• Title/Summary/Keyword: Light Sensitivity

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DEVELOPMENT OF CALCULATION METHOD OF SENSITIVITIES FOR LIGHT WATER REACTORS

  • Takeda, Toshikazu;Foad, Basma
    • Nuclear Engineering and Technology
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    • v.45 no.6
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    • pp.753-758
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    • 2013
  • A new method of calculating sensitivity coefficients of core characteristics relative to infinite-dilution cross sections has been developed. Conventional sensitivity coefficients are evaluated for the changes of effective cross sections which are dependent on individual models of core and cell. Therefore a correction has been derived to the conventional sensitivity coefficients based on the perturbation theory. The accuracy of the present method has been verified by comparing numerical results of sensitivity coefficients with a reference Monte-Carlo method.

A study on the Application Plan of Light Elements in Liturgy Space (전례공간에서의 빛요소 적용에 대한 계획방안 연구)

  • Bahn, Sang-Chul;Kim, Ki-Hyok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.521-536
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    • 2016
  • In Catholic Cathedrals, the Liturgy space is central to the worship of the church and the player. The composition of the liturgical space affects the sensitivity of the worshiper. Because this sensitivity is connected with the faith, it is a very important consideration for planning elements. In this study, the light sensitivity of the elements that identify the most important factors in changing the devotion and in liturgical space was planned to emphasize the role of light. Understanding the meaning and importance of the liturgical space determine the spatial phase and role. Therefore, to analyze the functional and emotional properties of the light, the properties, roles and conditions of the light were organized. The data was analyzed as the target of sensitivity to light. Through the case studies of light, the effectiveness and adequacy as well as the application conditions could be understood. The results obtained in this study suggest a plan for light elements applied in the liturgical space.

A Study on the Operating Principle of the Light-emitting and -receiving Part of the Photoelectric Sensitivity Tester (광전식감도시험기의 발광부와 수광부 작동원리에 관한 연구)

  • Yoon, Hun-Ju;Kwon, Seong-Pil;Kim, Hyeong-Gweon;SaKong, Seong-Ho
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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    • pp.151-154
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    • 2008
  • The advanced technical data collected from home and abroad have properly been analyzed, so that they are useful to improve the photoelectric sensitivity tester. The results of this study have quickly been supplied to the related industry. Our research and development team has verified the response characteristics of the light-emitting and -receiving part of the photoelectric sensitivity tester in order to help the local manufacturer to study, develope and produce their photoelectric detectors.

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펜던트형 감성조명 LED 등기구 모듈개발

  • Seo, Dong-Won;Kim, Yeong-Geun;Kim, Jin-Sa;Kim, Geum-Taek;Choe, Un-Sik;Song, Min-Jong;Song, Myeong-Hyeon;Park, Chun-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.264-264
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    • 2009
  • The sensitivity lighting of pendant type used Micro-controller AVR, embodiment method for Munsell chromaticity diagram system and adoption method for light source lens respectively. About a plan design of light fixture, LED circuit designed flow chart of circuits and LED driver of organizations in electron device. For used Solidworks soft ware program, LED light source must take a heat shink part and LED light fixture module for sensitivity lighting of pendant type into considerations

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Improvement of Sensitivity in Porous Silicon Alcohol Gas Sensors by UV Light (자외선조사에 의한 다공질 실리콘 알코올 센서의 감도 개선)

  • Kim, Seong-Jin;Choe, Bok-Gil
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.9
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    • pp.676-680
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    • 1999
  • To do breath alcohol measurement, a sensor is necessary that it can detect low alcohol gas concentration of 0.01% at least. In this work, a capacitance-type alcohol gas sensor using porous silicon layer is developed to measure low alcohol gas concentration. The sensor using porous silicon layer has some sensitivity at room temperature by very large effective surface area, but there is still much room for improvement. In this experiment, we measured the capacitance of the sensor under 254 nm UV light on the porous silicon layer, in which alcohol solution was kept in a flask at 25, 35, and $45^{\circ}C$ by a heater. As the result, the improvement of sensitivity by illuminating UV light was observed. The increasing rate of the capacitance was shown to be double more than those measured under UV-off state. It is supposed that UV light activates response of the oriental and interfacial polarizations which have slow relaxation time for AC field.

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Fringe Sensitivity of Projection Moire Topography Due to Position of Light Source and Object Distance According to Grating Periods (영사식 무아레 토포그래피에서 격자 주기에 따른 물체거리와 광원의 위치에 대한 무늬 민감도 변화)

  • Oh, Hyun Seock;Ju, Yun Jae;Jo, Jae Heung
    • Korean Journal of Optics and Photonics
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    • v.27 no.2
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    • pp.67-72
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    • 2016
  • In projection moire topography, the investigation of fringe sensitivity, which means the change rate of fringe order according to object height, is important and necessary to reduce the measurement error of the shape of an object. Using the fringe sensitivity, the determination of the absolute orders of moire fringes can be performed very easily and rapidly. The important parameters in the determination of absolute orders of fringes are the positions of light source and object, and the grating period in projection moire topography. Among these parameters, the fringe sensitivity due to the transverse motion of the light source and the longitudinal motion of the object according to grating periods are analyzed and compared. As a result, whereas the fringe sensitivity in the transverse-motion method increases linearly and gradually as the distance between light source and imaging sensor increases, the fringe sensitivity due to the longitudinal-motion method decreases dramatically as the distance between imaging lens and object increases. In these methods, the fringe sensitivity and its change increase as the grating period increases.

