• School Mathematics
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• v.14 no.4
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• pp.469-493
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• 2012

The purpose of this study is find the relation between students' concept and types of proof construction. For this, four undergraduate students majored in mathematics education were evaluated to examine how they understand mathematical concepts and apply their concepts to their proving. Investigating students' proof with their concepts would be important to find implications for how students have to understand formal concepts to success in proving. The participants' proof productions were classified into syntactic proof productions and semantic proof productions. By comparing syntactic provers and semantic provers, we could reveal that the approaches to find idea for proof were different for two groups. The syntactic provers utilized procedural knowledges which had been accumulated from their proving experiences. On the other hand, the semantic provers made use of their concept images to understand why the given statements were true and to get a key idea for proof during this process. The distinctions of approaches to proving between two groups were related to students' concepts. Both two types of provers had accurate formal concepts. But the syntactic provers also knew how they applied formal concepts in proving. On the other hand, the semantic provers had concept images which contained the details and meaning of formal concept well. So they were able to use their concept images to get an idea of proving and to express their idea in formal mathematical language. This study leads us to two suggestions for helping students prove. First, undergraduate students should develop their concept images which contain meanings and details of formal concepts in order to produce a meaningful proof. Second, formal concepts with procedural knowledge could be essential to develop informal reasoning into mathematical proof.

• Korean Journal of Logic
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• v.18 no.3
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• pp.307-335
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• 2015

An important component in Prawitz's and Dummett's proof-theoretic accounts of validity is the condition for validity of open arguments. According to their accounts, roughly, an open argument is valid if there is an effective method for transforming valid arguments for its premises into a valid argument for its conclusion. Although their conditions look similar to the proof condition for implication in the BHK explanation, their conditions differ from the BHK account in an important respect. If the premises of an open argument are undecidable in an appropriate sense, then that argument is trivially valid according to Prawitz's and Dummett's definitions. I call this 'the triviality problem'. After a brief exposition of their accounts of proof-theoretic validity, I discuss triviality problems raised by undecidable atomic sentences and by Godel sentence. On this basis, I suggest an emendation of Prawitz's definition of validity of argument.

• Korean Journal of Logic
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• v.3
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• pp.27-51
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• 2000

이글의 기본적인 목적은 2치를 포함한 다치 논리 체계들간의 관계를 검토하는 데 있다. 이를 위하여 여기서는 명제를 대상으로 한 형식 의미 해석체계들 간에 고러해야 할 의미론적 확장 개념을 분명히 하였다. 구체적으로 다음의 두 작업이 수행되었다 첫째로 2치와 다치 논리 또는 다치 논리들간에 적용될 만한 의미론적 확장 개념을 의미해석의 바탕을 이루는 진리치 함수와 진리연산에 맞게 정의하였다. 둘째로 정의의 적합성을 확장, 비확장 사례 증명을 통해 예증해 보였다.

• Communications of the Korean Mathematical Society
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• v.19 no.4
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• pp.585-599
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• 2004

본 연구에서는 학교수학에서 증명지도의 문제점을 정당화의 측면에서 분석하고, 정당화의 한 방법으로서 확률론적 정당화를 제시하며, 학교수학에서 정당화 지도의 교육적 가치, 정당화 지도의 방향, 정당화 지도의 예와 지도 방법에 대해 논의한다. 이러한 논의에 근거하여 학교수학에서의 정당화 지도의 필요성 및 가능성에 관하여 살펴본다. 본 연구에서 '증명'은 고전적인 의미에서의 증명, 즉 엄밀한(rigorous) 증명, 수학적(mathematical) 증명이고, '정당화'는 기존의 수학적 증명 개념은 물론, 다양한 논증 기법을 포함하는 넓은 의미이다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.12
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• pp.3127-3137
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• 1998

