• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.3
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• pp.199-205
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• 2013

In this study, the methodology for the fatigue life prediction using finite element method(FEM) in wire, bundle and assembly level of the wire harness system and the development of the fatigue life test machine for the numerical analysis are investigated. To obtain stress-life(S-N) histories of the componential wires of the system, five kinds of wires are prepared and applied to the repeated bending motion using developed fatigue life test equipment. Equivalent model of the wire from the rule of mixtures theory is used for the material modeling of sheath and wire core combination. Contact conditions among the wires, taping conditions are established through the bundle level test and numerical bundle analysis. Wire and bundle level results are adopted for the assembly level analysis. For the assembly level analysis, real wire harness system including bundle and grommet is numerically modeled and applied contact condition between wires with real opening motion. The fatigue life more than 700,000 cycles of the assembly is obtained from the FEM, and it is confirmed that the result has good agreement with the experimental result.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.118-125
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• 2012

In this paper, an approach to designing controllers for the tension/movement control of working robot to install a stringing wire cable is presented. To design a controller, when the robot moves a certain distance maintaining constant tension, the dynamic model of a stringing wire cable which considers effects of weights according to changing lengths is presented. Also the tension at startup of the working robot is studied by numerical analysis which is based on the equation of the dynamic wire model. From the dynamic model for a stringing wire cable, working robot for tension/movement control is suggested and designed a feedforward controller with a accelerator gain to suppress a mutual interference of the both tasks of tension/movement control. Depending on the operating conditions of the working robot, the effectiveness of the suggested system has been verified by the simulation and experimental results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.10
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• pp.1069-1077
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• 2015

In tunnel excavation using blast, the wire saw rock cutting method generates a discontinuity perimeter around the center cut, and thus prevents blast vibration propagation to reduce vibration and noise. Therefore, the method is expected to be easy to use and economical compared with other methods. In this paper, the cutting mechanism of wire saw in tunnel excavation is investigated. A model describing the changes in cutting depth and wire saw shape inside a rock during cutting is established and validated for this purpose. Through a simulation using the model, the important characteristics of wire saw cut are investigated, and the influences of cutting conditions, such as wire saw tension, wire saw speed, feed speed, depth, and diameter of boring, on cutting performance are also examined. A method to improve the cutting performance is proposed based on the results.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.9
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• pp.24-29
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• 2010

This paper presents the RF modeling for silicon nanowire MOSFET with 30 nm channel length and 5 nm channel radius. Equations for analytical parameter extraction are derived by analysis of Y-parameter. Accuracies of the new model and extracted parameters have been verified by 3-dimensional device simulation data up to 100 GHz. The model verifications are performed under conditions of saturation region ($V_{gs}$ = $_{ds}$ = 1 V) and linear region ($V_{gs}$ = 1 V, $V_{ds}$ = 0.5 V). The RMS modeling error of Y-parameters was calculated to be 1 %.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.69-69
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• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.792-797
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• 1996

형상모델링(Geometric Modeling)은 컴퓨터 기술의 발전과 더불어 실제 3차원 물체를 정확하게 표현하려는 형태로발전하였다. 와이어프레임 모델링(Wireframe Modeling) 기술은 3차원 형상을 빠르게 모델링하고 이로 부터 치수 기입이 된 정확한 2차원 도면의 생성을 가능하게 하였다. 그러나, 면을 표현할 수 없기 때문에 모델의 표현이 모호해질 수 있다. 1960년대에 자유곡면의 가공을 위해 개발된 곡면 모델링(Surface Modeling) 기법은 NC 가공과 컴퓨터를 이용한 금형의 제작을 가능하게 했고 와이어프레임 모델링보다는 더 상세하게 모델 을 표현할 수 있게 되었다. 본 연구의 목적은 개방형 구조를 갖는 복합다양체 모델러에서의 불리안 작업을 구현하고 이의 결과를 가시화 하는데 있으며 개략적인 개방형 형상 모델링 시스템 Fig.1과 같다

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.265-268
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• 2002

