• Journal of the Korean School Mathematics Society
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• v.20 no.4
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• pp.405-422
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• 2017

Nim games were divided into three stages : one file, two files and three files game, and inquiry activities were conducted for middle school mathematically gifted students. In the first stage, students easily found a winning strategy through deductive reasoning. In the second stage, students found a winning strategy with deductive reasoning or inductive reasoning, but found an error in inductive reasoning. In the third stage, no students found a winning strategy with deductive reasoning and errors were found in the induction reasoning process. It is found that the tendency to unconditionally generalize the pattern that is formed in the finite number of cases is the cause of the error. As a result of visually presenting the binary boxes to students, students were able to easily identify the pattern of victory and defeat, recognize the winning strategy through game activities, and some students could reach a stage of justifying the winning strategy.

• Journal of The Korean Association For Science Education
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• v.33 no.1
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• pp.181-192
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• 2013

This study aims to explore scientific reasoning that students and their teachers constructed in elementary science classroom discourses in terms of basic reasoning types; deduction, induction, and abduction. For this research, data were collected from 13 classes of 4th grade science activities during a period of three months and analyzed three types of scientific reasoning in elementary school science discourses. We found that deduction (one discourse segment), induction (one discourse segment), and deduction-abduction (two discourse segments) were presented in the discourses. They showed that: first, scientific reasoning proceeded explicitly or implicitly in elementary science discourses; second, the students and their teachers have potentials to increase the quality of reasoning depending on their inter-subjectivity; and last, the students' background knowledge were very important in the development of their reasoning. Implication and remarks on science education and research were presented based on this results as well.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1680-1686
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• 1996

The deterministic update method of intensional predicates in a parallel deductive database that deductive database is distributed in a parallel computer architecture in needed. Using updated data from the deterministic update method, a strategy for parallel evaluation of intensional predicates is required. The paper is concerned with an approach to updating parallel deductive database in which very insertion or deletion can be performed in a deterministic way, and an extended parallel semi-naive evaluation algorithm in a parallel computer architecture. After presenting an approach to updating intensional predicates and strategy for parallel evaluation, its implementation is discussed. A parallel deductive database consists of the set of facts being the extensional database and the set of rules being the intensional database. We assume that these sets are distributed in each processor, research how to update intensional predicates and evaluate using the update method. The parallel architecture for the deductive database consists of a set of processors and a message passing network to interconnect these processors.

• Korean Journal of Logic
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• v.21 no.1
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• pp.59-96
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• 2018

${\bot}$It is often said that in a purely formal perspective, intuitionistic logic has no obvious advantage to deal with the liar-type paradoxes. In this paper, we will argue that the standard intuitionistic natural deduction systems are vulnerable to the liar-type paradoxes in the sense that the acceptance of the liar-type sentences results in inference to absurdity (${\perp}$). The result shows that the restriction of the Double Negation Elimination (DNE) fails to block the inference to ${\perp}$. It is, however, not the problem of the intuitionistic approaches to the liar-type paradoxes but the lack of expressive power of the standard intuitionistic natural deduction system. We introduce a meta-level negation, ⊬$_s$, for a given system S and a meta-level absurdity, ⋏, to the intuitionistic system. We shall show that in the system, the inference to ${\perp}$ is not given without the assumption that the system is complete. Moreover, we consider the Double Meta-Level Negation Elimination rules (DMNE) which implicitly assume the completeness of the system. Then, the restriction of DMNE can rule out the inference to ${\perp}$.

• Journal of The Korean Association of Information Education
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• v.22 no.5
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• pp.575-583
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• 2018

This study approached EPL learning with deductive teaching and learning methods and inductive teaching and learning methods which are grammar teaching and learning methods. In the entry site, lectures provided for elementary school students in grades 5 to 6 were set as deductive learning courses. Based on this, inductive learning process was developed and each learning process was composed of 12 periods. After conducting the research, EPL utilization evaluation, learning satisfaction and immersion test were conducted between the two groups. It was difficult to obtain statistically meaningful results between the two groups. However, in the three tests, the mean value of groups using inductive teaching and learning methods was high. If we construct a long-term learning process and conduct research, we think that statistically meaningful results are produced between the two groups.

• The Korean Journal of Financial Management
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• v.11 no.1
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• pp.1-29
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• 1994

