• Proceedings of the Korean Society of Computer Information Conference
• /
• 2022.07a
• /
• pp.549-552
• /
• 2022

본 논문에서는 가상현실에서 헤드 마운티드 디스플레이(Head mounted display, HMD) 사용자와 Non-HMD 사용자에게 사용자의 걷기, 뛰기, 절름발이 움직임을 몰입감 있게 표현하기 위한 새로운 가상현실(VR, Virtual Reality) 인터페이스를 제안한다. 가상현실에서는 몰입감을 높이기 위해 시각적 감각을 활용한 HMD와 사용자의 자세나 움직임을 추적하는 장비를 활용하지만, 일반적인 사용자들에게 HMD 보급은 많이 이루어져 있지 않으며, 비용적인 측면과 멀미로 인해 가상현실 콘텐츠에 몰입하기 어렵다. 본 논문에서는 효율적으로 몰입도를 높이고 비용적인 부담을 줄여주기 위해 아두이노를 활용한 새로운 보행 인터페이스 장치를 제안한다. 보행 인터페이스 장치는 사용자의 다리 가속도 정보를 기반으로 사용자의 상태 변화에 맞게 패턴을 설정하여 사용자의 걷기, 뛰기, 절름발이 움직임을 통해 사용자 캐릭터의 움직임을 제어하고 표현할 수 있는 새로운 결과를 보여준다.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.3
• /
• pp.109-119
• /
• 2011

The virtual reality (VR) technology has been used as the application of architectural presentation or simulation tool in the field of industry. The high immersion and intuitive visual information are the great merits of design evaluation or environmental simulation when we are using the virtual environments. But the distortion of distance perception in VR is still a big problem when the accuracy of distance presentation is strictly required. For example, distance estimation is especially important when the virtual environments are applied to the presentational tool for evaluation the space design or planning in the field of architecture. If there are some perception error between the built space in real and represented space in virtual, the accurate design evaluation or modification of design is hard to be carried out during the design development stage. In this paper, we have carried out some experiments about distance estimation in the immersive virtual environments to verify the factors and their influence. We made a hypothesis that the lack of the information for the user in VR causes the different distance estimation from the real world because users are usually comfortable with moving fast and long distance in VR environments compared with moving slow and short distance in real space. So, we carried out basic experiment to prove our hypothesis that the lack of information makes subjects estimate the distance of walking in VR shorter compared with the same distance in real. Also, among the factors that probably affect the distance estimation in VR, we have verified the influence of the image resolution. The influence of resolution degradation of image on the distance estimation was verified with the condition of static and dynamic images. The results showed that the resolution has deep relation with the distance estimation. For example, the subject underestimated the distance at the lower resolution condition. We also found the methods of the making the lower resolution image could affect on the visual perception of subjects.

• Journal of The Korean Society of Integrative Medicine
• /
• v.7 no.1
• /
• pp.9-17
• /
• 2019

Purpose : This study assessed the effects of transcranial direct current stimulation (tDCS) on balance, fall efficacy, and fall-related fitness in stroke patients, using a cohort of 30 stroke patients divided into two groups. Methods : The experimental group (was given transcranial direct current stimulation in a virtual reality program) and the control group was given false tDCS in virtual reality. there were 15 patients in each group, receiving appropriate treatment over 30 sessions (30 minutes per session per week over a six-week period). In order to assess the change in balance before and after the intervention, the Berg Balance scale was utilized. Fall efficacy was evaluated using the Korean Falls Efficacy Scale for the Elderly (FES-K), The following exercises were performed by patients to assess fall-related fitness : sitting down in a chair and standing up : walking a 244 cm round= trip, and standing on one foot. Results : After the intervention, the experimental group exhibited significantly increased fall efficacy and fall-related fitness, while the control group exhibited no change. These findings suggest that tDCS has positive effects on balance, fall efficacy, and fall-related fitness in stroke patients. Conclusion : Using tDCS as an intervention would bring positive effects on balance, fall efficacy, and fall-related fitness in stroke patients undergoing rehabilitation.

