• Journal of the Korean School Mathematics Society
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• v.13 no.1
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• pp.23-43
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• 2010

This study is to investigate how much highschool students, who have learned functional concepts included in the Middle school math curriculum, understand chapters of the function, to analyze the types of errors which they made in solving the mathematical problems and to look for the proper instructional program to prevent or minimize those ones. On the basis of the result of the above examination, it suggests a classification model for teaching-learning methods and teaching material development The result of this study is as follows. First, Students didn't fully understand the fundamental concept of function and they had tendency to approach the mathematical problems relying on their memory. Second, students got accustomed to conventional math problems too much, so they couldn't distinguish new types of mathematical problems from them sometimes and did faulty reasoning in the problem solving process. Finally, it was very common for students to make errors on calculation and to make technical errors in recognizing mathematical symbols in the problem solving process. When students fully understood the mathematical concepts including a definition of function and learned procedural knowledge of them by themselves, they did not repeat the same errors. Also, explaining the functional concept with a graph related to the function did facilitate their understanding,

• Education of Primary School Mathematics
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• v.12 no.1
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• pp.1-20
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• 2009

The purposes of this study are to analyze elementary school student's intuitive thinking in the process of mathematical problem solving and to analyze elementary school student's errors of intuitive thinking in the process of mathematical problem solving. According to these purposes, the research questions can be set up as followings. (1) How is the state of illumination of the elementary school student's intuitive thinking in the process of mathematical problem solving? (2) What are origins of errors by elementary school student's intuitive thinking in the process of mathematical problem solving? In this study, Bogdan & Biklen's qualitative research method were used. The subjects in this study were 4 students who were attending the elementary school. The data in this study were 'Intuitine Thinking Test', records of observation and interview. In the interview, the discourses were recorded by sound and video recording. These were later transcribed and analyzed in detail. The findings of this study were as follows: First, If Elementary school student Knows the algorithm of problem, they rely on solving by algorithm rather than solving by intuitive thinking. Second, their problem solving ability by intuitive model are low. What is more they solve the problem by Intuitive model, their Self- Evidence is low. Third, in the process of solving the problem, intuitive thinking can complement logical thinking. Last, in the concept of probability and problem of probability, they are led into cognitive conflict cause of subjective interpretation.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.3-12
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• 2000

The multi-region model, to describe preferential flow, is an equation representing solute transport in soils by dividing soil into numerous pore groups and using the hydraulic properties of the soil. As the model partial differential equation (PDE) is solved numerically with finite difference methods. a modified equivalent partial differential equation(MEPDE) of the partial differential equation of the multi-region model is derived to analyze the accuracy and consistency of the solution of the model PDE and the Von Neumann method is used to analyze the stability of the finite difference scheme. The evaluation obtained from the MEPDE indicated that the finite difference scheme was found to be consistent with the model PDE and had the second order accuracy The stability analysis is performed to analyze the model PDE with the amplification ratio and the phase lag using the Von Neumann method. The amplification ratio of the finite difference scheme gave non-dissipative results with various Peclet numbers and yielded the most high values as the Peclet number was one. The phase lag showed that the frequency component of the finite difference scheme lagged the true solution. From the result of the stability analysis for the model PDE, it is analyzed that the model domain should be discretized in the range of Pe < 1.0 and Cr < 2.0 to obtain the more accurate solution.

• School Mathematics
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• v.15 no.1
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• pp.101-120
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• 2013

