• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.984-994
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• 2020

It is reported that about 20% of accidents at nuclear power plants in Korea and abroad are caused by human error. One of the main factors contributing to human error is fatigue, so it is necessary to prevent human errors that may occur when the task is performed in an improper state by grasping the status of the operator in advance. In this study, we propose a method of evaluating operator's fitness-for-duty (FFD) using various parameters including eye movement data, subjective fatigue ratings, and operator's performance. Parameters for evaluating FFD were selected through a literature survey. We performed experiments that test subjects who felt various levels of fatigue monitor information of indicators and diagnose a system malfunction. In order to find meaningful characteristics in measured data consisting of various parameters, hierarchical clustering analysis, an unsupervised machine-learning technique, is used. The characteristics of each cluster were analyzed; fitness-for-duty of each cluster was evaluated. The appropriateness of the number of clusters obtained through clustering analysis was evaluated using both the Elbow and Silhouette methods. Finally, it was statistically shown that the suggested methodology for evaluating FFD does not generate additional fatigue in subjects. Relevance to industry: The methodology for evaluating an operator's fitness for duty in advance is proposed, and it can prevent human errors that might be caused by inappropriate condition in nuclear industries.

• Journal of the Ergonomics Society of Korea
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• v.36 no.4
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• pp.343-353
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• 2017

Objective: This study aims to evaluate the efficiency of two representative subway map design types, namely a diagram type and a geographical type using physiological metrics, performance metrics, and self-reported metrics, which are representative usability metrics. Background: Subway maps need to be designed in order for users to quickly search and recognize subway line information. Although most cities' subway maps currently use the diagram type designed by Henry Beck, New York City's subway map has recently been changed to the subway map type combined with the geographical type designed by Michael Hertz. However, not many studies on its efficiency are found, and the studies that are available mainly depend on questionnaire surveys or take on a subjective behavioral study type based on experts' experiences. In this regard, evaluation through a more objective method is needed. Method: This study employed usability metrics as a method to evaluate the efficiency of information search targeting the diagram type and geographical type subway maps used mostly as subway maps. To this end, physiological metrics obtained through eye tracking, task completion time, representative metric of task performance, and subjective evaluation metrics were used for the suitability evaluation of subway map designs. Results: In the result of gaze movement distance analysis, no significant difference was shown in the two design types in terms of a process finding a departure station from the starting point and a process finding a transfer station between the departure station and arrival station (destination). However, the gaze movement distance in the process finding the arrival station at the departure station was significantly shorter in the geographical type, rather than in the diagram type. The analysis of task completion time showed a result similar to the gaze movement distance analysis result. Task completion time was significantly shorter in the geographical type, rather than in the diagram type, which is in the process finding the arrival station at the departure station. In other information search processes, no significant difference was shown. As a result of subjective evaluation metrics analysis, no significant difference was revealed in the two design types. Conclusion: An analysis on the two representative subway map design types was carried out via the adoption of usability metrics. As a result, although no significant difference was shown in some information search processes, it was revealed that information search was easier in the geographical type overall. Also, it was found that usability metrics can be effectively used to evaluate the design types of subway maps. Application: The study results can be used to set design direction to offer ease in information search on subway lines. The study also can be used as a method to evaluate a subway map's design type.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.724-731
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• 2016

The purpose of this study was to determine what rules or patterns exist when people gaze at a villa savoye, which is probably Le Corbusier's best known building, using eye-movement tracking techniques. Villa savoye was designed, addressing his emblematic "Five Points", such as pilotis, functional roofs, free floor plans, long horizontal windows, and freely-designed facades. This study examined how the villa savoye's facade image is formed in an objective manner. This study selected a total of 56 test subjects, and showed them an image of a villa savoye. Using eye-movement tracking tools, this study recorded where they mostly gazed at when seeing the building. In addition, an experiment was carried out to test the different points of view, relating to visual attention, between the two groups with different levels of knowledge in architecture. To analyze the data, the Gaze Frequency was used as the key indicator. The results showed that the subjects have a higher degree of attention to either the door or window in general than in former studies. The architecture major group showed that they gazed the experiment image more evenly.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.151-154
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• 2010

