• 제목/요약/키워드: Logical

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NAS를 위한 신뢰성과 확장성이 있는 저장 장치 시스템 (Reliable and Flexible Storage System for NAS Environments)

  • 이태근;강용혁;엄영익
    • 정보처리학회논문지D
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    • 제10D권7호
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    • pp.1085-1092
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    • 2003
  • 대용량, 고속의 멀티미디어 서비스가 일반화됨에 따라 컨텐츠를 저장하는 서버의 저장 장치 또한 대용량화되고 있다. 그러나 서버를 구성하는 다른 하드웨어 구성 요소에 비해 상대적으로 느린 저장 장치의 입출력 속도와 물리적 또는 논리적인 오류는 시스템 전반의 성능을 저하시키는 원인이 되고 있다. 또한 컨텐츠의 지속적인 증가로 인한 유연한 확장성이 필요하게 되었다. 본 논문에서는 이러한 문제점을 해결하기 위해 소프트웨어 RAID 사용하여 저장 장치의 성능을 향상시키고 신뢰성을 높였으며, LVM을 사용하여 저장 장치에 확장성을 부여하였다. 리눅스 커널 2.4.x에서 제공하는 이러한 기능들을 사용하여 신뢰성과 확장성이 있는 저장 장치를 구현하고 성능을 평가하였다.

수리논술형 문제에 대한 초등학교 5학년 학생들의 문제해결력과 수학적 정당화 과정 분석 (An Analysis of Problem-solving Ability and Mathematical Justification of Mathematical Essay Problems of 5th Grade Students in Elementary School)

  • 김영숙;방정숙
    • 한국수학교육학회지시리즈A:수학교육
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    • 제48권2호
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    • pp.149-167
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    • 2009
  • This study was aimed to examine problem-solving ability of fifth graders on two types of mathematical essay problems, and to analyze the process of mathematical justification in solving the essay problems. For this purpose, a total of 14 mathematical essay problems were developed, in which half of the items were single tasks and the other half were data-provided tasks. Sixteen students with higher academic achievements in mathematics and the Korean language were chosen, and were given to solve the mathematical essay problems individually. They then were asked to justify their solution methods in groups of 4 and to reach a consensus through negotiation among group members. Students were good at understanding the given single tasks but they often revealed lack of logical thinking and representation. They also tended to use everyday language rather than mathematical language in explaining their solution processes. Some students experienced difficulty in understanding the meaning of data in the essay problems. With regard to mathematical justification, students employed more internal justification by experience or mathematical logic than external justification by authority. Given this, this paper includes implications for teachers on how they need to teach mathematics in order to foster students' logical thinking and communication.

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수치지도 데이터의 논리적 모델에 관한 연구 (A Study on Logical Data Model for National Topographic Basedata)

  • 조우석
    • 한국측량학회지
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    • 제16권1호
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    • pp.139-147
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    • 1998
  • 국토에 대한 공간정보의 기본도로서 다양한 사용자의 요구사항을 충족시킬 수 있는 수치지도를 효율적으로 제작 및 유지관리하기 위해서는 수치지도의 데이터 모델과 구조 등 수치지도 데이터 구축에 대한 연구가 중점적으로 이루어져야 한다. 본 연구에서는 단순 지도제작을 목적으로 구축된 기존 수치지도의 데이터 모델에 대한 문제점을 파악하여, 개선된 수치지도 데이터 모델의 개념적ㆍ논리적 모델을 제시하였다. 제시된 수치지도 데이터 모델은 기존에 제작된 수치지도 데이터의 사용을 전제로 설계되었으며, 다양한 사용자의 요구사항을 반영하기 위해서 데이터 모델의 유연성에 중점을 두었고, 필요에 따라서 수정이 용이하도록 단계별 접근방법에 의해 설계되었다. 또한 제시된 수치지도 데이터 모델은 향후 객체 지향형 모델로 나아가기 위한 중간 단계의 데이터 모델이다.

