• 한국정보통신학회논문지
• /
• 제21권12호
• /
• pp.2365-2370
• /
• 2017

본 논문에서는 체험형 VR 환경을 고려한 동작 및 위치 인식 기법을 제안한다. 동작 인식은 신체부위에 복수개의 AHRS 디바이스를 부착하고 이를 기준으로 좌표계를 정의한다. 각각의 AHRS 디바이스로부터 측정되는 9축 움직임 정보를 기반으로 사용자의 동작을 인식하고 신체 분절 간의 관절각을 추출하여 동작을 보정한다. 위치인식은 AHRS 디바이스의 관성센서를 통해 보행 정보를 추출하여 상대위치를 인식하고 BLE Fingerprint를 이용하여 누적오차를 보정한다. 제안하는 동작 및 위치인식 기법의 구현을 위해 AHRS기반의 위치인식과 관절각 추출 실험을 진행하였다. 위치 인식 실험의 평균 오차는 0.25m, 관절 각 추출 실험에서 관절 각 평균 오차는 $3.2^{\circ}$로 나타났다.

• 펄프종이기술
• /
• 제44권2호
• /
• pp.18-28
• /
• 2012

This study was to develop a novel automatic system for measuring St$\ddot{o}$ckigt sizing degree and contact angle at a time. The conventional methods to measure sizing degree had serious problems in obtaining significant differences according to different dosages of a sizing agent, and moreover they disclosed unique limitation due to liquid types used and tester's subjectivity. However, the newly developed system could get reproducible results through total automation of all procedures including liquid dropping, image acquisition and measurement of both St$\ddot{o}$ckigt sizing degree and contact angle. For the St$\ddot{o}$ckigt sizing test, the automatic system could measure sizing degree with more definite differences according to different dosage of AKD, compared to the conventional method. For the contact angle test, the automatic system showed a similar trend to the conventional method but had smaller contact angles due to distortion of an image focus by a sheet curl than the conventional testing machine. The problem from the image out of focus due to specimen curl will be overcome with adopting a new specimen holder for the future system.

• 치과방사선
• /
• 제20권2호
• /
• pp.315-333
• /
• 1990

This study was performed to measure the skin absorbed doses from full mouth standard intraoral radiography (l4 exposures) in bisecting angle and paralleling techniques. Thermoluminescent dosimeters were used in a phantom. Circular tube collimator(60㎜ in diameter, 20㎝ in length) and rectangular collimator(35㎜ × 44㎜, 40㎝ in length) were set for bisecting angle and paralleling techniques respectively. All measurement sites were classified into 8 groups according to distance from each point of central rays. The results were as follows: 1. The skin absorbed doses from the paralleling technique were significantly decreased than those from the bisecting technique in both points at central ray and points away from central ray. The percentage rates of decrease were greater at points away from central ray than those at central ray. 2. The skin absorbed doses at the lens of eye, parotid gland, submandibular gland and thyroid region were significantly decreased in paralleling techniuqe, but those of the midline of palate remained similar in both techniques. 3. The highest doses were measured at the site 20mm above the point of central ray for the mandibular premolars in bisecting angle technique and at the point of central ray for the mandibular premolars in paralleling techniques. The lowest doses were measured at the thyroid region in both techniques.

• 대한소아치과학회지
• /
• 제5권1호
• /
• pp.64-75
• /
• 1978

In order to know cephalometric norms for the preschool children, this roentgeno cephalometric study was undertaken in each 50 Korean male and female children of primary dentition age from 4 to 5 year. The following results were obtained. 1. In the skeletal analysis, there was no significant difference between male and female in angular measurement and the linear measument of the male was generally greater than that of the female. 2. Saddle angle was $122.3^{\circ}$, articular angle was $147.6^{\circ}$, gonial angle was $119.4^{\circ}$ and the sum of each angle was $396.1^{\circ}$ in male and $396.6^{\circ}$ in female. 3. The ratio of mandibular body to anterior cranial base was about 1 : 0.91. 4. In the primary dentition, suggested that the nasion and point A move forward relative to sella turcica in a fashion, pogonion and point B are equal in angular position relative to plan S-N, bony chin and chin button was yet underdeveloped, and the forward growth of mandible was seen rapid than maxilla after 4 years. 5. Suggested that the percentage of anterior facial height to the posterior facial height were 64.4% in male and 64.1% in female. 6. Maxillary primary incisors was more upright than the permanent incisors, mandibular primary incisors was inclined lingually relative to the permanent incisor, and primary incisors was more upright than the permanent incisors. 7. Maxillary primary incisors in female was inclined labially than male. 8. In the the relationship of the upper lip and lower lip to the esthetic line, the upper lip was 2.11mm and the lower lip was 2.33mm front of the esthetic line.

