• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.55-65
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• 2007

This paper sought to investigate pupil size variability, pupil size parameters in terms of time domain and frequency domain, the autonomic activity change induced by posture change, degree of sleepiness and cognitive task (math task). With a specially designed pupil image acquisition system in the dark room, these three kinds of experiments were performed to induce a dominant state of sympathetic or parasympathetic activation. Electrocardiogram and pupil size were measured in all the experiments. Based on three experiments, we calculated heart rate variability. In the pupil size analysis, we calculated the mean and standard deviation of pupil size (in time domain), and proposed several frequency bands that exhibit different autonomic activation between different sessions. The results indicate that in terms of heart rate variability, posture change exhibited significant differences but not between sleepiness level, or between cognitive task. Pupil sizes differed only during the postures. And we found some frequency bands that correlated with autonomic activation in each experiment. While heart rate variability reflects posture change that need cardiac control, pupil size variability reflects not only posture induced autonomic activation but sleepiness and cognitive load, which is processed in the brain, in time and frequency domain parameter.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.187-198
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• 1995

The physiological change of eyes while viewing 3D TV was investigated. The change of pupil size was used as the measure of evaluation. The results are as follows: (1) The pupil size decreases after viewing 3D images. (2) The indoor illumination has a significant effect on the pupil size in both 2D and 3D cases. (3) Less change of pupil size were observed under the indoor illumination. Thus, if we only focus on the visual load on the eye, for viewing 3D images, it will be better to use indoor illumination.

• Korean Institute of Interior Design Journal
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• v.27 no.3
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• pp.136-144
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• 2018

The purpose of this study is to examined the unconscious response of the pupil in the observation toward the image in the eye-tracking experiments that target on a large complex cultural space. Twenty-five men participated in this experiment and the observation data were analyzed in seconds per minute on watching time. It could examine the unconscious response of information searching in the change of pupil size in the process of observing the space. The results could be defined as following several points. First, it was possible to outline the unconscious response characteristics of pupil by analyzing sudden changes in pupil size as total, cumulative, and individual. The response characteristics using frequency and time can be utilized as the analytical method to examine the degree of interest of spatial components according to the purpose of analysis in the future. Second, according to the over ${\pm}5%$ of cumulative variation rate on the pupil size change, during in the 60 seconds, the continuous pupil dilation was used 25.2 seconds in 8.8 rounds and the pupil reduction was used 18.0 seconds in 7.0 rounds. Third, when the variation rate of ${\pm}5%$ or more was regarded as the sudden changes on pupil size by individual variation, the pupil dilation was 7.2 rounds of 8.6 seconds and pupil reduction was 6.0 seconds in 5.0 rounds. This means that the pupil increases 9.3% in one expansion and decreases -8.5% in the reduction process. As regarding pupil changes as cumulative rate, it appeared high change rate on pupil reduction but it became higher on pupil dilation in individual.

• Korean Institute of Interior Design Journal
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• v.27 no.1
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• pp.29-38
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• 2018

This research is to analyze the change of pupil size in gender through the eye-tracking experiment in large complex cultural space. It is meaningful that figured out the common characteristics and differences from gender observation characteristics. Through this research, the analyzed results of the observation time measurement that appeared from the fixation and saccades pupil indicator able to define as follows. Firstly, it was suggested that there were differences between each gender and participants through extract pupil size that can be the standard examples for the case from male and female and the process of extracting the relative pupil size change on the hourly range. From the specific time range, it was possible to indicate bending characteristics and reversal phenomena of Fixation and Saccades. Second, the result was found equally from both male and female group that the rapid increment of pupil size at initial time range immediately after the eye-tracking experiment has been initiated. This can be considered to actively accepting the stress given by the subject through the extended pupil after 10 seconds that compare to indicated very low pupil size between 0 to 10 seconds after starting the experiment. Third, meanwhile 0 to 10 seconds after initial observation are the time of sudden change in the pupil size, therefore these time range data cannot be regarded as observed in the appropriate condition. Thus, it able to define the highest times of emotional processing for male as 10 to 80 seconds, and for female as 10 to 70 seconds. There was no definition of the time range data for observation experiment from previous research, this data can be considered to stable time to observation through the pupil extension. Therefore, it is possible to set suitable time of observation experiment to be around 70 to 80 seconds exclude initial experiment time.

