• Physical Therapy Korea
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• v.10 no.4
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• pp.17-22
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• 2003

대동작 운동 수행능력 측정도구(GMPM)는 뇌성마비 아동의 움직임을 질적인 면에서 평가하기 위해 개발된 도구이다. 이 연구의 목적은 대동작 운동 수행능력 측정도구의 측정자간 신뢰도를 알아보는 것이다. 뇌성마비 아동 10명(평균 5.6세, 범위 4~8세)에게 GMPM 평가를 실시하였다. 평가 과정을 비디오로 녹화하여 각 속성 항목별로 3명의 평가자간의 급간내 상관계수로 일치도를 보았다. 전반적으로 측정자간 신뢰도는 '불량~보통'범주에 속했다. 이 연구의 결과는 충분한 교육을 받지 않고 평가하면 그 결과를 신뢰하기 어렵다는 것을 말해준다. 향후 임상에서 GMPM을 이용하여 평가할 때 측정자간 신뢰도에 어떤 변화가 있는지 알아보는 연구가 필요하다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.3
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• pp.316-321
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• 2004

In this paper, we have developed a new mounting head system for flip chip. The proposed head system consists of a macro/micro positioning actuator for stable force control. The macro actuator provides 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 the surface of a PCB(printed circuit board). In order to show the effectiveness of the proposed macro/micro chip mounting system, we compared the proposed system with the conventional chip mounting head equipped with a macro actuator only. A series of experiments were executed under the mounting conditions such as 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 Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.11
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• pp.502-510
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• 2006

In this paper, we describe implementation of a computer access device for the severly motor-disability. Many people with severe motor disabilities need an augmentative communication technology. Those who are totally paralyzed, or 'locked-in' cannot use conventional augmentative technologies, all of which require some measure of muscle control. The forehead is often the last site to suffer degradation in cases of severe disability and degenerative disease. For example, In ALS(Amyotrophic Lateral Sclerosis) and MD(Muscular dystrophy) the ocular motorneurons and ocular muscles are usually spared permitting at least gross eye movements, but not precise eye pointing. We use brain and body forehead bio-potentials in a novel way to generate multiple signals for computer control inputs. A bio-amplifier within this device separates the forehead signal into three frequency channels. The lowest channel is responsive to bio-potentials resulting from an eye motion, and second channel is the band pass derived between 0.5 and 45Hz, falling within the accepted Electroencephalographic(EEG) range. A digital processing station subdivides this region into eleven components frequency bands using FFT algorithm. The third channel is defined as an Electromyographic(EMG) signal. It responds to contractions of facial muscles and is well suited to discrete on/off switch closures, keyboard commands. These signals are transmitted to a PC that analyzes in a time series and a frequency region and discriminates user's intentions. That software graphically displays user's bio-potential signals in the real time, therefore user can see their own bio-potentials and control their physiological signals little by little after some training sessions. As a result, we confirmed the performance and availability of the developed system with experimental user's bio-potentials.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.43-50
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• 2013

The stringent emission regulation and future shortage of fossil fuel motivate the research of alternative powertrain. In this study, a system of proton exchange membrane fuel cell has been modeled to analyze the performance of the fuel cell system for automotive application. The model is composed of the fuel cell stack, air compressor, humidifier, and intercooler, and hydrogen supply which are implemented by using the Matlab/Simulink(R). Fuel cell stack model is empirical model but the water transport model is included so that the system performance can be predicted over various humidity conditions. On the other hand, the model of air compressor is composed of motor, static air compressor, and some manifolds so that the motor dynamics and manifold dynamics can be investigated. Since the model is concentrated on the strategic operation of compressor to reduce the power consumption, other balance of components (BOP) are modeled to be static components. Since the air compressor model is empirical model which is based on curve fitting of experiments, the stack model is validated with the commercial software and the experiments. The dynamics of air compressor is investigated over unit change of system load. The results shows that the power consumption of air compressor is about 12% to 25% of stack gross power and dynamic response should be reduced to optimize the system operation.

• 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.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.3
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• pp.373-380
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• 2018

The small coastal vessel registered in Korea, small coastal vessels with a gross tonnage of 10 tons or less account for 94.6 % and among them, aged vessels over 16 years age indicate 40.6 %. In order to reduce GHG emissions from small coast vessels, discussions are underway to replace aging ships' propulsion units with eco - friendly propulsion facilities, and the electric propulsion ship is emerging as one of the measures. The electric propulsion system using the DFE rectifier, which was applied in the conventional large commercial vessel, was effective in reducing the harmonics and improving the DC output voltage of the DC link stage, but it occupied a large volume and caused an increase in the overall system price. Therefore, in this paper, we propose an electric propulsion system using AFE rectifier with a small volume of system that can be applied to a small coastal vessel. In order to analyze the effectiveness of the overall system, the load profile was applied to obtain accurate and rapid speed tracking performance of the propulsion motor affected by the speed load. In addition, the power factor and total harmonic distortion factor of the voltage and current on the improved power output side are derived through simulation.

