• Journal of The Korean Association For Science Education
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• v.28 no.5
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• pp.471-481
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• 2008

This study investigated connecting errors by students' field independence-dependence in learning chemistry concepts with multiple external representations in current science textbooks. Seventh graders (N=196) at a middle school were assigned to the BL and CL groups, which were respectively taught "Boyle's Law" and "Charles's Law." A field independence-dependence test was administered. After learning the target concept with text and picture emphasizing the particulate nature of matter, a connecting test was also administered. Five types of connecting errors were identified: Insufficient connection, misconnection, rash connection, impossible connection, and failing to connect. 'Failing to connect,' 'Misconnection,' and 'Rash connection' were found to be the frequent types of connecting errors regardless of the target concepts. The frequencies and percentages of the types of connecting errors were not significantly different between the field independent and field dependent students. Educational implications of these findings are discussed.

• Journal of the Korean Society for information Management
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• v.12 no.2
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• pp.213-223
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• 1995

It has known that different representations of either queries or documents, or different retrieval techniques retrieve different sets of documents. Recent works suggest that significant improvements in retrieval performance can be achieved by combining multiple representations or multiple retrieval techniques. In this paper we propose a simple method for retrieving different documents within a single query representation, a single document representation and a single retrieval technique. We classify the types of documents, and describe the properties of weighting schemes. Then. we explain that different properties of weighting schemes may retrieve different types of documents. Experimental results show that significant improvements can be obtained by combining the retrieval results form different properties of weighting schemes.

• Journal of the Korean Geographical Society
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• v.44 no.3
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• pp.301-322
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• 2009

This paper is an attempt to explore semiotic representations of subway space as the urban machine space of local mobility in terms of space, time and place. For this, the second section of the paper reviews the contours of the urban space of mobility in terms of 'machine space', 'non-place' and 'cognitive map'. The third section interprets the sings of 'spatial' and 'temporal' representations of subway space in Daegu, and suggests the implications of the semiotic representations. It is uncovered that various sign-scapes which coexist in the subway space in coordinated or contradictory ways product the space into multiple and complex techno-social spaces. That is, the spatio-temporal representations of the subway space form the space of 'non-place' on the one hand and the space of 'place' on the other hand, and involve the spatialization of 'memory' on the one hand and the spatialization of 'forgetting' on the other hand. Thus, the subway space should be regarded to be not only the space of 'mobility' which people move in and through, but also the space of 'identity' which has effects on the ways for them to see the machine space and its urban space.

• Journal of The Korean Association For Science Education
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• v.25 no.4
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• pp.533-540
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• 2005

This study investigated the effects of drawing and writing as methods to assist students in connecting and integrating multiple external representations provided in learning the particulate nature of matter. Seventh graders (N=224) at a coed middle school were assigned to a control group, a drawing group, and a writing group. The students were taught about "Boyle's Law" and "Charles's Law" for two class periods. Students observed macroscopic phenomena through experiments. After this observation, students in the control group learned the topic with both external visual and verbal representations simultaneously. Students in the drawing group drew their mental model from the external verbal representation provided, and then compared their drawing with external visual representation. Students in the writing group wrote their mental model from the external visual representation provided, and then compared their writing to the external verbal representation. The two-way ANCOVA results revealed that the scores of a conception test for the writing group were significantly higher than those for the control group. While the drawing group performed better than the control group, the difference is relatively smaller. There were no significant interactions between the instruction and spatial visualization ability in the scores of the conception test. Most students perceived the writing or drawing activities helpful in understanding the concepts, and a few students responded that the writing or drawing activity was interesting. Educational implications were discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.11a
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• pp.141-145
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• 1998

This paper CMOS full adder design method based on carry-propagation-free addition trees and a circuit technique, so called multiple-valued current-mode (MVCM) circuits. The carry-paopagation-free addition method uses a redundant digit sets called redundant positive-digit number representations. The carry-propagation-free addition is by three steps, and the adder can be designed directly and efficiently from the algorithm using MVCM circuit. We demonstrate the effectiveness of the proposed method through simulation(SPICE).

