• Journal of the Korean Data and Information Science Society
• /
• v.17 no.1
• /
• pp.63-76
• /
• 2006

Marine production forecasting in fisheries is a crucial factor for managing and maintaining fishery resources. Thus this paper aims to generate a forecasting model of total marine production. The most generally method of time series model is to generate the most optimal single forecasting model. But the method could induce a different forecasting results when it does not properly infer a model To overcome the defect, I am trying to propose a single forecasting through multiple time series model. In other word, by comparing and integrating the output resulted from ARIMA and VAR model (which are typical method in a forecasting methodology), I tried to draw a forecasting. It is expected to produce more stable and delicate forecasting prospect than a single model. Through this, I generated 3 models on a yearly and monthly data basis and then here I present a forecasting from 2006 to 2010 through comparing and integrating 3 models. In conclusion, marine production is expected to show a decreasing tendency for the coming years.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2007.12a
• /
• pp.129-130
• /
• 2007

A great variety of models including marine ecology model, water quality model, marine fluid model have been used in the marine research. The results of marine model is presented as a numerical value that is difficult for researcher to understand. In this paper, we developed a method for conversing and presenting results of marine models to visual form to improve the visualization of modelling results that is difficult to analyze and applied the method in actual practice.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.26 no.2
• /
• pp.64-72
• /
• 1989

A response prediction model is introduced for the non-lockin vibration of a marine riser in sheared flow, where the riser is modelled as linearly varying tensioned-beam. This prediction model is based on the Green's function approach and random vibration theory. This model, of course, can treat general beams having slowly varying spatial system parameters. According to the predicted result of a marine riser by the prediction model proposed in this paper, the dynamic behavior of a marine riser has the mixed characteristics of finite and infinite boundary behavior. Furthermore the velocity response distribution along the riser length is much similar with the sheared flow profile. The predicted response result of a marine riser having linearly varying tension was also compared to that of constant mean tensioned-beam model. It was found that the constant mean tensioned-beam case gives over-estimated responses at the top side of the riser.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.10
• /
• pp.1661-1666
• /
• 2003

The purpose of this study is to develop the simplified model of the crankshaft in the large marine engine for dynamic analysis. Because the actual engine system is under complex dynamic loading condition and it has multi-cylinder, the dynamic analysis is purchased at a high computation cost. In spite of this burden, the dynamic analysis must be perfonned to assure structural integrity of operating marine engine. Therefore, simplification of the analytic model is necessary for dynamic analysis. Beam-mass model, which is generated with the section property method, is the model simplified effectively. Section property method can provide desired section information by optimization technique. By applying beam-mass model to the crankshaft in the large marine engine, the usefulness of the proposed method was proven.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.387-388
• /
• 2006

This article provides a dynamic analysis model for huge marine engine that examined analytically variation effects of frequency response by fitting of transverse stays such as hydraulic type. First, vibration analysis using the three dimensional finite element models for the huge marine engine has performed in order to find out the dynamic characteristics. Second, three dimensional finite elements model for the huge marine engine was modifued so that generate forcing nodes in crosshead part and top bracing nodes in cylinder frame part. Third, a system matrix and output matrix was derived for the general siso(single input single out) state space model. Finally, developed state space model for the three dimensional finite elements model for the huge marine engine without the additional modifying process.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.3
• /
• pp.323-333
• /
• 2014

In this paper, the wakes behind a square cylinder were simulated using two kinds of different turbulence models for the eddy viscosity concept such as the zero- and the one-equation model in which the former is the mixing length model and the latter is the k-equation model. For comparison between numerical and analytical solutions, we employed three skill assessments: the correlation coefficient(r) for the similarity of the wake shape, the error of maximum velocity difference(EMVD) for the accuracy of wake velocity and the ratio of drag coefficient(RDC) for the pressure distribution around the structure. On the basis of the numerical results, the feasibility of each model for wake simulation was discussed and a suitable value for the empirical constant was suggested in these turbulence models. The zero-equation model, known as the simplest turbulence model, overestimated the EMVD and its absolute mean error(AME) for r, EMVD and RDC was ranging from 20.3 % to 56.3 % for all test. But the AME by the one-equation model was ranging from 3.4 % to 19.9 %. The predicted values of the one-equation model substantially agreed with the analytical solutions at the empirical mixing length scale $L=0.6b_{1/2}$ with the AME of 3.4 %. Therefore it was concluded that the one-equation model was suitable for the wake simulation behind a square cylinder when the empirical constant for eddy viscosity would be properly chosen.

• 한국전산유체공학회:학술대회논문집
• /
• 2006.05a
• /
• pp.129-132
• /
• 2006

A Pacific Ocean circulation model based on the RIAM Ocean Model (RIAMOM) with $1/6^{\circ}C\;and\;1/12^{\circ}C$ horizontal resolution successfully reproduced the peculiar circulation structures of the Pacific Ocean. The volume transports of model agree very well with the results of observations in the northwestern Pacific Ocean. Also our model successfully reproduced the observed structures of the northeastward Ryukyu Current with a subsurface core at $500{\sim}600m$. A Possible mechanism for the subsurface current core of the Ryukyu Current is proposed focusing on the blocking effect of the Ryukyu Island Chain.

• Proceedings of KOSOMES biannual meeting
• /
• 2018.06a
• /
• pp.159-159
• /
• 2018

• Journal of Fisheries and Marine Sciences Education
• /
• v.11 no.1
• /
• pp.43-58
• /
• 1999

To instruct in accordance with learner's trait & preceding knowledge, letting the learner control the learning activities is the important task of educator & major goal of the Education Department this year. This article intends to provide useful Instructional Model for the teachers in fisheries marine high school, when they design the individualized teaching model using motivation. One of the major reason for the fisheries marine high school students' low learning achievement is due to the neglecting motivation elements in teaching - learning processes. Recently, with assistance of the information communication technology development, various teaching methods such as Individualized Multimedia Mediated Instruction, Internet Instruction, have come to the major method in activating motivation and computer-mediated instruction considering the learner's individual difference is the useful tools for the instructional efficiency. Because current navigation text book of fisheries marine high school have special characteristic considering the spacial context & time series from departing port to entering port, Teachers can maximize learner's learning accomplishment by using individualized multimedia & providing similar situation like a real navigation(simulating), representing this text characteristics. Thus this paper searches for the specifications of Keller's Motivation Model & Sweeter's Tutorial Model to solve instructional efficiency problems in fisheries marine high school & developed an efficient instructional design by integrating two models.

• Journal of Environmental Science International
• /
• v.15 no.9
• /
• pp.819-827
• /
• 2006

We study on the dynamic interaction with a simulated physical-biological coupled model response to nutrient reduction scenario in Jinhae Bay. According to the low relative errors, high regression coefficients of COD and DIN, and realistic distribution in comparison to the observation, our coupled model could be applicable for assessing the marine ecosystem response to nutrient input reduction in Jinhae Bay. Due to the new construction and expansion of sewage treatment plant from our government, we reduce 50% nutrient inputs near Masan Bay and sewage treatment plant. COD achieves Level II in Korea standard of the water quality from the middle of the Masan Bay to all around Jinhae Bay except the inner Masan Bay remaining at Level III. When our experiment reduces 50% nutrient inputs near Masan Bay and Dukdong sewage treatment plant simultaneously, COD decreases to about 0.1-1.2 mg/L $(128^{\circ}30'{\sim}128^{\circ}40'\;E,\;35^{\circ}05'{\sim}35^{\circ}11'\;N)$. The COD from the middle of the Masan Bay to Jinhae Bay achieves Level II.