• Journal of Biosystems Engineering
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• v.39 no.2
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• pp.87-95
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• 2014

Purpose: The purpose of this study was to design a variable frequency LED light system for plant factory which combined red, blue, green, white, and UV lights and controlled the ratio of the light wavelength. In addition, this study evaluated the performance of each combination of LED to verify the applicability. Methods: Four combinations of LED (i.e. Red+Blue, Red+Blue+Green, Red+Blue+White, Red+Blue+UV) were designed using five types of LED. The system was designed to control the duty ratio of each wavelength of LED by 1% interval from 0~100%, the pulse by 1Hz interval from 1~20kHz. Response characteristics of the control system, spectral distribution of each combination, light uniformity and uniformity ratio were measured to test the performance of the system. Results: Clean waveforms were measured from 10Hz to 10kHz regardless of duty ratio. Frequency distortion was observed within 5% of inflection point at frequencies above 10kHz regardless of duty ratio, but it was judged negligible. Spectra showed a normal distribution, and maximum PPF with duty ratio of 100% was $271.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for the Red+Blue combination. PPF of the Red+Blue+Green combination was $258.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and that of the Red+Blue+White combination was $273.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. PPF of the Red+Blue+UV combination was $267.7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Uniformity ratio for the area excepting border showed 0.90 for the Red+Blue and Red+Blue+White combinations, 0.87 for the Red+Blue+Green combination, and 0.88 for the Red+Blue+UV combination. The light was irradiated evenly at the area excepting border, so it was suitable for plant growing. Conclusions: From the results of this study, response characteristics of the control system, spectral distribution of each combination, light uniformity and uniformity ratio were suitable for applying into the plant factory.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.282-289
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• 2019

Reflective and solar LED road studs are being used as a way of securing visibility for road environments. Road markers have various advantages and disadvantages in terms of versatility, efficiency, simplicity and visibility as individual products of reflective type and solar LED. However, in addition to the above, it is possible to prevent secondary accident after accident, It has a common drawback that it is difficult to have. In this paper, we propose a road stud system incorporating a wireless control function using RF - based communication with existing solar LED road studs and a system for controlling them. The proposed system is called the smart road stud system and it can control the equipment through the central control unit and the relay unit connected to the central control room by incorporating the RF communication function in the existing solar LED road stud. In addition, since it is possible to control the lighting method, color, etc. according to the road condition, it is possible to provide the driver with the state of the road to perform the function for preventing the second accident after the accident. It also adds features that minimize the ongoing power consumption of LED and RF communications. In order to verify the validity of the proposed system, prototypes were produced and it was confirmed that it is possible to act as a university for prevention of accident after accident by linking with other traffic system besides accident prevention function by securing existing visibility.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.123-132
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• 2017

This study was aimed to investigate the effect of 1)irradiation with several different ratios using red, green, and blue LEDs and 2)various pulsed light irradiation with 50% duty ratio using red and blue LEDs on the growth and morphogenesis of three lettuce cultivars (Lactuca sativar L. cv. 'Jukchukmeon', 'Lolo Rosa', and 'Grand Rapid') in hydroponics culture system for 4 weeks after transplanting. Seeds were sown in rock-wool plug trays and they were placed in a culture room which was controlled at $23{\pm}1^{\circ}C/18{\pm}1^{\circ}C$ temperature and 50-60/70-85% for day and night, respectively, during cultivation period. Irradiated RGB ratios with LEDs were 6:3:1, 5:2.5:2.5, 3:3:4, 2:2:6, and 1:1:8 with $110{\pm}3{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD on the surface of cultivation bed. The frequencies of pulsed lighting was 50, 100, 500, 1,000, 5,000, 10,000, 25,000Hz (20, 10, 0.1, 0.04 ms) with red and blue LEDs and 50% duty ratio. At the RGB ratio of 6:3:1, the average fresh weight of 'Jukchukmeon' was significantly higher than that of other RGB treatments, but no significant difference compared to the fluorescent treatment. The average fresh weight at 1:1:8 RGB ratio in 'Lolo Rosa' was significantly lower than that of other RGB treatments. Leaf number and fresh weight of 'Grand Rapid' were significantly lower in the control and 1:1:8 RGB treatments, compared to the other RGB treatments. As the ratio of blue light increased, leaf length decreased and leaf shape became round in three lettuces. Although there is little change in growth, it could not be found any tendency to affect the growth and morphogenesis of three lettuces caused by increasing or decreasing frequency of pulsed lighting with 50% duty ratio at the $72{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.77-83
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• 2014

Visible light communication is a converging communication by technologies that enable solutions using the LED Lighting. There is a need to research about it in order to improve the performance of the wireless communication by using a Color LED and improve the efficiency of data. In this paper, Assume the General indoor communication environment and LED communication systems based on CSK-OFDM applied to a MIMO communication system, We studied about transmitting method of more efficient communication. After performing the simulation based on IEEE 802.15.7 Standardization, as a result of the analysis of performance, it was confirmed the there is a significant impact on the performance of SNR and BER performance by the transmitting method based on MIMO and external noise using the LED communication system based on CSK-OFDM.

• Journal of Platform Technology
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• v.6 no.3
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• pp.17-22
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• 2018

Smart home is a technology for monitoring and controlling all the information about a house by integrating various home applications like cooling, heating, lighting, kitchen and security systems into a network. Although home appliances have become more convenient to use due to the development of smart home technology, they are also more vulnerable to information security hazards. Unauthorized visitors may have access to any of home appliance to arbitrarily control it or acquire information. This causes serious privacy and security problems, which should be solved to further smart home technology. This present paper proposed a dynamic user access control system for privacy protection in smart homes. The proposed system defines the role of a user of smart home services by automatically identifying the status information of the user and dynamically controls the access range for the service. In this way, the privacy of a user can be protected and the inter-smart device service is effectively provided. Consequently, the proposed dynamic user access control for smart home will improve the security service for protecting privacy in smart home devices.

