• Journal of the Korean Society for Library and Information Science
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• v.42 no.1
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• pp.335-358
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• 2008

According to Wayne A. Wiegand in the 1998, he research to The "Amherst Method": The Origins of the Dewey Decimal Classification Scheme. Although a debate about the origins of the Dewey Decimal Classification Scheme has been going on for generations, historical consensus remains elusive. This paper contributes information to the historiography on the origins of the scheme: 1) by grounding an account of Dewey's thinking as he was crafting the DDC on an analysis of a large body of sources than previous classification historians have consulted; and 2) by expanding and deepening historical understanding of the contextual forces influencing on the classification structure. Because the DDC idea as it first occurred to M. Dewey in Amherst in 1872-73 is an important in the history of library development in the world. He outlined the first draft of his decimal scheme and submitted it to the Amherst College Library Committee on 8 May 1873. This paper analysis to "Three Genetic Paper", that is 1) The Merits of the System, 2) Library Classification System, 3) Its Special Adaption to our Library.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.2
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• pp.104-110
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• 1997

Increase of marine transpotation in coastal area frequently yields oil spill accidents due to collision or grounding of oil tankers, which affects great deal of damages on ocean environments. Exact prediction of oil pollution area in time domain, which is called oil map, is very important for effective and efficient oil recovery and minimization of environmental damage. The prediction is carried out by considering the two distinct processes which are initial diffusion on the still water surface and advection due to tide, wind wave induced surface currents. In the present paper, only the initial diffusion is dealt with. Somewhat new simulation model and its numerical scheme are proposed to predict it. Simple diffusion experiment is also carried out to check the validity of the present method. Furthermore, some example simulations are performed for virtual oil spill accident. Quite realistic oil map including oil thickness distributions can be obtained by the present model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.1
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• pp.101-108
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• 2005

When a heavy rain occurs, many electrical shock victims are produced every year because lamp poles are under water. In order to prevent electrical shock accidents at a street lamp, the investigation was carried out at real field conditions. The investigation was performed about the circuit configuration of a panel board, a wiring method, a grounding conductor, a lamp pole and so on. The related regulation was analyzed and the problems were presented. Also, the domestic and foreign things were compared and analyzed by the investigation of the field conditions, and the related standard was already revised. Through investigating the field conditions and analyzing the related regulation, it is intended to present the real data to establish more effective preventive measures against electrical shock accidents at a street lamp to be installed on the road. In the future, the analytical data can be applied to stabilize other electrical facilities on the road as well as a street lamp, and to reduce the electrical disasters.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.5
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• pp.110-116
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• 2003

With the growth of aircraft performance and needs for light aircraft, the problems associated with hail impacts on aircraft during flights and grounding become and important issue. These hail encounters can cause severe damages to aircraft and result in major concerns in safety and cost. Since nearly all external components of the commercial and military aircraft-in particular, the nose section and the leading edge of the wing and tail-are subject to damages, much effort has been put into understanding of this problem. However, most of the previous studies have focused on the composite components and few results have been reported for the metallic components. In this paper, we study the ice impacts on the aluminum component with the finite element analysis method utilizing commercial non-linear dynamics solver LS-DYNA. The results are compared with the experimental data and a simple measure of the ice impact effects is proposed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.12
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• pp.975-986
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• 2013

This paper dealt with the fabrication and performance evaluation of the electronics housing made of lightweight composite materials, aiming at the enhancement of satellite mass savings by replacing conventional aluminum alloy widely used for satellite avionics with lightweight composite material. For this purpose, a fabrication process was designed to overcome low machinability of CFRP and to minimize the post-treatment. The composite housing with grid-stiffened and monolithic frame was made using co-curing method. Its performance was also evaluated regarding endurance, stiffness, thermal conductivity, electrical grounding, EMI protection and radiation shielding. The composite housing can provide the considerable mass savings over the aluminum housing with same dimension.

