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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 10, Issue 4 - Nov 2006
Volume 10, Issue 3 - Aug 2006
Volume 10, Issue 2 - May 2006
Volume 10, Issue 1 - Feb 2006
Selecting the target year
The Effects of Fuel Injection Skips on the Reduction of Harmful Exhaust Gases during an SI Engine Starting
Kim, S.S. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 5~11
During the SI engine starting up, starting conditions directly contribute to the harmful emissions in spark ignition engines. The effects of catalyst temperatures and fuel injection skip methods on HC emissions were investigated. The test was conducted on a 1.5L, 4-cylinder, 16 valve, multipoint-port-fuel-injection gasoline engine. To understand the formation of HC emissions, HC concentration was measured in an exhaust port using a Fast Response Flame Ionization Detector(FRFID). The result showed that HC emissions, which were generated during initial stage of the starting, could be reduced by coolant temperature and fuel injection skips. And through the vehicle test of ECE15+EUDC, it is convinced that the optimized fuel injection skip method according to coolant temperatures have favourable effects on the reduction of harmful exhaust emissions including HC during the SI engine start.
A Study on the Amelioration of Volumetric Efficiency by Variable Induction System in a Diesel Engine
Kang, H.Y. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 12~18
A three-degree of freedom model of intake system was contrived and investigated in various ways for the purpose of the amelioration of the volumetric efficiency in a low and transient engine speed for a multi cylinder diesel engine. The basic concept beyond this model started from the theory that each degree of freedom model has volumetric efficiency peak as many as its number of the degree of freedom. The volumetric efficiency affects significantly to the engine performance; torque characteristics, fuel economy and emission level. For commercial vehicles and stationary engines, the engine is designed so as to produce their best performance near the normal engine speeds, thus the low engine speed area has a tendency of poor volumetric efficiency. The aim of this study was highlighted on the amelioration of volumetric efficiency of low engine speed area in a multi cylinder diesel engine matched with an additional Helmholtz resonator. By the use of VIS(variable induction system) volumetric efficiency at low engine speed range was significantly improved. The availability of control by combination of VIS and CIS(conventional induction system) will be proposed as a variable induction system that would be an appropriate model for amelioration of the volumetric efficiency at low engine speed.
Performance and Emission Characteristics of a Controlled Auto-Ignition Gasoline Engine according to Variation of the Inlet-Air Temperature
Kim, H.S. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 19~24
This work treats a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. The fuel was injected indirectly into electrically heated inlet air flow. In order to keep a homogeneous air-fuel mixing, the fuel injector was water-cooled by a specially designed coolant passage. The engine performance and emission characteristics were investigated under the wide range of operating conditions such as 40 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, 150 to
in the inlet-air temperature, and
BTDC in the injection timing. The ultra lean-burn with self-ignition of gasoline fuel by heating inlet air was achieved in a controlled auto-ignition gasoline engine. It could be also achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxide significantly reduced by CAI combustion compared with conventional spark ignition engines.
Numerical Simulation for Heat Transfer and Fluid Flow in the Channel with
Oh, S.K. ; Kang, H.K. ; Kim, M.H. ; Bae, S.T. ; Ahn, S.W. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 25~33
A Study on Snow Melting System for the Anti-freezing Testing Road
Han, K.I. ; Lee, A.H. ; Cho, D.H. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 34~40
The snow melting system by electric heating wires which is adopted in this study is a part of road facilities to keep surface temperature of the road higher than freezing point of water for melting the snow accumulated on it. The system is designed to increase traffic safety and capacity. The electric heating wires are buried under paved road at a certain depth and operated automatically and manually. Design theory, amount of heating, and installation standard vary according to economic situation, weather condition, and installation place where the system applies. It is tried to figure out that the appropriate range of required heat capacity and installation depth and intervals for solving snowdrifts and freezing problems with the minimum electric power consumption. The most important factors to design the system are calculation of heating capacity depending on weather condition and depth and interval of the electric heating wires depending on air condition respectively. The study were performed under the range of the air temperatures(
), the intervals of the electric heating wires(70mm, 100mm, 125mm), and the installation depths(50mm, 70mm, 100mm). The ready made commercial program package was used to verify the experimental results.
