• 한국공간정보시스템학회 논문지
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• 제7권1호
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• pp.77-89
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• 2005

최근 이동 통신과 GPS 기술의 발달로 위치 기반 서비스에 대한 요구 및 관련된 연구가 활발히 진행되고 있다. 이동체 색인에 관한 기존 연구는 시간 도메인에 따라 과거 궤적 색인과 현재 및 미래 위치 색인으로 분류된다. 그러나 실세계 응용에서는 과거 궤적뿐만 아니라 현재 및 미래 위치 검색을 모두 요구하므로 모든 시간 도메인에 대한 질의를 지원하는 통합 색인을 개발해야 한다. 이 논문에서는 이동체의 과거 궤적을 표현하는 3차원 공간상의 선분과 이동체의 현재 및 미래 위치를 표현하는 시간에 대한 선형 함수를 하나의 색인에 구성함으로써 이동체의 과거, 현재, 미래의 위치 데이터가 통합된 새로운 색인인 PCR-tree(Past, Current R-tree)을 제안한다. PCR-tree 는 노드 내에 포함된 과거, 현재, 미래 위치 데이터에 대한 새로운 경계 영역을 가지며 색인의 모든 엔트리에 대한 단일 인터페이스를 제공한다. 그리고, 제안된 색인과 색인 실험 도구를 구현하여 모든 시간 도메인에 대한 질의 처리가 가능함을 보인다.

• Imaging Science in Dentistry
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• 제43권3호
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• pp.191-196
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• 2013

Purpose: This study assessed the accuracy of linear and angular measurements on panoramic radiographs taken at different positions in vitro. Materials and Methods: Two acrylic models were fabricated from a cast with normal occlusion. Straight and $75^{\circ}$ mesially and lingually angulated pins were placed, and standardized panoramic radiographs were taken at standard position, at an $8^{\circ}$ downward tilt of the occlusal plane compared to the standard position, at an $8^{\circ}$ upward tilt of the anterior occlusal plane, and at a $10^{\circ}$ downward tilt of the right and left sides of the model. On the radiographs, the length of the pins above (crown) and below (root) the occlusal plane, total pin length, crown-to-root ratio, and angulation of pins relative to the occlusal plane were calculated. The data were subjected to repeated measures ANOVA and LSD multiple comparisons tests. Results: Significant differences were noted between the radiographic measurements and true values in different positions on both models with linear (P<0.001) and those with angulated pins (P<0.005). No statistically significant differences were observed between the angular measurements and baselines of the natural head posture at different positions for the linear and angulated pins. Conclusion: Angular measurements on panoramic radiographs were sufficiently accurate and changes in the position of the occlusal plane equal to or less than $10^{\circ}$ had no significant effect on them. Some variations could exist in the pin positioning (head positioning), and they were tolerable while taking panoramic radiographs. Linear measurements showed the least errors in the standard position and $8^{\circ}$ upward tilt of the anterior part of the occlusal plane compared to other positions.

• The Journal of Korean Physical Therapy
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• 제19권5호
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• pp.1-10
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• 2007

Purpose: Leg-crossing sitting is very common for men and woman. No solid evidence exists for either a beneficial or a detrimental effect of this posture. This study investigated the change of activities of trunk muscles between the normal group and the low back pain group during various leg-crossing positions. Methods: The subjects were consisted of 10 subjects who don't have low back pain and 10 subjects who have low back pain. In this study, we used electromyography(EMG) to evaluate the activities of both the trunk muscles (rectus abdominis, external oblique, internal oblique, and multifidus) during various leg-crossing positions (up-right, leg-crossing, tailor-crossing, and ankle-crossing). We analyzed the data by using repeated one way ANOVA. Results: In normal group, there were increased in EMG activities of trunk muscles, but no significant differences during leg-crossing positions. In back pain group, there were increased in EMG activities of right external oblique, left. internal oblique, and both multifidus muscles in leg-crossing and tailor-crossing position, but no significant differences during leg-crossing positions. There was no significant difference of muscle activity of trunk muscles between the back pain group and the normal group. Conclusion: We suggest that low back pain people who have weak muscles of rectus abdominis, external and internal oblique are often experienced in leg-crossing posture than normal. To compensate this unstability of trunk, leg-crossing posture is substituted passive structure for activities of active muscle.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1966_1967
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• 2009

