• Title/Summary/Keyword: false negative

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Studies on the Improvement of Precision in Early Pregnancy Diagnosis by Milk Progesterone Test(EIA) in Dairy Cows (Milk Progesterone Test(EIA)에 의한 소의 임신조기판단 정확도 향상에 관한 연구)

  • 김정우
    • Korean Journal of Animal Reproduction
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    • v.13 no.3
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    • pp.149-156
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    • 1989
  • These experiment was carried out to improve the precision of early pregnancy diagnosis in dairy cattle. Changes in progesterone concentration of milk were measured by Enzyme Immunoassay(EIA) in 73 cows up to 21 days after insemination. The average concentraton of progesterone in milk was 1.9ng/ml at eatrus ; it increased to 17.8ng/ml on day 14, and thereafter it declined to 4.3ng/ml on day 21 in nonpregnant cows. Whereas in pregnant animals, it was maintained and elevated further to 22.2ng/ml on day 21. The accuracy of the pregnancy diagnosis for animals classified as positive (pregnant ; over 10ng/ml and decreasing rate<1.5) and negative (non-pregnant ; under 7ng/ml and decreasing rate>1.5) were 95% and 100% respectively. The samples ranging between 7ng/ml and 10ng/ml were classified as positive (decreasing rate<1.5) and negative(>1.5), which accuracy was 54.5% and 100% respectively. However this range appears to be of the most interest for the veterinary practitioner since cows in proestrus or early interestrus tend to have milk progesterone levels within this value. Causes for the insufficient precision of false pregnancy diagnosis are discussed.

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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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    • v.39 no.5
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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.

Direction of Global Citizenship Education in the Age of Infodemic : A Case Study of the COVID-19 Pandemic in Korea

  • Jisu Park
    • International journal of advanced smart convergence
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    • v.12 no.1
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    • pp.82-91
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    • 2023
  • In 2020 when the COVID-19 pandemic began in full-scale, the WHO Director-General warned of the dangers of an infodemic. The infodemic is a phenomenon in which false information spreads rapidly like an epidemic and causes chaos, and it was noted that the COVID-19 pandemic is not just limited to health problems, but also linked to a variety of issues such as human rights, economic inequality, various discrimination, hate speech, fake news, global governance etc. In the field of education, it is necessary to think about how to connect this global situation with school classes. Accordingly, this study suggested the direction for global citizenship education by analyzing how the infodemic spreads on Korean social media with the case of the recent global COVID-19 pandemic. According to the research results, the rate of negative emotions was higher than positive ones in the emotions that generate infodemic, while anxiety and anger were focused among negative emotions. In addition, the infodemic tended to spread widely with the feelings of anger rather than anxiety, and the feelings of anger led to advocating aggressive policies against certain country and regions. Therefore, global citizenship education is required to focus on a sense of duty and responsibility as a citizen, not on the level of national identity based on an exclusive sense of belonging. Furthermore, global citizenship education needs to lead to presenting a blueprint for education in a way that can enhance the awareness of the global community for joint response to global challenges and realize common prosperity based on sustainability and justice.

Delayed Parenchymal Transit During Tc-99m MAG3 Renography is a Valuable Sign in Diagnosing Urinary Obstruction in Patients with Early Hydronephrosis (초기의 수신증 환자의 요로폐쇄 진단에 있어 Tc-99m MAG3 신장 스캔시 실질통과지연 소견의 유용성)

