• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.153-159
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• 2012

Recently, tthe general users' demand on utilizing spatial information and the establishment of national spatial data such as land cover map are increasingly growing. But the lack of spatial information service for the general public is making it difficult for them to use spatial information and services. In this study, spatial information service strategies based on the concept of atlas, which is familiar to us through the student atlas, were proposed to promote the public users' utilization of land cover map. For this purpose, I reviewed current domestic status and overseas cases of land cover map service and proposed the future direction of spatial information service for land cover map in terms of contents, users, and system. Finally, I defined the basic concept, characteristics and functions of the Atlas Information System and recommended strategies for environmental spatial information service. The results of this study can be applied to various national spatial information as well as land cover map and contribute to the increase of general public users' utilization of national spatial data.

• School Mathematics
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• v.10 no.4
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• pp.537-555
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• 2008

The study aims to analyze elementary school students' understanding of the concept of equality sign in contexts, to reflect the types of contexts for equality sign which mathematics textbook series for $1{\sim}4$ grades on natural numbers and its operation provide, and to invetigate the effects of teaching methods of the concept of equality sign suggested in this research. In order to achieve these purposes, the origin, concept, and contexts of equality sign were theoretically reviewed and organized. Also the error types in using equality sign were reflected. Modelling, discussing truth or falsity of equations, identifying relations between numbers and their operation, conjecturing basic properties of numbers and their operations, experiencing diverse contexts for equality sign, and creating contexts for equality sign are set up as teaching methods for better understanding the concept of equality sign. The conclusions are as follows. Firstly, elementary school students' under-standing of the concept of equality sign varied by context and was generally far from satisfactory. In particular, they had difficulties in understanding the concept of the equal sign in contexts with operations on both sides. The most frequently witnessed error was to recognize equality sign as a result of operations. Secondly, student' lack of understanding of the concept of equality sign came from the fact that elementary textbooks failed to provide diverse contexts for equality sign. According to the textbook analysis, contexts with operations on the left side of the equal sign in the form of $a{\pm}b=c$ were provided excessively, with the other contexts hardly seen. Thirdly, teaching methods provided in the study were found to be effective for enhancing understanding the concept of equality sign. In other words, these methods enabled students to focus on relational understanding of concept of equality sign rather than operational one.

• Communications of Mathematical Education
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• v.19 no.1 s.21
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• pp.45-55
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• 2005

대학수학 1학년 과정(미분적분학)에서 정리, 정의 등 개념의 이해를 도와주기 위해 학생들이 갖는 어려움을 그들이 자주 겪는 실수를 통해 찾아내어 분석하고 올바른 이해의 길로 안내한다. 실수를 탓하기보다 학생의 편에 서서 이해하고 도움을 주도록 한다. 흔히 부딪칠 수 있는 예제 문제를 풀어보게 하고 공통으로 저지르는 실수를 제시하여 개념의 이해나 문제풀이를 바르게 하도록 이끌어 준다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.487-489
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• 2005

본 논문에서는 온톨로지의 개념구조를 이용한 웹페이지의 의미적 분류방법을 제안한다. 웹 문서들이 가지는 용어 정보들과 어휘들 간의 개념 구조를 파악하여 온톨로지를 확장시키면서 이를 문서분류에 적용하여 의미적 분류가 이루어지게 한다. 문서 분류는 문서들을 가장 잘 표현할 수 있는 자질들을 정하고 이러한 자질들을 통해 미리 정의된 2개 이상의 카테고리에 문서의 내용을 파악하여 가장 관련이 있는 카테고리로 할당하는 것이다. 본 논문에서는 웹 문서에서 추출한 용어 정보들의 유사도와 온톨로지 카테고리의 유사도를 계산하여 웹 문서를 분류하여 문서 분류를 위한 실험데이터나 학습과정 없이 바로 실시간으로 문서분류가 이루어지며, 결과적으로 온톨로지와 문서들이 가지는 고유한 의미와 관계의 식별을 통하여 보다 더 정확하게 문서분류를 가능하게 해준다.

• Journal of the Korean School Mathematics Society
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• v.21 no.3
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• pp.247-266
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• 2018

In this paper, three main concepts are chosen for this statistical estimation study, based on previous studies: confidence interval and reliability, sampling distribution of mean and population mean estimation, and relationships between elements of confidence interval. The main objectives of this study are as follows: 1. How are the attitudes that future math teachers and high school students have to ward the statistical estimation? 2. Is there some difference in the awareness of misconceptions about the statistical estimation that future math teachers and high school students have? A study result shows that both groups have difficulties in understanding statistical concepts and their meaning used in Unit Statistical Estimation. They tend to wrongly think that the meaning of reliability is the same as that of probability. They also have difficulties in understanding sample variance in the sampling distribution of mean, which makes it impossible to connect with population mean estimation. It is shown that relationships between elements consisting of confidence interval are not consistent.

