• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2770-2773
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• 2002

본 논문은 지능형 안전 자동차(ASV)의 범주인 차선이탈경보 및 방지시스템에 적용을 위한 차선검출 알고리즘을 나타낸다. 그러기 위해서는 차선검출의 높은 신뢰도가 우선 되어야 한다. 대부분의 고속도로는 직선로와 곡선로로 이루어져있고, 곡선 도로는 차선을 검출하는데 여러 가지 제약이 있다. 본 논문에서는 곡선 차선의 직선 근사화를 통한 신뢰성 있는 차선 검출을 위해서 입력되는 연속영상의 효율적인 처리 기법을 제안하고자 한다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.4
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• pp.280-285
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• 2000

The conventional ultrasonic linear motors developed so far utilize a standing wave and are of a pi-type or a hybrid transducer type structure. Traveling wave type bi-direction linear motors have not been developed yet. This paper describes design of a new bi-directional ultrasonic linear motor working by means of a traveling wave. With the finite element method we design and verify validity of the new structure. And we determine its optimal structure size of design variables material and boundary conditions for proper generation of the traveling wave.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.893-894
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• 2006

This paper presents a design and analysis solutions for the general class and control parameter estimation of slotted iron-cored Permanent Magnet Linear Synchronous Motor with Halbach magnetization stator and 3-phase winding mover. In our design and analysis, stator consisting of permanent magnets and slotted iron-cored coil mover are treated in a uniform way via magnetic vector potential. For one such motor structure, we give analytical formulas for its magnetic field, back electromotive force and trust force. Moreover, the detent force are calculated by the relative permeance function. In good agreement with the estimated values from the analyses, the experimental results and Finite Element Method (FEM) confirm the validity of the design and analysis framework.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.1
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• pp.109-116
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• 1999

To establish optimum cycle of the inverter-driven heat pump with a variation of frequency, the bypass orifice, which is a short tube having a bypass hole in the middle, was designed and tested. Flow characteristics of the bypass orifice were measured as a function of orifice geometry and operating conditions. Flow trends with respect to frequency were compared with those of short tube orifices and capillary tubes. Generally, the bypass orifice showed the best flow trends among them, that will enhance the seasonal energy efficiency ratio of an inverter heat pump system. Based on experimental data, the semi-empirical flow model was developed to predict mass flow rate through bypass orifices. The maximum difference between measured data and model's prediction was within ${\pm}5%$.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.231-234
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• 2011

본 논문은 교량의 안전진단을 위한 각 부재의 명명체계에 따라 직선형 교량모델의 각 부재에 대한 솔리드 객체의 고유번호를 일괄적으로 부여하기 위한 방법론을 제시한다. 개발된 방법론은 크게 3 단계의 프로세스로 이루어진다. 먼저, 부재의 종류별로 구분된 레이어로부터 각 부재에 대한 솔리드 객체의 도심을 추출하고, 이를 시점과 종점으로 이루어진 교축방향을 축으로 한 국부좌표계에 대해 변환한다. 이후 교축방향으로 정렬되는 객체를 식별하여 그룹핑하고 이를 교축 및 교축의 직각방향으로 순서로 정렬한다. 마지막으로 각 그룹 내 세그먼트들을 교축방향으로 정렬한다. 개발된 방법론에 따른 시범 응용모듈을 개발하였으며, 트러스 구조와 서로 다른 모델 좌표계를 가진 시범 교량모델을 대상으로 추출된 그룹의 개수와 각 객체의 명칭을 원래의 모델과 비교하여 그 적용성을 검토하였다.

• Journal of Power System Engineering
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• v.3 no.1
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• pp.74-79
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• 1999

This paper describes formulation for algorithm of time historical response analysis of vibration for straight-line structure. This method is derived from a combination of the transfer stiffness coefficient method and the Newmark method. And this present method improves the computational accuracy of the transient vibration response analysis remarkably owing to several advantages of the transfer stiffness coefficient method. We regarded the structure as a lumped mass system here. The analysis algorithm for the time historical response was formulated for the straight-line structure containing crooked, tree type system. The validity of the present method compared with the transfer matrix method and the Finite Element Method for transient vibration analysis is demonstrated through the numerical computations.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.201-206
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• 2007

In this paper, we apply a three-dimensional rigid-plastic finite element method to simulate an unsteady-state roll forming process. A typical roll forming process is investigated from the standpoint of computer simulation and its realistic analysis model is proposed. The material is considered as bulk material and discretized into hexahedral finite elements. The presented approach is applied to simulating the roll forming process of straight stringer used for aircraft structure.

• Journal of Welding and Joining
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• v.32 no.2
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• pp.4-8
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• 2014

In this research, GTA overlay welding system is developed for inside of straight pipes in various diameter. It can be applied to oil, ship building and plant industry, especially pipes connected to pressure vessels, for the purpose of cost reduction by cladding inside of pipes with corrosion and heat resistant alloys such as stainless steel or Inconel. Developed system consists of GTA power source, torch, wire feeding system, automatic arc length adjusting device, CCD camera and cooling unit. Two types of pipe inside overlay welding system are developed. One is for maximum 3m pipe length with 3 inch ~ 12 inch pipe outer diameter. Another type can be applied to maximum 12m pipe length with 7 ~ 24 inch OD. Developed system successfully produced inside cladded pipe and the results are shown through cross sectional images of the pipes.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.318-327
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• 2010

This paper deals with analysis on dynamic characteristic and circuit parameter of linear switched reluctance motor by electromagnetic analytical method. Above all, using space harmonic method, which is electromagnetic method, the air-gap flux density is analyzed in the both align and unaign positions, and the inductance profile, force characteristic and resistance per phase are calculated by means of the process. The validity of the analyzed results are demonstrated by the finite element method(FEM) and manufacture of the prototype machine. Second, the dynamic simulation is analyzed by the use of circuit parameters derived from analytical method, and the operating system of the prototype machine is manufactured to demonstrated the validity of simulation analysis. As a result, it is considered that the characteristic equation suggested in this paper will contribute to the design, analysis and application of LSRM.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.3-5
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• 2005

This paper presents a analysis solutions for the general class of iron-cored Permanent Magnet Linear Synchronous Motor(PMLSM) with vertical topologies. In our design and analysis, rotor consisting of permanent magnets and slot less iron-cored coil stator are treated in a uniform way via vector potential. For one such motor structure, we give analytical formulas for its magnetic field by permanent magnet and current coil and variation of the Back-EMF and magnetization inductance according to coil turns.