• Ocean and Polar Research
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• v.41 no.4
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• pp.233-250
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• 2019

A re-assessment of the age structure of the population of the Antarctic icefish Pseudochaenichthys georgianus based on body length data covering the years 1976-2009 and including larvae and postlarvae collected in 1989 and 1990 allowed us to define age groups 0, I, and II as containing fish with respective body lengths of 6-9 cm, 15-27 cm and 27-39 cm. Age at maturity (first spawning) was found to occur in age group III at body lengths that have been falling from 50.1 cm in 1979 to 45.4 cm in 1992. Considering postlarvae together with adult fish, the v. Bertalanffy growth curve parameters were determined as L_∞ = 60.62 cm, k = 0.4, t₀ = 0.25. Although the reasons for a maturity at shorter body lengths is not fully understood a host of environmental factors like increasing water temperatures and possibly changes in currents, interspecific competition, food availability, etc. are likely to be involved. Global warming (and not primarily overfishing) is likely to have been responsible for the disappearance of larger fish in the surface waters of South Georgia since 1977, for virtually all commercial fishing stopped in the early 1990s. On the other hand, the appearance of numerous younger spawning individuals suggests that larvae do survive in the colder deeper water below 200 m. The biomass of Ps. georgianus oscillates with a 4-year periodicity in contrast to that of the coexisting icefish Chaenocephalus aceratus: the former with a lower biomass in warm years and a higher one in cold years. The biomass of the third species of icefish in the region, i.e. Champsocephalus gunnari, also oscillates, but with a longer periodicity than that involved in the biology of the other two and its biomass increases in contrast to the other two species. The result is that the biomass all three species considered together is rather stable.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.2
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• pp.87-92
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• 2010

Large pressure on the growing population has increased rapid change in the LULC (land use/land cover) patterns in the watershed area. Spatial distribution of LULC information and its changes are desirable for any effective planning, managing and monitoring activities. The aim of the study is to produce the 1,50,000 scaled LULC change map for the sub-watershed, Western Moyar, India using the multi-temporal satellite image dataset of IRS LISS III images for the year 1989, 1999, and 2002. About 9 classes are extracted using onscreen visual interpretation techniques for all the three years. The change detection analysis was performed using matrix method for period I (1989-1999) and period II (1999-2002). The study reveals that the changes noticed in period II (1999-2002) is comparatively more than period I (1989-1999), which is dynamic information to protect the sub-watershed area from the deterioration and paves the way to for the sustainable development.

• The Korean Journal of Applied Statistics
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• v.28 no.1
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• pp.9-21
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• 2015

The support vector machine has been successfully applied to various classification areas due to its flexibility and a high level of classification accuracy. However, when analyzing imbalanced data with uneven class sizes, the classification accuracy of SVM may drop significantly in predicting minority class because the SVM classifiers are undesirably biased toward the majority class. The weighted $L_2$-norm SVM was developed for the analysis of imbalanced data; however, it cannot identify irrelevant input variables due to the characteristics of the ridge penalty. Therefore, we propose the weighted $L_1$-norm SVM, which uses lasso penalty to select important input variables and weights to differentiate the misclassification of data points between classes. We demonstrate the satisfactory performance of the proposed method through simulation studies and a real data analysis.

• Journal of the Korea Society of Computer and Information
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• v.26 no.1
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• pp.27-35
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• 2021

In this paper, we propose a new stacking ensemble framework for deep learning models which reflects the distribution of label embeddings. Our ensemble framework consists of two phases: training the baseline deep learning classifier, and training the sub-classifiers based on the clustering results of label embeddings. Our framework aims to divide a multi-class classification problem into small sub-problems based on the clustering results. The clustering is conducted on the label embeddings obtained from the weight of the last layer of the baseline classifier. After clustering, sub-classifiers are constructed to classify the sub-classes in each cluster. From the experimental results, we found that the label embeddings well reflect the relationships between classification labels, and our ensemble framework can improve the classification performance on a CIFAR 100 dataset.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.38-52
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• 2016

This study analyzed effects of Action Learning approach on enhancing learning motivation and improving problem-solving capacity in NCS vocational competency classes of Polytechnic College. Targeted group is B Polytechnic College located in Chungnam, and 53 students in experimental group and 64 students in control group. analysis of data is descriptive statistic analysis and the multivariate analysis of variance (MANOVA) method to study sub factors of learning motivation and problem-solving ability. As a result, Action Learning approach has a great influence on connection, confidence, and satisfaction, among the sub factors of learning motivation. also figured that the approach has positive effects on problem clarifying, cause analysis, alternative developing, planning/practicing, and performance assessment, among the sub factors of problem-solving capacity. Moreover, Polytechnic College's NCS vocational competency classes are desirably required to adopt the approach of Action Learning for their educational method, as it fosters basic competencies, such as understanding of diverse perspectives, communicating, leadership, interpersonal relationship, self-development, coping with conflicts, operating meetings, to be learned while students are doing problem-solving activities under a team-working atmosphere.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.1
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• pp.57-75
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• 2011

