Independence Polynomials and the Merrifield-Simmons Index of Mono-Layer Cylindrical Grid Graphs

Research on the independence polynomial of graphs has been very active.However,the computational complexity of determining independence polynomials for general graphs remains NP-hard.Letα(G)be the independence number of G and i(G;k)be the number of independent sets of order k in G,then the independence polynomial is defined as I(G;x)=∑_(k=0)^(α(G))i(G;k)x^(k),i(G;0)=1.In this paper,by utilizing the transfer matrix,we obtain an analytical expression for I(CGn;x)of mono-cylindrical grid graphs CGn and present a crucial proof of it.Moreover,we also explore the Merrifield-Simmons index and other properties of CGn.

On Signed Domination of Grid Graph

Let G(V, E) be a finite connected simple graph with vertex set V(G). A function is a signed dominating function f : V(G)→{−1,1} if for every vertex v ∈ V(G), the sum of closed neighborhood weights of v is greater or equal to 1. The signed domination number γs(G) of G is the minimum weight of a signed dominating function on G. In this paper, we calculate the signed domination numbers of the Cartesian product of two paths Pm and Pn for m = 6, 7 and arbitrary n.

Accurate querying of frequent subgraphs in power grid graph data

With the development of information technology, the amount of power grid topology data has gradually increased. Therefore, accurate querying of this data has become particularly important. Several researchers have chosen different indexing methods in the filtering stage to obtain more optimized query results because currently there is no uniform and efficient indexing mechanism that achieves good query results. In the traditional algorithm, the hash table for index storage is prone to "collision" problems, which decrease the index construction efficiency. Aiming at the problem of quick index entry, based on the construction of frequent subgraph indexes, a method of serialized storage optimization based on multiple hash tables is proposed. This method mainly uses the exploration sequence to make the keywords evenly distributed; it avoids conflicts of the stored procedure and performs a quick search of the index. The proposed algorithm mainly adopts the "filterverify" mechanism; in the filtering stage, the index is first established offline, and then the frequent subgraphs are found using the "contains logic" rule to obtain the candidate set. Experimental results show that this method can reduce the time and scale of candidate set generation and improve query efficiency.

Bounds on Fractional Domination of Some Products of Graphs

Let γ f(G) and γ~t f(G) be the fractional domination number and fractional total domination number of a graph G respectively. Hare and Stewart gave some exact fractional domination number of P n×P m (grid graph) with small n and m . But for large n and m , it is difficult to decide the exact fractional domination number. Motivated by this, nearly sharp upper and lower bounds are given to the fractional domination number of grid graphs. Furthermore, upper and lower bounds on the fractional total domination number of strong direct product of graphs are given.

Geodetic Number and Geo-Chromatic Number of 2-Cartesian Product of Some Graphs

A set S ⊆ V (G) is called a geodetic set if every vertex of G lies on a shortest u-v path for some u, v ∈ S, the minimum cardinality among all geodetic sets is called geodetic number and is denoted by . A set C ⊆ V (G) is called a chromatic set if C contains all vertices of different colors in G, the minimum cardinality among all chromatic sets is called the chromatic number and is denoted by . A geo-chromatic set Sc ⊆ V (G) is both a geodetic set and a chromatic set. The geo-chromatic number of G is the minimum cardinality among all geo-chromatic sets of G. In this paper, we determine the geodetic number and the geo-chromatic number of 2-cartesian product of some standard graphs like complete graphs, cycles and paths.

On (t, r) Broadcast Domination of Directed Graphs

A dominating set of a graph G is a set of vertices that contains at least one endpoint of every edge on the graph. The domination number of G is the order of a minimum dominating set of G. The (t, r) broadcast domination is a generalization of domination in which a set of broadcasting vertices emits signals of strength t that decrease by 1 as they traverse each edge, and we require that every vertex in the graph receives a cumulative signal of at least r from its set of broadcasting neighbors. In this paper, we extend the study of (t, r) broadcast domination to directed graphs. Our main result explores the interval of values obtained by considering the directed (t, r) broadcast domination numbers of all orientations of a graph G. In particular, we prove that in the cases r = 1 and (t, r) = (2, 2), for every integer value in this interval, there exists an orientation of G which has directed (t, r) broadcast domination number equal to that value. We also investigate directed (t, r) broadcast domination on the finite grid graph, the star graph, the infinite grid graph, and the infinite triangular lattice graph. We conclude with some directions for future study.

