• Korean Journal of Radiology
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• 제1권1호
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• pp.51-55
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• 2000

Objective: To determine the accuracy of CT and positron emission tomography (PET) in the diagnosis of recurrent uterine cervical cancer. Materials and Methods: Imaging findings of CT and PET in 36 patients (mean age, 53 years) in whom recurrent uterine cervical cancer was suspected were analyzed retrospectively. Between October 1997 and May 1998, they had undergone surgery and/or radiation therapy. Tumor recurrence was confirmed by pathologic examination or follow-up studies. Results: In detecting recurrent uterine cervical cancer, the sensitivity, specificity, and accuracy of CT were 77.8%, 83.3%, and 80.5%, respectively, while for PET, the corresponding figures were 100%, 94.4%, and 97.2%. The Chi-square test revealed no significant difference in specificity (p = .2888), but significant differences in sensitivity (p = .0339) and accuracy (p = .0244). Conclusion: PET proved to be a reliable screening method for detecting recurrent uterine cervical cancer, but to determine the anatomical localization of recurrent tumors, and thus decide an adequate treatment plan, CT was eventually needed.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2327-2331
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• 2015

Purpose: To determine the accuracy of visual inspection with acetic acid (VIA) in detecting high-grade cervical intraepithelial neoplasia (CIN) in pre- and post-menopausal women with atypical squamous cells of undetermined significance (ASC-US) and low grade squamous intraepithelial lesion (LSIL) Papanicolaou (Pap) smears. Materials and Methods: Two hundred women (150 pre-menopausal and 50 post-menopausal) with ASC-US and LSIL cytology who attended the colposcopy clinic, Thammasat University Hospital, between March 2013 and August 2014 were included. All women underwent VIA testing and colposcopy by gynecologic oncologists. Diagnostic values of VIA testing including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting high-grade CIN were determined using the histopathology obtained from colposcopic-directed biopsy as a gold standard. Results: VIA testing was positive in 54/150 (36%) pre-menopausal women and 5/50 (10%) post-menopausal women. Out of 54 pre-menopausal women with positive VIA testing, 15 (27.8%) had high-grade CIN and 39 (72.2%) had either CIN 1 or insignificant pathology. Ten (10.4%), 43 (44.8%) and 43 (44.8%) out of the remaining 96 pre-menopausal women with negative VIA testing had high-grade CIN, CIN 1 and insignificant pathology, respectively. Out of 5 post-menopausal women with positive VIA testing, there were 4 (80%) women with high-grade CIN, and 1 (20%) women with insignificant pathology. Out of 45 VIA-negative post-menopausal women, 42 (93.3%) women had CIN 1 and insignificant pathology, and 3 (6.7%) had high-grade CIN. Sensitivity, specificity, PPV and NPV of the VIA testing were 59.4%, 76.2%, 32.2% and 90.8%, respectively (60%, 68.8%, 27.8% and 89.6% in pre-menopausal women and 57.1%, 97.7%, 80% and 93.3% in post-menopausal women). Conclusions: VIA testing may be used as a screening tool for detecting high-grade CIN in women with minor cervical cytological abnormalities in a low-resource setting in order to lower the rate of colposcopy referral.

• 정보과학회 논문지
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• 제43권8호
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• pp.848-856
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• 2016

해상 안전을 위한 선박의 탐색 및 식별은 매우 중요하다. 선박의 탐색은 레이더로 가능하나, 식별은 선박자동식별장치, 통신장비, 시각 등에 의해 이루어지며, 이러한 식별수단이 불능 시 레이더 운용자의 경험과 지식을 바탕으로 선박의 기동특성을 참고하여 식별하는 매우 어려운 경우가 발생한다. 본 논문에서는 지속적인 관찰임무를 수행해야 할 선박 탐색요원의 임무를 보조하기 위하여 레이더 상 선박의 기동특성을 이용, 자동식별 및 사고발생 가능성을 탐지하는 방법을 제안한다. 4가지 유형의 선박 정보, 레이더 상 접촉거리 및 침로, 속력을 이용하여 그 특징을 추출하고, SVM을 활용하여 식별 정확도를 평가하였으며, 이를 이용한 자동식별 알고리즘을 통해 사고발생 가능성이 있는 선박을 선별하는 방법을 제시하였다. 실험 결과 90% 이상의 식별 정확도를 보였으며, 실제 사고선박인 세월호의 정보를 자동식별 알고리즘에 적용하여 선별 가능함을 보였다. 이 방법은 다양한 상황에서 선박 탐색요원의 경험과 지식을 효과적으로 보완하고, 다수의 선박 중 관심필요선박을 사전 식별하여 정보를 제공함으로서 탐색요원의 노력을 경감시키고, 문제점을 보다 빨리 인지하는데 도움이 될 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7061-7064
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• 2014

