• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.373-380
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• 2010

The purpose of this study was to evaluate the effect of balance training on gait stability. The study population included 17 male high school students who were divided into 3 groups, each of which underwent one of the following types of balance-training programs for 8 weeks: 1 foot standing on cushion foam, trunk muscle training, and inverted body position training. 0, 4, and 8 weeks, the following experiment was performed: The participants were asked to close their eyes and take 17 steps; the stability of forward and sideward movement was determined, and the direction linearity was measured. The results revealed that all the training programs caused a decrease in stride deviation and an increase in the and the stride length, thereby improving the stability of forward movement. All the programs decreased the variation in step width and were thus also effective in improving the stability of sideward movement. The inverted body position training program was considered very effective because the cross point appeared on post hoc graphic analysis after 4 weeks, and the deviation length for 10 m was low, i.e., below 4 cm. All the programs were effective with respect to direction linearity because they decreased the deviation in direction widths. The results indicate that whole-body neurocontrol training is more effective than simple muscle training and local focused balance training, although this neurocontrol training-in the form of inverted body position training-required a longer training period than did the other programs.

• The Journal of Advanced Prosthodontics
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• v.10 no.6
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• pp.401-407
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• 2018

PURPOSE. When performing an occlusal procedure, it is recommended that the patient should be sitting straight with the head in a natural position. An inappropriate mandibular position caused by an incorrect occlusal record registration or occlusal adjustment can result in damaged teeth and cause functional disorders in muscles and temporomandibular joints. The purpose of this study was to clarify the influence of horizontal cephalic rotation on mandibular position by investigating the three-dimensional positions of condylar and incisal points. MATERIALS AND METHODS. A three-dimensional jaw movement measurement device with six degrees of freedom (the WinJaw System) was used to measure condylar and incisal points. The subjects were asked to sit straight with the head in a natural position. The subjects were then instructed to rotate their head horizontally $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, $40^{\circ}$, $50^{\circ}$and $60^{\circ}$ in the right or left direction. RESULTS. The results indicated that horizontal cephalic rotation made the condyle on the rotating side shift forward, downward, and toward the inside, and the condyle on the counter rotating side shift backward, upward, and toward the outside. Significant differences in deviations were found for angles of rotation higher than $20^{\circ}$. The incisal point shifted in the forward and counterrotating directions, and significant differences were found for angles of rotation higher than $20^{\circ}$. CONCLUSION. The mandibular position was altered by horizontal cephalic rotations of more than $20^{\circ}$. It is essential to consider the possibility of deviation of the mandibular position during occlusal procedures.

• Journal of IKEEE
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• v.19 no.3
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• pp.335-341
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• 2015

Recently a demand for high precision absolute position transducer is increasing in order to control thickness in steel industry. LVDT (linear variable differential transformer) is widely used to measure the absolute position in the linearly moving cylinder under poor factory environment. In this paper we implement the three phase LVDT with a high resolution of one micron and L/D (LVDT to digital) converter. First we designed U, V, and W three phase signaling using FPGA. Second a pulse output algorithm is designed for position information with A and B phase waveforms. Finally the performance is compared with previous sensors. Experiments show that the linearity deviation error is 0.009788 [mm] and the average sinusoidal THD is 0.0751%, which means 2.2% and 33% more improved result than the previous sensors respectively.

• Korean Journal of Computational Design and Engineering
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• v.9 no.1
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• pp.35-43
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• 2004

It is well known that the five-axis machining has advantages of tool accessibility and machined surface quality when compared with conventional three-axis machining. Traditional researches on the five-axis tool-path generation have addressed interferences such as cutter gouging, collision, machine kinematics and optimization of a CL(cutter location) or a cutter position. In the paper it is presented that optimal CL data for a face-milling cutter moving on a tool-path are obtained by incorporating TSS(tool swept surface) model. The TSS model from current CL position to the next CL position is constructed based on machine kinematics as well as cutter geometry, with which the deviation from the design surface can be computed. Then the next CC(cutter-contact) point should be adjusted such that the deviation conforms to given machining tolerance value. The proposed algorithm was implemented and applied to a marine propeller machining, which proved effective from a quantitative point of view. In addition, the algorithm using the TSS can also be applied to avoid cutter convex interferences in general three-axis NC machining.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.135-141
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• 2021