Study on the Energy Saving for School Buildings - through thermal effect of the transparent insulated opaque envelopes -
Lee, S. ; Kim, S.H. ; Kim, K.C. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 41~45
The thermal effect of a transparent insulated opake wall with solar energy was investigated theoretically. The heat gain through transparent insulated opake wall was studied for relative simple conditions. The stationary heat transport effect was studied for layer which is built on the opake wall. This study shows that a relative low solar radiation intensity causes a great heat reduction through the transparent insulated opake wall.
Study on Abrasive Wear Behaviour of a Carbon Fiber Composites
Koh, S.W. ; Yang, B.C. ; Kim, H.J. ; Kim, J.D. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 46~51
Present study was investigated the effect of the particle of the counterface of unidirectional carbon fiber reinforced composite. The friction coefficient of composite and the specific wear rate different sliding velocity were measured for this materials. The friction track of counterface was observed by an optical microscope and scanning electron microscope. There were insignificant effects of the specific wear rate under lower Sic abrasive particle, however it showed high effect on
abrasive particle size. There were significant effects of friction and wear behavior of the fiber direction under 0.3m/s sliding speed. Major failure mechanisms can be classified such as microfracture, plowing, microcutting, cutting and cracking.
A Study of Mechanical Properties in Compression on High density Graphite Products with Expanded Graphite
Shin, Y.W. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 52~59
Graphite is well known as a material which has high-temperature thermostable property, chemical resistance against acid and alkaline state also is very easy to environment. Nowadays the need of graphite product is increasing rapidly because of its advantages. In this paper, the mechanical property of newly developed graphite products with high density is investigated with especially in compression test. I introduced the graphite specimens for this study by NGF method with two expandable graphite and compared to the specimens of commercial graphite sheet from expanded graphite which made by the rolling process. I investigated the characteristics of these materials by measuring specific weight, hardness, compressive strength and investigating structures by SEM, It is verified that the graphite products with NGF method has superior properties for using gasket materials than that of commercial graphite sheet.
Crack-Healing Behavior of
Ceramics for Textile Machinery
An, B.G. ; Kim, M.K. ; Ahn, S.H. ; Kim, J.W. ; Park, I.D. ; Nam, K.W. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 60~64
Alumina ceramic for textile machinery was sintered and subjected to three-point bending. A semicircular surface crack was made on each sample. Crack-healing behavior was systematically studied, as a function of crack-healing temperature and crack size. The bending strength and fracture toughness of the crack-healed sample from
were investigated. A statistical approach based on Weibull distribution was applied to the test data to evaluate the dispersion in the fracture toughness. Alumina ceramic for textile machinery have the ability to heal after cracking, from over
. The material can completely heal a
diameter semielliptical crack. The fracture toughness could be explained by 2-parameter Weibull distribution.
Characteristics of Acoustic Waves That Propagate in Buried Iron Water Pipes
Park, K.J. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 65~70
A study of the possible axisymmetric modes that propagate at low frequencies in buried, water-filled iron pipes is presented. It is well known that for a vacuum-pipe-vacuum system the sole non-torsional axisymmetric mode that exists at low frequencies is the fundamental L(0,1) mode. When a pipe is filled with water and still surrounded by a vacuum it is also known that another mode then appears which at low frequencies is characterized by predominantly axial water-borne displacements. In addition to these modes, this paper explores two other, less well known axisymmetric modes whose existence depends on the acoustic properties of the outer medium that surrounds a pipe. In this paper the predicted characteristics of these modes are presented.
A Study on the Temperature and Electrical Characteristics of Carbon Heater
Jin, Z.H. ; Shim, K.J. ; Kong, T.W. ; Jeong, H.M. ; Chung, H.S. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 71~76
This paper aims to study several type heaters which are mica heater, film heater, quartz heater and rod heater and to get an temteraturel and electrical characteristics. These four type heaters have a merit in many fields than present electric heater with nichrome wire. Carbon and mica plate heater have higher heat efficiency and less electromagnetic waves. Also it has been reported that far infrared ray emission from this heater is good for our health. Additionally heating element is thin and lighter plate. For these reasons, they will be widely used to various application such as room-heating or manufacturing goods. Experimental result confirmed that when 220V current authorized, the temperature, electric current, electric power and the resistance rise to stationary state in early stage. Moreover, the temperatures and electric characteristics show a good stability.
