• Title/Summary/Keyword: False Positive

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Clinical Value of Dividing False Positive Urine Cytology Findings into Three Categories: Atypical, Indeterminate, and Suspicious of Malignancy

  • Matsumoto, Kazumasa;Ikeda, Masaomi;Hirayama, Takahiro;Nishi, Morihiro;Fujita, Tetsuo;Hattori, Manabu;Sato, Yuichi;Ohbu, Makoto;Iwam, Masatsugu
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2251-2255
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    • 2014
  • Background: The aim of this study was to evaluate 10 years of false positive urine cytology records, along with follow-up histologic and cytologic data, to determine the significance of suspicious urine cytology findings. Materials and Methods: We retrospectively reviewed records of urine samples harvested between January 2002 and December 2012 from voided and catheterized urine from the bladder. Among the 21,283 urine samples obtained during this period, we located 1,090 eligible false positive findings for patients being evaluated for the purpose of confirming urothelial carcinoma (UC). These findings were divided into three categories: atypical, indeterminate, and suspicious of malignancy. Results: Of the 1,090 samples classified as false positive, 444 (40.7%) were categorized as atypical, 367 (33.7%) as indeterminate, and 279 (25.6%) as suspicious of malignancy. Patients with concomitant UC accounted for 105 (23.6%) of the atypical samples, 147 (40.1%) of the indeterminate samples, and 139 (49.8%) of the suspicious of malignancy samples (p<0.0001). The rate of subsequent diagnosis of UC during a 1-year follow-up period after harvesting of a sample with false positive urine cytology initially diagnosed as benign was significantly higher in the suspicious of malignancy category than in the other categories (p<0.001). The total numbers of UCs were 150 (33.8%) for atypical samples, 213 (58.0%) for indeterminate samples, and 199 (71.3%) for samples categorized as suspicious of malignancy. Conclusions: Urine cytology remains the most specific adjunctive method for the surveillance of UC. We demonstrated the clinical value of dividing false positive urine cytology findings into three categories, and our results may help clinicians better manage patients with suspicious findings.

Clearance of False-positive Antigen-Antibody Reactions of a Diagnostic Antigen Production in Escherichia coli with Human Sera

  • Noh, Kap-Soo;Kim, Jong-Wan;Ha, Suk-Hoon;Yoo, Wang-Don;Jeon, Weong-Joong;Kim, Hyun-Su
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.4 no.1
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    • pp.63-65
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    • 1999
  • Although many pharmaceutically useful proteins are produced in E. coli expression system, it is very are rare for the system to be used in the production of diagnostic antigen due to a major problem, i.e., false-positive reaction of e. coli host-derived proteins contaminating purified diagnostic antigen with human sera. The N (nucleocapsid) protein of Seoul virus causing haemorrhagic fever with renal syndrome (HFRS) was produced in E. coli BL21 (DE3), and used for the detection of N protein-specific antibodies in human sera. Using the N protein as a diagnostic antigen of HFRS, the false-positive reaction was cleared by merely mixing the test sera with the extract of E. coli host strain not harboring expression plasmid.

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A Blind Watermarking Scheme Using Singular Vector Based On DWT/RDWT/SVD (DWT/RDWT/SVD에 기반한 특이벡터를 사용한 블라인드 워터마킹 방안)

  • Luong, Ngoc Thuy Dung;Sohn, Won
    • Journal of Broadcast Engineering
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    • v.21 no.2
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    • pp.149-156
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    • 2016
  • We proposed a blind watermarking scheme using singular vectors based on Discrete Wavelet Transform (DWT) and Redundant Discrete Wavelet Transform (RDWT) combined with Singular Value Decomposition (SVD) for copyright protection application. We replaced the 1st left and right singular vectors decomposed from cover image with the corresponding ones from watermark image to overcome the false-positive problem in current watermark systems using SVD. The proposed scheme realized the watermarking system without a false positive problem, and shows high fidelity and robustness.