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음의 횟수에 관한 개념 정의 및 학습화 전략 (THE DEFINITION OF NEGATIVE COUNTING NUMBER AND TEACHING MODEL)

  • 김명운
    • 대한수학교육학회지:수학교육학연구
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    • 제8권2호
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    • pp.527-540
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    • 1998
  • In the teacher's guide of mathematics textbook for the 1st grade of the middle school, the clear and logical reason why the multiplication of negative number to negative number makes positive number, and $a^{-m}$ with a>0 and m>0, is defined by ${\frac{1}{a^m}}$ is not given. When we define the multiplication or the power by successive addition or successive multiplication of the same number, respectively, we encounter this ambiguity, in the case that the number of successive operations is negative, In this paper, we name this number, negative counting number, and we make the following more logical and intuitive definition, which is "negatively many successive operations is defined by positively many successive inverse operations." According to this new definition, we define the multiplication by the successive addition or the successive subtraction of the same number, when the multiplier is positive or negative respectively, and the power by the successive multiplication or the power is positive or negative, respectively. In addition, using this new definition and following the E.R.S Instruction strategy which revised and complemented the Bruner's E.I.S Instruction strategy, we develope new teaching model available in the 1st grade class of middle school where the concept of integers, three operations of integers are introduced.ntroduced.

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서술어의 논항 구조와 의미적 특성에 관한 연구 (Argument Structures of Predicates and Their Semantic Aspects in Korean.)

  • 이영헌
    • 한국언어정보학회지:언어와정보
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    • 제2권2호
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    • pp.155-183
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    • 1998
  • The purpose of this paper is to explore the syntactic criteria for determining a secondary predicates as a predicate modifier or a conjunction, and to formalize the semantic aspects of the [-ke] structure as a predicate in Korean. Syntactically, the [-ke] structure is considered to be a secondary predicate when the shared arguments appear in both the [-ke] structure and the main verb structure. On the other hand, if they do not appear in both structures, the [-ke] structure is considered to be a connective element. Semantically the [-ke] structure has numerous aspects such as depictives, resultatives, objectivity, and emphasis. The depictives of the secondary predicate can be formalize as $p{\wedge}q$ where p represents a propositional expression of the secondary predicate and q is a propositional expression of the main verb. Resultatives have the logical form $q{\rightarrow}{\Box}p$, because the consequence has to always be true. However, objectivity has the logical form $q{\rightarrow}{\diamondsuit}p$, because the consequence can be either true or false. Emphasis is represented as $q{\rightarrow}p{\uparrow}$ because the secondary predicate represents the polarity of the event.

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학생들의 정당화 유형과 탐구형 소프트웨어의 활용에 관한 연구 (A study of the types of students' justification and the use of dynamic software)

  • 류희찬;조완영
    • 대한수학교육학회지:수학교육학연구
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    • 제9권1호
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    • pp.245-261
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    • 1999
  • Proof is an essential characteristic of mathematics and as such should be a key component in mathematics education. But, teaching proof in school mathematics have been unsuccessful for many students. The traditional approach to proofs stresses formal logic and rigorous proof. Thus, most students have difficulties of the concept of proof and students' experiences with proof do not seem meaningful to them. However, different views of proof were asserted in the reassessment of the foundations of mathematics and the nature of mathematical truth. These different views of justification need to be reflected in demonstrative geometry classes. The purpose of this study is to characterize the types of students' justification in demonstrative geometry classes taught using dynamic software. The types of justification can be organized into three categories : empirical justification, deductive justification, and authoritarian justification. Empirical justification are based on evidence from examples, whereas deductive justification are based logical reasoning. If we assume that a strong understanding of demonstrative geometry is shown when empirical justification and deductive justification coexist and benefit from each other, then students' justification should not only some empirical basis but also use chains of deductive reasoning. Thus, interaction between empirical and deductive justification is important. Dynamic geometry software can be used to design the approach to justification that can be successful in moving students toward meaningful justification of ideas. Interactive geometry software can connect visual and empirical justification to higher levels of geometric justification with logical arguments in formal proof.

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과학 컴퓨터 보조 학습 프로그램의 효과분석에 관한 연구 (An Analysis of the Effectiveness of Tutorial CAI Programs According to the Learner's Characteristics in Science Teaching)

  • 양일호;정진우
    • 한국과학교육학회지
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    • 제11권1호
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    • pp.37-50
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    • 1991
  • The CAI (Computer-Assisted Instruction) system for science teaching has been increasing both in quantity and in quality during the last two decades. However, science learning by computer has not played a leading role in the science teaching process. Therefore, the purpose of this study was to analyze the effectiveness of tutorial CAI programs according to the learner's characteristics such as sex, inquiry skills, attitudes toward science subject, logical thinking skills, achievement motivation, science content achievement in science teaching. One group pretest-posttest design was used as an experimental design. The three tutorial science CAI programs were used for thirty males and females selected in grade eight. According to the analysis of CAI achievement scores the female students showed significantly higher (P<0.05) than the male students. Also, one-way analysis of variance was used to investigate the effects of interaction between sex and achievement motivation. The significant difference on the effects of interaction between sex and achievement motivation has not found. The effects of tutorial CAI between logical thinking skills, attitudes toward science subject, inquiry skills, achievement motivation, science content achievement according to upper and lower levels were investigated by using the statistical analysis of one-way ANOVA. The results indicate that tutorial CAI might provides a good opportunities for the improvement of science achievement to the lower level students of attitudes toward science subject, inquiry skills, science content achievement.

