• Tunnel and Underground Space
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• v.32 no.6
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• pp.568-585
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• 2022

In the present study, we proposed a numerical method for simulating thermally induced fracture slip using a grain-based distinct element model (GBDEM). As a part of DECOVALEX-2023, the thermo-mechanical loading test on a saw-cut rock fracture conducted at the Korea Institute of Civil Engineering and Building Technology was simulated. In the numerical model, the rock sample including a saw-cut fracture was represented as a group of random Voronoi polyhedra. Then, the coupled thermo-mechanical behavior of grains and their interfaces was calculated using 3DEC. The key concerns focused on the temperature evolution, thermally induced principal stress increment, and fracture normal and shear displacements under thermo-mechanical loading. The comparisons between laboratory experimental results and the numerical results revealed that the numerical model reasonably captured the heat transfer and heat loss characteristics of the rock specimen, the horizontal stress increment due to constrained displacement, and the progressive shear failure of the fracture. However, the onset of the fracture slip and the magnitudes of stress increment and fracture displacement showed discrepancies between the numerical and experimental results. We expect the numerical model to be enhanced by continuing collaboration and interaction with other research teams of DECOVALEX-2023 Task G and validated in further study.

• Journal of Internet Computing and Services
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• v.24 no.6
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• pp.171-180
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• 2023

Hydrogen energy technology is gaining importance in the era of the Fourth Industrial Revolution, offering military advantages when applied to military vehicles due to its characteristics such as reduced greenhouse gas emissions, noise, and low vibration. Korea's military has initiated the Army Tiger 4.0 plan, focusing on hydrogen application, downsizing, and AI-based smart features. The Ministry of National Defense plans to collaborate with the Ministry of Environment to expand hydrogen charging stations nationwide, anticipating increased deployment of military hydrogen vehicles. However, considering the Jet Fire and VCE(Vapor Cloud Explosion) nature of hydrogen, ensuring safety during installation is crucial. Current military guidelines specify a minimum safety distance of 2m from adjacent buildings for charging stations. Scientific methods have been employed to quantitatively assess the accident damage range of hydrogen, proposing a minimum safety distance beyond the affected area.

• Communications of Mathematical Education
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• v.20 no.2 s.26
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• pp.295-326
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• 2006

Despite the importance of mathematics education, many students in high school have lost their interests and felt difficulties and they don't have 'mathematical' experience with meanings attached because of the entrance examination. This paper attempted to resolve these problems and find the teaching-method with which students can study by themselves with more confidence. Nowadays students' use of Internet is very popular. After develop 'the development of mathematical power' program based on mathematics history, history, science, the application of problems in real world, and self-evaluation, I made students repeat them after making teaching lessons in classroom as moving pictures. Through this processes, I attempted to develop the Self-Directed Learning' ability by making public education substantial. First of all I analyzed the actual conditions on 'Self-Directed Learning' ability in mathematics subject, the conditions of seeing and hearing in Internet learning program, and students' and their parents' interests in Internet education. By analyzing the records, I observed the significance of the introducing mathematics history in mathematics subject in early stager, cooperative-learning, leveled-learning, self-directed learning, and Internet learning. Actually in aspect of applying 'the development of mathematical power' program, at first I made up the educational conditions to fix the program, collected the teaching materials, established the system of teaching-learning model, developed materials for the learning applying Internet mail and instruments of classroom, and carried out instruction to establish and practice mathematics learning plan. Then I applied the teaching-learning model of leveled cooperation and presentation loaming and at the same time constructed and used the leveled learning materials of complementary, average, and advanced process and instructed to watch teaching moving pictures through Internet mail and in the classroom. After that I observed how effective this program was through the interest arid attitude toward mathematics subject, learning accomplishment, and the change of self-directed learning. Finally, I wrote the conclusion and suggestion on the preparation of conditions fur the students' voluntary participation in mathematics learning and the project and application on 'the development of mathematical power' program and repeated learning with the materials of moving pictures in classroom.