An Improved Bayesian Spam Mail Filter based on Ch-square Statistics (카이제곱 통계량을 이용한 개선된 베이지안 스팸메일 필터)

  • Kim Jin-Sang;Choe Sang-Yeol
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2005.04a
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    • pp.403-414
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    • 2005
  • Most of the currently used spam-filters are based on a Bayesian classification technique, where some serious problems occur such as a limited precision/recall rate and the false positive error. This paper addresses a solution to the problems using a modified Bayesian classifier based on chi-square statistics. The resulting spam-filter is more accurate and flexible than traditional Bayesian spam-filters and can be a personalized one providing some parameters when the filter is teamed from training data.

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Test Bed Design of Fire Detection System Based on Multi-Sensor Information for Reduction of False Alarms (화재감지 오보 감소를 위한 다중정보기반 시스템의 Test Bed 설계)

  • Lee, Kijun;Kim, Hyeong Gweon;Lee, Bong Woo;Kim, Tae-Ok;Shin, Dongil
    • Journal of the Korean Institute of Gas
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    • v.16 no.6
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    • pp.107-114
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    • 2012
  • Fire detection system is used for detection and alarm-generation of danger in case of fire. Most fire detection systems being used these days often malfunction from false positive and false negative errors. To improve detection reliability, an integrated fire detection algorithm using multi-senor information of heat, smoke and carbon monoxide detectors is suggested, then built and tested using the LabVIEW environment. Simulated using sensor measurement data offered by National Institute of Standards and Technology (NIST), possibility of reducing false positive and false negative errors is verified.

Change of Proximal Descending Aortic False Lumen after Conventional Repair of Acute Type I Dissection: Is It Always Unfavorable?

  • Kim, Sue Hyun;Kim, Jun Sung;Shin, Yoon Cheol;Kim, Dong Jung;Lim, Cheong;Park, Kay-Hyun
    • Journal of Chest Surgery
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    • v.48 no.4
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    • pp.238-245
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    • 2015
  • Background: Some patients show favorable changes in the descending aortic false lumen after conventional repair of acute type A dissection, although the incidence of favorable changes has been reported to be low. We aimed to investigate the incidence of positive postoperative changes in the false lumen and the factors associated with positive outcomes. Methods: In 63 patients who underwent surgery for type A acute dissection as well as serial computed tomography (CT) scanning, morphological parameters were compared between the preoperative, early postoperative (mean interval, 5.4 days), and late CT scans (mean interval, 31.0 months) at three levels of the descending thoracic aorta. Results: In the early postoperative CT images, complete false lumen thrombosis and/or true lumen expansion at the proximal descending aorta was observed in 46% of the patients. In the late images, complete thrombosis or resolution of the proximal descending false lumen occurred in 42.9% of the patients. Multivariate analysis found that juxta-anastomotic false lumen thrombosis was predictive of favorable early changes, which were in turn predictive of continuing later improvement. Conclusion: Even after conventional repair without inserting a frozen elephant trunk, the proximal descending aortic false lumen showed positive remodeling in a substantial number of patients. We believe that the long-term prognosis of type A dissection can be improved by refining surgical technique, and particularly by avoiding large intimal tears at the anastomosis site during the initial repair.

Fine Needle Aspiration Biopsy Cytology of Breast Tumors (세침 천자 검사로 진단된 유방종양의 세포병리학적 연구)

