• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.2
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• pp.65-71
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• 2013

Nonlinear loads with harmonics exist in an actual power system where harmonic currents make voltage distortion. The sum of reactive power measured at individual load is different from the measured reactive power at a bus in a power system with linear and non-linear loads. In this study, ANN(artificial neural network) load modeling technique with consideration of harmonics is introduced for more accurate component load modeling and an impact coefficient is proposed for aggregation of component loads. Results of this research show more accurate load modeling method. Since precise data for power system analysis can be acquired, the proposed method will be used for power system planning and maintenance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.138-143
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• 2005

A hierarchical tree structure of clusters has advantages for the network design due to its scalability and simple routing protocol. In this paper, the cluster tree routing protocol is studied for the wireless sensor network. From the numerical analysis results, the data aggregation in the intermediate nodes reduces the number of communication message and saves the energy of sensor nodes, but it may result in increased data traffic latency. And also the selection of cluster head can increase the relaying hops very high.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7B
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• pp.602-607
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• 2006

A subscriber-oriented service became necessary for the QoS management due to the development of network. BcN(Broadband convergence Network) which incorporates communication, broadcasting and internet not only improves the quality of the communication and broadcasting service but also. aims at broadband service. Therefore, QoS management for each subscriber becomes more important. Not yet, however, the discussion for the subscriber oriented QoS management is not activated. Although, there are several techniques for subscriber distinction using flow information, IP information or MAC information, but they are only processed in layer 3 network. Actually, it is impossible to manage QoS of all subscriber's in layer 3 network. In this paper, we propose a method for QoS management scheme that does not need additional processes or large hardware in layer 2 network and analyze efficiency and overheads. We propose the first subscriber-oriented service method in layer 2 network that is applicable to either existing network or BcN.

• ETRI Journal
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• v.30 no.2
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• pp.238-248
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• 2008

At the extremes of the complexity-performance plane, there are two exemplary QoS management architectures: Integrated Services (IntServ) and Differentiated Services (DiffServ). IntServ performs ideally but is not scalable. DiffServ is simple enough to be adopted in today' core networks, but without any performance guarantee. Many compromise solutions have been proposed. These schemes, called quasi-stateful IntServ or stateful DiffServ, however, have not attracted much attention due to their inherently compromising natures. Two disruptive flow-based architectures have been recently introduced: the flow-aware network (FAN) and the flow-state-aware network (FSA). FAN's control is implicit without any signaling. FSA's control is even more sophisticated than that of IntServ. In this paper, we survey established QoS architectures, review disruptive architectures, discuss their rationales, and points out their disadvantages. A new QoS management architecture, flow-aggregate-based services (FAbS), is then proposed. The FAbS architecture has two novel building blocks: inter-domain flow aggregation and endpoint implicit admission control.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.3
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• pp.416-420
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• 2002

Traditional queueing analyses are very useful for designing a network's capacity and predicting there performances, however most of the predicted results from the queueing analyses are quite different from the realistic measured performance. And recent empirical studies on LAN, WAN and VBR traffic characteristics have indicated that the models used in the traditional Poisson assumption can't properly predict the real traffic properties due to under estimation of the long range dependence of network traffic and self-similarity In this parer self-similar characteristics over statistical approaches and real time network traffic measurements are estimated It is also shown that the self- similar traffic reflects network traffic characteristics by comparing source model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.104-107
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• 2002

Traditional queueing analyses are very useful for designing a network's capacity and predicting there performances, however most of the predicted results from the queueing analyses are quite different from the realistic measured performance. And recent empirical studies on LAN, WAN and VBR traffic characteristics have indicated that the models used in the traditional Poisson assumption can't properly predict the real traffic properties due to under estimation of the long range dependence of network traffic and self-similarity. In this paper self-similar characteristics over statistical approaches and real time network traffic measurements are estimated. It is also shown that the self-similar traffic reflects network traffic characteristics by comparing source model.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.481-484
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• 2000

In this paper, we describe the design and implementation of IPv6 LAN. The legacy protocol for Internet is IPv4(IP version 4). The ability of IPv4 is not enough for modern real time multimedia communication services. So IPv6(IP version 6) protocol was suggested to resolve the problems of IPv4. We implemented IPv6 LAN using sTLA(sub Top Level Aggregation identifier) address and KOREN(KOrea Research and Experimental Network). Our IPv6 LAN is connected with 6TAP(Chicago), WIDE(Tokyo), and SingAREN(Singapore). We used a dedicated router, Windows 2000 PC host FreeBSD PC host, Solaris 7 workstation and Solaris 8 workstation for IPv6 NDP(Neighbor Discovery Protocol) protocol test. To support all data services including voice and video, IP protocol should be enhanced because the characteristics of modern network services are requiring QoS(Quality of Service) functions, auto-configuration, security, mobility and so on. So a new IP protocol, IPv6, has been developing to meet the requirements. In this paper, we introduce the implementation method and configuration information of IPv6 LAN.

• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.169-174
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• 2010

EPCIS(EPC Information Services) system is a core component of EPCglobal Architecture Framework offering information of the freights, the time of awareness and the location of awareness on the EPCglobal Network. The role of EPCIS is to exchange information based on EPC. There are four kinds of event data which are object event data, aggregation event data, quantity event data, and transaction event data. These EPCIS events data are stored and managed in EPCIS repository. This paper deals with the method which diversifies the data flow load of intensive EPCIS events and effectively manages EPCIS repository for exchanging data smoothly. In order to verify a effectiveness, we measure the performance of the system using a simulation by comparing the existing method with the suggested method.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.6
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• pp.695-701
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• 2014

Blackhole attacks having a unauthorized change of routing data will cause critical effects for transmission performance. The transmission performance will be improved to the a certain level by using or having IDS(Intrusion Detection System)/IPS(Intrusion Prevention System) as countermeasures to blackhole attacks. In this papar, the effects of IDS to ene-to-end performance of packet aggregation transmission are analyzed on MANET(Mobile Ad-hoc Network) with IDS under blackhole attacks. MANET simulator based on NS-2 is used to analyze performance parameters as MOS, connection ratio, delay and packet loss rate as standard performance parameters, an another performance factor which is suggested in this paper. VoIP(Voice over Internet Protocol) traffics, one of voice services, is used for performance analysis. A suggestion for IDS implementation on MANET with packet aggregations under blackhole is shown as one of results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.7
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• pp.1759-1772
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• 2023

Chinese named entity recognition (NER) is a challenging work that seeks to find, recognize and classify various types of information elements in unstructured text. Due to the Chinese text has no natural boundary like the spaces in the English text, Chinese named entity identification is much more difficult. At present, most deep learning based NER models are developed using a bidirectional long short-term memory network (BiLSTM), yet the performance still has some space to improve. To further improve their performance in Chinese NER tasks, we propose a new NER model, IDCNN-BiLSTM-Highway, which is a combination of the BiLSTM, the iterated dilated convolutional neural network (IDCNN) and the highway network. In our model, IDCNN is used to achieve multiscale context aggregation from a long sequence of words. Highway network is used to effectively connect different layers of networks, allowing information to pass through network layers smoothly without attenuation. Finally, the global optimum tag result is obtained by introducing conditional random field (CRF). The experimental results show that compared with other popular deep learning-based NER models, our model shows superior performance on two Chinese NER data sets: Resume and Yidu-S4k, The F1-scores are 94.98 and 77.59, respectively.