• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.5
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• pp.1071-1082
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• 2021

COVID-19 has changed a lot in our daily lives, where school classes and remote classes have been combined or converted to remote classes. Many students spent more time online, and cyberbullying, such as indiscriminate disclosure of their personal information, bullying of their classmates online, increased. In this paper, we propose an online education program as a countermeasure against cyberbullying. This program is designed for elementary, middle, and high school students and can also be used for informatics or ethics classes in the 2015 curriculum. The proposed program is divided into four major themes: 'Cyberbullying,' 'Information Security,' 'Cyber Crime,' and 'Language Violence,' and is divided into a total of ten topics according to its connection. It was organized to teach the topics evenly by grade. Also, the program's feasibility was verified by experts on the selection of educational contents and organizing of contents. In the future, it will be necessary to apply for this program and conduct an effectiveness analysis to measure whether it has effectively contributed to the decrease in cyberbullying rates among students and the improvement of coping skills.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.271-284
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• 2021

The purpose of this study is to explore the current status and effects of online discussion classes in universities. To this end, a survey was conducted on university students attending a total of four universities in Seoul and Gyeonggi Province to diagnose their perceptions of the operation of online discussion classes and their effects. The collected data were analyzed using frequency analysis, descriptive statistical analysis, cross-analysis, F-test, T-test, and Scheffe test by applying SPSS program. As a result of the study, first, it was found that 'non-real-time recorded lessons' and 'real-time interactive video lessons' were mainly conducted at universities after the COVID19 crisis. Second, in the online class method, 'real-time interactive video class' had a positive effect on 'debate class preference' and was found to be more meaningful. Third, college students recognized participation in online discussion classes as a foundation for expanding creative thinking skills, suggesting that strengthening through smooth communication and exchanges based on learners' sufficient cognitive processes on discussion methods and procedures is more helpful.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.113-118
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• 2010

Due to diverse soil-forming environments and different purposes of the soil classification, numerous soil classification systems have been developed worldwide. The World Reference Base for Soil Resources (WRB) and the Soil Taxonomy of the United States are well-known in Korea. However, the German Soil Systematics based on somewhat different principles from the two former systems is little-known. The objective of this paper is therefore to give a short overview of the principles of the German Soil Systematics. The German Soil Systematics consists of a six-level hierarchical structure which comprises soil divisions, soil classes, soil types, soil subtypes, soil varieties, and soil subvarieties. Soils in Germany are firstly classified into one of four soil divisions according to the soil moist regime: terrestrial soils, semi-terrestrial soils, semi-subhydric/subhydric soils, and peats. Terrestrial soils are subdivided into 13 soil classes based on the stage of soil formation and the horizon differentiation. Semi-terrestrial soils are differentiated into four classes regarding the source of soil moist: groundwater, freshwater, saltwater, and seaside. Semi-subhydric/subhydric soils are subdivided into two classes: semi-subhydric and subhydric soils. Peats are classified into two classes of natural and anthropogenic origins. Classes can be compared to orders of the U.S. Taxonomy. Classes are subdivided into 29 soil types with regard to soil forming-processes for terrestrial soils, into 17 types with regard to the soil formation for semi-terrestrial soils, into five types with regard to the content of organic matter for semi-subhydric/subhydric soils, and also into five types with regard to peat-forming processes for peats. The soil mapping units in Germany are types, which can be additionally subdivided into ca. 220 subtypes, several thousands of varieties and subvarieties using detailed nuances of morphologic features of soil profile. Soil types can be compared to great groups of the U.S. Taxonomy.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.601-605
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• 2005

Three lines of White Leghorn (WL) chickens (IWJ, IWG and IWC) maintained at Central Avian Research Institute, Izatnagar (UP), were used for chorioallantoic membrane (CAM) and liver tumour (LT) assay. Eleven-day-old embryos of each line were partitioned into three groups and inoculated with 0.2 ml of subgroup A, subgroup C and an equal mixture of subgroup A and C Rous sarcoma virus (RSV). Subgroup virus receptor on the cell surface membrane for subgroup A is coded for by tumour virus a (tva) locus and for subgroup C by tumour virus c (tvc) locus. The random association of the genes at the tva and tvc loci in IWJ and IWC line was assessed and the $x^2$-values for phenotypic classes were found to be significant, indicating the linkage between the tva and tvc loci. The linkage value was estimated to be 0.09 on pooled sex and pooled line basis. On the basis of four subclass tumour phenotypes a 4-allele model was proposed for tva locus having $a^{s1}$, $a^{s2}$, $a^{r1}$ and $a^{r2}$ alleles and the frequencies were calculated as 0.47, 0.13, 0.13 and 0.27 for IWJ line, 0.31, 0.33, 0.14 and 0.22 for IWG line and 0.44, 0.11, 0.21 and 0.24 for IWC line, respectively. Similarly, for tvc locus the frequencies of four alleles i.e. $c^{s1}$, $c^{s2}$, $c^{r1}$ and $c^{r2}$ were calculated as 0.42, 0.20, 0.21 and 0.17 for IWJ line, 0.42, 0.17, 0.27 and 0.14 for IWG line and 0.30, 0.21, 0.16 and 0.33 for IWC line, respectively. The $x^2$-values for all classes of observations were not significant (p>0.05), indicating a good fit to the 4-allele model for the occurrence of 4-subclass tumour phenotypes for tva and tvc loci. On the basis of the 2-allele model both tva and tvc locus carries three genotypes each. But, on the basis of the 4-allele model tva and tvc locus carries 10 genotypes each. The interaction between A-resistance and C-resistance (both CAM and LT death) was ascertained by taking the 10 genotypes of tva locus and 3 genotypes of tvc locus by pooling the lines and partitioning the observations into 3 classes. The $x^2$-values for the genotypic classes of CAM (-) LT (+) and CAM (-) LT (-) phenotypes to mixed virus (A+C) infection were found to be highly significant (p<0.01), indicating increased resistance, which indicates the joint segregation of $a^r$ and $c^r$ genes, suggesting the existence of close linkage between the tva and tvc loci. Therefore, an indirect selection approach using subgroup C viruses can be employed to generate stocks resistant to subgroup A LLV, obviating contamination with the most common agent causing LL in field condition.

