• Korean Journal of Cognitive Science
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• v.6 no.1
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• pp.47-71
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• 1995

A psychological disturbance caused by letters in double image was termed as'letter sickness'.The effects of stimulus exposure time and letter familiarity on the letter sickness were measured to test a hypothesis that disturbances in eye movement and recognition stages is the cause of letter sickness.Letter sickness incteased significantly as stimulus exposure time lengthened from 50ms,100ms,to 3000ms.It was also significantly higher with familiar Hangul letters as compared with less familiar foreign letters and meaningless words as compared with meaningful words,respectively.These experimental findings imply that letter sickness is caused by the failure of adjusting eye movements to dismiss the double images.that the more familiar the letters.the more strongly the letter-identification process is commotted,resulting in the increased effect of disturbance from double image.and that the disturbance effect of double image is amplified when it is hard to extract the meaning from familiar letters.An experiment where subjects were made to learn Braille-like symbols consisting of 6 dots to test the hypothesis that the stronger the tendency to process the meaning of a symbol,the stronger becomes letter sickness due to double image,also showed that letter sickness significantly increased as a function of learning.

• Safety and Health at Work
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• v.12 no.4
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• pp.536-543
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• 2021

Background: Sickness absenteeism is an area of concern in nursing and is more concerning given the recent impacts of the COVID-19 pandemic on healthcare. This study is one of two meta-analyses that examined sickness absenteeism in nursing. In this study, we examined demographic, lifestyle, and physical health predictors. Methods: We reviewed five databases (CINAHL, ProQuest Allied, ProQuest database theses, PsycINFO, and PubMed) for our search. We registered the systematic review (CRD de-identified) and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Additionally, we used the Population/Intervention/Comparison/Outcome Tool to improve our searches. Results: Following quality testing, 17 articles were used for quantitative synthesis. Female employees were at higher risks of sickness absenteeism than their male counterparts (OR = 1.73; 95% CI: 1.33-2.25). Nursing staff who rated their health as poor had a greater likelihood of experiencing sickness absence (OR = 1.38; 95% CI: 1.19-1.60). Also, previous sick leave predicted future leaves (OR = 3.35; 95% CI: 1.37-8.19). Moreover, experiencing musculoskeletal pain (OR = 2.41 95% CI: 1.77-3.27) increased the likelihood of sickness absence with greater odds when it is a back pain (OR = 3.05; 95% CI: 1.66-5.62). Increased age, physical activity, and sleep were not associated with sick leave. Conclusion: Several variables were statistically associated with the occurrence of sickness absenteeism. One primary concern is the limited research in this area despite alarming rates of sick leave in healthcare. More research is required to identify predictors of sickness absence, and thereby, implement preventative measures.

• Health Policy and Management
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• v.29 no.2
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• pp.112-129
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• 2019

Currently, the South Korean Government does not provide sickness benefits from the National Health Insurance, which is different from most other Organization for Economic Cooperation and Development countries. The sickness benefit guarantees a part of lost income due to injuries or diseases. The purpose of this study is to propose a sickness benefit scheme for South Korea. To this end, we compare health care systems, sickness benefit schemes, and delivery systems of those in Germany, Japan, and Sweden, focusing on the seven categories: management authority, object, level of payment, duration of payment, qualification requirements, connection with paid sick leave of workplace, and financial resources, and as to delivery system, the six categories: the number of procedures, transferring document between institutions, whether or not utilizing electronic reporting system, applicant, and administrative convenience. Based on the implications derived from the case study, we propose the sickness benefit scheme and its delivery pathway and other details for South Korea. This study is first to propose the sickness benefit for health insurance in Korea with its level of details. More studies should follow with case studies of other countries, as well as productive debates to build a feasible and sustainable sickness benefit system in South Korea.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.603-611
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• 2022

As the era of metaverse approaches, there are challenges that need to be solved. Among them, 'cyber motion sickness' is a representative problem from 2016;when VR technology began to attract attention. According to the theory of sensory conflict, motion sickness is caused when the perceived direction of motion information and the expected value are not the same. The paper was written to theoretically explore the relationship between brain cognition and cyber motion sickness, and to prove the effect of user immersion on motion sickness symptoms based on this. Through the SSQ experiment, it was found that the rotation value of the camera aggravates the symptoms of cyber motion sickness and can alleviate cyber motion sickness by increasing the immersion of the game by giving the viewer visual and shift missions to solve. This study was conducted to solve the problem of cyber motion sickness during the process of developing the VR rhythm game "beatale", and it is expected to be the basis for improving cyber motion sickness not only in the development of the project but also in the production of VR contents in the future.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.2
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• pp.430-436
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• 2014

Excessive motion of the ship in rough sea would affect body's fatigue, cognitive ability, motion sickness, and the proficiency of activity. Among them symptoms of motion sickness are similar to fatigue and nausea. Motion sickness causes sudden degradations of ability to perform tasks in physical and psychological aspects, and causes delays or failure in mental activity, and also takes a significant amount of time recovering. In this study, questionnaire for MSI(Motion Sickness Incidence) survey was taken for the students aboard the training ship of Kaya to the open sea far from land. Motion sickness analysis was performed as comparing the results of questionnaire based on sea state, incident angle, economical speed, and location in the ship.

