• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1467-1469
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• 2015

일반적인 홍채 인식 방법은 홍채 근육이 형성하는 고유 패턴에 기초하여 사용자를 식별한다. 홍채의 주요 기능은 자연광의 양에 따라 동공의 크기를 제어하는 것이다. 그러므로 홍채 패턴은 조명 조건의 변화에 따라 팽창 및 수축한다. 홍채 패턴의 변형에도 불구하고 강력한 인식의 정확도를 보장하기 위해 이전의 연구에서는 홍채 근육은 선형적으로 변형된다고 가정하여, 홍채의 트랙을 선형적이고 균일하게 할당하였다. 그러나 홍채 패턴은 실제로 특정 홍채 근육의 복잡한 움직임으로 인해 비선형적으로 변형된다. 이러한 문제점을 극복하기 위해 Dynamic Warping 방법을 사용하여 비선형성을 고려한 새로운 매칭 방법을 제안한다.

• Journal of The Korean Association For Science Education
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• v.34 no.8
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• pp.795-806
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• 2014

The purpose of this study is to develop an intervention program for improvement of elementary science-poor students' Basic Science Process Skill (BSPS) and to validate the intervention program's effectiveness using eye-tracker. The participants of this study were 35 elementary science-poor students. This study's method was the analysis of real-time eye movements during basic science process skill problem solving. SMI's 120 Hz iView XTM RED was used to collect EMD (eye movement data). Experiment 3.4 and BeGaze 3.4 programs were used to design experiment and to analyze EMD. The results of this study are as follows. First, we developed an intervention program including BSPS instructional strategy, behavior of teachers & student according instructional strategy stage, teachinglearning plan and learning note. Second, science poor students' BSPS ability has improved statistically significantly through the application of intervention program and BSPS problem-solving time decreased statistically significantly. Third, AFT (average fixation time) of BSPS Question and keyword area decreased statistically significantly. Fourth, APD (average pupil diameter) of BSPS problem-solving process expanded statistically significantly. Fifth, AST (average saccade time) of BSPS problem-solving process increased statistically significantly. Sixth, AFET (average fixation entry time) of BSPS problem-clue area was accelerated statistically significantly, AFT of BSPS problem-clue area reduced statistically significantly.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.6
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• pp.291-298
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• 2012

Carbamoylphosphate (CMPO) [CMPO analogue; 2-(diphenylphosphoryl)-N-(3-(triethoxysilyl)propyl)acetamide]silane, as a functional self-assembled molecules, grafted mesoporous silicates were prepared by simple hydrolysis and condensation reaction. Pore sized tailored mesoporous silicates such as MCM-41, SBA-15, or amorphous silica nanoparticles were adopted as host materials. The surface area of ordered mesoporous silicates was ranged from 680 $m^2/g$ to 1310 $m^2/g$ with different pore diameters that estimated to be ca. 2.3~9.1 nm by BJH method. Among the OMMs host materials, SBA-15(II) has higher loading ratio (~35 wt%) of CMPO derivative than other OMMs. Accessibility to CMPO silane functional groups in the surface of mesoporous silicas was studied by lanthanide ions sorption experiments. All of the CMPO modified OMMs favors the smaller Eu(III) and Nd(III) cations than La(III) for relative larger ionic radius.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.533-538
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• 2014

Purpose: This study is to investigate correlation between eye fatigue and letter contrast according to letter contrast changes on monitor display. Methods: Reading speed test were carried out for 53 subjects (mean age: $22.68{\pm}1.85$ years) who have over Best-corrected visual acuity (BCVA) 1.0, and 45 subjects, who could read over 123 out of 163 letters among 53 subjects were selected. They were asked to read the letters which were composed of Black (contrast 100%), Dark gray (contrast 80%), Gray (contrast 80%), Light gray (contrast 30%) randomly. The change of their eye fatigue by letter contrast on monitor display was measured by monitoring their eyes with an eye-tracker while they were reading letters. Results: Event Duration (sec) was 33.635 for Black, 32.266 Dark gray, 33.936 for Gray, and 34.848 for Light gray. Average of Fixation Duration (sec) was 0.224 for Black, 0.218 for Dark gray, 0.239 for Gray and 0.243 for Light gray. Average of Pupil diameter (mm) was 41.133 mm for Black, 41.160 mm for Dark gray, 40.880 mm for Gray and 40.459 mm for Light gray. Frequency (blinks/sec) was 0.211 for Black, 0.206 for Dark gray, 0.221 for Gray, and 0.238 for Light gray. Conclusions: Event Duration and average of Fixation Duration were the shortest for Dark gray and the longest for Light gray. In average Pupil diameter was the biggest Dark gray and the smallest for Light gray. Blink Frequency (blinks/sec) was the lowest for Dark gray and the highest for Light gray. Visual fatigue by brightness of letters on monitor display was the least for Dark gray followed by Black, Gray and Light gray.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.121-128
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• 2009

