UOF图表到SVG矢量图转换的研究与实现

为有效解决图表不兼容、难以共享和互操作的问题,分析UOF图表到SVG图形转换的可行性,构建基于XSL的UOF图表到SVG的转换模型.针对图表转换过程中的几个关键问题,提出解决方案;实现UOF二维柱状图、二维条形图、二维和三维饼状图等图表到SVG图形的转换.实验和统计结果表明,转换覆盖了UOF图表的主要功能点,扩展了UOF图表,为用户提供了动态交互功能,且转换结果具有较高的相似度.     

Pattern vectors from algebraic graph theory

Graph structures have proven computationally cumbersome for pattern analysis. The reason for this is that, before graphs can be converted to pattern vectors, correspondences must be established between the nodes of structures which are potentially of different size. To overcome this problem, in this paper, we turn to the spectral decomposition of the Laplacian matrix. We show how the elements of the spectral matrix for the Laplacian can be used to construct symmetric polynomials that are permutation invariants. The coefficients of these polynomials can be used as graph features which can be encoded in a vectorial manner. We extend this representation to graphs in which there are unary attributes on the nodes and binary attributes on the edges by using the spectral decomposition of a Hermitian property matrix that can be viewed as a complex analogue of the Laplacian. To embed the graphs in a pattern space, we explore whether the vectors of invariants can be embedded in a low-dimensional space using a number of alternative strategies, including principal components analysis (PCA), multidimensional scaling (MDS), and locality preserving projection (LPP). Experimentally, we demonstrate that the embeddings result in well-defined graph clusters. Our experiments with the spectral representation involve both synthetic and real-world data. The experiments with synthetic data demonstrate that the distances between spectral feature vectors can be used to discriminate between graphs on the basis of their structure. The real-world experiments show that the method can be used to locate clusters of graphs.     

Graphix a graph theory sub language

GRAPHIX is a PASCAL based graph theory sub-language. It provides a set of graph theory algorithms, and allows the user to program directly in terms of graph structures theory algorithms, and allows the user to program directly in terms of graph structures with no knowledge of the internal representation of the graph. A preprocessor has been written to convert GRAPHIX/PASCAL programs into pure PASCAL. The main problems of a sub-language and preprocessing have been overcome in the design of the language and the preprocessor. An example of a GRAPHIX/PASCAL program is provided.     

Drawing pictures of solid objects using a graph plotter

This paper describes a method of producing shaded pictures of three-dimensional polyhedral objects in which the computer time depends only on the complexity of the objects and not on the resolution required. Objectives of the paper are to describe how hidden lines are detected and how the visible lines are assembled to form closed polygonal areas which may be shaded. The detection of hidden lines is carried out efficiently using a sorting technique. Visible lines are assembled to form closed polygons for shading, using programming devices such as the tree, the two-way list, the two-way circular list, and the stack.     

Computerized facility layout with graph theory

This paper describes a plant layout procedure based on graph theory. Given a relationship chart for the departments of the layout, the branch and bound technique is used to obtain an optimal relationship diagram. The planar representation of this relationship diagram is next obtained via a single planarity testing procedure. The planar graph's dual graph is found which gives the topology of the proposed final layout. Due to the time and complexities involved, the entire layout procedure described to this point is computerized.Using the topology of the dual graph, one can place the departments into the final layout. An example is presented to demonstrate the plant layout procedure in its entirely.     

Neural networks and graph theory

The relationships between artificial neural networks and graph theory are considered in detail. The applications of artificial neural networks to many difficult problems of graph theory, especially NP-complete problems, and the applications of graph theory to artificial neural networks are discussed. For example graph theory is used to study the pattern classification problem on the discrete type feedforward neural networks, and the stability analysis of feedback artificial neural networks etc.     

A-to-D conversion from paper records with a desktop scanner and a microcomputer

A novel method for digitizing signals contained in paper records is presented. This method is based on the use of an inexpensive optical scanner to translate the image on paper into a binary, bit map data structure. Several algorithms which recognize the signal line in the bit map and translate it into a series of numbers which are equivalent to the output of electronic analog-to-digital converters are described. The method was validated by comparison both with idealized test patterns of varying frequency content and with electronically digitized pressure and pressure time derivative tracings from chronically instrumented dogs. The root mean square error for the physiological signals was 3.5-3.9% of peak-to-peak full scale, corresponding to roughly 50% more than the thickness of the signal line on the paper.     

