• 제목/요약/키워드: proof

검색결과 2,553건 처리시간 0.051초

3시간 내화도료의 개발을 위한 내화성능 및 부착특성 평가에 관한 실험적 연구 (The experimental study on the Evaluation of fire-proof performance and bond characteristics for development of 3hours Fire-Proof paint)

  • 김수영;김성길;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.63-64
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    • 2012
  • Recently, Fire-proof performance of buildings becomes important to ensure safety. As a result, fire-proof paint is required for 3 hours. However, Experiments are only performed by standard KS F 2271 for estimation of fire-proof paint. Because there is no domestic estimation standard for performance of fire-proof paint as well. So estimation standard of fire-proof paint is needed to guarantee their performance for establishing quality system and to assure same performance for safety of people in the building from unpredicted fire accident. Owing to these reasons, we studied comparative estimation for quality performance of two kinds of fire-proof paint and bond performance.

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수학 교육에서 ‘증명의 의의’에 관한 연구 (A Study on the Meaning of Proof in Mathematics Education)

  • 류성림
    • 한국수학교육학회지시리즈A:수학교육
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    • 제37권1호
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    • pp.73-85
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    • 1998
  • The purpose of this study is to investigate the understanding of middle school students on the meaning of proof and to suggest a teaching method to improve their understanding based on three levels identified by Kunimune as follows: Level I to think that experimental method is enough for justifying proof, Level II to think that deductive method is necessary for justifying proof, Level III to understand the meaning of deductive system. The conclusions of this study are as follows: First, only 13% of 8th graders and 22% of 9th graders are on level II. Second, although about 50% students understand the meaning of hypothesis, conclusion, and proof, they can't understand the necessity of deductive proof. This conclusion implies that the necessity of deductive proof needs to be taught to the middle school students. One of the teaching methods on the necessity of proof is to compare the nature of experimental method and deductive proof method by providing their weak and strong points respectively.

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방습 효과가 우수한 환경친화적인 방습지(2보) -방습 도공지의 재생 특성- (Environmentally Friendly Paper with Superior Moisture -Proof Properties(II) -Recyclable properties of moisture-proof paper-)

  • 이명구;유재국
    • 펄프종이기술
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    • 제35권1호
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    • pp.13-18
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    • 2003
  • This study was done in an effort to evaluate the possibility of recyclability of moisture-proof paper. Because it is difficult to recycle laminated moisture-proof paper, a mixture of styrene-butadiene latex(SB latex) and wax emulsion was used as moisture-proof paper chemicals. A bar coater was applied to make moisture-proof paper and the coated weight was 17 g/$m^2$. The mixing ratios of SB latex to wax emulsion were 85 : 15, 87 : 13, and 90 : 10, respectively. It was observed that the moisture-proof paper treated with SB latex and wax emulsion at the appropriate ratio could be recycled effectively. The moisture-proof paper was similar to base paper in degree of pulping, and there was no significant difference in dispersion between moisture-proof paper and base paper. Most of wax particle which caused the spots during drying process could be removed by flotation process. Tensile strength and tear strength of handsheets made of both moisture-proof paper and base paper after pulping was measured to examine the fiber bonding and no significant difference in mechanical properties was observed.

기하증명과제에서 나타나는 중학교 1학년 학생들의 증명스키마와 그 특징 (Seventh Graders' Proof Schemes and Their Characteristics in Geometric Tasks)

  • 변규미;장경윤
    • 대한수학교육학회지:수학교육학연구
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    • 제27권2호
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    • pp.191-205
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    • 2017
  • 본 연구는 서울의 C중학교 1학년 학생들이 기하 증명 문제를 해결하는 과정에서 보여주는 증명스키마 유형과 그 특징을 조사한 것이다. 자료 분석은 Harel, & Sowder의 증명스키마 유형에 기초하여 이루어졌다. 연구 결과, 학업성취수준에 따라 학생들이 사용하는 증명스키마 유형에 차이가 있었다. 상위권에서 하위권으로 갈수록 변형적 증명스키마를 사용하는 학생의 비율이 감소하였고 귀납적(측정) 증명스키마를 사용하는 학생의 비율은 증가하였다. 또한 증명과정에서 비형식적인 부호 사용하기, 문제에서 주어진 그림 특정 비율로 인식하기 등 각 증명스키마 유형마다 고유한 특징이 나타났다. 이를 바탕으로 4개의 의미 있는 결론을 추출하였고, 이것이 증명 교수 학습에 주는 시사점을 논의하였다.

국내 오프셋 인쇄물 평가를 위한 최적의 Proofing 조건에 관한 연구 (A Study on Optimal Proofing Conditions for Evaluation of the Domestic Offset Prints)

  • 이원규;조가람;구철회
    • 한국인쇄학회지
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    • 제29권1호
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    • pp.1-21
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    • 2011
  • Because of high demand of color quality of the prints, proof prints are more important for end-user to predict and correct the final prints directly as an intermediate. Thus, proof prints can be used as a reference to take minimum ${\Delta}E^*ab$between the originals and finals in the field. The advantage of proof prints is to predict and correct color easily through the RIP(Raster Image Processor) without printing plates and plate making steps. While, it is thought that the proof systems are almost equivalent to the press in the past, present proof systems are more simple to take proof prints more easily due to the automation and digitalization. This paper addresses a method to perform an accurate profiling according to proof paper types and find optimal proof papers which meet proofing requirement. Although proof papers are matched with ISO 12647-7, we were trying to reduce ${\Delta}E^*ab$, In addition to the above, through the Gamut Mapping and Iteration, We were trying to find optimal proofing conditions.

