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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
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Volume & Issues
Volume 37, Issue 8 - Nov 2013
Volume 37, Issue 7 - Nov 2013
Volume 37, Issue 6 - Sep 2013
Volume 37, Issue 5 - Jul 2013
Volume 37, Issue 4 - May 2013
Volume 37, Issue 3 - May 2013
Volume 37, Issue 2 - Mar 2013
Volume 37, Issue 1 - Jan 2013
Selecting the target year
Soundness evaluation of friction stir welded A2024 alloy by non-destructive test
Ko, Young-Bong ; Kim, Gi-Beom ; Park, Kyeung-Chae ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 135~143
DOI : 10.5916/jkosme.2013.37.2.135
Friction Stir Welding (FSW) was developed, it is successfully commercialized in the field of transportation vehicles. In this study, we analyzed the defects of A2024-T4 alloy using non-destructive test of radiograph, ultrasonic, electrical conductivity and destructive test of microstructure observation, tensile strength. As the results of experiment, mapping of defects was obtained. Fine defects which were not detected in radiograph test were detected in ultrasonic test, and it enabled efficient detection of defects by difference of sound pressure and color. The values of electrical conductivity was decreased as amount of defects was increasing. Joint efficient of defect-free weldment that found by non-destructive and destructive test was 91%. Therefore it was considered that non-destructive test of friction stir welded A2024-T4 Alloy was an efficient method.
Analysis of nano-cluster formation in the PECVD process
Yun, Yongsup ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 144~148
DOI : 10.5916/jkosme.2013.37.2.144
In this paper, the ultra water-repellent thin films were prepared by RF PECVD. On the basis of surface morphology, chemical bonding states and plasma diagnostics, a formation model of clusters for the ultra water-repellent films was discussed from considerations of formation process and laser scattering results. Moreover, using laser scattering method, the relative change of quantity of nano-clusters or size of agglomerates could be confirmed. From the results, the films were deposited with nano-clusters and those of agglomerates, which formed in organosilicon plasma, and formation of agglomerates were depended on the deposition time.
Design of pulsatile pump and performance test for pulsatile flow generation
Joo, Yoon-Ha ; Kim, Kyung-Won ; Lee, Yeon-Ho ; Kwak, Moon-Kyu ; Lee, Choon-Young ; Lee, Jong-Min ; Park, Cheol-Woo ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 149~155
DOI : 10.5916/jkosme.2013.37.2.149
For in-depth research of blood flow, it is important to create pulsating flow like the blood flow from heart beat. In this study, we developed a heart mimicking pulsatile pump and evaluated its performances. Main body of pump was produced using a piston pump, and its rpm and duty ratio was modulated by DC motor and encoder. To determine the part dimensions, principle stress theory and simple fluidic pressure analysis were used. The performance of pulsating pump was evaluated by comparing the pressure values and their deviations according to experimental variables. For the results, the output value of pressure followed the distribution of pulsating flow and its deviation was negligible. Through this study, we expect the established pulsating pump can be widely used in study of blood flow produce easy ways to related researchers.
Characteristic calculations of flowfield around a square prism having a detached splitter plate using vortex method
Ro, Ki-Deok ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 156~162
DOI : 10.5916/jkosme.2013.37.2.156
The characteristics of the unsteady flowfield of a square prism having a detached splitter plate at the wake side were investigated by advanced vortex method. The instantaneous and average velocity field and pressure field around a square prism without and having splitter plate were calculated by forcing the gap ratio having the maximum drag reduction rate, at Reynolds number
and the width ratio H/B=1.0 of splitter to the prism width. The drag and lift coefficients on the square prism were also obtained. The calculated results agree with the measured drag coefficients and pressure distributions on the square prism. The vortices of the opposite direction at upside and down side of the splitter plate were generated by installing of the plate. And the drag on the square prism was decreased by increasing of the pressure of back face of the prism with the vortices.
Influence of guide vane shape on the performance and internal flow of a cross flow wind turbine
Son, Sung-Woo ; Singh, Patrick Mark ; Choi, Young-Do ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 163~169
DOI : 10.5916/jkosme.2013.37.2.163
In order to make the vertical-axis cross flow wind turbine commercially feasible, a guide vane is adopted and the effect of the guide vane shape is examined in order to improve the wind turbine performance. CFD analysis on the performance and internal flow of the turbine is carried out for the wind turbine model. The result shows that when the guide nozzle is installed, almost over two times of power coefficient are achieved in comparison with the case of no guide nozzle installation. The guide nozzle acts as a role of suppressing the flow resistance at the blade passage, which is found when the guide nozzle is installed. Moreover, in this study, two kinds of the guide vane with a straight type and a curved type are adopted and compared. The curved guide vane nozzle produces higher power coefficient in comparison with that of straight guide vane nozzle.
