期刊文献+
共找到274篇文章
< 1 2 14 >
每页显示 20 50 100
The Independence-Separation Problem on the 3-D Rook’s Graph
1
作者 Paul A. Burchett 《Open Journal of Discrete Mathematics》 2016年第3期167-173,共7页
Both independence and independence-separation problems on chessboard graphs have been studied in detail, with hundreds of papers in the broader independence category, and several on the independence-separation problem... Both independence and independence-separation problems on chessboard graphs have been studied in detail, with hundreds of papers in the broader independence category, and several on the independence-separation problem variant for chessboard graphs. In this paper, the inde-pendence-separation problem is considered on the d-dimensional rook’s graph. A lower bound of k, for , is found for the independence-separation number on the d-dimensional rook’s graph, denoted by . For the case where , it is found that when n is odd and , . Conjecture and discussion are added. 展开更多
关键词 CHEss Independence-separation Number Independence Number p-Dimensional Grid-Line graphs p-Dimensional rook’s graph
下载PDF
基于S7-1500 GRAPH语言的交通灯控制系统设计
2
作者 仲济艳 《科技视界》 2023年第18期77-80,共4页
文章介绍了一种基于S7-1500 GRAPH语言的交通灯控制系统设计方法。通过对系统需求的分析和功能设计的实现,成功地实现了交通灯控制逻辑程序的设计和实现,并通过调试和测试结果分析,验证了系统的运行效果和稳定性。文章还对S7-1500 GRAP... 文章介绍了一种基于S7-1500 GRAPH语言的交通灯控制系统设计方法。通过对系统需求的分析和功能设计的实现,成功地实现了交通灯控制逻辑程序的设计和实现,并通过调试和测试结果分析,验证了系统的运行效果和稳定性。文章还对S7-1500 GRAPH语言在交通灯控制系统中的应用效果进行了评估,并探讨了进一步改进和优化方案。 展开更多
关键词 s7-1500 graph语言 交通灯控制系统 控制逻辑程序设计
下载PDF
Combining ability and gene action studies for yield and fibre traits in Gossypium arboreum using Griffings numerical and Haymans graphical approach
3
作者 SUKRUTHA Bhimireddy RAJESWARI Sivakami +3 位作者 PREMALATHA N. BOOPATHI Narayana Manikanda THIRUKUMARAN K. MANIVANNAN A. 《Journal of Cotton Research》 CAS 2023年第3期141-156,共16页
Background For the purpose of utilising hybrid vigour to produce possible hybrids with a suitable level of stability,the knowledge of gene activity and combining ability is a crucial prerequisite before choosing desir... Background For the purpose of utilising hybrid vigour to produce possible hybrids with a suitable level of stability,the knowledge of gene activity and combining ability is a crucial prerequisite before choosing desirable parents.The present study was carried out with six parents crossed in full diallel fashion and generated 30 F1 hybrids.These hybrids were evaluated in two replications in Randomized Block Design at Department of Cotton,TNAU for combining ability and gene action.Diallel analysis was carried out according to Griffing’s method-I(parents + F_(1) + reciprocals) and model-I and Hayman’s graphical approach by using