Heuristic method to check the realisability of a graph into a rectangular plan

The problem of mapping a graph into rectangles so that they cover a rectangular plan is considered. The graph may represent the basic scheme of a house or of a building, in which different design requirements are collected. To cope with this problem the authors have chosen a three steps approach: determining whether a graph can be mapped in this way (first step); automatically generating some of its realisations (second step); then how a given plan can be reduced to the rectangular one is analysed (third step).A heuristic approach to the general solution of the first step is proposed. It is a problem with a practical application in areas such as architectural design or compacting of electronic circuits, to which no general solution has been found in the specialised bibliography.     

Strategies for interconnection networks: Some methods from graph theory

Interconnection networks require dense graphs in the sense that many nodes with relatively few links may be connected with relatively short paths. Some recent constructions of such dense graphs with a given maximal degree Δ and diameter D (known as (Δ, D) graphs) are reviewed here. The paper also contains an updated table of the best known (Δ, D) graphs.     

Leakage diagnosis with a contamination mitigation control framework using a graph theory based model

This work proposes an operational management approach for water distribution networks (WDNs) that can detect and localize leakages while also mitigating contamination resulting from these leaks. The primary emphasis of this work is the development of a contamination mitigation control scheme. A leak typically leads to a drop in network pressure that increases the risk of contamination. A leakage localization algorithm is responsible for detecting and localizing the leakage in the WDN. When a leak is detected in the network the contamination mitigation control is activated. The flow and pressure settings of the pumps are regulated by the contamination mitigation control in an optimal manner to minimize the risk of contamination. The entire framework is tested on the Smart Water Infrastructure Laboratory situated at Aalborg University, Denmark and a large-scale benchmark water network, which is part of a city network, L-town.     

Hydrologic routing with a microcomputer

Low cost and increasing capability favour the use of microcomputers as design tools, particularly in the less developed countries, who may not have easy access to large computers. In this paper a 281 statement BASIC program, which is listed and explained, was developed for routing flood waves along a network of rivers and reservoirs, or a combination of both. Although the program may not be as versatile as similar mainframe packages it can compute much of what was previously done on larger machines.     

图注意力网络的场景图到图像生成模型

目的 目前文本到图像的生成模型仅在具有单个对象的图像数据集上表现良好，当一幅图像涉及多个对象和关系时，生成的图像就会变得混乱。已有的解决方案是将文本描述转换为更能表示图像中场景关系的场景图结构，然后利用场景图生成图像，但是现有的场景图到图像的生成模型最终生成的图像不够清晰，对象细节不足。为此，提出一种基于图注意力网络的场景图到图像的生成模型，生成更高质量的图像。方法 模型由提取场景图特征的图注意力网络、合成场景布局的对象布局网络、将场景布局转换为生成图像的级联细化网络以及提高生成图像质量的鉴别器网络组成。图注意力网络将得到的具有更强表达能力的输出对象特征向量传递给改进的对象布局网络，合成更接近真实标签的场景布局。同时，提出使用特征匹配的方式计算图像损失，使得最终生成图像与真实图像在语义上更加相似。结果 通过在包含多个对象的COCO-Stuff图像数据集中训练模型生成64×64像素的图像，本文模型可以生成包含多个对象和关系的复杂场景图像，且生成图像的Inception Score为7.8左右，与原有的场景图到图像生成模型相比提高了0.5。结论 本文提出的基于图注意力网络的场景图到图像生成模型不仅可以生成包含多个对象和关系的复杂场景图像，而且生成图像质量更高，细节更清晰。     

