• Korean Journal of Cognitive Science
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• v.14 no.1
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• pp.17-28
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• 2003

In order to provide natural images with a specified depth through three-dimensional display system, the stereo images should be similar to those projected from real environment as much as possible. Even when two persons see an identical scene, the binocular Parallax between two images of an object varies as a function of one's inter-pupilary distance (IPD). In this study, we investigated whether individual differences, such as IPD and accommodative vergence, would affect the perception of three dimensional scene provided by stereo-images. Results showed that a person's IPD is correlated with the limit of screen and binocular parallax for single vision, and affects the perceived depth of an object on fixation. More specifically, with longer IPD the limit of screen and binocular parallax for single vision is decreased, and the perceived depth is reduced. These results suggest that the screen and binocular parallax of an object should be calibrated with regard to users IPD to provide natural stereo-images with a specified depth and to Prevent double vision.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.1-8
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• 2014

The virtual avatar is a principal way as media for communicating language and affective feelings in virtual environment. As similar purpose, this study evaluates user's visual feeling according to the changes of iris color and pupil size of virtual avatar which is considered as new factors for representing realistic avatar. Virtual avatars were configured by pupil accommodation and iris color(green, brown). After presenting above image to 32 participants, a questionnaire(18 items) based on previous studies was created, and reported as a 5-point scale. Experimental result showed that the case of adopting pupil accommodation induced more realistic visual feeling of subjects. This result can be regarded as a basis for designing realistic virtual avatar by confirming the effectiveness of pupil accommodation of avatar in terms of representing visual presence.

• Journal of Preventive Medicine and Public Health
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• v.30 no.3 s.58
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• pp.599-608
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• 1997

We studied on change of lens accommodation and pupil light reflex caused by VDT work in six women and compared them with those of other office works. The results were as follows. 1. In VDT work the accommodation contraction velocity decreased during the first 2-hr VDT task, then recovered markedly by the end of the one-hour lunch break, and decreased again by the end of the 2nd 2-hr VDT task. Changes of relaxation velocity showed similar pattern although it was less typical than that of contraction velocity 2. There was no marked change in accommodation contraction velocity and amplitude of accommodation in general office work and near-distance office work, and in the near-distance office work accommodation relaxation velocity decreased according to work load without recovery after lunch break. 3. Initial pupil diameter, initial pupil area of light reflex decreased significantly during VDT task only in VDT work and didn't recover after lunch break. These results suggest possibility that changes of accommodation contraction velocity, accommodation relaxation velocity, near point distance, and pupil diameter and area are useful in evaluating characteristics of VDT work. For this, more research adjusted individual differences, circadian rhythm, emotional stress needs.

• Journal of the Korea society of information convergence
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• v.6 no.2
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• pp.51-55
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• 2013

The accomodation is made to see near objects. This accomodation have different characteristics from individual to individual. Difference also occurs accommodation of the theory and real. This is accomodative-lag. Depth of focus directly affects the accomodative-lag. Depth of focus is affected by the refractive power and the size of the pupil. Depth of focus becomes deeper as the size of the pupil is small, the refractive power is increased. The accomodative-lag occur more as depth of focus is deep. In this paper, a study was made of the relationship of the accomodative-lag and refractive power. A Monocular Estimation Method(MEM) use for measuring the accomodative-lag. Results were measured by MEM, it tended to increase the refractive power so as to increase the accodative-lag. The accomodative-lag amount was measured at 0.51D. Men were measured at 0.52D, women were measured at 0.49D. The accomodative-lag by gender tended also increases the amount of refractive power increases.

