• Journal of the Korean Society of Physical Medicine
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• v.11 no.3
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• pp.119-124
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• 2016

PURPOSE: The aim of this study was to evaluate activation of accessory respiratory muscles using electromyography during chest expansion upper extremity flexion, abduction, and external rotation exercises with an elastic band in children with cerebral palsy. METHODS: The subjects were 10 children with cerebral palsy. The inclusion criterion for participation was a Gross Motor Function Classification System level of I to III. The subjects were instructed to perform upper extremity flexion, abduction, and external rotation exercises with inspiration, and extension, adduction, and internal rotation exercises with expiration while seated on a chair without a backrest. PM (Pectoralis major), SCM (sternocleidomastoid), RA (rectus abdominis), and EO (external oblique) muscle activities were measured using electromyography. RESULTS: All tested muscles showed a statistically significant increase in activity after elastic band exercise. There were significant differences in PM, SCM, RA, and EO results after chest expansion exercise using elastic band. SCM showed the largest increase in activity after use of elastic bands, at $52.37{\pm}45.88$%, followed by the RA ($50.56{\pm}79.31$), EO ($35.42{\pm}35.45$), and PM ($31.72{\pm}25.64$). The increase in the SCM was greatest, followed by increases in the RA, EO, and PM CONCLUSION: These finding suggest that activity of accessory respiratory muscles increases with use of elastic bands during chest expansion exercise in cerebral palsy.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.205-213
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• 2003

The fiber reinforced composite material is widely used in the multi-industrial field where the weight reduction of the infrastructure is demanded because of their high specific modulus and specific strength. It has two main merits which are to cut down energy by reducing weight and to prevent explosive damage preceding to the sudden bursting which is generated by the pressure leakage condition. Therefore, Pressure vessels using this composite material in comparison with conventional metal vessels can be applied in the field such as defense industry, aerospace industry and rocket motor case where lightweight and the high pressure are demanded. In this paper, for nonlinear finite element analysis of E-glass/epoxy filament winding composite pressure vessel receiving an internal pressure, the standard interpretation model is developed by using the ANSYS, general commercial software, which is verified as the accuracy and useful characteristic of the solution based on Auto LISP and ANSYS APDL. Both the preprocessor for doing exclusive analysis of filament winding composite pressure vessel and postprocessor that simplifies result of analysis have been developed to help the design engineers.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.330-337
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• 2016

In this paper, component sizing and analysis of the novel plug-in hybrid electric vehicle powertrain configuration is conducted. Newly proposed powertrain configuration in prior study has an internal combustion engine and two electric motors. To optimize component size of the vehicle system and reduction gear ratio, component sizing methodology is proposed and conducted. Required power for vehicle's dynamic performance is calculated to decide minimum power requirement of powertrain component combination. Component size of engine and electric motor are optimized using vehicle simulation to maximize fuel economy performance. Optimized powertrain configuration and vehicle simulation results present validation of newly proposed vehicle system.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.1-8
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• 2010

In this paper, we present some results of technical surveys, power analyses, and weight estimation on electric propulsion systems for 1-ton class Personal Air Vehicles(PAV) applications. When hybrid electric propulsion is adopted, its power performance using fuel cells and batteries in inferior to that of internal combustion engines. However, hybrid electric propulsion systems may replace IC engines when energy density and power density reach 0.75 kW$^*$hr/kg and 2.5 kW/kg, respectively.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.992-996
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• 2004

Small electric motors in an automobile perform various tasks such as engine cooling, pumping, and in heating, ventilating, and air-conditioning (HVAC) system. At present, most of dc motors are supplied by 12V or 24V batteries. However, DC motors surfer from lack of efficiency, low life cycles and unreliability. Therefore, there is a growing interest in substituting DC motors for advanced AC motors including switched reluctance motors. Although there are several other forms SRM converters, they are either unsatisfactory to the control performance or unsuitable for the 12V-battery powered 3-phase SRM drives. Taking into account the requirement for effective operation and simplicity structure of converter in the limited internal environment of automobiles, the author inclines toward selecting the modified C-dump converter as well as the energy efficient C-dump converter. This is so that more economical and efficient converter topology in automobile industries can be utilized. This paper describes the foundation for the design and development of a 12V-250W-3000rpm SRM drives for automobiles. Furthermore, complete circuit, computer simulation and experiment results are presented to verify the performance of the C-dump converters.