Materials requirement planning with a microcomputer

Materials requirement planning (MRP) has been implemented on equipment ranging from early EAM punchcard equipment to the largest mainframe computers. The availability of relatively capable microcomputers raises the possibility of MRP systems for small operations. A major obstacle is that the concepts underlying most MRP systems are such that both time and memory capability become critical. A system of three programs has been developed using a different computational concept. The “Gozinto” method is used for structuring bill of materials data, and matrix multiplication is used for data manipulation and report generation. The system is reasonably fast, and uses disc memory to alleviate memory constraints. Written in UCSD Pascal, it is usable in any microcomputer supporting that language that has two disc drives and a minimum of 56K of memory. The first program is the bill of materials processor, which receives bill of materials data input from the CRT and stores it on disc using any firm's part coding system. The bill of materials file is then reindexed to develop a triangular matrix. This matrix is then inverted to arrange the bill of materials data in “indented” form. The second “planning” program receives input from the CRT to develop a data base containing master schedule, inventory, order, lot size and other data. The matrix multiplication of the data base and the indented bill of materials is then done on a disc-to-disc basis, obviating the need for large working memory. This second program also provides for revision of the data base as the time periods progress. Results are printed by a third program that essentially despools the matrix products. Limited testing using data from a cooperating firm indicates usefulness with a minimal computer configuration. Extension to larger firms seems feasible with modest memory expansion.     

Floor plan design using block algebra and constraint satisfaction

Architectural floor plan layout design is what architects and designers do when they conceptually combine design units, such as rooms or compartments. At the end of this activity, they deliver precise geometric schemas as solutions to particular problems. More research on this topic is needed to develop productive tools. The authors propose orthogonal compartment placement (OCP) as a new approach to this activity. OCP includes a problem formulation and a solution method in which qualitative and quantitative knowledge are combined. Topological knowledge underlies human spatial reasoning. Computers can adequately perform repetitive topological reasoning. We believe that OCP is the first approach in CAAD to incorporate a full relational algebra to generate floor plan layouts. Based on block algebra (BA) and constraint satisfaction (CS), OCP can generate candidate solutions that correspond to distinct topological options. The analysis of a case study using a prototype tool is included.     

嵌段共聚物球形胶束体系的标度理论及其与均匀场理论的对比研究

本文建立了用于嵌段共聚物胶束体系定量计算的标度理论模型,讨论了标度理论与均匀场模型的差异。在极性和非极性溶剂体系中,定量考察了平衡态胶束聚集数、胶束过渡区聚合物浓度分布、胶束半径和内界面处的聚合物浓度等平衡性质,以及嵌段共聚物嵌段比例、摩尔质量等因素对上述性质的影响。与实验及均匀场模型的对比结果硅示,均匀场模型的拟均相假设对胶束聚集数等平衡性质的计算不会产生显著偏差,标度理论模型与均匀场模型都能够较好地描述胶束体系,两模型也获得了较好的一致。此外,标度理论模型能够给出胶束内的浓度分布。即使在高聚集数的情况下,胶束内界面处溶剂的含量仍然很高（〉50％）,这表明有必要对内界面张力的计算进行修正,而均匀场模型则忽略了此项修正。     

GraphClus,a MATLAB program for cluster analysis using graph theory

Cluster analysis is used in numerous scientific disciplines. A method of cluster analysis based on graph theory is discussed and a MATLAB? code for its implementation is presented. The algorithm is based on the number of variables that are similar between samples. By changing the similarity criterion in a stepwise fashion, a hierarchical group structure develops, and can be displayed by a dendrogram. Three indexes describe the homogeneity of a given variable in a group, the heterogeneity of that variable between two groups, and the usefulness of that variable in distinguishing two groups. The algorithm is applied to both a synthetic dataset and a set of trace element analyses of lavas from Mount Etna in order to compare GraphClus to other cluster analysis algorithms.     

Drawing graphs by eigenvectors: theory and practice

The spectral approach for graph visualization computes the layout of a graph using certain eigenvectors of related matrices. Two important advantages of this approach are an ability to compute optimal layouts (according to specific requirements) and a very rapid computation time. In this paper, we explore spectral visualization techniques and study their properties from different points of view. We also suggest a novel algorithm for calculating spectral layouts resulting in an extremely fast computation by optimizing the layout within a small vector space.     

Covering a graph with cycles

In several areas of engineering and telecommunications, it is necessary to determine a least cost cover of a graph by means of cycles. We propose a highly efficient yet simple heuristic for this difficult problem. On test problems it consistently produces optimal or near optimal solutions.This article describes a lower bounding procedure and heuristics for the Cycle Cover Problem which consists of determining a least cost cover of an undirected graph with simple cycles. Applications of this problem arise in network design and in telecommunications. Computational results demonstrate the quality of the proposed heuristics. On 100 vertex graphs, the best of these consistently produces optimal or quasi-optimal solutions.