• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1635-1636
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• 2013

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.326.2-326
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• 1999

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.789-792
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• 2003

Pipe inspection has a great importance to ensure safety for the nuclear power plant. In this paper, we designed visual inspection module for the tube internal, which diameter is 15${\sim}$20mm. And we made inspection module which consisted of CCD camera and light. And the relation between image and real world coordinate is established. Image processing is performed to calculate mapping parameter and analyze the size of defect. For the calculation of mapping parameter, experiment is performed using grid type test pattern. Acquired image is processed to extract image coordinate. Edge detection, thresholding, median filtering and morphology filtering is applied to extract grid pattern. Extracted image coordinate is used to calculate image to real world mapping. Lens distortion was considered and corrected to get exact data. Coordinate transformation data is provided for the users to recognize easily. Experiment was performed using grid type test pattern, we extracted lens distortion parameter and real coordinate of defect point. Radial distortion of lens was corrected but tangential distortion was not considered. As continuum to this study, the tangential distortion of lens is considered and improvement of analy zing technique for the tube internal be explored continuously.

• Spatial Information Research
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• 제13권3호
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• pp.297-307
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• 2005

본 연구는 예당저수지의 합리적인 유지와 준설사업의 기초자료를 확보하기 위하여 수행하였다. 퇴적량 산정을 위한 내용적 측량을 DGPS 음향 측심기를 이용하여 2004년 11월 $25\~30$일간 수행하였다. 인공위성으로부터 위도와 경도신호는 1 초 간격으로 UTM 좌표 계로 수신하였다. 수심 값은 0.2초 간격으로 MIDAS Surveyor에 있는 Eecho sounder sensor 로 측정하였다 Arc Info GIS 프로그램을 사용하여 우리나라 좌표계인 TM좌표로 변환하였다. 등수심선도 작성은 Sufer, Arc View와 Auto CAD Program을 사용하였다. 저수지 용량은 평균등고선면적법으로 산정하였다. 예당저수지의 유효저수량을 결정하기 위한 이번 조사의 결과는 4,601.6ha-m로 기왕의 유효저수량보다 약 5.425ha-m정도 퇴적된 것으로 파악되었다.

• 지적과 국토정보
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• 제54권1호
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• pp.103-115
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• 2024

삼변망조정계산은 지적도면을 세계측지계 도면으로 변환함에 있어 좌표변환계산의 문제점을 보완할 수 있다. 첫째, 광범위한 지역에 걸쳐 상호 정합하는 기준점 좌표를 결정할 수 있다. 둘째, 지역의 특정 점을 중시하는 계산처리를 할 수 있다. 셋째, 구속조건에 의해 지역망 전체의 형상을 유지하는 해를 구할 수 있다. 이로써 측량 공통점의 좌표를 지역의 측량체계에 알맞게 결정할 수 있다. 기타원점계열 등 원점이 다른 지역 간에 걸쳐 있는 이질적 측량성과를 단일 원점 기준의 성과로 산출하는 데에도 활용가능하다. 여러 지역에 걸쳐 특성이 다른 공통점의 지역측지계 좌표를 정확하게 구할 수 있으므로, 지역측지계 도면을 세계측지계 도면으로 변환하는 작업을 안정적으로 수행할 수 있게 한다.

• KSTLE International Journal
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• 제5권2호
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• pp.52-56
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• 2004

The hard disk drive performance depends strongly on air bearing characterisitcs of the head slider. The objective of the slider design is to provide accurate positioning of the magnetic read/write element at the very small height above the disk. Application of the numerical methods is required due to complexity of the air bearing surface of the slider. The Boundary-Fitted Coordinate System Divergence Formulation method can be used for calculation of pressure distribution in the case of steep film thickness gradients. In the present work, the interpolating functions used in the expression for the Couette flow are modified in order to improve the solution characteristics in the extremely high compressibility number region. The advantages of the modified method are demonstrated on example of the flat skewed slider. Finally, the modi.ed method is applied to analysis of the static characteristics of the femto-slider. The analysis results indicate the effect of the silder's air bearing surface crown on the flying height and the pitching angle in steady state position.

• International Journal of Aeronautical and Space Sciences
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• 제7권2호
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• pp.155-174
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• 2006

Parabolized stability equations for compressible flows in general curvilinear coordinate system are derived to deal with a broad range of transition prediction problems on complex geometry. A highly accurate finite difference PSE code has been developed using an implicit marching procedure. Compressible and incompressible flat plate flow stability under two-dimensional and three¬dimensional disturbances has been investigated to test the present code. Results of the present computation are found to be in good agreement with the multiple scale analysis and DNS data. Stability calculation results by the present PSE code for compressible boundary layer at Mach numbers ranging from 0.02 to 1.5 are also presented and are again seen to be as accurate as the spectral method.

• 한국소음진동공학회논문집
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• 제17권11호
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• pp.1086-1092
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• 2007

This paper is concerned with the vibration analysis of a rectangular plate with multiple circular holes. On the contrary to the case of rectangular plate with multiple rectangular holes, it is very difficult to perform qualitative analysis on natural vibration characteristics because of geometrical inconsistency. In this paper, we applied the Independent Coordinate Coupling Method(ICCM) to the addressed problem, which was developed to compute natural vibration characteristics of the rectangular plate with a circular hole and proven to be computationally effective. The ICCM is based on Rayleigh-Ritz method but utilizes independent coordinates for each hole domain. By matching the deflection conditions for each hole imposed on the expressions, we can easily derive the reduced mass and stiffness matrices. The resulting equation is then used for the calculation of the eigenvalue problem. The numerical results show the efficacy of the Independent Coordinate Coupling Method.

• Interaction and multiscale mechanics
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• 제2권4호
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• pp.413-430
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• 2009

The stator tooth is a key component of the electromechanical integrated toroidal drive system. The stator tooth is spiral in shape and the calculation of its displacements is difficult. In this paper, using the coordinate transformation method, the displacements of the stator tooth in the local coordinate system are expressed as the function of the variable in the drive coordinate system. Using the minimum potential energy principle, the equations of the displacements of the stator tooth under the loads are deduced. The displacement distributions within the stator tooth are investigated and the changes of the displacement distributions along with the main parameters are analyzed. This research can offer the basis for the strength and stiffness design of the drive system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.137-140
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• 1999

A lot of researcher have proposed a method of kernel identifying nonlinear system by use of Wiener kernels[6-7] or Volterra kernel[5] and so on. In this research, the authors proposed a method of identifying Volterra kernels for nonlinear system by use of pseudorandom M-sequence in which a crosscorrelation function between input and output of a nonlinear system is taken[4]. we can be applied to an MISO nonlinear system or a system which depends on its input amplitude[2]. But, there exist many systems in which it is difficult to determine a Volterra kernel having the same time coordinate on the crosscorrelation function. In those cases, we have to estimate Volterra kernel by using its neighboring points[4]. In this paper, we propose a new method for not estimating but obtaining Volterra kernel having the same time coordinate using calculation between the neighboring points. Some numerical simulations show that this method is effective for obtaining higher order Volterra kernel of nonlinear control systems.