• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.157-165
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• 2011

As the contents of information were reinforced the rules of computer science, it was necessary to develop the new teaching and learning plans and various education materials that encourage students and easy to access. So, in this study developed a wide ran of play activities and educational materials without using a computer for the area of information representation and applied to 68 students, second grade of middle school for 4 weeks. After the class, the effect on the learning achievement was verified by the t-test. As a result, it was shown that there was a significant difference between learning with play activities materials and the traditional lecture-type. It means that learning with play activities materials in the information representation influences a positive effect to the learning achievement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.677-684
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• 2017

Smart devices are used in a variety of industries, because applications for them are easy to develop and portable. However, industrial equipment can cause security problems for information and accidents when controlling the actuator of the equipment at a remote location. In this paper, we studied methods of solving these problems and the advantages of applying smart control systems to industrial equipment. We propose a manual manipulation method using queries and a smart control access procedure for controlling equipment using a smart device. In addition, we propose a data transmission method employing multiple encryption protocols and a user authentication method using unique information from the smart device and Q & A as the communication data protection and user authentication methods, respectively. In order to evaluate its performance, an operation test of the smart control system and user authentication comparison experiment were performed. In order to understand the advantages of applying the smart control system to the equipment, we conducted a comparative experiment with a teach pendant and evaluated its reaction time in case of error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5397-5402
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• 2012

Accidents involving electric equipment and economical loss by power quality deterioration related to harmonics show a rising tendency A passive filter is economic and efficient in suppressing harmonics but many engineers and designers are reluctant to install a passive filter to defect harmonics at their power system because of problems such as harmonic amplification and the probability of generating series or parallel resonance with the power system. This work introduces that passive filters will be very available to defeat harmonic problems of the power system if passive filters are well designed. We describe method and process of harmonic passive filter design. And the passive filter for the power system having harmonic problems due to use of nonlinear loads like as 100HP DC motor system, an extruding machine, an air blower and other loads are designed. Experimental results verify the performance of the passive filter designed by the described method and procedure.

• The Journal of Korean Association of Computer Education
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• v.13 no.2
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• pp.1-14
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• 2010

Previous researches on the improvement of logical thinking in Informatics subject have used general logical thinking test and only limited improvement of logical thinking by programming learning result. In this study, the operational definition of the logical thinking in problem-solving process on Informatics education is different from the general logical thinking and the logical thinking of the other subjects. Firstly, we suggested the operational definition of components of logical thinking using the open questionnaire by expert and research team discussion. Also, we suggested the relationship between the operational definition and contents of the 'problem-solving methods and procedure' section in secondary Informatics subject. Finally, this study developed the evaluation contents based on the operational definition of components of logical thinking. The components of logical thinking which was required in problem-solving process on Informatics subject were ordering reasoning, propositional logic, controlling variables, combinatorial logic, proportional reasoning. We suggested the relationship between operational definition and problem-solving process and assessment of logical thinking in problem-solving process on Informatics subject. This paper will give meaningful insight to supply the guideline of the teaching strategy and evaluation methods for improving the logical thinking in Informatics education.

• Journal of Educational Research in Mathematics
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• v.19 no.4
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• pp.565-584
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• 2009

This study is aimed at providing the theoretical framework of characteristics of mathematical thinking processes and structuring the thinking process patterns of the mathematical gifted students through the analysis of their cognitive thinking processes. For this purpose, this study is trying to analyze characteristics of mathematical thinking processes of the mathematical gifted students in an objective and a systematic way, by using think-aloud method. For comparative study, the analysis framework with the use of the thinking characteristic code as a content-oriented method and the problem-solving processes code as a process-oriented method was developed, and the differences of thinking characteristics between the two groups chosen by the coding system which represented the subjects' thinking processes in the form of the language protocol through thinking-aloud method were compared and analyzed.

• Journal of KIISE:Software and Applications
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• v.32 no.12
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• pp.1205-1216
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• 2005

Component-based Development (CBD) is gaining popularity as an effective reuse technology. Especially commercial-off-the-shelf (COTS) components are mainly for inter-organizational reuse, rather than intra-organizational reuse. One of the essential tasks in CBD is to reuse the right components that provide the functionality and interface required by component consumers. If candidate components provide a limited applicability and customizability, a component consumer cannot reuse the components in application development. To resolve this partial matching problem, we need smart connectors that fill the gap between candidate components and the specification of components required. Previous researches about smart connector describe only connector types to resolve mismatch problems. However, previous researches do not address the identification and design method to resolve the problems. In this paper, we suggest taxonomy of various mismatch problems to identify partial match problems between requirements of the application and components. We identify smart connector types and suggest a systematic process for designing smart connectors using the taxonomy. Therefore, components that have the problems can be used to develop applications.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.5
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• pp.56-64
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• 2006

Station collocation of closely placed multiple GEO spacecraft is required to avoid the problem of collision risk, attitude sensor interference and/or occultation. This paper presents the method of obtaining the orbit correction scheme for collocating two GEO spacecraft within a small station-keeping box. The relative motion of each spacecraft with respect to the virtual geostationary satellite is precisely expressed in terms of power and trigonometry functions. This closed-form orbit propagator is used to define the constraint conditions which meet the requirements for the station collocation. Finally, the technique of constrained optimization is used to find the orbit maneuver sequence. Nonlinear simulations are performed and their results are compared with those of the classical method.

• The Journal of Korean Association of Computer Education
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• v.11 no.4
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• pp.1-12
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• 2008

This paper proposes basic algorithmic thinking based problem models applicable immediately without additional learnings and it problems basic problems and evaluation methods using material factors in an elementary course of mathematics For these purposes, an algorithmic thinking based problem model and it's basic problem models are proposed based on flowchart design methods with 5 degrees of difficulties. And algorithmic thinking based basic problems are developed by applying the proposed basic problem models into material domain in an elementary course of mathematics. And this paper proves the validity of developed basic problems in defining then as algorithmic thinking based basic problems through experiments and statistical analyses. The experimental results are analyzed in views of variety and effectiveness evaluation of answer algorithms and suitability of allocating 5 degrees of difficulties to the developed basic problems.

• Journal of the Korean School Mathematics Society
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• v.20 no.2
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• pp.163-186
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• 2017

The purpose of this paper is to propose the policy change of teachers education in Korea with an analysis of America statistical literacy education. we found the difference of statistical literacy education between Korea and America with each nation's social and educational environment. We can get the need of new change for statistic teacher's education in Korea. We think of Mathematics teachers should know about the difference between statistics and mathematics at school mathematics. And they should know the new change thinking about teaching method and process assesment methods. Second, Teachers should focused on teaching of problem solving and statistical thinking ability based on data analysis than the teaching of probability and mathematical theory.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.215-226
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• 2007

To verify the performance of roadside barriers, occupant risk indices are calculated from acceleration and angular velocity data of vehicle crash tests. The occupant risk indices to be computed include THIV(Theoretical Head Impact Velocity), PHD(Post-impact Head Deceleration), ASI(Acceleration Severity Index), OIV(Occupant Impact Velocity) and ORA(Occupant Ridedown Acceleration). There is a confusion due to different values of occupant risk indices produced for the same test data because various computational procedures and data processing methods can be applied to compute them. To slove this problem the effects of various numerical procedures and data processing methods on occupant risk indices were investigated. If the sampling rate specified in the guidelines is used for full-scale vehicle crash tests, an interpolation of impact time and numerical integration methods do not result in an appreciable change of THIV and OIV. The way to determine 10msec moving average for PHD and zero offset of data processing should be specified in the guidelines because 10msec moving average and zero offset methods have a significant influence on occupant risk indices.