• Transactions of Materials Processing
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• v.27 no.4
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• pp.201-210
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• 2018

An airbag is an essential automotive component used in all kinds of vehicles such as an internal combustion engine and an electric motor vehicle and is used to minimize the damage of an occupant in the event of an accident. Airbag-related parts are being monopolized by a small number of foreign companies around the world. In this situation, it is necessary to develop and research the airbag-related part molding technology for expansion of the domestic airbag-related market and corporate export. As a part of this research, we have developed a mold for airbag inflator cap. The development consists of three steps which are the design of components, analysis of the design and verification of it. In the case of the design, the transfer type mold was designed for the multi-cylindrical shaped feature. Analysis was then conducted on the design. By examining the results of analysis, changing features and numbers of punches and dies were added in the analysis and repeatedly analyzed. After the addition, proper dimensions from the analysis were achieved, and prototypes were practically produced and verified. In the case of prototype verification, Pressurizing Burst Test was conducted on the existing products and the prototype. By comparing the results of the test, the possibility of replacing the existing product of the airbag inflator cap is presented in this paper.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.110-116
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• 2020

Aircraft hydraulic oil reservoirs made with aluminum 7075 have an anodized coating to enable airtightness and corrosion resistance. To maintain a stable oil pressure, the internal surface roughness of the reservoir should be less than approximately 0.2 ㎛. To this end, precision polishing must be performed. However, ensuring the processing quality is challenging, as most polishing operations are performed manually, owing to which, the inner surface roughness is not uniform, and the product quality is irregular. Therefore, we developed a special superfinishing machine to realize the efficient inner polishing of an aircraft hydraulic oil reservoir, by using an abrasive film to improve the process throughput and uniformity. In the experiment involving the superfinishing of an anodized aluminum 7075 cylinder specimen by using the proposed machine, a higher surface roughness than that achieved in the repetitive manual polishing process could be realized.

• Journal of Oriental Neuropsychiatry
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• v.17 no.2
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• pp.167-177
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• 2006

Objective : We aimed to study the relationship between the post-stroke depression and acceptance of the stroke. Method : For this study, 80 stroke patients were surveyed by using questionnaires for CES-D, acceptance for stroke, and social support. Result & Conclusion : 1. Acceptance for stroke varied inversely as the post-stroke depression. 2. The acceptance for the stroke appeased the negative influence caused by the stress of the stroke, and the post-stroke depression was biggest predictable variant. And location of the stroke were the predictable variants of the post-stroke depression. 3. When the gender, location of the stroke, motor power, age, period of stroke, and social support were controlled, the group with depression and the one without depression had a significant difference in the acceptance of the stroke.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.12
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• pp.57-63
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• 2002

In this paper, the feedforward control with least mean square (LMS) adaptive algorithm is proposed and examined to reduce rotating error by runout of an active magnetic bearing system. Using eddy-current type gap sensor fur control, the electrical runout caused by non-uniform material properties of sensor target produces rotational error amplified in feedback control loop, so this runout should be eliminated to increase rotating accuracy. The adaptive feedforward controller is designed and examined its tracking and stability performances numerically with established frequency response function. The tested grinding spindle system is manufactured with a 5.5 ㎾ internal motor and 5-axis active magnetic bearing system including 5 eddy current gap sensors which have approximately 15 ~ 30 ${\mu}{\textrm}{m}$ of electrical runout. According to the experimental analysis, the error signal in radial bearings is reduced to less than 5 ${\mu}{\textrm}{m}$ when it is rotating up to 50,000 rpm due to applying the feedforward control for first order harmonic frequency, and vibration of the spindle base is also reduced about same frequency.

• The Journal of Korean Physical Therapy
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• v.32 no.1
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• pp.44-51
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• 2020

Purpose: This study translated the developmental coordination disorder questionnaire'07 (DCDQ'07) into Korean and investigated the psychometric properties of the Korean DCDQ (DCDQ-K) using validation processes. Methods: The subjects were 300 parents with typically developing children aged 5-15 years (162 girls and 138 boys, mean age 9.24 years, SD 2.59) across the country. To develop the Korean DCDQ, a forward-backward-original author feedback-panel meeting-pilot study with parents was done. The internal consistency, test-retest reliability performed two weeks apart, content validity, discriminative validity, convergent validity, and constructive validity were examined with the pre-version of the DCDQ-K. Results: Approximately 15.33% of the subjects were probably shown DCD using DCDQ-K. Significant differences in age and province were observed in the DCDQ-K total score. The reliabilities and validities were good in the DCDQ-K. Conclusion: The DCDQ-K is a reasonable screening tool for DCD children.