INDOSTAT software.Results Analysis of variance for combining ability indicated that mean square values of GCA,SCA and reciprocals were highly significant for all the traits except for the uniformity index.RG763 and K12 showed highly positively significant GCA effects for most of the yield traits while PA838 and K12 for fibre quality traits,so they were found as best general combiners.PAIG379 × K12 and PDB29 × K12 for yield traits,and PDB29 × PA838,RG763 × PA838,and CNA1007 × RG763 cross combinations for fibre quality traits could be recommended for future breeding programms.Conclusion The results of both Griffing’s and Hayman’s approaches showed that non-additive gene action predominates as SCA variance was bigger than GCA variance,so heterosis breeding is thought to be a more fruitful option for enhancing GCA of many traits. 展开更多
关键词 Gene action Combining ability Diallel analysis Hayman’s approach Griffing’s approach Vr-Wr graph Desi cotton
下载PDF
Global Dynamic Modeling of Electro-Hydraulic 3-UPS/S Parallel Stabilized Platform by Bond Graph 被引量:11
4
作者 ZHANG Lijie GUO Fei +1 位作者 LI Yongquan LU Wenjuan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第6期1176-1185,共10页
Dynamic modeling of a parallel manipulator(PM) is an important issue. A complete PM system is actually composed of multiple physical domains. As PMs are widely used in various fields, the importance of modeling the ... Dynamic modeling of a parallel manipulator(PM) is an important issue. A complete PM system is actually composed of multiple physical domains. As PMs are widely used in various fields, the importance of modeling the global dynamic model of the PM system becomes increasingly prominent. Currently there lacks further research in global dynamic modeling. A unified modeling approach for the multi-energy domains PM system is proposed based on bond graph and a global dynamic model of the 3-UPS/S parallel stabilized platform involving mechanical and electrical-hydraulic elements is built. Firstly, the screw bond graph theory is improved based on the screw theory, the modular joint model is modeled and the normalized dynamic model of the mechanism is established. Secondly, combined with the electro-hydraulic servo system model built by traditional bond graph, the global dynamic model of the system is obtained, and then the motion, force and power of any element can be obtained directly. Lastly, the experiments and simulations of the driving forces, pressure and flow are performed, and the results show that, the theoretical calculation results of the driving forces are in accord with the experimental ones, and the pressure and flow of the first limb and the third limb are symmetry with each other. The results are reasonable and verify the correctness and effectiveness of the model and the method. The proposed dynamic modeling method provides a reference for modeling of other multi-energy domains system which contains complex PM. 展开更多
