• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.211-213
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• 2008

To detect partial discharge of 154kV joint box, we have made experiment by using the Al-foil electrode sensor. Generally the signals which are detected in partial discharge test of underground power transmission cable are accompanied with both noises of high voltage and noises of surrounding power cable. The most noise in near to end part of joint box is corona, beside other noises flowed from surrounding area. Partial discharge test is difficulty due to these noises. First, we had used Al-Foil sensor on middle joint box of 154[kV] underground transmission power cable, and then analysed reliability of calibration signal by using the Al-Foil electrode sensor of NJB. From above results, decrement properties measured highly. But incase of injecting calibration signal of 500[pC] after measuring signals in IJB, the S/N ratio had about 25[dB] acquisition.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1197-1204
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• 2004

The metropolitan cities and operation companies of urban transit railway are driving to construct the LRT(light rail transit) system because of the advantage of construction cost and environmental serviceability. This study suggests the optimal design method of steel box girder considering dynamic characteristics of LRT with rubber wheel. The behavior and design constraints are formulated based on the structural design criteria for LRT. Genetic algorithm is applied to the minimum weight design of structural system. A typical example is solved to illustrate the applicability of the proposed minimization algorithm. From the results of application example, the optimum design of steel box girder is successfully accomplished. Therefore, this system can act as a consultant to assist novice designers in the design of steel box girder for LRT with rubber wheel.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.61-64
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• 2003

The finite element method based on the refined beam theory is applied to the vibration problem of rotation composite box beams. The present beam model includes a number of non-classical structural effects such as transverse shear, warping deformations, geometric non-linearities. The nonlinear finite element equations of motion are obtained from Hamilton's principle. Vibration characteristics versus various parameters such as ply angle, collective pitch angle, pretwist and precone are investigated for rotation box ben and relevant conclusions are outlined.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.61-64
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• 2002

In this study, It was designed and developed optimal rotary dressing system of centerless grinding using for ferrule machining. Dressing shaft's dropping is calculated by Finite Element Method, and bearing 7206ADB, 7005ADB is selected. Dressing wheel $GC\Box \;200\Box\; G\Box\; m\Box\; V-100^*25^*16$ is selected by pre-research. Also Motor, pulley, belt are selected, 0.4Kw-60Hz, 48.2 mm diameter, 2-5M-730 type, each.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.401-408
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• 2001

The main objective of this study is to analyze the distortion of curved steel box girders. For the distortional analysis of steel box girders, two approaches are presented. One is the development of approximate formulas obtained by applying Ritz method. The other is the formulation of stiffness matrix which is derived from the exact solution of the differential equation for distortion. Distortional analysis is carried out by utilizing 3-dimensional elements of a structural analysis computer program (SAP2000). The present analysis focuses on the distortional stress and the effects of the diaphragm. The results of several example cases are compared with those by the Nakai, Sakai, Heins, and Oleinik's theory and get the effect of diaphragm spacing on the distortional warping stress of the curved steel box girder.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.2
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• pp.103-109
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• 2001

In this paper, the prestressing order of tendons is studied to minimize a bursting force of an anchorage. The bursting forces is a primary factor of anchorage failures. The forces of the anchorage depend on the prestressing order and size of the tendons, if a lot of tendons are introduced to the anchorage. Many studies have been made to analyze the bursting force of the anchorage. However, the studies have been limited to the bursting forces of the anchorage having one or two tendons. PSC box girder bridges usually have a lot of tendons. And the difference of the bursting forces lies in the prestressing order of the tendons. As a result of the lack of studies on the prestressing order for the bridges, the order depends on the designer's intuition and experiences. It may be stated that this study should be useful for determining the reasonable prestressing order of tendons for the PSC box girder bridges.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.660-665
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• 2002

A concrete box culvert has been widely used as a typical structure in case of crossing the railroad and highway. Due to the simplicity of it's own shape, in company with the development of computers many studies on the computer-aided automatic design have been continuously carried out. In this paper, an automated design algorithm has been proposed by the analysis of the existed design data of box culverts. From a viewpoint of the users, a data base system has been constructed to carry out the total design process completely through the minimum input data and by means of direct input method on the monitor screen. And an automatic design program for railroad box culverts, in which one-stop process from the structural calculation to the quantity estimation is possible, has been developed.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.3 no.1
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• pp.1-7
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• 2000

A new alternative for large deepwater field development is described. This "Oil Box" (aka "Box Spar") is a multifunction vessel capable of floating drilling, production, storage and offloading (FDPSO). It is distinguished from other Floating Production, Storage and Offloading (FPSO) vessels by its unique hull form and oil storage system. It's main advantages are flexibility derived from the floatover deck option, use of proven top tensioned riser technology, and motion characteristics which make it operable in a wide range of environmental conditions.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.3
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• pp.163-174
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• 2023

Though box compression strength (BCS) is commonly used as a performance criterion for shipping containers, estimating BCS remains a challenge. In this study, artificial neural networks (ANN) are implemented as a new tool, with a focus on building up ANN architectures for BCS estimation. An Artificial Neural Network (ANN) model can be constructed by adjusting four modeling factors: hidden neuron numbers, epochs, number of modeling cycles, and number of data points. The four factors interact with each other to influence model accuracy and can be optimized by minimizing model's Mean Squared Error (MSE). Using both data from the literature and "synthetic" data based on the McKee equation, we find that model estimation accuracy remains limited due to the uncertainty in both the input parameters and the ANN process itself. The population size to build an ANN model has been identified based on different data sets. This study provides a methodology guide for future research exploring the applicability of ANN to address problems and answer questions in the corrugated industry.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.2
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• pp.64-69
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• 2010

This paper designs the ABC(Advanced Block Cipher) algorithm which is a 64byte block encryption algorithm, improves the performance of encryption process time, and makes an key exchange using EC-DH. The ABC algorithm reduces basic memory occupation rates using the original data position exchange method which is a data swap key without S-Box, IP-Box and etc. Also, it prepares the exposure of symmetric key using the unfixed encryption(decryption) key excepting the fixed encryption(decryption) key. Therefore, the proposed ABC algorithm in this paper is a proper encryption algorithm in lower memory environment and mobile banking.