• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.49-59
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• 2012

Although 3D stereoscopic movies had been paid attention to a few times since the 1900's, the interest had not been last. Most researchers pointed out the reason came from human factors because the early in the 3D technology growth had to develop technological possibility to realize 3D videos and ignore the importance viewers' perspective. In the 2D video research, many studies have explored the factors which make people got immersed or involved and felt visual fatigue, but they have not been the main issues in the 3D research until now. The present research believes human factor issue is one of the most important parts to accelerate 3D industry and thus, we try to make reliable and valid assessments to evaluate 3D video which are perceived characteristics, impression, and presence.

• Journal of the Korean Society of Systems Engineering
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• v.4 no.1
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• pp.35-43
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• 2008

Generally, in analysis of reliability of Design and Development Phase, reliability of electrical components is analyzed based on standards such as MIL-HDBK-217F, Bellcore Issue 4,5,6 by analyzing stress of architectural side (Power, Voltage, Current and quality level of components) of weapon system and stress of operational side (operational environment, operational temperature, Operational Profile). But the reliability of mechanical components is analyzed based on the data book of failure history of mechanical parts called NPRD-95(Nonelectronic Parts Reliability Data-95) without any analysis of above stress. However, even if it's the same mechanical parts, it might have different failure rate(fatigue, wear, corrosion) during operation depending on how weary(stress : pressure, vibration, temperature during operation) the parts are. Therefore, analyzing reliability using just data book can cause big difference in reliability instead of analyzing based upon stressfulness that parts might have, operational concept, and other various factors. Thus, This paper will guide the way of predicting reliability by organizing ways of predicting reliability for system organization and adopt ing NSWC-98/LE1(Naval Surface Warfare Center-98/LE1) for mechanical components.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.426-438
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• 2020

This study aimed to identify the components of the nurses' exposure experiences and clarify the semantic structure of nurses by analyzing the participants' experiences of exposure to radiation. The participants in this study were nine nurses who worked for at least six months in the operating room of a City General Hospital. The data were collected using in-depth interviews and analyzed using the phenomenological method by Giorgi's (2004). As a result, six components were derived: "worrying about the disease by repeated radiation exposures", "exhausting physically and mentally," "trying to protect themselves against radiation exposure", "feeling of internal confusion and conflict", "demanding improvement of work environment", and "accepting and adapting to reality". In conclusion, nurses participating in radiation exposure surgery are concerned about the possibility of disease, experience physical and mental fatigue, and then consider changing their occupation. On the other hand, they try to accept and adapt to reality by considering the possibility of a job change or trying to protect themselves from the harsh environment. To develop a radiologically safe environment, systematic and effective resolutions must be secured at the organizational level.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.119-124
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• 2008

Many automobile assembly workers often do several cycles of tasks continuously, i.e., without breaks, to get a longer break. This is not recommended since the dose of fatigue increases exponetially with time and it takes much longer time to recover. In this study, a laboratory experiment was conducted to investigate the effect of work/rest schedules on workload of a repetitive upper-limb task. Eleven male subjects participated in the experiment, in which simulated screw driving tasks were carried out repetitively with 3 different work/rest schedules: standard breaks(1 cycle of work at a time, 60 20-s breaks), medium breaks(5 cycles of work at a time, 12 100-s breaks), and long breaks(10 cycles of work at a time, 6 200-s breaks). The result showed that medium- and long-breaks schedules significantly increased the level of perceived discomfort and %HRR as compared to the standard-break schedule. The subjects' preference was not statistically different among work/rest schedules, which might be caused from the absolutely low level of workload of the experimental tasks. From the results, it is recommended to have frequent and shorter breaks rather than infrequent and longer breaks to decrease the level of physical workload. A more expanded studies, however, should be carried out to provide more practical safety guidelines on the work practice of continuous working without breaks among automobile assembly workers.

• Journal of the Korean Institute of Landscape Architecture
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• v.14 no.1
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• pp.45-60
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• 1986