  • Lee, Won-Woo;Moon, Dae-Hyuk;Kim, Jae-Seung;Ryu, Jin-Sook;Lee, Hee-Kyung
    • The Korean Journal of Nuclear Medicine
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    • v.36 no.5
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    • pp.306-313
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    • 2002
  • Purpose: Diuretic renography (DR) can be false negative in patients with upper urinary tract obstruction due to low compliance of the renal pelvis. Delayed parenchymal transit (DPT) may be a valuable sign in case of false negative DR. We compared the diagnostic values of DR and DPT during Tc-99m MAG3 diuretic scan in adults with suspected unilateral obstructive uropathy. Materials and Methods: Fifty-four patients(male:female=30:24, age: $40.7{\pm}15.5$ yrs) who underwent Tc-99m MAG3 diuretic scan due to suspicious unilateral obstructive uropathy were analyzed. DR with a $T_{1/2}\;of\;>\;15min$ was considered as positive for obstruction. DPT was considered to be present when there was delayed appearance of radioactivity in the renal pelvis and prolonged retention of radioactivity in the renal parenchyma. The renal area ratio was defined as the ratio of pixel number of hydronephrotic kidney over that of normal contralateral at $1{\sim}2min$ images. Definition of obstruction was improved hydronephrosis after intervention, or aggravated hydronephrosis without intervention. Non-obstruction was defined as unchanged hydronephrosis over 6 months. Results: Twenty-six renal units had obstruction and 28 no obstruction. The sensitivities of DR and DPT were 69% (18/26) and 50% (13/26) respectively. Two renal units with DPT but negative DR showed the renal area ratio of <1.1. Among the 20 obstructive renal units with DPT or positive DR, 13 with DPT had lower renal area ratio than 7 renal units without DPT ($0.97{\pm}0.20\;vs\;1.30{\pm}0.41,\;p<0.05$). Differential renal function was not significantly different between these groups. DPT correctly diagnosed all renal units with non-obstruction (specificity 100%), while the specificity of DR was 89% (25/28). Conclusion: DPT during Tc-99m MAG3 diuretic scan may be a valuable sign in diagnosing urinary obstruction especially in patients with false negative DR and early HN.

A Comparison of Conventional Cytology and ThinPrep Cytology of Bronchial Washing Fluid in the Diagnosis of Lung Cancer (폐암의 진단 검사 중 기관지 세척액에서 ThinPrep검사법과 기존의 세포검사법의 유용성에 대한 비교)

  • Kim, Sang-Hoon;Kim, Eun Kyung;Shi, Kyeh-Dong;Kim, Jung-Hyun;Kim, Kyung Soo;Yoo, Jeong-Hwan;Kim, Joo-Young;Kim, Gwang-Il;Ahn, Hee-Jung;Lee, Ji-Hyun
    • Tuberculosis and Respiratory Diseases
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    • v.62 no.6
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    • pp.523-530
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    • 2007
  • Background: A ThinPrep$^{(R)}$ Processor was developed to overcome the limitations of conventional cytology and is widely used to diagnose various cancers. This study compared the diagnostic efficacy of conventional cytology for lung cancer with that of the ThinPrep$^{(R)}$ cytology using the bronchial washing fluid. Methods: The bronchial washing fluid of 790 patients from Jan. 2002 to Dec. 2006, who were suspected of gaving a lung malignancy, was evaluated. Both ThinPrep$^{(R)}$ and conventional cytology were performed for all specimens. Result: Four hundred forty-six men and 344 women were enrolled in this study, and 197 of them were diagnosed with cancer from either a bronchoscopic biopsy or a percutaneous needle aspiration biopsy. ThinPrep$^{(R)}$ cytology showed a sensitivity, specificity, positive predictive value, negative predictive value and false negative error rate of 71.1%, 98.0%, 92.1%, 91.1%, 8.9%, respectively. The conventional cytology showed sensitivity, specificity, positive predictive value, nagative predictive value and false negative error rate of 57.9%, 98.0%, 90.5%, 87.5%, 12.5%, respectively. For central lesions, the sensitivity of conventional cytology and ThinPrep$^{(R)}$ were 70.1% and 82.8%, respectively. Conclusion: ThinPrep$^{(R)}$ cytology showed a higher sensitivity and lower false negative error rate than conventional cytology. This result was unaffected by the histological classification of lung cancer. Therefore, ThinPrep$^{(R)}$ cytology appears to be a useful method for increasing the detection rate of lung cancer in bronchial washing cytology test.

Improved Spam Filter via Handling of Text Embedded Image E-mail

  • Youn, Seongwook;Cho, Hyun-Chong
    • Journal of Electrical Engineering and Technology
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    • v.10 no.1
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    • pp.401-407
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    • 2015
  • The increase of image spam, a kind of spam in which the text message is embedded into attached image to defeat spam filtering technique, is a major problem of the current e-mail system. For nearly a decade, content based filtering using text classification or machine learning has been a major trend of anti-spam filtering system. Recently, spammers try to defeat anti-spam filter by many techniques. Text embedding into attached image is one of them. We proposed an ontology spam filters. However, the proposed system handles only text e-mail and the percentage of attached images is increasing sharply. The contribution of the paper is that we add image e-mail handling capability into the anti-spam filtering system keeping the advantages of the previous text based spam e-mail filtering system. Also, the proposed system gives a low false negative value, which means that user's valuable e-mail is rarely regarded as a spam e-mail.

