• Korean Journal of Poultry Science
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• v.26 no.2
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• pp.109-118
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• 1999

Hen's eggs have been regarded as one of the best animal bioreactors to produce biologically active peptides originated from many organisms including human. Despite the last decade's efforts to produce transgenic chicken for any commercial purposes, the results so far reported are very disappointing, indicating that hen's eggs are very difficult to crack for transgenesis. Comparatively large female gamete with enormous amount of yolk may be one of the major obstacles in achieving a similar feat to those of other vertebrate species including mouse, sheep, fish and frog. The delay or less efficiency evidenced may instruct to try an alternative way of gens transfer into chicken egg. Sperm-mediated gene transfer is one of them, and may require a great deal of understanding of mechanisms involved in early fertilization and embryonic development. In other animals where the technique was successful, basic mechanisms have been well studied and established only by painstaking efforts for decades. This paper discusses the accumulated knowledge on early fertilization mechanism in the chicken and how can this information be utilitzed to find the alternative gene transfer in making transgenic chicken.

• Molecules and Cells
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• v.44 no.5
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• pp.328-334
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• 2021

The advent of the major histocompatibility complex (MHC) multimer technology has led to a breakthrough in the quantification and analysis of antigen-specific T cells. In particular, this technology has dramatically advanced the measurement and analysis of CD8 T cells and is being applied more widely. In addition, the scope of application of MHC multimer technology is gradually expanding to other T cells such as CD4 T cells, natural killer T cells, and mucosal-associated invariant T cells. MHC multimer technology acts by complementing the T-cell receptor-MHC/peptide complex affinity, which is relatively low compared to antigen-antibody affinity, through a multivalent interaction. The application of MHC multimer technology has expanded to include various functions such as quantification and analysis of antigen-specific T cells, cell sorting, depletion, stimulation to replace antigen-presenting cells, and single-cell classification through DNA barcodes. This review aims to provide the latest knowledge of MHC multimer technology, which is constantly evolving, broaden understanding of this technology, and promote its widespread use.

• Proceedings of the Safety Management and Science Conference
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• 2010.11a
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• pp.113-129
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• 2010

Proper pre-safety training is one of core mandatory in order to reduce injuries at the construction fields. In this study, we investigate the employee's opinions of safety training, safety recognition, the actual conditions of safety through survey. As a result of study, incident factors are roughly divided into technical factor, managerial factor, and educational factor. We confirmed that the educational factor led by deficiency of safety awareness and knowledge was the major factor. It needs to be resettled or revised properly to match with the incident trends and the safety training curriculum should also be improved and drastically revised with special quality. The managerial workers' safety recognition is lower than the site ones regarding the correct understanding of the importance of the training.. It suggest that the education method and system in construction fields might have fundamental problems.

• STI Policy Review
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• v.4 no.2
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• pp.1-18
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• 2013

As the value and role of intellectual property increases in our knowledge-based economy, countries around the world have exerted various efforts to secure, utilize, and protect their intellectual property. The present study diagnoses the level of IP infrastructure of major OECD countries and analyzes their characteristics and impact. According to the diagnosis, the US, Switzerland, and Germany form a leading group followed by the mid-level countries of Korea, Ireland, Australia, and France, with Spain and Italy in the bottom group. In contrast to Korea's competitiveness in S&T and R&D infrastructures, its competitiveness in IP infrastructure is lower than the OECD average. This is thought to be due to Korea's IP infrastructure being hastily formed under the influence of international pressures rather than having been gradually built up by internal needs. A TFP analysis of the impact of IP infrastructure on economic growth shows IP infrastructure positively influences economic growth. Though this analysis is limited due to inability to secure sufficient data and indicators, it is a useful guide for understanding the nature and key characteristics of IP infrastructure.

• Journal of the Korean Society for Library and Information Science
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• v.51 no.2
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• pp.255-279
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• 2017

In a qualitative approach, this study investigated users' perceptions associated with their satisfactions in the process of using the scholarly resource search functions of the academic version of the NAVER search engine. For this study, the data was collected from a group of undergraduate students, who conducted academic information searches in the field of own major disciplinary areas, using the Web portal. Based on the data, students' satisfactions and dissatisfactions along with the reasons of their perceptions were analyzed. The results presented users' perceptions in various evaluation criteria based on the three major domains: system interfaces, retrieval mechanisms and search results. Based on the results, the study proposed the following suggestions: 1) the enhancements of the system interfaces and HELP guidances based the limited user knowledge on basic system terminologies 2) the improvements of the retrieval mechanisms associated with understanding the contexts of the search terms presented by users 3) the necessity of the user education due to the insufficient user knowledge of the retrieval mechanisms and the search functions.

