• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.196-202
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• 2021

Currently, as Korea enters into a fast aging society, the problem of dementia population is increasing. In this paper, we intend to contribute to the improvement of welfare for the elderly by developing virtual reality technology and related interface technology to effectively perform hand movements known as effective methods for preventing and treating dementia. As the content of the research and development of this paper, it is designed to be easy for the elderly to use and stimulate brain function by applying VR technology using sensors, and to activate mental and physical activities for the elderly who are marginalized in terms of cultural welfare. We intend to develop by classifying the types of games and contents that can induce them. As a result of this thesis, we developed contents using virtual reality to improve cognitive abilities for elderly people with poor cognitive ability to activate the brains of users' cognition, memory, and attention to prevent and treat dementia I want to contribute.

• ETRI Journal
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• v.44 no.2
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• pp.327-338
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• 2022

Classification models for human action recognition require robust features and large training sets for good generalization. However, data augmentation methods are employed for imbalanced training sets to achieve higher accuracy. These samples generated using data augmentation only reflect existing samples within the training set, their feature representations are less diverse and hence, contribute to less precise classification. This paper presents new data augmentation and action representation approaches to grow training sets. The proposed approach is based on two fundamental concepts: virtual video generation for augmentation and representation of the action videos through robust features. Virtual videos are generated from the motion history templates of action videos, which are convolved using a convolutional neural network, to generate deep features. Furthermore, by observing an objective function of the genetic algorithm, the spatiotemporal features of different samples are combined, to generate the representations of the virtual videos and then classified through an extreme learning machine classifier on MuHAVi-Uncut, iXMAS, and IAVID-1 datasets.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.573-577
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• 2015

Safety is paramount for construction industry throughout the world. Human errors which contribute to more than half of construction accidents, could be proactively prevented through effective education and training methods. Although Virtual Reality (VR) and Augmented Reality (AR) have gained much attention in various disciplines, few studies applied them for construction safety education. This research presents a new approach in construction safety education by utilizing VR and AR. The vision of aligning teaching & learning strategies is examined in order to ensure the potential benefits of the new method. This innovative approach shifts safety education from "Listen, and I will forget. See, and I may remember" towards "Practice, and I understand".

• Journal of the Korea Fashion and Costume Design Association
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• v.22 no.2
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• pp.117-136
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• 2020

The purpose of this study is to analyze changes in high-tech fashion along with the types and characteristics of high-tech fashion that have appeared recently providing diverse material for the fashion field. High-tech fashion requires such research to learn how much distance one has in one's life. It is also meaningful to predict what direction high-tech fashion research may be needed. For research methods, previous research and literary studies were considered and photographs in which high-tech techniques were used were collected using the keyword 'high-tech fashion'. High-tech fashion types can be organized into the four types of luminescent types, mutual interaction types, 3D printing fashion, and virtual fashion. The research results were as follows. First, luminescent fashion was an important expression method of high-tech fashion. Materials for luminescent fashion first started with LED electric wire connections and many methods have been attempted with the appearance of electrically conductive clothing material, such as luminescent lasers and beam projectors. Second, interactive high-tech fashion often appears as variable fashion. The work of Hussein Chalayan, which was combined with advanced technology, set up a base for variable type interactive high-tech fashion in the 2000s. As bioengineering technology has developed, fashion that interacts with the environment without an energy source has appeared and the interaction among fashion, people, and the environment can be seen. Third, diverse forms of expressiveness in virtual reality such as 3D CLO shows a great difference with past high-tech fashion. Simple and diverse attempts made through virtual fittings reduce the limitations of time and space, permit interaction, and add a sense of reality through speed and dynamic physical beauty. Fourth, 3D printed fashion expresses complex and detailed clothing material that is different from those before with the development of computer 3D modeling technology. Modeling that can imitate geometric and bio-engineered structures is possible and mysterious feelings are passed on to people through creative expressions.

• Journal of Periodontal and Implant Science
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• v.48 no.2
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• pp.124-134
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• 2018

Purpose: Clinicians must examine tooth wear to make a proper diagnosis. However, qualitative methosds of measuring tooth wear have many disadvantages. Therefore, this study aimed to develop and evaluate quantitative parameters using the cusp area and volume of virtual dental models. Methods: The subjects of this study were the same virtual models that were used in our former study. The same age group classification and new tooth wear index (NTWI) scoring system were also reused. A virtual occlusal plane was generated with the highest cusp points and lowered vertically from 0.2 to 0.8 mm to create offset planes. The area and volume of each cusp was then measured and added together. In addition to the former analysis, the differential features of each cusp were analyzed. Results: The scores of the new parameters differentiated the age and NTWI groups better than those analyzed in the former study. The Spearman ${\rho}$ coefficients between the total area and the area of each cusp also showed higher scores at the levels of 0.6 mm (0.6A) and 0.8A. The mesiolingual cusp (MLC) showed a statistically significant difference (P<0.01) from the other cusps in the paired t-test. Additionally, the MLC exhibited the highest percentage of change at 0.6A in some age and NTWI groups. Regarding the age groups, the MLC showed the highest score in groups 1 and 2. For the NTWI groups, the MLC was not significantly different in groups 3 and 4. These results support the proposal that the lingual cusp exhibits rapid wear because it serves as a functional cusp. Conclusions: Although this study has limitations due to its cross-sectional nature, it suggests better quantitative parameters and analytical tools for the characteristics of cusp wear.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.569-581
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• 2008

