• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.675-687
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• 2017

In the aerospace industry, we have produced various models according to operational conditions and the environment after development of the base model is completed. Therefore, when design change is necessary, there are modification and updating costs of the circuit whenever environment variables change. For these reasons, recently, in various fields, system designs that can flexibly respond to changing environmental conditions using field programmable gate arrays (FPGAs) are attracting attention, and the rapidly changing aerospace industry also uses FPGAs to organize the system environment. In this paper, we design the controller area network (CAN) intellectual property (IP) protocol used instead of the avionics protocol that includes ARINC-429 and MIL-STD-1553, which are not suitable for small unmanned aerial vehicle (UAV) systems at the register transistor logic (RTL) level, which does not depend on the FPGA vender, and we verify the performance. Consequentially, a Spartan 6 FPGA model-based system on chip (SoC) including an embedded system is constructed by using the designed CAN communications IP and Xilinx Microblaze, and the configured SoC only recorded an average 32% logic element usage rate in the Spartan 6 FPGA model.

• Journal of the Korea Society of Computer and Information
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• v.22 no.10
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• pp.83-92
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• 2017

Reconnaissance is performed gathering information from a series of scanning probes where the objective is to identify attributes of target hosts. Network reconnaissance of IP addresses and ports is prerequisite to various cyber attacks. In order to increase the attacker's workload and to break the attack kill chain, a few proactive techniques based on the network-based moving target defense (NMTD) paradigm, referred to as IP address mutation/randomization, have been presented. However, there are no commercial or trial systems deployed in real networks. In this paper, we propose a threat model and the request for requirements for developing NMTD techniques. For this purpose, we first examine the challenging problems in the NMTD mechanisms that were proposed for the legacy TCP/IP network. Secondly, we present a threat model in terms of attacker's intelligence, the intended information scope, and the attacker's location. Lastly, we provide seven basic requirements to develop an NMTD mechanism for the legacy TCP/IP network: 1) end-host address mutation, 2) post tracking, 3) address mutation unit, 4) service transparency, 5) name and address access, 6) adaptive defense, and 7) controller operation. We believe that this paper gives some insight into how to design and implement a new NMTD mechanism that would be deployable in real network.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.6
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• pp.768-773
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• 2010

This paper presents the performance verification of the optimal state feedback controller via inverted pendulum systems. The proposed method generates the optimal control inputs satisfying both the constrained input and the performance specification. In addition, it reduces the steady-state error by adopting the integral control technique. In order to verify the performance of the proposed method, we apply both the proposed method and the general state feedback control to an inverted pendulum, CEM-IP-01 in the experiment.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.215-218
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• 2000

The windup phenomenon appears and degrades control performance when a controller with integrating action is used and the plant input is limited. An anti-windup integral -proportional(IP) controller is proposed for the variable-speed motor drives and it is experimentally applied to the speed control of a vector-controlled induction motor driven by a pulse width modulated (PWM) voltage source inverter(VSI). Although the operating conditions like motor load and speed command is changed under the limited plant input it is experimentally verified that the speed response has much improved performance such as no overshoot and fast settling time and the maximum plant input is also effectively utilized.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1231-1234
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• 1992

In this paper a self-tuning control algorithm has been utilized to control speed of a rolling mill DC drive system. Inner current control loop is composed of predictive current controller and the outer speed control loop is composed of the self-tuning PI or IP controller. Computer simulation results reveal that the adaptive control algorithm using self-tuning control is capable of following the typical set point variations required for a rolling mill in conjunction with load torque variations on the shaft of the drive.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.570-578
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• 1999

This paper aims at developing remote control system to control and monitor distributed various devices t through Internet or information communication network. SNJV!P(Simple Network l\ilanagement Protocol) and R Rectifier system with SN:\IP are adoptL'Cl for applied system with network management protocoJ, respectiveJy. F For controJling and monitoring distributed devices in realtime, Java environment software is constructed. Also g general--purpose interface controller between network device and applied device is pro[XJsed. The ProPOSL'Cl c controller is also able to control various devices with communication network remotely.