Reasons for Variation in Sensitivity and Specificity of Visual Inspection with Acetic Acid (VIA) for the Detection of Pre-Cancer and Cancer Lesions of Uterine Cervix

  • Parashari, Aditya;Singh, Veena
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7761-7762
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    • 2013
  • Alternative strategies such as visual inspection of cervix with acetic acid, are real time, economical and easily implemented methods for cervical cancer screening. However, variable sensitivity and specificity have been observed in various community based studies. The possible reasons could include variation in man power training, light source used for visualization, and preparation of diluted (4-5%) acetic acid and its storage. A standardized protocol for training, teaching material (easy to understand in the local language) for trainees, supervision and reinforcement by intermittent and supplementary training to check the quality of their observation, a standard protocol for preparation dilute acetic acid and its storage and a standard good light source (equivalent to day light) are needed to minimize the variation in sensitivity and specificity of VIA in community settings.

Changes of Contrast Sensitivity According to Light Transmittance of Color Lenses (색렌즈의 광투과율에 따른 대비감도 변화)

  • Lee, Sun-Haeng;Lee, Yoon-Jeong;Cho, Hyun-Gug
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.11
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    • pp.3427-3433
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    • 2009
  • This paper attempted to suggest the standards of light transmittance based on the analysis of the changes in contrast sensitivity of photopic condition according to the light transmittance of tinted lenses. The subjects of the experiment were 24 male and 13 female adults with normal ocular functions. They were asked to wear four tinted lenses (gray, brown, red, and green) in turn. The light transmittance of the lenses were 80~90%, 60~80%, 43~60%, and 30~43%, respectively. Contrast sensitivities were measured by using F.A.C.T. chart. The results showed that contrast sensitivities were decreased in proportion to the decrease of the light transmittance, and visual sensitivity of brown lenses were the highest and that of red lenses were the lowest. The results of the experiments suggested that the light transmittance should be over 38% for brown, gray and green lenses, and over 52% for red lenses. Accordingly the appropriate light transmittance should be considered when tinted lenses are selected for the purpose of eye protection in everyday life.

Preliminary study on the visual sensitivity of Oreochromis niloticus using LED light source for the aquaculture development in Uganda

  • Esther Kagoya;Kyoungmi Kang
    • Fisheries and Aquatic Sciences
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    • v.26 no.8
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    • pp.514-523
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    • 2023
  • The visible threshold of Oreochromis niloticus responded to high light intensity under short wavelengths, whereas the response to low light intensity under long wavelengths was low, with a minimum visual threshold of 574 nm of LED lights. Movement distance of O. niloticus was dropped at 31℃ and increased abnormally at 37℃ under natural light. Comparing movement distance under red (622 nm) and green (518 nm) lights of LED, movement distance and swimming speed under red and green lights were higher than under natural light. However, the movement distance decreased rapidly at 31℃ under red light and lowest at 33℃ under green light. After that, there was a tendency to adapt to high water temperatures gradually. Consequently, red and green lights may be recommended for O. niloticus's aquaculture because the red and green lights have a positive effect on growth performance, survival rate, and metabolism, as shown in previous studies. It is necessary to control the water temperature below 32℃ because abnormal behavior above 32℃ revealed under red and green LED lights and natural light.

A Novel Ultraviolet Sensor using Photoluminescent Porous Silicon (광 루미네슨스 다공질 실리콘을 이용한 새로운 자외선 센서)

  • Min, Nam-Gi;Go, Ju-Yeol;Gang, Cheol-Gu
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.9
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    • pp.444-449
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    • 2001
  • In this paper, a novel ultraviolet sensor is presented based on a photoluminescent porous silicon. Porous silicon layer was formed by chemical etching of surface of pn junction in a $HF(48%)-HNO_3(60%)-H_20$ solution. Incident ultraviolet(UV) light is converted to visible light by photoluminescent porous silicon layer, and then this visible light generates electron-hole pairs in the pn junction, which produces a photocurrent flow through the device. In order to maximize detection efficiency, the peak sensitivity wavelength of the pn junction diode was matched with the peak wavelength of Photoluminescence from porous silicon layer. The porous silicon ultraviolet sensor showed a large output current as UV intensity increases and but very low sensitivity to visible light. The detection sensitivity of porous silicon sensor was calculated as 2.91mA/mW. These results are expected to open up a possibility that the present porous silicon sensor can be used for detecting UV light in a visible background, compared to silicon UV detectors which have an undesirable response to visible light.

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