• Title/Summary/Keyword: low light intensity

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Deep Learning-Based Lighting Estimation for Indoor and Outdoor (딥러닝기반 실내와 실외 환경에서의 광원 추출)

  • Lee, Jiwon;Seo, Kwanggyoon;Lee, Hanui;Yoo, Jung Eun;Noh, Junyong
    • Journal of the Korea Computer Graphics Society
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    • v.27 no.3
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    • pp.31-42
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    • 2021
  • We propose a deep learning-based method that can estimate an appropriate lighting of both indoor and outdoor images. The method consists of two networks: Crop-to-PanoLDR network and LDR-to-HDR network. The Crop-to-PanoLDR network predicts a low dynamic range (LDR) environment map from a single partially observed normal field of view image, and the LDR-to-HDR network transforms the predicted LDR image into a high dynamic range (HDR) environment map which includes the high intensity light information. The HDR environment map generated through this process is applied when rendering virtual objects in the given image. The direction of the estimated light along with ambient light illuminating the virtual object is examined to verify the effectiveness of the proposed method. For this, the results from our method are compared with those from the methods that consider either indoor images or outdoor images only. In addition, the effect of the loss function, which plays the role of classifying images into indoor or outdoor was tested and verified. Finally, a user test was conducted to compare the quality of the environment map created in this study with those created by existing research.

Analysis of Spatial and Vertical Variability of Environmental Parameters in a Greenhouse and Comparison of Carbon Dioxide Concentration in Two Different Types of Greenhouses (온실 환경요인의 공간적 및 수직적 특성 분석과 온실 종류에 따른 이산화탄소 농도 비교)

  • Jeong, Young Ae;Jang, Dong Cheol;Kwon, Jin Kyung;Kim, Dae Hyun;Choi, Eun Young
    • Journal of Bio-Environment Control
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    • v.31 no.3
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    • pp.221-229
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    • 2022
  • This study was aimed to investigate spatial and vertical characteristics of greenhouse environments according to the location of the environmental sensors, and to investigate the correlations between temperature, light intensity, and carbon dioxide (CO2) concentration according to the type of greenhouse. Temperature, relative humidity (RH), CO2, and light sensors were installed in the four-different vertical positions of the whole canopy as well as ground and roof space at the five spatial locations of the Venlo greenhouse. Also, correlations between temperature, light intensity, and CO2 concentration in Venlo and semi-closed greenhouses were analyzed using the Curve Expert Professional program. The deviations among the spatial locations were larger in the CO2 concentration than other environmental factors in the Venlo greenhouse. The average CO2 concentration ranged from 465 to 761 µmol·mol-1 with the highest value (646 µmol·mol-1) at the Middle End (4ME) close to the main pipe (50Ø) of the liquefied CO2 gas supply and lowest (436 µmol·mol-1) at the Left Middle (5LM). The deviation among the vertical positions was greater in temperature and relative humidity than other environments. The time zone with the largest deviation in average temperature was 2 p.m. with the highest temperature (26.51℃) at the Upper Air (UA) and the lowest temperature (25.62℃) at the Lower Canopy (LC). The time zone with the largest deviation in average RH was 1 p.m. with the highest RH (76.90%) at the LC and the lowest RH (71.74%) at the UA. The highest average CO2 concentration at each hour was Roof Air (RF) and Ground (GD). The coefficient of correlations between temperature, light intensity, and CO2 concentration were 0.07 for semi-closed greenhouse and 0.66 for Venlo greenhouse. All the results indicate that while the CO2 concentration in the greenhouse needs to be analyzed in the spatial locations, temperature and humidity needs to be analyzed in the vertical positions of canopy. The target CO2 fertilization concentration for the semi-closed greenhouse with low ventilation rate should be different from that of general greenhouses.

