• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.644-647
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• 2003

The predictive maintenance can help to avoid the serious plant breakdowns and catastrophies. This paper deals with the fault diagnosis of the rotor of the induction motor which is widely used in the plants. In order to detect the broken bar, the Extended Kalman Filter is adopted to estimate the rotor resistance on the base of model-based method. The proposed estimation method is simulated with the aid of Matlab.

• Childhood Kidney Diseases
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• 제24권1호
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• pp.27-35
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• 2020

Purpose: Urinary tract infections (UTIs) are the most common and serious bacterial infections in children. Therefore, early diagnosis of vesicoureteral reflux (VUR) for treatment planning and the identification of noninvasive markers that can predict renal injury are important in patients with UTIs. We analyzed the clinical features of pediatric UTIs commonly encountered by general practitioners and reinterpreted the blood tests and imaging findings to identify the important clinical predictive markers of VUR in order to selectively perform VCUG. Methods: This retrospective study was performed among 183 children diagnosed with a UTI or acute pyelonephritis. Results: The most significant predictor of high grade and bilateral VUR identified using area under the curve analyses was hydronephrosis on kidney ultrasound images with renal cortical defects on dimercaptosuccinic acid (DMSA) kidney scan simultaneously, followed by hydronephrosis only on kidney ultrasound. Conclusion: The presence of hydronephrosis on kidney ultrasound images or cortical defects or asymmetric kidneys on the DMSA kidney scans can be predictive markers of VUR, reducing the need for VCUG. Our study can thus help minimize the exposure to radiation among patients through selective VCUG.

• 대한관절경학회지
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• 제7권2호
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• pp.215-219
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• 2003

목적 : 단순 방사선 사진에서 슬관절 외측 원판형 연골판을 진단하는데 도움이 되는 새로운 방사선 소견인 대퇴외과 절삭 징후(cut-off sign)를 관찰하여 이를 보고하고, 이의 진단적 의의를 특이도, 민감도, 양성 예측도, 음성 예측도와 함께 보고하고자 한다. 대상 및 방법 : 관절경 시술로 확진 된 50예의 완전 원판형 연골군과 50예의 정상 대조군을 대상으로 하였으며, Tunnel view에서 보이는 대퇴 외과와 내과의 내측부의 최장 길이를 측정하여 비율을 비교 분석하였다. 결과 : 원판형 연골군에서 대퇴 내과부 길이와 외과부 길이의 비율의 평균은 0.716 이였으며, 정상 대조군에서는 0.902 이었다. 이를 T-test로 분석했을 때, t-value는 -11.13 (p<0.0001)로 두 군간에 매 우 유의 한 차이를 나타내었으며, 또한 경계값(cut point)을 0.8로 하여 chi-square test로 분석했을 때 통계적으로 두 군간에 유의한 차이가 있었으며, 민감도 $76\%$, 특이도 $100\%$였으며, 양성 예측도 $100\%$, 음성 예측도 $80.6\%$로 나타났다. 절삭 징후는 육안적으로도 뚜렷한 차이를 보여 원판형 외측 반월상 연골을 단순 방사선 사진에서 진단할 수 있는 매우 좋은 간접적인 소견이라고 생각한다. 결론 : 대퇴 외과 절삭 징후는 단순 방사선 검사의 Tunnel view에서 원판형 연골을 진단할 수 있는 좋은 방사선 소견이며, $100\%$의 특이도와 $100\%$의 양성 예측도를 나타내는 우수한 진단소견으로 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7433-7438
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• 2013

Aim: To identify new biomarkers for NPC diagnosis with an anti-EBV Western blot test kit. Methods: Serum samples from 64 NPC patients and healthy subjects with four specific VCA-IgA/EA-IgA profiles were tested with an anti-EBV Western blot test kit from EUROIMMUN AG. Proteins were quantified with scores of intensity visually assigned to the protein bands. The markers which showed statistical differences between the NPC and non-NPC subjects were further evaluated in another 32 NPC patients and 32 controls in comparison with established biomarkers including VCA-IgA, EA-IgA, EBV-related protein IgG, and EBV DNA. Results: Among the markers screened, EA-D p45-IgG showed a statistically significant difference (p < 0.05) between NPC and non-NPC subjects with VCA-IgA positivy. In 32 VCA-IgA positive NPC patients and 32 control subjects, the diagnostic accuracy of EA-D p45-IgG was 78.1% with a positive predictive value of 77.8% and a negative predictive value of 78.6%. In the verification experiment, the specificity and sensitivity of EA-D p45-IgG were 75.0% and 90.6 %, respectively. Conclusions: EA-D p45-IgG might be a potential biomarker for NPC diagnosis, especially among VCA-IgA positive subjects.

