• Clinical and Experimental Pediatrics
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• 제57권7호
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• pp.310-316
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• 2014

Purpose: Prader-Willi syndrome (PWS) is a complex genetic disorder that results from the lack of paternally expressed genes in the chromosome 15q11-q13 region. This study was performed to delineate the clinical features of PWS infants and toddlers and the effects of two-year growth hormone (GH) treatment according to gender and age at the start of treatment. Methods: The clinical characteristics and the results of the GH treatment were reviewed retrospectively for 30 PWS patients diagnosed by molecular genetic testing and clinical manifestations. Results: The mean age at diagnosis with PWS was 13.7 months (2-47 months of age). All patients showed the characteristics of facial dysmorphism, including brown hair and almond-shaped eyes. Most patients showed developmental delays/mental retardation (93.3%), cryptorchidism (75%), feeding problems in infancy (73.3%), and neonatal or infantile hypotonia (66.7%). Among 30 patients, 14 PWS infants and toddlers had been treated with GH for more than two years. Two years of GH treatment resulted in an improvement in head circumference-standard deviation score (HC-SDS), body weight-SDS, insulin-like growth factor-1 (IGF-1) SDS, IGF binding protein-3 (IGFBP-3) SDS, lean body mass, and bone mineral content, especially in IGFBP-3 SDS and motor development in PWS patients younger than two years of age. There was significant increase in IGF-1 SDS and IGFBP-3 SDS among male PWS patients after GH treatment. Conclusion: Our study showed increases in IGFBP-3 SDS and an improvement in motor development among individuals under two years of age after GH treatment, and significant difference in IGF-1 SDS and IGFBP-3 SDS by gender.

• Journal of Advanced Marine Engineering and Technology
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• 제36권1호
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• pp.172-178
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• 2012

이동식 발전설비는 이송이나 설치의 편리성과 산간지역이나 도서지역 등의 전력 공급이 어려운 지역에서도 사용할 수 있는 장점을 갖고 있다. 하지만 기존의 이동식 발전설비는 공기식 시동시스템에 의해 기동 되므로 공기 압축기 및 탱크시스템 등이 필요하다. 이러한 장치의 추가로 공기시동시스템은 비용 및 용적률 측면에서 손실이 발생하고 에너지 효율이 감소하게 된다. 본 연구에서는 공기식 시동시스템의 단점을 개선하기 위해서 에너지 효율의 증가, 부피와 용적률 및 비용의 절감, 안전사고의 위험성 감소, 시동의 정확성 증가 및 시동시간의 감소 효과를 기대할 수 있는 전기시동전동기인 직류직권전동기를 개발하였다.

• The Journal of Korean Physical Therapy
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• 제13권3호
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• pp.799-814
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• 2001

This study was performed to investigate the clinical pictures and rehabilitation service patterns of stroke patients in cities of kimchon(kumi), jinju. pohwang, jeonju and jeju from January 1,2001 to march. Authors developed structured questionnaire, and distributed it to each physical therapist. Total number of distributed questionnaire was 400, and 301 questionnaire were col looted and analysed finally.1. The occurrence rate of hemorrhagic stroke(60.5%) was higher than that of ischemic stroke(39.5%). The highest incidence of the stroke was noted in the group of 50 years and ratio of male to female 1.3 : 1. 2. The several warning sign is motor deficit(42.5%). headache. dizziness, vomitting(31.9%) and difficulty speaking or understanding(10.6%). 3. The most important contributing factor of stroke was hypertension both hemorrhagic(50.0%) and ischemic stroke(40.3%). 4. In the painful stroke patients(53.2%). the major problems were shoulder pain(51.3%) and shoulder-hand syndrom(31.3%). 5. In hemorrhagic stroke. the seasonal preference was autumn and summer. In ischemic stroke. the seasonal preference was autumn and winter. 6. In the surgery, hemorrhgic stroke(44.5%) was higher than that of ischemic stroke(20.2%). 7 The major impairment were motor deficit(95.3%), psychological deficits(24.4%), hearing and speech deficit(23.4%). vision deficit(14.7%) and perception deficit(12.7%). 8. The rehabilitation services for stroke patients were physical therapy(98.0%), occupational therapy(41.5%), oriental therapy(35.1%), speech therapy(17.5%) and psychological therapy(7.4%). 9. The start of rehabilitation service was different according to surgery. 36.5% of patients started physical therapy in 4 week and 32.0% of patients started in 8 week later in surgery and 53.1% of patients started physical therapy in 2 week in not surgery( P<0.05). 10. The highest frequency of rehabilitation service was six times per week.

