• Title/Summary/Keyword: Illuminance Measurement

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Dimensional Measurement of Radiometric Aperture by Optical Edge Detection (가장자리의 광학적 검출방법에 의한 복사계용 개구 크기의 정 밀 측정)

  • 강창호;박승남;김석원;이동훈;고득현
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.278-279
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    • 2003
  • 광도의 기본 단위인 칸델라(Candela) 눈금은 물론 복사조도(irradiance), 조명도(illuminance)와 같은 유도 단위를 실현하기 위해서는 검출기의 시야를 한정하는 개구면적의 정밀한 측정이 필요하다. 여기에서는 가장자리의 광학적 검출방법에 의한 개구면적의 산출방식을 소개하고, 가우시안광에 의한 면적 측정법의 측정값과도 비교하여 그 결과를 보여준다. 기존의 개구 면적 측정방식으로 한가지 방법은 탐촉자를 물리적으로 접촉시켜서 개구의 가장자리를 결정하고, 개구의 기하학적 모양을 원으로 가정하여 면적을 산출하는 방식이 있는데, 이 방법을 사용하면 기계적인 접촉에 의하여 칼날과 같았던 개구의 가장자리가 손상을 입게 되기 때문에 측정이 잘못되는 것은 물론이고, 이렇게 측정된 개구를 사용하게되면 손상된 부위에 의한 면적의 변화와 이로 인한 산란이 증가하게 된다. (중략)

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A Study on Atmospheric Turbulence-Induced Errors in Vision Sensor based Structural Displacement Measurement (대기외란시 비전센서를 활용한 구조물 동적 변위 측정 성능에 관한 연구)

  • Junho Gong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.3
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    • pp.1-9
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    • 2024
  • This study proposes a multi-scale template matching technique with image pyramids (TMI) to measure structural dynamic displacement using a vision sensor under atmospheric turbulence conditions and evaluates its displacement measurement performance. To evaluate displacement measurement performance according to distance, the three-story shear structure was designed, and an FHD camera was prepared to measure structural response. The initial measurement distance was set at 10m, and increased with an increment of 10m up to 40m. The atmospheric disturbance was generated using a heating plate under indoor illuminance condition, and the image was distorted by the optical turbulence. Through preliminary experiments, the feasibility of displacement measurement of the feature point-based displacement measurement method and the proposed method during atmospheric disturbances were compared and verified, and the verification results showed a low measurement error rate of the proposed method. As a result of evaluating displacement measurement performance in an atmospheric disturbance environment, there was no significant difference in displacement measurement performance for TMI using an artificial target depending on the presence or absence of atmospheric disturbance. However, when natural targets were used, RMSE increased significantly at shooting distances of 20 m or more, showing the operating limitations of the proposed technique. This indicates that the resolution of the natural target decreases as the shooting distance increases, and image distortion due to atmospheric disturbance causes errors in template image estimation, resulting in a high displacement measurement error.

Measurement of Bangudae Rock Joint Using Non-adhesive, Non-contact Inclinometer Slope Laser Measuring System (비부착, 비접촉 방식의 계측기를 이용한 반구대암각화 암반 절리면의 계측)

  • Kim, Jae Hyun;Lee, Sang Ok;Chung, Kwang Yong;Han, Min Su
    • Journal of Conservation Science
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    • v.37 no.6
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    • pp.617-625
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    • 2021
  • Daegokcheon Stream in Daegok-ri, Ulju-gun, is an area with a developed valley and bedrock from Gajisan Provincial Park to the confluence of the Taehwa River across the Yangsan Fault. To measure the rock of Bangudae petroglyphs, the mineralogical weathering, joints, and scours or cavities at the bottom were confirmed. The measurement was carried out for a short period of time on the joint of the bedrock on which the Bangudae petroglyphs were engraved. Compared to the measured value obtained using existing optical fiber (Ch4 150 ㎛), a displacement value of 300 ㎛ was obtained using the non-attached, non-contact type of measuring instrument. In the future, it is inferred that this instrument could be used for various cultural properties if the HSV-value suitable for illuminance and various measurement experiences are stored.

