• 한국산학기술학회논문지
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• 제17권5호
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• pp.717-722
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• 2016

본 논문은 고장발생 초기 고장전류의 크기에 따라 피크전류제한 기능을 갖도록 하나의 철심에 기존 1차 코일과 2차 코일이 병렬로 연결된 초전도 소자 1과 추가적인 철심을 사용하여 3차 권선에 초전도 소자 2가 연결된 자기결합형 초전도한류기를 제안하였다. 이중 철심을 이용하여 코일 1과 코일 2간 병렬로 연결한 자기결합형 초전도한류기가 고장발생시 피크전류를 초전도 소자 1만이 분담하는 것을 확인할 수 있었다. 그 이유는 초기 사고전류의 순간적인 요소가 커서 초전도 소자 1이 ?치되어 작동하였으나, 코일 3에 흐르는 전류가 임계전류를 초과하지 않았고, 이로 인해 초전도 소자 2가 ?치되어 작동하지 않았기 때문이다. 사고 시 피크전류를 순차적인 초전도 소자로 제한하기 위해서는 코일 1이 낮은 자기인덕턴스 값을 갖고 있으면서도 코일 2보다 코일 3이 보다 높은 자기인덕턴스 값을 갖도록 설계해야 할 것이다. 또한, 고장 발생 초기 사고전류의 크기를 결정하는 고장조건 중의 하나인 1차 코일과 2차 코일간의 권선비가 0.25일 때 두 SFCL의 전류제한 및 회복특성에 대한 검증을 선로단락실험을 통해 분석되었다. 이 단락실험의 분석결과, 가극결선인 경우가 감극결선한 경우보다도 전류제한 및 회복특성이 더욱 우수함을 확인할 수 있었다.

• Journal of Korean Neurosurgical Society
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• 제66권3호
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• pp.324-331
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• 2023

Objective : We aimed to analyze the effectiveness of external neurolysis on the common peroneal nerve (CPN) in patients with posture-induced compressive peroneal neuropathy (PICPNe). Further, we aimed to examine the utility of magnetic resonance imaging (MRI) in assessing the severity of denervation status and predicting the postoperative prognosis. Methods : We included 13 patients (eight males and five females) with foot drop who underwent CPN decompression between 2018 and 2020. We designed a grading system for assessing the postoperative functional outcome. Additionally, we performed MRI to evaluate the denervation status of the affected musculature and its effect on postoperative recovery. Results : The median time to surgery was 3 months. The median preoperative ankle dorsiflexion and eversion grades were both 3, while the average functional grade was 1. Posterior crural intermuscular septum was the most common cause of nerve compression, followed by deep tendinous fascia and anterior crural intermuscular septum. There was a significant postoperative improvement in the median postoperative ankle dorsiflexion and eversion grades and average postoperative functional (4, 5, and 2.38, respectively). Preoperative ankle eversion was significantly correlated with denervation status. Additionally, the devernation status on MRI was positively correlated with the outcome favorability. However, denervation atrophy led to a less favorable outcome. Conclusion : Among patients with intractable PICPNe despite conservative management, surgical intervention could clinically improve motor function and functional ability. Additionally, MRI examination of the affected muscle could help diagnose CPNe and assess the postoperative prognosis.

• 대한정형외과학회지
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• 제55권2호
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• pp.117-126
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• 2020