Varietal Differences of Photorespiration and RuBP Carboxylase Activity in Rice Leaves (수도(水稻) 엽신(葉身)의 광호흡(光呼吸) 및 RuBPCarboxylase 활성(活性)의 품종간(品種間) 차이(差異))

  • Hong, Young-Pyo;Hwang, Young-Soo;Ryu, In-Soo;Han, Ki-Hak
    • Korean Journal of Soil Science and Fertilizer
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    • v.17 no.1
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    • pp.46-50
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    • 1984
  • Four rice cultivars (two japonicas and two japonica x indica hybrids) were grown in the hydroponic medium in order to investigate the photorespiration rate and ribulose-1, 5-bisphorphate carboxylase (EC 4, 1, 1;39) activity. The results were as follows: 1. Photorespiration rate was increased by the increasing light intensity as well as photosynthesis until light saturation point. Hangangchalbyeo of a hybrid variety had higher photorespiration rate than two japonicas(Jiniubyeo and Seolakbyeo) and one hybrid(Nampungbyeo) tested at ear formation stage. 2. Ribulose-1, 5-bisphosphate carborylase of hybrids were very sensitive to temperature showing lower activities at low temperature and much higher activities at high temperature than that of japonicas.

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MONTE-CARLO RADIATIVE TRANSFER MODEL OF THE DIFFUSE GALACTIC LIGHT

  • Seon, Kwang-Il
    • Journal of The Korean Astronomical Society
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    • v.48 no.1
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    • pp.57-66
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    • 2015
  • Monte-Carlo radiative models of the diffuse Galactic light (DGL) in our Galaxy are calculated using the dust radiative transfer code MoCafe, which is three-dimensional and takes full account of multiple scattering. The code is recently updated to use a fast voxel traversal algorithm, which has dramatically increased the computing speed. The radiative transfer models are calculated with the generally accepted dust scale-height of 0.1 kpc. The stellar scale-heights are assumed to be 0.1 or 0.35 kpc, appropriate for far-ultraviolet (FUV) and optical wavelengths, respectively. The face-on optical depth, measured perpendicular to the Galactic plane, is also varied from 0.2 to 0.6, suitable to the optical to FUV wavelengths, respectively. We find that the DGL at high Galactic latitudes is mostly due to backward or large-angle scattering of starlight originating from the local stars within a radial distance of r < 0.5 kpc from the Earth. On the other hand, the DGL measured in the Galactic plane is mostly due to stars at a distance range that corresponds to an optical depth of $${\sim_\sim}$$ 1 measured from the Earth. Therefore, the low-latitude DGL at the FUV wavelength band would be mostly caused by the stars located at a distance of $r{\leq}0.5$ kpc and the optical DGL near the Galactic plane mainly originates from stars within a distance range of $1{\leq}r{\leq}2kpc$. We also calculate the radiative transfer models in a clumpy two-phase medium. The clumpy two-phase models provide lower intensities at high Galactic latitudes compared to the uniform density models, because of the lower effective optical depth in clumpy media. However, no significant difference in the intensity at the Galactic plane is found.

Synthesis and Luminescence Properties of Sr/SmSi5N8:Eu2+ Phosphor for White Light-Emitting-Diode

  • Luong, Van Duong;Lee, Hong-Ro
    • Journal of Surface Science and Engineering
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    • v.47 no.4
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    • pp.192-197
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    • 2014
  • Red-emitting nitride phosphors recently attracted considerable attention because of their high thermal stability and high color rendering index properties. For excellent phosphor of white light-emitting-diode, ternary nitride phosphor of $Sr/SmSi_5N_8:Eu^{2+}$ with different $Eu^{2+}$ ion concentration were synthesized by solid state reaction method. In this work, red-emitting nitride $Sr/SmSi_5N_8:Eu^{2+}$ phosphor was successfully synthesized by using multi-step high frequency induction heat treatment. The effects of molar ratio of component and experimental conditions on luminescence property of prepared phosphors have been investigated. The structure and luminescence properties of prepared $Sr/SmSi_5N_8:Eu^{2+}$ phosphors were investigated by XRD and photoluminescence spectroscopy. The excitation spectra of $Sr/SmSi_5N_8:Eu^{2+}$ phosphors indicated broad excitation wavelength range of 300 - 550 nm, namely from UV to visible area with distinct enhanced emission peaks. With an increase of $Eu^{2+}$ ion concentration, the peak position of emission in spectra was red-shifted from 613 to 671 nm. After via multi-step heat treatment, prepared phosphor showed excellent luminescence properties, such as high emission intensity and low thermal quenching, better than commercial phosphor of $Y_3Al_5O_{12}:Ce^{3+}$. Using $Eu_2O_3$ as a raw material for $Eu^{2+}$ dopant with nitrogen gas flowing instead of using commercial EuN chemical for $Sr/SmSi_5N_8:Eu^{2+}$ synthesis is one of characteristic of this work.