• 전력전자학회논문지
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• 제9권1호
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• pp.17-24
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• 2004

터보 제너레이터의 시동기는 터보 샤프트 발전 시스템 시동기의 구성인 기어박스, DC 전동기, 저 전압 축전지를 대신하여 고속 발전기, 인버터 그리고 승압기로 구성된다. 터보 제너레이터는 시동 시 고속 회전이 요구되어 고속발전기는 수십 $\mu$Η의 낮은 누설 인덕턴스를 가지며, 인버터는 높은 전압의 DC link 전압이 필요하다. 본 연구에서는 시동기 구현을 위해 축전지 전압을 높은 전압으로 승압하는 대 용량 승압기를 개발하였다. 그리고 낮은 누설 인덕턴스를 갖는 전동기 권선에 높은 주파수의 전류 제어를 위해 정밀 고속 연산을 수행하는 인버터 드라이버의 설계와 안정된 점화를 위한 터보 제너레이터의 시동 알고리즘을 제안하였다. 또한 개발한 시동기로 터보 제너레이터의 시동을 수행하여 성능을 확인하였다.

• 조명전기설비학회논문지
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• 제19권2호
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• pp.114-123
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• 2005

서보 설비를 위한 순차적 파라미터 자동 튜닝 알고리즘을 갖는 영구자석 동기전동기(Permanent Magnet Synchronous Motor: PMSM)의 비선형 속도 제어 기법이 제시된다. 비선형 제어 방식은 시스템 파라미터와 부하상태가 정확하게 일치하지 않는 경우 만족스러운 성능을 줄 수 일다. 최근에 향상된 속도 제어 성능을 위해 적응형 기법, 슬라이딩 모드 제어, 및 관측기에 기반 한 기법들이 제안되었다. 하지만, 이 방법들은 관성의 큰 변화, 속도의 빠른 과도 특성 및 샘플링 주기 증가와 같은 특정한 조건에서 더 이상 만족스러운 성능을 제공하지 않는다. 일반적으로, 속도 동특성에 영향을 주는 주요 파라미터를 동시에 추정하기는 쉽지 않다. 이를 해결하기 위해 설치 및 기동시 전동기 주요 파라미터를 시간 구간 별로 나누어 자동으로 추정하는 순차적 파라미터 튜닝 알고리즘이 제안된다. 제안된 방식이 DSP TMS320C31을 이용하여 구현되고 유용성이 시뮬레이션과 실험을 통해 입증된다.

• 대한한방내과학회지
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• 제24권2호
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• pp.283-289
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• 2003

Background and Purpose : Hemiplegic upper extremity is a problem frequently encountered in the rehabilitation of patients with stroke. In Korean traditional medicine, moxibustion has been used clinically in treatment of stroke patients with hemiplegia. So far, its efficacy has not been proven clinically. The purpose of this study was to evaluate the efficacy of the moxibustion in treating hemiplegic upper extremity in stroke patients. Design : Randomized Control Trial. Subjects and Methods : Forty hemiplegic stroke patients admitted to Kyunghee oriental medicine hospital were randomized into the treatment with standard physiotheraphy combined with Moxibustion-group or Control-group with standard physiotherapy alone. It took them 2-5 weeks from the onset to start this study. Moxibustion was applied at LI4(合谷), LI11(曲池), TE3(中渚), TE5(外關) in hemiplegic hand, once a day for 2weeks. The effect of treatment on hemiplegic upper extremity was assessed using Fugl-Myer motor scale, Motricity Index and Modified Barthel Index(drinking/feeding, dressing upper body, grooming) Results : These 2 groups had comparable clinical characteristics; sex, age, plegic side (Rt., Lt.), pretreatment impairment. After two weeks, patients in the moxibustion group perfomed better on Fugl-Myer test and Motricity index test. The differences were significant.(P=0.038, 0.002) But Results on the Modified Barthel Index revealed no effect.(P=0.348) Conclusion : This results suggest that moxibustion is an effective treatment for improvement of motor function of hemiplegic upper extremity.

