• The Korean Journal of Applied Statistics
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• v.33 no.5
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• pp.541-553
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• 2020

The receiver operating characteristic (ROC) curve is expressed as both sensitivity and specificity; in addition, some optimal thresholds using the ROC curve are also represented with both sensitivity and specificity. In addition to the sensitivity and specificity, the expected usefulness function is considered as disease prevalence and usefulness. In particular, partial the area under the ROC curve (AUC) on a certain range should be compared when the AUCs of the crossing ROC curves have similar values. In this study, partial AUCs representing high sensitivity and specificity are proposed by using sensitivity and specificity lines, respectively. Assume various distribution functions with ROC curves that are crossing and AUCs that have the same value. We propose a method to improve the discriminant power of the classification models while comparing the partial AUCs obtained using sensitivity and specificity lines.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1787-1793
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• 2008

Fingerprint Recognition System is made up of Off-line treatment and On-line treatment; the one is registering all the information of there trieving features which are retrieved in the digitalized fingerprint getting out of the analog fingerprint through the fingerprint acquisition device and the other is the treatment making the decision whether the users are approved to be accessed to the system or not with matching them with the fingerprint features which are retrieved and database from the input fingerprint when the users are approaching the system to use. In this paper, we propose a new data structure, called Union and Division, for processing binarized digital fingerprint image efficiently. We present a minutiae extraction algorithm that is using Union and Division and consists of binarization, noise removal, minutiae extraction stages.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.309.1-312
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• 1998

일반적으로 음향 문제에 상용되는 경계요소법은 Kirchhoff-Helmholtz 적분 방정식에 약특이성과 강특이성의 커널을 갖고 있어, 경계면에 매우 근접한 음장을 해석할 때 수치 적분 과정에서 큰 오차를 유발한다. 본 연구에서는 평면파 성분을 이용하여 약특이성 방정식 및 특이성이 제거된 음장 음압의 과도한 오차는 약특이성 경계 적분 방정식의 적용으로 제거될 수 있었다. 부드러운 경계면을 가진 경우는 모든 특이성의 제거가 가능하여 특이성 처리를 위한 특별한 처리가 불필요하게 되었다. 제안된 방법을 검증하기 위하여 몇 가지 단순한 모델에 대하여 경계 요소 계산을 수행하였고, 경계면 부근의 근접 음장에서 음압 예측의 정확도가 향상되는 결과를 얻었다.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.239-243
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• 2010

Even though clinical use DRE, PSA and TRUS for screening while diagnosing prostate cancer early, however, we cannot achieve to diagnose it accurately by one method. Thus, mutual supplements are strongly required in diagnosis. It means that we should identify relationship between prostate volume and serum PSA under different ages for better diagnosis. The subjects(405 men) visited the department of diagnostic radiology in a general university hospital from January 2008 to December 2008, who was going to take the prostatic evaluation by TRUS. 13 men, who did definite diagnosis of prostate cancer before through biopsy, were excluded in this study. All data were expressed as mean and standard deviations by using SPSS 14.0 package programs and were analyzed by using one-way ANOVA to evaluate the effect of different ages. And Scheffe Post hoc comparison is accomplished in order to make significant difference in prostate volume, PSA and PSAD according to ages. Pearson correlation was used for ages, prostate volume, PSA and PSAD. According to examination, the subjects' prostate volume and serum PSA level increase as person's age. We can see significant difference between group over 70 years and group from 40 and 50 years. Moreover, age, prostate volume and serum PSA have significant positive correlation. Even though we can get variations in serum PSA level by changing prostate volume according to ages, it is worthwhile to mention that more strong association for prostate volume is observed than ages in elevation of serum PSA. Therefore, it is strongly recommended to consider prostate volume weightly when it comes to evaluate for men with elevated PSA level. Finally, TRUS is an excellent extra equipment to diagnose prostate cancer because it can contribute to early diagnose and pertinent treatment of prostate cancer.

• Journal of the Korean GEO-environmental Society
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• v.24 no.9
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• pp.25-32
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• 2023

The Korean Industrial Standards (KS F) have a various regulations for measuring the weight of dried soil and rock. However, if the dried weight is measured in air after drying at 110±5℃ or 105±5℃, a weight singularity occurs, in which the weight decreases and then increases as the measurement time continues. In this study, basaltic rock from Ulleung Island was oven dried at 40 to 110℃. The weight was measured on an electronic scale with a sensitivity of 0.0001g (0.1mg) to find weight singularities. A method to easily determine the dry weight using the weight singularities was presented. As a result of analyses of the singularity of rock specimen according to temperature, the singularities were appeared in the temperature range of 40 to 110℃, and the weight of the singularity was smaller as the heating temperature increased. In particular, the weight singularity duration appeared, and the duration of the singularity was shorter as the heating temperature increased. The results of the convection measurement experiment showed that the cause of the singularity is the convection phenomenon caused by the contact of the heated rock with the air. The weight decrease of oven dried rock occurs when the effect of convection is dominant over the effect of air moisture absorption. Conversely, the weight increase of rock occurs when the effect of air moisture absorption is dominant over the effect of convection.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.103-107
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• 2016

