• Science of Emotion and Sensibility
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• v.22 no.3
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• pp.3-20
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• 2019

With advancements in technology of virtual reality, it is used for various purposes in many fields such as medical care and healthcare, but as the same time there are also increasing reports of nausea, eye fatigue, dizziness, and headache from users. These symptoms of motion sickness are referred to as cybersickness, and various researches are under way to solve the cybersickness problem because it can cause inconvenience to the user and cause adverse effects such as discomfort or stress. However, there is no official standard for the causes and solutions of cybersickness at present. This is also related to the absence of tools to quantitatively measure the cybersickness. In order to overcome these limitations, this study proposed quantitative and objective cybersickness evaluation method. We measured 128-channel EEG waves from ten participants experiencing visually stimulated virtual reality. We calculated the relative power of delta and alpha in 11 regions (left, middle, right frontal, parietal, occipital and left, right temporal lobe). Multiple regression models were obtained in a stepwise manner with the motion sickness susceptibility questionnaire (MSSQ) scores indicating the susceptibility of the subject to the motion sickness. A multiple regression model with the highest under the area ROC curve (AUC) was derived. In the multiple regression model derived from this study, it was possible to distinguish cybersickness by accuracy of 95.1% with 11 explanatory variables (P_D.MF, P_D.LP, P_D.MP, P_D.RP, P_D.MO, P_A.LF, P_A.MF, P_A.RF, P_A.LP, P_A.RP, P_A.MO). In summary, in this study, objective response to cybersickness was confirmed through 128 channels of EEG. The analysis results showed that there was a clearly distinguished reaction at a specific part of the brain. Using the results and analytical methods of this study, it is expected that it will be useful for the future studies related to the cybersickness.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.255-255
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• 2017

본 연구에서는 고속으로 활주하는 선박의 승선감 향상 및 운항성능 특성 연구를 위해 30ton급 세관감시정의 측정위치에 따른 멀미도 해석을 수행하였다. 특히, 관공선내의 선원들은 유사시에 신속 정확한 판단이 요구되므로 측정위치에 따른 멀미도의 영향에 대한 연구가 필요할 것으로 판단하였다. 멀미도 평가는 ISO 2631-3(1985)을 기준으로 하였다. 평가 기준은 30분, 2시간, 8시간 이후 성인 100명 중 10명이 멀미를 한다는 국제표준 지표이며 조우주파수와 수직가속도 성분으로 나타난다. 멀미도 해석은 Maxsurf Motion 모듈을 이용하였다. 30ton급 세관감시정은 고속활주형 선박의 특성을 갖기 때문에 선속에 따른 트림변화를 고려하였다. 입사각은 선체 전 방향에서의 영향을 고려한 범위로 선정하였다. 선속의 경우 선박 운용상태(정박, 저속, 고속)을 고려하여 적용하였다. 측정위치의 경우 선원들의 주 활동 구역을 고려하여 선정하였다. 해석결과 멀미도의 영향은 30knot, $180^{\circ}$의 경우에 가장 크게 분석되었다.

• Journal of KIISE
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• v.45 no.3
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• pp.251-279
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• 2018

Users can experience cybersickness when interacting with virtual reality (VR). The symptoms of cybersickness are similar to those of motion sickness which include eye fatigue, disorientation, and nausea. Despite the longstanding interest of user's discomfort, inconsistent results have been drawn on the underlying mechanisms and solutions of cybersickness. In this study, we propose an integrated view of cybersickness connecting causes of the symptoms, human perception model, and measurements of cybersickness. Cybersickness-related factors of previous research are reorganized into content, hardware, and human factors as well as analyzed in terms of VR fidelity. Also, pros and cons that measure the degree of cybersickness are discussed.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.184-193
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• 2017

This work shows how to create an algorithm and implementation for motion and image matching between a vehicle simulator and Unity 3D based virtual object. The motion information of the virtual vehicle is transmitted to the real simulator via a RS232 communication protocol, and the motion is controlled based on the inverse kinematics solution of the platform adopting rotary-type six actuators driving system. Wash-out filters to implement the effective motion of the motion platform are adopted, and thereby reduce the dizziness and increase the realistic sense of motion. Furthermore, the simulator system is successfully designed aiming to reducing size and cost with adaptation of rotary-type six actuators, real driving environment via VR (Virtual Reality), and control schemes which employ a synchronization between 6 motors and 3rd order motion profiles. By providing relatively big sense of motion particularly in impact and straight motions mainly causing simulator sickness, dizziness is remarkably reduced, thereby enhancing the sense of realistic motion.