In this paper, methods are proposed for creating a curved line in a navigation mesh, which is used in a windows based virtual reality or games. The main geographies used in a windows based virtual reality or games are created by using either grids or navigation meshes. When using grids, it is difficult to create a natural geography. Multiple grids are needed to ensure precise descriptions, which can result in system overload. A navigation mesh was developed to address this issue since the navigation mesh has the benefit of placing fewer loads on the system than a grid method. The drawback, however, is that the movements of character in navigation mesh are less natural. In this paper, a method for creating a curved line using round curves is proposed in order to resolve this issue. Using the methods for creating a curved line proposed in this paper in a windows based virtual reality or games will eliminate the unnatural or awkward movement of characters that arises in the use of a navigation mesh.

• Journal of Korean Academy of Nursing
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• v.52 no.2
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• pp.121-133
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• 2022

Purpose: This study examined the impact of a virtual reality intervention program based on psychological needs on behavioral and psychological symptoms, apathy, and quality of life (QOL) in patients with dementia or mild cognitive impairment living in nursing facilities. Methods: This study is nonequivalent control group pretest-posttest design of quasi-experimental study. The study collected data from November 18, 2020 to July 24, 2021 from patients with dementia or mild cognitive impairment (30 in the experimental group and 30 in the control group) at three nursing facilities in G city using self-reporting and caregiver-informant reporting methods. The analysis employed the chi-square test, Fisher's exact test, paired t-test, independent t-test, Wilcoxon signed rank test, Mann-Whitney U, repeated measures ANOVA, GEE, using SPSS/WIN 27.0. Results: The severity of behavioral and psychological symptoms (Wald 𝛘² = 2.68, p = .102) and the care burden of caregivers (Wald 𝛘² = 1.72, p = .190) were not significant and was no significant time and group interaction effect (Wald 𝛘² = 0.63, p = .426, Wald 𝛘² = 0.52, p =. 471). The difference in apathy and QOL score were statistically significant for the group-time interaction (F = 43.65, p < .001; F = 4.35, p = .041). Conclusion: The virtual reality intervention program of this study shows a positive effect on the apathy reduction and QOL of patients with dementia or mild cognitive impairment residing in nursing facilities.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.3
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• pp.87-94
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• 2013

The progress that becomes a basis for measuring the outcome of project is a core of project control. Follow-up corrective actions are determined depending on the degree of their differences. The methods of measuring the project progress have been developed though a variety of research and many were verified through the cases. Among such methods, this study selected Start/Finish method and Fixed Formula method. In order to check the limitations of the progress utilized in the two methods, the study compared their progresses to the progress of Percentage Complete method and analyzed the differences shown in their actual applications. Through this, it suggested the forms and scale of the projects appropriate to the application of Fixed Formula method. As for the research progress method, the study first generated a number of virtual project schedules for the establishment of an analysis model. These project schedules were varied in a way that they had different project periods and the number of different activities. The study also generated numerous project schedules for difference test. After establishing a virtual schedule plan by the scale of projects, it measured their progresses by period, analyzed the differences and repeated this procedure to obtain the results.

• Journal of the Korea Computer Graphics Society
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• v.24 no.3
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• pp.11-20
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• 2018

This study proposes collaboration based multi-user interaction to provide improved presence and satisfying experience to multiple HMD users in immersive virtual reality. The core of the proposed multi-user interaction is to present the direction in which HMD users in virtual reality environment can interact through communication and collaboration with each other based on their separate roles and behaviors. Each user in the virtual collaborative environment uses a hand to interact with a virtual environment or virtual objects. Based on the basic structure, this study designs methods (synchronization and communication) that can be achieved a common goal together through communication and collaboration. Then, this study creates a virtual reality application of arcade genre that considers communication and collaboration in order to verify whether the proposed multi-user interaction provides improved presence and satisfaction experience. And, the survey experiments are conducted for participants. Through these processes, it is confirmed that the interaction in the proposed immersive virtual collaborative environments provide the presence and experience that is satisfactory to all users.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.757-765
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• 2017

GNSS (Global Navigation Satellite System) Position Accuracy depends on pseudo-range measurement and DOP (Dilution Of Precision) which indicates about navigation satellite geometry. Pseudo-Range has many error sources such as satellite clock, orbit, ionosphere, troposphere, multipath and so on. For the improvement of the accuracy, user can use corrected pseudo-range in DGPS (Differential Global Positioning System), which is one of the relative positioning methods. But, stationary station is needed in relative positioning. In case of DOP, Signal reception environment is important. If receiver sets in the center of city, it could be interrupted reception by buildings. This environment leads to decrease the number of visible satellites and to increase DOP. This paper proposes the concept of GNSS positioning with virtual satellites which have usable VRM (Virtual Range Measurement). Via virtual satellites and VRM, users could get an accurate position. Especially referred virtual satellites constellation has an effect on vertical error.