• 한국지능시스템학회논문지
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• 제26권2호
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• pp.135-140
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• 2016

비동기 순차 회로를 위한 교정 제어기는 회로를 재설계하지 않고도 회로 내에 존재하는 여러 고장을 탐지하고 극복하는 능력을 보인다. 이번 논문에서는 교정 제어기의 크기를 줄이기 위한 방법으로서 정적 교정 제어기(static corrective controller)를 제안한다. 동적 제어기에 비해 정적 제어기는 제어기 상태가 필요 없으므로 조합 회로(combinational circuit)만으로 구현 가능하다. 본 논문에서는 상태 천이 고장에 대한 정적 내고장성 교정 제어기가 존재할 조건과 설계 과정을 규명한다. 또한 제안된 제어 기법을 FPGA로 구현된 SEU 오류 카운터에 적용하여 그 효용성을 실험적으로 검증한다.

• 대한기계학회논문집A
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• 제30권4호
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• pp.435-441
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• 2006

The anterior cruciate ligament(ACL) is an important stabilizer of knee joint. The ACL injury of knee is common and a serious ACL injury leads to ligament reconstruction surgery. Gait analysis is essential to identify knee condition of patients who display abnormal gait. The purpose of this study is to evaluate and classify knee condition of ACL deficient patients using a nonlinear dynamic method. The nonlinear method focuses on understanding how variations in the gait pattern change over time. The experiments were carried out for 17 subjects(l2 healthy subjects and five subjects with unilateral deficiency) walking on a motorized treadmill for 100 seconds. Three dimensional kinematics of the lower extremity were collected by using four cameras and KWON 3D motion analysis system. The largest Lyapunov exponent calculated from knee joint flexion-extension time series was used to quantify knee stability. The results revealed the difference between healthy subjects and patients. The deficient knee was significantly unstable compared with the contralateral knee. This study suggests an evaluation scheme of the severity of injury and the level of recovery. The proposed Lyapunov exponent can be used in rehabilitation and diagnosis of recoverable patients.

• 대한후두음성언어의학회지
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• 제20권2호
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• pp.118-125
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• 2009

Bilateral vocal fold immobility (BVFI) is a challenging condition which may result from diverse etiologies including vocal fold paralysis, synkinesis, cricoarytenoid joint fixation, and interarytenoid scar. Most patients present with dyspnea and stridor, but sometimes with a breathy dysphonia. Careful history taking, laryngoscopic evaluation under general anesthesia or awaken status, laryngeal EMG, and imaging studies with CT and/or MRI are helpful for providing a precise diagnosis and planning appropriate managements. In children, congenital neurological disorder is one of the most common etiologies, and spontaneous recovery has been reported in more than 50% of cases. Therefore, observation for more than 6 months while securing the upper airway with tracheostomy if needed is a generally accepted rule before deciding any destructive procedure to be undertaken. In children with advanced posterior glottic stenosis, laryngotracheal reconstruction with rib cartilage graft should be considered. In contrast to children, BVFI most commonly occurs as sequalae of surgical complication in adults. Diverse static or dynamic procedures can be applied; posterior cordotomy, vocal fold lateralization, endoscopic or open arytenoidectomy, arytenoid abduction, and reinnervation, electrical laryngeal pacing, which need to be carefully selected according to each patient's needs and pathophysiology of BVFI.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.307-309
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• 2004

In this study, we have evaluated and classified arthritic pathology using the auscultation of knee joint sound. Six normal persons and 11 patients with knee problem were enrolled. Six patients of Group 1 needed an orthopeadic surgery because of the ruptured wounds of meniscus or ACL(Anterior Cruciate Ligament) and 5 patients of Group 2 diagnosed as osteoarthritis. Subjects were taken knee flexion and extension being seated in a chair for 20 seconds which repeated 3 times. Also subjects stood up and sit down repeatedly in the same way. After the movement of knee was divided into 18 degrees, the pitch perturbation according to partial degrees was analyzed and the DTW(Dynamic Time Warping) method was applied for normalizing a time-axis and unpaired t-test was used for statistic results among groups. As a result, the amplitude and frequency perturbations of group 2 was higher than group 1(p<0.05) and showed a characteristic 'w-shape' in angle-amplitude graph. These results suggest that the analysis of knee joint sound might assist in early diagnosis of knee joint disease.

• Annals of Clinical Neurophysiology
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• 제1권1호
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• pp.76-79
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• 1999

The most significant factor in pathogenesis of vascular headaches like migraine and cluster headache is dynamic changes of diameters of the cerebral arteries. TCD is a valuable noninvasive tool to assess the cerebral hemodynamic status by measuring the flow velocities of the intracranial cerebral arteries around the circle of Willis. TCD can evaluate flow velocities and vasoreactivity of the patients with a vascular headache during the ictal phase as well as during intericatal phase. Distribution of the changes recorded differ between types of headaches and also between the major ictal symptoms. The changes suggest the presence of prolonged vasospasm interictally and more marked relaxation of the cerebral arteries. TCD can be used to monitor the long-term clinical course of patients with vascular headache by correlation the symptomatic improvement and TCD data before and after long-term pharmacological prophylactic treatments. During the ictal phases large intervention. The results may be used in selecting and evaluating the agents for abortive therapy for acute attacks. In conclusion TCD can quantitatively evaluate vascular headaches when making diagnosis and classification and can provide guidelines to choose more individualized therapeutic options for both acute and long-term treatment.

