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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Marine Engineering
Journal Basic Information
Journal DOI :
Korean Society of Marine Engineers
Editor in Chief :
Volume & Issues
Volume 32, Issue 8 - Nov 2008
Volume 32, Issue 7 - Nov 2008
Volume 32, Issue 6 - Sep 2008
Volume 32, Issue 5 - Jul 2008
Volume 32, Issue 4 - May 2008
Volume 32, Issue 3 - May 2008
Volume 32, Issue 2 - Mar 2008
Volume 32, Issue 1 - Jan 2008
Selecting the target year
The Effect of Ethanol Mixing Rate on Engine Performance
Park, Kweon-Ha ; Park, Hong-Il ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 663~669
DOI : 10.5916/jkosme.2008.32.5.663
A rapid growth of automobile industry has become a major cause for the environmental pollution of big cities, which has driven the emission regulation into extreme. The study of alternative fuel is one of the many researches for improving car emissions. In this study, the effect of an ethanol mixing rate on the engine performance of exhaust emissions, fuel consumption and a maximum torque is assessed for a gasoline engine without any retrofit. The result shows that maximum torque is not reduced in the range of ethanol mixing rate of 10 to 15%. CO and NOx is reduced with the increase of ethanol mixing rate and the fuel consumption remains in similar level.
The Performance of a Diesel Engine Using Lubricant Containing Nano-metal Powder
Park, Kweon-Ha ; Choi, Jae-Sung ; Kim, Dae-Hyun ; Kim, Young-Nam ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 670~676
DOI : 10.5916/jkosme.2008.32.5.670
A diesel engine requires a high Performance of lubrication because of the extreme conditions such as high temperature and pressure during combustion process in a cylinder. Many researches to improve the lubrication performance on the extreme condition have been executed. The lubricant oil suspended with nano-metal particles is the one of the measure. In this study, the nano-lubricant oil is applied on a commercial diesel engine, and the engine performance is tested. The results show the increase of maximum torque and the decrease of cylinder pressure, exhaust gas temperature, CO emission.
A Study on the Hybrid Propulsion System for Fishing Boat
Oh, Jin-Seok ; Jo, Kwan-Jun ; Park, Choung-Hwan ; Ham, Youn-Jae ; Kwak, Jun-Ho ; Lee, Ji-Young ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 677~683
DOI : 10.5916/jkosme.2008.32.5.677
The electric propulsion system us closely related with the economical efficiency of ship operation. Fuel efficiency is mainly decided by propulsion system such as diesel engine, propulsion motor and steam turbine. The hybrid propulsion system for fishing boat consists of diesel engine and battery as propulsion power source. This paper is to design battery capacity according to power consumption with ship operation condition, and to test the power consumption of model ship in the circulating water channel. As a result. it can be known that the optimum ship operation condition affects the fuel efficiency.
A Study of the Heat Conduction Phenomena with a Phase Lag of Heat Flux
Jin, Chang-Fu ; Kim, Kyung-Kun ; Chung, Han-Shik ; Jeong, Hyo-Min ; Choi, Du-Yeol ; Choi, Soon-Ho ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 684~690
DOI : 10.5916/jkosme.2008.32.5.684
In most engineering applications related with the heat conduction phenomena, a conventional Fourier heat conduction equation has been successfully applied and it has supplied quite reasonable results. However, it is well known that the Fourier heat conduction equation is failed in the application to the extremely small space and short time, in other words, a nano-scale system and a pico-second time. In this study, non-Fourier effect was evaluated in the heat conduction by considering the concept of a phase lag model. The results show the existence of a heat wave, which means that the heat is transferred with a finite speed while an infinite speed of heat transfer is assumed in the conventional Fourier heat conduction. In addition, the copper and the gold are tested to evaluate the phase lag time between the heat flux and the temperature gradient. The results show that the gold has the heat wave speed faster than that of the copper consistent with the prediction based on an actual experiment.
