• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.497-500
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• 1995

In this paper, a program for real time simulation of a vehicle is developed. The program uses relative coordinates and BEF(Backward Difference Formula) numerical integration method. Numerical tests showed that the proposed implicit method is more stable in carring out the numerical integration for vehicl dynamics than the explicit method. Hardware requirements for real time simulation are suggested. Algorithms of parallel processing is developed with DSP (digital signal processor).

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.151-159
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• 2003

This study presents method for self-calibration of the SEM(Scanning Electron Microscope) stereo image using the standard microprobe with same grid pattern and using parallel and central perspective projection equation. Result showed that parallel projection method is more suitable for standard microprobe. The maximum error of 3D coordinates acquired by this method did not exceed 5 $\mu\textrm{m}$, and DSM(Digital Surface Model) for three dimensional measurement of the rock sample was generated by the digital photogrammetry. This result can be used for quantification of micro scale change of shape and analysis of the micro morphology of rock due to weathering.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.5
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• pp.543-547
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• 2009

This paper describes the design, simulation, development, and experiment of a six degree-of-freedom micropositioning parallel manipulator. A movable stage was supported with six links, each of which extends with a dc-servo micropositioning actuator. In case of parallel manipulator, while the solution of the inverse kinematics is easily found by the vectors of the links which are composed of the joint coordinates in base and platform, but forward kinematic is not easily solved because of the nonlinearity and complexity of the parallel manipulator's kinematic output equation with the multi-solutions. The movable range of the prototype was ${\pm}25mm$ in the x- and y-directions and ${\pm}12.5mm$ in the z-direction. The minimum incremental motion of the prototype was $1{\mu}m$ in the x- and y-directions and $0.5{\mu}m$ in the z-direction. The repeatability of the prototype was ${\pm}2{\mu}m$ in the x- and y-directions and ${\pm}1{\mu}m$ in the z-direction. The motion performance was also evaluated by not only the computer simulation of CAD model but also the experiment using a capacitive sensor system.

• Journal of Power Electronics
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• v.10 no.4
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• pp.419-427
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• 2010

A parallel control strategy in capacity proportion frequency allocation mode for shunt active power filters (APFs) is proposed to overcome some of the difficulties in high power applications. To improve the compensation accuracy and overall system stability, an improved selective harmonic current control based on multiple synchronous rotating reference coordinates is presented in a single APF unit, which approximately implements zero steady-state error compensation. The combined decoupling strategy is proposed and theoretically analyzed to simplify selective harmonic current control. Improved selective harmonic current control forms the basis for multi-APF parallel operation. Therefore, a parallel control strategy is proposed to realize a proper optimization so that the APFs with a larger capacity compensate more harmonic current and the ones with a smaller capacity compensate less harmonic current, which is very practical for accurate harmonic current compensation and stable grid operation in high power applications. This is verified by experimental results. The total harmonic distortion (THD) is reduced from 29% to 2.7% for a typical uncontrolled rectifier load with a resistor and an inductor in a laboratory platform.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.4
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• pp.301-310
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• 2013

The aim of the present study is to enhance query speed of large 3D point cloud indexed in octree by parallel query using multi-cores. Especially, it is focused on developing methods of accessing multiple leaf nodes in octree concurrently to query points residing within a radius from a given coordinates. To the end, two parallel query methods are suggested using different strategies to distribute query overheads to each core: one using automatic division of 'for routines' in codes controlled by OpenMP and the other considering spatial division. Approximately 18 million 3D points gathered by a terrestrial laser scanner are indexed in octree and tested in a system with a 8-core CPU to evaluate the performances of a non-parallel and the two parallel methods. In results, the performances of the two parallel methods exceeded non-parallel one by several times and the two parallel rivals showed competing aspects confronting various query radii. Parallel query is expected to be accelerated by anticipated improvements of distribution strategies of query overhead to each core.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.9
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• pp.764-775
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• 2002

