• Journal of Oral Medicine and Pain
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• v.14 no.1
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• pp.89-103
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• 1989

In order to evaluate the influences of Myo-monitoring on masticatory muscles, Myo-monitoring on 31 normal persons and 30 persons with one more temporomandibular dysfunction symptoms during 45 minutes or above. The author observed velocities of mandibular opening and closing movement, variabilities of mandibular rest position and EMG activities of temporal and masseter muscles. The obtained results were as follows : 1. There were no significant differences on velocities of mandibular opening and closing movement between before and after Myo-monitoring. 2. There were significant differences on vertical dimension and total dimension form mandibular rest position to centric occlusion between before and after Myo-monitoring but no significant differences on anteroposterior and lateral dimension. 3. Activities of temporal and masseter muscles were decreased in Myo-Monitoring. 4. There were disappeared significant differences on EMG activity values between normal and symptom groups after myo-monitoring.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.10a
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• pp.29-34
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• 1993

In many circumstances, it is desired to move a mass from one position to another without inducing any vibration in the mass being moved. Two such problems are considered here: the motion of a pendulum initiated by the specified motion of its support. In each case, it is desired that the system start at rest and come to rest in the second position. A simple strategy for the specified motion is given here. The method is motivated by engine cam-follower design. The force required to move the system in question is determined as well as the maximum value of the force required (and the times at which these forces take place) is determined.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.724-743
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• 2000

One of the biggest clinical problems of osseointegrated implant prosthesis is the excessive stress caused by bite forces which are transfered directly into the bone through the osseointegrated implant fixtures. So several biodynamic problems occur when there is an excessive fatigue stress. The factors of stress distribution are the number, kind, position, arrangement of the implants, and the distance between the implants, and the kind, quality of superstructure prosthesis and connection type between the rest implant and the superstructure. Recently, a distal short additional implant, socalled rest implant, is employed to reduced the stresses in conventional cantilevered prostheses. This study was undertaken to analyze the stresses transfered by osseointegrated implant cantilevered prostheses depending upon the number and the position of implants, the presence of rest implant, and the type of their connection. Three dimensional finite element analysis was attempted using ANSIS ver. 5.3 program under IBM INDIGO computer. The results were as follows : 1. The rest implant influenced on the pattern of stress distribution on the anterior area of the mandible and the superstructure. 2. In the group employing the rest implants, the fixed type of connection between the rest implant and the superstructure was more stable than the ball attachment type on the stress distribution. 3. In the group employing the ball attachment between the rest implant and the superstructure, the case with 4-implants(on canine, premolar) was little more stable than the case with 6-implants and the case with 4-implants(on incisor, premolar) on the stress distribution. 4. In the cantilevered group, the case with 4-implants(on incisor, premolar) and the case with 6-implants were more stable than the case with 4-implants(on canine, premolar) on the stress distribution. 5. In all of the group, the case with 6-implants and the fixed type of connection was the most stable and the case with 4-implants (on canine, premolar) was the most unstable on the stress distribution.

• Journal of Welding and Joining
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• v.27 no.1
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• pp.71-78
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• 2009

In the circumferential welding of pipe, welding phenomenon changes with the position of pipe. Especially in the overhead position, back bead of vertical-up position would be sunk. To investigate the size of back bead and keyhole with the change of the flow rate of pilot and shield gas at each position, bead-on plate welds were conducted on 6mm thickness SS400 with inclined-up position. When the rest of welding conditions remained constant, the width of back bead was increased as the flow rate of pilot gas was increased. And back bead tended to convex as the flow rate of shield gas was increased.

