基于分区法的2-RGV调度问题的模型和算法

以某救灾物资自动化立体仓库为背景,研究了出库过程中的2-RGV调度问题.为避免运行于直线轨道上的两辆穿梭车发生碰撞,将存取系统划分为不重叠的两个区域,并将两个区域内的运送分别分配给两辆穿梭车.建立了基于区域划分的2-RGV调度问题的混合整数线性规划模型,目标是最小化所有物料的总出库时间.提出了一个混合遗传算法求解该问题,并采用包含穿梭车顺序、穿梭车分配及出库站分配的染色体编码方式.算例试验显示提出的模型和算法能够有效求解该问题.     

电路二等分问题的强化半定规划松弛

将表示电路的超图转化成带权值的无向图，从而将电路二等分问题转化成图的划分问题，图的划分问题存在已知的半定规划松弛，在此半定规划松弛基础上增加两个非线性结束，得到了强化半定规划松弛，定理和数值试验保证了强化半定规划松弛给出原问题一个更好的下界。     

完全图的剖分图的线图的谱

如果一个图G的邻接矩阵A(G)的特征多项式的所有特征值全为整数,则称图G是整的.设图L2(Kp):L(s(Kp))是完全图Kp的剖分图S(Kp)的线图.在这篇文章里,我们利用图的理论给出了S(Kp)和L2(Kp)的特征多项式及其谱.对于图L2(Kp),得到了其补图、线图、线图的补图及补图的线图的特征多项式.也证明了这些图都是整图.这些整图的发现是对整图的研究的一个新贡献.     

Graph contractability problem for VLSI layer assignment

Abstract

The layer assignment problem for VLSI routing is the problem of determining which layers can be used for routing the wire segments in the interconnections of nets so that the number of vias is minimized. In this paper, we transform the problem of layer assignment for three‐layer routing to the contractability problem of 3‐colorable graph. This problem is shown to be NP‐complete and a heuristic algorithm is proposed on the basis of the graph contractability model. From our experimental results, the algorithm is faster and efficient to generate very good results. In the average, the number of vias can be reduced by 30 percent or so.     

基于图论和拓扑的三相电力系统故障中的Z回路构造

本文研究了如何利用图论和拓扑构造Z回路矩阵,以便分析带有故障的三相电力系统.可靠的电力供应增长需求促进了人们使用计算机进行电力系统分析.电力系统分析对于故障分析,特别是电力系统的保护和控制起着非常重要的作用.应用图论原理构造的不产生回路关联矩阵的Z回路,优于网络分析和电路设计中使用的其它方法.本文通过某些拓扑关系、线形...     

条形图和圆环图数据占比映射的比较研究

目的 研究在观察时间受限制的条件下,条形图和圆环图在映射数据占总体比值关系时的优势。方法 实验设计了3种尺寸（占屏幕7.5%,15%,22%）和3种映射取值（1,1/2,1/3）的条形图和圆环图,被测对象对图形映射的数据占比进行判断,以获得2种形态的判断时间均值和错误率均值。实验使用计算机化实验生成系统E-prime收集数据,使用SPSS进行数据统计和分析。结果 映射取值为1、1/2、1/3条件下,条形图的3种尺寸判断时间均值均低于圆环图;条形图判断错误率均值为2.51%,低于圆环图的错误率4.03%;2种图的映射取值越小,判断的速度越慢。结论 条形图的映射判断速度和准确性比圆环图更具有优势,更适合应用于时空受限制的场景,有助于数据可视化设计时减少因数据堆集而导致的信息过载。     

动静圆柱坐标系下Navier-Stokes方程的分区算法

通过耦合相对和绝对圆柱坐标系下的三维Navier-Stokes方程,本文采用高精度高分辨率的三阶ENN格式及LU-SGS隐式解法进行子域求解;提出了动静子域干涉面的重合处理与重叠处理,并最终发展了一种新的分区算法。通过对某带进口导叶的三级轴流压气机的数值实验,验证了该分区算法的有效性,计算结果与实验数据吻合较好。     

Mathematical programming model for centralised master planning in ceramic tile supply chains

The object of this article is to develop a centralised replenishment, production, and distribution model for ceramic tile supply chains. These supply chains are assumed to be multi-item, multi-supplier, multi-facility, multi-type and multi-level distribution centres. The model deals with multi-period master planning where sourcing considerations for replenishments, production facilities, and distribution centres are important to maximise an objective function involving the total net profit. This model is deterministic and has been formulated as a mixed-integer linear programming (MILP) model. An example based on modifications of real-world industrial problems is presented.     

