• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.12
• /
• pp.54-62
• /
• 2013

In this study, a mock powder room was installed with variable LED lighting environments in order to conduct the experiments. The experimental conditions include luminaire type, illuminance ratio, vertical illuminance and color temperatures. The evaluation methods used were the Semantic Differential Method and a subjective evaluation on activities through observation. The SD evaluation result factor analysis categorizes ideas into three factors: brightness, emotion, and glare. The vertical bracket or the combined luminaire (luminous panel+ Vertical bracket) has better brightness than luminous panel. A vertical illuminance of 500lx is not significantly difference as compared to 600lx, allowing 500lx to be considered standard. The emotional atmosphere is evaluated as being better at lower color temperature. The luminous panel is the best for reducing glare while the vertical bracket is the worst. The best conditions differ according to the illuminance ratio of the luminous panel and vertical bracket. In the subjective evaluation (satisfaction with lighting environment, suitability to activity) the combined luminaire and 4000K received the best evaluation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.26 no.9
• /
• pp.424-433
• /
• 2014

The purpose of this study is to evaluate the effectiveness in the lighting performance of mixed type light-shelf, by comparing and analyzing the internal light-shelf, external light-shelf, and mixed-type light-shelf. The performance of light-shelf was evaluated according to the angle of light-shelf at summer solstice, winter solstice, vernal equinox, and autumn equinox. The comparative analysis between the internal light-shelf, external light-shelf, and mixed-type light-shelf was carried out using the performance evaluation and analysis method. The result of performance evaluation is shown as follows. The mixed type light-shelf showed the highest lighting performance all at summer solstice, winter solstice, vernal equinox, and autumn equinox, followed by the external light-shelf and the internal light-shelf in the same order. The mixed type light-shelf was the most favorable for bringing daylight to indoors by adjusting the angle of light-shelf, and it also showed the highest lighting performance in terms of uniformity ratio of illumination which indicates the quality of light.

• Journal of Convergence for Information Technology
• /
• v.8 no.5
• /
• pp.153-158
• /
• 2018

In this paper, we have studied a dimming level control method to satisfy both lighting and communication performance in visible light communication system. In the case of the most commonly used OOK and RZ-OOK modulation schemes, continuous Burst Zero Duration will seriously degrade the lighting function. This causes not only the illumination but also the performance of the entire system to deteriorate. Through this study, we analyzed the dimming level characteristics of the existing system and proposed the Illegal Pulse Insertion (IPI) algorithm as a technique to increase the dimming level. Through this, it is possible to effectively control the dimming level and improve the QoS of both lighting and communication by resolving the flicker phenomenon and dimming level reduction in the existing modulation and demodulation system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.162-162
• /
• 2010

In this study, optical analysis for 100W LED safety street lighting was conducted. Experimental research on such single LED was the first undertaken. simulation modeling based on optical properties of single LED has compared single LED product also designed 100W simulation modeling has compared average road illuminance with Korean Industrial Standards for LED safety street lighting(KS C7658:2009). 100W safety street lighting (model: CE180-ST-OS) designed by simulation has been also compared between product and 100W simulation modeling, and error rates have showed average 5.6[%]. Designed 100W LED safety street lighting base on simulation modeling was proven by comparison experiments. Through the simulations and the corresponding analysis, it was found that the tested 100W LED safety street lamp had reasonable performance. Design method for LED safety Street lamps have been summarized, based on the optical analysis.

• Korean Institute of Interior Design Journal
• /
• v.13 no.6
• /
• pp.167-174
• /
• 2004

The purpose of this study is to examinethe present illumination conditions in office environment and to suggest an efficient illumination plan in office planning process. Illumination conditions in work environment were surveyed in 6 offices to investigate whether the present illumination conditions were appropriate to the work type. The results of this study are as follows: Most of the general Illuminance level in the area of work were all at an adequate level, except one. The average Illuminance level in the all meeting rooms were met for the standard. Illuminance in the all reception area were extremely over the standard, The illuminations of this area were rather designed according to the image of the company than the standard. As for the illumination method in the area of general work, four offices used a general lighting by a direct lighting type, while two offices used a general lighting and a task lighting at the same time. This survey suggested that first, each company should consider illumination plan in the building planning process, second, illumination plan considering the type of places is needed, and third, illumination environment may be differentiated according to the work type. In conclusion, efficient illumination environment should be considered in office building planning process, especially In terms of illumination materials and methods.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.10
• /
• pp.9-15
• /
• 2012

