• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.1 no.2
• /
• pp.69-80
• /
• 1997

Effects of light on leaf senescence of Phaseolus vulgaris were investigated by measuring the disassembly of chlorophyll-protein complexes in detached leaves which had been kept in the dark or under light. The loss of chlorophyll accompanied by degradation of chlorophyll-protein complexes. PSI (photosystem I) complex containing LHCI (light harvesting complex of PSI) apoproteins was rapidly decreased after the early stage of dark-induced senescence. RC(reaction center)-Core3 was slightly increased until 4 d and slowly decreased thereafter. As disassembly of LHCII trimer progressed after the late stage of senescence, there was a steady increase in the relative amount of SC(small complex)-2 containing LHCII monomer. On the other hand, white and red light adaptation caused the structural stability of chlorophyll-protein complexes during dark-induced senescence. Particularly, red light was more effective in the retardation of LHCII breakdown than white light, whereas white light was slightly effect in protecting the disassembly of PSI complex compared to red light. These results suggest, therefore, that light may be a regulatory factor for stability of chlorophyll-protein complexes in the senescent leaves.

• Journal of Distribution Science
• /
• v.13 no.9
• /
• pp.19-27
• /
• 2015

Purpose - In a global economy, marketers are required to understand service quality from an international consumer viewpoint. Despite the increased need for cross-cultural research, few studies have developed service quality research international in scope. The present research aims to shed light on variations in airline service quality among international consumers. Research design, data, and methodology - Conducting crosscultural research, this study compares airline service quality variations, investigating an international consumer group and a Korean consumer group. T-test and factor analyses are applied to examine mean scores and factor structure of the airline service dimensions. Results - The results indicate there are significant differences in mean comparisons between the groups. The international consumers indicate significantly higher service perception scores than the Koreans. Further, we find that the factor structure of airline service quality diverges between the groups. The international group considers airline service quality in four dimensions, while Koreans consider it in two. Conclusions - The study sheds new light on international service variations and suggests that the field of airline service quality may differ by nations and/or cultures.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.05a
• /
• pp.65-68
• /
• 2003

This study is intended to look into the influence of environment and construction factor on bleeding of concrete. According to the results, as wind is light, relative humidity is high and temperature is low, the amount of bleeding increases greatly, and evaporation speed is influenced greatly by order of wind, temperature and humidity. As the properties of bleeding by construction factor, the amount of bleeding increases with an increase of placing thickness, but the bleeding ratio, the amount of bleeding per unit volume, increases with a decrease of the placing thickness. Bleeding speed is fastest at about 90 minute after placing concrete. Also, as wind is light, relative humidity is high, temperature is low and the placing thickness is thick, bleeding speed grow faster.

• Journal of IKEEE
• /
• v.18 no.3
• /
• pp.335-340
• /
• 2014

Recently, LED (Light Emitting Diode) becomes to be useful to apply for the lightening sources in electric systems and the lightening equipment since the power is less consumed with high efficiency, and the size and the weight of LED are small and light, respectively. The LED is controlled with constant current and SMPS (Switching Mode Power Supply). It is necessary for the LED manufacturer to secure the fundamental technology of designing LED chip, and to study the methodology to improve the power factor (PF) and to design the operational circuit for the development of LED to reduce the power loss in the application of LED lightening. The direct AC (Alternating Current) LED driving circuit, HV9910, is widely used in the industry field. In this paper, it is to evaluate the improved methodology for the power factor and efficiency through simulations when PFC (Power Factor Correction) and Noise Filter are added to HV9910.

• Current Optics and Photonics
• /
• v.5 no.1
• /
• pp.8-15
• /
• 2021

An elliptical zone plate (EZP) array is important in off-axis optical systems because it provides two advantages. First, the residual beam and the main source are not focused in the same direction and second, the light from the observation plane is not reflected back towards the beam source. However, the fill factor of the previous EZP array was about 76% which was a little low. Hence, this EZP array could not collect the maximum amount of illumination light, which affected the overall optical performance of the lens array. In this study, we propose a new EZP array design with a 97.5% fill factor used in off-axis imaging system for enhancement of brightness and contrast. Then, direct laser lithography was used to fabricate the high fill factor EZP array by moving the XY linear stage of the system in a zigzag motion. The imaging properties of the proposed EZP array were experimentally verified at the focal plane and compared with the previous model.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.625-628
• /
• 2004

Porous anodic alumina(PAA) which has arrays of nano size holes, was incorporated into organic light emitting devices. Porous anodic alumina on glass scattered the light generated from emitting layer and was decreased the waveguiding modes within the glass. An increase in the device coupling-out factor for the scattering structure is demonstrated.

• Microbiology and Biotechnology Letters
• /
• v.17 no.2
• /
• pp.170-172
• /
• 1989

It is preyed that marine algae, Chlorella pyrenoidosa can synthesize about 3.52% of eicosapentaenoic (EPA) of dry cell weight at the light intensity of 10 W/$\m^2$ which is optimal light intensity of producing EPA at $25^{\circ}C$. An equation to predict the amounts of EPA in the culture broth is derived as an exponential form with 0.91 of the correlation factor. The behavior of cell growth follows a photo-inhibition model by showing 12 W/$\m^2$ of saturation light intensity.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.10a
• /
• pp.285-287
• /
• 2008

This paper represents the electric power load leveling effect of the Light Control System(LCS). The lighting of typical mid-large commercial buildings is the major factor of daytime electric power consumption. Since the national peak power demand occurs in between 11:00 and 16:00, the dimming control of light can contribute the decrease of the power demand We will discuss the load leveling effect of dimming control with LCS.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.1
• /
• pp.48.2-48.2
• /
• 2019

Tidal disruption events (TDEs) provide evidence for quiescent supermassive black holes (SMBHs) in the centers of inactive galaxies. TDEs occur when a star on a parabolic orbit approaches close enough to a SMBH to be disrupted by the tidal force of the SMBH. The subsequent super-Eddington accretion of stellar debris falling back to the SMBH produces a characteristic flare lasting several months. It is theoretically expected that the bolometric light curve decays with time as proportional to $t^{-5/3}$. However, some of the observed X-ray light curves deviate from the $t^{-5/3}$ decay rate, while some of them are overall in good agreement with the $t^{-5/3}$ law. Therefore, it is required to construct the theoretical model for explaining these light curve variations consistently. In this paper, we revisit the mass fallback rates semi-analytically by taking account of the stellar internal structure, orbital eccentricity and penetration factor. We find that the mass fallback rate is shallower than the standard $t^{-5/3}$ decay rate independently of the polytropic index, and the orbital eccentricity only changes the magnitude of the mass fallback rate. Furthermore, the penetration factor significantly can modify the magnitude and variation of mass fallback rate. We confirm these results by performing the computational hydrodynamic simulations. We also discuss the relevance of our model by comparing these results with the observed light curves.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.46 no.2
• /
• pp.93-103
• /
• 2004

In trench excavation, essential factor of earth-retaining temporary work structure should be easy taking to pieces and movement, and dead weight must be less. This paper studies about the light weight material and application as earth-retaining structure to prevent the slope failure of sand soil ground caused by the variation of groundwater level in trench excavation. That is, light weight earth-retaining structural is proposed and a simulation with FEM on application of proposed structural in sandy soil is presented. The results are summarized as follows; (1) The study proposed FRP H-shaped pannel for the light weight member, and also presented estimation method about stability. (2) Mechanical property (bending moment, shear force, axial force, displacement) were changed according to groundwater level, but these values had been within enough safety rate and allowable stress. Therefore, proposed light weight pannel with FRP is available for bracing structure in trench excavation.