Shape design and flow analysis on a 200W-class gyromill type vertical axis wind turbine rotor blade
Cho, Woo-Seok ; Kim, Hyun-Su ; Choi, Young-Do ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 170~177
DOI : 10.5916/jkosme.2013.37.2.170
This study is focused on the shape design and flow analysis on a 200 W-class Gyromill type vertical axis wind turbine rotor blade. Single tube theory is adopted for the shape design of the turbine blade. 2-dimensional CFD analysis is conducted to examine the turbine performance with basic shape, and then 3-dimensional shape is determined from the examination of the performance. By the CFD analysis on the 3-dimensional shape of the wind turbine, performance of the turbine is examined and also, shape of the wind turbine rotor blade is determined accordingly. From the results of this study, a 200 W-class Gyromill type vertical axis wind turbine rotor blade is designed and the reliability of the design method is confirmed by CFD analysis.
Stress analysis of bucket rotating part of the compact excavator
Shin, Suk-Shin ; Noh, Jong-Ho ; Park, Jong-Ho ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 178~182
DOI : 10.5916/jkosme.2013.37.2.178
In mining and its similar industries, compact excavators are used commonly in narrow working spaces, of which bucket must be rotated essentially. Considering of those applications, many kinds of the compact excavators have been developed, but any stress evaluation of bucket rotating part had not been attempted. In this study, using of the finite element method and Spare solver, stress analysis has been performed on the bucket rotating parts and its adjacent parts of compact excavator, with using an excavation stress model, in various directions and positions. Resultantly, it has been defined that stress of connector in the rotating part is a little higher, due to its shape, than those remained parts of which stress are shown equally as 1 MPa. Especially in the moving parts, the stress of bucket pin and rotating pinion gear has been calculated as 7.7 MPa and 40 MPa respectively.
Development of engine room monitoring system complied with IEC 61162-3 international standards for ship's network
Kim, Jong Hyun ; Yu, Yung Ho ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 183~191
DOI : 10.5916/jkosme.2013.37.2.183
International network standards for SOLAS ship are composed of instrument network that controls and monitors machine in real time, shipboard control network that controls and monitors system through computer by human and telecommunication network that connects ship and shore. This paper describes development of stack for instrument network protocol complied with NMEA 2000 that is IEC 61162-3 international standards for SOLAS ship and also that of engine room monitoring system using the developed stack. Developed engine room monitoring system is certified by NMEA according to standards that require to pass about 1,600 test procedures.
A study on the stabilization and controller design for directional pan-tilt system
Shin, Suk-Shin ; Noh, Jong-Ho ; Park, Jong-Ho ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 192~198
DOI : 10.5916/jkosme.2013.37.2.192
This paper presents the stabilization and design of a pan-tilt control part for the directional pan-tilt system for shipboard directional equipment. In order to control each control axis with compensation for ship motion, the 2 degree of freedom(2DOF) PID controller is designed and its parameters are tuned using a real-coded genetic algorithm(RCGA). Simulation demonstrates the effectiveness of the 2 DOF PID controller tuning.
A multi carrier selectable routing scheme by normalized transmission characteristics (MCS-NTC) at marine multi-carrier MANETs
Son, Jooyoung ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 199~204
DOI : 10.5916/jkosme.2013.37.2.199
Marine data communications still look for a novel data communication system at sea because of the restriction of bandwidths and costs of current carriers. In order to make the most efficient use of the broadband land carriers at sea, this paper proposes a routing scheme (MCS-NTC) at a marine MANET model. The routing scheme optimizes the route by choosing optimal nodes and carriers among the traditional and land carriers based on normalized transmission characteristics of applications and carriers. The performance is compared with the max-win method (OMH-MW) scheme considering the specific values of transmission characteristics. The result shows that our scheme derives more efficient routes than the previous one in terms of the transmission characteristics such as bandwidth, cost, delay, the number of hops and carriers.
A three-step sentence searching method for implementing a chatting system
Jeon, Won-Pyo ; Song, Yoeng-Kil ; Kim, Hark-Soo ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 205~212
DOI : 10.5916/jkosme.2013.37.2.205
The previous chatting systems have generally used methods based on lexical agreement between users' input sentences and target sentences in a database. However, these methods often raise well-known lexical disagreement problems. To resolve some of lexical disagreement problems, we propose a three-step sentence searching method that is sequentially applied when the previous step is failed. The first step is to compare common keyword sequences between users' inputs and target sentences in the lexical level. The second step is to compare sentence types and semantic markers between users' input and target sentences in the semantic level. The last step is to match users's inputs against predefined lexico-syntactic patterns. In the experiments, the proposed method showed better response precision and user satisfaction rate than simple keyword matching methods.
An improvement algorithm for localization using adjacent node and distance variation analysis techniques in a ship
Seong, Ju-Hyeon ; Lim, Tae-Woo ; Kim, Jong-Su ; Park, Sang-Gug ; Seo, Dong-Hoan ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 213~219
DOI : 10.5916/jkosme.2013.37.2.213
Recently, with the rapid advancement in information and communication technology, indoor location-based services(LBSs) that require precise position tracking have been actively studied with outdoor-LBS using GPS. However, in case of a ship which consists of steel structure, it is difficult to measure a precise localization due to significant ranging error by the diffraction and refraction of radio waves. In order to reduce location measurement errors that occur in these indoor environments, this paper presents distance compensation algorithms that are suitable for a narrow passage such as ship corridors without any additional sensors by using UWB(Ultra-wide-band), which is robust to multi-path and has an error in the range of a few centimeters in free space. These improvement methods are that Pythagorean theory and adjacent node technique are used to solve the distance error due to the node deployment and distance variation analysis technique is applied to reduce the ranging errors which are significantly fluctuated in the corner section. The experimental results show that the number of nodes and the distance error are reduced to 66% and 57.41%, respectively, compared with conventional CSS(Chirp spread spectrum) method.
