基于EMFP-树的频繁模式挖掘算法

针对MFP-tree挖掘算法的不足,给出了一个频繁模式挖掘算法EMFP。算法通过将事务数据库的每条事务支持度进行裁剪以及为EMFP-树的节点添加子树个数计数器等措施来提高EMFP-树的挖掘算法的效率。实验结果表明,EMFP-树的挖掘算法是一个高效的频繁模式挖掘算法,其性能优于MFP算法。     

INFI-90系统的应用

INFI - 90系统具有物理位置分散、系统功能分散、控制功能分散以及显示、操作、管理集中的特点。它由分布式网络 (INFI NET) ,过程控制单元 (PCU) ,操作员接口站 (WSA) ,工程师工作站 (EWS)以及计算机接口单元 (CIU)等组成。其通讯系统带载能力大 ,适应各种规模、各种要求的过程控制 ,实际运行证明 ,系统技术先进 ,质量可靠 ,已成为电力、冶金、化工、建材等行业主要推荐使用的智能型分布控制系统之一。     

拖线阵声纳的匹配场后置波束形成干扰抵消方法

根据拖曳线列阵对本舰噪声的接收响应机理，提出了一种用于本舰干扰抵消的新方法，即在现有后置波束形成干扰抵消器的基础上，利用本舰噪声在拖线阵上的拷贝场向量直接进行干扰波束形成，从而更好地达到消除本舰强干扰的目的。同时，还将匹配场干扰抵消方法推广应用于同方向强干扰背景下的弱目标检测问题。理论与仿真分析表明，匹配场PIC比基于平面波的PIC具有更好的干扰抑制性能。     

催化裂化装置应用MFP技术的工业试验

介绍了多产丙烯和低硫燃料油组分的催化裂化与加氢脱硫(MFP)技术在催化裂化装置的改造内容、工业试验以及工业应用。以MIP-CGP工艺为空白标定,对比了在专用催化剂占系统藏量50%和80%时MFP工艺操作条件和产品分布的变化。结果表明,采用MFP技术后,产物氢分布改善,液化气中丙烯和异丁烯含量大幅增加,低碳烯烃收率和选择性得到提高,并且维持了干气量和生焦量的稳定。催化裂化技术从追求高转化率向高选择性的转变,实现了碳氢资源高效利用;同时可以根据市场需求变化灵活调整生产方案,实现经济效益的最大化。     

布尔型关联规则挖掘算法研究

在分析FP_growth关联规则挖掘算法的基础上,提出了一种MFP的算法,给出了算法的工作原理。MFP算法能在一次扫描事务数据库过程中,把该数据库转换成MFP树,然后对MFP树进行关联规则挖掘。MFP算法比FP_growth算法减少一次对事务数据的扫描,因此具有较高的时间效率。     

基于MFP方法的Web用户访问模式的模式发现

针对Web用户访问模式问题，采用最大频繁访问路径（MFP）方法可以挖掘出更有普遍意义的模式。给出一种新的用户访问模式树WUAP tree结构，并采用E OEM模型，综合考虑了页面拓扑结构及用户浏览路径等多个数据源，进一步提出了一种Web访问模式挖掘算法WUAP mine。该算法不用产生候选集和递归，只对事务数据库进行一次扫描，对WUAP tree结构进行深度优先遍历一次，就可从WUAP tree结构上直接查询出Web用户频繁访问模式。最后，从理论和实践上推导和验证了它的有效性和高效性。     

Performance of energy-aware and link-adaptive routing metrics for ultra wideband sensor networks

