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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Marine Engineering
Journal Basic Information
Journal DOI :
Korean Society of Marine Engineers
Editor in Chief :
Volume & Issues
Volume 31, Issue 8 - Nov 2007
Volume 31, Issue 7 - Nov 2007
Volume 31, Issue 6 - Sep 2007
Volume 31, Issue 5 - Jul 2007
Volume 31, Issue 4 - May 2007
Volume 31, Issue 3 - May 2007
Volume 31, Issue 2 - Mar 2007
Volume 31, Issue 1 - Jan 2007
Selecting the target year
Development Tendency of Wave Energy Conversion System
Oh, Jin-Seok ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 893~898
DOI : 10.5916/jkosme.2007.31.8.893
Introduction of Air Cooling and Heating System by Using Ocean Thermal Energy in KMU
Gug, Seung-Gi ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 899~903
DOI : 10.5916/jkosme.2007.31.8.899
A Study on the Performances of Exhaust Gas Purification at Process on the Development of Corona Discharge Type Electrostatic Precipitator for Diesel Engines
Son, Byong-Ho ; Bae, Jong-Uk ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 904~910
DOI : 10.5916/jkosme.2007.31.8.904
In this study an experimental research has been conducted to reduce NOx and smoke emission from diesel engine exhaust gas simultaneously by application of corona discharge type electrostatic precipitator(ESP). The ESP was installed between exhaust gas silencer and outlet terminal of exhaust gas system. The operating conditions as input parameters taken in this experiment were corona power input, gas velocity and equivalence ratio of gas. It was found that the corona discharge type ESP has notable effect on reducing smoke in exhaust gas but appeared to bring slight effect on reducing NOx.
A Study on the Structure and Characteristics of Light-duty FC Hybrid Vehicle
Bong, Tae-Keun ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 911~917
DOI : 10.5916/jkosme.2007.31.8.911
Global primary energy demand is projected to increase by 1.7% per year from 2000 to 2030. Almost three-quaters of the increase in demand will come from the transportation sector. Fuel cell hybrid vehicle technology has the potential to significantly reduce energy and harmful emissions, as well as our dependence on foreign oil. In this paper, a systematic and logical methodology is developed and improved mainly to design light duty fuel cell hybrid electric vehicle. We investigated structure and characteristics of light duty FC hybrid vehicle carefully. It can easily be expanded to analyze vehicle-to-grid power connectable plug-in NeHEV. A fuel cell hybrid neighbourhood electric vehicle configuration has been studied in-depth utilizing the proposed methodology.
A Study on Finite Element Modeling Method of Yaw Bearing for Wind Turbine
Lee, Dong-Hwan ; Ko, Woo-Sick ; Lee, Hyoung-Woo ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 918~923
DOI : 10.5916/jkosme.2007.31.8.918
Recently, the interest for renewable energy producing system is increasing rapidly. Among these, the wind turbine is most highlighted. It is installed at severe environment and generated electricity for a long time to exceed twenty years. Components of wind turbine are required high reliability. Therefore, structural strength analysis for wind turbine is needed for an accurate FE model. This paper is to provide reliable fine element modeling method of yaw bearing for wind turbine.
Analysis on the Technology R&D of the Fuel Cell Systems for Power Generation in Ships
Kim, Myoung-Hwan ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 924~931
DOI : 10.5916/jkosme.2007.31.8.924
Now, there are two big issues threatening global society, which are the depletion of fossil fuels and the environmental disruption. Therefore, marine diesel engine, taking up over 95% share of the marine power market, has met the environmental and economical problems, too. These problems have caused a necessity of new, alternative power systems in ships and fuel cell systems has been playing a central role as one of the alternatives. This paper analyzes the characteristics of marine fuel cell systems, R&D trends of advanced countries, and mapping out R&D strategy of Korea.
Molecular Dynamics Study for Improving the Adhesion of Paint
Yang, Young-Joon ; Lee, Chi-Woo ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 932~938
DOI : 10.5916/jkosme.2007.31.8.932
The interaction between adherent molecules and gas molecules was modeled in molecular scale and simulated by the molecular dynamics method in order to understand the evaporation and removal processes of adherent molecules on metallic surface using high temperature gas flow. Methanol molecules were chosen as adherent molecules to investigate effects of adhesion quantify and gas molecular collisions because the industrial oil has too complex structures of fatty acid. The effects of adherent quantify, gas temperature and surface temperature for the evaporation rate of adherent molecules and the molecular removal mechanism were investigated and discussed in the present study. Evaporation and removal rates of adherent molecules from metallic surface calculated by the molecular dynamics method showed the similar dependence on surface temperature shown in the experimental results.