There have been light pollution standards just for architectural lighting and sign in the "Light Pollution Abatement Law" so far. However, both of them regulate only one of the three main light pollution elements-"Glare". Therefore, it is imperative to do research on the other two light pollution elements-"Upward" and "Light Trespass" and make proper restriction. Subsequently, this study focuses on the upward light from the street light and suggests its analysis method. Eventually, this study aims to make viable management which is suitable for the nation and, in addition, to suggest appropriate level of restriction to "Light Pollution Abatement Law" by doing site survey.

• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.10
• /
• pp.78-88
• /
• 1995

For producing iron or steel products with good quality, the concentration of the material components should be analyzed quickly with high relability using XRF(Fluorescent X-Ray Spectrometer). Since the analysis results are much dependent upon the surface con- dition, the samples have to be prepared to have good test condition. This study presents an image processing system for inspecting the surface condition of the iron test sample. In order to use thd computer vision system, we need to develop a lighting device and image processing algorithm. For the adequate lighting device of inspection system, the indirect lighting device is contrived to cut the external light and provide uniform, stable and cold light. The image processing algorithm is aimed to reduce inspection time and to get similar analyzing results to those of the experienced operators. At first, the image processing algorithm checks whether the surface of the iron sample is ground well or not. Then, the defects; hole or dig are conted and surface condition is evaluated. In addition, the algorithm gives the reliability of the analyzing results in order to help operator's decision.

• ETRI Journal
• /
• v.45 no.6
• /
• pp.1022-1034
• /
• 2023

In this study, the impact of varying lighting conditions on recognition and decision-making was considered. The luminosity approach was presented to increase gesture recognition performance under varied lighting. An efficient framework was proposed for sensor-based sign language gesture identification, including picture acquisition, preparing data, obtaining features, and recognition. The depth images were collected using multiple Microsoft Kinect devices, and data were acquired by varying resolutions to demonstrate the idea. A case study was designed to attain acceptable accuracy in gesture recognition under variant lighting. Using American Sign Language (ASL), the dataset was created and analyzed under various lighting conditions. In ASL-based images, significant feature points were selected using the scale-invariant feature transformation (SIFT). Finally, an artificial neural network (ANN) classified hand gestures using specified characteristics for validation. The suggested method was successful across a variety of illumination conditions and different image sizes. The total effectiveness of NN architecture was shown by the 97.6% recognition accuracy rate of 26 alphabets dataset with just a 2.4% error rate.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.53 no.4
• /
• pp.205-209
• /
• 2004

This research is investigated an energy saving system based on human detecting technique. It saves a lot of energy by automatic switching method of lighting, appliance, and so on. Existence of people on space is detected by infrared ray sensor. If there is not anybody during definite time, then main controller of system sends "power off" signal to lighting switches, and outlets. When people are detected again, turn on lighting switches and outlets. Result of this research is adaptable for classrooms and offices, and great effect of energy saving is expected.

• Proceedings of the KIEE Conference
• /
• 2006.10c
• /
• pp.431-433
• /
• 2006

The goal of this paper is improvement of vision inspection accuracy by using histogram specification operation. The histogram is composed of horizontal axis of image intensity value and vertical axis of pixel number in image. In appearance vision inspection, the histogram of reference image and input image are different because of minutely lighting distinction. The minutely lighting distinction is main reason of vision inspection error in many cases. Therefore we made an effort for elevation of vision inspection accuracy by making the identical histogram of reference image and input image. As a result of this area separation histogram specification algorithm, we could increase the exactness of vision inspection and prevent system error from physical and spirit condition of human. Also this system has been developed only using PC, CCD Camera and Visual C++ for universal workplace.