• Journal of Fisheries and Marine Sciences Education
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• v.6 no.2
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• pp.190-197
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• 1994

In this paper, 2513 marine casualties occurred in Korean waters, during 1989-1993, were analysed by the Multivariate Data Analysis Method. The main results obtained were as follows : 1. Moat of marine casualties resulted from the human factors such as careless operation and insufficient engine maintenance. Engine trouble accounted for main patten of accidents and great number of accidents occurred in fishing vessels. 2. From the point of view of the damage of human life and properties, accidents took place in cargo ships, passenger ships and tankers were serious, but in fishing vessels, those were not so serious. 3. Grounding, collision mainly resulted from careless operation, however flooding and capsizing were much affected by bad weather and material defect.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.558-561
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• 2018

Human errors have known as a majority of maritime navigational accidents such as collision and grounding. A large number of relevant research applied indirect research methods such as survey and interview. The research methods are limited to collect objective data regarding human errors due to its nature. Therefore, the purpose of this study is to improve the limitation of human error measurement of navigators by applying wearable sensors. Infrared sensors by using a 3-D printer to accommodate the special environment of a ship were developed for the study. As results, a significant reliance on the Integrated Navigation System including Electronic Chart Display and Information System (ECDIS) and Radar. The results are expected to motivate further research to investigate human errors of ship navigators to reduce the maritime navigational accidents.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.10
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• pp.1364-1370
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• 2014

Power system fault analysis has been based on symmetrical component method, which describes power system elements by positive, negative and zero sequence impedance. Obtaining accurate line impedances as possible are very important for estimating fault current magnitude and setting distance relay accurately. Especially, accurate calculation of zero sequence impedance is important because most of transmission line faults are line-to-ground faults, not balanced three-phase fault. Since KEPCO has started measuring of transmission line impedance at 2005, it has been revealed that the measured and calculated line impedances are well agreed within reasonable accuracy. In case of underground transmission lines, however, large discrepancies in zero sequence impedance were observed occasionally. Since zero sequence impedance is an important input data for distance relay to locate faulted point correctly, it is urgently required to analyze, detect and consider countermeasures to the source of these discrepancies. In this paper, development of pre/post processor to ATP (Alternative Transient Program) version of EMTP (Electro-Magnetic Transient Program) for sequence impedance calculation was described. With the developed processor ATP-cable, effects of ground resistance and ECC (Earth Continuity Conductor) on sequence impedance were analyzed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.11
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• pp.1543-1550
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• 2015

Ferroresonance is a non-linear vibrational phenomenon that is generated by the electrical interaction of the inductance component with the capacitor component of a certain capacitance as the device of the inductance component such as a transformer is saturated due to the degradation, the waveform distortion of current and voltage, and the oscillation of overcurrent and overvoltage in a system. Recently, ferroresonance was generated from the waveform distortion of current and voltage, or the overvoltage or undervoltage phenomenon caused by the nature of an electrical power system and design technology of the transformer in the three phase transformer system. Hence, in general, ferroresonance analyzed by converting to the LC equivalent circuit. However, in general, the aforementioned analytical method only applies to the resonance phenomenon that is generated by the interaction of the capacitance of bussbar and grounding, and switching as the capacitor component with PT and the transformer as the inductance component in a system. Subsequently, the condition where ferroresonance was generated since overvoltage was supplied as line voltage to the phase voltage and thus the iron core is saturated due to the interconnection between grounded and ungrounded systems could not be analyzed when single phase PT was connected in a ${\Delta}$/Y connection system. In this study, voltage swell in the configuration of grounded circuit of a step-up transformer with the ${\Delta}-{\Delta}$ connection linked to PT for control power and the ferroresonance generated by overvoltage when the line voltage of the ${\Delta}-{\Delta}$ connection was connected to the phase voltage of the grounded Y-Y connection were analyzed using PSCAD / EMTDC through the failure case of the transformer caused by ferroresonance in the system with the ${\Delta}-{\Delta}$/Y-Y connection, and subsequently, the preventive measure of ferroresonance was proposed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.394-405
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• 2022

This paper presents the numerical estimation results of oil outflows from damaged single-hull and double-hull ships by using computational fluid dynamics (CFD) simulations. A CFD method for multi-phase flow analysis was used, and the effects of numerical parameters on oil flows was investigated. Numerical simulations were conducted to predict the changes in oil outflows under various damage conditions owing to grounding or collision accidents and verified through available experimental results. The present numerical results showed a good agreement with the experimental results according to the geometrical characteristics of single and double hulls. In particular, the oil outflows from double hulls accompanying complex interactions between water and oil were reasonably predicted a shown in the experiment. This study established a reliable CFD technique necessary for estimating the oil outflows of damaged ships.