A New Cultivar Cymbidium 'White Princess' with White Color and Vigorous Growth (생육이 강한 대형 백색계 심비디움 'White Princess' 육성)

  • Kim, Mi-Seon;Cho, Hae-Ryong;Lee, Hye-Kyung;Lim, Jin-Hee;Choi, Sung-Yul;Kim, Young-Jin
    • FLOWER RESEARCH JOURNAL
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    • v.16 no.4
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    • pp.295-298
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    • 2008
  • A new Cymbidium cultivar 'White Princess' was released by the National Horticultural Research Institute (NHRI) in 2005. A cross was made in 1995 between 'Cymbidium 2113', light purple colored petal and medium plant sized variety, and 'Lucky Rainbow Randevous', a dark purple petal with red lip and large type variety. The ninety progenies were obtained after planting and acclimatization in green house. In 2000, a line (9526747) was selected and multipliticed after test of its flower color, leaf shape, flower stalk, and vigorous growing habit. After evaluation trial for two growing seasons, the selected line was named as 'White Princess'. The 'White Princess' has white petals (WN 155A) with red lip (RP59D) color and large sized leaves, and flowers (leaf length is about 88 cm and flower diameter is about 8 cm) with semi-erect flower stalks. Blooming started from December to January in optimal culture conditions. High temperature (more than $30^{\circ}C$) and low light intensity(less than 10,000Lux) should be avoided for the appropriate growth.

The Study on the Physiological Differences for Major Fabaceae, Glycine soja and Glycine max in Korea (국내 주요 콩과식물인 돌콩(Glycine soja)과 백태(Glycine max) 간의 생리적 차이에 관한 연구)

  • Park, Jae-Hoon;Kim, Eui-Joo;You, Young-Han
    • Korean Journal of Ecology and Environment
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    • v.54 no.2
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    • pp.120-124
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    • 2021
  • In order to understand the vegetative role of Glycine soja, we studied the basic physiological characteristics between Glycine soja and Glycine max. For this study, the light intensity (μmol m-2 s-1) on leaf surface, leaf temperature (℃), transpiration rate (mmol m-2 s-1), photosynthetic rate (μmol m-2 s-1), substomatal CO2 partial pressure (vpm) of Glycine soja and Glycine max were measured, and the quantum yield, photosynthesis rate per substomatal CO2 partial pressure were calculated. In the results of simple regression analysis, the increasing quantum yield decreases leaf temperature both of Glycine soja and Glycine max and the increasing leaf temperature decreases transpiration rate in case of Glycine soja. However, in case of Glycine max, the increasing leaf temperature decreases substomatal CO2 partial pressure, photosynthetic rate, and photosynthetic rate per substomatal CO2 partial pressure as well as transpiration rate. Also, increasing transpiration rate increases substomatal CO2 partial pressure while decreases photosynthetic rate per substomatal CO2 partial pressure. Thus, Glycine soja is relatively more easily adaptable to severe environments with low soil nutrients and high light levels. Compared to Glycine max susceptible to water loss due to a water-poor terrestrial habitat, the physiological traits of Glycine soja has a high average transpiration rate and are less susceptible to water loss will act as a factor that limits the habitat according to soil moisture.

