• The Korean Journal of Cytopathology
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• v.19 no.2
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• pp.111-118
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• 2008

Background : Cervicovaginal cytology is a screening test of uterine cervical cancer. The sensitivity of cervicovaginal cytology is less than 50%, but studies of cytologic/histologic correlation are limited. We analyzed the diagnostic accuracy of cervicovaginal cytology in the detection of the squamous epithelial lesions of the uterine cervix and investigate the cause of diagnostic discordance. Materials and Methods : We collected a total of 481 sets of cervicovaginal cytology and biopsies over 5 years. The cytologic diagnoses were categorized based on The Bethesda System and the histologic diagnoses were classified as negative, flat condyloma, cervical intraepithelial neoplasia (CIN) I, CIN II, CIN III, or squamous cell carcinoma. Cytohistologic discrepancies were reviewed. Results: The concordance rate between the cytological and the histological diagnosis was 79.0%. The sensitivity and specificity of cervicovaginal cytology were 80.6% and 92.6%, respectively. Its positive predictive value and negative predictive value were 93.7% and 77.7%, respectively. The false negative rate was 19.4%. Among 54 false negative cytology cases, they were confirmed by histology as 50 flat condylomas, 2 CIN I, 1 CIN III, and 1 squamous cell carcinoma. The causes of false negative cytology were sampling errors in 75.6% and interpretation errors in 24.4%. The false positive rate was 7.4%. Among 15 false positive cytology cases, they were confirmed by histology as 12 atypical squamous cells of undetermined significance (ASCUS) and 3 low grade squamous intraepithelial lesions (LSIL). The cause of error was interpretation error in all cases. The overall diagnostic accuracy of cervicovaginal cytology was 85.7%. Conclusions : Cervicovaginal cytology shows high overall diagnostic accuracy and is a useful primary screen of uterine cervical cancer.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.60 no.3
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• pp.107-111
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• 2017

Background and Objectives The bedside head impulse test (bHIT) in bare eyes often overlooks possible vestibular losses by missing the corrective saccade. This is why it is necessary to compare bHIT against video head impulse test (vHIT), which is more accurate in identifying vestibular losses than the bedside test. Subjects and Method A total of 51 vHIT positive ears underwent the study, and out of those, 47 were diagnosed with dizziness. bHIT and vHIT were performed for patients, and the occurrence rate of overt saccade (OS) was calculated. Results Among the 51 vHIT positive ears, 33 (64.7%) were bHIT positive ears and 18 ears (35.3%) were bHIT negative. Patterns of positive vHIT were classified as A: no corrective saccade, B: covert saccade (CS) only, C: OS only, and D: CS with OS (CS+OS), which were 45 out of 51 ears (88%). The occurrence rate of OS was higher in the bHIT positive group than in the bHIT negative group (p=0.05), and higher in the CS negative group (CS-) than in the CS positive group (CS+) (p<0.001). Conclusion Possible causes of false negative results of bHIT are seen as following: the absence of corrective (covert and overt) saccade, the occurrence of CS only, and missing the OS during the bHIT (probably due to low occurrence rate of OS). The occurrence of CS should be considered as an important factor in false negative bHIT when lowering the occurrence rate of OS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.3
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• pp.938-957
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• 2023

The limited computing power of sensor nodes in wireless sensor networks (WSNs) and data tampering during wireless transmission are two important issues. In this paper, we propose a scheme for independent individual authentication of WSNs data based on digital watermarking technology. Digital watermarking suits well for WSNs, owing to its lower computational cost. The proposed scheme uses independent individual to generate a digital watermark and embeds the watermark in current data item. Moreover, a sink node extracts the watermark in single data and compares it with the generated watermark, thereby achieving integrity verification of data. Inherently, individual validation differs from the grouping-level validation, and avoids the lack of grouping robustness. The improved performance of individual integrity verification based on proposed scheme is validated through experimental analysis. Lastly, compared to other state-of-the-art schemes, our proposed scheme significantly reduces the false negative rate by an average of 5%, the false positive rate by an average of 80% of data verification, and increases the correct verification rate by 50% on average.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1197-1207
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• 2018

PowerShell is command line shell and scripting language, built on the .NET framework, and it has several advantages as an attack tool, including built-in support for Windows, easy code concealment and persistence, and various pen-test frameworks. Accordingly, malwares using PowerShell are increasing rapidly, however, there is a limit to cope with the conventional malware detection technique. In this paper, we propose an improved monitoring method to observe commands executed in the PowerShell and a deep learning based malware classification model that extract features from commands using Convolutional Neural Network(CNN) and send them to Recurrent Neural Network(RNN) according to the order of execution. As a result of testing the proposed model with 5-fold cross validation using 1,916 PowerShell-based malwares collected at malware sharing site and 38,148 benign scripts disclosed by an obfuscation detection study, it shows that the model effectively detects malwares with about 97% True Positive Rate(TPR) and 1% False Positive Rate(FPR).