  • Kim, In-Sook;Lee, Jung-Dal
    • The Korean Journal of Cytopathology
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    • v.1 no.1
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    • pp.51-59
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    • 1990
  • Fine needle aspiration biopsy cytology (FNA) for diagnosis of a variety of breast tumors has been proven to be a simple, safe, and cost saving diagnostic methodology with high accuracy. Cytologic specimens from 1,029 fine needle aspirations of the breast during last 3-year period were reviewed and subsequent biopsies from 107 breast lesions were reevaluated for cytohistological correlation. FNA had a sensitivity of 81.6% and a specificity of 98.3%. One oui of 107 cases biopsied revealed a false positive result (0.9%) and the case was due to misinterpretation of apocrine metaplastic cells in necrotic backgound as malignant cells. A false negative rate was 8.4% (9 of 107 cases biopsied). Six of 9 false negative cases were resulted from insufficient aspirates for diagnosis, and remaining three of 9 false negative cases revealed extensive necrosis with no or scanty viable cells on smears. The results indicate that for reducing false positive and false negative rates of FNA, an experienced cytopathologist and a proficient aspirator are of great importance.

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A Method for Synthesizing Features for the Accuracy of Predicting Cancer (암 예측의 정확성을 위한 특성 합성 방법)

  • Shin, SeungYeon;Kim, Hyunjin;Park, Sanghyun
    • Annual Conference of KIPS
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    • 2016.10a
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    • pp.525-526
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    • 2016
  • machine learning 기법 중 하나인 logistic regression을 이용하여 benign sample과 breast cancer sample을 구분할 수 있는데, 이 연구를 통해 classification의 정확도를 높이고 false positive와 false negative의 비율을 줄이려고 했다. 그래서 logistic regression의 parameter 값을 바탕으로 regression function에 영향을 많이 주는 feature 들을 선택하고, 영향력 있는 feature 들을 더한 새로운 feature를 추가했다. 그 결과 정확도와 F-score가 증가했으며, false positive, false negative의 비율이 감소했다.

A Study on Combined IDS Model For Performance Improving (성능 향상을 위한 통합 침입 탐지시스템에 대한 연구)

  • Hong, Seong-Kil;Won, Il-Yong;Song, Doo-Heon;Lee, Chang-Hun
    • Annual Conference of KIPS
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    • 2003.11c
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    • pp.1843-1846
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    • 2003
  • 네트워크 기반의 공격 및 비정상 행위를 정확히 탐지하고 판단하기 위한 기존의 탐지 모델은 공격 룰셋의 패턴매칭 기반인 Misuse Detection System을 사용하고 있다. 그러나 이 시스템의 특성상 새로운 공격의 미탐지 및 공격 오인등으로 False Positive 가 높다는 단점이 있다. 본 논문은 전체 시스템의 성능을 판정하는 False Positve 에러율을 줄여 성능을 향상하기 위해 Meachine Learning기반의 Anomaly Detection System 을 결합한 새로운 탐지 모델을 제안하고자 한다. Anomaly Detection System 은 정상행위에 대한 비교적 높은 탐지율과 새로운 공격에 대한 탐지가 용이하다. 본 논문에서는 각 시스템의 탐지모델로 Snort 와 인스턴스 기반의 알고리즘인 IBL 을 사용했으며, 결합모델의 타당성을 검증하기 위해서 각 탐지 모델의 False Positive와 False Negative 에러율을 측정하였다.

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Understanding the genetics of systemic lupus erythematosus using Bayesian statistics and gene network analysis

  • Nam, Seoung Wan;Lee, Kwang Seob;Yang, Jae Won;Ko, Younhee;Eisenhut, Michael;Lee, Keum Hwa;Shin, Jae Il;Kronbichler, Andreas
    • Clinical and Experimental Pediatrics
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    • v.64 no.5
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    • pp.208-222
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    • 2021
  • The publication of genetic epidemiology meta-analyses has increased rapidly, but it has been suggested that many of the statistically significant results are false positive. In addition, most such meta-analyses have been redundant, duplicate, and erroneous, leading to research waste. In addition, since most claimed candidate gene associations were false-positives, correctly interpreting the published results is important. In this review, we emphasize the importance of interpreting the results of genetic epidemiology meta-analyses using Bayesian statistics and gene network analysis, which could be applied in other diseases.