• 제목/요약/키워드: Light-dark test

검색결과 110건 처리시간 0.035초

아이트래커를 이용한 모니터 글자 대비도에 따른 눈의 피로도 연구 (The Study of Visual Fatigue by Monitor Letter Contrast with an Eye Tracker)

  • 김하림;정주현
    • 한국안광학회지
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    • 제19권4호
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    • pp.533-538
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    • 2014
  • 목적: 모니터 글자 대비 변화에 따른 눈의 피로도를 측정하여 모니터 글자 대비도와 눈의 피로도의 연관성에 대해 연구하고자 하였다. 방법: 최대교정시력 1.0 이상의 피검자 53명(평균연령 $22.68{\pm}1.85$) 중 읽기속도 검사에 통과한 45명(평균연령 $22.68{\pm}1.85$)을 대상으로 각각 Black(대비 100%), Dark gray(대비 80%), Gray(대비 60%), Light gray(대비 30%) 글자로 이루어진 4가지 시표를 무작위로 읽도록 하였다. 피검자가 시표를 읽는 동안 아이트래커로 피검자의 안구를 추적하여 모니터 글자 대비에 따른 피검자의 눈의 피로도의 변화를 측정하였다. 결과: 피검자들의 평균측정시간은 Black, Dark gray, Gray, Light gray에서 33.635 sec, 32.266 sec, 33.936 sec, 34.848 sec로 측정되었다. 평균안구고정시간은 Black, Dark gray, Gray, Light gray에서 0.224 sec, 0.218 sec, 0.239 sec, 0.243 sec로 측정되었다. 평균동공크기는 Black, Dark gray, Gray, Light gray에서 41.133 mm, 41.160 mm, 40.880 mm, 40.459 mm로 측정되었다. 평균 눈깜박임 빈도수는 Black, Dark gray, Gray, Light gray에서 0.211 blinks/sec, 0.206 blinks/sec, 0.221 blinks/sec, 0.238 blinks/sec로 측정되었다. 결론: 피검자들의 평균측정시간과 평균안구고정시간은 Dark gray가 가장 짧았으며, Light gray에서 가장 길었다. 평균 동공크기는 Dark gray에서 가장 컸으며, Light gray에서 가장 작았다. 평균 눈 깜박임 빈도수는 Dark gray에서 가장 적었으며, Light gray에서 가장 많았다. 모니터 글자 밝기에 따른 눈의 피로도는 Dark gray에서 가장 적었으며 Black, Gray, Light gray 순으로 증가하였다.

Model-independent Constraints on Type Ia Supernova Light-curve Hyperparameters and Reconstructions of the Expansion History of the Universe

  • Koo, Hanwool;Shafieloo, Arman;Keeley, Ryan E.;L'Huillier, Benjamin
    • 천문학회보
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    • 제45권1호
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    • pp.48.4-49
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    • 2020
  • We reconstruct the expansion history of the universe using type Ia supernovae (SN Ia) in a manner independent of any cosmological model assumptions. To do so, we implement a nonparametric iterative smoothing method on the Joint Light-curve Analysis (JLA) data while exploring the SN Ia light-curve hyperparameter space by Markov Chain Monte Carlo (MCMC) sampling. We test to see how the posteriors of these hyperparameters depend on cosmology, whether using different dark energy models or reconstructions shift these posteriors. Our constraints on the SN Ia light-curve hyperparameters from our model-independent analysis are very consistent with the constraints from using different parameterizations of the equation of state of dark energy, namely the flat ΛCDM cosmology, the Chevallier-Polarski-Linder model, and the Phenomenologically Emergent Dark Energy (PEDE) model. This implies that the distance moduli constructed from the JLA data are mostly independent of the cosmological models. We also studied that the possibility the light-curve parameters evolve with redshift and our results show consistency with no evolution. The reconstructed expansion history of the universe and dark energy properties also seem to be in good agreement with the expectations of the standard ΛCDM model. However, our results also indicate that the data still allow for considerable flexibility in the expansion history of the universe. This work is published in ApJ.

