• 조명전기설비학회논문지
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• 제24권5호
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• pp.77-85
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• 2010

본 논문은 LED 램프를 사무소 건물에 효과적으로 사용하기 위하여 새로운 통합적 에너지 시뮬레이션을 수행한 연구 결과이다. 일반적으로 LED 램프는 다른 램프에 비하여 에너지 절감효과가 매우 우수하지만 현재 형광램프보다 낮은 광속과 좁은 광분포 등 아직 사무소 건물에 적용하기는 다각적인 검토가 필요하다. 연구결과 냉난방에너지가 20[%] 증가하고 현재 형광등을 대체하기 위해서는 90[lm/$m^2$] 이상으로 설계해야 한다. 따라서 LED램프를 사무소 건물에 적용하기 위해서 광에너지, 냉난방에 미치는 영향 및 사무실환경에 미치는 광분포를 통합적으로 해석하였으며 앞으로 이 결과는 LED 램프를 통한 효과적인 에너지절약 환경을 구축하는 데 중요한 자료를 제공할 것으로 확신한다.

• KIEAE Journal
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• 제8권1호
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• pp.53-60
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• 2008

The daylighting affects on the human biological cycles and physiological alterations. Daylighting is also an important element in visual comfort and it sometimes influences the quality of vision. Therefore the absence of natural light during the day brings contradictory result. To solve the problems of natural light lack and provide sufficient daylight in interior spaces, it might be necessary to apply some daylighting systems. One of these systems, light pipe system, which is simple, cheep and easily constructed, is very useful to apply for small buildings. The light pipe is simple means of directing daylighting (diffuse and direct lighting)into interior space. In order to application of light pipe system in Korea, it is necessary to optical data of light pipe system. This study aims to evaluate preliminary experiment of the daylighting environment of light pipe system. Light pipe system, that aspect ratio is 1:2(diameter and length), was installed in a windowless mock-up with $27m^2$. The mock-up model was constructed as a prototype of Korean office surface. Illuminance was measured with a Topcon IM-5 Luxmeter to evaluate the distribution of the illuminance on a floor. The indoor and outdoor illuminance and the internal/external illuminance ratio are compared to discuss with in the graphs. Luminance was measured with Radiant imaging Promertric 1400 that is digital photometer to evaluate the distribution of luminance on interior surface. The contrast of luminance is discussed with table and graphs.

• 한국농림기상학회지
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• 제10권4호
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• pp.141-148
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• 2008

피음처리에 의한 네 참나무 수종(신갈나무, 졸참나무, 상수리나무, 굴참나무)의 광합성 반응 특성을 조사하기 위하여, 차광막으로 전천광을 35%, 55%. 75% 차광 처리한 조건과 전광조건에서 엽생장과 엽록소함량을 측정하고 광-반응 곡선과 A-Ci 곡선을 통하여 광합성계의 특성을 조사하였다. 그 결과, 굴참나무와 상수리나무는 엽생장, 엽록소함량, 순양자수율을 증가시키고 엽록소 a/b와 탄소고정효율을 감소시켜 빛의 흡수량과 광합성에 대한 이용효율을 높이는 적응 반응을 나타냈다. 신갈나무는 굴참나무와 상수리나무와 같은 경향의 적응반응을 보였지만 광합성 광화학계 활성의 저하로 낮은 광합성 능력을 나타냈다. 졸참나무는 가장 낮은 내음성 적응반응을 나타냈다.

• Fibers and Polymers
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• 제2권1호
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• pp.123-130
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• 2001

Photoresponsive side chain copolymer and homopolymer containing an aminonitroazobenzene were synthesized for studying photoisomerization behavior and photo-induced anisotropy. Trans-to-cis photoisomerization was observed under the exposure of a circularly polarized visible light with UV-Vis absorption spectroscopy. Reorientation of polar azobenzene molecules induced optical anisotropy under a linearly polarized light at 532nm. Polarized absorption spectroscopy was employed to investigate the anisotropy of the polymer film during irradiationg of the excitation light. Layers of two photosensitive polymers were used for aligning liquid crystal(LC) molecules instead of one of the rubbed polyimide layers in the conventional twisted nematic cell. For producing homogeneous alignment of a nematic LC molecule, a linearly polarized light was exposed to the films of two polymers. The stability of the LC alignment upon the linearly polarized light exposure was also studied.

• 자동차안전학회지
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• 제14권4호
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• pp.6-15
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• 2022

In this study, a traffic light recognition algorithm was implemented and validated for low-speed special purpose vehicles in an urban environment. Real-time image data using a camera and YOLO algorithm were applied. Two methods were presented to increase the accuracy of the traffic light recognition algorithm, and it was confirmed that the second method had the higher accuracy according to the traffic light type. In addition, it was confirmed that the optimal YOLO algorithm was YOLO v5m, which has over 98% mAP values and higher efficiency. In the future, it is thought that the traffic light recognition algorithm can be used as a dual system to secure the platform safety in the traffic information error of C-ITS.