• Korean Journal of Optics and Photonics
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• v.15 no.1
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• pp.79-85
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• 2004

We report on a transmittance controlled photomask with phase patterns on the back quartz surface. Theoretical analysis for changes in illumination pupil shape with respect to the variation of size and density of backside phase patterns and experimental results for improvement of critical dimension uniformity on a wafer by using the transmittance controlled photomask are presented. As phase patterns for controlling transmittance of the photomask we used etched contact-hole type patterns with 180" rotative phase with respect to the unetched region. It is shown that pattern size on the backside of the photomask must be made as small as possible in order to keep the illumination pupil shape as close as possible to the original pupil shape and to achieve as large an illumination intensity drop as possible at a same pattern density. The distribution of illumination intensity drop suitable for correcting critical dimension error was realized by controlling pattern density of the contact-hole type phase patterns. We applied this transmittance controlled photomask to a critical layer of DRAM (Dynamic Random Access Memory) having a 140nm design rule and could achieve improvement of the critical dimension uniformity value from 24.0 nm to 10.7 nm in 3$\sigma$.TEX>.

• Optical Science and Technology
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• v.5 no.3
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• pp.7-15
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• 2001

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1159-1162
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• 2005

휴대폰에 이용한 금융 활동이 늘어남에 따라 휴대폰 상에서의 보안의 필요성이 높아지게 되었다. 기존의 비밀번호 기반의 보안을 넘어 생체인식 기술이 휴대폰에 필요하게 되었다. 특히 홍채인식 기술이 지문인식이나 얼굴인식, 목소리 인식 등의 다른 생체인식 기술에 비해 신뢰성과 정확성 면에서 휴대폰에 적합한 기술이다. 본 논문에서는 휴대폰 환경에서 만족할 만한 성능과 처리시간을 보여주는 홍채인식 방법을 제안하고자 한다. 밝기와 대조를 조절하여 동공의 어두운 부분과 동공 반사광을 이용하여 홍채영역을 추출하는 방법을 제안한다. ARM 계열의 프로세서를 사용하는 휴대폰 프로세서의 특징에 맞도록 기존의 방법에서 사용되었던 실수 연산 방법을 줄여 처리 속도를 개선하였다. 실험 결과는 제안하는 방법의 휴대폰 환경에서 실시간으로 홍채인식을 수행하기에 적합한 성능을 보인다는 것을 보여준다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.425-431
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• 2006

In order to investigate the effects of ethylene on the seed development of three corn types (dent, sweet, and super sweet corns), aminoethoxyvinyl glycine (AVG) and silver thiosulfate (STS) and ethephon (2-chloroethylphosphonic acid, CEPA) were applied either on whole plants or shanks of ears at 9 and 21 days after silking. Ethylene production of developing super sweet corn seeds was much higher than those of sweet and dent corns. The cavity in the endosperm tissues of the super sweet corn started earlier and endosperm was collapsed more severely compared to those of sweet and dent corns. Ethylene production seemed to be related to the death of endosperm cells to form a cavity. Application of AVG and STS reduced ethylene production and delayed cavity formation in endosperm of super sweet corn seeds, while CEPA increased ethylene production and enhanced the time of cavity formation. AVG and STS increased 100-seed weight, while CEPA decreased.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.1117-1123
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• 2009

Head fixed type multi-focus display system using Galvano-scanner and DMD(Digital Micro-mirror Device), which is able to perfectly accommodate, can solve eye fatigue due to conflict between convergence eye movement and accommodation action in stereoscopic display. This system is able to accommodate through making convergence point about each view point and offering it in front of observer's pupil by using laser scanning method. In this paper, we analyzed laser scanning method of this multi-focus display system. And multi-focus display system based on this analysis was made, which showed that focus adjustment was possible through video camera. As a result, formation principle of view point of multi-focus system by laser scanning method was verified.

• Analytical Science and Technology
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• v.14 no.4
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• pp.349-355
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• 2001

A series of micro- and mesoporous activated carbons were prepared from phenolic resin using a metal treated chemical activation methodology. $N_2$-adsorption data were used to characterize the surface properties of the produced activated carbons. Results of the surface properties and pore distribution analysis showed that phenolic resin can be successfully converted to micro- and mesoporous activated carbons with specific surface areas higher than $962.3m^2/g$. Activated carbons with porous structure were produced by controlling the amount of metal chlorides($CdCl_2$, $CuCl_2$). Pore evolvement was shown to be most effected by the incremental addition of metal chloride. From the thermodynamic DSC data, enthalpy formations(${\Delta}H$) of first endothermic reaction were increase with the incremental addition of metal chloride.