• Journal of Broadcast Engineering
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• v.26 no.6
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• pp.704-713
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• 2021

This paper proposes a method to prioritize the virtual objects to be selected, considering both the user's hand and the geometric relationship with the virtual objects and the user's intention which is recognized in advance. Picking up virtual objects in VR content is an essential and most commonly used interaction. When virtual objects are located close to each other in VR, a situation occurs in which virtual objects that are different from the user's intention are selected. To address this issue, this paper provides different weights for user intentions and distance between user's hand and virtual objects to derive priorities in order to generate interactions appropriately according to the situation. We conducted the experiment in the situation where the number of virtual objects and the distance between virtual objects are diversified. Experiments demonstrate the effectiveness of the proposed method when the density between virtual objects is high and the distance between each other is close, user satisfaction increases to 20.34% by increasing the weight ratio of the situation awareness. We expect the proposed method to contribute to improving interaction skills that can reflect users' intentions.

• Journal of Fashion Business
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• v.14 no.4
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• pp.161-173
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• 2010

This study aims to examine for efficient production methods of custom-tailored clothing and application of 3D virtual clothing system in custom-tailored clothing market, by producing and analyzing both real clothing and 3D virtual clothing. For this study, a middle-aged woman is selected as the subject figure and one-piece is selected as the experimental clothes item. In real clothing, I conducted the wearing evaluation for experts and the subject figure. And In the virtual clothing, I conducted the wearing evaluation with i-Designer using 3D virtual clothing on simulation program. There are some differences between the data from body scanning and the real body size. In the custom-tailored clothing market in which the fitness is important, the research which measures the more exact data is needed. And in the case of complicate design, the functions which measure the activity and the fitness variously and correct the parts of curves are needed. This study experiments the availability of application of 3D Virtual Clothing System in custom-tailored clothing market by selecting one-piece as the experimental clothes item. So the follow-up studies for the other designs and fabrics are needed. Also, if the studies for checking the clothes pressure, the amount of composure, the space between skin and clothing when the virtual model wearing clothes is walking or shaking his arms are proceeding, then 3D virtual clothing System is applicable in custom-tailored clothing market. But there are some restrictions and lack of education in virtual clothing System yet, and it makes hard for workers in clothing market to use it in real production. However, 3D virtual clothing System will be practical in real market if there would be more research on its usability and practicality, and workers in clothing market can be easily educated on techniques of 3D virtual clothing system.

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.89-100
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• 1998

A multi-user virtual reality system supports shared environments for concurrent accesses by multiple users. The performance of these systems depends heavily on the network environments. This paper experiments an effective network model for shared virtual environments. This model has a middle layer called groups placed between the server and its clients, and the tasks of server are distributed to these groups. Using groups solves some of the problems of existing systems such as lack of scalability, message overheads, and latency due to message passing among locally communicating entities in the virtual environment. Some experiments show lower overhead than existing distributed virtual environment systems in WAN as well as LAN environments. This model also supports a method that can be used to construct application specific network environments using message handler which allows user-defined message formats.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.13-27
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• 2020

Purpose: The purpose of this study is to present a recoil measurement and analysis of K2 rifle for the development of a virtual reality marksmanship training in the Republic of Korea Army. Methods: For the recoil measurement, a test-bed is built by a barrel that has exact dimensions of K2 rifle and three piezoelectric pressure sensors mounted on the barrel. Data of over 200 rounds of 5.56mm M193 and K100 bullets are collected and analyzed from live fire experiments. For the recoil analysis, both the free recoil method and the gas exhaust aftereffect method are used to calculate a recoil velocity, momentum and kinetic energy of K2 rifle by applying the law of conservation of momentum. In addition, a new method is proposed that uses the third law of motion and the chamber pressure model for the recoil measurement Results: The results show how different between the previous and proposed methods with respect to M193 and K100 bullets of K2 rifle. In M193, the free recoil method demonstrates 1.113, 4.197, and 2.335, the gas exhaust aftereffect method computes 1.698, 6.407, and 5.441, and the proposed method calculates 0.990, 3.734, and 1.848 in recoil velocity, momentum and kinetic energy, respectively. In K100, the free recoil method demonstrates 1.190, 4.487, and 2.669, the gas exhaust aftereffect method computes 1.776, 6.699, and 5.949, and the proposed method calculates 1.060, 3.998, and 2.119 in recoil velocity, momentum and kinetic energy, respectively. Conclusion: This study implements live fire experiments to provide recoil velocity, momentum, and kinetic energy of K2 rifle using both M193 and K100 bullets. For the development of the army virtual reality marksmanship, the results in this paper would be useful to design and produce a gun and/or a rifle of virtual reality.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.1
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• pp.19-28
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• 2021

