• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.10
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• pp.766-770
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• 2013

This paper tried to develop a BLDC electric motor securing the 800 W-level watertight structure for driving the outboard motor. For this purpose, this paper developed a high-efficient controller-integrating BLDC electric motor system for underwater propulsion and designed and developed a triple watertight structure. Besides, this study developed a outboard motor integrating motor, propeller and controller based on the production of a controller for BLDC motor which can the speed control by selecting low-voltage, high-current power element. The characteristics of developed outboard motor were 24 V input voltage, over 800 W motor output, and max. 3,000 rpm motor, and 84.9% motor efficiency, and the developed outboard motor could secure the watertight structure in 5 m in water depth.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.387-392
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• 1986

DC motor is excellent in controllability and efficiency, but vulnerable in maintenance with respect to AC motor owing to the development of power devices and microelectronics, excellent AC motor drives which have characteristics as similar as DC motor's have been developed. Thyristor motor equipment that has an important role with Inverter in the field of AC motor drives was developed in the late 1960. There was no research about thyristor motor in Korea, then thyristor motor equipment was all imported. By this we started to develop in 1983, was tested in 1984, 1985. Now we express ourselves about thyristor motor equipment development procedure and characteristics.

• Annals of Clinical Neurophysiology
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• v.2 no.2
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• pp.107-113
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• 2000

Background & Objectives : Motor evoked potentials(MEPs) to magnetic trans cranial stimulation were performed to evaluate upper motor neuron involvement and relationship to lower motor neuron involvement in motor neuron disease patients. Method : MEPs were obtained in the 17 consecutive patients with motor neuron disease. These patients were divided into three group based on clinical evidence of upper and lower motor neuron involvement, bulbar symptom; amyotrophic lateral sclerosis(ALS), progressive muscular atrophy(PMA), progressive bulbar palsy(PBP). MEPs were recorded from abductor pollicis brevis and abductor hallucis muscles. Abnormal MEPs were defined by delayed central motor conduction time or absent MEP. Results : MEPs were abnormal in 64%(11/17) of patients; 100%(7/7) in ALS, 64%(4/7) in PMA, 0%(0/3) in PBP respectively. In 68 total recording muscles, 34 muscles had evidence of motor weakness and showed abnormal responses in 59%(20/34). Whereas 34 muscles with normal strength, only 3%(1/34) of muscles showed abnormal response. Conclusion : MEPs are well correlated with upper motor neuron signs in ALS and may detect masking upper motor neuron signs in PMA. The muscles with lower motor neuron sign(weakness) usually relate with abnormal MEPs reponses.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.8
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• pp.1035-1041
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• 2007

An improvement of driving motor burning damages on a couplingless type warship fire pump is studied. The pump consists of an induction motor a pump-motor shaft and a volute type impeller. The burning damage had occured by changing the material of the pump-motor shaft from carbon steel(SM 45C) to stainless steel(STS 316) for improving anti-corrision properity in sea water. It is shown that a material change on the pump-motor shaft can reduce the efficiency of driving motor and may cause motor burning in the process of pump development stage. This kind of motor burning problem can be solved by increasing the efficiency of the motor and changing the geometry of the inner parts.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.2
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• pp.67-74
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• 2017

PURPOSE: The purpose of this study was to investigate the difference and relationship between sensory processing abilities, gross motor and fine motor capabilities in children with cerebral palsy. METHODS: 104 children with cerebral palsy participated in the study. Sensory processing abilities of the subjects were measured by Short Sensory Profile (SSP). Gross and fine motor abilities were each measured using the Gross Motor Function Classification System (GMFCS) and Manual Ability Classification System (MACS), respectively. RESULTS: There were significant correlations between SSP level and GMFCS (R=.72, p<.00) or MACS (R=.77, p<.00) levels. Significant differences were showed each gross motor (p=.01) and fine motor level (p=.00) among sensory processing level of children. In addition, sub-items of sensory processing as Tactile sensitivity, Movement sensitivity, Auditory filtering and Low energy/Weak were significantly were showed significant correlations gross motor and fine motor level (p=.01). Also, multiple regression result was showed that as MACS level and GMFCS level were higher, the SSP total score was higher all of participants (adjusted $R^2=.62$). CONCLUSION: Sensory processing abilities of children with cerebral palsy were related with gross motor and fine motor capabilities. Also gross motor and fine motor capabilities are as higher, the sensory processing skill was well of cerebral palsy.

