• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.382-387
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• 1992

In order to obtain desired arc welding performance, we already developed an arc welding robot system that enabled coordinated motions of dual arm robots. In this system one robot arm holds a welding target as a positioning device, and the other robot moves the welding torch. Concerning to such a dual arm robot system, the positioning accuracy of robots is one important problem, since nowadays conventional industrial robots unfortunately don't have enough absolute accuracy in position. In order to cope with this problem, our robot system employed teaching playback method, where absolute error are compensated by the operator's visual feedback. Due to this system, an ideal arc welding considering the posture of the welding target and the directions of the gravity has become possible. Another problem still remains, while we developed an original teaching method of the dual arm robots with coordinated motions. The problem is that manual teaching tasks are still tedious since they need fine movements with intensive attentions. Therefore, we developed a 3-dimensional vision guided robot control method for our welding robot system with coordinated motions. In this paper we show our 3-dimensional vision sensor to guide our arc welding robot system with coordinated motions. A sensing device is compactly designed and is mounted on the tip of the arc welding robot. The sensor detects the 3-dimensional shape of groove on the target work which needs to be weld. And the welding robot is controlled to trace the grooves with accuracy. The principle of the 3-dimensional measurement is depend on the slit-ray projection method. In order to realize a slit-ray projection method, two laser slit-ray projectors and one CCD TV camera are compactly mounted. Tactful image processing enabled 3-dimensional data processing without suffering from disturbance lights. The 3-dimensional information of the target groove is combined with the rough teaching data they are given by the operator in advance. Therefore, the teaching tasks are simplified

• Korean Journal of Applied Biomechanics
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• v.14 no.1
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• pp.27-40
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• 2004

The purpose of this study was to provide basic data for improving athletic performances by analyzing the kinematic variables of the Double Backward Somersault on the Parallel Bars through the 3D motion analysis. The subjects in this study were 5 male gymnasts who were ranked as national athletes. The results are as follows. 1. A total time(Mean Time) of performance showed $2.72{\pm}0.82\;sec$. and flight time to landing after releasing was 0.87sec.(mean). In order to perform better stable flying movement, the flight time should be increased. 2. In the change of velocity of the center of mass, when the increasing ascension velocity of the upper point was high, the position in the top point was high on releasing. 3. In the position variable of the center of mass, the mean of upper-bottom position in horizontal posture was $242.1{\pm}6.5cm$, $232.8{\pm}6.4cm$ in releasing, and $265.0{\pm}5.6cm$ in the highest point. This result is explained that the position of center of mass can be raised by using elastic power when wrist raised the bar in the releasing movement. 4. The angle of shoulder joint was $271.1{\pm}14.0$. Such a big angle influences a negative effect on the releasing velocity, because trunk is not a position in the enough vertical direction. 5. The ankle of hip joint in hand-standing was $191.1{\pm}5.9$, $118.8{\pm}5.3$ in releasing, and $122.3{\pm}5.3$ in taking on. Therefore, the result suggests that trunk should be straightly raised in taking on.

• Journal of the Ergonomics Society of Korea
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• v.33 no.2
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• pp.143-153
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• 2014

Objective: The aim of this study is to investigate the effects of trunk-forearm supported sitting on trunk flexion angle, trunk extensor fatigue and seat contact pressure. Background: The relationship between sitting posture and musculoskeletal disorders of the trunk extensor fatigue and seat contact pressure has been documented. The trunk-forearm support type ergonomic chair was devised from the fact that trunk-forearm support has been reported to reduce trunk extensor activity and discomfort. Method: Using three different sitting postures, upright ($P_1$), trunk-forearm supported ($P_2$) and normal sitting ($P_3$), six healthy subjects participated in the study. Motion capture system was used to collect head and trunk flexion angle, and surface electromyography (sEMG) was used to collect myoelectric signal of upper trapezius, lower trapezius, erector spinae, multifidus, and pressure mat system was used to measure seat contact pressure. Results: When trunk and forearm were supported by the ergonomic chair, higher head flexion angle showed upright > trunk-forearm supported > normal in order, and muscle fatigue showed less than upright and normal sitting. Mean seat contact pressure decreased 19% than upright sitting. But muscle fatigue was not affected by each condition. Conclusion: Trunk-forearm supported sitting of the ergonomic chair showed positive effect in respect of trunk and head flexion angle, trunk extensor fatigue, seat contact pressure. To acquire comprehensive understanding of the effectiveness of the ergonomic chair, further studies such as anatomical effects from measurement of external applied loading effect to the body from interface pressure analysis are required. Application: The results of the publishing trend analysis might help physiological effects of trunk-forearm support type chair.

• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.345-353
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• 2013

Objective: This research measured physiological and psychological effects of Vibroacoustic stimulation(VA) to scapular and sacrum of supine position on the mattress. Background: When vibroacoustic stimulation applies to human body, it has a positive influence on physiological and psychological effects by stimulating the organs, tissues and cells of whole body. Method: This experiment was conducted to 10 normal males in two conditions: no stimulation and vibroacoustic stimulation. No stimulation experiment was executed as a supine position for 30 minutes without any vibrational stimulus, while vibroacoustic stimulation was transmitted by the vibrational speaker, which uses 40Hz frequency. Subjects had a laser Doppler flowmeter probe in scapular, sacrum, and also had 8 channel electroencephalogram(EEG) measurement sensor in the scalp. Blood pressure and skin temperature were measured in two conditions with an underlying posture for 30 minutes. Additionally, blood flow rate and EEG were measured before and after for two minutes on two conditions. Results: According to the vibroacoustic stimulation, blood flow rate and skin temperature were increased, while blood pressure was decreased. When using vibroacoustic stimulation compared to no stimulation, blood flow rate went approximately two times higher, and skin temperature also higher 3~4 times. Furthermore, the relative alpha power of brain wave was significantly increased when we applied to vibroacoustic stimulation. Conclusion: This experiment tested the VAT embedded in mattress in two conditions. According to this experiment, VAT decreases blood pressure, improves not only a physiological effect on blood flow rate as well as skin temperature, but also psychological functions by increasing relative alpha power. Application: The results of the publishing trend analysis might help physiological and psychological effects of vibroacoustic stimulation.

• Journal of Korea Multimedia Society
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• v.22 no.5
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• pp.535-546
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• 2019

Recently, there have been a lot of researches on the whole face replacement system, but it is not easy to obtain stable results due to various attitudes, angles and facial diversity. To produce a natural synthesis result when replacing the face shown in the video image, technologies such as face area detection, feature extraction, face alignment, face area segmentation, 3D attitude adjustment and facial transposition should all operate at a precise level. And each technology must be able to be interdependently combined. The results of our analysis show that the difficulty of implementing the technology and contribution to the system in facial replacement technology has increased in facial feature point extraction and facial alignment technology. On the other hand, the difficulty of the facial transposition technique and the three-dimensional posture adjustment technique were low, but showed the need for development. In this paper, we propose four facial replacement models such as 2-D Faceswap, OpenPose, Deekfake, and Cycle GAN, which are suitable for the Cox platform. These models have the following features; i.e. these models include a suitable model for front face pose image conversion, face pose image with active body movement, and face movement with right and left side by 15 degrees, Generative Adversarial Network.

• Korean Journal of Applied Biomechanics
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• v.21 no.3
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• pp.269-279
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• 2011

This study was analyzed the characteristics on the stability of posture while conducting a through two and half rotation technic of pench$\acute{e}$ in rhythmic gymnastics. Two rhythmical gymnastics player(LKH and SSJ) who is a member of the national team were selected, and for obtain the kinematic and kinetic variables were used a ProReflex MCU 240 infrared camera(Qualisys, Sweden) and a Type9286A force platform(Kistler, Switzerland). The mechanical factors were computed by using Visual3D program and Matlab R2009a. During the landing and rotation phase the results showed following characteristics; 1) In medial-lateral and horizontal displacement of the support foot, LKH showed smaller movement than SSJ, but SSJ showed smaller movement than LKH in swing foot. LKH showed bigger movement in medial-lateral axis of COP and vertical axis of COG, but SSJ showed bigger movement in horizontal axis of COP and medial-lateral axis of COG. 2) SSJ showed bigger maximum horizontal and vertical velocity at P1 and P2 than LKH. 3) In the inclination angle of COP and COG, SSJ showed smaller change than LKH, but within medial-lateral tilt of the shoulder, LKH performed rotation motion in horizontal position than SSJ. There was no differences in each force components during rotation, but on landing phase, the results showed a characteristic that SSJ exerted bigger breaking force and vertical force than LKH.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.357-363
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• 2012

