• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.5
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• pp.530-535
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• 2004

We have studied 90$^{\circ}$ twisted nematic mode switching by fringe electric field(F-TN mode) using a liquid crystal (LC) with negative dielectric anisotropy. In the device, two polarizers are parallel each other, electrodes exist only on bottom substrate, and one of rubbing direction is coincident with polarizer axis. Therefore, the cell shows a black state before a voltage is applied. With a bias voltage generating fringe-electric field, the LC twists perpendicular to fringe electric field such that the LCs are almost homogeneously aligned except near the bottom surface since the negative type of the LC is used. Consequently, the new device exhibits much wider viewing angle than that of the conventional TN mode due to in-plane switching and relatively high transmittance since the LC director above whole electrode area aligns parallel to the polarizer axis.

• Journal of Information Display
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• v.2 no.1
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• pp.1-4
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• 2001

We propose a dual in-plane parallel electrode structure of a vertical configuration of a helix-deformed ferroelectric liquid crystal (HDFLC) mode for better brightness than a single in-plain electrode case. This structure provides high brightness in addition to the analog gray scale capability, fast response, and wide-viewing characteristics. In contrast to a conventional HDFLC in a planar geometry, smectic layers arrange themselves parallel to the substrates and thus extremely uniform alignment of molecules in a large area is naturally achieved in our new configuration.

• Electronics and Telecommunications Trends
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• v.34 no.2
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• pp.10-18
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• 2019

Since the introduction of CRT(Cathode Ray Tube) in the 1950s, display technologies have been developed continuously. Flat panel displays such as PDP(Plasma Display Panel) and LCD(Liquid Crystal Display) were commercialized in the late 1990s, and OLED(Organic Light Emitting Diodes) and Micro-LED(Micro-Light Emitting Diodes) are now being developed and are becoming widespread. In the future, we expect to develop ultra-realistic, flexible, embedded sensor displays. Ultra-realistic display can be applied to AR/VR(Augmented Reality/Virtual Reality) devices and spatial light modulators for holography. The sensor-embedded display can be applied to robots; electronic skin; and security devices, including iris recognition sensors, fingerprint recognition sensors, and tactile sensors. AR/VR technology must be developed to meet technical requirements such as viewing angle, resolution, and refresh rate. Holography requires optical modulation technology that can significantly improve resolution, viewing angle, and modulation method to enable wide-view and high-quality hologram stereoscopic images. For electronic skin, stable mass production technology, large-area arrays, and system integration technologies should be developed.

• The Journal of Korean Society for School & Community Health Education
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• v.8 no.2
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• pp.35-48
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• 2007

Background & Objective: The purpose of this study was to identify the level of health behavior and taking courses related with those subjects by college students and analyse the factors that have effect on these issues so that provide a basic material in developing policy and education program that can increase the level of health behavior for them. Methods: A questionnaire was applied 1,500 college students for two months from October 10 to 30, 2007. Results: 1) When viewing the objects of this study as general traits and social economic ratio, 'female' was 59.4%, BMI index of '20-14' was 52.7%, department of natural science was 47/7%, and 'their own house' was 51.0%. 2) When viewing the experience of taking courses related with health by the trait of demography and sociology, 'no' was most high by showing 42.2%, and those of female. under 19 in BMI index, and the department of natural science showed no experience. 3) When viewing satisfaction with college life they showed $3.00{\pm}0.71$, stress level in college life $2.84{\pm}0.41$, the level of health behavior $2.06{\pm}0.65$. 4) When viewing taking courses related with health, stress in college life. and health behavior according to satisfaction with college life they showed $2.06{\pm}0.59$. 5) When viewing the level of health behavior according to demographic and sociological traits, the habit of eating was $2.48{\pm}0.52$ and health care was $2.96{\pm}0.47$. 6) When viewing the effect of factors on health behavior, there were gender, age, residence area, grade, and satisfaction with college life. Conclusion: As we can see from the results above, it is the fact that the students in college are neglecting the subjects related with health owing to short period of education and major based education by the education aim of fostering professional career manpower. Therefore it needs open many culture courses for the subject related with health in college for the students to increase their health level as well as their major, and also there needs combined improvement of college and government system.

