• 한국안광학회지
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• 제15권2호
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• pp.151-154
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• 2010

목적: 시축과 홍채의 편심에 따른 정밀모형안의 광학적 성능 변화를 분석하고자 하였다. 방법: 기존에 설계되어진 Radial GRIN과 Spherical GRIN 형태의 수정체를 갖는 정밀모형안을 이용하여 홍채의 위치를 코 방향으로 0.5 mm 편심시키고 시축은 절점을 기준으로 코방향으로 $5^{\circ},$ 아래로 $2.5^{\circ}$ 기울여 중심와의 위치에 상측초점이 위치하도록 하였다. 그리고, 실제의 눈과 동일하도록 광학계를 구성하여 광학적 성능 변화를 분석하였다. 결과: 전체적인 수차 분포가 실안의 성능과 비교하여 많은 차이를 나타내고 있었다. 특히, 광학계의 중앙 부위를 통과하는 영역에서 가장 큰 차이를 나타내고 있었다. 그리고, 구면수차가 가장 큰 차이를 나타냈으며, 주변부 굴절력 오차와 상면만곡은 (+) 방향으로 수차분포가 치우쳐져 있었다. 결론: 시축과 홍채 편심을 고려한 실안과 유사한 정밀모형안을 설계하는데 있어서 가장 유념해야 할 부분은, 광학계의 중앙 부위를 통과하는 영역에서의 수차 보정이다. 먼저, 가장 큰 차이를 나타내고 있는 구면수차를 보정하고, (+)방향으로 치우쳐 있는 주변부 굴절력 오차와 상면만곡은 (-)방향으로 이동하도록 고려해야 할 것이다.

• 한국운동역학회지
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• 제15권4호
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• pp.85-95
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• 2005

The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle during One Hand Backhand Stroke and Two Hand Backhand in tennis. For the movement analysis three dimensional cinematographical method(APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVIEW 6.1 graphical programming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and racket head direction were defined. 1. In three dimensional maximum linear velocity of racket head the X axis and Y axis(horizontal direction) showed $-11.04{\pm}2.69m/sec$, $-9.31{\pm}0.49m/sec$ before impact, the z axis(vertical direction) maximum linear velocity of racket head did not show at impact but after impact this will resulted influence upon hitting ball. It could be suggest that Y axis velocity of racket head influence on ball direction and z axis velocity influence on ball spin after impact. The stance distance between right foot and left foot was mean $75.4{\pm}5.86cm$ during one hand backhand stroke and $72.6{\pm}4.67cm$ during two hand backhand stroke. 2. The three dimensional anatomical angular displacement of trunk in interna rotation-external rotation showed most important role in backhand stroke. and is follwed by flexion-extension. the three dimensional anatomical angular displacement of trunk did not show significant difference between one hand backhand stroke and two hand backhand stroke but the three dimensional anatomical angular displacement of trunk was bigger than one hand backhand stroke. 3. while backhand stroke, the flexion-extension and adduction-abduction of right shoulder joint showed significant different between one hand backhand stroke and two hand backhand stroke. the three dimensional anatomical angular displacement of right shoulder joint showed more flex and abduct in one hand backhand stroke. 4. The three dimensional anatomical angular displacement of left shoulder showed flexion, adduction, and external rotation at impact. after impact, The angular displacement as adduction-abduction of left shoulder changed motion direction as abduction. angular displacement of left shoulder as flexion-extension showed bigger than the right shoulder.

• Restorative Dentistry and Endodontics
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• 제21권1호
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• pp.339-352
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• 1996

Many dentists have been taken an interest in restoration of severly damaged teeth after endodontic treatment and it is a true that there are lots of studies about it. In these days, although we have used Para-Post, pins, threaded steel post, cast gold post and core, and so on, as a method of restoration frequently, it has been in controversy with the effects of them on the teeth and surrounding periodontal tissue. In this study, we assume that the crown of the upper 1st premolar was severly damaged, and after the root canal therapy, two most common types of restoration were carried out ; 1) coronal-radicular amalgam restoration, 2) after setting up the Para-Post, restore with amalgam core and gold crown. After restoration, in order to present the concentration of stress at internal portion of the tooth and the surrounding periodontal tissue, we doveloped a 2-dimensional finite element model of labiopalatal section, then loaded forces from 2 long perpendicular to the lingual incline of buccal ridge an the middle point, parallel to the long direction axis of tooth at the fossa-were applied. The analyzed results were as follows : 1. Stress of the normal first premolar was concentrated on the most weakest anatomical structure, that is, cervical area, and no stress on the bifurcated area of the canal. 2. Crown restoration after root canal therapy causes large stress concentration on the bifurcated area of the canal. This stress concentration has larger value in case of lateral movement of mandible, and there are decrease in the stress concentration compared with natural tooth. 3. Coronal-radicular amalgam restoration method transports more stress to the tooth structure than restoration using Para-Post. 4. There are more stress concentration around Para-Post in the case of lateral movement, and we have more favo rable result when restored with Para-Post. 5. Generally, stress in the lateral movement is larger than stress in the perpendicular load.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.571-575
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• 2015