An Experimental Study on Fluid Flow and Heat Transfer Around Four Circular Cylinders of In-line
Choe, Soon-Youl ; Kim, Min-Soo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 691~697
DOI : 10.5916/jkosme.2008.32.5.691
Heat exchangers are commonly used in practice in a wide range of application, from heat and air-conditioning system in a household, to chemical processing and power production in large plant. An Experimental study was conducted to investigated the fluid flow and heat transfer around four circular cylinders of in-line in a cross flow of air. The local and average heat transfer characteristics for tube banks are investigated in the present study. Heat transfer in a heat exchanger usually involves convection in each fluid and conduction through the wall separating the two fluid. The in-line pitch ratio was in the range
, where L is the center distance and d the cylinder diameter, and in the Reynolds number
. The local and mean Nusselt numbers were estimated. Subsequently, the heat transfer characteristics of four circular cylinders are found to exhibit a strong dependency upon the separation point of their upstream cylinders.
Performance Analysis of a Cross Flow Hydro Turbine by Runner Blade Number
Choi, Young-Do ; Jin, Chang-Fu ; Lim, Jae-Ik ; Kim, You-Taek ; Lee, Young-Ho ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 698~706
DOI : 10.5916/jkosme.2008.32.5.698
Performance improvement of Small hydro turbine is a very important subject to solve in the stage of introduction and development of the turbine. Cross-flow hydro turbine should be also studied more in detail for the turbine performance in order to extend the sites of application. In order to improve the turbine performance, the effect of the turbine shape on the turbine performance should be examined. Therefore, the effect of runner blade number on the turbine performance is investigated by use of a commercial CFD code. The results show that runner blade number gives remarkable effect on the efficiency and output power of the turbine. Pressure on the surface of the runner blade changes considerably by the blade number at Stage 1, but relatively small change of velocity distribution occurs in the flow passage.
An Experimental Analysis on the Spray Structure of Multi-component Fuels Using Magnification Photograph and Mie Scattering Images
Myong, Kwang-Jae ; Yoon, Jun-Kyu ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 707~716
DOI : 10.5916/jkosme.2008.32.5.707
The objective of this study was to analyze the effect of mixed fuel composition and mass fraction on spray inner structure in evaporating transient spray under the variant ambient conditions. Spray structure and spatial distribution of liquid phase concentration were investigated using a thin laser sheet illumination technique on the three component mixed fuels. A pulsed Nd:YAG laser was used as a light source. The experiments were conducted in a constant volume vessel with optical access. Fuel was injected into the vessel with electronically controlled common rail injector. Used fuel contains i-octane(
) and n-hexadecane(
) that were selected as low-, middle- and high-boiling point fuel, respectively. Experimental conditions are 42 MPa, 72 MPa and 112 MPa in injection pressure,
in ambient gas density, 300 K, 500 K, 600 K and 700 K in ambient gas temperature, 300 K and 368 K in fuel temperature and different fuel mass fraction. Experimental results indicated that the multi-component fuels made two phase region mixed vapor and liquid so that it would are helpful to improve combustion, for the fuels of high boiling point component could accelerate evaporation very much according as low boiling point fuel was added to high boiling point fuel.
A Measurement and Evaluation of the Indoor Thermal Conditions in Summer of a Newly-Launched 8,500GT Chemical Carrier
Hwang, Kwang-Il ; Doe, Geun-Young ; Cho, Hyo-Jae ; Woo, Sang-Woo ; Shin, Dong-Keol ; Lim, Seong-Taek ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 717~723
DOI : 10.5916/jkosme.2008.32.5.717
The purpose of this study is to measure and analyze the indoor thermal conditions of a 8,500GT class chemical carrier which was launched on July 2007. The measurement was operated from 4th June to 4th June 2007, just before handing over to Owner. Followings are the results of this study. (1)The temperature variations of supply air were related to the outdoor temperature variations, but the humidity was stable at
. (2)The temperature variations at the representative position of bridge, restaurant, crew's cabin showed gentle slopes. but that of conference room was very steepy. The humidities of bridge and restaurant were unstable because of outdoor-contact and cooking, respectively. (4)The temperature and humidity of ECR(Engine Control Room) which was designed to supply heating and cooling by PAC(Package Air Conditioner) were directly affected by the operating conditions of PAC. (5)The measured supply air volume from dampers of bridge, crew's cabin and conference room were satisfied with the design supply air volume. (5)For the improvement of the indoor thermal conditions, the temperature of crew's cabin and restaurant and the humidity of conference room, and the temperature and humidity of bridge should be controlled, respectively.
