• Journal of The Korean Association For Science Education
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• v.30 no.5
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• pp.621-635
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• 2010

Problem-based Learning (PBL) has been known as an effective strategy for dealing with various aspects of education such as the enhancement of students' motivation, interest in subjects, academic achievement, and cooperative abilities. However, PBL has not been widely implemented in secondary schools. The purpose of this study is to investigate secondary school teachers' perception of problem-based learning and their way of applying it. Data was collected through semi-structured interviews with nine secondary school teachers. Five of them had experience in implementing PBL, while four of them had interest in using PBL but had not yet had the experience. Different concepts were extracted and categorized. Nvivo 2.0 was used for analysis. The results were as follows: Changes in student attitude toward class, improvement on cooperation with others, self-regulated learning skills, and satisfaction from students' positive comments on PBL enabled teachers to become more enthusiastic and positive toward PBL. The stress of developing proper problems and the enormous amounts of time and efforts required in using PBL were shown as barriers for teachers in implementing PBL. However, some negative perspectives about PBL changed into positive after teachers experience PBL. By examining each teacher's way of implementing PBL, several teaching strategies suitable to their school systems were suggested.

• Journal of The Korean Association For Science Education
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• v.42 no.4
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• pp.439-448
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• 2022

The goal of this study is to develop a protocol that can be used for the purpose of developing inquiry class expertise in science teacher PLC, and to explore the possibility of field application of the developed protocol through test application with in-service teachers. PLC protocol for science inquiry class, consisting of five stages, was developed and applied sequentially to six participating teachers. In order to check the applicability of the protocol, the participating teachers wrote a reflection journal for each stage, and after the completion of the five-stage protocol, the participants' perceptions of the protocol were investigated through a group interview. The results are as follows: first, a protocol for enhancing science teachers' professionalism of inquiry classes was composed and developed in five stages such as (1) Revealing ideas about science inquiry classes, (2) Sharing science inquiry class experiences, (3) Looking together at students' scientific inquiry results, (4) Building literacy for science inquiry teaching, and (5) making science inquiry lesson plans. Second, the possibility of extensive application of the PLC protocol developed in this study was confirmed through the reflection journal and post-interview analysis results of the participants. According to the participating teachers, the protocol helped the systematic operation of PLC and teachers' participation. In addition, by experiencing the five-stage protocol, the teachers had an opportunity to reflect on their inquiry classes and ponder for improvement, and gained confidence in inquiry classes. Based on the research results, ways to develop and utilize the PLC protocol for science teachers were suggested.

• Journal of Science Education
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• v.46 no.1
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• pp.109-120
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• 2022

Fraction division is the content that is important but difficult to learn because it includes the process of finding a numerical expression in the real-world context, the process of making a context that matches a numerical expression, how to solve division, and the justification of standard algorithm. This study analyzes the word problems and problem solving methods about fraction division which elementary pre-service teachers represented. Pre-service teachers have more difficulty in making word problem where the dividend is less than the divisor and they also show typical errors in making the word problems. There were differences in the methods presented according to the contexts of division in problem solving. Through this study, it is necessary to rethink the teaching methods for fraction division instruction in the curriculum for pre-service teachers and analyze the formation process of 'knowledge for content and teaching' because of the differences in responses between grades.

• Journal of Agricultural Extension & Community Development
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• v.29 no.4
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• pp.225-250
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• 2022

This study aims to examine the effects of infant's social development forest experience activities through meta-analysis. The final nine studies(total of 165 in the experimental group and 159 in the control group) were selected as a method of systematic review. Meta-analysis on overall effect size estimation, chi-square test, significance analysis, publication bias analysis, and subgroup analysis was performed using the R program. The overall effect size of 9 studies was 1.59, indicating a large effect size. As a result of subgroup analysis of the sub-factors of sociality, autonomy showed the largest effect size at 1.47, the adjusted effect size of cooperation was 1.34, the effect size adjusted for peer interaction was 1.29, and the adjusted effect size for perspective-taking ability was 0.97. All were found to have a statistically significant effect. To analyze the moderating effect, a meta-regression analysis was conducted on the participation period(4, 5~6, 7~8weeks), the number of sessions(6~10, 11~15, 16~20), the frequency per week(1, 2, 5), and the participation time(40, 60, 90, 120, 150min), but there was no statistical difference. Although not statistically significant, the effect size was larger when the participation period was 4 weeks, the number of sessions was 16 to 20, the frequency was 2 times per week, and the participation time was 40 minutes. This results can be usefully utilized by policy makers and forest commentators related to the vitalization of forest education through forest experience activities.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.265-274
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• 2021