재무관리의 모든 영역을 완벽하게 이해하기 위하여는 기업재무관리와 투자론을 비롯하여 금융산업 전체에 대한 연역적 방법에 의한 이론의 정립과 실증분석을 통한 이론의 정립이 관건이라 할 수 있다. 이 논문에서는 실증 분석을 수행함에 있어 우리나라에서 활발하게 논의가 진행되지 않는 시계열분석의 영역을 살펴보았다. 그것은 이와 같은 분야를 천착해 봄으로써 이 분야가 재무관리에 대한 통찰력과 현실 적합성의 판단력을 배양하는데 큰 공헌을 할 수 있으리라는 믿음 때문이다. 이 논의를 통하여 시계열 분석에 대한 활발한 연구가 진행되기를 기대하고 있다. 시계열 확률과정에 대한 재무관리이론을 연역적으로 도출하기는 용이하지 않다. 시계열 분석에서 제시되는 여러 방법론을 재무관리의 시계열에 적용하여 그 시계열의 성질과 특성을 파악하면 그것이 그대로 현실에 적용될 수 있을 것이다. 이러한 연구의 결과는 어떤 형태로든 연역적 방법에 의한 이론의 정립에 깊은 영향을 미칠 것이다. 뿐만 아니라 연속시간의 틀과 이시적(異時的) 양태하(樣態下)에서 많은 재무관리 모형들이 개발되고 있으며, 동태적 상황을 해명하는 의도에서 이 모형들이 연구되고 있는 만큼 시계열 분석은 이 분야에 직접적으로 이용될 수 있다. 시계열 분석에서 제시된 많은 모형들이 재무관리의 실증적 현상을 설명하는데 효과적으로 활용될 수 있다. 뿐만 아니라 현재 연역적으로 개발된 모형들이 설명할 수 없는 부분을 시계열 분석이 직접적으로 해명할 수 있는 능력을 확보하고 있음도 제시되었다. 증권의 현가모형(現價模型), 이자율의 기간구조, 효율적 시장가설도 주가의 변동성 등은 시계열 분석의 다양한 기법을 사용하여 검증되어야 하며, 이 경우 특히 분산의 추정방법을 여러 측면에서 개발해 야 할 것이다. 시계열 분석에서는 두개 또는 그 이상의 기법을 하나로 통합하는 방법이 있을 수 있다. ARIMA와 ARCH가 결합되는 것을 본 바 있다. 구조적(構造的) 변화(變化)(structural change)모형(模型)과 ARCH의 결합도 가능하다. 다른 분야로서는 변동성(變動性)에 관한 연구이다. 변동성(變動性)에 관한 연구는 variance bounds test에 한정된 감이 있으나 정보와 변동성의 관계가 중요시되고 있는 만큼 정보집합과 시계열 분석 기법의 결합은 변동성의 연구에 새로운 지평을 열어줄 것으로 보인다. 따라서 정보집합의 형성에 따라 새로운 추정방법이 개발될 여지가 풍부하다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.4
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• pp.245-250
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• 2002

This paper presents a priori and the local font classification method. The font classification uses ascenders, descenders, and serifs extracted from a word image. The gradient features of those sub-images are extracted, and used as an input to a neural network classifier to produce font classification results. The font classification determines 2-font styles (upright or slant), 3-font groups (serif, sans serif, or typewriter), and 7-font names (PostScript fonts such as Avant Garde, Helvetica, Bookman, New Century Schoolbook, Palatino, Times, or Courier). The proposed a priori and local font classification method allows an OCR system consisting of various font-specific character segmentation tools and various mono-font character recognizers.

• Journal of The Korean Association For Science Education
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• v.25 no.3
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• pp.327-335
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• 2005

This study investigates student achievement and science-related attitudes on STS hypothetical deductive instruction strategy in the water section of high school chemistry. Two 11th grade co-ed high school classes participated in the study; one control group and one treatment group. After being taught for 10 class periods during the second semester. ANCOVA analysis revealled no significant difference (p>.05) between two groups' achievement tests. However, analysis by ANCOVA did show that the scores for science-related attitudes in the treatment group were significantly higher than those of the control group (p<.05). In particular, the scores of science learning contents and science value about science-related attitude were significantly higher in the treatment group.

• Communications of Mathematical Education
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• v.24 no.2
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• pp.325-344
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• 2010

The purpose of this study is to investigate what influences students' preferences on empirical and deductive proofs and find their relations. Although empirical and deductive proofs have been seen as a significant aspect of school mathematics, literatures have indicated that students tend to have a preference for empirical proof when they are convinced a mathematical statement. Several studies highlighted students'views about empirical and deductive proof. However, there are few attempts to find the relations of their views about these two proofs. The study was conducted to 47 students in 7~9 grades in the transition from empirical proof to deductive proof according to their mathematics curriculum. The data was collected on the written questionnaire asking students to choose one between empirical and deductive proofs in verifying that the sum of angles in any triangles is $180^{\circ}$. Further, they were asked to provide explanations for their preferences. Students' responses were coded and these codes were categorized to find the relations. As a result, students' responses could be categorized by 3 factors; accuracy of measurement, representative of triangles, and mathematics principles. First, the preferences on empirical proof were derived from considering the measurement as an accurate method, while conceiving the possibility of errors in measurement derived the preferences on deductive proof. Second, a number of students thought that verifying the statement for three different types of triangles -acute, right, obtuse triangles - in empirical proof was enough to convince the statement, while other students regarded these different types of triangles merely as partial examples of triangles and so they preferred deductive proof. Finally, students preferring empirical proof thought that using mathematical principles such as the properties of alternate or corresponding angles made proof more difficult to understand. Students preferring deductive proof, on the other hand, explained roles of these mathematical principles as verification, explanation, and application to other problems. The results indicated that students' preferences were due to their different perceptions of these common factors.

• Journal of the Korean Physical Therapy Association
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• s.1
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• pp.83-84
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• 1977