• Architectural research
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• v.1 no.1
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• pp.31-40
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• 1999

In this age of "Information", many people consider it a deterrent to information flow to provide a hierarchy with private rooms in a modern office layout. There are others, however, who insist that visual and acoustical privacy are more important than any other design factor in achieving higher productivity. The debate may never end, but the partitioned open plan, which is a new form of the vast open plan, has merits of each concept - open and closed layout. Consequently, office design has dramatically shifted to partitioned open planning, with shorter, temporary walls or partitions, originally intended for increasing privacy and diminishing hierarchy, yet still keeping flexibility in spatial organization. The introduction of low-level partitioned spaces in an office layout, however, produces a complicated lighting design problem. Obviously, accurately predicted daylighting performance data are needed not only for daylighting design but for artificial lighting system design. Scale models of 12 sets of unit partitioned spaces are constructed and extensive scale model measurements of both daylight and reflected sunlight have been performed within an artificial sky simulator. The prototype-building interior is modeled with different partition configurations, each of which is modeled using the different envelope geometry and exterior configurations, and then the variations in interior light levels are estimated. The result indicates that partitioned spaces employed in an open plan of modern offices still offer a large potential for daylighting and energy saving as well. Much of the savings may derive from the cumulative effect of reflected sunlight. Optimal design for building envelope geometry and exterior configuration promises additional savings.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.429-436
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• 2013

In this study, we researched a pendant-type aspherical optical system, which could be applied to street lighting and security lighting in Europe. The goal of this research was eco-friendly artificial lighting that could be used for the one-to-one replacement of ordinary lighting. LED lighting was miniaturized by using one COB LED Module and one aspherical optical system, which could control the luminosity of the LED. Through the aspherical optical system, the light distribution angle could be controlled in a range of $140^{\circ}$ for the X-axis and $40^{\circ}$ for the Y-axis. This means that this optical system is appropriate for catenary-type lighting, which is widely used in Europe on both narrow and broad roads. The performance was determined using a lighting simulation program. This lighting system simulation showed that road rates M4 and M5 could be satisfied, with the condition of a 13-m height and 50-m distance (U0 and TI). The simulation program estimated that light pollution, which disturbs sleep, could beeliminated in the European streetlight case. Determining methods for the light distribution control, performance, and optimal lighting setup conditions is very important to prevent light pollution. Moreover, the initial step of developing the lighting system design and post management will require an effort with much analysis.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.139-139
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• 1999

In this paper, the result of study in artificial lighting uniformity ratio yield method subject to lecture room are reported. It is desirable that the application of equation ① U=Ei/Ex×100 cannot be used to the mean value in place to be effective of light and darkness. And it is desirable that the application of equation ② U=Ei/Ea×100 or equation ③ U=(Ea-Ei)/Ea×100 be used to the mean Value equality illumination conditions. Also, requiring preparation of judgement standard, uniformity ratio equation agree with actual circumstances in this country. It must be considered intensity of illumination and specificity of space in established standard.

• Journal of the HCI Society of Korea
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• v.14 no.2
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• pp.5-12
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• 2019

Social exclusion, which does not fulfill the desire for respect as one of the most basic human desires, makes those who perceive themselves to be socially excluded seek physical warmth. However, very few studies have examined whether this phenomenon-wherein social exclusion develops a preference for warmth-can be generalized to the emotional or symbolic aspects, such as the color of lighting. This study aimed to verify the effects of perceived social exclusion on warm lighting preferences, and two experiments were performed for this purpose. In Experiment-1, participants who were respected by people the previous day were assigned to the group that did not perceive social exclusion (non-perceived social exclusion group), and those who were not respected were assigned to the group that perceived social exclusion (perceived social exclusion group). Following this, their preference for warm lighting (3000K), neutral lighting (4000K), and cold lighting (6000K) was measured. The results showed that the perceived social exclusion group had a stronger preference for warm lighting and a weaker preference for cold lighting than did their counterparts. Moreover, the perceived social exclusion group showed a strong preference for warm lighting over neutral lighting; they also showed a weak preference for cold lighting. In Experiment-2, after assigning the participants into groups as in Experiment-1, the participants' preference for a space with warm lighting, neutral lighting, and cold lighting was measured. The results showed that the perceived social exclusion group had a stronger preference for the space with warm lighting and a weaker preference for cold lighting than did their counterparts. Further, the perceived social exclusion group showed a strong preference for the space with warm lighting over the space with neutral lighting; they also showed a weak preference for the space with cold lighting. The findings of this study have implications that can be applied to designing living spaces for people who experience social exclusion, such as handicapped individuals, multicultural families, or immigrant workers, as well as developing artificial intelligence services and cyber-friend characters for this demographic.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1989.10a
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• pp.59-64
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• 1989

Daylight is regarded by most people as preferred light source for interior lig-hting. With poper design, daylight can save electric lighting during daytime. This paper attemptes to show that bett-er use of daylight might be the balanced use of supplementary artificial lighting at times and places where the natural 1-ighting is inadequate with consequent c-ost and energy saving.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2001.02a
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• pp.160-166
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• 2001

• Journal of the Korea Society of Computer and Information
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• v.15 no.3
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• pp.111-119
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• 2010

An artificial light source has a character that a light emits from a point to all directions with many radial and straight ray shapes. It is very difficult and complex to render those emitting lights. Also, users have difficulty in expressing exactly 3D objects because of colors varying with changing of a light and having many parameters. In this paper, to solve those problems we design an artificial light source using X3D to create a model that represents easily many radial and straight ray shapes and propose the online system that each factors of colors to be reflected by a light is separated and then users can control them to detect object's colors by a mouse. Various light sources with reality can be easily created using proposed system.