• International Journal of Computer Science & Network Security
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• v.23 no.4
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• pp.123-133
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• 2023

Active queue management (AQM) is a leading congestion control system, which can keep smaller queuing delay, less packet loss with better network utilization and throughput by intentionally dropping the packets at the intermediate hubs in TCP/IP (transmission control protocol/Internet protocol) networks. To accelerate the responsiveness of AQM framework, proportional-integral-differential (PID) controllers are utilized. In spite of its simplicity, it can effectively take care of a range of complex problems; however it is a lot complicated to track down optimal PID parameters with conventional procedures. A few new strategies have been grown as of late to adjust the PID controller parameters. Therefore, in this paper, we have developed a Squirrel search based PID controller to dynamically find its controller gain parameters for AQM. The controller gain parameters are decided based on minimizing the integrated-absolute error (IAE) in order to ensure less packet loss, high link utilization and a stable queue length in favor of TCP networks.

• Journal of the Korean Solar Energy Society
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• v.32 no.6
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• pp.106-112
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• 2012

As a fuel cell converts the chemical energy of the fuel cell into electrical energy by electrochemical reaction, the fuel cell system is uniquely integrated technique including fuel processor, fuel cell stack, power conditioning system. The residential fuel cell-PCS(Power Conditioning System) needs to convert efficiently the DC current produced by the fuel cell into AC current using single-phase DC-AC inverter. A single-phase DC-AC inverter has naturally low frequency ripple which is twice frequency of the output current. This low frequency(120Hz) ripple reduces the efficiency of the fuel cell. This paper presents notch filter with IP voltage controller to reject specific 120Hz current ripple in single-phase inverter. The notch filter is designed that suppress just only specific frequency component and no phase delay. Finally, the proposed notch filter design method has been verified with computer simulation and experimentation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.19-24
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• 2018

The IP Multimedia Subsystem(IMS) is an architectural framework for delivering IP multimedia services to mobile users. In order to guarantee the reliability and Quality of Service(QoS) of a variety of multimedia services, we need a new evolutionary approach that maintains the IMS based signaling platform which can perform the processing of flow through distributed controllers. Software Defined Network(SDN) is an architecture purporting to be distributed, dynamic, cost-effectives as well as adapting and seeking to be suitable for the high-bandwidth, dynamic nature of today's applications. It requires some methods for the control plane to communication with the data plane. One of such mechanisms is OpenFlow which is a prominent standard protocol and interface that is responsible for managing the network resources by using the remote SDN controller. In this paper, we propose a straightforward approach for integrating SDN technology together with the IMS architecture. Therefore we propose and construct a combined architecture model that performs flow processing using OpenFlow via the IMS based signaling platform, which maintains the existing telecom call service. Additionally, we describe some relevant experimentation results from the proposed architecture.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.559-566
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• 2016

Software defined network (SDN) can effectively improve the performance of traffic engineering and will be widely used in backbone networks. Therefore, new energy-saving schemes must take SDN into consideration; this action is extremely important owing to the rapidly increasing energy consumption in telecom and Internet service provider (ISP) networks. Meanwhile, the introduction of SDN in current networks must be incremental in most cases, for technical and economic reasons. During this period, operators must manage hybrid networks in which SDN and traditional protocols coexist. In this study, we investigate the energy-efficient traffic engineering problem in hybrid SDN/Internet protocol (IP) networks. First, we formulate the mathematical optimization model considering the SDN/IP hybrid routing mode. The problem is NP-hard; therefore, we propose a fast heuristic algorithm named hybrid energy-aware traffic engineering (HEATE) as a solution. In our proposed HEATE algorithm, the IP routers perform shortest-path routing by using distributed open shortest path first (OSPF) link weight optimization. The SDNs perform multipath routing with traffic-flow splitting managed by the global SDN controller. The HEATE algorithm determines the optimal setting for the OSPF link weight and the splitting ratio of SDNs. Thus, the traffic flow is aggregated onto partial links, and the underutilized links can be turned off to save energy. Based on computer simulation results, we demonstrate that our algorithm achieves a significant improvement in energy efficiency in hybrid SDN/IP networks.