• 제목/요약/키워드: false negative

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Modification-robust contents based motion picture searching method (변형에 강인한 내용기반 동영상 검색방법)

  • Choi, Gab-Keun;Kim, Soon-Hyob
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.215-217
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    • 2008
  • The most widely used method for searching contents of mot ion picture compares contents by extracted cuts. The cut extract ion methods, such as CHD(Color Histogram Difference) or ECR(Edge Change Ratio), are very weak at modifications such as cropping, resizing and low bit rate. The suggested method uses audio contents for indexing and searching to make search be robust against these modification. Scenes of audio contents are extracted for modification-robust search. And based on these scenes, make spectral powers binary on each frequency bin. in the time-frequency domain. The suggested method shows failure rate less than 1% on the false positive error and the true negative error to the modified(using cropping, clipping, row bit rate, addtive frame) contents.

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Usefulness of Brushing Cytology in the Diagnosis of the Patients with the Stricture of Biliary Tree (담도계 협착 환자의 진단에 솔질 세포검사의 유용성)

  • Park, Mi-Ok
    • The Korean Journal of Cytopathology
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    • v.11 no.1
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    • pp.11-18
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    • 2000
  • Pancreaticobiliary tract strictures are frequent Indications for endoscopic retrograde cholangiopancreatography(ERCP). We have investigated the brushing cytology in order to determine its efficacy for diagnosis of pancreaticobiliary malisnancies. Brushing cytology during ERCP was evaluated in 56 patients with biliary tract stricture presenting to the Catholic Hospital of Taegu-Hyosung from April 1997 to August 1999. A comparison was made between the cytologic and histologic diagnoses on 32 cases from 30 patients. A diagnosis of malignancy was establishied in 78.1%, benign in 15.6%, and inadequate in 6.3% of the cases. Statistical data on cytologic diagnoses in strictures of the bile duct were as follows; specificity and sensitivity of blushing procedure was 100% & 83.3%, respectively: sensitivity of interpretation was 89.3%: with no false positive cases and 3 false negative cases: predictive value for malignancy was 100% & 100%, respectively: predictive value for benign was 28.6% & 40%,, respectively: overall diagnostic efficiency was 84.4%. It is concluded that brush cytology is a diagnostically reliable, highly specific technique for malignant lesions encounted at ERCP, although a negative result does not rule out the diagnosis of malignancy.

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Detection of Extravasated Contrast Media Using an Infrared Ray Based Extravasation Detection Accessory System (적외선 기반의 혈관외유출 검출시스템을 이용한 조영제의 혈관외유출 검출)

  • Kweon, Dae-Cheol;Jang, Keun-Jo
    • Journal of Biomedical Engineering Research
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    • v.30 no.5
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    • pp.412-417
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    • 2009
  • The purpose of this study was to assess the ability of this device during clinically important episodes of extravasation. The extravasation detection accessory (EDA) system was based of infrared ray with detection sensor, an amplifier, alarm device, receiver, cable and a computer based system. This study was a prospective, observational study in which the EDA system was used to monitor the automated mechanical injection of contrast media. Three hundred patients referred for contrast media enhanced body computed tomography studied in a prospective, observation study in which the EDA system was used to identify and interrupt any injection associated with clinically important extravasation. There were 8 true-positive cases, 276 true-negative cases, 15 false-positive cases and 1 false-negative cases. The EDA system had a sensitivity of 88.8% and a specificity of 94.8% for the detection of clinically important extravasation. The EDA system had good sensitivity for the detection of clinically important extravasation and the EDA system has the clinical potential for the early detection of extravasation of the contrast medium that is administered with power injectors.

A Study on Utterance Verification Using Accumulation of Negative Log-likelihood Ratio (음의 유사도 비율 누적 방법을 이용한 발화검증 연구)

  • 한명희;이호준;김순협
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.3
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    • pp.194-201
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    • 2003
  • In speech recognition, confidence measuring is to decide whether it can be accepted as the recognized results or not. The confidence is measured by integrating frames into phone and word level. In case of word recognition, the confidence measuring verifies the results of recognition and Out-Of-Vocabulary (OOV). Therefore, the post-processing could improve the performance of recognizer without accepting it as a recognition error. In this paper, we measure the confidence modifying log likelihood ratio (LLR) which was the previous confidence measuring. It accumulates only those which the log likelihood ratio is negative when integrating the confidence to phone level from frame level. When comparing the verification performance for the results of word recognizer with the previous method, the FAR (False Acceptance Ratio) is decreased about 3.49% for the OOV and 15.25% for the recognition error when CAR (Correct Acceptance Ratio) is about 90%.

Activated Viewport based Surveillance Event Detection in 360-degree Video (360도 영상 공간에서 활성 뷰포트 기반 이벤트 검출)

  • Shim, Yoo-jeong;Lee, Myeong-jin
    • Journal of Broadcast Engineering
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    • v.25 no.5
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    • pp.770-775
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    • 2020
  • Since 360-degree ERP frame structure has location-dependent distortion, existing video surveillance algorithms cannot be applied to 360-degree video. In this paper, an activated viewport based event detection method is proposed for 360-degree video. After extracting activated viewports enclosing object candidates, objects are finally detected in the viewports. These objects are tracked in 360-degree video space for region-based event detection. The proposed method is shown to improve the recall and the false negative rate more than 30% compared to the conventional method without activated viewports.

