• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.6
• /
• pp.161-167
• /
• 1996

In five-axis milling, optimal CL-data (cutter location data) should be generated to have advantages over three-axis milling in terms of accuracy and efficiency. This paper presents an algorithm for generating collision-free CL-data for five-axis milling using potential energy method. By virtually charging the cutter and part surfaces with static electricity, global collision as wells as local interference is eliminated. Additionally, machining efficiency is improved by minimizing the curvature difference between the part surface and tool swept surface at a CC-point (cutter contact point) simultaneously.

• Korean Journal of Organic Agriculture
• /
• v.15 no.4
• /
• pp.377-398
• /
• 2007

The objectives of this thesis were to search for effective methods of the livestock manure management through analysis of the livestock manure management cost and prepare for cuts in greenhouse gases emission by applying CDM in the fields of livestock in 2013. In the situation where most farmhouses are disposing the pig manure by ocean disposal, it is urgent to make an alternative plan since ocean disposal will be prohibited from 2012. Biogasplant is being highlighted from the point that can produce heat and electricity by using methane generated when the manure is disposed, and that can produce barnyard manure and liquid manure. As biogasplant generates energy using methane, it will contribute to decreasing global warming with the effect of greenhouse gases reduction, and trading emission reductions through CDM will result in creating revenue.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.10a
• /
• pp.583-586
• /
• 2012

Wind turbine industry is booming and spending a lot on research for improving the performance of its present machines and increasing their capacity. Wind turbine requires service life of about 20 years and each canponents of wind turbine requires high durability, because installation and maintenance costs are more expensive than generated electricity by wind-turbine. So the design of wind turbine must be verified in various condition before production step. For this work, high reliability model for analysis is required. Drivetrain model is modeled by multibody dynamic modeling method. The model constituted with rotor blades, hub, main shaft, gear box, high speed shaft and generator. Natural frequency and torsional stiffness of drivetrain are calculated and analyzed.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.6
• /
• pp.334-339
• /
• 2004

In this study, a new UC (Unit Commitment) algorithm is proposed to consider the uncertainty of a daily load profile. The proposed algorithm calculates the UC results with the lower load level than the one generated by the conventional load forecast and the more hourly reserve allocation. In case of the worse load forecast, the deviation of the conventional UC solution can be overcome with the proposed method. The proposed method is tested with sample systems, which shows that the new UC algorithm yields completely feasible solution even though the worse load forecast is applied. Also, the effects of the uncertain hourly load demand are statistically analyzed especially by the consideration of the average over generation and the average under generation. Finally, it is shown that independent power producers participating in electricity spot-markets can establish bidding strategies by means of the statistical analysis. Therefore, it is expected that the proposed method can be used as the basic guideline for establishing bidding strategies under the deregulation power pool.

• Proceedings of the Safety Management and Science Conference
• /
• 2012.04a
• /
• pp.421-433
• /
• 2012

The objective of this study is to obtain the optimal process condition and the maximum decomposition efficiency by measuring the decomposition efficiency, electricity consumption, and voltage in accordance with the change of the process variables such as the frequency, maintaining time period, concentration, electrode material, thickness of the electrode, the number of windings of the electrode, and added materials etc. of the harmful atmospheric contamination gases such as NO, $NO_2$, and $SO_2$etc. with the plasma which is generated by the discharging of the specially designed and manufactured $TiO_2$ catalysis reactor and SPCP reactor.

• Journal of the Korean Solar Energy Society
• /
• v.29 no.3
• /
• pp.37-44
• /
• 2009

The field-surveyed and measured energy consumption data is processed to develop building energy demand models for heating, hot water, cooling, and electricity. The load models are systematically organized as a database and hourly loads for a span of year (8760 hours) are generated by the program. Rased on those models a Microsoft Access application program is developed to calculate energy demands for a Community Energy System (CES) composed of 17 types of buildings. User-friendly interfaces are provided to assist non-expert end users and necessary tools to link the calculation results to subsequent coagulations such as operation simulation or economic assessment.

• Journal of Power Electronics
• /
• v.16 no.6
• /
• pp.2192-2201
• /
• 2016

Wind energy is currently the fastest-growing electricity source worldwide. The cost efficiency of wind generators must be high because these generators have to compete with other energy sources. In this paper, a system that utilizes an open-winding permanent-magnet synchronous generator is studied for wind-energy generation. The proposed system controls generated power through an auxiliary voltage source inverter. The VA rating of the auxiliary inverter is only a fraction of the system-rated power. An adjusted control system, which consists of two main parts, is implemented to control the generator power and the grid-side converter. This paper introduces a study on the effect of unbalanced voltages for the wind-generation system. The proposed system is designed and simulated using MATLAB/Simulink software. Theoretical and experimental results verify the validity of the proposed system to achieve the power management requirements for balanced and unbalanced voltage conditions of the grid.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.55 no.3
• /
• pp.159-167
• /
• 2006

According to industrial development, all fields using chemical instrument and material are generated an electrostatics. Electrostatic problems were very important part to all these components, moving system, printer, clothe machines etc. This paper was represented an analysis of electrostatic electrification by FEM (finite element method) of industrial type Inkjet plotter. Here electrostatics distribution analysis is accomplished by Maxwell-2D. We are showed an electrostatics generation source by rubbing and meager profits of electric charge. It know electronic values with each system position by experiment. These are decreased through earth and electricity shielding. Therefore this paper is proved by the simulation and experiment result.

• ETRI Journal
• /
• v.37 no.5
• /
• pp.951-960
• /
• 2015

For a conventional power metal-oxide-semiconductor field-effect transistor (MOSFET), there is a trade-off between specific on-state resistance and breakdown voltage. To overcome this trade-off, a super-junction trench MOSFET (TMOSFET) structure is suggested; within this structure, the ability to sense the temperature distribution of the TMOSFET is very important since heat is generated in the junction area, thus affecting its reliability. Generally, there are two types of temperature-sensing structures-diode and resistive. In this paper, a diode-type temperature-sensing structure for a TMOSFET is designed for a brushless direct current motor with on-resistance of $96m{\Omega}{\cdot}mm^2$. The temperature distribution for an ultra-low on-resistance power MOSFET has been analyzed for various bonding schemes. The multi-bonding and stripe bonding cases show a maximum temperature that is lower than that for the single-bonding case. It is shown that the metal resistance at the source area is non-negligible and should therefore be considered depending on the application for current driving capability.

• Journal of IKEEE
• /
• v.19 no.2
• /
• pp.232-236
• /
• 2015

Super-junction trench MOSFET (SJ TMOSFET) devices are well known for lower specific on-resistance and high breakdown voltage (BV). For a conventional power MOSFET (metal-oxide semiconductor field-effect transistor) such as trench double-diffused MOSFET (TDMOSFET), there is a tradeoff relationship between specific on-state resistance and breakdown voltage. In order to overcome the tradeoff relationship, a SJ TMOSFET structure is suggested, but sensing the temperature distribution of TMOSFET is very important in the application since heat is generated in the junction area affecting TMOSFET. In this paper, analyzing the temperature characteristics for different number bonding for SJ TMOSFET with an embedded temperature sensor is carried out after designing the diode temperature sensor at the surface of SJ TMOSFET for the class of 100 V and 100 A for a BLDC motor.