• Imaging Science in Dentistry
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• 제42권1호
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• pp.19-24
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• 2012

Purpose : Field of view and voxel resolution of cone beam computed tomography (CBCT) might affect the diagnostic capability. This study was performed to compare between the standard and HiRes zoom modes in the diagnosis of external root resorption (ERR) using CBCT. Materials and Methods : Sixty three small cavities (0.25 mm depth and 0.5 mm diameter) were simulated on the buccal, lingual, and proximal surfaces at three different levels of 16 roots of teeth. After covering the root with nail varnish, the roots were inserted in the sockets and the model was placed in a water-containing lacuna. CBCT scans were taken in both standard and HiRes zoom modes using NewTom VG (QR srl Company, Verona, Italy). Then, an observer assessed the images to determine the presence or absence of the cavities. This process was repeated by increasing the size and depth of cavities to 0.5 mm depth and 1 mm diameter. Data were analyzed by McNemar test. The sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio in evaluation of the simulated cavities were calculated. Results : There was a significant difference between the two imaging modes in diagnosing the shallow cavities (p=0.02).The sensitivity of the standard zoom in detecting the shallow cavities was lower than that of the HiRes zoom. The likelihood ratio of the HiRes zoom was higher in the diagnosis of both cavity types. Conclusion : This study suggested that a smaller voxel size in the HiRes zoom mode of CBCT is preferred for diagnosis of ERR.

• Asian Pacific Journal of Cancer Prevention
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• 제15권10호
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• pp.4169-4173
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• 2014

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is highly accurate in diagnosing mediastinal lymphadenopathies of lung cancer and benign disorders. However, the utility of EBUS-TBNA in the diagnosis of mediastinal lymphomas is unclear. The aim of this study was to determine the diagnostic value of EBUS-TBNA in patients with suspected lymphoma. Materials and Methods: Sixty-eight patients with isolated mediastinal lymphadenopathy and suspected of lymphoma were included in the study. EBUS-TBNA was performed on outpatients under moderate sedation. The sensitivity, specificity, negative predictive value and diagnostic accuracy of EBUS-TBNA were calculated. Results: Sixty-four patients were diagnosed by EBUS-TBNA, but four patients with non-diagnostic EBUS-TBNA required surgical procedures. Thirty-five (51.5%) patients had sarcoidosis, six (8.8%) had reactive lymphadenopathy, nine (13.3%) had tuberculosis, one (1.5%) had squamous cell carcinoma, two (2.9%) had sarcoma and fifteen (22%) had lymphoma (follicular center cell, large B-cell primary, and Hodgkin lymphomas in three, two, and ten, respectively). Of the 15 lymphoma patients, thirteen were diagnosed by EBUS and two by thoracotomy and mediastinoscopy. The sensitivity, specificity, negative predictive value, and diagnostic accuracy of EBUS-TBNA for the diagnosis of lymphoma were calculated as 86.7%, 100%, 96.4%, and 97%, respectively. Conclusions: EBUS-TBNA can be employed in the diagnosis of mediastinal lymphoma, instead of more invasive surgical procedures.

• Asian Pacific Journal of Cancer Prevention
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• 제16권1호
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• pp.201-204
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• 2015

Background: This study was designed to determine the accuracy of bronchoalveolar lavage fluid cytology (BAL) using histopathologic examination of transbronchial biopsy specimens as the gold standard in diagnosis of lung carcinoma at our center. Materials and Methods: A retrospective study was conducted to investigate a total of 388 patients who were suspected of having lung cancer and had undergone fiberoptic bronchoscopy in Shahid Sadoughi hospital from 2006 to 2011. Lung masses were proven to be malignant by histology. Results: Transbronchial lung biopsy (TBLB) identified malignancy in 183 of the 388 cases, including 48 cases (26.2%) with adenocarcinoma, 4(2.1%) with bronchioloalveolar carcinoma, 47(25.6%)with squamous cell carcinoma, 34(18.5%) with well-diffentiated neuroendocrine carcinoma, 35(19.1%) with small cell carcinoma, 14 (7.6%) with non-small cell carcinoma, and 1 (0.54%) with large cell carcinoma. A total of 205 cases were correctly classified as negative. BAL was also performed in 388 patients; 86/103 cases were consistent with the final diagnosis of lung cancer and 188/285 cases were correctly classified as negative. The sensitivity of BAL was 46.9%(CI:41.9%, 51.8%)) and its specificity was 91.6%(CI:88.8%, 94.3%). BAL had a positive predictive value (PPV) of 83.4%(CI:79.7%, 87.1%) and a negative predictive value (NPV) of 65.8%(CI:61%, 70.5%). The overall accuracy of BAL was 70.5% and the exact concordance was 39%. Conclusions: Our findings suggest that BAL cytology is not sensitive but is a specific test for diagnosis of lung carcinoma. If transbronchial lung biopsy is combined with bronchoalveolar lavage, the positive diagnostic rate will be further elevated.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3031-3035
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• 2012