Deep-Learning Approach for Text Detection Using Fully Convolutional Networks

  • Tung, Trieu Son;Lee, Gueesang
    • International Journal of Contents
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    • v.14 no.1
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    • pp.1-6
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    • 2018
  • Text, as one of the most influential inventions of humanity, has played an important role in human life since ancient times. The rich and precise information embodied in text is very useful in a wide range of vision-based applications such as the text data extracted from images that can provide information for automatic annotation, indexing, language translation, and the assistance systems for impaired persons. Therefore, natural-scene text detection with active research topics regarding computer vision and document analysis is very important. Previous methods have poor performances due to numerous false-positive and true-negative regions. In this paper, a fully-convolutional-network (FCN)-based method that uses supervised architecture is used to localize textual regions. The model was trained directly using images wherein pixel values were used as inputs and binary ground truth was used as label. The method was evaluated using ICDAR-2013 dataset and proved to be comparable to other feature-based methods. It could expedite research on text detection using deep-learning based approach in the future.

The roles of endoscopic ultrasound in the diagnosis of pancreatobiliary cancer (췌·담도암 진단에 있어서 내시경초음파의 역할)

  • Kim, Kook Hyun
    • Journal of Yeungnam Medical Science
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    • v.33 no.2
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    • pp.77-84
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    • 2016
  • Pancreatic cancer, the 4th leading cause of cancer-related death in the United States, has a very poor prognosis. Cholangiocarcinoma originates from either intrahepatic or extrahepatic bile duct, and its incidence is gradually increasing worldwide. Endoscopic retrograde cholangiopancreatography with brush cytology has a high false-negative rate for the diagnosis of biliary malignancy. Recently, endoscopic ultrasonography (EUS) has emerged as the potential modality to detect pancreatic cancer. EUS-guided fine needle aspiration for cytologic analysis made it possible to overcome the obstacle in differentiating between benign and malignant lesions in the pancreatobiliary lesion, and it has been well established as a safe and effective procedure. Herein, the clinical application of EUS in the diagnosis of pancreatobiliary cancer was reviewed.

The Value of High Resolution Ultrasonography in Diagnosis of Thyroid Nodule (갑상선 결절의 진단에 있어서 고해상능 초음파검사의 가치)

  • Shim Hyung-Jin;Choung Hue-Moon;Yoon Jung-Han;JeGal Young-Jong;Park Jin-Gyoon
    • Korean Journal of Head & Neck Oncology
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    • v.6 no.2
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    • pp.114-118
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    • 1990
  • A clinical study of 37 cases with thyroid nodules, which were treated by surgical excision and confirmed pathologically at the Department of Surgery, Chonnam National University Medical School, from Dec. 1988 to Feb. 1990, was conducted and following results were obtained in ultrasonographic evaluation of thyroid nodules. 1) The thyroid adenoma were showed well-defined margin, homogenous internal echo and surrounding Halo, but thyroid cancer were showed ill-defined margin, inhomogenous internal echo and no surrounding Halo. 2) The sensitivity of high resoution ultrasonography compared with pathologic diagnosis to thyroid cancer was 87.5%, specificity 94.1%, accuracy 88%, false positive 5.88%, and negative 12.5%.

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Estimation in Group Testing when a Dilution Effect exists

  • Kwon, Se-Hyug
    • Communications for Statistical Applications and Methods
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    • v.13 no.3
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    • pp.787-794
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    • 2006
  • In group testing, the test unit consists of a group of individuals and each group is tested to classify units from a population as infected or non-infected or estimate the infection rate. If the test group is infected, one or more individuals in the group are presumed to be infected. It is assumed in group testing that classification of group as positive or negative is without error. But, the possibility of false negatives as a result of dilution effects happens often in practice, specially in many clinical researches. In this paper, dilution effect models in group testing are discussed and estimation methods of infection rate are proposed when a dilution effect exists.