• PNF and Movement
• /
• 제15권2호
• /
• pp.149-157
• /
• 2017

Purpose: The purpose of this study was to assess the effect of using smartphones for tele-rehabilitation on head position and neck dysfunction in workers with visual display terminal (VDT) syndromes over a four-week period. Methods: Sixteen VDT workers volunteered to participate in stretch exercise and posture education sessions. The subjects were divided into three groups as follows: five subjects in the visit group (VSG), six subjects in the video group (VEG), and five subjects in tele-rehabilitation group (TG). The subjects in all the groups performed the exercises three days per week for four weeks. Cranial rotation angle (CRA), craniovertebral angle (CVA) measurement, and neck disability index (NDI) tests were performed before and four weeks after the intervention. Results: No significant difference in the CRA and CVA variables was found among groups. No significant difference in the CRA variable was found within each group. A significant difference in the CRA variable was found in the VSG after the four-week intervention. No significant difference in NDI was found among the groups. The NDIs among all the groups were significantly decreased after the intervention when compared with the NDIs measured before the intervention. Conclusion: The use of smartphones in the tele-rehabilitation of VDT workers with neck pain was found to be as effective on neck function as the conventional intervention method. The tele-rehabilitation of VDT workers with neck dysfunctions may be presented as an alternative way.

• 패션비즈니스
• /
• 제10권4호
• /
• pp.151-162
• /
• 2006

This study investigated into the effects of the colors of warp and weft on the overall colors of fabrics, along with the visual changes of colors by the measuring angle of both warp and weft, by means of cross-dyeing of cotton/PET union fabrics. First, the reflectance of polyester is higher than that of cotton over the whole wavelength. Second, the dyeing of polyester uses the disperse dyes and that of cotton uses fiber-reactive dyes, the differences in the features of dyes and the reflectance of fabrics cause the same colors to be perceived different by the angle of observation. Third, the dyeing of cotton and PET fabrics individually with the same color revealed that the dyeing of cotton and PET fabrics in one bath resulted in a small difference in colors between the two fabrics than the separate dyeing in two bathes. In the case of one bath, the dyeing of PET fabrics followed by that of cotton fabrics resulted in a small difference in color than the dyeing in the reversed order. Fourth, when cotton/PET union fabrics were dyed in ten colors, the difference in colors between the two fabrics was small; and due to the difference in the density of warp and weft of union fabrics, some difference was detected in comparison with the results of separate dyeing of cotton and PET fabrics in one bath. The latter did not produce the changes in color which was recognizable with the naked eyes. Fifth, when cotton/PET union fabrics were dyed in ten colors, any color change was not observed by the measuring angle, and the inclination in the direction of warp or weft resulted in the tendency of color-deepening. In the measurement of the latter, the inclination in the direction of weft resulted in the higher color-deepening than that in the direction of warp, due to the influence of weft.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
• /
• pp.202-202
• /
• 1999

The Polyethylene (PE), Polystyrene (PS) and Polytetrafluoroethylene (PTFE) surface modification was investigated by hydrogen io assisted reaction (H-IAR) in oxygen environment. The IAR is a kind of surface modification techniques using ion beam irradiation in reactive gas environment. The energy of hydrogen ion beam was fixed at 1keV, io dose was varied from 5$\times$1014 to 1$\times$1017 ions/$\textrm{cm}^2$, and amount of oxygen blowing gas was fixed 4ml/min. Wettability was measured by water contact angles measurement, and the surface functionality was analyzed by x-ray photoelectron spectroscopy. The contact angle of water on PE modified by argon ion beam only decrease from 95$^{\circ}$ to 52$^{\circ}$, and surface energy was not changed significantly. But, the contact angle using hydrogen ion beam with flowing 4ml/min oxygen stiffly decreased to 8$^{\circ}$ and surface energy to 65 ergs/cm. In case of PS, the contact angle and surface energy changes were similar results of PE, but the contact angle of PTEE samples decreased with ion dose up to 1$\times$1015 ions/$\textrm{cm}^2$, increased at higher dose, and finally increased to the extent that no wetting was appeared at 1$\times$1017 ions/$\textrm{cm}^2$. These results must be due to the hydrogen ion beam that cleans the surface removing the impurities on polymer surfaces, then hydrogen ion beam was activated with C-H bonding to make some functional groups in order to react with the oxygen gases. Finally, unstable polymer surface can be changed from hydrophobic to hydrophilic formation such as C-O and C=O that were confirmed by the XPS analysis, conclusionally, the ion assisted reaction is very effective tools to attach reactive ion species to form functional groups on C-C bond chains of PE, PS and PTFE.

