• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.157-160
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• 2002

For a company operating lots of vehicle, such as taxi companies or delivery company, a system telling the position of each vehicle is essential. Conventional methods are based on personal communication between a operator in head-office and driver at the car. Since driver cannot respond to the communication while he drives or when lie is out of car. the communication often fails. So, a system identifying and reporting the vehicle position offers groat help to those kind of company.

• Imaging Science in Dentistry
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• v.35 no.1
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• pp.25-31
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• 2005

Purpose : To evaluate the stability of the segmental occlusal plane and anatomical line as the reference line for measuring the mesiodistal tooth angulation in panoramic radiography and to determine the mean angle and the range of the mesiodistal tooth angulation in Korean population with normal occlusions. Materials and Methods : Twenty nine subjects (15 men, 14 women) with normal occlusion were selected. A total of 29 panoramic radiograms were taken at normal head position and then 10 images of 5 subjects selected were repeatedly taken with repositioning 2 times at each of the head down (V-shaped occlusion) and up (horizontal occlusion) for evaluation of stability of adopted reference lines by using PM2002CC (Planmeca, Finland). The images were traced with adoption of two test reference lines and the long axes of the teeth. The mesial angles formed by each reference line and the long axes of the teeth were measured and analyzed. Results : With anatomical reference line, the mesiodistal tooth angulations of the molars showed the significant difference by over 5 degree between the normal and each changed head position. With segmented occlusal reference line, deviations of mesiodistal tooth angulations by the two changed head positions were less than 1 degree. The means, standard deviations, and maximum and minimum values of mesiodistal tooth angulations to segmental occlusal reference line on panoramic radiography were determined. Conclusion : It would appear that mesiodistal tooth angulations to segmental occlusal plane as reference line in panograms are predictable as standards of normal occlusion and useful for evaluation of tooth arrangement between adjacent teeth.

• PNF and Movement
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• v.18 no.2
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• pp.265-273
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• 2020

Purpose: The purpose of the study was to investigate the effects of HMD (head mounted display)-based virtual reality balance training on static balance in young adults, and whether appropriate balance training can help healthy adults to improve balance ability in daily living. Methods: The study subjects were 14 healthy adults. Subjects received 20 minutes of HMD-based virtual reality balance training 3 times per week for 4 weeks. Static balance was measured before, during, and after training and after one month. Static balance was measured in a total of 8 conditions, and the results were classified as visual (F1), somatosensory (F5-6), vestibular (F2-4), and central nervous system (F7-8). Results: The test results showed no significant difference in pre-training, post-training, and follow-up results under all conditions at Fourier index F1, F5-6, and F7-8 frequencies. For the F2-4 frequency, there was a significant difference before and after training under NC (neutral head position, eyes closed, firm surface) and PC (neutral head position, eyes closed, elastic surface) conditions. The NC condition returned a significant decrease of F2-4 frequency in post-training testing as compared to pre-training, and the PC condition showed a significant decrease of F2-4 frequency between the pre-training and mid-training tests, and between the pre-training and post-training tests. Conclusion: These results indicate that HMD-based balance training can improve balance ability, even in normal adults, and seems especially effective for vestibular function training.

• Journal of the Korea Society of Computer and Information
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• v.23 no.2
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• pp.35-43
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• 2018

In this paper, we propose a grid-based efficient routing protocol for a mobile sink in wireless sensor networks. In the proposed protocol, the network is partitioned into grids and each grid has a grid head. For the efficient routing to a mobile sink, the proposed protocol uses a mobile sink representative node to send the data to a mobile sink and grid heads are used as a mobile sink representative node. Furthermore, the proposed protocol uses nodes in the boundary of the center grid as position storage nodes. The position storage nodes store the position of a mobile sink representative node and provide source nodes with it for data delivery. With these features, the proposed protocol can reduce a lot of overhead to update the position information and improve the delay of data delivery to a mobile sink. The proposed protocol performs better than other protocols in terms of the delay and the energy consumption per node in the performance evaluation.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.7
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• pp.544-550
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• 2000

Among the several types of 3D display methods the autostereoscopic method has an advantage that we can enjoy a 3D image without any additional device but the method has a disadvantage of a narrow viewing zone so that the moving viewer coannot see the 3D image continuously. This disadvantage can be overcome with the detectioni of viewer's positional movement by head tracking. In this paper we suggest a method of detecting the position of the moving viewer's two eyes by using images obtained through a color CCD camera, The suggested method consists of the preprocessing process and the eye-detection process. Through the experiment of applying the suggested method we were able to find the accurate two-eyes position for 78 images among 80 sample input images of 8 different men with the processing speed of 0.39 second/frame using a personal computer.

