Undeniable signature scheme based over group ring

D. Chaum and H. van Antwerpen first introduced the concept of an undeniable signature scheme where the verification step is verified with the signer’s co-operation. In this paper, first we discuss a combination of Discrete Logarithm Problem (DLP) and Conjugacy Search Problem (CSP) analysing its security. Then we propose an undeniable signature scheme in a non-abelian group over group ring whose security relies on difficulty of the combination of the DLP and the CSP. The complexity and security of our proposed scheme has also been discussed.     

A group signature based buyer coalition scheme with trustable third party

Despite the large number of existing buyer coalition schemes and increasing need for trusting relationship in buyer coalitions, no current buyer coalition scheme explicitly addresses trust issues within these schemes in a formalised manner. Without establishing a trusting relationships among various roles, many buyers may not be willing to join the coalitions. This study proposes a solution, in the form of an algorithmic design, as a response to the above need. Specific features of the proposed solution are: (i) the use of ‘group signature’ in order to guarantees anonymity within a group that results in trustfulness of the relationships and (ii) introducing a new role called ‘authority’ to maintain and implement anonymity. In addition, the proposed scheme is capable of maintaining ‘correctness’ and ‘accountability’ by both identifying misbehaved buyers as well as implementing various punishment methods.Knowledge domain of the study is the common space between three overlapping fields including Electronic Commerce, Communication Technologies and Information Systems.     

A multivariate double EWMA process adjustment scheme for drifting processes

The “predictor-corrector” feedback controller, a process adjustment scheme proposed for semiconductor manufacturing run-to-run processes that drift, is extended to the multiple-input-multiple-output case. The controller is based on two coupled multivariate Exponentially-Weighted-Moving-Average (EWMA) equations, thus its performance depends on the choices of EWMA weight matrices. Stability conditions are given for a pure gain process adjusted with a MIMO double EWMA (EWMA) controller. It is shown that the stability conditions are invariant with respect to various realistic drift disturbance models. Recommendations on how to choose the EWMA weight matrices are given. An analysis is conducted to assess the impact of errors in the estimates of the process gains. The proposed MIMO EWMA feedback controller is compared to the common practice of using multiple single-input-single-ouput dEWMA controllers running in parallel.     

Uniform threshold intensity distribution-based quantitative multivariate imaging cytometry

Implementation of quantitative analytical approaches to image-based cellular assays remains a major challenge. We disclose a tool to achieve automatic rapid quantitative cellular imaging analysis based on uniform threshold intensity distribution. An acousto-optic tunable filter-based, quantitative multivariate imaging cytometer was set up to elucidate drug-induced cell death dynamics via cell viability and apoptosis/necrosis measurements in the human myeloid leukemia cell line, HL-60. Cells were treated with various drugs (camptothecin, naringenin, sodium salicylate) at different concentrations and time intervals. The developed protocol can directly depict and quantitate targeted cellular moieties, subsequently enabling a method that is applicable to various cellular assays with special reference to next generation drug discovery screening. This may also complement certain flow-cytometric measurements in studying quantitative physiology of cellular systems.     

An encryption/signature scheme with low message expansion

Abstract

Secrecy, authenticity and integrity are three major services provided by the public key cryptography. To provide these three services via the ElGamal public key cryptosystem and Signature scheme, the message expanding ratio is four and the overhead of communication is heavy. In this paper, a concurrent encryption/signature scheme will be proposed to provide these three services with a lower message expanding ratio. In the new scheme, the signer can encrypt and sign the message concurrently so the signature that serves as the ciphertext is a pair of integers. Thus the message expanding ratio can be decreased to two.     

Monitoring compositional data using multivariate exponentially weighted moving average scheme

Recently, the monitoring of compositional data by means of control charts has been investigated in the statistical process control literature. In this article, we develop a Phase II multivariate exponentially weighted moving average control chart, for the continuous surveillance of compositional data based on a transformation into coordinate representation. We use a Markov chain approximation to determine the performance of the proposed multivariate control chart. The optimal multivariate exponentially weighted moving average smoothing constants, control limits, and out‐of‐control average run lengths have been computed for different combinations of the in‐control average run lengths and the number of variables. Several tables are presented and enumerated to show the statistical performance of the proposed control chart. An example illustrates the use of this chart on an industrial problem from a plant in Europe.     

