• 한국멀티미디어학회논문지
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• 제22권5호
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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.

• 대한치과교정학회지
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• 제51권6호
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• pp.407-418
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• 2021

Objective: To investigate differences in the heritability of skeletodental characteristics between twin pairs with skeletal Class I and Class II malocclusions. Methods: Forty Korean adult twin pairs were divided into Class I (C-I) group (0° ≤ angle between point A, nasion, and point B [ANB]) ≤ 4°; mean age, 40.7 years) and Class II (C-II) group (ANB > 4°; mean age, 43.0 years). Each group comprised 14 monozygotic and 6 dizygotic twin pairs. Thirty-three cephalometric variables were measured using lateral cephalograms and were categorized as the anteroposterior, vertical, dental, mandible, and cranial base characteristics. The ACE model was used to calculate heritability (A > 0.7, high heritability). Thereafter, principal component analysis (PCA) was performed. Results: Twin pairs in C-I group exhibited high heritability values in the facial anteroposterior characteristics, inclination of the maxillary and mandibular incisors, mandibular body length, and cranial base angles. Twin pairs in C-II group showed high heritability values in vertical facial height, ramus height, effective mandibular length, and cranial base length. PCA extracted eight components with 88.3% in the C-I group and seven components with 91.0% cumulative explanation in the C-II group. Conclusions: Differences in the heritability of skeletodental characteristics between twin pairs with skeletal Class I and II malocclusions might provide valuable information for growth prediction and treatment planning.

• 센서학회지
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• 제31권6호
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• pp.433-440
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• 2022

Recently, owing to global warming, average summer temperatures are increasing and the number of hot days is increasing is increasing, which leads to an increase in heat stroke. In particular, outdoor workers directly exposed to the heat are at higher risk of heat stroke; therefore, preventing heat-related illnesses and managing safety have become important. Although various wearable devices have been developed to prevent heat stroke for outdoor workers, applying various sensors to the safety helmets that workers must wear is an excellent alternative. In this study, we developed a smart helmet that measures various vital signs of the wearer such as body temperature, heart rate, and sweat rate; external environmental signals such as temperature and humidity; and movement signals of the wearer such as roll and pitch angles. The smart helmet can acquire the various data by connecting with a smartphone application. Environmental data can check the status of heat wave advisory, and the individual vital signs can monitor the health of workers. In addition, we developed an algorithm that classifies the risk of heat-related illness as normal and abnormal by inputting a set of vital signs of the wearer using a support vector machine technique, which is a machine learning technique that allows for rapid binary classification with high reliability. Furthermore, the classified results suggest that the safety manager can supervise the prevention of heat stroke by receiving feedback from the control system.

• The Journal of Advanced Prosthodontics
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• 제15권4호
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• pp.179-188
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• 2023

PURPOSE. This in vitro study aimed to evaluate the performance of digital intraoral scanners in a completely edentulous patient with angled and parallel implants. MATERIALS AND METHODS. A total of 6 implants were placed at angulations of 0°, 5°, 0°, 0°, 15°, and 0° in regions #36, #34, #32, #42, #44, and #46, respectively, in a completely edentulous mandibular polyurethane model. Then, the study model created by connecting a scan body on the implants was scanned using a model scanner, and a 3D reference model was obtained. Three different intraoral scanners were used for digital impressions (PS group, TR group, and CS group, n = 10 in each group). The distances and angles between the scan bodies in these measurement groups were measured. RESULTS. While the Primescan (PS) impression group had the highest accuracy with 38 ㎛, the values of 104 ㎛ and 171 ㎛ were obtained with Trios 4 IOSs (TR) and Carestream 3600 (CS), respectively (P = .001). The CS scanner constituted the impression group with the highest deviation in terms of accuracy. In terms of dimensional differences in the angle parameter, a statistically significant difference was revealed among the mean deviation angle values according to the scanners (P < .001). While the lowest angular deviation was obtained with the PS impression group with 0.185°, the values of 0.499° and 1.250° were obtained with TR and CS, respectively. No statistically significant difference was detected among the impression groups in terms of precision values (P > .05). CONCLUSION. A statistically significant difference was found among the three digital impression groups upon comparing the impression accuracy. Implant angulation affected the impression accuracy of the digital impression groups. The most accurate impressions in terms of both distance and angle deviation were obtained with the PS impression group.

