数字电视传输流循环播放码流预处理的研究与实现

数字电视传输流在循环播放时需要实时更新节目时钟基准、音视频解码时间标签和显示时间标签，接收机（机顶盒）才能正确解码．为此，提出并实现了通过对数据流进行预处理生成报告文件，循环播放时再按报告文件实时更新定时参数的算法、解决了多个传输流文件之间以及单个传输流文件循环播放时头尾的无缝粘接．使机顶盒接收、解码、系统时基、声音、图像以及声音与图像之间均能良好同步．     

FPGA同步设计及实现

介绍了FPGA设计中的同步设计技术及实现,给出了FFT运算实例,比较了采用FPGA同步设计前后FFT运算速度的不同,通过比较采用同步设计前后FFT运算速度的不同,可以看出合理采用FPGA同步设计技术可以大大提高系统工作频率．     

基于DSP异步电动机直接转矩控制系统设计

介绍了异步电动机直接转矩控制系统的基本原理,阐述了基于 TMS320F240 DSP 为核心的控制系统,此系统采用交-直-交电压型变频电路,整个系统按功率电路板,DSP 控制板,15V 开关电源进行模块化设计,并从软件上加以实现。通过程序的调试和系统的仿真实验结果表明该系统具有良好的性能。     

Localizing Test Power Consumption for Scan Testing

IntroductionScan design makes test generation of the circuit be thatof a combinational one . However , scan testing needs toscanin values of all scanflip-flops for eachtest patternthatcan make the test application cost and test powerconsumption prohibitively high. Test data volumecorresponding to scan testing is also large compared withthat of a non-scan circuit . The circuit can be burn out iftest power consumptionis toolarge during test application.Test data volume is also very i mportant f…     

太原电台播出系统设计

电台的播出系统在节目的交换、处理、传输、控制和播出中起着重要的作用。对太原电台播出系统的设计理念、设计原则进行了简要的介绍，并对其电源系统、音频信号流程、监测系统、监视系统、时钟系统等的技术指标及技术性能进行了重点阐述。     

基于CPLD的数字系统设计

以数字钟的设计过程为例，介绍复杂可编程逻辑器件(CPLD)在数字系统设计中的应用，说明了CPLD、硬件描述语言和EDA开发软件的重要作用，给出了主要电路模块的VHDL设计和操作方法。     

雉科基部类群分子钟的标定

使用 10个细胞色素b蛋白质全序列对雉科基部类群的分子钟进行了顺序标定 .以鸡形目 /雁形目的分歧时间作为锚定点 ,估计雉科 /珠鸡科 林鹑科的分歧时间为 (46 .94± 7.2 7)× 10 6aBP ,Francolinus/Bambusicola Gallus,Bambusicola/Gallus和Gallusgallus/G .sonneratii的分歧时间为 (40 .36± 8.4 0 )× 10 6 ,(35 .5 3± 8.15 )× 10 6 和 (8.5 2± 3.89)× 10 6 aBP .基于生物地理格局 ,我们推测 :①雉科起源于同南美洲分离之后的非洲 ;②在Francolinus的分化过程中 ,该属的某些成员通过印度的漂移从非洲进入欧亚大陆 ;③侵入新的生境后 ,Bambusicola和Gallus的共同祖先迅速从地Francolinus分歧出来 ;④原始的Bambusicola被Gallus排挤到南中国地区 ;⑤Gallus的祖先种分裂为大陆型和岛屿型 2类 ,前者分化为Gallusgallus和G .sonneratii,后者则分化为G .lafayettei和G .varius.估计结果同前两点假设是一致的 .     

一种使Charge-pump的输出电压稳定的时钟电路

随着工艺的提高和电源电压的降低,需要能够在低电压下工作的电路。该文介绍了一种能在1.8V电压下工作的时钟产生器。它的频率随着电源电压的增大而减小,随着温度的升高而增大,并能抑制制程的偏差对频率产生的影响。从而使Charge-pump的输出电压稳定。     

Molecular phylogeny of the specialized schizothoracine fishes （Teleostei： Cyprinidae）,with their implications for the uplift of the Qinghai-Tibetan Plateau

Molecular phylogeny of three genera containing nine species and subspecies of the specialized schizothoracine fishes are investigated based on the complete nucleotide sequence of mitochondrial cytochrome b gene. Meantime relationships between the main cladogenetic events of the specialized schizothoracine fishes and the stepwise uplift of the Qinghai-Tibetan Plateau are also conducted using the molecular clock, which is calibrated by geological isolated events between the upper reaches of the Yellow River and the Qinghai Lake. Results indicated that the specialized schizothoracine fishes are not a monophyly. Five species and subspecies of Ptychobarbus form a monophyly. But three species of Gymnodiptychus do not form a monophyly. Gd.integrigymnatus is a sister taxon of the highly specialized schizothoracine fishes while Gdo pachycheilus has a close relation with Gd. dybowskii, and both of them are as a sister group of Diptychus maculatus. The specialized schizothoracines fishes might have originated during the Miocene(about 10 MaBP), and then the divergence of three genera happened during late Miocene (about 8 MaBP). Their main specialization occurred during the late Pliocene and Pleistocene (3.54-0.42 MaBP). The main cladogenetic events of the specialized schizothoracine fishes are mostly correlated with the geological tectonic events and intensive climate shift happened at 8, 3.6, 2.5 and 1.7 MaBP of the late Cenozoic.Molecular clock data do not support the hypothesis that the Qinghai-Tibetan Plateau uplifted to near present or even higher elevations during the Oligocene or Miocene, and neither in agreement with the view that the plateau uplifting reached only to an altitude of 2000 m during the late Pliocene(about 2.6 MaBP).     

改进的前跳虚时钟调度算法

基于前跳虚时钟算法原理提出了一种新的调度算法，它将业务所预留的带宽和链路的剩余带宽实时分离，并用剩余带宽改善其他种类业务的QoS特性，使得带宽资源的分配更加灵活，理论分析和仿真证明，算法不仅降低了“尽力而为”业务的平均时延，还具有确定的时延保证和公平性。