• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.628-631
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• 2000

A new control method for precision robust speed control of a PMSM(Permanent Magnet Synchronous Motor) using load torque observer is presented. With this system we can obtain more reliable eye moving singal(nystagmus) Until now rotating chair system which is called 2D-optokinetic stimulator is used to make dizzincess. However an inclined rotating chair system witch is 3D-optokinetic stimulator is needed to obtain the precise dizziness data. This 3D-optokinetic sitimulator include unbalanced load aused by unbalanced center of mass. For this case new compensation method is considered to obtain robust speed control using load torque observer. To reduce the effect of this disturbance we can use dead-beat observer which has high gain. The application of the load torque observer is published in [1] for position control. A problem of using speed information such as amplifying effect of noise is reduce by moving average process. The experimental results are depicted in this paper to show the effect of this proposed algorithm.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제17권2호
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• pp.130-136
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• 1995

Vestibuloplasty are following categories : Mucosal advancement(submucous), secondary epithlization(reepithelization) and grafting vestibuloplasty. Although certain procedures are indicated for alveolar bone loss and sulcus shortening, relapse can occur. Every efforts to minimize or compensate for it is controversy. O'Steen(1970) reported the mucous graft methods that none of vestibular shrinkage and graft contracture. 15patients in mucous graft vestibuloplasty with fibrin adhesive system(Beriplast) were taken in cases of alveolar bone resorption and mucosal shortening due to traumatized alveolar bone defects, senile atrophic alveolar bone, postoperative cyst or tumor resection, edentulous alveolar bone loss, and others. A technique in the use of small piece of palatal mucosa$(1{\times}20mm)$ from the lateral aspect of the palate with adhesive system provided to secure the skin grafts, avoid stent fixation, postoperative patient's comfort and less time-consuming than the standard technique, especially excellent bleeding control.

• The Journal of Korean Physical Therapy
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• 제32권3호
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• pp.152-156
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• 2020

Purpose: The subjective visual vertical (SVV) test is used to evaluate the otolith function in the inner ear. This study compared the different balance ability according to the results of the SVV in healthy adults. Methods: This study recruited 30 normal healthy subjects who did not have neurological and musculoskeletal disorders. The subjects were divided into experimental and control groups based on the results of SVV: experimental group, >2°; control group, <2°. The static balance ability was evaluated using the Fourier Index, which could evaluate the balance capacity objectively and quantitatively. Results: The mean angle of the SVV in the experimental and control groups was 4.44° and 0.59°, respectively. In the result of the Fourier series, the F1 frequency band in the experimental group showed a significantly higher value under one condition compared to the control group (p<0.05). In the F2-4 and F5-6 frequency bands, the experimental group showed a significant increase in the Fourier series value under the four conditions compared to the control group (p<0.05). In the F7-8 frequency band, significantly higher values of the Fourier series were observed in the experimental group under the three different conditions (p<0.05). Conclusion: These results showed increased trunk sway while maintaining static balance in the experimental group who showed a larger SVV angle compared to the control group. The SVV can be applied to evaluate the vestibular system and balance ability in normal adults.

• 한국전문물리치료학회지
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• 제11권4호
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• pp.51-60
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• 2004

Falls are common, costly, and a leading cause of death among older adults. The major predisposing factors of a fall may include age-related deterioration in the dynamic system composed of auditory, somatosensory, vestibular, visual, musculoskeletal, and neuromuscular subsystems. Older adults with a history of frequent falls demonstrated significant reductions in gait velocity, muscle force production, and balance performance. These altered neuromechanical characteristics may be further exaggerated when faced with conflicting multisensory conditions. Despite the important contribution of multisensory function on the sensorimotor system during postural and locomotor tasks, it remains unclear whether multisensory intervention will produce dynamic balance improvement during locomotion in older adults with a history of frequent falls. Therefore, the purpose of this paper is to address important factors associated with falls in elderly adults and provide theoretical rationale for a multisensory intervention program model.

• 대한물리치료과학회지
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• 제5권4호
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• pp.851-860
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• 1998

The purpose of this study was to quantitatively observe changes in postural stability of double leg support and single limb stance. Thirty-six healthy subjects participated in the study. Postural stability were examined using Dynamic Balance System. Each trial was 25 sec in duration. Each of 6 conditions{double leg support and single limb stance ; eyes open in stable platform, eyes closed in stable platform, eyes open in dynamic platform) evaluated effect of visual, vestibular, proprioceptive system. Center of balance found for displacement to the left along the X axis in double leg support and to the forward on left toe in single limb stance. Sway index was the lowest in double leg support with eyes open in stable platform and the higher in single limb stance with eyes closed in stance platform. We believe that reliable and valid measures should be used to determine the contributing factors of our client's postural problems so that we can design the most effective treatment possible.

