• ETRI Journal
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• v.37 no.2
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• pp.380-386
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• 2015

Guaranteeing quality of service over a multihop wireless network is difficult because end-to-end (ETE) delay is accumulated at each hop in a multihop flow. Recently, research has been conducted on network coding (NC) schemes as an alternative mechanism to significantly increase the utilization of valuable resources in multihop wireless networks. This paper proposes a new section-based joint NC and scheduling scheme that can reduce ETE delay and enhance resource efficiency in a multihop wireless network. Next, this paper derives the average ETE delay of the proposed scheme and simulates a TDMA network where the proposed scheme is deployed. Finally, this paper compares the performance of the proposed scheme with that of the conventional sequential scheduling scheme. From the performance analysis and simulation results, the proposed scheme gives more delay-and energy-efficient slot assignments even if the NC operation is applied, resulting in a use of fewer network resources and a reduction in ETE delay.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.244-246
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• 2008

EMTP-RV is the very powerful program to analyze the dynamic operation of the power system. To use this package in the large complex power system, it is very important to simplify the power system to simple equivalent network. In our study the 100 MVA STATCOM is placed at 345kV "MIGUM" which is the one of the 345kV substations of the Korean Electric Power System that is consist of more than 1000 bus. MIGUM substation is connected with 7 separated transmission lines to main Korean Electric power system. We developed a new method to simplify the network except the substation that we want to analysis. The power system outside the 345kV substation is modeled into the equivalent network. The loop network outside the substation can be modeled to simplified Thevenin equivalent network. The proposed method is applied to IEEE-14 Reliability Test System and the results shows the effectiveness of the method.

• Korean Management Science Review
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• v.12 no.3
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• pp.97-115
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• 1995

Information sharing and automated office in the use of PC necessitate corporate network to implement business innovation. Building an efficient network requires competent knowledge on capabilities of various LAN technologies, hardwares and softwares that have rapidly improved in terms of efficiency and cost. This paper compares capabilities of network components: communication protocol, hardware, network operation system, low cost database software and mid-range priced SQL for application development. Also this study presents a new technology on virtual LAN and a selection guide among the various options of the network components which are suitable for PC-based small-sized network in balance of efficiency with economy. In the last section of this paper, a case of small-sized network is given for illustration.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1382-1385
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• 2002

By managing various communication networks collectively, Telecommunication Management Network (TMN) has appeared as a concept to aim for the unified and effective communication network operation and maintenance. IMT-2000 and other network such as PSTN, cellular networks and packet witching network that are integrated with IMT-2000 have been developed in different platforms - hardware and operating system, and a same circumstance will happen in the maintenance in the future. Also, it is difficult to approach to the standard for Ｑ3 interface implementation of the agent in TMN system that may occur in the development or the maintenance for the different platform of IMT-2000 and other networks that are integrated with IMT-2000. In order to solve this kind of Problems, this Paper suggests integrated network management agent of IMT-2000 based on the NTS model and Advanced Intelligent Network(AIN).

• Journal of IKEEE
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• v.23 no.4
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• pp.1314-1320
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• 2019

In this paper, we propose a new method for optimizing bit operations and applying them to DNN(Deep Neural Network) in software environment. As a method for this, we propose a packing function for bitwise optimization and a masking matrix multiplication operation for application to DNN. The packing function converts 32-bit real value to 2-bit quantization value through threshold comparison operation. When this sequence is over, four 32-bit real values are changed to one 8-bit value. The masking matrix multiplication operation consists of a special operation for multiplying the packed weight value with the normal input value. And each operation was then processed in parallel using a GPU accelerator. As a result of this experiment, memory saved about 16 times than 32-bit DNN Model. Nevertheless, the accuracy was within 1%, similar to the 32-bit model.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.309-314
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• 2006

