• 제목/요약/키워드: Science Concept

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Concept Optimization for Mechanical Product Using Genetic Algorithm

  • Huang Hong Zhong;Bo Rui Feng;Fan Xiang Feng
    • Journal of Mechanical Science and Technology
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    • 제19권5호
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    • pp.1072-1079
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    • 2005
  • Conceptual design is the first step in the overall process of product design. Its intrinsic uncertainty, imprecision, and lack of information lead to the fact that current conceptual design activities in engineering have not been computerized and very few CAD systems are available to support conceptual design. In most of the current intelligent design systems, approach of principle synthesis, such as morphology matrix, bond graphic, or design catalogues, is usually adopted to deal with the concept generation, in which optional concepts are generally combined and enumerated through function analysis. However, as a large number of concepts are generated, it is difficult to evaluate and optimize these design candidates using regular algorithm. It is necessary to develop a new approach or a tool to solve the concept generation. Generally speaking, concept generation is a problem of concept synthesis. In substance, this process of developing design candidate is a combinatorial optimization process, viz., the process of concept generation can be regarded as a solution for a state-place composed of multi-concepts. In this paper, genetic algorithm is utilized as a feasible tool to solve the problem of combinatorial optimization in concept generation, in which the encoding method of morphology matrix based on function analysis is applied, and a sequence of optimal concepts are generated through the search and iterative process which is controlled by genetic operators, including selection, crossover, mutation, and reproduction in GA. Several crucial problems on GA are discussed in this paper, such as the calculation of fitness value and the criteria for heredity termination, which have a heavy effect on selection of better concepts. The feasibility and intellectualization of the proposed approach are demonstrated with an engineering case. In this work concept generation is implemented using GA, which can facilitate not only generating several better concepts, but also selecting the best concept. Thus optimal concepts can be conveniently developed and design efficiency can be greatly improved.

Hausdorff Intuitionistic Fuzzy Filters

  • Park, Jin-Han;Park, Jin-Keun;Park, Jong-Seo
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2002년도 춘계학술대회 및 임시총회
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    • pp.114-118
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    • 2002
  • As a generalization of fuzzy sets, the concept of intuitionistic fuzzy sets was introduced by Atanassov [1]. By using intuitionistic fuzzy sets, we introduce and study the concept of intuitionistic fuzzy filters and define the concept of Hausdorffness on intuitionistic fuzzy filters, which can not be defined in crisp theory of filters, and study their properties for some extent.

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A WEAK ORDERING OF POSITIVE DEPENDENCE STRUCTURE OF STOCHASTIC PROCESSES

  • Ryu, Dae-Hee;Seok, Eun-Yang;Choi, In-Bong
    • Journal of applied mathematics & informatics
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    • 제5권2호
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    • pp.553-564
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    • 1998
  • In this paper we introduce a new concept of more weakly quadrant dependence of hitting times of stochastic processes. This concept is weaker than the more positively quadrant dependence of hitting times of stochastic processes. This concept is weaker than the more positively quadrant dependence and it is closed under some statistical operations of weakly positive quadrant dependence(WPQD) ordering.

귀추전략 과학수업이 초등학생의 과학적 개념 이해와 초인지에 미치는 영향 (The Effects of Science Classes Using Abductive Strategies Applied to Elementary School Students on Scientific Concept Understanding and Meta-cognition)

  • 김희연;강버들;유병길
    • 수산해양교육연구
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    • 제28권4호
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    • pp.1133-1142
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    • 2016
  • The purpose of this study was to verify the effects of science classes using abductive strategies on the scientific concept understanding and meta-cognition. The subjects included two classes of sixth graders from K Elementary School in B Metropolitan City and they divided into two groups. Research group was composed of 21 students(10 boys, 11 girls) and comparative group was composed of 21 students(11 boys, 10 girls). In order to achieve aims of this study, proper contents to apply abductive strategies were selected from the first semester science curriculum for sixth graders. Also five-steps study papers were designed to elicit abductive reasoning. While the research group received 20 times of reframed science lessons using abductive strategies, the comparative group received common science lessons according to the teachers' manual. The results of this study are as follows. First, science classes using abductive strategies were effective for the scientific concept understanding. Also there were statistically significant differences between the research group and the comparative group in overall science sub-domain. In the process of hypothesis formulating, students tried to find out scientific causes thoroughly to present the optimal explanation and they concentrated on the analysis of each scientific concept. It is thought that this process contributed to better understanding in scientific concepts. Second, science classes using abductive strategies were effective for improving meta-cognition. There were statistically significant differences between the two groups and especially in monitoring that is one of sub-factors of meta-cognition. It indicates that hypothesis formulating process gave positive effect on meta-cognition by stimulating critical thinking and manifesting elaboration.

The Effects of Generative Concept Map on Science Learning Achievement and Cognitive Load

  • OH, Suna;KIM, Yeonsoon
    • Educational Technology International
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    • 제17권2호
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    • pp.253-271
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    • 2016
  • This study investigated the effect of generative concept maps according to learning achievements and cognitive load. A total of 78 students in the first grade of middle school participated in this study. Before the experimental treatment was implemented, students had to fill out a questionnaire assessing prior knowledge. The study was designed where all the students were presented the same learning contents regarding photosynthesis; however, the two experimental groups were provided with different concept map methods: a learner-generative concept map (GCM) and an instructor-provided concept map (PCM). GCM students were asked to make a concept map by themselves in small groups while they are reading material. PCM students were instructed to study in small groups in order to read the material; however, they were provided a concept map developed by their teacher. The control group (CG) had the teacher present the learning contents in traditional lecture format with no accompanying concept map. The results show that there were significant differences in the achievements among the groups. CG showed higher achievement than both the experimental groups. There was also a significant difference in cognitive load. Although the GCM group did not obtain higher achievement than the other groups, the GCM group showed higher mental effort and lower physical fatigue than the other groups. The GCM group might have invested more effort to find and connect ideas when drawing their concept map with peers which is unlike the conditions for the PCM group and CG. In conclusion, we should consider applying GCM in teaching and learning design in order to increase learning achievement and decrease extraneous cognitive load.