• Journal of Korean Neurosurgical Society
• /
• 제44권3호
• /
• pp.124-130
• /
• 2008

Objective : Our purpose of this study is to compare insertion angles and screw lengths from Roy-Camille, Magerl, and our designed method for cervical lateral mass screw fixation in the Korean population by quantitative measurement of reformatted two dimensional (2D) computed tomography (CT) images. Methods : We selected thirty Korean patients who were evaluated with thin section CT scans and reconstruction program to obtain reformatted 2D-CT images of the transversal plane passing the cranio-caudal angle using three different techniques. We measured the minimum angle to avoid vertebral artery (VA) injury, the ideal angle and depth for bicortical screwing of cervical lateral mass. Morphometric measurements of the lateral masses from C3-C7 were also taken. Results : In all three techniques, the mean safety angles from the VA were less than 8 degrees and the necessary depth of the screw was about 14 mm for safety to the VA and for the bicortical purchase. In our designed technique, the mean $\beta$ angles of each level from C3 to C7 were 29.0. 29.8. 29.5. 26.3. and 23.9 degrees, respectively. Conclusion : Results of this study and data from the literature indicate that differences may exist between the Korean and Western people in the length and angle for ideal lateral mass screw fixation. In addition, our technique needs further cadaveric and clinical study for safety and efficacy for being performed as alternative method for cervical lateral mass fixation.

• 한국수자원학회논문집
• /
• 제32권3호
• /
• pp.255-263
• /
• 1999

연직벽 교대에서의 국부세굴심을 측정한 실험실 자료들이다. 이들 자료들은 교대의 끝단형상, 정렬각도, 흐름수심, 흐름경사에 따라 국부 세굴심의 영향을 주는 자료들로 포함한다. 모형교대 끝단 형상이 직사각형, 타원형, 끝단을 깎아낸 직사각형, 예연형인 교대에서 국부세굴의 양상이 실험적 연구에 의하여 분석되었다. 실험들은 4개의 교대 형상에 대하여 흐름수심을 약 1cm씩 증가시켜서 이동상 세굴 조건하에 실험을 하였다. 수로의 하상경사는 0.01%, 0.03% 0.05% 0.1%, 0.2%로 정렬각도는 30 $^{\circ}$, 60 $^{\circ}$, 90 $^{\circ}$, 120 $^{\circ}$, 150 $^{\circ}$로 변화시켜 실험을 실시하였다. 최대 세굴심은 끝단 형상이 직사각형, 타원형, 끝단을 깎아낸 직사각형, 예연형의 순서로 분석되었다. 실험결과들은 세굴심이 교대의 형상뿐만 아니라 정렬각도, 흐름수심, 수로경사에 따라 다르게 나타나는 것을 보여주었다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
• /
• pp.296-299
• /
• 2004

KARI precision attitude determination system has been developed for high accurate geo-coding of KOMPSAT-2 image. Sensor data from two star trackers and a IRU are used as measurement and dynamic data. Sensor data from star tracker are composed of QUEST and unit vector filter. Filter algorithms consists of extended Kalman filter, unscented Kalman filter, and least square batch filter. The type of sensor data and filter algorithm can be chosen by user options. Estimated parameters are Euler angle from 12000 frame to optical bench frame, gyro drift rate bias, gyro scale factor, misalignment angle of star tracker coordinate frame with respect to optical bench frame, and misalignment angle of gyro coordinate frame with respect to optical bench frame. In particular, ground control point data can be applied for estimating misalignment angle of star tracker coordinate frame. Through the simulation, KPADS is able to satisfy the KOMPSAT-2 mission requirement in which geo-location accuracy of image is 80 m (CE90) without ground control point.