Interest is growing in the design and development of square wave driven BLDC permanent magnet motors suitable for industrial automation, and the development of position detection circuits and drivers. However, this motor is somewhat limited in its application despite the price and functional advantages due to the decrease in efficiency due to switching loss and vibration and noise. In the process of designing and assembling a BLDC motor, the magnetic pole angle is not uniform or the magnetic flux distribution is distorted due to problems in magnetic circuit design or product non-uniformity in the assembly process. Therefore, these things cause position detection deviation and deteriorate the motor characteristics. In addition, the sine wave driven BLDC system can operate stably only when the signal generated from the position sensor is accurately fed back to the driver. However, since the generated signal cannot perform stable position detection due to the occurrence of DC offset component due to magnetic flux density deviation or magnetization technology, which is an external influence, this study intends to study the proposed circuit that can remove the DC offset component.

• Journal of Acupuncture Research
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• v.20 no.6
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• pp.27-35
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• 2003

Objective: We intended to show the relation between whiplash injury and deviation of upper cervical through analysing patients having deviation of upper cervical injuried by whiplash. Methods: We chose 40 patients who have been admitted for whiplash injury syndrome in vertebral-joint center of Conmaul oriental medical hospital during 2001.10.1-2003.10.15. We examined cervical simple X-ray of them according to the traffic accident patterns and the position in the veicle. Results: The 97% of the cases showed AS deviation and the 95% of them complained neck pain. The first cases collided from the back on the driving seat showed AS deviation. The second cases collided from the front on the back seat showed AS deviation of left lateral misalignment of atlas. The third cases collided from the front on the assistant seat showed AS deviation of right lateral misalignment of atlas.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.21.1-21.6
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• 2016

Background: The Le Fort I osteotomy is one of the most widely used and useful procedure to correct the dentofacial deformities of the midface. The changes of the maxilla position affect to overlying soft tissue including the nasal structure. Postoperative nasal septum deviation is a rare and unpredicted outcome after the surgery. There are only a few reports reporting the management of this complication. Case Presentation: In our department, three cases of the postoperative nasal septum deviation after the Le Fort I osteotomy had been experienced. Via limited intraoral circumvestibular incision, anterior maxilla, the nasal floor, and the anterior aspect of the septum were exposed. The cartilaginous part of the nasal septum was resected and repositioned to the midline and the anterior nasal spine was recontoured. Alar cinch suture performed again to prevent the sides of nostrils from flaring outwards. After the procedure, nasal septum deviation was corrected and the esthetic outcomes were favorable. Conclusion: Careful extubation, intraoperative management of nasal septum, and meticulous examination of preexisting nasal septum deviation is important to avoid postoperative nasal septum deviation. If it existed after the maxillary osteotomy, septum repositioning technique of the current report can successfully correct the postoperative septal deviation.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1858-1862
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• 2005

Stepping motor normally operates without feedback and may loss the synchronization. This problem can be prevented by using positional feedback. This paper introduces one method for closed loop control of stepping motor and a method for combining full-step control and micro-step control. This combination controlling apparatus can perform position control with high accuracy in a high speed, so that it will not suffer from vibration (or hunting) problem when stopping motor. Controlling apparatus contains a position counter block for detecting rotor position of stepping motor, a driving block for supplying current to windings of stepping motor, a control block for comparing output signal of position counter block with command position (desired position) and outputting current command signal based on deviation between current position and command position of rotor. To output current command signal, the control block refers to a sine wave data table. This table contains value of duty cycle of Pulse Width Modulation signal. As the second object of this paper, the process of building this data table is also presented.

