• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.34-39
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• 2021

This study investigated the anti-cancer effects of Salicornia herbacea L. fractions in human ovarian cancer cells (OVCAR-3). S. herbacea powder was extracted with 95% EtOH and sequentially fractionated with hexane, dichloromethane (DCM), ethyl acetate, butanol, and H2O. Further, the growth inhibitory effects of the six fractions were determined using the MTS assay. The DCM fraction dramatically decreased cell viability. Similarly, the cell cycle was arrested at the subG1 phase in DCM-treated cells. To confirm apoptosis, the cells were stained with annexin V/FITC-PI solution. Total, early, and late apoptotic cells were significantly increased in the DCM fraction. The mRNA expression of Bcl-2 was reduced, whereas the pro-apoptotic factors Bax and Bak were increased in DCM fraction-treated cells. These results indicated that the DCM fraction in S. herbacea exhibited strong apoptotic effects through the p53-dependent signaling pathway.

• Journal of the Korean Society for Library and Information Science
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• v.55 no.3
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• pp.17-56
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• 2021

The purpose of this study was to focus on the discussion on the introduction of the librarian qualification certification system, which is being discussed as a way to raise the qualification level of experts as a system for expert certification and to raise social awareness as experts. First, the introduction of the library and information science curriculum certification system was discussed. Second, the issues to be considered when introducing the certification system were discussed. In other words, we analyzed in depth what matters we should consider when discussing the certification system. Third, the components of domestic and overseas certification systems were investigated and analyzed, and measures applicable to the librarian qualification certification system were discussed. Fourth, it was proposed to introduce a certification system for the Department of Library and Information Science. Also, based on the results of the analysis, it was suggested what could be a problem when introducing the certification system to the Department of Library and Information Science in Korea and what contents should be reviewed. In this study, in order to propose the introduction of the librarian qualification certification system, the purpose of the librarian qualification certification system, the certification criteria, the certification institution, and the contrast between the university and the Department of Library and Information Science were also dealt with in detail.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.33-40
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• 2021

Automatic Speech Recognition(ASR) is a technology that analyzes human speech sound into speech signals and then automatically converts them into character strings that can be understandable by human. Speech recognition technology has evolved from the basic level of recognizing a single word to the advanced level of recognizing sentences consisting of multiple words. In real-time voice conversation, the high recognition rate improves the convenience of natural information delivery and expands the scope of voice-based applications. On the other hand, with the active application of speech recognition technology, concerns about related cyber attacks and threats are also increasing. According to the existing studies, researches on the technology development itself, such as the design of the Automatic Speaker Verification(ASV) technique and improvement of accuracy, are being actively conducted. However, there are not many analysis studies of attacks and threats in depth and variety. In this study, we propose a cyber attack model that bypasses voice authentication by simply manipulating voice frequency and voice speed for AI voice recognition service equipped with automated identification technology and analyze cyber threats by conducting extensive experiments on the automated identification system of commercial smartphones. Through this, we intend to inform the seriousness of the related cyber threats and raise interests in research on effective countermeasures.

• Journal of Korea Entertainment Industry Association
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• v.14 no.5
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• pp.15-26
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• 2020

Local product is the key driver of regional economic growth. Despite abundant attention - there remains to examine about sustainable growth of local products. While previous studies have focused on local product brand and tourism effects, we need to know more about other way or mind-set that upgrade local product quality in local circumstances. This research topic's goal is to provide an academic implication to discuss sustainable growth and local product developments in Gyeongju bread and waxy barley bread from succession and entrepreneurship view with practical lesson for fostering local products. In-depth case study conducted within ancient capital Gyeongju bread and waxy barley bread provided combined evidence that craftsmanship and entrepreneurship is vital to the sustainable growth of local bread. Our study suggests that how succession is deployed serves as a key engine for the craftsmanship and entrepreneurial mind of local product business ownership.

• Journal of the Korean Geotechnical Society
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• v.37 no.11
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• pp.61-69
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• 2021

In this study, scale down model bridge piers were fabricated and non-destructive experiments conducted with an impact load to determine scours in the ground adjacent to the bridge piers using the natural frequency of the bridge piers. Three scale-model bridge piers with different heights were fabricated, and they penetrated the ground at a depth of 0.35 m. The scours around the bridge piers were simulated as a side scour and foundation scour. The experiments were conducted in 13 steps, in which scouring around the model bridge piers was performed in 0.05 m excavation units. To derive the natural frequency, the impact load was measured with three accelerometers attached to the model bridge piers. The impact load was applied with an impact hammer, and the top of the model bridge pier was struck perpendicularly to the bridge axis. The natural frequency according to the scour progress was calculated with a fast Fourier transform. The results demonstrated that the natural frequency of each bridge pier tended to decrease with scour progress. The natural frequency also decreased with increasing pier height. With scour progress, a side scour occurred at 70% or higher of the initial natural frequency, and a foundation scour occurred at less than 70%.