Graph theoretic algorithm for automatic operation sequencing for progressive die design

The paper presents a formal graph representation scheme for stamping operation sequencing for sheetmetal progressive dies and a graph theoretic method for automatic determination of the stamping operation sequence. Operation relations are represented by two graphs: an operation precedence graph and an adjacency graph. The first represents precedence constraints defined by best manufacturing practices. The second represents geometric infeasibility relations between operations. Each operation is a member of both graphs. The graphs are automatically generated from a set of stamping operations, which in turn are associated with stamping features of a part. The operation precedence graph is then verified to be acyclic using a coloured Depth First Search. Based on the operation precedence graph, a modified topological sort algorithm is applied to cluster the operations into partially ordered sets. Finally, a graph-colouring algorithm is applied to the operation adjacency graph on the partially ordered operation sets. The algorithm is implemented in C++ and is fully integrated with SolidWorks computer-aided design system. A case study is presented to illustrate the algorithm.     

基于SLIC超像素分割的图分割算法

图像分割是对图像进行分析和理解的关键步骤,是计算机视觉的基本技术之一.计算复杂度是评判一个图像分割算法好坏的重要标准,因此降低算法的计算复杂度是当前图像分割领域的主要任务之一.本文提出了一种基于SLIC超像素分割的图像分割方法.该方法利用SLIC算法生成超像素,通过构造相应的相似性矩阵,有效降低了Ncut分割算法的计算复杂度,大幅度缩短了Ncut算法的运行时间.由于SLIC超像素分割算法的准确性与高效性,在进行三类自然图像分割实验时,本文提出的方法无论在分割效果,还是在运行时间上,都要明显优于Ncut分割方法及它的改良算法.     

Topological Characterization of Book Graph and Stacked Book Graph

Degree based topological indices are being widely used in computer-aided modeling, structural activity relations, and drug designing to predict the underlying topological properties of networks and graphs. In this work, we compute the certain important degree based topological indices like Randic index, sum connectivity index, ABC index, ABC₄ index, GA index and GA₅ index of Book graph B_n and Stacked book graph B_m,n. The results are analyzed by using edge partition, and the general formulas are derived for the above-mentioned families of graphs.     

Expanding Hot Code Path for Data Cleaning on Software Graph

Graph analysis can be done at scale by using Spark GraphX which loading data into memory and running graph analysis in parallel. In this way, we should take data out of graph databases and put it into memory. Considering the limitation of memory size, the premise of accelerating graph analytical process reduces the graph data to a suitable sizewithout too much loss of similarity to the original graph. This paper presents our method of data cleaning on the software graph. We use SEQUITUR data compression algorithm to find out hot code path and store it as a whole paths directed acyclic graph. Hot code path is inherent regularity of a program. About 10 to 200 hot code path account for 40%-99% of a program’s execution cost. These hot paths are acyclic contribute more than 0.1%-1.0% of some execution metric. We expand hot code path to a suitable size which is good for runtime and keeps similarity to the original graph.     

Multi-Head Attention Graph Network for Few Shot Learning

The majority of existing graph-network-based few-shot models focus on a node-similarity update mode. The lack of adequate information intensifies the risk of overtraining. In this paper, we propose a novel Multi-head Attention Graph Network to excavate discriminative relation and fulfill effective information propagation. For edge update, the node-level attention is used to evaluate the similarities between the two nodes and the distribution-level attention extracts more in-deep global relation. The cooperation between those two parts provides a discriminative and comprehensive expression for edge feature. For node update, we embrace the label-level attention to soften the noise of irrelevant nodes and optimize the update direction. Our proposed model is verified through extensive experiments on two few-shot benchmark MiniImageNet and CIFAR-FS dataset. The results suggest that our method has a strong capability of noise immunity and quick convergence. The classification accuracy outperforms most state-of-the-art approaches.     