关键词 screw bond graph multi-energy domains 3-UPs/s parallel mechanism electro-hydraulic servo system
下载PDF
The Number of Minimum Roman and Minimum Total Dominating Sets for Some Chessboard Graphs
5
作者 Paul A. Burchett 《Open Journal of Discrete Mathematics》 2020年第1期31-44,共14页
In this paper, both the roman domination number and the number of minimum roman dominating sets are found for any rectangular rook’s graph. In a similar fashion, the roman domination number and the number of minimum ... In this paper, both the roman domination number and the number of minimum roman dominating sets are found for any rectangular rook’s graph. In a similar fashion, the roman domination number and the number of minimum roman dominating sets are found on the square bishop’s graph for odd board sizes. Also found are the number of minimum total dominating sets associated with the light-colored squares when n?&#8801;1(mod12)? (with n>1), and same for the dark-colored squares when n?&#8801;7(mod12) . 展开更多
关键词 TOTAL DOMINATION ROMAN DOMINATION Bishop’s graph rook’s graph Chess
下载PDF
基于PSO-GRNN和D-S证据理论的电网分区故障诊断 被引量:3
6
作者 邹红波 宋璐 +2 位作者 张馨煜 段治丰 宋家乐 《智慧电力》 北大核心 2023年第3期25-30,45,共7页
针对大电网中保护和断路器误动、拒动、信息丢失等不确定的电网故障信息以及现有电网分区方法的不足,提出了基于粒子群优化广义回归神经网络(PSO-GRNN)和D-S证据理论的电网分区故障诊断方法。首先,通过改进图形分割法将大电网划分为相... 针对大电网中保护和断路器误动、拒动、信息丢失等不确定的电网故障信息以及现有电网分区方法的不足,提出了基于粒子群优化广义回归神经网络(PSO-GRNN)和D-S证据理论的电网分区故障诊断方法。首先,通过改进图形分割法将大电网划分为相互重叠的不同区域,降低故障诊断难度。然后在各个区域建立PSOGRNN诊断模块,根据故障警报信息,并行完成各自的故障诊断任务。最后,采用D-S证据理论对相邻区域的重叠区域进行分析,以实现对重叠区域的综合故障诊断。仿真结果表明,该方法能有效识别非重叠区域和重叠区域的故障,容错能力强,诊断准确率高。 展开更多
关键词 电网分区 故障诊断 改进图形分割法 粒子群算法 广义回归神经网络 D-s证据理论
下载PDF
西门子s7 GRAPH在探料系统中的运用
7
作者 徐坤龙 《有色冶金设计与研究》 2015年第3期63-65,共3页
概述了韶关冶炼厂探料系统的应用现状,分析了现用PLC程序的优缺点。为了使得程序更简练,增强易读性,运用西门子s7 GRAPH重新编写了探料程序,并进行了仿真运行。仿真实践证明,采用顺序控制程序编程完全可以实现工艺要求,且更加简练、方便。
关键词 探料系统 顺序功能图 s7 graph 编程
下载PDF
Understanding Alzheimer’s Disease through Graph Theory
8
作者 V. Yegnanarayanan Y. Krithicaa Narayanaa 《Journal of Applied Mathematics and Physics》 2020年第10期2182-2195,共14页
<div style="text-align:justify;"> We know that functional and structural organization is altered in human brain network due to Alzheimer’s disease. In this paper we highlight how Graph Theory techniqu... <div style="text-align:justify;"> We know that functional and structural organization is altered in human brain network due to Alzheimer’s disease. In this paper we highlight how Graph Theory techniques, its structural