Outlier detection research in ocean data has traditionally been performed using statistical and distance-based machine learning algorithms. Recently, AI-based methods have received a lot of attention and so-called supervised learning methods that require classification information for data are mainly used. This supervised learning method requires a lot of time and costs because classification information (label) must be manually designated for all data required for learning. In this study, an autoencoder based on unsupervised learning was applied as an outlier detection to overcome this problem. For the experiment, two experiments were designed: one is univariate learning, in which only SST data was used among the observation data of Deokjeok Island and the other is multivariate learning, in which SST, air temperature, wind direction, wind speed, air pressure, and humidity were used. Period of data is 25 years from 1996 to 2020, and a pre-processing considering the characteristics of ocean data was applied to the data. An outlier detection of actual SST data was tried with a learned univariate and multivariate autoencoder. We tried to detect outliers in real SST data using trained univariate and multivariate autoencoders. To compare model performance, various outlier detection methods were applied to synthetic data with artificially inserted errors. As a result of quantitatively evaluating the performance of these methods, the multivariate/univariate accuracy was about 96%/91%, respectively, indicating that the multivariate autoencoder had better outlier detection performance. Outlier detection using an unsupervised learning-based autoencoder is expected to be used in various ways in that it can reduce subjective classification errors and cost and time required for data labeling.

• Journal of the Korean earth science society
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• v.22 no.5
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• pp.350-359
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• 2001

The purpose of this study is to develop theme-based integrated science unit by the interdisciplinary approach and to analyze it's effects on the science achievement and the attitude towards science learning. 'Interaction' and 'Stability' were selected as the integrated themes, and the main concept and subconcept in relation to the themes were extracted from the four areas of science, and the learning contents were constructed in the integrated ways. While the main concept have relevance to subconcept in the interaction, the main concept have little relevance to subconcept in the stability. Therefore, the stability was to fit with middle school integrated science theme, but the interaction was not. The theme-based integrated science units developed was implemented in middle school, and the results are follows. First, the science achievement of group of theme-based integrated science teaching is significantly higher than those of group of traditional teaching. Second, the scores of the test of attitude toward science learning of the group of theme-based integrated science teaching is significantly higher than those of group of traditional teaching. Third, the students' perception of theme-based integrated science teaching was positive. The students have participation, interest, motivation in theme-based integrated science teaching, and students have difficulty in learning theme-based integrated science teaching.

• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.3
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• pp.93-105
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• 2008

Semi-supervised learning uses a small amount of labeled data to predict labels of unlabeled data as well as to improve clustering performance, whereas unsupervised learning analyzes only unlabeled data for clustering purpose. We propose a new clustering-based semi-supervised learning method by reflecting the initial predicted labels of unlabeled data on the objective function. The initial prediction should be done in terms of a discrete probability distribution through a classification method using labeled data. As a result, clusters are formed and labels of unlabeled data are predicted according to the Information of labeled data in the same cluster. We evaluate and compare the performance of the proposed method in terms of classification errors through numerical experiments with blinded labeled data.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.5
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• pp.395-399
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• 2009

In this work, we describe the syntactic tag prediction system for Korean using the decision tree and CRFs. Generally they select features by their intuition. It depends on their prior knowledge. In this works, we combine features systematically using the decision tree. We also analyze errors and optimize features for the best performance. From the result of experiments, we can see that the proposed method is effective for the syntactic tag estimation and will be helpful for the syntactic analysis.

• Journal of The Korean Association of Information Education
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• v.15 no.4
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• pp.543-550
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• 2011

STEAM education is a topic-based curriculum to integrate the concepts into other subjects such as science, technology, engineering, art and mathematics in order to improve the students' interesting, understanding, integrated thinking and problem solving ability. In this paper, we designed STEAM curriculum in the form of Project-based Learning and developed the material for elementary students. We also developed the android-based application through searching for a utilization of IT simulation for enhancement the students' Project-based Learning effect.

• Hwankyungkyoyuk
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• v.24 no.3
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• pp.44-55
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• 2011

This study examined the effects of RSM (Regional Science education resource Map), developed and provided by Busan metropolitan city Office of Education, at high schools in Busan. Two group of students, who were in the same level of achievement as well as other environmental conditions, participated in this study. Twenty nine of students as an experimental group experienced outdoor activities utilizing RSM, while thirty of students as a control group did not participate in any outdoor activities. The results indicated that compared to the control group of students, the experimental group of students represented a significant improvement in students' environmental attitudes, local ecological interest and eco-friendly behavior. The teachers who guided outdoor activities utilizing RSM suggested that RSM needs to be further subdivided by seasons as well as local districts. They also suggested that RSM needs to be linked with a school curriculum.