• Korean Journal of Clinical Laboratory Science
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• v.45 no.4
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• pp.149-153
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• 2013

Candidiasis is a fungal infection of the most common causes; generally, opportunistic infections occur often in patients with weakened immune systems. Because of high rates in fungal infection patients and increasing frequency of being isolated from clinical materials, quickly identifying of Candida albicans is critical. By identifying 404 yeast cell strains of referred samples via API 20C kits, NGL and PRO tests and Germ tube (GT) test were conducted and compared. In the 3.0 McFarland yeast cells, 0.1% ${\rho}-nitrophenyl-N-acetyl-{\beta}-D-galactosaminide$ (NGL) and 0.04% ${\small{L}}$-proline ${\beta}$-naphtylamide (PRO) were each put in test tubes and incubated at $35^{\circ}C$ for 15, 30, 60 and 90 minutes. Afterwards, 1 drop of 2% NaOH was applied, and if the color turned yellow; it was positive for NGL test. Afterwards, 1% ${\rho}$-dimethylaminocinnamaldehyde was applied, and if the upper layer turned pink or red, it was positive for PRO test. NGL and PRO tests were conducted for all C. albicans and identified accurately within 30 minutes. In NGL, PRO test, false-positive, negative were not seen, whereas, GT test showed false-positive in 1 strain and false-negative in 3 strains. Therefore, sensitivity and specificity of NGL, PRO tests were 100% and 99.5%, respectively, and positive and negative predictive rate were 99.5% and 100%, respectively. However, GT test sensitivity and specificity were 98.5% and 99.5%, respectively, and positive and negative predictive rates were 99.5% and 98.5%, respectively. In conclusion, NGL, PRO tests are better than GT tests for sensitivity and specificity, therefore, these reliable tests will be useful in clinical laboratories.

• Tuberculosis and Respiratory Diseases
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• v.69 no.6
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• pp.442-449
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• 2010

Background: Melanoma antigen genes (MAGE) are expressed in many human malignant cells and are silent in normal tissues other than in testis and in placenta. But MAGE expression in benign lung diseases, such as pulmonary tuberculosis or cases with severe inflammation, needs further evaluation to overcome false-positive findings. We evaluated detection rates of the melanoma antigen genes (MAGE) RT-nested PCR in bronchoscopic washing samples from patients with benign lung disease, as well as in patients with malignancies. Methods: Bronchial washing fluid from 122 patients was used for cytological examination and MAGE gene detection using RT-nested-PCR of common A1-6 mRNA. We compared the results from the RT-nested PCR and the pathologic or bacteriologic diagnosis. We also analyzed the expression rate and false positive rate of MAGE gene. Results: Among 122 subjects, lung cancer was diagnosed in 23 patients and benign lung disease was diagnosed in 99 patients. In patients with lung cancer, the positive rate of MAGE expression was 47.8% (11/23) and in benign lung disease group, the expression rate was 14.1% (14/99). Among benign lung disease group, the expression rate of MAGE gene (25.0%) in patients with pulmonary tuberculosis (11/44) was especially high. Conclusion: MAGE A1-6 RT-nested PCR of bronchial washing fluid can be used as a complementary method in lung cancer, but that test results in a high false positive rate in tuberculosis patients.

