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초등학생의 수학적 정당화에 관한 연구 (A study on mathematical justification activities in elementary school)

  • 권성룡
    • 한국수학교육학회지시리즈C:초등수학교육
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    • 제7권2호
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    • pp.85-99
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    • 2003
  • In this paper, firstly examined various proofs types that cover informal empirical justifications by Balacheff, Miyazaki, and Harel & Sowder and Tall. Using these theoretical frameworks, justification activities by 5th graders were analyzed and several conclusions were drawn as follow: 1) Children in 5th grade could justify using various proofs types and method ranged from external proofs schemes by Harel & Sowder to thought experiment by Balacheff This implies that children in elementary school can justify various mathematical statements of ideas for themselves. To improve children's proving abilities, rich experience for justifying should be provided. 2) Activities that make conjectures from cases then justify should be given to students in order to develop a sense of necessity of formal proof. 3) Children have to understand the meaning and usage of mathematical symbol to advance to formal deductive proofs. 4) New theoretical framework is needed to be established to provide a framework for research on elementary school children's justification activities. Research on proof mainly focused on the type of proof in terms of reasoning and activities involved. But proof types are also influenced by the tasks given. In elementary school, tasks that require physical activities or examples are provided. To develop students'various proof types, tasks that require various justification methods should be provided. 5) Children's justification type were influenced not only by development level but also by the concept they had. 6) Justification activities provide useful situation that assess students'mathematical understanding. 7) Teachers understanding toward role of proof(verification, explanation, communication, discovery, systematization) should be the starting point of proof activities.

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해외 신재생연료 의무혼합제도 비교분석 연구 (Study on Comparison of Nenewable Fuel Standard Policy on Global)

  • 임의순;김재곤;정충섭
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 추계학술대회 초록집
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    • pp.150.1-150.1
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    • 2011
  • The global rise of greenhouse gas(GHG) emissions and its potentially devastating consequences require a comprehensive regulatory framework for reducing emissions, including those from the transport sector. alternative fuels and technologies have been promoted as a means for reducing the carbon intensity of the transport sector. Renewable fuel policies were historically motivated by energy security concerns, and to promoted agricultural industries. In the last decade, biofuels have also been discussed as low or net-zero carbon soures of energy for transportation. Hence, the development of biofuels has been supported by a range of policy instruments, including volumetric targets or blending mandates, tax incentives or penalties, preferential government purchasing, government funded research, development in world-wide. As one of the most powerfuel instruments, renewable fuel mandates require fuel producers to produce a pre-defined amount(or share) of biofuels and blend them with petroleum fuel. In this study, we reviewed Renewable Fuel Standard(RFS, USA), Renewable Transport Fules Obligation (RTFO, UK) as a renewable fuel mandate policy to reduce GHG. This includes not only mandate system for blending of biofuels in transport fuels, but also sustainability to use biofuels in this system.

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측정을 목적으로 시료에 변형을 가하지 않아도 되는 새로운 관성모멘트 실험 장치의 개발 (Development of a New Moment of Inertia Experiment Apparatus That Does Not Require Deformation of a Sample for Measurement Purpose)

  • 남형주
    • 공학교육연구
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    • 제23권3호
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    • pp.32-40
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    • 2020
  • A new moment of inertia experiment apparatus different from the existing one has been developed, which does not require deformation of a sample in order to fix it to the apparatus. This new experiment apparatus was able to experiment with constant-shaped objects that did not deform the samples, so that it enabled them for conducting an experiment which is close to an ideal rigid model dealt in the general physics course. The new experimental apparatus was easy and accurate in measuring the physical quantity by using the experimental principle of physical pendulum. In the results of the measurement of the moments of inertia of the six samples, all measurements were made to be accurate enough to measure with very small errors within 1%. In addition, it has been found to be useful as an experiment apparatus to understand the concept of the moment of inertia and to prove the formula for moment of inertia. Therefore, if the new moment of inertia experiment apparatus developed in this study is used in students' experiments, it is expected that students will be able to greatly increase their understanding of the concept of moment of inertia.

