• Journal of Yeungnam Medical Science
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• v.15 no.1
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• pp.143-150
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• 1998

The aim of this study was to evaluate domestic enzyme immunoassay(EIA) kit 'LG RCD 3.0' (LG) for the detection of antibody to hepatitis C virus(anti-HCV) in comparision with Axsym HCV version 3.0(Axsym), Cobas Core anti-HCV EIA(Cobas). Cobas kit shows better clear distinction between positive and negative by signal/cutoff ratio(S/C), but it also reveal relatively high false positive rate. The concordance rate of test results between LG and Axsym was 96.2%, between LG and Cobas was 95.5%, and total agreement between three EIA kit was 93.9%. LG were relative poor distinction between positive and negative results, but it could be applied clinically as a screening tool for hepatitis C in general population. The SIC of one false negative result by LG was 0.91, and false positive were less than 4.0, therefore we concluded it is necessary to confirm by immunoblotting assay when SIC were between 0.8 and 4.0.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.151-156
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• 2006

Purpose : The aim of this study was to determine the accuracy of clinical and radiologic assessments in detecting positive cervical lymph nodes in oral cancer. Materials and Methods : We had reviewed the preoperative clinical, radiologic and postoperative histopathologic reports of 46 patients who had been diagnosed as oral cancer and underwent surgical excision combined with neck dissection (52 sides of neck) in the Department of Oral and Maxillofacial Surgery, College of Dentistry, Yonsei University from the July 1, 1992 to the April 30, 1999. Results : The results were as follows 1. The male to female ratio was 4.38 : 1 and the mean age was 57. 2. Sensitivity values for the preoperative assessment of cervical lymph node metastasis in oral cancer were 62.5 % in clinical examination and 50.0 % in radiologic assessments. Specificity values were 77.8 % in clinical examination and 94.4 % in radiologic assessments. 3. False positive values were 44.4 % in clinical examination and 20.0 % in radiologic assessments. False negative values were 17.6 % in clinical and 19.0% in radiologic assessments. 4. Overall efficiency values were 73.1 % in clinical examination and 80.8 % in radiologic assessments. Summary : There were some limits on the accuracy of clinical and radiologic assessments in the preoperative detection of the cervical lymph nodes in oral cancer. To improve the accuracy, it is important to communicate between clinician and radiologist, and adjunctive diagnostic measures, ultrasound and fine needle aspiration cytology, were helpful increasing the overall efficiency. In the high risk sites (oral tongue and floor of the mouth) the false negative value is higher and the overall efficiency in radiologic evaluation is lower than those of the low risk sites (gingiva and alveolar ridge, retromolar trigone and buccal mucosa ). The elective neck dissection should be considered in the high risk sites.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.8 s.338
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• pp.33-40
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• 2005

This paper presents a structure of the searcher using a diversity in array antenna systems operating in the cdma2000 1x signal environments. The new technique exploits the fact that the In-phase and quadrature components of interferers can respectively be viewed as an independent gaussian noise at each antnna element in most practical cdma signal environments. The proposed PN acquisition scheme is a singles-dwell PN acquisition system consisting of two stages, that is, the searching stage and the verification stage. The searching stage independently correlates the receiver multiple signals with PN generator of each antenna element for obtaining the synchronous energy at the entire region. Then, the searching results of each antenna element are non-coherently combinind. The verification stage compares the searching energy with the optimal threshold, which is predesigned in the lock detector, and decides whether the acquisition is successful or fail. In this paper, we analyzed the effect of tile diversity order to determine the mean acquisition time. In general, it is known that the mean acquisition time significantly decrease as the number of antenna elements increases. But, as the diversity order goes up, the enhancement of the performance is saturated. Therefore, to decrease the mean acquisition time of the searcher, we must design the optimal array antenna systems by considering the operating SNR range of the receiver, the probability of detection $P_D$ and that of false alarm $P_{FA}$ . The Performance of the proposed PN acquisition scheme is analyzed in frequency selective Rayleigh fading channels. In this paper, the effect of the number of antenna elements on PN acquisition scheme is shown according to the probability of detection $P_D$ and that of false alarm $P_{FA}$.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.16 no.2
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• pp.70-78
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• 2016