Recently, in the field of education, various attempts have been made to apply virtual reality technology to an educational field and use it as an educational medium. Accordingly, in the science subject area, it is necessary to simulate science experiments that can make various and active experiments out of various limitations such as space and situation by using virtual reality environment construction technology. In this study, after selecting a physics course from a science subject, an experimental simulation using a parabolic motion formula, one of physical phenomena, is implemented in a virtual space, and then used in actual physics education based on the learning standards of the STEAM theory. Prove this is possible. Through this, it was confirmed that a specific educational model using virtual reality space can be designed, and it shows that education can be conducted with more effective educational methods in various subjects of education through the combination of traditional educational model and modern technology. Regarding the results of the research, it suggests the possibility of future research plans and practical use in the educational field.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1738-1745
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• 2016

In this paper, we present localization and autonomous navigation method using GPU(Graphics Processing Unit)-based SIFT(Scale-Invariant Feature Transform) algorithm and virtual force method for mobile robots. To do this, at first, we propose the localization method to recognize the landmark using the GPU-based SIFT algorithm and to update the position using extended Kalman filter. And then, we propose the A-star algorithm for path planning and the virtual force method for autonomous navigation of the mobile robot. Finally, we demonstrate the effectiveness and applicability of the proposed method through some experiments using the mobile robot with OPRoS(Open Platform for Robotic Services).

• Journal of Mechanical Science and Technology
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• v.17 no.11
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• pp.1616-1627
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• 2003

This paper describes a mini linear optical pickup actuator. To reduce the size, inner yokes are designed to guide the mover and outer yokes of permanent magnets are removed. Magnetic circuit method is used to determine the thrust force. Virtual path method is proposed to analyze the open magnetic circuit analysis. The magnetic circuit of the proposed actuator can be a closed circuit due to the virtual path model of the outer magnetic flux. The validity of virtual path method is evaluated by comparing to the FEM analysis. Structural vibration is investigated using FEM and the design of the mover is modified to improve the vibration characteristic. Dynamic characteristic experiments shows that the performance of the proposed actuator is enough to be used as a coarse and fine seeking actuator simultaneously and the thrust force margin for loading a focusing actuator is guaranteed.

• Knowledge Management Research
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• v.10 no.3
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• pp.153-173
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• 2009

Virtual world typically characterized by Second Life (www.secondlife.com) has been successfully drawing a great deal of potential users all around the world. Attention towards 3D avartars has been increasing exponentially especially in the electronic commerce world. 3D avatars have firm position in the virtual world. This study is launched to explore this research void in which trust transference from 3D-avatars-sales representative to customers purchase intention will be especially analyzed on. To perform experiments, a research model was built in a form of path analysis. Two types of 3D avatars were designed and implemented-at-tractive type and professional type. Questionnaire survey was adopted, and empirical analysis results were obtained from the research model. Results reveal that the proposed hypotheses are proven with statistical significance.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.4
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• pp.175-184
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• 2010

This paper designs a virtual USB drive for mobile devices which gives an illusion of a traditional USB flash memory drive and provides capacity-free storage space over IP network. The virtual USB drive operating with a S3C2410 hardware platform and embedded linux consists of USB device driver, an iSCSI-enabled network stack, and a seamless USB/iSCSI tunneling module. For performance enhancement, it additionally provides a kernel-level seamless USB/iSCSI tunneling module and data sharing with symbol references among kernel modules. Experiments reveal that the kernel-level implementation can improve the I/O performance up to 8 percentage, as compared with the user-level implementation.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.5
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• pp.413-417
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• 2002

The Internet technology has been recognized not only as a tool far communication in the 21st century but also as an environment for enabling changes in the paradigm of teaching and learning. This paper describes a web-based system development for chemical engineering education. Simulation and visualization of dynamic systems in the environment of a standard web-browser is made possible by extending its capabilities. ActiveX control is used to simulate the system tool far online representation of Virtual Lab. System that is developed using visual basic. The courseware is classified into tutorial, exercises, and virtual experiments.