共查询到19条相似文献,搜索用时 93 毫秒
1.
卡诺图法化简多变量逻辑函数的探讨 总被引:3,自引:0,他引:3
一般教材中都认为多变量的逻辑函数用卡诺图法化简比较麻烦,所以不采用该方法,而一些教材和资料所介绍的循环码的书写方法都比较麻烦,很容易出错。实际上,有时用卡诺图法化简还是比较方便的。文中提出了书写循环码的一种简单、快速、不容易出错的方法,指出了用卡诺图法化简多变量逻辑函数与少变量逻辑函数之间的差异,总结了多变量卡诺图最小项的合并规则,并用该方法对多变量逻辑函数进行了化简分析。 相似文献
2.
3.
雷海亮 《电气电子教学学报》1995,(4)
平面网路含有多线圈耦合时,列写回路方程或网孔方程比列写节点方程进行网络分析要简单一些,但是对稍为复杂的网络列写网孔方程时,初学电路的同学往往容易漏项。本文的目的是介绍一种系统的方法,根据这种方法就可以一步一步地列写互感电路的网孔方程。此方法系统、条理、步骤清晰,不易出错漏项,是直接列写复杂互感电路网孔方法的有效方法,还可很容易地推广引用计算机建立网孔方程 相似文献
4.
5.
6.
基于探索MSI可编程同步二进制加法计数器74LS161改变应用方向进行功能扩展的目的,采用逻辑修改的方法给出了在二进制计数的基础上实现循环码计数的设计方法,即以74LS161已有的状态输出Q3Q2Q1Q0为变量定义循环码计数器的状态输出量Q3′Q2′Q1′Q0′进行改变计数规律的设计。给出了在函数卡诺图上进行输出函数最小化求解设计方法。从现成的函数出发,实现待求函数可扩展专用集成电路的应用范围并简化循环码计数的设计过程。所述方法给出了MSI可编程计数器改变应用方向的逻辑修改方法。 相似文献
7.
重叠视野域内多摄像机目标交换算法 总被引:2,自引:0,他引:2
多摄像机之间重叠视野区域内目标交接问题是实现多摄像机监控系统持续目标跟踪的关键,传统方法是在摄像机重叠视野区域内采用特征匹配方法或基于视野分界线的目标交接算法。但是特征匹配计算量较大,受摄像机参数设置因素影响较大,实用性不高。而基于视野分界线的目标交接算法由于新目标的检测存在延时,仅利用该方法来实现一致性标号容易出错。近年来,出现了利用投影不变量,计算目标在相邻摄像机中的投影位置来进行目标交接的方法,取得较好效果。但在多个目标相距较近的情况下,投影过程中产生的误差会造成目标对应错误。文中提出一种投影不变量 相似文献
8.
单板机作为写片的廉价设备,在写片量不大的情况下,使用简便.但是,在写片量大的正常批量生产中,就感到写片太慢,无法适应大批量生产的要求.单板机的操作方法要求插拔片子必须在断开电源的情况下进行,而断电后RAM存贮器中的信息就失去了,上电后必须重新调入.因此,手续很繁琐,写片多了往往还会出错.一旦出错,就得擦除、重写,花费更多的时间.片子的插拔也不是一件容易事,需要事先成型后才能顺利地插入插座内.拔出时,必须小心才不致于弄弯管脚,否则将花费更多的时间.以TP-801 相似文献
9.
Tadao Kasami提出了一种循环码的覆盖多项式译码法,该方法实现简单,速度也较快。但是,该方法的关键是寻求循环码的一个覆盖多项式集合。给定一个循环码,求取它的覆盖多项式集合目前尚无系统的方法。本文首先对循环码进行了分类,而后对Ⅱ-型循环码覆盖多项式的个数给出了一个上界,并且给出了一种具体求取Ⅱ-型循环码的覆盖多项式集合的一种方法。 相似文献
10.
时序逻辑电路设计是《数字电子技术》课程中一个难度大、综合性高的部分,它综合了组合逻辑电路和时序逻辑电路的内容。在进行状态机设计时,随着输入逻辑变量的增加,状态数目将呈指数倍急剧增加,这会使整个设计变得复杂且容易出错。以一个延时开关控制器的设计为例,提出了一种状态机输入变量简化的方法,降低了设计过程的复杂程度。 相似文献
11.
