• Information Systems Review
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• v.6 no.2
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• pp.47-63
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• 2004

As Internet usages proliferate, the interests on cyber space and virtual community increase. The purpose of this study is to find the role of cognitive absorption as an intermediate variable. It is a variable that links factors that affect on members' usage of virtual community and cognitive absorption. The result of this study shows that challenges, skills, perceived reality, and needs affect the usage of virtual community through cognitive absorption, while only interactivity affects the usage of virtual community directly. This shows that cognitive absorption plays an important role in the usage of virtual community. The major contribution in this study is that cognitive absorption influences on the usage of virtual community greatly. If there is a way to increase the intensity of cognitive absorption, it will strongly help increase the performance of virtual community.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.11
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• pp.2764-2783
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• 2012

Network virtualization supports future Internet environments and cloud computing. Virtualization can mitigate many hardware restrictions and provide variable network topologies to support variable cloud services. Owing to several advantages such as low cost, high flexibility, and better manageability, virtualization has been widely adopted for use in network virtualization platforms. Among the many issues related to cloud computing, to achieve a suitable cloud service quality we specifically focus on network and performance isolation schemes, which ensure the integrity and QoS of each virtual cloud network. In this study, we suggest a virtual network platform that uses Xen-based virtualization, and implement multiple virtualized networks to provide variable cloud services on a physical network. In addition, we describe the isolation of virtual networks by assigning a different virtualized network ID (VLAN ID) to each network to ensure the integrity of the service contents. We also provide a method for efficiently isolating the performance of each virtual network in terms of network bandwidth. Our performance isolation method supports multiple virtual networks with different levels of service quality.

• Journal of the Korean Society of Costume
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• v.61 no.9
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• pp.1-14
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• 2011

The purpose of this study was to understand the relationship between one's social-self image and Online Avatar image. Influence of these virtual images on one's attitude toward real world and commitment to the virtual world was examined. In addition, the gender difference was examined. A structural equation model with social self image as exogenous variable and influence of Avatar as endogenous variable was designed. Real and ideal Avatar images were the mediating variable in the model. Survey questionnaire was developed and data from 425 respondents were analyzed. Results indicated that the conceptual model was a good fit to the data. Respondents who perceived their social self-images importantly were likely to have real images of Avatars. Ideal image and real image had significant on commitment to virtual world and attitudes toward the real world. For male respondents, social self image had stronger influence on real image of Avatar and ideal image had stronger influence on commitment to virtual world than female respondents.

• Communications of the Korean Mathematical Society
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• v.39 no.1
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• pp.247-257
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• 2024

We use the structure of skew braces to enhance the biquandle counting invariant for virtual knots and links for finite biquandles defined from skew braces. We introduce two new invariants: a single-variable polynomial using skew brace ideals and a two-variable polynomial using the skew brace group structures. We provide examples to show that the new invariants are not determined by the counting invariant and hence are proper enhancements.

• East Asian mathematical journal
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• v.35 no.1
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• pp.31-40
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• 2019

We introduce a family of polynomial invariants by using intersection index defined from a Gauss diagram of a long virtual knot, and we give some properties for long virtual knots. We extend these polynomials so that we give two-variable polynomial invariants and some example.

• Journal of Information Processing Systems
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• v.8 no.3
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• pp.421-436
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• 2012

Different types of fingerprint detection algorithms that are based on extraction of minutiae points are prevalent in recent literature. In this paper, we propose a new algorithm to locate the virtual core point/centroid of an image. The Euclidean distance between the virtual core point and the minutiae points is taken as a random variable. The mean, variance, skewness, and kurtosis of the random variable are taken as the statistical parameters of the image to observe the similarities or dissimilarities among fingerprints from the same or different persons. Finally, we verified our observations with a moment parameter-based analysis of some previous works.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.3-9
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• 2008

This paper is related to hair-blending for 2D virtual color hairstyler based on the semi-automatic field morphing. The proposed 2D virtual color hair-styler is characterized as generating virtual hairstyles using the variable morphing mask instead of the fixed one for the semi-automatic morphing, and then hair-blending the generated virtual hairstyles using sigmoid function around the boundary region of the variable morphing mask. The proposed method is able to generate the virtual hairstyles with an easy-to-use interface based on semi-automatic field morphing. According to the proposed method, a user can shorten the working time and even an unskilled user can obtain natural hairstyles as he or she designates a small number of external user inputs.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1167-1172
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• 2017

Desktop computers, which were the main means of Internet use and information activity, were pushed out by smart devices that emphasized mobility and simplicity. The recent information production and consumption activities are performed through smart devices, but there is no input device for smart devices that can fully replace traditional input devices such as full-size PC compatible keyboards. Because of the small size of the virtual keyboard that uses the touch screen of the smart device, typographical error occurs at a high rate. In this paper, we propose a variable virtual keyboard that minimizes the typographical errors of the conventional virtual keyboards. The proposed method minimizes the user 's input error by adjusting the size of each key of the virtual keyboard based on accumulated dataset of position and pressure of the user' s input error even though there is no difference in the key position arrangement of the conventional virtual keyboards.

• Educational Technology International
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• v.22 no.1
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• pp.1-21
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• 2021

This study examined the effects of egocentric distance and screen size on learners' perceived virtual presence in a virtual reality environment with a large-screen display. Sixty-four undergraduate students participated in the study, which used a 3×2 randomized-block factorial design with repeated measures. Two independent variables were included: 1) egocentric distance, or the physical distance between the viewer's position and a screen display, and 2) screen size, or different screen heights with fixed width. Learners' perceived virtual presence, comprising involvement, spatial presence, and realness, was the dependent variable. Results showed that egocentric distance had significant effects on virtual presence, while screen size had none. A detailed discussion and implications are provided.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.16-19
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• 1996

In this paper, a sliding mode control scheme that guarantees the smoothness of the control signal and the exponential error convergence is proposed for robot manipulators. The proposed method inserts a low pass filter (LPF) in front of the plant, and the virtual controller is designed for the virtual plant - the combination of the LPF and the robot manipulator. The virtual control signal contains high frequency components because of a switching function. The real control signal, however, always shows a smooth curve since it is an output of the LPF. In addition to the smoothness of the control signal is always assured, the overall system is in the sliding mode at all times, that is, its performance is always invariant under the existence of parameter uncertainties and external disturbances. The closed-loop system is shown to be globally exponentially stable.