parameters like connectivity, diameter, vertex centrality, betweenness centrality, clustering coefficient, degree distribution, cluster analysis and graph cores are involved to analyse magnetoencephalography data to explore functional network integrity in Alzheimer’s disease affected patients. We also record that both weighted and unweighted undirected/directed graphs depending on functional connectivity analysis with attention to connectivity of the network and vertex centrality, could model and provide explanation to loss of links, status of the hub in the region of parietal, derailed synchronization in network and centrality loss at the vital left temporal region that is clinically significant were found in cases carrying Alzheimer’s disease. We also notice that graph theory driven measures such as characteristic path length and clustering coefficient could be used to study and report a sudden electroencephalography effect in Alzheimer’s disease through entropy of the cross-sample. We also provide adequate literature survey to demonstrate the latest and advanced graphical tools for both graph layouts and graph visualization to understand the complex brain networks and to unravel the mysteries of Alzheimer’s disease. </div> 展开更多
关键词 graphs Alzheimer’s Disease Brain Networks Centrality Measures
下载PDF
Solving Electrical Circuits via Graph Theory
9
作者 Jan Vrbik 《Applied Mathematics》 2022年第1期77-86,共10页
Solving for currents of an electrical circuit with resistances and batteries has always been the ultimate test of proper understanding of Kirchoff’s rules. Yet, it is hardly ever emphasized that a systematic solution... Solving for currents of an electrical circuit with resistances and batteries has always been the ultimate test of proper understanding of Kirchoff’s rules. Yet, it is hardly ever emphasized that a systematic solution of more complex cases requires good understanding of the relevant part of Graph theory. Even though this is usually not covered by Physics’ curriculum, it may still be of interest to some teachers and their mathematically inclined students, who may want to learn details of the rigorous approach. The purpose of this article is to provide a concise derivation of a linear set of equations leading to a unique solution of the problem at hand. We also present a simple computer program which builds such a solution for circuits of any textbook size. 展开更多
关键词 Kirchoff’s Laws Connected graph Incidence Matrix spanning Tree Fundamental Cycles
下载PDF
A NEW CLASS OF LOCALLY CONVEX SPACES AND THE GENERALIZATION OF KALTON'S CLOSED GRAPH THEOREM
10
作者 丘京辉 《Acta Mathematica Scientia》 SCIE 1985年第4期389-397,共9页
