• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.382-389
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• 2011

BACKGROUND: Light-emitting diodes (LEDs) with lower electric cost and the specific wavelength have been considering as a novel light source for plant production in greenhouse conditions as well as in a closed culture system. Supplementary lighting for day-length extension was considered as light intensity, light quality, and/or photoperiod control on plant growth and development. Effects of supplementary blue or red LED radiation with lower light intensity on growth of Ageratum (Ageratum houstonianum Mill., cv. Blue Field), African marigold (Tagetes erecta L., cv. Orange Boy), and Salvia (Salvia splendens F. Sello ex Ruem & Schult., cv. Red Vista) were discussed during sunrise and sunset twilight in the experiment. METHODS AND RESULTS: Supplementary lighting by blue and red LEDs for 30 (Treatment B30; R30) or 60 (Treatment B60; R60) min. per day were established in greenhouse conditions. Photosynthetic photon flux for supplementary radiation was kept at $15{\mu}mol\;m^{-2}\;s^{-1}$ on the culture bed. Natural condition without supplementary light was considered as a control. The highest shoot and root dry weights were shown in African marigold exposed by red light for 60 min. per day. Supplementary blue and red lighting regardless of the radiation time significantly stimulated development of lateral branches in African marigold. Stem growth in Ageratum and Salvia seedlings was significantly promoted by red radiation as well as natural light. CONCLUSIONS: Extending of the radiation time at sunrise and sunset twilight using LEDs stimulated reproductive growth of flowering plant species. Different characteristics on growth under supplementary blue or red lighting conditions were also observed in the seedlings during supplementary radiation.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.76-88
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• 2010

Recently, LED background image devices are used for the production of broadcasting programs. But the effective advantages of LED background image devices are not realized for good HD video quality because the correlations between lighting sources and LED background image devices are not analyzed yet. In this paper, we analyze the color change and light intensity that lighting sources and the light intensity ratio of LED background images influence on a subject, making use of equipments used in real broadcasting, and examine the correlations between HD video quality and the light intensity ratio of LED background images. As a result in this experiment, the video is most expressed having an 20[IRE] effect on a subject when the light intensity of LED background image is 6%. When the LED background image is light, the light and darkness of video is distorted and when the LED background image is dark, the colors of image are distorted.

• Journal of Biosystems Engineering
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• v.25 no.3
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• pp.213-220
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• 2000

Grafting of fruit-bearing vegetables has been widely used to increase the resistance to soil-borne diseases, to increase the tolerance to low temperature or to soil salinity, to increase the plant vigor, and to extend the duration of economic harvest time. After grafting, it is important to control the environment around grafted seedlings for the robust joining of a scion and rootstock. Usually the shading materials and plastic films are used to keep the high relative humidity and low light intensity in greenhouse or tunnel. It is quite difficult to optimally control the environment for healing and acclimation of grafted seedlings under natural light. So the farmers or growers rely on their experience for the production of grafted seedling with high quality. If artificial light is used as a lighting source for graft-taking of grafted seedlings, the light intensity and photoperiod can be easily controlled. The purpose of this study was to develop a prototype system for the graft-taking enhancement of grafted seedlings using artificial lighting and to investigate the effect of air current speed on the distribution of air temperature and relative humidity in a graft-taking enhancement system. A prototype graft-taking system was consisted by polyurethane panels, air-conditioning unit, system controller and lighting unit. Three band fluorescent lamps (FL20SEX-D/18, Kumho Electric, Inc.) were used as a lighting source. Anemometer (Climomaster 6521, KANOMAX), T-type thermocouples and humidity sensors (CHS-UPS, TDK) were used to measure the air current speed, air temperature and relative humidity in a graft-taking system. In this system, air flow acted as a driving force for the diffusion of heat and water vapor. Air current speed, air temperature and relative humidity controlled by a programmable logic controller (UP750, Yokogawa Electric Co) and an inverter (MOSCON-G3, SAMSUNG) had an even distribution. Distribution of air temperature and relative humidity in a graft-taking enhancement system was fairly affected by air current speed. Air current speed higher than 0.1m/s was required to obtain the even distribution of environmental factors in this system. At low air current speed of 0.1m/s, the evapotranspiration rate of grafted seedlings would be suppressed and thus graft-taking would be enhanced. This system could be used to investigate the effects of air temperature, relative humidity, air current speed and light intensity on the evaportranspiration rate of grafted seedlings.

