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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korea Society For Power System Engineering
Journal Basic Information
Journal DOI :
The Korea Society for Power System Engineering
Editor in Chief :
Volume & Issues
Volume 14, Issue 6 - Dec 2010
Volume 14, Issue 5 - Oct 2010
Volume 14, Issue 4 - Aug 2010
Volume 14, Issue 3 - Jun 2010
Volume 14, Issue 2 - Apr 2010
Volume 14, Issue 1 - Feb 2010
Selecting the target year
A Study on the Accuracy Improvement Technique Using GPS Clock
Chea, G.H. ; Sakamoto, K. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 5~10
Both the accuracy and stability of the clock get from the GPS receiver are considered in the range of pps. And we verified the system clock stability of a micro-controller system using the pps pulse supplied by the GPS receiver. In complex system of digital processing, the rack of precise timing signal may cause the serious problem or breakdown accident. To get rid of these undesirable problems, we introduced VCXO circuit to a micro-controller system to preserve high accurate clock stability.
The Characteristics of Performance and Exhaust Emission on Simultaneous Application with Biodiesel Fuel and Oxygen Component in a C.I. Engine
Choi, S.H. ; Oh, Y.T. ; Lee, D.H. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 11~15
Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions from the diesel engines are recognized as main cause which has a great influence on environment. In this study, the potential of biodiesel fuel and oxygenated fuel(ethylene glycol mono-n-butyl ether; EGBE) was investigated as an effective method of decreasing the smoke emission. The smoke emission of blending fuel(EGBE 0~20 vol-%) was reduced in comparison with diesel fuel and it was reduced approximately 64% at 2000 rpm, full load in the 20% of blending rate. On the contrary NOx emissions from biodiesel fuel and EGBE blended fuel were increased compared with diesel fuel. Torque and brake specific energy consumption(BSEC) didn't have large differences.
A Study on the Distribution of Injected Urea into the Exhaust Pipe in a SCR System
Choi, J.H. ; Lee, Y.C. ; LEE, S.W. ; Cho, Y.S. ; LEE, S.H. ; Oh, S.K. ; Dong, Y.H. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 16~21
This research focused on the spray and distribution characteristics of urea solution by applying flow visualization techniques and did durability and driver test on injectors as well. The spray characteristics of urea solution was observed by CCD camera. Also, the distribution characteristics of urea solution was evaluated quantitatively as well by using 3D laser scanner equipment. It was considered that it was reasonable to use the injector for gasoline engine in order to inject the urea. The best distribution chart result was observed near 45cm distance difference between catalyst and urea spray injector. As a result of trapped urea distribution chart analysis, optimal pressure and volumetric flow rates of air and urea were derived in order to improve the distribution of Urea. This information may contribute to provide fundamental data in the future.
Characteristics of Decrease Effect in Fouling on Plate Heat Exchanger Using Air Bubble
Baek, S.M. ; Choi, W.J. ; Yoon, J.I. ; Seol, W.S. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 22~26
Generally, it is a method to remove the fouling cleaning the plate heat exchanger with chemicals or polishing with a brush or cloth after stopping the equipment and disassembling heat exchanger. However, the equipment must be stopped and taken apart when using this method, which causes an unnecessary work to assemble again after cleaning it. In this study, it has developed and tested the equipment which can automatically clean the fouling on plate heat exchanger at regular intervals with air bubbles. It indicated that the overall heat transfer coefficient had decreased without significant differences similar to that calculated without air bubbles until after 72 hours when making air bubbles to remove fouling ingredient on the surface of heat transfer area every 10 minutes per 2 hours. However, it showed that there was a 10% higher of heat transfer effect compared to the case without air bubbles of after 192 hours.
Efficiency Comparison according to Power Conversion Method and Performance Estimation for Battery Source BLDC Motor Propulsion System of Small Ships
Jeong, T.Y. ; Jeong, S.K. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 27~33
We investigate some operation characteristics and energy efficiency of the BLDC motor system driven by different two types power conversion method depends on same battery source for applying to electrical motor propulsion system of a small ship. Also, we suggest an estimation manner of operating performances such as total running distance and operating speed of ships from basic discharge voltage characteristics of batteries. Through some experiments, direct power conversion was better than indirect method on the view point of energy efficiency and the voltage discharge characteristics could be used as important design factor for estimating operating performances of small ships driven by electrical motors.