• 한국정보기술학회 영문논문지
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• 제8권2호
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• pp.147-157
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• 2018

In this study, we analyzed an outdoor visible light communication system and implemented it through a simulation. We designed a Reed-Solomon encoder, a variable interleaver structure, and set it to the Institute of Electrical and Electronics Engineers (IEEE) 802.15.7 PHY I specification mode. We also analyzed the performance of an additive white gaussian noise (AWGN) channel environment using a root-raised-cosine (RRC) filter, implemented a MATLAB simulation and analyzed its performance. The results showed a requirement for an additional signal-to-noise ratio (SNR) of approximately 1.5 dB in a 3-ray multipath visible light channel environment than in an AWGN environment.

• 한국환경농학회지
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• 제38권1호
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• pp.61-67
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• 2019

최근 10년 동안 LED등의 인공광원을 사용하여 작물을 재배한 많은 연구들이 수행되었다. 인공광원 중 LED를 조사한 연구가 가장 많았고, 이는 LED의 에너지 효율성 및 광합성에 필요한 특정파장 비율을 디자인하여 조사할 수 있는 장점 때문이라 여겨진다. 광질이 작물 기능성 물질 생산에 큰 영향을 미쳤는데, 밀폐시설과 시설재배에서의 영향에 차이가 있었다. 밀폐시설에서 재배할 때 인공광의 광질에 따라 증가되는 기능성물질차이 외에도, 동일 광질을 사용하더라도 작물별로 증가되는 기능성물질이 달랐다. 자연광을 주광원으로 이용하고 인공광을 보광으로 사용한 연구에서, 밀폐시설에서의 연구와 동일한 광질을 보광으로 사용하더라도 기능성물질 생산 측면에서는 다른 결과를 보였다. 따라서, 밀폐시스템과 시설재배에 대한 보광연구 양쪽 모두 필요하다고 판단된다. 또한 광질에 의한 기능성물질 함량의 증가와 별도로 작물의 생산성이 고려된 기능성물질의 총생산량의 관점에서도 평가될 필요가 있다. 작물별, 광질별, 재배환경에 따라 작물의 기능성 물질이 차별적으로 증가할 수 있으므로, 기능성 물질 증진을 위한 작물 재배를 위해서는 환경제어-기능성물질-생산성이 종합적으로 평가되어야 할 것이다.

• 원예과학기술지
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• 제30권1호
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• pp.6-12
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• 2012

Early growth, pigmentation, protein content, and phenylalanine ammonia-lyase (PAL) activity of red curly lettuces (Lactuca sativa L.) grown under different lighting conditions were investigated. Fluorescent lamps (control), blue, red, and blue plus red light-emitting diodes (LEDs) were used as light sources for 10 days. An equal proportion (1:1) of blue and red LEDs was used in the mixed radiation condition. Compared with the control, monochromic red or blue lighting increased fresh and dry weights of 'Ttuksum' and 'Jaju' lettuces. Anthocyanin synthesis was also significantly promoted by the mixed radiation of blue and red LEDs. The mixed radiation also increased the protein content and PAL enzyme activity of 'Ttuksum' leaves by about 200% compared to other treatments. Anthocyanin content was the highest in lettuces subjected to the mixture radiation of blue and red light treatment, while anthocyanin synthesis was inhibited by monochromic red light. The results of the present study indicate that growth and pigment synthesis in lettuces are significantly enhanced by exposure to mixed radiation from blue and red LEDs.

• 웰빙융합연구
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• 제5권4호
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• pp.19-31
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• 2022

Purpose: This study was conducted to identify indoor air quality in various living spaces using sensors that can measure noise, vibration, fine dust, and odor in real time and to propose optimal indoor air quality maintenance management using Internet of Things(IoT). Research design, data and methodology: Using real-time sensors to monitor physical factors and environmental air pollutants that affect the comfort of the residential environment, Noise, Vibration, Atmospheric Pressure, Blue Light, Formaldehyde, Hydrogen Sulfide, Illumination, Temperature, Ozone, PM10, Aldehyde, Amine, LVOCs and TVOCs were measured. It were measured every 1 seconds from 4 offices and 4 stores on a small scale from November 2018 to January 2019. Results: The difference between illuminance and blue light for each measuring point was found to depend on lighting time, and the ratio of blue light in total illumination was 0.358 ~ 0.393. Formaldehyde and hydrogen sulphide were found to be higher than those that temporarily attract people in an indoor office space that is constantly active, requiring office air ventilation. The noise was found to be 50dB higher than the office WHO recommendation noise level of 35 ~ 40dB. The most important factors for indoor environmental quality were temperature> humidity> illumination> blue light in turn. Conclusions: Various factors that determine the comfort of indoor living space can be measured with real-time sensors. Further, it is judged that the use of IoT can help maintain indoor air quality comfortably.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.358-361
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• 2004

The photocatalytic degradation of Endocrine Discruptors, dibuthyl phthalate(DBP) has been investigated over TiO$_2$ photocatalysts irradiated with a ultraviolet (UV) light. The effect of operational parameters, i.e., reaction time, light intensity, pH and additive on the degradation rate of aqueous solution of Endocrine Discruptors has been examined. Results show that the employment of efficient photocatalysts and the selection of optimal operational parameters may lead to degradation of Endocrine Discruptors solutions.