• Title/Summary/Keyword: Illumination system

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Space Simulation Test and Thermal Verification of HAUSAT-2 STM (Structural-Thermal Model) by Using Surface Heaters (표면히터를 이용한 HAUSAT-2 위성 STM의 우주모사 및 열해석 검증 연구)

  • Lee, Mi-Hyeon;Kim, Dong-Woon;Hwang, Ki-Lyong;Chang, Young-Keun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.11
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    • pp.106-114
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    • 2005
  • This study addresses space simulation test results and thermal modelling verification of HAUSAT-2 nanosatellite STM (Structural-Thermal Model). The thermal modelling of the HAUSAT-2 has been modified in accordance with test results. Thermal analysis results were repeatedly compared with test results for modified thermal modelling. It is verified that the analysis results for modified thermal modelling agree well with test results. Some surface heaters were implemented to simulate solar illumination for HAUSAT-2 Thermal Vacuum/Balance Test. A low-cost and effective thermal test methodology, which is applicable to ultra-small satellite system, was proposed and verified by test results in this study.

Effect of Ginseng Saponin on the Circadian Rhythm of Pentobarbital-induced Sleep in Mouse (인삼 Saponiol이 Mouse의 Pentobarbital수면 Circadian Rhythm에 미치는 영향)

  • Shin S.G.;Kim M.S.
    • The Korean Journal of Pharmacology
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    • v.15 no.1_2 s.25
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    • pp.13-19
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    • 1979
  • Circadian susceptibility of sleeping induced by pentobarbital was observrd in male DDO mouse treated with phenobarbital and ginseng saponin. The pentobarbital elimination rate was also measured in the same animal. The mouse had been maintained for one week under 12 hours of artificial illumination extending from 06:00 to 18:00 hours alternating with 12 hours of darkness. During the period the animals were administered intraperitoneally with 100mg/kg of phenobarbital for three days or 10mg/kg and 100mg/kg of ginseng saponin for seven days. At 24 hours after last injection pentobarbital sleeping time and elimination rate were measured following intraperitoneal administration of 50mg/kg of pentobarbital sodium. In a control group treated with saline, the duration of pentobarbital-induced sleep varied with circadian rhythmicity, which had a trough at 02:00 hours of light phase and a crest at 14:00 hours of dark phase. And the elimination rate measured at 02:00 hours was faster than that at 14:00 hours. Pretreatment with phenobarbital markedly shortened the pentobarbital steeping time and abolished the circadian rhythmicity. Those were correlated with the increased pentobartital elimination by phenobarbital throughout light and dark phases examined. Ginseng saponin, given for seven days in a dose of 10mg/kg or 100mg/kg, did not affect the circadian rhythmicity of sleeping and the elimination rate. Sleeping time during light phase, however, was somewhat shortened in ginseng treated animals, which was not matched with the finding of unaltered elimination rate. It seemed that the central nervous system stimulating effect of ginseng saponin might be involved in the findings observed.

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The Role of the Pattern Edge in Goldfish Visual Motion Detection

  • Kim, Sun-Hee;Jung, Chang-Sub
    • The Korean Journal of Physiology and Pharmacology
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    • v.14 no.6
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    • pp.413-417
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    • 2010
  • To understand the function of edges in perception of moving objects, we defined four questions to answer. Is the focus point in visual motion detection of a moving object: (1) the body or the edge of the object, (2) the leading edge or trailing edge of the object, (3) different in scotopic, mesopic and photopic luminance levels, or (4) different for colored objects? We measured the Optomotor Response (OMR) and Edge Triggering Response (ETR) of goldfish. We used a square and sine wave patterns with black and red stripes and a square wave pattern with black and grey stripes to generate OMR's and ETR's in the goldfish. When we used black and red stripes, the black leading edges stimulated an ETR under scotopic conditions, red leading edges stimulated an ETR under photopic conditions, and both black and red leading edges stimulated an ETR under mesopic luminance levels. For black and gray stripes, only black leading edges stimulated an ETR in all three light illumination levels. We observed less OMR and ETR results using the sine wave pattern compared to using the square wave pattern. From these results, we deduced that the goldfish tend to prefer tracking the leading edge of the pattern. The goldfish can also detect the color of the moving pattern under photopic luminance conditions. We decided that ETR is an intriguing factor in OMR, and is suitable as a method of behavioral measurement in visual system research.