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The Effects of Cognitive Conflict on Students' Conceptual Change in Physics

  • Lee, Young-Jick;Kwon, Jae-Sool
    • 한국과학교육학회지
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    • 제22권5호
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    • pp.923-943
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    • 2002
  • The purpose of this study was to investigate the relation between the levels of cognitive conflict and students' conceptual change. In this study, 30 Korean high school students were selected from 450 10th graders by examining the pretest results. Two different strategies were used to induce cognitive conflicts in students, an anomalous or conflict situations; demonstrations and logical arguments against students' preconception. After arousing the students' cognitive conflict, the level of cognitive conflict was rated. Pretest, post-test and delayed post-test were administered to check the conceptual change. The tests consisted of 5 items in mechanics and electricity, respectively. Therefore, the demonstration method showed effective conceptual change, more than the logical argument method did. Students changed their conceptions more easily and frequently in the area of mechanics than in electricity. Students who showed higher levels of cognitive conflict indicated more positive conceptual change than those who showed lower conflict levels. 59 cases (56%) out of 105 who experienced high levels of cognitive conflict were changed into scientific conceptions one month later; however only 16 cases (35%) out of 46 who experienced low levels of cognitive conflict changed into scientific conceptions. Students who experienced higher levels of cognitive conflict showed higher rates of conceptual change. It could be concluded that designing instruction to induce cognitive conflict is a useful strategy to promote conceptual change.

다학제 교육의 근간으로서 '디자인 사고'에 대한 연구 (The Study of Design Thinking as Foundation of Multidisciplinary Education)

  • 박성미;김수화
    • 수산해양교육연구
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    • 제25권1호
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    • pp.260-273
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    • 2013
  • This study aims to reflect experts' opinions in analyzing a design thinking as foundation of multidisciplinary education. For this purpose, a delphi survey was conducted with 20 experts in three sessions from May 1 to June 25, 2012. To analyze the collected data, descriptive statistics, including frequency, percentage, the mean, and standard deviation were implemented, and internal reliability test on the survey instrument was carried out for statistical processing. The main results are as follows : First, the delphi analysis on intuitive thinking of design thinking suggested 7 items(to pursue the possibility of outside, to pursue the possibility of applying new forms of technology, content planning, facing a complex real-world phenomena etc.). Second, the delphi analysis on logical thinking of design thinking suggested 7 items(executed repeatedly, reasoning and verification, artificial intelligence, a decision support system etc.) Third, the delphi analysis on subjective thinking of design thinking suggested 9 items(user experience measuring, user satisfaction ratings, user requirements analysis, user interface design, behavioral responses of the human etc.). Fourth, the delphi analysis on objective information of design thinking suggested 8 items(information management system, simulation, production process, information exchange and sharing etc.). According to the results of the delphi analysis, design thinking can be seen as the foundation of multidisciplinary education. Suggestions were made for discussion about the main results and further researches.

최적화에 기반을 둔 LAD의 패턴 생성 기법 (Optimization-Based Pattern Generation for LAD)

  • 장인용;류홍서
    • 한국컴퓨터정보학회논문지
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    • 제11권1호
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    • pp.11-18
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    • 2006
  • LAD(Logical Analysis of Data)는 Boolean-logic에 기반을 둔 데이터 마이닝 방법론이다. LAD에 의한 데이터 분석 시 중요한 과정은 데이터 집합에 숨겨진 구조적 정보를 패턴의 형식으로 발견해내는 패턴 생성 단계이다. 기존의 패턴 생성 방법은 열거법에 기반을 두고 있어 높은 차수의 패턴을 생성하는 것은 실질적으로 불가능하였다. 본 논문에서는 최적화에 기반을 둔 패턴 생성 방법론을 제안하고 혼합 정수 선형 모형과 SCP(Set Covering Problem)의 두 가지 모형을 제안한다. 기계학습 분야에서 널리 쓰이는 데이터 집합에 대해 제안된 패턴 생성 방법을 이용한 분석 실험을 통하여 기존의 패턴 생성 방법으로는 생성될 수 없는 패턴을 쉽게 생성하는 효율성을 입증하였다.

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