Background: Though open surgical biopsy is the procedure of choice for the diagnosis of bone tumors, many disadvantages are associated with this approach. The present study was undertaken to evaluate the role of fine needle aspiration cytology (FNAC) as a diagnostic tool in cases of bony tumors and tumor-like lesions which may be conducted in centers where facilities for surgical biopsies are inadequate. Methods: The study population consisted of 51 cases presenting with a skeletal mass. After clinical evaluation, radiological correlation was done to assess the nature and extent of each lesion. Fine needle aspiration was performed aseptically and smears were prepared. Patients subsequently underwent open surgical biopsy and tissue samples were obtained for histopathological examination. Standard statistical methods were applied for analysis of data. Results: Adequate material was not obtained even after repeated aspiration in seven cases, six of which were benign. Among the remaining 44 cases, diagnosis of malignancy was correctly provided in 28 (93.3%) out of 30 cases and categorical diagnosis in 20 (66.67%). Interpretation of cytology was more difficult in cases of benign and tumor-like lesions, with a categorical opinion only possible in seven (50%) cases. Statistical analysis showed FNAC with malignant tumors to have high sensitivity (93.3%), specificity (92.9%) and positive predictive value of 96.6%, whereas the negative predictive value was 86.7%. Conclusion: FNAC should be included in the diagnostic workup of a skeletal tumor because of its simplicity and reliability. However, a definitive pathologic diagnosis heavily depends on compatible clinical and radiologic features which can only be accomplished by teamwork. The cytological technique applied in this study could detect many bone tumors and tumor-like conditions and appears particularly suitable as a diagnostic technique for rural regions of India as other developing countries.

• Archives of Plastic Surgery
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• 제37권4호
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• pp.375-379
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• 2010

Purpose: The nasal bone is the most frequently fractured facial bone. Discordance between the CT reading by the radiologist and the diagnosis by the plastic surgeon is not uncommon. This study examined the discordance and proposes a method for reducing the rate of discordance. Methods: The CT readings by the radiologist were compared with the diagnosis by the plastic surgeon in 716 patients with a clinically suspected nasal bone fracture. The CT reading was classified as the following: a nasal bone fracture, suspicious nasal bone fracture, old nasal bone fracture, no nasal bone fracture. The sensitivity, specificity and positive predictive value of the CT reading were calculated. Results: A nasal bone fracture was diagnosed in 646 patients by the plastic surgeon and confirmed intraoperatively. The reading of a "nasal bone fracture", "suspicious nasal bone fracture", "old nasal bone fracture" and "no nasal bone fracture" was 85.8%, 4.6%, 0.6% and 9.1% respectively. The sensitivity and specificity of the CT reading were 95.0% and 92.9%, respectively. The positive predictive value of the CT reading was 99.3%. The reading of "nasal bone fracture" that was not a nasal bone fracture clinically was 17.1% (12 of 70), and the reading of "no nasal bone fracture" or "old nasal bone fracture" that was found to be a nasal bone fracture clinically was 3.3% (21 of 646). The discordance rate between the CT reading by the radiologist and the diagnosis by the plastic surgeon was 4.6%. Conclusions: To reduce the discordance rate, we propose to hold a meeting with the plastic surgery-radiology staff to communicate the information regarding a suspicious or old nasal bone fracture.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기설비전문위원
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• pp.2-3
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• 2005

국내 전기설비진단연구회에서 GIS 고장을 예방할 목적으로 고안한 예방진단 기술지도 초안을 바탕으로하여 결함의 종류와 진단기술의 종류, 년도별 기술 개발 목표, 기술지도 등을 제시하였다.