• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.5
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• pp.2396-2413
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• 2018

Trust management is one of the most challenging issues for the highly heterogeneous Internet of Things (IoT). In the context of the IoT, it is difficult to evaluate the node's trustworthiness in the same trust model when a node provides different services. Guaranteeing the availability of the trust management service is another significant challenge because of the dynamic nature of IoT environments. With these issues in mind, this paper propose a robust and adaptive trust management system for the IoT that is able to measure the trustworthiness of nodes based on feedbacks collected from participants in a specific context and ensure the availability of trust management services. The main contributions of our system are: 1) Proposing a partly decentralized trust management framework, which improves the resiliency of the trust mechanism; 2) Proposing an adaptive trust evaluation scheme and a three-dimensional context representation makes trust evaluation more accurate and specific; 3) Enhancing the adaptive trust evaluation scheme by incorporating a bad behavior factor in trust estimation, which efficiently distinguishes misleading feedbacks from On-Off attacks. Simulation results show the good performance of the proposed system and especially show effectiveness against On-Off attacks compared to other trust mechanisms.

• Proceedings of the Korea Society of Design Studies Conference
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• 2004.05a
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• pp.294-295
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• 2004

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.1958-1969
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• 1996

This paper proposed a new approach to adaptive call admission control based on a neural network for multiple service classes with different quality of service (QoS) in the ATM-based Broadband Integrated Services Digital Networks. the proposed method extend Hiramatsu's neural network based "leaky pattern table" method for the single QoS[1, 2, 3] to deal with multiple services with different QoS by constructing multiple pattern tables based on each service's acceptance or rejection at the call set-up requests, and by simultaneously controlling each service's QoS according to the target QoS of the service and the trunk capacity. Computer simulation results on two service classes with different traffic characteristics and different cell loss rates as QoS, highlight good performance and effectiveness of the proposed call admission controller for multiple service classes.e classes.

• ETRI Journal
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• v.32 no.5
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• pp.665-675
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• 2010

Recent research on mobile Internet protocol television and digital right management (DRM) interconnections has focused on multimedia technologies designed to enhance content scalability and adaptive content distribution. However, due to the architectural and scalable limitations, recent systems are not flexible and securable with respect to their adaptive content distribution and protective policy management. Therefore, we propose a content protective multi-agent platform that provides secure multimedia services, correlation management, pattern-based management, and multi-source multi-use (MsMu)-based services. Our architecture, supported by DRM, lets us create a rich set of MsMu-based content protection and seamless multimedia services through the extension of one source multi-use (OsMu)-based content services. We have verified our platform, which provides scalable and securable services with a 17% lower service response time by using a testbed.

• International Journal of Contents
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• v.2 no.2
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• pp.10-16
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• 2006

In this paper, we propose a predictive resource metric region (RMR) based radio resource metric estimation (RRME) mechanism, which utilizes a resource metric mapping function (RMMF), both of which permit efficient inter-working between the physical layer and higher layers for envisaging multimedia service applications over a CDMA communication system platform. The RMR can provide the acceptable resource region where QoS and acceptable link quality can be guaranteed with an achievable resource margin to be utilized in terms of capacity margin, the degree of confidence (DCL) of user, second-order statistics of Eb/Io. With predicted capacity margin and variance, DCL can deliver decision parameters with which an adaptive QoS based admission control can perform well taking capacity and resource availability into account in a dynamic and predictive manner. Combined with advanced techniques such as adaptive modulation or rate control and power control, the proposed mechanism can adjust the conventional stringent link quality information efficiently, and deliver accurate information of the resource availability. Thus, these can guarantee the maximization of resource utilization of multimedia service applications.

• Journal of KIISE:Information Networking
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• v.37 no.3
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• pp.234-242
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• 2010

The demand on various broadcasting services has been greatly increasing in the area of mobile communication. In IEEE802.16e standard and mobile WiMAX, the multicast broadcast service (MBS) uses shared downlink channel for efficiently supporting a number of users. In this paper we propose a dynamic modulation and coding scheme with relay network to enhance the performance of MBS. The proposed approach employs the adaptive modulation and coding scheme for both the base station and relay station to achieve consistently high throughput. The result of computer simulation with NS-2 shows that the throughput and transmission time are significantly improved by using the proposed approach compared to the existing schemes having a fixed modulation level for the RSs.

• Journal of the Korean Society for Library and Information Science
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• v.41 no.4
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• pp.229-250
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• 2007

This paper suggested a way to solve the problems by using domain experts who are already in the significant level of knowledge in those fields. For the purpose of achieving our goal, a very simple and efficient approach to construct the knowledge-base which can play an important role in providing researchers with essential information in need was proposed. In addition, the Adaptive R&D Information Service Portal with a new schema structure and a construction method of representing expert's knowledge efficiently was developed. With the simplicity and expandability of the proposed system it can be a good model for a similar system to be developed.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.9
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• pp.495-502
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• 2004

A rapid growth of the Internet user and rich media content cause an excessive server load and high network traffic, and thus it decreases the quality of service. A solution to this problem is to distribute the content on multiple replicated servers. However, in this circumstance, clients face additional task of selecting the best server to provide proper so${\gamma}$vice which clients request. This paper is intended to propose an adaptive server selection mechanism for a client request based on distance and server load. This will offer a fast and scalable service in response to the increase of massive and realtime multimedia content and contribute to floating a new business model of digital content service.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5917-5935
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• 2018

Adaptive Multi-Rate Codec is one of the codecs which is used for making voice calls. It helps to connect people who are scattered in various geographical areas. It adjusts its bit-rate according to the user's channel conditions. It plays a vital role in providing an improved speech quality of voice connection in Long Term Evolution (LTE). There are some constraints which need to be addressed in providing this service profitably. Quality of Service (QoS) is the dominant mechanism which determines the quality of the speech in communication. On several occasions, number of users are trying to access the same channel simultaneously by standing in a particular region for a longer period of time. It refers to Multi-user channel sharing problem which leads to resource loss very often. The main aim of this paper is to develop a novel RSA - QoS scheduling algorithm for reducing the Resource Loss Ratio. Eventually, it increases the throughput.The simulation result shows that the RSA - QoS increases the number of users for accessing the resources better than the existing algorithms in terms of resource loss and throughput. Ultimately, it enhances the QoS in Mobile Networks.

• The Journal of Society for e-Business Studies
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• v.18 no.4
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• pp.25-43
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• 2013

Two of the most important changes in the global market can be represented with Hyper-connection and Glocalization. To cope with these changes and secure the competitive advantages, it is essential to develop the standard organization, policy, processes and criteria for service management. In addition, the service management system is required to effectively support the R&D project management. In this research, an adaptive framework and system architecture for designing R&D project management process using cloud computing has been introduced. With the proposed system, it is able to overcome the limitations of traditional service management and treat the demand from the market in agility. Moreover, it may be possible to present more value than customers want and secure the competitive advantages in the global market with the proposed system.