Wireless sensor networks are energy constrained since sensors operate with limited battery capacity. Thus, energy consumption is one of the most critical issues in the design of routing protocols. In addition, the link quality needs to be taken into account in the route decision for a wireless multihop network in order to efficiently exploit the inherent spatial diversity. In this paper we consider energy-aware and link-adaptive routing strategies for UWB (Ultra Wide Band) sensor networks. We utilize the ranging capabilities offered by UWB and employ adaptive modulation to take advantage of favorable link conditions. Different routing metrics are proposed based on the availability of sensor node’s location, link quality and next hop battery capacity information. These routing metrics integrate the measure of next hop remaining battery capacity with the throughput performance measures, Maximum Forward Progress (MFP) or Maximum Information Progress (MIP). The effectiveness of these metrics is evaluated in different simulation scenarios in terms of network throughput and lifetime for both random and grid sensor network topologies. Jinghao Xuis a D.Sc. candidate of the Department of Electrical and Computer Engineering at the George Washington University. He received his B.Sc. and M.S. degrees in telecommunication and electrical engineering from the Tianjin University, China, in 1993 and 1996, respectively. From 1996 to 2001, he was with Research Institute of Telecommunication Transmission of Ministry of Information Industry, Beijing, China, and China Wireless Telecommunication Standards group, where he was involved in the standardization of IMT-2000 communication systems for China. His research interests include performance evaluation and modeling of wireless ad hoc networks, Ultra Wide Band systems and multiuser detection techniques. Bojan M. Peric received the B.S. degree in electrical engineering from the University of Belgrade, Belgrade, Serbia and Montenegro in 2001. He is currently working toward the D.Sc. degree in electrical engineering at the George Washington University, Washington, DC. His research interests include wireless communications, with an emphasis on ad hoc networks. Branimir R. Vojcic is a professor in, and a past Chairman of, the Department of Electrical and Computer Engineering at the George Washington University. He has received his Dipl. Ing., M.Sc. and D.Sc. degrees from the University of Belgrade in Serbia and Montenegro in 1980, 1986 and 1989, respectively. His current research interests are in the areas of communication theory, performance evaluation and modeling mobile and wireless networks, mobile internet, code division multiple access, multiuser detection, adaptive antenna arrays, space-time coding and ad-hoc networks. He has also been an industry consultant and has published and lectured extensively in these areas. He co-authored the book: The cdma2000 System for Mobile Communications. Dr Vojcic received NSF CAREER Award in 1995. He is a Senior Member of IEEE, was an Associate Editor for IEEE Communications Letters and is presently an Associate Editor for Journal on Communications and Networks.     

宽带距离深度域最小二乘矩阵滤波器的设计

设计出基于拷贝向量处理的适用于宽带信号滤波的距离深度域矩阵滤波器。提出利用最小二乘原理将矩阵滤波器的设计问题转化为超定线性方程组求解问题,通过对线性方程组最小二乘解化简重构,得出最小二乘矩阵滤波器为期望拷贝向量矩阵与实际拷贝向量矩阵右伪逆的乘积。通过对宽带信号频谱中能量较高的频点进行采样处理,可以将矩阵滤波器应用于宽带信号处理。分别对垂直均匀线列阵接收到的窄带和宽带数据进行处理,发现宽带矩阵滤波器可以保证水听器阵在恶劣环境中更加有效地工作。相比于二阶锥规划矩阵滤波器,距离深度域最小二乘矩阵滤波器更快捷,滤波之后目标源与干扰源的相对幅度更大,有利于目标检测。     

固定干扰抑制的声场匹配方法

利用波导中的声场匹配与自由空间中的阵列处理的相似性,从自由空间的阵列零点方法出发推导～一种适用于波导中垂直阵列声场匹配的抑制固定干扰的方法。通过声场模型预报已知空间位置干扰的声传播特征,形成空间矢量。在保持期望点增益的前提下,约束干扰点邻域增益,得到垂直阵列的零点指向干扰的阵列权向量。     

Algebraic approach for the diagnosis of turbine cycles in nuclear power plants

According to plant operating staff's practical needs, authors proposed a diagnosis model to identify the performance degradation of steam turbine cycles in nuclear power plants (NPPs). The essential idea of this study is how to identify the intrinsically degraded component which causes electric loss. Authors found that there were not so many turbine cycle diagnosis applications in NPPs currently because of technical, financial, or social characteristics of the plant. So a great part of the diagnosis has been dependent on operating staff's experience and knowledge. However as economic competition becomes severe, the efficiency staffs is asking for reliable and practical advisory tools. For the solution of these shortcomings, authors proposed a simple and intuitive diagnosis concept based on the superposition rule of degradation phenomena, which can be derived by simple algebra and correlation analysis. Though the superposition rule is not so significant statistically, almost all of the performance indices under normal operation are fairly compatible with this model. Authors developed a prototype model of quantitative root-cause diagnosis and validated the background theory using the simulated data. The turbine cycle advisory system using this model was applied to Gori NPP units 3&4.