• Science of Emotion and Sensibility
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• v.4 no.1
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• pp.23-31
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• 2001

Psychological and physiological effects from simulator sickness could be an important bias factor for sensibility evaluation. The present experiment investigated the effects of simulator sickness on sensibility evaluation in the controlled condition of driving a car for 60 minutes on a constant speed (60km/h) in graphic simulator. The simulator sickness was measured and analysed for every five minutes using their subjective evaluation and physiological signals. Results of the subjective evaluation showed that there was significant difference between rest and driving condition at 10 minutes from the start of driving, and the level of difference was increased linearly with time. The analysis on central and autonomic nervous systems showed the significant difference between rest and driving conditions after 5 minutes from the start of the driving on the parameters $\alpha$/total and $\beta$/total, and increased level of sympathetic nervous system. But there was no significant difference between different time conditions. The results indicates that physiological changes from simulator sickness can be a bias factor in objective evaluation of human sensibility which also, uses physiological signals. That is, the changes on the parameter $\alpha$/total and $\beta$/total, and on activation level of sympathetic nervous system from simulator sickness can be a bias factor for evaluation of the level of pleasantness and tension. Therefore the effort on improving the analysis by minimizing or eliminating the bias factors should be done for better and accurate sensibility evaluation in simulator environments.

• Korean Journal of Community Nutrition
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• v.8 no.2
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• pp.138-148
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• 2003

Morning sickness during pregnancy is a very common functional problem with different kinds of symptom, but little data are available concerning the nutrition intervention program fur pregnant women in local area. A total of 152 pregnant women who had experienced morning sickness were surveyed to investigate the relationships between morning sickness, nutrient intakes and pregnancy outcome. The results showed that prevalent symptoms were nausea (68.4%), heartburn (59.2%), morning sickness (48.7%), vomiting (42.1%), and constipation (44.7%). The onset of the symptom occurred during the first 3 months (9.3 $\pm$ 2.3 weeks) ; 21.1% of the subjects was experienced two symptom at the same time. This significantly correlated with vomiting (p < 0.01), nausea (p < 0.001), morning sickness (p < 0.001), and heartburn (p < 0.01) with pregnancy weight. There were also correlations between the four symptoms and nutrient intakes. Mean birth weight of 21 newborns was 3.06 $\pm$ 0.42 kg, and the one and five minutes of Apgar scores were 7.74 $\pm$ 0.99 and 8.84 $\pm$ 0.69, respectively. There were negative correlations between vomiting and pregnancy outcomes (p < 0.05). Our data support that morning sickness, especially vomiting during pregnancy is associated with Apgar score and body weight of newborn. (Korean J Community Nutrition 8(2) : 138~148, 2003)

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2531-2546
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• 2021

For several years, virtual reality (VR) and augmented reality (AR) technologies have been improving. However, some hurdles remain that slow down the distribution of VR and AR devices, such as head-mounted display (HMD), and related consumer content. One issue is VR motion sickness, which has been experienced by users using 360 degree VR content via HMD. This paper discusses the related international standardization work that classifies the factors causing VR sickness, and proposes the process for VR sickness level evaluation. Among the factors causing VR sickness, many research institutes regard minimizing MTP (Motion-to-Photon) latency as the key enabler to mitigate VR sickness. Thus, this paper introduces research trends of MTP latency measurement and MTP latency mitigation. This paper categorizes the research on MTP latency measurement into 2 categories of hardware-based approach and software code-level approach. The 2 approaches have different pros and cons depending on use-case, purpose, and architecture of each multimedia system. The pros and cons are addressed in this paper. Additionally, the research on mitigating MTP latency with diverse strategies such as proactive computing, caching, and edge server technology is explained, and compared to conventional technologies, shows improved performance.

• Science of Emotion and Sensibility
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• v.23 no.3
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• pp.79-90
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• 2020

The inconsistency in different sensory information causes virtual reality (VR) sickness. This research verifies whether the consistent sensory information reduces VR sickness within treadmill-based virtual reality. Furthermore, we examined the inconsistency between the visually perceived walking speed by optical flow in VR and the physically perceived walking speed in treadmill walking on VR sickness. In Experiment 1, participants reported VR sickness levels while experiencing an increase in the virtual reality. We compared the VR sickness level reported on the standing still condition with that on the treadmill-walking condition. Based on our results, less VR sickness and more sense of presence and immersion were reported on the treadmill-walking condition than on the standing still condition. In Experiment 2 and Experiment 3, the effect of inconsistency between perceived visual speed and perceived walking speed on VR sickness was examined. Interestingly, participants reported less sickness when the perceived visual speed was faster than the perceived walking speed, compared to when the sense of speed was consistent. These results imply that allowing participants to walk on a treadmill while experiencing virtual reality reduces VR sickness. Hence, the perceived visual-walking speed consistency is not necessarily required to reduce VR sickness.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.485-491
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• 2014

In this paper, it is proposed that the effects of simulator sickness due to scene movement in ship handling simulator can be measured by using center of pressure (COP) and a simulator sickness questionnaire (SSQ). For experiments of simulator sickness, twelve participants are exposed to scenes movement from ship handling simulator according to three steps of sea states. During experiments, COPs for subjects are measured by force plate. After exposure to scenes movement, subjects describe their sickness symptoms by answering the SSQ. Throughput analysing the results of scene movement, SSQ, and COP, the relation between the simulator sickness and COP is investigated. It is suggested that formulations for SSQ score and COP with respect to sea state are obtained by the curve fitting technique, and the longitudinal COP can be used for measuring the simulator sickness.