• Journal of Korea Game Society
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• v.7 no.3
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• pp.77-88
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• 2007

In this paper, we present a new fire animation and visualization scheme. The most difficult problem in creating fire animation is how to simulate the mechanism of emitting lighting and heat of fire. We attack the difficulty by presenting a hybrid scheme that combines the simulation scheme and the combustion process in voxelized space where the numerical solution of the classical fluid equations is implemented. Therefore, the combustion process is simulated at each voxel and the amount of heat generated at the voxel is estimated. The generated heat will increase the temperature at the voxel, where results in the increase of turbulent motion of fire. We also propose a visualization scheme that modifies the photon mapping algorithm in order to render fire and various lighting effects of fire to the environments.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.459-465
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• 2014

Visible light communications (VLC) using the intensity modulation of light-emitting diodes (LEDs) provides a new communication medium to overcome the shortage of radio spectrum, and allows reuse of LED lighting infrastructures. Orthogonal frequency-division multiplexing (OFDM) was introduced to VLC for its merits in mitigating the fading effects resulting from delay spread, and in avoiding low-frequency ambient interference. Noise and clipping are two major factors that degrade the performance of OFDM in VLC. A larger signal easily overcomes noise, but experiences impairment by clipping. Therefore, degradation due to clipping has a trade-off relationship with that due to noise, depending on the signal amplitude of OFDM. In this paper, the optimal signal amplitude in the trade-off is obtained by simulation when the dimming and LED intensity are given. The former indicates a user's requirement for lighting, and the latter represents the channel quality. The required LED intensity-to-noise ratio, as the channel quality that guarantees dimming as well as an adequate bit-error rate (BER), is also discussed.

• Journal of the Korean Solar Energy Society
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• v.34 no.3
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• pp.66-74
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• 2014

In this paper, the performance of Hybrid Dimming control system for Daylighting system is evaluated by accredited tests. The system controls the balance of illuminance of daylight between daylight system and LED light system. It makes the normal illuminance of interior without the effects of weather by controlling the LED depending on the brightness of outside. For the tests, 6 diffusers($600{\times}300mm$) were installed in lighting area($36m^2$) and normal operation of the system sensors were tested about the interference of sunlight. The results of the examinations were satisfied with the criteria of accredited tests. Further research is the verification of energy saving effect by comparing the Hybrid Dimming control system to current artificial light system.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.218-227
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• 2021

Background: Artificial light at night has recently been identified as a major factor adversely affecting global insect diversity. Here, we compared the insect diversity in Gwangneung Forest Biosphere Reserve, specifically in the Korea National Arboretum (with no artificial light at night), with that of three nearby urban sites with a gradient of artificial light at night (five locations at each site). We analyzed the effects of the artificial night lighting index, mean annual temperature, and field light intensity (lux) at night on the insect community structure. Results: The urban sites generally exhibited higher species richness and abundance as well as clear indicator species compared with the control site. The size distribution of the collected insects markedly differed between the control and the three urban sites. The abundance of herbivorous and omnivorous insects increased and decreased, respectively, with the increase in light intensity. Species richness of herbivorous and omnivorous insects was likely correlated with the field light intensity at night and artificial night lighting index, respectively. Conclusions: This study demonstrates the association between nighttime environment and marked changes in insect community structure and revealed consequent transition of ecosystem services by changes in trophic group composition.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.332-340
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• 2018

Supplemental lighting with artificial light sources is a practical method that enables normal growth and enhances the yield and quality of fruit vegetable in greenhouses. The objective of this study was to investigate the effect of sulfur plasma lamp (SP) and high-pressure sodium lamp (HPS) as supplemental lighting sources on the growth and yield of paprika. For investigating the effectiveness of SP and HPS lamps on paprika, the effects of primary lighting on plant growth were compared in growth chambers and those of supplemental lighting were also compared in greenhouses. In the growth chamber, plant height, leaf area, stem diameter, number of leaves, fresh weight, and dry weight were measured weekly at SP and HPS from 2 weeks after transplanting. In the greenhouse, no supplemental lighting (only sunlight) was considered as the control. The supplemental lights were turned on when outside radiation became below $100W{\cdot}m^{-2}$ from 07:00 to 21:00. From 3 weeks after supplemental lighting, the growth was measured weekly, while the number and weight of paprika fruits measured every two weeks. In the growth chamber, the growth of paprika at SP was better than at HPS due to the higher photosynthetic rate. In the greenhouse, the yield was higher under sunlight with either HPS or SP than sunlight only (control). No significant differences were observed in plant height, number of node, leaf length, and fresh and dry weights between SP and HPS. However, at harvest, the number of fruits rather than the weight of fruits were higher at SP due to the enhancement of fruiting numbers and photosynthesis. SP showed a light spectrum similar to sunlight, but higher PAR and photon flux sum of red and far-red wavelengths than HPS, which increased the photosynthesis and yield of paprika.

• KIEAE Journal
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• v.13 no.5
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• pp.59-66
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• 2013

Current Architectural Facade Designs have been trending to increased glass areas resulting in increasing impact on interior lighting and daylighting. In regards to indoor environmental quality, the increase in window space has a large impact on the daylighting received which ultimately impacts the liveability of a space. Especially when considering seasons, in the summer, excessive daylighting can result in glare as well as put an increased load in conditioning the air space further reducing energy efficiency. As a result, in order to improve the sustainability performance of a building, it is important to limit the natural lighting exposure to properly meet the needs and conditions of the building occupants. One of the most representative features to limit excessive sunlight exposure, is to incorporate operable blind systems. To this end, this research has been based on simulations performance through the Radiance Program. Radiance is capable of analyzing performance of daylight and impact of sunlight. Through analysis of different slat angles and blind shapes, impact and minimization of energy usage was evaluated. Furthermore, seasonal analysis was performed in order to understand the effects of seasonal climate factors. Ultimately this research provides an analysis of operable blinds optimization and effects of blind shape, control factors and angle of shading.