• Journal of Environmental Impact Assessment
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• v.28 no.1
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• pp.63-70
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• 2019

Artificial lighting is an essential part, but it causes light pollution due to unnecessary or excessive use of light. Light pollution has negative effects such as power waste, adverse health effects, destruction of the ecosystem. But currently, light pollution is managed only post-management. The purpose of this study is to standardize methods of environmental impact assessment focusing on light pollution to effectively manage and reduce the negative effect of areas that may cause light pollution in advance.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.60-63
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• 2007

Light is a critical element for people to live and do creative activities in residential buildings. Especially, light in dinning room is the most important thing for psychological and emotional effects but people are living under the poor light environment. Most people even isn't well aware of good lighting environment. Also, the domestic lighting designers just follow the Korean Standards illuminance but it isn't appropriate to our cultural and social sides. This study investigates illuminance and color temperature of dining tables, and also analyzed the results of those in actual residential buildings.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.4
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• pp.231-234
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• 2013

This paper introduces a mixture of background subtraction technique and K-Means clustering algorithm for removing shadows from video sequences. Lighting conditions cause an issue with segmentation. The proposed method can successfully eradicate artifacts associated with lighting changes such as highlight and reflection, and cast shadows of moving object from segmentation. In this paper, K-Means clustering algorithm is applied to the foreground, which is initially fragmented by background subtraction technique. The estimated shadow region is then superimposed on the background to eliminate the effects that cause redundancy in object detection. Simulation results depict that the proposed approach is capable of removing shadows and reflections from moving objects with an accuracy of more than 95% in every cases considered.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.2
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• pp.1-6
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• 1998

It is required to determine proper values for the maintenance factor according to traffic volume in the freeway lighting design. This paper presents a simple method to seperate of the effect of surrounding environment and that of traffic volume, which is based on the IESNA treatment with additional assumptions on their effects. Furthermore, it is found that prevailing concept for the maintenance factor does not necessarily yield a proper value for light loss factor, so that an additional factor of 0.9 should be included as an equipment factor.factor.

• Korean Institute of Interior Design Journal
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• v.21 no.6
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• pp.243-251
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• 2012

Theatricals have been with human's history for a long time. And It is also receiving a lot of love in modern times. The stage is recognized another space of time by spectators during the play and the production actualize fictional world by using all destination things on the stage. Therefore, the design of the stage has symbolism and the production needs semiological. The Elements expressed through the stage is composed of stage equipment, costume, lighting, stage effects and the production needs light, sound and costume designers, a stage manager, grips an advertising director for the play. The study analysis on symbolic image on the view of semigical with focused on "Vishnvovvi sad" of Anton Chekhov. The details of the study are symbolism of stage effect and costume, lighting, stage equipment. Furthermore, The study analyze way to symbolic Express korean characteristics and This research is an excellent source for students who are studying the semilogical analysis of stage.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.838-843
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• 2006

In our modern society, such electric facilities as lighting, elevators, water supplies, drainages, waste water treatments and landscape lighting are being more enlarged, diversified and technology-intensive owing to outstanding technological development, while they require reliable and safe electricity. On the other hand, as more electric energy is consumed with more complicated systems operated, any accident from a personal electric system is likely to have wider spreading effects. In particular, the electric receivers and transformers installed for such public facilities as subway stations require highest safety, reliability and economy, but such requirements tend to be less considered than such financial requirements as budget conditions, much less their safety and reliability. In such a circumstance, this study was aimed at suggesting some standards for safe, reliable and economic subway electric systems in terms of their scale, location and uses. Specifically, this study put forwards the ways to optimize and standardize the electric systems including receivers and transformers for subway stations in order to make them safer, more reliable and economic.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.63-66
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• 2009

Lighting currents are one of major influences on the dynamic performance of ground electrodes. High lighting current intensity changes in the dynamic grounding performance due to ionization of the soil and very fast fronted pulses. The previous analysis has often been based on quasi-static approximation that is not applicable to very fast fronted pulses. To extend the analysis to fast fronted pulses in this paper, the full-wave analysis method based in the rigorous electromagnetic-field theory approach is used and the effects of the ionization of the soil me disregarded. Based on the simulation results, the empirical formulas applicable for slow and very fast fronted lightning current pulses me reviewed; therefore the validity of the theoretical approach is verified through comparison between the calculated and measured results.