气枪震源的发展与使用分析(上)

本文从气枪震源的发展入手,对各类气枪的性能、参数和工作原理进行了分析比较,列出了各类气枪的常用阵列。分析出了影响气枪参数的因素,并给出了气枪充气时间的计算方法及气枪阵列的设计方法。     

气枪震源的发展与使用分析(下)

本文从气枪震源的发展入手,对各类气枪的性能、参数和工作原理进行了分析比较,列出了各类气枪的常用阵列。分析出了影响气枪参数的因素,并给出了气枪充气时间的计算方法及气枪阵列的设计方法。     

Fault-tolerant routing algorithm based on disjoint paths in 3-ary n-cube networks with structure faults

The Journal of Supercomputing - The 3-ary n-cube network is widely used in large-scale multi-processor parallel computers. It is an important issue to design high-performance communication...     

篮球比赛视频节目中短管哨声检测方法

提出了一种检测篮球比赛视频中重要音频关键词（短管哨声）的方法。通过分析短管哨声的频谱分布特性提出一种二级检测方法：首先提取特定子带能量峰指数特征,并采用门限决策方法获得关键词候选集;第二级再结合梅尔频率倒谱系数和支持向量机得到最终的关键词检测结果。选取时长为1378s的NBA篮球比赛音频片段作为测试序列．验证了本方法具有正确率和检出率分别为95．45％和91.3％的性能。     

Fault-tolerant hamiltonian cycles and paths embedding into locally exchanged twisted cubes

The foundation of information society is computer interconnection network, and the key of information exchange is communication algorithm. Finding interconnection networks with simple routing algorithm and high fault-tolerant performance is the premise of realizing various communication algorithms and protocols. Nowadays, people can build complex interconnection networks by using very large scale integration (VLSI) technology. Locally exchanged twisted cubes, denoted by (s + t + 1)-dimensional LeTQ_s,t, which combines the merits of the exchanged hypercube and the locally twisted cube. It has been proved that the LeTQ_s,t has many excellent properties for interconnection networks, such as fewer edges, lower overhead and smaller diameter. Embeddability is an important indicator to measure the performance of interconnection networks. We mainly study the fault tolerant Hamiltonian properties of a faulty locally exchanged twisted cube, LeTQ_s,t − ( f_v + f_e), with faulty vertices f_v and faulty edges f_e. Firstly, we prove that an LeTQ_s,t can tolerate up to s−1 faulty vertices and edges when embedding a Hamiltonian cycle, for s≥2, t≥3, and s≤t. Furthermore, we also prove another result that there is a Hamiltonian path between any two distinct fault-free vertices in a faulty LeTQ_s,twith up to (s − 2) faulty vertices and edges. That is, we show that LeTQ_s,t is (s−1)-Hamiltonian and (s−2)- Hamiltonian-connected. The results are proved to be optimal in this paper with at most (s − 1)-fault-tolerant Hamiltonicity and (s − 2) fault-tolerant Hamiltonian connectivity of LeTQ_s,t.     

A Live Migration Algorithm for Containers Based on Resource Locality

With the wide application of cloud computing, the scale of cloud data center network is growing. The virtual machine (VM) live migration technology is becoming more crucial in cloud data centers for the purpose of load balance, and efficient utilization of resources. The lightweight virtualization technique has made virtual machines more portable, efficient and easier to management. Different from virtual machines, containers bring more lightweight, more flexible and more intensive service capabilities to the cloud. Researches on container migration is still in its infancy, especially live migration is still very immature. In this paper, we present the locality live migration model where we take into account the distance, available bandwidth and costs between containers. Furthermore, we conduct comprehensive experiments on a cluster. Extensive simulation results show that the proposed method improves the utilization of resources of servers, and also improves the balance of all kinds of resources on the physical machine.

     

基于TCP协议的音频流媒体QoE的定量研究

流媒体接收端音频的初始延时或中断,以及采用自适应播放产生的播放速率变化是基于TCP协议的音频流媒体的用户体验质量下降的主要原因。介绍了一种中断强度的概念,并通过模拟实际网络环境的主观音质测试方法来分析中断强度对QoE的影响。结果表明,在可用带宽发生变化时,中断强度和主观音质测试得分有很好的相关性,平均相关系数为-0.9。从而表明中断强度可以作为评价音频流媒体QoE的客观评价参数。此外,还对播放速率变化对QoE的影响进行了主观音质测试,变速算法为波形相似叠加算法。测试结果显示,当变速因子超过105%时,音质下降严重,测试结果可以作为自适应播放中参数设置的参考。     

基于EaacPlus的可分层可分级音频编码系统

在多媒体通信中,一方面要求音频业务质量能适应不断变化的网络带宽,体现一定的层次性;另一方面,要求音频信源能够按码率任意截断从而更好地适应信道变化,以保证音频业务质量要求。这种信源的分层分级码流在网络传输时,更便于信道不对等保护技术的使用。提出了一种音频业务的可分层模型和基于EaacPlus核心编码器的可分层可分级音频编码方案。实验表明,分层模型的使用使得音质具有较强的层次感;可分级码率的增加能够带来音质的连续增强。     

A DAB transmitter prototype with high flexibility and low cost

The design and implementation of a DAB transmitter prototype is proposed. The system architecture, ensemble multiplexer, channel encoder, OFDM (orthogonal frequency division multiplexing) modulator and other digital baseband parts are described. The prototype is fully compatible with ETS 300 401 and other related standards. It supports different services with various data formats and provides a convenient PC-based user interface. All I/Os and core parts are based on a modular design with a universal internal interface, hence the prototype can be flexibly configured to adapt to different requirements. Compared with existing products, the proposed transmitter prototype offers higher flexibility and lower cost.     

DAB接收机及其芯片设计的新趋势

文中介绍了ＤＡＢ接收机及其芯片的功能，发展过程，最新进展，并从技术角度分析了最新的ＤＡＢ接收机芯片的设计方法和发展趋势。