软件性能测试解析与优化

软件性能测试是检测系统性能瓶颈、提升软件质量的重要手段。目前,对性能测试的研究一般都停留在某些特定的技术上,没有形成系统的测试方法论,导致大多数测试人员仅仅掌握了一些零散的性能测试知识,缺乏测试的规范性和逻辑性．测试效果不理想。为了将缺陷和错误消灭在萌芽之中,从软件工程的角度出发,对性能测试方法论进行研究．概要指出性能测试应该是软件设计过程的一个必备环节。根据实际的性能设计经验,提出了性能设计的基本要求和主要过程。为软件测试人员提供了软件测试的过程依据,并提出了软件测试的优化方案,提高了软件测试的效率。     

RFID系统数据处理方案研究

读写器与标签通信过程中产生大量冗余数据,将对RFID系统通信构成较大负荷,降低了系统效率。在此研究了一种可灵活配置的RFID系统数据处理方案,该方案基于嵌入式数据库技术,在读写器平台上根据不同的系统配置,实现了不同的数据处理过程。实测证明,采用该方案的RFID系统,输出的冗余数据明显减少,有效降低了系统的通信负荷,提升了读写器的智能性及系统效率,在实际工程应用中取得了良好效果。     

一种基于能量比较的音频零水印方案(英文)

Zero-watermark technique,embedding watermark without modifying carriers,has been broadly applied for copyright protection of images.However,there is little research on audio zerowatermark.This paper proposes an audio zero-watermark scheme based on energy relationship between adjacent audio sections.Taking use of discrete wavelet transformation(DWT),it gets power approximations,or energies,of audio segments.Then,it extracts the audio profile,i.e.the zero-watermark,according to the relative size of energies of consecutive fragments.The experimental results demonstrate that the proposed scheme is robust against general malicious attacks including noise addition,resampling,low-pass filtering,etc.,and this approach effectively solves the contradiction between inaudibility and robustness.     

块交错方案在移动图像通信系统中的应用

提出了一种适合于卷积码的新的交错方案块交错方案,并对采用块交错方案的(2,1,3)卷积码在移动图像通信系统中的抗干扰性能进行了计算机模拟,且与周期交错方案的结果做了比较.模拟结果表明周期交错方案不适合于卷积码,而采用块交错方案的(2,1,3)卷积码可明显改善图像质量,大大提高了快衰落移动信道环境中图像通信系统的可靠性.     

兴山县有线数字电视系统技术方案的实施

主要介绍制定兴山县有线数字电视系统设计方案的依据、系统的功能、频道规划、系统配置、技术指标、设备选型、工程概算、质量保证措施等方面的经验。     

In-network caching for energy efficiency in content-centric networking

Recently, Internet energy efficiency is paid more and more attention. New Internet architectures with more energy efficiency were proposed to promote the scalability in energy consumption. The eontent-eentrie networking （CCN） proposed a content-centric paradigm which was proven to have higher energy efficiency. Based on the energy optimization model of CCN with in-network caching, the authors derive expressions to tradeoff the caching energy and the transport energy, and then design a new energy efficiency cache scheme based on virtual round trip time （EV） in CCN. Simulation results show that the EV scheme is better than the least recently used （LRU） and popularity based cache policies on the network average energy consumption, and its average hop is also much better than LRU policy.     

A Parallel-Based Lifting Algorithm and VLSI architecture for DWT

A novel Parallel-Based Lifting Algorithm （PBLA） for Discrete Wavelet Transform （DWT）, exploiting the parallelism of arithmetic operations in all lifting steps, is proposed in this paper. It leads to reduce the critical path latency of computation, and to reduce the complexity of hardware implementation as well. The detailed derivation on the proposed algorithm, as well as the resulting Very Large Scale Integration （VLSI） architecture, is introduced, taking the 9/7 DWT as an example but without loss of generality. In comparison with the Conventional Lifting Algorithm Based Implementation （CLABI）, the critical path latency of the proposed architecture is reduced by more than half from （4Tm ＋ 8Ta）to Tm ＋ 4Ta, and is competitive to that of Convolution-Based Implementation （CBI）, but the new implementation will save significantly in hardware. The experimental results demonstrate that the proposed architecture has good performance in both increasing working frequency and reducing area.     

一种新的基于提升多小波变换的图像融合方法

多小波是一种新的小波,它在理论上所表现出来的优势以及它在应用领域所具有的潜力,使其受到高度重视。在短短的几年时间内,它在图像处理方面的应用已取得了一定的成效。提升方法不仅是现存小波变换的一种快速算法,而且是构造新的小波变换的一种工具。本文根据提升方法和多小波变换的特点,对多小波实现了提升变换,并把这种基于提升方法的多小波变换应用于图像融合,结果表明有更好的效果。     

基于二维提升结构的SAR相干斑噪声抑制

针对SAR图像提出了一种新的二维提升变换斑点噪声抑制方法.这种方法利用提升结构构造的双正交小波所具有的良好的逼近和重构性能,以及平滑面区域的特性而实现.仿真时将阈值去噪环节加入变换中.仿真结果表明,本文提出的二维提升变换方法在充分抑制图像斑点噪声的同时,能很好地保持均匀区域内的辐射特性,图像中的边缘、细小特征和点目标,以及图像的纹理特征,克服了传统降噪方法的不足,具有较好的视觉效果.     

NACR: A New Adaptive Channel Reservation in Cellular Communication Systems

Future Personal Communication Networks (PCN) will employ microcells and picocells to support a higher capacity, thus increasing the frequency of handoff calls. Forced call terminations due to handoff call blocking are generally more objectionable than new call blocking. The proposed guard channel schemes for radio channel allocation in cellular networks reduce handoff call blocking probability at the expense of increases in new call blocking probability by giving resource access priority to handoff calls over new calls in call admission control. Under uniform traffic assumptions, it has been shown that a fixed number of guard channels leads to good performance results. In a more realistic system, non-uniform traffic conditions should be considered. In this case, the achieved call blocking probability may deviate significantly from the desired objective. In this paper, we propose a new adaptive guard channel scheme: New Adaptive Channel Reservation (NACR). In NACR, for a given period of time, a given number of channels are guarded in each cell for handoff traffic. An approximate analytical model of NACR is presented. Tabu search method has been implemented in order to optimize the grade of service. Discrete event simulations of NACR were run. The effectiveness of the proposed method is emphasized on a complex configuration.