基金投资收益的数学模型

本文将基金投资的收益问题最终归结为线性规划问题求解 .鉴于国库券发行的随机性 ,本文分别推导了应用确定型数学模型和概率均值的方法求出了近似公式 ,从而简化了问题的求解 .文章还对误差进行了估计 ,最后 ,根据银行确定利率的原则 ,改进为一个更简单的模型 ,经检验是可行的     

乳化炸药配方设计的数学方法

文中建立了乳化炸药配方设计的数学模型，利用数学方法讨论了氧平衡以及不同含量的硝酸铵、硝酸钠、水和乳化剂对乳化炸药爆热的影响。计算得到了乳化炸药的几个较佳理论配方。进行爆炸性能测定后，发现理论配方的乳化炸药与现有生产配方相比，具有较大的作功能力。     

IFS行扫描分块压缩编码

基于分块自动分形压缩PIFS理论，提出了一种新的行扫描双门限自适应多级分块压缩方法。与普通近距分块压缩方法相比，在基本保证解码质量(PSNR)的前提下，编码时间大幅降低，又压缩比有一定的提高；对于较细致的图像，在压缩比基本不变的情况下能保持较高的解码质量。在此基础上，又提出了一种新的行扫描H－V多级分块方法，与双门限自适应多级分块方法相比，压缩比有一定的提高，而解码质量略有下降。     

Partitioning computations and parallel processing

Local Area Networks (lans) provide for file transfers, electronic mail and for access to shared devices such as printers, tape drives and large disks. Butlan do not usually provide for pooling the power of their computer workstations to work concurrently on programs demanding large amounts of computing power. This paper discusses the issues involved in partitioning a few selected classes of problems of general interest for concurrent execution over alan of workstations. It also presents the conceptual framework for supervisory software, a Distributed Computing Executive, which can accomplish this, to implement a ‘Computing Network’ namedcone. The classes of problems discussed include the following: problems dealing with the physics of continua, optimization as well as artificial intelligence problems involving tree and graph searches and transaction processing problems. This work was funded by the Knowledge-based Computer Systems Project of the Department of Electronics, Government of India.     

Mathematical models and a hunting search algorithm for the no-wait flowshop scheduling with parallel machines

Majority of researches in no-wait flowshop scheduling assume that there is only one machine at each stage. But, factories commonly duplicate machines in parallel for each operation. In this case, they balance the speed of the stages, increase the throughput of the shop floor and reduce the impact of bottleneck stages. Despite their importance, there is no paper to study the general no-wait flowshop with parallel machines. This paper studies this problem where the objective is to minimise makespan. Since there is no mathematical model for the problem, we first mathematically formulate it in form of two mixed integer linear programming models. By the models, the small instances are optimally solved. We then propose a novel hunting search metaheuristic algorithm (HSA) to solve large instances of the problem. HSA is derived based on a model of group hunting of animals when searching for food. A set of experimental instances are carried out to evaluate the algorithm. The algorithm is carefully evaluated for its performance against an available algorithm by means of statistical tools. The related results show that the proposed HSA provides sound performance comparing with other algorithms.     

A Practical Approach to Constructing a Knowledge Graph for Cybersecurity

Cyberattack forms are complex and varied, and the detection and prediction of dynamic types of attack are always challenging tasks. Research on knowledge graphs is becoming increasingly mature in many fields. At present, it is very significant that certain scholars have combined the concept of the knowledge graph with cybersecurity in order to construct a cybersecurity knowledge base. This paper presents a cybersecurity knowledge base and deduction rules based on a quintuple model. Using machine learning, we extract entities and build ontology to obtain a cybersecurity knowledge base. New rules are then deduced by calculating formulas and using the path-ranking algorithm. The Stanford named entity recognizer (NER) is also used to train an extractor to extract useful information. Experimental results show that the Stanford NER provides many features and the useGazettes parameter may be used to train a recognizer in the cybersecurity domain in preparation for future work.