• 소음진동
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• 제11권1호
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• pp.125-131
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• 2001

There is a clearance between the parts of a machine due to design tolerance, manufacturing error, wear, looseness, or misalignment. If the clearance is large, the vibration and noise of the machine is generally large. Therefore, the analysis on the nitration and noise of a machine can tell the clearance of the machine, which reveals the condition of the machine, i.e., the existence of faults and the safety of the machine. The investigation of this kind of research should be on the basis of experimental results. A link mechanism with a clearance at a joint between the coupler and locker is made for the investigation of the condition monitoring of a machine due to clearance. The vibration and sound are measured from the link driving system during the operation. The signals are clarified using line enhancement technique. The noise removed signals are used to develop the dynamic model of the system for a model based fault diagnosis. Also this study showed that the clarified signals can be used for the calculation of the joint forces between the coupler and rocker and for the correlation between the vibration and sound levels and the clearance sizes.

• 지능정보연구
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• 제6권1호
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• pp.83-96
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• 2000

본연구는 웹 상에서 원격 협력 학습을 위한 수준별 협력 학습자 진단 및 스케줄링 에이전트의 설계와 구현에 관한 연구이다. 원격 협력 학습은 동일한 학습내용에 흥미를 갖는 아동이 동시에 학습할 수 있는 환경이 필요하며 학습자의 지식 또한 비슷한 수준이어야 효과적인 협력학습을 할 수 있다. 분산 환경의 이질적인 학습자를 모으기 위해서는 좀 더 자율적이고 지능적인 시스템이 필요하며 학습자에 대한 지식을 표현하는 학습자 모델이 요구된다. 이를 위해 에이전트 시스템이 적절하게 사용될수 있으며 학습자의 수준을 판단하기 위한 진단 에이전트와 협력학습이 가능한 여러명의 학습자들을 알맞은 시간과 서버에 연결하는 스케줄링 에이전트를 웹 기반 지능형 교수 시스템에 접목하였다. 학습자 수준을 진단하는 진단 에이전트는 확신도를 높이기 위해 3-모수 로지스틱 확신공식과 시간 가중치 확신인자 공식을 적용하여 신뢰도를 높였다 또한 협력학습의 스케줄링을 위해 다양한 제약조건들의 최적해를 구하기 위해 제약 만족 문제(CSP)로 스케줄링 에이전트를 모델링하였다 본 연구에서 설계 구현한 협력학습자 진단 및 스케줄링 에이전트의 효율성을 살펴보기 위해 여러명의 학습자를 대상으로 실험하였다. 실험을 통해 각 학습자의 지식 수준 진단과 다수의 학습자가 적절한 협력학습을 하기 위한 스케줄링이 매우 효율적으로 이루어짐을 볼 수 있었다.

• The Korean Journal of Pain
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• 제26권4호
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• pp.368-373
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• 2013

Background: Bertolotti's syndrome (BS), a form of lumbago in lumbosacral transitional vertebrae, is an important cause of low back pain in young patients. The purpose of this study was to assess the etiology of low back pain and the efficacy of treatment offered to patients with BS. Methods: All patients of BS Castellvi type1a during a period of 6 months were enrolled in the study. The patients underwent interventional pain procedures for diagnosis and pain relief. Response to the therapy was assessed based on VAS and ODI scores. A 50% decrease in VAS score or a VAS score less than 3 would be considered adequate pain relief. Results: All 20 patients diagnosed with BS during the 6-month observation period had scoliosis. Common causes of back pain were the ipsilateral L5-S1 facet joint, neoarticulation, the SI joint, and disc degeneration. Responses to various interventions for pain relief were different and inconsistent from patient to patient. In particular, responses to interventions for neoarticular pain were generally poor. Conclusions: Pain in patients with BS does not usually respond to interventional pain treatment. A very dynamic treatment approach must be pursued while managing BS patients, and the treatment plan must be individualized at various stages in order to obtain satisfactory pain relief.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2004년도 추계 종합학술대회 논문집
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• pp.402-407
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• 2004

인터넷은 사용이 매우 간편한 도구인 월드와이드웹의 등장으로 인하여 가장 독보적이면서도 강력한 지원을 제공하는 세계에서 가장 간편한 네트워크 자원이 되었다. 더 나아가 정적인 2차원을 넘어서 3차원 View 웹 서비스와 같은 동적인 서비스를 제공하는 많은 방법들이 제시되었다. 본 논문에서는 MRI, CT, PET 같은 2차원 의료 영상을 쌓아 만든 3차원 데이터를 웹에서 인터액티브하게 가시화 하는 볼륨 렌더링 View 프로그램을 제시할 것이다. 이를 위해 우리는 COM기술을 바탕으로 하는 ActiveX 컴포넌트인 OCX 컨트롤로 만들어 웹 페이지에서 실현 가능하도록 하였다. 또한 인터넷만 있으면 쉽게 원격에서도 3차원 가시화를 통한 영상 분석을 할 수 있는 기능을 제공하여 질병의 진단에 크게 기여 할 것으로 기대된다.

• Computers and Concrete
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• 제25권1호
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• pp.15-27
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• 2020

During the past decades, the application of acoustic emission techniques (AET) through the diagnosis and monitoring of the fracture process in materials has been attracting considerable attention. AET proved to be operative among the other non-destructive testing methods for various reasons including their practicality and cost-effectiveness. Concrete and rock structures often demand thorough and real-time assessment to predict and prevent their damage nucleation and evolution. This paper presents an overview of the work carried out on the use of AE as a monitoring technique to form a comprehensive insight into its potential application in brittle materials. Reported properties in this study are crack growth behavior, localization, damage evolution, dynamic character and structures monitoring. This literature review provides practicing engineers and researchers with the main AE procedures to follow when examining the possibility of failure in civil/resource structures that rely on brittle materials.