• Journal of the Korean Society of Earth Science Education
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• v.16 no.1
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• pp.72-86
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• 2023

The purpose of this study is to examine what epistemological beliefs pre-service teachers have about science depending on the situation, and to explore in-depth changes in epistemological beliefs through disciplinary reading. For this purpose, 77 essays written by pre-service elementary school teachers after reading Feynman's 'the meaning of it all' were analyzed using an inductive analysis method. As a result of the study, the epistemological beliefs of pre-service teachers were divided into two situations: 'science in subject learning' and 'science in daily life', and the epistemological beliefs formed in the 'science handled by scientists' situation were analyzed after reading the book. Each situation was divided into sub-categories of 'Impression of Knowledge', 'Source of Knowledge', 'Justification of Knowledge', 'Variability of Knowledge', 'Structure of Knowledge', and 'Value of Knowledge Acquisition' to reveal differences in sophisticated beliefs and naive belief levels. As a result, it was derived that Feynman's science lecture influenced pre-service teachers in terms of establishing new perspectives and recontextualizing existing epistemological beliefs. This study is meaningful in that pre-service teachers' scientific epistemological beliefs may vary depending on the situation, and that the scope and depth of epistemological beliefs may be expanded to include scientists' beliefs in science through disciplinary reading.

• Journal of Korean Elementary Science Education
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• v.42 no.1
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• pp.127-148
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• 2023

In this study, we used an analysis of the literature on socio-scientific issues (SSI) classes to examine domestic SSI class research and to determine the characteristics of SSI class research for each subject. A search for papers related to SSI classes published in Korea Citation Index-listed journals and candidate journals of the Korea Research Foundation found 95 relevant papers, which were then categorized according to participants and topics. Studies with both pre-service and experienced teachers attempted to investigate SSI-related perceptions. Studies of pre-service teachers tended to examine the level and development pattern of argumentation or to analyze decision-making characteristics and informal reasoning. Studies of experienced teachers tended to analyze instructional expertise in SSI teaching activities, focusing on teachers with substantial SSI teaching experience. Middle and high school students-related studies examined student decision-making and reasoning processes in SSI learning activities, developed SSI class programs, and analyzed educational effects. Examining the characteristics of SSI classes for elementary school students was difficult because few such studies have been published. However, the characteristics that elementary school students show in SSI learning situations could be inferred. A plan to revitalize SSI classes in the elementary science education field from the perspective of teacher education and class research is suggested.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2C
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• pp.83-94
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• 2008

In this study an effective stress analysis was performed to evaluate liquefaction potential and ground settlement for reclaimed sites. The effective stress model can simulate the stiffness degradation due to excess pore pressure and resulting ground deformation. It is applicable to a wide range of strain. An equivalent linear analysis suitable for low strain levels was also carried out to compare the effective stress analysis. Shear stress ratio calculated from an equivalent linear analysis was used to determine SPT blow count to prevent liquefaction. Depending on the magnitude of potential earthquake and fine contents, the SPT blow count was converted into an equivalent cone tip resistance. It was compared with the measured cone tip resistance. The measured elastic shear wave velocity and cone tip resistance from two reclaimed sites in Incheon were used to perform liquefaction analyses. Two liquefaction evaluation methods showed similar liquefaction potential which was evaluated continuously. The predicted excess pore pressure ratio of upper 20 m was between 40% and 70%. The calculated post-shaking settlement caused by excess pore pressure dissipation was less than 10 cm.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.4
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• pp.295-306
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• 2010

Contrary to an intact rock, the jointed rock mass shows strain-dependent deformation characteristics (elastic modulus and damping ratio). The maximum elastic modulus of a rock mass can be obtained from an elastic wave-based exploration in a small strain level and applied to seismic analyses. However, the assessment and application of the non-linear characteristics of rock masses in a small to medium strain level ($10^{-4}{\sim}0.5%$) have not been carried out yet. A non-linear dynamic analysis module is newly developed for FLAC3D to simulate strain-dependent shear modulus degradation and damping ratio amplification characteristics. The developed module is verified by analyzing the change of the Ricker wave propagation. Strain-dependent non-linear characteristics are obtained from disks of cored samples using a rock mass dynamic testing apparatus which can evaluate wave propagation characteristics in a jointed rock column. Using the experimental results and the developed non-linear dynamic module, seismic analyses are performed for the intersection of a shaft and an inclined tunnel. The numerical results show that vertical and horizontal displacements of non-linear analyses are larger than those of linear analyses. Also, non-linear analyses induce bigger bending compressive stresses acting on the lining. The bending compressive stress concentrates at the intersection part. The fundamental understanding of a strain-dependent jointed rock mass behavior is achieved in this study and the analytical procedure suggested can be effectively applied to field designs and analyses.

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.156-168
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• 2024

This study was carried out to provide fundamental data for forest land and the environment by investigating the vegetation structure and soil properties of forest land where Sarcodon impricatus are present. The study area was divided into the Quercus mongolica community, dominated by Q. mongolica and the Quercus variabilis community, a mixed forest with Q. variabilis, Q. mongolica and Pinus densiflora. Also, Calamagrostis arundinacea in the former community and Disporum smilacinum and Carex siderosticta in the latter community showed significant levels as indicator species. Both communities showed a strong correlation between available phosphate and pH, sand, and clay, and the high organic matter content and slightly acidic pH of the soil are believed to be related to the development of S. impricatus. The species appearing at the lower layer continue to dominate because the species appearing at the upper layer have secured realized niches. The site was distributed in a relatively humid place in a north-east direction, and soil was developed with a thin litter layer and low rock exposure. In the selected S. impricatus growing areas, vegetation centered on highly adaptable species to disturbance or external interference was developed. Therefore, it is expected to be used as fundamental data to promote the occurrence of S. impricatus during artificial cultivation, as it is possible to identify the stand where S. impricatus occurs indirectly.