• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.33-41
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• 2015

With rapid rise of virtualization technology from diverse types of cloud computing service, security problems such as data safety and reliability are the issues at stake. Since damage in virtualization layer of cloud service can cause damage on all host (user) tasks, Hypervisor that provides an environment for multiple virtual operating systems can be a target of attackers. This paper propose a security structure for protecting Hypervisor from hacking and malware infection.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1236-1251
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• 2013

Sharing geo-tagged photos has been a hot social activity in the daily life because these photos not only contain geo information but also indicate people's hobbies, intention and mobility patterns. However, the present raw geo-tagged photo routes cannot provide information as enough as complete GPS trajectories due to the defects hidden in them. This paper mainly aims at analyzing the large amounts of geo-tagged photos and proposing a novel travel route restoring method. In our approach we first propose an Interest Measure Ratio to rank the hot spots based on density-based spatial clustering arithmetic. Then we apply the Hidden Semi-Markov model and Mean Value method to demonstrate migration discipline in the hot spots and restore the significant region sequence into complete GPS trajectory. At the end of the paper, a novel experiment method is designed to demonstrate that the approach is feasible in restoring route, and there is a good performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.6
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• pp.3029-3045
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• 2017

The main processes of a cognitive radio system include spectrum sensing, spectrum decision, spectrum sharing, and spectrum conversion. Experimental results show that these stages introduce a time delay that affects the spectrum sensing accuracy, reducing its efficiency. To reduce the time delay, the frequency spectrum prediction was proposed to alleviate the burden on the spectrum sensing. In this paper, the deep recurrent neural network (DRNN) was proposed to predict the spectrum of multiple time slots, since the existing methods only predict the spectrum of one time slot. The continuous state of a channel is divided into a many time slots, forming a time series of the channel state. Since there are more hidden layers in the DRNN than in the RNN, the DRNN has fading memory in its bottom layer as well as in the past input. In addition, the extended Kalman filter was used to train the DRNN, which overcomes the problem of slow convergence and the vanishing gradient of the gradient descent method. The spectrum prediction based on the DRNN was verified with a WiFi signal, and the error of the prediction was analyzed. The simulation results proved that the multiple slot spectrum prediction improved the spectrum efficiency and reduced the energy consumption of spectrum sensing.

• Proceedings of the Technology Innovation Conference
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• 1997.12a
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• pp.104-130
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• 1997

This study empirically examined different patterns of collaborative R&D project with their key success factors(KSFs), using data from 80 projects in the Korean electronic parts industry The patterns in this study were categorized into 4 types by two criteria : product types(off-the-shelf/unique) and project initiator (focal/partner). The bivariate relationships revealed that project characteristics (technological complexity, demand certainty), partner characteristics(the number of partners, precious experience), process characteristics (participation in the project formulation, specificity of the collaboration process and outcomes) appear to be different among four types of collaboration. Furthermore, this study found that each type of collaborative R&D projects has different KSFs for their commercial success. The KSFs of type 1 (off-the-shelf product and focal organization initiation), for instance, include the strategic importance of the project, the problem solving performance of the focal organization while those of type 4(unique product and partner initiation) are technological complexity, demand certainty, reliability of partner relationship, specificity of the goals, specificity of the process and outcomes, information sharing. Finally, based on this empirical results, managerial, policy, and theoretical implications of the study were discussed.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.139-142
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• 2005

Recently research interest in Knowledge Management (KM) has grown rapidly. Companies regard intellectual capital as important asset and strive to deploy KM in an organization to gain a competitive edge. Many organizations currently engage in knowledge management in order to leverage knowledge both within their organization and externally to their shareholders and customers. Most of the previous research related to KM are dedicated to investigate the role of information technology in extracting, capturing, sharing, coverting organizational knowledge. Knowledge workers, however, are paid less attention though they are the key players in KM activities such as knowledge creation, dissemination, capture and conversion. We regard knowledge workers as a major component of KM and starting point of understanding organizational knowledge activities. Therefore we adopt a method to understand and analyze knowldge workers' social relationships. In this paper we investigate Social Network Analysis (SNA) as a tool for analyzing knowledge network. We introduce the basic concept of SNA and suggest a framework for implementing knowledge network by explaining how SNA can be used for analyzing knowledge network. We also propose a numerical method for identifying knowledge workers using SNA after classifying knowledge workers. The suggested method is expected to help understanding key knowledge players within an organization.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.249-255
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• 2014