A Study on the Thermal Analysis for the Robotic Arm of the Cord Blood Storage Tank
Yun, Sang-Kook ; You, Sam-Sang ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 724~729
DOI : 10.5916/jkosme.2008.32.5.724
Umbilical cord blood has been recently considered an attractive potential alternative as a source of stem cell transplantation to curing diseases such as leukemia, cancers, immune disorders. Normally the stored system of the umbilical cord blood specimen is equipped with a computer-controlled robotic arm that enables the samples to locate the identification places in liquid nitrogen tank at regulated temperature as about
. As the half of robotic arm is in the air and the rest part is submerged in liquid nitrogen, the temperature of robotic arm varies from ambient to liquid nitrogen temperature. In this study the temperature variation of upper part of arm above tank lid was thermally analysed by using the commercial code of Ansys. The result of analysis was that the upper part of robotic arm was seriously frozen due to heat transfer from liquid nitrogen as low as -
. In order to solve the frost problem of robotic arm, small PTFE tube block as resistance material was introduced into the lower part of tank lid instead of the whole stainless steel(SUS) robotic arm. The results showed that the temperature of robotic arm above the lid was higher enough, and this method would be one of the very effective measure to solve the problem.
A Study on the Flow Characteristics in Computer Case by Crossflow Fan.
Lee, Haeng-Nam ; Park, Gil-Moon ; Jung, Hann-Byul ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 730~736
DOI : 10.5916/jkosme.2008.32.5.730
The purpose of this study is to find out a flow characteristics when a crossflow-fan is installed inside the computer case and to provide information about the preliminary data of cooling efficiency of CPU and a flow inside and outside of a computer case. Under the condition of operating the fan inside the experimental duct we changed the position of a installation of the slot, and the experiment measured with PIV and the results are as follows. Under the influence of the crossflow-fan installed to the air discharging side, mean velocity between 35 to 45 on the point 80 of the Slot 0.2.3 of the case increased and it influences discharging the air inside of the computer case. On the left-upper end. which isn't directly influenced by the suction-discharging fan installed inside the PC, a flow occurs caused by vortex due to the Sirocco-Fan and Slot installed on the center of the right side. We can see that a flow distribution increases when the Sirocco-Fan operates and a whirl appears stronger between the slot and the suction fan. It is thought that this phenomenon is influenced by a flow while it is on the way of entering from the suction-fan and going out to the discharging-fan.
A Study on Preferential Diffusion Effects in
Kim, Tae-Kwon ; Park, Jeong ; Ha, Ji-Soo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 737~746
DOI : 10.5916/jkosme.2008.32.5.737
Numerical study is conducted to grasp preferential diffusion effects on flame characteristics in
syn-gas diffusion flames diluted with
. The models of Sun et al. and David et al., which have been well known to be best-fitted for
synthetic mixture flames. are evaluated for
synthetic mixture flames diluted with
. Comparison of flame structures with mixture-averaged species diffusion and suppression of the diffusivities of
and H was made. The behaviors of maximum flame temperatures with those species diffusion models are not explained by scalar dissipation rate but by the nature of chemical kinetics. Importantly-contributing reaction steps to heat release rate are also compared for the three species diffusion models in
flames with and without
Natural Convection Correlation of Circular Finned Tube Heat Exchanger
Kang, Hie-Chan ; Jang, Hyun-Soon ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 747~752
DOI : 10.5916/jkosme.2008.32.5.747
An experimental study has been conducted on the natural convection heat transfer for the 7 kinds of circular finned tube heat exchangers. Empirical correlation was suggested at the range of 3,500
A Study on Programming Development Forming Design Automated of CAM for Coil Spring Forming Tool
Park, Chul-Woo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 753~758
DOI : 10.5916/jkosme.2008.32.5.753
A CAM program for forming design Automated of CAM for Spring using car was developed in this study. This program was written in AUTO LISP on the AUTO CAD system with a personal. An approach to the system is based on the kinemateic of the object function. We make a determination of an cam programming. A CAM spline is continuous in displacement. velocity and acceleration. This program which can design Coil Spring shapes will successfully support CAN designing and manufacturing for Small & Medium companies.
