• 대한수학교육학회지:학교수학
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• 제14권3호
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• pp.297-313
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• 2012

학생들에게 증명을 보다 이해하기 쉽게 전개하는 대안으로, 내러티브의 잠재력과 그 효과를 함수의 평행 이동이라는 사례에서 논의한다. 내러티브의 구성 요소를 고려하여, 평행 이동한 함수의 식을 유도하는 증명을 내러티브로 구성하였다. 두 집단의 학생들에게 내러티브와 형식적 증명을 각각 제시하고, 내러티브가 증명을 제시하는 것보다 함수의 평행 이동에 대한 도구적 및 관계적 이해라는 측면에서 유의미한 효과가 있는지를 살펴보았다. 실험집단과 비교집단에서 사후 도구적 및 관계적 이해 검사 결과의 차이가 통계적으로 유의하지는 않았으므로, 내러티브로 제시하는 것이 증명을 제시하는 것보다 함수의 평행 이동에 대한 도구적 및 관계적 이해의 측면에서 더 효과적이라는 결론을 내릴 수는 없었다. 그러나 학생들의 관계적 이해 반응과 수업 평가에 대한 질적 분석에서는 비교집단과 실험 집단사이에서 몇 가지 다른 양상을 발견할 수 있었으며, 형식적 증명을 보완할 수 있는 내러티브의 가능성을 찾아볼 수 있었다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.153-158
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• 1997

This paper describes a formal safety analysis technique which is demonstrated by performing empirical formal safety analysis with the case study of beamline hutch door Interlock system that is developed by using PLC(Programmable Logic Controller) systems at the Pohang Accelerator Laboratory. In order to perform formal safety analysis, we have built the Z formal specifications representation from user requirement written in ambiguous natural language and target PLC ladder logic, respectively. We have also studied the effective method to express typical PLC timer component by using specific Z formal notation which is supported by temporal history. We present a formal proof technique specifying and verifying that the hazardous states are not introduced into ladder logic in the PLC-based safety critical system.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제13권3호
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• pp.217-233
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• 2009

The purpose of this study is to describe how dynamic geometry systems can be useful in proof activity; teaching sequences based on the use of dynamic geometry systems and to analyze the possible roles of dynamic geometry systems in both teaching and learning of proof. And also dynamic geometry environments can generate powerful interplay between empirical explorations and formal proofs. The point of this study was to show that how using dynamic geometry software can provide an opportunity to link between empirical and deductive reasoning, and how such software can be utilized to gain insight into a deductive argument.

• International Journal of Railway
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• 제5권2호
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• pp.65-70
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• 2012

This paper introduced a novel railway system, Automatic Train Protection and Block (ATPB) briefly, which is proposed to improve the efficiency of existing regional train lines with low cost in Japan. The biggest superiority of ATPB system is a great use of universal and mature technologies, such as GPS and regular mobile telephone networks, so that there is nearly no increment of trackside equipments in the reconstruction. Then in order to guarantee the system safety, a formal model of ATPB is established and analyzed by formal method VDM++. Firstly, the specification is specified by VDM++ formally without ambiguity. Secondly, its internal consistency is proved by discharging the proof obligations. And finally, its satisfiability is checked by systematic testing, which executes specification and checks the outputs against corresponding inputs.

• 대한수학교육학회지:수학교육학연구
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• 제9권2호
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• pp.419-438
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• 1999

This paper explored the impact of dynamic geometry software such as CabriII, GSP on student's understanding deductive justification, on the assumption that proof in school mathematics should be used in the broader, psychological sense of justification rather than in the narrow sense of deductive, formal proof. The following results have been drawn: Dynamic geometry provided positive impact on interacting between empirical justification and deductive justification, especially on understanding the necessity of deductive justification. And teacher in the computer environment played crucial role in reducing on difficulties in connecting empirical justification to deductive justification. At the beginning of the research, however, it was not the case. However, once students got intocul-de-sac in empirical justification and understood the need of deductive justification, they tried to justify deductively. Compared with current paper-and-pencil environment that many students fail to learn the basic knowledge on proof, dynamic geometry software will give more positive ffect for learning. Dynamic geometry software may promote interaction between empirical justification and edeductive justification and give a feedback to students about results of their own actions. At present, there is some very helpful computer software. However the presence of good dynamic geometry software can not be the solution in itself. Since learning on proof is a function of various factors such as curriculum organization, evaluation method, the role of teacher and student. Most of all, the meaning of proof need to be reconceptualized in the future research.

