• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제20권10호
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• pp.10-18
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• 2006

In this thesis paper the effect that the change in the brightness of headlights has on a driver's perception had been researched. For this research, an indoor laboratory was constructed and designed. Then, a system to measure the reaction braking time of finding obstacle and the subject's brain waves after a moment of change in the headlamp's brightness was constructed. And before the real experiment was began, the trial experiment to decide test time, subject's rest time, detailed experimental steps, the headlamp's patterns of voltage change and an obstacle course was executed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제21권10호
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• pp.13-21
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• 2007

Based on the measurement results, a limit value for the change of the brightness of the headlamp, and an estimation algorithm considering the driver's safety was developed. Limitation values concerning being uncomfortable, blinking, and brightness change were indicated based on a subjective estimation of the psychological estimation. Also a safety estimation algorithm and a limitation value for stopping safely without the threat of obstacles to the vehicle were indicated by the perception measurement.

• Journal of Korea Multimedia Society
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• 제19권9호
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• pp.1723-1737
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• 2016

When watching 3D contents, people often experience various visual discomforts like tiredness, dryness, headaches, and dizziness. Previous researches on visual discomfort analyzed and concluded vergence-accommodation conflict, viewing distance, and brightness changes to be the causes of visual discomfort. Yet it is necessary to systematically analyze the visual discomfort due to the changes in object, background brightness and viewing distance. In this paper, we produce four videos that have four different background brightness and two different viewing distances to solve analyze the visual discomfort from watching 3D contents. We measure and analyze eye-blink and saccadic movement, saccadic latency, Nearest Point of Convergence (NPC), and participant survey for amore accurate result compared to previous researches. Our results show that the eye-blink rate and saccadic latency increase when the background is bright and viewing distance is close while the saccadic movement decreases in the same environment. However, NPC only changes when the background brightness changes. We confirm that the bright background and near viewing distance create greater visual discomfort and decrease depth perception abilities.

• Journal of the Korean Data and Information Science Society
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• 제19권2호
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• pp.475-485
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• 2008

One of main issues in watermarking is to resolve the strength of watermark for solving the problem of trade-off between fidelity and robustness of watermarking. In the previous research, the strength of watermark has been resolved fixed value generally without considering local image characteristics such as image brightness, contrast, and edge. This paper proposes a new model to predict the strength of watermark considering local image characteristics such as image brightness, contrast, and edge for digital wavelet transform(DWT)-based image watermarking. For the study, psychological experiment was fulfilled to measure the human image perception and regression analysis showed the proposed model was statistically significant at the level of ${\alpha}\;=\;0.01$. Also the model is practically validated on fidelity and robustness of watermarking.

• Journal of the Korean Society of Costume
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• 제44권
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• pp.104-116
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• 1999

This study was intended to make an inquiry into the effect of lines, shapes and colors (achromatic colors) as apparel design elements on the perceptions of facial size, brightness and shape through an empirical research based on the theories of visual perception and optical illusion that have been studied in Gestalt Psychology, which becomes the basis of apparel design principles. It was shown that the facial size was influenced by the collar size, the degree of neckline cut, and the thickness of the trimming line. The white scarf with the white jacket made the face look darkest while the black scarf with the black jacket made the face look brightest. When the neckline had the characteristic of the line contrasted with the facial shape, the oval-shaped face was perceived to be the most ideal. When the facial shape and the neckline shape were similar, the facial shape was perceived to be more highlighted.