21-hydroxylase deficiency (21-OHD), most common form of congenial adrenal hyperplasia, is categorized into classical forms, including the salt-wasting (SW) and the simple virilizing (SV) types, and nonclassical (NC) forms based on the severity of the disease. Newborn screening for 21-OHD has been performed in Korea since 2006. $17{\alpha}$-hydroxyprogesterone (17-OHP) is a marker for 21-OHD and is measured using a radioimmunoassay or a fluoroimmunoassay. Premature and low birth weight infants are likely to give false positive 17-OHP findings, therefore, cutoff values for these infants should be determined based on gestational weeks or birth weight. ACTH simulation test is helpful when the 17-OHP shows equivocal increase, and it is gold standard for diagnosis of NC type. Recently, liquid chromatography linked with tandem mass spectrometry was developed for rapid, highly specific, and sensitive analysis of multiple analytes. Molecular analysis of CYP21A2 is useful for confirming diagnosis of mild SV or NC type, predicting prognoses, and genetic counseling. In order to make newborn screening for 21-OHD more efficient, early detection of boy with SW type, early determination of girl with ambiguous genitalia, detection of NC type, and overcoming of false positive in premature and low birth weight infants should be considered. Above all, early treatment should be started when the patient is suspected as having 21- OHD clinically before confirming the diagnosis to prevent adrenal crisis. Here, author reviewed recent articles of guideline and proposed guideline for 21-OHD.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.4143-4147
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• 2016

Purpose: We evaluated all PET/CTs acquired for patients without a primary diagnosis of colorectal cancer, and compared results for those who had subsequent colonoscopy within 6 months, to assess the accuracy of FDG PET/CT for detection of incidental pre-malignant polyps and malignant colon cancers. Materials and Methods: Medical records of 9,545 patients who underwent F-18 FDG PET/CT studies over 3.5 years were retrospectively reviewed. Due to pre-existing diagnosis of colorectal cancer, 818 patients were excluded. Of the remainder, 157 patients had colonoscopy within 6 months (79 males; mean age 61). We divided the colon into 4 regions and compared PET/CT results for each region with colonoscopy and histopathologic findings. True positive lesions included colorectal cancer, villous adenoma, tubulovillous adenoma, tubular adenoma and serrated hyperplastic polyp/hyperplastic polyposis. Results: Of 157 patients, 44 had incidental colonic uptake on PET/CT (28%). Of those, 25 had true positive (TP) uptake, yielding a 48% positive predictive value (PPV); 9% (4/44) were adenocarcinoma. There were 23 false positive (FP) lesions of which 4 were hyperplastic polyp, one was juvenile polyp and 7 were explained by diverticulitis. Fifty eight patients had false negative PET scans but colonoscopy revealed true pre-malignant and malignant pathology, yielding 23% sensitivity. The specificity, negiative predictive value (NPV) and accuracy were 96%, 90% and 87%, respectively. The average SUVmax values of TP, FP and FN lesions were 7.25, 6.11 and 2.76, respectively. There were no significant difference between SUVmax of TP lesions and FP lesions (p>0.95) but significantly higher than in FN lesions (p<0.001). The average size (by histopathology and colonoscopy) of TP lesions was 18.1 mm, statistically different from that of FN lesions which was 5.9 mm (p<0.001). Fifty-one percent of FN lesions were smaller than 5 mm (29/57) and 88% smaller than 10 mm (50/57). Conclusions: The high positive predictive value of incidental focal colonic FDG uptake of 48% for colonic neoplasia suggests that colonoscopy follow-up is warranted with this finding. We observed a low sensitivity of standardly acquired FDG-PET/CT for detecting small polyps, especially those less than 5 mm. Clinician and radiologists should be aware of the high PPV of focal colonic uptake reflecting pre-malignant and malignant lesions, and the need for appropriate follow up.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.281-289
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• 2000

Background : Mycobacterial culture is a confirmatory test to detect. M. tuberculosis, but it takes at least 6 weeks to diagnose. PCR is a rapid and sensitive method, but it is known that PCR has a high false positive rate due to contamination, and a high false negative rate due to inhibitors. It is also known that LCR and PCR-Hybridization, recently developed methods, are more specific methods than PCR in terms of detecting M. tuberculosis. In this study, we estimated the clinical utility of in house PCR, LCR and PCR-Hybridization for the detection of M. tuberculosis. Methods : We evaluated 75 specimens, upon which M. tuberculosis culture based testing was requested, by PCR LCR, and PCR-Hybridization and compared results. Mycobacterial culture was performed on 3% Ogawa media for 8 weeks, and an in house PCR, LCx Mycobacterium tuberculosis assay kit (Abbott Laboratories, North Chicago, III) and the AMPLICOR M. tuberculosis test kit (Roche Molecular Systems, Inc. Branchburg, NJ. USA). Results : In the view of the culture results, the sensitivities of the three tests were 40%, 80%, and 100% and their specificities were 98.6%, 94.3%, and 94.3%. Conclusion : LCR and PCR-Hybridization are rapid and sensitive methods for detecting M. tuberculosis in clinical laboratories.

