数字电视市场运营探析

有线数字电视在上一代模拟有线电视的网络硬件平台和节目平台的基础上，采用数字压缩调制等技术使用户终端能够接收尽可能多的节目并最大程度地还原信号源的节目质量．并通过CA加密系统实现节目源的有条件接收。我们从关注这一日渐成熟的、具有较高性价比     

数字机顶盒信号播放设备评析

目前正是各运营商热烈关注并全力推动机顶盒市场开发和用户普及工作的关键时期，大众对数字电视的理解和感受都集中在机顶盒本身，实际上真正能够展现数字信号所有魅力的是机顶盒输出所连接的显示播放设备，它才是数字信号与用户之间最后的也是最关键的接口，它的各项参数指标的优劣将极大地     

填充料细度对水工沥青混凝土性能的影响

近年来沥青混凝土作为防渗材料，在我国水工建筑中得到了广泛应用。与道路工程的沥青混凝土不同的是，水工沥青混凝土具有良好的粘弹性及抗渗性。目前，国家规范对填充料的细度尚无明确规定，通过调整沥青混凝土的填充料细工，对沥青混凝土的各项性能进行了系统的试验和分析，研究表明：适宜的填充料细度及掺量，能有效地改善沥青混凝土性能，提高其抗渗性。     

铝合金汽车零部件试制成功

湖北省东风襄樊旋压件股份有限公司试制成功一种用铝合金材料制成的汽车发动机皮带轮。目前，将铝合金成功运用到旋压皮带轮部件上，在我国尚属首次。     

重庆净空工程见成效

蓝天、白云增多了,粉尘也比以前少了,这是重庆市实施的“五管齐下”净空工程和控制尘污染措施所取得的显著成效。今年上半年,重庆市主城区环境空气质量达到二级以上的天数频率为69.6％,比去年同期增加30.3％。     

基于改进遗传算法的QoS感知Web服务组合

传统遗传算法在种群初始化的时候,普遍采用均匀取种法或随机取种法,这些方法生成的种群的平均适应度比较低,难以保证算法的搜索效率。文中提出一种改进的遗传算法用于QoS敏感的Web服务组合,采用两种不同的算法进行服务选择,避免了随机生成初始种群给算法带来的负面影响。并且,该算法将路径模板化以减少服务组合的工作量,用染色体可变长的编码方式来解决组合服务的多路径选择问题。通过仿真实验,与传统的算法相比,所提出的算法在实现服务组合时收敛更快,最优解的适应度更高。     

An estimate of the incidence of dark cutting beef in the United Kingdom

Eight slaughterplants with throughputs ranging from 20 to 300 animals per day were examined to estimate the incidence of dark cutting beef in the United Kingdom. Four thousand, eight hundred and sixteen animals were surveyed and information concerning animal category, source, season and preslaughter handling conditions recorded. Muscle samples were removed to estimate glycogen concentration and after incubation, ultimate pH. The overall incidence of dark cutting (pHu ≥ 6·0) was 4·1%. Increased incidence was associated with short (≤ 20 miles) and long (≥ 150 miles) transport distances. Slaughter on the day of arrival rather than overnight lairage also increased the incidence. Plants were classified into small (killing ≤ 50 animals per day) or large (killing ≥ 100 per day). Eighty per cent of the animals slaughtered passed through the large plants, and a higher incidence was also associated with these plants. Bulls had the highest incidence and heifers the lowest. A seasonal effect was recorded with the highest incidence found between July and October. The results, however, indicate that factors in addition to those examined are also important.