• Journal of the Korean Society of Earth Science Education
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• v.14 no.2
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• pp.193-201
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• 2021

This study is a study of factors affecting pre-service teachers' learning immersion in online science classes. The results of a survey on the responses of 88 pre-primary teachers to online science classes were interpreted. In online science class, independent variables were set as ease, usefulness, and social presence, and dependent variables were set as learning immersion. Online science classes were conducted based on the university's LMS system. The results of the study were interpreted by regression analysis for t-test, correlation between factors, and multicollinearity test in pre-post-responses of pre-service teachers for ease, usefulness, and social presence. The results of this study are as follows. First, there was a significant effect in the before-and-after tests of factors in the online science class. Second, the correlation coefficient between factors in online science class is .306 for sense of community and mutual support and concentration at the significance level of .01, and .354 for learning immersion and open communication, indicating that there is a correlation. Third, considering the effective results of the pre-post test of each factor in the online science class, it cannot be interpreted that a particular factor had an effect, but it is interpreted that learning was immersed in ease, usefulness, and a sense of social presence.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.610-621
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• 2021

The soil creep, primarily caused by earthquakes and torrential rainfall events, has widely occurred across the country. The Korea Forest Service attempted to quantify the soil creep susceptible areas using a discriminant value table to prevent or mitigate casualties and/or property damages in advance. With the advent of advanced computer technologies, machine learning-based classification models have been employed for managing mountainous disasters, such as landslides and debris flows. This study aims to quantify the soil creep susceptibility using several classifiers, namely the k-Nearest Neighbor (k-NN), Naive Bayes (NB), Random Forest (RF), and Support Vector Machine (SVM) models. To develop the classification models, we downscaled 292 data from 4,618 field survey data. About 70% of the selected data were used for training, with the remaining 30% used for model testing. The developed models have the classification accuracy of 0.727 for k-NN, 0.750 for NB, 0.807 for RF, and 0.750 for SVM against test datasets representing 30% of the total data. Furthermore, we estimated Cohen's Kappa index as 0.534, 0.580, 0.673, and 0.585, with AUC values of 0.872, 0.912, 0.943, and 0.834, respectively. The machine learning-based classifications for soil creep susceptibility were RF, NB, SVM, and k-NN in that order. Our findings indicate that the machine learning classifiers can provide valuable information in establishing and implementing natural disaster management plans in mountainous areas.

• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.360-375
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• 2019

This paper tries to study the ecosystem after constructing the network of the continuing transactions associated with distribution industry with the data of more than 50 thousands firms provided by the Korean enterprise data (KED) for 2015. After applying the clustering method, one of social network analysis tools, we find the firms in the network grouped into 732 clusters occupying about 80% of whole distribution industry sales in KED data. The firms in a cluster have most of their transactions with other firms in the cluster. But the clusters have smaller firm numbers in the cluster and sales portion of the biggest firms in the industry than the case of the manufacturing industry. The Input-output analysis for the biggest distribution firms show that the small and medium size enterprise(SME)s have very high sale dependency on a main firm in some clusters. This fact implies more efficient fair transaction policies within the clusters. And small number of big distribution firms have very high rear production linkage effects on SMEs or on the 10th or 31th group with high portion of SME employment. They should be considered important in the SME growth and employment policies.

• International Area Studies Review
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• v.21 no.4
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• pp.223-245
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• 2017

This study is examined interaction between carbon market with stock market using a multivariate GARCH(DCC) model. Carbon market is EU ETS EUA price, stock market is the iron and cement stock price which has relatively energy intensive and massive carbon emissions sector in the industrial sector. It also analyzed changes in the correlation between the markets through an analysis of correlation coefficients. Moreover, it checked whether there was marketability expansion(or expansion of carbon emissions reduction) through the analysis above. As a result of empirical tests, it showed that the price spillover effect was insignificant. In addition, it represented that there was a weak correlation between the two markets since the volatility spillover effect disappeared in the second phase by an external shock(a financial crisis). Moreover, it was revealed that there were no significant changes although there was a weak upward trend in terms of the correlation between the carbon market and the stock market. This implies that emission rights could not expand marketability to financial market as a commodity(or did not play its natural role of the reduction of carbon emission).

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.83-98
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• 2021

This study identified the influence of employees' hybrid start-up intention (intention to start a business while maintaining a job) on the employees' self-determination motivation (intrinsic motivation, extrinsic motivation) and prior knowledge through the Model of Goal-directed Behavior (MGB). We used a PLS-SEM called SmartPLS 3.0 for 126 valid samples collected by judgement extraction for office workers throughout June 13, 2020 to July 3, 2020, and empirically evaluated the measurement model (internal consistency reliability, convergent and discriminant validity) and the structural model (multicollinearity, determination coefficient, effect size, predictive relevance, etc.). Only the intrinsic motivation for realizing the hybrid start-up goal of office workers had a significant impact on the hybrid start-up attitude and subjective norms, and the prior knowledge of hybrid start-up had a significant impact on the hybrid start-up desire and the hybrid start-up intention. In order to induce hybrid start-ups for workers with unstable employment, we need systems and programs that can inspire employees with intrinsic motivation and knowledge about hybrid start-up, so follow-up researches are necessary to analyze about government systems and consulting support that can promote hybrid start-up.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.819-825
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• 2020