COBRA 표준명세는 표준을 만족하는 구현에서 제공해야 할 기능뿐만 아니라 서비스 제공 모듈의 사용자 인터페이스도 IDL을 사용하여 엄격하게 정의하고 있다. CORBA 표준에 대한 확신과 신뢰성을 가지기 위해서는 IDL(Interface Definition Language)로 기술된 표준명세를 정형화하고 수학적으로 엄격히 증명할 필요가 있다. 본 논문에서는 CORBA 표준을 정형적으로 명세하고 검증할 방법을 제시한다. 먼저 표준모듈을 Larch/CORBA IDL(LCB)를 사용하여 정형적으로 명세하고, LCB의 의미론에 준하여 LCB 명세를 LSL(Larch Shared language)로 변환한다. 변환한 LCB 명세와 LSL 증명논리를 사용하여 특성을 수학적으로 증명한다. 변환기반의 LCB 의미론을 정립하여 제안한 방법의 이론적 바탕을 마련하고 CORBA 이름서비스명세에 실제 적용하여 그 효용성을 보인다.

• The KIPS Transactions:PartB
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• v.9B no.1
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• pp.23-28
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• 2002

A fundamental problem in building an intelligent agent is that an agent does not understand the meaning of its perception or its action. One reason that an agent cannot understand the world is partially caused by a syntactic approach that converts a semantic feature into a simple string. To solve this problem, Cohen introduces a semantic approach that an agent autonomously learns a meaningful representation of physical schemas, on which some advanced conceptual structures are built, from physically interacting with environment using its own sensors and effectors. However, Cohen does not deal with a meta level of conceptual primitive that makes recognizing a schema possible. We propose that negation is a meta schema that enables an agent to recognize a physical schema. We prove some semantic aspects of negation.

• Journal of Educational Research in Mathematics
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• v.14 no.2
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• pp.143-156
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• 2004

Lakatos's mathematical philosophy implies that the mathematical knowledge is quasi-empirical and provides the context where mathematics grows and develops. So, it is educationally significant. But, it is not easy to apply Lakatos's methodology to teaching elementary mathematics, because Lakatos's logic of the mathematical discovery is based on the proofs and refutations but elementary mathematics does not contain any proof. This study is to develop the schemes that apply Lakatos's methodology to teaching elementary mathematics and to provide the teaching examples. I devised the teaching process and the curriculum development method. And I developed the teaching examples.

• Journal for History of Mathematics
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• v.21 no.2
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• pp.55-70
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• 2008

This study is about the Data which is one of Euclid's writing. It dealt with the organization of contents, formal system and mathematical meaning. First, we investigated the organization of contents of the Data. Second, on the basis of this investigation, we analyzed the formal system of the Data. It contains the analysis of described method of definition, proposition, proof and the meaning of 'given'. Third, we explored the mathematical meaning of the Data which can be classified as algebraic point of view, geometric point of view and the opposite point of view to 'The Elements'.

• Journal for History of Mathematics
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• v.25 no.2
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• pp.11-21
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• 2012

The interdisciplinary study explores the Euler's theology through his mathematical landmarks. From the mathematico-theological perspective, we first address Euler's theological backgrounds, and then show the implications of Euler's identity as his mathematical Christology.

• Journal of the Korea Society for Simulation
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• v.21 no.2
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• pp.19-30
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• 2012

In recent decades, it has been known that the Discrete Event System Specification, or DEVS, formalism provides sound semantics to design a modular and hierarchical model of a discrete event system. In spite of this benefit, practitioners have difficulties in applying the semantics to real-world systems modeling because DEVS needs to specify a large size of sets of events and/or states in an unstructured form. To resolve the difficulties, this paper proposes an extension of the DEVS formalism, called the Structured DEVS formalism, with an associated graphical representation, called the DEVS diagram, by means of structural representation of such sets based on closure property of set theory. The proposed formalism is proved to be equivalent to the original DEVS formalism in their model specification, yet the new formalism specifies sets in a structured form with a concept of phases, variables and ports. A simplified example of the structured DEVS with the DEVS diagram shows the effectiveness of the proposed formalism which can be easily implemented in an objected-oriented simulation environment.