• Journal of Korean Society of Forest Science
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• v.97 no.6
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• pp.634-640
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• 2008

The purpose of this study is to clarify the physiological effects of Shinrin-yoku (taking in the atmosphere of the forest of forest bathing). The subjects were twelve male university students ($21.6{\pm}2.1$ years old). On the first day, six subjects were sent to a forest area, and the others to a city area. On the second day, the subjects were sent to the opposite areas for a cross check. The subjects were seated on chairs and viewing the landscapes of their given areas for 15 minutes. HRV (Heart Rate Variability) and diastolic blood pressure were used as physiological indices. Diastolic blood pressure and LF/(LF+HF) components of HRV in the forest area were significantly lower than in the city area. And HF power components of HRV in the forest settings were significantly enhanced than in city settings. In conclusion, the results of the physiological measurements show that Shinrin-yoku was able to effectively relax people in both mind and body.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.569-573
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• 2014

We demonstrate a low-cost, superbly efficient way of etching for the nano-, and micro-sized pyramid patterns on (100)-oriented Si wafer surfaces for use as a patterned master. We show a way of producing functional optical films for the viewing angle direction brightness-enhancement of Lambertian LED (light emitting diode)/OLED (organic light emitting diode) planar lighting applications. An optimally formulated KOH (Potassium hydroxide) wet etching process enabled random-positioned, and random size-distributed (within a certain size range) pyramid patterns to be developed over the entire (100) silicon wafer substrates up to 8" and a simple replication process of master patterns onto the PC (poly-carbonate) and PMMA (poly-methyl methacrylate) films were performed. Haze ratio values were measured for several film samples exhibiting excellent values over 90% suitable for LED/OLED lighting purposes. Brightness was also improved by 13~14% toward the viewing angle direction. Computational simulations using LightTools$^{TM}$ were also carried out and turned out to be in strong agreement with experimental data. Finally, we could check the feasibility of fabricating low-cost, large area, high performance optical films for commercialization.

• Journal of Information Display
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• v.4 no.1
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• pp.9-13
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• 2003

An overview of author activity in the area diffractive LCDs are given. The formation of colour spectrum DL CDs is made by switchable phase diffraction gratings created in a LC layer due to using of comb-like electrodes. The offered DLCDs functionate without polarizes, have high contrast and spectral of pure colours, broad viewing ngles. The existing production equipment can be adapted to manufacturing of DLCD without considerable alterations.

• Korean Institute of Interior Design Journal
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• v.16 no.2 s.61
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• pp.233-241
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• 2007

Circulation planning for exhibition space depends on visitors, exhibition documents and exhibition space. To make visitors feel sympathy for the exhibition and meet visitors' movement and its spatial factors in the exhibition, guidelines for the planning layout of exhibition and exhibition space are needed. This research was aimed at gathering guidelines about the circulation planning for exhibition space for visitors who can acquire exhibition information in a natural way and enjoy the whole aspect of exhibition or enjoy preferential exhibition by investigating and analyzing viewing types of visitors, layout of exhibition and space unit exhibition. The result of this research was summarized as the following. 1) It needs optional viewing space large enough to be seen clearly so that all exhibition space can be seen at a glance at the main entrance of exhibition. 2) Layout of exhibition is needed for island-exhibition position and optional space preparation, when visitors pass by an article on exhibition short-cut. 3) Layout of exhibition is needed for double sided exhibition.

• Proceedings of the KSRS Conference
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• v.2
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• pp.651-654
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• 2006

Infrared channels of newly launched Japanese geostationary satellite, MTSAT-1R are compared with well calibrated MODIS/Terra infrared measurements at 3.7, 6.7, 11, 12 ${\mu}m$ bands. There are four steps in this intercalibration method: 1) data collection, 2) spectral response function correction, 3) data collocation, and 4) calculation of mean bias and conversion coefficients. In order to minimize the navigation error of MTSAT-1R, comparisons are made over the area in which the viewing angle of MTSAT-1R is less than 50$^{\circ}$. The calibration method was tested for August 2005 and within the 40$^{\circ}N$-40$^{\circ}S$, 100$^{\circ}$E-180$^{\circ}$E domain. The differences of spectral response functions were corrected through radiative transfer model simulation. Constructing collocated data differences in viewing geometry, observation time and space were taken into account. In order to avoid the radiance variation induced by cloud presence, clear-sky targets are selected as intercalibration target. The mean biases of 11, 12, 6.7, and 3.7 ${\mu}m$ bands are about -0.16, 0.36, 1.31, and -6.69 K, suggesting that accuracies of 3.7 ${\mu}m$ is questionable while other channels are comparable to MODIS

• Journal of Information Display
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• v.5 no.2
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• pp.23-26
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• 2004

For high end, large area displays, all current LC modes require some degree of optical compensation to improve the front of screen viewing experience. Currently most optical films are laminated to the outside of the LCD cell, between the glass and polariser. In this paper we wish to show how it is possible to integrate the compensating optical film within a VA mode LCD cell. The paper will describe the process of making the biaxial film through the process of in-situ photopolymerisation of an aligned film of reactive mesogens in the cholesteric phase using polarised UV light. The film can be made on the colour filter array side of the LCD panel. In addition the process of fabricating a VA mode LCD containing this film will be described and the performance of this module will be presented.