• Journal of Preventive Medicine and Public Health
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• v.20 no.1 s.21
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• pp.114-119
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• 1987

The author investigated the effect of some variables such as age, sex and the experience of past vaccination on the validity of PHA. The changing pattern of the validity with the change of PHA diagnostic criteria, and the relationship between PHA test result and RIA Ratio Unit were also studied. The results obtained were as follow; 1) No statistically significant difference was found in sensitivity, specificity and negative predictability by sex, but positive predictability was significantly higher in male than that in female. 2) Positive predictability was shown to become higher with the increase of age and nagative predictability was found to be significally different among age groups, but no statistically significant difference was found in sensitivity and specificity by age group. 3) Significantly low specificity and high positive predictability were found in past vaccined group, but no statistically significant difference was found in sensitivity and negative predictability between past vaccined group and non-vaccined group. 4) False negative cases by PHA were found to be the weak positive reactors by RIA and false positive rate of PHA was as high as 46.3 per cent. 5) Sensitivity and specificity of PHA at the diagnostic criteria of HBsAb titer 1:2 were 98.4% and 53.8% respectively, but after increasing the HBsAb titer to 1:64 as the diagnostic criteria the results were 60.0% and 95.6% respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7381-7384
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• 2015

This study was conducted to 1206 women who had cervical cancer screening at Chonburi Cancer Hospital. The spilt-sample study aimed to compare the efficacy of abnormal cervical cells detection between liquid-based cytology (LBC) and conventional cytology (CC). The collection of cervical cells was performed by broom and directly smeared on a glass slide for CC then the rest of specimen was prepared for LBC. All slides were evaluated and classified by The Bethesda System. The results of the two cytological tests were compared to the gold standard. The LBC smear significantly decreased inflammatory cell and thick smear on slides. These two techniques were not difference in detection rate of abnormal cytology and had high cytological diagnostic agreement of 95.7%. The histologic diagnosis of cervical tissue was used as the gold standard in 103 cases. Sensitivity, specificity, positive predictive value, negative predictive value, false positive, false negative and accuracy of LBC at ASC-US cut off were 81.4, 75.0, 70.0, 84.9, 25.0, 18.6 and 77.7%, respectively. CC had higher false positive and false negative than LBC. LBC had shown higher sensitivity, specificity, PPV, NPV and accuracy than CC but no statistical significance. In conclusion, LBC method can improve specimen quality, more sensitive, specific and accurate at ASC-US cut off and as effective as CC in detecting cervical epithelial cell abnormalities.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.2
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• pp.117-123
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• 2022

Currently the number of COVID-19 cases is increasing rapidly around the world. One way to restrict the spread of COVID-19 infection is to find confirmed cases using rapid diagnosis. The previously proposed group testing problem assumed without measurement noise, but recently, false positive and false negative cases have occurred during COVID-19 testing. In this paper, we define the noisy group testing problem and analyze how much measurement noise affects the performance. In this paper, we show that the group testing system should be designed to be less susceptible to measurement noise when conducting group testing with a low positive rate of COVID-19 infection. And compared with other developed reconstruction algorithms, our proposed algorithm shows superior performance in noisy group testing.

• The Korean Journal of Cytopathology
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• v.8 no.2
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• pp.120-128
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• 1997

Fine needle aspiration cytology of breast lesion is well known as a simple, economic and effective diagnostic modality. For the evaluation of cytohistologic correlation, 256 cases of cytologic smears and subsequent histologic sections during 2-year period from Jan. 1995 to Dec. 1996 were reviewed. 1. Fifteen cases(5.9%) were proven as insufficient for evaluation, and 13 of them were fibrocystic change histologically. One case of carcinoma exhibiting sufficient amount of aspirates with no malignant cells on smear was regarded as inadequate. 2. Cytohistologic correlation of 240 cases revealed sensitivity 87.0%, specificity 100.0%, positive predictive value 100.0%, negative predictive value 97.0%, false positive rate 0.0% and false negative rate 13.0%. Total diagnostic accuracy is 95.7%. 3. Total 6 cases of negative were due to small amount of aspirates containing scantiness of malignant cells in two and underestimation in four. 4. Diagnostic concordance rates of fibrocystic change and fibroadenoma were 95.5% and 80.0%, respectively. Diagnostic discrepancies were noted in 7 cases of fibrocystic change and 6 cases of fibroadenoma, however, cytologic discrimination of two entities was not easy in seven of them. 5. In a case of phyllodes tumor and a case of duct ectasia, the discrepancy was due to targeting error. Other three cases(lymphoma, adenomyoepithelioma and granulomatous mastitis) were misinterpreted because of poor acquaintance with those entities. Diagnostic accuracy of fine needle aspiration cytology of breast lesions are relatively high. However, good technique on aspiration and adequate interpretation are necessary to reduce the false negative rate and the discrepancy between cytologic and histologic diagnoses.