• Journal of The Korean Association For Science Education
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• v.30 no.2
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• pp.304-322
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• 2010

The purpose of this study is to explore the effects of student-centered instruction using analogies for middle school students' learning of the photosynthesis concept. Participants in this study were 8th grade students at a middle school in Seoul (N=132). The students were divided into two groups for implementation. In the experimental group the teaching materials containing analogies were used while the contents of a science textbook were taught in the control group. The results of this study indicated that student-centered instruction using analogies was more effective than traditional methods of instruction for understanding photosynthesis concepts and the students' attitude toward the science class. Analogies were also found to contribute to developing an understanding of the photosynthesis concept through activating students' prior knowledge, focusing on structural features of the target concept and elaborating knowledge. In addition, analogies play an important role in activating small group discussions, improving students' meta-cognitive skills, and revealing and revising of misconceptions about photosynthesis. Moreover, analogies can help improve students' interests and self-efficiency in science classes.

• Journal of Korean Elementary Science Education
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• v.28 no.3
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• pp.292-303
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• 2009

In this study, we investigated the characteristics of the analogies, the mapping understanding, and the mapping errors on saturated solution of scientifically-gifted and general elementary students. Fifth graders (n=60) at four scientifically-gifted education institutes in Seoul and/or Gyeonggi province and fifth graders (n=91) at three elementary schools in Seoul were selected and assigned to the scientifically-gifted group and the general group respectively. After the students of each group performed the experiment and were taught about the target concept in the first class, they administered the test on the self-generating analogies on the target concept in the second class. The results revealed that the students in the scientifically-gifted group made more analogies, especially verbal/pictorial, structural/functional, enriched, and higher systematic ones, and had deeper understanding of the analogy than those in the general group. The numbers of the shared attributes included in the student-generated analogies and the scores of the mapping understanding of the students in the scientifically-gifted group were significantly higher than those in the general group. The students in the scientifically-gifted group had fewer mapping errors than those in the general group. However, not a few students in the scientifically-gifted group had at least one mapping error. Educational implications of these findings are discussed.

• Journal of the Korean Chemical Society
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• v.50 no.6
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• pp.486-493
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• 2006

study investigated the relationship between conceptual understanding and mapping errors induced in learning chemistry concept with two analogies presented in current science textbooks. Each of the two groups from 7th graders (N=260) in three middle schools studied with one of the analogies, and then a conception test and a mapping test were administered. Analyses of the results indicated that students conceptual understanding has a significant relationship with their understanding about the mapping. The scores of the conception test and the mapping test for the unshared attributes were lower than those for the shared attributes. Five types of mapping errors were also identified: overmapping, mismapping, failure to map, rash mapping, and artificial mapping. Many representative misconceptions were found to be associated with their mapping errors. Educational implications are discussed.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.43-44
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• 1995

The diffusion behavior of liquid into polymer has been described by Fick's law, but the departure from Fickian diffusion is frequently found. In this study, 'noble' expressions for the rates of relaxation and sorption are introduced to eliminate these limitations. The ralaxation-sorption coupled mechanism model are based on the possibility of contacting liquid molecule and the active site which has the numerical concept of free volume. The concept has an analogy of reaction rate expressed by the possibility of collision with molecules and used in adsorption and reactive extraction etc. The new model simulated by Rungc-Kutta method for initial-value problem and Fickian diffusion is caompared with experimental data. The results show that the ralaxation-sorption coupled mechanism is able to account well for Fickian and non-Fickian sorption behavior including sigmoid and two-stage. In addition, this model has a chance of expansion to multi-component sorption with ease.

• Progress in Superconductivity and Cryogenics
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• v.14 no.1
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• pp.34-37
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• 2012

In this paper, configurations and performance of a pulse tube engine (PTE) are investigated. The configuration of PTE is basically designed by using a concept of energy flow. The configurations of PTE are classified as a PTE with two pistons and a PTE with one piston. First, the PTE with two pistons is simulated and the Carnot efficiency is about 41 %. The phase difference of between motion of two pistons located at expander and compressor mainly effects the performance of the PTE. Second, the PTE with one piston is designed. From a concept of analogy, the piston of compressor is replaced by a compliance tube and a resonator. The PTE with one piston is identical with a thermoacousic engine and has the large volume because the compliance tube and resonator are consisted of large volume tubes. Therefore, we will consider each usefulness of the compact PTE with two pistons and the huge PTE with one piston for PTE applications and the judgement of feasibility.

