• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.77-80
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• 2005

Wireless sensor networks(WSN) technology has various applications such as surveillance and information gathering in the uncontrollable area of human. One of major issues in WSN is the research for reducing the energy consumption and reliability of data. A system with forward error correction(FEC) can provide an objective reliability while using less transmission power than a system without FEC. In this paper, we propose to use LDPC codes of various code rate(0.53, 0.81, 0.91) for FEC for WSN. Also, we considered node-to-node interference in addition to AWGN channel. The proposed system has not only high reliable data transmission at low SNR, but also reduced transmission power usage.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.2
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• pp.93-99
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• 2001

A new type geometric and mathematical network reduction model is introduced. Large-scale network is analyzed with analytic approach. The graph has many nodes, branches and loops. Circuit equation are obtained from these elements and connection rule. In this paper, the analytic relation between voltage source has a mutual different graphic property. Node-reduction procedure is achieved with this circuit property. Consequently voltage source value is included into the adjacent node-analyzing equation. A resultant model equations are reduced as much as voltage source number. Matrix rank is (n-1-k), where n, k is node and voltage source number. The reduction procedure is described and verified with geometric principle and circuit theory. Matrix type circuit equation can be composed with this technique. The last results shall be calculated by using computer.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.479-482
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• 2019

Node.js 는 자바스크립트 런타임으로 확장성 있는 웹 애플리케이션 개발에 주로 사용되는 플랫폼이다. 자바스크립트는 수 년에 걸쳐 많은 발전을 이뤘으며 현재는 Node.js 로 서버 사이드까지 자리 잡아 웹이라는 생태계에서 빼놓을 수 없는 요소가 되었다. 본 논문은 Node.js 에 관한 전반적인 이론을 포함하여 자바스크립트 특성으로 인하여 Node.js 에서 자주 발견되는 취약점의 탐색 방법을 모듈 관점에서 다뤄보고자 한다. 또한 취약점이 발생하는 다양한 패턴과 해당 패턴을 막기 위하여 적용된 Mitigation 을 실제 모듈을 예시로 살펴보며 분석해보고자 한다.

• Korean Journal of Computational Design and Engineering
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• v.1 no.1
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• pp.65-75
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• 1996

This paper describes an automatic finite element(FE) mesh generation for three-dimensional structures consisting of free-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, i.e. analysis model, (b) generation of nodes, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional solid and shell structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional solid and shell structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

• 전기의세계
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• v.17 no.2
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• pp.11-15
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• 1968

One of the most important methods used in the modern analysis of linear networks and systems is the signal flow graph technique, first introduced by S.J. Mason in 1953. In essence, the signal-flow graph technique is a graphical method of solving a set of simultaneous. It can, therefore, be regarded as an alternative to the substitution method or the conventional matrix method. Since a flow-graph is the pictorial representation of a set of equations, it has an obvious advantage, i.e., it describes the flow of signals from one point of a system to another. Thus it provides cause-and-effect relationship between signals. And it often significantly reduces the work involved, and also yields an easy, systematic manipulation of variables of interest. Mason's formula is very powerful, but it is applicable only when the desired quantity is the transmission gain between the source node and sink node. In this paper, author summarizes the signal-flow graph technique, and stipulates three rules for conversion of an arbitrary nonsource node into a source node. Then heuses the conversion rules to obtain various quantities, i.e., networks gains, functions and parameters, through simple graphical manipulations.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.2
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• pp.73-78
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• 1992

Numerical method by Abdi et al. for obtaining a stress singularity near a crack perpendicular to the interface between two elastic materials is reviewed. More efficient and simple method to obtain crack singularity by shifting a mid-side node of 8-node isoparametric element is presented. It is observed that the present analysis provides increased accuracy for the expression of the opening displacement and the determination of the optimal position of the mid-side node for a wide range of material properties.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.3
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• pp.343-348
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• 2005

This paper describes an automatic finite element (FE) mesh generation for three-dimensional structures consisting of free-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, i.e. analysis model, (b) generation of nodes, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional solid structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional solid structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

• Fashion & Textile Research Journal
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• v.1 no.1
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• pp.50-55
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• 1999

The repeatability of fabric drape was studied. Two methods for draping were used and the relation between node distributions was investigated using statistical analysis. With this, the relationship between node distribution and fabric mechanical properties was studied. The repeated measurements showed that there was no evidence that fabric has intrinsic node number and the mechanical properties influence on the number of nodes.

• Journal of the Korean Institute of Telematics and Electronics
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• v.10 no.5
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• pp.39-44
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• 1973

In general, solution of electric networks requires both node and loop analysis, in which node pair voltages and loop currents are treated as network variables, but the conjugate quantities of these variables (the branch currents and node pair voltages respectively) are to be obtained through additional solving operation. In case of networks with magnetic coupling, however, the coupling keeps the conjugate variables mutually dependent and its final solution requires further calculation. In this paper is analyzed the method of obtaining the conjugate quantities through treatment of the problrm in a subspace with dimensions of number of magnetically coupled branches.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.33-42
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• 2010

Patterning with a geodesic line is essential for economical or efficient usage of membrane materialsin fabric tension membrane structural engineering and analysis. The numerical algorithm to determine the geodesic line for membrane structures is generally classified into two. The first algorithm finds a non-linear shape using a fictitious geodesic element with an initial pre-stress, and the other algorithm is the geodesic line cutting or searching algorithm for arbitrarily curved 3D surface shapes. These two algorithms are still being used only for the three-node plane stress membrane element, and not for the four-node element. The lack of a numerical algorithm for geodesic lines with four-node membrane elements is the main reason for the infrequent use of the four-node membrane element in membrane structural engineering and design. In this paper, a modified numerical algorithm is proposed for the generation of a geodesic line that can be applied to three- or four-node elements at the same time. The explicit non-linear static Dynamic Relaxation Method (DRM) was applied to the non-linear geodesic shape-finding analysis by introducing the fictitiously tensioned 'strings' along the desired seams with the three- or four-node membrane element. The proposed algorithm was used for the numerical example for the non-linear geodesic shape-finding and patterning analysis to demonstrate the accuracy and efficiency, and thus, the potential, of the algorithm. The proposed geodesic shape-finding algorithm may improve the applicability of the four-node membrane element for membrane structural engineering and design analysis simultaneously in terms of the shape-finding analysis, the stress analysis, and the patterning analysis.