This paper constructs the probability model of the multi-valued KM_1M_2 clock controlled generator,and discusses the probability distributing,homogeneous Markov property,ergodic property,strict placidity,numeral chara...This paper constructs the probability model of the multi-valued KM_1M_2 clock controlled generator,and discusses the probability distributing,homogeneous Markov property,ergodic property,strict placidity,numeral character and the property of large numbers of the random variables with this kind of output sequence.It gets the probability formula of the coincidence of the output sequence with the input sequence,and gives important reference to the design and analysis of the multi-valued key stream clock controlled generator in cryptography.展开更多
In this paper, the mutual information between clock-controlled input and output sequences is discussed. It is proved that the mutual information is a strictly monotone increasing function of the length of output seque...In this paper, the mutual information between clock-controlled input and output sequences is discussed. It is proved that the mutual information is a strictly monotone increasing function of the length of output sequence, and its divergent rate is gaven.展开更多
The Controller Area Network (CAN) is a well established control network for automotive and automation control applications. Time-Triggered Controller Area Network (TTCAN) is a recent development which introduces a ses...The Controller Area Network (CAN) is a well established control network for automotive and automation control applications. Time-Triggered Controller Area Network (TTCAN) is a recent development which introduces a session layer,for message scheduling,to the existing CAN standard,which is a two layer standard comprising of a physical layer and a data link layer. TTCAN facilitates network communication in a time-triggered fashion,by introducing a Time Division Multiple Access style communication scheme. This allows deterministic network behavior,where maximum message latency times can be quantified and guaranteed. In order to solve the problem of determinate time latency and synchronization among several districted units in one auto panel CAN systems,this paper proposed a prototype design implementation for a shared-clock scheduler based on PIC18F458 MCU. This leads to improved CAN system performance and avoid the latency jitters and guarantee a deterministic communication pattern on the bus. The real runtime performance is satisfied.展开更多
针对PTP(precise time protocol)协议在应用层获取软件时间戳导致时钟同步精度下降的问题,提出一种基于MAC(media access control)层获取硬件时间戳的PTP同步优化方案。设计了以STM32F407微处理器为核心的PTP时钟应用平台,在MAC层实现...针对PTP(precise time protocol)协议在应用层获取软件时间戳导致时钟同步精度下降的问题,提出一种基于MAC(media access control)层获取硬件时间戳的PTP同步优化方案。设计了以STM32F407微处理器为核心的PTP时钟应用平台,在MAC层实现了硬件时间戳获取,避免了由于协议栈软件处理延时产生的不确定性;针对PTP时钟晶振老化导致的时间同步偏差及网络延迟抖动问题,采用迭代方法优化了本地时钟频率调节算法,提高了频率校正精度。经实际测试,主从时钟偏差的RMS(root mean square)优于20 ns,提升了时钟同步精度。展开更多
随着高清电视和网络媒体的快速发展,音视频同步技术在广播电视节目制作中的重要性日益突出。通过对当前音视频同步系统的分析,深入研究节目时钟参考(Program Clock Reference,PCR)、显示时间戳(Presentation Time Stamp,PTS)/解码时间戳...随着高清电视和网络媒体的快速发展,音视频同步技术在广播电视节目制作中的重要性日益突出。通过对当前音视频同步系统的分析,深入研究节目时钟参考(Program Clock Reference,PCR)、显示时间戳(Presentation Time Stamp,PTS)/解码时间戳(Decoding Time Stamp,DTS)、音视频缓冲区控制等关键技术在实际制作环境中的应用。基于自适应缓冲区控制的音视频同步方案能将音视频延迟控制在±15 ms以内,满足广播级节目制作要求。展开更多
目的探讨钟基因Per2和钟控基因血管内皮生长因子(VEGF)、Ki67、c-Myc和P53在颊黏膜癌变不同阶段的昼夜节律变化规律以及与癌变发生发展的关系。方法 90只叙利亚金黄地鼠置于12 h光照和12 h黑暗交替环境中饲养,用二甲基苯并蒽(DMBA)涂抹...目的探讨钟基因Per2和钟控基因血管内皮生长因子(VEGF)、Ki67、c-Myc和P53在颊黏膜癌变不同阶段的昼夜节律变化规律以及与癌变发生发展的关系。方法 90只叙利亚金黄地鼠置于12 h光照和12 h黑暗交替环境中饲养,用二甲基苯并蒽(DMBA)涂抹颊黏膜建立金黄地鼠颊癌模型,分别在DMBA涂抹前,涂抹6周和14周后的24 h内的6个不同时间点处死动物,获取正常颊黏膜、癌前病变和癌症3个不同阶段昼夜6个不同时间的组织。经病理学检查确认后,采用实时荧光定量聚合酶链反应检测各时间点Per2、VEGF、Ki67、c-Myc和P53 m RNA的相对表达量,并行余弦分析,以中值、振幅和峰值位相时为指标反映各基因表达的昼夜节律特征。结果 Per2、VEGF、P53和c-Myc m RNA在癌变3个阶段的表达均具有昼夜节律性(P<0.05),而Ki67 m RNA仅在正常黏膜和癌前病变阶段的表达具有昼夜节律性(P<0.05)。Per2和P53 m RNA表达的中值随着癌症的发展而降低(P<0.05),VEGF、c-Myc和Ki67 m RNA表达的中值随着癌症的发展而上升(P<0.05);P53 m RNA的振幅随着癌症的发展而降低(P<0.05),Per2、VEGF、Ki67和c-Myc m RNA的振幅在癌前病变和癌症阶段均高于正常组(P<0.05);在癌前病变阶段,Per2、VEGF和c-Myc m RNA的峰值位相时较正常组提前,而Ki67和P53 m RNA的峰值位相时较正常组滞后。结论随着癌症的发生和发展,钟基因Per2和肿瘤相关钟控基因VEGF、Ki67、c-Myc、P53表达的昼夜节律特征发生明显改变。展开更多
基金Supported by the Computer Network and Information Security Foundation of Ministry of Education Laboratory(20040108)
文摘This paper constructs the probability model of the multi-valued KM_1M_2 clock controlled generator,and discusses the probability distributing,homogeneous Markov property,ergodic property,strict placidity,numeral character and the property of large numbers of the random variables with this kind of output sequence.It gets the probability formula of the coincidence of the output sequence with the input sequence,and gives important reference to the design and analysis of the multi-valued key stream clock controlled generator in cryptography.
