• Journal of Korean Ophthalmic Optics Society
• /
• v.19 no.4
• /
• pp.533-538
• /
• 2014

Purpose: This study is to investigate correlation between eye fatigue and letter contrast according to letter contrast changes on monitor display. Methods: Reading speed test were carried out for 53 subjects (mean age: $22.68{\pm}1.85$ years) who have over Best-corrected visual acuity (BCVA) 1.0, and 45 subjects, who could read over 123 out of 163 letters among 53 subjects were selected. They were asked to read the letters which were composed of Black (contrast 100%), Dark gray (contrast 80%), Gray (contrast 80%), Light gray (contrast 30%) randomly. The change of their eye fatigue by letter contrast on monitor display was measured by monitoring their eyes with an eye-tracker while they were reading letters. Results: Event Duration (sec) was 33.635 for Black, 32.266 Dark gray, 33.936 for Gray, and 34.848 for Light gray. Average of Fixation Duration (sec) was 0.224 for Black, 0.218 for Dark gray, 0.239 for Gray and 0.243 for Light gray. Average of Pupil diameter (mm) was 41.133 mm for Black, 41.160 mm for Dark gray, 40.880 mm for Gray and 40.459 mm for Light gray. Frequency (blinks/sec) was 0.211 for Black, 0.206 for Dark gray, 0.221 for Gray, and 0.238 for Light gray. Conclusions: Event Duration and average of Fixation Duration were the shortest for Dark gray and the longest for Light gray. In average Pupil diameter was the biggest Dark gray and the smallest for Light gray. Blink Frequency (blinks/sec) was the lowest for Dark gray and the highest for Light gray. Visual fatigue by brightness of letters on monitor display was the least for Dark gray followed by Black, Gray and Light gray.

• The Bulletin of The Korean Astronomical Society
• /
• v.45 no.1
• /
• pp.48.4-49
• /
• 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.

• Mycobiology
• /
• v.39 no.1
• /
• pp.1-6
• /
• 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.

• Science of Emotion and Sensibility
• /
• v.15 no.1
• /
• pp.57-64
• /
• 2012

The purpose of this study was to compare the visual sensibility of red shirts in university students of two countries, Korea and China in order to suggest the color planning for shirts. Seven tonal red shirts' visual sensibility and preferences were evaluated by the students of Korea and from China in the sense of sight. Evaluated data were analyzed by using frequency analysis, average, factor analysis and t-test. The visual sensibility of red shirts was classified into three factors: sporty, romantic and classic. Those factors of visual sensibility showed a significant difference according to nationality and gender. The Chinese students had a more sporty feel to the strong tone, and a more classic feel to the dark tone than the Korean students. The deep tone red shirts was reputed to be more romantic by the Korean students, but the light tone and the pale tone were considered more romantic by the Chinese students. Meanwhile, the effects of nationality and gender on seven tone of preferences for red shirts was significantly differed.

• Animal cells and systems
• /
• v.8 no.4
• /
• pp.301-306
• /
• 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.

• The Korean Journal of Food And Nutrition
• /
• v.23 no.1
• /
• pp.23-29
• /
• 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.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.10 no.1
• /
• pp.37-45
• /
• 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.

• International Journal of Highway Engineering
• /
• v.15 no.5
• /
• pp.111-122
• /
• 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.

• Transactions on Electrical and Electronic Materials
• /
• v.18 no.1
• /
• pp.35-41
• /
• 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.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.27 no.5
• /
• pp.114-119
• /
• 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.