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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 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 Reason Why to Use Acoustic Waves on the Sea-Bottom Survey
Kim, Seong-Ryul ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 481~489
DOI : 10.5916/jkosme.2008.32.4.481
Occurrence of Tsunami and Warning System
Kim, Hyun-Seung ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 490~497
DOI : 10.5916/jkosme.2008.32.4.490
A Numerical Study on the Characteristics of Tumble and Internal Flow According to Intake Port for Marine Engine
Lee, Byoung-Hwa ; Chang, Young-June ; Jeon, Chung-Hwan ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 498~505
DOI : 10.5916/jkosme.2008.32.4.498
Many researches have been studied on in-cylinder flow as one of dominant effects for an engine combustion. The combustion phenomena of reciprocating engine is one of the most important processes affecting performance and emissions. One effective way to improve the engine combustion is to control the motion of the charge inside a cylinder by means of optimum induction system design. It is believed that the tumble and swirl motion generated during intake breaks down into small-scale turbulence in the compression stroke of the cycle. However, the exact nature of their relationship is not well known. To know this relationship definitely, this paper describes analytical results of the tumble motion, swirl motion, turbulence intensity, turbulence inside the cylinder of marine engine. 3-D computation has been performed by using STAR-CD solver and es-ice.
The Inflow Characteristics of Fresh Air in the Combustion Chamber having the Radical Injector
Park, Kweon-Ha ; Jeon, Jae-Hyeuk ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 506~513
DOI : 10.5916/jkosme.2008.32.4.506
The engine containing a radical injector has been studied to improve the performances of efficiency and to reduce the exhaust emissions recently. The engine is far different from general compression ignition engines or spark ignition engines for the concept of combustion process. The inflow characteristic from main chamber into radical chamber during compression stroke is important because the radical chamber must have enough fresh air to generate appropriate radicals. The numerical simulation is performed in each specific shape and the engine speed by using KIVA code. The result shows that the fresh air inflow from main chamber into the radical chamber is the best at 45 degree of the hole angle.
The Effect of Lubricant Containing Copper Alloy Nano-powder on Shafting Stability and Torque of a Diesel Engine
Park, Kweon-Ha ; Kim, Young-Nam ; Kim, Young-Il ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 514~521
DOI : 10.5916/jkosme.2008.32.4.514
Many research works for improving a boundary lubrication performance have been executed by using solid lubricants, and been tried to apply an engine lubrication. However those general lubricants have not been applied on engines due to the extreme conditions such as very high temperature and pressure during combustion process in a cylinder. In this study a lubricant containing copper alloy nano-powder is applied on a diesel engine driven by an electric motor. Torques and shaft vibrations are measured, then an engine friction loss and rotating stability are assessed. The results show that the frequency of the vibration is about the same as that of a general lubricant, but the amplitudes in the both X and Y direction are reduced as well as the friction loss is reduced.
A Study on the Characteristic of the Hydrostatic Bearing in the Hydraulic Cylinder
Kang, Hyung-Sun ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 522~527
DOI : 10.5916/jkosme.2008.32.4.522
On designing of hydrostatic bearing, load, quantity of oil, stiffness and friction load are considered as basic characteristics. For the analysis of these basic characteristics, pressure distribution by oil film is obtained. Speed of piston, clearance, leakage of oil, eccentricity, shape and roughness of bearing affect the results which are the analysis of basic characteristics of load, quantity of oil, stiffness and friction load. The relationship among those factors are required for optimum designing of hydrostatic bearing for machining tool. Reynold's Equation is calculated through finite element method. Load, leakage of quantity and pressure distribution as variation of length, land length ratio, eccentricity and axial velocity of bearing are investigated. Then optimum design variables are obtained.
A Numerical Study on Performance Characteristics of a Closed Circuit Cooling Tower with Multi Paths
Kim, Eun-Pil ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 528~533
DOI : 10.5916/jkosme.2008.32.4.528
A closed circuit cooling tower having high temperature of cooling water and small water flow rate is investigated. To study the characteristics of the heat transfer of heat exchanges in a cooling tower with multi paths a numerical method is used. The results show that the staggered tube arrangements in a bank show better performance than aligned ones for temperature variation with various outer diameters of tube bundles. In case of one pass, the 15.88 mm tube case shows about 9% better performance than the 25.4 mm tube case. In two paths, the tube outside diameter of 15.88 mm show about 14.4% better results than the 25.4 mm diameter case.