슬관절의 퇴행성 관절염에서 슬관절 전치환술은 널리 시행되고 있고 그 빈도도 점점 증가되고 있다. 수술 후 일상생활로의 복귀, 근력 및 운동범위의 회복 등 기능 회복을 위한 노력이 이루어져야 하고 이는 환자 요인, 수술 술기 및 재활 등 다양한 관점에서 접근해야 한다. 환자의 연령이나 비만의 정도, 성별, 대퇴사두근의 근력 등이 수술 후 기능 회복에 영향을 줄 수 있고 환자의 기대치나 만족도 같은 정신적인 상태도 영향을 준다. 기능 회복을 위하여 수술 전부터 환자교육 및 통증 조절, 대퇴사두근 근력의 강화 같은 치료를 시행할 수 있다. 수술 후 냉찜질 및 압박, 경피적 전기 신경 자극 치료, 신경근육 전기 자극 치료, 저주파 저강도 자기장 치료, 대퇴사두근의 근력운동, 관절범위 운동과 같은 물리치료도 적용할 수 있다. 최근에는 수중에서 근력과 균형감각을 회복시키는 수 치료도 점점 시행되는 추세이다. 이런 기능 회복을 위한 치료들은 수술 후 단기적으로만 시행될게 아니라 장기적으로 꾸준히 시행되는 것이 중요하며 술자는 환자의 상태나, 순응도, 사회적, 심리적 상황 등을 고려하여 적절히 적용하여야 한다.

• Journal of Magnetics
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• 제20권1호
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• pp.52-56
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• 2015

The purpose of the current study was to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) in conjunction with mirror therapy on the balance function of patients with sub-acute stroke hemiparesis. This study was conducted with 36 subjects who were diagnosed with a hemiparesis due to stroke. Participants in the experimental (19 members) and control groups (17 members) received rTMS and sham rTMS during 10 minute sessions each, which were carried out five days per week for four weeks. This was followed by the mirror therapy over 30 minute sessions, which were carried out five days per week for four weeks. Motor recovery was assessed by balance index, dynamic limits of stability, Berg balance scale, and time up go test. The change values of the balance index ($-2.06{\pm}1.99$ versus $-0.41{\pm}1.11$), dynamic limits of stability ($3.68{\pm}2.71$ versus $1.17{\pm}2.38$), and time up go test ($-7.05{\pm}5.64$ score versus $-3.35{\pm}5.30$ score) were significantly higher in the experimental group than in the control group (p < 0.05). At post-test, balance index ($4.08{\pm}1.14$ versus $5.09{\pm}1.04$), dynamic limits of stability ($13.75{\pm}0.60$ versus $11.73{\pm}3.53$), and time up go test ($23.89{\pm}4.51$ versus $28.82{\pm}3.07$) were significantly higher in the experimental group than in the control group (p < 0.05). In the experimental group, significant differences were found in the pre- and post-test scores for the balance index, dynamic limits of stability, Berg balance scale, and time up go test (p < 0.01). In the control group, a significant difference was observed between the pre- and post-test only for the Berg balance scale and time up go test (p < 0.05). These findings demonstrate that the application of 1Hz rTMS in conjunction with mirror therapy can be helpful in improving the balance function of patients with sub-acute stroke hemiparesis, and this may be used as a practical adjunct to routine rehabilitation therapy.

• Journal of Korean Neurosurgical Society
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• 제52권6호
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• pp.523-527
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• 2012

Objective : The incidence of spontaneous spinal epidural hematoma (SSEH) is rare. Patients with SSEH, however, present disabling neurologic deficits. Clinical outcomes are variable among patients. To evaluate the adequate treatment method according to initial patients' neurological status and clinical outcome with comparison of variables affecting the clinical outcome. Methods : We included 15 patients suffered from SSEH. Patients were divided into two groups by treatment method. Initial neurological status and clinical outcomes were assessed by the American Spinal Injury Association (ASIA) impairment scale. Also sagittal hematoma location and length of involved segment was analyzed with magnetic resonance images. Other factors such as age, sex, premorbid medication and duration of hospital stay were reviewed with medical records. Nonparametric statistical analysis and subgroup analysis were performed to overcome small sample size. Results : Among fifteen patients, ten patients underwent decompressive surgery, and remaining five were treated with conservative therapy. Patients showed no different initial neurologic status between treatment groups. Initial neurologic status was strongly associated with neurological recovery (p=0.030). Factors that did not seem to affect clinical outcomes included : age, sex, length of the involved spinal segment, sagittal location of hematoma, premorbid medication of antiplatelets or anticoagulants, and treatment methods. Conclusion : For the management of SSEH, early decompressive surgery is usually recommended. However, conservative management can also be feasible in selective patients who present neurologic status as ASIA scale E or in whom early recovery of function has initiated with ASIA scale C or D.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.480-480
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• 2000

