• Transactions of the Society of Information Storage Systems
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• v.9 no.1
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• pp.22-27
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• 2013

In this paper we are presenting a architecture of Co ion decorated graphene oxide as an electrode for supercapacitor application. Graphene oxide, which is exfoliated by oxidant from graphite, is the material for solving the problem of mass production and coating on the surface of working electrode. The $Co^{2+}$ ions are coated by using layer by layer(LBL) method on graphene oxide foam. The metal ion decorated graphene oxide shows enhanced capacitance performance when tested as supercapacitor electrode, showing the specific capacitance of $827Fg^{-1}$.

• Journal of Power Electronics
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• v.12 no.6
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• pp.912-924
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• 2012

In hybrid renewable power systems, the use of a multiple-input dc/dc converter (MIC) leads to simpler circuit and lower cost, when compared to the conventional use of several single-input converters. This paper proposed a novel three-input buck/boost/buck-boost converter, which can be used in applications with various values of input voltage. The energy sources in this converter can deliver power to the load either simultaneously or individually in one switching period. The steady relationship, the power management strategy and the small-signal circuit model of this converter have been derived. With decoupling technology, modeling and regulator design can be obtained under multi-loop control modes. Finally, three generating methods of a multiple-input buck/boost/buck-boost converter is given, and this method can be extended to the other multiple-input dc/dc converters.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3141-3143
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• 1999

Fuel cell systems offer high energy efficiencies for transportation application. In addition, they can use alcohols and alternative fuels as the fuel, while producing little or no noxious emissions. Fuel cell-powered energy source should be competitive in performance characteristics and in capital and maintenance costs with internal combustion engine systems. From computer simulation program, battery and fuel cell energy output and total power profile, motor power, battery energy output, fuel cell energy output. It simulates the performance of fuelcell/battery powered energy source operation over any user inputted transit route cycle, and provides performance criteria through user specifications for preliminary design consideration.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.3
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• pp.261-268
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• 2002

This paper represents that auto tunings of membership functions and weights in the fuzzy neural networks are effectively performed by immune algorithm. A number of hybrid methods in fuzzy-neural networks are considered in the context of tuning of learning method, a general view is provided that they are the special cases of either the membership functions or the gain modification in the neural networks by genetic algorithms. On the other hand, since the immune network system possesses a self organizing and distributed memory, it is thus adaptive to its external environment and allows a PDP (parallel distributed processing) network to complete patterns against the environmental situation. Also, it can provide optimal solution. Simulation results reveal that immune algorithms are effective approaches to search for optimal or near optimal fuzzy rules and weights.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.3
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• pp.22-27
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• 2012

In oceanic flight routes, HF radio and satellite data links have been used for air-to-ground communication, but these systems have long propagation delay and low data throughput. In this paper, we propose a reliable system to overcome the weakness of current HF radio and satellite communication systems for oceanic aeronautical flight routes. The proposed scheme uses only one aeronautical VHF channel in multi-hop oceanic communication environments and supports a hybrid type of multiple access, which consists of random access and TDMA (Time Division Multiple Access) scheme. The proposed system improves performance on delay and throughput as an effective solution to communicate end-to-end on the oceanic flight routes and strengthens the reliability of oceanic aeronautical communication.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.305-309
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• 2003

In recent large power plants, the excitation system has the static type, which is characterized by the fast response to increase the transient stability. The high capacity excitation systems developed in KEPRI is either a hot back-up, hybrid hot back-up (analog + digital) or triple modular redundant digital type, both well proven by actual tests and applied in commercial operation. The large excitation systems have been developed taking into consideration the parameters of large scale power plants, resulting in high costs and subsequently are supplied at higher prices. When used at small sized power plants, the cost impact is relatively high. As a countermeasure to such a situation, KEPRI has recently developed a reliable, miniature digital excitation system, which is one-board type, convenient and adequate for low-price, small-sized (0.5MW∼200MW) power plants.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.71-72
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• 2014

This paper presents a method to find the fault location on the DC cables for the HVDC transmission systems which utilizes a hybrid topology of the diode rectifier and the voltage-source converter (VSC) in the wind farm (WF) side. First, the DC-cable fault occurring in this HVDC system is analyzed in detail. Then, the DC-cable fault location is detected from the two relative voltages located on the same section of the cable, which are estimated from a pair of DC-cable voltage and current measurements. The effectiveness of the method is verified by the simulation results.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.563-570
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• 2006

Distributed control architecture is based on sharing control and data between multiple nodes on a network Communication and task sharing can be distributed between multiple control computers. Although many communication protocols exist, such as TCP/IP and UDP, they do not have the determinism that realtime control demands. Fiber-optic reflective shared memory creates the opportunity for realtime distributed control. This architecture allows control and computational tasks to be divided between multiple systems and operate in a deterministic realtime environment. One such shared memory architecture is based on Curtiss-Wright ScramNET family of fiber-optic reflective memory. MTS has built seismic and structural control software and hardware capable of utilizing ScramNET shared memory, opening up infinite possibilities in research and new capabilities in Hybrid and Model-In-The-Loop control.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.11a
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• pp.408-411
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• 2006

Currently, the nano economy threatens the mass economy. This is based on the internet business models. In the nano business models based on internet, the diversely personalized services are needed. Many researches of the personalization on the web have been studied. The web usage mining using click stream data is a tool for personalization model. In this paper, we propose an internet business model using evolutionary support vector machine and web response survey as a web usage mining. After analyzing click stream data for web usage mining, a personalized service model is constructed in our work. Also, using an approach of web response survey, we improve the performance of the customers' satisfaction. From the experimental results, we verify the performance of proposed model using two data sets from KDD Cup 2000 and our web server.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.238-238
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• 2012

Report is devoted to place and role of numerical simulation in design of rocket propulsion systems. In introduction advanced solutions in liquid propellant rocket engines design are presented. Further essence of design process described briefly. The central place of method of solution of direct problem in design process was shown. Numerical simulation for solving direct problem of fluid dynamic was used as the alternative to theoretical and experimental approaches. Main features of numerical models of processes in propulsion systems were observed. Some results of simulation and (or) design of different types of chemical propulsion system were presented also. The combined rocket engine, rocket engine with injection of after-turbine gas into supersonic part of the nozzle, solid propellant engine and hybrid propulsion engine are under consideration.