• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5B
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• pp.771-776
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• 2010

In this paper, we present an efficient centralized dynamic bandwidth allocation scheme with multicasting for asymmetric 10G-Ethernet Passive Optical Networks (10G-EPONs). The proposed scheme is based on multicast-burst polling and provides quality of service (QoS) with class of service (CoS) to different lasses of packets. It is shown that a well-known conventional interleaved polling scheme severely decreases downstream channel capacity for user traffic when the upstream network load is low (avalanche gate frequency). To overcome this problem, we have proposed a multicast burst polling scheme which shows impressively lower downstream bandwidth consumption compare to IPACT and moreover it did not show the light load penalty problem. Simulation results using an OPNET tool show that the multicast burst polling effectively eliminates light-load penalty and minimizes downstream bandwidth consumption under avalanche gate frequencies.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.35-43
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• 2004

An arbitration method is proposed to resolve a collision and arbitrate beacon transmissions in an indoor Positioning system consisting of multiple beacons and listeners. Although two or more beacons may compete to transmit signals simultaneously, a single winner in the competition is determined autonomously through the arbitration process while they are transmitting. So, it can continue to send its data, but the others give up their transmissions during the arbitration process. As a consequence, update rate for location information and channel utilization can be improved by avoiding that all beacons fail due to a collision. Once a beacon succeeds in transmitting its signal, a low-level priority is assigned to it. And a high-level priority is allocated to a beacon which gave up its transmission during arbitration process. This will guarantee every beacon has fair transmission opportunity with the arbitration method. As no centralized control is required among beacons, a Positioning system can still be easily deployed and expanded with this arbitration method.

• Journal of the Korean Society of Costume
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• v.63 no.1
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• pp.56-63
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• 2013

This study provides comparative analysis on the parodying of the body and political powers in the traditional animation and Shrek Series based on the discourse of Foucault. For the research, parody theories and Foucault's discourse were reviewed through the literature study, and Shrek Series was analyzed through positive study. The Shrek Series overturned stereotypes of the traditional animation by means of parody, especially showing a true body and a political power in the post-modern society. Foucault focused on the body and newly changed political power in the post-modern society. A body was changed into resistant and combative forms rather than obedient and submissive under control of the community power. In addition, political power was changed into relationship-oriented, decentralized and creative power rather than the centralized and class-based. In the traditional fairy tales, heroes and heroines are beautiful and perfect characters who obtain wealth and honor and live a happy life forever. However, heros and heroines in the Shrek Series are not attractive and do not have the ideal body shape, but rather have creative and active personalities and show indifference towards wealth and honor. Furthermore, their dress colors show the change into lower value and higher chroma. The Shrek Series is a future-oriented animation which created a fluid body and a creative political power in the post-modern society.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.93-102
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• 2017

Recently increasing usage of smartphones makes the Internet of Things (IoT) a leading technology that can collect and share data through sensor networks and wireless communication such as low-power Bluetooth (BLE). BLE-based application can provide operators more precise information on Automatic Door system by remotely diagnosing the system faults through wireless sensor networks and sensors around the Automatic Door. In this paper, a smart device with extended BLE module is implemented which can monitor and Control the system states and faults remotely without on-site diagnostic. while maintaining system integrity so that increase efficiency of time and costs for system management. We can use the results of this research as a basis in evaluating reliability of data between devices, extending communication module in Controller of obsolete Door systems, and establishing centralized monitoring systems in near future with multi-channel Door Controls.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.669-674
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• 2017