• 한국운동역학회지
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• 제34권2호
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• pp.53-62
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• 2024

Objective: The purpose of this study was to analyze the differences in kinematic factors according to stretching treatment, myofascial release treatment, and static stretching treatment conditions during squat. Method: Twelve males with resistance training experience participated in this study. Participants performed squats without treatment (Pre-Test), and performed squats after treatment with the myofascial release technique (MRT) and static stretching (SS) on different days (post-test). Squat movements were captured using eight motion capture cameras (sampling rate: 250 Hz), and the peak joint angles of the ankle, knee, hip, and pelvis were calculated for each direction. One-way repeated ANOVA and Bonferroni post hoc analyses using SPSS 27 (IBM Corp. Armonk NY, USA) were used to compare the peak joint angle of the lower extremity joints and pelvis among the normal condition (squat without treatment), MRT condition (squat after MRT treatment) and SS condition (squat after static stretching). The statistical significance level was set at .05. Results: It was observed that the maximum ankle joint flexion angle during squats was statistically reduced under conditions of myofascial release and static stretching (p<.05), in comparison to the scenario where no stretching was performed. Furthermore, static stretching was found to enhance the maximum hip flexion angle during squat (p<.05), whereas the myofascial release stretching technique resulted in the minimal posterior pelvic tilt angle (p<.05). Conclusion: Employing myofascial release stretching as a preparatory exercise proved to be more efficacious in maintaining body stability throughout the execution of high-intensity squat movements by effectively managing the posterior tilt of the pelvis, as opposed to foregoing stretching or engaging in static stretching.

• 한국운동역학회지
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• 제12권2호
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• pp.159-177
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• 2002

본 연구는 철봉운동에서 기본이 되는 동작인 몸펴 한번 뒤돌아 내리기 동작을 단계적으로 분석한 후, 이를 토대로 하여 현재 시합상황 중 가장 널리 사용되는 응용동작인 몸펴 두 번 뒤돌아 내리기 동작과 몸펴 두 번 뒤돌며 한번 비틀어 내리기 동작의 운동학적 분석을 수행하여 개개분절 간의 상호작용을 해부학적 3차원 각운동과 각속도로 설명하고 이해할 수 있는 운동학적 자료를 제시하는데 있다. 피험자들은 현재 K대학교에 재학중이며 대학 대표선수인 남자 기계체조 선수 7명을 선정하였으며, 연구에 사용된 인체의 모델은 Zatsiorsky와 Seluyanov(1983, 1985)이 사용한 16개의 분절로 이루어진 인체의 모델을 사용하였다. 신체무게중심이 이동방향을 설명할 수 있는 투사각도 및 투사속도는 공중동작의 회전수가 증가할수록 신체무게중심이 투사되는 각도가 증가되며, 이렇게 증가된 신체무게중심의 투사각도는 신체무게중심의 최고점을 증가시키는 경향을 보였다. 3차원 투사속도를 살펴본 결과 Z방향(수직방향)은 공중돌기 회전수가 증가할수록 증가하는 경향이 나타났으나, 운동진행 방향인 Y방향 속도와 좌우측 기울기를 설명할 수 있는 X방향 속도에서는 의미 있는 차이를 보이지 않았다. 철봉 내리기 공중동작에서의 신체분절 및 각도 변화도 중요하지만 각운동량을 만들어내기 위한 동작준비구간의 각도 변화가 더욱더 중요하다고 할 수 있다. 즉, 상체가 철봉 아래 봉과 수직될 때부터 릴리즈 순간까지의 각도 변화에 주목해야 하는 데, 회전수가 증가할수록, 어깨관절 각도와 엉덩관절 각도 변화가 두드러지게 나타나 준비구간의 추기기 동작(Whip swing)의 주된 관절로 작용을 한다. 관성좌표계에 대한 상체의 움직임을 나타내는 3차원 방향의 각도 즉, 뒤돌기(somersault)각도, 틀기(twist)각도 그리고 기울기(tilt)각도로 설명이 되는데, 본 연구의 결과 릴리즈시 뒤돌기 각은 세가지 내리기 동작 유형에 따라 평균 57,7도, 38.8도 그리고 39.7도로 나타났으며, 기울기 각은 평균 -1.5도, -5.4도 그리고 -8.4도로 유의한 차이를 보이고 있으며, 틀기각도는 평균 13.4도, 10.6도 그리고 23.3도로 몸펴 두번 뒤돌며 한번 비틀어 내리기 경우 가장 큰 수치를 나타냈다.

