• Journal of Power Electronics
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• v.2 no.1
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• pp.19-24
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• 2002

The torque of SRM depends on a phase current and the inductance of the motor. But the inductance is saturated nonlinearly according to the position and current. To drive the motor effectively, the control scheme should take into account the nonlinear characteristics of the magnetic material. This paper proposes an optimal control scheme for high efficiency drive of SRM by adjusting both the turn-on and turn-off angle. The high efficiency drive points are simulated and searched by using GA-Neural Network The switching angles are nonlinearly varied with rotor speed and load.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.553-554
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• 2014

이전에 쿠쿠 샌드박스(Cuckoo Sandbox)에서 가지고 있었던 가상환경의 분석환경시스템에서 실머신 기반에서 분석이 가능하도록 구현하는 과정에서 네트워크 덤프(Network Dump)와 관련된 문제가 존재한다. 이런 문제를 해결하기 위해 Server PC와 실머신을 NAT(Network Address Translation)를 사용하여 해결할 수 있는지 알아보고 분석한 결과를 가상머신으로 분석한 결과와 비교하여 차이점이 있는지 알아보고자 한다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.1
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• pp.12-22
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• 2000

This paper presents the window-based permit distribution scheme for efficient medium access control to support multiclass traffic in APON(ATM over passive optical network). The proposed MAC protocol considers the characteristics of QoS(Quality of Service) for various traffic classes. A periodic RAU(request access unit) in upstream direction, includes dedicative request fields for each traffic category within the request slot. The transmission of upstream cell is permitted by the proposed window-based spacing scheme which distributes the requested traffic into several segments in the unit of one spacing window. The delay sensitive traffic source such as CBR or VBR with the stringent requirements on CDV and delay, is allocated prior to any other class. In order to reduce the CDV, so that the permit arrival rate close to the cell arrival rate, Running-Window algorithm is applied to permit distribution processing for these classes. The ABR traffic, which has not-strict CDV or delay criteria, is allocated flexibly to the residual bandwidth in FIFO manner. UBR traffic is allocated with the lowest priority for the remaining capacity. The performance of proposed protocol is evaluated in terms of transfer delay and 1-point CDV according to various offered load. The simulation results show that our protocol has the prominent improvement on CDV and delay performance with compared to the previous protocol.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.701-705
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• 2002

This paper describes implementation of IPv6-IPv4 transition toolbox named as 6TALK(IPv6 TrAansLator of Krv6) and some scenarios using 6TALK which enables IPv6 island to connect other IPv6 island or IPv4 island seamlessly. 6TALK implements some transition mechanisms suggested in NGTrans Working Group of IETF. Those mechanisms are composed of basic mechanism, tunneling, and applied mechanism such as DSTM. 6TALK provides functions which enable IPv6 network at the edge of existing network to communicate with IPv4 network by using these transition mechanisms. As major transition mechanisms in 6TALK we adopt NAT-PT/SIIT and DSTM/DSTM options and as implementation environment we use Linux Kernel 2.4.18 and Netfilter framework. Software modules implemented in Linux kernel was ported to hardware box using Motorola MPC 8260 processor. The transition mechanisms used in 6TALK are the ones predicted to be used in initial transition step to IPv6.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.442-445
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• 2000

Amphiphilic polyurethane(APU) particle is a polymeric surfactant, and could increase the solubility of 2-methylnaphthalene significantly. 2-Methylnaphthalene was recovered by the precipitation of APU particles and was degraded by Acinetobacter sp. K2-2. APU particle was recovered and reused after treatment of triethylamine.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.343-343
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• 2006

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.427-430
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• 2002

The switched reluctance motor (SRM) drive system provides a good adjustable speed characteristics. But driving of SRM is nonlinear changed according to rotor position angle and phase current because of saturation in magnetic circuit, and it is difficult to drive the high efficiency. This paper proposes find point of high efficiency in variable load that are used to control switch-on/off angles and input voltage.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2404-2406
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• 2000

Chua's circuit is a simple electronic network which exhibits a variety of bifurcation and attractors. The circuit consists of two capacitors, an inductor, a linear resistor, and a nonlinear resistor. In this paper, a transmitter and a receiver using two identical Chua's circuits are proposed and synchronizations of a T or ${\pi}$ type power line are investigated. Since the synchronization of the power line system is impossible by coupled synchronization, theory having both the drive-response and the coupled synchronization is proposed. As a result, the chaos synchronization has delay characteristics in the power line transmission system caused by the line parameters L and C

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.01a
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• pp.133-134
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• 2018

본 논문에서는 네트워크상에 연결된 두 개의 단말이 클라우드나 외장형 메모리 없이 파일을 송수신할 수 있는 방법을 제안하고 이를 구현한다. 제안한 방법은 NAT로 나눠진 두 단말사이의 송수신을 위하여 TCP- Relaying 기법을 활용함으로써 데이터의 송수신을 하여 신뢰도는 높이면서 간단한 파일을 송수신할 수 있다.

• Journal of KIISE
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• v.44 no.7
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• pp.668-673
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• 2017

Deep neural networks have shown remarkable performance in various fields of pattern recognition such as voice recognition, image recognition and object detection. However, underlying mechanisms of the network have not been fully revealed. In this paper, we focused on empirical analysis of the network parameters. The Faster R-CNN(region-based convolutional neural network) was used as a baseline network of our work and three important parameters were analyzed: the dropout ratio which prevents the overfitting of the neural network, the size of the anchor boxes and the activation function. We also compared the performance of dropout and batch normalization. The network performed favorably when the dropout ratio was 0.3 and the size of the anchor box had not shown notable relation to the performance of the network. The result showed that batch normalization can't entirely substitute the dropout method. The used leaky ReLU(rectified linear unit) with a negative domain slope of 0.02 showed comparably good performance.