• Journal of Educational Research in Mathematics
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• v.23 no.2
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• pp.153-171
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• 2013

The purpose of this study is to investigate characteristics of students' problem solving processes based on their mathematical thinking styles and thus to provide implications for teachers regarding how to employ multiple representations. In order to analyze these characteristics, 202 university freshmen were recruited for a paper-and-pencil survey. The participants were divided into four groups on a mathematical-thinking-style basis. There were two students in each group with a total of eight students being interviewed. Results show that mathematical thinking styles are related to defining a mathematical concept, problem solving in relation to representation, and translating between mathematical representations. These results imply methods of utilizing multiple representations in learning and teaching mathematics by embodying Dienes' perceptual variability principle.

• Human Ecology Research
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• v.57 no.1
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• pp.41-50
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• 2019

This study investigated the significant difference in the influences of pregnant couples' attachment representation for parents of origin on their psychological symptoms according to groups. One hundred and eighty two pregnant couples answered the questionnaire. Data were analyzed by means of frequency, percentages, t-test. Pearson's correlation using SPSS ver. 21.0 and multiple group structural equation modeling using AMOS ver. 20.0. The findings are as follows. First, there were significant differences in attachment representations according to parents of origin and psychological symptoms between pregnant women and spouses. Second, there were negative influences of attachment representations to parents of origin on psychological symptoms for both the pregnant women group and their spouses group, respectively. Last, the negative effects of attachment representation for parents of origin on their psychological symptoms according to groups were significantly different; consequently, the impact on the spouses group was stronger than the pregnant women group. The results imply that policies to help pregnant couples reduce psychological symptoms should be provided. In addition, the unexpected result on the weaker impact of pregnant women's attachment representation for parents of origin on their psychological symptoms suggests it is better to consider other factors simultaneously (such as a romantic attachment to spouses) that might provide a moderating role. The study results are meaningful because it is the first to apply a statistically advanced method to analyze pregnant women and spouses in relation to parents of origin on their psychological symptoms.

• Honam Mathematical Journal
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• v.33 no.4
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• pp.441-452
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• 2011

The enormous success of the theory of hypergeometric series in a single variable has stimulated the development of a corresponding theory in two and more variables. A wide variety of investigations in the theory of several variable hypergeometric functions have been essentially motivated by the fact that solutions of many applied problems involving partial differential equations are obtainable with the help of such hypergeometric functions. Here, in this trend, we aim at presenting further decomposition formulas for Saran function $F_E$, which are used to give some integral representations of the function $F_E$. We also present a system of partial differential equations for the Saran function $F_E$.

• Korean Journal of Child Studies
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• v.17 no.1
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• pp.213-226
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• 1996

The aim of this study was to investigate the relationships of mothers' authoritative and authoritarian childrearing attitudes to their 5-year-old children's attachment representations and to teacher-rated social competence. The sample consisted of 69 mothers and their 5-year-old children from intact families. Children were interviewed to assess the quality of their attachment representations using Slough & Greenberg's(1990) version of the Separation Anxiety Test(SAT). Mothers were administered the Childrearing Practices Report Q-sort(Block, 1965) and filled out questionnaires regarding their childhood experiences, their marital relationship and their psychological well-being. In addition, teachers rated children's social competency in school settings using Kohn's(1972) Social Competence Scale. Hierarchical multiple regression showed that mothers' high scores on affective components of authoritative parenting and low scores on authoritarian attitudes are closely associated with children's secure attachment as well as teacher-rated social competence.

• Research in Mathematical Education
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• v.24 no.2
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• pp.111-130
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• 2021

This exploratory study focuses on analyzing three mathematics textbooks in Germany, Singapore and South Korea to reveal similarities and differences in their introductions of fraction concepts. Findings reveal that all three countries' textbooks introduce fraction concepts predominantly by using pictorial representations such as area models, but the introductions of multiple fraction constructs vary. The Singaporean and South Korean textbooks predominantly used a part-whole construct to introduce fractional concepts while the German textbook introduced various constructs sequentially in the first pages using several scenarios from different real-life situations. The findings were represented using visual representations, which we called textbook signatures. The textbook signatures provided configurations of the textbook features across the three countries. At the end of paper, we share insights and limitations about the use of textbook signatures in the research on textbook analysis.