• Journal of the Ergonomics Society of Korea
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• v.34 no.2
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• pp.191-198
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• 2015

Objective: As a cue for desired mood, we attempted to identify types of sitting postures when people are involved in various tasks during their working hours. Background: Physical behaviors in reaction to user contexts were studied, such as automated posture analysis for detecting a subject's emotion. Sitting postures have high feasibility and can be detected robustly with a sensing chair, especially when it comes to an office. Method: First, we attached seven sensors, including six pressure sensors and one distance sensor, to an office chair. In Part 1, we recorded participants' postures while they took part in four different tasks. From the seven sensors, we gathered five sets of data related to the head, the lumbar, the hip, thigh pressure and the distance between the backrest and the body. We classified them into four postures: leaning forward, upright, upright with the lumbar supporting, and leaning backward. In part 2, we requested the subjects to take suitable poses for the each of the four task types. In this way, we compared the matches between postures and tasks in a natural setting to those in a controlled situation. Results: We derived four types of sitting postures that were mapped onto the different tasks. The comparison yielded no statistical significance between Parts 1 and 2. In addition, there was a significant association between the task types and the posture types. Conclusion: The users' sitting postures were related to different types of tasks. This study demonstrates how human emotion can interact with lighting, as mediated through physical behavior. Application: We developed a posture-based lighting system that manipulates the quality of office lighting and is operated by changes in one's posture. Facilitated by this system, color temperatures ranging between 3,000K and 7,000K and illuminations ranging between 300lx and 700lx were modulated.

• KIEAE Journal
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• v.17 no.3
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• pp.5-13
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• 2017

Purpose: Various studies have been performed to address the issue of increased energy use by buildings. In particular, research on complex envelopes that combines diverse envelope element techniques is currently in progress in the building sector. The present study aimed to develop an awning system using a light shelf, and to verify its validity through performance evaluation. Method: In the present study, a testbed was established for the performance evaluation of the awning system using a light shelf, and the uniformity ratio and lighting energy consumption were compared and analyzed relative to those with no awning and light shelf installation (Case 1), awning installation (Case 2), and light shelf installation (Case 3). Result: 1) In the present study, an awning system using a light shelf (Case 4) where an opening is made on the awning screen and natural light can be introduced through the light shelf located at the bottom was developed. 2) The optimum standard for Case 4 obtained through the performance evaluation was a 0.6m lighting length and a 2m extension length at a light shelf angle of $30^{\circ}$. 3) Case 4 with the optimum standard had a 5.5% lower uniformity ratio than Case 2, but had a higher uniformity ratio than Case 1 and Case 3. 4) Case 4 with the optimum standard showed 13.3%, 44.6%, and 0%~8.7% lighting energy reductions compared to Case 1, Case 2, and Case 3, respectively. 5) Based on the above results, Case 4 suggested in the present study was found to be effective for indoor light environment improvement and lighting energy reduction.

• KIEAE Journal
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• v.17 no.3
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• pp.83-90
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• 2017

Purpose: With the increase in the energy consumption in the building sector, many studies have recently been conducted to address this issue. Due to its efficiency, diverse studies on a light-shelf, which is a natural lighting system, are in progress. However, there has been no research on the external illumination that determines the performance of a light-shelf. Therefore, the present study aimed to prepare the external illumination standard for securing the lighting performance of a light-shelf through the light-shelf performance evaluation based on a 1:1 scale testbed, and to suggest a height-adjustable light-shelf based on an open and closed concept for the case in which the lighting performance of the light-shelf significantly deteriorates, by collecting the external illumination. Method: In this study, a 1:1 scale testbed was established for performance evaluation, and the external illumination standard for securing the performance of the light-shelf was prepared by comparing the lighting performance of the light-shelf depending on the open and closed condition of the light-shelf and the external illumination. Result: 1) In this study, a light-shelf that can be opened or closed depending on the external illumination was suggested. As a result, the prospect right can be secured by creating the condition where there is no light-shelf installation by moving the light-shelf to the top of the window when the lighting performance is not secured. 2) In the summer solstice, the external illuminations appropriate for lighting energy reduction were more than 75,000 lx and 60,000 lx for the light-shelf width of 0.3 m and 0.6 m, respectively. 3) In the intermediate period, the external illumination appropriate for lighting energy reduction was 60,000 lx. In the winter solstice, making the condition where there is no light-shelf installation by closing the light-shelf would be appropriate. 4) Based on the aforementioned results, the external illumination standard for the opening and closing of the height-adjustable light-shelf based on an open and closed concept suggested in this study was 60,000 lx, and the light-shelf with a width of 0.6 m would be advantageous for lighting energy reduction.