• The Journal of Korean Physical Therapy
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• v.15 no.2
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• pp.75-84
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• 2003

The purpose of this study was to review of mechanism and application methodology about mental practice. The mental practice is symbolic rehearsal of physical activity in the absence of any gross muscular movements. Human have the ability to generate mental correlates of perceptual and motor events without any triggering external stimulus, a function known as imagery, Practice produces both internal and external sensory consequences which are thought to be essential for learning to occur, It is for this reason that mental practice, rehearsal of skill in imagination rather than by overt physical activity, has intrigued theorists, especially those interested in cognitive process. Several studies in sport psychology have shown that mental practice can be effective in optimizing the execution of movements in athletes and help novice learner in the incremental acquisition of new skilled behaviors. There are many theories of mental practice for explaining the positive effect In skill learning and performance. Most tenable theories are symbolic learning theory, psyconeuromuscular theory, Paivio's theory, regional cerebral blood flow theory, motivation theory, modeling theory, mental and muscle movement nodes theory, insight theory, selective attention theory, and attention-arousal set theory etc.. The factors for influencing to effects of mental practice are application form, application period, time for length of the mental practice, number of repetition, existence of physical practice.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.4
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• pp.71-80
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• 2019

PURPOSE: This study examined whether a task-oriented training program is an effective intervention to improve the body function, activity, and participation of children with cerebral palsy (CP). METHODS: Ten children with CP (7-13 years old) performed a task-oriented training program for eight weeks (three sessions per week, 30 minutes each). The taskoriented training program consisted of eight activities. The subjects' body function was assessed using a handheld dynamometer, goniometer, Modified Ashworth Scale (MAS), Balance Performance Monitor (BPM), and the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP). The subjects' activity and participation were assessed using the Gross Motor Function Measure (GMFM) and Timed Up and Go (TUG) test. RESULTS: Task-oriented training provided significant improvements in the subjects' body function. The subjects improved the bilateral isometric muscle strength of the hip flexors, extensors and abductors, knee flexors and extensors, and ankle dorsi- and plantar flexors (p<.05). Bilateral passive hip flexion, abduction, and external rotation, knee flexion, and ankle dorsi- and plantar flexion were also increased (p<.05). In addition, the MAS score of the hip adductors decreased (p<.05) and the BOTMP score increased after training (p<.05). The subjects' activity and participation also improved significantly after training, increasing the GMFM score (p<.05) and decreasing the TUG score (p<.05). On the other hand, the BPM score did not change after training. CONCLUSION: This study suggests that a task-oriented training program can be an effective intervention to improve the body function, activity, and participation for children with CP.

• Clinical and Experimental Pediatrics
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• v.63 no.11
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• pp.438-446
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• 2020

Background: Most developmental screening tools in Korea are adopted from foreign tests. To ensure efficient screening of infants and children in Korea, a nationwide screening tool with high reliability and validity is needed. Purpose: This study aimed to independently develop, standardize, and validate the Korean Developmental Screening Test for Infants and Children (K-DST) for screening infants and children for neurodevelopmental disorders in Korea. Methods: The standardization and validation conducted in 2012-2014 of 3,284 subjects (4-71 months of age) resulted in the first edition of the K-DST. The restandardization and revalidation performed in 2015-2016 of 3.06 million attendees of the National Health Screening Program for Infants and Children resulted in the revised K-DST. We analyzed inter-item consistency and test-retest reliability for the reliability analysis. Regarding the validation of K-DST, we examined the construct validity, sensitivity and specificity, receiver operating characteristic curve analysis, and a criterion-related validity analysis. Results: We ultimately selected 8 questions in 6 developmental domains. For most age groups and each domain, internal consistency was 0.73-0.93 and test-retest reliability was 0.77-0.88. The revised K-DST had high discriminatory ability with a sensitivity of 0.833 and specificity of 0.979. The test supported construct validity by distinguishing between normal and neurodevelopmentally delayed groups. The language and cognition domain of the revised K-DST was highly correlated with the K-Bayley Scales of Infant Development-II's Mental Age Quotient (r=0.766, 0.739), while the gross and fine motor domains were highly correlated with Motor Age Quotient (r=0.695, 0.668), respectively. The Verbal Intelligence Quotient of Korean Wechsler Preschool and Primary Scales of Intelligence was highly correlated with the K-DST cognition and language domains (r=0.701, 0.770), as was the performance intelligence quotient with the fine motor domain (r=0.700). Conclusion: The K-DST is reliable and valid, suggesting its good potential as an effective screening tool for infants and children with neurodevelopmental disorders in Korea.

• Physical Therapy Korea
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• v.24 no.1
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• pp.51-60
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• 2017

Background: In cerebral palsy (CP), parents' quality of life and rearing attitude are considered possible factors that influence patients' quality of life, function level, and performance in daily activities. Despite these facts, little attention has been given to demonstrate a relation between these factors. Objects: This study aimed to demonstrate the relationship between parents' quality of life, functional level, and performance in daily activities, the quality of life of school-aged children with spastic CP. Methods: This study included 24 parents of school-aged children with spastic CP. The KIDSCREEN-52 and World Health Organization quality of life (WHOQOL)-BREF questionnaires (including physical, psychological, social, and environmental domains) were used as research tools to assess the quality-of-life profiles of the children with spastic CP and those of their parents, respectively. In addition, the function levels and performance in daily activities of the children with CP were assessed by using the gross motor function measure (GMFM) and modified Barthel index (MBI). Correlation and multiple regression analyses were performed to clarify the determinants of the quality of life of the children with CP. Results: The KIDSCREEN-52 score correlated with the total score (r=.735, p<.01) and all domains of the WHOQOL-BREF questionnaire (physical: r=.542, p<.01; psychological: r=.690, p<.01; social: r=.568, p<.01; and environmental: r=.783, p<.01). In addition, significant correlation was found between the KIDSCREEN-52 and MBI scores (r=.411, p<.05), and between the MBI and GMFM scores (r=.427, p<.05). After controlling for age, gender, paralytic type, GMFM, and MBI, the WHOQOL-BREF score ($R^2=.621$), particularly in the environmental domain ($R^2=.699$), remained independently related to the quality of life of the children. Conclusion: These findings suggest that the quality of life of school-aged children with spastic CP can be influenced by the quality of life of their parents. This study provides useful information for future studies to investigate the quality of life of children with CP.