• KIEAE Journal
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• v.16 no.3
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• pp.71-76
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• 2016

Purpose: This study aimed at improving the indoor environment of the office building by measuring the indoor environment and conducting a survey. Method: The measurement was conducted from January 13 to March 16 in 2012, targeting 44 sites in same office building located in Seoul, South Korea. The lists of measurement such as dry-blub temperature, relative humidity, formaldehyde (HCHO), asbestos, carbon monoxide (CO), carbon dioxide (CO2), volatile organic compounds (VOCs) and particle pollution (PM10) were measured. In addition, illuminance which belongs to light environment and noise in sound[acoustical] environment were measured respectively. Result: The buildings showed overall pleasant conditions. In terms of the thermal, air, sound, and visual environment, each measurements were satisfied with the requirements in standard, within pleasant ranges, except several sites. However, the survey results were revealed that the office workers were mostly dissatisfied with their indoor environment. Given that the measured values were mostly within standards, the results of survey might have resulted from a compensation mentality biased toward the subjects in psychological terms.

• Conservation Science in Museum
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• v.18
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• pp.65-76
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• 2017

Following advances in technology and with the growing need for renewable energy, fluorescent and halogen lamps are being replaced by LED lighting in museum systems. This paper researched the setting of standards for the diverse lighting systems in addition to the LED lighting that are expected to be introduced in museums in the future. Contrary to previous belief, LEDs were shown to only barely emit in the ultraviolet region, but the visible rays were confirmed to produce discoloration depending on illuminance-hours. When the color change by LED lamps at the color temperature of 2800K, or warm white, was compared with 5500K, or white, the emission spectrum analysis confirmed that the blue spike increased at a higher color temperature and caused more discoloration. This suggests that in addition to illumination, color temperature should be considered by including the emission spectrum when museums set lighting environment standards.

• Land and Housing Review
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• v.13 no.1
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• pp.131-140
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• 2022

A smart window is a new building material that can realize energy savings in a building. Smart windows can freely adjust Visible Light Transmittance (VLT) and solar gain coefficient (g-value) according to the situation. Smart windows include such technologies as Electrochromic (EC), Suspended Particle Device (SPD), and Polymer Dispersed Liquid Crystal (PDLC). Recent research on building energy savings through the VLT and g-value control functions of smart windows is being actively conducted and meaningful results are being drawn. However, since most of the research is focused on energy savings, research on the indoor environment is somewhat lacking. A building is a space where people live and the comfort of life should be prioritized before energy savings. Therefore, in this study, analysis on the daylight performance of an office space was carried out. Through green building standards such as LEED, BREEAM, CASBEE, and G-SEED, the daylight performance was reviewed according to VLT value changes of the smart window. In addition, a study was conducted on the VLT range of the electrochromic façade that can maintain a comfortable indoor environment. The smart window used electrochromic control with a wide range of VLT. The study showed that the minimum VLT of a smart window that can satisfy G-SEED is 25% or more. In addition, it was found that the VLT change of the electrochromic smart window did not significantly affect the uniformity of the room. When the LEED standard was applied, the minimum VLT value of the electrochromic smart window that must be maintained according to each orientation of the building was derived.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.1
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• pp.9-18
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• 2010

This research surveys actual conditions in order to examine the lighting environments of the elderly's residential 50 households. The results is as following. First, The elderly indicated that they felt the living room and the kitchen are usual degree, dark only in bedrooms and rest rooms of brightness. And about satisfactory degree of residential illumination is being above of usual Satisfaction. Second, Problems of lighting environments of elderly's houses were brightness and management, when lighting environmental reconstruct, considered brightness and equipment superannuation, and they want the focus on brightness in the reconstruction. Third. Operating method of lighting was used almost overall lighting in bedroom and bathroom, overall lighting and part lighting are used together in kitchens. The living room has a lot of cases which uses only a general illumination, but the cases which overall lighting and part lighting are used together has occupied 40[%]. Fourth, An average Illuminance of the bedroom is 104.17[lx], an average unifonnity ratio is 60.22[%]. The livingroom's average is 116.15[lx], 51.48[%]. The sink's average is 236.40[lx], the table average is 160.73[lx] in the kitchen. The washstand's average is 109.81[lx], the chamber's average pot is 74.33[lx] in the bathroom. These results are generally darker than the standard.

• Journal of the Korean Geotechnical Society
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• v.39 no.2
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• pp.31-42
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• 2023

A study was conducted to use soil color obtained from digital im ages as an indicator of soil water content. Digital images of Jumoonjin standard sand with five different water contents were captured under nine different lighting conditions. Through digital image processing, the soil color of the sample was obtained based on the CIELAB color system, and the effect of lighting conditions and water content on the soil color was analyzed. The results indicated that L^* showed a high correlation with illuminance, whereas a^* and b^* showed a high correlation with color temperature. As the water content increased, L^*, which represents the brightness of the soil color, decreased, and a^* and b^* increased. Therefore, the soil color changed from green and blue to red and yellow. Based on the regression analysis results of lighting conditions, water content, and soil color, a water content predicting method based on the soil color of silica-based sand photographed under irregular light conditions was proposed. The proposed method can predict the water content with a m axim um error of 0.29%.

