• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권5호
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• pp.283-294
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• 2004

This paper introduces the new Direct Torque Control(DTC) method based on the estimated torque in Switched Reluctance Motor(SRM) and applies the proposed DTC to SRM for the instantaneous torque ripple reduction. The nonlinear characteristics of SRM is considered in the calculation of the estimated torque and the theory is described in this paper. Current control is one of the kernel elements of torque controller and the performance of the current control should be high for this work. But the conventional PI current control has a weak point in SRM application because of motional EMF. Consequently, this paper makes up for the weakness of PI controller through present of new current controller, that is termed the non-interference current control. The ability of proposed torque and current controller is verified through simulation and experiment.

• 전기학회논문지P
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• 제66권1호
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• pp.1-6
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• 2017

Recently, many motor analysis methods have been developed and studied. Among these methods, the finite element method(FEM) and the analytic method are most popular in field engineers because of the accuracy of FEM and the convenience and rapid analysis time of the analytic method. Contrary, the finite element method has a weakness in calculation time and it is not easy to obtain the instantaneous characteristics value of motor with the analytic method. In this paper, the authors proposes a novel method for calculating the instantaneous characteristics of motors with the magnetic slot equivalent circuit.

• Annals of Clinical Neurophysiology
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• 제8권1호
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• pp.102-105
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• 2006

We present a case with stepwise weakness and sensory involvement of both hands for more than 2 months. His nerve conduction study findings revealed prolonged terminal latencies, decreased motor and sensory conduction velocities and conduction blocks of both ulnar nerves, more severely on left side. And there were other abnormalities manifested with mononeuropathy multiplex. Increased cerebrospinal fluid protein was found. We diagnosed him as Lewis-Sumner syndrome and tried high dose oral steroid therapy for 2 months. He showed improvement of motor functioning with persistent conduction block.

• 전기학회논문지P
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• 제55권2호
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• pp.78-82
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• 2006

This paper is proposed genetic algorithm tuning(GAT) control)or for high performance of induction motor drive. We employed GA to the classical PI controller. The approach having ability for global optimization and with good robustness, is expected to overcome some weakness of conventional approaches and to be more acceptable for industrial practices. The control performance of the GAT PI controller is evaluated by analysis for various operating conditions. The results of experiment prove that the proposed control system has strong high performance and robustness to parameter variation, and steady-state accuracy and transient response.

• Journal of Korean Neurosurgical Society
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• 제56권3호
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• pp.254-256
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• 2014

Weakness of the dorsiflexor muscles of the ankle or toe, referred to as foot drop, is a relatively common presentation. In most cases, foot drop is caused by a lower motor neuron disease such as peroneal peripheral neuropathy, L4-5 radiculopathic sciatic neuropathy, or polyneuropathy. Although upper motor neuron lesions can present as foot drop, the incidence is very rare. Here, we report an extremely rare case in which foot drop was the only presenting symptom of cerebral infarction.

• Clinical Pain
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• 제18권2호
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• pp.88-91
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• 2019

Unexplained pain and weakness, i.e., without obvious predisposing factors, are often encountered by physiatrists and efforts should be made to determine the cause. A 63-year-old male presented with radiating pain in his right arm and mild weakness of the right hand. An electrodiagnostic examination revealed distal symmetric sensory polyneuropathy in the upper and lower extremities, and denervation potentials in the forearm muscles, which were inconsistent with the cervical spine MRI images and symptoms. A predisposing undiscovered disease was revealed, i.e., squamous cell carcinoma in the lung; brain metastasis affecting the left primary motor cortex was also detected. Therefore, we concluded that the pain and weakness were related to paraneoplastic syndrome and brain metastases of the hand knob. The observed denervation potentials were characterized as trans-synaptic changes in the brain metastasis. This case highlights the importance of unexplainable focal pain and weakness in the increasing prevalence of cancer.

