• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.199-205
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• 2018

The aim of this study was to confirm that effects of supplemental LED illumination on a strawberry yield and fruit quality when strawberry grown on a bottom bed to be deficient ambient light due to shading of a upper bed during cultivation by a two-bed bench system. A strawberry was cultivated as a drip irrigation system in the two-bed bench system filled with a strawberry exclusive media from October 2015 to January 2016. The upper and the bottom bed without LED illumination for growth of a strawberry were using as a control. For LED light treatments, from 10 am to 4 pm, we illuminated LEDs as $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light intensity by using blue, red, and mixing LED (blue plus red) on the strawberry plants of the bottom bed. In the yield of strawberry fruit, the strawberry grown on the bottom bed treated with the blue LED significantly increased compared with that of the bottom bed part control, and increased to by near 90% of the strawberry output of the upper bed part control. The soluble sugar content of strawberry fruit grown on the upper bed part control and on the bottom bed illuminated with blue or mixed LED was higher than that of red LED and the control of the bottom bed. The content of anthocyanin was the highest increased in the strawberry grown on the upper bed part control that received a lot of ambient light, however when comparing only the bottom bed, strawberry fruits grown on all LED treatments were higher than that of the control. Therefore, we considered that using of the blue LED light on the bottom bed of two-bed bench system during strawberry cultivation is advantageous for the increase of yield and improvement of fruit quality.

• Korean Journal of Optics and Photonics
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• v.4 no.1
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• pp.15-21
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• 1993

This paper describes the design and development of a KrF excimer laser stepper and discusses the detailed system parameters and characterization data obtained from the performance test. We have developed a deep UV step-and-repeat system, operating at 248 nm, by retrofitting a commercial modules such as KrF excimer laser, precision wafer stage and fused silica illumination and 5X projection optics of numerical aperture 0.42. What we have developed, to the basic structure, are wafer alignment optics, reticle alignment system, autofocusing/leveling mechanisms and environment chamber. Finally, all these subsystem were integrated under the control of microprocessor-based controllers and computer. The wafer alignment system comprises the OFF-AXIS and the TTL alignment. The OFF-AXIS alignment system was realized with two kinds of optics. One is the magnification system with the image processing technique and the other is He-Ne laser diffraction type system using the alignment grating on the wafer. 'The TTL alignment system employs a dual beam inteferometric method, which takes advantages of higher diffraction efficiency compared with other TTL type alignment systems. As the results, alignment accuracy for OFF-AXIS and TTL alignment system were obtained within 0.1 $\mu\textrm{m}$/ 3 $\sigma$ for the various substrate on the wafers. The wafer focusing and leveling system is modified version of the conventional systems using position sensitive detectors (PSD). This type of detection method showed focusing and leveling accuracies of about $\pm$ 0.1 $\mu\textrm{m}$ and $\pm$ 0.5 arcsec, respectively. From the CD measurement, we obtained 0.4 $\mu\textrm{m}$ resolution features over the full field with routine use, and 0.3 $\mu\textrm{m}$ resolution was attainable under more strict conditions.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.3
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• pp.112-118
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• 2009

Skin color segmentation techniques have been widely utilized for face/hand detection and tracking in many applications such as a diagnosis system using facial information, human-robot interaction, an image retrieval system. In case of a video image, it is common that the skin color model for a target is updated every frame for the robust target tracking against illumination change. As for a single image, however, most of studies employ a fixed skin color model which may result in low detection rate or high false positive errors. In this paper, we propose a novel method for effective skin color segmentation in a single image, which modifies the conditions for skin color segmentation iteratively by the image feedback of segmented skin color region in a given image.

• Clean Technology
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• v.6 no.1
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• pp.71-78
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• 2000

Removal rates of hydrogen sulfide were investigated to known effects of several light sources with external and internal irradiation on the desulfurization using C. thiosulfatophilum. In the case of internal illumination system, optical-fiber photobioreactor was applied to increase the light availability. Furthermore, sunlight was used as the main light energy in the daytime and metal-halide lamp was applied as an additional light energy at night. Light energy of 99% was saved by the application of the LED's array in comparison with the incandescent light source. $H_2S$ removal rates at 5,000 lux in a 4-L photobioreactor were shown as 0.040, 0.138, 0.136, and 0.134 (${\mu}mol$ $H_2S/min$)/(mg protein/L), respectively, in the following order of light sources, when several light sources such as fluorescent, energy-saving, incandescent, halogen lamp, and filtered light at 460 nm were applied. Removal rate per unit cell concentration with the internal light diffused optical-fibers increased about 1 six times as much as that with the external light sources. Removal rate per unit cell concentration, using sunlight in the daytime and a metal-halide lamp at night, was 0.41 less than 0.869 (${\mu}mol$ $H_2S/min$)/(mg protein/L) using a 400 W metal-halide lamp day and night, since the automatic sunlight collection system can transmit the light intensity as only 10% of that with a metal-halide lamp.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.1
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• pp.75-86
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• 2012

