• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.832-847
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• 2007

The purpose of the study was to analyze and interpret parent-child dyadic discourses in depth with emphases on the ZPD system in a museum, an informal learning setting. Second graders and their parents from Seoul and its environs were voluntarily participated in the study. Data were collected from the museum documents, the photos of exhibits, and the video recordings of dyadic discourses at and between exhibits. The documents and the photos were analyzed to investigate what the topics, medium and goals of the exhibits were. The video recordings were all transcribed and analyzed to understand what and how they talked to each other through the lens of the ZPD system; situation definition, intersubjectivity, and semiotic mediation, The results of the study consisted of two parts. First, it showed that parent-child dyadic discourses were categorized in four: (1) within the actual developmental level; (2) in the zone of proximal development; (3) toward the potential developmental level; and (4) out of developmental level. The most common categories were the dyadic discourses within the actual developmental level and in the zone of proxima I development. Second, the representative cases in each categories were described and interpreted to understand the nature of parent-child dyadic discourses. It can be concluded that we gained some important understandings of an intrinsic attribute of parent-child discourses in a museum, an informal learning setting. Based on the results of the study, it can be suggested that museums make efforts to cultivate the affordance of exhibit environment to promote visitor's learning.

• Journal of the Korean School Mathematics Society
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• v.12 no.4
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• pp.493-508
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• 2009

This study investigates aspects of the zone of proximal development (ZPD), the distance between the actual development and the potential development. Out of 18 university students taking a geometry course, two students with the same actual developmental level in the van Hiele model in the pre-test and post-test were interviewed for measuring their potential developmental level. Based on the communicational approach to cognition, the characteristics of the two interviewees' discourse on 3D reflective symmetry were identified. There were considerable differences between the two interviewees in terms of their potential developmental level. Methodological implications for how to investigate students' ZPD in mathematics education research were addressed.

• The Mathematical Education
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• v.44 no.1 s.108
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• pp.41-65
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• 2005

In this paper we make an experiment in order to test whether the teaching method with the Zone of Proximal Development (ZPD) developed by Vygotsky can be more effective and well applied in the middle school pratces. Based on this investigation, we conclude that ZPD help to efficiently enhance the study of students, in particular, the inferior student group. Moreover, if we divide the student by more precise stoups, the ZPD will be more effective on teaching and learning in middle school. Lastly, we arrive at the conclusion that a continuous teaching with ZPD will improve the student attitude positively in solving mathematical problem even it does not appeared apparently on this test.

• Journal of the Korean Geographical Society
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• v.37 no.4
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• pp.425-441
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• 2002

This study focused on the geographical concepts development and its zone of proximal development(ZPD) through the collaborative interaction. Among the conclusions are: 1) Students who have higher cognitive structure represented the Creator Seoul Metropolitan Area(GSMA) as a geographical concepts, not as a spontaneous concepts. The concepts is developed from concrete facts, subordinate element concept to basic element concept hierarchically. The most difficult concept that the learner should internalize was represented as the basic element concept. 2) Although ZPD of GSMA is individualized, it could be divided into 9 types. The ZPD was developed differently according to the qualitative differences how much more and how systematically represented the geographical concepts. The characteristics shown in this development procedure was that there was a quality change based on quantity extensive.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.4
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• pp.371-377
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• 2021

This research proposes the best combination of tropospheric delay models for Korean Positioning System (KPS). The overall results are based on real observation data of Japanese Quasi-Zenith satellite system (QZSS), whose constellation is similar to the proposed constellation of KPS. The tropospheric delay models are constructed as the combinations of three types of zenith path delay (ZPD) models and four types of mapping functions (MFs). Two sets of International GNSS Service (IGS) stations with the same receiver are considered. Comparison of observation residuals reveals that the ZPD models are more influential to the measurement model rather than MFs, and that the best tropospheric delay model is the combination of GPT3 with 5 degrees grid and Vienna Mapping Function 1 (VMF1). While the bias of observation residual depends on the receivers, it still remains to be further analyzed.