• Tribology and Lubricants
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• 제39권2호
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• pp.81-85
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• 2023

This study presents an experimental investigation of the effects of surface roughness on gas foil thrust bearing (GFTB) performance. A high-speed motor with the maximum speed of 80 krpm rotates a thrust runner and a pneumatic cylinder applies static loads to the test GFTB. When the motor speed increases and reaches a specific speed at which a hydrodynamic film pressure generated within the gap between the thrust runner and test GFTB is enough to support the applied static load, the thrust runner lifts off from the test GFTB and the friction mechanism changes from the boundary lubrication to the hydrodynamic lubrication. The experiment shows a series of lift-off test and load-carrying capacity test for two thrust runners with different surface roughnesses. For a constant static load of 15 N, thrust runner A with its lower surface roughness exhibits a higher start-up torque but lower lift-off torque than thrust runner B with a higher surface roughness. The load capacity test at a rotor speed of 60 krpm reveals that runner A results in a higher maximum load capacity than runner B. Runner A also shows a lower drag torque, friction coefficient, and bearing temperature than runner B at constant static loads. The results imply that maintaining a consistent surface roughness for a thrust runner may improve its static GFTB performance.

• 한국자동차공학회논문집
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• 제17권2호
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• pp.118-125
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• 2009

Calculation of indicated mean effective pressure(IMEP) requires high cylinder pressure sampling rate and heavy computational load. Because of that, it is difficult to implement in a conventional electronic control unit. In this paper, a cylinder pressure based real-time IMEP estimation method is proposed for controller implementation. Crank angle at 10-bar difference pressure($CA_{DP10}$) and cylinder pressure difference between $60^{\circ}$ ATDC and $60^{\circ}$ BTDC($DP_{deg}$) are used for IMEP estimation. These pressure variables can represent effectively start of combustion(SOC) and fuel injection quantity respectively. The proposed IMEP estimation method is validated by transient engine operation using a common-rail direct injection diesel engine.

• 한국소음진동공학회논문집
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• 제19권8호
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• pp.788-794
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• 2009

Various types of latch designs for hard disk drives using load/unload mechanism have been introduced to protect undesired release motions of a voice coil motor(VCM) actuator from sudden disturbances. Recently, various inertia-type latches have been widely used because locking performance is better than that of other types of latch. However there has been a limit in the inertia type in order to guarantee perfect latch and unlatch operations because of changes in latch/unlatch conditions due to mechanical tolerance and temperature-dependent friction. In this paper, a reliable and robust magnetic latch mechanism is proposed through only simple modifications of coil and yoke shapes in order to overcome the mechanical limit of current inertia-type latches. This new magnetic latch does not have only a simple structure but it also ensures reliable operations and anti-shock performance. The operating mechanism of the proposed latch is theoretically analyzed and optimally designed using an electromagnetic simulation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.467-472
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• 2005

Load/Unload(L/UL) technology includes the benefits, that is, increased areal density, reduced power consumption and improved shock resistance contrary to contact start stop(CSS). It has been widely used in portable hard disk drive and will become the key technology for developing the small form factor hard disk drive. The main objectives of L/UL are no slider disk contact or no media damage. For realizing those, we must consider many design parameters in L/UL systems. In this paper, we focus on the effect of the ramp profile. We can find out the lateral velocities in L/UL process through experiments and simulations for force of voice coil motor and friction force on ramp. And then, we will gain the optimal design of ramp slope to maintain the minimum clearance of suspension dimple and slider with FE model. In special, after finding the point at which air bearing breaks and designing the ramp, we will identify the results for improving unload performance.