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Cultural Characteristics of Ophiocordyceps heteropoda Collected from Korea

  • Sung, Gi-Ho;Shrestha, Bhushan;Han, Sang-Kuk;Sung, Jae-Mo
    • Mycobiology
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    • 제39권1호
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    • pp.1-6
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    • 2011
  • Isolates of Ophiocordyceps heteropoda (Kobayasi) collected from Mt. Halla on Jeju-do, Korea were tested for mycelial growth on different agar media and in the presence of different carbon and nitrogen sources. Similarly, isolates were also incubated at different temperatures as well as under continuous light and dark conditions. Growth was better on Hamada agar, basal medium, and malt-yeast agar, but poor on Czapek-Dox agar. Different carbon sources such as dextrin, saccharose, starch, lactose, maltose, fructose, and dextrose resulted in better growth. Complex organic nitrogen sources such as yeast extract and peptone revealed the most effective growth. Mycelial growth was best at $25^{\circ}C$. The growth rate was faster in the dark than the light, but mycelial density was less compact in the dark.

한국과 중국 대학생의 빨간색 셔츠에 대한 시각적 감성 비교 (Comparison of Visual Sensibility for Red Shirts between Korean and Chinese University Students)

  • 반홍우;최종명
    • 감성과학
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    • 제15권1호
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    • pp.57-64
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    • 2012
  • 본 연구는 빨간색 셔츠의 시각적 감성을 비교 분석하여 소비자 감성을 반영한 셔츠의 색채기획에 도움을 주고자, 한국과 중국 대학생을 대상으로 온라인상에서 시각적 평가방법으로 7가지 톤의 빨간색 색지와 빨간색 셔츠에 대한 시각적 감성과 선호도를 평가하였다. 평가된 자료는 빈도 분석, 평균, 요인 분석, t-test를 실시하여 분석하였다. 빨간색 셔츠의 시각적 감성은 스포티, 로맨틱, 클래식 등 3개의 감성요인이 추출되었는데, 이 요인들은 톤, 성과 국적에 따라 유의한 차이가 나타났다. 중국 대학생은 한국 대학생에 비해 strong톤의 빨간색 셔츠가 더 스포티하고, dark톤이 더 클래식하다고 지각하였다. 또한 한국 대학생은 deep톤의 빨간색 셔츠를 로맨틱하다고 평가하였으나, 중국 대학생은 light톤과 pale톤의 셔츠를 로맨틱하다고 평가하였다. 한편, 7가지 톤의 빨간색 셔츠에 대한 선호도는 국적 및 성에 따라 유의한 차이를 보였다. 중국 대학생은 한국 대학생보다 dark톤과 pale톤의 빨간색 셔츠를 더 구매하고 싶어 하였으나, 한국 대학생은 strong톤의 셔츠를 더 선호하였다. 또한 남자 대학생이 dark와 dull톤의 빨간색 셔츠를 더 선호하는 반면, 여자 대학생은 light톤의 빨간색 셔츠를 더 선호하였다.

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Comparative Analysis of the Responses to Intruders with Anxiety-Related Behaviors of Mouse

  • Kim, Sang-Hyeon;Kang, Eun-Chai;Park, Chan-Kyu
    • Animal cells and systems
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    • 제8권4호
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    • pp.301-306
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    • 2004
  • Anxiety in mice can be measured by behavioral reactivity to social or non-social stressors. These behaviors were compared by performing the resident-intruder test (social) as well as the light-dark transition and open-field tests (non-social) for the FVB, C57BL/6, and BALB/c lines of mouse. The three inbred lines showed significant differences in their responses to intruder mice. Three factors, accounting for about 68% of the total variance, were extracted from the scores obtained from the three behavioral tests. The first two major factors are primarily associated with the anxiety-related behaviors. One includes anxiety behaviors with a locomotive basis, while the other includes defecation measured in both anxiety tests. The third factor explains the three social behaviors, facial investigation, ano-genital investigation, and following, observed in the resident intruder test, although facial investigation is also moderately associated with the second factor. The results indicate that the behavioral responses to an intruder share a component distinct from anxiety-related behaviors.