이혼예방을 위한 최근 미국 가족정책에 관한 소고 -결혼허가증제도 및 서약결혼제도를 중심으로- (Some Thoughts on Recent Family Policies Designed to Prevent Divorce in the United States of America: With Special Regard to the Marriage License and the Covenant Marriage)

  • 김혜선;박희성
    • 가정과삶의질연구
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    • 제19권2호
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    • pp.13-21
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    • 2001
  • The purpose of this study is to examine the Marriage Preparation and Preservation Act adopted in Florida which require premarital counseling and covenant marriage laws of Louisiana and Arizona among many kinds of family policy which recently are designed to prevent divorce in the United States of America. Most of states in the U.S. require the marriage license prior to having a marriage ceremony. Covenant marriage legislation has admirable motives to strengthen marriage and cure the defects of the no-fault system. In that legislation, the imposition of waiting period for the no-fault ground of divorce, proof of fault requirements, consent requirements, and mandatory course or counseling attendance will likely serve as deterrents to those seeking divorce as a first resort. To sum up, by offering preventive measures in the form of premarital counseling and waiting period before marriage, covenant marriage will force couples entering marriage to carefully consider their actions before they act and prevent broken marriages in the first place. In response to rising divorce rates, the Koreas family policy has put its emphasis of fixing social problems accompanied with family dissolution. Rather, this study suggests that attention in Korea also should be shifted from broken marriages to preventing them.

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Flexible Low Power Consumption Active-Matrix OLED Displays

  • Hack, Mike;Chwang, Anna;Hewitt, Richard;Brown, Julie;Lu, JengPing;Shih, ChinWen;Ho, JackSon;Street, R.A.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.609-613
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    • 2005
  • Advanced mobile communication devices require a bright, high information content display in a small, light-weight, low power consumption package. In this paper we will outline our progress towards developing such a low power consumption active-matrix flexible OLED ($FOLED^{TM}$) display. Our work in this area is focused on three critical enabling technologies. The first is the development of a high efficiency long-lived phosphorescent OLED ($PHOLED{TM}$) device technology, which has now proven itself to be capable of meeting the low power consumption performance requirements for mobile display applications. Secondly, is the development of flexible active matrix backplanes, and for this our team are employing poly-Si TFTs formed on metal foil substrates as this approach represents an attractive alternative to fabricating poly-Si TFTs on plastic for the realization of first generation flexible active matrix OLED displays. Unlike most plastics, metal foil substrates can withstand a large thermal load and do not require a moisture and oxygen permeation barrier. Thirdly, the key to reliable operation is to ensure that the organic materials are fully encapsulated in a package designed for repetitive flexing. We also present progress in operational lifetime of encapsulated T-PHOLED pixels on planarized metal foil and discuss PHOLED encapsulation strategy.

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온라인 서포트벡터기계를 이용한 온라인 비정상 사건 탐지 (Online abnormal events detection with online support vector machine)

  • 박혜정
    • Journal of the Korean Data and Information Science Society
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    • 제22권2호
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    • pp.197-206
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    • 2011
  • 신호처리 관련 응용문제에서는 신호에서 실시간으로 발생하는 비정상적인 사건들을 탐지하는 것이 매우 중요하다. 이전에 알려져 있는 비정상 사건 탐지방법들은 신호에 대한 명확한 통계적인 모형을 가정하고, 비정상적인 신호들은 통계적인 모형의 가정 하에서 비정상적인 사건들로 해석한다. 탐지방법으로 최대우도와 베이즈 추정 이론이 많이 사용되고 있다. 그러나 앞에서 언급한 방법으로는 로버스트 하고 다루기 쉬운 모형을 추정한다는 것은 쉽지가 않다. 좀 더 로버스트한 모형을 추정할 수 있는 방법이 필요하다. 본 논문에서는 로버스트 하다고 알려져 있는 서포트 벡터 기계를 이용하여 온라인으로 비정상적인 신호를 탐지하는 방법을 제안한다.

임베디드 시스템에서 사용 가능한 적응형 MFCC 와 Deep Learning 기반의 음성인식 (Voice Recognition-Based on Adaptive MFCC and Deep Learning for Embedded Systems)

  • 배현수;이호진;이석규
    • 제어로봇시스템학회논문지
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    • 제22권10호
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    • pp.797-802
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    • 2016
  • This paper proposes a noble voice recognition method based on an adaptive MFCC and deep learning for embedded systems. To enhance the recognition ratio of the proposed voice recognizer, ambient noise mixed into the voice signal has to be eliminated. However, noise filtering processes, which may damage voice data, diminishes the recognition ratio. In this paper, a filter has been designed for the frequency range within a voice signal, and imposed weights are used to reduce data deterioration. In addition, a deep learning algorithm, which does not require a database in the recognition algorithm, has been adapted for embedded systems, which inherently require small amounts of memory. The experimental results suggest that the proposed deep learning algorithm and HMM voice recognizer, utilizing the proposed adaptive MFCC algorithm, perform better than conventional MFCC algorithms in its recognition ratio within a noisy environment.

