• Journal of ILASS-Korea
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• v.19 no.1
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• pp.9-14
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• 2014

Performance of DI diesel engine with high-pressure fuel injection equipment is directly related to its emission characteristics and fuel consumption. So, the electro-hydraulic injector for the common-rail injection system should be designed to meet the precise high fuel delivery control capability. Currently, most high pressure injector in use has a needle driven by the solenoid coil energy or the piezo actuator controlled by charge-discharge of output pulse current. In this study, macroscopic spray approaching method was applied under constant volume chamber to research the performance of three different injectors : solenoid, indirect-acting piezo and direct-acting piezo type for CR direct-injection. LED back illumination for Mie scattering was applied on the liquid spray visible of direct-acting piezo injector, including hydraulic-servo type solenoid and piezo-driven injectors. As main results, we found that a direct-acting piezo injector had better a spray tip penetration than hydraulic-servo injectors in spray visualization.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.71-78
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• 2017

Visible light communication (VLC) offers communication function in addition to illumination. Because the signal communication capacity per cable is 1,000 times compared to the power line communication (PLC), optical fiber is being advertised as the basis of the information and communication. Also dimming control of LED is an important component needed to provide energy savings and quality of life. This study configured multi-hop VLC system model in a building using optical fiber and analyzed the power performance of two of modulations using dimming techniques. The transmission power and received power were used to compare the power performance in multi-hop VLC environments.

• Journal of the Korean Society of Costume
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• v.58 no.2
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• pp.120-133
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• 2008

The purpose of this study is to analysis types of light and to find the characteristics of light in contemporary fashion design. In a scientific context, light is electromagnetic radiation of a wavelength that has the characteristics of straightness, reflection, refraction, scattering and diffraction. But in philosophical speculations, light has been used as a metaphor of 'being', 'to-be' or 'enlightenment.' And through the ages, people have tried to represent and apply the light into plastic art like painting and architecture. The types of light in fashion design was categorized as those; reflective light from the surface of clothing which is the result of interaction between illumination and material, representative light as the pattern of light or light effect such as sun or its rays and optical or psychedelic patterns, luminescent light from light emitting material like phosphorescence or LED which combines into fashion design, projective light from a medium to reveal virtual patterns on the surface or a fashion design itself using holography. These lights in fashion design can be considered as reflection of emphasis of sexuality, longing for fantasy and mystique, visualization of interaction and communication and groping for the play.

• Journal of Biosystems Engineering
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• v.32 no.2 s.121
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• pp.130-135
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• 2007

An on-line real time grading and sorting system for dried oak mushrooms was developed for on-site application. Quality grades of the mushrooms were determined according to an industrial specification. Three dimensional visual quality features were used for the grading. A progressive color computer vision system with white LED illumination was implemented to develop an algorithm to extract external quality patterns of the dried oak mushrooms. Cap (top) and gil (stem) surface images were acquired sequentially and side image was obtained using mirror. Algorithms for extracting size, roundness, pattern and color of the cap, thickness, color of the gil and amount of rolled edge of the dried mushroom were developed. Utilizing those quality factors normal and abnormal ones were classified and normal mushrooms were further classified into 30 different grades. The sorting device was developed using microprocessor controlled electro-pneumatic system with stainless buckets. Grading accuracy was around 97% and processing time was 0.4 s in average.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.3
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• pp.1-8
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• 2012

This study investigated current status of lighting environment, residents' awareness of lighting and lighting use according to behavior in the living room of apartment to determine current lighting trends and their related problems. The living rooms of newly-built apartment units(133~165[$m^2$] and larger than 166[$m^2$] within the past five years) were examined. The results are summarized as follows. 1. Resident satisfaction with current living room lighting was the highest in 'illumination' and the lowest was 'energy savings' regardless of the size of living room. 2. This kind of ceiling lighting layout, 133~165[$m^2$] unit used central lighting and larger than 166[$m^2$] units used central lighting and cove lighting. Regarding light sources, 133~165[$m^2$] linear FL, halogen, larger than 166[$m^2$] bulb-type FL are widely used. LED are now being found in the living room corridor and kitchen walls of newly-built apartment houses. 3. Watching TV and reading books were commonly behaved in the living room. Conversations between family, having desserts, resting, housekeeping, and entertaining were usually done weekdays, while having desserts and conversations between family were done weekends. Use of lighting as main behaviors is properly and differently required due to the distinct uses of lighting as residents' behaviors or their life style.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1388-1391
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• 2010

In this paper, we present a design and implementation of U-learning system using pen based augmented reality approach. Student has been given a smart pen and a smart study book, which is similar to the printed material already serviced. However, we print the study book using CMY inks, and embed perceptually invisible dot patterns using K ink. Smart pen includes (1) IR LED for illumination, IR pass filter for extracting the dot patterns, and (3) camera for image captures. From the image sequences, we perform topology analysis which determines the topological distance between dot pixels, and perform error correction decoding using four position symbols and five CRC symbols. When a student touches a smart study books with our smart pen, we show him/her multimedia (visual/audio) information which is exactly related with the selected region. Our scheme can embed 16 bit information, which is more than 200% larger than previous scheme, which supports 7 bits or 8 bits information.