• Korean Journal of Organic Agriculture
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• v.24 no.1
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• pp.99-114
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• 2016

This study was conducted to evaluate effects of various eco light sources with various lighting distance in 'Viking' rose (Rosa spp.) on the growth and flowering quality to be applied for farm sites. Treatment included 10-, 20-, and 30-RL (-BL, -RBL, -FL, and -IL), which referred to red LED (blue LED, red+blue LED, fluorescent, and incandescent) lighting at 10 cm, 20 cm, 30 cm respectively, apart from flowers. NL referred to natural light as a control. Growth and flowering of 'Viking' rose were non-destructively measured at 4, 6, and 8 weeks after treatment (WAT). FL treatment increased plant height at 4, 6, and 8 WAT, regardless of lighting distance, with the shortest height observed for the NL-treated flowers. 30 RL treatment also increased plant height at 6 and 8 WAT. Stem diameter and number of leaves were not significantly different for all the treatments at 8 WAT, with the lowest values observed for RBL treated-flowers among the light source treatments. Number of root was the greatest for the 30 BL-treated flowers (10.0) but the fewest for the 30 FL (4.7). Length of flower neck at 6 WAT was the extended by 6~7 cm in the 10 FL and 20 FL treatments as well as by 5~6 cm in the 20 RL and 30 RL treatments, inducing 100% of flowering. NL increased $a^*$ (29) of flower color, with the lowest value (10) observed for 20 RL. All things considered, 30 RL would be the best interaction treatment of source and distance of eco light to improve plant height and flowering quality of 'Viking' rose.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.5
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• pp.246-254
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• 2013

Translucent opal glass was fabricated in order to substitute polycarbonate diffuser of LED lighting for the purpose of improving the durability problem. Calcium phosphate was used for the opacifier of opal glass and melted at $1550^{\circ}C$ for 2 hrs in electric furnace. Because opal glass was made by phase separation and growth of opacifier grains during cooling procedure after forming of melted glass, we identified the effect of opaque properties by the change of forming and cooling temperature, as R.T. (room temperature), $850^{\circ}C$, $1100^{\circ}C$ and $1200^{\circ}C$. As the results, it had excellent optical properties for the diffuser of LED lighting in the fabricated sample of forming and cooling at $1200^{\circ}C$, with no dazzling from direct light by high haze value over 82 % and low parallel transmittance value under 10 %. For the thermal properties, it had expressed thermal expansion coefficient of $6.352{\times}10^{-6}/^{\circ}C$ and softening point of $839^{\circ}C$.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.147-161
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• 2021

Through photogrammetry techniques, what current researches can achieve at present is rough 3D mesh and color map of objects, rather than usable photo-realistic 3D assets. This research aims to propose a new method to create photo-realistic 3D assets that can be used in the field of visualization applications. The new method combines photogrammetry with computer graphics modeling. Through the description of the production process of three objects in the real world - "Bullet Box", "Gun" and "Metal Beverage Bottle," it introduces in details the concept, functions, operating skills and software packages used in the steps including the photograph object, white balance, reconstruction, cleanup reconstruction, retopology, UV unwrapping, projection, texture baking, De-Lighting and Create Material Maps. In order to increase the flexibility of the method, alternatives to the software packages are also recommended for each step. In this research, 3D assets are produced that are accurate in shape, correct in color, easy to render and can be physically interacted with dynamic lighting in texture. The new method can obtain more realistic visual effects at a faster speed. It does not require large-scale teams, expensive equipment and software packages, therefore it is suitable for small studios and independent artists and educational institutions.

• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.400-410
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• 2013

This study was carried out to investigate the effects of feeding the broilers that are exposed to extreme heat stress by control of inverse lighting times with night restricted feeding of extreme heat diet(EHD1, 2: extreme heat diet) containing different amount of soy oil, molasses, amino acids and vitamin C on short chain fatty acid and blood lipid profile. 300 broiler chickens(Abaica strain) were randomized into four dietary treatment groups according to a randomized block design on the day they were hatched. The four dietary treatment groups were: T1(EHD 1, 10:00~19:00 Dark, 19:00~10:00 Light), T2(EHD 2, 10:00~19:00 Dark, 19:00~10:00 Light), T3(EHD 1, 09:00~18:00 Dark, 18:00~09:00 Light), T4(EHD 2, 09:00~18:00 Dark, 18:00~09:00 Light). The body weight gain of the broilers was highest in T2, and high in order T1, T4, T3(p<0.05). Weights of the lymphoid organ, thymus and bursa of Fabricius were high in T1, T2 as compared to T3, T4 but spleen was lower in T4 than T1, T2, T3(p<0.05). Blood triglyceride, total cholesterol and glucose were higher in T1, T2 than T3, T4(p<0.05). LDL-C was high in orderT4, T3, T2, T1 but HDL-C showed the opposite trend(p<0.05). Blood concentrations of IgG, IgG and IgM were higher in T1, T2 than inT3, T4, but the corticosterone concentration decreased significantly in them. In T1 and T2, Lactobacillus in the feces increased, but total aerobic bacteria, E.coli, coliform bacteria was decreased rather significantly, compared with those in T3 and T4(p<0.05). Concentrations of acetic acid, propionic acid and total SCFA in cecum were high in order T2, T1, T3, T4, but butyric acid, isobutyric acid, valeric acid, isovaleric acid were lower in T1, T2 than in T3, T4 (p<0.05).