在嵌入式系统的应用中,程序代码中存在着相当多的局部变量,这些局部变量的使用范围(生存期)通常都很小.相关指令在流水中需要局部变量的值可以直接从旁路逻辑中得到,并在流水中完成局部变量值的全部使用.对这种局部变量就没有必要将流水输出结果写回寄存器文件,以减少对寄存器文件(RF)的读写操作次数,从而降低对寄存器文件端口的读写要求.决定是否将结果写回寄存器文件的关键的是要确定寄存器的生存期以及流水中旁路逻辑的情况,本文根据所设计的媒体处理器提出了一种确定程序代码中寄存器生存期的算法,并通过指令编码实现对硬件结构的使能控制,即对流水输出结果写回寄存器文件的控制.软件仿真结果表明,对DSP中不同的应用程序平均可以减少94%的寄存器文件写次数. 相似文献
12.
It is shown that there exists a class of error correcting codes which can be viewed both as binary cyclic codes and as multilevel cyclic codes. This class contains not only the Burton codes but also some Reed Solomon codes. The conditions which codes of this class must satisfy are explained and some simple examples are given 相似文献
13.
Optimal binary cyclic redundancy-check codes with 16 parity bits (CRC-16 codes) are presented and compared to those in existing standards for minimum-distance, undetected-error probability on binary symmetric channels (BSCs) and properness. The codes in several cases are seen to be superior at block lengths of practical interest when they are used on low-noise BSCs. The optimum minimum distance obtainable by some CRC-16 codes is determined for all block lengths. For several typical low-noise BSCs the minimum undetected error probability achievable with some CRC-16 codes is given for all block lengths 相似文献
14.
Is the class of cyclic codes asymptotically good? 总被引:1,自引:0,他引:1
Martinez-Perez C. Willems W. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2006,52(2):696-700
There is the long-standing question whether the class of cyclic codes is asymptotically good. By an old result of Lin and Weldon, long Bose-Chaudhuri-Hocquenhem (BCH) codes are asymptotically bad. Berman proved that cyclic codes are asymptotically bad if only finitely many primes are involved in the lengths of the codes. We investigate further classes of cyclic codes which also turn out to be asymptotically bad. Based on reduction arguments we give some evidence that there are asymptotically good sequences of binary cyclic codes in which all lengths are prime numbers provided there is any asymptotically good sequence of binary cyclic codes. 相似文献
15.
16.
《IEEE transactions on information theory / Professional Technical Group on Information Theory》2002,48(7):2069-2078
Using a particular construction of generator matrices of the q-ary image of qm-ary cyclic codes, it is proved that some of these codes are invariant under the action of particular permutation groups. The equivalence of such codes with some two-dimensional (2-D) Abelian codes and cyclic codes is deduced from this property. These permutations are also used in the area of the soft-decision decoding of some expanded Reed-Solomon (RS) codes to improve the performance of generalized minimum-distance decoding 相似文献
17.
Sakata S. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1991,37(4):1200-1203
A method of decoding two-dimensional (2-D) cyclic codes by applying the 2-D Berlekamp-Massey algorithm is proposed. To explain this decoding method, the author introduces a subclass of 2-D cyclic codes, which are called 2-D BCH codes due to their similarity with BCH codes. It is shown that there are some short 2-D cyclic codes with a better cost parameter value. The merit of the approach is verified by showing several simple examples of 2-D cyclic codes 相似文献
18.
19.
van Eupen M. van Lint J.H. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1993,39(2):409-422
There are many ways to find lower bounds for the minimum distance of a cyclic code, based on investigation of the defining set. Some new theorems are derived. These and earlier techniques are applied to find lower bounds for the minimum distance of ternary cyclic codes. Furthermore, the exact minimum distance of ternary cyclic codes of length less than 40 is computed numerically. A table is given containing all ternary cyclic codes of length less than 40 and having a minimum distance exceeding the BCH bound. It seems that almost all lower bounds are equal to the minimum distance. Especially shifting, which is also done by computer, seems to be very powerful. For length 40⩽n ⩽50, only lower bounds are computed. In many cases (derived theoretically), however, these lower bounds are equal to the minimum distance 相似文献