Purpose: We investigated how the movement of iris and visual axis affects the finite schematic eye Methods: Using the schematic eye with the crystalline lens in the existing forms of the radial GRIN and the spherical GRIN, the iris centre was moved 0.5 mm in nasal direction and visual axis was tilted $5^{\circ}$ in same direction, with the additional degree of 2.5 down to locate the focal point in fovea. This study analyzed performance change of the optical system, designing it same as the real eye. Results: The whole aberration distribution showed a considerable difference in performance in comparison with the real eye; the biggest difference shown at the central field of optical system. The spherical aberration showed the biggest difference, and a peripheral power error and field curvature leaned toward (+) direction in aberration distribution. Conclusions: When designing the schematic eye with the performance similar with that of the real eye by taking into consideration the iris centre and visual axis, the aberration at the center field of optical system in particular should be corrected. Spherical aberration which showed the biggest difference should be corrected in the first place. In addition, a peripheral power error and field curvature that leaned toward (+) direction should be moved toward (-) direction.

• Sleep Medicine and Psychophysiology
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• v.10 no.1
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• pp.52-60
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• 2003

Objectives: Stage 1 sleep provides important information regarding interpretation of nocturnal polysomnography, particularly sleep onset. It is a short transition period from wakeful consciousness to sleep. The lack of prominent sleep events characterizing stage 1 sleep is a major obstacle in automatic sleep stage scoring. In this study, utilization of simultaneous EEG and EOG processing and analyses to detect stage 1 sleep automatically were attempted. Methods: Relative powers of the alpha waves and the theta waves were calculated from spectral estimation. A relative power of alpha waves less than 50% or relative power of theta waves more than 23% was regarded as stage 1 sleep. SEM(slow eye movement) was defined as the duration of both-eye movement ranging from 1.5 to 4 seconds, and was also regarded as stage 1 sleep. If one of these three criteria was met, the epoch was regarded as stage 1 sleep. Results were compared to the manual rating results done by two polysomnography experts. Results: A total of 169 epochs were analyzed. The agreement rate for stage 1 sleep between automatic detection and manual scoring was 79.3% and Cohen’s Kappa was 0.586 (p<0.01). A significant portion (32%) of automatically detected stage 1 sleep included SEM. Conclusion: Generally, digitally-scored sleep staging shows accuracy up to 70%. Considering potential difficulty in stage 1 sleep scoring, accuracy of 79.3% in this study seems to be strong enough. Simultaneous analysis of EOG differentiates this study from previous ones which mainly depended on EEG analysis. The issue of close relationship between SEM and stage 1 sleep raised by Kinnari remains a valid one in this study.

• The Journal of Internal Korean Medicine
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• v.15 no.1
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• pp.176-209
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• 1994

