• Title/Summary/Keyword: Strobe Light

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Physiological and Behavioral Studies on the Stimulating Effect of Strobe Light -III - Heart Rate Change of Jack Mackerel by Strobe Light Intensity - (스트로보광의 자극효과에 관한 행동 생리학적 연구 -III - 스트로보광 강도에 의한 전갱이의 심박수변화 -)

  • 안영일;유원귀문
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.39 no.2
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    • pp.128-133
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    • 2003
  • Stimulus effects of strobe light on jack mackerel Trachurus japonicus were studied by measuring the heart rate change according to the different strobe light intensity of 5~75 lx$\cdot$s. Heart rate was observed for 60 min: 10 min before, 30 min during and 20 min after the strobe light stimulus. The measurement of heart rate was repeated three times at 2 hour intervals. The results showed that the heart rate increased during stimulus but temporarily decreased immediately after ending of stimulus. The heart rate changes in both during and after stimulus were decreased with reducing light intensities. The heart rate change according to the repeated experiment was not remarkably different under the lower light intensity

Physiological and Behavioral Studies on the Stimulating Effect of Strobe Light-IV Electroretinogram of Jack Mackerel by Strobe Light Frequency and Intensity (스트로보광의 위협효과에 관한 행동생리학적 연구-IV 스트로보광의 섬광빈도 및 강도에 의한 전갱이의 망막활동전위)

  • An, Yeong-Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.2
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    • pp.132-137
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    • 2004
  • In order to assess electrophysiological responses of fish, a recording of Electroretinogram (ERG) was made on the dark-adapted eyes of anesthetized jack mackerel Trachurus japonicus in the strobe-flash frequency range of 1.7~25 Hz and in the intensity range of 56~415 lx.s. The amplitude change of the ERG is highest at the moment when the strobe light is irradiated and becomes weakest soon after, then gradually increases and becomes stable. The amplitude of the ERG by strobe flash frequencies looked stable tendency after about 12~17 minutes elapsed. During the test duration of 30 minutes, the maximum of amplitude change and stimulation amount over all the tested frequencies was found at 10 Hz. The reduction of the flash intensity caused the decrease in the amplitude and stimulation amount.

The Effect of Disturbed Vision on Gait Parameters of the Young Healthy Population (혼란스러운 시각의 영향에 따른 보행요소들의 평가)

  • Kim Kyoung;Park Young-Han;Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.12 no.1
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    • pp.41-47
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    • 2000
  • BACKGROUND AND PURPOSE. The purpose of this study is to investigate the effect of the disturbed vision on the gait distance parameters on the healthy young population. SUBJECTS. Twenty four healthy college aged individuals are randomly assigned to both a condition with a strobe light and the other condition without a strobe light. METHODS. The instrumentation used for gait analysis is the GaitRite electronic walkway system with a personal IBM computer. The examiner naked all the subjects to walk 6 times on the gait mat without the strobe light and. 6 times on the mat with the strobe light. The first 4 trials were practice and the last two trials were recorded in both conditions. The gait parameters analyzed were as follows : velocity, cadence, step length, and heel to heel base of support. RESULTS. Paired samples t-test used for this study did not found any significant differences between the two conditions because the p-values that were analyzed on the experiment were Utter than 0.05. The gait parameters that were analyzed included cadence, velocity, left and right heel to heel base of support, and left and right step length. DISCUSSION AND CONCLUSION. Based on this population, the condition of disturbed vision via the effect of the strobe light was not significantly challenging to compromise the body's sensory systems. However, in the elderly population, these systems can undergo age related changes. Visual changes rapidly decline in people 60 to 80 years of age and changes in the vestibular system include $20-40\%$ reduction in hair cells.

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A Study on Strobe Control over LED Lighting System for Machine Vision (머신비전을 위한 LED 조명시스템의 스트로브 제어 구동에 관한 연구)

  • Kim, Tae-Hwa;Lee, Cheon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.34 no.2
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    • pp.121-125
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    • 2021
  • The machine vision technology has been widely used in the industrialized nations like the United States, Japan, and EU in the various industries from the late 1980s. Machine vision inspection system mainly consists of a camera, optics, illumination and an image acquisition system. Optimization of the illumination light source is very important. This paper shows a comparison between Pulse Width Modulation (PWM) control and strobe control in driving LED lighting system for machine vision. PWM control method has problems such as a temperature rising of LED and a flickering in image measurement for inspection. In contrast, the proposed strobe control method can suppress the temperature of LED light source below 40℃. Also, it can remove the flickering problem through a synchronization between a frame grabber and a camera shutter. Finally, the strobe control method was shown to extract clearer images with a high precision compared to PWM control method.

