• The Mathematical Education
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• v.37 no.1
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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.

• The Mathematical Education
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• v.46 no.4
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• pp.423-443
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• 2007

Based on the framework of Huffered-Ackles, Fuson and Sherin(2004), data were analyzed in terms of 3 components: explaining(E), questioning(Q) and justifying(J) of students' mathematical concepts and problem solving in a math classroom. The students used varied presentations to explain and justify their mathematical concepts and ideas. They corrected their mathematical errors or misconceptions through discourses. In addition, they constructed and clarified their concepts and thinking while they were interacted. We were able to recognize there was a special feature in discourses that encouraged the students to construct and develop their mathematical concepts. As they participated in math class and received feedback on their learning, the whole class worked cooperatively in a positive way. Their discourse was improved from the level of the actual development to the level of the potential development and the pattern of interaction moved from ERE(Elicitaion-Response-Elaboration to PD(Proposition Discussion).

• The Mathematical Education
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• v.60 no.4
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• pp.409-429
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• 2021

This study investigated instructional methods for fractional division emphasizing algebraic thinking with sixth graders. Specifically, instructional elements for fractional division emphasizing algebraic thinking were derived from literature reviews, and the fractional division instruction was reorganized on the basis of key elements. The instructional elements were as follows: (a) exploring the relationship between a dividend and a divisor; (b) generalizing and representing solution methods; and (c) justifying solution methods. The instruction was analyzed in terms of how the key elements were implemented in the classroom. This paper focused on the fractional division instruction with problem contexts to calculate the quantity of a dividend corresponding to the divisor 1. The students in the study could explore the relationship between the two quantities that make the divisor 1 with different problem contexts: partitive division, determination of a unit rate, and inverse of multiplication. They also could generalize, represent, and justify the solution methods of dividing the dividend by the numerator of the divisor and multiplying it by the denominator. However, some students who did not explore the relationship between the two quantities and used only the algorithm of fraction division had difficulties in generalizing, representing, and justifying the solution methods. This study would provide detailed and substantive understandings in implementing the fractional division instruction emphasizing algebraic thinking and help promote the follow-up studies related to the instruction of fractional operations emphasizing algebraic thinking.

• Journal of Korean Elementary Science Education
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• v.30 no.1
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• pp.61-70
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• 2011

In this study, we examined the types and the characteristics of elementary school teachers' strategies for coping with critical incidents in science classes. Teachers' epistemological beliefs about science were then investigated on the bases of the types of their coping strategies. The teachers (N=107) in 23 elementary schools were asked to respond to an open-ended question about the critical incidents they had experienced in science classes and how to cope with them. Seven types of coping strategies were identified as follows: avoiding, reinterpretation, adjusting, prevaricating, justifying, exploring, and explaining. Among them, adjusting and justifying were the major strategies. In order to classify teachers' epistemological beliefs about science, their coping strategies were grouped into four categories such as transferring facts, constructing facts, transferring meanings, and constructing meanings. The results indicated that most teachers still possessed traditional epistemological beliefs about science. The potential of critical incidents as a probe for revealing teachers' epistemological beliefs about science is discussed.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.2
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• pp.147-156
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• 1993

Recently a new concept of shadow prices, called average shadow price, has been developed. This paper provides a dual problem and the corresponding duality theorems justifying this new shadow price. The general duality framework is used. As an important secondary result, a new reduced class of price function, the pp. h.-class, has been developed for the general duality theory. This should be distinguished from other known reductions achieved in some specific areas of mathematical programming, in that it sustains the strong duality property in all the mathematical programs. The new general dual problem suggested with this pp. h.-class provides, as an optimal solution, the average shadow prices.

• The Journal of Information Technology
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• v.1 no.1
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• pp.133-153
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• 1998

This study investigates the reasons why firms choose to adopt CIM technologies and the decision making process involved in justifying them. In addition, factors that contribute the successful implementation of CIM are identified. Finally, this suggests a strategical model based on the above result of analysis with investigating the justification, evaluation, implementation, and adaptation of CIM.

• The Korean Journal of Financial Management
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• v.8 no.1
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• pp.123-137
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• 1991

This paper developes a multiperiod trading model of securities price formation which extends the notion of market created risk introduced by Kraus and Smith [1989]. It is shown that stock price volalitility can depend on combinations of market parameters known to the market participants only imperfectly. Resulting portfolio rebalancing equilibria generate self-justifying price movements while market fundamental remain unchanged.

• Korean Journal of Social Welfare
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• v.59 no.3
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• pp.253-280
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• 2007

This study explores the discoures of family and family policy in the legislative process of Strong Family Act. Critical discourse analysis was used. The results are follows. The Strong Family Act made family issue as a political agenda in spite of much critics. The characteristics of the family discourse in "strong family camp": 1) The emphasis on the moral principle in family 2) denial of deinstitutionalization of family 3) regarding the family problem as a moral and individual problem 4) regarding the state as managing and controling the family. The characteristics of the family discourse in "critical camp": 1) strong family discourse is related to "the family" ideology 2) regarding the family problem as a social, structural problem 3) regarding the state as subsiding, supplementing families. The characteristics of the family policy discourse in "strong family camp": 1) casual efficiency as justifying logics 2) family policy as means to recover family values 3) deunifying the family policy. On the one hand, the characteristics of the family policy discourse in "critical camp": 1) social consensus and academic discussion as justifying logics 2) regarding the family policy as a means of gender equality and strategical point of welfare state expansion. The discourse of family and family policy, especially 'Strong Family Discourse" resulted in conjugation of nationalism and neoliberalism.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.1
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• pp.43-50
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• 2013

The narrow dynamic range of most smart phone cameras is severely limited. It usually is narrower than the dynamic range of most scenes. So we proposes a illuminance dynamic range expansion using multi-point knee for smart phone camera. Such as logarithmic functions the proposed method compress the image sensor output signal. Additionally, the proposed method was merged into the gamma that is essential circuit for any cameras. To justifying multi-point knee effectiveness, we configure the control and quality evaluation system for smart phone camera module. Experimental results show that the lost information by cut off and saturated affectively reconstructed in darker and in brighter areas. Finally this methods have advantage to implement without any changing hardware for conventional smart phones.

• Journal of the Korean Mathematical Society
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• v.42 no.2
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• pp.305-334
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• 2005

The objective of this study is to analyze the decay characteristics of the hat interpolation wavelet coefficients of some smooth functions defined in a two-dimensional space. The motivation of this research is to establish some fundamental mathematical foundations needed in justifying the adaptive multiresolution analysis of the hat-interpolation wavelet-Galerkin method. Though the hat-interpolation wavelet-Galerkin method has been successful in some classes of problems, no complete error analysis has been given yet. As an effort towards this direction, we give estimates on the decaying ratios of the wavelet coefficients at children interpolation points to the wavelet coefficient at the parent interpolation point. We also give an estimate for the difference between non-adaptively and adaptively interpolated representations.