Effect of EEG Wave Type on Visual Cortex of Visual Target according to Position of Fixation Point (주시점의 위치에 따른 시 표적이 시피질의 뇌파에 미치는 영향)

  • Kim, Douk-Hoon;Cho, Jin-Wook;Nam, Sang-He
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.1
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    • pp.101-105
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    • 2000
  • This study was to investigate the effect of EEG wave type on visual cortex of visual target according to position of fixation point on the Korean. Visual evoked potential system used the BIO-Pag and recorded to 586 computer. The illumination was 500 lux and the visual target was red light dot of 3 cm size. The results of the convergence and divergence as follows: The visual stimulation waves on the visual cortex have about 70% of delta wave, about 10% of beta wave, about 9% of theta wave and about 7% of alpha wave respectively. The convergence state was much more appeared the fast wave on the comparative of the divergence. Therefore, the convergence state was much more producted the beta and alpha wave on the comparative of the divergence. On the other hand, on the convergence and divergence, the histogram amplitude of EEG wave appeared almost the non-Gaussian shape. According to the phase analysis of amplitude of EEG wave almost all type was linear shape.

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Robust Facial Expression Recognition using PCA Representation (PCA 표상을 이용한 강인한 얼굴 표정 인식)

  • Shin Young-Suk
    • Korean Journal of Cognitive Science
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    • v.16 no.4
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    • pp.323-331
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    • 2005
  • This paper proposes an improved system for recognizing facial expressions in various internal states that is illumination-invariant and without detectable rue such as a neutral expression. As a preprocessing to extract the facial expression information, a whitening step was applied. The whitening step indicates that the mean of the images is set to zero and the variances are equalized as unit variances, which reduces murk of the variability due to lightening. After the whitening step, we used the facial expression information based on principal component analysis(PCA) representation excluded the first 1 principle component. Therefore, it is possible to extract the features in the lariat expression images without detectable cue of neutral expression from the experimental results, we ran also implement the various and natural facial expression recognition because we perform the facial expression recognition based on dimension model of internal states on the images selected randomly in the various facial expression images corresponding to 83 internal emotional states.

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Road Image Enhancement Method for Vision-based Intelligent Vehicle (비전기반 지능형 자동차를 위한 도로 주행 영상 개선 방법)

  • Kim, Seunggyu;Park, Daeyong;Choi, Yeongwoo
    • Korean Journal of Cognitive Science
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    • v.25 no.1
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    • pp.51-71
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    • 2014
  • This paper presents an image enhancement method in real road traffic scenes. The images captured by the camera on the car cannot keep the color constancy as illumination or weather changes. In the real environment, these problems are more worse at back light conditions and at night that make more difficult to the applications of the vision-based intelligent vehicles. Using the existing image enhancement methods without considering the position and intensity of the light source and their geometric relations the image quality can even be deteriorated. Thus, this paper presents a fast and effective method for image enhancement resembling human cognitive system which consists of 1) image preprocessing, 2) color-contrast evaluation, 3) alpha blending of over/under estimated image and preprocessed image. An input image is first preprocessed by gamma correction, and then enhanced by an Automatic Color Enhancement(ACE) method. Finally, the preprocessed image and the ACE image are blended to improve image visibility. The proposed method shows drastically enhanced results visually, and improves the performance in traffic sign detection of the vision based intelligent vehicle applications.

A Study on the Effective Maintenance Method of the Stair Passage Leading Light installed In the Shopping Building (상가건물 계단통로유도등의 유지관리 효율화 방안에 관한 연구)

  • Lee, Young-Sam
    • Journal of the Korea Safety Management & Science
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    • v.18 no.1
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    • pp.1-8
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    • 2016
  • This study was conducted by survey and inspection of stair passage leading lights in shopping buildings which are more than 5 stories and have an underground parking lot located at Pyeongtaek-si and Seongnam-si. Number of shopping building for this study is 30 and of stair passage leading light inspected by two lights in each shopping building is 60. The result of this study is that the type of installed leading lights is LED(77%), and 60% of leading lights has problem such as no cleaning, scratch and discoloration, etc. The height of installed leading lights meets the fire law which is less than 1m from the floor. Visible condition of leading lights is good except some leading lights which have a little visible problem due to banner advertisement. 37% of standby power has flickered and went out. 93% of total leading lights meets the fire law which is more than 1lux from 0.5m distance, but cold cathode fluorescent lamps(CCFLs) have the problem which not meets proper brightness level based on fire law. In additional measurement result, zero lux of leading lights is 32%(from 1m distance), 68%(from 1.5m distance) and 98%(from 2m distance). Leading light is very important facility because it is eyes and guide when emergency. Therefore, proper fire facility operating function inspection and total detailed inspection are important to keep the good condition of leading light except simple visual check, and also improvement in law system of type approval, fire construction inspection and illumination level will be needed.