Measurement and Simulation of Interior Luminous Environment for the Decision Process of Building Remodeling (건물 개보수의 의사결정과정에서 필요한 실내의 빛환경 측정 및 시뮬레이션 -사례중심으로-)

  • 최안섭;성민기
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.5
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    • pp.8-13
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    • 2001
  • The make a decision for building remodeling, the economical value of the remodeled building should be analyzed and existing situation of the building system should be checked. For the energy issues related to the building remodeling process, careful diagnosis and re-designs of existing system should be proposed. In this research, the luminous environment for Seoul K Co. headquaters and Seoul S hotel were measured and then the re-design processes of building illumination systems were researched. With measured illuminance quantities of there cases, computer simulations for the existing situation and re-design were conducted.

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A Study on Driver's Perception over the Change of the Headlamp's Illuminance : 2. Driver's Perception Property (전조등 조도변동에 대한 운전자의 인식연구 : 2. 운전자의 시인 특성)

  • Kim, Gi-Hoon;Lee, Chang-Mo;Jung, Seun-Gun;Jo, Duk-Su;Suk, Dae-Ill;Jo, Mun-Seong;Kim, Hyng-Keon;Kim, Huyn-Ji;An, Ok-Hee;Kim, Hoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.10
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    • pp.1-12
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    • 2007
  • Through this experiment driver's perception were measured. An analysis of the perception measurement result analyzed the subject's obstacle perception response time according to voltage patterns. The difference in the reaction time between men and women was also analyzed. Futhermore, the obstacle perception response time was analyzed according to the rate of the brightness of the headlamp. The relative delay time was analyzed In reference to times when there was no voltage change.

A Study on the Standby Power Characteristics of Sensor Luminaires (광원별 센서등기구의 대기전력 특성에 관한 연구)

  • Park, Chang-Yong;Seo, Jeong-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.10
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    • pp.9-15
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    • 2014
  • Standby power, so called an electric vampire, is a power which is consumed by appliances and office equipments connected to power sources while the devices are not performing. Sensor luminaires consist of PIR(Pyroelectric Infrared Ray) sensor, illuminance sensor(CdS), and light source. The sensor luminaires are one of the devices that consume a huge amount of standby power; it stands by for an average sum of 23 hours a day and performs only when moving subjects are detected under it, which barely takes up an hour per day. The purpose of this study is to provide basic materials to the selection of standby power items and to enable to explore a way to decrease the standby power by measuring and analyzing the power consumption of sensor luminaires. According to the results, the average standby power of LED sensor luminaires is 1.1W which is significantly higher than other products, and decrease in the standby power consumption of SMPS is important through the measurement.

A Study on Driver's Perception over the Change of the Headlamp's Illuminance : 4. Test and analysis of Driver's brain wave (전조등 조도변동에 대한 운전자의 인식연구 : 4. 운전자의 뇌파측정 및 분석)

  • An, Ok-Hee;Kim, Hyun-Jin;Kim, Gi-Hoon;Kim, Hoon;Kim, Hyun-Ji
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2006.05a
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    • pp.125-130
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    • 2006
  • In this study, tests of brain waves were carried out to investigate the driver's physiological characteristics by the change of the headlight. The participants were 20 men in their 20s and twenty-three different conditions in combinations of waveform of light, voltage, and alteration time were used. The measurement of the brain waves was performed by internationally standardized 10-20 method using LXE3232-RF. The results were analyzed by Power Spectrum Analysis using alpha-, and beta-wave and by the analysis of different brain domains using Brain wave Map. The results were as follows. 1. From the results of the Brain wave Map analysis, it was suggested that A waveform increases mental stress and B waveform affects mental and visual stress. The longer the stimulation time, the more stress level was detected. 2 The voltage alteration time of B waveform should be kept less than 1500msec, and the voltage should not fall below 11.5V.

