• Journal of Korea Multimedia Society
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• v.24 no.1
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• pp.67-74
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• 2021

As IoT(Internet Of Things) devices like a smart sensor have constrained power sources, a power strategy is critical in WSN(Wireless Sensor Networks). Therefore, it is necessary to figure out the residual power of each sensor node for managing power strategies in WSN, which, however, requires additional data transmission, leading to more power consumption. In this paper, a residual power estimation method was proposed, which uses ignorantly small amount of power consumption in the resource-constrained wireless networks including WSN. A residual power prediction is possible with the least data transmission by using Machine Learning method with some training data in this proposal. The performance of the proposed scheme was evaluated by machine learning method, simulation, and analysis.

• Journal of the Korea Computer Industry Society
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• v.3 no.9
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• pp.1251-1260
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• 2002

Real-time application programs have synchronization constraints which need to be met between media-data. Synchronization method represents feedback method including virtual client-side buffer. This buffer is used in buffer level method. It is client-leading synchronization that is absorbing variable transmission delay time and that is synchronizing by feedback control. It is the important factor for playback rate and QoS if the buffer level is normal or not. To solve the problems, we can control the start of transmission in multimedia server by appling filtering, control and network evaluation function. Synchronization method is processing for smooth presentation without cut-off while media is playing out. When audio frame which is master media is in high threshold buffer level we decrease play out time gradually, otherwise we increase it slowly.

• Journal of Korea Multimedia Society
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• v.15 no.3
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• pp.372-379
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• 2012

This paper presents a group based propagation method for multi-hop transmission, in order to deliver an emergency message to the reasonable size of vehicle troop. A group head is selected in considering of the position information of vehicles and radio transmission range. With benefits of the group based transmission, it is possible to minimize the unnecessary transmissions and the possibility of message collisions. We evaluate the performance of the proposed scheme compared with conventional schemes. Simulation results show that the message propagation performance is so stable regardless of vehicle's congestion degree.

• Journal of Multimedia Information System
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• v.5 no.1
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• pp.27-34
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• 2018

In recent years, with the blooming of Internet of Things (IoT) and Cloud Computing (CC), researchers have begun to discover new methods of technological support in all areas (e.g. health, transport, education, etc.). In this paper, in order to achieve a type of network that will provide more intelligent media-data transfer new technologies were studied. Additionally, we have been studied the use of various open source tools, such as CC analyzers and simulators. These tools are useful for studying the collection, the storage, the management, the processing, and the analysis of large volumes of data. The simulation platform which have been used for our research is CloudSim, which runs on Eclipse software. Thus, after measuring the network performance with CloudSim, we also use the Cooja emulator of the Contiki OS, with the aim to confirm and access more metrics and options. More specifically, we have implemented a network topology from a small section of the script of CloudSim with Cooja, so that we can test a single network segment. The results of our experimental procedure show that there are not duplicated packets received during the procedure. This research could be a start point for better and more efficient media data transmission.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.831-841
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• 2003

In wireless ATM network, Mobile terminals must offer function and QoS such as terminal of wire ATM network. The fast notification of BS (Base Station) scheduler about ATM cells arriving in mobile terminals is a critical item of the ATM-based centrally controlled MAC protocol. But, Collision is arisen at process that several mobile terminals require data transmission by contention method through uplink and because of re-transmission by collision, throughput of decrease and transmission delay increases. In this paper, We propose the MAC protocol that decide optimized request mini-slot's number considering number of request terminal predicted as statistical and its posterior throughput. According to simulation result, could know that proposed protocol shows high performance delay and throughput.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5A
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• pp.474-481
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• 2010

In this paper, we present an effective cross layer-based video transmission algorithm over multi-hop mobile ad hoc networks. The proposed algorithm selects the most efficient PHY mode of wireless LAN multi-rate service at each node in a distributed way based on the available information at application, MAC, and physical layers in order to minimize end-to-end delay and maintain packet loss rate in tolerable range at the receiver. Finally, experimental results are provided to show superior performance of the proposed algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3B
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• pp.232-238
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• 2006

We propose a novel call admission control scheme which improves the handoff drop and the new call block probabilities of high priority services, minimizing the negative impact on low priority services, in multimedia service cellular networks. This paper proposes three schemes to solve this problem; the packing scheme in which available channels of a cell distributed to each frequency channel are concentrated on one frequency channel and a high transmission rate service is assigned to the frequency channel; the queuing scheme in which the queue is used for high transmission rate calls; and the power reallocation scheme in which the power assigned to calls under service is temporarily reduced and a high transmission rate service is allowed. The simulation results revealed that our scheme improved the drop and the block probabilities of the high priority services compared with the conventional scheme.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.723-726
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• 2000

In this paper, we present an abstract object-oriented plat-form model .suitable for the real-time distributed telecommunication system. The proposed platform is constructed upon the extended version of the real-time, distributed operating system, SROS(Scalable Real-time Operating System), that is developed at ETRI and successfully operated in the ATM switching system for several years. The object-oriented software development and maintenance methodology will resolve the current software crisis in the area of telecommunication and switching systems due to the everlasting maintenance about the huge amount of the existing software and the ever increasing needs for the better and new communication services. In general, an object-oriented software platform realizes the object-oriented methodology and possesses many good aspects like high productivity, better reusability, easy maintenance, et at. The platform is also designed to present the distributed multimedia service in addition to real-time event delivery. Recently, we have been implementing a couple of prototype bated on the proposed platform. Reflecting the evaluation results from these prototypes, the final platform specification will be determined.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11B
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• pp.693-699
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• 2007

In this Paper we present analysis of efficiency for various encapsulation methods to transport IP datagram over terrestrial digital multimedia broadcasting (T-DMB). The multimedia broadcasting system transmitted in one-way needs the data reliability for efficient transmission. And then It is able to select the independent data service using If encapsulation over T-DMB. We examine the compatibility in adopting T-DMB and the overhead of transmission occurring encapsulation. it also needs the full analysis of data framing because the cost of return channel is relatively higher. We do analysis based on theoretical calculation and propose an efficient, reliable and adaptable method in T-DMB.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.242-242
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• 2003