• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.651-658
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• 2020

The basic medical subjects are essential for the understanding of the major in the department of health science and are very important. Anatomy is one of the fundamental areas of medical education. On the other hand, the application of new teaching method is being attempted in various fields. Station rotation model, one of the blended learning, is also one of the popular teaching method. Station rotation model allows students to rotate through stations on a fixed schedule, where at least one of the stations is an online learning station. This study investigate the satisfaction of students when applying station rotation model to anatomy class. Each station in the station rotation model consisted of VR application learning, online problem solving, model observation and oral test. After applying station rotation model (2 weeks) to the 'Functional anatomy and Practice' course taken by 37 students of the'Department of Occupational Therapy'at H University, this study conducted a satisfaction survey compare with lecture class for students taking the course. At the result, station rotation model was significantly higher than lecture class in both understanding, interest, concentration and diversity degree. Based on these results, I suggest applying the station rotation model to the anatomy class because it also showed high satisfaction in that.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.345-362
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• 2017

Various data visualization methods are utilized to analyze a huge amount of data. Among various methods, a three-dimensional image requires the rotation of the image to show a stereo image on a two-dimensional screen. This study discusses two methods of batch method and real-time method, which make it possible to construct of stereo images to improve the restriction of the three-dimensional image display with virtual reality. This investigation can be useful to better explore a three-dimensional data structure.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.2
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• pp.137-144
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• 2010

In general, spinal fusion surgery takes pressure off the pain induced nerves, by restoring the alignment of the spine. Therefore spinal fixation system is used to maintain the alignment of spine. In this study, a biomechanical study was performed comparing the SROM(Spinal Range Of Motion) of three types of system such as Rigid, Dynesys, and Fused system to analyze the behavior of spinal fixation system inserted in vertebra. Dynesys system, a flexible posterior stabilization system that provides an alternative to fusion, is designed to preserve inter-segmental kinematics and alleviate loading at the facet joints. In this study, SROM of inter-vertebra with spinal fixation system installed in the virtual vertebra from L4 to S1 is estimated. To compare with spinal fixation system, a simulation was performed by BRG. LifeMOD 2005.5.0 was used to create the human virtual model of spinal fixation system. Through this, each SROM of flexion, extension, lateral bending, and axial rotation of human virtual model was measured. The result demonstrates that the movement of Dynesys system was similar to normal condition through allowing the movement of lumbar.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1179-1186
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• 2022

Building Information Modeling (BIM) is widely used to efficiently share, utilize and manage information generated in every phase of a construction project. Recently, mixed reality (MR) technologies have been introduced to more effectively utilize BIM elements. This study deals with the haptic interactions between humans and BIM elements in MR to improve BIM usability. As the first step in interacting with virtual objects in mixed reality, we challenged moving a virtual object to the desired location using finger-pointing. This paper presents the procedure of developing a haptic interface system where users can interact with a BIM object to move it to the desired location in MR. The interface system consists of an MR-based head-mounted display (HMD) and a mobile application developed using Unity 3D. This study defined two segments to compute the scale factor and rotation angle of the virtual object to be moved. As a result of testing a cuboid, the user can successfully move it to the desired location. The developed MR-based haptic interface can be used for aligning BIM elements overlaid in the real world at the construction site.

• Journal of Korea Multimedia Society
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• v.11 no.11
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• pp.1575-1591
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• 2008

In this paper, we propose a new method detecting foot motion capture in order to overlap in realtime foot's 3D virtual model from stereo cameras. In order to overlap foot's virtual model at the same position of the foot, a process of the foot's joint detection to regularly track the foot's joint motion is necessary, and accurate register both foot's virtual model and user's foot in complicated motion is most important problem in this technology. In this paper, we propose a dynamic registration using two types of marker groups. A plane information of the ground handles the relationship between foot's virtual model and user's foot and obtains foot's pose and location. Foot's rotation is predicted by two attached marker groups according to instep of center framework. Consequently, we had implemented our proposed system and estimated the accuracy of the proposed method using various experiments.