A kinematic and dynamic optimal design of a new parallel-type rolling mill based upon Stewart platform manipulator is investigated. To provide sufficient degrees-of-freedom in the rolling process and the structural stability of each stand, a parallel manipulator with six legs is considered. The objective of this new parallel-type rolling mill is to permit an integrated control of the strip thickness, strip shape, pair crossing angle, uniform wear of the rolls, and tension of the strip. By splitting the weighted Jacobian matrices Into two parts, the linear velocity, angular velocity, force, and moment transmissivities are analyzed. A manipulability measure, the ratio of the manipulability ellipsoid volume and the condition number of a split Jacobian matrix, is defined. Two kinematic parameters, the radius of the base and the angle between two neighboring Joints, are optimally designed by maximizing the global manipulability measure in the entire workspace. The maximum force needed in the hydraulic actuator is also calculated using the structure determined through the kinematic analysis and the Plucker coordinates. Simulation results are provided.

• Design Convergence Study
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• v.14 no.4
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• pp.1-16
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• 2015

This study aims to understand distribution of the sentimental words on each genre and find relationship between box office performance and sentimental words in movie review using 673 movies that have more than 1,000 reviews. For the analysis, crawling movie reviews and made data was composed movie genre, movie name, sales, attendance, screen, normal attendance, 7 sentimental words. For analysis results, we used correlation analysis and Parallel coordinates. As a results, First, the highest box office value of the genre is comedy and the lowest box office value of the genre is horror through analyze box office on each genre. Secondly, Movie genre of fantasy feel a lot of boring emotion and Movie genre of SF feel a lot of anger emotion even if 'Happy' and 'Surprise' have highest sentiment value on every genre. Third, We found 'Anger' increase sentimental value when 'Disgust' increase sentimental value and 'Surprise' decrease sentimental value when 'Happy' increase sentimental value through analyze correlation relationship between sentimental words using total data. Fourth, We found 'Happy' have linear relationship between box office and 'Fear' have non-linear relationship between box office through analyze sentimental words according to box office performance.

• 전자공학회논문지 IE
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• v.46 no.1
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• pp.23-30
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• 2009

In this paper, the intelligent vision system for an effective and intelligent path-planning of an industrial AGV system based on stereo camera system is proposed. The depth information and disparity map are detected in the inputting images of a parallel stereo camera. The distance between the industrial AGV system and the obstacle detected and the 2D Path coordinates obtained from the location coordinates, and then the relative distance between the obstacle and the other objects obtained from them. The industrial AGV system move automatically by effective and intelligent path-planning using the obtained 2D path coordinates. From some experiments on AGV system driving with the stereo images, it is analyzed that error ratio between the calculated and measured values of the distance between the objects is found to be very low value of 2.5% on average, respectably.

• The Korean Journal of Applied Statistics
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• v.14 no.1
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• pp.177-190
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• 2001

전통적으로 많이 사용하는 군집분석의 방법들은 개체간의 거리를 고려하여 이들을 분류해 내는 것이며, 따라서 거리 측정 방법에 따라 여러 형태의 군집분석 방법이 나타나게 된다. 어떤 방법을 적용하던 간에 그 결과는 고정된 수치로써 나타난다. 다차원 자료의 구조파악이 몇 개의 수치로 나타나게 되면 어쩔 수 없이 정보의 손실이 발생하게 된다. 이를 보완하기 위해 시각적 매체를 동원하여 다차원 자료의 구조를 파악하는 연구가 있었으며, 이를 시각적 군집분석이라고 명명하고 있다. 본 연구에서는 시각적 군집분석에 대한 기본적 개념과 이를 위한 통계 도형의 활용, 구현방법 등에 대해 살펴보기로 한다.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.125-128
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• 2002

This paper propose a rectification technique by applying the Projection matrices derived from perspective projection matrices estimated from self-calibrated stereo image pairs. The derivation is made such that two epipolar lines are in parallel. Rectified images are generated by reprojecting corresponding image points. For the performance analysis of this technique, vertical coordinates of rectified points are compare to those obtained by the technique[3].