Synthetic Aperture Radar(SAR) imaging system is independent of solar illumination and weather conditions; however, SAR image is difficult to interpret as compared with optical images. It has been increased interest in multi-sensor fusion technique which can improve the interpretability of $SAR^{\circ\circ}$ images by fusing the spectral information from multispectral(MS) image. In this paper, a multi-sensor fusion method based on high-frequency extraction process using Fast Fourier Transform(FFT) and outlier elimination process is proposed, which maintain the spectral content of the original MS image while retaining the spatial detail of the high-resolution SAR image. We used TerraSAR-X which is constructed on the same X-band SAR system as KOMPSAT-5 and KOMPSAT-2 MS image as the test data set to evaluate the proposed method. In order to evaluate the efficiency of the proposed method, the fusion result was compared visually and quantitatively with the result obtained using existing fusion algorithms. The evaluation results showed that the proposed image fusion method achieved successful results in the fusion of SAR and MS image compared with the existing fusion algorithms.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.1-7
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• 2004

As we know, topography of korea is composed of many mountains. Also, the volume of traffic is increasing more and more nowadays. So, many tunnels are being constructed to reduce cost of transport and time. Thus, tunnel illumination was considered as the most important thing to make safe traffic conditions. In the past, we installed luminaires on the wall in tunnel, but currently we are installing those on the ceiling. Wherever luminaires are installed on the ceiling, the electric designer may not have known the proper point to install luminaires. Therefore, we researched this project to resolve above problems with abundant experience and accurate data through simulation(Lightscape program). As a result of research, mounting luminaires on the ceiling are better than wall because uniformity is more regular and utilization factor is also higher and then brightness is adequate as well, whereby installation on the ceiling is economical. Therefore, it is suitable that luminaires are installed on the ceiling in tunnel than wall.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2836-2843
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• 2015

Due to metallicity of materials, a vessel has a limitation to adopt RF-based wireless communication technologies for the inner communication means. Visible Light Communication(VLC) can be a sound alternative to dissolve such a limitation. Using a visual light as a transmission medium, VLC is free from radio interferences and restriction of radio usages which are typically related to RF-based wireless communications. In addition, VLC can not only require the facility cost relatively low because of being possibly converged with existing LED illumination, but also be harmless to the human body. This paper proposes an indoor location-based emergency call service system solution for ships using the VLC technology that supports 256Kbps data rate and 5m transmission distance. This paper presents real implementation and testing results of the solution which verifies the propriety of the proposal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.9-16
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• 2018

Images with lower illumination from the light source or with dark regions due to shadows, etc., can improve subjective image quality by using retinex-based image enhancement schemes. The retinex theory is a method that recognizes the relative lightness of a scene, rather than recognizing the brightness of the scene. The way the human visual system recognizes a scene in a specific position can be in one of several methods: single-scale retinex, multi-scale retinex, and multi-scale retinex with color restoration (MSRCR). The proposed method is based on the MSRCR method, which includes a color restoration step, which consists of three phases. In the first phase, the existing MSRCR method is applied. In the second phase, the dynamic range of the MSRCR output is adjusted according to its histogram. In the last phase, the proposed method transforms the retinex output value into the display dynamic range using a logarithm transformation function considering human visual system characteristics. Experimental results show that the proposed algorithm effectively increases the subjective image quality, not only in dark images but also in images including both bright and dark areas. Especially in a low lightness image, the proposed algorithm showed higher performance improvement than the conventional approaches.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.558-566
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• 2015

LED, the next-generation light source, rapidly develops and has advantages of low power, high efficiency, and long life. Accordingly, an interest in lightings by using LED rises. If emotional lighting is implemented by using LED, all colors can be represented by using 3 primary colors of light, differently from the conventional single-color lighting. LED emotional lightings which can control human emotions continue to be developed thanks to these advantages. This study was conducted to design an algorithm for expressing LED emotional lighting in line with the situation and temperature by extracting colors for concentration and resting situations in indoor environment and mixing them with colors of the temperature felt by user. The LED emotional lighting designed with a neuro-fuzzy system was found to have effects on user's emotions during concentration and resting.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.575-580
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• 2010

Eye gaze as a form of input was primarily developed for users who are unable to use usual interaction devices such as keyboard and the mouse; however, with the increasing accuracy in eye gaze detection with decreasing cost of development, it tends to be a practical interaction method for able-bodied users in soon future as well. This paper explores a low-cost, robust, rotation and illumination independent eye gaze system for gaze enhanced user interfaces. We introduce two brand-new algorithms for fast and sub-pixel precise pupil center detection and 2D Eye Gaze estimation by means of deformable template matching methodology. In this paper, we propose a new algorithm based on the deformable angular integral search algorithm based on minimum intensity value to localize eyeball (iris outer boundary) in gray scale eye region images. Basically, it finds the center of the pupil in order to use it in our second proposed algorithm which is about 2D eye gaze tracking. First, we detect the eye regions by means of Intel OpenCV AdaBoost Haar cascade classifiers and assign the approximate size of eyeball depending on the eye region size. Secondly, using DAISMI (Deformable Angular Integral Search by Minimum Intensity) algorithm, pupil center is detected. Then, by using the percentage of black pixels over eyeball circle area, we convert the image into binary (Black and white color) for being used in the next part: DTBGE (Deformable Template based 2D Gaze Estimation) algorithm. Finally, using DTBGE algorithm, initial pupil center coordinates are assigned and DTBGE creates new pupil center coordinates and estimates the final gaze directions and eyeball size. We have performed extensive experiments and achieved very encouraging results. Finally, we discuss the effectiveness of the proposed method through several experimental results.