구조물의 건전성 모니터링을 위한 유도초음파 응용 구조손상 탐지기법 (A Guided Wave-Based Structural Damage Detection Method for Structural Health Monitoring)

  • 고한석;이우식
    • 한국철도학회논문집
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    • 제12권3호
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    • pp.412-419
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    • 2009
  • 구조물 건전성 모니터 링에서 구조물에 발생한 손상을 어떠한 방법으로 가장 효율적이고 정확하게 탐지하느냐는 매우 중요한 연구과제이다. 기존의 대부분 SHM기술에서는 구조물에 손상이 발생하기 이전에 측정해 놓은 탄성파신호를 손상 검출을 위한 기준 데이터로서 활용하고 있다. 본 연구에서는 Lamb파를 이용하는 pitch-catch (PC)-기법을 기반으로 기준 데이터를 필요로 하지 않는 새로운 SHM기술을 제안하였다. 또한 손상 신호에 이미지화 기법을 적용하여 손상의 위치를 이미지화 함으로써 손쉽게 파악할 수 있도록 하였다. 제안된 SHM기술은 알루미늄 평판 시편에 대한 실험을 통해 응용 가능성을 고찰하였다.

CISG상 권리부적합에 대한 매수인의 구제권에 관한 연구 (A Study on the Buyer's Remedies in respect of Defects in Title under CISG)

  • 민주희
    • 무역상무연구
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    • 제61권
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    • pp.3-28
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    • 2014
  • This study describes the buyer's remedies regarding defects in title under CISG. Although CISG stipulates the seller's liability for the delivery of conforming goods physically at Art. 35 and legally at Art. 41 and Art. 42 respectively, the buyer's remedies are not distinguished between non-conformity governed by Art. 35 and defects in title governed by Art. 41 and Art. 42. If the seller does not fulfill his obligation under Art. 41 and Art. 42 to deliver goods which are free from third party claims, the buyer should pay attention to which remedies are available under CISG. Under CISG, for defects in title in the delivered goods, the buyer is entitled to require performance in Art. 46 (1) unless he has resorted to a remedy which is inconsistent with this requirement, to declare the contract avoided by strictly limiting the situation in which the failure by the seller to perform his obligation amounts to a fundamental breach of contract in Art. 49, to claim damages in Art. 74, and to suspend the performance of his obligation where it becomes apparent that the seller will not perform a substantial part of his obligation in Art. 71 (1). Unlike Art. 35 non-conformity, the buyer may not require delivery of substitute goods under Art. 46 (2), claim repair under Art. 46 (3), and declare price reduction for title defects under Art. 50.

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Current Issues & Prospects of International Space Law

  • Zwaan, Tanja Masson
    • 항공우주정책ㆍ법학회지
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    • 제25권1호
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    • pp.237-259
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    • 2010
  • This paper first gives a brief overview of the history of space law making in the international geopolitical context and recalls some of the main principles as elaborated in the framework of the United Nations. Next, several topics are discussed that will require the attention of space lawyers in the near future. They are the International Space Station, space debris, exploitation of space resources, space tourism, private property rights in space, and militarization and weaponization of space. The paper raises some questions in each of these areas that need to be addressed and concludes that the general legal framework for space activities under public international law as contained in the UN treaties is in place, and is sufficiently general and flexible to enable and encourage states to carry out space activities in an orderly manner. However, as demonstrated by the examples discussed in the paper, the time has come for the international community to agree on the further development of these general principles, starting perhaps with space debris, imminent 'new' uses of space such as space tourism, or some of the 'age old' issues such as the weaponisation of outer space that will continue to require our attention and vigilance. Whether such rules can be in the form of non binding guidelines, codes of conduct and the like, or should be embodied in solid legal instruments creating rights and obligations remains to be seen.

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