• Research in Mathematical Education
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• v.4 no.2
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• pp.63-77
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• 2000

The purpose of this article is to devise the activities based on van Hiele levels of geometric thought using computer software, Geometer\\\\`s Sketchpad(GSP) as a tool. The most challenging task facing teachers of geometry is the development of student facility for understanding geometric concepts and properties. The National Council of teachers of Mathematics(Curriculum and Evaluation Standards for School Mathematics, 1991; Principles and Standards for School Mathematics, 2000) and the National Re-search Council(Hill, Griffiths, Bucy, et al., Everybody Counts, 1989) have supported the development of exploring and conjecturing ability for helping students to have mathematical power. The examples of the activities built is GSP for students ar designed to illustrate the ways in which van Hiele\\\\`s model can be implemented into classroom practice.

• Journal of Biosystems Engineering
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• v.13 no.4
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• pp.30-37
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• 1988

A mathematical model was developed and programmed for computer simulation of a prototype hot water boiler system with rice hull furnace to predict the temperature distributions in the rice hull furnace and water tank, mass flow rate of hot water and thermal efficiency of the system under various operation and design conditions. The effects of feed rate of rice hull, thickness of the furnace wall, the type of heat exchanger, diameter of the water circulation pipe, etc, on the performance of the system can be evaluated with this model. The validity and simulation results of this model will be published in the next paper.

• Journal of Drive and Control
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• v.14 no.3
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• pp.32-39
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• 2017

In this study, a mathematical model of the pneumatic part in a gas blow-down system is proposed. The mathematical model consists of four major parts: pressure vessel, reservoir, pressure regulator and pipe-line. To ensure accuracy in long-time simulations, heat transfer between gas and pressure vessel is considered. The model is validated by comparing simulation results with experimental data. Experiments are conducted on the ground, where free convection can be assumed. Simulation results indicate the proposed model can accurately describe behavior of a gas blow-down system. Therefore, it may be used for design and analysis of similar systems with a slight modification.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.7
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• pp.872-880
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• 2007

The development of a Marine Engine Room Simulator system for training and research is described. Development objectives of the system are for both student training, research and development work. The system includes a distributed server/client architecture for 1 to 1, or 1 to many client simulation operation through OPC server, complete separation of visual elements from the controlling routines and the ability to work on the mathematical model independent of the controller and visual systems. A graphical user interface for the man-machine interface has been developed and the mathematical model has been updated. Various engine room operational situations can be simulated. The use of marine engine room simulator for training of sea going engineers and its competency for STCW-95 is discussed.

• Journal of Navigation and Port Research
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• v.36 no.9
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• pp.715-720
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• 2012

This paper is to introduce the development of a LCD monitor-based pilots' ship handling simulator installed in the office of Korea Maritime Pilots Association. This simulator is composed of hardware which includes working server array, operation PC, monitor array, rudder, thruster and telegraph peripheral devices, and software which includes ship mathematical model software, ship conning software, image supporting software and so on. In this simulator, MMG mathematical model is used to create thirteen(13) ship models, which are based on sea trial data & pilots' opinion. According to requirements of pilots, virtual scenes of different port areas are built, and some required additional functions are also developed. By using this simulator, pilots can fulfill all kinds of training exercises, design of channel approaching ports, traffic safety analysis, prevention of accident research and other tasks, so as to grasp the characteristics of different ships, and accumulate experience for piloting.

• Communications of Mathematical Education
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• v.29 no.4
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• pp.625-642
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• 2015

The purpose of this study was to develop and verify the feedback-enhanced performance assessment model through a variety of assessment strategies focused on the development of students. In order to achieve the purpose of this study, we analyzed the achievements of the sixth grade curriculum standards and set the central achievement standards in core competencies. We then established an evaluation plan to take advantage of a variety of methods and develop an assessment tool for process-based evaluation during lessons. We applied this assessment model to 6th grade students while teaching and learning mathematics in the classroom. The result of applying the performance evaluation model showed the improvement of students' reflective thinking ability. Also, some students who was not achieved at the level of 'N' could develop to the level of 'N + 1'. A long term research using various assessment strategies should be continued for effective help of students' mathematical development.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.31-39
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• 2013

A virtual chassis platform for Fuel Cell Hybrid Electric Vehicles(FCHEV) has been developed, and a virtual platform similar to the actual system has been composed. In addition, major components such as a motor, fuel cell and battery for the virtual platform have been constructed by using a mathematical formulation. The FCHEV virtual platform using a detailed model based on the mathematical formula is capable of simulating various conditions according to changes of the control logic and component modules to evaluate performance, considering the vehicle dynamic characteristics. Usability of the mathematical model has been verified by comparative simulations according to the motor current control variation. In addition, reliability of the developed virtual chassis platform has been verified by simulating its fuel consumption with the UDDS(Urban Dynamometer Driving Schedule) FTP-72 velocity profile.

• Research in Mathematical Education
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• v.15 no.1
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• pp.93-104
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• 2011

Sixty-four EC-6 teacher candidates were asked to elaborate on the method they used when interrupting seven mathematical pictorial models. The instrument used was research designed but modeled after a 4th grade released state tests. This study was conducted in the southern part of the United States. A panel of experts worked with the researcher to determine the most appropriate initial approach to interrupting the mathematical pictorial model. The pictorial models examined such concepts as measurement, place value and time. Since the questions were on a 4th grade level, it was expected that the teacher candidates would score 100%, however, this was not the case. The results will be given in the paper as each question is discussed. The results of the survey are being used to develop teaching modules for teacher candidates in mathematics methodology classes.

• Education of Primary School Mathematics
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• v.14 no.2
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• pp.135-145
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• 2011

When mathematicians solve the new problems, they present the solutions to their colleagues for getting the approval. If the solution is accepted, it will be theorems. This phenomenon also happens to classrooms in elementary and secondary school. That is main reason to emphasize mathematical communication activities in mathematics education. This study is aimed to develop teaching and learning model for the improvement of mathematical communication ability, applicate the teaching and learning model to two groups and analyze for mathematical thoughts. This study is a case study of 3rd grader's activities. Eight students, four are group applied the teaching and learning model and four are traditional group. The results have been drawn as follows: First, students in the teaching and learning model group induced richer interactions for student's understanding and investigation when we compare to those of traditional group. Second, students in the teaching and learning model group have the chance to explain their thoughts. And we can observe students to clear on their thought through speaking and discussing. This model makes students to enhance organizing, forming and clearing in their mathematical thoughts and is effective to estimate of students thought for teacher.

• Communications of Mathematical Education
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• v.21 no.2 s.30
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• pp.271-282
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• 2007

Producing tools for actively meeting social needs in a radical changing society due to the development of modern technology has been shifted from physical ability to intelligent ability. The prominence of educating creativity is perceived as a good preparation in order to deal with them. Considered that assessment which is systematic activity to collect, analyze, diagnose, and judge information of a series of instruction practices is means to impart evidence and feedback of teaching learning practices, education and assessment is placed on reciprocal relationship. Nevertheless, there has been some tendency of neglect of assessment, comparing education for upbringing creativity. In this paper model of pencil and paper problem is discussed focusing on the sub-components of creativity and problem solving as one of the variety of means to extend mathematical creativity.