• Journal of Internet Computing and Services
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• v.4 no.6
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• pp.33-42
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• 2003

A XML Instance repository model based on the Edge-Labeled Graph is suggested for storing the XML instance in Relational Databases, This repository model represents the XML instance as a data graph based on the Edge-Labeled Graph, extracts the defined value based on the structure of data path, element, attribute, and table index table presented as database schema, and stores these values using the Mapper module, In order to support querry, XML repository model offers the module translating XQL which is a query language under XPATH to SQL, and has DBtoXML generator module restoring the stored XML instance. As a result, it is possible to represent the storage relationship between the XML instances and the proposed repository model in terms of Graph-based Path, and it shows the possibility of easy search of specific element and attribute information.

• Journal of Korea Multimedia Society
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• v.22 no.9
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• pp.1036-1045
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• 2019

Relational databases have a notion of normalization, in which the model for storing data is standardized according to the organization's business processes or data operations. However, the graph database is relatively early in this standardization and has a high degree of freedom in modeling. Therefore various models can be created with the same data, depending on the database designers. The essences of the graph database are two aspects. First, the graph database allows accessing relationships between the objects semantically. Second, it makes relationships between entities as important as individual data. Thus increasing the degree of freedom in modeling and providing the modeling developers with a more creative system. This paper introduces different graph models with test data. It compares the query performances by the results of response speeds to the query executions per graph model to find out how the efficiency of each model can be maximized.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.2
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• pp.11-17
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• 1975

The paper examined the character structure as a basic study for the recognition of Korean characters. In view of concave structure, line structure and node relationship of character graph, the algebraic structure of the basic Korean characters is are analized. Also, the degree of complexities in their character structure is discussed and classififed. Futhermore, by describing the fact that some equivalence relations are existed between the 10 vowels of rotational transformation group by Affine transformation of one element into another, it could be pointed out that the geometrical properting in addition to the topological properties are very important for the recognition of Korean characters.

• Journal of the Korean Operations Research and Management Science Society
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• v.21 no.1
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• pp.131-146
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• 1996

In this paper, we describe the facial structure of the steiner problem in a directed graph by formulating it as set covering problem. We first characterize trivial facets and derive a necessary condition for nontrival facets. We also introduce a class of valid inequalities with 0-1 coefficients and show when such inequalities define facets.

• Journal of the Korean Institute of Navigation
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• v.22 no.2
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• pp.81-87
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• 1998

On this paper, the methods of optimization research of the fishing navigation using the graph theory are substantiated on the basis of the proposed probable model of the fishing vessel navigator's activity. The graph theory is concered about the transitionform the top graph to the rib one. And the definition of the additional system elements (quasi elements) necessary to provide the effectiveness during the fishing navigation are also substantiated herein. This approach helps to optimize the structure of any fishing vessel monitoring system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.273-278
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• 1995

In this paper, we propose "a graph structured fuzzy system" which is able to represent the fuzzy system with a graph and optimizes the fuzzy membership functions and fuzzy rule bases using genetic algorithms. It performs the structure identification phase and parameter tuning phase simultancously through the evolutionary process. Additionally, it alleviates some of the drawbacks associated with the current fuzzy construction method with respect to the explosive increase of fuzzy rules which is inevitably encountered whenever the fuzzy systems are applied to problems with the high-dimensional input space.

• Environmental and Resource Economics Review
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• v.12 no.4
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• pp.687-708
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• 2003

The purpose of this paper is to introduce time-series causality analysis by combining time-series technique with graph theory. Vector autoregressive (VAR) models can provide reasonable interpretation only when the contemporaneous variables stand in a well-defined causal order. We show that how graph theory can be applied to search for the causal structure In VAR analysis. Using Maryland crop cash prices and CBOT futures price data, we estimate a VAR model with directed acyclic graph analysis. This expands our understanding the degree of interconnectivity between the employed time-series variables.

• ETRI Journal
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• v.29 no.3
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• pp.381-389
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• 2007

In this paper we propose a graph-theoretic method based on linear congruence for constructing low-density parity check (LDPC) codes. In this method, we design a connection graph with three kinds of special paths to ensure that the Tanner graph of the parity check matrix mapped from the connection graph is without short cycles. The new construction method results in a class of (3, ${\rho}$)-regular quasi-cyclic LDPC codes with a girth of 12. Based on the structure of the parity check matrix, the lower bound on the minimum distance of the codes is found. The simulation studies of several proposed LDPC codes demonstrate powerful bit-error-rate performance with iterative decoding in additive white Gaussian noise channels.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.4
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• pp.65-72
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• 1994

An independent set of nodes is a set of nodes no two of which are joined by an edge. An independent set is called maximal if no more nodes can be added to the set without destroying its independence. The greatest number of maximal independent set is the maximum possible number of maximal independent set of a graph. We consider the greatest number of maximal independent set in connected graphs with fixed numbers of edges and nodes. For arbitrary number of nodes with a certain class of number of edges, we present the connected graphs with the greatest number of maximal independent set. For a given class of number of edges, the structure of graphs with the greatest number of maximal independent set is that the two components are completely joined; one consists of disjoint triangles as many as possible and the other is the complete graph with remaining nodes.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.467-470
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• 1998

In this paper, we propose a matrix star graph which improves the network cost of the well-known star grah as an interconnection network. We analyze its characteristics in terms of the network parameters, such as degree, scalability, routing, and diameter. The proposed matrix star graph MS2,n has the half degrees of a star graph S2n with the same number of nodes and is an interconnection network with the properties of node symmetry, maximum fault tolerance, and recursive structure. In network cost, a matrix star graph MS2,n and a star graph S2n are about 3.5n2 and 6n2 respectively which means that the former has a better value by a certain constant than the latter has.