• Journal of The Korean Association For Science Education
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• v.25 no.6
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• pp.650-657
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• 2005

The study purported to develop STS education course material at the university level in order to enhance science literacy and understanding of the relationships among science, technology and society. A developed STS course was provided to 265 freshmen and sophomore students, majoring in the Humanities and the Social Sciences, the Natural Sciences and Engineering, and Fine Arts. Students participated in the survey examining changes in students' attitudes toward and perspectives on STS before and after the implementation. Ten questionnaires were selected from VOSTS for the survey. One additional questionnaire asked the students to elaborate their opinions on the need for a STS education course. The responses to the survey were analyzed according to types of questions and students' majors. As result, the developed STS course significantly increased students' science literacy. Among the participants, 97.7% responded that there is a need for STS education and provided reasons for such need. These results imply that there is a definite need for a STS class at the university level. According to the analyses of responses, there were different responses depending on the students' major. These differences imply that the major, academic background, level of interest in science, and knowledge of science of the students affect their perceptions on identifying the need for a STS education course.

• Journal of Korean language education
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• v.29 no.3
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• pp.1-24
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• 2018

The purpose of this study was to analyze teachers' questions in the actual general Korean classroom for academic purposes and identify types of questions. The results of the question analysis by type identified 713 teacher's questions in total: echoic questions made up 41% while epistemic questions were 19.3% and expended question turned out to make up 39.7%. 'Comprehension check questions' were 29%, which was a major part in the echoic question. 'Referential questions' were a major part in the epistemic question. Also, the research discovered that 'knowledge integration' questions held the largest majority in expended questions. Since the teacher-led lecture was often conducted in the problem-presentation stage, the percentage of Echoic question was high; and moreover, the problem-solving stage promoted to come up with more improved solutions of the problem. In the outcome and presentation stage, it was discovered that the questions aimed to check understanding of content in the subject and expand thoughts. Therefore, it is necessary to develop strategies for teacher's questions by phase and further conduct research on the interaction between learners and teacher's questions in the future.

• Educational Technology International
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• v.10 no.1
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• pp.41-57
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• 2009

Cognitive presence, a sense of "being there" cognitively, has recently been considered as an important indicator for students' engagement in e-learning. There is, however, no widely accepted scale to measure the level of cognitive presence since most studies have put their effort to set and clarify the conceptual framework with qualitative methodology. This study reviewed existing theories on cognitive presence and related fields extensively and developed a new self-report scale for measuring the conceived level of cognitive presence. The reliability and validity of the scale was tested against 723 undergraduate students in two consecutive studies, 418 in the preliminary and 305 in the follow-up study. Three major constructs to measure the perceived level of cognitive presence were: 1) clear understanding, 2) knowledge construction, and 3) learning management. This paper reports the final results of the two independent studies.

• Journal of the Korean earth science society
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• v.32 no.7
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• pp.798-808
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• 2011

The purpose of this study was to explore middle school students' perceptions about earth systems in order to implement the 2009 revised national science curriculum effectively. A total of 1219 students participated in the survey and asked to determine their basic understandings about earth systems, self-reported knowledge level, and perceived significance level of the 23 earth systems concepts (contents). In relation to students' basic understandings about earth system, approximately 67% students reported that they didn't know about the term of the earth system. Atmosphere and hydrosphere were highly perceived as major component of earth system. However, cryoshere was perceived to be least familiar by the subjects. The findings also showed that students' self-reported knowledge level and significance level about major ESU#4, #5, #6 related concepts (contents) were significantly different by gender. Most of male students were more knowledgeable and perceived more significant than female students. Regarding the difference of the perceived significance level by grade, 10 out of 23 concepts were significantly different. Some implications for implementing the revised curriculum and school fields were discussed.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.441-447
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• 2005

The present study is aimed at understanding the flow physics associated with a safety valve applied to LNG ship engines. One-dimensional gasdynamic analyses and axisymmetric, compressible Navier-Stokes computations have been carried out to provide a qualitative and quantitative knowledge base for an effective design of the safety valve. Gasdynamic forces and thrust coefficients are obtained regarding a change in chamber pressure and distance between the nozzle exit and valve sheet which are major parameters to offer a variation in the flow feature. The present results show that the control of the passage area between the nozzle exit and valve sheet can attenuate the strength of shockwave generated in front of the valve sheet, which causes harm to stable system operation.