• Title/Summary/Keyword: Light Control

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Changes in nocturnal insect communities in forest-dominated landscape relevant to artificial light intensity

  • Lee, Hakbong;Cho, Yong-Chan;Jung, Sang-Woo;Kim, Yoon-Ho;Lee, Seung-Gyu
    • Journal of Ecology and Environment
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    • v.45 no.4
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    • pp.218-227
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    • 2021
  • Background: Artificial light at night has recently been identified as a major factor adversely affecting global insect diversity. Here, we compared the insect diversity in Gwangneung Forest Biosphere Reserve, specifically in the Korea National Arboretum (with no artificial light at night), with that of three nearby urban sites with a gradient of artificial light at night (five locations at each site). We analyzed the effects of the artificial night lighting index, mean annual temperature, and field light intensity (lux) at night on the insect community structure. Results: The urban sites generally exhibited higher species richness and abundance as well as clear indicator species compared with the control site. The size distribution of the collected insects markedly differed between the control and the three urban sites. The abundance of herbivorous and omnivorous insects increased and decreased, respectively, with the increase in light intensity. Species richness of herbivorous and omnivorous insects was likely correlated with the field light intensity at night and artificial night lighting index, respectively. Conclusions: This study demonstrates the association between nighttime environment and marked changes in insect community structure and revealed consequent transition of ecosystem services by changes in trophic group composition.

Particle Sizing Using Light Scattering and Neural Networks (산란이론과 신경회로에 의한 입자크기계측)

  • 남부희;이상재;박민현;이영진;이석원;류태우;방병렬
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.6
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    • pp.447-453
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    • 2000
  • Using the scattering theory of laser light, we analyze the particle sizing method. The scattered profile measured by the photodetector is sampled, scale conditioned by a 32 channel analog-to-digital converter, and is analyzed with the transform matrix from the light energy signals to the weights of the particle sizes. The particle size distribution is classified using the Hopfield neural network method as well as the conventional nonnegative least square method.

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Voltage Source HVDC System Controller Design (전압형 HVDC 시스템 제어기설계)

  • 곽주식
    • Proceedings of the KIPE Conference
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    • 2000.07a
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    • pp.645-650
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    • 2000
  • this paper deals with HVDC Light(High Voltage Direct Current) system using space vector PWM(SVPWM) method. Because the system of this paper has d-q control scheme for HVDC Light system. HVDC Light system represented in this paper is capable of controlling active and reactive power independently. For this system. V-I curve and control methods are proposed. Also this paper describes the design of a digital system for applications in power converters such as those that would be used in the next generation of HVDC system. Finally HVDC system is implemented using DSP TMS320C31

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Effect of the Enrichment of Blue Light to Red Light on the Evapotranspiration and Graft-taking of Grafted Seedlings (적색광에 대한 청색광의 부가 조사가 접목묘의 증발산과 활착에 미치는 영향)

  • 김용현;박현수
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2001.04b
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    • pp.34-38
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    • 2001
  • 광질(light quality)은 식물의 생장과 형태형성 반응에 커다란 영향을 미친다(Hart, 1988; Fujiwara and Kozai, 1995). 기온, 상대습도, 광량 등의 물리적 환경 요소가 접목묘의 증발산속도 또는 활착에 미치는 효과가 최근에 보고(Kim, 2000)된 바 있으나, 증발산과 활착 특성에 미치는 광질의 영향에 관한 연구는 전무한 실정이다. 자연광에는 다양한 광질이 포함되어 있으나, 식물의 생장 또는 형태형성 반응을 촉진할 수 있는 특정한 파장의 광을 선택하여 조사하기가 쉽지 않다. (중략)

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Effect of bamboo shoot dietary fiber on gel properties, microstructure and water distribution of pork meat batters

  • Li, Ke;Liu, Jun-Ya;Fu, Lei;Zhao, Ying-Ying;Zhu, He;Zhang, Yan-Yan;Zhang, Hua;Bai, Yan-Hong
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.7
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    • pp.1180-1190
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    • 2020
  • Objective: To develop healthier comminuted meat products to meet consumer demand, the gel properties, rheological properties, microstructure and water distribution of pork meat batters formulated with various amounts of bamboo shoot dietary fiber (BSDF) were investigated. Methods: Different levels of BSDF (0% to 4%) were added to pork batters, and the pH, color, water-holding capacity, texture and rheological properties of pork batters were determined. Then, pork batters were analyzed for their microstructure and water distribution using scanning electron microscopy (SEM) and low-field nuclear magnetic resonance (LF-NMR). Results: Compared with the control, BSDF addition into meat batters showed a significant reduction in L*-value and a significant increase in b*-value (p<0.05). BSDF addition of up to 4% reduced the pH value of pork batters by approximately 0.15 units; however, the cooking loss and expressible water loss decreased significantly (p<0.05) with the increased addition of BSDF. The hardness and gel strength were noticeably enhanced (p<0.05) as the content of BSDF increased. The rheological results showed that BSDF added into pork batters produced higher storage modulus (G') and loss modulus (G") values. The SEM images suggested that the addition of BSDF could promote pork batters to form a more uniform and compact microstructure. The proportion of immobilized water increased significantly (p<0.05), while the population of free water was decreased (p<0.05), indicating that BSDF improved the water-holding capability of pork batters by decreasing the fraction of free water. Conclusion: BSDF could improve the gel properties, rheological properties and water distribution of pork meat batters and decrease the proportion of free water, suggesting that BSDF has great potential as an effective binder in comminuted meat products.