• Journal of IKEEE
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• v.26 no.2
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• pp.150-159
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• 2022

In this paper, we propose a physics simulation for augmented reality (AR) billiards content. The characteristics of the physics simulation for the proposed AR billiards content are as follows. First, physical equations are derived by calculating the force and moment of inertia applied to the billiards ball to realize the motion of the billiards ball similar to the real one in the AR environment. Then, we determine the velocity and angular velocity of the virtual billiards ball associated with the rotation of the virtual billiards ball with respect to the impact point. Second, using some vectors such as incidnet vector, normal vector, reflection vector, the trajectory of the virtual billiards ball would be implement. these equations are applied to AR environment so that AR billiards content could be implement. This physics simulation allows users to feel like the real world using a virtual pool table and induce them to interact with the real environment. As a result of the experiment, the accuracy range between the path of the real billiards ball and the path of the virtual billiards ball was calculated to be 97.75% to 99.11%. Therefore, it was determined that the performance of the physics simulation for the AR billiards content proposed in this paper performs similarly to the path of the real billiards ball.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.167-173
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• 2022

The size of the virtual reality market is growing every year, but cybersickness that occurs in virtual reality has not been resolved yet. In this paper, results were derived through experiments on the relationship between cybersickness and gaze guidance occurring in virtual reality contents. Using eye tracking technique, the relationship of gaze movement with cybersickness was identified. The experiment was divided into two groups to find out whether visual induction affects cyber sickness. In addition, the results were analyzed by dividing the two groups to check whether cyber sickness showed different results according to gender. We also analyzed using the SSQ questionnaire to measure cybersickness. We tried to understand the relationship between gaze guidance and cybersickness through two methods. As a result of the experiment, it was found that the induction of a clear gaze caused the concentration of the gaze, and it was effective in cybersickness through the rotation of the camera. In order to alleviate cyber sickness, it has been confirmed that concentrating one's eyes through gaze-guided production is effective for cyber sickness. It is hoped that this result will be used as a way to alleviate cyber sickness for producers who want to use virtual reality to produce content.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.2
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• pp.93-106
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• 2021

In general, segment lining tunnel refers to a tunnel formed by connecting precast concrete segments as a ring and connecting such rings to each other in the longitudinal direction of the tunnel. As the structural properties of the segment lining is highly dependent on the behavior of the segment joints, thus correct modelling of joint behavior is crucial to understand and design the segment tunnel lining. When the tunnel is subjected to ground loads, the segment joint behaves like a hinge that resists rotation, and when the induced moment exceeds a certain limit of the rotation then it may enter into non-linear field. In understanding the effect of the segment joint on the lining behavior, a moment-rotation relationship of the segment joint was explored based on the Japanese practice and Janssen's approach commonly used in the actual design. This study also presents a method to determine the rotational stiffness of joint refer to the bearing strength. The rotation of the segment joint was estimated in virtual design conditions based on the existing models and the proposed method. And the sectional force of the segment lining and joint were calculated along with the estimated rotation. As the rotation at the segment joint increases, the joint contact area decreases, so the designer have to verify the segment joint for bearing strength as well. This paper suggests a consistent method to determine the rotational stiffness and bearing strength of joints.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.451-457
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• 2020

In this study, the degree of motion sickness displayed according to actions in virtual reality is measured based on the SSQ tool, a measuring tool, and factors and symptoms affecting cyber motion sickness are investigated through comparative analysis. In the first experiment, the operation method experiment, the simple operation method is measured to be highly affected by the Nausea factor. As symptoms of this, nausea, burp and headache symptoms were developed. In the second experiment, the larger the body rotation radius, the higher the motion sickness was measured, and the greater the influence of Nausea factors. Symptoms of this were the symptoms of burping, headaches, and a full head. In the third experiment, the physical mobility experiment, motion sickness was measured highly in the non-action controller. It was measured to be greatly affected by the Nausea factor. Symptoms of this include fever, headache, and a full head. Through this study, we found that the more fixed and simple the body is operated in virtual reality, the more sensitive the user is to motion sickness, and the larger the radius of rotation, the more sensitive it is to motion sickness. This study is meaningful in identifying factors and symptoms that affect motion sickness and VR manipulation, and is expected to be used by developers in the future to recognize the degree and symptoms of motion sickness of users and to develop content.

• Journal of the Korean earth science society
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• v.35 no.3
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• pp.180-191
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• 2014

In this study, a geological field trip learning program using 3 Dpanorama virtual reality (PVR) techniques is developed to learn about the Chaeseokgang area located in a national park near Byeonsan-bando, Jeonbuk, Korea. The developed $360^{\circ}{\times}180^{\circ}$ PVR program can show every face of observational points and interact as zoom-in, zoom-out and image rotation. For the educational effects of the materials, it is provided with a compass, a protractor for measuring the dip of strata and observation of specimen of observational points. It also assists students to learn by providing enlarged images, pop-up windows, and expert explanation main observational points. The program is applied to the class of 35 gifted students in middle school to investigate the effectiveness of the program. The results showed that positive responses of the students were 85% or more. It is suggests that this program be used as indirect situated learning material and a solution to geological field trip problems like cost, safety, distance, and so on geological learning of middle school science.