• The Journal of Korean Society for Radiation Therapy
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• v.1 no.1
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• pp.70-78
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• 1985

The intrauterine irradiation is essential to achieve adequate tumor dose to centeral tumor mass in radio therapy for uterine malignancy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The comparison study of currently using 2 systems was undertaken. The simulation films and medical records of 135 patients who was treated with intrauterine irradiation at one of general hospitals in Busan and Seoul between Jan. 1983 and June 1983, were critically analized and physical parameters of low dose rate system and remote controlled high dose rate system were measured. The physical parameters include distances between lateral walls of vaginal fornices, longitudinal and lateral angles of tandem to the body axis, the distance from the external os of uterine cervix to the central axis of ovoids, the radiation dose ratio to rectum and bladder to reference point A. Followings were summary of study results: 1. In distances between lateral walls of vaginal fornices the low dose rate system showed wide distribution and relatively larger distances. In low dose rate system 5.0-5.9 cm was $55.89\%$ 6.0-6.9 cm: $23.53\%$, 4.0-4.9cm: $10.29\%$, 3.0-3.9cm: $10.29\%$, and in high dose rate system 5.0-5.9cm was $80.59\%$, 4.0-4.9cm: $17.91\%$, $6.0\~6.9\;cm:\;1.5\%$. 2. In lateral angulation of tandem to body axis, the low does system revealed mid position (the position along body axis) $64.7\%$, Lt. deviation $19.13\%$ and Rt. deviation $16.17\%$. However the high dose rate system revealed mid position $49.26\%$ Lt. deviation $40.29\%$ and Rt. deviation $10.45\%$. 3. In longitudinal angulation of tandem to body axis the mid position was $11.77\%$ and anterior angulation $88.23\%$ in low dose rate system but in high dose rate system the mid position was $1.56\%$ and anterior angulation $98.44\%$. 4. Down ward displacement of ovoids below external os was only $2.94\%$ in low dose rate system and $67.69\%$ in high dose rate system. 5. The radiation dose ration to rectum to reference point A was $102.70\%$ in high dose rate system and $70.09\%$ in low dose rate system. The dose ratio to bladder to reference point A was $78.14\%$ in high dose rate system and $75.32\%$ in low dose rate system.

• Journal of the Korean Wood Science and Technology
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• v.15 no.2
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• pp.67-78
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• 1987

This study was designed to investigate the effect of board thickness and ring angle on the characteristics including internal check. ring failure, surface check, end check, collapse, thickness shrinkage and width shrinkage of press-drying. The exprimental materials of 6mm-. 9mm- and 12mm-thick board were taken from heartwood and sapwood of oak (Quercus acutissima Carr.) respectively. And boards were numbered according to position in the log(No. 1 to No. 4 for heartwood :md No. 9 for sapwood). Press-drying was at $145^{\circ}C$ platen temperature and 3.5kg/$Cm^2$ platen pressure. The results of this study were summarized as follows. 1. Drying rates for sapwood materials were greater than those for heartwood materials. And drying rates for thinner materials were greater than those for thicker materials. 2. The thinner boards were. the severer surface checking developed in the heartwood materials, and surface checking for heartwood materials had no tendency in board position for the same thickness. Sapwood materials were completely free from surface checking. 3. End checking for heartwood materials had no tendency in board position. The greater deviation of ring angle from perfectly edge-grained was, the severer and checking developed in the sapwood materials. But end checking did not occur in 6mm-thick sapwood materials. 4. The greater deviation of ring angle from perfectly edge-grained was, the severer end checking developed for heartwood and sapwood materials. As board thickness increased, maternal checking developed more severely for heartwood and sapweed materials. 5. For heartwood materials, ring failure, reduced with increasing deviation of ring angle from perfectly edge-grained except 12mm-thick material and showed no significant difference attributable to board thickness. Sapwood materials were completely free from ring failure. 6. For heartwood and sapwood materials, collapse was slight and showed no significant differences attributable to both board thickness and board position. 7. As deviation of ring angle from perfectly edge-grained increased, shrinkage of board thickness decreased for heartwood and sapwood materials. 8. Shrinkage of board width showed no significant differences attributable to both board thickness and board position for heartwood and sapweed materials.