一种基于软件无线电的频谱扫描技术

在无线电综合测试仪的设计中,频谱扫描是一项基础技术.将需要扫描的频谱划分成子带,进而提出了一种通过在模拟前端采用可变频率本振的混频器和低通滤波器实现子带信号分离,然后对子带信号进行采样并且变换到频域,最后将所有子带频谱拼接获得完整频谱的技术.为了实现该技术,设计了一个由软件无线电(Software-defined Radio,SDR)接收机和数字信号处理片上系统(System on Chip,SOC)组成的软件无线电平台.随后,在基于该平台实现的综测仪原型上对频谱分析技术进行了验证.仿真和实验表明,该方法和原型样机能够对0~6 GHz范围的频谱进行扫描,同时具有较低的噪声水平和较好的动态范围,且能够提供相位谱,因而适用于嵌入式频谱仪和无线电综测仪的应用场合.     

一种基于偏好的查询扩展方法

为克服语言歧义性和用户使用简短查询语句的习惯对搜索引擎查询准确率造成的影响,提出了一种基于偏好的查询扩展方法.该方法将用户对网页的偏好转化为对知识库中概念的偏好,建立用户兴趣模型,在该模型基础上对原始查询结果进行分析,挑选出与用户偏好关联最紧密的关键词加入原查询,解决了基于局部分析的查询扩展方法在初次检索质量不高时性能恶化的问题.实验表明,本文提出的方法相对于传统的查询扩展算法可以大幅度提高查询精度.     

Investigation and characterization of a control scheme for multivariate quality control

A new scheme for multivariate statistical quality control is investigated and characterized. The control scheme consists of three steps and it will identify any out-of-control samples, select the subset of variables that are out of control, and diagnose the out-of-control variables. A new control variable selection algorithm, the backward selection algorithm, and a new control variable diagnosis method, the hyperplane methods, are proposed. It is shown by simulation that the control scheme is useful in cases where the process variables are correlated and where they are uncorrelated.     

A colour image retrieval scheme based on Z-scanning technique

Abstract

This paper proposes a new colour image retrieval scheme using Z-scanning technique for content-based image retrieval (CBIR). In recent years, the CBIR is a popular research topic for image retrieval. This paper proposes a scheme which employs the Z-scanning technique to extract directional intensity features for measuring the similarity between query and database images. In the multiple channel images, each colour channel can be processed individually or combined into a grey channel Y. In order to extract the features by Z-scanning technique from all images, each channel of all images must be divided into several N×N blocks. In each block, F pairs of pixels are scanned by a ‘Z’ direction to obtain the texture features. Each colour channel can be obtained an M×M Z-scanning co-occurrence matrix (ZSCM) for storing the probability of each relationship of all closest blocks. At the similarity measure stage, the ZSCMs of query image and database images are compared to measure their similarity. The experimental results show that the proposed scheme is beneficial for image retrieval when the images include the same texture or object. On the other hand, the proposed scheme also can get better retrieval results and more efficiency than colour correlogram (CC) technique for colour texture images. Another technique uses motif co-occurrence matrix (MCM) as the feature in similarity measurement. The experimental results show the proposed ZSCM can get better retrieval results and higher recall and precision values than the CC and MCM techniques for public image databases.     

A scheme of reversible information hiding based on SMVQ

Abstract

In this paper, we propose two reversible information hiding schemes based on side-match vector quantisation (SMVQ). In 2006, Chang et al. proposed a data-hiding scheme based on SMVQ coding. In order to increase both the image quality and the embedding capacity, we improve their method by embedding multiple secret bits into a block and finding out the second selected codeword from the full codebook. In addition, we propose another reversible information hiding scheme whose output is a pure VQ index table. The weighted bipartite graph is used to model our scheme and the matching approach is used to find out the best solution. Compared with Chang et al.’s scheme, we have higher visual quality in the experimental results.     

基于ICA-CEEMD小波阈值的传感器信号去噪

针对传感器在采集信号时混入不同的噪声,提出一种基于ICA-CEEMD小波阈值的组合去噪算法。该方法是对一维含噪信号进行剪切分段、平移和拼接,得到几个不同的含噪信号作为独立分量分析(ICA)的输入通道信号。通过ICA的盲源分离技术使得信号和噪声进行初步分离。再利用互补集合经验模态分解(CEEMD)对分离信号进行分解去噪,由于不同的高频和低频噪声,需要对分解的高阶和低阶固有模态函数(IMF)进行处理。对第一层和最后一层IMF利用3σ原则提取细节信息,进一步抑制模态混叠影响,重构去噪信号。最后,利用小波阈值对重构信号做去噪处理,提升去噪效果和性能指标。为验证该方法的有效性,进行了仿真和中北大学汾机实测实验,结果表明,该方法在去噪效果和性能指标上都优于小波软阈值去噪和基于CEEMD的小波阈值去噪方法,是一种有效的信号去噪新方法。     