Heat Transfer Characteristics of R-1270 using 12.7mm Inner Fin Tube
Yoon, Jung-In ; Seong, Gwang-Hoon ; Shim, Gyu-Jin ; Jin, Byoung-Ju ; Baek, Seung-Moon ; Moon, Choon-Geun ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 534~541
DOI : 10.5916/jkosme.2008.32.4.534
This paper deals with the heat transfer characteristics of R-290 (Propane), R-600a (Iso-butane) and R-1270 (Propylene) as an environment friendly refrigerant and R-22 as a HCFC's refrigerant for evaporating. The experimental apparatus has been set-up as conventional vapor compression type refrigeration and air-conditioning system. The test section is a horizontal double pipe heat exchanger. Evaporating heat transfer measurements were performed for smooth tube with the outer diameters of 12.70, 9.52 and 6.35 mm and micro-fin tube 12.70 mm, respectively. For the smooth and micro-fin tubes measured in this study, the evaporating heat transfer coefficient was enhanced according to the increase of the mass flux and decrease of the tube diameter. The local evaporating heat transfer coefficients of hydrocarbon refrigerants were superior to those of R-22 and the maximum increasing rate of heat transfer coefficient was found in R-1270. The average evaporating heat transfer coefficients in hydrocarbon refrigerants showed 20 to 28% higher values than those of R-22. Also, the evaporating heat transfer coefficients of R-22 in the tube diameter of the 12.70 mm smooth and micro-fin tube were compared. Generally, the local heat transfer coefficients for both types of tubes increased with an increase of the mass flux. The heat transfer enhancement factor (EF) between smooth and micro-fin tube varied from 1.9 to 2.7 in all experimental conditions.
Evaporation Heat Transfer and Pressure Drop of Mixture Refrigerant R-407C
Roh, Geon-Sang ; Oh, Hoo-Kyu ; Son, Chang-Hyo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 542~549
DOI : 10.5916/jkosme.2008.32.4.542
The evaporation heat transfer coefficient and pressure drop of R-22 and R-407C in a horizontal copper tube were investigated experimentally. The main components of the refrigerant loop are a receiver, a compressor, a mass flow meter, a condenser and a double pipe type evaporator (test section). The test section consists of a smooth copper tube of 6.4 mm inner diameter. The refrigerant mass fluxes were varied from 100 to
and the saturation temperature of evaporator were
. The evaporation heat transfer coefficients of R-22 and R-407C increase with the increase of mass flux and vapor quality. The evaporation heat transfer coefficients of R-22 is about
higher than that of R-407C. The evaporation pressure drop of R-22 and R-407C increase with the increase of mass flux. The pressure drop of R-22 is similar to that of R-407C. In comparison with test results and existing correlations, correlations failed to predict the evaporation heat transfer coefficient of R-22 and R-407C. therefore, it is necessary to develope reliable and accurate predictions determining the evaporation heat transfer coefficient of R-22 and R-407C in a horizontal tube.
Performance Characteristics of Air Driven Ejector According to the Position Changes and the Shape of Driving Nozzle
Ji, Myoung-Kuk ; Kim, Pil-Hwan ; Park, Ki-Tae ; Utomo, Tony ; Chung, Han-Shik ; Jeong, Hyo-Min ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 550~556
DOI : 10.5916/jkosme.2008.32.4.550
The aim of this research is to analyze the influence of motive pressure, driving nozzle position and nozzle throat ratio on the performance of ejector. The experiment was conducted in the variation of motive pressure of 0.196, 0.294, 0.392 and 0.490MPa respectively. The position of driving nozzle was varied in difference locations according to mixing tube diameter(0.5d, 1d, 2d, 3d, 4.15d, 5d and 6d). The experimental results show when the nozzle outlet is located at 3d, the flow characteristics change abruptly. It is shown that the suction flow rate and pressure lift ratio of ejector is influenced by the driving nozzle position. At nozzle position location of the Id of mixing tube diameter the performance of ejector gives the best performance.
A Study on the Tribological Characteristics of Automobile Gear Oil with Addition of Compound Additives
Choi, Nag-Jung ; Youn, Suk-Bum ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 557~562
DOI : 10.5916/jkosme.2008.32.4.557
In this paper, experiments have been performed for the investigation of tribological characteristics of automobile gear oil with the addition of ZDDP and DEP by using the FALEX WEAR TEST MACHINE. The results are as follows. The wear characteristics of gear oil was improved by adding compound additives. The extreme pressure of gear oil increases and then decreases with the applied load. The maximum extreme pressure of gear oil with compound additive is bigger then that of pure gear oil. The friction coefficient of pure gear oil monotonically increases with the temperature, but that of gear oil mixed with the additives decreases at the high temperature.