실시간으로 입력되는 영상으로부터 이동객체의 움직임 특징을 분석하는 시간적 히스토그램 기반의 행동패턴분석 알고리즘을 제안한다. 이동객체의 추적 및 분석을 위해 배경과 이동객체를 분리하는 배경학습을 행한다. 배경학습으로 추출된 이동객체는 무게중심 및 좌표연관성을 이용하여 객체를 식별한 후 객체별 추적을 행한다. 추적된 각 객체의 시작프레임, 종료프레임, 좌표정보, 크기정보를 연결리스트에 저장하여 관리한다. 시간적 히스토그램은 x, y좌표와 시간을 이용해 움직임 특징 패턴을 정의한 것으로 각 객체의 좌표정보와 비교하여 움직임특징 및 행동패턴을 파악한다. 시간적 히스토그램 기반 행동패턴분석시스템은 자체 수집한 데모영상에 대한 실험을 통해 초당 45~50 fps의 높은 처리속도를 유지하며 95%이상의 높은 추적율을 확인하였다.

• 대한치과보철학회지
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• 제28권2호
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• pp.125-146
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• 1990

The relationale for recording mandibular movement is to accurately adjust an articulator. Techniques to record mandibular movement include radiographic interpretation, extraoral tracing, and intraoral recording materials. This study was performed to compare the concylar guidance inclination and Bennett shift(immediate & progressive side shift)obtained by using an electronic pantograph, pantograph and wax interocclusal records in Korean. Ten adults who have normal occlusion and are free of TMJ dysfunction were selected and clutches were constructed. At first Pantronic survey was performed three times by using an kinematic hinge axis according to manufacturer's direction. Next pantographic survey was performed three times and the articulator was adjusted with each pantographic recording. And then maxillary cast was attached to the articulator with pantographic as a face-bow and the mandibular cast was mounted to the articulator with centric relation record. Three protrusive, three left lateral and three right lateral wax interocclusal records were taken on the subjects and the articulator was adjusted with each interocclusal record. Protrusive condylar inclination, lateral condylar inclination, immediate side shift and progressive side shift obtained by using electronic pantograph, pantograph and wax interocclusal record were compared and analized. The results were as follows; 1. The average left and right protrusive and orbiting condylar inclination($33.7^{\circ},\;37.1^{\circ},\;40.6^{\circ},\;43.5^{\circ}$) record with Pantronic was significantly greater than that recorded with other methods. 2. The average left and right protrusive and orbiting condylar inclination($24.8^{\circ},\;27.0^{\circ},\;31.4^{\circ},\;32.4^{\circ}$)recorded with wax interocclusal record was less than that of other methods. 3. The average left and right immediate side shift(0.57mm,0.44mm)recorded with wax interocclusal record was greater than that of other methods and the average left rigtht immmediate side shift(0.30mm,0.41mm)recorded with Pantronic was significantly greater than that recorded with pantograph(0.11mm,0.20mm). 4. The average variance of wax interocclusal was signivicantly higher than that of other methods.

• 대한치과교정학회지
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• 제49권3호
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• pp.188-193
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• 2019

Objective: The aim of this finite element study was to clarify the mechanics of tooth movement in palatal en-masse retraction of segmented maxillary anterior teeth by using anchor screws and lever arms. Methods: A three-dimensional finite element method was used to simulate overall orthodontic tooth movements. The line of action of the force was varied by changing both the lever arm height and anchor screw position. Results: When the line of action of the force passed through the center of resistance (CR), the anterior teeth showed translation. However, when the line of action was not perpendicular to the long axis of the anterior teeth, the anterior teeth moved bodily with an unexpected intrusion even though the force was transmitted horizontally. To move the anterior teeth bodily without intrusion and extrusion, a downward force passing through the CR was necessary. When the line of action of the force passed apical to the CR, the anterior teeth tipped counterclockwise during retraction, and when the line of action of the force passed coronal to the CR, the anterior teeth tipped clockwise during retraction. Conclusions: The movement pattern of the anterior teeth changed depending on the combination of lever arm height and anchor screw position. However, this pattern may be unpredictable in clinical settings because the movement direction is not always equal to the force direction.

