循环码的周期分布的新的计算公式

本文在［１］文的基础上进一步分析了循环码的周期分布的性质，给出了新的计算方法和公式，并且确定了一些熟知的循环码的周期分布。     

基于AOP的面向对象程序的单元测试的应用

利用AOP编程思想来对系统代码和日志记录进行修改和优化,降低系统板块的依赖性,保证单元测试的正确性,实现软件系统的最大应用目标。基于AOP角度,面向对象程序的单元测试进行分析和阐述,来在增加对AOP编程思想了解,掌握单元测试的方法。     

因特网上的的数据传输

主要阐述ＴＣＰ／ＩＰ协议、数据在协议层之间的传送过程以及数据在网络和计算机系统之间传输的实现。     

自然的就是最好的

事实上,很多物品的灵感来自于自然,专业一些的说法叫仿生。不过这种黎法似乎显得太过严肃和学术,对于那些生活中和身边的物品,称它们是向自然讨教得来的一种“比喻”更形象。     

合适的就是最好的

随着PC技术的发展,硬盘的容量和性能越来越高了,但是,该买什么样的硬盘,这是很多囊中羞涩的用户所困惑的,下面笔者就结合自己的经验跟大家介绍一下,如何选择一块合适自己的硬盘.     

细胞的内质网的超微结构

细胞的内质网呈网状遍布于细胞质内,所以也可称之为内质网膜系统。内质网是细胞的内膜系统的重要成分,在蛋白质合成,脂类合成和糖原代谢等方面起着重要作用。研究证明细胞内的许多膜性结构均来源于内质网,因而它在细胞的内膜系统中占有中心地位。内质网的微细结构的观察与研究对了解细胞的正常生理和病理改变具有重要意义。我们对培训的非洲绿猴肾上皮细胞(CV-1),人早幼粒白血病细胞(HL-60)、活检的人体胃粘膜细胞和胃癌细胞以及手术切除的人体结肠细胞和结肠癌细胞等数种细胞的内质网,应用电镜技术和光镜技术进行了观察与分析。     

现场总线的的定义

现场总线以数字信号取代模拟信号，在3C技术即计算机（Computer）、控制（Control）、通信（Communication）的基础上，大量现场检测与控制的信息就地采集、就地处理、就地使用，     

测试用例的复用技术的研究

软件测试是确保软件质量的可靠手段,是软件开发过程中必不可少的重要环节。随着软件项目中各类干系人对软件质量的要求不断提高,软件测试作为保证软件质量的主要途径之一,其重要性越来越受重视。随着软件复杂性提高,软件测试的复杂性也不断提高,测试成本不断增加,同时软件复用技术也在不断发展,软件测试成本的提高和软件复用技术的发展,促使了软件测试复用技术的不断发展。测试复用技术在软件领域得到了广泛的应用,在某些行业软件中得到了很好的应用,比如证券行业。     

无失真并行数据压缩的脉动阵列ASIC设计

本文提出适用于无失真并行数据压缩的超大规模ASIC的逻辑电路设计.与其他传统的串行或小规模并行无失真数据压缩的硬件或软件方法相比,本文的Systolic阵列结构有更好的并行性、实时性和普适性.对ASIC的时序和功能进行的模拟验证,证明了逻辑和电路设计的正确性和有效性.     

EPON系统的动态带宽分配算法

针对EPON系统上行链路多个ONU共享带宽的拓扑结构,分析了制定带宽分配策略所需考虑的基本因素,介绍了一种新的动态带宽分配算法,通过动态请求分配机制,实现上行链路的高效利用。     

基于合作博弈的多虚拟机实时迁移带宽分配机制

IaaS云计算平台采用虚拟机实时迁移技术进行资源动态调度和管理。在实际应用场景下,需要并行实时迁移多个虚拟机。由于实时迁移算法本身以最大利用带宽的方式进行数据传输,存在着迁移进程间竞争带宽的问题,无法保证带宽全局最优分配,影响整体迁移的性能。提出一种基于合作博弈的多虚拟机实时迁移带宽分配机制,将带宽分配问题建模为一个纳什议价,通过求解纳什议价解得到帕累托最优的带宽分配方案,并在实际的虚拟化平台上进行了实现。实验结果表明,相比标准的并行实时迁移,所提出的带宽分配机制能够公平有效地分配带宽,提高了并行实时迁移的性能。     

Adaptive Minimum Symbol Error Rate Beamforming Assisted Detection for Quadrature Amplitude Modulation

We consider beamforming assisted detection for multiple antenna aided multiuser systems that employ the bandwidth efficient quadrature amplitude modulation scheme. A minimum symbol error rate (MSER) design is proposed for the beamforming assisted receiver, and it is shown that this MSER design provides significant performance enhancement, in terms of achievable symbol error rate, over the standard minimum mean square error (MMSE) design. A sample-by-sample adaptive algorithm, referred to as the least symbol error rate, is derived for adaptive implementation of the MSER beamforming solution. The proposed adaptive MSER scheme is evaluated in simulation using Rayleigh fading channels, in comparison with the adaptive MMSE benchmarker.     