基于图形的入侵检测系统(GrIDS)

本文提出一种基于网络活动行为图的入侵检测模型(GrIDS)。GrIDS模型采用分层的体系结构,收集被监控的计算机的活动数据以及网络流量数据,并将此信息集合为网络活动的行为图,以表征因果结构的网络活动,从而几乎实时地检测大规模的自动或协同攻击。

基于RedisGraph的电网CIM/XML数据模型构建与应用

电网拓扑分析在电力系统运行规划中应用广泛。现有研究中,电网拓扑信息多以关系型数据库或图数据库的方式存储于磁盘,在查询速度上受限于数据库本身的特性。为了提高电网拓扑信息的查询速度,文章提出了一种基于内存型图数据库RedisGraph的电网拓扑模型构建与查询方法。首先概述了CIM/XML文件的数据结构和RedisGraph存储数据的方式,然后据此设计了将CIM/XML数据模型转换为电网拓扑图数据模型的方案,并实现了基于RedisGraph的拓扑搜索,最后基于构建的图数据模型进行拓扑搜索测试。结果表明,提出的基于RedisGraph的电网拓扑构建与查询方案能更好地满足大规模复杂电网的拓扑分析业务的性能需求。

智能电网中基于二分图匹配的网络切片资源分配算法

为了解决智能电网中多类业务的服务质量需求难以同时得到满足的问题并兼顾电力终端和网络侧经济效用,提出了一种基于二分图匹配的网络切片资源分配算法。针对智能电网场景中的控制类和采集类业务,为电力终端分别制定相应的投标信息,并据此计算支付价格和效用矩阵;将网络切片与电力终端之间的资源分配建模为二分图匹配问题,根据不同业务的时延、传输速率或能耗需求,向终端分配不同的切片资源以最大化系统效用。仿真结果表明,相较于已有的双向拍卖算法和贪心算法,所提算法能够提高10%~20%的系统效用。

The Independence-Separation Problem on the 3-D Rook’s Graph

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.

基于GATv2模型的虚假数据注入攻击检测方法

虚假数据注入攻击(False data injection attack,FDIA)能够躲避传统不良数据检测器,给智能电网的稳定运行带来了挑战。因此,提出了一种基于改进图注意力网络(Graph attention network v2,GATv2)模型的FDIA检测方法。首先,基于电力系统结构和FDIA的特性,构建模型所需数据集;然后,根据电力系统的拓扑信息和运行信息建立图数据;设计基于GATv2的检测模型对电网图数据的空间特征进行提取,进而检测注入的虚假数据攻击;最后,在IEEE 14节点和IEEE 118节点系统上验证了GATv2模型的有效性,且仿真结果表明GATv2模型检测性能优于其他模型,检测准确率达到98%以上,在不同攻击节点数和不同攻击强度情况中都具有较好的鲁棒性。

基于本体和知识图谱的城市空间数字底座架构及应用

为支撑城市数字化转型,解决目前智慧城市数据不能满足多领域兼容覆盖的需要、数据孤岛等问题,本文提出融合城市动静态多源数据、城市数据运算方案和数据组织管理方案的城市空间数字底座的概念,进而提出一种依托本体框架的城市空间数字底座架构,以多源多模知识图谱为核心来管理城市治理的数据模块、数据运算模块、数据可视化模块和城市服务模块,使得所有数据和事件、行为都在同一框架与协议下运作。本架构有三个特点:①依托本体框架,构建语义解释器覆盖领域全要素,保证数据结构完整和质量可靠;②数据与业务脱钩,原始数据从具体事物中抽象出来,重构为知识单元,适度脱敏推动数据融合;③空间运算升级为知识运算,利用知识图谱通过知识推理、知识发现等来优化传统计算,拓展服务边界及节省运算资源。通过知识图谱的管理架构,可以保证城市空间数字底座的数据质量可靠性、完整性、可解释性和共享性,确保了空间数字底座对城市空间信息服务的支撑能力。

面向语法加权图文本的方面情感三元组抽取

方面情感三元组抽取包括方面抽取、意见抽取和方面情感分类3项任务,以管道方式解决该任务的研究方法无法利用元素之间的交互信息,同时也会造成错误传播和冗余训练。基于此,提出一种基于门控注意力和加权图文本的方面情感三元组抽取方法。采用双向长短时记忆网络学习句子的序列特征表示;利用门控注意力单元学习单词之间的线性联系;利用语法距离加权图卷积网络增强三元组元素之间的交互;利用网格标记推理策略预测三元组。在4个公开数据集上进行实验,结果表明:所提方法可以有效增强三元组元素之间的交互,提高三元组抽取的准确率;同时,所提方法的F1值分别为57.94%、70.54%、61.95%和67.66%,与基准模型相比均有所提高。

抑制不同运行方式下故障电流的直流电网网架结构优化方法

直流电网故障电流水平决定了限流装置成本以及换流元件寿命,而通过网架结构优化可有效降低故障电流水平。然而,现有的网架结构故障电流水平评价指标存在一定误差,且不能反映不同运行方式下的综合故障电流水平。因此,提出一种抑制不同运行方式下故障电流的直流电网网架结构优化方法。首先给出直流电网短路故障电流的计算方法;然后提出基于图论的网架结构通用表示方法,在此基础上提出正常运行方式及N–1运行方式下的故障电流水平综合评价指标;最后提出一种以抑制不同运行方式下故障电流的直流电网网架结构优化方法,并通过PSCAD/EMTDC软件在六端直流电网中验证了所提方法的有效性。

