• 정보저장시스템학회논문집
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• 제6권1호
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• pp.1-5
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• 2010

Holographic data storage system(HDSS) has many noise sources - crosstalk, scattering and inter pixel interference, etc. Generally the intensity of a light generated from the laser source has Gaussian distribution and this ununiformity of light also can make the data page to have a low SNR. A beam apodizer is used to make the laser as a flat-top beam but the intensity distribution is not strictly uniform. The intensity of light can be controlled using image mask. In this paper the intensity distribution of light used for HDSS is controlled by a digital image mask. The digital image mask is changed arbitrarily in real-time with suggested algorithm for the HDSS.

• Journal of information and communication convergence engineering
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• 제13권4호
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• pp.280-285
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• 2015

Double random phase encryption (DRPE) is one of the well-known optical encryption techniques, and many techniques with DRPE have been developed for information security. However, most of these techniques may not solve the fundamental security problem caused by using fixed phase masks for DRPE. Therefore, in this paper, we propose a key phase mask updating scheme for DRPE to improve its security, where a spatial light modulator (SLM) is used to implement key phase mask updating. In the proposed scheme, updated key data are obtained by using previous image data and the first phase mask used in encryption. The SLM with the updated key is used as the second phase mask for encryption. We provide a detailed description of the method of encryption and decryption for a DRPE system using the proposed key updating scheme, and simulation results are also shown to verify that the proposed key updating scheme can enhance the security of the original DRPE.

• Journal of Animal Science and Technology
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• 제64권1호
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• pp.1-9
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• 2022

Equilume light masks had no impact on hastening the resumption of estrous cyclicity in mares maintained in outdoor pastures on the mainland of Korea due to the cold weather conditions. Jeju Island is a major horse-breeding site in Korea and is warmer than the mainland during the winter season. Therefore, the primary objective of this study was to explore the efficiency of the Equilume light mask on the resumption of seasonal estrous cycles in Thoroughbred mares on Jeju Island. A total of 20 nonpregnant mares were randomly divided into the Equilume light mask (n = 9) and stable lighting (n =11) groups. The experiment was performed at seven different horse-breeding farms located on Jeju Island from November 15, 2020, to February 15, 2021. The mares were exposed to the respective lights from 16:00 to 23:00. Follicle size and uterine edema were measured by ultrasound scanning. Body condition scores (BCS) were also monitored during the experiment. Statistical analysis was conducted using the SAS and SPSS software, and p-values of < 0.05 were considered statistically significant. Two of the nine (22.2%) mares in the Equilume light mask group and three of the 11 (27.28%) mares in the stable lighting group were still cycling in December and January, which were considered as all-year-round cycling mares. On February 15, there was no difference between groups in the resumption of early seasonal estrus cycle, which was determined by follicles > 25 mm in addition to uterine edema. All mares in the Equilume light mask group and five of the eight mares (62.5%) in the stable lighting group had resumed cycling. Interestingly, six of the seven mares (87.5%) in the Equilume light mask and four of eight mares (50%) in the stable lighting group had already ovulated on February 15 (p > 0.05), as determined by the presence of a recent corpus luteum. No difference was observed in BCS and uterine edema between groups (p > 0.05). In conclusion, the Equilume light mask can be an effective approach to induce early seasonal estrus cycles of mares in Jeju Island, and it also enhances the efficiency of farm management by reducing labor.

• 한국동물생명공학회지
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• 제35권2호
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• pp.171-176
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• 2020

Advancing the estrous cycle of mares is an essential breeding strategy that is routinely conducted by Thoroughbred breeders to improve economic outcomes. For this purpose, Equilume light masks have been developed as an alternative to existing technologies such as artificial lighting or hormonal treatments because they are considered as valid as existing methods with additional animal welfare advantages. For example, with the Equilume light masks, horses can be let out into the pasture, whereas they have to be kept indoors during lighting treatment. Because the function of Equilume light mask on the estrous cycle of mares is influenced by environmental factors such as nutrition condition and temperature, Equilume light mask should be studied in various environments. The objective of the present study was thus to verify the effect of Equilume light masks on the onset of the estrous cycle in Thoroughbred mares in South Korea. Mares were randomly selected and separated into two groups at two Thoroughbred horse breeding farms. The mares in the treatment group were equipped with Equilume light masks from November 18 to February 10 the following year. The body condition, the number and size (> 35 mm) of uterine follicles, and the uterine horn score of the mares were assessed on January 6 and February 10. The body condition scores were not different between the two groups. The treatment with the Equilume light mask had no positive effects on developing follicles and the reproductive tract. In conclusion, the use of Equilume light masks did not influence the seasonal resumption of the estrus cycles in Thoroughbred mares in South Korea.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.705-708
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• 2014

We demonstrate the blue InGaN/GaN multiple quantum wells light-emitting diodes (LEDs) with an embedded air-gap photonic crystal (PC) which was fabricated by the lateral epitaxial overgrowth of GaN layer on the tungsten (W) nano-masks. The periodic air-gap PC was formed by the chemical reaction of hydrogen with GaN on the W nano-mask. The optical output power of LEDs with an air-gap PC was increased by 26% compared to LEDs without an air-gap PC. The enhanced optical output power was attributed to the improvement in internal quantum efficiency and light extraction efficiency by the air-gap PC embedded in GaN layer.