Production of Haploid and Doubled Haploid Plants from Isolated Microspore Culture of Hot Pepper (Capsicum annuum L.) (고추 소포자를 이용한 반수체 및 배가반수체 생산)

  • Eun Joon Park;Yul Kyun Ahn;Doek Ho Kwon;Eun Young Yang
    • Journal of Practical Agriculture & Fisheries Research
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    • v.25 no.4
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    • pp.90-102
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    • 2024
  • Haploid/double haploid plants developed from isolated microspores can significantly accelerate plant breeding. Haploid plants can naturally double their chromosomes to create a pure homozygous line of diploid plants. We present a method for producing embryos from isolated microspores of hot peppers (Capsicum annuumL.). We analyzed the polyploidization levels of the regenerated plants. The donor plants produced the optimal stage of microspores following short-term growth under low-intensity light, which resulted in high rates of embryogenesis and cotyledonary embryogenesis. To find an efficient culture method, liquid, doubled-layer, and 2-step cultures were tested. Liquid culture yielded the highest number of embryos, whereas the highest efficiency for cotyledonary embryogenesis was afforded by the doubled-layer culture. When normal cotyledonary embryos were transplanted onto a regeneration medium, they developed into complete plants. From these, 208 plants were tested via flow cytometric analysis, and 35.6% and 72.7% of the chromosomes from the Milyang-jare and LV2319 genotypes, respectively, were found to be spontaneous double haploids. These results are the same as those obtained on analyzing horticultural characteristics, including the size of leaves and the size and shape of fruits. The present study provides information on the practical application of isolated microspore culture of hot peppers, factors that affect embryogenesis, and methods for polyploidy testing.

Cell Death Inhibition Effect of Antioxidant Activity by 630 and 850 nm LEDs in RAW264.7 Cells

  • Hee Eun Kim;Eun Young Kim;Jin Chul Ahn;Sang Joon Mo
    • Current Optics and Photonics
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    • v.8 no.5
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    • pp.441-455
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    • 2024
  • This study objective was to evaluate the effects and mechanisms of low-level laser therapy in H2O2-induced cell death in mouse macrophage RAW264.7 cell. After irradiation with 630 and 850 nm wavelength diode lasers with an intensity of 10 mW/cm2 in RAW264.7 cells treated with 0.7 Mm H2O2, the effects and mechanisms of the two wavelengths on cell death inhibition were evaluated using MTT assay, ROS staining, TUNEL assay, flow cytometry analysis, and Western blot analysis. As a result, 630 or 850 nm light-emitting diodes (LED) were irradiated for 10 or 40 minutes to increase cell viability with H2O2 by about 1.7- or 1.6-fold, respectively. In addition, irradiation with two LEDs showed significant ROS scavenging effects, and TUNEL-positive cells were significantly reduced by 45.7% (630 nm) and 37.8% (850 nm) compared to cells treated with H2O2 alone. The Bax/Bcl-2 ratio of cells irradiated with both LEDs was significantly lower than that of cells treated with H2O2 only, and the expression of procaspase-3 and cleaved PARP was also significantly expressed in the direction of suppressing cell death. In conclusion, ROS scavenging activity by both LEDs irradiation leads to the expression of cell death pathway proteins in the direction of inhibiting cell death.

Enhanced Hydrophilic Property of TiO2 Thin Film Deposited on Glass Etched with O2 Plasma

  • Kim, Hwa-Min;Seo, Sung Bo;Kim, Dong Young;Bae, Kang;Sohn, Sun Young
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.3
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    • pp.152-155
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    • 2013
  • $TiO_2$ films were deposited on glass substrates with and without $O_2$ plasma etching by using the RF-magnetron sputtering method. We focused on the effect of surface structure on the photoinduced hydrophilic properties of $TiO_2$ films, fabricated on different surface conditions according to the presence or absence of the $O_2$ plasma treatment on glass substrates. The wettability and photoinduced hydrophilic properties of the $TiO_2$ films were investigated according to the changes in water contact angles under UV light irradiations with a very low intensity of 0.1 $mW/cm^2$. The photoinduced hydrophilic properties on the $TiO_2$ formed above the plasma treated glass were also superior to those on the $TiO_2$ formed above the bare glass. This enhanced $TiO_2$ film has been used practically for self cleaning and anti-fogging glasses.