Cooperative private searching in clouds

With the increasing popularity of cloud computing, there is increased motivation to outsource data services to the cloud to save money. An important problem in such an environment is to protect user privacy while querying data from the cloud. To address this problem, researchers have proposed several techniques. However, existing techniques incur heavy computational and bandwidth related costs, which will be unacceptable to users. In this paper, we propose a cooperative private searching (COPS) protocol that provides the same privacy protections as prior protocols, but with much lower overhead. Our protocol allows multiple users to combine their queries to reduce the querying cost while protecting their privacy. Extensive evaluations have been conducted on both analytical models and on a real cloud environment to examine the effectiveness of our protocol. Our simulation results show that the proposed protocol reduces computational costs by 80% and bandwidth cost by 37%, even when only five users query data.     

高炉炉料结构的优化和探索

在世界铁矿石资源状况日趋紧张的环境下,对宝钢高炉的用矿结构变化进行了探讨。多年来,宝钢高炉不断优化炉料结构,逐步降低球团矿比例,增加烧结矿比例,并针对不同高炉的情况制定了适宜的炉料结构,这对降低生铁成本起到了积极的作用。     

基于故障树的贝叶斯网络建造方法与故障诊断应用

文章首先指出应用贝叶斯网络模型进行设备故障诊断具有的优势,提出了由常用的故障树模型建造贝叶斯网络的方法。然后详细比较了故障树与贝叶斯网络在诊断推理和模型表达方面的特点,并以实例进行说明。     

高速连铸结晶器保护渣流变特性的研究

用改进的可变转速粘度仪测定了连铸保护渣(％：1.47MgO，12．98Al2O3，47．57SiO2，7．71Na2O，28．52CaO，1．75TiO2)的流变特性，以试验总误差为测量牛顿流体时所容许的最大偏差，由试验得到不同转速下剪切速率D和剪切应力τ，作出τ～D对数曲线，经回归得出熔渣本构方程，以判别熔体是否为非牛顿流体。结果表明，在1200℃较低温度下，该保护渣仍为牛顿流体，如再加入较多的CaO，则保护渣变为非牛顿流体。     

谐振式变换器电路结构分析

本文着重对电压源串联型谐振变换器的理论问题和电路结构作了分析，对电流源并联型谐振变换器也作了概略的介绍。     

Effect of niobium on thermal stability and impact toughness of Nd-Fe-B magnets with ultra-high intrinsic coercivity

The effects of Nb on the thermal stability and impact toughness of ultra-high intrinsic coercivity of Nd-Fe-B magnets were investigated.The results showed that the addition of Nb could improve the thermal stability,and obviously increased the impact toughness of sintered Nd-Fe-B magnets.The optimum thermal stability of sintered Nd-Fe-B magnets was obtained when the content of Nb was 1.0 at.%.The maximum impact toughness of sintered Nd-Fe-B magnets was obtained when the content of Nb was 1.5 at.%,but the magnetic properties of sintered Nd-Fe-B magnets drastically deteriorated when the content of Nb increased from 1.0 at.% to 1.5 at.%.The microstructure showed that overfull Nb addition made many ultra-fine grains get together,which led to the density of sintered Nd-Fe-B magnets decline and drastically deteriorated the magnetic properties of sintered Nd-Fe-B magnets.     

股骨颈骨折的护理体会

股骨颈骨折是以髋部疼痛,腹股沟中点附近有压痛和纵轴叩击痛为主要表现的股骨头下至股骨颈基底部骨折.是老年常见的骨折之一,尤以老年女性较多.股骨颈骨折大多数是外旋暴力所引起的螺旋形骨折或斜形骨折.高龄患者因年老、体弱、多病、脏器功能减退等多方面原因,股骨骨折后易发生并发症.因此,对这类患者的护理工作极为重要.     

基于行为的Android恶意软件判定方法及其有效性

针对当前Android平台资源受限及恶意软件检测能力不足这一问题,以现有Android安装方式、触发方式和恶意负载方面的行为特征为识别基础,构建了基于ROM定制的Android软件行为动态监控框架,采用信息增益、卡方检验和Fisher Score的特征选择方法,评估了支持向量机(SVM)、决策树、k-邻近(KNN)和朴素贝叶斯(NB)分类器四类算法在Android恶意软件分类检测方面的有效性。通过对20916个恶意样本及17086个正常样本的行为日志的整体分类效果进行评估,结果显示,SVM算法在恶意软件判定上准确率可以达到93%以上,误报率低于2%,整体效果最优。可应用于在线云端分析环境和检测平台,满足海量样本处理需求。     

Real-time rendering of deformable heterogeneous translucent objects using multiresolution splatting

In this paper, we present a novel real-time rendering algorithm for heterogenous translucent objects with deformable geometry. The proposed method starts by rendering the surface geometry in two separate geometry buffers—the irradiance buffer and the splatting buffer—with corresponding mipmaps from the lighting and viewing directions, respectively. Irradiance samples are selected from the irradiance buffer according to geometric and material properties using a novel and fast selection algorithm. Next, we gather the irradiance per visible surface point by splatting the irradiance samples to the splatting buffer. To compute the appearance of long-distance low-frequency subsurface scattering, as well as short-range detailed scattering, a fast novel multiresolution GPU algorithm is developed that computes everything on the fly and which does not require any precomputations. We illustrate the effectiveness of our method on several deformable geometries with measured heterogeneous translucent materials.