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. This paper proposes maximum torque control of IPMSM drive using adaptive learning fuzzy neural network and artificial neural network. This control method is applicable over the entire speed range which considered the limits of the inverter's current md voltage rated value. For each control mode, a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using adaptive teaming fuzzy neural network and artificial neural network. The hybrid combination of neural network and fuzzy control will produce a powerful representation flexibility and numerical processing capability. Also, this paper proposes speed control of IPMSM using adaptive teaming fuzzy neural network and estimation of speed using artificial neural network. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The proposed control algorithm is applied to IPMSM drive system controlled adaptive teaming fuzzy neural network and artificial neural network, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper proposes the analysis results to verify the effectiveness of the adaptive teaming fuzzy neural network and artificial neural network.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2164-2168
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• 2003

Real time control system such as in factory automation fields, defense field, aerospace, railway industries, financial trading and so forth, includes multiple computers on multiple nodes, and share data to process various actions and functions. This is similar to multitasking in a multiprocessor computer system. The task processing efficiency of such system is proportionally increased by process speed of each process computer. And also it is greatly influenced by communication latencies of each node. To provide proper operation of such real time system, a network that can guarantee deterministic exchange of certain amount of data within a limited time is required. Such network is called as a real time network. As for modern distributed control system, the timeliness of data exchange gives important factor for the dynamics of entire control system. In a real time network system, exchanged data are determined by off-line design process to provide the timeliness of data. In other word, designer of network makes up a network data table that describes the specification of data exchanged between control equipments. And by this off-line design result, the network data are exchanged by predetermined schedule. First, this paper explains international standard real time network TCN (Train Communication Network) applied to the KHST (Korean High Speed Train) project. And then it explains the computer program developed for design tool of network data table of TCN.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1695-1700
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• 2011

In this paper, we introduce the network infrastructure in an advanced emu test line in Deabul. New technology has been applied to advanced EMU(DMU, integrated broadcasting system, black box and etc). In order to efficient and safely test of new developed train, failure, operation, status of test line and weather information should be monitored in real time. We has implemented a wireless and optical network infrastructure for reliability and scalability. The wireless communication capability between a car and ground is 20Mbps and back-hole network has 50Mbps of the communication performance. The network between test tracks and control office was established in the optical network. That can improve communication reliability.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.917-921
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• 2004

Principle of mailing list was distributed messages to all subscribers in one time. But mailing list operation has constructed a network traffic problem. Because mailing list manager distributed mails without concentrate on subscriber network. If our network has many of subscribers, there will be redundant data in traffic channel. Submailing list has purpose to reduce problems. Analyses of mailing list characteristic in electronic mail were a feature of submailing list system, which manage by human hand (Network Administrator). That will cause trouble for network traffic if Network Administrator could not seek for mailing list characteristic from e-mails in due time. This article will present ideas and recognize methodology for automatic working in submailing list system. Recognize step begin with capture process, which use to trap e-mail information from transfer channel. Next process is preparing raw data into recognition format. Then the third one is recognize part and find out confidential factor. The last process is make decision and determine which electronic mail has properties of mailing list characteristic. Afterward deliver result to submailing list for carry on.

• Journal of the Korea Society of Computer and Information
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• v.22 no.4
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• pp.75-82
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• 2017

While the internet has evolved in terms of information sharing and efficiency, it is still prone to security attacks and remains vulnerable even when equipped with a security mechanism. Repeated patching against hacks involves excessive wear of system equipment and high costs. Methods of improving network security include the introduction of security equipment and network partitions, but they have not been fully effective. A fundamental solution is the Operation Content Network (OCN), which enables the strengthening of authentication. In this paper, Instead of following the existing TCP/IP system, OCN establishes an immunity-based security system through content-centric communications. Data transmission occurs over a Content Centric Network (CCN), which is provided with a protocol verified by the CCNx group. Areas protected by OCN rely only on CCN for communication without using any IP. As such, it defends the system against unknown attacks, including zero-day attacks.