A Measurement and Evaluation on the Indoor Thermal Conditions in Spring of a New Training ship
Shin, Dong-Keol ; Lee, Jin-Uk ; Lee, Hyong-Ki ; Park, Youn-Cheol ; Hwang, Kwang-Il ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 939~946
DOI : 10.5916/jkosme.2007.31.8.939
The purpose of this study is to measure and analyze the ship's indoor thermal conditions and also to integrate experimental database of those, supplied and controlled by ship's HVAC. On this study, temperature, humidity and air volume of 6 different needs' cabin are measured on a newly-launched training ship during 2nd through 5th of April, 2007. Followings are the results of this study. (1)Because only partial loads are needed in spring season, the air volume from diffusers are measured as below 20%. (2)The temperatures are ranged between
and those are within comfort temperature range proposed by AHREA. (3)But humidities in cabins are very low and it could be the reason of a cold and/or a skin disease. (4)From the student cabins' measurements which have different supply diffuser(s), it is clear that the design is suitable for this case. (5)Because of low humidity, only 16.1% among the measured data are satisfied with the comfort standard range proposed by ASHREA. To improve the predictability and the comfort, HVAC should maintain the humidity as
Occurrence Mechanism and Characteristics of Pressure Pulsation in a Positive Displacement Hydraulic Turbine
Choi, Young-Do ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 947~953
DOI : 10.5916/jkosme.2007.31.8.947
Occurrence of pressure pulsation in positive displacement hydraulic turbine is one of the principal problems which should be cleared to improve the turbine performance and to put the turbine to practical use. Therefore, present study is tried to examine the occurrence mechanism and characteristics of the pressure pulsation CFD analysis and experimental measurement are implemented in this study to clarify the phenomena of unsteady pressure pulsation. The results show that occurrence reason of the pressure pulsation is not only due to a series of opening and closing of the chamber formed between rotor and casing wall but also due to the variation of rotational speed of following rotor. The pressure pulsation causes torque variation and the curve patterns of the torque variation conforms to that of the pressure pulsation. Pressure in the chamber is equal to the averaged value of inlet and outlet pressures. Sudden pressure decrease by accelerated through-flow between lobe and casing wall results in torque loss.
Design Of Air-Distribution System in a Duct
Kang, Hyung-Seon ; Cho, Byung-Ki ; Koh, Young-Ha ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 954~960
DOI : 10.5916/jkosme.2007.31.8.954
The purpose of this paper is to obtain design method of air-distribution system. Air-distribution system is composed of blower, duct, diffusers and measuring equipment. The air-flow rate from each diffuser is not equal. The air-flow rate is calculated with the combined equations which are Bernoulli's equation, continuity equation and minor loss equations. Inlet condition and outlet condition are adapted in each duct system. Then square difference between function of maximum air-flow rate and minimum air-flow rate is used as an object function. Area of diffuser and velocity are established as constraints. To minimize the object function, the optimization method is used. After optimization the design variables are selected under satisfaction of constraints. The air-distribution system is calculated again with the result of optimized design variable. It is shown that the air-distribution system has the equal air-flow rate from diffusers.
Surface Transformation Hardening for Rod-shaped Carbon Steels by High Power Diode Laser
Kim, Jong-Do ; Kil, Byung-Lea ; Kang, Woon-Ju ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 961~969
DOI : 10.5916/jkosme.2007.31.8.961
The laser material processing has replaced a conventional material processing such as a welding, cutting, drilling and surface modification and so on. LTH(Laser Transformation Hardening) is one branch of the laser surface modification process. A lot of energy is needed for the LTH process to elevate workpiece surface to temperature of the austenite transformation(
), which results from utilizing a beam with a larger size and lower power intensity comparatively. The absorptivity of the laser energy with respect to material depends on the wave length of a beam. This study is related to the surface hardening for the rod-shaped carbon steel by the high power diode laser(HPDL) whose beam absorptivity is better than conventional types of lasers such as
or Nd:YAG laser. Because a beam proceeds on the rotating specimen the pretreated hardened-phase can be tempered and softened by the overlapping between hardened tracks. Accordingly, the longitudinal hardness measurement and observation of the micro structure was carried out for an assessment of the hardening characteristics. In addition, a hardening characteristics as a hardenability of materials was compared in the point of view of the hardness distribution and hardening depth and width.