• 한국운동역학회지
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• 제12권1호
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• pp.63-87
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• 2002

The purpose of this study was to analyze the kinematic variables when Uchi-mata(inner thigh reaping throw) performing by Kumi-kata(engagement position, basic hold) types A, B(A: grasping part-behind neck lapel, B: chest lapel) in Judo with three dimensional analysis technique DLT method by videography. The subjects were four male judokas who have been training in Yong-In University(YIU), on Korean Representative level and Uchi-mata is their tokui-nage(favorite technique), the throwing form was filmed on two S-VHS 16mm video camera( 30frame/sec. Panasonic). Kinematic variables were temporal, posture, and COG. The data collection was performing by Uchi-mata. Six good trials were collected for each condition (type A, B) among over 10 trials. The mean values and the standard deviation for each variable were obtained and used as basic factors for examining characteristics of Uchi-mata by Kumi-kata types. The results of this analysis were as follows : 1) Temporal variables The total time elapsed(TE) by Uchi-mata of types A, B were 1.45, 1.56 sec. respectively. Types A shorter than B. 2) Posture variables In performing of Uchi-mata, the range of flexion in type A, left elbow was $45^{\circ}$ and B was $89^{\circ}$ from Event 2(E2) to Event 6(E6). Type A and B were quite different in right elbow angle in Event1(E1). Left shoulder angle of type A was extended and type B was flexed in E4. Both types right shoulder angles were showed similar pattern. Also both hip angles(right/left) were showed similar pattern. When type A performed Uchi-mata the knee-angle of supporting foot showed $142^{\circ}$in the 1st stage of kake phase[KP], and extended to $147^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $86^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $126^{\circ}$in the 1st stage of KP, and extended to $132^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $106^{\circ}$in the 1st stage of KP, and extended to $121^{\circ}$in the 2nd stage of KP. When type B performed Uchi-mata the knee-angle of supporting foot showed $144^{\circ}$in the 1st stage of KP, and extended to $154^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $92^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $132^{\circ}$in the 1st stage of KP, and extended to $140^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $103^{\circ}$in the 1st stage of KP, and extended to $115^{\circ}$in the 2nd stage of KP. During Uchi-mata performing, type A showed pulling pattern and type B showed lift-pulling pattern. As Kumi-kata types, it were different to upper body(elbow, shoulder angle), but mostly similar to lower body(hip, knee, ankle angle) on both types. 3) C. O. G. variables When the subjects performed Uchi-mata, COG of type A, B up and down in vertical aspect was 71cm, 73.8cm in height from the foot in the 2nd stage of KP. As Kumi-kata types, it were different on medial-lateral direction aspect but weren't different in Kuzushi phase on vertical direction aspect.

• 한국운동역학회지
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• 제17권2호
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• pp.145-156
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• 2007