• Science of Emotion and Sensibility
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• v.20 no.3
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• pp.39-48
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• 2017

In order to verify the effectiveness of marketing in the basketball stadium, this study measured and analyzed the gaze frequency and interest when the pupil was expanded by using the eye-tracking technology among various neuro marketing techniques of marketing. To analyze the section where the pupil size get expanded, interval of pupil size was higher than 2.275% (2 sigma data) and higher than 0.135% high (3 sigma data). Overall the valid data was analyzed by inflection points according to gaze frequency. We also analyzed the correlation between overall valid data and the ranges where the pupil size was significantly increased. The result showed that the correlation between overall valid data and pupil size 2 sigma data showed the highest correlation with 0.805. The pupil size 2 sigma data and pupil size 3 sigma data showed a correlation with 0.781, overall the valid data and pupil size 2 sigma data showed a correlation with 0.683. Therefore, it is concluded that, the section where the pupil size was expanded and the section at which gaze frequency is higher in the eye-tracking data were similar. However, the correlation between data of pupil size is determined to be significantly expanded and overall the valid data is decreased.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.1-7
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• 2007

To determine the effect of posture change on autonomic activity and to investigate valid parameters to reflex the autonomic activity from time-series pupil size data, a posture-related experiment was performed with 15 subjects, which involved measuring their electrocardiograms and pupil sizes. The experimental procedure consisted of three-sequence postures-supine, sitting and upright-for 5 minutes each, with rest sessions between postures. The subjects were notified of the entire experimental procedure. The parameters of the subjects' heart rate variability showed significant differences between the postures (heart rate: 63-70-80 beat, normalized low frequency power: 28-50-75, normalized high frequency power: 72-49-25 and ratio: 0.5-1.2-4.4 in supine-sitting-upright position respectively) as did the parameters of their mean pupil sizes (41300-53900-53700 pixels respectively) and the major frequencies (the third trend: 0.23-0.2-0.18 Hz respectively) of their pupil size variability according to changes in their autonomic activities induced by posture change. The experiment thus proved that posture change affects autonomic activity and that such activity can be estimated by the parameters of pupil size as similar as heart rate variability.

• Journal of the Ergonomics Society of Korea
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• v.14 no.2
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• pp.25-32
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• 1995

The physiological change of eyes while viewing 3D TV was investigated. The change of pupil size was used as the measure of evaluation. The results are as follows : (1) The pupil size decreases after viewing 2D and 3D image and the the tendency is more critical with 3D images. (2) The indoor illumination has a significant effect on the pupil size in both 2D and 3D cases. (3) Less chage of pupil size were observed under the indoor illumination. Thus, if we only focus on the visual load on the eye, for viewing 3D image, it will be better to use indoor illumination.

• Journal of Korean Ophthalmic Optics Society
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• v.1 no.2
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• pp.7-11
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• 1996

The size of pupil with pupillary light reflex is determined by the amount of a luminance. and it is dependent with the distribution function of the retinal illuminance which is the amount of transmittance for the external light due to the size of pupil, and the detector of cone and rod due to the amount of the luminance. The change of the pupil size with the luminance can be expressed with the mathematical model $$y(x)={\alpha}+{\beta}\frac{1}{1+{e}{x}{p}(x-x_0)/{\theta}}$$ where ${\alpha}$ is the size of the pupil diameter in a maximum value of the luminance, ${\beta}$ is the deviation of the pupil's diameter between maximum and minimum, ${\theta}$ is the parameter showed the degree of a sensitivity. Comparing with the experimental value of P.Moon et al, We known that the equation of the model is very compatible.

• Science of Emotion and Sensibility
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• v.21 no.2
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• pp.15-28
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• 2018

The purpose of this study was to conduct eye-tracking experiments to target large spaces and to analyze the characteristics of pupil gaze by gender. By analyzing the change of pupil size in the eye-tracking experiment, we suggest a template for objective and scientific analyses of gender observation data. Additionally, based on the difference between gender and time to pupil size change, we noted the characteristic of time that gather the visual perception data information and showed that females attend to interesting elements of visual information one to two seconds slower than males. In the initial "$1sec{\rightarrow}2sec$", the pupil size has been increased in leap condition of male and in fixed condition of female. In addition, if condition limits to fixed observation to view the change rates on gender then the pupil size of female was larger than male before 9 seconds, while male's pupil size was larger after 9 seconds. This indicates that females obtain visual information through a relatively larger pupil size during the first 1-8 seconds after stimulus presentation, while males acquire it between 10-15 seconds after input. However, based on the result that the pupil size of female was larger than male on the change of observation time, the pupil size movement on female was energized to watch more interest element after a certain period of time.

• Science of Emotion and Sensibility
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• v.20 no.1
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• pp.31-40
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• 2017

The present study used one of research techniques which is eye gaze tracking for neuromarketing. When pupil's size of men dilated over than three sigma (0.135%), the interest and eye movement in observation were measured. According to statistical analysis of previous studies, three sigma range is meaningful therefore sigma range was used as operational definition because 'pupil dilatation' is difficult to be define in eye gaze tracking data. Pictures of basketball games were selected as visual stimuli and 90% effective ratio of total 7,200 data were calculated. Thus, 29 of 34 participants were used for test. Pupil's size was calculated by applying pupil's width and height into a formular; [Pupil's size = Pupil width/2${\times}$Pupil height/$2{\times}{\pi}$]. In conclusion, billboard utilized for sports marketing had meaningless effects because gaze frequency to basketball player and surrounding environment was higher than that to billboard when participantsas game spectators diltaed their pupil's size over than three sigma. Thus, it was required using new marketing strategies like neuromarketing to increase utility through the present study.