• 대한치과교정학회지
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• 제52권1호
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• pp.42-52
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• 2022

Objective: This study compared soft tissue changes after extraction of the four premolars followed by maximum retraction of the anterior teeth according to the type of anterior teeth movement: tipping and translation. Methods: Patients who had undergone orthodontic treatment involving the extraction of four premolars were retrospectively selected and divided into either the tipping (n = 27) or translation (n = 26) groups based on the retraction of the incisor root apex and the axis changes of the incisors during the treatment period. Lateral pre- and post-treatment cephalograms were analyzed. Results: There were no significant differences between the tipping and translation groups before treatment. The retraction amounts of the root apex of the upper and lower incisors in the tipping group were 0.33 and 0.26 mm, respectively, and 5.02 and 5.31 mm, respectively, in the translation group (p < 0.001). The posterior movements of soft tissue points A and B in the tipping group were 0.61 and 1.25 mm, respectively, and 1.10 and 3.25 mm, respectively, in the translation group (p < 0.01). The mentolabial sulcus angle increased by 5.89° in the tipping group, whereas it decreased by 8.13° in the translation group (p < 0.001). Conclusions: An increased amount of retraction of the incisor root apex led to the increased posterior movement of soft tissue points A and B, and this appeared more distinct in cases involving the lower incisor and lower lip.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.89-89
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• 2022

Soybean (Glycine max (L.) Merr.) is a representative food resource. To preserve the integrity of soybean, it is necessary to protect soybean yield and seed quality from threats of various pests and diseases. Riptortus pedestris is a well-known insect pest that causes the greatest loss of soybean yield in South Korea. This pest not only directly reduces yields but also causes disorders and diseases in plant growth. Unfortunately, no resistant soybean resources have been reported. Therefore, it is necessary to identify the distribution and movement of Riptortus pedestris at an early stage to reduce the damage caused by insect pests. Conventionally, the human eye has performed the diagnosis of agronomic traits related to pest outbreaks. However, due to human vision's subjectivity and impermanence, it is time-consuming, requires the assistance of specialists, and is labor-intensive. Therefore, the responses and behavior patterns of Riptortus pedestris to the scent of mixture R were visualized with a 3D model through the perspective of artificial intelligence. The movement patterns of Riptortus pedestris was analyzed by using time-series image data. In addition, classification was performed through visual analysis based on a deep learning model. In the object tracking, implemented using the YOLO series model, the path of the movement of pests shows a negative reaction to a mixture Rina video scene. As a result of 3D modeling using the x, y, and z-axis of the tracked objects, 80% of the subjects showed behavioral patterns consistent with the treatment of mixture R. In addition, these studies are being conducted in the soybean field and it will be possible to preserve the yield of soybeans through the application of a pest control platform to the early stage of soybeans.

• Radiation Oncology Journal
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• 제14권1호
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• pp.69-76
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• 1996

목적 : electronic portal imaging device(EPID)를 이용하여 폐암 환자에서 시행한 검증 영상을 분석하여 3차원 입체 조형치료계획 시 자세 오차(set-up error)와 종양의 이동 거리를 고려한 적절한 차폐 여유를 평가해 보고자 한다. 대상 및 방법 : 1995년 연세암센터 치료방사선과에 내원하여 EPID가 장착된 Clinac 2100C/D를 이용하여 치료받은 폐암 환자 10명을 대상으로 하였다. 환자 1인 당 1 port에 대한 검증 영상을 매일 얻어 random 오차와 systematic 오차를 구했고, 치료 1회 당 중복 영상을 얻어 종양의 움직임을 구했다. 매일 얻은 검증 영상은 103개이었고, 중복 영상은 10개이었다. 결과 : 전체 10 명의 환자의 x 축, y 축으로의 평균 이동은 각각 1.41 mm, 1.78 mm 이었고 systematic 이동은 표준편차가 x 축, y 축으로 각각 4.63 mm, 4.11 mm이었다. random 이동은 각 환자의 평균 이동으로부터 x 축, y 축으로 표준편차가 각각 4.17 mm, 3.31 mm 이었다. 호흡에 의한 y 축으로의 이동은 평균 12.2 mm이었고, 표준편차는 4.03 mm 이었다. 결론 : 폐암 환자에서 3차원 방사선치료를 시행하려고 할 경우 치료 계획 시 clinical target volume에서 x, y 축으로 각각 10 mm, 25 mm 정도의 여유가 필요하다고 보이며, 치료 초기에 각 환자별로 매일 EPID를 이용하여 얻은 검증 영상과, 중복 영상으로 차폐 여유를 적절히 조절해 주어야 할 것이다.

• 제어로봇시스템학회논문지
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• 제19권2호
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• pp.107-112
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• 2013

In this paper, we discuss a 3-dimensional localization sensor node using EM waves (Electromagnetic waves) with RSSI (Received Signal Strength Indicator). Generally EM waves cannot be used in underwater environment, because the signal is highly attenuated by the water medium according to the distance. Although the signal quickly reduces in underwater, the reducing tendency is very clear and uniform. Hence EM waves have possibility as underwater distance sensors. The authors have verified the possibility by theory and several experiments, and developed calibration methods in case of linear and planer environment. For 3-dimensional localization in underwater, it must be known antenna's radiation pattern property in electric plane(called E-plane). In this paper, we proceed experiments to verify attenuation tendency with z axis movement, PLF (Polarization Loss Factor) and ILF (Inclination Loss Factor) with its theoretical approach.