• 한국전기전자재료학회논문지
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• 제19권2호
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• pp.162-168
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• 2006

Recently, diagnosis techniques have been investigated to detect a Partial Discharge associated with a dielectric material defect in a high voltage electrical apparatus, However, the properties of detection technique of Partial Discharge aren't completely understood because the physical process of Partial Discharge. Therefore, this paper analyzes the process on surface discharge of polymer insulator using wavelet transform. Wavelet transform provides a direct quantitative measure of spectral content in the time~frequency domain. As it is important to develop a non-contact method for detecting the kaolin contamination degree, this research analyzes the electromagnetic waves emitted from Partial Discharge using wavelet transform. This result experimentally shows the process of Partial Discharge as a two-dimensional distribution in the time-frequency domain. Feature extraction parameter namely, maximum and average of wavelet coefficients values, wavelet coefficients value at the point of $95\%$ in a histogram and number of maximum wavelet coefficient have used electromagnetic wave signals as input signals in the preprocessing process of neural networks in order to identify kaolin contamination rates. As result, root sum square error was produced by the test with a learning of neural networks obtained 0.00828.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.662-665
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• 2004

Recently, diagnosis techniques have been investigated to detect a partial discharge associated with a dielectric material defect in a high-voltage electrical apparatus However, the properties of detection technique of PD aren't completely understood because the physical process of PD. Therefore, this paper analyzes the process on Surface Discharge of Polymer Insulator using Wavelet transform. Wavelet transform provides a direct quantitative measure of spectral content in the time-frequency domain. As it is important to develop a non-contact method for detecting the Contamination Degree, this paper analyzes the electromagnetic waves emitted from PD using Wavelet transform. This paper experimentally shows the process of PD as a two-dimensional distribution in the time-frequency domain. This method is shown to be useful for detecting prediction of contamination degree.

• 상하수도학회지
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• 제23권4호
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• pp.417-430
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• 2009

A BNR comprehensive performance evaluation (BNR CPE) system was established employing system-oriented evaluation methodology for biological nutrient removal (BNR) processes based on the CPE techniques developed by U.S. EPA for evaluation of conventional biological processes. The BNR CPE system applied to five domestic BNR plants adopting $A^2/O$ process confirmed that all target plants except the smallest one had not any serious defective performance and process stability was enhanced with increasing plant size. The system also clearly verified relatively poor performances in anoxic reactors without exception mainly due to influent carbon limit rather than functional defect. Consistent good performances were confirmed even during both winter season and wet weather generally known to be difficult to achieve satisfactory removals. Presentation of evaluation results by modified radar chart system simplified and clarified the evaluation and analysis procedures. The BNR CPE system could not only discover readily the causes of present and prospective poor performances but also facilitate the suggestion of their optimization options. Mutual effect and cause-and-effect among operation parameters and unit processes were also found easily using the evaluation system. The system justified that the adverse effect of defective operating parameters could be compensated by other favorable parameters, especially in anaerobic and anoxic reactors as well as during the winter season.

• 정보학연구
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• 제7권3호
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• pp.113-118
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• 2004

기존의 누설전류기법에서 한층 진일보된 비접촉식 수신용 안테나를 이용하여 복잡한 지역과 광범위한 지역에서 효율적인 고분자 애자의 오손정도를 진단하기 위하여 본 연구를 착수하였다. 착수된 연구는 가공된 챔버 내 설치된 고분자애자에 인위적으로 카올린과 소금을 혼합후 증류수에 혼합하여 인공 오손실시 후 방사전자파와 스페트럼 그리고 부분방전전하량을 동시에 측정 후 전자파 신호에 대한 카올린의 오손정도에 대한 특징추출을 위하여 다우비치 이산웨이블렛 변환기법에 적용 후 각각의 통계적인 파라미터의 특징을 추출하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2485-2487
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• 2000

In this paper, we use a fuzzy algorithm to detect and diagnose the error which is caused by time delay of the computer-controlled system. Generally, a computer-controlled system is composed of computer and process. And they communicate the data each other. In data communication, error occurs by some reasons, such as noise, disturbance, hardware defect, etc. Time delay is one of the reasons. And time delay makes it difficult to distinguish whether the system really has a problem or not. Therefore, we need to detect and diagnose the error from time delay. For difficulty of modeling and ambiguity of classification, we use a fuzzy algorithm. To verify the better performance of the proposed algorithm, we exemplified by some simulation results.

• Restorative Dentistry and Endodontics
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• 제41권4호
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• pp.316-321
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• 2016

Although it is challenging, the early diagnosis of a vertical root fracture (VRF) is crucial in order to ensure tooth preservation. The purpose of this clinical case report was to describe reparative surgery performed to treat a tooth affected by an incomplete VRF. A 26 year old male patient was suspected to have a VRF in a maxillary left central incisor, and an exploratory flap was performed in order to confirm the diagnosis. After detecting the fracture, the lesion was surgically treated, the fracture and the infected root-end were removed, and a platelet-rich plasma membrane was used to cover the defect in order to prevent bacterial migration. A 24 month clinical and radiological follow-up examination showed that the tooth was asymptomatic and that the healing process was in progress. The surgical approach described here may be considered an effective treatment for a combined endodontic-periodontal lesion originating from an incomplete VRF and a recurrent periapical lesion.

