• 제목/요약/키워드: Average Illumination

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Illumination Control of LEDs in Visible Light Communication Using Manchester Code Transmission

  • Lee, Seong-Ho
    • 센서학회지
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    • 제25권5호
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    • pp.303-309
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    • 2016
  • In this paper, we introduce a new method for controlling the illumination of LEDs in visible light communication (VLC) by changing the duty cycle of Manchester code. When VLC data were transmitted in Manchester code, the average optical power of the LEDs was proportional to the duty cycle. In experiments, we controlled the illumination of a $3{\times}3$ LED array from 10% to 90% of its peak value by changing the duty cycle of the Manchester code. The synchronizing clocks required for encoding and decoding the Manchester code were supplied by pulse generators that were connected to a 220 V power line. All pulse generators made the same pulses with a repetition frequency of 120 Hz, and they were synchronized with the full-wave rectified voltage of the power line. This scheme is a very simple and useful method for constructing indoor wireless sensor networks using LED light.

천이주파수 변조를 이용한 가시광통신의 조명제어 (Illumination Control in Visible Light Communication Using Transition Frequency Modulation)

  • 이성호
    • 센서학회지
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    • 제30권2호
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    • pp.99-104
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    • 2021
  • In this study, we utilized the duty factor of the transition frequency modulation (TFM) for the illumination control of the light emitting diode (LED) light in visible light communication (VLC). The average optical power is linearly proportional to the duty factor in TFM waveforms. We used the transition frequencies of Na=5 and Nb=1 for the high and the low bits, respectively, of the non-return-to-zero (NRZ) data in the VLC transmitter. A resistor and capacitor high-pass filter (HPF) was used in the VLC receiver to eliminate the 120 Hz optical noise from adjacent lighting lamps and the spikes at the HPF output were used to recover NRZ data from the TFM waveform. In experiments, the illumination of the LED light was controlled in the range of 25-90% of the constant-wave optical power by changing the duty factor of the TFM waveforms.

주택의 조명과 거주자의 면경착용 실태조사연구 (A Study on the Illumination of Household and Research on the Actual Conditions of Wearing Spectacles in Dwellers)

