• Journal of the Korean Wood Science and Technology
• /
• v.39 no.2
• /
• pp.140-147
• /
• 2011

The strength properties of wooden retaining wall which was made with pitch pine were evaluated. Wooden retaining wall was made with diameter 90 mm of pitch pine round posts treated with CUAZ-2 (Copper Azole). The length of the front stretcher of the retaining wall was 3,000 mm. The distance between the headers (the notched member) is 1,000 mm in center and is 900 mm in side. There were connections every 2,000 mm because actually the length of stretcher is limited in the retaining wall. The strength test was carried out according to connection type because the section between stretchers can act as a defect. A result of the strength test according to connection type confirms that connection does not act as defect because the strength of retaining wall in single stretcher is similar to that in the section between stretchers. The strength test of the wooden retaining wall was carried out in 5 types according to the condition of the base section. When the upper soil pressure was 9.8 kN/$m^2$, the maximum load of the retaining wall fixing the front foundation shows higher values than those of others. But the total deformation is lower in the retaining wall not to fix a base section than in that to fix a base section. It is thought that the retaining wall not to fix a base section shows low value because the deformation is distributed throughout the retaining wall and it is confirmed that the soil pressure affects supporting the structure because the deformation of the retaining wall under low pressure is 3~4 fold higher than those of others. The failure mode of the retaining wall is the overturning type because the high section is deformed. Mostly, the failure mode is the separation of the header in the notched section.

• Journal of the Korean Society of Earth Science Education
• /
• v.13 no.2
• /
• pp.175-185
• /
• 2020

The purpose of this study is to investigate the usages and problems of distance science learning and learner behavior analysis. This study established an Sixteen-weeks period of experimental treatment from March to June 2020, and the students who participated in the study formed a research group of 128 students in 2nd grade of their advanced classes who are attending the second semester of B university of education and taking courses in 'teaching research 1'. B university of education is singleness class that doesn't have compare group, so this study is constituted only study group. The results of the study were as follows. First, The students who took science learning remotely liked using the university's LMS system. Second, it was not efficient for the faculty member's scientific data presentation to operate smoothly in the online system. Third, it is necessary to set various educational platforms as a standardized platform. Looking at the pros and cons of various platforms may vary depending on the suitability of education, but if the LMS system, which is a professional teaching support method, is upgraded to meet the needs of learners, the satisfaction of higher instructors and learners will be higher.

• Journal of Digital Convergence
• /
• v.15 no.11
• /
• pp.67-76
• /
• 2017

To conduct research using small group learning with advanced technology in school, small group collaborative learning was conducted in virtual reality called Second Life for high school history class to verify the effects of the role of group members (leader, group member) in collaborative learning activities in this study. Two classes of the second grade of high school were selected randomly and 20 groups were also randomly assigned, and each group was consisted of three members (1 leader and two group members). Academic achievement and satisfaction with academic activities were used to verify the effect of the role as measurement tools, and collected quantitative data were tested by independent sample t. As a result, it was found that performing the role of leader in collaborative learning activities in virtual reality was effective in promoting enhancing students' academic achievement and increasing satisfaction level. Lastly, utilization and improvement of small group collaborative learning using virtual reality in the field of education were discussed.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.25 no.6
• /
• pp.1549-1560
• /
• 2015

For the past few years, personal information breach incidents, great and small, occurred constantly. Accordingly, the Personal Information Protection related Ordinances are enacted and amended persistently, and the information security products also keep advancing and developing in the same way. There are the certification systems such as Common Criteria Evaluation and Validation(CC) and Korea Cryptographic Module Validation Program(KCMVP) for the information security products. These are also strictly carried out. This paper analyzes and categorizes the 5 Personal Information Protection related Ordinances in the aspects of technical protection measures by using key words. Here are the 5 related ordinances; 'the Personal Information Protection Act', 'the Act on Promotion of Information and Communications Network Utilization and Information Protection, etc', 'the Act on the Protection, Use, Etc, of Location Information', 'the Use and Protection of Credit Information Act', and 'the Electronic Financial Transactions Act.' Moreover, this study analyzes the association between the technical protection measures in the 5 relevant laws and the information security products that are obtaining the CC Evaluation & Validation(CC) and the products that are now produced at KISIA's member companies.

• 전자공학회논문지 IE
• /
• v.43 no.1
• /
• pp.46-51
• /
• 2006

Recently, smart card system which is known as easy to portable and also safe from physical, electrical, and software attack is observed to manage information that becomes the target of security in safety. And java card graft upon java technology to smart card platform is having very good advantage with object-oriented techniques and also, java card have the open type OS that can show the same action in different hardware characteristic which allows various application programs. In this paper, we introduced independent execution characteristic of java platform because being set to each smart card was uncomfortable till now and we designed access control member card that allows several administrators in different access privilege by single card using java card. Several administrators can approach to various information of file type that is included on issued card to user by using different PIN. In the proposed method, confirmation of personal information, administration contents update, demand by contents, is possible by single card. At this moment, wish to do safer user certification that improve security limitation which is from PIN, used for user certification, and signature data. In the proposed method, as design and implementation of utilization technology of java card, biometrics, user certification which uses multi PIN, provide that more safety and conveniently.

