• 제목/요약/키워드: Deductive

검색결과 281건 처리시간 0.025초

쌍대비교에 기반한 승법적 효용함수의 결정 (Determination of Multiplicative Utility Function Based on the Pair-wise Comparisons)

  • 김경모
    • 품질경영학회지
    • /
    • 제33권1호
    • /
    • pp.64-72
    • /
    • 2005
  • The ever increasing demand for enhanced competitiveness of engineered products requires "designing-in-quality" strategies that can effectively and efficiently incorporate concepts of uncertainty and quality into design. Multi-attribute utility function is commonly used to represent the decision-maker's preference on multiple design attributes under conditions of uncertainty and risk. One of the major issues in implementing this approach concerns the generation of appropriate utility function, especially in a complex engineering design environment. Typically, the decision maker's preference is revealed through lottery questions rather than being structured on the deductive reasoning to reflect the nonlinear tradeoffs among the attributes. The use of such intuitive procedures can lead to inexact preference information that may result in inaccuracy and rank reversal problems. This paper presents an alternative procedure based on the pair-wise comparisons between design alternatives towards a consistent preference presentation in assessing multiplicative utility function. The effectiveness of the overall procedures is tested with the aid of an injection-molding process design for a capacitor can and the results are discussed.

역동적 기하 환경에서 비례를 이용한 중학교 함수의 작도 (Construction of Elementary Functions through Proportions on the Dynamic Environment)

  • 류희찬;윤옥교
    • 대한수학교육학회지:학교수학
    • /
    • 제13권1호
    • /
    • pp.19-36
    • /
    • 2011
  • 본 연구는 중학교 학생들에게 닮은 삼각형의 대응변 사이에 성립하는 비례적 성질에 기초하여 함수를 작도할 수 있는 기회를 제공함으로써 대수적 함수와 그것의 기하학적 성질에 관한 학생들의 직관을 촉진시키기 위한 것이다. 또한, 학생들이 선택한 작도 방법에 관한 정당화의 과정을 강조함으로써 연역적 추론능력을 향상시키고자 하였다. 이 예비 연구의 결과로서 학생들이 함수를 작도하는 과정에서 나타나는 사고 과정의 특징과 교사의 역할에 관해 기술하였다.

  • PDF

국가 수학 교육 과정의 구성 및 운영에 관한 재고 (Reconsideration the construction and implementation of the national curriculum in mathematics)

  • 서동엽
    • 대한수학교육학회지:학교수학
    • /
    • 제1권2호
    • /
    • pp.571-588
    • /
    • 1999
  • Our mathematical curriculum has been revised frequently compared to another countries. The frequent revisions may mean that the current curriculum is not so complete in the selected contents of each grade levels. The idea is partially supported by the fact that the didactics of mathematics has both hypothesis-deductive and hypothesis-constructive property. Investigating the items which are used in TIMSS study and based on the relatively common curriculums of 40 more countries, the styles of them are a bit different from those of our textbooks of primary and secondary school. Hence, we consider that the construction and implementation of our mathematical curriculum may be a large scale of experiment for the improved curriculum carried by the nation. Additionally, we propose less compulsive curriculum than the current for minimizing the possible trial and errors.

  • PDF

자동차 Cooling Fan용 비등각 축류홴 소음해석 (Acoustic Analysis of Unevenly Pitched Fan of Automobile Cooling Pack System)

  • 송우석;이정수;김주용;이승배
    • 유체기계공업학회:학술대회논문집
    • /
    • 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
    • /
    • pp.567-571
    • /
    • 2004
  • The 2-dimensional unsteady flows on and around the cambered airfoils were computed by applying LES with the deductive dynamic SGS model. The unsteady flow field were used as inputs to compute the far-field sounds and directivity patterns from rotating blades by a hybrid approach that exploits Farassat's formula. The BEM (Boundary Element Method) was applied to predict the frequency characteristics from the rotating blades for the cases of even- and uneven-pitched fans. The BEM results suggested that the unevenly pitched fan have less pronounced discrete peaks at BEF frequencies, which was confirmed by the experiment.

  • PDF

Inductance Measurement of Interior Permanent Magnet Synchronous Motor in Stationary Frame of Reference

  • Lee, Geun-Ho;Choi, Woong-chul;Lee, Byeong-Hwa;Jung, Jae-Woo;Hong, Jung-Pyo
    • Journal of Magnetics
    • /
    • 제16권4호
    • /
    • pp.391-397
    • /
    • 2011
  • An inductance measurement method for interior permanent magnet synchronous machine (IPMSM) is proposed in this paper. In this method, the motor is measured at standstill condition, and only a 3-phase voltage source, an oscilloscope and a DC voltage source are required. Depending on the deductive dq-axis voltage equations in the stationary frame of reference, the dq-axis inductances at different current magnitude and vector angle can be calculated by the measured 3-phase voltages and currents. And hence, the saturation and cross-magnetizing effect of the inductances are measurable. This paper introduces the principle equations, experiment setup, data processing, and results comparison on the concentrated-winding and distributed-winding IPMSMs.