• Journal of Biosystems Engineering
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• v.23 no.6
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• pp.591-598
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• 1998

Light intensity and spectral characteristics of different types of fluorescent lamps were tested to investigate their possibility as the artificial lighting sources for the close illumination applied in the transplant production factory. Photosynthetic photon flux densitiy(PPF), illuminance and irradiance for all lamps decreased logarithmically with an increase of the vertical distance from the lighting source. The fluorescent lamp specially designed plant growth (PG lamp) showed a maximum spectral irradiance at the wavelength of 660nm. However, it showed lower irradiance than that of a standard fluorescent lamp at the range of wavelength between 500 and 600nm. On the other hand, PG lamp showed higher PPF and lower illuminance than those of the standard fluorescent lamp. The maximum peak of spectral characteristics for both of the single and twin three-bind fluorescent lamps was shorn at the wavelength of 545m and the next peaks were shown at the wavelength of 610nm and 435nm, respectively. Since the red fluorescent lamp has a narrower peak at the wavelength of 660nm, it may be useful for the supplementary red lighting. For three of standard, single three-band and twin three-band fluorescent lamps, the values of conversion factor for converting illuminance to PPF fell within the narrow range from 76 to 791x/$\mu$molㆍm$^{-2}$ ㆍs$^{-l}$ . However, for PG lamp, it was 29.71x/$\mu$molㆍm$^{-2}$ ㆍs$^{-1}$. Also, the values of conversion factor for converting PPF to irradiance of fluorescent lamp used in this study ranged between 4.85 and 5.34$\mu$molㆍm$^{-2}$ ㆍs$^{-1}$/Wㆍm$^{-2}$ .

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.279-286
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• 2013

Purpose: This study was conducted to analyze the utilization efficiencies of electric energy and photosynthetically active radiation of lettuce grown under red LED, blue LED and fluorescent lamps with different photoperiods. Methods: Red LED with peak wavelength of 660 nm and blue LED with peak wavelength of 450 nm were used to analyze the effect of three levels of photoperiod (12/12 h, 16/8 h, 20/4 h) of LED illumination on light utilization efficiency of lettuce grown hydroponically in a closed plant production system (CPPS). Cool-white fluorescent lamps (FL) were used as the control. Photosynthetic photon flux, air temperature and relative humidity in CPPS were maintained at 230 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $22/18^{\circ}C$ (light/darkness), and 70%, respectively. Electric conductivity and pH were controlled at 1.5-1.8 $dS{\cdot}m^{-1}$ and 5.5-6.0, respectively. The light utilization efficiency based on the chemical energy converted by photosynthesis, the accumulated electric energy consumed by artificial lighting sources, and the accumulated photosynthetically active radiation illuminated from artificial lighting sources were calculated. Results: As compared to the control, we found that the accumulated electric energy consumption decreased by 75.6% for red LED and by 70.7% for blue LED. The accumulated photosynthetically active radiation illuminated from red LED and blue LED decreased by 43.8% and 33.5%, respectively, compared with the control. The electric energy utilization efficiency (EEUE) of lettuce at growth stage 2 was 1.29-2.06% for red LED, 0.76-1.53% for blue LED, and 0.25-0.41% for FL. The photosynthetically active radiation utilization efficiency (PARUE) of lettuce was 6.25-9.95% for red LED, 3.75-7.49% for blue LED, and 2.77-4.62% for FL. EEUE and PARUE significantly increased with the increasing light period. Conclusions: From these results, illumination time of 16-20 h in a day was proposed to improve the light utilization efficiency of lettuce grown in a plant factory.

• Journal of Biosystems Engineering
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• v.26 no.4
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• pp.379-384
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• 2001

To enhance the smooth graft-taking of grafted seedlings, the excessive evapotranspiration from grafted seedlings just after grafting should be avoided. A measurement system of the evapotranspiration rate of grafted seedling under artificial lighting was set up to investigate the effect of physical environment on the evapotranspiration and graft-taking characteristics of grafted seedlings quantitatively. The evapotranspiration rate of grafted seedlings affected by relative humidity and light intensity were analyzed using the measurement system. The hypocotyl of watermelons (Citrullus vulgaris cv. Sweetdew, Hungnong Seed Co.) was slantly cut and then inserted into a hole on the stem of rootstock (Lagenaria siceraria cv. FR-King, Hungnong Seed Co.). Grafted seedlings were healed and joined for 5 days under cool-white fluorescent lamps (FL20SEX-d/18, Keumho Electric Co.) with photoperiod of 12h$.$d$\^$-1/ except dark period for one day after grafting in a closed graft-taking enhancement system developed by Kim(2000). The evapotranspiration rate and graft-taking of grafted seedling at air temperature of 23$\^{C}$ and air current speed of 0.1m$.$s$\^$-1/ was highly affected by relative humidity. But light intensity showed higher effect on the stem length of scion than relative humidity. In conclusion, it was suggested that relative humidity should be controlled at higher than 90% with photosynthetic photon flux of 50$\mu$mol$.$m$^2$$.$s$\^$-1/ to increase the survival of grafted seedlings and to produce healthy seedlings.