Investigation on Freezing in the Freezing Compartment of a Side by Side Refrigerator
Kim, Y.K. ; Jung, H.Y. ; Choi, Y.H. ; Lee, Y.W. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 34~39
A side by side refrigerator is popularly used one among electric home appliances according to the rise of the customer's living standard. But the frost problem in freezing compartment comes out whenever we develop the high quality refrigerator. In this research, internal flow simulation and temperature measurement were carried out by using CFD and T-type thermocouple respectively in order to understand freezing mechanism. It was revealed that the amount of frost beneath the 1st and 2nd shelves is approximately 40% of total frost and the cause of frost generation is due to bad circulation of low speed cold flow. Using this analysis, the shapes of outlets under shelves are modified. So, the amount of frost in this modified model decreases 6% comparing to original one.
Development of Three-Dimensional Flow Velocity Component Measurement System with Straight-Type Five-Hole Pressure Probe Using Ch Language
Oh, S.H. ; Kim, J.K. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 40~46
This paper shows the development process for measuring three-dimensional flow velocity components in a web-browser. The system is developed in an embeddable C/C++ interpreter Ch and Ch-CGI toolkit. The interface for the web-based measurement system consists of a set of web HTML files and Ch files for CGI. All of data in web browser are passed to Ch-CGI script to generate the output of new HTML file. PC-Server and PC-Client can submit measurement parameters and receive the text/graphical results each other. PC-Client can control the test equipment by using a parameters that received from PC-Server. It also can pass the test results between the web-based measurement system. In summary, the designed measurement system is evaluated, the outputs shown well on the web browser.
The Study for Reduction of Stress Concentration at the Stepped Shaft According to Two Types of External Force
Park, I.S. ; Shim, J.J. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 47~52
In this study, Finite Element Analysis have been adopted to analyze reducing stress effect and used to induce the sensitivity of design parameter on various techniques which was used for reducing stress. And so it can be utilized as a data to design on similar model. The effect of reducing stress with respect to change of relief groove radius can be increased by 27.3~18.2 % more than radius of fillet. And if a shoulder fillet radius is larger, additional reducing stress by relief groove radius is not obtained. And there was only little effect on reducing stress by changing the center point of groove radius along horizontal direction. In the case that undercut radius is 1.5mm, Max. Equivalent stress is reduced by 5.71% under bending force and 11.11% under torsion. The best effect of reducing stress at undercut model was yielded when the undercut radius is a forth of difference of stepped shaft radius.
Analysis of Wave Loads of Ships with Advancing Speed in Regular Waves
Lee, S.C. ; Doh, D.H. ; Goo, J.S. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 53~58
A three-dimensional source distribution method is presented for the prediction of motions and vertical bending moments of ships travelling with forward speed in regular waves. Comparisons between theoretical and experimental results are shown for the motion responses and vertical bending moment of the S175 container ship model by Watanabe et al. The model ship was made of synthetic resins so as to simulate bending rigidity of a full scale ship. Numerical results are compared with experimental and numerical ones obtained in the literature. The results of comparison confirmed the validity of the proposed approach.
Effect of Alloying Element on the High Temperature Tensile Property of Ferritic Stainless Steel for Automotive Exhaust System
Song, J.Y. ; Lee, I.S. ; Ahn, Y.S. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 59~64
Ferritic stainless steel is currently increasingly used for automotive exhaust material. The material for exhaust manifold is used in the temperature range of 500∼
. Therefore, high temperature characteristic is an important one that affects it's life span. It has been investigated the effect of alloying elements of Cr, Mo, Nb, Ti in the ferritic stainless steel for exhaust manifold on the high temperature tensile strength. There was a few difference in the tensile strength at
with the exception of low Cr steel, but the steels containing higher Cr, Mo or Nb elements showed significantly higher tensile strength at the temperature of
. The precipitates of the specimens after heat treating at the test temperature were electrolytic extracted, and quantitatively analysed using by SEM-EDS and TEM. The alloying elements of Cr and Mo increased the tensile strength as a solid solution strengthener, and on the other hand Nb element enhanced the strength by forming the fine intermetallic compounds such as NbC or
One Board Controller Design with ATmega 128 Chip for Manetic Levitation System
Choung, K.G. ; Yang, J.H. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 1, 2010, Pages 65~70
Magnetic levitation system is nonlinear and inherently unstable, so it is difficult to control. Analog control circuit was widly used as the controller of magnetic levitation system, but digital controller is now substituted for analog controller according to development of digital electronics. In this study, Atmel AVR series, ATmega 128 which is a kind of
-processor for digital controller is used because the chip is cheap and popular. We designed and made ATmega 128 one-board controller and aimed to verify validity through the experiance of levitation response.