To establish a rapid and accurate detection of Phytophthora pinifolia, which is a quarantine pathogenic fungus in Korea, a species-specific primer was developed based on the ras-related protein (Ypt1) gene. Species-specific primer based on the DNA sequences of Ypt1 gene amplified 193 bp polymerase chain reaction (PCR) product for P. pinifolia. The primer pair yielded the predicted PCR product size exactly in testing with target pathogen DNAs, but not from the other 10 species of Phytophthora and 14 species of other phytopathogenic fungi. The primer pair also showed only the species-specific amplification curve on realtime PCR on target pathogen DNA. The detection sensitivity of real time PCR using species-specific primer pair was 10 to 100 times higher than conventional PCR, with 1 to $10pg/{\mu}L$.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.200-207
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• 2014

Arrhythmia electrocardiogram signal contains a specific unusual heartbeat with abnormal morphology. Because unusual heartbeat is useful for diagnosis and classification of various diseases, such as arrhythmia, detection of unusual heartbeat from the arrhythmic ECG signal is very important. Amplitude and kurtosis at R-peak point and RR interval are characteristics of ECG signal on R-wave. In this paper, we provide a method for detecting unusual heartbeat based on these. Through the value of the attribute deviates more from the average value if unusual heartbeat is more certainly, the proposed method detects unusual heartbeat in order using the mean and standard deviation. From 15 ECG signals of MIT-BIH arrhythmia database which has R-wave distortion, we compare the result of conventional method which uses the fixed threshold value and the result of proposed method. Throughout the experiment, the sensitivity is significantly increased to 97% from 50% using the proposed method.

• Korean journal of applied entomology
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• v.34 no.2
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• pp.140-146
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• 1995

Changes in protein content during oocyte development was measured and egg-specific protein was characterized from the eggs in Lucilia illustris. During normal development ovarian protein was rapidly increased at 72hr and reached maximum at 96hr after a protein meal, when the eggs were fully matured. Purified protein from the ovaries by gel filtration of DEAE-cellulose an Sephacryl S-200 was loaded on 7.5% native polyacrylamide gel electrophoresis and identified at ${R}_{f}$ 0.4 as egg-specific protein, which has a mol. wt of 110,000. A total of 13 amino acids in th egg-specific protein was identified and expecially asparagine, glutamic acid, and tyrosine were highly concentrated. Five fatty acids were also identified. It is suggested that there is a specific protein in the eggs of L. illustris except yolk protein synthesized and secreted by fat body.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.482-488
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• 2002

Purpose : We performed this study to evaluate the diagnostic usefulness of endoscopic finding of nodular gastritis, CLO and HpKit test for H. pylori infection in children. Methods : Gastroduodenal endoscopy and mucosal biopsy were performed on 212 children who visited our hospital between Jul. 1999 and May 2000 due to abdominal pain. We performed CLO and HpKit test for H. pylori with the time interval of 15, 30 minutes, 1, 2, 3, 24, 48, 72, 96, 120 and 144 hours. Histological examination of H. pylori was made by H-E or Alcian yellow stain with biopsy specimens. Sensitivity, specificity, positive predictive and negative predictive value of nodular gastritis, CLO and HpKit test were calculated from the analysis of above data. Results : Sensitivity and specificity of 3 hour-CLO test was 68.4% and 100% respectively. Sensitivity and specificity of 3 hour-HpKit test was 65.8% and 100% respectively. No significant difference in sensitivity and specificity was found between in 3 hour-CLO and HpKit test(P>0.05). Sensitivity of CLO test increased as time lapsed, but corresponding specificity did not decrease as time lapsed(sensitivity and specificity at 144 hours : 89.5% and 94.8% respectively). However, sensitivity of HpKit test increased as time lapsed, but specificity markedly decreased. Sensitivity and specificity of the nodular gastritis was 78.9% and 93.7% respectively. Conclusion : Both CLO and HpKit test have relatively low sensitivity and specificity for the detection of H. pylori in 3 hours of testing in children. The endoscopic finding of nodular gastritis is another good standard in the diagnosis of H. pylori infection in children.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.100-106
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• 2009

Purpose: The study was to assess I-123-N-(3-iodopropen-2-yl)-2[beta]-carbomethoxy-3[beta]-(4-cholorophenyl) tropane(IPT) SPECT in differential diagnosis among early stage of Parkinson's disease(PD) and essential tremor(ET) and normal control(NL) groups quantitatively. Materials and Methods: I-123 IPT brain SPECT of 50 NL, 20 early PD, 30 advanced PD, and 20 ET were performed at 20 minutes and 2 hours. Specific/nonspecific binding of striatum was calculated by using right and left striatal specific to occipital non-specific uptake ratio(striatum-OCC/OCC). Results: Mean value of specific/nonspecific binding ratio was significantly different between advanced PD group and NL group. However, significant overlap of striatal specific/nonspecific binding ratio was observed between PD group and ET group. Bilateral striatal specific/nonspecific binding ratios were decreased in advanced PD. Lateralized differences in the striatal uptake of I-123 IPT correlated with asymmetry in clinical findings in PD group. Conclusion: I-123 IPT SPECT may be a useful method for the diagnosis of PD and objective evaluation of progress of clinical stages. Care should be made in the differential diagnosis of early stage of PD and other motor disturbances mimicking PD such as ET in view of significant overlap in striatal I-123 specific/nonspecific binding ratio.