• Journal of Institute of Convergence Technology
• /
• v.6 no.2
• /
• pp.15-20
• /
• 2016

This paper presents the effects of a virtual mass on the stability boundary of a virtual spring in the haptic system. A haptic system consists of a haptic device, a sampler, a virtual rigid body and zero-order-hold. The virtual rigid body is modeled as a virtual spring and a virtual mass. According to the virtual mass and the sampling time, the stability boundary of the virtual spring is analyzed through the simulation. As the virtual mass increases, the value of the virtual spring to guarantee the stability gradually increases and then decreases after reaching the maximum value. These simulation results show that the addition of the virtual mass enables to expand the stability boundary of the virtual spring.

• The International Journal of Costume Culture
• /
• v.13 no.2
• /
• pp.118-129
• /
• 2010

Digital technology introduced into the clothing and fashion industry is evolving to digital virtual fashions and consumer-centered mass-customized production systems. Today the application of such 3D virtual try-on systems is being expanded gradually in the clothing industry. This study purposed to make virtual avatars and virtual garments using OptiTex and V-stitcher virtual software and compared the appearance of the virtual garments put on the virtual avatars. For this, we created virtual avatars and virtual garments using body measurements obtained from jive subjects of top jive body shapes, respectively, using $[TC]^2$ body scanner. According to the results of comparing the outcomes of the two different virtual software systems, virtual avatar II of V-Stitcher tended to have a more round and lifted hip and the waist line at a higher position. In addition, the body curves and shapes of a virtual avatar affect the appearance of virtual garments. This study applied the same body measurements to virtual avatars and the same pattern to virtual garments, but when different kinds of virtual software were used, the virtual avatars and virtual garments showed different appearance and fit. This result may mean that when customers buy apparel products using different kinds of virtual try-on systems, their evaluation of appearance can vary depending on the virtual try-on system. Therefore, research needs to be made actively for the development and use of linkage programs that can reflect actual body measurements between virtual software systems and 3D body scanning systems.

• Kyungpook Mathematical Journal
• /
• v.57 no.1
• /
• pp.145-161
• /
• 2017

If a virtual knot diagram can be transformed to another virtual one by a finite sequence of crossing changes, Reidemeister moves and virtual moves then the two virtual knot diagrams are said to be homotopic. There are infinitely many homotopy classes of virtual knot diagrams. We give necessary conditions by using polynomial invariants of virtual knots for two virtual knots to be homotopic. For a sequence S of crossing changes, Reidemeister moves and virtual moves between two homotopic virtual knot diagrams, we give a lower bound for the number of crossing changes in S by using the affine index polynomial introduced in [13]. In [10], the first author gave the q-polynomial of a virtual knot diagram to find Reidemeister moves of virtually isotopic virtual knot diagrams. We find how to apply Reidemeister moves by using the q-polynomial to show homotopy of two virtual knot diagrams.

• Journal of Institute of Convergence Technology
• /
• v.10 no.1
• /
• pp.41-45
• /
• 2020

This paper presents the effects of a virtual mass on the stability boundary of a virtual spring in the haptic system with first-order-hold. The virtual rigid body is modeled as a virtual spring and a virtual mass. When first-order-hold is applied, we analyze the stability boundary of the virtual spring through the simulation according to the virtual mass and the sampling time. As the virtual mass increases, the stability boundary of the virtual spring gradually increases and then decreases after reaching the maximum value. The results are compared with the stability boundary in the haptic system with zero-order-hold. When a virtual mass is small, the stability boundary of a virtual spring in the system with first-order-hold is larger than that in the system with zero-order-hold.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.34 no.12
• /
• pp.1968-1979
• /
• 2010

New technology that includes 3D body scanning, digital virtual human, and digital virtual garments has had a significant impact on the current apparel industry. Virtual simulation technology enables the visualization of a 3D virtual garment on a virtual avatar so that consumers can try on garments with their virtual avatars before purchasing. However, the manual virtual avatar provided for online apparel shopping currently has revealed limitations on the different body sizes and shapes of customers. This study analyzes the process of designing the automatic virtual avatar and the manual virtual avatar using OptiTex software; in addition, the study compares the practicality of the automatic virtual avatar with that of the manual virtual avatar. Data was examined by evaluating how much each virtual avatar is similar to the real body and how well it matched the needs of the current apparel industry. In the study, Avatar 1 was automatically created from three-dimensional body scan data and Avatar 2 was manually created from body measurements. The virtual avatar images laid over a real body image and the results were evaluated by comparing the simulated sizes of virtual avatars with those of a real body. Consequently, Avatar 1 was evaluated as more similar to the real body than Avatar 2 in all five body shapes. This study illustrates that an automatic virtual avatar might solve the fit problem that is the most common reason for a high return rate for online shopping. The results show that future virtual simulation technology needs to be improved for the practicality of the virtual avatars.