• KIEAE Journal
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• v.16 no.4
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• pp.63-69
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• 2016

Purpose: This preliminary study investigated a potential of the water wall systems that provide heat storage and natural lighting control simultaneously. Method: In order for transparency of the water wall to be controlled, the study first proposed two measures: to adjust transparency of the water wall; to control transparency of water wall surface. The performance of two measures then was verified and compared by experiments. In addition, a trade-off between heat collect and heat storage resulting from using additive for adjusting transparency was investigated. Result: The experiment showed that the two measures are similar in performance. The investigation of trade-off relation showed the additive should have the same heat storage as the water to prevent decrease in thermal performance of the water wall. As an economical measure to control transparency of the water wall, this study suggested a measure of secondary heat transfer systems using shading device that first absorbs solar radiation and then transfers heat to the water wall. The experiment show that performance of the proposed measure is similar to controlling transparency of water wall surface. In conclusion, it is expected that the performance of the water wall can be economically maximized by using the proposed mean in terms of heating, cooling and lighting energy saving.

• Korean Institute of Interior Design Journal
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• v.18 no.6
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• pp.104-114
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• 2009

The purpose of study was understanding necessity of environment design for underground parking lot in residential design plan and grasping design plans of 'Activity Support' that considerate women, exclude women's unsecured feeling at underground parking lot. The inquiry analyzed 6 design plan in design competition that considerate women according to precede studies, a theory of CPTED, a design guide for wayfinding, and survey. A ramp, circulation, entrance, lighting, ventilation, and space design plan are proceed on this study The result are as below. First, a rectilinear figure ramp suits entrance plan on the circulation, but if it is not possible, cross-using of rectilinear and curvilinear figure ramp plan is desirable. Second, on the circulation plan, vehicles circulation plan and equality parking distribution plan got accomplished generally, and help senses of direction because it is planed network systemize. On a large scale underground parking lot, simplify parking circulation to convenience entrance and exit for weak in sense of direction. Third, the shape and material that‘s environmentally conscious will be in use to the entrance plan. As the first stage to the underground, artwork that women prefer can modulate the rejection of underground space. Forth, natural lighting system and ventilation can make the environment-friendly space, decrease the women’s rejection to the underground, it can also keep a natural watch on the space. Fifth, on the space design plan, it can use bright and comfortable design of wall and ground to decrease the women‘s rejection, also it is useful to the sense of direction. LED indirect lighting plan that 58.7% of women prefers on survey reflects women’s state of desire that bright and atmosphere. In addition, proper use of plans that subsidiary facilities, rest area with Sunken, and nature-friendly material can minimize differences of underground and ground parking lot.

• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.164-171
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• 1999

Tomato yield and harvest date were analyzed to examine the productivity of Single Truss Tomato Production System(STTPS) for four regions in Korea. It was found that the solar radiation was not sufficient to get the maximum tomato yield during the low light seasons. The difference of total annual yield between Suwon and Jinju regions was about 12kg.m$^{-2}$ . These results indicate that supplemental lights are needed to increase the yield. The availability of natural light should be considered in deciding the locations of tomato greenhouses. The harvest date could be adjusted by using supplemental lighting. The development and implementation of the lighting control strategies are required for reducing electricity expense.

• Journal of the Korean Home Economics Association
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• v.48 no.5
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• pp.17-24
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• 2010

Although design, color, and material are important elements in stage costumes, stage lightning also plays significant role in the presentation of stage costumes. Costumes color, material and perception can be significantly influenced by visual effects. Stage illumination can be arranged or managed so that colors are closely related to or enhanced or change the effects of costume colors on the runway or display at specific times. The results of this thesis are as follow; 1) Fabric tone, name, brightness, and chroma of colors were changed by the colors of stage lighting. 2) An achromatic color was changed to a chromatic color after being combined with colors of stage lighting. 3) Stage illuminations can make fabric, colors look similar to stage colors. 4) Plain satin silk fabric which reflects light shows high brightness and chroma after being influenced by stage lighting its shining effects and color changes were clear and apparent. 5) Velvet pile fabric which absorbs light shows low brightness and chroma after being influenced by stage lightning its shining effects and changes of colors were not clear and apparent. In conclusion, natural lights did not significantly influence fabric colors and perception, while artificial lights had wide range of effects on fabric colors and perception.