• The Korean Journal of Air & Space Law and Policy
• /
• v.6
• /
• pp.267-283
• /
• 1994

Application of space technology in the field of communication and remote sensing becomes increasingly important in human life. Advancement of communications means shinks the size of our globe and that of remote sensing techniques improves the quality of human well-being. It is a world trent for each country to make its best effort in advancing its capabilities in these fields sometimes independently and other times jointly with other nations. Korea being no exception to this world trend is planning various starategies in application and development of space technologies. However, unfortunately, Korea is a new commer in this field. Statellite Technology Research Center (SaTReC) of Korea Advanced Institute of Science and Technology (KAIST) initiated to aquire satellite technology by sending its graduates abroad in 1989. As a result KITSAT-1 was launched in 1992 and KITSAT- 2 was launched in 1993 and they became Korea's first two satellites in orbits. Academic program including On-the Job-Training for Korean students at the University of Surrey, UK, is also an innovative scheme of mixing education and practical know-how for successful technology transfer, which resulted in a small but very capable and effective satellite experts group in Korea for self-propelled research and development in space activities. In this context, space development strategy should be considered in terms of the following factors; (1). Participation in international space activities as an active member to utilize international organization and to contribute to the peaceful use of space, (2). Development of national defence structure for independent activities in space, (3). Enhancement of manpower utilization for space development and promotion of national pride and (4). Education of youngsters for the extension of intellectual activities into the limitless space. In order to make very costly space development project most efficient, governmental level space development organization directed by the head of nation should be established and should manage all space development programs making full use of its all available resources including the advantage of the university based R&D capability.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.2
• /
• pp.437-444
• /
• 2017

The purpose of this study is to analyze the factors affecting the reverse mortgage utilization and satisfaction of the elderly. Based on the survey data of the reverse mortgage demand in 2016, we carried out empirical analysis using the binary logit model and the ordered logit model. First of all, as a result of the empirical analysis using the binary logit model, the determinants of using the reverse mortgage were age, region, assets, household member, children with financial help, and education level. As a result of the empirical analysis using the ordered logit model, the determinants of the satisfaction level of the reverse mortgage were estimated to be age, gender, and region. Based on the results of the empirical analysis, it is necessary to find a way to increase the participation rate of the reverse mortgage and to improve the satisfaction of the user.

• The Plant Pathology Journal
• /
• v.36 no.4
• /
• pp.314-322
• /
• 2020

Interplay between histone acetylation and deacetylation is one of the key components in epigenetic regulation of transcription. Here we report the requirement of MoHDA1-mediated histone deacetylation during asexual development and pathogenesis for the rice blast fungus, Magnaporthe oryzae. Structural similarity and phylogenetic analysis suggested that MoHDA1 is an ortholog of Saccharomyces cerevisiae Hda1, which is a representative member of class II histone deacetylases. Targeted deletion of MoHDA1 caused a little decrease in radial growth and large reduction in asexual sporulation. Comparison of acetylation levels for H3K9 and H3K14 showed that lack of MoHDA1 gene led to significant increase in H3K9 and H3K14 acetylation level, compared to the wild-type and complementation strain, confirming that it is a bona fide histone deacetylase. Expression analysis on some of the key genes involved in asexual reproduction under sporulation-promoting condition showed almost no differences among strains, except for MoCON6 gene, which was up-regulated more than 6-fold in the mutant than wild-type. Although the deletion mutant displayed little defects in germination and subsequent appressorium formation, the mutant was compromised in its ability to cause disease. Wound-inoculation showed that the mutant is impaired in invasive growth as well. We found that the mutant was defective in appressorium-mediated penetration of host, but did not lose the ability to grow on the media containing H₂O₂. Taken together, our data suggest that MoHDA1-dependent histone deacetylation is important for efficient asexual development and infection of host plants in M. oryzae.

• Solar Energy
• /
• v.18 no.1
• /
• pp.3-18
• /
• 1998

Since entered into force in 1994, United Nations Framework Convention on Climate Change(UNFCCC) would require all the member nations to adopt national programme for mitigating climate change and industrialized countries to undertake specific commitments of carbon dioxide emission reduction. Considering all the situation, it may be safe to assume that Korea would undertake such commitment early in the next century. Unfortunately, however, we are in the position that is very disadvantageous in preparing national strategies for carbon dioxide reduction mainly due to our rigid energy-intensive economic structure and poor geographic conditions. Solar energy is regarded as most available renewable energy resource in Korea and hence development of solar energy technology would serve as one of most effective alternatives for energy conservation and renewable energy utilization. In this regard, the presenting paper discuss the perspectives on solar energy development in relation to carbon dioxide reduction strategies. Such technologies of solar cell mass production and solar heating were considered to be most advantageous among many solar energy solutions discussed in this paper.

• Journal of the Korean housing association
• /
• v.26 no.5
• /
• pp.123-131
• /
• 2015

The purpose of this study is to suggest an optimum guide line of the unit plan design in national housing (less than $85m^2$ of exclusive floor area in a dwelling unit). The unit plan of apartment have been improved diversely for the residents, and the family members per household have been decreased for decades comparing with the past. In contrast, the living space per household has been increased steadily, it is because of the improvement of the living standard. The unit plan have been improved from 2-bay corridor access type and 2~3 and 4-bay staircase type. In december 2005, the balcony was permitted to be used as exclusive living area without the increase of the original living area by law. So the apartment residents have been able to use more spacious area exclusively in a dwelling unit. On the other hand, the legalization on permitting balcony area into a exclusive area resulted in a distorted wide and enlarged plan only for the business profit improvement lately. The living environment has been changed differently unlike at the time of the legislation of the national housing. The family member per household has been decreased and the related law and the institution has also been changed. Moreover It has passed 40 years since the legislation of national housing ($85m^2$). So, The size of national housing should be reviewed according to the current trend in terms of the decrease of household and the utilization of balcony area.