• 전자공학회논문지B
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• 제33B권2호
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• pp.10-19
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• 1996

This paper presents a finger-shaped multisensor system which can measure the tyep and position of a target surface by contactl. The multi-sensor system consists of a sphere-shpaed optical tactile sensor located at the finger tip and a force/torque sensor located at the joint of a finger. The optial tactile sensor determines the type and position of the target surface using the shape and position of the CCD image of the touching area generated by a contact between the sensor and the taget surface. The force/torque sensor also determines the position and surface normal vector by applying the distributionof forces and torques t the contact point to the equations of finger shape. The measurements on the position and surface normal vector at a contact point obtined by two individual sensors are fused using a statistical method. The integrated sensor system has 0.8mm error in position measurement and 1.31$^{\circ}$ error in normal vector measurement. The developed sensor system has many applications, such as autonomous compliance control, automatic grasping and recognition, etc.

• 한국해양공학회지
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• 제21권4호
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• pp.55-60
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• 2007

In contrast to the method in Part I, which is considered to be the general approach, Part II pursues a closed-form solution. However, this closed-form solution is available only in the 2D situation under the assumption that the moving object is restricted to a 2D space, and also requires the use of only two laser-slit sensors. Since the motion of the container loaded on top of an AGV is restricted to a plane parallel to the ground, it can be considered a 2D motion. As a simple method, but with a high cost, the use of a laser scanner is also discussed. Since the approach in Part I already uses three laser-slit sensors, it is desirable to use the schemes presented in Part II for supplementary purposes.

• 한국정밀공학회지
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• 제24권6호
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• pp.66-71
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• 2007

Development of a locomotive mechanism for the capsule type endoscopes will largely enhance their ability to diagnose disease of digestive organs. As a part of it, there should be provided a detection device of their position in human organs for the purpose of observation and motion control. In this paper, a permanent magnet outside human body was employed to project magnetic field on a capsule type endoscope, while its position dependent flux density was measured by three hall-effect sensors which were orthogonally installed inside the capsule. In order to detect the 2-D position data of the capsule with three hall-effect sensors including the roll, pitch and yaw angle, the permanent magnet was extra translated during the measurement. In this way, the 2-D coordinates and three rotation angles of a capsule endoscope on the same motion plane with the permanent magnet could be detected. The working principle and performance test results of the capsule position detection device were introduced in this paper showing that they could be also applied to 6-DOF position detection.

• 제어로봇시스템학회논문지
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• 제22권10호
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• pp.839-846
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• 2016

Bin picking is a task of picking a small object from a bin. For accurate bin picking, the 3D pose information, position, and orientation of a small object is required because the object is mixed with other objects of the same type in the bin. Using this 3D pose information, a robotic gripper can pick an object using exact distance and orientation measurements. In this paper, we propose a 3D vision technique for accurate measurement of 3D position and orientation of small objects, on which a paper label is stuck to the surface. We use a maximally stable extremal regions (MSERs) algorithm to detect the label areas in a left bin image acquired from a stereo camera. In each label area, image features are detected and their correlation with a right image is determined by a stereo vision technique. Then, the 3D position and orientation of the objects are measured accurately using a transformation from the camera coordinate system to the new label coordinate system. For stable measurement during a bin picking task, the pose information is filtered by averaging at fixed time intervals. Our experimental results indicate that the proposed technique yields pose accuracy between 0.4~0.5mm in positional measurements and $0.2-0.6^{\circ}$ in angle measurements.

• 제어로봇시스템학회논문지
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• 제16권2호
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• pp.202-205
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• 2010

When we render 3D sound images using headphones or speakers, the main key of this technology is the Head-related transfer function (HRTF) database. Even though there are various HRTF databases, they have some drawbacks such as detrimental effects caused by imperfect measuring environment and insufficient measurement points. Moreover there is no database with Korean subjects. We are planning to develop the HRTF database for Korean. As a first step to establish the HRTF database aimed at Korean, the new HRTF measurement system with minimized aforementioned drawbacks is designed. In this paper, the newly designed HRTF measurement system is introduced and the overall effects caused by the diffraction of the apparatus, especially the headrest and backrest of the chair, are analyzed. The backrest of the chair does not distort the HRTFs significantly while the headrest makes significant distortion on the HRTFs and it could have significant effects on directional perception. We determined acceptable head rotation angle and head position of the subject for accurate HRTF measurement based on the experiments with B&K HATS. We conclude that the 3 degrees of the head rotation and the 1.5cm front/back/left/right shift of the head do not distort the HRTFs significantly.