Use of tar color additives as a light filter to enhance growth and lipid production by the microalga Nannochloropsis gaditana

  • Shin, Won-Sub;Jung, Simon MoonGeun;Cho, Chang-Ho;Woo, Do-Wook;Kim, Woong;Kwon, Jong-Hee
    • Environmental Engineering Research
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    • v.23 no.2
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    • pp.205-209
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    • 2018
  • The spectral composition of light can affect the growth and biochemical composition of photosynthetic microalgae. This study examined the use of light filtering through a solution of soluble colored additives, a cost-effective method to alter the light spectrum, on the growth and lipid production of an oleaginous microalga, Nannochloropsis gaditana (N. gaditana). Cells were photoautotrophically cultivated under a white light emitting diode (LED) alone (control) or under a white LED that passed through a solution of red and yellow color additive (4:1 ratio) that blocked light below 600 nm. The specific growth rate was significantly greater under filtered light than white light ($0.2672d^{-1}$ vs. $0.1930d^{-1}$). Growth under filtered light also increased the fatty acid methyl ester (FAME) yield by 22.4% and FAME productivity by 80.0%, relative to the white light control. In addition, the content of saturated fatty acids was greater under filtered light, so the biodiesel products had better stability. These results show that passing white light through an inexpensive color filter can simultaneously enhance cellular growth and lipid productivity of N. gaditana. This approach of optimizing the light spectrum may be applicable to other species of microalgae.

Effect of Interrelationship between Blood Melatoni or Estrogen and Light Cycle on Performance of Korean Native Chicken (혈중 멜라토닌 혹은 에스트로겐과 광주기의 상호작용이 재래닭의 생산성에 미치는 영향)

  • 류경선;강창원
    • Korean Journal of Poultry Science
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    • v.24 no.2
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    • pp.85-90
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    • 1997
  • An experiment was conducted to investigate the relationship between blood hormone levels and light cycle on performance of Korean native chicken. One hundred and two Korean native chickens were grouped into three treatments of natural light cycle (Control), 13L:11D (T2), and 16L:8D (T3). The egg production, egg weight, feed intake, serum melatonin and estrogen level were periodically measured from 22 to 34 weeks, respectively. The laying rates of T2 and T3 were significantly higher than that of the Control (P

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A Study on RF Network-Based Guard Light System with Bidirectional Control (RF 네트워크 기반 보안등 양방향 제어 시스템에 관한 연구)

  • Choi, Jeong-Won;Lee, Ho-Geun;Oh, Duk-Hwan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.1
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    • pp.92-98
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    • 2013
  • In this paper, Completely beyond the existing conventional Guard Light management system, introduced the 447Mhz band wireless sensor network Guard Light to manage efficiently the shape of the new system is proposed. In addition, about wireless sensor network technology, control server technology, application layer protocol technology etc which is core technology for the proposed system configuration, it was verified by the design and experiment. Especially studying wireless Guard Light System(about 1,700 node configuration) commercially installed in the Daegu area as a results of the study, I would like to prove the effectiveness of the study.

Localization System for Mobile Robot Using Electric Compass and Tracking IR Light Source (전자 나침반과 적외선 광원 추적을 이용한 이동로봇용 위치 인식 시스템)

  • Son, Chang-Woo;Lee, Seung-Heui;Lee, Min-Cheol
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.8
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    • pp.767-773
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    • 2008
  • This paper presents a localization system based on the use of electric compass and tracking IR light source. Digital RGB(Red, Green, Blue)signal of digital CMOS Camera is sent to CPLD which converts the color image to binary image at 30 frames per second. CMOS camera has IR filter and UV filter in front of CMOS cell. The filters cut off above 720nm light source. Binary output data of CPLD is sent to DSP that rapidly tracks the IR light source by moving Camera tilt DC motor. At a robot toward north, electric compass signals and IR light source angles which are used for calculating the data of the location system. Because geomagnetic field is linear in local position, this location system is possible. Finally, it is shown that position error is within ${\pm}1.3cm$ in this system.