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The Field Survey of Indoor Environment of the Office Building (오피스 건물의 실내 환경 실태 조사)

  • Yang, Young Kwon;Kang, In Sung;Chung, Min Hee;Moon, Jin Woo;Park, Jin Chul
    • KIEAE Journal
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    • v.16 no.3
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    • pp.71-76
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    • 2016
  • Purpose: This study aimed at improving the indoor environment of the office building by measuring the indoor environment and conducting a survey. Method: The measurement was conducted from January 13 to March 16 in 2012, targeting 44 sites in same office building located in Seoul, South Korea. The lists of measurement such as dry-blub temperature, relative humidity, formaldehyde (HCHO), asbestos, carbon monoxide (CO), carbon dioxide (CO2), volatile organic compounds (VOCs) and particle pollution (PM10) were measured. In addition, illuminance which belongs to light environment and noise in sound[acoustical] environment were measured respectively. Result: The buildings showed overall pleasant conditions. In terms of the thermal, air, sound, and visual environment, each measurements were satisfied with the requirements in standard, within pleasant ranges, except several sites. However, the survey results were revealed that the office workers were mostly dissatisfied with their indoor environment. Given that the measured values were mostly within standards, the results of survey might have resulted from a compensation mentality biased toward the subjects in psychological terms.

Design and Implementation of Wireless Lighting LED Controller using Modbus TCP for a Ship (Modbus TCP를 이용한 선박용 무선 LED 제어기의 설계 및 구현)

  • Jeong, Jeong-Soo;Lee, Sang-Bae
    • Journal of Navigation and Port Research
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    • v.41 no.6
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    • pp.395-400
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    • 2017
  • As a serial communications protocol, Modbus has become a practically standard communication protocol and is now a commonly available means of connecting industrial electronic devices. Therefore, all devices can be connected using the Modbus protocol with the measurement and remote control on ships, buildings, trains, airplanes and more. The existing Modbus that has been used is based on serial communication. Modbus TCP uses Ethernet communication based on TCP / IP which is the most widely used Internet protocol today; so, it is faster than serial communication and can be connected to the Internet of Things. In this paper, we designed an algorithm to control LED lighting in a wireless Wi-Fi environment using the Modbus TCP communication protocol, and designed and implemented a LED controller circuit that can check external environmental factors and control remotely through the integrated management system of a ship. Temperature, humidity, current and illuminance values, which are external environmental factors, are received by the controller through the sensors, and these values are communicated to the ship's integrated management system via the Modbus protocol. The Modbus can be connected to Master devices via TCP communication to monitor temperature, humidity, current, illuminance status and LED output values, and also users can change the RGB value remotely in order to change to the desired color. In addition, in order to confirm the implementation of the controller, we developed a simulated ship management system to monitor the temperature, humidity, current and illumination conditions, and change the LED color of the controller by changing the RGB value remotely.

The comparison between measurement and prediction values for the vertical illuminances by relux program in the survey region (상용 조명해석 프로그램(Relux)을 이용한 가로등 주택침입광 예측값과 실측값 비교)

  • Jung, Dae-Kwan;Park, Hyung-Kyu;Jung, Joon-Sig
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.1
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    • pp.98-104
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    • 2018
  • The assessment of the light trespass in terms of light pollution is difficult due to the complexity of light environments. As a result, the light pollution research has examined the influences of light pollution using simulation program such as RELUX. However, there still exists a differences between the real measurement value and the simulation value for the light trespass. In this paper, we analyzed the light trespass using the RELUX simulation program, and compared results with real measurement values. In this study, the regions (Seoul, Incheon, etc.) were investigated regarding the light trespass for outdoor lighting. The survey of vertical illuminance was analyzed measuring point (more than 2 point) out the window that was expected to light trespass for the higher anticipated to illumination. The illuminational predicted values for the RELUX program were compared with maximum one. As a result of this study, the illuminational errors between the measurement values and predicted values for the simulation were examined from -0.97 lx to 0.65 lx except 2.08 lx and -7.70 lx. The light trespass was analyzed the higher by how much the located close to the height, length, width of the outdoor lighting for the window. For measuring predicted values using RELUX, it was not sufficiently considered in the simulation conditions because of environmental factors and investigator error etc. Limitations of this study include the limited number of measurements, and greater field data is required in future studies.