信息驱动的大电网运行态势知识图谱框架及构建模式研究

基于大电网海量、高维的各类实时测量及仿真模拟信息,依托大数据、人工智能、知识图谱等先进信息技术,深度挖掘和表征电网运行态势知识并直观形象展示,是建设大电网在线智能主动安全防御体系的核心。首先,在智能全景系统思想体系下,采用“物理系统+信息系统+知识图谱”融合机制,综合考虑电网不同运行场景的稳定状态评估指标和优化控制策略信息,给出电网运行态势知识图谱的基本概念及内涵,并详细介绍其核心要素及构建目标。然后,依托智能电网调度时空大数据支撑平台,设计电网运行态势知识图谱软件功能架构,包含多源信息融合、时空大数据平台、态势图谱引擎、知识关联推理、图谱业务应用和友好人机交互等6个层次模块。在此基础上,给出自顶向下的电网运行态势知识图谱构建模式,并系统性介绍逻辑架构、技术架构、知识建模、知识抽取、知识融合、知识加工、知识更新、图结构存储、可视化引擎等构建技术。最后,研发大电网运行态势知识图谱智能构建及可视化系统,并在某省级电网开展测试应用,为实现信息驱动的大电网智能全景主动安全防御提供技术支撑。

基于知识图谱技术的电网项目数据关联分析

为解决电网项目数据关联难度大的问题,提出了基于知识图谱技术的电网项目数据关联分析。分析了历史项目特征提取和新增储备项目特征提取方法,论述了基于规则的信息抽取和基于序列标注的信息提取方法,以及电力项目知识图谱的基本构成和构建方法,提出了项目多维关联分析平台,论述了分析方法和分析流程,并提出了系统网络结构,结合实际应用说明了所提系统的应用效果。

基于图表映射融合技术的大电网运行业务平台化人机交互设计

为更好满足大电网运行业务中高效感知电网状态的需求,开展了软件前后端数据组织和接口设计方面的研究。在融合海量人机交互技术关键要素的基础上,提出一种大电网分析模型图模一体化与多关系表数据映射与融合的平台化技术方案,并通过2669个厂站大电网案例验证方法的有效性。结果表明,所提方法在实现诸多功能需求基础上具备较高的模型检索效率与优秀的前端渲染性能,可为大电网运行业务人机交互设计提供参考。

结合句法结构和语义信息的方面情感三元组抽取

为解决先前方面情感三元组抽取方法中忽略句法结构和语义信息的问题,提出一种结合句法结构和语义信息的抽取模型。使用BERT预训练模型编码输入语句,同时编码句法结构特征。通过注意力层学习词对间的语义信息。将句法结构特征和语义信息输入图卷积网络,增强对单词间句法结构的学习。通过网格解码生成情感三元组。在lap14、res14、res15、res16数据集上的实验结果表明,该模型在精确率、召回率和F1值上相较其它基线模型有显著提升,有效提升方面情感三元组抽取效果。

基于逻辑知识图谱的电网信息快速检索方法

旨在探索基于逻辑知识图谱的电网信息快速检索方法,以解决电网领域庞大而复杂的数据管理和检索挑战。通过构建逻辑图谱,将电网实体以节点形式呈现,并通过逻辑关系揭示它们之间的依赖和联系,从而为电网信息管理提供了一种智能、准确、实时的解决方案,有望推动电网系统的智能化和可持续发展,期望能够为相关人员提供参考。

基于图数据库的中压配电网网格搜索引擎系统

为了缩短中压配电网网格搜索引擎系统平均响应时长,提升系统搜索召回率,设计一种基于图数据库的中压配电网网格搜索引擎系统。通过搜索器和接口设计系统硬件部分;系统软件部分包括中压配电网网格采集模块、图数据库存储模块和电网网格搜索引擎模块,通过中压配电网网格采集模块采集配电网中设备信息,采用广度优先遍历算法,逐个确认各设备的通电状态,利用图数据模型,通过图数据库存储模块对采集到的设备信息进行规范化处理,创建索引模块,利用关系数据库系统建立中介数据电子目录,根据电子数据目录逐个生成集合对象,根据集合对象创建数据文件,利用图文索引功能,通过索引模块对中压配电网的设备信息进行搜索,根据系统硬件和软件两部分设计完成基于图数据库的中压配电网网格搜索引擎系统设计。经实验证明,该系统的平均响应耗时短及用户满意度高,鲁棒性强。