• Transactions on Electrical and Electronic Materials
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• 제3권2호
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• pp.1-5
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• 2002

Alignment effects for nematic liquid crystal (NLC) and electro-optical (EO) characteristics of the ion beam (IB) aligned twisted nematic (TN)-liquid crystal display (LCD) with oblique ion beam exposure on the diamond-like carbon (DLC) thin film surface were studied. A high pretilt angle of 3.5$^{\circ}$ in NLC by ion beam exposure on the DLC thin film layer can be measured. An excellent voltage-transmittance (V-T) curve of the ion beam aligned TN-LCD was observed with oblique ion beam exposure on the DLC thin film surface for 1 min. Also, a faster response time for the ion beam aligned TN-LCD with oblique ion beam exposure on the DLC thin film surface for 1 min can be achieved.

• 한국수산과학회지
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• 제53권6호
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• pp.965-967
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• 2020

Two shark species captured in Samcheok in 2006 and Ulsan in 2013, previously reported as Heptranchias perlo and Alopias pelagicus, were confirmed to in fact be Hexanchus griseus and A. superciliosus, respectively, neither of which has previously been reported in Korea. H. griseus has six gill slits and is thus distinguishable from Heptranchias perlo, which has seven gill slits. A. superciliosus is clearly distinguishable from A. pelagicus and A. vulpinus, members of the family Alopiidae, due to its large eyes and a groove extending from the center of the head to both eyes. The keys to the family Hexanchidae, including H. griseus, and the family Alopiidae, including A. superciliosus, were presented along with the morphological characteristics of these two new shark species. These two species were given the Korean names "Gi-reum-sang-eo" and "Keun-nun-hwan-do-sang-eo," with reference to their morphological characteristics and English names.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.181-184
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• 2000

A new photo-alignment material, copoly (PM4Ch-ChMA), copoly (poly (4-methacryloyloxy) chalcone-chalconemethacryl) was synthesized and the electro-optical (EO) characteristics for the photo-aligned vertically aligned (VA)-LC display (LCD) were investigated. The monodomain alignment of the NLC for the photo-aligned VA-LCD by linearly polarized UV exposure on the photo-dimerized copoly (PM4Ch-ChMA) surfaces was observed. Excellent voltage-transmittance characteristics for the photo-aligned VA-LCD by UV exposure for 1 min. on the copoly (PM4Ch-ChMA) surfaces were achieved. The response time of the photo-aligned VA-LCD by UV exposure on for 1 min. the copoly (PM4Ch-ChMA) surfaces was about 39.3 ms. The response time for the photo-aligned VA-LCD decreased with increasing UV exposure time.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.537-540
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• 1999

Effect of alignment layers on pretilt angle generation and electrical characteristics in nematic liquid crystal(NLC) by using photo-alignment techniques on polyimide (PI) surface with side chain were studied. The generated pretilt angle of the NLC on rubbed PI surface with 1-layer is almost the same as that of the 2-layers. However, the generated pretilt angle of the NLC on photo-induced PI surface with 2-layers is larger than that of the 1-layer. Therefore, the pretilt angle of the NLC on photo-induced PI surface is attributed to surface roughness due to photo-depolymerization of the polymer with UV light irradiation on PI surface. Next we observed the same characteristics of voltage-transmittance (V-T) and response time for 1- and 2-layers on PI surface. We also observed the same voltage holding ratio (VHR) characteristics for 1- and 2-layers on photo-aligned PI surface. Consequently, we suggest that the VHR of photo-aligned TN-LCD is higher than that of the rubbing-aligned TN-LCD.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.433-433
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• 2007

In this paper, we investigated the feasibility of applying ZnO:Al films to display devices as transparent electrodes, and reported the electro-optical (EO) characteristics of VA cells using ZnO:Al electrodes and compared them with those of VA cells using ITO electrodes. The experiment results show that a uniform vertical LC alignment and a large pretilt angle were achieved. Also, the good voltage-transmittance curve, response time, and capacitance-voltage characteristics were observed for the rubbing aligned VA-LCD using ZnO:Al electrodes m comparison with ITO electrodes. In other words, the vertical alignment mode based on the ZnO:Al electrodes showed appropriate electro-optical characteristics and high transparency in comparison with that based on the ITO electrodes. These results indicated that the transparent ZnO:Al electrodes of the liquid crystal displays could substitute the ITO electrodes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.400-400
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• 2007

In this study, we investigated liquid crystal (LC) alignment with ion beam (IB) that non contact alignment technique on polyimide and electro-optical characteristics of twisted nematic (TN)-liquid crystal display (LCD) on the polyimide under various ion beam angles. In this experiment, polyimide layer was coated on glass by spin-coating and Voltage-transmittance(VT) and response time characteristics of the TN cell were measured by a LCD evaluation system. The good characteristics of the nematic liquid crystal (NLC) alignment with the ion beam exposured polyimide surface was observed. In addition, it can be achieved the good EO properties, and residual DC property of the ion beam aligned TN cell on polyimide surface.

