• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.417-420
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• 2001

The monitoring system for maintaining on-site wastewater treatment plants(Biofilter) was developed. Proposed system applied PLC(Programmable Logic Controller) technique. In process of development, the research against the monitoring parameters which will be able to represent condition and operation of the plants was accomplished. These parameters are ORP(Oxidation-Reduction Potential), Water Level, Pump and Power on/off. Also, to measure, collect, transfer and display these parameters, DMU(Data Measurement Unit), MCU(Main Controller Unit) and Display Board were produced.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.283-287
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• 2005

In this paper, one general approach is proposed for the design of power system that can be applicable for next generation LEO satellite application. The power system consists of solar panels, battery, and power control and distribution unit(PCDU). The PCDU contains solar array modules, battery interface modules, low-voltage power distribution modules, high-voltage distribution modules, heater power distribution modules, on-board computer interface modules, and internal DC/DC converter modules. The PCDU plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. We review the functional schemes of the main constitutes of the PCDU such as the battery interface module, the auxiliary supply module, solar array regulators with maximum power point tracking(MPPT) technology, heater power distribution modules, spacecraft unit power distribution modules, and instrument power distribution module.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.540-543
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• 2010

POWER PC series are common to the Central Processing Unit for Military Single Board Computer. Among them, G4 group, which contains the 74xx series supported by Freescale manufacturer is mainly used in the Military applications. We focus on the Interface between memory and controller. PCB stacking method, component routing, impedance matching and harsh environment for Military spec are the main constraints for implementation. Also, we developed memory as a module for the consideration of Military environments. The overall type of SBC should be designed by the form of 6U VME or 3U VME.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.3
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• pp.294-300
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• 1995

In aquaculture industrial field, an automatic management and control system is needed to cope with the difficulties such as expensive wage, ripe age of management worker and risk according to the unexpected change of environmental conditions in the aquarium. This paper introduces an automatic aquarium monitoring and control system. The system is developed using PC single board computer. A PC can be connected to multi-single hoard computers, and the communication between PC and single board computers is based on RS-422/485 interfacing method. The physical data of pH, DO, temperature and water level etc. are real-timely treated in the single board computer though individual transducers, transfered to the main monitoring PC through RS-422/485 communication, and those data are graphically shown on the PC monitor. Furthermore, the environmental circumstance can be monitored through the image processing system, and the emergency system can be operated under the condition of environmental incident such as electric power stoppage, DO deficiency, pump shut down and low level water etc.

• Journal of Power Electronics
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• v.3 no.4
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• pp.230-238
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• 2003

Electric vehicles (EV) demands for greater acceleration, performance and vehicle range in pure electric vehicles plus mandated requirements to further reduce emissions in hybrid electric vehicles (HEV) increase the appeal for combined on-board energy storage systems and generators. And the power electronics plays an important role in providing an interface between fuel cells (FC) and loads. This paper deals with a multiple input DC-DC power converter devoted to combine the power flowing of multi-source on energy systems. The multi-source is composed of (i) FC system as a prime power demands, (ii) super capacitor banks as energy storage devices for high and intense power demands, (iii) superconducting magnetic energy storage system (SMES), (iv) multiple input DC-DC power converter and (v) a three phase inverter-fed permanent magnet synchronous motor as a drive. In this system, It is used super capacitor banks and superconducting magnetic energy replaces from the battery system. The modeling and transient performance simulation is effective for reducing transient influence caused by sudden charge of effective load. The main purpose of power electronic converters is to convert the DC power output from the fuel cell and other to a suitable AC voltage, which can be connected to electric loads directly (PMSM). The fuel cell and other output is connected to the DC-DC converter, which regulates the DC link voltage.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1305-1308
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• 1987

This paper presents a design of an optimized implantable biotelemetry system and the fabrication of custom CMOS LSI for implementing this system. The internal circuits of this system are fabricated on a single silicon chip with a size of $4{\times}5mm^2$. This LSI is designed and fabricated not only to get as small size and low power dissipation as possible, but also to have multiple function. Its main functions are to select one of implanted sensors and to accomplish ON - OFF power switching of an implanted battery by receiving appropriate Command signals and control signals fran external circuits. The internal system which was assembled on a bread-board using fabricated LSI chip is confirmed to work as designed. The total power dissipation of this interal system was $10.12{\mu}W$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.326.2-326
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• 2002

A PDP(Plasma Display Panel) module consists of a discharge panel, a SMPS for power supply, driving boards for panel control, and a logic board. Driving boards supply high voltage pulses to induce glow dischargein the PDP panel. The electrical pulses excite the circuit elements and subsequentlyacoustic noises. The main sources of the noise in the circuit are the transformer of SMPS and the power MOSFET of driving boards, and the heat sinks often amplify the noise level. (omitted)

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.2
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• pp.136-145
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• 2000

The objective of this study is to evaluate the human performance relating to the layouts of the two different hand switch types with two and three buttons in the nuclear power plants. Using a computer simulation, the cognitive performance for the hand switch layouts was measured on the basis of response and task completion times. Comparative analyses were performed with three different layouts representing the current switch arrangements in the Yonggwang nuclear plants 5 and 6 and Ulchin 3 and 4, respectively. Statistical analyses revealed that the performance of the two-buttoned switch layouts was found to be better than those of the three-buttoned switch. Furthermore, the superiority of the two-buttoned switch type is consistent regardless of various layout types. These results imply that the difference of the cognitive performance can be attributable to the switch types rather than to the switch layouts. Therefore, from the cognitive perspective, the two-buttoned switch type is recommended for future power nuclear plants.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.3
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• pp.342-348
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• 2013

It proposes an efficient control algorithm to increase electric power transmission efficiency between photovoltaic power generating system and the grid. The main controller finds a maximum efficiency condition by considering the quantity of power generated from PV arrays, the number of inverters, and efficiency of PV inverter. According to the condition, a relay board arranges a point of contract of PV arrays. By the disposition of PV arrays, it assigns the optimized power on each PV inverter. Operational principle of the proposed maximum efficiency point tracking algorithm is given in detail. To verify the validity of the proposed approach, computer-aided simulation and experiment carried out.

• Journal of Power Electronics
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• v.6 no.2
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• pp.104-113
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• 2006

Satellites have provided the impetus for the orderly development of reliability engineering research and analysis because they tend to have complex systems and hence acute problems. They were instrumental in developing mathematical models for reliability, as well as design techniques to permit quantitative specification, prediction and measurement of reliability. Reliability engineering is based on implementing measures which insure an item will perform its mission successfully. The discipline of reliability engineering consists of two fundamental aspects; $(1^{st})$ paying attention to details, and $(2^{nd})$ handling uncertainties. This paper uses some of the basic concepts, formulas and examples of reliability theory in application. This paper emphasizes the practical reliability analysis of a Low Earth Orbit (LEO) Micro-satellite power subsystem. Approaches for specifying and allocating the reliability of each element of the power system so as to meet the overall power system reliability requirements, as well as to give detailed modeling and predicting of equipment/system reliability are introduced. The results are handled and analyzed to form the final reliability results for the satellite power system. The results show that the Electric Power Subsystem (EPS) reliability meets the requirements with quad microcontrollers (MC), two boards working as main and cold redundant while each board contains two MCs in a hot redundant.