• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.136-141
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• 2007

The frequency accuracy and phase alignment is necessary for ensuring the quality of service (QoS) for applications such as voice, real-time video, wireless hand-off, and data over a converged access medium at the telecom network. As telecom networks evolve from circuit to packet switching, proper synchronization algorithm should be meditated for IP networks to achieve performance quality comparable to that of legacy circuit-switched networks. The Time of Packet (ToP) specified in IEEE 1588 is able to synchronize distributed clocks with an accuracy of less than one microsecond in packet networks. But, The ToP can be affected by impairments of a network such as packet delay variation. This paper proposes the efficient method to minimize the expectable delay variation when ToP synchronizes the distributed clocks. The simulation results are presented to demonstrate the improved performance case when the efficient ToP transmit algorithm is applied.

• The Transactions of the Korea Information Processing Society
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• v.7 no.7
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• pp.2161-2168
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• 2000

Since most of the existing web cache structures are static, they cannot support the dynamic request change of he current WWW users well. Users re generally using multiple programs in several different windows with rapid preference change within a relatively short period of time. We develop a network-path based algorithm. It organizes a cache according to the network path of the requested URLs and build a network cache farm where caches are logically connected with each other and each cache has its own preference over certain network paths. The algorithm has been implemented and tested in a real site. The performance results show that the new algorithm outperforms the existing static algorithms in the hit ratio and response time dramatically.

• Journal of Korea Multimedia Society
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• v.21 no.3
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• pp.391-399
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• 2018

In this paper, we construct and compare various guitar chord classification systems using perceptron neural network and convolutional neural network without pre-processing other than Fourier transform to identify the optimal chord classification system. Conventional guitar chord classification schemes use, for better feature extraction, computationally demanding pre-processing techniques such as stochastic analysis employing a hidden markov model or an acoustic data filtering and hence are burdensome for real-time chord classifications. For this reason, we construct various perceptron neural networks and convolutional neural networks that use only Fourier tranform for data pre-processing and compare them with dataset obtained by playing an electric guitar. According to our comparison, convolutional neural networks provide optimal performance considering both chord classification acurracy and fast processing time. In particular, convolutional neural networks exhibit robust performance even when only small fraction of low frequency components of the data are used.

• International Journal of Control, Automation, and Systems
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• v.6 no.4
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• pp.596-606
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• 2008

In this paper, we present a co-design methodology of dynamic optimal network-bandwidth allocation (ONBA) and adaptive control for networked control systems (NCSs) to optimize overall control performance and reduce total network-bandwidth usage. The proposed dynamic co-design strategy integrates adaptive feedback control with real-time scheduling. As part of this co-design methodology, a "closed-loop" ONBA algorithm for NCSs with communication constraints is presented. Network-bandwidth is dynamically assigned to each control loop according to the quality of performance (QoP) information of each control loop. As another part of the co-design methodology, a network quality of service (QoS)-adaptive control design approach is also presented. The idea is based on calculating new control values with reference to the network QoS parameters such as time delays and packet losses measured online. Simulation results show that this co-design approach significantly improves overall control performance and utilizes less bandwidth compared to static strategies.

• Journal of the Korea Society of Computer and Information
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• v.23 no.10
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• pp.81-86
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• 2018

In the field of mobile games, social network games are steadily increasing in market scale and public interest every year. This paper proposes a method to design a social network game, which is one of the most successful genres in mobile games. The method uses Unity3D, the most commonly used engine for mobile game development. NGUI, a versatile developmental tool of Unity3D, is used to create shops and battle UIs. This paper particularly focuses on how to use the web hosting service to search and operate the necessary data from the database in the server. In addition, the proposed social network game is easy to implement real-time battle using Animator and Raycast, and is characterized by efficient battle implementation through time delay using Coroutine function.

• Journal of the Korean Society for Railway
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• v.10 no.1 s.38
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• pp.88-95
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• 2007

TCN(Train Communication Network) adopts the master/slave protocol to implement real-time communication. In this network, a fault on the master node, cased by either hardware or software failure, makes the entire communication impossible over TCN. To reduce fault detection and recovery time, this paper propose the contention based mastership transfer algorithm. Slave nodes detect the fault of master node and search next master node using the proposed algorithm. This paper also shows the implementation results of a SoC-based Fault-Tolerant MVB Controller(FT-MVBC) which includes the fault-detect-logic as well as the MVB network logic to verify this algorithm.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.6
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• pp.403-408
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• 2005

As the increasing integrity of VLSI, the BIST(Built-In Self Test) is used as an effective method to test chips. Generally the pseudo-random test pattern generation is used for BIST. But it requires too many test patterns when there exist random This paper proposes and presents a new efficient network architecture for Reflective Memory System (RMS). A time to copy shared-data among nodes effects critically on the entire performance of the RMS. In this paper, the recent researches about the RMS are investigated and compared. The device named Topology Conversion Switch(TCS) is introduced to realize the proposed network architecture. One of the RMS based industrial control networks, Ethernet based Real-time Control Network (ERCnet), is adopted to evaluate the performance of the proposed network architecture for RMS.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.721-728
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• 2013

Big data is one of the most spotlighted technological trends in these days, enabling new methods to handle huge volume of complicated data for a broad range of applications. Real-time network traffic analysis essentially deals with big data, which is comprised of different types of log data from various sensors. To tackle this problem, in this paper, we devise a big data based platform, RENTAP, to detect and analyse malicious network traffic. Focused on military network environment such as closed network for C4I systems, leading big data based solutions are evaluated to verify which combination of the solutions is the best design for network traffic analysis platform. Based on the selected solutions, we provide detailed functional design of the suggested platform.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.4
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• pp.693-704
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• 2020

As a company's network structure is getting bigger and the number of security system is increasing, it is not easy to quickly detect abnormal traffic from huge amounts of security system events. In this paper, We propose traffic visualization analysis system(FDANT-PCSV) that can detect and analyze security events of information security systems such as firewalls in real time. FDANT-PCSV consists of Parallel Coordinates visualization using five factors(source IP, destination IP, destination port, packet length, processing status) and Sankey visualization using four factors(source IP, destination IP, number of events, data size) among security events. In addition, the use of big data-based SIEM enables real-time detection of network attacks and network failure traffic from the internet and intranet. FDANT-PCSV enables cyber security officers and network administrators to quickly and easily detect network abnormal traffic and respond quickly to network threats.

• Journal of Korea Game Society
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• v.7 no.2
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• pp.101-112
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• 2007

Along with the development of mobile technology, mobile game has undergone a change from downloadable game to network game, where a large number of users connect to server and play real-time game with a mobile phone. In order to develop these mobile network games economically, a proper, suitable game engine is needed. This study proposes the result of design and implementation of RWMMO-GE(Realtime Wireless Massively Multiplayer Online RPG Game Engine) that is used to develop a mobile network game. The structure of RWMMO-GE, which is the research result of this study, consists of major components such as Network/Client Module, Object Module, Map Tool, Script Editor, and Character Editor. The characteristics of the multiplayer mobile game developed by this engine is that a large number of players can play real-time game in a single map, which implies a possibility of a new business model in this area. This research is a result of the RWMMO-GE supported by 2006 IT Excellent Technology Support Project(No:A1300-0601-0125) of IITA(Institute Information Technology Advancement).