International comparative studies of students' performance in mathematics have shown that Korean students possess very negative attitudes toward mathematics, while they are ranked as one of the highest in the cognitive achievement of mathematics. This has prompted mathematics educators to seek for a way to improve the quality of mathematics education. In this context, this research has been conducted to investigate the learning style of Korean middle school students under the assumption that it is of essence to understand the characteristics of our students as mathematics learners. For the purpose, in-depth interview had been conducted and sixteen middle students participated in the interview. The students were chosen to represent the average group of their age-cohorts based on their performance in mathematics and their SES. The interview was designed as a semi-structured clinical interview. In the interview, the students were given mathematical tasks dealing with central themes in the domain of function. Each student was given about 30 to 50 minutes to solve the tasks. After an interviewee finished the tasks, s/he was asked to explained how s/he solved the tasks. The researchers asked additional questions to clarify the students' understanding of the mathematical themes in the tasks and to identify their strategies for learning mathematics. The analysis of the in-depth interview has primarily identified the characteristics of the students' understanding of the main themes in function and then has been extended to investigate their characteristic styles for learning mathematics. The analysis of the interview identified the learning styles of the students as 'inductive learning based on prototypical cases', 'repeated practice of exemplar mathematics problems', 'disengaged learning', and 'double standards in learning mathematics'. Based on the results of the analysis, this research presents the implications for the improvement of mathematics education.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.137-144
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• 2007

This study involves an analytical approach to determine transit dispatching schedules (headways) Determining a time schedule is an important process in transit system planning. In general, the transit headway should be shorter during the peak hour than at non-peak hours for demand-responsive service. It allows passengers to minimize their waiting time under inelastic, fixed demand conditions. The transit headway should be longer as operating costs increase, and shorter as demand and waiting time increase. Optimal headway depends on the amount of ridership. and each individual vehicle dispatching time depends on the distribution of the ridership. This study provides a theoretical foundation for the dispatching scheme consistent with common sense. Previous research suggested a dispatching scheme with even headway. However, according to this research, that is valid for a specific case when the demand pattern is uniform. This study is a general analysis expanding that previous research. This study suggests an easy method to set a time table without a complex and difficult calculation. Further. if the time axis is changed to the space axis instead, this study could be expanded to address the spacing problems of some facilities such as roads. stations, routes and others.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.388-393
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• 2003

도시화 속도의 증가와 더불어 3차원 자료 획득의 출처가 다양해지연서, 도로 및 건물경계선과 같은 선형 GIS 정보에 대한 신속한 갱신 또한 요구되고 있다. 임의의 출처 자료로부터 대상 자료를 갱신하기 위해서는 가장 먼저 두 자료간의 위치 관계를 결정하여야 하며, 특히 영상정보와 같은 출처 자료와 GIS 자료와 같은 대상 자료간의 위치 관계를 결정하기 위하여 기존에 제시되어온 대부분의 방법들은 두 개 자료간의 관계를 정의 할 수 있는 기준정과 같은 정확한 점 정합 요소(point matching entities)를 요구하고 있다. 따라서 정확한 정합 요소들을 획득할 수 없는 경우 영상과 GIS 자료간의 위치 관계를 결정할 수 없을뿐더러 위치 관계 정립의 결과는 정합 요소들의 분포 및 정확도에 매우 의존하게 된다. 또한 이러한 점 정합 요소들을 정의하기 위해서는 대부분의 경우 수동적으로 이루어질 수밖에 없다. 따라서 본 연구에서는 영상 및 GIS 자료의 선형 정보를 이용하여 정확한 점 정합 요소들을 모르더라도 영상과 GIS 자료간의 위치 관계를 결정할 수 있는 기법을 제시하고자 한다. 사용된 알고리즘은 개선된 Hough 변환(Modified Hough Transform)을 기반으로 다수의 선형 정보 중에 정합되는 요소들을 자동으로 찾아내고 이들을 최소제곱법으로 풀이함으로써 두 데이터간의 기하학적 변환 관계를 결정하는 기법이다. 본 연구에서는 이와 같은 접근을 통해 데이터간의 기하학적 변환 관계를 결정한 후, 영상 상에는 존재하지만 GIS 자료에는 존재하지 않는 선형 정보에 대한 갱신 여부를 확인하고 갱신함으로써 3차원 위치 자료의 자동 생성에 대한 가능성을 제시하고자 한다.로 갈수록 퇴적이 우세한 것으로 관측되었다.보체계의 구축사업의 시각이 행정정보화, 생활정보화, 산업정보화 등 다양한 분야와 결합하여 보다 큰 시너지 효과와 사용자 중심의 서비스 개선을 창출할 수 있는 기반을 제공할 것을 기대해 본다.. 이상의 결과를 종합해볼 때, ${\beta}$-glucan은 고용량일 때 직접적으로 또는 $IFN-{\gamma}$ 존재시에는 저용량에서도 복강 큰 포식세로를 활성화시킬 뿐 아니라, 탐식효율도 높임으로써 면역기능을 증진 시키는 것으로 나타났고, 그 효과는 crude ${\beta}$-glucan의 추출조건에 따라 달라지는 것을 알 수 있었다.eveloped. Design concepts and control methods of a new crane will be introduced in this paper.and momentum balance was applied to the fluid field of bundle. while the movement of′ individual material was taken into account. The constitutive model relating the surface force and the deformation of bundle was introduced by considering a representative prodedure that stands for the bundle movement. Then a fundamental equations system could be simplified considering a steady state of th

