• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.61.6-61
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• 2001

In this paper, we propose a method to analyze measured data from 3D Laser tracking system and to enhance precision performance of a Cartesian robot. Position data are obtained over the stroke of a Cartesian robot with variable speeds. The measured data is need to model errors with several different sources. In general, the error is a function of part accuracy, assembly accuracy, temperature, and control etc. After the sources of errors are identified, they are used to enhance precision performance. The proposed method is more complete than others because we use very accurate 3D Laser tracking system.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.6
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• pp.408-414
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• 2004

In this paper, a disturbance observer based sliding mode control is proposed to attenuate disturbance responses in an active magnetic bearing system, which is subject to base motion. An algorithm which decouples disturbance observation dynamics from sliding mode dynamics is suggested. This algorithm preserves the robustness of the sliding mode control and satisfies reachability condition in the presence of external disturbance and parameter uncertainties. Along with experimental results, it is shown that the proposed control is effective in disturbance rejection without any additive disturbance measurement.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.1
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• pp.97-109
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• 2014

This study developed a functional dress shirt for adult males that reflected the body surface variation of a human body section by motion. This study conducted a 3D body scan for 8 subjects in their 40's based on the Size Korea 2010 database. Data recorded the proper posture change value and body surface change value to develop functional dress shirts for adult males. We scanned the subjects with a 3D body scanner for five primarily male wearing dress shirts and operating postures, right standing, arms raised to $90^{\circ}$ horizontal forward position, arms raised $90^{\circ}$ to the horizontal position side, lift up the arm $180^{\circ}$, and arm forward $90^{\circ}$ in a bent posture. We analyzed the 3D scan data from those motions to examine change of length using 3D software Rapidform XOS. The results indicated that the body surface sections with contraction were the front and rear shoulder area, armpit and central length as well the width of arms at more than 10%. The increased body section included the body and armpit back length; in addition, the rear arm vibration girth and under arm girth were more than 10%. In order to reflect the size variation of for each motion, the ease amount of the front and rear shoulder length and width needs to be reduced 20% because it affects the shoulder length during the right standing. The results suggest that the ease amount of the shoulder length should be minimal. The ease amount of the back size needs to be 0.5-2cm bigger and set 0.5-1.5cm longer than the dress shirt length side drooping to compensate for the side length shortage of each motion. The sleeve length needs to be 0-0.5cm shorter, and ease amount of the girth of sleeve bottom needs to be reduced 0-0.7cm due to the size variation of arms. However, the girth of the rear arms is suggested to be 0-0.6cm longer in the ease amount to the rear arm girth as the extension is more than 10% over the width and length of each motion.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.145-155
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• 2013

In this paper, we proposed a $4{\times}4$ block parallel architecture of interpolation for high-performance H.264/AVC Fractional Motion Estimation in 8K UHD($7680{\times}4320$) video real time processing. To improve throughput, we design $4{\times}4$ block parallel interpolation. For supplying the $10{\times}10$ reference data for interpolation, we design 2D cache buffer which consists of the $10{\times}10$ memory arrays. We minimize redundant storage of the reference pixel by applying the Search Area Stripe Reuse scheme(SASR), and implement high-speed plane interpolator with 3-stage pipeline(Horizontal Vertical 1/2 interpolation, Diagonal 1/2 interpolation, 1/4 interpolation). The proposed architecture was simulated in 0.13um standard cell library. The gate count is 436.5Kgates. The proposed H.264/AVC Fractional Motion Estimation can support 8K UHD at 30 frames per second by running at 187MHz.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.6
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• pp.965-977
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• 2021

The study aimed to analyze the functional differences in 3D virtual garment programs and compare body scan data with the corresponding 3D virtual models. We selected 3D virtual garment programs, formed virtual models in a representative size for high-school male cyclists, and analyzed them using the Design-X program. The results were as follows. In the 3D virtual garment programs, the anthropometric items for virtual model forming differed significantly from the standard anthropometric items suggested by Size Korea. Comparing the lower body scan data and virtual models formed by the 3D virtual garment programs, the biggest difference was in the shapes of the waist and hips, i.e., the flatness values of the waist and hips were different for each program in the cross-section view. In the lower body, a data-input-based program was needed for changing the exact measurement position of the waist circumference and hips' shape in detail. If a 3D virtual garment program provides functions for the virtual model's joint angle input and free motion transformation, it is expected to be widely used in the sportswear industry.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.1
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• pp.105-112
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• 2013

This paper presents the structural design and finite element analysis of precision stage based on a double triangular parallel mechanism for precision positioning and large force generation. Recently, with the acceleration of miniaturization in mobile appliances, the demand for precision aligning and bonding has been increasing. Such processes require both high precision and large force generation, which are difficult to obtain simultaneously. This study aimed at constructing a precision stage that has high precision, long stroke, and large force generation. Actuators were tactically placed and flexure hinges were carefully designed by optimization process to constitute a parallel mechanism with a double triangular configuration. The three actuators in the inner triangle function as an in-plane positioner, whereas the three actuators in the outer triangle as an out-of-plane positioner. Finite element analysis is performed to validate load carrying performances of the developed precision stage.

