基于系统管理IC的电源管理方案

嵌入式系统中CPU、ASIC、FPGA、存储器等复杂器件通常需要严格的电源排序。文章以MAX16046系统管理芯片为核心,提供了高度集成的排序、监测和电源裕量调节解决方案,并给出了实现该方案的具体步骤。     

An effective scheduling scheme for multi-hop multicast in wireless mesh networks

With the utilization of concurrent transmission strategy, a throughput-enhanced scheduling scheme is devised for multicast service in wireless multi-hop mesh networks. Since the performance of a multicast mechanism is constrained in a wireless setting due to the interference among local wireless transmissions, the interference relationships are first characterized by introducing a graph transformation method. Based on the graph transformation, the multicast scheduling problem is converted to the graph coloring problem, and then a capacity greedy algorithm is designed to provide concurrent transmission scheduling so that the demanded multicast transmission rate can be achieved. Moreover, the necessary and sufficient conditions of multicast schedulable feasibility are derived. Through corresponding simulations, it is shown that the proposed strategy can enhance the throughput of wireless multi-hop multicast systems significantly.     

Modelling concurrency with comtraces and generalized comtraces

Comtraces (combined traces) are extensions of Mazurkiewicz traces that can model the “not later than” relationship. In this paper, we first introduce the novel notion of generalized comtraces, extensions of comtraces that can additionally model the “non-simultaneously” relationship. Then we study some basic algebraic properties and canonical representations of comtraces and generalized comtraces. Finally we analyze the relationship between generalized comtraces and generalized stratified order structures. The major technical contribution of this paper is a proof showing that generalized comtraces can be represented by generalized stratified order structures.     

The implementation guidance for practicing network isolation by referring to ISO-17799 standard

In these years, the company budgets are raised dramatically for eliminating the security problems or mitigating the security risks in companies, but the numbers of incidents happening on computer systems in intranet or internet are still increasing. Many researchers proposed the way–to isolate the computers storing sensitive information for preventing information on these computers revealed or vulnerability on these computers exploited. However, there are few materials available for implementing network isolation. In this paper, we define ways of network isolation, “physical isolation” and “logical isolation”. In ISO-17799, there is no implementation guidance for practicing network logical isolation but auditing network physical isolation. This paper also provides the implementation guidance of network isolation in two aspects. One is for the technique viewpoints. The other aspect is for management viewpoints. These proposed implementation outlines and security measures will be considered in revising the security plan, “The Implementation Plan for Information Security Level in Government Departments” [“The implementation plan for information security level in government departments,” National Information and Communication Security Taskforce, Taiwan R.O.C., Programs, Jul. 20 2005].     

智能仪表非线性自动校正方法研究

针对智能仪表不便于进行复杂计算、内存有限和实时性要求高等特点,在比较了几种常用的非线性校正方法的基础上,通过对智能仪表的非线性特性曲线的一般性分析,运用分段直线逼近曲线的方法,给出了一种通用的智能仪表非线性自动校正算法.同时讨论了该算法的原理、修正方法及校正参数的存储结构.并详细介绍了该算法在称重仪表中的具体应用.实践证明这种算法简单、实用,效果良好.     

一种基于自适应量化嵌入器的隐写方法

感知质量和容量一直是图像隐写算法设计中难以折中的两个要素,如何取得更好的综合性能已吸引了很多研究者的兴趣.提出一种基于自适应量化嵌入器的隐写方法.这一方法通过改变某一载体信号所在子空间的索引来调制秘密信息,自适应特性体现在决定着子空间尺寸的分割码本的设计上.将这种隐写方法用于以2×2图像块为单元的数字图像隐写算法设计中,并将分割码本设计得具备HVS特性以取得较好的折中效果.实验表明,算法在感知质量和容量方面具有较好的综合性能.     

基于小波多分辨率分析的指横纹定位新算法

针对指横纹感兴趣区域(ROI)难以准确定位的问题,在明确提出指横纹ROI定义的前提下,提出利用小波多分辨率分析进行指横纹ROI自动检测定位的新算法.该方法利用纹理相似性原理,在高频子图采用基于特征向量和区域生长法产生指横纹的候选子区域集合,然后利用低频子图Radon投影得到的指横纹的区域特征对候选子区域进行验证,最后结合直线拟合手指轮廓得到指横纹在原图的有效位置,最终实现指横纹ROI的精准定位.实验证明该算法不仅能有效克服噪声以及手形姿态变化的影响,并且对多种情况有很强的鲁棒性.     

一种多核处理器存储层次性能评估模型

一种用于评估多核处理器存储层次性能的模型,使用排队论建模,求解速度快,可以在设计早期给出不同配置参数对处理器整体性能的影响,从而调整存储层次结构,优化设计.     

Design and simulations of a new biaxial silicon resonant micro-accelerometer

This paper presents a new biaxial silicon resonant micro-accelerometer. The device basically consists of a single proof mass, four pairs of decoupled beams, four lever mechanisms and two pairs of resonators, which provides 2-D in-plane acceleration measurement with the decoupled two pairs of resonators. Structure optimization is implemented by taking advantage of the finite element analyses. From the simulation results we can see that the effective frequencies of two acceleration sensitive modes are 1010.18 and 1010.13 Hz respectively, and the undesired modes and effective modes are isolated apparently. Additionally, high linear relationship between the input acceleration and the resonant frequency shifts of resonators are demonstrated by the input–output characteristic simulation. Moreover, simulation results reveal the scale factor for the x-axis is 180.03 Hz/g, and the scale factor for y-axis is 180.75 Hz/g, while the cross-axis sensitivity for x-axis is 0.046 Hz/g, and the cross-axis sensitivity for y-axis is 0.027 Hz/g. The high sensitivity and low cross-axis sensitivity are thus adequately confirmed. By the way, the simulation of temperature dependent characteristics demonstrate that the differential scheme can effectively suppress the influence of temperature variation, and the thermal analysis shows that the device can bear the thermal stress induced by temperature change. All these simulations above can verify the feasibility of the structure design.     

Tied factors analysis for high-dimensional image feature extraction and recognition application

Feature extraction from images, which are typical of high dimensionality, is crucial to the recognition performance. To explore the discriminative information while depressing the intra-class variations due to variable illumination and view conditions, we propose a factor analysis framework for separate “content” from “style,” identifying a familiar face seen under unfamiliar viewing conditions, classifying familiar poses presented in an unfamiliar face, estimating age across unfamiliar faces. The framework applies efficient algorithms derived from objective factor separating functions and space mapping functions, which can produce sufficiently expressive representations of feature extraction and dimensionality reduction. We report promising results on three different tasks in the high-dimensional image perceptual domains: face identification with two benchmark face databases, facial pose classification with a benchmark facial pose database, extrapolation of age to unseen facial image. Experimental results show that our approach produced higher classification performance when compared to classical LDA, WLDA, LPP, MFA, and DLA algorithms.