• Proceedings of the Korean DIstribution Association Conference
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• 2006.05a
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• pp.165-192
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• 2006

본 연구의 목적은 소비자의 하이테크 제품 선택에 있어 브랜드와 제품 성능의 상대적 중요성을 결정하는데 영향을 미치는 요인들을 도출하는데 있다. 영향 요인들은 크게 제품 요인과 소비자 요인으로 분류하였는데, 제품 변수로는 제품의 평가 용이성과 제품의 혁신성을 고려하였고, 소비자 요인으로는 소비자 관여도, 소비자 지식, 소비자 혁신성을 고려하였다. 또한 제품의 쾌락성/이성성 정도와 제품의 노출 정도에 의해 4가지 제품군으로 분류하여, 제품의 유형이 변수들의 영향력에 미치는 조절적 역할을 연구하였다. 연구에 대한 주된 결론은 다음과 같다. 첫째, 하이테크 제품 전반적으로 소비자 혁신성, 소비자 지식, 제품 평가의 용이성, 제품의 혁신성이 제품 선택에 있어서 브랜드의 중요성을 결정하는데 영향을 미치는 변수로 나타났다. 즉, 소비자들은 지식수준이 낮을수록, 소비자 혁신성이 낮을수록, 제품의 평가 용이성이 낮을수록, 제품의 혁신성이 낮을수록 브랜드 위주의 제품을 선택하는 것으로 나타났다. 둘째, 제품의 쾌락성 정도에 따라서 브랜드의 상대적 중요도에 영향을 미치는 변수들이 달라지는데, 쾌락재의 경우에는 소비자 혁신성을 제외한 모든 변수가 브랜드의 상대적 중요도에 영향을 미치나, 실용재의 경우에는 제품 평가의 용이성과 제품 혁신성, 그리고 소비자 혁신성이 영향을 미치는 변수로 나타났다. 셋째, 제품의 노출 정도에 따라서 공공재의 경우에는 소비자 혁신성, 제품 평가 용이성, 제품 혁신성이 유의한 변수로 나타났고, 개인재의 경우에는 소비자 지식과 제품 평가 용이성이 영향을 미치는 변수로 나타났다.가치가 유의한 영향을 미치는 것으로 확인되었다. 그러나 소비자의 금전효용가치는 PB제품의 선호도와는 직접적인 관계가 없는 것으로 나타났으며, PB제품구매의 지각적 가치가 PB제품 선호도에 가장 큰 영향을 미치는 것으로 나타났다. 이와 같은 연구결과는 경제성을 추구하는 소비자라 하더라도 PB제품의 지각적 품질수준 여하에 따라 PB제품의 판매가치가 크다고 지각될 때에만 PB제품을 선호하는 것으로 풀이할 수 있다. 본 연구는 최근에 큰 관심의 대상이 되고 있는 PH의 연구자와 유통업계 실무자들에게 유익한 전략적 시사점을 제공할 수 있을 것으로 기대된다. 지자체가 대형유통점에 대한 규제를 강화하는 것이다. 먼저, 대형유통점의 불공정거래행위에 대한 감시감독과 처벌을 강화하는 것은 당연한 것이다. 그러나 정부가 아닌 지자체가 이를 주도하기는 사실 어려움이 있다. 그리고 대형유통점이 영업행위를 영업시간제한에서부터 출점제한에 이르기까지 규제하는 건은 심사숙고하여야 한다. 대형유통점이 국가경제 및 지역사회에 미치는 영향이 부정적인가 긍정적인가에 대해 국내외 학계와 업계에서 여전히 많은 논란이 있기 때문이다. 정부와 지자체에 의한 시장개입은 반드시 필요한 경우에 한해 합당한 방법에 의해 이루어져야 한다. 대형유통점에 대한 규제는 지역사회에 미치는 영향을 다면적으로 평가한 결과에 근거하여 이루어져야 할 것이다. 대부분의 지자체는 체계적인 평가시스템과 객관적인 통계 자료를 갖고 있지 못한 실정이다. 향후 가장 시급한 과제는 시장개방 이후 지난 10년간 대형유통점이 지역사회에 미친 영향에 관한 광범위한 통계자료를 수