Background: To assess the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of intraoperative gross examination (IGE) of uterine specimens in determining deep myometrial invasion and cervical invasion compared to final histology. Materials and Methods: The clinical, surgical and histological data of all FIGO stage I-II endometrial cancer (EC) patients who had primary surgery were reviewed. Results of the IGE for myometrial invasion and cervical invasion were compared to the final histology. The sensitivity, specificity, PPV, NPV, and accuracy of the IGE in determining deep myometrial invasion and cervical invasion were calculated. Association between clinico-pathological factors and discrepancy between IGE and final histology in the determination of myometrial invasion was also assessed. A p-value of <0.05 was considered significant. Results: From January 2007 to December 2012, 179 patients diagnosed with clinical stage I-II endometrial cancer underwent surgical staging. The sensitivity and specificity of IGE in detecting deep myometrial invasion were 42.4% and 90.0%, respectively, and the PPV and NPV were 67.6% and 76.1%. The overall accuracy of IGE was 74.3%. The sensitivity and specificity of IGE in identifying cervical invasion were 28.6% and 97.5%, respectively, while the PPV and NPV were 60.0% and 91.1%. The overall accuracy of IGE was 89.4%. Conclusions: The sensitivity of IGE for detecting deep myometrial invasion and cervical invasion in early-stage EC is too low to be used alone. Alternative methods including intraoperative frozen section analysis, preoperative three dimensional ultrasound, and preoperative magnetic resonance imaging should be strongly considered.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.783-788
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• 2001

Voids created with concrete construction or deterioration result in serious weakness from the aspects of both structural and durable function. Ultrasonic method using image processing technique was used for detecting pattern of voids in concrete in this study Experimental investigation was carried out for three types(patterns) of void in concrete. The effect of curing period of concrete and ultrasonic measurement method was also investigated. As a result it has been verified that the semi-direct measurement method is more effective than the other methods for detecting pattern of voids in concrete in ultrasonic method using image processing technique. The longer the curing period of concrete is, the better the detection accuracy of void pattern can be obtained.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.373-382
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• 1993

A non-contact sensor for detecting distance from field surface to a predetermined location of a tractor will be useful to control precise height of implements such as tillage machinery, mowers etc.. An optical and an ultrasonic sensors were designed and fabricated . The indoor and outdoor experiments were conducted to obtain the static and dynamic characteristics of the two sensors at several moisture levels of four soils and on the soil surface with a designed shape. The results revealed that the optical sensor is unsuitable for soils with high moisture content but showed better detecting accuracy on the irregularity of soil surface.

• 한국측량학회지
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• 제6권2호
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• pp.42-52
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• 1988

본 연구에서는 인공위성 데이타를 사용하여 솔잎혹파리에 의한 산림피해를 추출해 봄으로써 인공위성 데이타가 산림의 병충해감지에 유용함을 입증하는 것이 주된 목적이라고 하겠다. 또한 이러한 산림지역 피해지추출에 유용한 Band의 선정과 산림지역에서 나타나는 그림자의 영향을 감소시켜 보다 정확한 분석결과를 얻는 것도 그 목적으로 하고있다. 인공위성 데이타는 LANDSAT-5의 TM을 사용하였으며 분류정확도 향상과 그림자 영향의 감소를 위하여 화상처리기법인 Spatial Filtering과 화상간연산처리를 행하였다. 연구결과 TM 데이타는 산림의 병충해피해지역감지에 유용하였으며 식물에 대한 분류시 Band 4와 Band 5가 효과적이었다. 또한 Spatial Filtering과 화상간연산처리는 그림자영향감소에 효과적이었으며 특히 화상간연산처리는 산림과 기타 지역과의 분류정확도 향상에도 커다란 도움이 되었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.10039-10043
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• 2014