Finite Element Modeling of Electrochemical Governing Equations for Ionic Polymer Actuators
Kang, Sung-Soo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 759~767
DOI : 10.5916/jkosme.2008.32.5.759
Bending deformation of an ionic polymer actuator(IPA) on applied low electric field across its thickness is dominated by electroosmosis of hydrated ions and self-diffusion of free water molecules. In the study by Popovic et al., two processes are assumed to occur sequentially in the way that fast electroosmosis is followed by self-diffusion and finite element formulation for the basic field equations are proposed. However the motions of hydrated ions and water molecules occur at the same time. In this study, those two processes are considered simultaneously and finite element formulation is conducted for the basic field equations governing electrochemical response of an IPA. Some numerical studies for IPA are carried out in order to show the validity of the present formulation.
Voice Activity Detection Based on Signal Energy and Entropy-difference in Noisy Environments
Ha, Dong-Gyung ; Cho, Seok-Je ; Jin, Gang-Gyoo ; Shin, Ok-Keun ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 768~774
DOI : 10.5916/jkosme.2008.32.5.768
In many areas of speech signal processing such as automatic speech recognition and packet based voice communication technique, VAD (voice activity detection) plays an important role in the performance of the overall system. In this paper, we present a new feature parameter for VAD which is the product of energy of the signal and the difference of two types of entropies. For this end, we first define a Mel filter-bank based entropy and calculate its difference from the conventional entropy in frequency domain. The difference is then multiplied by the spectral energy of the signal to yield the final feature parameter which we call PEED (product of energy and entropy difference). Through experiments. we could verify that the proposed VAD parameter is more efficient than the conventional spectral entropy based parameter in various SNRs and noisy environments.
A Hybrid Course-Based Routing Protocol Suitable for Vessel Ad Hoc Networks
Son, Joo-Young ; Mun, Seong-Mi ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 775~784
DOI : 10.5916/jkosme.2008.32.5.775
It is not easy to access very high speed Internet services at sea due to some technical and economical problems. In order to realize the very high speed Internet services at sea like on land, new communication network models based on MANET should be adopted. In this paper, a new MANET model at sea is provided, which considered the ocean environments, and the characteristics and movement of vessels. On the basis of the fact that most vessels navigate on the predetermined courses, which are the shortest paths between source and destination ports in most cases, a type of location oriented routing protocol is proposed in this paper. The Hybrid Course-Based Routing Protocol(HCBR) makes use of the static information such as courses and positions of ports to proactively find the shortest paths not only among ports but also the cross points of courses. HCBR also makes use of the locational information of vessels obtained via GPS and AIS systems to reactively discover the shortest route by which data packets are delivered between them. We have simulated the comparison of the performance of HCBR with those of LAR scheme 1 and scheme2, the most typical protocols using geographical information. The simulation results show that HCBR guarantees the route discovery even without using any control packet. They also show that HCBR is more reliable(40%) and is able to obtain more optimal routes(10%) than LAR scheme1 and scheme2 protocols.
Control of Unstable Systems Concerned with the Performance Indexes and Constraints
Ahn, Jong-Kap ; Lee, Yun-Hung ; So, Myung-Ok ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 785~790
DOI : 10.5916/jkosme.2008.32.5.785
A technique for determining the feedback gain of the states feedback controller using a real-coded genetic algorithm(RCGA) is presented. It is concerned with the states error to the performance index of a RCGA. As for assessing the performance of the controller three performance criteria (ISE. IAE and ITAE) are adopted. And designing the controller involves a constrained optimization problem. Therefore a real-coded genetic algorithm incorporating the penalty strategy is used. The performance of the proposed method is demonstrated through a set of simulation about an inverted pendulum system.
Enhancement of Ship's Wheel Order Recognition System using Speaker's Intention Predictive Parameters
Moon, Serng-Bae ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 5, 2008, Pages 791~797
DOI : 10.5916/jkosme.2008.32.5.791
The officer of the deck(OOD) may sometimes have to carry out lookout as well as handling of auto pilot without a quartermaster at sea. The purpose of this paper is to develop the ship's auto pilot control module using speech recognition in order to reduce the potential risk of one man bridge system. The feature parameters predicting the OOD's intention was extracted from the sample wheel orders written in SMCP(IMO Standard Marine Communication Phrases). We designed a pre-recognition procedure which could make some candidate words using DTW(Dynamic Time Warping) algorithm, a post-recognition procedure which made a final decision from the candidate words using the feature parameters. To evaluate the effectiveness of these procedures the experiment was conducted with 500 wheel orders.