초등학생의 반려동물 사육경험이 과학에 대한 흥미, 과학호기심, 과학자아개념에 미치는 영향 (The Effects of Elementary School Students' Breeding Companion Animals on Interest, Curiosity, and Self-Concept in Science)

  • 김지원;강지훈;유병길
    • 한국초등과학교육학회지:초등과학교육
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    • 제40권2호
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    • pp.267-281
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    • 2021
  • 본 연구의 목적은 현대사회에서 급증하고 있는 반려동물과 관련하여 반려동물의 사육경험이 초등학생의 과학에 대한 흥미, 과학호기심 및 과학자아개념에 미치는 영향을 알아보는 것이다. 본 연구의 목적을 달성하기 위해 초등학교 6학년 학생 474명을 대상으로 반려동물 사육경험에 따른 과학에 대한 흥미, 과학호기심, 과학자아개념 수준을 ANOVA 및 독립표본 t검정을 통해 비교·분석하였다. 분석 결과, 반려동물 사육경험이 있는 학생의 과학에 대한 흥미, 과학호기심, 과학자아개념이 사육경험이 없는 학생보다 통계적으로 더 높게 나타났다. 학생들은 흥미와 호기심을 느끼며 반려동물 사육활동에 참여하며, 반려동물을 사육하기 위해 필요한 지식을 습득하는 과정 및 성공적인 사육경험으로 인하여 자아개념도 높아진 것으로 판단된다. 본 연구의 결과는 그동안 과학교육 분야에서 많이 연구되지 않았던 반려동물을 소재로 하여 반려동물 사육경험이 과학교육에 주는 시사점에 대해 논의하였다는 점에서 의미가 있다.

중학교 2학년 학생들의 순환개념 이해에 대한 연구 (An Understanding of Cycle Concept and A Composition Element of the Middle School Student)

  • 이동은;한신
    • 대한지구과학교육학회지
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    • 제4권2호
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    • pp.126-133
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    • 2011
  • This study explored different concepts by handing out the questionnaires asking the 6 students of the second year of junior high school who had no lesson on cycle "which words related to cycle are suggested?" In regard to the stimulation of the word 'cycle', students relate it to different fields that they learn at school such as biology, environmentology, and earth science. The analyzed results from the answers by students are as follows. First, it resulted in from analysis on the questionnaire and the half-structured interviews that students were unable to expand the concept of cycle to the scientific concept, and perceived it fragmentarily. Secondly, their understanding on the system of the earth was low and they understood the concept of cycle with a unilinear thought rather than a systematic thought. Therefore, we need to synthesize the students' unilinear thoughts on cycle shown through this study and an effective educational strategy for their continuous, systematic thoughts, is essential.

초등학생의 호흡 개념 이해에 대한 연구 (A Cross-age Study on Elementary Students이 Understanding of the Concept of Respiration)

  • 성정희;김영수
    • 한국초등과학교육학회지:초등과학교육
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    • 제19권2호
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    • pp.57-74
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    • 2000
  • Students' concepts of scientific phenomena have become a point of focus in science education research. This study investigated into developmental process and mechanism of the students' respiration concept through a cross-age study. This study utilized the 1st, 3rd, 6th grade elementary students to find out changes in student's understanding of the concept of respiration. The 1st and 3rd grade level students were interviewed what the respiration mean and whether each of living things respires, etc. The 6th grade students were interviewed and tested. Respiration is a word that students come across often in everyday life. It was found that they were more likely to associate respiration with its more common concept of breathing or gas exchange as opposed to its more scientific definition as the process in which nutrients are oxidized to provide energy. This trend didn't improve as they advanced grade. This is an indication that the knowledge system of student is split into a generic knowledge system and scientific knowledge system. Understanding of concept increased and differentiated across grade levels but that understanding was limited. They overcome their tendency to base their understanding of respiration on their understanding of human phenomena and learn to integrate their understanding of biological phenomena through a one organ - one role type of logic. They also intuitively explain everything based on their own experience.

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Data Mining for Uncertain Data Based on Difference Degree of Concept Lattice

  • Qian Wang;Shi Dong;Hamad Naeem
    • Journal of Information Processing Systems
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    • 제20권3호
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    • pp.317-327
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    • 2024
  • Along with the rapid development of the database technology, as well as the widespread application of the database management systems are more and more large. Now the data mining technology has already been applied in scientific research, financial investment, market marketing, insurance and medical health and so on, and obtains widespread application. We discuss data mining technology and analyze the questions of it. Therefore, the research in a new data mining method has important significance. Some literatures did not consider the differences between attributes, leading to redundancy when constructing concept lattices. The paper proposes a new method of uncertain data mining based on the concept lattice of connotation difference degree (c_diff). The method defines the two rules. The construction of a concept lattice can be accelerated by excluding attributes with poor discriminative power from the process. There is also a new technique of calculating c_diff, which does not scan the full database on each layer, therefore reducing the number of database scans. The experimental outcomes present that the proposed method can save considerable time and improve the accuracy of the data mining compared with U-Apriori algorithm.