Iris recognition is a biometric technology which can identify a person using the iris pattern. Recently, iris information is used in many fields such as access control and information security. It is important for the iris recognition system to extract the feature which is invariant to changes in iris patterns. Those changes can be occurred by the influence of lights, changes in the size of the pupil. In this paper, we propose a novel method based on vector summation of gradient orientation vectors. Experimental results show that the proposed method reduces processing time with simple vector calculation, requires small feature space and has comparable performance to the well-known previous methods.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.786-791
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• 2007

Aerodynamically generated noise is dominant when the train speed approaches 300km/h. This noise sources is caused by the turbulent flow separations or vortex shedding from the train structure. Experiments were performed to investigate the characteristics of aerodynamic noise sources generated from exterior of the KTX trains and HSR-350x, especially from the inter-coach spacing. Measurements of both the inside and outside of the cabin are carried out to investigate the characteristics of the noise. Effect of the size of the mud-flap has been investigated through an wind tunnel test and it has been found that the low frequency noise is strongly dependent on the size of the gap. Also performed is an array measurement to locate different noise sources from the high-speed train. spectral characteristics of exterior noise sources are examined.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3C
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• pp.268-273
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• 2009

Iris recognition is a biometric technology which can identify a person using the iris pattern. It is important for the iris recognition system to extract the feature which is invariant to changes in iris patterns. Those changes can be occurred by the influence of lights, changes in the size of the pupil, and head tilting. In this paper, we propose a novel method based on local gradient orientation histogram which is robust to variations in illumination and rotations of iris patterns. The proposed method enables high-speed feature extraction and feature comparison because it requires no additional processing to obtain the rotation invariance, and shows comparable performance to the well-known previous methods.

• Korean Journal of Optics and Photonics
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• v.26 no.5
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• pp.249-254
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• 2015

In this paper we propose a binocular holographic three-dimensional (3D) imaging system using optical scanning holography. To realize a binocular 3D holographic imaging system, we could acquire the complex holograms of a real object after designing a holographic display system based on interpupillary distance and pupil size, and these holograms could be optically reconstructed following numerical signal processing with an amplitude spatial light modulator. The proposed binocular 3D holographic imaging system using optical scanning holography was verified experimentally.

• Journal of the Korean Chemical Society
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• v.32 no.5
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• pp.443-451
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• 1988

New crown ether dye-Ⅰ and dye-Ⅱ having an azo group(-N=N-) were synthesized from monobenzo-15-crown-5 and dibenzo-18-crown-6. These dyes showed ${\lambda}_{max}$ of 377 and 383nm respectively. The complexes of alkali metal ions ($Na^+$, $K^+$, $Cs^+$) with dye ligands showed band shift (390~400nm) and intensity increased. For a given anion, the extraction constants are in the order of $K^+$ < $Cs^+$ < $Na^+$ for dye-Ⅰ and $Cs^+$ < $Na^+$ < $K^+$ for dye-Ⅱ. These results show that the selectivity of crown ethers toward the alkali metal ions is dependant on the charge density of cation and the size of crown ether cavity. For a given cation, the order of the extraction constant is $Cl^-$ < $Br^-$ < $I^-$ < picrate. This order coincides with the degree of anion solvation effect.

• Korean Journal of Acupuncture
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• v.29 no.4
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• pp.554-562
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• 2012

Objectives : The purpose of this research is to verify the effects of the Electromagnetic acupuncture(EMA) on BL15 by Pupil size variability(PSV) which is directly related to the activation of the Autonomic Nervous System. Methods : Thirty male subjects participated in this study and were divided into three groups(non-stimulated, manual acupuncture and EMA group). The size of pupil was measured in the cube place of $60{\times}60{\times}60$ cm in order to avoid the effect of the surrounding circumstances. All subjects were measured the size of left pupil about 200sec in the constant illumination. Results : We observed the decrease in PSV of manual acupuncture group compared to non-stimulation group, but it was not significant statistically(p>0.05). The decrease in PSV of EMA group was observed in comparison to two groups, and we confirmed the result of significant difference statistically(p<0.05). Conclusions : We concluded that EMA treatment method is enough to activate in the parasympathetic nerve system by inducing the biotransformation.