Retinomotor Responses of Jack Mackerel Trachurus Japonicus and Carp Cyprinus Carpio to Strobe Light (스트로보광에 의한 전갱이와 잉어의 망막운동반응)

  • 안영일
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.31 no.4
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    • pp.379-384
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    • 1995
  • The retinomotor responses of jack mackerel, Trachurus japonicus and carp, Cyprinus carpio were studied for the different strobe flash frequencies in respects of the application of the light stimulus to herding and barrier system. The strobe flash frequencies ranged at 1.7, 5, 10, 25, 430Hz in jack mackerel and 1.7, 5, 25Hz in carp. The retinal adaptation ratio was examined histologically according to the time elasped of 1, 5, 10, 30min after turning on the light in each experimental condition. Cone index were determined in order to express the retinal adaptation ratio. Jack mackerel showed an increase of the retinal adaptation ratio ranging from average 27% at the pre-stimulus light to 42.6%, 49.8%, 59.8% and 83.1% at the irradiation times of 1, 5, 10 and 30min., respectively. Carp showed an increase of the retinal adaptation ratio ranging from average 28.4% at the pre-stimulus light to 51%, 53.9% and 91.3% at the irradiation times of 1, 5 and 30min., respectively. The light adaptation process was observed to be fast approximately in order of 430Hz, 25Hz, 5Hz, 1.7Hz and 10Hz for jack mackerel, and 25Hz, 5Hz and 1.7Hz for carp, and to be light-adaptated in 30 minutes.

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The Necessity of Introducing Fire Point Notification Displays in Complex Buildings to Reduce Required Safe Escape Time(RSET) (RSET 감소를 위한 복합건축물의 화재발생지점 알림표시등 도입 필요성)

  • Jusung Kim;Jongkwen Ha;Hasung Kong
    • Journal of the Korea Safety Management & Science
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    • v.26 no.3
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    • pp.71-82
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    • 2024
  • In modern society, buildings are becoming more complex, and the population is becoming more densely populated. Such large buildings require a variety of evacuation measures, as there is a high possibility of large-scale human casualties due to increased evacuation distance and evacuation time in the event of a fire. Strobe light and exit sign light are used as important evacuation equipment to provide early warning and evacuation directions. In this thesis, we conducted a fire simulation assuming that a fire occurrence point notification function and a strobe light function were added to equipment such as visual alarms and evacuation guidance, and compared and analyzed the difference in evacuation completion time with existing equipment. The scenarios for the simulation were divided into "general fire situations" and "fire location and evacuation exit guidance situation" and the differences in evacuation completion time in the event of a fire were compared and analyzed for each floor from the 1st floor to the 3rd floor. The maximum travel distance to complete evacuation in the case of a fire on the first floor decreased by 80.6 m and the evacuation completion time decreased by 329.4 seconds, and the maximum travel distance to complete evacuation in the case of a second-floor fire decreased by 28.5 m and the evacuation completion time by 438.8 seconds. During the fire on the third floor, the maximum distance decreased until evacuation was completed to 3.4 m, and the evacuation completion time was reduced by 355.6 seconds. It is expected that if the congestion level of evacuation routes is reduced by utilizing the congestion level of evacuation exits when fire alarm systems and evacuation equipment are activated, the evacuation completion time will be further shortened and evacuations will be carried out quickly and safely.

Visualization of Electro-hydrodynamic Ink Jetting using CCD Camera (CCD 카메라를 사용한 전기수력학적 잉크젯 토출 현상 가시화)

  • Kwon, Kye-Si;Lee, Dae-Yong
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.3
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    • pp.295-301
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    • 2012
  • The method for spraying of liquids through an electrical field has become a printing method since it can make very small droplet. For electro-hydrodynamic jet printing to become a reliable jetting tool, the jetting performance should be characterized with respect to various jetting conditions. To optimize jetting conditions, the jetting behavior should be measured. In this study, we present a visualization techniques to measure jetting behavior from electro-hydrodynamic (EHD) inkjet head. Unlike most previous method, we use the CCD camera to measure the jetting behavior. For this purpose, LED light is synchronized with jetting signal and sequential image was obtained by adjusting the delay time of the LED light. Finally, merits and demerits of using CCD camera were discussed to measure jetting image from EHD inkjet head.

Development of a Test Stand for Measuring Ink Jetting Performance (잉크젯 토출 특성 평가 장치 개발)

  • Kwon, Kye-Si
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.8
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    • pp.45-50
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    • 2008
  • An ink jetting measurement system has been developed such that the velocity as well as the volume of ink droplets can be measured. In order to measure the ink droplet, a strobe LED light was synchronized to the droplet firing signal in order to obtain frozen droplet images. Then, a LabVIEW based software was developed for the analysis of the droplet image. For the efficient droplet analysis, a user generated rectangular shaped ROI (Region of Interest) was used. By using ROI, the ink droplet image can be easily isolated from the other structures such as printhead and the processing area can be minimized.

In vivo Imaging Flow Cytometer (세포 이미징 기능을 겸비한 생체 유세포 분석기)

  • Lee, Ho
    • Journal of the Korean Society of Visualization
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    • v.5 no.1
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    • pp.9-11
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    • 2007
  • We introduce an in vivo imaging flow cytometer, which provides fluorescence images simultaneously with quantitative information on the cell population of interest in a live animal. As fluorescent cells pass through the slit of light focused across a blood vessel, the excited fluorescence is confocally detected. This cell signal triggers a strobe beam and a high sensitivity CCD camera that captures a snap-shot image of the cell as it moves down-stream from the slit. We demonstrate that the majority of signal peaks detected in the in vivo flow cytometer arise from individual cells. The instrument's capability to image circulating T cells and measure their speed in the blood vessel in real time in vivo is demonstrated. The cell signal irradiance variation, clustering percentage, and potential applications in biology and medicine are discussed.