오프라인 검증을 지원하는 안전한 요킹증명 프로토콜 (A Secure Yoking-Proof Protocol Providing Offline Verification)

  • 함형민
    • 한국콘텐츠학회논문지
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    • 제21권2호
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    • pp.113-120
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    • 2021
  • RFID (Radio Frequency Identification) 요킹증명은 여러 객체의 물리적 근접성을 보장하기 위해 한 쌍의 RFID 태그를 하나의 리더 장치로 동시에 스캔하고 이를 검증하기 위한 방법을 제공한다. 최초 제안된 요킹증명 프로토콜들은 생성된 증명을 검증하기 위해 리더 장치와 온라인으로 연결된 온라인 검증자가 필수적이며, 이 조건은 요킹증명이 적용 가능한 환경을 제한한다. 이 같은 제한 조건을 완화하기 위해, 온라인 검증자가 필요하지 않은 오프라인 요킹증명에 대한 연구가 제안되었다. 그러나 이 프로토콜들은 안전한 요킹증명의 생성 및 검증을 보장하지 못하며, 최초 제안된 요킹증명 기법에 비해 상대적으로 더 많은 연산을 태그에게 요구한다. 본 논문에서는, 온라인 검증자가 필요 없는 안전하고 효율적인 오프라인 요킹증명 프로토콜을 제안한다. 제안하는 오프라인 요킹증명 프로토콜은 기존의 프로토콜들보다 상대적으로 적은 횟수의 연산으로 안전한 요킹증명의 생성 및 검증이 가능하며, 별도의 추가 장치 없이 한 쌍 이상의 태그에 대한 증명이 가능한 그룹증명으로의 확장도 지원한다. 분석 결과는 제안된 프로토콜이 안전하고 효과적으로 오프라인 검증을 제공한다는 것을 보인다.

Efficient Proof of Vote Validity Without Honest-Verifier Assumption in Homomorphic E-Voting

  • Peng, Kun
    • Journal of Information Processing Systems
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    • 제7권3호
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    • pp.549-560
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    • 2011
  • Vote validity proof and verification is an efficiency bottleneck and privacy drawback in homomorphic e-voting. The existing vote validity proof technique is inefficient and only achieves honest-verifier zero knowledge. In this paper, an efficient proof and verification technique is proposed to guarantee vote validity in homomorphic e-voting. The new proof technique is mainly based on hash function operations that only need a very small number of costly public key cryptographic operations. It can handle untrusted verifiers and achieve stronger zero knowledge privacy. As a result, the efficiency and privacy of homomorphic e-voting applications will be significantly improved.

중학교 수학에서 증명을 위한 공리 취급에 관한 연구 (A Note on Treatment of Axioms for Proof in Middle School Mathematics)

  • 김흥기
    • 한국수학교육학회지시리즈A:수학교육
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    • 제40권2호
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    • pp.291-315
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    • 2001
  • There are some problems in the introduction of proof in middle school mathematics. Among the problems, one is the use of postulates and the another is the methods of proof how to connect a statement with others. The first case has been treated mainly in this note. Since proof means to state the reason logically why the statement is true on the basis of others which have already been known as true and basic properties, in order to prove logically, it is necessary to take the basic properties and the statement known already as true. But the students don't know well what are the basic properties and the statement known already as true for proving. No use of the term postulation(or axiom) cause the confusion to distinguish postulation and theorem. So they don't know which statements are accepted without proof or not accepted without proof, To solve this problems, it is necessary to use the term postulate in middle school mathematics. In middle school mathematics, we present same model of the introduction of proof which are used the postulates needed for the proof.

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Problem Posing in the Instruction of Proof: Bridging Everyday Lesson and Proof

  • Kim, Hangil
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제24권3호
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    • pp.255-278
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    • 2021
  • Proof serves a critical role in mathematical practices as well as in fostering student's mathematical understanding. However, the research literature accumulates results that there are not many opportunities available for students to engage with proving-related activities and that students' understanding about proof is not promising. This unpromising state of instruction of proof calls for a novel approach to address the aforementioned issues. This study investigated an instruction of proof to explore a pedagogy to teach how to prove. The teacher utilized the way of problem posing to make proving a routine part of everyday lesson and changed the classroom culture to support student proving. The study identified the teacher's support for student proving, the key pedagogical changes that embraced proving as part of everyday lesson, and what changes the teacher made to cultivate the classroom culture to be better suited for establishing a supportive community for student proving. The results indicate that problem posing has a potential to embrace proof into everyday lesson.

RFID tag를 위한 강력한 Yoking Proof Protocols (Strong Yoking Proof Protocols for RFID Tags)

  • 조정식;여상수;김성권
    • 한국통신학회논문지
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    • 제32권3A호
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    • pp.310-318
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    • 2007
  • RFID 시스템은 작고 값싼 태그를 물품에 부착하여, 이를 이용해서 물품들을 식별하는 비접촉식 자동인식 시스템이다. 이 시스템은 현재 가장 많이 사용되고 있는 접촉식 판독 기법인 바코드를 대처할 것으로 예상된다. RFID 시스템은 다양한 응용분야가 존재한다. 그 중 Ari Juels는 2개의 태그가 동시에 인식된 것을 증명할 필요가 있는 환경을 설명하고, 이를 위한 프로토콜로 yoking proof 프로토콜을 제안하였다. 하지만 yoking proof 프로토콜은 재생 공격에 약하다. 이를 보완하기 위한 변형된 yoking proof 프로토콜들이 제안되었지만, 역시 재생 공격에 자유롭지 못했다. 본 논문에서는 기존 yoking proof프로토콜들의 문제점을 분석하고 이를 바탕으로 재생 공격을 어렵게 하는 새로운 프로토콜을 제안한다. 또한 이 프로토콜을 n개의 태그에 대한 yoking proof를 제공할 수 있도록 프로토콜을 확장시켰다.