基于ARM平台的高清视频信号编解码器优化设计

由于原始编解码器存在编解码速度慢,耗费时间长的问题,无法满足人们需求,提出了基于ARM平台的高清视频信号编解码器优化设计。在ARM平台下对接口进行分离,从代码和结构两方面对编码器进行精简,进而对相应程序进行优化;针对解码器优化过程,优化C级别和熵解码,并移除多余结构体以及冗余函数,重新建立哈夫曼查表,完成高清视频信号快速解码。通过实验验证结果可知,优化后的编解码器速度快,且耗费时间较短。     

校园网高清视频直播传输系统设计

为了在提高视频画面质量的同时不增加网络负载,根据学校网络结构的特点,分析数据在传输过程中的一些关键技术指标,采用多级软件组播的思想,提出一种具有并发能力强、实时性高、高清稳定的视频直播传输系统.该系统解决了节点加入与退出的管理,单点故障处理,跨校区分布式部署等问题,既能保证用户观看效果又能提升网络带宽的利用率.     

河北电视台高清演播室内部通话系统设计

介绍高清演播室中内部通话系统的构成,并结合河北电视台高清演播室装配的通话系统,阐述了不同工作区域内部通话的各自特点,重点介绍通过控制软件ECS设置通话矩阵的功能.     

A study of the properties of compacts from silicified microcrystalline celluloses

The paper deals with a study of tensile strength and disintegration time of compacts made from silicified microcrystalline celluloses, Prosolv SMCC 90, and Prosolv HD 90, in dependence on compression force, addition of two types of lubricants, and two active ingredients. The lubricants were magnesium stearate and sodium stearyl fumarate in a concentration of 0.5%, the active ingredients being ascorbic acid and acetylsalicylic acid in a concentration of 50%.

Prosolv SMCC 90 proved to be better compatible than Prosolv HD 90; the compacts were of higher strength, which was markedly increased with increasing compression force. Prosolv HD 90 was more sensitive to additions of lubricants, and a greater decrease in strength was recorded due to the influence of sodium stearyl fumarate. The effect of lubricants on the strength of compacts in the presence of active ingredients was not identical. The disintegration time of compacts from Prosolv HD 90 without as well as with lubricants was shorter than from Prosolv SMCC 90 and was increasing with increasing compression force. Disintegration time was increased with added lubricants, and it was markedly shortened by addition of active ingredients. Compacts containing ascorbic acid possessed a shorter disintegration time than those containing acetylsalicylic acid, and it was not markedly influenced by the presence of lubricants.     

基于以太网络的宇航用高清摄像机的硬件设计

由于目前现有工业用摄像机无法满足空间大温度范围、强振动环境等要求,提出了能够适应空间环境的基于以太网络视频传输的高清一体摄像机.该摄像机在完成包括H.264,JPEG2000,MPEG4等图像编码算法的同时,支持空间以太网络协议进行传输和控制.针对宇航环境使用要求,从结构设计、力学设计、热设计、电磁兼容设计等方面进行可靠性设计和仿真验证,满足质量轻、温度适应性好、可靠性高等要求.经过鉴定试验验证,所设计的高清一体摄像机可以可靠地在空间严苛环境中工作.     

计算机等级考试上机考试系统中的问题与解决

针对四川省高校计算机等级考试上机考试系统中存在的服务器与客户机的连接方式选择、试卷内容发送、考试计时等主要问题,提出了解决方法。     

Extravascular lung water index: a new method to determine dry weight in chronic hemodialysis patients

To assess the dry weight of chronic hemodialysis (HD) patients, the extravascular lung water index (ELWI) as a volume parameter was investigated to identify fluid overload. Forty-two patients (30 males, 12 females) with a mean age of 55.7+/-13.0 years who were clinically not overhydrated were connected to the PiCCO system before starting HD treatment. We determined ELWI (normal range 3-7 mL/kg) and the following parameters: global end-diastolic volume index (GEDI, normal range 680-800 mL/m(2)) and intrathoracic blood volume index (ITBI, normal range 850-1000 mL/m(2)) before and after HD to assess the volume status. Brain natriuretic peptide (BNP), aldosterone, and renin as vasoactive hormones were measured at the beginning and at the end of HD treatment as well. In 28 of the 42 patients (67%), elevated values of ELWI were found, indicating interstitial volume overload. There were significant correlations between ELWI and cardiac function index (p=0.003; Pearson's coefficient -0.451), global ejection fraction (p=0.012; Pearson's coefficient -0.389), ITBI (p=0.004; Pearson's coefficient 0.437), and GEDI (p=0.004; Pearson's coefficient 0.437). No significant relations among ELWI and mean arterial pressure (MAP), BNP, aldosterone, and renin were found. In conclusion, the use of ELWI is safe in chronic HD patients and identifies fluid-overloaded patients, who show no obvious signs of hypervolemia. The determination of ELWI is an excellent method to quantify the exact volume in chronic HD patients.     

Distillation of hydrogen isotopes for polarized HD targets

We have developed a new cryogenic distillation system to purify Hydrogen-Deuteride (HD) gas for polarized HD targets in LEPS experiments at SPring-8. A small amount of ortho-H₂ (∼0.01%) in the HD gas plays an important role in efficiently polarizing the HD target. Since there are 1-5% impurities of H₂ and D₂ in commercially available HD gases, it is necessary to purify the HD gas up to ∼99.99%. The distillation system is equipped with a cryogenic distillation unit filled with many small stainless steel cells called “Heli-pack”. The distillation unit consists of a condenser part, a rectification part, and a reboiler part. The unit is kept at the temperature of 17-21 K. The Heli-pack has a large surface area that makes a good contact between gases and liquids. An amount of 5.2 mol of commercial HD gas is fed into the distillation unit. Three trials were carried out to purify the HD gas by changing temperatures (17.5 K and 20.5 K) and gas extraction speeds (1.3 ml/min and 5.2 ml/min). The extracted gas was analyzed using a gas analyzer system combining a quadrupole mass spectrometer with a gas chromatograph. One mol of HD gas with a purity better than 99.99% has been successfully obtained for the first time. The effective NTP (Number of Theoretical Plates), which is an indication of the distillation performances, is obtained to be 37.2±0.6. This value is in good agreement with a designed value of 37.9. The HD target is expected to be efficiently polarized under a well-controlled condition by adding an optimal amount of ortho-H₂ to the purified HD gas.     

基于FPGA汽车尾灯的设计

采用自顶向下的设计方法,介绍利用Verilog HDL硬件描述语言设计的汽车尾灯控制器的思路和技巧,在MAX+PLUSII开发环境中编译和仿真所设计的程序,并在FPGA芯片上下载验证。     

新型智能节水控制器的研制与开发

分析了目前公共厕所水的使用情况和现有节水器存在的不足,采用单片机控制技术,设计一种新型智能节水控制器,阐述了系统的设计思想、工作原理、软硬件设计特点.对厕所水资源的使用进行精细控制,达到节水目的.