Singular value decomposition based data distortion strategy for privacy protection

Privacy-preserving is a major concern in the application of data mining techniques to datasets containing personal, sensitive, or confidential information. Data distortion is a critical component to preserve privacy in security-related data mining applications, such as in data mining-based terrorist analysis systems. We propose a sparsified Singular Value Decomposition (SVD) method for data distortion. We also put forth a few metrics to measure the difference between the distorted dataset and the original dataset and the degree of the privacy protection. Our experimental results using synthetic and real world datasets show that the sparsified SVD method works well in preserving privacy as well as maintaining utility of the datasets. Shuting Xu received her PhD in Computer Science from the University of Kentucky in 2005. Dr. Xu is presently an Assistant Professor in the Department of Computer Information Systems at the Virginia State University. Her research interests include data mining and information retrieval, database systems, parallel, and distributed computing. Jun Zhang received a PhD from The George Washington University in 1997. He is an Associate Professor of Computer Science and Director of the Laboratory for High Performance Scientific Computing & Computer Simulation and Laboratory for Computational Medical Imaging & Data Analysis at the University of Kentucky. His research interests include computational neuroinformatics, data miningand information retrieval, large scale parallel and scientific computing, numerical simulation, iterative and preconditioning techniques for large scale matrix computation. Dr. Zhang is associate editor and on the editorial boards of four international journals in computer simulation andcomputational mathematics, and is on the program committees of a few international conferences. His research work has been funded by the U.S. National Science Foundation and the Department of Energy. He is recipient of the U.S. National Science Foundation CAREER Award and several other awards. Dianwei Han received an M.E. degree from Beijing Institute of Technology, Beijing, China, in 1995. From 1995to 1998, he worked in a Hitachi company(BHH) in Beijing, China. He received an MS degree from Lamar University, USA, in 2003. He is currently a PhD student in the Department of Computer Science, University of Kentucky, USA. His research interests include data mining and information retrieval, computational medical imaging analysis, and artificial intelligence. Jie Wang received the masters degree in Industrial Automation from Beijing University of Chemical Technology in 1996. She is currently a PhD student and a member of the Laboratory for High Performance Computing and Computer Simulation in the Department of Computer Science at the University of Kentucky, USA. Her research interests include data mining and knowledge discovery, information filtering and retrieval, inter-organizational collaboration mechanism, and intelligent e-Technology.     

嵌入式远程测控终端与PLC通信的研究

基于μClinux的多线程机制完成了一套中央空调远程测控终端系统,分析了嵌入式系统PLC的通信过程。通过在嵌入式处理器芯片上扩展网络接口将PLC连接到Internet,打破了PLC经由串口直接连接Internet的速率瓶颈,为实现分布式实时远程监控系统提供了一种高速率的解决方法。     

Exploring the synergistic use of multi-scale image object metrics for land-use/land-cover mapping using an object-based approach

This study presents a new method for the synergistic use of multi-scale image object metrics for land-use/land-cover mapping using an object-based classification approach. This new method can integrate an object with its super-objects’ metrics. The entire classification involves two object hierarchies: (1) a five-level object hierarchy to extract object metrics at five scales, and (2) a three-level object hierarchy for the classification process. A five-level object hierarchy was developed through multi-scale segmentation to calculate and extract both spectral and textural metrics. Layers representing the hierarchy at each of the five scales were then intersected by using the overlay tool, an intersected layer was created with metrics from all five scales, and the same geometric elements were retained as those of the objects of the lowest level. A decision tree analysis was then used to build rules for the classification of the intersected layer, which subsequently served as the thematic layer in a three-level object hierarchy to identify shadow regions and produce the final map. The use of multi-scale object metrics yielded improved classification results compared with single-scale metrics, which indicates that multi-scale object metrics provide valuable spatial information. This method can fully utilize metrics at multiple scales and shows promise for use in object-based classification approaches.     