Fixed node reduction technique using relative coordinate estimation algorithm
Cho, Hyun-Jong ; Kim, Jong-Su ; Lee, Sung-Geun ; Kim, Jeong-Woo ; Seo, Dong-Hoan ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 220~226
DOI : 10.5916/jkosme.2013.37.2.220
Recently, with the rapid development of factory automation and logistics system, a few workers were able to manage the broad workplace such as large vessels and warehouse. To estimate the exact location of these workers in the conventional wireless indoor localization systems, three or more fixed nodes are generally used to recognize the location of a mobile node consisting of a single node. However, these methods are inefficient in terms of node deployment because the broad workplace requires a lot of fixed nodes compared to workers(mobile nodes). Therefore, to efficiently deploy fixed nodes in these environments that need a few workers, this paper presents a novel estimation algorithm which can reduce the number of fixed nodes by efficiently recognizing the relative coordinates of two fixed nodes through a mobile node composed of three nodes. Also, to minimize the distance errors between mobile node and fixed node, rounding estimation(RE) technique is proposed. Experimental results show that the error rate of localization is improved, by using proposed RE technique, 90.9% compared to conventional trilateration in the free space. In addition, despite the number of fixed nodes can be reduced by up to 50% in the indoor free space, the proposed estimation algorithm recognizes precise location which has average error of 0.15m.
Detecting and correcting errors in Korean POS-tagged corpora
Choi, Myung-Gil ; Seo, Hyung-Won ; Kwon, Hong-Seok ; Kim, Jae-Hoon ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 227~235
DOI : 10.5916/jkosme.2013.37.2.227
The quality of the part-of-speech (POS) annotation in a corpus plays an important role in developing POS taggers. There, however, are several kinds of errors in Korean POS-tagged corpora like Sejong Corpus. Such errors are likely to be various like annotation errors, spelling errors, insertion and/or deletion of unexpected characters. In this paper, we propose a method for detecting annotation errors using error patterns, and also develop a tool for effectively correcting them. Overall, based on the proposed method, we have hand-corrected annotation errors in Sejong POS Tagged Corpus using the developed tool. As the result, it is faster at least 9 times when compared without using any tools. Therefore we have observed that the proposed method is effective for correcting annotation errors in POS-tagged corpus.
Development of the simulator for marine auxiliary boiler system
Kim, Myoung-Hwan ; So, Myung-Ok ; Jung, Byung-Gun ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 236~241
DOI : 10.5916/jkosme.2013.37.2.236
It requires long time and high cost for an apprentice engineer to reach the level of getting various experiences of engine space machinery and preparing for emergency situations. Therefore reducing the time and cost, several types of simulator that give the very similar surroundings to the ship engine room, relevant to STCW-95 are used for systematic education and training to get many experiences and good judgement in emergency. Since most simulators that are operated in Korea were imported from foreign countries, it is difficult to directly implant the amendments of STCW Convention and reflect International Maritime Organization (IMO) model courses. This study describe a development of marine auxiliary boiler simulator that makes the apprentice engineer easier to understand the relationship between equipments in steam system such as auxiliary boiler, exhaust gas boiler, and steam turbine.
A proposal of marine geophysical exploration techniques for offshore plant installation
Ha, Ji-Ho ; Ko, Hwi-Kyung ; Cho, Hyen-Suk ; Chung, Woo-Keen ; Ahn, Dang ; Shin, Sung-Ryul ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 2, 2013, Pages 242~251
DOI : 10.5916/jkosme.2013.37.2.242
Recently, while global concern over offshore resources exploration and development is being increased rapidly, offshore plant industry is highlighted as an industry of high added value. Along with this global trend, domestic concern over offshore plant development is being increased as well. In the overseas case, a marine geotechnical survey guideline for confirming characteristics of seabed sediments is available at the time of installation of offshore plant but such guideline is not available in our country. In this study, survey techniques fit for domestic marine environment was applied according to overseas guideline at southern coastal area, Korea. Among the marine geophysical survey techniques being proposed abroad, magnetic survey and seabed photograph were excluded. However, highly reliable data analysis was enabled for marine geophysical survey, which includes in-situ coring investigation and laboratory soil test. In addition, continuous ocean current survey was included to find scour potential due to the current around the offshore plant. Although coring depth is not so deep, we predicted geological structure through the analysis of amplitude features of seismic data. Characteristics of seabed sediments cold be obtained regionally and directly through combined analysis of marine geophysical survey data and coring data.