文摘In this paper, the mutual information between clock-controlled input and output sequences is discussed. It is proved that the mutual information is a strictly monotone increasing function of the length of output sequence, and its divergent rate is gaven.
文摘The Controller Area Network (CAN) is a well established control network for automotive and automation control applications. Time-Triggered Controller Area Network (TTCAN) is a recent development which introduces a session layer,for message scheduling,to the existing CAN standard,which is a two layer standard comprising of a physical layer and a data link layer. TTCAN facilitates network communication in a time-triggered fashion,by introducing a Time Division Multiple Access style communication scheme. This allows deterministic network behavior,where maximum message latency times can be quantified and guaranteed. In order to solve the problem of determinate time latency and synchronization among several districted units in one auto panel CAN systems,this paper proposed a prototype design implementation for a shared-clock scheduler based on PIC18F458 MCU. This leads to improved CAN system performance and avoid the latency jitters and guarantee a deterministic communication pattern on the bus. The real runtime performance is satisfied.
文摘针对PTP(precise time protocol)协议在应用层获取软件时间戳导致时钟同步精度下降的问题,提出一种基于MAC(media access control)层获取硬件时间戳的PTP同步优化方案。设计了以STM32F407微处理器为核心的PTP时钟应用平台,在MAC层实现了硬件时间戳获取,避免了由于协议栈软件处理延时产生的不确定性;针对PTP时钟晶振老化导致的时间同步偏差及网络延迟抖动问题,采用迭代方法优化了本地时钟频率调节算法,提高了频率校正精度。经实际测试,主从时钟偏差的RMS(root mean square)优于20 ns,提升了时钟同步精度。
文摘随着高清电视和网络媒体的快速发展,音视频同步技术在广播电视节目制作中的重要性日益突出。通过对当前音视频同步系统的分析,深入研究节目时钟参考(Program Clock Reference,PCR)、显示时间戳(Presentation Time Stamp,PTS)/解码时间戳(Decoding Time Stamp,DTS)、音视频缓冲区控制等关键技术在实际制作环境中的应用。基于自适应缓冲区控制的音视频同步方案能将音视频延迟控制在±15 ms以内,满足广播级节目制作要求。
文摘目的探讨钟基因Per2和钟控基因血管内皮生长因子(VEGF)、Ki67、c-Myc和P53在颊黏膜癌变不同阶段的昼夜节律变化规律以及与癌变发生发展的关系。方法 90只叙利亚金黄地鼠置于12 h光照和12 h黑暗交替环境中饲养,用二甲基苯并蒽(DMBA)涂抹颊黏膜建立金黄地鼠颊癌模型,分别在DMBA涂抹前,涂抹6周和14周后的24 h内的6个不同时间点处死动物,获取正常颊黏膜、癌前病变和癌症3个不同阶段昼夜6个不同时间的组织。经病理学检查确认后,采用实时荧光定量聚合酶链反应检测各时间点Per2、VEGF、Ki67、c-Myc和P53 m RNA的相对表达量,并行余弦分析,以中值、振幅和峰值位相时为指标反映各基因表达的昼夜节律特征。结果 Per2、VEGF、P53和c-Myc m RNA在癌变3个阶段的表达均具有昼夜节律性(P<0.05),而Ki67 m RNA仅在正常黏膜和癌前病变阶段的表达具有昼夜节律性(P<0.05)。Per2和P53 m RNA表达的中值随着癌症的发展而降低(P<0.05),VEGF、c-Myc和Ki67 m RNA表达的中值随着癌症的发展而上升(P<0.05);P53 m RNA的振幅随着癌症的发展而降低(P<0.05),Per2、VEGF、Ki67和c-Myc m RNA的振幅在癌前病变和癌症阶段均高于正常组(P<0.05);在癌前病变阶段,Per2、VEGF和c-Myc m RNA的峰值位相时较正常组提前,而Ki67和P53 m RNA的峰值位相时较正常组滞后。结论随着癌症的发生和发展,钟基因Per2和肿瘤相关钟控基因VEGF、Ki67、c-Myc、P53表达的昼夜节律特征发生明显改变。