  • 석호작;남철현
    • 한국환경보건학회지
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    • 제17권2호
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    • pp.54-66
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    • 1991
  • As a result of measuring illumination and making up a question at home visit directly by investigator who trained over twenty days period from October 4 to 24, 1990, in order to render help which illumination problem against house, society against eyes or framing of health instruction potgram by seizing natural lighting actual conditions of house and actual conditions of wearing spectacles and by investigating interrelationship, I can summarize as follows. 1) In property of investigation subject, woman 66.9%, In an age, the twenties was largest of 27.4%, the forties was 20.2%, the fifties was 18.6%, the thirties was 17.4%. In academic career, those of upper secondary school grauates was largest of 28.6%, those who possess university career was 25.9%, those who middle school career was 20.9%, decoding of Korean alphabet was 2%. 2) By a residence area, a big city was 43.3%, farming and fishing villages were 20.3%, the rest was a small town and the administrative office of town, township. In positon of house, the middle area was 43.6%, resident of suburb area was 38.0%. In form of house, a Korean-style house was 40.8%, a western-style house was 34.8%, an apartment house was 11.0%. In the a standard of living, the middle classes 77.2%, the lower classes were 15.3%. In residential house unit of area, from 21 to 30 unit of area was largest of 31.5%, from 10 to 20 unit of area was 19.9%, from 31 to 40 was 18.7%. 3) The wearing spectacles rate of study user was 44.1%. By the area, those who wearing spectacles was more than a half of 50.8% in the resident of big city area. As passing from the farm area to the city, that is being resident of big city was high wearing spectacles rate. In position of house, as being residence in central street showed high wearing spectacles rate. (central street was 51.5%, the middle area was 44.5% and the suburb area was 40.1%.) It seemed similarity difference a variable by position of house from wearing spectacles in standard of 1%. By form of house, wearing spectacles rate those who resident in apartment house was 49.5%, that rate those who resident in a western-style house was high of 49.0%, that rate those who resident in a Korean-style house was the lowest 39.0%. By social position of resident in room, in students case who study showed very high, as university students were very high of 62.3% idn wearing spectacles rate, middle and high school students 'were 50.0%, members of society were 47.6%, workers 20.3%. It seemed similarity difference from academic career in standard of 1%. By an age, the thirties was high of 54.1% in wearing spectacles rate, the twenties was 43.2%, the teenage was the lowest of 11.8%. 4) In illumination of study, over 200Lux was high of 40.1%. but below 99Lux which inappropriate illumination to see the books was 32.4%. Average by area, below 99Lux was 22.7% and over 400Lux was 50.0% in case of wooden floor. As examine by area, below 99Lux was high of 27.0% a case of wooden floor in the big city area, it was not good in illumination passing from the farm area(15.0%) to the city(19.0%). Average illlumination by area of the main living room below 99Lux was high of 37.5%, less than 200Lux was 58.5% of whole. In general, illumination of the main livingroom was inappropriate. By area, the big city was 32.5% below 99Lux, the middle and small city area were 33.8%, town and township area were 45.0%, farming and fishing area were 42.8%. By area, in the big city, illumination of study was 52.5% over 200Lux and 28.9% below 99Lux. In case of the middle and small city, study user of below 99Lux was 38.8% and over 200Lux was 46.9%. In case of the seat of town township, below 99Lux was 34.1% and over 200Lux was 39.7%. In case of farming and fishing area, illumination of study was 33.4% below 99Lux and 48.4% over 200Lux. It tends to high rate of inappropriate illumination. 5) By position of house, in case of wooden floor, less than 100Lux was 24.5% in central street. It was bad illumination than others position of house. In case of the main livingroom, less than 100Lux was 40.4% in the suburb area. It was bad iliumnation than others position of house. In case of study, less than 100Lux was 35.4% in the middle area, it was worse in illumination. In case of the main living room, is seemed similarity difference in standard of 1%. 6) By form of house, in case of wooden floor, illumination of less than 100Lux was 23.8% in a western-style house, it was bad illumination than others form of house. In case of the main livingroom, illumination of less than 100Lux was 47.4% in a Korean-style house, it was remarkably bad illumination than others form of house. In case of study, a Korean-style house was 38.8%, it was very bad illumination than others form of house. In case of the main livingroom and study, it seemed similatrity difference each as P < 0.01 and P < 0.05 in standard of 1%. 7) The wearing spectacles rate of those who use room of illumination over 400Lux was 40.7%, and that of those who use room of illumination less than 100Lux was 28.1%. It seemed similarity differecce in standard of 1%. 8) In period of wearing spectacles, 21.3% of total investigator-highest-was from before five years, 8.6% was from before three years. Among those who use of illumintion less than 99Lux, 34.0% began to wear spectacles from before two years 31.7% was from before five years, 30.3% was from before four years. It seemed similarity difference from period of wearing spectacles by illumination in standard of 1 %. 9) Among cause which sight grow worse, the first was that it was each 33.2% and 27.4% in response rate because watch TV nearly to wearing spectacles person and non-wearing person. The second was that a lot of seeing books was 25.3% in wearing spectacles person and response rate for dark illumination was 7.4% in nonwearing spectacles person. It seemed similarity difference in standard of 1%. (P < 0.01). 10) In experience which take medicine good for eyes, it was 50.1% in wearing spectacles person and 8.5% in non-wearing spectacles person. It seemed similarity difference in standard of 1%(P < 0.01). As we have seen above, inappropriate illumination can be a cause of wearing spectacles. Nevertheless, actually, is realities to indifferent against illumination of house. So it must learn knowledge about health obstacle of illumination through society instruction and school eduction against students as well as general residents. In case that natural lighting is inappropriate structural of house, we must be able to maintain appropriate illumination through artificial illumination. And so eyes which is core of human life have to be protected, related the authorities, related group, and all health medical personnel will organically cooperate with and make efforts.

