨了青奥会对南京城市空间发展的三方面影响：助推南京实现城市总体发展战略;加快城市空间更新;优化城市空间结构,促进城市空间拓展。     

新一代资源回收·循环集成技术与生态化产业体系

本文将以化冶所几项代表性工作为例介绍新一代资源回收．循环集成技术研究成果及绿色工程化学新兴学科的科学内涵。     

双阈值法在图像边缘检测中的应用

在多尺度小波变换局部模极大值图的基础上,分别以图像边缘链的长度和按边缘链长自适应分块的块灰度作为双重阈值检测图像的边缘。实验表明,采用这一方法,可获得单像素宽、定位精准、抗噪声效果好的边缘图像。     

Analysis of affinely equivalent Boolean functions

By some basic transforms and invariant theory, we give two results: 1) an algorithm, which can be used to judge if two Boolean functions are affinely equivalent and to obtain the equivalence relationship if they are equivalent. This is useful in studying Boolean functions and in engineering. For example, we classify all 8-variable homogeneous bent functions of degree 3 into two classes; 2) Reed-Muller codes R(4,6)/R(1,6), R(3,7)/R(1,7) are classified efficiently.     

STRENGTH DESIGN OF PREMIUM THREADED CASING CONNECTION

Using premium casing connections instead of API ones is one of the most effective technique to prevent casing failure. The factors contribute to the strength of premium casing connections are studied with FEA and full-scale test. The criterions are presented that ensure the connection's strength higher than the pipe. At the same time, the method is given to decrease the peak stress of the connection so as to improve its anticorruption property. At last, full-scale tests are done to test the strength of the connections designed with the method described, the results show that the connection's strength is higher than the pipe. This indicated that the method described is effective in designing premium casing connection.     

闸瓦温升与摩擦因数对提升机安全制动的影响机理研究

针对闸瓦温升和闸瓦摩擦因数对制动安全影响较大的问题，进行了闸瓦摩撩试验，研究分析了闸瓦温升、滑速和比压3个因素对摩擦因数和制动安全的影响，提出了基于神经网络的闸瓦摩擦因数预测模型及生产过程中应注意的几个问题．研究结果表明，闸瓦温升对摩擦因数影响最大，因此，企业一定要注意选用摩擦因数具备较高热稳定性的闸瓦，并建议在使用前进行检验；在下放重物时采用低速运行，避免超载，并对制动器状态和温升进行监测．