• 한국항행학회논문지
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• 제15권2호
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• pp.227-233
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• 2011

본 논문에서는 저면적 ISDB-T 시간 디인터리버 구조를 제안하였다. ISDB-T는 일본과 중남미에서 많이 사용되고 있는 이동형 TV 표준으로써 긴 인터리빙을 이용하여 다른 표준에 비해 높은 성능을 보이고 있다. 그러나 긴 인터리빙을 구현하기 위해서는 많은 지연 버퍼가 필요하다. 지연 버퍼들은 주소 레지스터가 있어야 하므로 주소 레지스터의 개수도 많아진다. 본 논문에서는 디인터리버의 등가 변환을 통해 주소 레지스터의 개수를 크게 줄이는 구조를 제안하였다. 실험 결과를 통해 디인터리버의 면적을 줄일 수 있음을 확인할 수 있었다.

• 한국소음진동공학회논문집
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• 제20권11호
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• pp.1033-1037
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• 2010

Accelerometer and laser vibrometers are widely used to measure vibration of structures like a building or piping. Recently, the research measuring vibration by using camera image is introduced. This method can measure multi-points simultaneously. Also, it is possible to measure in the long distance. When we measure the vibration using a camera, the parameter analysis is needed. Therefore, this paper took the experiment for the camera lens selection. An error by the camera images characteristic was theoretically analyzed and we verified through an experiment. And the accuracy of the method measuring the vibration displacement by using the camera images was analyzed.

• 한국정밀공학회지
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• 제24권5호
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• pp.127-134
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• 2007

Presented in the paper is an algorithm to generate a section curve by slicing a point cloud including tens of thousands of points. Although, there have been previous research results on the slicing problem, they are quite sensitive on the density variations of the point cloud, as well as on the local noise in the point cloud. To relive the difficulties, three technological requirements are identified; 1) dominant point sampling, 2) avoiding local vibration, and 3) robustness on the density changes. To satisfy these requirements, we propose a new slicing algorithm which is based on a node-sphere diagram. The algorithm has been implemented and tested with various examples.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.87-90
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• 1988

This paper reports a simple posteriori error estimate method for adaptive finite element mesh generation using quadratic shape function especially for the magnetic field problems. The elements of quadratic shape function have more precise solution than those of linear shape function. Therefore, the difference of two solutions gives error quantity. The method uses the magnetic flux density error as a basis for refinement. This estimator is tested on two dimensional problem which has singular points. The estimated error is always under estimated but in same order as exact error, and this method is much simpler and more convenient than other methods. The result shows that the adaptive mesh gives even better rate of convergence in global error than the uniform mesh.

• 한국기계연구소 소보
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• 통권19호
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• pp.81-92
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• 1989

This paper presents a simple identification method of the actual kinematic parameters for the robot with parallel joints. It is known that Denavit-Hartenberg's coordinate system is not useful for nearly parallel joints. In this paper, the coordinate frames are reassigned to model the kinematic parameter between nearly parallel joints by four parameters. The proposed identification method uses a straight ruler about 1m long. A robot hand is placed by using a teaching pendant at the prescribed points on the ruler, and corresponding error function is defined. The identified kinematic parameters which make the error function zero are obtained by iterative least square error method based on the singular value decomposition. In the compensation of joint angles, only the position is considered because the usual applications of robot do not require a precise orientation control.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.851-856
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• 2007

Recently, the matter controlling lateral drift is important in high rise buildings, In particular, seismic control dampers, such as mass damper and hysteretic damper, are emerging in the field of actively reducing drift. But. seismic control dampers have weak points with the lack of quantitative analysis and maintenance of the device. Accordingly, in this study we examine the structural characteristic of Steel Elasto-Plastic Hysteretic Damper, which is needless of maintenance, and then consider the basic conditions in the design and construction of the optimal seismic control effect which uses this device.

• 전기학회논문지
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• 제65권12호
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• pp.2094-2102
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• 2016

In this paper, we propose an extended Kalman filter(EKF)-based simultaneous localization and mapping(SLAM) method using laser corner pattern matching for mobile robots. SLAM is one of the most important problems of mobile robot. However, existing method has the disadvantage of increasing the computation time, depending on the number of landmarks. To improve computation time, we produce the corner pattern using classified and detected corner points. After producing the corner patterns, it is estimated that mobile robot's global position by matching them. The estimated position is used as measurement model in the EKF. To evaluated proposed method, we preformed the experiments in the indoor environments. Experimental results of proposed method are shown to maintain an accuracy and decrease the computation time.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1999년도 춘계 학술대회논문집
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• pp.177-185
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• 1999

The airfoil design optimization procedures based on the Navier-Stokes equations were developed, This procedure enables more realistic and practical transonic airfoil designs. The modified Hicks-Henne functions were used to generate the shape of airfoils. Five Hick-Henne functions were used to design upper surface of airfoil only. To enhance the ability of Hick-Henne function to generate various airfoil shape with limited number of functions, the positions of control points were adjusted through optimization procedure. The design procedure was applied to the single-point design for the drag minimization problem with lift and area constraints. The result shows the capability of the procedure to generate much realistic airfoils with very small drag-creep in the low transonic regime. This is mainly due to the viscosity effect of Navier-Stokes flow analysis. However, in the higher transonic range tile drag-creep appears. The multi-point design is shown to be an effective way to avoid the drag-creep and improve off-design performance which is very similar in the Euler design.

• 한국컴퓨터그래픽스학회논문지
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• 제10권1호
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• pp.15-21
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• 2004

This paper proposes a real-time technique for simulating large rotational deformations. Modal analysis based on a linear strain tensor has been shown to be suitable for real-time simulation, but is accurate only for moderately small deformations. In the present work, we identify the rotational component of an infinitesimal deformation, and extend linear modal analysis to track that component. We then develop a procedure to integrate the small rotations occurring al the nodal points. An interesting feature of our formulation is that it can implement both position and orientation constraints in a straightforward manner. These constraints can be used to interactively manipulate the shape of a deformable solid by dragging/twisting a set of nodes, Experiments show that the proposed technique runs in real-time even for a complex model, and that it can simulate large bending and/or twisting deformations with acceptable realism.

• 전기학회논문지
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• 제61권5호
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• pp.721-725
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• 2012

In this paper, a novel analysis on the nonlinear response of a power amplifier (PA) with the intermodulation distortion (IMD) asymmetry is proposed based on the mutislice behavioral model. The coefficients of the odd-order and even-order polynomial of that model are represented with the PA practical circuit parameters such as intercept points, gain and amplitudes of excitation inputs. We also develop the analytic expressions to distinguish baseband frequency effect from second harmonic effect on the IMD asymmetry. We also validate the derived analytic expressions through measurements.