1. The Jung-Sa(正邪) of the Excessive Liver-Symptoms belongs to the eleven symptoms, there are blue face, blue thin fingernail, anger, fancy of larg body, dizziness, eye flame, Bell's palsy, hard swelling pain at braest, side pain going on the belly from the side, side pain and movement at the left side. 2. The Mi-Sa(微邪) of the Excessive Liver-Symptoms belongs to the four symptoms, there are meat in eye, edema in cheek, lack of appetite and diarrhea. 3. The Juk-Sa(賊邪) of the Excessive Liver-Symptoms belongs to the only one symptom, this is nosebleeding. 4. The Hu-Sa(虛邪) of the Excessive Liver-Symptoms belongs to the three symptoms, there are scrotum constraction, strain in belly and constipation. 5. The Sil-Sa(實邪) of the Excessive Liver-Symptoms belongs to the twenty eight symptoms, there are red eye, raised eyes(兩眼上?), spitting blood, sternocostal turgid pain, turgidity in belly, drooping testis, vomiting water acid, sickening, belching, confusion, impatience, frequent forgetfulness, headache, giddness, eye pain, deaf, ringing in the ear, feeling inverse, drying mouth, stuffiness sensation in the chest, chest pain, stuffiness sensation in the belly, bellyache, quadriplegia, spasm of extremities, tremor, alternate spells of fever and chills, high fever and strain in muscle. 6. Those symptoms, Red corner of the eye, red face, swelling on the forehead, stiff-neck and back strong, opisthotonos, constracture of the limbs, vomiting yellow bitter water, speech impediment, epilepsy, depression, strong tongue, different thing in throat, fullness and distention of the gastric region, feeling sick and tenesmus, have no connected with the Excessive Liver-Symptoms(肝實證) 7. The Excessive Liver-Symptoms(肝實證) is connected with the ganjabyoung(肝自病) and Hwa(火) which the pathology is, than because Mock(木) is excessive and Mock-Saeng-Hwa(木生火), the ganjabyoung(肝自病) and Sil-Sa(實邪) are many. 8. There are the sixteen symptoms with the exception of The Excessive Liver-Symptoms(肝實證), because supposed that the scholars in medicine included the union syndroms(合病), the combine syndroms(兼病) and the analysis of symptoms(辨證) in The Analysis of Five Visceral Symptoms. 9. During consideration of the symptoms at the above statements, where are many causes by Gan-Pung(肝風), there is difficult of distinction between the excessive Liver-Symptoms(肝實證) and C.V.A(Cerebral Vascular Attack). Because than NaeKyung(內經) distinguished between the excessive Liver-Symptoms(肝實證) and C.V.A., the future medical specialists connected with the excessive Liver-Symptoms(肝實證) and C.V.A.. 10. An appearance of Sang-Hwa(相火) that the liver possessed is divided into an appearance of Hwa(火), there will be making a study att the more necessary. 11. The cuases of each syndroms are consist of the origins of syndroms, its pathology and the positions where the syndroms appeared, I consider that is the various ways how judge the syndroms except the Five Pathogenic Factors(五邪). 12. If more than study will be achieved in all, the new definition will be standed about the Excessive and Deficient Five Visceral Syndroms(五臟虛實證), I consider this will be the foundation data that study the Oriental Medicine and the important data that is a judgement standard of clininc.

• Journal of Science Education
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• v.37 no.1
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• pp.142-156
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• 2013

The purpose of this study was to analyze observation characteristics through eye movement according to cognitive style. For this, developed observation task that can be shown the difference between wholistic cognitive style group and analytic cognitive style group, measured eye movement of university students who has different cognitive style, as given observation task. It is confirmed the difference between two cognitive style groups by analysing gathered statistics and visualization data. The findings of this study were as follows; First, Compared observation sequence and pattern by cognitive style, analytic cognitive style group is concerned with spider first and moving on surrounding environment, whereas wholistic cognitive style group had not fixed pattern as observing spider itself and surrounding area of spider alternately or looking closely on particular part at first. When observing entire feature and partial feature, wholistic cognitive style group was moving on Fixation from outstanding factor without fixed pattern, analytic cognitive style had certain directivity and repetitive investigation. Second, compared the ratio of observation, analytic cognitive style group gave a large part to spider the very thing, wholistic cognitive style group gave weight to surrounding area of spider, and analytic group shown higher concentration on observing partial feature, wholistic cognitive style group shown higher concentration on observing wholistic feature. Wholistic cognitive style group gave importance to partial features in surrounding area, and wholistic feature of spider than analytic cognitive style group, analytic cognitive style group was focus on partial features of spider than wholistic cognitive style group. Through the result of this study, there are differences of observing time, frequency, object, area, sequence, pattern and ratio from cognitive styles. It is shown the reason why each student has varied outcome, from the difference of information following their cognitive style, and the result of this study help to figure out and give direction to what observation fulfillment is suitable for each student.