In this paper, we proposed a fuzzy-neuro controller to control the speed of wound rotor induction motor with slip energy recovery. The speed is limited at some range of sub-synchronous speed of the rotating magnetic field. Control speed by adjusting resistance value in the rotor circuit that occurs the efficiency of power are reduced, because of the slip energy is lost when it passes through the rotor resistance. The control system is designed to maintain efficiency of motor. Recently, the emergence of artificial neural networks has made it conductive to integrate fuzzy controllers and neural models for the development of fuzzy control systems, Fuzzy-neuro controller has been designed by integrating two neural network models with a basic fuzzy logic controller. Using the back propagation algorithm, the first neural network is trained as a plant emulator and the second neural network is used as a compensator for the basic fuzzy controller to improve its performance on-line. The function of the neural network plant emulator is to provide the correct error signal at the output of the neural fuzzy compensator without the need for any mathematical modeling of the plant. The difficulty of fine-tuning the scale factors and formulating the correct control rules in a basic fuzzy controller may be reduced using the proposed scheme. The scheme is applied to the control speed of a wound rotor induction motor process. The control system is designed to maintain efficiency of motor and compensate power factor of system. That is: the proposed controller gives the controlled system by keeping the speed constant and the good transient response without overshoot can be obtained.

• Journal of Korean Neurosurgical Society
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• 제47권1호
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• pp.17-25
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• 2010

Objective: The focus of this study is brain plasticity associated with semantic aspects of language function in patients with medial temporal lobe epilepsy (mTLE) Methods: Using longitudinal functional magnetic resonance imaging (fMRI), patterns of brain activation were observed in twelve left and seven right unilateral mTLE patients during a word-generation task relative to a pseudo-word reading task before and after anterior temporal section surgery. Results: No differences were observed in precentral activations in patients relative to normal controls (n = 12), and surgery did not alter the phonological-associated activations. The two mTLE patient groups showed left inferior prefrontal activations associated with semantic processing (word-generation>pseudo-word reading), as did control subjects. The amount of semantic-associated activation in the left inferior prefrontal region was negatively correlated with epilepsy duration in both patient groups. Following temporal resection, semantic-specific activations in inferior prefrontal region became more bilateral in left mTLE patients, but more left-lateralized in right mTLE patients. The longer the duration of epilepsy in the patients, the larger the increase in the left inferior prefrontal semantic-associated activation after surgery in both patient groups. Semantic activation of the intact hippocampus, which had been negatively correlated with seizure frequency, normalized after the epileptic side was removed. Conclusion: These results indicate alternation of semantic language network related to recruitment of left inferior prefrontal cortex and functional recovery of the hippocampus contralateral to the epileptogenic side, suggesting an intra- and inter-hemispheric reorganization following surgery.

• Journal of Korean Neurosurgical Society
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• 제45권2호
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• pp.118-121
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• 2009