• Journal of Korean Elementary Science Education
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• v.43 no.4
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• pp.554-564
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• 2024

This study investigated the mediating effect of maintained situational interest on the relationship between situational interest and individual interest among elementary school students during optical illusion classes. The subjects of this study were 67 fifth-grade students (27 boys and 40 girls) from an elementary school in a metropolitan city. Four optical illusion classes were conducted at four-day intervals. Immediately after each class, the students' triggered situational interest levels, maintained situational interest levels, and emerging individual interest levels were assessed and analyzed. The analysis indicated that all nine interest variables measured across three of the classes showed positive and significant correlations. In addition, at the same time point, triggered situational interest directly affected the development of maintained situational interest and emerging individual interest, or indirectly affected the development of emerging individual interest through maintained situational interest as a mediator. In particular, in every class, triggered and maintained situational interest influenced emerging individual interest. However, triggered situational interest exhibited a greater influence on the development of individual interest compared to maintained situational interest. Based on exploring the relationship between phases of interest development as a key factor in learning motivation, implications for science education were discussed.

• Journal of Science Education
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• v.43 no.3
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• pp.300-317
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• 2019

This study aims to find how storytelling classes using fairy tales related to science museum exhibits have an effect on positive experience about science. For this study, the theoretical background and preceding studies on the relevance of science education and literature were collected and based on the characteristics of assimilation and the educational value of assimilation, naturally connected to the exhibits in relation to their own life, so that individuals could explore science even out-of-school. Four types of activities were developed by linking four fairy tales mentioned in elementary school textbooks to the G science museum exhibits. Seven elementary school teachers verified the validity of the activity materials. Classes through the developed activity materials were conducted four times in a row, one and a half hours at every turn for 10 students. A positive experience about science test was conducted on the students in a study to confirm that this activity has caused significant changes in science academic emotion among sub-domains of positive experience about science. In order to find the factors that affected the science academic emotion, we interviewed the students in the study and their parents. The results of this study show that the use of fairy tales related to science museum exhibits has led to a significant change in science academic emotion by reducing the burden of learning through the exhibition experience at the science museum, which creates scientific curiosity and recognizes them as a playground.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.778-787
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• 2022

This study was performed to obtain basic data in relation to instructional design and teaching strategy according to instructional modes. For the purpose of this study, participants evaluated the qualities of the instructions they attended and the results of the evaluation were compared according to 4 instructional modes(content class, online real-time class, online and face-to-face mixed class, and face-to-face class). As a result of the study, there were differences in the evaluation regarding the appropriateness of the course according to instructional modes. That is, satisfaction with lecture progress was lower in the online real-time classes than in content classes, mixed classes, and face-to-face classes. As a result of the descriptive lecture evaluation analysis, in the content class type, students answered that they were satisfied with the easily understandable and interesting explanations. In the case of the online real-time classes, it was found that they were satisfied with thorough preparation and effective communication. In the mixed class type, they said they were satisfied with the systematic class and passionate lecture, and in the face-to-face classes, the pleasure of interaction and the enthusiasm of the instructor were identified as the main reasons for satisfaction. It was analyzed that the satisfaction characteristic commonly derived from the four class types was the enthusiasm of the instructor. The results of this study are expected to provide implications for instructional design and teaching strategy establishment according to each instructional mode.

• Bulletin of the Korean Mathematical Society
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• v.34 no.3
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• pp.447-457
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• 1997

Let A be a $C^*$-algebra and $A^**$ its enveloping von Neumann algebra. Pedersen and Akemann developed four concepts of lower semicontinuity for elements of $A^**$. Later, Brown suggested using only three classes: strongly lsc, middle lsc, and weakly lsc. In this paper, we generalize the concept of weak semicontinuity [1, 3] to the case of unbounded operators affiliated with $A^**$. Also we consider the generalized version of the conditions of the Brown's theorem [3, Proposition 2.2 & 3.27] for unbounded operators.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06c
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• pp.205-209
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• 1994

This paper presents a variable rate speech coding method with phonetic segmentation, called for PSVXC. Multiple access techniques that require efficient encoding of speech to achieve capacity improvements are currently emerging in the cellular telephone system. The variable rate speech coder have the reduced average data rate required to transmit conversational speech. Each frame of active speech is classified into one of four phonetic classes. A distinct coding configuration and bit-rate is applied to each category. And also a split vector quantization is used to accurately quantize the LPC information using LSP parameters.

• Bulletin of the Korean Mathematical Society
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• v.49 no.2
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• pp.373-379
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• 2012

In this paper, we nd the inclusion relation among four categories of posets, i.e., ideal-homogeneous, tower-homogeneous, quasi-complement-preserved, and complement-preserved posets.