• 제목/요약/키워드: False Negative Rate

검색결과 162건 처리시간 0.028초

간흡충증 진단을 위한 피내반응검사의 의의 (Diagnostic Value of the Intradermal Test for the Infection with Clonorchis sinensis)

  • 김종호;윤봉영;이헌주;이현우
    • Journal of Yeungnam Medical Science
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    • 제5권2호
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    • pp.47-52
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    • 1988
  • 1988년 8월초부터 9월말동안 영남의료원 내과를 내원한 사람중 1304명에서 대변도말검사를 실시하였으며, 이중 443명에서는 간흡충증 피내반응검사를 하였고, 간흡충증이 의심되는 79명에 대해서는 집란법을 동시에 시행하여 간흡충증을 조사한 결과 다음과 같은 결과를 얻었다. 1) 간흡충 감염율은 3.8%였다. 2) 간흡충증 피내반응검사의 감수성은 82.1%(32/39명)이었고, 특이성은 64.6%(261/404명)이었다. 3) 도말검사상 음성이었으나 피내반응검사가 양성이면서 간흡충증이 의심되거나, 양 검사 모두 음성이나 말초 호산구성 세포의 증가로 간흡충증이 의심되는 사람 79명을 집란법으로 조사한 결과 79명중 16명에서 간흡충란이 발견되었다. 4) 도말검사상 음성이었으나 집란법으로 충란이 발견된 16명중 13명은 경감염이었고 3명은 중등감염된 것으로 나타났다. 이상의 결과에서 간흡충증이 의심되는 환자에게는 반드시 대변도말검사와 함께 피내반응검사를 실시하고 필요시 집란법으로 EPG와 EPD을 조사한 후 확진하여 치료하는 것이 바람직하리라 생각된다.

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Evaluation of Selective Media Containing Iron Source and Alpha-Glucosidase Substrates for Enterobacter sakazakii (Cronobacter spp.) Detection

  • Chon, Jung-Whan;Seo, Kun-Ho;Yim, Jin-Hyeok;Bae, Dongryeoul;Kim, Binn;Kim, Tae-Jin;Jeong, Dongkwan;Song, Kwang-Young
    • Journal of Dairy Science and Biotechnology
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    • 제39권1호
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    • pp.9-19
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    • 2021
  • Enterobacter sakazakii (Cronobacter spp.) causes meningitis, necrotizing enterocolitis, sepsis, and bacteremia in neonates and children and has a high mortality rate. For rapid E. sakazakii detection, various differential and selective media containing α-glucosidase substrates, such as 5-bromo-4-chloro-3-indolyl-α-D-glucopyranoside (BCIG) or 4-methylumbelliferyl-α-D-glucoside (α-MUG), have been developed as only E. sakazakii exhibits α-glucosidase activity in the genus Enterobacter. However, Escherichia vulneris (family: Enterobacteriaceae) can also utilize α-glucosidase substrates, thereby resulting in false positives. Various iron sources are known to promote the growth of gram-negative bacteria. This study aimed to develop a selective medium containing α-glucosidase substrates for E. sakazakii detection that would eliminate false positives, such as those of E. vulneris, and to determine the role of iron source in the medium. Three previously developed (TPD) media, i.e., Oxoid, OK, and VRBG, and the medium developed in this study, i.e., NGTE, were evaluated using 58 E. sakazakii and 5 non-E. sakazakii strains. Fifty-four E. sakazakii strains appeared as fluorescent or chromogenic colonies on all four media that were assessed. Two strains showed colonies on NGTE medium and not on TPD media. In contrast, the remaining two strains showed colonies on TPD media and not on NGTE medium. None of the non-E. sakazakii strains showed fluorescent or chromogenic colonies on any of the evaluated media except E. vulneris, which showed colonies on TPD media and not on NGTE medium. This study demonstrated that the newly developed NGTE medium was not only equally efficient in promoting the growth of bacterial colonies when compared with the currently available media but also eliminated false positives, such as E. vulneris.