• Journal of Internet Computing and Services
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• v.23 no.2
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• pp.29-35
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• 2022

UV rays have beneficial or harmful effects on the human body depending on the degree of exposure. An accurate UV information is required for proper exposure to UV rays per individual. The UV rays' information is provided by the Korea Meteorological Administration as one component of daily weather information in Korea. However, it does not provide an accurate UVI at the user's location based on the region's Ultraviolet index. Some operate measuring instrument to obtain an accurate UVI, but it would be costly and inconvenient. Studies which assumed the UVI through environmental factors such as solar radiation and amount of cloud have been introduced, but those studies also could not provide service to individual. Therefore, this paper proposes a deep learning model to calculate UVI using solar object information and sunlight characteristics to provide an accurate UVI at individual location. After selecting the factors, which were considered as highly correlated with UVI such as location and size and illuminance of sun and which were obtained through the analysis of sky images and solar characteristics data, a data set for DNN model was constructed. A DNN model that calculates the UVI was finally realized by entering the solar object information and sunlight characteristics extracted through Mask R-CNN. In consideration of the domestic UVI recommendation standards, it was possible to accurately calculate UVI within the range of MAE 0.26 compared to the standard equipment in the performance evaluation for days with UVI above and below 8.

• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.299-305
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• 2015

Modbus is a serial communications protocol, it has since become a practically standard communication protocol, and it is now a commonly available means of connecting industrial electronic devices. Therefore, it can be connected with all devices using Modbus protocol to the measurement and remote control on the ships, buildings, trains, airplanes and etc.. In this paper, we add the Modbus communication protocol to the existing lighting controller sensitivity to enable verification and remote control by external environmental factors, and also introduces a fuzzy inference system was configured by external environmental factors to control LED lighting. External environmental factors of temperature, humidity, illuminance value represented by the LED through a fuzzy control algorithm, the values accepted by the controller through the sensor. Modbus is using the RS485 Serial communication with other devices connected to the temperature, humidity, illumination and LED output status check is possible. In addition, the remote user is changed to enable it is possible to change the RGB values in the desired color change. Produced was confirmed that the LED controller output is based on the temperature, humidity and illumination.

• Journal of Internet Computing and Services
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• v.24 no.2
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• pp.19-26
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• 2023

Humans have adapted and evolved to natural light. However, as humans stay in indoor longer in modern times, the problem of biorhythm disturbance has been induced. To solve this problem, research is being conducted on lighting that reproduces the correlated color temperature(CCT) of natural light that varies from sunrise to sunset. In order to reproduce the CCT of natural light, multiple LED light sources with different CCTs are used to produce lighting, and then a control index DB is constructed by measuring and collecting the light characteristics of the combination of input currents for each light source in hundreds to thousands of steps, and then using it to control the lighting through the light characteristic matching method. The problem with this control method is that the more detailed the steps of the combination of input currents, the more time and economic costs are incurred. In this paper, an LED lighting control method that applies interpolation and combination calculation based on the minimum spectral power distribution information for each light source is proposed to reproduce the CCT of natural light. First, five minimum SPD information for each channel was measured and collected for the LED lighting, which consisted of light source channels with different CCTs and implemented input current control function of a 256-steps for each channel. Interpolation calculation was performed to generate SPD of 256 steps for each channel for the minimum SPD information, and SPD for all control combinations of LED lighting was generated through combination calculation of SPD for each channel. Illuminance and CCT were calculated through the generated SPD, a control index DB was constructed, and the CCT of natural light was reproduced through a matching technique. In the performance evaluation, the CCT for natural light was provided within the range of an average error rate of 0.18% while meeting the recommended indoor illumination standard.

• Progress in Medical Physics
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• v.18 no.2
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• pp.98-106
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• 2007

In June 2005, Yonsei University Medical Center, Severance Hospital upgraded a full-PACS system by adding twenty (5 mega pixels) Totoku ME511L flat panel LCD display devices for diagnostic interpretation purposes. Here we report upon the quantitative (or visual) acceptance testing of the twenty Totoku ME511L display devices for reflection, luminance response, luminance spatial dependency, resolution, noise, veiling glare, and display chromaticity based on AAPM TG 18 report. The tools used in the tests included a telescopic photometer, which was used as a colorimeter, illuminance meter, light sources for reflection assessment, light-blocking devices, and digital TG18 test patterns. For selected 8 flat panel displays, mean diffuse reflection coefficient ($R_d$) was $0.019{\pm}0.02sr^{-1}$. In the luminance response test, luminance ratio (LR), maximum luminance difference ($L_{max}$), and deviation of contrast response were $550{\pm}100,\;2.0{\pm}1.9%\;and\;5.8{\pm}1.8%$, respectively. In the luminance uniformity test, maximum luminance deviation was $14.3{\pm}5.5%$ for the 10% luminance of the TG18-UNL10 test pattern. In the resolution test with luminance measurement method, percent luminance (${\Dalta}L$) at the center was $0.94{\pm}0.64%$. In all cases of noise testing, rectangular target In every square in the three quadrants was visible and all 15 targets except the smallest one in the every corner pattern and the center pattern. The glare ratio (GR) was $12,346{\pm}1,995$. The color uniformity, (u',v'), was $0.0025{\pm}0.0008$. Also, the research results of qualify control guideline of primary disply devices suitable for domestic circumstance are presented All test results are in-line with the criteria recommended by AAPM TG18 report and are thus fully acceptable for diagnostic image interpretation. As a result, the acceptance testing schedule described provides not only an acceptance standard but also guidelines for quality control, optimized viewing conditions, and a means for determining the upgrading time of LCD display devices for diagnostic interpretation.