• Land and Housing Review
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• v.10 no.3
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• pp.17-22
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• 2019

In recent years, crime has been steadily increasing, causing not only economic damage but also aggravating the social atmosphere. The CPTED(Crime Prevention Through Environmental Design) guideline, which is an environmental crime prevention design technique, reduces the possibility of crime by implementing a proper defensive design plan through appropriate lighting design in the city and reduces the fear of crime. Among the various principles of CPTED, the proper use of street lamps and CCTV is considered to be an important factor in enabling natural surveillance. In this study, the authors identified and quantified the current status of the installation of street lamps and CCTV in each autonomous district of Seoul. The physical quantity of lighting and social factor quantified from light lamps and CCTV data, respectively, were expected to support the guidelines presented by CPTED. Therefore, we conducted statistical analysis based on quantified values and found that street lamps and CCTV had a statistically significant relationship with crime rate. In addition, the correlation between the safety index and the crime rate, calculated by dividing the number of street lamps and CCTVs by area, was also analyzed and an R2 value of 0.647 was confirmed.

• Journal of the Korea Computer Graphics Society
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• v.17 no.3
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• pp.21-31
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• 2011

This paper presents a practical method to estimate the directions of light sources in real environment, using a mirror sphere placed on a set of known natural features in augmented reality. For the stable result of static lighting, we take the multiple images around the sphere and estimate the principal light directions of the vector clusters for each light source in realtime. We also estimate the moving illuminant for changes of the scene illumination, and augment the virtual objects onto the real image with the proper highlighting and shadows. The proposed method of this paper can be applied to augmented reality visualization without any previous information respecting the environmental illuminations.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.220-227
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• 2012

This study was conducted to analyze the seeding quality of paprika and the growth and early yield after transplanting of paprika nursed under artificial light and natural light. In this study, blue LED, red LED, and white fluorescent lamps (FL) were used as artificial lighting sources. Photoperiod, average photosynthetic photon flux, air temperature, and relative humidity in a closed transplants production system (CTPS) were maintained at 16/8 h, $204{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 26/$20^{\circ}C$, and 70%, respectively. Leaf length, leaf width, leaf area, top fresh weight and dry weight of paprika seedlings, and chlorophyll content in paprika leaves nursed under LED and fluorescent lamps for 21 days after experiment were significantly affected by light treatments. As compared with the control (white FL), leaf area of paprika grown under blue LED, red LED, and natural light was decreased by 63%, 63%, and 28%, respectively. Top dry weight of paprika grown under blue LED, red LED, and natural light was 64%, 50%, and 22%, respectively, compared with the control. Number of leaves on 18 days after transplanting showed with red LED, blue LED, and natural light by 86%, 84%, and 48%, respectively, compared with the control. On 114 days after transplanting, paprika nursed under blue LED and red LED had relatively short plant height. This result might be caused that the elongation of its internodes was suppressed by the illumination of sole blue or red light. Average number of fruits per plant harvested during 4 weeks after first harvest was 3.5 with red LED, 3.3 with blue LED, 1.0 with natural light, and 2.2 with control, respectively. Early yield of paprika nursed under red LED, blue LED, natural light, and control were 453 g/plant, 403 g/plant, 101 g/plant, and 273 g/plant, respectively. Larger fruit of 136 g was harvested with red LED treatment. Even though the early yield of paprika was greatly increased with artificial lighting, but total yield was almost similar as the harvest period after transplanting in greenhouses was lengthened. From the above results, we could understand that paprika nursed under white FL, blue LED, and red LED showed good growth after transplanting and was early harvested by a week as compared to the natural light. Therefore, the white FL, blue LED, and red LED as the artificial lighting sources in CTPS could be strategically used to enhance the seedling quality, to shorten the harvest time, and to increase the yield of paprika.