전기전도도(電氣傳導度) 측정(測定)에 의한 유우(乳牛) 준임상형(準臨床型) 유방염(乳房炎)의 진단(診斷)에 관한 연구(硏究) 1. 전기전도도법(電氣傳導度法)과 간접검진법(間接檢診法)(CMT 및 총체세포수(總體細胞數))과의 비교(比較) (Studies on the Diagnosis of Subclinical Mastitis in Cows by the Measurement of the Electrical Conductivity: 1. Comparison of Various Methods of Handling Conductivity Data with the Use of California Mastitis Test and Direct Somatic Cell Count)

  • 강병규
    • 대한수의학회지
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    • 제24권1호
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    • pp.91-98
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    • 1984
  • A total of 466 foremilk from dairy farms in Chonnam district was examined for the subclinical mastitis over a period of one year, using a method of the electrical conductivities(EC); absolute conductivity(AC) and differential conductivity(DC) and quarter difference value(QD), in relation to the California mastitis test(CMT) and the direct somatic cell count(DSCC). The compatibility and efficiency rating between the EC values and the other screening tests was conducted. Obtained results are summarized as follows. 1. A linear relationship was found between the EC values and the CMT scores and direct somatic cell counts and it was found that electrical conductivity measurements were comparable with other screening tests for diagnosing animals with mastitis. 2. Compatibilities between the EC and CMT were 70.4% in AC, 74.6% in DC and 70.7% in QD, and that of the EC and DSCC were 53.0% in AC, 63.1% in DC and 53.2% in QD. On the other hand, relative efficiency ratings of Postle's equation between EC and CMT were 37.3% in AC, 26.5% in DC and 13.6% in QD, and that of the EC and DSCC were 33.1% in AC, 20.2% in DC and 11.9% in QD. 3. In the foremilk samples collected from damaged quarters determined by EC, the false positive rate wart higher than the false negative rate, and consequently tests of EC produced lower compatibility or efficiency rating scores. These tendencies suggested that any factors other than the mastitic condition influencing the EC values might be existed.

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신생아의 출생 체중에 따른 혈액 여과지 17alpha-hydroxyprogesterone의 농도 분석 및 판정 기준 조정 (Analysis and Cut-off Adjustment of Dried Blood Spot 17alpha-hydroxyprogesterone Concentration by Birth Weight)

  • 박승만;권애린;양송현;박은아;최재황;황미정;남현경;이은희
    • 대한유전성대사질환학회지
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    • 제14권2호
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    • pp.150-155
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    • 2014
  • The measurement of $17{\alpha}$-hydroxyprogesterone ($17{\alpha}$-OHP) in a dried blood spot on filter paper is an important for screening of congenital adrenal hyperplasia (CAH). Since high levels of $17{\alpha}$-OHP are frequently observed in premature infants without congenital adrenal hyperplasia, we evaluated cuts-off based on birth weight and performed validation. Birth weight and $17{\alpha}$-OHP concentration data of 292,204 newborn screening subjects in Greencross labopratories were analyzed. The cut-off values based on birth weight were newly evaluated and validated with the original data. The mean $17{\alpha}$-OHP concentration were 7.25 ng/mL in very low birth weight (VLBW) group, 4.02 ng/mL in low birth weight (LBW) group, 2.53 g/mL in normal birth weight (NBW) group, and 2.24 ng/mL in heavy birth weight (HBW) group. The cut-offs for CAH were decided as follows: 21.12 ng/mL for VLBW and LBW groups and 11.14 ng/mL for NBW and HBW groups. When applied new cut-offs for original data, positive rates in VLBW and LBW groups were decreased and positive rates in NBW and HBW groups were increased. The cut-offs based on birth weight should be used in the screening for CAH. We believe that our new cut-off reduce the false positive rate and false negative rate and our experience for cut-off set up and validation will be helpful for other laboratories doing newborn screening test.

외과적으로 처치한 갑상선 결절 (A Clinical Study of Surgically Managed Thyroid Nodule)