By introducing the notions of L-spaces and L_r-spaces, a complete generalization of Kalton's closed graph theorem is obtained. It points out the class of L_r-spaces is the maximal class of range spaces for the clo... By introducing the notions of L-spaces and L_r-spaces, a complete generalization of Kalton's closed graph theorem is obtained. It points out the class of L_r-spaces is the maximal class of range spaces for the closed graph theorem when the class of domain spaces is the class of Mackey spaces with weakly * sequentially complete dual.Some examples are constructed showing that the class of L_r-spaces is strictly larger than the class of separable B_r-complete spaces.Some properties of L-spaces and L_r-spaces are discussed and the relations between B-complete (resp. B_r-complete) spaces and L-spaces (resp. L_r-spaces) are given. 展开更多
关键词 A NEW CLAss OF LOCALLY CONVEX sPACEs AND THE GENERALIZATION OF KALTON’s CLOsED graph THEOREM
下载PDF
图的多项式与Hosoya指标 被引量:3
11
作者 马海成 李生刚 《东北师大学报(自然科学版)》 CAS CSCD 北大核心 2013年第4期41-44,共4页
设G是一个图,珚G,μ(G,x)和Z(G)分别表示图G的补图,匹配多项式和Hosoya指标,对Z(G)给出了由μ(珚G,x)表示的一个积分公式和一个求和公式;设H是Kn,n+a的一个生成子图,ρ(H,x)和珮H分别表示图H的車多项式和完全二分补图,对Z(H)给出了由ρ(... 设G是一个图,珚G,μ(G,x)和Z(G)分别表示图G的补图,匹配多项式和Hosoya指标,对Z(G)给出了由μ(珚G,x)表示的一个积分公式和一个求和公式;设H是Kn,n+a的一个生成子图,ρ(H,x)和珮H分别表示图H的車多项式和完全二分补图,对Z(H)给出了由ρ(珮H,x)表示的一个积分公式和一个求和公式;最后提出了有关公式化简的两个问题. 展开更多
关键词 匹配多项式 車多项式 HOsOYA指标
下载PDF
测量匹配网络S参数的转换模型 被引量:13
12
作者 窦建华 徐兰天 杨学志 《电子测量与仪器学报》 CSCD 2011年第2期191-197,共7页
给出了复特征阻抗间的S参数转换模型、差模和共模的S参数转换模型。该模型基于亥姆霍兹方程、戴维南定理,采用信号流图的分析方法,完成了任意特征阻抗间的S参数转换以及不同工作模式下的S参数转换。该模型弥补了矢量网络分析仪(VNA)测... 给出了复特征阻抗间的S参数转换模型、差模和共模的S参数转换模型。该模型基于亥姆霍兹方程、戴维南定理,采用信号流图的分析方法,完成了任意特征阻抗间的S参数转换以及不同工作模式下的S参数转换。该模型弥补了矢量网络分析仪(VNA)测量匹配网络S参数的不足。该模型转换的结果与软件仿真的结果进行比较结果表明,S参数的幅度误差小于0.025 dB,相位误差小于0.018°;共模和差模输入阻抗的幅度误差小于0.05 dB,相位误差小于0.35°。 展开更多
关键词 匹配网络 s参数 转换模型 信号流图
下载PDF
S-网的活性分析 被引量:5
13
作者 段华 曾庆田 《小型微型计算机系统》 CSCD 北大核心 2004年第11期1975-1978,共4页
讨论了一类结构简单的 Petri网—S-网的活性问题 ,给出了各类 S-网的活性判定定理并给出了判定算法 .算法主要计算工作是变迁的前序库所集和后继变迁集以及极大强连通子网的判断 ,这三个过程实际上是一个树的搜索过程 ,因此算法易于实现 。
关键词 PETRI网 s-网 s-图 活性
下载PDF
基于混合遗传模拟退火算法的SaaS构件优化放置 被引量:20
14
作者 孟凡超 初佃辉 +1 位作者 李克秋 周学权 《软件学报》 EI CSCD 北大核心 2016年第4期916-932,共17页
目前,对于SaaS优化放置问题的研究都是假定云环境中的虚拟机的种类和数量都是确定的,即,在限定的资源范围内进行优化.然而,在公有云环境下,SaaS提供者所需要的云资源数量是不确定的,其需要根据Iaa S提供者所提供的虚拟机种类以及被部署... 目前,对于SaaS优化放置问题的研究都是假定云环境中的虚拟机的种类和数量都是确定的,即,在限定的资源范围内进行优化.然而,在公有云环境下,SaaS提供者所需要的云资源数量是不确定的,其需要根据Iaa S提供者所提供的虚拟机种类以及被部署的SaaS构件的资源需求来确定.为此,站在SaaS提供者角度,提出一种新的SaaS构件优化放置问题模型,并采用混合遗传模拟退火算法(hybrid genetic and simulated annealing algorithm,简称HGSA)对该问题进行求解.HGSA结合了遗传算法和模拟退火算法的优点,克服了遗传算法收敛速度慢和模拟退火算法容易陷入局部最优的缺点,与单独使用遗传算法和模拟退火算法相比,实验结果表明,HGSA在求解SaaS构件优化放置问题方面具有更高的求解质量.所提出的方法为SaaS服务模式的大规模应用提供了理论与方法的支撑. 展开更多
关键词 软件即服务(saas) saas构件优化放置 虚拟机网络图 混合遗传模拟退火算法