• Journal of Institute of Control, Robotics and Systems
• /
• v.15 no.3
• /
• pp.306-314
• /
• 2009

The pelvis platform is the mechanical part which accomplishes the activities of diminishing the disturbances from the lower body and maintaining a balanced posture. When a biped robot walks, a lot of disturbances and irregular vibrations are generated and transmitted to the upper body. As there are some important machines and instruments in the upper body or head such as CPU, controller units, vision system, etc., the upper part should be isolated from disturbances or vibrations to functions properly and finally to improve the biped stability. This platform has 3 rotational degrees of freedom and is able to maintain balanced level by feedback control system. Some sensors are fused for more accurate estimation and the control system which integrates synchronization and active filtering is simulated on the virtual environment.

• Journal of Drive and Control
• /
• v.17 no.1
• /
• pp.44-50
• /
• 2020

For the requirement of accurate tracking control and the safety of physical human-robot interaction, torque control is basically desirable for humanoid robots. Because of the complexity of humanoid robot dynamics, the TDC (time-delay control) is practical because it does not require a dynamic model. However, there occurs a considerable error due to discontinuous non-linearities. To solve this problem, the TDC-FLC (fuzzy logic compensator) is applied to humanoid robots. The applied controller contains three factors: a TDE (time-delay estimation) factor, a desired error dynamic factor, and FLC to suppress the TDE error. The TDC-FLC is easy to execute because it does not require complicated humanoid dynamic calculations and the heuristic fuzzy control rules are intuitive. TDC-FLC is implemented on the whole body of a humanoid, not on biped legs even though it is performed by a virtual humanoid robot. The simulation results show the validity of the TDC-FLC for humanoid robots.

• Journal of Korea Multimedia Society
• /
• v.19 no.12
• /
• pp.2036-2043
• /
• 2016

The $360^{\circ}$ Virtual Reality (VR) live-action movies are filmed by attaching multiple cameras to a rig to shoot the images omni-directionally. Especially, for a live-action film that requires a variety of scenes, the director of photography and his staff usually have to operate the rigged cameras directly all around the scene and edit the footage during the post-production stage so that the entire process can incur much time and high cost. However, it will also be possible to acquire high-quality omni-directional images with fewer staff if the camera rig(s) can be controlled remotely to allow more flexible camera walking. Thus, a $360^{\circ}$ VR filming system with remote-controlled camera rig has been proposed in this study. The movie producers will be able to produce the movies that provide greater immersion with this system.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2002.05c
• /
• pp.479-484
• /
• 2002

본 논문에서는 다중 사용자 간의 상호 작용과 공동 작업을 가능하게 하는 3차원 그래픽 기반의 가상 현실 시스템인 YVES(Yonsei Virtual Environment System) 의 성능향상을 위한 아바타 객체의 효과적인 동기화 방법에 대하여 제안하였다. YVES 는 연세대학교 컴퓨터과학과 멀티미디어 연구실에서 2001년도에 개발된 시스템이다. YVES의 사용자간 동기화 알고리즘은 기존의 방법에 비해 객체의 Poping현상을 없애고 동기화를 유지한 점에서 개선되었다고 할 수 있었다. 그러나 원래의 경로와는 변화된 다른 경로가 설정된다는 것과 이동이 완료되었을 때 수정된 경로로 향한 객체 진행 방향을 완료시점에서 원래의 진행방향으로 수정해야 항으로써 자연스럽지 못한 움직임을 보인다는 것이 문제점으로 지적되었다. 이를 보완하기 위해서 본 논문에서는 기존의 움직임 벡터를 새로 움직여야 할 움직임 벡터에 반영하여 새로운 경로가 원래의 경로와 보다 근접할 수 있도록 하고, 이동의 완료시점에서 객체가 향하는 방향이 원래 경로로 이동했을 경우와 동일하도록 하는 알고리즘을 제안하고, 각 알고리즘을 동일한 이동경로를 적용하여 비교하였다.