  • 홍관의;이명복;문철;김익수
    • 대한두경부종양학회지
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    • 제10권2호
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    • pp.91-101
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    • 1994
  • Nodular thyroid disease is a common clinical problem. The problem in clinical practice is to distinguish malignant or potentially malignant tumor from harmless nodules. The cases of thyroid nodule surgically managed at Department of General Surgery, Soon Chun Hyang Univ. Hospital during the period Jan. 1985 to July. 1992 were reviewed retrospectively. To assess method of distinguishing malignant from benign lesions of the thyroid gland, we reviewed 162 patients with thyroid nodule. There were 61(37.7%) malignant nodules and 101(62.3%) benign nodules. According to the review, distinguishing the benign from the malignant nodule with history, physical examination, clinical manifestation, and duration of illness was not suggested sufficiently. In ultrasonogram of 73 cases, 57.5% of nodules were solid, 20.6% were cystic, 21.9% were mixed solid and cystic. Of these, 28.5% of the operated solid lesions, 12.5% of the mixed lesions, and only 6.7% of the cystic lesions were malignant. Thyroid scanning of 82 cases revealed cold nodules in 60 patients(73.2%), of which 26 cases were malignant(36.6%) 137 patients underwent fine needle aspiration cytology(FNAC), and these results were as follow: sensitiviey was 70.6%, specificity was 93.0%, false-positive rate was 14.3%, and false-negative rate was 15.8%. 41 patients underwent frozen biopsy, and the results as follow: sensitivity was 80.0%, specificity was 89.7%. Neither scintigraphy nor ultrasonogram has sufficient specificity to distinguish benign from malignant nodule. But FNAC and frozen biopsy have sufficient accuracy to differentiate benign from malignant nodule. In the benign nodules, the most common type of operation was total lobectomy (60.4%). Of the malignant nodules, total thyroidectomy with or without modified radical neck dissection was performed in 30 cases(49.2%). We conclude that the single technique used to determine the differential diagnosis of a thyroid nodule are unrealiable. It is therefore essential to combine all avaiable clinical and laboratory information.

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Treefrog lateral line as a mean of individual identification through visual and software assisted methodologies

  • Kim, Mi Yeon;Borzee, Amael;Kim, Jun Young;Jang, Yikweon
    • Journal of Ecology and Environment
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    • 제41권12호
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    • pp.345-350
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    • 2017
  • Background: Ecological research often requires monitoring of a specific individual over an extended period of time. To enable non-invasive re-identification, consistent external marking is required. Treefrogs possess lateral lines for crypticity. While these patterns decrease predator detection, they also are individual specific patterns. In this study, we tested the use of lateral lines in captive and wild populations of Dryophytes japonicus as natural markers for individual identification. For the purpose of the study, the results of visual and software assisted identifications were compared. Results: In normalized laboratory conditions, a visual individual identification method resulted in a 0.00 rate of false-negative identification (RFNI) and a 0.0068 rate of false-positive identification (RFPI), whereas Wild-ID resulted in RFNI = 0.25 and RFNI = 0.00. In the wild, female and male data sets were tested. For both data sets, visual identification resulted in RFNI and RFPI of 0.00, whereas the RFNI was 1.0 and RFPI was 0.00 with Wild-ID. Wild-ID did not perform as well as visual identification methods and had low scores for matching photographs. The matching scores were significantly correlated with the continuity of the type of camera used in the field. Conclusions: We provide clear methodological guidelines for photographic identification of D. japonicus using their lateral lines. We also recommend the use of Wild-ID as a supplemental tool rather the principal identification method when analyzing large datasets.

접근 기록 분석 기반 적응형 이상 이동 탐지 방법론 (Adaptive Anomaly Movement Detection Approach Based On Access Log Analysis)

  • 김남의;신동천
    • 융합보안논문지
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    • 제18권5_1호
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    • pp.45-51
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    • 2018
  • 데이터의 활용도와 중요성이 점차 높아짐에 따라 데이터와 관련된 사고와 피해는 점점 증가 하고 있으며, 특히 내부자에 의한 사고는 그 위험성이 더 높다. 이런 내부자의 공격은 전통적인 보안 시스템으로 방어하기 힘들어, 규칙 기반의 이상 행동 탐지 방법이 널리 활용되어오고 있다. 하지만, 새로운 공격 방식 및 새로운 환경과 같이 변화에 유연하게 적응하지 못하는 문제점을 가지고 있다. 본 논문에서는 이에 대한 해결책으로서 통계적 마르코프 모델 기반의 적응형 이상 이동 탐지 프레임워크를 제안하고자 한다. 이 프레임워크는 사람의 이동에 초점을 맞추어 내부자에 의한 위험을 사전에 탐지한다. 이동에 직접적으로 영향을 주는 환경 요소와 지속적인 통계 학습을 통해 변화하는 환경에 적응함으로써 오탐지와 미탐지를 최소화하도록 설계되었다. 프레임워크를 활용한 실험에서는 0.92의 높은 F2-점수를 얻을 수 있었으며, 나아가 정상으로 보여지지만, 의심해볼 이동까지 발견할 수 있었다. 통계 학습과 환경 요소를 바탕으로 행동과 관련된 데이터와 모델링 알고리즘을 다양화 시켜 적용한다면 보다 더 범위 넓은 비정상 행위에 대해 탐지할 수 있는 확장성을 제공한다.