The purposes of this study were to investigate kinematic parameters of racket head and upper extremities during squash back hand stroke and to provide quantitative data to the players. Five Korean elite male players were used as subjects in this study. To find out the swing motion of the players, the land-markers were attached to the segments of upper limb and 3-D motion analysis was performed. Orientation angles were also computed for angular movement of each segment. The results were as follows. 1) the average time of the back hand swing (downswing + follow-through) was 0.39s (0.24 s + 0.15 s). 2) for each event, the average racket velocity at impact was 11.17m/s and the velocity at the end of swing was 8.03m/s, which was the fastest swing speed after impact. Also, for each phase, 5.10m/s was found in down swing but 7.68m/s was found in follow-through. Racket swing speed was fastest after the impact but the swing speed was reduced in the follow-through phase. 3) in records of average of joints angle, shoulder angle was defined as the relative angle to the body. 1.04rad was found at end of back swing, 1.75rad at impact and it changes to 2.35 rad at the end of swing. Elbow angle was defined as the relative angle of forearm to upper arm. 1.73rad was found at top of backswing, 2.79rad at impact, and the angle was changed to 2.55rad at end of swing. Wrist angle was defined as the relative angle of hand to forearm. 2.48rad was found at top of backswing, 2.86rad at impact, and the angle changes to 1.96rad at end of swing. As a result, if the ball is to fly in the fastest speed, the body has to move in the order of trunk, shoulder, elbow and wrist (from proximal segment to distal segment). Thus, the flexibility of the wrist can be very important factor to increase ball speed as the last action of strong impact. In conclusion, the movement in order of the shoulder, elbow and the wrist decided the racket head speed and the standard deviations were increased as the motion was transferred from proximal to the distal segment due to the personal difference of swing arc. In particular, the use of wrist (snap) may change the output dramatically. Therefore, it was concluded that the flexible wrist movement in squash was very important factor to determine the direction and spin of the ball.

• The Journal of Korean Physical Therapy
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• 제13권2호
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• pp.467-475
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• 2001

The purpose of this study was to evaluate changes of static lumbar lordosis by different heel heights in normal adults and patients with herniation of nucleus pulposus(HNP). The lumbar lordosis was examined while standing on barefoot, on heel support with 4cm heel, and with 8cm heel in 10 normal adults and 10patients with HNP. Standing lumbar lateral view was performed by 20 minutes adaptation with corresponding shoe types. The angle of lumbar lordosis was taken with Wiltse and Winter's method(angles between upper margin of 1 st lumbar body and upper margin of 5th lumbar body). The results of this study were as follow: 1. Significant statistical decrease in lumbar lordosis was observed as heel heights were increased from barefoot to 8cm high heel in normal adults(p<0.05). 2. There were no significant differences in lumbar lordosis according to three different heel heights in patients with HNP(p>0.05). 3. In comparison of barefoot, There were statistically significant decrease in HNP patients compared with normal adults in terms of lumbar lordosis(p<0.05).

• 한국운동역학회지
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• 제13권3호
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• pp.253-264
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• 2003

This study aims at finding the structure of spike technique by analysing comparatively the spike action by excellent and by non-excellent players throughout the section from a flying jump to the time of landing for the correct analysis of spike action and tries to help athletes and coaches to execute a scientific training. For the objected person of this study, six of H College athletes three of excellent athletes and three of non-excellent athletes, presently registered as athlete with the Korea Volleyball federation) were chosen, and the factors of analysis were analysed upon performance time of action by section, human body centered displacement, change of articulation angle, speed change of articulation of the upper limbs, uniformity of the articulation of the upper limbs upon impact, etc. The conclusion of this study is as follow: 1. In the time required for taking action, it shows to take $1.067{\pm}0.057$ seconds for the group of excellent athletes and $1.034{\pm}0.033$ seconds for the group of non-excellent athletes. Although there was not big difference between two groups in the performance time of action, it showed that the group of excellent athletes takes longer compared to the group of non-excellent athletes. And it was found by the result of this study that the group of excellent athletes stays longer in the duration of flight. 2. In the displacements of horizontal movement and vertical movement, it was found that the group of excellent athletes have moved more than the group of non-excellent athletes in the horizontal movement of the center of human body 3. In the angles of wrist and knee, it was found that the excellent athletes have shown little than the non-excellent athletes in the entire sections, but that in the angle of elbow, the non-excellent athletes have shown bigger than the excellent athletes.. 4. In the speed of the articulation of the upper limbs upon impact, it was found that the group of excellent athletes have shown bigger than the group of non-excellent athletes, and that in the maximum value of the articulation of the upper limbs, the maximum value for the hand was indicated upon impact and that forearm and upper arm have shown the maximum value just before the impact. 5. In the uniformity of articulation of the upper limbs at the time of impact, the group of excellent athletes showed bigger than the group of non-excellent athletes in all the articulations.