• 한국레이저가공학회지
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• 제15권2호
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• pp.11-14
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• 2012

In this paper, we have made a proposal concerning the beam shaping mask(BSM) using random-array slits to control intensity distribution profile of laser beam and demonstrated its proprieties experimentally. When a lot of slits are set out irregularly, diffraction patterns of light does not appear but granularity patterns as a bundle of fibers appear. Intensity distribution profile is controlled by densities distribution of circular slits arrayed randomly because the number of slits and its area means amount of light energy through BSM. Namely as the number of slits in high intensity area is increased and that in low intensity area decreased, amount of light energy is same over all local parts. So gaussian intensity distribution could be changed to flat-top.

• 대한전자공학회논문지SD
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• 제43권8호
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• pp.1-5
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• 2006

본 논문은 극자외선 리소그래피용 마스크의 결함을 극자외선을 이용하여 검출하는 방법과 기존의 가시광선을 이용하여 결함을 검출해 내는 시스템과 비교하고, 인위적으로 만들어진 결함을 이용하여 극자외선이 결함에 조사되었을 때의 반사되는 패턴을 분석하였다. 포커스된 극자외선을 래스터 스캔 방식으로 조사하면서 반사되는 극자외선의 세기를 비교함으로서 결함을 발견해 내는 시스템을 구축하였고, 이를 이용하여 기존의 가시광선을 이용하는 결함 검출 장비와 상관 실험을 진행하여 반사된 빛의 세기로 예측한 결함의 크기가 두 검출 방법 사이에 강한 상관관계를 가짐을 확인하였다. 또한, 인광판을 이용하여 극자외선이 결함에 조사되어 반사되는 패턴을 영상화하여 크기별, 결함의 종류별로 다른 프린지 패턴을 가지는 것을 확인하였다.

• 수면정신생리
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• 제28권1호
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• pp.27-33
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• 2021

목 적 : 본 연구의 목적은 침실에서 야간 조명이 강제적으로 사용되는 교정기관 내 정신과적 입원 환자들에게 상업용 활동 추적기와 수면일지를 통해 안대 착용과 완전 소등이 수면 상태에 주는 효과들의 차이를 조사하는 것이다. 방 법 : 본 연구는 3일 연속 밤 동안 수행되었다. 국립법무병원에 입원된 29명의 정신질환자들에게 무작위 연구 번호가 배정되었으며, 첫 날에는 야간 조명 환경에서 평소처럼 취침했다. 29명 연구대상자들은 다른 날에는 야간 조명환경에서 안대를 착용한 채 취침하였으며, 또 다른 날에는 완전 소등 환경에서 안대 없이 취침하였다. 29명 연구대상자들은 상업용 활동 추적기를 착용하면서 취침하도록 요청되었으며, 다음 날 아침 수면일지를 작성하였다. 연구대상자들은 이러한 둘째 밤과 셋째 밤의 침실 조도 환경 변화를 무작위로 겪도록 배정되었다. 결 과 : 조명 하 수면 환경과 안대 착용 수면 환경 비교 시, 안대 착용 수면 환경에서 수면 후 각성 시간이 짧았고, 수면 만족도가 높았다(각각, Z = 3.66, p < 0.017 ; Z = 2.69, p < 0.017). 또한, 조명 하 수면 조건과 소등 하 수면 조건 비교 시, 소등 하 수면 조건에서 수면 후 각성 시간이 짧았고, 수면 효율, 수면 만족도가 높았다(각각, 31.14분 대 15.00분, Z = 2.40, p < 0.017 ; 79.40% 대 88.10%, Z = 3.02, p < 0.017 ; 2.97점 대 4.10점, Z = 3.88, p < 0.017). 그러나 안대 착용 수면과 소등 하 수면 비교에서는 유의미한 차이가 없었다. 결 론 : 본 연구 결과 정신질환자나 교정기관의 수용자에게 수면을 개선시키기 위해 완전 소등 또는 환경 개선이 불가능할 경우에는 안대 착용을 권장하는 것이 주관적인 수면의 질과 만족도를 높이는데 유용한 방법이 될 수도 있겠다.

• 한국광학회지
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• 제8권4호
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• pp.345-352
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• 1997

최신(4GDRAM)의 MASK design에서는 전자기파의 산란에 의한 효과를 고려해 주는 것이 매우 중요하다. 이를 위하여 시간 영역에서의 요한 차분법을 도입하여 직접 마스크 함수를 계산하였다. 새롭게 도입한 마스크 함수를 사용함으로써 마스크와 렌즈의 효과뿐만 아니라, submicron 노광용 위상 변이 마스크의 식각된 옆벽에서의 산란효과를 정확하게 설명할 수 있었다. 산란효과를 줄이기 위해 변형된 마스크의 형태에 따른 특성을 살펴보았고, dual etch back에 의한 마스크 변형이 가장 좋은 공정 여유도를 제공함을 확인하였다.

• 제어로봇시스템학회논문지
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• 제14권4호
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• pp.348-352
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• 2008

Deformation of the shadow mask is one of the problems encountered during the deposition of organic materials for manufacturing large size organic light emitting diode (OLED). The larger the glass substrate, the larger the shadow mask becomes. As the size of the shadow mask increases, its deformation becomes more severe, thereby making it difficult to deposit organic materials in a precise pattern on a substrate. In this paper, a new method for reducing drooping of the shadow mask for large size OLED vapor depositions is proposed. The proposed shadow mask with cross stripe wires has higher stiffness than the pure shadow mask, which results in reducing drooping of the shadow mask. A commercial FEM program, ANSYS, is used for the evaluation of the proposed shadow mask. The analysis showed that the shadow mask with cross stripe wires have an effect on reducing drooping about 18.6% or more.