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GCNXSS: An Attack Detection Approach for Cross-Site Scripting Based on Graph Convolutional Networks

  • Pan, Hongyu;Fang, Yong;Huang, Cheng;Guo, Wenbo;Wan, Xuelin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권12호
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    • pp.4008-4023
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    • 2022
  • Since machine learning was introduced into cross-site scripting (XSS) attack detection, many researchers have conducted related studies and achieved significant results, such as saving time and labor costs by not maintaining a rule database, which is required by traditional XSS attack detection methods. However, this topic came across some problems, such as poor generalization ability, significant false negative rate (FNR) and false positive rate (FPR). Moreover, the automatic clustering property of graph convolutional networks (GCN) has attracted the attention of researchers. In the field of natural language process (NLP), the results of graph embedding based on GCN are automatically clustered in space without any training, which means that text data can be classified just by the embedding process based on GCN. Previously, other methods required training with the help of labeled data after embedding to complete data classification. With the help of the GCN auto-clustering feature and labeled data, this research proposes an approach to detect XSS attacks (called GCNXSS) to mine the dependencies between the units that constitute an XSS payload. First, GCNXSS transforms a URL into a word homogeneous graph based on word co-occurrence relationships. Then, GCNXSS inputs the graph into the GCN model for graph embedding and gets the classification results. Experimental results show that GCNXSS achieved successful results with accuracy, precision, recall, F1-score, FNR, FPR, and predicted time scores of 99.97%, 99.75%, 99.97%, 99.86%, 0.03%, 0.03%, and 0.0461ms. Compared with existing methods, GCNXSS has a lower FNR and FPR with stronger generalization ability.

구내방사선 사진상의 인접면 치아우식진단능 평가 (Diagnostic Performance of the Intraoral Radiographs on the Interproximal Dental Caries)

  • 김수지;강병철
    • 치과방사선
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    • 제28권1호
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    • pp.37-46
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    • 1998
  • The purpose of this study was to evaluate the diagnostic performance of the senior dental students for the proximal dental caries on intraoral radiographs and to compare it with the dental hospital residents, the reference group. It was also investigated the diagnostic performance according to the carious lesion depth. Thirty-five intraoral periapical and bitewing radiographs with 213 proximal surfaces included in this study were selected from the dental patients at Chonnam National University Hospital. The observers were 181 senior dental students from 5 dental schools and 40 dentists who were second year resident from 5 dental hospitals. They were asked to evaluate the presence or the absence of the proximal dental caries. The results were as follows: 1. The mean of the hitting rate for the overall observers was 184.51 surfaces and the diagnostic accuracy was 86.62%. 2. The diagnostic performance of the sound proximal tooth surfaces was very high, i.e., 91.5% true negative rate and 8.5% false positive rate. 3. The diagnostic performance of the dentist group was higher than the student group(P<0.05). 4. The proximal dental caries perceptibility increased as the lesion depth increased significantly(P<0.001) except no difference between the carious lesion depth III and IV (P>0.001).

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Imbalanced SVM-Based Anomaly Detection Algorithm for Imbalanced Training Datasets

  • Wang, GuiPing;Yang, JianXi;Li, Ren
    • ETRI Journal
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    • 제39권5호
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    • pp.621-631
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    • 2017
  • Abnormal samples are usually difficult to obtain in production systems, resulting in imbalanced training sample sets. Namely, the number of positive samples is far less than the number of negative samples. Traditional Support Vector Machine (SVM)-based anomaly detection algorithms perform poorly for highly imbalanced datasets: the learned classification hyperplane skews toward the positive samples, resulting in a high false-negative rate. This article proposes a new imbalanced SVM (termed ImSVM)-based anomaly detection algorithm, which assigns a different weight for each positive support vector in the decision function. ImSVM adjusts the learned classification hyperplane to make the decision function achieve a maximum GMean measure value on the dataset. The above problem is converted into an unconstrained optimization problem to search the optimal weight vector. Experiments are carried out on both Cloud datasets and Knowledge Discovery and Data Mining datasets to evaluate ImSVM. Highly imbalanced training sample sets are constructed. The experimental results show that ImSVM outperforms over-sampling techniques and several existing imbalanced SVM-based techniques.