• Journal of The Korean Society of Integrative Medicine
• /
• v.10 no.3
• /
• pp.233-246
• /
• 2022

Purpose : The study aims to determine the effects of virtual and non-virtual realities in a normal person's mirror walk on gait characteristics. Methods : Twenty male adults (Age: 27.8 ± 5.8 years) participated in the study. Reflection markers were attached to the subjects for motion analysis, and they walked in virtual reality environments with mirrors by wearing goggles that showed them the virtual environments. After walking in virtual environments, the subjects walked in non-virtual environments with mirrors a certain distance away after taking a 5 min break. To prevent the order effect caused by the experiential difference of gait order, the subjects were randomly classified into groups of 10 and the order was differentiated. During each walk, an infrared camera was used to detect motion and the marker positions were saved in real time. Results : Comparison between the virtual and non-virtual reality mirror walks showed that the movable range of the leg joints (ankle, knee, and hip joints), body joints (sacroiliac and atlantoaxial joints), and arm joints (shoulder and wrist joints) significantly differed. Temporal characteristics showed that compared to non-virtual gaits, the virtual gaits were slower and the cycle time and double limb support time of virtual gaits were longer. Furthermore, spacial characteristics showed that compared to non-virtual gaits, virtual gaits had shorter steps and stride lengths and longer stride width and horizontally longer center of movement. Conclusion : The reduction in the joint movement in virtual reality compared to that in non-virtual reality is due to adverse effects on balance and efficiency during walking. Moreover, the spatiotemporal characteristics change based on the gait mechanisms for balance, exhibiting that virtual walks are more demanding than non-virtual walks. However, note that the subject group is a normal group with no abnormalities in gait and balance and it is unclear whether the decrease in performance is due to the environment or fear. Therefore, the effects of the subject group's improvement and fear on the results need to be analyzed in future studies.

• Journal of Computational Design and Engineering
• /
• v.1 no.3
• /
• pp.213-222
• /
• 2014

This paper reviews and identifies issues in the application of virtual commissioning technology for automated manufacturing systems. While the real commissioning of a manufacturing system involves a real plant system and a real controller, the virtual commissioning deals with a virtual plant model and a real controller. The expected benefits of virtual commissioning are the reduction of debugging and correction efforts during the subsequent real commissioning stage. However, it requires a virtual plant model and hence still requires significant amount time and efforts. Two main issues are identified, the physical model construction of a virtual device, and the logical model construction of a virtual device. This paper reviews the current literature related to the two issues and proposes future research directions to achieve the full utilization of virtual commissioning technology.

• Korean Journal of Computational Design and Engineering
• /
• v.13 no.5
• /
• pp.323-333
• /
• 2008

Various virtual gloves have been developed for the past four decades. These gloves have sensors that can measure bending angles at finger joints and the positions as well as orientations of hands. Previous researches were mostly concentrated on utilizing different kinds of sensors. As the technology matured, more interests are given towards building virtual reality applications. Furthermore, due to the recent reduction of costs, these devices have been widely adopted. Our particular interest lies in three-dimensional applications where virtual objects are grasped and manipulated. For these applications, it is crucial to accurately measure finger joints angles for realistic object interactions with the virtual hand. With inaccurate measurements, virtual hands would penetrate inside virtual objects after they are grasped. Or alternatively, virtual objects would be grasped before hands are making any contacts with virtual objects. In this paper, we introduce new design of virtual gloves for improved finger joints measurements.

• Fashion & Textile Research Journal
• /
• v.14 no.1
• /
• pp.83-89
• /
• 2012

Recent rapid development of computer, information communication and Web service technologies is exerting considerable effects on all industrial areas. As such digital technologies are also introduced to the clothing and fashion industry and create 'virtual garment environment' consisting of 3D virtual bodies, virtual garments and virtual try-on systems, consumers are now able to try virtual garments on their virtual body online. This study was conducted in order to analyze consumers' tendency of clothing purchase using 3D virtual simulation technology, which is increasing attention throughout the world, and to propose strategies on the development of virtual try-on technology for activating apparel online shopping. The subjects of this study were men and women aged 18 or older living in the North Carolina State, U.S., and a questionnaire survey was conducted with them on their tendency of apparel online shopping and their preference for real garments and virtual garments. According to the results of this study, consumers' awareness of apparel shopping using virtual try-on was still low. Moreover, in the results of surveying consumers' purchase preference for real garments and virtual garments, preference was highest for real garment (P), which was followed by virtual garments OA, OB and BB. Based on the results of this study, for the activation of apparel online shopping using virtual simulation technology, it is considered necessary to provide services implementing virtual try-on similar to consumers' actual try-on. This requires further active research and technology development on virtual try-on simulation using digital technologies.

• Journal of Digital Contents Society
• /
• v.9 no.2
• /
• pp.317-323
• /
• 2008

The purpose of this study is to show typology of virtual world and to look out how virtual world develops especially in Korea. As paradigm changes, the scientific virtual reality and world wide web are absorbed into 3-D virtual world in Metaverse. The metaverse is the convergence of virtually enhanced physical reality and physically persistent virtual space. There are two categories of virtual world, the Ludic Virtual World which is oriented from games like MMORPGs and the Social Virtual World which is oriented from network communication system. Compared to North America and Europe, the Ludic Virtual World and game society grow and develop quickly in Korea. It's because Korean users prefer the online environment where millions of people live out a collective fantasy existence.