下载PDF
二部图的[r,s,t]-着色 被引量:9
15
作者 龚劬 张新军 《重庆大学学报(自然科学版)》 EI CAS CSCD 北大核心 2007年第12期95-97,共3页
给出了二部图G的[r,s,t]-色数的界及它达到下界时的条件,讨论了星作为特殊二部图的[r,s,t]-色数,得到的结果为若G是二部图,v1,v2∈VΔ,v1v2E(G),u∈V,■u1∈NG(u),使得dG(u1)=1,且s≥2t,r≤t,则r,χs,t(G)=(Δ-1)s+1;若G是二部图,... 给出了二部图G的[r,s,t]-色数的界及它达到下界时的条件,讨论了星作为特殊二部图的[r,s,t]-色数,得到的结果为若G是二部图,v1,v2∈VΔ,v1v2E(G),u∈V,■u1∈NG(u),使得dG(u1)=1,且s≥2t,r≤t,则r,χs,t(G)=(Δ-1)s+1;若G是二部图,且r≥(Δ-1)s+2t,则r,χs,t(G)=r+1;若G是二部图,且(Δ-1)s+t<r≤(Δ-1)s+2t,则r,χs,t(G)≤(Δ-1)s+2t+1;若G是二部图,则rΔ+1≤r,χr,r(G)≤r(Δ+1)+1。 展开更多
关键词 [r s t]-着色 [r s t]-色数 二部图
下载PDF
类S-图的语言性质分析 被引量:16
16
作者 曾庆田 吴哲辉 《计算机科学》 CSCD 北大核心 2002年第5期120-122,共3页
1 引言 Petli网作为系统模拟和分析的工具已得到广泛的应用.Petri网一个变迁序列可理解为一个字符串,字符串集合为一种语言.所有可能发生的变迁序列的集合表征了一个Petri网的运行特征,可用网中可能出现的变迁序列来分析Petri网的性能.H... 1 引言 Petli网作为系统模拟和分析的工具已得到广泛的应用.Petri网一个变迁序列可理解为一个字符串,字符串集合为一种语言.所有可能发生的变迁序列的集合表征了一个Petri网的运行特征,可用网中可能出现的变迁序列来分析Petri网的性能.Hack[1]和Peterson[2]最早从事这方面的研究. 展开更多
关键词 s-图 语言性质分析 图灵机 PETRI网
下载PDF
一种改进的CSGC频谱分配算法 被引量:3
17
作者 滕志军 李可 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2014年第11期119-122,共4页
基于图论着色的频谱分配算法未充分考虑用户实际带宽需求,针对这一问题,本文在原算法基础上提出了一种改进的CSGC频谱分配算法.该算法引入了空闲频谱和用户请求两个时间因子,通过设置用户优先级函数,在进行二次频谱分配时最大限度地满... 基于图论着色的频谱分配算法未充分考虑用户实际带宽需求,针对这一问题,本文在原算法基础上提出了一种改进的CSGC频谱分配算法.该算法引入了空闲频谱和用户请求两个时间因子,通过设置用户优先级函数,在进行二次频谱分配时最大限度地满足用户需求.仿真结果表明,该算法不仅保留了原CSGC算法的性能,而且大幅度提高了频谱利用率. 展开更多
关键词 图论 频谱 分配 用户优先级
下载PDF
基于OWL-S过程模型的Web服务发现方法 被引量:5
18
作者 曾一 胡延强 洪豪 《计算机工程》 CAS CSCD 2012年第17期28-31,共4页
现有Web服务发现方法未考虑过程行为的相关信息,导致所发现的服务不能较好地满足用户需求且查准率较低。针对该问题,提出一种基于OWL-S过程模型的Web服务发现方法。将OWL-S过程模型转化为过程图,根据两过程图的相似度,判断两服务过程的... 现有Web服务发现方法未考虑过程行为的相关信息,导致所发现的服务不能较好地满足用户需求且查准率较低。针对该问题,提出一种基于OWL-S过程模型的Web服务发现方法。将OWL-S过程模型转化为过程图,根据两过程图的相似度,判断两服务过程的匹配程度。实验结果表明,该方法能准确地匹配两服务的过程模型,具有较高的执行效率和较好的匹配效果。 展开更多
关键词 WEB服务 WEB服务本体语言 过程模型 过程图 相似度 过程匹配
下载PDF
关于完全图的Mycielski图的循环色数的若干结果 被引量:4
19
作者 刘红美 聂晓冬 《数学研究》 CSCD 2004年第4期407-416,共10页
给出了任意图 G的多重 Mycielski图 Mm (G)的简单定义方式 ,用不同的方法证明了当完全图 Kn 的阶数 n足够大时 ,Mm(Kn)的循环色数等于其点色数 .特别证明了 ,n =7,8,9时 ,M3 (Kn)的循环色数等于其点色数 ,从而使得“当 n m +2 ,有χc(Mm... 给出了任意图 G的多重 Mycielski图 Mm (G)的简单定义方式 ,用不同的方法证明了当完全图 Kn 的阶数 n足够大时 ,Mm(Kn)的循环色数等于其点色数 .特别证明了 ,n =7,8,9时 ,M3 (Kn)的循环色数等于其点色数 ,从而使得“当 n m +2 ,有χc(Mm(Kn) ) =χ(Mm(Kn) ) =m +n成立”的猜想有了更新的进展 . 展开更多
关键词 循环着色 MYCIELsKI图 循环色数
下载PDF
无向双环网络G(N;±r,±s)的图形仿真算法 被引量:5
20
作者 刘辉 许发信 +1 位作者 方木云 杭婷婷 《计算机工程》 CAS CSCD 北大核心 2011年第6期272-273,276,共3页
传统的L形瓦仿真方法无法直接用于研究无向双环网络。针对上述问题,将直角坐标系引入无向双环网络中,提出一种新的图形仿真算法。利用该算法可以快速仿真出无向双环网络G(N;±r,±s)的图形,同时标注其直径、平均距离及节点的具... 传统的L形瓦仿真方法无法直接用于研究无向双环网络。针对上述问题,将直角坐标系引入无向双环网络中,提出一种新的图形仿真算法。利用该算法可以快速仿真出无向双环网络G(N;±r,±s)的图形,同时标注其直径、平均距离及节点的具体分布。通过研究仿真图形,得出单位步长无向双环网络G(N;±r,±s)直径、平均距离的分布规律。 展开更多
关键词 无向双环网络G(N ±r ±s) 直角坐标系 图形仿真算法 直径 平均距离
下载PDF
上一页 1 2 14 下一页 到第
使用帮助 返回顶部