• Journal of Internet Computing and Services
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• v.16 no.3
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• pp.43-57
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• 2015

In this thesis was conducted to propose a method for efficient information retrieval using concept lattices. Since this thesis designed a new system based on ordinary concept lattices, it has the same approach method as ontology, but this thesis proposes new concept lattices to be used by establishing collaborative relations between objects and concepts that users are likely to search information more efficiently. The system suggested by this thesis can be summarized as below. Firstly, this system leads to a collaborative search by using Three kinds of concepts, such as keyword concept lattices, which focus on input key words, expert concept lattices recommended by experts and theme concept lattices, and based on these 3 concept lattices, it will help users search information they want more efficiently. Besides, as the expert concept and the keyword concept become combined, further providing users with the frequency of keyword and the frequency of category, this system can function to recommend key words related to search words entered by users. Another function of this system is to inform users of key words and categories used in users' interested themes by using the theme concept lattices. Secondly, when there is not keyword entered by a user, it is possible for users to achieve the goal of search through the secondary search when this system provides them with key words related to the input keyword. Thirdly, since most of the information is managed while being dispersed, such dispersed and managed information not only has different expression methods but changes as time goes. Accordingly, By using XMDR for efficient data access and integration of distributed information, this thesis proposes a new technique and retrieval system to integrate dispersed data.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.557-568
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• 2008

An ontology as the core element of Semantic Web is a formal specification of a conceptualization of shared domain knowledge. The use of well-defined ontologies can increase the quality of interoperable information systems in the area of Semantic Web. However, in practice, it is not easy to develop high-quality ontologies which have no errors. Therefore, with methodologies for ontology design, various methods or tools for ontology analysis supporting for error-detection might be very helpful for ontology developers. In this paper, we propose a novel approach for analyzing the core constructs of ontology based on the Formal Concept Analysis and develop a tool that supports error-checking ontologies. Our approach can serve not only as a guidance to modify the existing ontologies, but also as a valuable tool in developing high-quality ontologies.

• Communications of Mathematical Education
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• v.25 no.1
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• pp.63-78
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• 2011

The purpose of this study is to explore a teaching method of limits of functions with more intuitive and visual of CAS graphing calculators rather than with the rigorous ${\epsilon}-{\delta}$ method. Texas Instruments Voyage200 CAS graphing calculators are used for studying the possibility of the use of technology in calculus course. For this, various related theoretical constructs are reviewed: concept image, concept definition, cognitive conflict, the use of visualization of technology for calculus concepts, the theory of APOS, and local straightness. Based on such theoretical constructs this study suggests a teaching method of limits of functions with embodied visualization of CAS graphing calculators.

• Journal of The Korean Association For Science Education
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• v.40 no.3
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• pp.253-269
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• 2020

This study aims to develop items to diagnose pre-service physics teachers' understanding of the conceptual knowledge of modern physics, based on the achievement criteria presented in the 2015 revised national science curriculum, and to identify the validity and reliability of the newly developed items. Data were collected from 467 pre-service physics teachers in the Physical Education Department or Science Education Department (Physics Education Major) of 15 universities across the nation. In this study the content validity, substantive validity, the internal structure validity, generalization validity, and the external validity proposed by Messick (1995) were examined by various statistical tests. The results of the MNSQ analysis showed that there was no nonconformity in the 23 items. The internal structure validity was confirmed by the standardized residual variance analysis, which shows that the 22 items was unidimensional. The generalization validity was confirmed by differential item functioning (DIF) analysis about groups lectured or not modern physics/quantum mechanics. In addition, item analysis and test analysis based on classical test theory were performed. The mean item difficulty is 0.66, mean item discrimination is 0.47 and mean point biserial coefficient obtained was 0.41. These results for item parameters satisfied the criteria respectively. The reliability of the internal consistency of the KR-20 is 0.77 and the Ferguson's delta obtained was δ = 0.972. By Rasch model analysis, the item difficulty (item measures) was discussed.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.99-99
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• 2015

본 연구에서는 금강 유역을 대상으로 토양저류함수모형기반의 개념적 강우유출모형의 장기 유출모의를 평가하였다. 연구유역인 금강 22개 계측유역을 주요 유역특성인자(면적, 경사도, SCS-CN등)을 수문학적 거리 산정방법을 활용하여 3개의 유역그룹을 선정하였다. 적용모형인 개념적 강우유출모형은 3개의 토양저류함수모형[확률분포모형(PDM: Probability Distributed Moisture), 유역습윤지수모형(CWI: Catchment Wetness Index), 수정펜맨타입모형(MP: Modified Penman type model)]과 3개의 유역추적모형[병렬2선형 저류지 유출 모형(2PAR: 2-conceptual reservoirs in parallel), 빠른 지표하 흐름을 고려한 병렬 2선형 저류지 유출모형(2PMP: 2Macro-pre Approach parallel structure), 병렬 3선형 저류지 유출모형(3PAR: 3-conceptual reservoirs in parallel)]의 조합인 9개의 모형을 사용하였으며, 2006년부터 2012년의 일자료를 바탕으로 검정(Calibration), 2001년부터 2005년의 일자료를 검증(Validation)을 Monte carlo method(Uniform Random Sampling)로 수행 후, 모형의 성능은 NSE(Nash sutcliffe Efficiency)로 평가하였다. 분석결과 유역그룹에 대한 모형성능의 편차는 작아서 유역그룹에 대한 토양저류 함수모형의 뚜렷한 상관성을 확인할 수 없었다. 이는 금강 유역을 단일 유역 그룹으로 적용할 수 있음을 제시하고 있다. 검정 검증성능 및 검정매개변수의 개수를 바탕으로 적용성 평가를 실시한 결과에서 토양저류함수모형인 확률분포모형(PDM)과 유역추적모형의 병렬2선형 저류지 유출모형(2PAR)와 빠른 지표하 흐름을 고려한 병렬2선형 저류지 유출모형(2PMP)의 조합이 금강 22개 유역에서 적용성이 우수함을 확인하였다. 향후 이 모형을 바탕으로 금강유역의 대표적인 강우유출모형을 개발하고자 한다.