• Smart Media Journal
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• v.11 no.6
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• pp.9-17
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• 2022

In the COVID-19 pandemic era, non-contact services were demanded and the use of extended reality and metaverse services increased rapidly in various applications. In this paper, we analyze Gather.town, ifland, Roblox, and ZEPETO metaverse platforms in terms of user interaction, avatar-based interaction, and virtual world authoring. Especially, we distinguish interactions among user input techniques that occur in the real world, avatar representation techniques to represent users in the virtual world, and interaction types that create a virtual world through user participation. Based on this work, we highlight the current trends and needs of human-metaverse interaction and forecast future opportunities and research directions.

• Journal of Korea Game Society
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• v.22 no.1
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• pp.65-76
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• 2022

What difference does the metaverse experience have from the real world? This study investigated the effect of space size and dialogue topic on metaverse user experience. The results from a 3(space size: reality vs. metaverse in an open room vs. metaverse in a closed room) x 2(dialogue topic: positive vs. negative) mixed factorial design experiment (N = 75) revealed statistically significant effects of space on responsiveness, and dialogue topic on closeness. This result implies that designing metaverse for non-immersive devices should include careful considerations regarding the characteristics of the user's real space.

• International Journal of Computer Science & Network Security
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• v.22 no.11
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• pp.373-380
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• 2022

The field of land surveying is changing dramatically due to the way data is processed, analyzed and presented. Also, there is a growing demand for digital spatial information, coming primarily from the GIS (Geographical Information System) user community. Such a demand has created a strong development potential for a new land surveying software. An overview of the development and capabilities of a land surveying software platform based on the Windows system, SurveyingMap, is presented. Among its many features, SurveyingMap provides a lot of adaptability for networks adjustment, geodetic and plane coordinates transformation, contouring, sectioning, DTM (Digital Terrain Model) generation, and large scale mapping applications. The system output is compatible with well known computer aided drafting (CAD) /GIS packages to expand its scope of applications. SurveyingMap is also suitable for non-technical users due to the user-friendly graphic user interface. The system could be used in engineering, architecture, GIS, and academic teaching and research, among other fields. Two applications of SurveyingMap, extension of field control and large scale mapping, for the case study area are established. The results demonstrate that the system is adaptable and reasonably priced for use by college and university students.

• Journal of computational fluids engineering
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• v.13 no.2
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• pp.62-67
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• 2008

This study aims to investigate numerically the static stiffness characteristics of porous air bearing and to estimate appropriate permeability values of porous medium. In particular, a new roughness model is proposed and implemented into the commercial CFD code (FLUENT Ver. 6.2) by using C language based user subroutine. The predicted results are extensively compared with experimental data. The roughness model is also validated through comparison with the results from open literature. It is found that the predictions for static stiffness are in good agreement with experimental data. Therefore, the suggested model based on the roughness Reynolds number can be used in studying the stiffness characteristics of porous air bearing effectively. In addition, numerical simulations of various diameter size and conditions are conducted. According the results, it is expected that the static stiffness of porous air bearing has the non-linear characteristics.

• Journal of Korea Multimedia Society
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• v.18 no.4
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• pp.499-505
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• 2015

Security supports are a significant factor in the design of mobile ad hoc networks. In the dynamic topology where the node changes frequently, private key generation and revocation for newly joining and leaving nodes must be considered. In addition, the identities of individual nodes must be protected as well in mobile networks to avoid personal privacy concerns. This paper proposes ID-based private key revocation scheme and non-interactive key agreement scheme in anonymous MANETs. The proposed scheme provides the user privacy using pseudonyms and private key generation and revocation schemes with consideration of dynamic user changes. Therefore, our schemes can be applied in dynamic and privacy-preserving MANETs which are helpful to share multimedia data.

• Journal of Information Processing Systems
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• v.9 no.2
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• pp.259-270
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• 2013

A speaker's intentions can be represented by domain actions (domain-independent speech act and domain-dependent concept sequence pairs). Therefore, it is essential that domain actions be determined when implementing dialogue systems because a dialogue system should determine users' intentions from their utterances and should create counterpart intentions to the users' intentions. In this paper, a neural network model is proposed for classifying a user's domain actions and planning a system's domain actions. An integrated neural network model is proposed for simultaneously determining user and system domain actions using the same framework. The proposed model performed better than previous non-integrated models in an experiment using a goal-oriented dialogue corpus. This result shows that the proposed integration method contributes to improving domain action determination performance.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.18-25
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• 2020

In the fifth generation (5G) and beyond 5G (B5G) mobile communication, non-orthogonal multiple access (NOMA) has attracted great attention due to higher spectral efficiency and massive connectivity. We investigate the impacts of the channel estimation errors on the bit-error rate (BER) of NOMA, especially with the single-user decoding (SUD) receiver, which does not perform successive interference cancellation (SIC), in contrast to the conventional SIC NOMA scheme. First, an analytical expression of the BER for SUD NOMA with channel estimation errors is derived. Then, it is demonstrated that the BER performance degrades severely up to the power allocation less than about 20%. Additionally, we show that for the fixed power allocation of 10% in such power allocation range, the signal-to-noise (SNR) loss owing to channel estimation errors is about 5 dB. As a consequence, the channel estimation error should be considered for the design of the SUD NOMA scheme.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.576-580
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• 2004

In this paper, we present a design and implementation of a TV-Anytime compliant STB to provide personalized content consumption according to user preferences and various terminal/network conditions. This paper mainly details with a metadata engine which consists of meta data de-multiplexing, metadata decoding, and metadata-based content browsing. For personalized content consumption, the proposed metadata engine provides the following key functionalities: advanced EPG, non-linear segment navigation wirh Tables-of-Content and/or event-based summary, automatic recommendation of user-preferred programs, and etc. The implemented STB employing the metadata engine is successfully tested with a set of service scenarios in an end-to-end broadcasting test-bed.

• Journal of the Korea Society of Computer and Information
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• v.3 no.1
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• pp.35-46
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• 1998

In the Information Retrieval System. the relevance of retrieved items is determined by the judgement of the user and thus the evaluation of the system efficiency counts on the cognizance of users to some extent. The relevance feedback mechanism provides a device allowing iterative searches during which the query can be modified and refined based on user input from the relevant documents. The feedback system are generally reported to outperform non-feedback systems. The procedures and algorithms to implement the feedback mechanism are surveyed in this paper.

• Asia pacific journal of information systems
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• v.10 no.3
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• pp.41-59
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• 2000

The role of information systems(IS) is far more important in business operations today. Managers recognize information as a major resource of the organization, and non-expert end users positively participate in information system development processes. This phenomenon is considered user-led information system development(ULD), where users define the information requirements, oversee system testing, manage system development, and lead the overall project. Based on a socio-technical approach, this study examines the impact of ULD on IS success. This paper also investigates the moderating effects of various contextual factors on the relationships between ULD and the success. The questionnaire was developed and the data was collected from the end users who participated in implementing ERP systems. The results showed that ULD positively affects the success. For the moderating variables, IT complexity was found to have a strong effect on the relationship between ULD and the success while business complexity and top management support have partial effects. Surprisingly, resource adequacy was not found to have the effect. This study provides academia and practitioners with a number of implications and guidelines regarding why and when to introduce ULD in their IS development initiatives.