• 대한수학교육학회지:수학교육학연구
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• 제21권1호
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• pp.57-65
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• 2011

이 연구는 학교수학에서 대학수학으로의 이행과정에서 정의와 증명의 변화와 관련하여, 기하학에서 공리적 방법의 발달과정을 분석하였다. 고대 그리스에서 현대수학적인 공리적 방법으로의 변화를 이해하는데 있어서, 상수 혹은 변수라는 기본용어의 성격 차이는 중요한 지표이다. 특히 기본용어의 상수에서 변수로의 성격 변화는 수학에서 정의와 증명 개념 및 수학에 대한 인식 변화를 설명한다. 이러한 수학사적 분석은 대학수학의 입문과정에서 형식적 정의와 증명 개념의 의미를 설명하는 데 유용하게 사용될 수 있으리라 기대된다.

• 대한수학회논문집
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• 제23권3호
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• pp.307-312
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• 2008

In this note we first give a simple, direct proof of a combinatorial determinant involving the usual higher derivatives and then obtain a corresponding result in positive characteristic.

• International Journal of Railway
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• 제2권3호
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• pp.99-106
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• 2009

Checks and tests before putting safety facilities into service as well as the results of these tests are essential, time consuming and may show great variations between each other. Economic constraints and the increasing complexity associated with the development of computerized tools tend to limit the capacity of the classic approval process (manual or automatic). A reduction of the validation cover rate could result in practice. This is not compatible with the French national plan to renew the interlocking systems of the national network. The method and the tool presented in this paper makes it possible to formally validate new computerized systems or evolutions of existing French interlocking systems with real-time functional interpreted Petri nets. The aim of our project is to provide SNCF with a method for the formal validation of French interlocking systems. A formal proof method by assertion, which is applicable to industrial automation equipment such as interlocking systems, and which covers equally the specification and its real software implementation, is presented in this paper. With the proposed method we completely verify that the system follows all safety properties at all times and does not show superfluous conditions: it replaces all the indoor checks (not the outdoor checks). The advantages expected are a significant reduction of testing time and of the related costs, an increase of the test coverage rate, an answer to the new demand of railway infrastructure maintenance engineering to modify and validate computerized interlocking systems. Formal methods mastery by infrastructure engineers are surely a key to prove that more safety is not necessarily more expensive.

• 정보처리학회논문지D
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• 제8D권1호
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• pp.62-70
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• 2001

소프트웨어 컴포넌트의 기능에 대한 정확한 서술은 컴포넌트의 활용을 위한 필수 조건이며 특히, 실시간 시스템과 같은 엄밀성을 요하는 분야에는 더욱 중요한 요소로 작용한다. 본 논문에서는 컴포넌트의 이해를 높이는 수단으로 패턴에 기반한 정형적 표현 및 검증에 관한 내용을 소개한다. 특히 본 논문은 컴포넌트 기능 서술 시 VDM++를 이용하는 명세 방법, 주어진 명세에 대한 정제와 정합성 검증에 관한 정형기법의 활용방법을 제시한다.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제22권4호
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• pp.471-487
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• 2008

본 연구에서는 해석학 강좌를 운영하는 과정에서 얻어진 학생들의 수학적 발명의 사례를 제시하고 분석하여, 수학적 발명과 관련된 구체적인 교수-학습 과정, 얻어진 수학적 산출물들, 이들의 수학적 의의를 기술하였다.