基于VLAN技术的局域网络建设

基于VLAN技术建设的局域网已广泛应用于工程实际中。但随着人们对网络安全要求的不断提高,仅仅靠VLAN技术已不能满足更加细致的访问控制策略要求。VLAN技术结合交换机其他安全配置的综合应用将成为局域网建设的一个新方向。本文结合工程实际提出一种更安全的基于VLAN技术的局域网建设方法。     

Novel classical post-processing for quantum key distribution-based quantum private query

Existing classical post-processing (CPP) schemes for quantum key distribution (QKD)-based quantum private queries (QPQs) including the \(kN\rightarrow N\), \(N\rightarrow N\), and \(rM\rightarrow N\) ones have been found imperfect in terms of communication efficiency and security. In this paper, we propose a novel CPP scheme for QKD-based QPQs. The proposed CPP scheme reduces the communication complexity and improves the security of QKD-based QPQ protocols largely. Furthermore, the proposed CPP scheme can provide a multi-bit query efficiently.     

Droplets coalescence and mixing with identical and distinct surface tension on a wettability gradient surface

The influence of identical and distinct surface tensions on the coalescence and mixing of droplets after a direct collision on a wettability gradient surface (made from a self-assembled monolayer, SAM technique) was investigated. The results indicate that their mixing is driven sequentially by interior convection and diffusion; the convection endures less than 100 ms but dominates more than 60 % of the mixing. If the stationary droplet has a large surface tension (73.28 mN × m^?1), whether the moving droplet has a large surface tension (73.28 mN × m^?1) or a small surface tension (38.63 mN × m^?1), the mushroom-shaped mixing pattern is generated within the coalesced droplet that enhances the convective mixing and also significantly enlarges the interface for mass diffusion. The mixing index of these two cases was greater than 0.8 at 120 s after the collision. For the cases in which the stationary droplet with a small surface tension collided by the moving droplet with a large surface tension, a mixing pattern with a round-head shape developed, which was insufficient to benefit the mixing. When the stationary and moving droplets both had small surface tension, the moving droplet was unable to merge with stationary droplet and had poor mixing quality due to the small surface Gibbs energy of both stationary and moving droplets. For the collision of droplets of identical surface tension, the surface tension affects the coalescence behavior; for the collision of droplets with distinct surface tension, the coalescence behavior and mixing quality depend on the colliding arrangement of stationary and moving droplets.     

Improved DV-Hop based on parallel and compact whale optimization algorithm for localization in wireless sensor networks

Wireless Networks - Improving localization performance is one of the critical issues in Wireless Sensor Networks (WSN). As a range-free localization algorithm, Distance Vector-Hop(DV-Hop) is...     

Analysis of chaos and FRET reaction in split-and-recombine microreactors

The mixing and reaction performance of a split-and-recombine (SAR) microreactor was enhanced on modification of the geometric configuration. A rotation of fluid is induced on shrinking the structure of the splitting and reorientation region in alternate directions, thus improving the pattern of multi-lamination and enhancing the chaos of the fluid. To design and to analyze systematically the performance of the reactors, an effective method involving chaotic analysis and fluorescent resonant-energy transfer (FRET) is proposed. The structural design of a passive microreactor to generate an effective contact between the reagents is of great practical significance. SAR microreactors of four types with various microstructures were designed to illustrate the effects of geometric patterns (i.e., arrangement and dimensions) on mixing and reaction. Through analysis of the chaos, we revealed numerically the dynamic mixing governed by multi-lamination and chaotic mechanisms in the devices. The results show that specific structural designs induce rotation and rearrangement of fluids, thus elongating their material interface; the mixing of the fluids consequently improved. We investigated the hybridization of two complementarily labeled oligonucleotides in the devices by means of FRET. How the devices affected the rate of hybridization was thereby assessed, verifying that FRET is a technique capable of estimating the practical applicability of these devices.     

Clustering of temporal gene expression data by regularized spline regression and an energy based similarity measure

Clustering analysis of temporal gene expression data is widely used to study dynamic biological systems, such as identifying sets of genes that are regulated by the same mechanism. However, most temporal gene expression data often contain noise, missing data points, and non-uniformly sampled time points, which imposes challenges for traditional clustering methods of extracting meaningful information. In this paper, we introduce an improved clustering approach based on the regularized spline regression and an energy based similarity measure. The proposed approach models each gene expression profile as a B-spline expansion, for which the spline coefficients are estimated by regularized least squares scheme on the observed data. To compensate the inadequate information from noisy and short gene expression data, we use its correlated genes as the test set to choose the optimal number of basis and the regularization parameter. We show that this treatment can help to avoid over-fitting. After fitting the continuous representations of gene expression profiles, we use an energy based similarity measure for clustering. The energy based measure can include the temporal information and relative changes of the time series using the first and second derivatives of the time series. We demonstrate that our method is robust to noise and can produce meaningful clustering results.     

居住小区价格与公共服务网络可达性的相关性研究

提出了居住小区公共服务网络的概念,考虑居住小区与各类公共服务节点之间的最短路径、最快路径、次短路径和次快路径等四个指标,以皮尔逊积矩相关系数评估各类公共服务节点可达性与居住小区住房价格的相关性,建立了计算模型,从而识别出对居住小区住房价格影响较大的因素,以武汉市居住小区公共服务网络为例进行了实证分析.结果表明,本方法能够效识别对居住小区价格有重要影响的公共服务要素,为居住小区规划和公共服务优化配置提供决策支持.     

基于巡逻小车的人脸遮挡异常事件实时检测

近年来,随着城市化进程的加快,银行、政府、学校等场所的安全越来越成为人们关心的问题,智能监控已成为目前的一个研究热点问题. 本文主要研究室内巡逻小车监控下,面部异常遮挡问题. 本文首先对监控视频进行前景提取;接着,基于提取的前景,进行肩部定位、头部区域椭圆拟合;然后通过肤色检测判断人脸区域;最后,通过Haar检测器检测人脸区域的眼睛和嘴巴,以此来判断是否存在异常遮挡行为. 实验结果表明,本文提出的算法能够实时、有效的检测出面部异常遮挡问题.     

同源视频Copy-Move篡改检测及恢复

针对同源视频序列的copy-move篡改方式, 提出一种通过度量图像内容间的相关性, 来实现对视频序列的copy-move篡改检测并恢复的方法. 首先将视频帧内容转化为一系列连续的图像帧, 对图像分块, 提取每帧图像的8个特征矢量, 再利用欧氏距离计算帧间相关性, 并通过添加偏差矩阵构造动态偏差阈值, 检测出copy-move篡改序列且精确至帧, 从而实现对视频序列的篡改检测与恢复. 实验表明, 该算法对同源视频序列的copy-move篡改检测及恢复能够取得理想的效果.