• Journal of the Korean Society of Radiology
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• v.79 no.6
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• pp.359-364
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• 2018

There are two forms of cryptococcal meningitis immune reconstitution inflammatory syndrome (CM-IRIS): paradoxical CM-IRIS and unmasking CM-IRIS. It is important to distinguish paradoxical CM-IRIS and CM relapse because mortality of CM-IRIS is higher than that of CM without IRIS, and paradoxical CM-IRIS and CM relapse requires different treatment. We report a case of paradoxical CM-IRIS that well matches the clinical findings with MR findings during three years follow-up of a HIV infected patient and new MRI finding is also introduced to help distinguish them.

• Journal of Biomedical Engineering Research
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• v.25 no.1
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• pp.83-86
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• 2004

The variation of the directional properties of an image is used to extract the iris code for human identification. In order to conserve the original information while minimizing the effect of noise, scale-space filtering is applied. Resulting binary codes have been tested on a set of 272 iris images obtained from 18 persons.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.440-444
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• 2014

Iris yellow spot virus (IYSV) is a plant pathogenic virus which has been reported to continuously occur in onion bulbs, allium field crops, seed crops, lisianthus, and irises. In South Korea, IYSV is a "controlled" virus that has not been reported, and inspection is performed when crops of the genus Iris are imported into South Korea. In this study, reverse-transcription polymerase chain reaction (RT-PCR) and nested PCR inspection methods, which can detect IYSV, from imported crops of the genus Iris at quarantine sites, were developed. In addition, a modified positive plasmid, which can be used as a positive control during inspection, was developed. This modified plasmid can facilitate a more accurate inspection by enabling the examination of a laboratory contamination in an inspection system. The inspection methods that were developed in this study are expected to contribute, through the prompt and accurate inspection of IYSV at quarantine sites to the plant quarantine in South Korea.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.133-137
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• 2006

In iris recognition, iris segmentation plays a very important role because its accuracy affects directly to the performance of the whole system. This paper proposes a new approach for segmenting iris that is fast, accurate and especially robust to occlusion and illumination. In this method, a circular filter is used for detecting the center of the inner circle. Then, a technique to linearize the limbus is applied and the limbus is detected using a linear filter. Experimental results show that the proposed method has promising performance for improving the iris recognition accuracy.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.4
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• pp.468-472
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• 2004

This paper presents an intelligent iris recognition system which consists of quality check, iris localization, feature extraction, and verification. For the quality check, the local statistics on the pupil boundary is used. Gaussian mixture model is used to segment and localized the iris region. The feature extraction method is based on an optimal waveform simplification. For the verification, we use an intelligent variable threshold.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.863-864
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• 2008

To predict the iris matching performance and guarantee its reliability, image quality measure prior to matching is desired. An analysis on iris image degradation factors which deteriorate matching performance is a basic step for iris image quality measure. We considered five degradation factors-white-out, black-out, noise, blur, and occlusion by specular reflection-which happen generally during the iris image acquisition process. Experimental results show that noise and white-out degraded the EER most significantly, while others on EER were either insignificant or degradation images resulted in even better performance in some cases of blur. This means that degradation factors that affect the performance can be different from those based on human perception or image degradation evaluation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2424-2441
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• 2012

In this paper, we propose a fake iris detection method that combines the optical and textural features of the human eye. To extract the optical features, we used dual Purkinje images that were generated on the anterior cornea and the posterior lens surfaces based on an analytic model of the human eye's optical structure. To extract the textural features, we measured the amount of change in a given iris pattern (based on wavelet decomposition) with regard to the direction of illumination. This method performs the following two procedures over previous researches. First, in order to obtain the optical and textural features simultaneously, we used five illuminators. Second, in order to improve fake iris detection performance, we used a SVM (Support Vector Machine) to combine the optical and textural features. Through combining the features, problems of single feature based previous works could be solved. Experimental results showed that the EER (Equal Error Rate) was 0.133%.

• Transactions of the Society of Information Storage Systems
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• v.5 no.2
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• pp.53-57
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• 2009

This study is concerned with the design of a camera iris-shutter device for producing force. The camera iris-shutter with yoke should have a smaller size and a bigger magnetic force than the previous model. Since the induced magnetic force operates shutter movement, the magnetic force maximization for a given input current is an important issue. To achieve the goal, new system is designed by the topology optimization method. The design is refined through the design of experiments to find the detail camera iris shutter design satisfying design constraints.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.19-25
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• 2006

Iris recognition is a bio metric personal identification which uses iris pattern of the pupil, and it is recognized as one of the best technology in personal identification and information security field. Before iris recognition, it is very important to search center of pupil. In recent years, there was developed many searching algorithms of center of pupil, but all most method are too many processing time. In this paper, we proposed a new method for searching center of pupil. This method is greatly reduced processing time about 30% compared with other algorithm using Hough transformation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.332-335
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• 2005

A Study on the moving iris tracking and the screen cursor controlling is presented in this paper. The screen cursor is moved by center position of iris moving to extent of eye. The experimental result shows that the moving of iris and screen cursor are accord with distance and size of screen for the optimal tolerance is reduced the tracking error.