• Journal of Convergence for Information Technology
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• v.7 no.4
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• pp.97-103
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• 2017

The purpose of this study was to investigate muscle activity of cervical erector spinae & upper trapezius while using a smartphone according to anterior pelvic tilt & posterior pelvic tilt in sitting position. & we also want to obtain basic data necessary for development of IoT devices. Fifteen healthy men & women aged 20-30 were enolled, After anterior pelvic tilt & posterior pelvic tilt in sitting position were adjusted, they used a smartphone for 5 minutes & EMG signal was measured simultaneously. We used median 3 minutes of measured EMG signal. The results of this study were as follows: In the sitting position, the use of smartphone in anterior pelvic tilt had significantly lower %RVC values in both cervical erector spinae (p <.001), left upper trapezius (p <.001) & right upper trapezius (p <.002) in comparison with posterior pelvic tilt. This means that anterior pelvic tilt make vertebrae maintain normal curvature & prevent forward head posture occurred while using a smartphone. It reduces loads around neck & shoulders, so that %RVC value is significantly lowered. In the future, new posture corrected IoT devices with an aspect of pelvic tilt should be developed.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.3
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• pp.289-294
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• 2013

PURPOSE: The purpose of this study was to examine differences in erect spinae activities at different height of table during ultrasound therapy in order to propose a optimum work environment. METHODS: Twenty five healthy adult males and females volunteered to participate in this study. EMG signals of both erector spinae(T10, T12, L2, L4) were recorded throught the surface electromyography system at different height of table(45cm, 56.2cm, 67.5cm) during ultrasound therapy work. RESULTS: The higher table heights was, the lower %RVC of the T10, T12, L2, L4 erect spinae at both sides. The left and right T10, T12 and the left L4 showed significant differences. The lower the spinal level was, the higher %RVC of both erect spinae at 45cm, 56.2cm, 67.5cm. The left erect spinae at 56.2cm, right erect spinae at 45cm, 67.5cm showed significant differences. CONCLUSION: The muscle activities of both erect spinae decreased at higher table height and increased lower spinal level. We identified lower table height are risk factor of spine work related musculoskeletal disorders.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.63-74
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• 2005

J. R. PARK. The Analysis of Electrimyography and Kinematic of Kumdo Player's Head Hitting. Korean Journal of Sport Biomechanics, Vol. 15, No. 1, pp. 63-74, 2005. The purpose of this study were to describe and compare the selected electromyographical muscle activities of arm and kinematic data of kumdo player's head hitting. Using surface electrode electromyography, we evaluated muscle activity in 6 male players during head hitting motion. Surface electrodes were used to record the level of muscle activity in the carpi radialis, deltoid, triceps, biceps muscles during the player's head hitting. These signals were compared with %RVC(Reference voluntary contraction) which was normalized by IEMG(Integrated EMG). The kumdo head hitting motion was divided into two phases: back swing, down swing. we observed patterns of arm muscle activity throughout two phases of the kumdo head hiting The results can be summarized as follows: right elbow angle had decreased and left deltoid muscle's activation had higher than right deltoid muscle's activation, right carpi radialis muscle's activation had higher than left carpi radialis muscle's activation in back swing phase, knee angle had decreased and left triceps muscle's activation had higher than right triceps muscle's activation, right deltoid muscle's activation had higher than left deltoid muscle's activation, right carpi radialis muscle's activation had higher than left carpi radialis muscle's activation in down swing phase

• Korean Journal of Applied Biomechanics
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• v.14 no.2
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• pp.167-178
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• 2004

The purpose of this study was to describe and compare the selected electromyographical muscle activities of trunk and hip during Professional and Amateur golfer's Iron swing. Using surface electromyography, we evaluated muscle activities in 6 male professional golfers and 6 male amateur golfers during the golf iron swing. Surface electrodes were used to record the level of muscle activity in the right abdominal oblique, left abdominal oblique, right erector spinae, left erector spinae, right rectus abdominis, left rectus abdominis, right gluteus maximus, left gluteus maximus muscles during the golfer's swing. These signals were compared with IEMG(Integrated EMG) which was normalized by %RVC(Reference voluntary contraction). The golf swing was divided into three phases: take away, forward swing-acceleration, follow-through. We observed patterns of trunk muscle activity throughout three phases of the golf swing. The results can be summarized as follows: LES(Left Erector spinae) had statistically significant difference in take away and forward swing-acceleration phases. It was showed no significant difference in follow-through phase.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.67-74
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• 2005