• The KIPS Transactions:PartB
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• v.14B no.2
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• pp.65-70
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• 2007

Red tide is becoming hot issue of environmental problem worldwide since the 1990. Advanced nations, are progressing study that detect red tide area on early time using satellite for sea. But, our country most seashores bends serious. Also because there are a lot of turbid method streams on coast, hard to detect small red tide area by satellite for sea that is low resolution. Also, method by sea color that use one feature of satellite image for sea of existent red tide area detection was most. In this way, have a few feature in image with sea color and it can cause false negative mistake that detect red tide area. Therefore, in this paper, acquired texture information to use GLCM(Gray Level Co occurrence Matrix)'s texture 6 information about high definition land satellite south Coast image. Removed needless component reducing dimension through principal component analysis from this information. And changed into 2 principal component accumulation images, Experiment result 2 principal component conversion accumulation image's eigenvalues were 94.6%. When component with red tide area that uses only sea color image and all principal component image. displayed more correct result. And divided as quantitative,, it compares with turbid stream and the sea that red tide does not exist using statistical feature analysis about texture.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.390-394
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• 2004

The genetically modified glyphosate-tolerant soybean contains the following introduced DNA sequences: the EPSPS (5-enol-pyruvylshikimate-3-phosphate synthase) gene from Agrobacterium sp. strain CP4, the 35S promoter from the cauliflower mosaic virus, and the NOS terminator from Agrobacterium tumefaciens. In the present study, detection of these introduced DNAs was performed by amplification using the polymerase chain reaction (PCR). A multiplex PCR method was also applied to prevent false positive results. When primers for 35S promoter, nos3', CTP(chloroplast transit peptide), and CP4 EPSPS (EPSPS from Agrobacterium sp. CP4) were used, positive results were obtained in PCR reactions using DNA from genetically modified glyphosate-tolerant soybeans. There were no false positive results when using DNA from non-genetically modified soybeans. The CP4 EPSPS gene was detected when less than 125 pg glyphosate-tolerant soybean DNA was amplified. Lectin Lel and psb A were amplified from both non-genetically modified and genetically modified glyphosate-tolerant soybean DNA. Multiplex PCR was performed using different primer sets for actin Sacl, 35S promoter and CP4 EPSPS. The actin gene was detectable in both non-genetically modified and glyphosate-tolerant soybeans as a constant endogenous gene. Target DNAs for the 35S promoter, and CP4 EPSPS were detected in samples containing 0.01-0.1% glyphosate-tolerant soybean, although there were variations depending on primers by multiplex PCR. Soybean seeds from five plants of non-genetically modified soybean were co-cultivated for six months with those of genetically modified soybean, and they were analyzed by PCR. As a result, they were not positive for 35S promoter, nos3' or CP4 EPSPS. Therefore, these results suggest there was no natural crossing of genes between glyphosate-tolerant and non-genetically modified soybean during co-cultivation, which indicates that gene transfer between these plants is unlikely to occur in nature.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.9
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• pp.830-837
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• 2015

Space debris has been a major issue recently for the space-active nations because its growing population is expected to increase the collision risk with operational satellites. Radar and electro-optical system has been used for space debris surveillance, which may cause unnecessary anti-collision manoeuvers due to their low tracking accuracy. So an additional tracking system is required to improve the predicted orbit accuracy and then to jude the anti-collision maneouvers more efficiently. The laser tracking system has been considered as an alternative to decrease these unnecessary manoeuvers. Korea Astronomy and Space Science Institute has been developing a space object laser tracking system which is capable of laser tracking for satellites with retro-reflectors and for space debris using high power laser, and satellite imaging using adaptive optics. In this study, the tracking capability is analyzed for space debris using high power laser based on link budget, false alarm probability and signal detection probability.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.9
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• pp.361-368
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• 2014

The LPR(License plate recognition) system has been developed to efficient control for complex traffic environment and currently be used in many places. However, because of light, noise, background changes, environmental changes, damaged plate, it only works limited environment, so it is difficult to use in real-time. This paper presents a heuristic segmentation algorithm for robust to noise and illumination changes and introduce a real-time license plate recognition system using it. In first step, We detect the plate utilized Haar-like feature and Adaboost. This method is possible to rapid detection used integral image and cascade structure. Second step, we determine the type of license plate with adaptive histogram equalization, bilateral filtering for denoise and segment accurate character based on adaptive threshold, pixel projection and associated with the prior knowledge. The last step is character recognition that used histogram of oriented gradients (HOG) and multi-layer perceptron(MLP) for number recognition and support vector machine(SVM) for number and Korean character classifier respectively. The experimental results show license plate detection rate of 94.29%, license plate false alarm rate of 2.94%. In character segmentation method, character hit rate is 97.23% and character false alarm rate is 1.37%. And in character recognition, the average character recognition rate is 98.38%. Total average running time in our proposed method is 140ms. It is possible to be real-time system with efficiency and robustness.