• Journal of Korean Port Research
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• v.4 no.1
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• pp.21-31
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• 1990

The application of computer model to the port and harbor development is categorized in the field of port development policy, economic analysis and evaluation, civil engineering analysis, hydrodynamic analysis, evaluation of social and natural environment effect, etc. The study in this paper, however, is limited to hydrodynamic analysis, especially the analysis of water wave propagation and response to the shore structure due to the construction and implementation of shore boundary, the mathematical formulation of the numerical model is established systematically based on the hybrid Element Method and applied to solving the wave refraction, diffraction and radiation problems for a circular basin, the artificial beach or lagoon in terms of coastal zone development.

• The Pure and Applied Mathematics
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• v.20 no.1
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• pp.59-70
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• 2013

The purpose of this study was to develop a zero-inflated Rasch (ZI-Rasch) model, a combination of the Rasch model and the ZIP model. The ZI-Rasch model was considered in this study as an appropriate alternative to the Rasch model for zero-inflated data. To investigate the relative appropriateness of the ZI-Rasch model, several analyses were conducted using PROC NLMIXED procedures in SAS under various simulation conditions. Sets of criteria for model evaluations (-2LL, AIC, AICC, and BIC) and parameter estimations (RMSE, and $r$) from the ZI-Rasch model were compared with those from the Rasch model. In the data-model fit indices, regardless of the simulation conditions, the ZI-Rasch model produced better fit statistics than did the Rasch model, even when the response data were generated from the Rasch model. In terms of item parameter ${\lambda}$ estimations, the ZI-Rasch model produced estimates similar to those of the Rasch model.

• Journal of Navigation and Port Research
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• v.34 no.8
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• pp.629-634
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• 2010

Mathematical model of maneuvering motion for a Mobile Harbor is established and versatile applications to the special situations of maneuvering are attempted. The Mobile Harbor in this research has twin Azipod thruster and twin bow thruster. In order to predict the maneuverability of Mobile Harbor, a mathematical model was developed on the basis of MMG model, and some model test results were adopted for the simulation of Mobile Harbor. As a result, the turning motions of the Mobile Harbor were successfully calculated. and the optimal berthing system was completed.

• Communications of Mathematical Education
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• v.29 no.2
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• pp.255-279
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• 2015

Educating for character was emphasized in 2009 reformed Korea national mathematics curriculum. Thus, in this study we basically conducted to realize the character education. This study aimed to develop the teaching and learning materials for character education in middle school. For the purpose of this study, the following study was carried out. First, we investigated the concept of character education. Second, based on this, we extracted the three factor(altruism, rationality, course orientation) for character education in mathematics teaching and learning. Third, we developed five teaching and learning models for character education. The five kinds of models are 'Respect model', 'Self-directed model', 'Cooperation-centered model', 'Self-interest model, 'Story sympathy model'. Finally, We have developed a teaching and learning materials in accordance with the models. And, we applied to the classroom and confirmed its effectiveness.

• The Mathematical Education
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• v.53 no.2
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• pp.201-217
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• 2014

This research has an intention of developing a professional development program. We proposed an alternative mathematics teacher training model based on the situated learning theory, community of practice, and reflective practitioner. The developed mathematics teacher professional development program recruited participation unit that was consisted of 3 or 4 teachers in same school and total of 28 teachers from 9 schools. Also, there were 18 mentors to support each school. In this sense, it can be called multi-tired teacher community professional development program. Through the program, the teachers improve their teaching competency. Also, the operation ability of teacher learning community was improved. Learning community culture has been formed in each school. It shows ability that the explorative learning community can be operated voluntarily although the program finished. Furthermore, community shared corporate responsibility about open class. They recognize open class as a new method to improve community teaching ability than a tool to evaluate individual teaching ability.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.966-970
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• 2005

On the basis of the development of KSLV-1, KoDSat was designed and manufactured to demonstrate the performance of KSLV-1. KoDSat is exposed to a severe vibrational environment at launch. The structural reliability of KoDSat has to be verified using vibrational test. The structural compatibility and verification of components between analysis and test can be proved using environmental vibration test. In this paper, we review the structural characteristic of thruster control unit for a space launch vehicle and design TCU housing using mathematical model. In order to verify the structural compatibility and reliability, half-sine shock, random and sing sweep vibration test was performed. Especially, sing sweep vibration test result is compared with analysis result and mathematical model is verified.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.591-594
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• 2002

In this study, we develop automatic design program, which create 3D model of spur gear and helical gear used VisualLISP and create helical gear in the CATIA using 2D profile of gear. This model become the standard models which give not only in itself mold information but also compare processed product with measuring date. Spur gear require mathematical examination of involute curve and trocoidal fillet curve. Automatic design program, which have a mathematical development create the profile of spur gear.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.47-56
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• 2013

Rolling speed, roll gap, and cooling pattern in hot strip finishing mill process should be determined before inserting strip into roll. Such parameters are initially calculated by a mathematical set-up model. The technique to find adequate roll speed via a mathematical model has inherently limit because required working conditions are various and rolling process is nonlinear. To improve the accuracy of initial rolling speed for a finishing mill, this paper suggests a correction technology for initial rolling speed. The proposed method was implemented in hot strip mill process. As the results, the magnitude of width error in strip head-end part caused by excessive strip tension was decreased remarkably.

• Communications for Statistical Applications and Methods
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• v.18 no.2
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• pp.257-266
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• 2011

The rapid development of airlines, has made airports busier and more complicated. The assignment of scheduled to available gates is a major issue for daily airline operations. We consider the over-constrained airport gate assignment problem(AGAP) where the number of flights exceeds the number of available gates, and where the objectives are to minimize the number of ungated flights and the total walking distance or connection times. The procedures used in this project are to create a mathematical model formulation to identify decision variables to identify, constraints and objective functions. In addition, we will consider in the AGAP the size of each gate in the terminal and also the towing process for the aircraft. We will use a greedy algorithm to solve the problem. The greedy algorithm minimizes ungated flights while providing initial feasible solutions that allow flexibility in seeking good solutions, especially in case when flight schedules are dense in time. Experiments conducts give good results.

• Research in Mathematical Education
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• v.1 no.1
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• pp.7-12
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• 1997

The curriculum differentiation is supposed to maximize individual strength and possibilities of the students, and to maximize educational efficiency by differentiating the instructions according to students' abilities, aptitudes, needs and interests. The Ministry of Education has suggested a stepwise model for school mathematics. This model is named "Stepwise Curriculum Differentiation"(段階別 敎育課程 差別化). In this paper, we would like to make a specific proposal for the 7th curriculum. Our proposal reflects fully the guidelines of the Ministry of Education. It is also based on the national curriculum history up to the present time. It could be used as a reference for the continuing work of curriculum reformation. We suggest dividing the contents of mathematics for 1-10th graders into about 15 steps, to use the step-based textbooks instead of the grade-based ones, and to prepare evaluation standards for each step. We also suggest that the classes for grades 11-12 be organized according to their optional courses and/or their steps.