• Journal of Microbiology and Biotechnology
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• v.33 no.9
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• pp.1250-1256
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• 2023

Herein, different extracts of Scenedesmus deserticola JD052, a green microalga, were evaluated in vitro as a potential anti-aging bioagent. Although post-treatment of microalgal culture with either UV irradiation or high light illumination did not lead to a substantial difference in the effectiveness of microalgal extracts as a potential anti-UV agent, the results indicated the presence of a highly potent compound in ethyl acetate extract with more than 20% increase in the cellular viability of normal human dermal fibroblasts (nHDFs) compared with the negative control amended with DMSO. The subsequent fractionation of the ethyl acetate extract led to two bioactive fractions with high anti-UV property; one of the fractions was further separated down to a single compound. While electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy analysis identified this single compound as loliolide, its identification has been rarely reported in microalgae previously, prompting thorough systematic investigations into this novel compound for the nascent microalgal industry.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.304-312
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• 2023

Plant breeding is a time-consuming process, mainly due to the limited annual generational advancement. A speed breeding system, using LED light sources, has been applied to accelerate generational progression in various crops. However, detailed protocols applicable to soybeans are still insufficient. In this study, we report the optimized protocols for a speed breeding system comprising 12 soybean varieties with various maturity ecotypes. We investigated the effects of two light qualities (RGB ratio), three levels of light intensity (PPFD), and two soil conditions on the flowering time and development of soybeans. Our results showed that an increase in the red wavelength of the light spectrum led to a delay in flowering time. Furthermore, as light intensity increased, flowering time, average internode length, and plant height decreased, while the number of nodes, branches, and pods increased. When compared to agronomic soil, horticultural soil resulted in an increase of more than 50% in the number of nodes, branches, and pods. Consequently, the optimal conditions were determined as follows: a 10-hour short-day photoperiod, an equal RGB ratio (1:1:1), light intensity exceeding 1,300 PPFD, and the use of horticultural soil. Under these conditions, the average flowering time was found to be 27.3±2.48 days, with an average seed yield of 7.9±2.67. Thus, the speed breeding systems reduced the flowering time by more than 40 days, compared to the average flowering time of Korean soybean resources (approximately 70 days). By using a controlled growth chamber that is unaffected by external environmental conditions, up to 6 generations can be achieved per year. The use of LED illumination and streamlined facilities further contributes to cost savings. This study highlights the substantial potential of integrating modern crop breeding techniques, such as digital breeding and genetic editing, with generational shortening systems to accelerate crop improvement.

• Journal of Mushroom
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• v.14 no.4
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• pp.249-252
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• 2016

Timing, place, and the high-tech industry to overcome barriers to the introduct of the so-called "smart agriculture". The core factors of precision agriculture, including temperature, humidity, location information, and real summary information, are all significant for ICT controlling technique. The system is a four-season container allowing mushroom product, humidity, illumination, and factors such as carbon dioxide were regulated to create the optimal environment for mushroom cultivation. Hericium erinaceum (also called Lion's Mane Mushroom, Bearded Tooth Mushroom, or Bearded Tooth Fungus) is an edible and medicinal mushroom in the tooth fungus group. During approximately 40 days of incubation, 1.4 kg of oak sawdust was used as the test medium. The humidity, temperature, and $CO_2$ density were maintained at >85-95%, $18-20^{\circ}C$, and 700-1,000 ppm, respectively, in the container type culture system. The time for primordium formation was observed to be 4-7 days. The amount of fruitbody production was 74-95 g per bag. This technique will be used to establish a new community support program, in conjunction with international movement, domestic sales and exports are also planned.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.1
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• pp.80-82
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• 2013

White light emitting diode (LED) determined the most appropriate color temperature in reading lighting evaluated fatigue degree of eye according to color temperature. The eye fatigue degrees are determined by brightness and color temperature. Therefore, we measured the results of eyes test according to the change of color temperature and brightness. Experiments except for astigmatic corrected visual acuity of 0.8 more and age 20 to 25 years old, male and female college students was conducted in 100 patients. And constant illumination conditions, visual acuity was measured by varying the color temperature. The optometry at 10 minutes in the darkroom adapted eye. And then the temperature of $25{\pm}3$ degrees, the humidity was carried out at $50{\pm}5%$. As a result of typical color temperature of white light (5,600 K) has identification of the readability.