• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3A
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• pp.286-295
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• 2008

In this paper, we consider the use of orthogonal multiple beams (OMBs) to simultaneously achieve multi-user diversity and multiplexing gain in a packet-based wireless system. Previous OMB scheme considers the use of a fixed number of multiple beams equal to the number of transmit antennas. However, unless the number of active users is sufficiently large, the use of a fixed number of multiple beams may not provide desired performance due to the interference signal transmitted through other beams, being even worse than the use of a single beam. To alleviate this problem, we consider the adjustment of the number of beams in use to maximize the spectral efficiency according to the operating condition. Simulation results show the validity of the proposed scheme.

• The Journal of Information Systems
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• v.29 no.2
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• pp.27-50
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• 2020

Purpose The research on the effective use of IS needs to embrace the alignment to organization learning process, which expands the limited focus on dynamic capability of IS use. In addition, it should be done in multi-level analysis with system, user, task, and organization. The current study suggests the inclusion of multi-level analysis of effective use of IS in the perspective of exploration and exploitation. Design/methodology/approach This review selected the representative studies in IS discipline which have investigated the effective use of IS, dynamic capability, operational capability, exploration, exploitation, or organizational learning. In the search of academic archives with those keywords, seventeen papers which have been most cited were chosen and validated whether the focus constructs are directly theorized or validated the suggested keywords. In addition, the level of analysis was verified whether it includes one or more levels of system, individual, task, or organization. Based on the initial analysis of dynamic capability, the further review of research on explorational and exploitational capabilities was implemented. Findings The present review study on previous literature on effective use of IS presented that it is largely implemented in the level of individual but few of them has included organization level. Similarly, the direct investigation of explorational and exploitational use of IS has not been done so much. The needs of study on effective use of IS in depth have been inquired for a decade. However, the review presented that it still lacks profound theories and empirical validations compared to those of adoption stage of IS. Based on the review, future research on the transition between explorational and exploitational use of IS is suggested.

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.67-77
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• 1998

In this paper we describe a development of a multi user game using 3D graphics and multicasting. First, we represent a virtual reality world by 3D graphics technology. Next, we use computer communication technology for the purpose of interaction among multi users. As a result, multi users share 3D graphics objects and play games. The goal of this paper is a development of a system that enables multi users to play games sharing a virtual world represented by 3D graphics. We use the OpenInventor library and C++ language for 3D graphics scene representation, and IP multicasting protocols for computer communication. The system allows to use Polhemus Fastrak 3D input device that recognizes the 3D position and 3D orientation. As an example we present a game that demonstrates the effect of piano concert by multi piano players who are distributed in a computer network.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.3
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• pp.13-20
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• 2013

In this paper, we propose a multi-scale crack detection method. This method uses decomposition, composition, and shape properties. It is based on morphology algorithm, crack features. We use a morphology operator which extracts patterns of crack. It segments cracks and background using opening and closing operations. Morphology based segmentation is better than existing integration methods using subtraction in detecting a crack it has small width. However, morphology methods using only one structure element could detect only fixed width crack. Thus, we use decomposition and composition methods. We use a decimation method for decomposition. After decomposition and morphology operation, we get edge images given by binary values. Our method calculates values of properties such as the number of pixels and the maximum length of the segmented region. We decide whether the segmented region belongs to cracks according to those data. Experimental results show that our proposed multi-scale crack detection method has better results than those of existing detection methods.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.304-310
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• 2008

Currently energy use planning council system is mandatory especially for the urban development project planned on a specified scale or more. The goal of existing demand prediction was to calculate the maximum load by multiplying energy load per unit area by building size. The result of this method may be exaggerated and has a limit in the information of period load. The paper suggests a new forecasting process based on standard unit household in order to upgrade the limit in demand prediction method of multi-family housing complex. The new process was verified by comparing actual using amount of multi-family housing complex to forecasting value of energy use plan.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1321-1332
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• 2016

Wireless sensor networks (WSN) are self-organized networks that typically consist of thousands of low-cost, low-powered sensor nodes. The reliability and availability of WSNs can be affected by faults, including those from radio interference, battery exhaustion, hardware and software failures, communication link errors, malicious attacks, and so on. Thus, we propose a novel multi-agent fault tolerant system for wireless sensor networks. Since a major requirement of WSNs is to reduce energy consumption, we use multi-agent and mobile agent configurations to manage WSNs that provide energy-efficient services. Mobile agent architecture have inherent advantages in that they provide energy awareness, scalability, reliability, and extensibility. Our multi-agent system consists of a resource manager, a fault tolerance manager and a load balancing manager, and we also propose fault-tolerant protocols that use multi-agent and mobile agent setups.

• Journal of the Korea Society of Computer and Information
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• v.22 no.10
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• pp.121-128
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• 2017

In this paper, we propose a multi-label classification method in which multi-label classification estimation techniques are applied to resolving location prediction problem. Most of previous studies related to location prediction have focused on the use of single-label classification by using contextual information such as user's movement paths, demographic information, etc. However, in this paper, we focused on the case where users are free to visit multiple locations, forcing decision-makers to use multi-labeled dataset. By using 2373 contextual dataset which was compiled from college students, we have obtained the best results with classifiers such as bagging, random subspace, and decision tree with the multi-label classification estimation methods like binary relevance(BR), binary pairwise classification (PW).

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.207-210
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• 2009

According to the recent demand for materials for use in various displays and solid state lightings, new phosphors with improved performance have been pursued consistently. Multi objective genetic algorithm assisted combinatorial material search (MOGACMS) strategies have been applied to various multi-compositional inorganic systems to search for new phosphors and to optimize the properties of phosphors.

• Journal of Korean Society for Quality Management
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• v.33 no.3
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• pp.59-70
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• 2005

The purpose of this research is to identify the impact of trust on user acceptance of mobile banking and to identify if causalities among these factors are different between Internet and mobile banking. To test this model, this research applies the technology acceptance model(TAM) that incorporates trust. Additionally, this research use structural equation modeling to test the model and examine cross-group differences using a multi-group comparison method. The empirical results indicate that all path is significant expect the path from trust to intention to use. The results of a multi-group comparison test indicated that the path from trust to attitude, from trust to intention to use, from perceived usefulness to attitude and from perceived to intention to use are different between Internet and mobile banking.

• KIEAE Journal
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• v.6 no.1
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• pp.39-46
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• 2006

Multi-use housing and commercial buildings have been emerged according to social and economic changes of CBD in Seoul Metropolitan Areas. The purpose of this study is to clarify the characteristics of the multi-use building, to analyze the problems on the base of survey and to suggest the solutions for architectural planning, focusing on eco-friendly dwelling environment. A field survey with 46 subjects has been carried out with structured questionnaire. Some problems in planning of the complex building have been discussed in terms of environmental issues and design criteria. In conclusion, basic planning directions for improving the building environmental quality have been suggested.