자색고구마로부터 붉은 색소 농축물의 추출 및 그 색소 분말의 제조 특성 (Extraction of Natural Red Color Pigment Concentrate and Manufacturing Characteristics of Pigment Powder from Purple-Fleshed Sweet Potato)

  • 구본순;송대식
    • 한국식품영양학회지
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    • 제23권1호
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    • pp.23-29
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    • 2010
  • Pigment concentrates with violet-red color and sweet taste were obtained from purple-fleshed sweet potato(PFSP) using ethyl alcohol and water. Extract from general potato(GP) were used as a control. The relative stability of PFSP pigment concentrate(PFSPPC) in a storage test over 15 days was confirmed in the order of dark > fluorescence > sun-light irradiation. The relative stability of GP pigment concentrate(GPPC) in a storage test over 15 days was confirmed in the order of sun-light > fluorescence > dark storage. The RRP of PFSPPC was higher than that of GPPC, but the color strength of GPPC was 1/2 that of PFSPPC. Treatment of PFSPPC with aluminum potassium sulfate(0.2~0.3%, w/w) best improved its stability. The improved RRPs of PFSPPC were 45.16~47.31% in sun light irradiation, 55.91~60.22% in fluorescence irradiation, and 76.34~75.97% in dark storage conditions. In substituting aluminum potassium sulfate for chitosan, an amount of 0.2~0.3%(w/w) was suitable, giving similar results in improving pigment stability for all concentrates tested. Also, freeze-dried PFSPPC powder was manufactured as a substitute for dextrin, and also as a substitute for chitosan to the extent of 0.25%(w/w). The results of storage stabilite for freeze-dried PFSPPC and GPPC powder over 15 days, irradiation were, PRRs of 74.47~89.36% and 61.54~76.92%, respectively. The stability improving effect of freeze dried PFSPPC powder was confirmed by the results of storage experiments at various conditions. The use of freeze-dried PFSPPC powder was therefore confirmed to be an effective treatment for general foods.

여고생의 복색 선호와 성격특성과의 상관연구 (The Relationship Between Color & Clothing Color Preference And Personality Traits Among High School Girls)

  • 나수임;한명숙
    • 한국의류학회지
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    • 제10권1호
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    • pp.37-45
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    • 1986
  • The purpose of this study was to investigate the relationship between color & clothing color preferences and three personality traits. Personality traits were measured with chung's Personality Scale. The questionare measuring Color & Clothing color preferences consisted of items designed to assess color preference, color repugnance clothing color preferences. These questionaire were administered to 302 senior high school girls in Seoul. Statistical analysis consisted of corelation and chi-square-test. The result were; 1) Activity, stability, sociability was no significant related to color preference. 2) Activity, sociability was positively related to color repugnance in Value but stability was no significant. 3) Sociability and stability was positively related to color preference, but activity and stability was no significant. 4) There was a positive relationship between color preference and clothing color preference. (r=0.8867) 5) The most preferred colors were white, light blue, and light green. The most repugnated colors were light red, dark red purple, and dark yellow. 6) The most preferred clothing colors were yellow, pink, and green in Spring, white and blue in Summer all kinds of colors, colors in Autumn, and Black and Grey in Winter.