• Journal of the Korea Computer Graphics Society
• /
• v.24 no.3
• /
• pp.1-10
• /
• 2018

This study proposes an immersive interaction optimized for the user's experience environment to provide an improved presence for both HMD and Non-HMD users in the asymmetric virtual reality (VR) environment. The core of the proposed immersive interaction is to distinguish the differences of the asymmetric environment between the HMD and Non-HMD users and present the optimized interaction to the user. And, in order to increase the presence by providing improved immersion in the asymmetric virtual reality environment given to each user, we design the walking interaction to improve the immersion of space for the HMD users, a hand-based interface that improves immersion by fully understanding and managing the situation through direct control. Finally, through the experiment using questionnaire, it is verified that the immersive interaction provides all users with an enhanced presence and specialized experience in each environment experience. Through these processes, we confirmed that the Non-HMD user can be immersed in an asymmetric virtual reality using by proposed interaction as participant rather than assistant with HMD user.

• Journal of Korean Society of Rural Planning
• /
• v.28 no.1
• /
• pp.1-15
• /
• 2022

A Care farm is known to have positive effects on various people in psychological, physical, and social aspects. However, care farm services for the disabled, transportation disadvantaged, and socially disadvantaged are limited. This study conducted a demand survey in order to provide basic data for development of the Agro-Healing Virtual Reality Therapy(AVRT) system. The respondents were the ordinary person(n=127) and the disabled person(n=72), and the survey items consisted of 4 categories and 20 items, including intention to use AVRT, requirements for use, factors to be considered when developing the system, and content and program preferences. The intention to use a AVRT was found to be at a high level of 80% or more by respondent characteristics. In addition, similar results were shown in all items such as virtual reality experience, willingness to use, appropriate use time, and willingness to pay by respondent characteristics, and correlation by item was determined through correlation analysis. As for the conditions of use, both sides preferred rural types and were found to have the purpose of healing. However, there were concerns about dizziness in common between system use, and in the case of the disabled person, there were difficulties in purchasing expensive equipment. In the development of the AVRT system, the part of sensory priority, important technology level, and color preference were evaluated, and the preference of content and programs to be developed in the system was identified. Fruit, vegetables, flowers, and animals preferred mandarin, tomato, tulips, and dogs first, horticultural healing preferred harvest management for the ordinary person, plant cultivation for the disabled person, and forest healing and animal education preferred walking and dog-related programs. However, agricultural work was found to be a program with high preference for making processed foods for the ordinary person and creating an animal breeding environment for the disabled person. The result of this study is expected to provide reference data that can be suggested for the development of Agro-healing Virtual Reality Therapy system.

• KIISE Transactions on Computing Practices
• /
• v.22 no.2
• /
• pp.113-118
• /
• 2016

The walking speed of handicapped people generally is slower than that of normal people. So it is difficult for them to cross at crosswalks within the allotted time provided by the traffic light. This problem can be solved by expanding the time of the traffic light. However, if the latency of the traffic light is increased without distinguishing the handicapped among all other pedestrians, the efficiency of traffic signal lights will decrease. In this paper, we propose a smart traffic signal connecting mechanism between the previous pedestrian traffic signal and a pedestrian's device (smartphone). This Smart pedestrian traffic light, through this mechanism, minimizes traffic congestion by providing additional walking time only to the handicapped among pedestrians. This crosswalk traffic light recognizes the handicapped using a technique called Internet of things (IOT). In this paper, we extract the data necessary to build an effective smart crosswalk traffic light mechanism through simulation techniques. We have extracted different kinds of traffic signal times with our virtual simulation environment to verify the efficiency of the smart crosswalk pedestrian traffic light system. This approach can validate the effective delay time of the traffic signal time through a comparison based on number of pedestrians.