• Journal of Korean Neurosurgical Society
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• 제45권4호
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• pp.246-248
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• 2009

Atlantoaxial rotatory fixation (AARF) in adult is a rare disorder that occurs followed by a trauma. The patients were presented with painful torticollis and a typical 'cock robin' position of the head. The clinical diagnosis is generally difficult and often made in the late stage. In some cases, an irreducible or chronic fixation develops. We reported a case of AARF in adult patient which was treated by immobilization with conservative treatment. A 25-year-old female was presented with a posterior neck pain and limitation of motion of cervical spine after a traffic accident. She had no neurological deficit but suffered from severe defect on the scalp and multiple thoracic compression fractures. Plain radiographs demonstrated torticollis, lateral shift of odontoid process to one side and widening of one side of C1-C2 joint space. Immobilization with a Holter traction were performed and analgesics and muscle relaxants were given. Posterior neck pain and limitation of the cervical spine' motion were resolved. Plain cervical radiographs taken at one month after the injury showed that torticollis disappeared and the dens were in the midline position. The authors reported a case of type I post-traumatic AARF that was successfully treated by immobilization alone.

• Tuberculosis and Respiratory Diseases
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• 제58권2호
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• pp.188-192
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• 2005

47세 여자가 흉부 엑스선상 종격동 종괴가 우연히 발견되어 입원하였다. 16개월전 흉부 엑스선은 정상이었고 흉부 전산화단층촬영에서 좌측 흉곽 하부에 미세한 선음영을 포함한 지방 음영 종괴가 관찰되었고 횡격막의 결손이 의심되었다. 흉강경을 시행하여 그물막 이탈을 확인하였고 개흉술을 통해 횡격막 복원술을 시행하였다. 저자들은 지방음영의 종격동 종괴가 관찰되었을 때는 감별진단에 반드시 그물막의 횡격막 이탈을 생각하여야 할 것으로 생각한다.

• 대한핵의학회지
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• 제35권6호
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• pp.371-377
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• 2001

목적: 요통을 호소하는 암환자에서 골스캔을 시행하여 척추골의 섭취증가를 보이는 경우, 골전이와 양성 골질환의 구분이 모호한 경우가 많다. 이에 척추골 SPECT를 추가로 시행하는 것이 악성과 양성 골질환을 감별하는데 도움이 되는지 알아보고자 섭취양상을 분석하였다. 대상 및 방법: 3년간 척추골 SPECT를 시행한 108명의 환자중 SPECT에서 이상 섭취 병변을 보이고 임상적으로 추적이 가능하였던 45명의 환자의 67개의 병변의 척추골 SPECT소견을 다음과 같이 구분하고 임상소견 및 방사선학적 소견과 비교하였다. 1. 척추체: A. 전반적인 섭취증가, B. 추간판에 연한 선상의 섭취증가, C. 냉소의 동반, D. 분절상 섭취증가, 2. 척추후면체 A. 척추체 후면(lamina, pedicle 등), B. 추간판후면(후관절 등), C 극돌기 결과: 골전이 병변(18)은 척추체의 냉소동반(6), 분절상 섭취증가(5)가 특징적이었으며, 퇴행성변화(28)는 추체연의 선상 섭취증가(12), 추간판후면의 후면체 섭취증가(15), 압박골절(21)은 전반적인 척추체 섭취증가(9) 및 추체연의 섭취증가(9), 냉소동반(1), 분절상 섭취증가(1)와 극돌기의 섭취증가(3)을 보였다. 결론: 척추골 SPECT의 섭취증가 양상은 냉소동반, 분절상 섭취증가를 보이는 경우에 골전이 병변의 가능성이 크지만 압박골절에서도 같은 소견을 보일 수 있으므로 주의하여야 할 것이며, 퇴행성 질환은 특징적인 소견을 보이므로 감별이 가능하였다. 그러므로 골스캔 후 척추골 섭취 이상이 있는 암환자에서 추가 SPECT검사가 도움이 될 것으로 생각된다.

• 대한치과보철학회지
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• 제60권4호
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• pp.382-394
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• 2022

심한 치주염을 가진 환자의 치료는 환자의 개개 치아의 정확한 진단과 전략적인 치료 계획을 통해 단계적으로 진행되어야 한다. 임플란트 지지 고정성 보철 수복은 국소의치에 비해 환자의 만족도가 높고, 안정적인 수직 고경을 유지할 수 있는 장점이 있지만, 경조직이 부족한 다수 치아 결손 부위에서는 심미적인 측면의 실패와 치료 기간이 길어진다는 점의 단점이 있을 수 있다. 또한 통상의 고정성 보철물을 제작하고 장착하는 데에는 일정 기간이 소요되는데, 이 기간 동안 임시 보철물은 치아의 기계적, 생물학적, 심미적 요구 조건을 만족시켜야 한다. 이번 증례 보고에서는 상악과 하악의 부분 무치악 환자에서 단계적인 접근을 통한 임플란트 고정성 보철물을 수복한 증례를 보고하고자 한다.