• 방송공학회논문지
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• 제19권2호
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• pp.215-226
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• 2014

3D 기술은 초기의 붐 이후 점차 느리게 확산되고 있다. 그 원인 중 하나로 현재 3D 입체 영상을 시청할 수 있는 디스플레이가 주로 안경을 사용하며 그 때문에 사용 환경이 제한적이라는 점을 들 수 있다. 이런 측면에서 본 연구에서는 기존에 주로 연구되었던 안경식 디스플레이가 아닌 휴대용 무안경식 3D 디스플레이를 대상으로 기존에 잘 연구되지 않았던 지각적 크로스톡과 입체 시각 피로를 측정하고 그 결과를 모형화 하였다. 그 결과 휴대용 무안경식 3D 디스플레이의 수평 위치에 따라 지각되는 크로스톡이 체계적으로 변화한다는 것을 확인하였다. 측정된 크로스톡은 화면 중심부에서 상대적으로 낮았으나 좌/우측으로 이동함에 따라 급격하게 증가하는 현상을 보였으며, 이런 변화 경향성은 입체 시각 피로 및 불편감 측정 과정에서도 나타났다. 본 연구의 결과는 무안경식 디스플레이를 설계하고 평가하는 과정에서 지각적 요소를 고려하는 것이 필요함을 시사한다.

• 전기전자학회논문지
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• 제13권2호
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• pp.220-223
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• 2009

A simple measurement system is built to estimate the dual-antenna diversity gain at 2.4GHz easily in open lab environment. To obtain multipath fading propagation channel, the system consists of two transmission horn that placed on opposite direction and a rotating stage mechanically changing the position of test dual-antenna with time over distance greater than one wavelength. Estimated diversity is nearly same as theoretical value such that measured diversity gain of 30mm separated is about 6dB similar to theoretical value of 5.7dB and increases monotonically with the increasing separation distance as predicted by the theory. Proposed measurement system that is simple enough to fit in a small space can evaluate the performance of various dual-antennas with a reasonable accuracy with lower 5% difference between the ten sets of measured waveform distribution and theoretical Rayleigh cumulative distribution.

• 한국정밀공학회지
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• 제17권8호
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• pp.60-70
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• 2000

In this paper a 3D position measuring device that finds the 3D position of an arbitarily placed object using a camersa system is introduced. The camera system consists of three stepping motors and a CCD camera and a laser. The viewing direction of the camera is controlled by two stepping motors (pan and tilt motors) and the direction of a laser is also controlled by a stepping motors(laser motor). If an object in a remote place is selected from a live video image the x,y,z coordinates of the object with respect to the reference coordinate system can be obtained by calculating the distance from the camera to the object using a structured light scheme and by obtaining the orientation of the camera that is controlled by two stepping motors. The angles o f stepping motors are controlled by a SGI O2 workstation through a parallel port. The mathematical model of the camera and the distance measuring system are calibrated to calculate an accurate position of the object. This 3D position measuring device can be used to acquire information that is necessary to monitor a remote place.

• 한국정밀공학회지
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• 제31권12호
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• pp.1133-1139
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• 2014

This paper proposes a simple method to improve a sensitivity of a straightness measurement system for a linear stage, which is applied to a system based on a geometric optic method. An optical system for this method is composed of a corner-cube retro-reflector, a ball-lens and a twodimensional position sensitive detector (2D PSD). The effectiveness of the proposed method was examined theoretically, and verified experimentally using a prototype measurement system. The results show that the measuring sensitivity was dependent on the size of the ball-lens and the setup position of PSD from the ball-lens, and that the proposed method is efficient method to improve the measuring sensitivity.

• 한국의류산업학회지
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• 제10권5호
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• pp.676-682
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• 2008

In this study a guideline of the 3D-fit pattern for the ECG(electrocardiogram) measurement of elderly's u-healthcare clothes was proposed. In the screening test of the ECG measurement band, ECG peak band was observable at the band pressure of 0.20 kPa. By employing a 3D body image, tight-fit 3D patterns were made at two different reduction rates of 21%(pattern 1) and 33%(pattern 2), and corresponding pressure of both of the clothes were 0.25 kPa and 0.54 kPa, respectively. Typical waves of ECG were found in both stationary and moving position. In terms of the subjective evaluation of the u-healthcare clothes when worn, it was confirmed that reduction pattern 1(0.25 kPa) conveyed comfortable clothing pressure and pleasantness, which is very close to the result of screening test of ECG band experiment. As results, it is recommended that reduction rate should be adjusted, so that clothing pressure is about 0.2 kPa for the elderly's comfortable and efficient u-healthcare clothes.