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Optical Design of LED module for Street Light Applications

  • Aung, Aye Thida;Yang, Jong-Kyung;Lee, Seung-Min;Lee, Jong-Chan;Park, Dae-Hee
    • 조명전기설비학회논문지
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    • 제22권11호
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    • pp.1-8
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    • 2008
  • In this paper, the optical properties of the 54[W] LED module have confirmed by changing the angles of LED modules for street light applications. The angle of LED module changed from the $0[^{\circ}]$ to $60[^{\circ}]$ varying by $20[^{\circ}]$ as horizontal direction ${\ominus}_1$. Morever, the angle of LED module changed from the $0[^{\circ}]$ to $15[^{\circ}]$ varying by $5[^{\circ}]$ as vertical direction ${\ominus}_2$. As a result of simulation, the average illumination was about 17[lux] and the overall illuminance uniformity was 0.29 for a 10.39[m] long and 6[m] wide illuminance area at height of 6[m], which is acceptable for street lighting illumination in the Illuminating Engineering Society(IES) standard.

주택 조명환경의 실태 연구 (A Survey on Residential Lighting Environment)

  • 이진숙
    • 한국주거학회논문집
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    • 제2권2호
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    • pp.13-20
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    • 1991
  • The purpose of this survey is to find out the problems in lighting conditions of Korean residence and bring up the improvement direction. 120 households were chosen at random among independent house and apartment house in Taejon for this survey.The results are as follows; 1) The illumination of apartment houses are 2/3 of the recommended illuminalion and that of Independent houses are 1/2 of the recommended. Thus, apartment houses have better lighting condition. 2) 7he average illumination level is improving, but it still does not reach the recommended level. Therefore, the considerable plan to maintain proper lighting levels and suit to the 1;ghting purposes is required.

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다시점 비디오 코딩에서 휘도 보상 방법에 적합한 디블록킹 필터링 방법 (A Deblocking Filtering Method for Illumination Compensation in Multiview Video Coding)

  • 박민우;박광훈
    • 방송공학회논문지
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    • 제13권3호
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    • pp.401-410
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    • 2008
  • 다시점 비디오 코딩에서는 뷰 또는 시간 방향 예측 시 현재 블록과 참조 블록간의 휘도 신호의 밝기의 차이를 보상하는 매크로 블록 단위 휘도 보상 툴이 포함되어 있다. 휘도 보상 툴을 사용함으로 객관적 화질 평가 측면에서 코딩 효율의 향상을 가져다주었지만, 주관적 화질 측면에서는 매크로블록 단위의 휘도 신호 평균값 보정에 의한 블록킹 현상이 많이 발생한다. 이 문제는 다시점 비디오 코딩에서 디블록킹 필터링의 강도를 설정하고 필터링을 수행하는 방법을 H.264/AVC의 방법을 그대로 적용하여 발생하는 것으로, 인터 블록 모드에서 휘도 보상을 수행한 평균값의 차이를 전혀 고려하지 않기 때문에 휘도 보상으로 인해 발생되는 블록킹 현상을 효율적으로 제거하지 못한다. 따라서 본 논문에서는 휘도 보상으로 발생하는 블록킹 현상을 분석하고 분석한 내용을 바탕으로 기존 알고리즘을 최소한으로 변경하면서, 효과적으로 디블록킹 필터링을 수행할 수 있는 방법을 제안한다. 제안하는 방법을 실제 적용하여 실험한 결과, 주관적 화질 측면에서 블록킹 현상이 사라지는 것을 확인할 수 있으며 평균적인 비트량을 측정하였을 때 최고 1.44% 감소하였다.