Pituitary apoplexy is a clinical syndrome caused by an acute ischemic or hemorrhagic vascular accident involving a pituitary adenoma or an adjacent pituitary gland. Pituitary apoplexy may be associated with a variety of neurological and endocrinological signs and symptoms. However, isolated third cranial nerve palsy with ptosis as the presenting sign of pituitary apoplexy is very rare. We describe two cases of pituitary apoplexy presenting as sudden-onset unilateral ptosis and diplopia. In one case, brain magnetic resonance imaging (MRI) revealed a mass in the pituitary fossa with signs of hemorrhage, upward displacement of the optic chiasm, erosion of the sellar floor and invasion of the right cavernous sinus. In the other case, MRI showed a large area of insufficient enhancement in the anterior pituitary consistent with pituitary infarction or Sheehan's syndrome. We performed neurosurgical decompression via a transsphenoidal approach. Both patients showed an uneventful recovery. Both cases of isolated third cranial nerve palsy with ptosis completely resolved during the early postoperative period. We suggest that pituitary apoplexy should be included in the differential diagnosis of patients presenting with isolated third cranial nerve palsy with ptosis and that prompt neurosurgical decompression should be considered for the preservation of third cranial nerve function.

• Parasites, Hosts and Diseases
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• 제61권2호
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• pp.194-197
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• 2023

Ascaris lumbricoides causes one of the most common soil-transmitted helminthiases globally. The worms mostly infect the human small intestine and elicit negligible or nonspecific symptoms, but there are reports of extraintestinal ectopic ascariasis. We describe a rare case of biliary ascariasis mistaken for biliary stent in a 72-year-old female patient with a history of liver resection. She visited our outpatient clinic complaining of right upper quadrant pain and fever for the past week. She had previously undergone left lateral sectionectomy for recurrent biliary and intrahepatic duct stones 2 years ago. Besides mildly elevated gamma-glutamyl transferase levels, her liver function tests were normal. Magnetic resonance cholangiopancreatography revealed a linear filling defect closely resembling an internal stent from the common bile duct to the right intrahepatic bile duct. A live female A. lumbricoides adult worm was removed by endoscopic retrograde cholangiopancreatography (ERCP). Despite a significant decrease of the ascariasis prevalence in Korea, cases of biliary ascariasis are still occasionally reported. In this study, a additional case of biliary ascariasis, which was radiologically misdiagnosed as the biliary stent, was described in a hepatic resection patient by the worm recovery with ERCP in Korea.

• Journal of Yeungnam Medical Science
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• 제22권1호
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• pp.96-103
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• 2005

뇌성마비로 인해 오른 손에서 단부전마비를 호소하는 환자를 대상으로 기능적 자기공명영상 장치와 경두개 자기 자극기를 사용하여 운동신경의 회복기전을 연구하였다. 대상자는 21세 된 남자 환자로 오른손에 경미한 운동 기능의 손상을 보였고, 자기공명영상의 소견에서 좌반구의 precentral knob에서 병변을 보였다. 기능적 자기공명영상 촬영은 한 명의 대상자와 여덟 명의 정상인을 대상으로 표준화된 헤드코일을 사용하여 1.5 T의 장치에서 BOLD 기술을 적용하여 실시하였다. 대상자들의 운동 수행은 1 Hz 주기로 손가락의 굴곡과 신전을 반복하는 과제가 제시되었다. 경두개 자기 자극은 원형 코일을 사용하여 코일의 앞쪽 부분이 대상자의 두피에서 1 cm 정도 떨어진 정접 부위에 적용되었고 양측의 짧은엄지벌림근에서 발생된 운동 유발 전위가 동시에 측정되었다. 자기공명영상의 결과에서 환자의 비손상측(좌측) 손과 정상군의 좌측 손의 운동 수행 시 오른쪽의 일차운동감각영역(SM1)의 precentral knob에서 활성도가 나타났다, 그러나, 환자의 손상측(우측) 손의 운동 수행 시, 좌측 일차운동감각영역의 손상된 precentral knob 내측 부위에서 활성도를 보였다. 또한, 경두개 자기 자극의 결과에서 손상측 짧은엄지벌림근에서 발생된 운동 유발 전위에 해당하는 뇌 부위가 환자의 정상측과 비교하여 1 cm 내측에서 발견되었다. 그러므로 손상측 손의 운동 기능이 손상된 precentral knob의 내측 부분으로 전위되어 신경재구성이 이루어진 것으로 추정되는 결론을 얻었다.