• Title/Summary/Keyword: Motor block

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Fatigue Life Evaluation of Motor Block Bracket Units for KTX-Sancheon Trains (KTX-산천 열차용 모터 감속기 고정대의 피로 수명 평가)

  • Lee, Chan-Woo;Lee, Dong-Hyong
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.6
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    • pp.626-631
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    • 2012
  • In this study, fatigue life of the motor block bracket units for KTX-Sancheon trains was assessed. Design evaluation for railway structures was performed based on the UIC 566 regulation, and test and evaluation of fatigue life in welded parts was performed in accordance with standard ERRI B 12/RP17 and ERRI B 12/RP60. The actual vehicle dynamic stress testing was executed in KTX-Sancheon service line with the service operating speed. The dynamic stress was measured with commercial data acquisition system (MGC plus). The cumulative damage was evaluated by applying standard BS 7608 - Class F and cycle counting was used rain-flow counting method. As a result, the motor block bracket units for KTX-Sancheon trains was designed to fit the regulation and the safety of fatigue life for 30 years, assuming that KTX-Sancheon trains travels 600,000km annually, were confirmed under current operating conditions.

A case of acute motor sensory axonal neuropathy presenting reversible conduction block

  • Lee, Dongah;Kim, Hyung Chan;Park, Kang Min;Park, Jinse;Ha, Sam Yeol;Kim, Sung Eun;Lee, Byung In;Kim, Jong Kuk;Yoon, Byeola;Shin, Kyong Jin
    • Annals of Clinical Neurophysiology
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    • v.20 no.1
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    • pp.49-52
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    • 2018
  • Reversible conduction block (RCB) was rare in patients with acute motor sensory axonal neuropathy (AMSAN). A-46-year-old man presented with paresthesia, weakness, diplopia, and dysarthria. Nerve conduction study (NCS) exhibited axonal changes with conduction block in motor and sensory nerves. His symptoms were rapidly progressed and recovered. Conduction block was disappeared in the follow-up NCS performed after 2 weeks. The AMSAN case with RCB showed rapid progress and rapid recovery of clinical symptoms as acute motor axonal neuropathy patients with RCB.

Newly Developed Urinary Retention and Motor Weakness of Lower Extremities in a Postherpetic Neuralgia Patient

  • Lee, Mi Hyun;Song, Jang Ho;Lee, Doo Ik;Ahn, Hyun Soo;Park, Ji Woong;Cha, Young Deog
    • The Korean Journal of Pain
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    • v.26 no.1
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    • pp.76-79
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    • 2013
  • During the early stage of postherpetic neuralgia, an epidural block on the affected segment is helpful in controlling pain and preventing progression to a chronic state. The main neurologic complication following an epidural block is cord compression symptom due to an epidural hematoma. When neurologic complications arise from an epidural block for the treatment of postherpetic neuralgia, it is important to determine whether the complications are due to the procedure or due to the herpes zoster itself. We report a case of a patient who was diagnosed with herpes zoster myelitis during treatment for postherpetic neuralgia. The patient complained of motor weakness in the lower extremities after receiving a thoracic epidural block six times. Although initially, we believed that the complications were due to the epidural block, it was ultimately determined to be from the herpes zoster myelitis.

A Study on Traction System Characteristics of High-Speed Train

  • Han, Young-Jae;Kim, Ki-Hwan;Seo, Sung-Il;Park, Chan-Kyoung;Han, Seong-Ho;Kim, Jong-Young;Kno, Ae-Sook
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1724-1726
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    • 2003
  • Korean High-Speed Train (350km/h), composed of 2 power cars, 2 motorized car and 3 trailer cars, has been developed and is under trial test. To verify the design requirements for the functions and traction performances of the train, KRRI (Korea Railroad Research Institute) decided to evaluate traction performances of the train during trial test. For this purpose, torque, velocity, voltage and current must be measured. KRRI has developed a measurement system that can measure vast and various signals effectively. In this paper, we introduce traction performances of Korean High-Speed Train. The traction measurement items are focused on the verification of motor block performances. Motor block consists of 2 motors. By this test, we verified traction performances of Korean High-Speed Train.

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The Fundamental Characteristics of Novel Switched Reluctance Motor with Segment Core Embedded in Aluminum Rotor Block

  • Oyama Jun;Higuchi Tsuyoshi;Abe Takashi;Tanaka Keisuke
    • Journal of Electrical Engineering and Technology
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    • v.1 no.1
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    • pp.58-62
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    • 2006
  • We proposed a novel segment type switched reluctance motor (SRM) in which the segment core was embedded in aluminum (conductive metal) rotor block in order to increase the mechanical strength and easy manufacturing as well as to improve the performance characteristics and reduce the vibration and acoustic noise. This paper explains the operation principle and the drive system and shows the experimental results in comparison with the VR type SRM.

Multifocal Motor Neuropathy (다초점성 운동신경병증)

  • Lee, Dong-Kuck
    • Annals of Clinical Neurophysiology
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    • v.4 no.2
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    • pp.98-107
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    • 2002
  • Multifocal motor neuropathy (MMN) is a chronic immune-mediated peripheral myelinopathy. The major clinical features include slowly progressive, painless, and asymmetric weakness, usually of distal limb muscle. Early in the course of the disease, weakness is not necessarily associated with muscle atrophy, owing to the initial primary involvement of peripheral myelin. Chronic progressive weakness is often associated with some degree of concurrent axonal loss and subsequent muscle atrophy. Sensory symptoms are usually mild or absent, and involvement of cranial and respiratory muscles is rare. The findings of multifocal motor conduction block, abnormal temporal dispersion, and focal conduction slowing at segments not at risk for common entrapment or compression injury, associated with normal sensory conduction studies along the same segments, are the hallmark electrophysiologic features of MMN. The slow progression and absence of upper motor neuron signs are the major clinical points that separate MMN from amyotrophic lateral sclerosis. The role of GM1 antibodies, found in high titers in 22~84% of MMN patients, remains uncertain. The contention that MMN is an autoimmune disorder is largely based on the often dramatic improvement in symptoms following the administration of intravenuos immunoglobulin or cyclophosphamide.