얼굴은 성별, 나이, 인종에 따라 다양한 특징을 가지고 있어서 개개인을 구별하기가 쉽고 내적인 상태를 쉽게 볼 수 있는 중요한 도구로 여겨지고 있다. 본 논문은 얼굴표정 애니메이션을 위한 효과적인 방법으로 실제얼굴의 피부조직 얼굴 근육 등 해부학적 구조에 기반한 근육기반모델링을 이용하는 방법을 소개하고자 한다. 제안하는 시스템의 구성은 얼굴 와이어프레임 구성과 폴리곤 메쉬분할 단계, 얼굴에 필요한 근육을 적용시키는 단계, 근육의 움직임에 따른 얼굴 표정생성단계로 이루어진다. 와이어프레임 구성과 폴리곤 메쉬 분할 단계에서는 얼굴모델을 Water[1]가 제안한 얼굴을 기반으로 하였고, 하나의 폴리곤 메쉬를 4등분으로 분할하여 부드러운 3D 얼굴모델을 보여준다. 다음 단계는 얼굴 표정생성에 필요한 근육을 30 개로 만들어 실제로 표정을 지을 때 많이 쓰는 부위에 적용시킨다. 그 다음으로 표정생성단계는 FACS 에서 제안한 Action Unit 을 조합하고 얼굴표정에 따라 필요한 근육의 강도를 조절하여 더 자연스럽고 실제감 있는 얼굴표정 애니메이션을 보여준다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1479-1485
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• 2010

In recent times, due to wire drawing of high carbon steel at a high speed to ensure a high productivity and high strength, axial residual stress are generated because of rapid increase in surface temperature. In the process, the temperatures of the wires increased because of the deformation of the wires and the friction between the die and wire. In particular, in the case of the wire drawing at a high speed, friction leads to a large temperature gradient so that considerable axial residual stress is generated on the surface. In this study, the relationship between axial residual stress and increase in the surface temperature was investigated, and a prediction model of uniform temperature was proposed. Then, a prediction model for residual stress was developed. The proposed model was verified by measuring the residual stress by X-ray diffraction on drawn wires.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.572-579
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• 2001

Recent industrial requirements for highly precise shape processing have brought the electric discharge machining (EDM) in great need. High precision in EDM is primarily achieved by high performance controllers. However there exists inherent precision loss due to structural deformation. On this background, we study structural deformation characteristics of wire cut EDM via finite element (FE) analysis and axiomatic design. Two different wire cut EDMs are selected as analysis models. 3D CAD package I-Deas is first used to construct FE models of wire cut EDMs, and then ABAQUS FE code is used for following structural analysis. Pertinency of FE mesh refinement is discussed in terms of ${\eta}-factor$. It is shown that performance accuracy of EDM depends strongly on the structural characteristics. Some design enhancements are suggested in an axiomatic design point of view. Finally we provide weight and temperature induced displacement discrepancies between wire end points as position functions of each subframe.

• Journal of the Korea Concrete Institute
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• v.19 no.6
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• pp.773-783
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• 2007

A simple unbonded-type shear strengthening technique for reinforced concrete beams using wire rope units is developed. Six two-span continuous T-beams externally strengthened with wire rope units and an unstrengthened control beam were tested. The main variables investigated were the amount and prestressing force of wire rope units. All specimens had the same geometrical dimension and arrangement of internal reinforcement. Influence of the distribution of vertical stresses in beam web owing to the prestressing force of wire rope units on the diagonal shear cracking load and the ultimate shear capacity of beams tested is presented. Based on the current study, it can be concluded that the amount and initial prestress of wire rope should be limited to be above 2.5 times the minimum shear reinforcement ratio specified in ACI 318-05 and below 0.6 times its own tensile strength, respectively, to ensure the enhancement of shear capacity and ductile failure mode of the strengthened beams. A numerical analysis based on the upper-bound theorem is developed to assess the shear capacity of continuous T-beams strengthened with wire rope units. From the comparisons of measured and predicted shear capacities, a better agreement is achieved in the proposed numerical analysis than in empirical equations recommended by ACI 318-05.