The purpose of this study was to investigate the effects of different saddle heights on lower-limb joint angle and muscle activity. Six elite cyclists(age: $32.2{\pm}5.2years$, height: $171.0{\pm}3.5cm$, weight: $79.7{\pm}5.6kg$, cycle career: $13{\pm}6.2years$) participated in three min. submaximal(90 rpm) pedaling tests with the same load and cadence based on saddle heights where subject's saddle height was determined by his knee flexion angle when the pedal crank was at the 6 o'clock position. Joint angles(hip, knee, ankle joints) and the activity of lower limb muscles(biceps femoris(BF), vastus lateralis(VL), tibialis anterior(TA) and gastrocnemius medial(GM)) were compared by measuring 3D motion and electromyography(EMG) data. Results showed that there were significant differences in minimum hip & knee joint angle and range of motion of hip and knee joint between saddle heights. Onset timing and integrated EMG of only BF among 4 muscles were significantly different between saddle heights. Especially there was a negative relationship between minimum hip joint angle and onset timing of BF in most subject, which means that onset timing of BF became fast as the degree of bending of the hip joint became larger by saddle height. Optimal pedaling will be possible through increased amount of muscle activation due to the appropriate burst onset timing by proper pedaling posture with adjusted saddle height.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.4
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• pp.79-91
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• 2011

This study divided school age by considering a change in the stage of body growth by age in elementary schoolgirls with the use of body scan data, and considered by comparing body size characteristics by school age. Elementary schoolgirls' body shape cannot be divided clearly. However, ages 7-10 were bound into the same group for the majority of girth, width, and thickness items. 7-8 years old, 9-10 years old, and 11-12 years old were bound into the same group in most items except ages 9 and 10 for the height item. Thus, significant difference was indicated between groups. Accordingly, this study divided the school age into three periods such as early stage(ages 7-8), middle stage(ages 9-10), and late stage(ages 11-12) in consideration of the stages for elementary schoolgirls' body-shape growth. As a result of analyzing body size according to division of school age, the higher school age leads to continuous growth. The notable growth was indicated especially in the middle stage and late stage. Examining centering on typical items related to the clothing construction, there was notable increase in waist thickness and hip thickness between early and middle stages and in height, weight, breast girth, waist circumference, back length, breast width, and waist width between middle and late stages. On the other hand, hip circumference, hip width, breast thickness, and length between shoulder edges were indicated to grow relatively and evenly among early, middle, and late stages. The lateral form was shown a clear difference in the forms of early, middle, and late stages in height and length of the whole body shape and in side thickness. The early and middle stages belong to body shape that abdomen is projected to be curved. The late stage showed right body shape which is straight and stable form in posture.

• Fashion & Textile Research Journal
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• v.4 no.3
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• pp.261-265
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• 2002

To propose a basic material that can improve the crumples in the knee area and can be applied as an element of garment design, the present study examined the elongation rates of the samples by differentiating the number of cutting lines according to the direction of the fabric, and then determined the puckering phenomenon by judging the conditions of the seams based on the looks of seam lines after bi-axil elongation. After the subjective evaluation on the knee areas of both the standard and modified trousers, the following conclusion was drawn : The elongation rates of the samples are: warp (3.98%)cross-legged (-0.2)>squatting down (-0.4); those in the modified trousers feel more comfortable when sitting on a chair (0.2)>cross-legged (0)>squatting down (-0.6). In the cross-legged posture, the modified trousers (0) has higher scores in the subjective evaluation than the standard ones (-0.2). The evaluation on the looks of needleworks in the samples with cutting lines along the direction of the fabric: weft2 (5.0)

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.116-121
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• 2004

It is known that the transportation stress of market pigs can affect their carcass quality and that blood concentrations of glucose, creatine kinase (CK) and lactate dehydrogenase (LDH) are indicators of the transportation stress. Fifty-seven gilts and 57 barrows weighing approximately 110 kg were randomly assigned into six groups in a 3 [high (0.31 $m^2/100$ kg BW)-, medium (0.35 $m^2$)- and low (0.39 $m^2$)-stocking densities]${\times}2$[1 h vs. 3 h transportation time] arrangement of treatments. Blood samples were taken during transportation and after 2 h lairage. The percentage of "standing" animals during transportation was less in the low- than in the mediumor high-stocking density; the opposite was true for the "sitting" posture. Plasma concentrations of glucose, CK and LDH increased after loading and declined to the resting levels after lairage. Concentrations of CK and LDH were greater in the 3 h vs. 1 h transportation group. Moreover, the LDH concentration was less in the low- than in the medium- or high-density group. Also detected was a significant interaction between the stocking density and transportation time in all of these blood variables. The incidence of pale, soft and exudative (PSE) carcass was greatest in the high-stocking density group. Interestingly, the PSE incidence increased following the 3 h vs. 1 h transportation at the low-density, but not at the medium-density. Results suggest that the medium-density may be preferable to the lowdensity in the long-distance transportation.