• Journal of Oral Medicine and Pain
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• v.25 no.2
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• pp.191-203
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• 2000

This study was performed to investigate the relationship between vertical dimension during swallowing and speech pattern in patients with temporomandibular disorders. For this study, 33 patients with temporomandibular disorders(TMDs), namely, 17 patients with disc displacement with reduction and 16 patients with disc displacement without reduction, and 30 normal subjects without any signs and symptoms in the masticatory system were selected as the patient group and as the normal group, respectively. Biopak $system^{(R)}$(Bioresearch Inc., Milwaukee, USA) was used for recording of electromyographic(EMG) activity(${\mu}V$) of the anterior temporalis, the superficial masseter, the sternocleidomastoideus and the trapezius insertion muscle during swallowing, and of mandibular positional change with function time(sec.) during swallowing and speech. A sentence of 'Sue is missing her house' was used for observing of speech pattern. Comparison between the two groups and relationship of the mandibular positional change and the function time between during swallowing and during speech were analysed by SPSS windows program. The results of this study were as follows : 1. Mean EMG activity of the trapezius insertion during swallowing was higher in the patient group, and the value was $3.4{\mu}V$ in patients and $2.1{\mu}V$ in normal subjects. 2. Vertica1 dimension(VD) at mandibular rest position before swallowing was slightly higher in the patient group, but VD at swallowing-late stage and at rest position after swallowing were not different between the two groups. 3. Swallowing time were 2.1 sec. in the patient group, and 1.5 sec. in the normal group, and the difference was significant. 4. VD during speech were generally higher in the normal group. In this case, speaking position showing the most difference between the two groups was 'her' position. The distance from habitual intercuspal position to 'her' position was 4.9mm in the patient group, and 6.6mm in the normal group. Speaking time was also longer in the patient group. 5. There were no difference in all observed items between the two categories of the patient group according to reduction of disc displacement. 6. Relationship between the positional changes during swallowing and speech were different between the patient group and the normal group. And in the normal group, VD at rest position before swallowing was negatively correlated with speaking time.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.53-71
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• 1991

This study was performed to investigate the muscular activity of the complete denture wearers compare with subjects with natural teeth. For the study, 10 subjects with natural dentition and 18 upper and lower complete denture wearers selected and the Bio-electric Processor EM2(Myo-tronics Reaserch, Inc., U.S.A.) with the surface electrodes was used to record electromyographic activity from the right and left middle of masseter and anterior temporal muscles of each subject during mandibular postural rest position, tapping of teeth from postural rest position, maximal clench, and right and left gum and raw carrow chewing. This results of this study were as follows : 1. In mandibular postural rest position, the denture wearers produces high muscular activity in contrast to natural objects(P<0.05) but, there was no difference between the state of denture removal and insertion, and the muscle activity of the anterior temporal muscle was high than the middle of masseter muscle in natural objects and denture wearers. 2. In tapping of teeth, there was no difference in muscle activity between natural objects and the state of denture removal of denture wearers. 3. In maximal clench, there was markedly lower denture wearers than natural objects in muscle activity, and the ratio of mean voltages was about 36 percentages. 4. In gum and raw carrow chewing, the activity was lower than natural object, the ratio was about 59 percentages. 5. In chewing, the mean voltages of the middle of masster muscle on the chewing side was highest, followed by the anterior temporal on the chewing side, the anterior temporal and masster muscles on the non-chewing side.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.233-246
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• 1994

The purpose of the present study was to investigate the difference of muscular activities of the tongue and lip muscles between anterior open-bite and normal occlusion during various function. Thirty eight subjects of 12.1-39.6 years were employed in this study : Eighteen subjects were anterior open-bites and tweenty subjects were normal occlusions. During rest position, maximum effort of lip sealing, command swallow of saliva and sucking & swallowing of juice, the electromyographic datas of the genioglossus, superior longitudinal muscle of tongue, upper and lower orbicularis oris were recorded and integrated with Medelec MS 25 electromyographic machine. Lateral cephalometric radiographs were taken on all subjects for the analysis of tongue posture and size. All data were recored and statistically processed. The findings of this study can be summerized as follows : 1. During the rest position, muscular activity of tongue was higher than that of lip muscle in open-bite, but no difference in normal occlusion group. 2. During the swallowing of juice, the activity of orbicularis oris was higher than that of genioglossus in open-bite. But the normal occusion was showed higher activity of tongue during the swallowing of juice. 3. The open-bite, compared to the normal occlusion, had higher value of tongue muscle activity during the rest position. 4. Compared to normal occlusion group, the open-bite had higher value of lip muscle activity during the sucking and swallowing of juice. 5. During the command swallow of saliva, the normal occlusion was showed harmonious swallowing pattern, but the open-bite showed much variation and disharmony in muscular contraction sequence, tended to absent of lip muscle activity. 6. At the lateral cephalometric radiographs, compared to the normal occlusion, the open-bite was showed lower tongue posture. But no difference was found in intermaxillary space. It is suggested that the open-bite, compared to the normal occlusion, had higher muscular activity of tongue during the rest position and various functions, showed lower tongue posture on the lateral cephalogram. In the development of anterior open-bite malocclusion, these factors may be an etiologic factor.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1747-1755
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• 2008