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화물자동차 보조 후미등화장치 설치에 따른 운전자 시인성 변화 (Legibility Change of Commercial Vehicles Equipped with the Rear Lighting System)

  • 조승진;이창희;금기정
    • 한국도로학회논문집
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    • 제15권5호
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    • pp.111-122
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    • 2013
  • PURPOSES : The purpose of this system (Rear Lighting System) is to provide illumination for the driver to operate the commercial vehicle safely after dark in highway, to increase the conspicuity of the vehicle, and especially be suggesting the finest observable improvement method, depending on color and pattern of rear lighting system of truck for midnight highway traffic. METHODS : Rear lightning system as an improving way for forward commercial vehicles lighting the securing sight from human factors and the surrounding environment in midnight driving. For this one, basic materials were collected from the data analysis about many types of problems, and filed investigation for establishing Driving Simulator. also taking statistic test to human volunteers after finding recognizable distance of them. RESULTS : As a result, color with the highest visuality is amber followed by green-red-blue as in order for all road types. Especially almost no difference is found between red and green, also when the light is turn off, recognizable distances is wide difference compared to turn on the light. One more thing about study per pattern, upper and entire lighting have similar recognizable distances, but under lighting shows short distance with difficulty securing sight from medians. And straight section shows similar recognizable distances. By finding visuality improvement method depending on color and pattern of supplement taillight, it is expected to suggest quantitative judgement standard for introducing regulation and improvement of supplement taillight. CONCLUSIONS : Night time vehicle conspicuity to the rear is provided by rear position lamps. this study is showed that the color of light ramp is not important to be safe driving, most important is to turn on the light, recognizable distances is big different compared to turn off the rear light, so when the drivng dark in highway, have to turn on the light for reducing risk.

Overall Illuminance Uniformity of IRED Lighting in Nighttime CCTV

  • Sa-Gong, Geon;Park, Yung-Jun;Park, Jung-Je;Lee, Suho
    • Transactions on Electrical and Electronic Materials
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    • 제18권1호
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    • pp.35-41
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    • 2017
  • This study looks at optimizinge light redistribution to improve the overall illuminance uniformity of commercial IRED modules. To obtain uniform illumination over a prescribed rectangular area, a freeform surface lens was evaluated using TracePro. The LED light overall illuminance uniformity regulated in KSC 7658 was verified using Relux software. Experimental test results showed 0.81 overall illuminance uniformity for rectangular light distribution of LED lights having a radiation angle of $80^{\circ}$. After fabricating prototype IRED lights based on these simulation results, illuminance performance was observed when used as actual IRED lighting with a nighttime CCTV system. Image observation photographs of the prototype $80^{\circ}$ rectangular IRED lights confirmed that object images can be seen clearly owing to high overall illuminance uniformity, and that dark regions of the CCTV screen were not shown.

인공광의 광원에 따른 실내 지피식물의 생육반응 (A Growth Responses of Indoor Ground Cover Plants according to a Light Source of Aritificial Light)

  • 방광자;박혜경;최경옥
    • 한국조경학회지
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    • 제27권5호
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    • pp.114-119
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    • 2000
  • This study was carried out to obtain fundamental information of growth response of ground cover plants under artificial light quality at indoor. Aglaonema 'Silver Queen', Hedera helix L., Hoya carnosa 'Tricolor' and Saintpaulia ionantha 'Frances' were examined under a 400lux light intensity consisted of Mercury lamp, True-lite lamp, incandescent lamp, dark-room and sunlight indoor condition. A data analysis were performed by GLM, Duncan's multiple range test and mean score with SAS program. Results of experiments are as follows; 1. A plant growth status was better showed under the True-lite lamp than sunlight. 2. A Saintpaulia ionantha flower color was responded in the first place, the deep pinkish red color of Saintpaulia ionantha flower was obtained under Mercury lamp and "True-lite lamp", "sunlight", and incandescent lamp were follow. Flower numbers of Saintpaulia ionantha after 60 days tended to decrease under every artificial light quality. 3. Leaf length and leaf width were increased under True-lite lamp, but most of plants was not significantly affected by artificial light quality. 4. A stem length of Hedera helix was increased the highest rank under sunlight also, one of artificial light, the highest increase rank was showed under incandescent lamp. 5. Chlorophyll content was highly increased under Mercury lamp, but was responded poor under incandescent lamp.

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