• Journal of Korean Academy of Nursing
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• v.17 no.1
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• pp.44-51
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• 1987

The purpose of this study is to identify the leadership and subordination of hospital nurses: to determine the leadership and subordination by nurses' characteristics, which are age, educational background, career, and position of nurses. 279 staff nurses, 13 charge nurses, 32 head nurses and 16 nurse supervisors were participated in this study during the period from Dec. 5 to Dec. 20, 1986. Subjects were instructed to rate at one of five points likert type scale on the 26 items of leadership and subordination. The reliability of the items (Cronbach's α) were 0.63∼0.84. Among the total 26 items, 8 items on authority, 4 items on human relation, 9 items on committment of position and 5items on committment of job were summed to cummulative scores in each category. As a result of data analysis nurses who perceive positive on authority are 68.6% and positive on human relation are 67.9%. The perception of authority is different by age, Career and position of nurses. (P<0.05). And nurses who perceive positive on committment of position are 84.7% and positive on committment of job are 62.1%. The perception of committment for position is different by age, career and position of nurses (P <0.05), and committment of job is different by age and position. (P<0.05).

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1060-1065
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• 2003

This paper contributes to development of a new chip mounting head system for flip chip. Recently, the LDM(Linear DC Motor) has been widely used, because it has particular merits than the rotary type motors. In this paper, we proposed a macro/micro positioning system for force control of a chip mounting system. In the proposed macro/micro system, the macro actuator provide the system with a gross motion while the micro device yields fine tuned motion to reduce the harmful impact force that occurs between very small sized electronic parts and PCB surface. In order to prove the effectiveness of the proposed macro/micro chip mounting system, we compared the proposed chip mounting head with the conventional chip mounting head equipped with a macro actuator only. A series of experiments were executed under the mounting conditions of various access velocities and PCB stiffness. As a result of this study, a satisfactory voice coil actuator as the micro actuator has been developed, and its performance meet well the specifications desired for the design of the chip mounting head system and show good correspondence between theoretical analysis and experimental results.

• The Journal of Korean Physical Therapy
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• v.29 no.4
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• pp.153-157
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• 2017

Purpose: The purpose of this study was to investigate the effect of self-postural control on foot pressure in subjects with forward head posture. Methods: Forty-two healthy adults were recruited in this study. Participants were divided into two groups: The forward-head postural (FHP) group (craniovertebral angle<$53^{\circ}$, n=22) and the control group (craniovertebral angle${\geq}53^{\circ}$, n=20). In the FHP group, foot pressure was measured using three different standing postures: Comfortable standing posture (CSP), subjective neutral standing posture (SNSP), and neutral standing posture with visual feedback (NSP-VP). Each position was performed in random order. In the control group, foot pressure was measured only using the comfortable standing posture. Results: With respect to CSP and SNSP, there was a significant difference on heel pressure between the two groups (p<0.05). Regarding NSP-VP, however, there was no significant differences on heel pressure between the two groups (p>0.05). Conclusion: We suggest that cervical posture control using visual feedback has a positive effect on the distribution of foot pressure in subjects with forward head posture.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.92-97
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• 2011

Vehicle lightings are very important for safe driving during night time. Since the eye recovery time after an exposure to oncoming headlights would take after several seconds, the aiming point of vehicle head lamps have to pass safety requirements. Despite the fact that vehicle inclination is variable with vehicle load conditions, the head lamps aiming point is usually fixed at a constant position which is set by car manufacturer. Consequently, vehicle head lamps under varying load conditions often make people in the opposing vehicle uncomfortable, and even worse, can cause an accident. This paper presents an active vehicle lighting mechanism to automatically adjust its aiming point, or cut-off line, in order to compensate the change in vehicle inclination resulting from load variations. The effectiveness of the proposed method is demonstrated through a set of simulations and experiments with a real vehicle.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.1
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• pp.65-72
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• 1991

For the enhancement of a comprehension in temporomandibular joint radiographs, the author has compared and analysed the roentgenographic images of the temporomandibular joint of human dry skull which was taken by submentovertex projection, panoramic radiography, oblique lateral transcranial projection, corrected anterio-posterior tomogram and corrected lateral tomogram. The obtained results were as follows. 1. The submentovertex projection represented in detail the both poles and the posterior surface of the condylar head of the mandible. 2. The oblique lateral transcranial projection represented the articular space, the outer contour of the condylar head and the position of the condylar head within the mandibular fossa, but the relationship of the temporomandibular joint was not revealed accurate, because of the oblique direction of a central ray in taking radiographs. 3. The corrected antero-posterior tomogram was superior method in representation of roent- genographic images of the superior surface and the both poles of the condylar head and the corrected lateral tomogram was considered as the most accurate method among some radiographic techniques for the interpretation of articular space and condyle-fossa relationship. 4. It was possible to observe three-dimensionally the head of condyle with the combinated use of submentovertex projection, corrected antero-posterior tomogram and corrected lateral tomogram.