This study explored the possibility of psychological testing as a way to proactively support underachieving students. Among the four-year college students that participated in our study, 43 students who participated in the academic warning support program for the second semester of 2019 and 30 students who had no academic warning experience used the data from the study personality type test. For data analysis, technical statistics, t-test, and correlation analysis were performed using jambi 1.1.9.0 to obtain the Pearson correlation. Studies have shown that the two classes of students differ in their learning behavior patterns. A student with a bachelor's degree warning scored high in the rest of the class, except for rebelliousness, perfection, mixed thoughts, hard work, satisfaction, single-mindedness and type satisfaction. This can be seen as a factor in the psychological conflict, such as the discrepancy between what one likes and what one studies, and lack of available support. It has been confirmed that psychology, emotional parts and economic support are needed as well as learning skills. In addition, this study is expected to provide basic data for proper preemptive support in schools, such as the prevention of dropouts and counseling programs.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.857-862
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• 2021

Recently, rapid climate change has had a significant impact on the bee ecosystem. The decrease in the number of bees and the change in the flowering period have a huge impact on the harvesting of beekeepers. Accordingly, attention is focused on smart beekeeping, which introduces IoT technology to beekeeping. According to the characteristics of beekeeping, it is impossible to continuously observe the beehive in the hive with the naked eye, and the condition of the hive is mostly dependent on knowledge from experience. Although a system that can measure partly through sensors such as temperature/humidity change inside the hive and measurement of the amount of CO2 is applied, there is no research on measuring the movement path and amount of movement of bees inside the beehive. Part of the migration of honeybees inside the hive can provide basic information to predict the most important cleavage time in beekeeping. In this study, we propose a device that detects the movement path of bees and measures and records data entering and exiting the hive in real time. The device proposed in this study was developed according to the honeycomb standard of the existing beehive so that beekeeping farms could use it. The development method used a photodetector that can detect the movement of bees to configure 16 movement paths and to detect the movement of bees in real time. If the measured honeybee movement status is utilized, the problem of directly observing the colony with the naked eye in order not to miss the swarming time can be solved.

• Journal of Korean Elementary Science Education
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• v.40 no.4
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• pp.520-544
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• 2021

This study aims to develop a scientific creativity test for exploring the relationship between elementary students' creative process and product. For this, the researcher reviewed the literatures of scientific creativity and developed the items based on the constructs of creative process and product. After a review conducted by nine science education specialists, a pilot test, and additional revision and supplementation of observation test, the test, consisting of two sets-"animals" and "plants"-was finally conducted on 105 fifth-grade students. The test results were analyzed by using statistical analysis software. WinSteps, SPSS, and AMOS. The main findings from this study are as follows. First, when it comes to scientific creativity, creative process consists of science knowledge, inquiry skills, and creative thinking skills (divergent, convergent, and associative thinking skills). Creative product in science is a new and scientifically useful idea realized in a certain form. Second, observation, which was selected as a representative inquiry skill in this research, should not be related to creative thinking skills. Third, among the rest of the items, usefulness had the lowest averages, as it was, perhaps, difficult to satisfy the teachers' criteria for the scientific validity and usefulness. Fourth, the Spearman correlation coefficients between the items of "animals" and "plants" to find out the parallel-form reliability were significant, except for the item of originality. Fifth, the test was satisfactory with regard to the three aspects of construct validity-convergent, discriminant, and nomological. This study concludes by discussing the usefulness of this test, which has the possibility of exploring the relationship between creative process and product and of playing a role as an authentic evaluation tool in school.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.24-31
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• 2021

The soundproof tunnels have been generally designed with H-beam girders, and the high weight of H-beam may cause the excessive design of the substructure. To solve this problem, this paper proposes a new soundproof tunnel girder design composed of pipes and discontinuous plates. First, the structural behavior of the straight girder according to the design parameters was examined through finite element analysis. The arrangement and shape of the plates were determined as the design parameter, to obtain the optimal design of girder. After then, the structural behavior and buckling stability of the arched girder were subsequently evaluated. As a result of the parameter analysis, it was confirmed that the axial force acting on the girder increased and the moment decreased as the ratio of unsupported sections decreased or the number of supporting plates increased. The stress concentration on the pipe member was relieved by increasing the long axis length of the elliptical plate. Arched girder analysis showed that the structural efficiency increase as the long axis of elliptical plate increase. As a result of the buckling evaluation, the buckling threshold load of the three connected girders was about 3.7 times higher than the design load. Consequently, it was confirmed that the proposed soundproof tunnel structure design satisfies both light weight and structural safety.

• Journal of Life Science
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• v.32 no.9
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• pp.690-697
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• 2022

This study was conducted to analyze genome of red sea cucumber and to use it as basic data for the development of genetic markers for red sea cucumber. Microsatellite marker analysis of Ulleungdo_normal and Ulleungdo_native red sea cucumbers revealed that dinucleotide simple sequence repeats (SSRs) had the highest ratio, at 81.3~81.4%, and the number of the detected SSRs tended to decrease as the number of repeating sequence units in SSRs increased. In general, microsatellites with between 5 and 10 iterations were most common. As the size of the SSR repeating sequence units increased, the SSR iterations gradually decreased. The di-, tri-, and tetra-nucleotides in SSRs were detected in the highest numbers as (AT)₅, (AAT)₅, and (AAAT)₅, respectively. (CG) and (CCG) had very low frequencies compared to the numbers of other repeating SSR units. The numbers of di-and tri-nucleotide repeats were up to 35 and 32, respectively, and then increased discontinuously up to 44 and 43 repeats, respectively. Tetra-, penta-, and hexa-nucleotides in SSRs occurred in numbers up to 25, 21 and 14, respectively. This analysis of red sea cucumber indicated that it maintains its own repetition sequence and repetition number; therefore, we suggest that using it as basic data for molecular marker will be possible in future research.