• Journal of Navigation and Port Research
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• v.32 no.5
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• pp.333-339
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• 2008

When a vessel is underway in a heavy weather, passengers and crew suffer from seasickness caused by ship motions such as pitch, heave or roll, or all combined Sickness induces drowsiness, dizziness, headache, stomachache etc, in extreme conditions, they are met with a serious trouble which is physiologically unrecoverable. It results in weakening of spiritual activities or making errors from decrease of motivation, dropping off skills, poor recognition and poor judgement. In this paper, it was examined the international standards concerning the occurrence of sickness and the execution of works, also evaluated the boarding comfort by conducting several times of questionnaire on cadets boarding on the training ship HANBADA As a result, it was confirmed that the main factor of occurring the sickness was the vertical acceleration and the level was more than 0.2g. Also, it was presented the way how to reduce the sickness by changing the speed and/or course in relation to the encounter period.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.823-827
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• 2001

인체에 영향을 미치는 진동을 분류하는데 가장 중요한 기준은 주파수이다. ISO의 인체진동관련 규격에서는 인체에 영향을 미치는 거동을 저주파수 운동(0.63Hz이하)과 진동(1~80Hz)으로 나누고 있다［1］. ISO 2631에서는 주파수별로 인체에 미치는 영향을 그림1과 같이 가중치로 정의하여 제시하고 있다. 저주파수 영역의 운동은 외부 거동(주로 수평방향)에 대하여 자세를 유지하기 위해 힘Tm게 되므로 물리적인 피로감을 줄 뿐만 아니라 'Motion sickness'란 증상을 유발한다.(중략)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.9
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• pp.905-912
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• 2008

Notion sickness is well known to be caused by long time exposure to the very low frequency motion in the multiple axes of human body Since the vestibular system for the perception of low frequency motion is located in the head, accurate measurement of 6 degree of freedom head motion is of great importance. In this study, the measurement system consisting of a safety helmet and 9 translational accelerometers was constructed for the estimation of 3 translational and 3 rotational motions of human head. Since estimation errors of 3 rotational components can be significantly magnified even by small offset of the sensitivity axis from the geometric center of an accelerometer, accurate measurement of sensitivity axis must be preceded. The method for accurate estimation of the offset was proposed, and the effect of offset on the estimation of angular acceleration was investigated.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.1
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• pp.113-123
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• 2017

Virtual reality technology is recognized as a next-generation technology and can create realistic environments like the real world and reproduce sensory experiences. And it is a cutting-edge technology that allows humans to experience the same real-world experience in a virtual world by computing the five senses with computers. Also Virtual reality is a technology that has the advantage of experiencing reality in cyberspace and is applied to content such as movies and games. However, many users who use virtual reality can feel cybersickness. And it especially in virtual reality games. This is an important issue for the virtual reality game industry to be resolved. Main symptoms of cyberscickness include dizziness, headache, and vomiting. Existing motion sickness and symptoms are similar, but the cause of cybersickness is different from traditional sickness. Therefore, this study uses virtual reality games and data from various organizations to determine the causes of cybersickness. Also, it intends to contribute to the development of the virtual reality game industry by presenting methods to supplement these problems.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.40-47
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• 2015

VR(virtual reality) which already is used commonly in diverse areas including entertainment, design, and simulation training is most important area in ICT. VR already has various uses within the tourism sector. As VR technology continues to evolve, there is little reason to doubt that it will become more prevalent throughout society and the tourism sector in particular. In this paper, we plan to improve the VR content to the market possibility and competitiveness of VR content in the culture industry. Out of focus, lens dust, motion blur, blur effect were minimized to improve the simulation sickness which caused by the cognitive dissonance in the HMD. And also, the content was considered UI design for user's immersion.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.4
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• pp.273-281
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• 2016

Background: Postoperative nausea and vomiting (PONV) is one of the most common postoperative complications. Despite this, few papers have reported the incidence and independent risk factors associated with PONV in the context of oral and maxillofacial surgery (OMFS). Therefore, we sought to determine the incidence of PONV, as well as to identify risk factors for the condition in patients who had undergone OMFS under general anesthesia. Methods: A total of 372 patients' charts were reviewed, and the following potential risk factors for PONV were analyzed: age, sex, body mass index, smoking status, history of PONV and/or motion sickness, duration of anesthesia, amount of blood loss, nasogastric tube insertion and retention and postoperative opioid used. Univariate analysis was performed, and variables with a P-value less than 0.1 were entered into a multiple logistic regression analysis, wherein P-values < 0.05 were considered significant. Results: The overall incidence of PONV was 25.26%. In the multiple logistic regression analysis, the following variables were independent predictors of PONV: age < 30 years, history of PONV and/or motion sickness, and anesthesia duration > 4 h. Furthermore, the number of risk factors was proportional to the incidence of PONV. Conclusions: The incidence of PONV in patients who have undergone OMFS varies from center to center depending on patient characteristics, as well as on anesthetic and surgical practice. Identifying the independent risk factors for PONV will allow physicians to optimize prophylactic, antiemetic regimens.