• Journal of the Korean Society of Marine Environment & Safety
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• v.11 no.1 s.22
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• pp.47-52
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• 2005

In this paper, we will introduce the predominant case on the marine leisure business of the overseas. Next we will analyze the current situation of the domestic marine leisure and draw up a plan to solve its problem At first, we will introduce the predominant case on the marine leisure business cf the overseas. Next we will analyze the current situation cf the domestic marine leisure and draw up a plan to solve its problem Finally we apply an environment friendly marina establishment to the archipelago at the southwest sea area and evaluate its validity.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.330-333
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• 2009

The time-dependent constitutive law was developed based on viscoelastic-plasticity to describe the time-dependent spring-back behavior of aluminum alloy 6022-T4 sheets. Besides nonlinear viscoelasticity, non-quadratic anisotropic yield function, Yld2000-2d, was used to account for the anisotropic yield behavior, while the combined isotropic-kinematic hardening law was used to represent the Bauschinger effect and transient hardening. For verification purposes, finite element simulations were performed for the draw-bending and the results were compared with experimental results.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.180-184
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• 2009

A novel set of experimental test tooling for measuring pulling and holding forces for drawbeads on binders inclined at a wide range of angles is introduced. A mechanical design featuring a single load cell, a male-female draw bead set, translation and rotation degrees of freedom, and a screw-driven clamping system has been incorporated into a standard tensile test machine. On a real time basis, restraining and holding force data with respect to draw-in displacement may be directly downloaded into a PC for data processing. The proposed experimental system represents a significant breakthrough in drawbead simulation technology due to its relatively low cost, clever design, and versatility. The system is shown to yield excellent experimental data suitable for verifying theory and numerical model predictions.

• Transactions of Materials Processing
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• v.20 no.5
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• pp.344-349
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• 2011

Variation of contact pressure causes change of friction coefficient, which in turn changes stress distribution in the sheet being formed and final springback. In the present study, U-draw bending experiments were carried out under constant blank holding force(BHF) and different blank sizes, and finite element analysis was conducted with and without considering contact pressure effect on friction. When the BHF was sufficiently high, the degree of springback was different between constant blank holding pressure condition and that with varying blank holding pressure. Finite element analysis considering the influence of contact pressure effect on friction could explain the occurrence of springback.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.60-63
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• 2007

The effect of process parameters on springback of AZ31B magnesium alloy sheet was investigated by performing 2D draw bending test at the elevated temperatures. And also the springback characteristics were studied different blank holding forces between 30 to 250 kgf. Springback was considerably reduced at higher temperatures than $200^{\circ}C$. The blank holding force in the range used, however, had little influence on springback in isothermal tests. For a given temperature, springback decreased with increasing blank holding force in non-isothermal tests.

• Transactions of Materials Processing
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• v.25 no.5
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• pp.295-300
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• 2016

Recently, Ultra High Strength Steel (UHSS) sheet metal has been widely used to improve lightweight structures in the automobile industry. Because UHSS sheets have high strength but low elongation, it is difficult to control winkle and thinning for complex shaped products. The draw beads on die surface were introduced in this study to reduce wrinkle and thinning. The positions and strength values of draw beads were selected as design variables and optimized using finite element analysis. The beads positions and strength of a mold for B-pillar part were designed with the proposed optimization method. The accuracy of die design from optimization was verified by comparing with the results from 3-D scanned geometry.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.1
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• pp.36-40
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• 2008

Most of the low-voltage feeder are designed with approximately balanced and connected at the three phase four wire systems. However, Most of the power distribution systems' load which is composed of single or three phase are unbalanced by generating load unbalance. Unbalanced current will draw a highly unbalanced voltage. The power factor of an induction motor at rated operation is between 25 and 90%, depending on the size and speed of the motor. However, many induction motors operate below the nominal rating, resulting in poor power factor. This condition needs power factor improvement. Addition of power capacitor at the motor terminal may draw to stress due to voltage unbalance. This paper presents operation characteristics on steady states of a three-phase induction motor under unbalanced voltages with power capacitor. The existence of voltage unbalance have an effect on stress of power capacitor.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.05a
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• pp.14-19
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• 2001

웹기반 시뮬레이션이란 인터넷을 기반으로 플랫폼에 관계없이 시뮬레이션을 실행할 수 있는 것으로 기존에 Jsim, SimJava, JavaSim, DEVS-Java등과 같은 다양한 도구들이 개발되었다. SimJava는 자바 프로그래밍 언어를 이용하여 시뮬레이션 라이브러리를 개발할 수 있는 이산 사건 시뮬레이션 패키지로 SimJava 패키지, SimAnim 패키지, SimDial 패키지로 구성되어 있다. SimJava는 문자기반의 시뮬레이션뿐만 아니라, 시뮬레이션 실행과정과 결과를 시각적으로 볼 수 있는 기능을 제공하기 때문에, 웹 기반 시뮬레이션에서 많이 사용되고 있다. 본 논문에서는 SimJava를 이용하여 웹에서 모델을 설계하고 시뮬레이션 및 애니메이션이 가능한 SimDraw를 제안한다. 특히 SimDraw는 동적 바인딩을 이용함으로 모델을 설계하고 번역할 필요 없이 바로 웹에서 실행된다.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.173-176
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• 2001

In this treatise information communication indust based change phenomenon of payment system of money explain and study and compare way ago value that use electronic comnunity of the world and presented correct electron money model in real condition of our country. Draw payment way that consider particular situation and korean situation and that wi introduce electron money model of the world and analyze merits and demerits and is money here upon. Electron money introduction of smart card way that support all off-line and on-line that I currency and the nearest topology here direction must is insisting and relate in use of this or presenting value of money flowchart and draw the validity and hangup by introducing electronic mono model who is presenting in Kyong-gi Province and Su-won current and go forward group. Proposed suitable electron money system in Korea situation by proposing money form and model of payment system that can satisfy all this at 1 situation and physical special quality of mon by conclusion and clarify flow of the value.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.12
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• pp.608-613
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• 2000

This paper describes a fault location technique using wavelets in underground transmission power cable system. Estimation of fault location is performed using data smapled at two ends underground system. In the case of 50% fault of total underground transmission line, fault location is calculated using sampled single-end data in underground transmission line. Traveling wave is utilized in capturing the travel time of the transients along the monitored lines between the relay and the fault point. This traveling time information is provided by the wavelet. Simulation was performed using EMTP, ATP Draw and MATLAB. The results of fault location shown in this paper will be evaluated as an effective suggestion for fault location in real underground transmission line.