• Journal of Educational Research in Mathematics
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• v.12 no.4
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• pp.473-491
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• 2002

This article analyzes mathematics education from dialectical materialism acknowledging the objectivity of knowledge. The thesis that knowledge is objective advances to the recognition that knowledge will be internalized, and an idea of zone of proximal development(ZPD) is established as a practice program of internalization. The lower side of ZPD, i.e. the early stage of internalization takes imitation in a large portion. And in the process of internalization the mediational means play an important role. Hereupon the role of mathematics teacher, the object of imitation, stands out significantly. In this article, treating the contents of study as follows, I make manifest that teaching and learning in mathematics classroom are united dialectically: I hope to findout the method of teaching-learning to mathematical knowledge from the point of view that mathematical knowledge is objective; I look into how analysis into units, as the analytical method of Vygotsky, has been developed from the side of mathematical teaching-learning; I discuss the significance of mediational means to play a key role in attaining the internalization in connection with ZPD and re-illuminate imitation. Based on them, I propose how the role of mathematics teachers, and the principle of organization to mathematics textbook should be.

• Journal of Fisheries and Marine Sciences Education
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• v.16 no.1
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• pp.35-49
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• 2004

The purpose of this study is to examine the effects of scaffolding instruction on motivated learning strategies and academic achievement. Subjects of this study were 96 middle school first grade students in Busan, who were randomly assigned to two experimental group and one control group. The one experimental group had received scaffolding instruction by teacher, and the other experimental group had received scaffolding instruction by the interaction of peers. Control group were given traditional lessons only by the method of lecture. Students were given English Academic Achievement Test, Motivated Strategies of Learning Questionnaire. T test and ANOVA were used to analyze date. The results of this study showed that scaffolding instruction by ZPD turned out to have a positive influence on motivated learning strategies and academic achievement.

• Journal of Advanced Navigation Technology
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• v.20 no.1
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• pp.23-28
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• 2016

In this paper, we verified accuracy of the satellite based augmentation system (SBAS) tropospheric delay correction model for the Korean region. We employed the precise data of the tropospheric zenith path delay (ZPD) which is provided by the international GNSS service (IGS). In addition, we compared the verification results with that of the Saastamoinen model and the Hopfield model. Consequently, the bias residual error of the SBAS tropospheric delay correction model is about 50 mm, whereas the Saastamoinen model and the Hopfield model are more accurate. This residual error by the tropospheric delay model can affect the SBAS user position accuracy, but there is no problem in SBAS accuracy requirement. If we modified the meteorological parameters for SBAS tropospheric model to appropriate in Korean weather environment, we can provide better SBAS service to the Korean user.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.666-672
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• 2004

Granular media filtration is used almost universally as the last particle removal process in conventional water treatment plants. Therefore, superb particle removal efficiency is needed during this process to ensure a high quality of drinking water. However, every particle can not be removed during granular media filtration. Besides the pattern of particle attachment is different depending on physicochemical aspects of particles and suspension. Filtration experiments were performed in a laboratory-scale filter using spherical glass beads with a diameter of 0.55 mm as collectors. A single type of particle suspension (Min-U-Sil 5) and pH control was used to destabilize particles. The operating conditions were similar to those of standard media filtration practice: a filtration velocity of 5 m/h. More favorable particles, i.e., particles with smaller surface charge, were well attached to the collectors especially during the early stage of filtration. This selective attachment of the lower charged particles caused the zeta potential distribution (ZPD) of the effluent to move to a more negative range. On the other hand, the ZPD of the effluent did not keep moving from less negative to more negative during the later stages of filtration, and this result was thought to be caused by two reasons: ripening effects and the detachment of flocs.

• Journal of the Korean Geographical Society
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• v.36 no.2
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• pp.161-176
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• 2001

This study is to find a theoretical basis for the effective teaching-learning of the geographical concept through comparing two cognitive pshychological perspectives: Piaget's cognitive development stage theory and Vygotsky's theory with higher mectal function and zone of proximal development(ZPD). Piaget't theory of cognitive development stage has been empirically proved in the spatial concept development and provided a basis for geographical educational psychology. In spite of this contribution, it has its own limitation in that students cannot learn cocepts beyond their cognitive development stage. On the other hand, Vygotsky supposed that concept development has been done by teaching-learning. This study suggests that Vygotsky's theory gives more comprehensive thoretical basis for its effective teaching-learning about the geographical concept development.