基于Top-K项频繁模式挖掘的研究及实现

频繁模式挖掘是关联规则、序列分析等数据挖掘任务的关键步骤,我们知道,当给定的最小支持度阈值非常小,将产生大量的频繁模式,反之,可能产生很少的模式或根本没有结果。用户有时仅对其中的部分项的频繁度感兴趣,这属于部分频繁模式挖掘问题。文章通过有效设置挖掘区间,讨论一种top—k项频繁模式挖掘问题,进而扩展到连续区间上的情况,最后将给出实验结果。     

高斯曲率约束的MRG骨架提取优化算法

三维模型的骨架保持了模型的拓扑特性,并被广泛应用于模型相似性比较、计算机动画及压缩等领域.根据多分辨率Reeb图的原理,提出了一种基于离散高斯曲率约束的骨架提取优化算法.通过计算网格顶点的离散高斯曲牢判断曲面局部凸凹特性,以获取模型表面的双曲极值点作为约束点;并依据约束点及其邻域的μ函数值产生的分裂线进行区域细分,获得子连通区域、确定关节点、形成优化的骨架结构.实验结果表明,该算法有效地突出了模型的拓扑分支特征以及模型表面的细节,提高了骨架提取的精度和效率.     

NY-1高功率微波辐射源功率密度的简易测量

微波的生物热效应能使蛋白质变性.蛋白质变性所需要的辐照时间取决于入射的功率密度,所以高功率微波功率密度的测量是研究微波生物效应的基础.利用纸水混合介质的介电常数,计算出微波波阻抗,利用介质和空气界面上的反射系数和介质中衰减系数以及蒸发的水的质量,从而求出入射的微波功率密度.     

外源RNA促进小鼠肠腺辐射损伤恢复的研究

ＢＡＬＢ／ ｃ小鼠１０４０ｃＧｙ＾６０Ｃｏγ射线腹部照射后，采用不同一源的ＲＮＡ、不同的注入剂量、途径、时间和次数等因素，研究外源ＲＮＡ对空肠肠腺存活率的影响。结果表明（１）不同来源的ＲＮＡ均可明显提高受照小鼠的腺存活率。（２）酵母ＲＮＡ的洲入剂量与肠腺存尖率之间呈一钟形曲线，局部肠腔注入的最适剂量为４０－６０μｇ／小鼠，腹腔和肌肉注入时为８０μｇ／小鼠。     

黄土包气带中核素二维迁移的试验研究

为了研究黄土包气带中放射性核素在垂直和水平方向上的二维迁移 ,在野外试验场的 C坑 (天然条件 )和 F坑 (人工喷淋条件 )进行了取样测量。将 85Sr、13 4Cs和 60 Co三种核素与黄土均匀混合 ,制成示踪源 ,埋置于坑底中心位置 ,距地表 1m,两坑示踪源层尺寸均为 5.5cm× 0 .6 cm。分别于埋置示踪源层后的第 783d(F坑 )和 10 72 d(C坑 )进行解体采样。使用专门制作的采样定位环 ,分层、分环采样。垂向分层 ,每层厚 1cm;水平方向分环 ,环的直径为 3～ 2 7cm,分 9种尺寸。在 C坑和 F坑分别采土样 2 4 1和 2 13个。用 Na I(Tl)γ谱仪测量土样中85Sr、13 4Cs和60 Co的活度 ,得到两坑中三种核素的比活度分布曲线。结果表明 ,13 4Cs和 60 Co的比活度峰在两试验坑中垂向迁移距离均小于 1cm,但也有一小部分迁移距离较大 ;而 85Sr的比活度峰在人工喷淋条件 (喷淋强度 1.5cm/d)的 F坑 ,向下迁移了约 13cm,在天然条件的 C坑 ,比活度峰仍在示踪源层 ,但在上、下二个方向上明显展宽。另外 ,还发现在水平方向上径向距为 11.3cm(F坑 )和 12 .8cm(C坑 )样品中也有三种核素的存在     

便携式βγ辐射仪的设计与研制

通过β、γ辐射仪的研制,介绍了用GM计数管作为探测器,采用单片机技术实现对β、γ剂量率的测量。     

2×2稠密棒束内超临界水的传热特性试验研究

在压力p=23～28 MPa、质量流速G=350～1 000 kg/(m²•s)、热流密度q=200～1000 kW/m²的试验参数范围内,对2×2棒束内超临界水的传热特性进行了试验研究。试验得到了加热管周向壁温分布规律,并就出现周向温度差异的原因进行了分析。此外,给出了压力、质量流速及热流密度等系统参数对平均传热特性的影响,分析了低质量流速下出现的传热恶化现象。试验结果表明：加热管周向壁温并不均匀,边角子通道壁温最高,中心子通道壁温最低,周向壁温的高低与横截面流通面积的不均匀性紧密相关。随着热流密度的提高或质量流速的降低,超临界水的传热受到抑制,当q/G增大到一定程度时,棒束内发生传热恶化。