Load balancing multipath routing protocol for mass remote sensing data downlink in LEO satellite network

LEO satellite networks can provide seamless real-time data communication for all kinds of users,which developed rapidly in recent years.At the mean time,the massive payload data down-link system of space data sources,such as remote sensing satellites,still make use of traditional storage and forward mode.The real-time performance of space mission data will be improved effectively,if such satellites are connected to LEO satellite networks equipped with inter satellite links.However,it is necessary to design a specialized satellite network load balancing routing algorithm.Satellite parallel edge-disjoint multipath routing protocol (SPEMR) was designed for remote sensing satellite real-time down-link applications.OPNET simulation results indicate that the performance degradation index(DI) of the multipath scheme implemented by SPEMR is 0.32,which is only 32% of the TLR and 21% of the traditional DSP scheme.It is demonstrated that SPEMR has the better capability of transmitting massive data in real time.     

FRR for latency reduction and QoS provisioning in OBS networks

We propose a forward resource reservation (FRR) scheme to reduce the data burst delay at edge nodes in optical burst switching (OBS) systems. We also explore algorithms to implement the various intrinsic features of the FRR scheme. Linear predictive filter (LPF)-based methods are investigated and demonstrated to be effective for dynamic burst-length prediction. An aggressive resource reservation algorithm is proposed to deliver a significant performance improvement with controllable bandwidth cost. By reserving resources in an aggressive manner, an FRR system can reduce both the signaling retransmission probability and the bandwidth wastage as compared with a system without the aggressive reservation. An FRR-based QoS strategy is also proposed to achieve burst delay differentiation for different classes of traffic. Theoretical analysis and simulation results verify the feasibility of the proposed algorithms and show that our FRR scheme yields a significant delay reduction for time-critical traffic without incurring a deleterious bandwidth overhead.     

机群系统上基于Hashing的多目标串匹配并行算法

基于孙子定理构造均匀的Hash函数并继承Karp-Rabin模式匹配思想，利用“筛选”方法，给出一种机群系统上的多目标串匹配并行算法。通过预处理将字符串映射成惟一的一对整数值，采用比较一对整数值来取代逐个字符比较字符串的方法使得匹配过程快速且比较结果是确定的：“筛选”节省了比较时间。算法分析和实验结果表明该并行算法简明、高效和可扩展。     

An embedded transmission scheme using PPM signaling with symmetric error-correcting codes for optical CDMA

An embedded transmission (ET) scheme is proposed to easily apply error-correcting codes into optical code-division multiple-access (CDMA) systems for immunity from multiple-access interference (MAI). The ET scheme offers high transmission capability over the traditional scheme using pulse position modulation (PPM) signaling, because a 2/sup J/-ary symbol of each user is embedded in the signature sequence with 2/sup J/ weighted positions. Furthermore, the ET scheme with 2/sup J/-ary PPM signaling makes the optical CDMA system J parallel transmission systems, because J bits consisting of 2/sup J/-ary symbol are separately decided. Since such a separate decision is a comparison decision, the effect of MAI added in the optical channel is converted to symmetric errors in the individual parallel transmission systems. Using the symmetric error-correcting (SEC) code immunizes the individual parallel transmission systems against MAI more easily than the embedded-modulation scheme described in because the ET scheme avoids using the asymmetric error correcting code, which is difficult to implement. We analyze the bit error rate under Poisson photon counting channel and show that the ET scheme has an advantage of good energy efficiency over the traditional scheme in applying SEC codes.     

可变GoP的MPEG视频的滤取和传输

根据网络的带宽情况,将MPEG视频的重要帧滤取出来并在网络上传输,帧滤取算法考虑了同一条流中视频的GoP发生改变的情况.为了进行视频传送的差错控制和恢复,该方案使用了牛顿插值Reed-Soloman编码进行冗余编码保护,能在网络带宽有限的情况下保证视频的传输质量.还针对不同的网络传输率和包丢失率对方案进行了实验.     

Utility-Based Rate-Controlled Parallel Wireless Transmission of Multimedia Streams with Multiple Importance Levels

Multimedia data often have different levels of importance such that more important bits are less error-tolerant. A new rate control method for transporting such multimedia data over parallel wireless links with heterogeneous reliability is proposed. Rate-controlled parallel transmissions (RCPT) of different layers of a multimedia stream with different levels of importance over a wireless channel that support multiple links with heterogeneous reliability can improve the efficiency in resource allocation while satisfying the quality of service requirement of the multimedia connection. To exploit RCPT, we present and evaluate a novel dynamic resource allocation method that decomposes the available radio resources into multiple sets of links with different levels of reliability. We mathematically formulate a rate control problem for the flexible RCPT scheme and develop an efficient real-time resource allocation algorithm with a remarkably fast rate of convergence. Simulation results show that the proposed method improves the utility and reduces the power consumed for delivery of a multimedia stream at the required quality of service, in comparison with a previous scheme, where different layers of each multimedia class are scheduled with dependency, and two schemes that provide homogeneous high or low reliability over all parallel links.