移动网同步问题分析及探讨

近年来,移动网同步设备越来越多,它已经被广泛的应用在各地移动网传输线路中。但是这种设备在应用中极容易受到网络同步问题的干扰,给整个通信网络的稳定性、安全性造成威胁。本文就移动网同步需求、影响同步质量的相关因素做了分析,并提出了有关提高移动同步质量的建议。     

实现OPAC查询机无人管理的一种方法

针对图书馆OPAC查询用计算机管理中普遍出现的一些问题，介绍了一种以“定时开机设置＋定点访问控制＋定时关机设置＋智能还原卡保护”相组合，实现查询机无人管理的方法。     

日历时种程序

童介绍利用单板机CTC通道实现电子时钟控制的硬件原理，软件编制和程序的使用。     

Timing issues in distributed testing

The objective of conformance testing is to determine whether an implementation under test (IUT) conforms to its specification. In distributed test architecture where there are multiple remote testers, the objective can be complicated by the fact that testers may encounter controllability and observability problems during the application of a test sequence. A certain amount of work has been done in the area of generating test sequence that is free from these problems. However, few researchers investigate them from the aspect of test execution. This work studies the test execution phase when test sequences are applied to the imple- mentation and it is pointed out that controllability and observability problems can be resolved if and only if the test system im- plements some timing constraints. When determining these constraints, the dynamic time information during test is taken into account, which reduces the test execution time and improves test efficiency further.     

电力系统短路实验控制系统的设计

介绍了一种适用于电力系统短路实验的实时数据采集和控制的系统。首先介绍了电力系统模型、控制系统的功能和整体设计，然后具体阐述了如何实现合闸角的准确控制以及如何实现定时输出。     

胸腔中的"定时炸弹"

一位年轻妇女差点死于动脉瘤破裂，笔者和这名妇女的丈夫由此开始找寻拯救其他患者于同样灾难的途径。     

用“定时定距法”发展学生耐力

定时定距法是体育教师根据学生情况,科学合理地规定跑的时间、跑的距离来发展学生耐力的一种方法。定时定距法包括:(1)集体定时不定距法,即教师对跑的总时间作出规定,如五分钟、八分钟、十二分钟等,而对学生跑速的快慢、跑程的长短不作具体限制和要求,让学生根据自己的水平,跑完老师规定的练习时间。这个练习可以安排在训练初,这时学生的身体还未达到     

80C51单片机定时误差的分析

随着80C51单片机在工业上的广泛应用,对定时精度的要求越来越高。但是由于指令周期考虑不全和硬件自身的原因易引起定时误差。从软硬件方面分析了误差原因,并针对误差不确定性的特点从指令执行周期、计数器初值、计数器当前值、适时开关中断四个方面给出了纠正方法。     

Incremental min-period retiming algorithm for FPGA synthesis based on influence of fan-outs

An improved linear-time retiming algorithm is proposed to incrementally optimize the clock period,especially considering the influence of the in-out degree of the critical combinational elements.Firstly,the critical elements are selected from all the critical combinational elements to retime.Secondly,for the nodes that cannot be performed with such retiming,register sharing is implemented while the path delay is kept unchanged.The incremental algorithm can be applied with the technology mapping to minimize the critical path delay and obtain fewer registers in the retimed circuit with the near-optimal clock period.Compared with Singh’s incremental algorithm,experiments show that the proposed algorithm can reduce the flip-flop count by 11% and look-up table(LUT) count by 5% while improving the minimum clock period by 6%.The runtime is also reduced by 9% of the design flow.     

ZL—1型智能定时打铃系统的设计

本文阐述了ＺＬ－１型智能定时打铃系统的工作原理，并讨论了有关智能化程序的设计方法。该系统以８０Ｃ３１单片机为核心部件，以双向可控硅作为输出控制元件，系统内部即时时钟通过查表实现各种定时控制。