This research aimed to explore the effects of collaborative writing activities in a mathematical context, specifically pertaining to areas such as numbers and operation, geometrical figure, and measurement in Mathematics: Level 5-b, on their mathematical achievement gain and disposition among Grade 5 students. To do this, out of a total of 62 students selected from two Grade 5 classes of J Elementary School in Dalseo-gu, Daegu City, who were found to be homogenic from the tests of math performance and dispositions, an experimental group(n=31) was designed and compared to a control group (n=31). Over a six week period from October to November in 2009, the experimental group was given collaborative writing lessons in math classes while the control group was given teacher-oriented regular lessons. The results were as follows. First, there was more or less considerable, though not significant, difference in overall mathematical achievement in the students experiencing collaborative writing activities when compared with the students in the control group. However, in terms of numbers and operation, a sub-category of mathematics, there was significant difference between the two groups. Second, the students experiencing collaborative writing activities were more positively affected in all sub-categories of mathematical disposition: confidence, flexibility, determination, curiosity, reflection, and value, than those in the control group. In summing up, the exposure of collaborative writing activities to mathematics learning was found to help students not only to have a concrete and proper grasp of the relevant problem solving process, which was observed from their mathematical achievement gain especially in the sphere of numbers and operation, but also to have their mathematical disposition set towards more positive direction, which was seen in all sub-categories of mathematical disposition measurement.

• Journal of Korean Society for Quality Management
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• v.39 no.1
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• pp.98-108
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• 2011

Clustering is an useful method to classify objects into subsets that have some meaning in the context of a particular problem and has been applied in variety of fields, customer relationship management, data mining, pattern recognition, and biotechnology etc. This paper addresses the unknown K clustering problems and presents a new approach based on a coevolutionary algorithm to solve it. Coevolutionary algorithms are known as very efficient tools to solve the integrated optimization problems with high degree of complexity compared to classical ones. The problem considered in this paper can be divided into two sub-problems; finding the number of clusters and classifying the data into these clusters. To apply to coevolutionary algorithm, the framework of algorithm and genetic elements suitable for the sub-problems are proposed. Also, a neighborhood-based evolutionary strategy is employed to maintain the population diversity. To analyze the proposed algorithm, the experiments are performed with various test-bed problems which are grouped into several classes. The experimental results confirm the effectiveness of the proposed algorithm.

• Journal of the Korean Society of Earth Science Education
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• v.4 no.2
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• pp.186-193
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• 2011

The aim of this study is to find out the effect of reading aloud science books on change of attitude toward the science, interest of instruction. Participants included 52 elementary school students. For this study, two classes were divided into experimental class and control class. The control class takes a regular instructions and the experimental class takes a reading aloud instructions. Two chapter were selected, 'Volcano and Rocks' and 'Family of the Sun', for this study. Students were treated for 12 hours. All the results were analyzed quantitatively and following conclusions were made. The students' scientific attitude in the experimental class were higher than those of students in the control class. However, according to statistical analysis, this result is meaningless. In the sub-parts, critical ability, cooperation and creativity were improved meaningfully. Instruction with reading aloud science books didn't show a meaningful difference in interest of instruction. However, in the sub-part, they showed meaningful improvement in attention and relevance.

• Korean Journal of Human Ecology
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• v.17 no.4
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• pp.601-608
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• 2008

The purpose of this study was to examine the effects of science activities using drawing on young children's scientific inquiry competences and scientific attitudes. The subjects of this research were a total of 40 young children at age 5 from two classes in G and C child care center which located in G city. The subjects were randomly assigned to two groups. The collected data were analyzed by t-test using SPSS program. The results of this study were as follow: First, experimental group which conducted the science activities using drawing showed significantly higher improvement in sub-factors of scientific inquiry competences, 'perseverance', 'creative', 'critical', and 'volunteering'. Second, experimental group which conducted the science activities using drawing showed significantly higher improvement in sub-factors of scientific attitudes, 'observing', 'measuring', and 'discussion'. Therefor, it might be concluded that science activities using drawing contributed to the development of scientific inquiry competences and scientific attitudes of young children.

• Korean Journal of Child Studies
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• v.31 no.1
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• pp.283-300
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• 2010

This paper investigated the effect of music and science integrated activities using instruments designed to test both musical concept and science inquiry process skills of children. The subjects of this study consisted of two classes of children aged 5 at H Kindergarten in Busan city. This study involved a class of 31 children using a music and science integrated curriculum as the experimental group and another class of 32 children using a traditional music and science curriculum as the control group. The integrated activities were used 12 times over a 6-week period. A test was taken to evaluate the effects of the integrated activities on the children's understanding on seven sub-categories of musical concepts and six sub-categories of science inquiry process skills. The results were that the experimental group showed significantly higher improvements in all subcategories of musical concept and science inquiry process skills, compared to the control group. Based on these results, we concluded that these integrated activities were effective in the development of both musical concepts and the science inquiry process skills of children.