• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.4
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• pp.436-442
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• 2006

It is important matter that inflect well allocated frequency resource in cellular network and is still more serious element in environment that provide multimedia services. Also, that do that make job scheduling how base station system or terminal according to this service request is important constituent that evaluate performance of whole system. channel allocation according to service kind causes big effect to whole system when hand off gets up in cellular network. This paper describes model and algorithm that increase two elements that is frequency allocation and job scheduling that consider multimedia service traffic special quality by emphasis that do mapping present in CDMA cellular system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.305-321
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• 2012

Since Internet Protocol (IP) is the most important protocol in Next Generation Networks (NGNs), 3rd Generation Partnership Project (3GPP) utilizes Session Initial Protocol (SIP) based on IP as the base protocol for negotiating sessions in IP Multimedia Subsystem (IMS). Different from traditional circuit-switched network, in IMS, the media traffic and signaling are delivered through IP transport. The media traffic may affect the signaling efficiency in core network, due to traffic collisions and best effort packets delivery. This paper proposes a novel path-migration mechanism for enhancing the traffic efficiency in integrated NGN-IMS. The simulation results show that the interference and traffic collision can be reduce by applying proposed path-migration mechanism and the signaling efficiency in core network can be improved with higher system capability and voice quality.

• Journal of Korea Multimedia Society
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• v.24 no.11
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• pp.1526-1537
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• 2021

Due to the difference between the underwater communication environment and the terrestrial communication environment, the radio communication mainly used on the ground cannot be used in underwater. For this reason, in the underwater communication environment, various communication media such as acoustic waves, infrared rays, light and so on has been studied, but there exist several difficulties in operating them individually due to their physical limitations. The concept for overcoming these difficulties is the very underwater multi-media communication, a method to select a communication medium best suitable for the current underwater environment among underwater communication multimedia whenever there occurs underwater communication failure. In this paper, we present an underwater multi-media communication network based on star topology and a fragmentation and reassembly technique to solve the problems caused by the different MTU (Maximum Transmission Unit) sizes among different underwater communication media. We also present the estimations and analysis on processing times in each of fragmentation and reassembly and the total data amount for transmitting fragments in our proposed underwater multi-media communication network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.524-526
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• 2022

Considering QoS only considering real-time multimedia service, it is possible to adjust the number of terminals and ensure them appropriately, but this study considers complex services considering real-time multimedia service and general data service. Since the amount of physical network resources is limited, the guarantee of the desired QoS can not be achieved unless the appropriate CAC is done. However, given the traffic profile and QoS spec of the entire network resource and the current service being provided, and the traffic profile and QoS spec of the newly requested service, it is quite difficult to determine exactly whether the new service request is acceptable from this. To do this, it is necessary to study in various directions from mathematical analysis to various simulations and statistical research based on data obtained from actual network operation.

• Journal of Korea Multimedia Society
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• v.18 no.4
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• pp.506-523
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• 2015

The intent is to determine whether or not the custody transfer is helpful for data transmission in challenging underwater communications when running Bundle protocol or underwater protocols. From the point of view defending side, Underwater Acoustic Network (UAN) will be a serious threat for its strong functionality long rang and high precision of surveillance and detection. Therefore, countermeasures must be taken to weaken its effect. Our purpose is analyzed that how to benefit from the UIoT to learn from, exploit and preserve the natural underwater resources. Delay/Disruption Tolerant Network (DTN) is essential part of the network heterogeneity communication network. The vulnerability and potential security factors of UIoT are studied thereafter. Security mechanisms for an underwater environment are difficult to apply owing to the limited bandwidth. Therefore, for underwater security, appropriate security mechanisms and security requirements must be defined simultaneously. The paper consists of mathematical and security model. Most important point of view in the security challenges of effective Buffer and Storage management in DTN.

• Journal of Korea Multimedia Society
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• v.12 no.7
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• pp.1022-1031
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• 2009

In this paper, we propose a researcher modeling technique based on ontology and construct social network for researchers using diverse relational properties. User ontology schema is created by extending the existing HR-XML model for a researcher model. User ontology schema and instance are created by OWL. We compose social network model for efficient cooperation between researchers using static relational properties such as educational background and dynamic relational properties such as co-authors and co-workers, etc. Closeness has direction because researcher network is differently configured by the researchers. We define inferencing rules using SWRL and inference ontology rules using racer inference machine to compose direct relationships between researchers. The proposed model for researchers can be applied to the cooperation model for researchers by retrieving common expert group dynamically.

• Journal of Internet Computing and Services
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• v.16 no.6
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• pp.133-141
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• 2015

Mass multimedia contents are shared through various social media servies including social network service. As social network reveals user's current situation and interest, highly satisfactory personalized recommendation can be made when such features are applied to the recommendation system. In addition, classifying the music by emotion and using analyzed information about user's recent emotion or current situation by analyzing user's social network, it will be useful upon recommending music to the user. In this paper, we propose a music recommendation method that makes an emotion model to classify the music, classifies the music according to the emotion model, and extracts user's current emotional state represented on the social network to recommend music, and evaluates the validity of our method through experiments.

• Journal of Korea Multimedia Society
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• v.12 no.4
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• pp.540-549
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• 2009

An arbitrary mobile device configures Ad-hoc network to provide the transmission of a data and services using wireless communications. A mobile device requires authentication and encryption key management to securely communicate in the Ad-hoc network. This paper examines the trend of the authentication in the Ad-hoc network and the group key management and suggests the plan for ID-based mutual authentication and group key establishment. ID-based mutual authentication in proposed scheme uses zero knowledge in the absence of shared information and is applied to establish a session key and group key. In addition, the proposed scheme is applied to Ad-hoc network to increase the efficiency and the safety of security technology.

• Journal of Korea Multimedia Society
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• v.8 no.8
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• pp.1108-1118
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• 2005

A mobile Ad Hoc network is a dynamic mobile wireless network that can be formed without the need for any pre-existing wired or wireless infrastructure. A mobile ad hoc node has limited battery capacity. Hence, Ad Hoc routing protocol ought to be energy conservative. Previous energy aware routing has limit in fairness among nodes and network wide power consumption. In this research, we propose a new routing protocol called Clustering Based Energy-Aware Routing(CBEAR) which can improve the problems. Simulation results show that the routing protocol improves fairness and network wide power consumption as well as life time of nodes.

• Journal of Korea Multimedia Society
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• v.9 no.3
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• pp.333-341
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• 2006

Recently, Random Constant worm is increasing The worm retards the availability of the overall network by exhausting resources such as CPU resource and network bandwidth, and damages to an uninfected system as well as an infected system. This paper analyzes the Power-Law network which possesses the preferential characteristics to restrain the worm from spreading. Moreover, this paper suggests the model which dynamically controls the spread of the worm using information about depth distribution of the delivery node which can be seen commonly in such network. It has also verified that the load for each node was minimized at the optimal depth to effectively restrain the spread of the worm by a simulation.