Background: In Pakistan thyroid cancer is responsible for 1.2% cases of all malignant tumors. Ultrasonography (US) is helpful in detecting cancerous thyroid nodules on basis of different features like echogenicity, margins, microcalcifications, size, shape and abnormal neck lymph nodes. We therefore aimed to calculate diagnostic accuracy of ultrasound in detection of carcinoma in thyroid nodules taking fine needle aspiration cytology as the reference standard. Materials and Methods: A cross-sectional analytical study was designed to prospectively collect data from December 2010 till December 2012 from the Department of Radiology in Aga Khan University Hospital, Karachi, Pakistan. A total of 100 patients of both genders were enrolled after informed consent via applying non-probability consecutive sampling technique. Patients referred to Radiology department of Aga Khan University to perform thyroid ultrasound followed by fine-needle aspiration cytology of thyroid nodules were included. They were excluded if proven for thyroid malignancy or if their US or FNAC was conducted outside our institution. Results: The subjects comprised 76 (76%) females and 24 males. Mean age was $41.8{\pm}SD$ 12.3 years. Sensitivity and specificity with 95%CI of ultrasound in differentiating malignant thyroid nodule from benign thyroid nodule calculated to be 91.7% (95%CI, 0.72-0.98) and 78.94% (0.68-0.87) respectively. Reported positive predictive value and negative PV were 57.9% (0.41-0.73) and 96.8% (0.88-0.99) and overall accuracy was 82%. Likelihood ratio (LR) positive was computed to be 4.3 and LR negative was 0.1. Conclusions: Ultrasonography has a high diagnostic accuracy in detecting malignancy in thyroid nodules on the basis of features like echogenicity, margins, micro calcifications and shape.

• 한국재난관리표준학회지
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• 제1권4호
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• pp.73-81
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• 2008

전자유도 탐사는 매설관로에서 발생되는 자기장을 측정하는 탐사방법으로 하나의 관로만 매설되어 있는 경우에는 20 cm 이내의 높은 정확도를 보이지만, 탐지대상 관로 인근에 다른 관로가 매설되어 있으면 자기장의 교란으로 정확도가 감소한다. 본 연구에서는 지하매설물 탐지 정확도 향상을 위하여 대칭성을 이용하여 매설관로의 수평위치를 검증하는 방법과 에너지 크기 비교법과 삼각법을 이용하여 매설심도를 검증하는 방법에 대해 고찰하였다. 다음으로 현재 판매되는 전자유도 탐사장비가 별도의 저장장치를 가지고 있지 않아 측정자료의 분석이 불가능한 문제를 개선하기 위하여, Bluetooth 무선통신장치를 이용하여 측정자료를 저장하는 방법을 개발하였다. 마지막으로 두 개의 인접관로를 하나로 오인하는 문제점을 개선하기 위하여 현장모형실험을 통해 인접관로의 거리에 따른 분해능을 고찰하였다.

• Imaging Science in Dentistry
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• 제45권3호
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• pp.141-145
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• 2015

Purpose: This study evaluated the diagnostic accuracy of the reverse contrast mode in intraoral digital radiography for the detection of proximal dentinal caries, in comparison with the original digital radiographs. Materials and Methods: Eighty extracted premolars with no clinically apparent caries were selected, and digital radiographs of them were taken separately in standard conditions. Four observers examined the original radiographs and the same radiographs in the reverse contrast mode with the goal of identifying proximal dentinal caries. Microscopic sections $5{\mu}m$ in thickness were prepared from the teeth in the mesiodistal direction. Four slides prepared from each sample used as the diagnostic gold standard. The data were analyzed using SPSS (${\alpha}=0.05$). Results: Our results showed that the original radiographs in order to identify proximal dentinal caries had the following values for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy, respectively: 72.5%, 90%, 87.2%, 76.5%, and 80.9%. For the reverse contrast mode, however, the corresponding values were 63.1%, 89.4%, 87.1%, 73.5%, and 78.8%, respectively. The sensitivity of original digital radiograph for detecting proximal dentinal caries was significantly higher than that of reverse contrast mode (p<0.05). However, no statistically significant differences were found regarding specificity, positive predictive value, negative predictive value, or accuracy (p>0.05). Conclusion: The sensitivity of the original digital radiograph for detecting proximal dentinal caries was significantly higher than that of the reversed contrast images. However, no statistically significant differences were found between these techniques regarding specificity, positive predictive value, negative predictive value, or accuracy.