The purpose of this study is to compare and analyze the muscle activations between the professional golfers without low back pain symptom and the professional golfers with low back pain symptom, and so identify the stress related to golf swings, and provide the basic data to minimize the low back pain and the injury risk. Using surface electrode electromyography, we evaluated muscle activity in 6 male professional golfers during the golf drive swing. Surface electrodes were used to record the level of muscle activity in the Abdominal Oblique, Elector Spinae, Rectus Abdominis, Gluteus Maximus muscles during the golfer's swing. These signals were compared with %RVC(Reference voluntary contraction) which was normalized by IEMG(Integrated EMG). The golf swing was divided into five phases: take away, forward swing, acceleration, early follow through, late follow through. we observed patterns of trunk muscle activity throughout five phases of the golf swing. The results can be summarized as follows: RES(Right Elector Spinae) had statistically significant difference in take away phase, LGM(Left Gluteus Maximus), LRA(Left Rectus Abdominis), LOA(Left Oblique Abdominal) had statistically significant difference in forward swing phase, RES(Right Elector Spinae), RGM(Right Gluteus Maximus), ROA(Right Oblique Abdominal) had statistically significant difference in acceleration phase, RES(Right Elector Spinae), RGM(Right Gluteus Maximus) had statistically significant difference in early follow-through phase, LES(Left Elector Spinae), RGM(Right Gluteus Maximus) had statistically significant difference in late follow through phase.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.4
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• pp.19-25
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• 2018

PURPOSE: This study was conducted to investigate the correlation between the activity of suprahyoid muscles, infrahyoid muscles and swallowing ability in stroke patients with dysphagia. METHODS: The subjects of this study were 120 patients who were diagnosed with CT or MRI stroke and had swallowing disorder at Daegu Metropolitan General Hospital from August 2014 to February 2017. The suprahyoid and infrahyoid muscle activity was measured in patients with dysphagia and the new videofluoroscopy swallowing studies scale (new VFSS scale) was used for evaluation of swallowing function. Correlation analysis was conducted using the measured data. RESULTS: The activities of suprahyoid muscles were 325.8 (%RVC) on average, while the average infrahyoid muscle activity was 302.65 (%RVC) and the average value of the new VFSS scale was 31.52. The total for oral organs was 3.62 on average and that for pharynx organs was 28.30 on average. The activity of the suprahyoid muscles showed a significant positive correlation with the activity of the infrahyoid muscles, but a significant negative correlation with the total oral phase, total pharyngeal phase and total new VFSS scale (p<.01). The activity of the infrahyoid muscles showed a significant negative correlation with the total oral phase, total pharyngeal phase, and total new VFSS (p<.01). CONCLUSION: Based on the results of this study, it is necessary for researchers to consider the infrahyoid and suprahyoid muscles when conducting swallowing rehabilitation.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.3
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• pp.279-286
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• 2015

The rapid increase of the current marine accidents is mainly due to the human execution errors. In an effort to address this, various kinds of researches such as construction of the digital vessels and vessel information monitoring systems have been conducted. But for safe navigation of vessels, it lack on systems study which can efficiently store, utilize and manage the mass data accepted by the vessel. In this paper, we propose a VWS(Virtual World System) that is based on the architecture of intelligent systems RVC(Reactive Layer-Virtual World-Considerative Layer) model of intelligent autonomous navigation system. VWS is responsible to store all the necessary information for safe navigation of the vessel and the information services to the sub-system of intelligent autonomous navigation system. VWS uses topology database to express the specific problem area, and utilizes a scheduling to reflect the characteristics of the real-time processing environment. Also, Virtual World defines API for the system to reflect the characteristics of the distributed processing environment. As a case study, the VWS is applied to a intelligent ship autonomous navigation system, and simulation is done to prove the effectiveness of the proposed system.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1201-1203
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• 2009

• Information and Communications Magazine
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• v.19 no.9
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• pp.31-42
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• 2002

CRL (Communications Research Laboratory, Independent Administrative Institution, Japan) is developing ITS wireless communication technologies in millimeter-wave frequency region. Technologies are categorized for inter-vehicle communications (IVC) and road-vehicle communications (RVC). In this paper, system concepts and the experimental facilities are introduced. The experimental facility for inter-vehicle communications is gotten ready in 60 GHz frequency region and the experimental system for road-vehicle communications is based on RoF (Radio on Fiber) technology in 36-37GHz frequency region.

• The Journal of Korean Physical Therapy
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• v.21 no.3
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• pp.47-52
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• 2009

Purpose: To examine the correlation between the gait speed and muscle activation or foot pressure in stroke patients. Methods: Twenty five functionally ambulant stroke patients (male/female: 15/10, mean age: $57.65\pm2.30$) were enrolled in this study. The patients were asked to walk on a plate at a self-selected and comfortable speed. Three walking trials were obtained and then averaged for data analysis. The gait speed and foot pressure were measured from a RS-Scan system. Activation of the quadriceps femoris muscle and biceps hamstring muscle (%RVC) were recorded using ProComp $Infiniti^{TM}$. Results: There was a significant positive correlation between Hamstring muscle activation (%RVC) and gait speed. The gait speed correlated with the foot pressure of the lateral metatarsal zone (M3-5) in the affected side. There was a correlation between the gait speed and the foot pressure of the lateral metatarsal (M3-5) and heel (medial, lateral) zone in the less-affected side. Conclusion: The gait speed is related to hamstring muscle activation and the characteristics of foot pressure. This information was observed in both the affected and less-affected sides, suggesting that rehabilitation programs should be implemented on both sides.