• International Journal of Highway Engineering
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• 제17권5호
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• pp.57-66
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• 2015

PURPOSES: Nighttime driving is very different from daytime driving because drivers must obtain nighttime sight-distances based on road lights and headlights. Unfortunately, nighttime driving conditions in Korea are far from ideal due to poor lighting and an insufficient number of road lights and inadequate operation and maintenance of delineators. This study is conducted to develop new standards for nighttime road visibility based on experiments of driver perception for nighttime visibility conditions. METHODS : In the study, perception level and satisfaction of nighttime visibility were investigated. A total of 60 drivers participated, including 34 older drivers and 31 young drivers. To evaluate driver perceptions of nighttime road visibility, fuzzy set theory was used because the conventional analysis methods for driver perception are limited in effectiveness for considering the characteristics of perception which are subjective and vague, and are generally expressed in terms of linguistic terminologies rather than numerical parameters. RESULTS : This study found that levels of nighttime visibility, as perceived by drivers, are remarkably similar to their satisfactions in different nighttime driving conditions with a log-function relationship. Older drivers evaluated unambiguously degree of nighttime visibility but evaluations by young drivers regarding it were unclear. CONCLUSIONS : A minimum value of brightness on roads was established as YUX 30, based on final analyzed results. In other words, road lights should be installed and operated to obtain more than YUX 30 brightness for the safety and comfort of nighttime driving.

• Journal of the Institute of Electronics and Information Engineers
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• 제52권2호
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• pp.141-147
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• 2015

The contrast of a display is generally evaluated by using the ratio of the minimum luminance to the maximum luminance of the display. However, this contrast ratio is not matched with perceived contrast because it uses only physical characteristic of display without considering human perceptual characteristics. In this paper, the proposed contrast measure that considers perceptually discriminable brightness within the range of display brightness is suggested. First, the range between the minimum and maximum brightness of display in CIECAM02 color space is calculated to measure the length of perceived brightness for the display. Next, brightness ranges which are perceptually same at each brightness level are determined by applying Weber-Fechner ratio and then, the number of brightness values within each brightness range is counted. Finally, perceptually discriminable brightness is defined as the sum of ratio between the number of brightness values in each brightness range and the perceptual contrast length of the display. In the experiments, preference test using various displays with random brightness patches is performed to evaluate perceived contrast. As a result, the proposed measure is more consistent with human perception than the previous contrast measures.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제21권10호
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• pp.1-12
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• 2007

Through this experiment driver's perception were measured. An analysis of the perception measurement result analyzed the subject's obstacle perception response time according to voltage patterns. The difference in the reaction time between men and women was also analyzed. Futhermore, the obstacle perception response time was analyzed according to the rate of the brightness of the headlamp. The relative delay time was analyzed In reference to times when there was no voltage change.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제16권1호
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• pp.43-53
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• 2016

In this study, under the assumption that there may be differences in colour attributes that can be perceived according to the brightness of the background and the size of the colour stimulus, a test was conducted where colour matching was done for stimulus sizes of $10^{\circ}$ and $20^{\circ}$ in terms of peripheral vision by varying the background brightness. The test results showed that depending on the background brightness and the specific combinations of the Munsell colour attributes used as the test stimulus, colours can be perceived differently even if they are the same colours. In addition, in contrast to findings from previous studies on colour perception according to the stimulus size, it was found that even if the size of the colour stimulus is relatively small, colours can be perceived more colourfully or more brightly with changes in the background brightness. Based on the findings of this study, degradation in image quality can be improved, which may occur when the size of the input image is changed at a later time, and also, contributions can be made when it comes to the reproduction of effective sold three-dimensional structures that reflect visual qualities when processing 3D holographic imagery, in addition to 2D imagery.

• The Journal of the Korea Contents Association
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• 제6권5호
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• pp.76-84
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• 2006

When a human-being gets a wrong perception about any object is a misunderstanding and what they feel through sense of sight is an optical illusion. The study about those illusions have been given out to not only the fields of fine art, design, and animation but also psychology First, this paper puts in order an op art, influenced in fine art and design, and animation using persistence of vision, relating an optical illusion. Second, it analyses the theory of art form using an optical illusion about brightness, saturation, contrast and luminosity of color. Finally, it makes an experiment of standard of perception on students. The study of art form using an optical illusion is another way to represent fine art comparisons and visual image including animation.