Development of Case-adaptation Algorithm using Genetic Algorithm and Artificial Neural Networks

  • Han, Sang-Min;Yang, Young-Soon
    • Journal of Ship and Ocean Technology
    • /
    • 제5권3호
    • /
    • pp.27-35
    • /
    • 2001
  • In this research, hybrid method with case-based reasoning and rule-based reasoning is applied. Using case-based reasoning, design experts'experience and know-how are effectively represented in order to obtain a proper configuration of midship section in the initial ship design stage. Since there is not sufficient domain knowledge available to us, traditional case-adaptation algorithms cannot be applied to our problem, i.e., creating the configuration of midship section. Thus, new case-adaptation algorithms not requiring any domain knowledge are developed antral applied to our problem. Using the knowledge representation of DnV rules, rule-based reasoning can perform deductive inference in order to obtain the scantling of midship section efficiently. The results from the case-based reasoning and the rule-based reasoning are examined by comparing the results with various conventional methods. And the reasonability of our results is verified by comparing the results wish actual values from parent ship.

  • PDF

The First Stage of Developing the Adolescent Friendship Social Capital Scale

  • Xu, Leilei
    • Child Studies in Asia-Pacific Contexts
    • /
    • 제2권1호
    • /
    • pp.29-43
    • /
    • 2012
  • The purpose of the study was to generate the candidate items for the Adolescent Friendship Social Capital Scale. Both inductive and deductive approaches were used to generate the scale items. Halpern's conceptual map of social capital served as the theoretical basis of this scale, and guided the development of items. Semi-structured interviews with adolescents in Sydney, Melbourne and Beijing generated the initial pool of scale items. Twenty-six items were generated for the Adolescent Friendship Social Capital Scale. The items are organised in four theoretical constructs: Bonding Networks, Bridging Norms, Bridging Sanctions, and Linking Networks. Each item is a short statement followed by a five-point Likert scale anchored by 1= "Strongly disagree" and 5= "Strongly agree". The scale has several advantages over previous measures of adolescent friendship networks and friendship social capital. The scale has a strong and clear theoretical structure, the scale items demonstrate initial construct and content validity, and the format of the scale enables the collection of continuous data. However, in order to ensure the validity and reliability of the scale, another two stages of research need to be conducted in the future: scale development and scale evaluation.

FTA(Fault Tree Analysis)에서 불확실한 위험분석을 위한 퍼지모형 연구 (A Study Fuzzy model for Risk Analysis of Uncertainly FTA(Fault Tree Analysis))

  • 임총규;박주식;강경식
    • 대한안전경영과학회지
    • /
    • 제4권1호
    • /
    • pp.37-47
    • /
    • 2002
  • Risk analysis is a formal deductive procedure for determining combinations of component failures and human errors that could result in the occurrence of specified undesired events at the system level. This method can be used to analyze the vast majority of industrial system reliability problems. This study deals with the application of knowledge-engineering and a methodology for the assessment & measurement of reliability, availability, maintainability, and safety of industrial systems using FTA(fault tree analysis), A fuzzy methodology for fault-tree evaluation seems to be an alternative solution to overcome the drawbacks of the conventional approach (insufficient Information concerning the relative frequencies of hazard events). To improve the quality of results, the membership functions must be approximated based on heuristic considerations, The purpose of this study is to describe the knowledge engineering approach, directed to integrate the various sources of knowledge involved in a FTA.

교과지식으로서의 유클리드 기하와 벡터기하의 연결성 (Mathematical Connections Between Classical Euclidean Geometry and Vector Geometry from the Viewpoint of Teacher's Subject-Matter Knowledge)

  • 이지현;홍갑주
    • 대한수학교육학회지:학교수학
    • /
    • 제10권4호
    • /
    • pp.573-581
    • /
    • 2008
  • 학교기하에서는 논증기하, 해석기하, 벡터기하 등의 다양한 접근을 다루고 있는데, 특히 이러한 유클리드 기하에 대한 다양한 접근 사이의 연결성은 기하학적 방법과 대수적 방법의 연 결성으로 볼 수 있다. 본 연구는 교과지식의 측면에서, 논증기하증명에서 벡터와 내적의 대수적 성질의 의미를 분석함으로서 학교 수학에서 기하학적 증명과 벡터와 내적을 이용한 대수적 증명의 연결성에 대하여 고찰하였다.

  • PDF

초등학교에서의 증명지도 (The Teaching of 'proof' in Elementary Mathematics)

  • 조완영
    • 한국수학교육학회지시리즈C:초등수학교육
    • /
    • 제4권1호
    • /
    • pp.63-73
    • /
    • 2000
  • The purpose of this paper is to address He possibility of the teaching of 'proof' in elementary mathematics, 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. 'Proof' has not been taught in elementary mathematics, traditionally. Most students have had little exposure to the ideas of proof before the geometry. However, 'Proof' cannot simply be taught in a single unit. Rather, proof must be a consistent part of students' mathematical experience in all grades. Or educators and mathematicians need to rethink the nature of mathematical proof and give appropriate consideration to the different types of proof related to the cognitive development of a notion of proof.

  • PDF