本文通过对维持体系运行条件的确定、体系运行效果的确认与验证、体系运行证据的收集留存及预防性控制等的研究阐明了基于ISO/FD IS 22000标准的饲料安全管理体系的实施、保持、持续改进和更新的具体要求和措施方法,为饲料生产企业ISO/F...本文通过对维持体系运行条件的确定、体系运行效果的确认与验证、体系运行证据的收集留存及预防性控制等的研究阐明了基于ISO/FD IS 22000标准的饲料安全管理体系的实施、保持、持续改进和更新的具体要求和措施方法,为饲料生产企业ISO/FD IS 22000饲料安全管理体系的实施、保持、改进和更新提供指南.展开更多
For direct sequence spread spectrum (DSSS) receivers, the capability of rejecting narrow-band interference can be significantly improved by a process of frequency-domain interference suppression (FDIS). The key is...For direct sequence spread spectrum (DSSS) receivers, the capability of rejecting narrow-band interference can be significantly improved by a process of frequency-domain interference suppression (FDIS). The key issue of this process is how to determine a threshold to eliminate interference in the frequency domain, which has been extensively studied. However, these previous methods are tedious or very complex. A simple and ef- ficient algorithm based on medians is proposed. The elimination threshold is only related to the median by a scale factor, which can be obtained by the numerical analysis. Simulation results show that the algorithm provides excellent narrow-band interfer- ence suppression while only slightly degrading the signal-to-noise ratio (SNR). A one-pass algorithm using logarithmic segmentation is further derived to estimate medians with low computational complexity. Finally, the FDIS is implemented in a field programmable gate array (FPGA) of Xilinx. Experiments are carried out by connecting the FDIS FPGA to a DSSS receiver, and the results show that the receiver has an effective countermeasure for a 60 dB interference-to-signal ratio (ISR).展开更多
标准英文标题:Technical product documentation—Organization and naming of layers for CAD—Part 2:Concepts,format and codes used in construction documentation标准中文标题:技术产品文件-CAD图层的组织和命名—第2部分:...标准英文标题:Technical product documentation—Organization and naming of layers for CAD—Part 2:Concepts,format and codes used in construction documentation标准中文标题:技术产品文件-CAD图层的组织和命名—第2部分:用于建筑文件的概念、格式和编码1编制背景和范围ISO 13567系列标准由两部分组成,为了解决CAD图层的组织和命名。ISO 13567-1为一般应用,ISO13567-2应用与建筑项目。ISO 13567系列标准旨在针对数据的组织建立一个共同的国际基础,数据组织是在CAD系统中,包含以图层形式数据的构建。展开更多
标准英文标题:Performance standards in building—Definition and calculation of area and space indicators标准中文标题:建筑性能标准——面积和空间指标的定义和计算1标准编制背景在建筑物空间测量得出的表面积和体积指标可用...标准英文标题:Performance standards in building—Definition and calculation of area and space indicators标准中文标题:建筑性能标准——面积和空间指标的定义和计算1标准编制背景在建筑物空间测量得出的表面积和体积指标可用于一些值的比较,如在功能上可利用的空间或体积的比例。作为规划的近似值,它们可以作为下一步工作的基础。展开更多
文摘本文通过对维持体系运行条件的确定、体系运行效果的确认与验证、体系运行证据的收集留存及预防性控制等的研究阐明了基于ISO/FD IS 22000标准的饲料安全管理体系的实施、保持、持续改进和更新的具体要求和措施方法,为饲料生产企业ISO/FD IS 22000饲料安全管理体系的实施、保持、改进和更新提供指南.
基金supported by the National Natural Science Foundation of China(60904090)
文摘For direct sequence spread spectrum (DSSS) receivers, the capability of rejecting narrow-band interference can be significantly improved by a process of frequency-domain interference suppression (FDIS). The key issue of this process is how to determine a threshold to eliminate interference in the frequency domain, which has been extensively studied. However, these previous methods are tedious or very complex. A simple and ef- ficient algorithm based on medians is proposed. The elimination threshold is only related to the median by a scale factor, which can be obtained by the numerical analysis. Simulation results show that the algorithm provides excellent narrow-band interfer- ence suppression while only slightly degrading the signal-to-noise ratio (SNR). A one-pass algorithm using logarithmic segmentation is further derived to estimate medians with low computational complexity. Finally, the FDIS is implemented in a field programmable gate array (FPGA) of Xilinx. Experiments are carried out by connecting the FDIS FPGA to a DSSS receiver, and the results show that the receiver has an effective countermeasure for a 60 dB interference-to-signal ratio (ISR).
文摘标准英文标题:Technical product documentation—Organization and naming of layers for CAD—Part 2:Concepts,format and codes used in construction documentation标准中文标题:技术产品文件-CAD图层的组织和命名—第2部分:用于建筑文件的概念、格式和编码1编制背景和范围ISO 13567系列标准由两部分组成,为了解决CAD图层的组织和命名。ISO 13567-1为一般应用,ISO13567-2应用与建筑项目。ISO 13567系列标准旨在针对数据的组织建立一个共同的国际基础,数据组织是在CAD系统中,包含以图层形式数据的构建。
文摘标准英文标题:Performance standards in building—Definition and calculation of area and space indicators标准中文标题:建筑性能标准——面积和空间指标的定义和计算1标准编制背景在建筑物空间测量得出的表面积和体积指标可用于一些值的比较,如在功能上可利用的空间或体积的比例。作为规划的近似值,它们可以作为下一步工作的基础。