• Carbon letters
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• v.10 no.2
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• pp.87-89
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• 2009

Carbon nanotubes, consisting of rolled graphene layer built from $sp^2$ units, have attracted the imagination of scientists as ideal macromolecules and their unusual physical and chemical properties make them useful in the fabrication of nanocomposites, nano-electronic devices and sensors etc. In this account, the current status and prospect of carbon nanotubes is described with a special emphasis on the safety issue of carbon nanotubes. Even though many challenges to be solved remain, extensive and intensive efforts in both academy and industry will clear out those problems soon and finally enable carbon nanotubes to play a key innovative material of 21st century in numerous industrial processes.

• International Journal of Control, Automation, and Systems
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• v.2 no.2
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• pp.144-155
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• 2004

This paper addresses the issue of position control of a chain of multiple mass-spring-damper (CMMSD) units which can be found in many physical systems. The dynamic model of a CMMSD system with any degrees of freedom is expressed in a closed-form for the convenience of the controller design. Backstepping and model reference adaptive control (MRAC) approaches are then used to develop two adaptive output feedback controllers to control the position of a CMMSD system. The proposed controllers rely on the measurements of the input (force) and the output (position of the mass unit at the end of the chain) of the system without the knowledge of its parameters and internal states. Simulations are used to verify the effectiveness of the controllers

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.4
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• pp.122-128
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• 2007

This paper represents the Input/Output (I/O) serial communication methods between overground and overhead controllers using a programmable logic controller (PLC). In general, the systems composed by overground and overhead controllers use exclusive serial communication units. This, however, has a demerit such as a high cost as well as some restrictions of the system itself. Thus, this paper suggests methods by I/O cards for data communication between overground and overhead controllers. In this system, there is no special card and it therefore has a lower cost and is more flexible than the exclusive serial communication unit.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.99-102
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• 1997

A neural spike sorting technique has been developed that also has the capability of template learning. A system of software has been written that first obtains the templates by learning, and then performs the sorting of the spikes into single units. The spike sorting can be done in real time. The template learning consists of spike detection based on the discrete Haar transform (DHT), feature extraction by clustering of spike amplitude and duration, classification based on rms error, and fabrication of templates. The developed algorithms can be implemented into real time systems using digital signal processors.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1646-1648
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• 1994

In the system of underground transmission line, the rate of electrical failure is very low, but, if once occuring, the failure evolves into a paralysis of the system, the time of restoration is very long, the damage from stopping of power supply is very serious, and the cost of restoration is very great. Because of these problems, you must try to protect the system and equipment from every electrical failure by contributing much carefulness to the design and operation of the underground system. This study summerizes the results of simmulation tests about the effect of installing this protection device on the insulated joint box and the terminal end box.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.54-65
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• 2000

This study was performed to analyze the changes of electrical conductivity with increasement of water requirements for desalinization in reclaimed tidelands and to obtain the basic data for developing prediction techniques of desalinization to be applicable in the beginning of tideland reclamation. Two different desalinization experiments were conducted through the leaching method by subsurface drainage and the rinsing method by surface darainage, using the samples of silt soil and silt loam soil collected in 5 units of tideland reclamation projects. Regression equations were obtained in order to investigate the changes of electrical conductivity during the desalinization of reclaimed tidelands and to estimate water requirements for desalinization.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1768-1771
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• 2002

Automatic Transmission System(ATS) was designed to replace the human's manual operation of the gear box. So far, this system operates with the fixed shift pattern information. In this paper, new algorithm considering driver's operation tendency is proposed. Also, to get rid of the uselessly frequent shift of the ATS, the conditions and the status of the vehicle would be included for the evaluation in making a decision of shifting. A field test is done in a car equipped with the computer set connected to Transmission Control Units(TCU) to check the status of the test car, and it shows the excellency of the proposed algorithm.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2557-2560
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• 2000

The protection system of the nuclear reactor and chemical reactor are representative of PPC(Plant Protection Controller). This PPC must be designed based on reliability as well as concept of safety, which is a failed system go a way of safe. PPC is consist of part of data acquisition, calculator, communication with redundancy, and a voter is important factor of reliability. Because it is serial connected. This paper presents a Design and Analysis of a Voting Mechanism considering Safety for NMR PPC Using EPLD. In the case of digital implementation a coincidence logic(voter) of PPC, it needs CPU and memory, so increase a number of units. Therefore the failure rate and cost is increased. On the contrary when it is designed EPLD or FPGA.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.687-689
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• 2000

Molten Carbonate Fuel Cell (MCFC) with high electrical efficiency and low environmental effect has been developed for the commercial application of power generation fields. Recently we have built a 25 kW molten carbonate fuel cell power generation system and tested it. The MCFC system is composed of diverse peripheral units such as reformer, pre-heater, water purifier. electrical loader, gas supplier, and recycling systems. The stack itself was made of 40 cells of $6.000 cm^2$ area each. The stack showed an output of 28.6 kW power and a reliable performance at atmospheric operation. while in pressurized operation the stack showed an output 25.6 kW lower than the atmospheric operation. The reason of lower performance of pressurized operation was caused from a gas cross over shown in few cells in the stack.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.3
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• pp.203-211
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• 1999

This paper presents a new approach on genetic on genetic algorithm to economic dispatch problem for valve point discontinuities. Proposed approach in this paper on genetic algorithms improves the performance to solve economic dispatch problem for valve point discontivuities through improved death penalty method, generation-apart elitism, atavism and sexual selection with sexual distinction. Numerical results on a test system consisting of 13 thermal units show that the proposed approach is faster, more robust and powerful than conventional genetic algorithms.