• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.135-136
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• 2017

In this paper, a spiral inductor is designed and its inductance is calculated by the expended Grover method. To verify this, a rectangular planar inductor is printed by inkjet printer using conductive ink and the calculated inductance value is compared with its measured value.

• Journal of Biosystems Engineering
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• v.9 no.1
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• pp.5-10
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• 1984

Using the renewal theory based on the Weibull distribution, an estimation was made on the number of replacement parts annually required for the after-service of some major parts of power tiller at the local repair shops or dealers. The production requirements of the parts were also estimated for the service in the next 5 years following the sales of power tillers.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.595-598
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• 2003

Elemental data was collected for agricultural biomass such as pruned branches with respect to unit area production and heating values. The results indicated that higher heating values for the biomass was comparable to those of woody biomass. Approximate estimations of power generation from biomass showed that over 100kW power plants could be installed in some districts.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.268-271
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• 2006

We have studied the backward wave oscillator, a power-pulsed generator oscillator at 20 GHz has higher frequency then current one. An absolute instability linear analysis was used for the purpose of designing the slow wave structure. A large diameter of the slow wave structure was adopted to prevent the breakdown brought about by the increase of power density.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.176-180
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• 2002

During the last two decades the laser beam has progressed from a sophisticated laboratory apparatus to an adaptable and viable industrial tool. Especially, in its welding mode, the laser offers high travel speed, low distortion, and narrow fusion and heat-affected zones (HAZ). The principal obstacle to selection of a laser processing method in production is its relatively high equipment cost and the natural unwillingness of production supervision to try something new until it is thoroughly proven. The major objective of this work is focused on the combined features of gas tungsten arc and a low-power cold laser beam. Although high-power laser beams have been combined with the plasma from a gas tungsten arc (GTA) torch for use in welding as early as 1980, recent work at the Ohio State University has employed a low power laser beam to initiate, direct, and concentrate a gas tungsten arcs. In this work, the laser beam from a 7 watts carbon monoxide laser was combined with electrical discharges from a short-pulsed capacitive discharge GTA welding power supply. When the low power CO laser beam passes through a special composition shielding gas, the CO molecules in the gas absorbs the radiation, and ionizes through a process known as non-equilibrium, vibration-vibration pumping. The resulting laser-induced plasma (LIP) was positioned between various configurations of electrodes. The high-voltage impulse applied to the electrodes forced rapid electrical breakdown between the electrodes. Electrical discharges between tungsten electrodes and aluminum sheet specimens followed the ionized path provided by LIP. The result was well focused melted spots.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.189-194
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• 2012

The main purpose of reactive power compensation monitoring system is to manage factory electrical installation efficiently by On-Off switching reactive power compensation equipment. The existing reactive power compensation monitoring system is only able to be managed by operator whenever electrical installation needed reactive power. Therefore, it may be possible for propagating the installation's faults when operator make the unexpected mistakes. To overcome the unexpected mistakes, in this paper, the author presents a reactive power compensation monitoring system for factory electrical installation using active database. by using active database production rule, stated system can minimize unexpected mistake and can operate centralized monitoring system efficiently. Test results on the five factory electrical installations show that performance is efficient and robust.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.271-278
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• 2016

Recently, reverse osmosis (RO) is the most common process for seawater desalination. A common problem in both RO and thermal processes is the high energy requirements for seawater desalination. The one energy saving method when utilizing the osmotic power is utilizing pressure retarded osmosis (PRO) process. The PRO process can be used to operate hydro turbines for electrical power production or can be used directly to supplement the energy required for RO desalination system. This study was carried out to evaluate the performance of both single-stage PRO process and two-stage PRO process using RO concentrate for a draw solution and RO permeate for a feed solution. The major results, were found that increase of the draw and feed solution flowrate lead to increase of the production of power density and water permeate. Also, comparison between CDCF and CDDF configuration showed that the CDDF was better than CDCF for stable operation of PRO process. In addition, power density of two-stage PRO was lower than the one of single-stage. However, net power of two-stage PRO was higher than the one of single-stage PRO.

• Journal of the Korean Society of Combustion
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• v.19 no.3
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• pp.8-17
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• 2014

The aims of this research were to evaluate effects of biomass co-firing to pulverized coal power plants and the variation of co-firing ratios on the plant efficiency related to power consumption of auxiliary system and flue gas characteristics such as production and component by process simulation based on the existing pulverized coal power plant. In this study, four kinds of biomass are selected as renewable fuel candidates for co-firing: wood pellet(WP), palm kernel shell(PKS), empty fruit bunch(EFB) and walnut shell(WS). Process simulation for various biomass fuels and co-firing ratios was performed using a commercial software. Gas side including combustion system and flue gas treatment system was considering with combination of water and steam side which contains turbines, condenser, feed water heaters and pumps. As a result, walnut shell might be the most suitable as co-firing fuel among four biomass since when 10% of walnut shell was co-fired with 90% of coal on thermal basis, flue gas production and power consumption of auxiliary systems were the smallest than those of other biomass co-firing while net plant efficiency was relatively higher than those of other biomass co-firing. However, with increasing walnut shell co-firing ratios, boiler efficiency and net plant efficiency were expected to decrease rather than coal combustion without biomass co-firing.

• IE interfaces
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• v.21 no.4
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• pp.403-410
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• 2008

Manufacture enterprise's environment is felt difficulty more and more by suddenly rise of oil and raw material price lately. In such difficult environment, Toyota Productive System is becoming good example to all enterprises because Toyota competitive power is rising every year. Now, Toyota Company is becoming benchmarking target. In this paper, we survey Toyota Production System, we try to apply advantage of Toyota Production System to Office Work. We propose TOOF (TOyota OFfice) system which is applied to modifying Toyota Production System in financial aid Business. We hope that Office Work are improved through TOOF system.

• The Korean Journal of Ecology
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• v.27 no.5
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• pp.301-306
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• 2004

The sensitivity to Cd of three ectomycorrhizal fungi, Paxillus involutus, Suillus bovinus and Rhizopogon subcaerulescens, was assessed and compared in terms of radial growth and dry mass production, using both agar and liquid culture. The radial growth of S. bovinus and R. subcaerulescens was significantly reduced at the lowest concentration (0.1mg Cd/L). The 50% effective concentration (EC$_{50}$) values calculated from radial growth rates of the ectomycorrhizal fungi showed that the sensitivity of the fungi to Cd was greatest in S. bovinus and lowest in R. subcaerulescens. Cadmium addition also significantly decreased dry mass production of the ectomycorrhizal fungi. The sensitivity of the fungi to Cd in terms of dry mass production, was greatest in S. bovinus and lowest in P. involutus. Higher growth rates of P. involutus and melanisation of R. subcaerulescens appeared to contribute to reduced Cd toxicity.