一种基于SSNF的新型阈值滤波去噪算法

介绍了一种空间选择性的噪声滤波（SSNF）方法，并在此工作之上提出了一种新的自适应于小波变换尺度的闽值函数，从而对经SSNF滤波之后的小波系数进行了进一步的阈值处理，以去除残留在系数中的噪声部分。仿真试验和理论分析表明，相比其它传统的去噪方法，该方法的优点在于：所得到的小波系数不仅连续性好，而且更加接近于未加噪信号的小波系数，阈值函数具有很大的灵活性和自适应性，并适用于一些掺杂非白噪声的场合。     

Monitoring multivariate aviation safety data by data depth: control charts and threshold systems

Aviation safety analysis is increasingly needed in regulating air traffic and safety, in light of the rapid growth in air traffic density. With the recent advances in computer technology, large amounts of multivariate aviation safety data are now routinely collected in databases. Many existing analysis methods prescribed in those databases and corresponding safety indictors are based on classical statistical analysis, and their applicability are considerably restricted by the requirement of normality. An alternative nonparametric methodology based on data depth is pursued in this paper. For a given multivariate sample, a data depth can be used to measure their depth or outlyingness with respect to the underlying distribution. The measure of depth leads to a center-outward ordering of the sample points. Derived from this ordering, Liu (1995) introduced a simple, yet effective, control chart for monitoring multivariate observations. The control chart is combined here with properly chosen false alarm rates to develop meaningful threshold systems for multivariate aviation safety data for both regulating and monitoring purposes. The developed procedure is applied to the aviation inspection results collected by the Federal Aviation Administration (FAA) inspection system. The threshold system serves as a standard for evaluating the performance of aircraft operators, and provides clear guidelines for identifying unexpected performances and for assigning appropriate corrective actions.     

利用CPM实现自适应OFDM系统研究

在正交频分复用(OFDM)系统中应用自适应技术能有效地提高系统性能。正交频分复用-连续相位调制(OFDM-CPM)通过CPM相关相位状态引入记忆,从而获得比传统OFDM更好的误码性能。文章提出了一种利用单一的CPM调制方式实现自适应OFDM-CPM系统的新方案。仿真结果表明,选取最佳的CPM参数组合,通过改变CPM的参数来实现自适应OFDM-CPM调制,能够获得比传统调制方式要低的门限值,同时系统硬件实现更为简单。     

基于信任网络的软件可信评价方法

研究了可信计算领域中的软件可信评价问题,提出了一种基于信任网络的软件可信度量方法,该方法通过信任网络模型将用户划分成不同的用户域,采用可信度量票据的方法保障设备的可信性;在设备可信的基础上建立可信风险树模型,分别从可信和风险两方面对软件进行可信度量,计算异常行为的风险概率;采用多台设备协同工作的方式,通过滑动窗口模型从用户域范围和管理域范围对软件进行可信评价。最后通过实验验证了该方法的正确性和可信性。     

Wavelet packet transform-based anti-jamming scheme with new threshold selection algorithm for GPS receivers

We propose a wavelet packet transform (WPT)-based adaptive predictor to cancel the jamming signal for global positioning system receivers. In addition, a new adaptive threshold selection algorithm, which exploits the information embedded in both time- and WPT-domains, is proposed. This threshold is used for the WPT de-noising algorithm to generate the reference signal for the adaptive predictor. Simulation results confirm that our method significantly outperforms one existing WPT-based anti-jamming scheme.     

A robust and secure watermarking scheme based on singular values replacement

Digital watermarking is an application associated with copyright protection. Any digital object can be used as a carrier to carry information. If the information is related to object then it is known as a watermark which can be visible or invisible. In the era of digital information, there are multiple danger zones like copyright and integrity violations, of digital object. In case of any dispute during rights violation, content creator can prove ownership by recovering the watermark. Two most important prerequisites for an efficient watermarking scheme are robustness and security. Watermark must be robust and recoverable even if a part of content is altered by one or more attacks like compression, filtering, geometric distortions, resizing, etc. In this work, we propose a blind watermarking scheme based on the discrete wavelet transform (DWT) and singular value decomposition (SVD). Singular values (SV??s) of high frequency (HH) band are used to optimize perceptual transparency and robustness constraints. Although most of the SVD-based schemes prove to be robust, little attention has been paid to their security aspect. Therefore, we introduce a signature-based authentication mechanism at the decoder to improve security. Resulting blind watermarking scheme is secure and robust.