In domestic interurban railway which runs between miles away city has foot rest for each chair. One of the interurban train Muunghwa, the chair can rotate in each direction. When chair rotates the foot rest gets damaged related to the position. Up to now many various solution was made to clear this problem but effect was insufficient. So solve this problem, approach was made in human body engineering point of view. Also Advanced country case study was made. Through this research the field point of issue will be cleared and so as customer satisfaction. This paper describes the effective methode to improve the foot rest damage problem.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.253-271
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• 1992

The purpose of this study was to investigate the difference of EMG activity of the Orbicularis oris and Mentalis muscle between normal occlusion and class III malocclusion group during various lip position and to find out whether any correlations exist between the muscular activity and craniofacial morphology. In this study, 50 subjects with a mean age of 22.9 Years (range 20.0-26.0) were investigated (25 subjects were normal occlusion, and 25 subjects were class III malocclusion). EMG data were recorded from the Orbicularis oris and Mentalis muscle during rest lip posture, lip position at maximum biting, lip position at maximum sealing effort, lip position at chewing, swallowing and phonation with the Medelec MS-25 electromyographic machine. Lateral cephalometric radiographs was taken with the mandible in intercuspal position on all subjects. All data were recorded and statistically processed. The findings of this study can be summerized as follows: 1. In normal occlusion, the maximal mean amplitude of upper lip during the lip position at chewing was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 2. In Class III malocclusion, the maximal mean amplitude of upper lip during the lip position at chewing, swallowing and phonation was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 3. Compare to normal occlusion, the Class III malocclusion was showed low maximal mean amplitude of upper lip during rest lip posture and the lip position at swallowing of saliva, and showed great maximal mean amplitude of lower lip and meantalis muscle during the lip position at chewing and phonation. 4. In normal occlusion, the maximal mean amplitude of upper lip during various lip position was not correlated with the length and thickness of upper lip, but the maximal mean amplitude of lower lip during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip. 5. In Class III malocclusion, the maximal mean amplitude of upper lip during rest lip posture was negatively correlated with the thickness of upper lip, and the maximal mean amplitude of lower lip and mentalis muscle during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not correlated with the cephalometric measurements of soft tissue. 6. The correlation between the maximal mean amplitude of orbicularis oris and mentalis muscle and cephalometric measurements of incisors was not nearly present. 7. In normal occlusion, the maximal mean amplitude of lower lip and mentalis muscle during the lip position at maximum biting was negatively correlated with the angle between palatal plane and mandibular plane. In Class III malocclusion, the maximal mean amplitude of upper lip, lower lip and mentalis muscle during function was negatively correlated with the length of maxilla, the maximal mean amplitude of upper lip and lower lip during function was negatively correlated with the SNA and SNPo, and the maximal mean amplitude of lower lip during the lip position at chewing was negatively correlated with the ANB.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.1
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• pp.29-35
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• 2017

It was hard for a conventional care-bed to be realized to a low-floor position due to a complex actuation mechanism installed under the mattress support platform. In this paper a mechanism design to set a low-floor position as well as to adjust back- and leg-rest angles was proposed. A dual motor was applied to the back- and leg-rest mechanism of which design parameters were determined by an optimal method. An elevation mechanism was also designed to enlarge a limited stroke range up to two times of its original stroke using a pulley mechanism. An evaluation test was performed by five healthy subjects ($24.4{\pm}0.5yrs.$) when going up from a floor position to a preset best position which was set to the 240mm height for a prototype low-floor bed and to the 600mm height for a conventional bed. As a result, the moving distance was 38% lower than the conventional bed when the subject used the low-floor bed. It showed that the low-floor care-bed reduced physical burdens and was effective to assist activities of daily living of the elderly people.