Facial Feature Extraction using Nasal Masks from 3D Face Image (코 형상 마스크를 이용한 3차원 얼굴 영상의 특징 추출)

  • 김익동;심재창
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.4
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    • pp.1-7
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    • 2004
  • This paper proposes a new method for facial feature extraction, and the method could be used to normalize face images for 3D face recognition. 3D images are much less sensitive than intensity images at a source of illumination, so it is possible to recognize people individually. But input face images may have variable poses such as rotating, Panning, and tilting. If these variances ire not considered, incorrect features could be extracted. And then, face recognition system result in bad matching. So it is necessary to normalize an input image in size and orientation. It is general to use geometrical facial features such as nose, eyes, and mouth in face image normalization steps. In particular, nose is the most prominent feature in 3D face image. So this paper describes a nose feature extraction method using 3D nasal masks that are similar to real nasal shape.

EEFL using intelligent lighting system control device (EEFL을 이용한 지능형 조명시스템 제어장치)

  • Park, Yang-Jae
    • Journal of Digital Convergence
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    • v.11 no.4
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    • pp.229-234
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    • 2013
  • The purpose of this study is to develop a lighting apparatus of the illuminance and color temperature to maximize the ability of the optimal combination of light sources that can be controlled efficiently control device. Finding people comfortable feeling for indoor lighting that can be used in a variety of color temperature illumination area by combining light sensitivity can be realized. Lighting apparatus for fluorescent lamps with different color temperature of 2000K and 8000K, and by varying the quantity of each of the fluorescent lamps, the illuminance of lighting equipment and color temperature through optical simulations were evaluated. By infrared remote control receiver, divided into 5 types of relaxation, conversation, meeting, hospitality, arts and the lighting environment you want to transfer the PC0 ~ PC4 through the parallel port on the mode selected by the user at the receiving end the DC voltage output. EEFL inverter input DC voltage and the DC input voltage, depending on the level of EEFL dimming value (illuminance and color temperature) lighting environment you want to create change while using a PIR sensor EEFL automatically turn off if people do not have was developed so that the power consumption so you can save.

Performance Evaluation of Energy Reduction of Light Shelf Applying Punching Plate

  • Choi, Yuchang;Lee, Heangwoo;Seo, Janghoo;Kim, Yongseong
    • KIEAE Journal
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    • v.14 no.6
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    • pp.5-13
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    • 2014
  • Various studies on lighting energy savings are conducted, given that lighting energy consumption accounts 23.5% of building energy consumption. Especially, external type light shelf's efficiency is acknowledged; however, its application is limited in Korea, where high rise building ratio is high, due to high wind pressure. This study delves into natural lighting system to cope with wind pressure, and proposes the punching plate-installed light shelf. This study actually draws lighting energy output, according to whether the punching plate is applied through the test-bed, and verifies the effectiveness of the punching plate-installed light shelf. The conclusion is presented below: First) The result of performance evaluation of light shelf with the punching plate in winter solstice showed that the awning area decreased as the opening ratio increased so that the indoor distributed illumination tended to increase, and $-40^{\circ}$ which was advantageous for awning was determined as the proper angle. Second) The light shelf with the punching plate in spring/autumn equinox shows improved lighting according to the angle, and the appropriate angle of light shelf with the punching plate has increased to $15^{\circ}$ and $20^{\circ}$ according to the opening ratio in comparison to $5^{\circ}C$ which is the appropriate angle of light shelf with no punching plate due to the reflection area reduced by the reflecting plate with holes. Third) The result of performance evaluation of light shelf with the punching plate in summer solstice showed that the lighting performance tended to decrease as the opening ratio increased. 4) The light shelf with the punching plate incurs a 50% energy loss in comparison to the light shelf with no punching plate. However, its effectiveness has been proven in the aspects that it can bring a 50% energy saving in comparison to the case with no installation of light shelf and that it can be designed in response to wind pressure on the high floors.