Public Satisfaction Analysis of Weather Forecast Service by Using Twitter (Twitter를 활용한 기상예보서비스에 대한 사용자들의 만족도 분석)

  • Lee, Ki-Kwang
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.2
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    • pp.9-15
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    • 2018
  • This study is intended to investigate that it is possible to analyze the public awareness and satisfaction of the weather forecast service provided by the Korea Meteorological Administration (KMA) through social media data as a way to overcome limitations of the questionnaire-based survey in the previous research. Sentiment analysis and association rule mining were used for Twitter data containing opinions about the weather forecast service. As a result of sentiment analysis, the frequency of negative opinions was very high, about 75%, relative to positive opinions because of the nature of public services. The detailed analysis shows that a large portion of users are dissatisfied with precipitation forecast and that it is needed to analyze the two kinds of error types of the precipitation forecast, namely, 'False alarm' and 'Miss' in more detail. Therefore, association rule mining was performed on negative tweets for each of these error types. As a result, it was found that a considerable number of complaints occurred when preventive actions were useless because the forecast predicting rain had a 'False alarm' error. In addition, this study found that people's dissatisfaction increased when they experienced inconveniences due to either unpredictable high winds and heavy rains in summer or severe cold in winter, which were missed by weather forecast. This study suggests that the analysis of social media data can provide detailed information about forecast users' opinion in almost real time, which is impossible through survey or interview.

Significancy of Fine Needle Aspiration Cytology on Thyroid Nodule (갑상선결절에서의 세침흡인세포검사의 진단적 의미)

  • 김기환;심윤상;오경균;이용식;장자준
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1993.05a
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    • pp.104-104
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    • 1993
  • Fine needle aspiration cytology(FNAC) is a valuable method in preoperative diagnosis of thyroid nodule. Authors evaluated one hundred and ten thyroid nodules by FNAC compared with the postoperative histopathologic diagnosis during the period from Jan. 1, 1989 through Dec. 31, 1992. The results were as followed. The sensitivity was 86.5%, specificity 90.4%, false-negative rate 13.5%, false-positive rate 9.6%, positive predictability 91.5%, negative predictability 60.1% and overall diagnostic accuracy 87.3 %.

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Interpretation of Image-Guided Biopsy Results and Assessment (영상유도하 조직검사의 해석과 판정)

  • Su Min Ha;Jung Min Chang
    • Journal of the Korean Society of Radiology
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    • v.84 no.2
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    • pp.361-371
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    • 2023
  • The success of image-guided breast biopsy depends on the biopsy method, needle selection, and appropriate technique based on the accurate judgment by the radiologist at biopsy. However, insufficient or inappropriate sampling of specimens may result in false-negative results or pathologic underestimation. Therefore, image-pathology concordance assessments after biopsy are essential for appropriate patient management. Particularly, the assessment of image-pathology concordance can avoid false-negative reports of breast cancer as a benign pathology. Therefore, this study aimed to discuss factors that impact the accurate interpretation of image-guided breast biopsy along with the appropriate assessments.

URL Normalization for Web Applications (웹 어플리케이션을 위한 URL 정규화)

  • Hong, Seok-Hoo;Kim, Sung-Jin;Lee, Sang-Ho
    • Journal of KIISE:Information Networking
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    • v.32 no.6
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    • pp.716-722
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    • 2005
  • In the m, syntactically different URLs could represent the same resource. The URL normalization is a process that transform a URL, syntactically different and represent the same resource, into canonical form. There are on-going efforts to define standard URL normalization. The standard URL normalization designed to minimize false negative while strictly avoiding false positive. This paper considers the four URL normalization issues beyond ones specified in the standard URL normalization. The idea behind our work is that in the URL normalization we want to minimize false negatives further while allowing false positives in a limited level. Two metrics are defined to analyze the effect of each step in the URL normalization. Over 170 million URLs that were collected in the real web pages, we did an experiment, and interesting statistical results are reported in this paper.

Genetic Algorithm based B-spline Fitting for Contour Extraction from a Sequence of Images (연속 영상에서의 경계추출을 위한 유전자 알고리즘 기반의 B-spline 적합)

  • Heo Hoon;Lee JeongHeon;Chae OkSam
    • Journal of KIISE:Software and Applications
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    • v.32 no.5
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    • pp.357-365
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    • 2005
  • We present a B-spline fitting method based on genetic algorithm for the extraction of object contours from the complex image sequence, where objects with similar shape and intensity are adjacent each other. The proposed algorithm solves common malfitting problem of the existing B-spline fitting methods including snakes. Classical snake algorithms have not been successful in such an image sequence due to the difficulty in initialization and existence of multiple extrema. We propose a B-spline fitting method using a genetic algorithm with a new initial population generation and fitting function, that are designed to take advantage of the contour of the previous slice. The test results show that the proposed method extracts contour of individual object successfully from the complex image sequence. We validate the algorithm by false-positive/negative errors and relative amounts of agreements.