Implement of Broadband Resistive Mixer for X-band FMCW Radar
Park, Dong-Kook ; Han, Tae-Kyoung ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 970~974
DOI : 10.5916/jkosme.2007.31.8.970
A mixer is a key component in the wireless communication systems. In this paper, we design a mixer which is used in a frequency modulated continuous wave(FMCW) radar system. The frequency sweep range of the radar is from 10 GHz to 11 GHz. The transmitted and received signals of the FMCW radar are applied to LO and RF ports of the mixer, respectively, but the frequency difference between the two signals, which is called "a beat frequency" is under a few KHz and depending on the distance to target. Thus the isolation between the LO and RF ports is very important factor to design this mixer. In this paper we propose a single balanced resistive mixer using GaAs MESFET for this application. We first design a single-ended type resistive mixer using a simulation tool, then design a balanced type to increase the LO-to-RF isolation of the mixer. We fabricated the mixer on the substrate of dielectric constant 10 and thickness 0.635 mm. The measured results show that the isolation and conversion loss of the mixer over the frequency band is 20dB and 10.5dB, respectively. The LO input power for operating the proposed mixer is +3dBm, which is lower than a general conventional mixer's LO power. The 1 dB compression point is 6dBm.
Modified Single-Phase SRM Drive for Low Torque Ripple and Power Factor Improvement
An, Young-Joo ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 975~982
DOI : 10.5916/jkosme.2007.31.8.975
The single-phase switched reluctance motor(SRM) drive requires DC source which is generally supplied through a rectifier connected with a commercial source. The rectifier is consist of a diode full bridge and a filter circuit. Usually the filter circuit uses capacitor with large value capacitance to reduce ripple component of DC power. Although the peak torque ripple of SRM is small, the short charge and discharge current of the filter capacitor draws the low power factor and system efficiency. A modified single phase SRM drive system is presented in this paper, which includes drive circuit realizing reduction of torque ripple and improvement of power factor. In the proposed drive circuit, one switching part and diode which can separate the output of AC/DC rectifier from the filter capacitor is added. Also, a upper switch of drive circuit is exchanged a diode in order to reduce power switching device. Therefore the number of power switch device is not changed, two diodes are only added in the SRM drive. To verify the proposed system, some simulation and experimental results are presented.
Characteristic Analysis of Inverter for Multi-phase BLDC motor
Oh, Jin-Seok ; Yoo, Heui-Han ; Kim, Jang-Mok ; Jo, Kwan-Jun ; Kwak, Jun-Ho ; Oh, Hyung-Shic ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 983~989
DOI : 10.5916/jkosme.2007.31.8.983
This paper decribes multi-phase BLDC motor with a minimum torque pulsation among BLDC motor used for electric propulsion system. Multi-phase BLDC motor has characteristic that phase of stator has more than 3-phase. This paper is modeling two type of BLDC motor, one has 3-phase and the other has 7-phase, and it shows simulation of them comparing its characteristics. As a result of simulation, the 7-phase BLDC motor shows better performance in terms of torque pulsation. It is also found that the torque pulsation is reduced further by increasing the number of phase.
Development of Whistle Signal Reception and Alert System for Small Vessel
Moon, Serng-Bae ; Oh, Jin-Seok ; Jun, Seung-Hwan ; Yang, Hyoung-Seon ; Jeong, Eun-Seok ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 990~997
DOI : 10.5916/jkosme.2007.31.8.990
In the last 5 years, collisions of fishing vessels have recorded about 54.6% of the total marine accidents. Specially about 64.0% of these collisions were caused by navigator's negligence of watch keeping during works. The purpose of this paper is to develop vessel detecting system that is able to receive the whistle blast of other vessel and make a warning sound and light when the fishermen can not confirm the approaching another vessel on account of fishing works. It is designed to receive the whistle signal blast by a weather tight microphone. The signal is processed by analog active filter in order to enhance the SNR(Signal to noise ratio). And this microprocessor-based system is programmed to do ADC(Analog to digital converting), FFT analysis, controls of warning sound and light.
A Study on the Transient Phenomenon Analysis of Ship Generator Synchronization
Oh, Sae-Gin ; Kim, Jong-Su ; Kim, Sung-Hwan ; Lee, Sung-Gun ; Jo, Sung-Kab ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 998~1004
DOI : 10.5916/jkosme.2007.31.8.998
Connecting a synchronous generator to a power system is a dynamic process, requiring the coordinated operation of many components and systems. The goal is to connect the oncoming generator to the system smoothly i.e without causing any significant bumps, surges, or power swings, by closing the ACB when the oncoming generator matches the power system in voltage magnitude, phase angle, and frequency. If oncoming generator voltage is not matched to the power system voltage, reactive power will flow either into or out of the system at the instant of ACB closure. If this voltage difference is too great, the reactive power flow may result in high transient stresses that could damage the windings of the generator. Also, if oncoming generator frequency is not matched to the power system frequency, transient power will flow between generator and power system. If the frequency difference is too great, the transient power flow is reflected into the prime mover shaft, and this may result in excessive shaft or coupling stress. This paper tries to prove the necessity of correct synchronization for ship generators through a transient phenomenon analysis.