ZCM에 의한 평균조도 계산용 Software개발 (The Development of Average illumination Calculation Software)

  • 윤미림;심상만;허남돈;김훈
    • 조명전기설비학회논문지
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    • 제15권3호
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    • pp.1-9
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    • 2001
  • 설계초기단계에서 고효율 조명기기의 채택을 원활하게 해주고, 동시에 LLF값을 산정 해줌으로써 건물설계에 적용되는 조명에너지를 절감해주기 위해서는 조명 설계 기법의 개선과 조명 설계 과정의 표준화가 필요하다. 이를 바탕으로 구역공간법(ZCM: Zonal Cavity Method)을 이용한 평균조도 계산용 소프트웨어를 개발하였다.

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웨이브렛 변환과 신경회로망을 이용한 SMD IC 패턴인식 (Pattern recognition of SMD IC using wavelet transform and neural network)

  • 이명길;이준신
    • 전자공학회논문지S
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    • 제34S권7호
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    • pp.102-111
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    • 1997
  • In this paper, a patern recognition method of surface mount device(SMD) IC using wavelet transform and neural network is proposed. We chose the feature parameter according to the characteristics of coefficient matrix which is obtained from four level discrete wavelet transform (DWT). These feature parameters are normalized and then used for the input vector of neural network which is capable of adapting the surroundings such as variation of illumination, arrangement of objects and translation. Experimental results show that when the same form of feature pattern, as is used for learning, is put into neural network and gained 100% rate ofrecognition irrespective of SMD IC kinds, location and variation of illumination. In the case of unused feature pattern for learning, the recognition rate is 85.9% under the similar surroundings, where as an average recognition rate is 96.87% for the case of reregulated value of illumination. Proosed method is relatively simple compared with the traditional space domain method in extracting the feature parameter and is also well suited for recognizing the pattern's class, position and existence. It can also shorten the processing tiem better than method extracting feature parameter with the use of discrete cosine transform(DCT) and adapt the surroundings such as variation of illumination, the arrangement and the translation of SMD IC.

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단독주택 공부방의 조명환경 실태조사 (Actual Conditions on the Illumination Environment of the Study Rooms in the Detached House)

  • 김현지;안옥희
    • 조명전기설비학회논문지
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    • 제19권7호
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    • pp.9-14
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    • 2005
  • 본 연구에서는 단독주택 공부방을 대상으로 조명환경 실태조사를 실시하였다. 그 결과, 공부방은 주로 형광등을 사용하였으며 배광방식은 직접조명 방식을 사용하고 있었다. 또한 국부조명을 사용하는 비율은 48.2[%]로 시작업이 효과적이지 못하였다. 내부공간 조도는 평균 131.41[lx]이며, 책상면 조도는 322.57[lx]로 최저허용조도의 54[%]에 해당하는 열악한 실정이었다. 또한 사용자의 조명환경에 비해 만족도는 높아 조명에 대한 인식이 매우 부족한 것으로 사료된다.

Single Plane Illumination Microscopy - MicroPIV를 이용한 버블 유동에서 외부 자계 영향을 받는 자성입자 가시화 (Flow Visualization of Magnetic Particles under the external magnetic field in bubbly flow using Single Plane Illumination Microscopy - MicroPIV)

  • 이창제;조경래;이상엽
    • 한국가시화정보학회지
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    • 제19권1호
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    • pp.36-42
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    • 2021
  • This study measured the velocity of magnetic particles inside the power generation using external heat sources. Single Plane Illumination Microscopy (SPIM) was used to measure magnetic particles that are simultaneously affected by bubbly flow and magnetic field. It has the advantage of reducing errors due to particle superposition by illuminating the thin light sheet. The hydraulic diameter of the power generation is 3mm. Its surface is covered with a coil with a diameter of 0.3 mm. The average diameter of a magnetic particle is 200nm. The excitation and emission wavelengths are 530 and 650nm, respectively. In order to find out the flow characteristics, a total of four velocity fields were calculated in wide and narrow gap air bubbles, between the wall and the air bubble and just below the air bubble. Magnetic particles showed up to 8.59% velocity reduction in the wide gap between air bubbles due to external magnetic field.