A Study for the Cooling Performance of a Brake with Heat Pipes
Kim, Moo-Geun ; Ko, Sung-Kyu ; Lee, Moon-Wan ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 563~569
DOI : 10.5916/jkosme.2008.32.4.563
During braking operation, the surfaces of disk have severe contact conditions and high frictional heat would be generated between disk and pad surfaces. The heat makes high temperature gradient on disk surfaces and results in thermal deformation. To enhance the frictional heat dissipation, heat pipes are embedded in the ventilated type disk along the radial direction. The temperatures of the inner vent type disk and the brake disk with heat pipes are compared at the same operating conditions. By comparison a brake disk with heat pipes has higher cooling performance than the inner vent type disk.
Effect of Process Parameters on Laser Weldability of AZ31 Magnesium Alloy
Kim, Jong-Do ; Kil, Byung-Lea ; Lee, Jung-han ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 570~577
DOI : 10.5916/jkosme.2008.32.4.570
Magnesium alloys are potentially useful as structural materials due to higher strength/weight ratio, heat conductivity and recyclability compared to other alloys. These alloys have attracted the interest of modern manufacturing such as the automobile, computer, communication and consumer electronic appliances industries. Hence welding techniques are required to be developed for these applications. Laser are known to be an excellent tool for them. This paper presents the laser weldability of AZ31 magnesium alloy with CW Nd:YAG laser. The low viscosity and surface tension of the melt pool make magnesium more difficult to weld than steel. As a result of this study, optimal process parameters could be obtained without weld defects. Also it was certain that cutting methods had influence on butt weldability.
A Study of the Upper Bound Analysis of Extrusion Process with Torsion
Park, Chul-Woo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 578~584
DOI : 10.5916/jkosme.2008.32.4.578
In this study, a extrusion process with torsion of the bottom die is investigated to improve the forming performance of conventional extrusion process. In the experiment, plasticine is used as a model material. The results of experiments are compared with the two numerical methods, the Experiment and the Finite Element Method(FEM). An attempt is made to link programs incorporating with the process variables obtained by commercial FEM software, DEFORM-3D a useful package. Numerical result is compared with experimental one. These results show that the torsional extrusion process is very useful process because this process can obtain the homogenous deformations.
Finite Element Analysis for Multi-stage Forging Process Design of Bolt with Nonaxisymmetric Washer Cam
Kim, Kwan-Woo ; Kim, Yi-Tae ; Kim, Wan-Jong ; Cho, Hae-Yong ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 585~595
DOI : 10.5916/jkosme.2008.32.4.585
Process design of multi-stage forging for a bolt with nonaxisymmetric washer cam has been studied by using finite element method. For shape complexity of the bolt, it is impossible to manufacture in a single stage forging. To design multi-stage forging for the bolt the forging load and fiber flow of each step have been analyzed by using commercial finite element code DEFORM-3D. Simulated results have been compared with experimental ones. Multi-stage forging process has been designed with four stages. The workpiece should be eccentric shape until third forging stage. And then bolt head and washer of eccentrical shape is created in last stage. As a results, It was predicted that shape of product would be good and effective strain would be uniformly distributed in the product. Also, it was predicted whether defects would exist or not by reviewing the fiber flow.
Analysis & Design of Cooling System for Electric Propulsion System
Oh, Jin-Seok ; Jo, Kwan-Jun ; Kwak, Jun-Ho ; Lee, Ji-Young ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 596~602
DOI : 10.5916/jkosme.2008.32.4.596
The cooling system is one of the most concerning factor for the reliability of the electric propulsion ship. Generally, a drive system operation in higher temperature decreases the device's reliability and power efficiency. The management of power loss and temperature of switching devices is indispensable for the reliability of the power electric system. In this paper, the switching devices are molded by IGBT, and the propulsion system is consisted of MIIR(Motor with Inverter Internal to Rotor). The system composition interacts with each other to calculate the loss and temperature of device. The calculation result is used for modeling and designing of the control and monitoring system for the electric propulsion system.