Optimum Structure and Deployment of an Abalone Reef for the Marine Ranching Creation in Jeonnam Archipelago of Korea
Kim, Chang-Gil ; Suh, Sung-Ho ; Cho, Jae-Kwon ; Oh, Tae-Gun ; Kim, Chul-Won ; Myoung, Jung-Goo ; Ryu, Cheong-Ro ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 1005~1012
DOI : 10.5916/jkosme.2007.31.8.1005
This study describes the optimum structure and deployment of an abalone reef for marine ranching creation in Jeonnam archipelago of Korea. The structure of an abalone reef was analyzed based upon the functions of both feeding and shelter. Deployments of abalone reefs were considered based upon the stability against waves in water depth shallower than 5 m. Also, the calculation of their stabilities was made to only rocks of abalone modules, and exposure coefficient of rocks used was 1.0 and 0.5. The results show that rocks of both 0.2 and 0.5 ton are unstable under the condition that exposure coefficient is 1.0 at a depth of 5 m, but that they are stable under the condition that exposure coefficient is 0.5. It means that, if the structures(e.g. breakwater blocks) for dissipating the energy of waves and currents are provided, small rocks of 0.2 ton can be used as an abalone reef.
A Study on Structural Analysis of Globe Valve for LNG Carrier
Kim, Dong-Kyoon ; Kim, Jeong-Hwan ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 1013~1019
DOI : 10.5916/jkosme.2007.31.8.1013
This paper is about structural analysis of globe valve for controlling cryogenic LNG's flow or stop in normal temperature. The used valve is demanded safety resistance for inner pressure and temperature variation caused by using it in cryogenic, high pressure surrounding. This study evaluates for safety resistance for inner pressure and temperature variation by heat transfer analysis in cryogenic surrounding, heat stress analysis in temperature variation and deformation analysis in high pressure.
A Study on Subsidence of Offshore Wind Power System Foundation
Seo, Dong-Il ; Shin, Sung-Ryul ; Lim, Jong-Se ; Yoon, Ji-Ho ; Jang, Won-Yil ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 1020~1027
DOI : 10.5916/jkosme.2007.31.8.1020
As a national enterprise has been expanded over and over, the worldwide energy consumption has been growing necessarily. Moreover, as recently energy spendings are on the increase in countries such as BRICs, it has resulted that a rise in the price of both oil and mineral resources and instability between supply and demand become serious issue in the world resources market. The recent high price of oil and mineral resources have a deep influence on economy and threaten energy security and even national prosperity of Korea. In addition to these, exhaustion of fossil fuels and the enhanced greenhouse effect which results from gases emitted as a result of fossil fuels has been in serious questions which occur a great deal of effort to secure clean energy resources all around the world. As it is considerably possible for Korea that the Kyoto protocol may come into effect on and after 2013, it is essential to require the technological development to promote energy efficiency as well as to develope safe and renewable energy resources. The wind energy technology which converts kinetic energy into electrical energy has been in the focus of the world's attention. In this study, two-dimensional numerical analyses were conducted to observe subsidence aspects of the sea bottom on differently applied loads and various ground conditions.
A Study on the Standard Criteria of Solid Particle Separation Test for Marine Centrifugal Purifier
Jeong, Sang-Hu ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 1028~1034
DOI : 10.5916/jkosme.2007.31.8.1028
In order to establish a criteria of solid particle separation performance test on marine centrifugal purifier at factory acceptance test, an investigation had been done on criteria of test standards, regulations and test specifications of purifier manufactures. KS V 7836, fuel oil and lubricating oil purifiers for marine use-centrifugal type, the criteria of solid particle separation is studied in the point of reality, restricts and analysis method. It is proposed that a reasonable criteria and analysis method should be adopted, and the current criteria shall be revised to adequate levels considering reasonable basis and industrial technology levels. Also, the test analysis conceptions, separation efficiency method and particle size restriction method, are reviewed to fulfil separation performance test for marine centrifugal purifiers.
A Study on the Burning Damage of a Driving Motor for Warship Fire Pump
Jeong, Sang-Hu ;
Journal of the Korean Society of Marine Engineering, volume 31, issue 8, 2007, Pages 1035~1041
DOI : 10.5916/jkosme.2007.31.8.1035
An improvement of driving motor burning damages on a couplingless type warship fire pump is studied. The pump consists of an induction motor a pump-motor shaft and a volute type impeller. The burning damage had occured by changing the material of the pump-motor shaft from carbon steel(SM 45C) to stainless steel(STS 316) for improving anti-corrision properity in sea water. It is shown that a material change on the pump-motor shaft can reduce the efficiency of driving motor and may cause motor burning in the process of pump development stage. This kind of motor burning problem can be solved by increasing the efficiency of the motor and changing the geometry of the inner parts.