• 대한원격탐사학회지
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• 제31권2호
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• pp.111-125
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• 2015

본 연구에서는 고해상도 위성영상인 TerraSAR-X와 WorldView-2 등을 융합하여 표적의 특성을 고려한 표적군(Group of targets) 검출을 수행하였다. 관심 대상으로 하는 표적은 고정되어 있으며, 군(Group)을 이루고 있는 특징이 있다. 표적 후보를 검출하기 위해 대상 물체의 레이더 후방산란 특성을 이용한 Constant False Alarm Rate (CFAR) 알고리즘을 적용하였다. 검출된 표적 후보군으로부터 비표적을 제거하기 위해 표적의 크기 정보를 이용한 화소 클러스터링, 표적군을 이루는 표적들간의 배치 특성을 이용한 네트워크 클러스터링. 그리고 SAR 간섭기법 적용이 가능한 간섭쌍이 있는 경우 긴밀도 정보를 이용하였다. 또한, 오경보(False Alarm)를 감소시키고 최종 표적을 결정하기 위해, 표적의 형태 정보를 추출할 수 있는 Electro-Optical (EO) 영상을 바탕으로 효과적인 타원 검출 기법을 개발하였다. 개발된 표적군 검출 알고리즘을 10개 지역에 적용한 결과, 표적군 검출율은 100%, 단일 표적에 대한 오경보율은 0.03~0.3개/$km^2$, 평균 오경보는 1.8군/$64km^2$로 낮은 오경보와 높은 검출율을 보이며 표적군이 검출되었다. 본 연구에서 개발된 표준화된 표적 검출 기법은 향후 무인화된 표적 검출 시스템 구축에 핵심적인 기술이 될 것으로 전망한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1765-1767
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• 1999

We synthesised a photo-alignment material of PM4Ch (poly(4-methacryloylloxychalcone)). The electro-optical (EO) characteristics of photo-aligned twisted nematic (TN)-liquid crystal display (LCD) with linearly polarized ultraviolet (UV) light irradiation on PM4Ch surface were investigated. The uniform alignment of NLC with polarized UV light irradiation on PM4Ch surface was measured. Also, We had The excellent voltage-transmittance characteristics of photo-aligned TN-LCD. The low threshold voltage of photo-aligned TN-LCD was measured. Moreover, the fast response time of photo-aligned TN-LCD on PM4Ch was successfully achieved. Finally The reduction DC voltage of photo-aligned TN-LCD decreases with increasing the UV light irradiation time on photo-dimerized PM4Ch surface.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1759-1761
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• 1999

The generation of pretilt in nematic liquid crystal(NLC)and electro-optical(EO) characteristics of photo-aligned twisted nematic (TN)-LCD with oblique p-polarized ultraviolet (UV) light irradiation on the two kinds of the soluble polyimide (PI) surfaces containing trifluoromethyl moieties were investigated. The generated pretilt angle of NLC is about $2.5^{\circ}$ with p-polarized UV light irradiation of $20^{\circ}$ on PI-3 surface at 20 min.; However pretilt angle of about $0.5^{\circ}$ are observed on PI-1 and PI-2 surfaces. The generated pretilt angle of NLC on PI-3 surface may be attributed to the trifluoromethyl moieties attached to the lateral benzene rings. The voltage-transmittance and response time characteristics of photo-aligned TN-LCD with p-polarized UV light irradiation of $20^{\circ}$ on PI-1 surfaceat at 20 min were almost same in comparison with the rubbing-aligned TN-LCD. However, the high threshold voltage and slow response are observed on PI-3 surface. Also, the decay time $\tau_d$ of photo-aligned TN-LCD is attributed to the anchoring energy of NLC.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.7-10
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• 2005

Plant water deficiency during drought season causes physiological stress and can be a critical indicator of forest fire vulnerability. In this study, we attempt to analyze the spectral characteristics of water stressed vegetation by using the laboratory measurement on leaf samples and the canopy reflectance spectra extracted from satellite hyperspectral image data. Leaf-level reflectance spectra were measured by varying moisture content using a portable spectro-radiometer. Canopy reflectance spectra of sample forest stands of two primary species (pine and oak) located in central part of the Korean peninsula were extracted from EO-l Hyperion imaging spectrometer data obtained during the drought season in 2001 and the normal precipitation year in 2002. The preliminary analysis on the reflectance spectra shows that the spectral characteristics of leaf samples are not compatible with the ones obtained from canopy level. Although moisture content of vegetation can be influential to the radiant flux reflected from leaf-level, it may not be very straightforward to obtain the spectral characteristics that are directly related to the level of canopy moisture content. Canopy spectra form forest stands can be varied by structural variables (such as LAt, percent coverage, and biomass) other than canopy moisture content.