• Proceedings of the KIPE Conference
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• 1998.11a
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• pp.68-72
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• 1998

The parameter through the motor designing program is used to predict motor response and design the motor drive circuits. The application programs such as "Saber" are often used for these. However, making the electrical model of motor for these simulation tool is uncomfortable and impossible for general users. Therefore, in this paper, we develop the "Spice" library generation program with the motor designing program "Motor Expert". This program will assist the user to make the motor library comfortablely and correctlyry comfortablely and correctly

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.300-302
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• 2000

There are two kinds of the synchronous motor, one is an induction type motor started without a driving system, the other is the one started with an external driving system. but, both are complicated. Nowadays, in order to devoid for the synchronous motor being complicated in design, line start permanent magnet(LSPM) motors are being developed. The LSPM motor is composed of the rotor that has interior permanent magnet and aluminum bar instead of general rotor. In this paper, we analyzed the characteristics of the LSPM motor which has both characteristics of an induction motor and a synchronous motor, and we compared the the LSPM motor characteristics with the induction motor.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.3
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• pp.105-109
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• 2017

PURPOSE: The purpose of this study was to investigate the effect of ankle dual task including motor training on the static balance, dynamic balance in the elderly. METHODS: 30 elderly people were randomly divided into 3 groups: 10 people in the single motor task group, 10 people in the double motor dual task group and 10 people in the motor-cognitive dual task group. In the double motor dual tasks group was performed ankle balance motor task additional motor task. Motor-cognitive dual task group was performed ankle balance motor task additional cognitive task. Single motor task group was performed ankle balance motor task. It was performed three times intervention a week for six weeks. Statistical analysis method was performed using one way ANOVA for comparison between groups, and the paired t-test was used for comparison pre and post intervention. RESULTS: Static and dynamic balance were significant differences between pre and post intervention by three groups (p<.05). In static balance, there was a significant difference among groups (p<.05), but there was not a significant difference between groups in dynamic balance (p>.05). CONCLUSION: The results of the research, the ankle balance dual task including motor or cognitive task was more effective than single motor task on static balance in the elderly.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.104-106
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• 2003

In recent years for propulsion of cooling fan in cars are more used electrical motors than the engine direct coupled type. But the electrical motor which is now used has the brush and the commutator. Because of the brush and the commutator the electrical motor has short life time, low efficiency and mechanical- electrical noise. Therefore it is tried to develope brushless dc motor. The motor is located in the hot air from the radiator. The motor temperature increases high and the increasing of the motor temperature rolls big in its character. The cooling fan motor has relative small in size and input voltage is low. For 300 w output power must be the current of the motor high which causes high copper loss. In this paper will be tested and analysed characteristics of a dc motor which is now used for cooling fan and a BLDC motor will be designed with same character of the brushed motor and with considering of improvement of the efficiency. After design the motor should be analysed and tested.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.4
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• pp.78-85
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• 1995

This paper covers stability and stabilization of Multi-Excited Induction Motor used in numberous electric equipment system of industrial field. The induction motor with multi-excitation has tow sets of three-phase system : One is connected to the AC source to supply most power required at the load, and the other is to the inverter for variable frequency and/or magnitude of voltage. The conventional induction motor is operated under single excitation mode only, that is called induction mode. But in multi-excited induction motor both the induction mode and the synchronous mode are possible, and the proposed multi-excited induction motor can be driven as a synchronous motor by the extra three-phase input. At the synchronous mode the efficiency is improved so higher than that at induction mode or conventional induction motor. The rating of the inverter used for speed control of numberous electric equipment system can be reduced upto one-tenth of that for conventional induction motor. Also the cost and maintenance fee of multi-excited induction motor can be reduced compared to any other motor.