• Archives of Orthopedic and Sports Physical Therapy
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• v.14 no.2
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• pp.1-8
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• 2018

Purpose: This study investigated the effect of the augmented reality (AR)-based knee joint short period exercise program and used a motion analyzer with a 3D camera to determine the range of motion and dynamic balance and further investigate the effects of therapeutic exercise on patients. Methods: This study used AR-based motion analysis and a Y-balance test to measure the range of motion (ROM) of each joint: the hip joint and the knee joint. After the measurements, an exercise program was applied to the subjects, using the knee motion program function, and the muscles of the quadriceps femoris and the hamstring were stretched or strengthened. Results: Our results showed knee joint extension at the dominant hip joint flexion position. While there was no significant difference (p>.05) at this position, there were significant differences in the non-dominant hips, unbalanced knee joint flexion, and superior knee joint flexion (p<.05). The Y-balance test using the non-dominant leg supported by the dominant legs showed that the absolute reach was $69.70{\pm}7.06cm$ before the exercise, and the absolute reach after the exercise was $77.56{\pm}6.09cm$ (p<.05). Conclusions: There was a significant difference when the movement of the lower limbs supported the superior limbs, and a significant difference was found in the ROM when the non-dominant side supported the dominant side. Therefore, the AR-based exercise program improves the balance of the human body and the range of motion of the joints, and research that aims to improve patients abilities should continue.

• Structural Engineering and Mechanics
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• v.61 no.6
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• pp.785-794
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• 2017

This paper is concerned with the comparative numerical and experimental study on the natural behavior and the motion responses of a 1/75 moored scale model of a 2.5 MW spar-type floating offshore wind turbine subject to 1-D regular wave. Heave, pitch and surge motions and the mooring tensions are investigated and compared by numerical and experimental methods. The upper part of wind turbine which is composed of three rotor blades, hub and nacelle is modeled as a lumped mass and three mooring lines are pre-tensioned by means of linear springs. The numerical simulations are carried out by a coupled FEM-cable dynamics code, while the experiments are performed in a wave tank equipped with the specially-designed vision and data acquisition system. Using the both methods, the natural behavior and the motion responses in RAOs are compared and parametrically investigated to the fairlead position, the spring constant and the location of mass center of platform. It is confirmed, from the comparison, that both methods show a good agreement for all the test cases. And, it is observed that the mooring tension is influenced by all three parameters but the platform motion is dominated by the location of mass center. In addition, from the sensitivity analysis of RAOs, the coupling characteristic of platform motions and the sensitivities to the mooring parameters are investigated.

• Journal of Sensor Science and Technology
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• v.18 no.6
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• pp.461-466
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• 2009

This paper represents a piezoelectric ultrasonic linear actuator with flexural vibration mode. The actuator is composed of two piezo ceramics, the elastic body, and the connecting tip. It is driven by the frictional force between the connecting tip and the linear motion guide. Unimorph actuators have flexural vibration. Its middle point is fixed so that suitable to the flexural vibration of $3/2\lambda$. These vibrations contribute to elliptical motion by mixed mode between longitudinal and transverse mode. It was generated when the ultrasonic electrical signals with 90 degree phase difference are applied to two ceramics. A linear movement can be easily obtained using the elliptical motion. The ATILA, FEM simulator has been used to design actuator and verify the kinetic and dynamic analysis. We used the ceramics of $20\times10\times1$ mm size and confirmed the flexural vibration of the $3/2\lambda$ at the 79 kHz through the scanning of 3D-vibrometer. The maximum velocity of actuator was 221 mm/sec and the thrust force of actuator was 2.7 N in 200Vp-p of additional voltage.

• Journal of Broadcast Engineering
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• v.5 no.2
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• pp.247-259
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• 2000

This paper introduces a new technique that reduces the search times and Improves the accuracy of motion estimation using high temporal and spatial correlation of motion vector. Instead of using the fixed first search Point of previously proposed search algorithms, the proposed method finds more accurate first search point as to compensating searching area using high temporal and spatial correlation of motion vector. Therefore, the main idea of proposed method is to find first search point to improve the performance of motion estimation and reduce the search times. The proposed method utilizes the direction of the same coordinate block of the previous frame compared with a block of the current frame to use temporal correlation and the direction of the adjacent blocks of the current frame to use spatial correlation. Based on these directions, we compute the first search point. We search the motion vector in the middle of computed first search point with two fixed search patterns. Using that idea, an efficient adaptive predicted direction search algorithm (APDSA) for block matching motion estimation is proposed. In the experimental results show that the PSNR values are improved up to the 3.6dB as depend on the Image sequences and advanced about 1.7dB on an average. The results of the comparison show that the performance of the proposed APDSA algorithm is better than those of other fast search algorithms whether the image sequence contains fast or slow motion, and is similar to the performance of the FS (Full Search) algorithm. Simulation results also show that the performance of the APDSA scheme gives better subjective picture quality than the other fast search algorithms and is closer to that of the FS algorithm.