As an attempt to characterize the pulse behaviors at the three pulse diagnosis positions in the oriental medicine which are called Chon, Gwan, and Cheok, we measure the pluse waveforms by SphygmoCor apparatus, that has been used widely for the evaluation of the arterial stiffness, and examine the Augmentation Index (AIx) at the aorta. For the study, twenty healthy men at the age of twenties have participated as the subject group. The pulse has been measured twice at the three palpation positions, and by two-way repeated measures ANOVA we tested the repeatability and the mean differences in the aortic AIx between Chon, Gwan, and Cheok. The AIx was found to be statistically different between the measurement positions. Duncan's test shows that the AIx is statistically different between Chon and the other two positions. Our study may be used as a reference for further scientific quantification of the pulse diagnosis.

• 대한물리의학회지
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• 제15권2호
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• pp.121-128
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• 2020

PURPOSE: This study examined the changes in the cross-sectional area (CSA) of the abductor hallucis muscle during various ankle positions while performing toespread-out (TSO) exercise. METHODS: Thirty subjects with an average age of 22.1 years were recruited for this study. All subjects were firstly measured for the angle of their first metatarsophalangeal joint using a goniometer. Those with angles greater than 15° were allocated to the HV group. The remaining subjects were placed in the normal group. The CSA of the abductor hallucis was measured by ultrasound in the resting position with no movement and three ankle positions: neutral (0°), plantarflexion (30°), and dorsiflexion (30°). All data were analyzed using a two-way mixed analysis of variance between the groups (normal and HV group) and within the groups (resting, neutral, plantarflexion, and dorsiflexion) to determine the group x position interaction effects. RESULTS: During TSO exercise in the normal group, the CSA of the abductor hallucis was significantly greater in both the plantarflexion and neutral positions compared to the resting position (p_adj < .01), and plantarflexion was significantly greater than the dorsiflexion position (p_adj < .01). During the TSO exercise in the HV group, the CSA of the abductor hallucis for plantarflexion was significantly greater than it was for the resting, neutral, and dorsiflexion positions (p_adj < .01). CONCLUSION: Based on the above results, the TSO exercise in plantarflexion is an effective rehabilitation exercise for subjects with HV.

• 한국전문물리치료학회지
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• 제2권1호
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• pp.44-50
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• 1995

The purpose of this study was to investigate which of 4 positions produced the highest action potential in the rectus femoris muscle of normal adult subjects. Testing was performed in supine with the right leg performing a simple straight leg raise with the knee fully extended. The left leg, however, was placed in 4 different positions: 1. Full support with $0^{\circ}$ flexion. 2. Flexed on the plinth with $60^{\circ}$ knee flexion and foot flat. 3. Same as N0.2 but with $90^{\circ}$ knee flexion. 4. Left leg hanging over the end of the plinth with $90^{\circ}$ knee flexion, $0^{\circ}$ hip flexion and no foot support. This study was designed to compare the level of electromyographic activity of the rectus femoris under 4 positions. Fourty-three healthy young adults performed three trials of each exercise condition in random order in the supine position. Electromyographic activity was recorded from surface electrodes. Rectus femoris action potentials in all 4 positions were significantly different. The highest action potential at the end of movement of the right leg occurred with the left leg hanging over the end of the plinth with $90^{\circ}$ knee flexion. It is therefore recommended the straight leg raising be performed with the contralateral leg flexed at $90^{\circ}$ over the end of the supporting surface to obtain a maximum rectus femoris isometric contraction.

• 한국정밀공학회지
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• 제26권11호
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• pp.99-107
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• 2009

Since a long work piece influences the natural frequency of the entire system with a miniature high speed spindle, a bar-feeder is used for a long work piece to improve the vibration characteristics of a spindle system. Therefore, it is very important to design optimally support positions between a bar-feeder and a long work piece for a miniature high speed spindle system. The goal of the current paper is to present an optimization method for the design of support positions between a bar-feeder and a long work piece. This optimization method is effectively composed of the method of design of experiment (DOE), the artificial neural network (ANN) and the genetic algorithm (GA). First, finite element models which include a high speed spindle, a long work piece and the support conditions of a bar-feeder were generated from the orthogonal array of the DOE method, and then the results of natural vibration analysis using FEM were provided for the learning inputs of the neural network. Finally, the design of bar-feeder support positions was optimized by the genetic algorithm method using the neural network approximations.

• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.107-117
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• 2016

We develop a new method to globally calibrate the feature points that are derived from the binocular systems at different positions. A three-DOF (degree of freedom) global calibration system is established to move and rotate the 3D calibration board to an arbitrary position. A three-DOF global calibration model is constructed for the binocular systems at different positions. The three-DOF calibration model unifies the 3D coordinates of the feature points from different binocular systems into a unique world coordinate system that is determined by the initial position of the calibration board. Experiments are conducted on the binocular systems at the coaxial and diagonal positions. The experimental root-mean-square errors between the true and reconstructed 3D coordinates of the feature points are 0.573 mm, 0.520 mm and 0.528 mm at the coaxial positions. The experimental root-mean-square errors between the true and reconstructed 3D coordinates of the feature points are 0.495 mm, 0.556 mm and 0.627 mm at the diagonal positions. This method provides a global and accurate calibration to unity the measurement points of different binocular vision systems into the same world coordinate system.

• 한국의류학회지
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• 제33권11호
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• pp.1794-1805
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• 2009

This study investigates the influence of slit positions on the microclimate temperature/humidity of garments. To design the slits, a market survey was performed to indicate the method to apply the slits, in addition to a literature survey about muscles and body surface variation through body movements. Based on the survey, three positions of slits were selected, shoulder slit, lowback slit, and midback slit, a slit width of 1cm and length to 30cm was used. The results showed that microclimate temperatures/humidity on the back according to the slit positions were in the order of, lowback, midback, and the shoulder. The lowback slit showed the highest effect on the temperature/humidity of a front trunk. Lowback slits affected on localized areas of the glutaeus maximus, erector spinae, and latissimus dorsi. Midback slits affected the back muscle and deltoid. Shoulder slits showed a more significant effect on the localized area of the deltoid versus other localized areas. In the subjective sensations, the lowback slit was cooler, dryer, and more comfortable than the other slits. For the subjective sensations by fabric characteristics, the slit positions correlated at |r|${\geq}.8$ and were significant at p<.001 The results show that the lowback slit has a superior air exchange effect and thermoregulation qualities.

• The Journal of Korean Physical Therapy
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• 제23권6호
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• pp.9-14
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• 2011

Purpose: The pelvic tilting exercise is a well recognized rehabilitation maneuver. However, little information is available on the changes of lumbar segmental motion during pelvic tilting. This study was conducted to measure the kinematics of the pelvic tilting exercise on the supine and prone positions via fluoroscopy. Methods: A total of 10 female subjects were enrolled. During anterior, neutral, and posterior pelvic tilting, radiographs were taken in each exercise via fluoroscopy (ARCADIS Orbic, Siemens, USA). Images were sent to the picture archiving communication system (PACS), and the digitized images were analyzed using LabVIEW software (National Instruments, USA). Lumbosacral lordosis and the intervertebral body angle, intervertebral disc angle, and intervertebral displacement were analyzed. Results: The results of lumbar kinematic analysis during three tilting postures in the supine and prone positions demonstrated that lumbosacral lordosis and the intervertebral body angle and intervertebral disc angle were significantly higher when the pelvis was tilted anteriorly (p>0.05). However, there was no significant difference between anterior and neutral tilting in the intervertebral disc angle at the L3/4 level in the prone position (p>0.05), and there was no significant difference among tilting positions in intervertebral body displacement in the prone position (p>0.05). Conclusion: This study provides scientific evidence about the pelvic tilting exercise in lumbosacral segmental motion. Depending on the pelvic tilting exercise, kinematic changes were demonstrated in both positions, especially in the supine position. It is suggested that the supine position is effective for mobility, but it should be used carefully for the LBP (Low back pain) patient with hypermobility.