• Journal of The Korean Association For Science Education
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• v.33 no.4
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• pp.778-793
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• 2013

The purpose of this study is to analyze observation characteristics through eye movement according to cognitive styles. To do this, we developed observation tasks that show the differences between wholistic cognitive style group and analytic cognitive style group, measured eye movement of university students with different cognitive styles after being given an observation task. The difference between two cognitive style groups is confirmed by analysing gathered statistics and visualization data. The findings of this study are as follows: First, to compare fixation time and frequency, we compared the average value of total time used in the observation task by the wholistic cognitive style group and analytic cognitive style group. The numbers of Fixation (total) and number of Fixations (30s), is based on the fact that the wholistic cognitive style group has more numbers of fixation (Total) and number of fixations (30s) means the wholistic cognitive style group can observe more points or overall features than the analytic cognitive style group, in contrast, the analytic cognitive style group tend to focus on a particular detail, and observe less numbers of points. Second, to compare observation object and area by cognitive style, the outcome of analysing visualization data shows that wholistic cognitive style group observes the surrounding environment of spider and web on a wider area, on the other hand, the analytic cognitive style group observes by focusing on the spider itself. Through the result of this study, there are differences in observation time, frequency, object, area, and ratio from the two cognitive styles. It also shows the reason why each student has varied outcome, from the difference of information following their cognitive styles, and the result of this study helps to figure out and give direction as to what observation fulfillment is more suitable for each student.

• Journal of architectural history
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• v.20 no.1
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• pp.77-93
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• 2011

Across the culture of Western Europe, dichotomy based on the visual sense has evolved. They believed eyes and ears requiring a distance related in recognition, are more developed than any other human senses in human body. Dominant position, as a condition to using a perspective, the eye has been just concentrated in the development of optical sight. But developed a variety of modern media, highlighting the importance of the other perception, it makes dichotomy to the expansion of perception over the single function of visuality. Recently, Guille Deleuze and Merleau-Ponty try to recover the sense of tactility segregated in skin from body keeping eyes for distance. By the result, the activity can be happened by being connected to the body rather than to eye in the space between the subject and object. From the phase of recognition where the human body tries to identify the object in the space considering a time, it will be changed for the subject to the phase of structure vice versa. Visual tactility is to eliminate the distance between subject and object. If the visual tactility is to erase the distance different from the visual in dichotomy, it will be occurred to having a tension and makes new relationship to work trying to move the subjective point of view in object. Like this evidence in analysis of architecture, it can be easy to find the Korean architecture rather than western architecture in terms of emphasizing the time and space. The fact, architecture of Lee Dynasty had been preserved and consisted basic form and style over the centuries makes us assume that visual tactility was considered as well as the visual sense. This study will be intensive in terms of visual and tactile inherent in the subject and how it is being connected to the movement in the space and time.

• Science of Emotion and Sensibility
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• v.21 no.2
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• pp.3-14
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• 2018

For satisfying consumer needs, commercial facilities require a variety of sale-related space expressions and eye-catching product arrangements; space composition can also be a direct marketing strategy. The human eye is the sensory organ that acquires the largest amount of information, and an analysis of visual information helps in understanding visual relations between . However, the existing studies are mostly focused on analysis of still frames in experimental images, and there is a lack of studies analyzing gaze information based on mobile images of commercial spaces. Therefore, this study analyzed emotional responses through gaze information of space users in reality using a video of a movement route through a commercial facility. The analysis targeted straight sections of the moving route; based on the data acquired, sectional characteristics of five gaze intensity ranges were examined. As a result, section A, the starting point of the route, had a low gaze intensity, while section B had the highest gaze intensity. This indicates that, starting in section B, the subjects explored the space in a stable way and needed time to adapt to the experimental video. In relation to space characteristics of the gaze-concentrated area, display formats of the right stores in 4 of 6 sections received greater attention. The gaze of consumers was mostly focused on props, and big gaze information was revealed in showcase display formats of the stores. In conclusion, this analysis method can provide highly useful direct design data about merchandise display and merchandise component arrangement based on consumer visual preference.