The purpose of the present studies is to establish more rational and practical planning theory for trails of gradient. The results drawn from this research work are as follow ; Mean angle according to topography of Jiga road is $3^{\circ}$33'in low part, $8^{\circ}$17'in middle park and $12^{\circ}$48'in high part. Here, we can find that the highest gradient of Jige roacl is $12^{\circ}$48, Which is showing the fact that jigs road is the most function road when we compare other roads. The regression coefficient between potential model pattern and calculuted model pattern is 0.8 withinTEX>$ 0~<5^{\circ}$, 0.5 within$ 6~10^{\circ}$, and 0.53 within $11~16^{\circ}$. The linear of these model pattern is lower in R & L value, and lager in S & A value according to be steeping gradient. It is thought that these fact are closely related with between human fatigue and R.S.A.L value. Accordingly, when we plan the trails of the gradient in city park, the from of trails is right to mix straight line with curve line within $0~5^{\circ}$, and sine wave close curve line within $6~10 ^{\circ}$, $l1~16^{\circ}$. But, in fact, It is absurd that potential model pattern is applied to the city park in park of corner, widely road and facilities. Therefore, It is thought that the study of this problems will be proceeded in the future. I can reduce the following equation in relation R & S by gradient ; 22 log (R-6.0)=47.96-$\delta$

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2054-2060
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• 2016

As the aging society is accelerated, the population with dementia grows significantly faster. Because there is no complete cure of dementia, it is of great importance to detect the disease at a very early stage and prevent its fast aggravation through evaluation of MCI(Mild Cognitive Impairment) which happens before dementia. The current assessment of MCI conducts only in the form of hand-written data and by 1:1 face to face communication between the subjects and the examiners. Due to this, both examiners' fatigue rate and evaluation error rate increase. Further, there are some limitations in utilizing and analyzing data collected. Against the problems, therefore, there is a need to develop a computerized system by which MCI is assessed, and the results are saved and analyzed. This paper presents the development of such a system enabling MCI evaluation, its related data collection and analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3579-3586
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• 2015

In this study, EEG, HRV, and Vibra image were compared and analyzed in the environmental test room due to stimulation of aroma and color temperature. The condition of the environmental test room was in temperature $25[^{\circ}C]$, relative humidity 50[RH%], air current speed 0.02[m/s] and illuminance 1000[lux] with setting up different sensory stimulation condition which are before exposure, single-sensory stimulation of Jasmine scent, single-sensory stimulation of RED color lighting, and multi-sensory stimulation of Jasmine scent and RED color lighting. The result of this study, at multi-sensory stimulation of Jasmine scent and RED color lighting, relative $S{\alpha}$ wave, SEF50, $SMR/{\theta}$ and SDNN were revitalized, and both sides ${\alpha}$ wave asymmetry index, stress index, fatigue degree, and HRT were decreased. Also, Viba image of tension/anxiety and stress were declined. Therefore multi-sensory stimulation of Jasmine scent and RED color lighting effects to increase the Neuro-energy like amenity, productivity of work efficiency, and concentration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.1-6
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• 2013

Three Surface cracks are among the more common flaws in aircraft and pressure vessel components. Accurate stress intensity analyses and crack growth rate data of surface-cracked components are needed for reliable prediction of their fatigue life and fracture strengths. Three Dimensional finite element method (FEM) was used to obtain the stress intensity factor for surface cracks existing in structures. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Nodes are generated by bucket method, and quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. To examine accuracy and efficiency of the present system, the stress intensity factor for a semi-elliptical surface crack in cylindrical structures subjected to pressure is calculated. Analysis results by present system showed good agreement with those by ASME equation and Raju-Newman's equation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.57-62
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• 2013

Because there is no suspension and differential devices at cart body, the deformation of the frame happened during kart driving affects the driving performance caused by the elastic deformation and the fatigue life of kart frame resulted from the permanent deformation. The dynamic behavior of kart caused by the torsional deformation during circular driving is the important factor of these two kinds of deformations. In order to analyze the dynamic behavior of kart at this curved section, GPS is used to trace the track of kart and the torsional stress at kart-frame has been measured with real time. The mechanical properties of kart-frames for leisure and racing are investigated through material property analysis and tensile test. Torsional stress concentration and frame distortion are investigated through stress analysis on frame on the basis of study result. The real karts for leisure and racing kart are also tested in each driving condition by using the driving analysis equipment. The driving behavior of kart at the curved section are investigated through this test. As the phenomenon of load movement due to centrifugal force at car is happened during circular driving, the torsional stress occurs at cart steel frame.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.1
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• pp.1-8
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• 2019

Motion sickness is dizziness symptom that occurs when movement detected in the vestibular organ and movement detected visually are collide with each other. When dizziness occurs, user complains of symptoms such as nausea and vomiting, sense of direction abnormality, and fatigue. These causes of dizziness are various and difficult to differentiate and treat the symptoms. Especially, among the types of dizziness VIMS(Visually Induced Motion Sickness) is a problem to solve in developing VR industry. These VIMS analysis can be done through user's vital signs measurement and feature analysis, and EEG characteristics analysis. Therefore, this paper is discuss the minimization of motion sickness caused by visual information based on EEG signal and present research trends related to it.