• Journal of Korean Philosophical Society
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• no.94
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• pp.163-192
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• 2011

A posteriori physicalists criticize non-physicalist arguments based on the framework of two-dimensional semantics. Most of them argue for physicalism based on the analogy between scientific identity statements and psychophysical identity statements. This paper argues for another version of aposteriori physicalism, so called physicalism employing 'phenomenal concept strategy' or 'exceptionalist strategy', which appeals to merely the nature of phenomenal concept without recourse to a semantic framework. Loar's phenomenal concept strategy employs the aspect of our recognitional ability of objects in criticizing non-physicalism, leading to the argument that phenomenal concepts are 'exceptional' in applying conceivability-possibility link. I critically examine Stoljar's, Chalmers', Raffman's criticisms against Loar's exceptionalists strategy. Loar's phenomenal concept strategy reflects well our psychological aspects surrounding the acquisition and the possession of 'phenomenal concept'. In several respects, Loar's exceptionalist version of a posteriori physicalism is the best explanation for accounting for both the explanatory gap and the a posteriority of psychophysical identity.

• Journal of The Korean Association For Science Education
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• v.27 no.7
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• pp.631-638
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• 2007

This study investigated the influences of a student-centered analogical instruction using physical analogies upon students' conception and application, retention of conception and application, perceptions of science classroom environment, and perceptions of analogical instruction. Six classes of seventh graders (N=208) at a middle school in Seoul were assigned to the control, the teacher-centered analogy (TCA), and the student-centered analogy (SCA) groups. They were taught about 'three states of matter' and 'motion of molecules' for 8 class hours. Analysis of the results revealed that the scores of the SCA group were significantly higher than those of the other groups in the conception test, retention test of conception and application, and perception test of science classroom environment. The scores of the SCA group in the application test were also higher than those of the other groups, but there was a significant difference only between the control and the SCA groups. The TCA group performed significantly better than the control group only in the test of the retention of application. In addition, the students in the SCA group exhibited more positive perceptions of the analogical instruction than those in the TCA group. Educational implications are discussed.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.5
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• pp.508-516
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• 1999

This paper presents a method for constructing composite power system effective load duration curves(CMELDC) at load points by Monte Carlo method. The concept of effective load duration curves(ELDC) in power system planning is useful and important in both HLII. CMELDC can be obtained from convolution integral processing of the probability function of unsupplied power and the load duration curve at each load point. This concept is analogy to the ELEC in HLI. And, the reliability indices (LOLP, EDNS) for composite power system are evaluated using CMELDC. Differences in reliability levels between HLI and HLII come from considering with the uncertainty associated with the outages of the transmission system. It is expected that the CMELDC can be applied usefully to areas such as reliability evaluation, probabilistic production cost simulation and analytical outage cost assessment, etc. in HLII, DC load flow and Monte Carlo method are used for this study. The characteristics and effectiveness of thes methodology are illustrated by a case study of the IEEE RTS.

• Journal of The Korean Association For Science Education
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• v.19 no.4
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• pp.645-652
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• 1999

The effects of number, source, and sequence of analogs on middle school students' concept recall and application were investigated. Based on the number (one/two) and source(everyday/science) of analogs, four types of learning materials were developed and pilot-tested. Prior to the treatment the field dependence/independence (FD/l) test was administered and the scores were used as a blocking variable. The learning materials were read by randomly assigned middle school students (N=88), and the concept recall and application test was administered immediately and four weeks later. In the immediate and retention tests, there were no significant main effects of number, source, and sequence of analogs. In the application problems of retention test. however, there were some significant interaction effects with students' FD/I. Field-independent students who learned with two analogs scored significantly higher than those who learned with one analog. In the case of using two analogs, field-dependent students who learned with everyday-analog first scored significantly higher than those who learned with science-analog first.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.3
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• pp.151-167
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• 1994

Initial screening is one of the most important and difficult processes in new product development. Many new product screening models have been developed in management and marketing. However practical applications of these models have been limited in part due to their complexity and inflexibility, and in part due to their excessive data requirements. Thus simple judgment models have been popular in practice. However, these models suffer from inaccuracy and inconsistency originating form human cognitive limitations. In light of the problem swith traditional screening methods, we propose a new approach for screening based on managers' past experience and intuitive judgments-screening by analogy, and develop a computerized case-based system for screening new financial service concepts. Using the system, managers can predict the potential performance of a new product concept based on the performance of past products that are similar to it in terms of product characteristics, firm's resources, and market conditions. Based on this prediction, managers make a screening decision.