Recently, creation and sharing of information make progress actively through the SNS(Social Network Service) such as twitter, facebook and so on. It is necessary to extract the knowledge from aggregated information and data mining is one of the knowledge based approach. Especially, emotion analysis is a recent subdiscipline of text classification, which is concerned with massive collective intelligence from an opinion, policy, propensity and sentiment. In this paper, We propose the emotion prediction method, which extracts the significant key words and related key words from SNS paragraph, then predicts the emotion using these extracted emotion features.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.6
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• pp.1996-2013
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• 2015

This paper considers a scenario that more D2D users exist in the cell, they compete for cellular resources to increase their own data rates, which may cause transmission interference to cellular users (CU) and the unfairness of resource allocation. We design a resource allocation scheme for selfish D2D users assisted by cooperative relay technique which is used to further enhance the users' transmission rates, meanwhile guarantee the QoS requirement of the CUs. Two transmission modes are considered for D2D users: direct transmission mode and cooperative relay transmission mode, both of which reuses the cellular uplink frequency resources. To ensure the fairness of resource distribution, Nash bargaining theory is used to determine the transmission mode and solve the bandwidth allocation problem for D2D users choosing cooperative relay transmission mode, and coalition formation game theory is used to solve the uplink frequency sharing problem between D2D users and CUs through a new defined "Selfish order". Through theoretical analysis, we obtain the closed Nash bargaining solution under CUs' rate constraints, and prove the stability of the formatted coalition. Simulation results show that the proposed resource allocation approach achieves better performance on resource allocation fairness, with only little sacrifice on the system sum rates.

• Journal of Distribution Science
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• v.12 no.3
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• pp.85-98
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• 2014

Purpose - This study primarily aims to represent the current trend of research on CPFR as a promising supply chain collaboration program and proposes a new framework for analyzing any collaboration programs in terms of three key collaborative features. Research design, data, and methodology - This study employs a literature review of selected studies that conduct research on CPFR. CPFR is analyzed based on the proposed framework that characterizes collaboration programs in terms of three key collaborative features. Results - The analysis based on the proposed framework reveals that the current form of CPFR continues to have some collaborative features that are not fully utilized to create an advanced collaboration program. The literature review indicates that most past studies ignore critical issues including the dynamic nature of the multiple-stage supply chain system and negotiation process for collaborative agreement in CPFR implementation. Conclusions - Results indicate that CPFR can become a better supply chain collaboration program by incorporating coordinative cost payment and joint decision making processes. Based on observations on the existing literature of CPFR, this study indicates several important issues to be addressed by future studies.

• The Journal of Society for e-Business Studies
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• v.9 no.2
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• pp.87-108
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• 2004

The current construction industry mainly uses paper-based construction documents which are produced during the whole life cycle. The paper-based information hinders to reuse the construction information, due to the inefficiency to exchange and share the construction information between designers and constructors. To overcome these problems, construction CALS/EC (Continuous Acquisition and Life Cycle Support/Electronic Commerce) has been proposed by the government. It supports efficient reusing, sharing and exchanging the construction information using digitalized drawings and documentations. This study intends to show the future applying methodologies of using the standardized key technologies in the construction CALS/EC based on the case study of Korea and several countries.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.237-240
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• 2012

This paper describes an implementation of ARIA crypto algorithm which is a KS (Korea Standards) block cipher algorithm. The ARIA crypto-core supports three master key lengths of 128/192/256-bit specified in the standard and the four modes of operation including ECB, CBC, CTR and OFB. To reduce hardware complexity, a hardware sharing is employed, which shares round function in encryption/decryption module with key initialization module. The ARIA crypto-core is verified by FPGA implementation, the estimated throughput is about 1.07 Gbps at 167 MHz.