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Improvement of Transient Characteristics at middle and low Speed Region of induction Motor using Adaptive identification (파라미터 적응동정에 의한 유도전동기의 중.저속운정 과도특성개선)

  • 이성근
    • Journal of Advanced Marine Engineering and Technology
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    • v.23 no.6
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    • pp.738-747
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    • 1999
  • Vector controlled induction motor have been widely used in high performance applications. How-ever the performance is sensitive to the variations of motor parameters especially the rotor time constant which varies with the temperature and the saturation of the magnetizing inductance. In this paper the authors propose new identifying method for time-varying parameters of an induction motor which is based on adaptive vector control with serial block algorithm. Vector con-trol system realized on synchronous frame and parameter identification system realized on sta-tionary frame are not easily affected by the vector control frame. Parameter mismatch in the control system results in heavy transient variation in speed and torque response. In order to compensate degradation of the responses at the middle and low speed region adaptive identifier is introduced. To verify the feasibility of this technique compute simu-lations carried out.

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The Study of Implicit Motor Learning Using a Serial Reaction Time Task (연속 반응시간 과제를 이용한 내재적 운동학습의 특성 연구)

  • Park, Ji-Won;Hong, Chul-Pyo;Kim, Jong-Man;Ha, Hyun-Geun;Kim, Yun-Hee
    • Physical Therapy Korea
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    • v.11 no.2
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    • pp.1-8
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    • 2004
  • Motor skill learning can be acquired implicitly without consciousness of what is being learned. The purpose of this study was to examine the characteristics of implicit motor learning in young and elderly people using a perceptual-motor task. Forty normal young and elderly subjects participated. A modified version of the Serial Reaction Time Task (SRTT) using six blocks of twelve perceptual motor sequences was administered. The paradigm consisted of the first random sequence block followed by the four patterned blocks and another random block. In each block, the go signal consisted of an asterisk displayed in the one of the four parallel arrayed boxes in the middle of the screen. Subjects were instructed to push the corresponding response buttons as quickly as possible. Young subjects demonstrated shorter reaction times during the consecutive patterned blocks reflecting appropriate learning accomplished. Elderly subjects were able to learn a perceptual-motor task with implicit knowledge, but the performance was lower than that of the young persons. These results indicated that implicit sequence learning is still preserved in elderly adults, but the rate of learning is slower.

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A study on performance measurement system of traction equipment (추진장치 성능측정 시스템에 관한 연구)

  • Han, Young-Jae;Kim, Seog-Won;Kim, Young-Guk;Park, Chan-Kyoung;Choi, Jong-Sun;Kim, Jung-Su
    • Journal of Sensor Science and Technology
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    • v.12 no.4
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    • pp.170-175
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    • 2003
  • The korean high speed train(350km/h), composed of 7cars that are 2 power cars, 2 motorized car and 3 trailer cars, has been developed and is under on-line test. To verify the design requirements about the functions and traction performances of this train, KRRI(Korea Railroad Research Institute) decided to evaluate traction performances of the train during on-line test. For this purpose, such as torque, velocity, voltage and current, must be measured. KRRI has developed the measurement system that can be measured vast and various signals effectively. In this paper, we introduce traction performances of korean high speed train. The traction measurement items are focused on the verification of motor block performances. Motor block are consist of 2 motor. For this test, we verified traction performances of korean high speed train.

Effects of Contralateral Seventh Cervical Nerve Transfer on Upper Extremity Motor Function in the Patients with Spastic Hemiplegia after Stroke: a Retrospective Cohort Study

  • Wonjae Choi
    • Physical Therapy Rehabilitation Science
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    • v.11 no.4
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    • pp.502-508
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    • 2022
  • Objective: Contralateral seventh cervical nerve transfer (contralateral C7 transfer) is a newly attempted method to restore upper extremity motor function in the patients with spastic arm paralysis. The aim of this study was to investigate the effects of contralateral C7 transfer on upper extremity motor function in the patients with spastic hemiplegia after stroke. Design: A retrospective cohort study. Methods: Thirty-four patients with spastic hemiplegia after stroke was investigated. All patients registered between January 2020 and February 2021. The subjects were assessed on upper extremity motor function, cognition, and spasticity before and after contralateral C7 transfer. The upper extremity motor function was measured using the Fugl-Meyer upper extremity scale and box & block test. The cognition and spasticity were assessed by Korean version mini mental state examination (K-MMSE) and modified Ashworth scale from baseline to 8 weeks after the surgery. Results: The Fugl-Meyer upper extremity scale and modified Ashworth scale were significantly improved after contralateral C7 transfer (p<0.05). However, box & block test and K-MMSE were no significant changes after the surgery (p>0.05). Conclusions: This study suggested that the contralateral C7 transfer was a feasible and practical approach to improve upper extremity motor function in the patients with spastic hemiplegia after stroke, but further study is required to identify the long-term effects after the contralateral C7 transfer.