• Science of Emotion and Sensibility
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• v.23 no.3
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• pp.11-18
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• 2020

This study aims to suggest the most stable color temperature that can relieve the anxiety of passengers in case of an elevator trapped accident. The experiment was conducted on 10 adult men in their 20s. The color temperature of the interior lighting of the elevator was adjusted to four stages (3,000 K; 6,000 K; 9,000 K; and 12,000 K). Electrocardiogram (ECG) was measured and analyzed to observe the reaction of the user's autonomic nervous system decline in 3,000 K; 6,000 K; 9,000 K compared with 12,000 K, where a statistically significant difference was recognized (p < 0.01). Among them, the activity of the sympathetic nervous system was the lowest under the condition of 3,000 K. Through this study, it was found that the color temperature of 3,000 K induced a sense of stability among passengers in the event of an elevator jam. If the results of this study are used, it seems that the stability of passengers will be secured in the event of an elevator jam.

• Journal of Korea Multimedia Society
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• v.14 no.2
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• pp.182-193
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• 2011

The aim of this paper is to present the methodology for hand tracking and hand gesture recognition. The detected hand and gesture can be used to implement the non-contact mouse. We had developed a MP3 player using this technology controlling the computer instead of mouse. In this algorithm, we first do a pre-processing to every frame which including lighting compensation and background filtration to reducing the adverse impact on correctness of hand tracking and hand gesture recognition. Secondly, YCbCr skin-color likelihood algorithm is used to detecting the hand area. Then, we used Continuously Adaptive Mean Shift (CAMSHIFT) algorithm to tracking hand. As the formula-based region of interest is square, the hand is closer to rectangular. We have improved the formula of the search window to get a much suitable search window for hand. And then, Support Vector Machines (SVM) algorithm is used for hand gesture recognition. For training the system, we collected 1500 hand gesture pictures of 5 hand gestures. Finally we have performed extensive experiment on a Windows XP system to evaluate the efficiency of the proposed scheme. The hand tracking correct rate is 96% and the hand gestures average correct rate is 95%.

• Journal of Korea Game Society
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• v.5 no.1
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• pp.45-52
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• 2005

This paper is re-lighting(reputation) that Ki-saeng is a artist in Chosun age to concern with history, social lives, role, art school of Ki-saeng and Ki-saeng and also is re-light and analysis educate system, rules, curriculum, time table of teaching, graduated album, photos of art school of Pyongyang Ki-saeng. And the using these traditional culture materials of Ki-saeng can create various digital contents of game contents, animation, drama, film and characters. Specially, it is propose to use culture contents that creation and pick out of beauty, talent, social system and art school of Ki-saeng in Chosun age willing to use concept design, scenario of game, animation, drama and film etc.

• Korean Institute of Interior Design Journal
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• no.17
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• pp.65-72
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• 1998

This study intends to analyze the various spatial structures and characteristics of the museum based on the two of the Renzo Piano's recent projects Menil Collection '||'&'||' Museum and Beyeler Foundation Museum Which defined the direction of the "Third Generation" in museum architecture with reference to the quality of spatial experience and design applications. Comparison and analysis were done on the basic spatial organization floor layout accessibility exhibition area lighting plan and circulation between the two museum. Through the itemized common characteristics of the museum the architect's proposal on meaning and direction of the new museum architecture can be viewed. The contemporary museums distinguish themselves quite clearly from their predecessors and this applies both to their own form and to their spatial organization. As the public demands and requests toward the museum building facility expand everyday the architect must respond by providing multiple types of space where people can experience different atmosphere in each area. One concept he used to create multi experienced area was manipulation of the natural light using by the state-of-the-art techniques of the light filtering system and multi-layering roof system to protect the valuable collections against the direct sunlight. But mainly it was to prove his strong belief in "architecture of light" by creating space with minimized meaning by purposely distinguished area in order to provide maximum support to the physical value of the collection " The connection with nature" is another concept which Piano used to provide the public a tranquil experience through out the architecture which engages in a lively dialogue with art. In spatial organization Piano concerned on functionality which not only concentrated on the visitor's point of view but also on the museum staff's comfort. Unlkie the traditional museum he alternates various size of exhibition areas for spatial hierarchy. Specially the spatial flexibility that the temporary exhibition areas are able to be expanded to the permanent exhibition areas by adjoining t재 spaces differentiate Piano's new museum from the rest. museum from the rest.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.117-123
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• 2013

The development of the latest emotional recognition and multimedia technology has changed the traditional broadcasting system. The previous broadcasting system, which was operated by the terrestrial broadcasters, is now transformed to the viewer-centered and bidirectional broadcasting through the convergence of internet, mobile and smart TV. In this paper, smart-phone application for estimating human emotion(sadness, anger, depression) has been developed and emerged with smart TV, thereby we can present broadcasting service for enhancing the sense of common humanity among people of same group. If there is friend in the depression, we can bring comfort to him by inviting one for TV program what I watch and having a honest talk with facial avatar or emoticon. The proposed emotional broadcasting service inter-working with smart-phone application can give feeling of belonging and happiness to the people suffering from the blues, and it can prevent him from attempting suicide. In addition, smart-phone based emotional broadcasting service can be expended to program recommendation service customized to user's emotion, emotional LED lighting service to maximize the sense of reality and home shopping service taking advantage of the mood of customer.