• Journal of Information Processing Systems
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• v.8 no.3
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• pp.445-458
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• 2012

Image feature extraction is one of the basic works for biometric analysis. This paper presents the novel concept of application of ridgelets for iris recognition systems. Ridgelet transforms are the combination of Radon transforms and Wavelet transforms. They are suitable for extracting the abundantly present textural data that is in an iris. The technique proposed here uses the ridgelets to form an iris signature and to represent the iris. This paper contributes towards creating an improved iris recognition system. There is a reduction in the feature vector size, which is 1X4 in size. The False Acceptance Rate (FAR) and False Rejection Rate (FRR) were also reduced and the accuracy increased. The proposed method also avoids the iris normalization process that is traditionally used in iris recognition systems. Experimental results indicate that the proposed method achieves an accuracy of 99.82%, 0.1309% FAR, and 0.0434% FRR.

• Journal of the Korean School Mathematics Society
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• v.12 no.3
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• pp.307-317
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• 2009

Formally p$\rightarrow$q means that affirming p one implicitly affirms q and that denying q one implicitly denies p. Denying p or affirming q do not lead to certain conclusions. Middle school students can recognize practical implication p$\rightarrow$q is true whenever p is false, but they don't recognize theoretical implication p$\rightarrow$q is true whenever p is false. They have not assimilated intuitively the complete structure of implication. Thus they do not distinguish naturally between the uncertain conclusion which can be drawn by affirming p and the certain rejection of p which follows from the negation of q. Also they can not recognize the uncertain conclusion which can be drawn by negation of p. There is no significant difference between practical conditional statements, formal conditional statements and conditional Inferences in advanced mathematics students. But there is a significant difference between formal conditional inferences and specific conditional inferences with statement p$\rightarrow$q is true when p is false.

• Journal of Korea Multimedia Society
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• v.14 no.9
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• pp.1125-1137
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• 2011

Recently, there have been previous research about the iris recognition in mobile device to increase portability, whose accuracy is affected by the quality of iris image. Iris image is affected by illumination environment during the image acquisition. The existing system has high accuracy in indoor environment. However the accuracy is degraded in outdoor environment, because the gray levels of iris patterns in image are changed, and ghost and eyelash shading regions are produced by the sunlight of various wavelengths into iris region. To overcome these problems, we propose new mobile iris camera system which uses the near-infrared (NIR) light illuminator of 850 nm and band pass filter (BPF) of 850 nm. To measure the performance of the proposed system, we compared it to the existing one with the iris images captured in indoor and outdoor sunlight environments in terms of the equal error rates (EER) based on false acceptance rate (FAR) and false rejection rate (FRR). The experimental result showed that the proposed system had the lower EERs than those of previous system by 0.96% (with frontal light in indoors), 4.94% (with frontal light in outdoor), 9.24% (with side light in outdoor), and 7% (with back light in outdoor), respectively.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.2
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• pp.69-80
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• 1999

Recently, social requirements of personal identification techniques are rapidly expanding in a number of new application ares. Especially fingerprint recognition is the most important technology. Fingerprint recognition technologies are well established, proven, cost and legally accepted. Therefore, it has more spot lighted among the any other biometrics technologies. In this paper we propose a new on-line fingerprint recognition algorithm for non-inked type live scanner to fit their increasing of security level under the computing environment. Fingerprint recognition system consists of two distinct structural blocks: feature extraction and feature matching. The main topic in this paper focuses on the feature matching using the fingerprint minutiae (ridge ending and bifurcation). Minutiae matching is composed in the alignment stage and matching stage. Success of optimizing the alignment stage is the key of real-time (on-line) fingerprint recognition. Proposed alignment algorithm using clique shows the strength in the search space optimization and partially incomplete image. We make our own database to get the generality. Using the traditional statistical discriminant analysis, 0.05% false acceptance rate (FAR) at 8.83% false rejection rate (FRR) in 1.55 second average matching speed on a Pentium system have been achieved. This makes it possible to construct high performance fingerprint recognition system.