Due to the depletion of fossil fuels and the increase in environmental pollution, electric vehicles are attracting attention as next-generation transportation and are becoming popular all over the world. As the interest in electric vehicles and the penetration rate increase, studies on the charging infrastructure with vehicle-to-grid (V2G) technology and information technology are actively under way. In particular, communication with the grid network is the most important factor for stable charging and load management of electric vehicles. However, with the existing centralized infrastructure, there are problems when control-message requests increase and the charging infrastructure cannot efficiently operate due to slow response speed. In this paper, we propose a new charging infrastructure using mobile edge computing (MEC) that mitigates congestion and provides low latency by applying distributed cloud computing technology to wireless base stations. Through a performance evaluation, we confirm that the proposed charging infrastructure (with low latency) can cope with peak conditions more efficiently than the existing charging infrastructure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.6
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• pp.397-405
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• 2014

Software-Defined Networking (SDN), which separates the control plane from the data plane and manages data planes in a centralized way, is now considered as a future networking technology, and many researchers and practitioners have dived into this area to devise new network applications, such new routing methods. Likewise, network security applications could be redesigned with SDN, and some pioneers have proposed several interesting network security applications with SDN. However, most approaches have just reimplemented some well-known network security applications, although SDN provides many interesting features, They didn't effectively use them. To investigate if we can use SDN in realizing sophisticated network security applications, we have designed and implemented an advanced network security application, Reflectornet, which redirects malicious or suspicious network trials to other security monitoring points (e.g., honeypot). In addition, we have tested its performance and practicability in diverse angles. Our findings and some insights will encourage other researchers to design better or intelligent network security applications with SDN.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.6
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• pp.379-386
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• 2014

Recently, middleboxes play a key role in many network settings such as firewalls, VPN gateways, proxies, intrusion detection and prevention systems, and WAN optimizers. However, achieving the performance and security benefits that middleboxes offer is highly complex, and therefore it is essential to manage middleboxes efficiently and dynamically. In this respect, Software-Defined Networking (SDN) offers a promising solution for middlebox policy enforcement by using logically centralized management, decoupling the data and control planes, and providing the ability to programmatically configure forwarding rules. Also, cloud computing and distributed Network Function Virtualization (NFV) can enable to manage middleboxes more easily. We introduce SDN-based middlebox management framework in integrated wired and wireless networks and discuss the further issues.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.4
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• pp.266-278
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• 2013

In this paper, to manage the efficient control of IP packet flows crossing multi-provider networks such as Internet, we propose a SDN(Software Defined Networking)-based policy controller. The proposed policy controller leverages the visibility of underlying network and manages both virtual links and ports to inter-connect networking elements. The controller is capable of quickly composing multiple on-demand virtual networks and dynamically managing the composed networks, thus it can provide more flexible and optimized overlay networking environment to end-user applications. More specifically, we first look into the proposed structure and features of policy controller. With two kinds of service applications, we then verify the applicability of the proposed controller by evaluating its service composition time.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.7
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• pp.1-10
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• 2002

Multidisciplinary Design Optimization (MDO) is a new design approach, which aims to reduce the design cycle and the development cost, while improving the performance of the product. In order to develop a framework software where the multidisciplinary design is possible, several methods about the analysis codes integration, the analysis and optimization process management, and the software architecture, are proposed in this study. Centralized DataBase Management System (DBMS) is adopted. Both the Dynamic Link Library(DLL) and the File Interface are suggested and implemented as analysis codes integration methods. To efficiently manage the optimization process and the data flow, the Graphic Programming approach is introduced. The proposed integration methods are verified by two test case examples: Simple house design example and the aircraft wing design problem using three dimensional Panel Code.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.1035-1044
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• 1998

A new multi-channel access scheme and the associated network architecture for a single-hop WDM local area network is proposed in this paper. The proposed architecture has Central Scheduling Node (CSN) for the transmission coordination among many users, which is one of the key issues in single-hop WDM networks. The data channels, source nodes, and destination nodes are selected at CSN in very simple menner. Our scheme can relive the control processing overhead at all nodes in the network which is caused in existing distributed scheduling algorithms. CSN is simple in the architecture can be implemented easily. in respect to the network performance, the maximum obtainable throughput is up to that of the ideal output queuing because of collision free scheduling. We use the MQMS (multi-queue multi-server) model for performance analaysis.