Analysis and Applications of Multi-user DS-PAM and TH-PPM UWB System
Sung, Tae-Kyung ; Kim, Dong-Seek ; Kim, Cheol-Seong ; Cho, Hyung-Rae ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 603~610
DOI : 10.5916/jkosme.2008.32.4.603
In this paper, analytical methods for calculating the average probability of bit error of direct sequence pulse amplitude modulation ultra wideband (DS-PAM UWB) system and time hopping pulse position modulation ultra wideband (TH-PPM UWB) system are given. For the multi-user DS-PAM UWB system, the bipolar pulse amplitude modulation is used in order to achieve better performance. As we know, more attention is paid to the TH-PPM UWB systems recently. In this paper. we first introduce the accurate BER calculation methods of the multi-user DS-PAM UWB and TH-PPM UWB systems and then give the performance analysis over the ideal AWGN channel and a correlation receiver. Furthermore, we also introduce their applications in image transmission and data transmission and give the simulation results. The analytical method yields simple and exact formulas relating the performance to the system parameters.
A Model Driven Architecture and Product Line Engineering Technique for Adaptable Contents Service of Ubiquitous Computing : Applying to Vessel U-Safety Monitoring
Lee, Seo-Jeong ; Choi, Mi-Sook ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 611~617
DOI : 10.5916/jkosme.2008.32.4.611
In ubiquitous environments, the content adaptable services can be dynamically provided to adapt the frequent changes of contexts. These services have common things that the kinds of context factors are limited to ubiquitous environment, though the contexts are flexible. To reuse service architecture can be reasonable for effective adaptable service. In this paper, we design a software architecture with product line techniques for content adaptable applications in ubiquitous environment. Description of product line is to define variation points and their variants, to find out the dependencies between them and to keep the model based architecture, their alternatives.
Interpolation-Based Adaptive LQ Control for Nonlinear Systems
Lee, Yun-Hyung ; Ahn, Jong-Kap ; Jin, Gang-Gyoo ; So, Myung-Ok ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 618~623
DOI : 10.5916/jkosme.2008.32.4.618
This paper presents a design method of the Interpolation-based adaptive LQ controller that is accomplished by getting the final controller interpolated with each gain of sub-LQ controllers. The Lagrange interpolation method is used in the scheme. The proposed controller is useful to control nonlinear systems which are especially changed the system parameters. The design method is illustrated by an application to the stabilization and tracking problems of an inverted pole system on a cart. Several cases of simulations are carried out in order to validate the control effectiveness and robustness. The simulation results are compared with those of LQ controller and prove the better control performance than LQ controller.
RCGA-Based State Observer Design for Container Cranes
Ahn, Jong-Kap ; Lee, Yun-Hyun ; Ryu, Ki-Tak ; Yoo, Heui-Han ; So, Myung-Ok ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 624~629
DOI : 10.5916/jkosme.2008.32.4.624
This paper presents a scheme for designing a state observer for container cranes. If the system is completely observable with a given set of outputs, then it is possible to determine the states that are not directly measured. We consider the reduced-order states observer with only trolley position detection and with trolley position and container angle detection. The gain matrix of the each state observer is adjusted using a RCGAs. A set of simulation works is carried out to demonstrate the effectiveness of the proposed scheme.
Monitoring System of Sandbar Variation of Estuary using Video-based Technique
Yoon, Han-Sam ; Ryu, Seung-Woo ; Kang, Tae-Soon ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 4, 2008, Pages 630~636
DOI : 10.5916/jkosme.2008.32.4.630
Monitoring the location of the shoreline and foreshore changes through the time and core tasks are carried out by coastal engineers for a wide range of research. With the advent of digital imaging technology, the shore-based video monitoring system provides many advantages than field surveys. This study presents the development and construction(installation) of video monitoring system to assist the study of coastal and shoreline dynamics and evolution, especially sandbar variation at the Nakdong river estuary. For the purpose of this study, at high building near the Dadea-po beach (St. 2) and Jinudo(island) (St. 1) foreshore region, where coastline variation is highly active, 5 video cameras installed; the coastline movement has monitored since Aug. 2007 using the systems. From the image results of video camera, the 'Spit' type sandbar appears at the foreshore region of Doyodeung and Dadea-po beach and measured the deposition process of Jinudo(island) foreshore region. As a result, the monitoring system using video-based technique built in this study would be able to identify changes in the area and width of shoreline and beach of Nakdong river estuary.