• 대한의용생체공학회:의공학회지
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• 제11권2호
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• pp.269-276
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• 1990

This study describes the battery functional test in order to explore vestibular oculomotor system. These tests are the following : a) acceleration test by using a pseudorandom stimulus. b) caloric test by considering both the constant temperature variation in the semicircular canals for a short time and the only head movement, to the fore and the back, for the ear ir- rigation, which gave us two types of stimulus (cold and warm) according to the only head position. c) optokinetic test by continuous constant velocity displacement of a large image fill- ing the entire subject's visual field. With relation to the clinical practices, some results of research programs which are at present in progress are presented.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• 제56권12호
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• pp.749-753
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• 2013

Basically stem cells have characteristics of multi-potency, differentiation into multiple tissue types, and self-renew through proliferation. Recent advances in stem cell biology can make identifying the stem-cell like cells in various mammalian tissues. Stem cells in various tissues can restore damaged tissue. Stem cells from the adult nervous system proliferate to form clonal floating colonies called spheres in vitro, and recent studies have demonstrated sphere formation by cells in the tympanic membrane, vestibular system, spiral ganglion, and partly in the organ of Corti. The presence of stem cells in the ear raises the possibilities for the regeneration of the tympanic membrane & inner ear hair cells & neurons. But the gradual loss of stem cells postnatally in the organ of Corti may correlate with the loss of regenerative capacity and limited hearing restoration. Future strategies using endogenous stem cells in the ear can be the another treatment modality for the patients with intractable inner ear diseases.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.206-210
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• 2004

This paper proposes a new training system for equilibrium sense using unstable platform. This training system for equilibrium sense consists of an unstable platform, a computer interface circuit and software program. Postural instability changes the weighting of different types of sensory information and the state of the equilibrium maintenance system. In order to improve the equilibrium sense, we developed software program such as a block game, sine curve training (SCT) and pingpong game using Visual C++. Using this system and training programs, we performed an experiment to train the equilibrium sense of a subject. To evaluate the effects of balance training, the time maintained on the target and the moving time to the target are measured. As a result, the moving time to the target and time to maintain cursor on the target improved through repeating equilibrium sense training. It was concluded that this system was reliable in the evaluation of equilibrium sense. We expect that this system might be applied to clinical use as an effective balance training system.

• International journal of advanced smart convergence
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• 제3권1호
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• pp.15-19
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• 2014

This study was compared the variation system of body posture condition for stability by the posture. We used a model of bio parameter on the basis of the move state in the standing posture. We compared the sway movement derived from average of the physical sensing condition. Vision condition of variation average (Vi-${\sigma}_{AVG-AVG}$) was verified slightly greater at $13.746{\pm}4.05$ unit. Vestibular condition of variation average (Ve-${\sigma}_{AVG-AVG}$) was verified slightly larger at $7.829{\pm}1.071$ unit. Somatosensory condition of variation average (So-${\sigma}_{AVG-AVG}$) was verified slightly smaller at $2.592{\pm}0.538$ unit. CNS condition of variation average (C-${\sigma}_{AVG-AVG}$) was verified slightly larger at $0.46{\pm}0.105$ unit. The valuation system will be to deduce the model of body management with falling and stroke and all that sort of things. There will be to infer a data algorithm and the evaluation of processing system.

• 한국정밀공학회지
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• 제22권8호
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• pp.192-198
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• 2005

In this paper, we propose a new training system for the improvement of equilibrium sense using unstable platform. The equilibrium sense, which provides orientation with respect to gravity, is important to integrate the vision, somatosensory and vestibular function to maintain the equilibrium sense of the human body. In order to improve the equilibrium sense, we developed the software program such as a block game, pingpong game using Visual C++. These training system for the equilibrium sense consists of unstable platform, computer interface and software program. The unstable platform was a simple structure of elliptical-type which included tilt sensor, wireless RF module and the device of power supply. To evaluate the effect of balance training, we measured and evaluated the parameters as the moving time to the target, duration to maintain cursor in the target of screen and the error between sine curve and acquired data. As a results, the moving time to the target and duration to maintain cursor in the target was improved through the repeating training of equilibrium sense. It was concluded that this system was reliable in the evaluation of equilibrium sense. This system might be applied to clinical use as an effective balance training system.