The Mechanical Properties and the Nondestructive Evaluation of Dissimilar Friction Welded Steel Bars
Jung, W.T. ; Kong, Y.S. ; Kim, S.J. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 77~82
In this study, dissimilar friction welding were produced using 15mm diameter solid bar in chrome molybedenum steel(SCM440) to carbon steel(S45C) to investigate their mechanical properties and the relationship between the weld parameters and the nondestructive coefficients, such as AE counts and ultrasonic attenuation coefficient. The main friction welding parameters were selected to endure good quality welds on the basis of visual examination, tensile tests, Vickers hardness surveys of the bond of area and heat affected zone. The specimens were tested as-welded and post weld heat treated(PWHT). The tensile strength of the friction welded steel bars was increased up to 100％ of the S45C base metal under the condition of all heating time. The ductility of PWHT specimens is higher than as-welded.
An Electrical Characteristics Analysis of Electronic Blood Pressure Depressor
Lee, K.S. ; Suh, J.H. ; Lee, J.W. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 83~89
Recently, the seriousness of high blood pressure was appeared as the most frequent disease of a the whole sickness in the world. However, the treatment of this disease is uncertain and produces an adverse reaction of a medicine therapy. Also, the patients are burdened with a fee for medical treatment. Therefore, in this paper, we studied effectively and financially to execute the treatment of high blood pressure using the Chinese medicine theorem that is recently arousing the great interest of the people. The main theories in this paper are blood vessel theory and acupuncture, respectively. Especially, the composed circuit systems are classified the blood pressure depressor part and the meridian points discrimination part, respectively. The blood pressure depressor part is composed generally of low-frequency generation circuit, charging-discharging circuit, and micro-computer circuit. Finally, this research have the advantage of discrimination parts such as regular voltage generating circuit, stimulus circuit, amplifying circuit, and alarm circuit.
Analysis of Decompression Control Characteristics of Pneumatic Pressure Control System Considering Heat Transfer Characteristics
Jang, J.S. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 90~95
Pneumatic control systems have been mainly used as a high speed operating system. Therefore, state change of air in a control volume was assumed to be adiabatic change and, pneumatic control systems have been analyzed by using this assumption. Especially, when absolute value of pressure change in the control volume is small, there is a tendency to neglect effect of temperature change on pneumatic control system because temperature change owing to pressure change is small. In this study, an effect of temperature change of air on the decompression control process was analyzed by considering change of mass flow rate, and heat transfer characteristics between air in the chamber and the chamber wall. As a result, this study could confirm that a slight temperature change of the air in the pneumatic pressure control system can influence on the dynamic characteristics of pressure response, and pressure control performance.
A Study on the Development of Anti-Seasickness Bed
Kim, Y.B. ; Lee, K.S. ; Suh, J.H. ; Choi, W.Y. ; Chae, G.H. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 1, 2006, Pages 96~101
In ship operation the consequence of roll and pitchingmotion can seriously degrade the performance of mechanical and personnel effectiveness. So many studies for the roll stabilization and trimming control system design have been performed and good results have been achieved where the stabilizing fins, tanks, rudders and flaps are used. However the ultimate objective of such approach should be focused on improving the boarding sensitivity. But there may exist many unsolved problems, for examples, ship control performance degradation and increasing of system complexity. So, the achieved control performance could not give us enough comfortable boarding sensitivity where the residual rolling and pitching motion are main drawbacks. To get rid of these disadvantages, the main hull control systems design approach has been considered using semiactive absorber. In this system, dampers, spring, dynamic dampers and control system with sensors are incorporated. In our system considered in this study, just two motors and control system with sensors are used for the bed. And the control system can be installed on each bed. So, we can control every bed on the specified control objective respectively. Above all, the good advantages of this system are the facts followed from simple idea and usefulness. Of course the structural modifications are needed. Considering disturbances, we design control system and verify the usefulness of developed system from the experimental study.