• 한국산학기술학회논문지
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• 제17권10호
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• pp.221-227
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• 2016

본 연구의 목적은 뇌성마비의 아동의 운동기술과 처리기술에 영향을 미치는 감각처리 요인을 증명하여 뇌성마비 아동을 위한 재활 치료 중재 시 임상적 고려 사항을 파악하고자 하였다. 서울시 소재 J 소아발달센터와 N 재활병원 병원에 내원 중인 뇌성마비 아동 36명을 대상으로 운동 및 처리기술 평가와 단축형 감각 프로파일 검사를 실시하였다. Pearson의 상관계수를 이용하여 뇌성마비 아동의 운동기술과 처리기술 및 감각처리능력과의 상관관계를 검증하였고, 위계적 다중회귀분석을 통해 운동기술과 처리기술에 영향을 주는 주된 감각처리 요인들을 검증하였다. 연구 결과, 운동기술은 감각처리 항목 중 청각여과하기, 활력부족/허약, 시/청각 민감성 항목과 유의미한 상관성을 나타내었다. 처리기술은 촉각민감성, 맛/냄새 민감성 항목과 유의미한 상관성을 나타내었다. 위계적 다중회귀 모형에서 운동기술에 영향을 주는 주요 요인은 움직임 민감성, 청각여과하기, 활력부족/허약 항목이었다. 처리기술에 영향을 주는 요인은 본 연구의 모형에서는 확증되지 않았다. 이번 연구는 뇌성마비 아동을 대상으로 일상생활 활동시 운동기술과 처리기술에 영향을 주는 감각처리 요인들의 관련성과 주요 요인을 검증하여 재활치료를 위한 기초자료를 제공하는데 그 의의가 있다. 추후 연구에서는 더 많은 뇌성마비 아동의 집단을 대상으로 연구가 진행되어 본 연구에서 확인되지 못한 처리기술에 영향을 주는 감각처리 요인들을 검증해볼 필요가 있다.

• Annals of Clinical Neurophysiology
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• 제11권2호
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• pp.74-77
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• 2009

We report a 23-year-old woman with adult Sandhoff disease, who presented with motor neuron disease phenotype. The patient had experienced progressive motor weakness in four extremities since 1 year prior to admission. Electrophysiological study revealed wide-spread denervation potentials, and the assay of total hexosaminidase involving A and B activities showed decreased levels of these activities, which was consistent with Sandoff disease. This is the first Korean case of adult Sanhoff disease presented as a motor neuron disease phenotype.

• Clinical and Experimental Pediatrics
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• 제49권10호
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• pp.1019-1025
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• 2006

Motor delay, when present, is usually the first concern brought by the parents of children with developmental delay. Cerebral palsy that is the most common motor delay, is a nonspecific, descriptive term pertaining to disordered motor function that is evident in early infancy and is characterized by changes in muscle tone, muscle weakness, involuntary movements, ataxia, or a combination of these abnormalities. A wide range of causative disorders and risk factors have been identified for cerebral palsy, and broadly classified into 5 groups; perinatal brain injury, brain injury related to prematurity, developmental abnormalities, prenatal risk factors, and postnatal brain injury. Delay in attaining developmental milestones is the most distinctive presenting complaint in children with cerebral palsy. A detailed history and thorough physical and neurologic examinations are crucial in the diagnostic process. The clinician should be cautious about diagnostic pronouncement unless the findings are unequivocal. Several serial examinations and history review are necessary. All children with cerebral palsy should undergo a neuroimaging study, preferably MRI, because an abnormality is documented on head MRI(89%) and CT(77%). The high incidence rates for mental retardation, epilepsy, ophthalmologic defects, speech and language disorders and hearing impairment make it imperative that all children with cerebral palsy be screened for mental retardation, ophthalmologic and hearing impairments, and speech and language disorders; nutrition, growth, and swallowing also should be closely monitored.

• 대한물리의학회지
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• 제6권2호
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• pp.189-197
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• 2011

Purpose: Trunk muscle weakness in the children with cerebral palsy can lead to postural and alignment problems, breathing difficulties, and so on. Therefore, children with cerebral palsy can benefit from exercises that strengthen the muscles in their trunks. The purpose of this study was to investigate the effects of trunk muscle strengthening exercise on functional gross movement and balance ability in children with spastic diplegic cerebral palsy. Methods: We used single group repeated measure design in 8 children(four males, four females; aged 6~12 years; mean 8.3 years) with diplegia. The functional gross motor outcome measured by using the GMFM and balance ability of all children was measured by pediatric balance scale. All participants were alternately received trunk strengthening exercise and neurodevelopment treatment for 40 minutes twice per week during 8 weeks. Results: Significant and clinical meaningful improvement in functional gross motor and balance ability were shown. Conclusion: The results indicate that trunk strengthening exercise has a positive effect on both functional gross motor and balance ability in children with spastic diaplegic cerebral palsy.