• Journal of the Korean Society of Safety
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• v.34 no.1
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• pp.82-89
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• 2019

The importance of aviation safety has been emphasized recently due to the development of aviation industry. Despite the efforts of each country and the improvement of screening equipment, screening tasks are still difficult and detection failures are frequent. The purpose of this study was to examine the effect of feedback on improving signal detection performance applying a Simulated Baggage Screening Program(SBSP) for improving aviation safety. SBSP consists of three parts: image combination, option setting and experiment. The experimental images were color-coded to reflect the items' transmittance of the x-rays and could be combined as researchers' need. In the option, the researcher could set up the information, incentive, and comments needed for training to be delivered on a number of tasks and times. Experiment was conducted using SBSP and participant's performance information (hit, missed, false alarms, correct rejection, reaction time, etc.) was automatically calculated and stored. A total of 50 participants participated and each participant was randomly assigned to feedback and non-feedback group. Participants performed a total of 200 tasks and 20(10%) contained target object(gun and knife). The results showed that when the feedback was provided, the hit, correct rejection ratio and d′ were increased, however, the false alarms and miss decreased. However, there was no significant difference in response criteria(${\beta}$). In addition, implications, limitations of this study and future research were discussed.

• Journal of Chest Surgery
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• v.36 no.6
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• pp.379-383
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• 2003

Background: An accurate diagnosis of the severity of the rejection after a heart transplantation relies on endomyo-cardial biopsy, but because of its invasiveness and the need for repeated examination makes it is an inappropriate monitoring method. Therefore, we have tried to find a monitoring method that is continuous and less invasive. Material and Method: Heterotopic heart transplantation using Ono-Lindsey Method was done in 20 rats, and then $^{99m}$ Tc-Pyrophosphate (PYP) scan was done after a month, Uptake ratio of transplanted heart to vertebrae (H/V) was obtained to be compared with the biopsy result. Result: Rejection was defined when the H/V uptake ratio was higher than 0.09, and we compared the uptake ratio with the results of biopsy. The result was true positives was 3, true negatives 12, false negatives 2, andfalse positives 3. Therefore sensitivity was 60% and specificity was 80%, diagnostic value was 75%. Conclusion: $^{99m}$Tc-Pyrophosphate (PYP) scan was a useful method for the evaluation of the heart transplantation rejection and it will be helpful for monitoring rejection as an non-invasive and simple method.hod.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.119-124
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• 2006

The present study evaluated the accuracy of MSD-related work criterion of Korea Ministry of Labor by using ergonomic workload evaluation methods. 1,948 manufacturing works in automobile industry were divided into 1,286 MSD-related risky works and 662 risk-free ones by using RULA, ANSI Z-365 and perceived discomfort evaluation. Then, the two types of works were evaluated by Labor Ministry work criterion to analyze the classification accuracy of the work criterion. The work criterion of Korea Labor Ministry had low hit and false alarm ratio(20 and 11%) and high miss and correct rejection ratio(80 and 89%), and the odd ratios of hit and correct rejection were 0.2 and 8.3, respectively. It can be concluded that the work criterion of Korea Labor Ministry is a conservative evaluation method which tends to evaluate a target work as risk-free.

• The Journal of the Acoustical Society of Korea
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• v.20 no.3
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• pp.3-7
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• 2001

In active sonar system using CW signal, when the noise included reverberation has not the white characteristics, the CFAR detector estimates high threshold. Because of this reason it cannot detect targets and not resolve the closely spaced multiple targets. In order to solve these problems, we propose an adaptive reverberation rejection filter The proposed filter is composed of an adaptive filter and a fixed filter with its coefficients. To study the performance of the proposed adaptive reverberation rejection filter, various experiments have been performed under In moving active sonar environments. As a results, the proposed method has the improved performance than the previous methods.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.6
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• pp.22-27
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• 2011

This paper presents an efficient technique to reduce PN code acquisition time considerably by adjusting threshold values in direct sequence spread spectrum (DS-SS) systems. The proposed algorithm employs a pre-dump mode prior to a search mode, and the pre-dump mode determines threshold values of both search and verification modes depending on its correlation energy, which can improve not only the rejection performance of false code phases in the search mode but also that in the verification mode. The proposed method can reduce the mean code acquisition time by about 40% without increase of hardware costs compared with the conventional technique.

• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.86-91
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• 1999

This paper presents the text-prompt method to overcome the weakness of text-dependent and text-independent speaker recognition. Enhanced dynamic time warping for speaker recognition algorithm is applied. For the real-time processing, we use a simple algorithm for end-point detection without increasing computational complexity. The test shows that the weighted-cepstrum is most proper for speaker recognition among various speech parameters. As the experimental results of the proposed algorithm for three prompt words, the speaker identification error rate is 0.02%, and when the threshold is set properly, false rejection rate is 1.89%, false acceptance rate is 0.77% and verification total error rate is 0.97% for speaker verification.