• Journal of the Korean School Mathematics Society
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• v.16 no.2
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• pp.383-407
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• 2013

As an alternative of making students active and independent under the passive learning conditions in school math classes, many researchers have paid much attention to problem posing and done a lot of research on it. Above all, Brown and Walter proposed What I f Not strategy as a means of problem posing. In this strategy, during the process of posing problems, the transformation of their attributes is inevitably made, and so after problem posing, the process is finished by explaining the problem. But only the simple transformation of attributes could pose wrong problems. It suggests that it is very important to recognize the relationship which leads to organic connection between attributes in order to pose the right problem. However, many other studies of problem posing haven't focused on this fact. Thus, this study tried to design a model of problem posing to help recognize inherent knowledge in the problem and then pose the right problem by adding an activity of meaning analysis. We concretely showed a model of problem posing emphasizing the analysis of meaning by means of an example, thereby examining the meaning of the model. This study expects students to have the chance to understand the true meaning of problem posing and to be active learners after all.

• School Mathematics
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• v.10 no.2
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• pp.155-179
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• 2008

Multiplication problems for the 7th curriculum focus on functional realms featuring the memorization and application of the multiplication table, exposing learners only to additive thinking characterized by simple counting and drawing. A diversity of research has yet to be conducted for the transition to multiplicative thinking that highlights the capability to solve problems by using multiplication and division in the expanded number scope like 'prime numbers', 'fractional numbers', and 'ratio/rates' and to describe accurately how they solved. This research was designed to develop and utilize teaching-learning materials for the transition of fifth graders' additive thinking to advanced multiplicative one and to analyze the application results in order to identify validity in material development. The following conclusions were made. First, the development and application of teaching-learning materials for multiplicative thinking cultivation facilitated the transition from additive thinking featuring simple counting and drawing to multiplicative thinking characterized by multiplication and accurate description in a more complicated and expanded number scope. Second, the development of materials featuring 'basic'-'intermediate'-'in-depth' courses by activity enabled learners to benefit from learning by level and expansion in number scope. Third, the use of topics and materials closely connected to daily lives stimulated learners' curiosity, helping them concentrate more on given problems. Fourth, communication between teachers and students or among learners themselves was promoted by continuously encouraging them to explain and by reviewing their documents identifying rules or patterns.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.3
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• pp.789-806
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• 2010

As calls for more attention toward social minority group increases in our society recently, in the field of mathematics education more attention toward an issue about mathematics underachievers is being amplified. Thus, the present study is to examine the effects of teaching method considering students' cognitive characteristics on mathematical underachievers' problem solving and mathematical disposition. For this study, 10 fifth graders identified as mathematical underachievers based on the results of the national level diagnosis assessment and school based assessment were voluntarily selected from an elementary school in Seoul. The results of this study found out the fact that students participating in this program improved in terms of an ability both to solve problems in various ways and to explain an process of problem solving using spoken or written language and drawings. In addition, learning environment respecting students' own mathematical ideas seems to positively influence students' attitudes toward mathematics learning and mathematical dispositions. Furthermore, this study pointed out that mathematical underachievers tend to have difficulty in expressing their own mathematical thinking by reason of linguistic limitation. Finally, the findings of this study imply that for effective teaching of mathematics underachievers, these students' own informal experience and knowledge about mathematics as well as their characteristics regarding learning difficulties should be strongly considered.