• Journal of the Korean Society for Library and Information Science
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• v.30 no.1
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• pp.89-123
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• 1996

The world has moved from the Cold War between the east and the west and moved toward the age without idealogy. It places emphasis on economic benefit and welfare of its own nation as its main point With this world trend, in order to sam the competitiveness and the reconciliation of the divided nation the north and the south Korea should be united. Once the north and the south are united, information society will be altered with the huge flow of the civilization. At the same time, the issue of how to operate library policies and system, in which effective acquisition, manipulation, accumulation, and dissemination of information un would be very important. From this point of view, the following conclusions are obtained in this study. Firstly, when building a national library preparing for the national unification. it is essential to introduce 1) the concept of policy and system for information society and 2) that of policy and system which has national-culture as its focus. Secondly, it is essential to prepare the cooperative-structure between libraries prior to the national unification. This kind of cooperation should gradually expand to an extent that allows actual benefits such as building union catalog, inter-library loan system, resource sharing, standardized cataloging rules, and exchange of dissertation... etc. Thirdly, developing the library policies and systems for the national unification must be based on the concept of the mutual cooperation as inter-dependent model rather than on the concept of the incorporation-absorption as a dominant model. The next point the principles of the followings in preparing the library policies should be considered: 1) free-competition, 2) revolution of consciousness through the social education, 3) independence and love for humanity, 4) scientific or reasonable thinking, 5) job responsibility, 6) democratic citizenship, 7) mind far collective life, 8) spirit of public interest 9) globalization In addition, the model of the library systems preparing for thenational unification should include the followings : 1) uniformity of library system and its authority, 2) establishment of research institutes for library policy and system, 3) exchange of library establishment and information resources, 4) building library networks, 5) establishment of education systems for the library and information science and enhancement of its quality, 6) modernizing and developing information technology and its transfer. Finally, the libraries in the north and the south has different concepts, goals, information resources, and the different ways of using them. Considering the practical aspects of the libraries and the reasons for their existence, they must structure the mutual cooperative system so as to minimize the shock when confronting the social changes, so-called the national unification.

• Korean Journal of Heritage: History & Science
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• v.49 no.3
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• pp.270-285
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• 2016

Various opinions and discussions have been actively in progress which are connected with cultural heritage since 'Sustainable Development Goals, SDGs' was announced by UN Sustainable Development Summit 2015 as Post-2015 Development Agenda. Apart from SDGs, conservation of cultural heritage itself stands on the basis of sustainability that originality, characteristic, diversity of cultural heritage should be permanently preserved. From that point of view, it is necessary to understand practical ODA for cultural heritage, far from theoretical approaches and policies. This paper is intended to look into the domestic and overseas situation related to ODA of Asian cultural heritage and the mentioned problems, future plans and challenges. First, the background and concepts about ODA were described and then ODA projects which have been carried out by Japan and China as typical ODA countries for Southeast Asia were introduced. ODA of cultural heritage in Korea has relatively recently started for restoration work for historic sites of Laos and Cambodia and its scale and performance do not come to much yet. Therefore, to develop ODA of cultural heritage, there are suggestions as in the followings. First, it is necessary to have a long-term master plan of ODA projects for sustainability of cultural heritage. Second, based on the view from the long-term perspective, the selection and focus for ODA partner countries should be considered, avoiding short-term projects aiming at a number of countries. Not widespread existing projects by other countries, but the model of Korean ODA for cultural heritage only Korea can conduct should be prepared. The next thing is connection with sustainability, and ultimately the conservation of cultural heritage should result in benefit to the natives by giving an impetus to economy as well as fostering tourism of local areas. To accomplish that connection, educational training and building capacity are suggested as the most suitable alternatives. Cultural heritage of each country reflects its indigenous originality and characteristics, therefore, the restoration work should be conducted by people in each country as the best way. From this point of view, ACPCS held by National Research Institute of Cultural Heritage will take a role of a specialized training program in Korean way. Lastly, establishment of a control tower for ODA in Korea is necessary. JCIC(Japan Consortium for International Cooperation in Cultural Heritage), which was set up in Japan for sharing information, establishment of cooperation system and prevention of overlapped projects will be an example we can take into consideration.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.20-30
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• 2003

This study was carried out to examine the e-Business status of Korea Forest Product Industries and to propose the development. The use level of e-Business in korea forest product industries have stayed in internal company information network integration stages. But lots of companies located in the insufficient of e-Business models, the lack of qualified staffs, and the shortage of e-Business operating technology and implementation. As the result of this study, the followings must be considered; 1. For the promotion of e-Business use, it is needed to maintain price competitiveness, quality competitiveness, and market correspondence capacity. 2. For the settlement of e-Business models, it is important to connect information network among cooperation companies as like forest products standardize, common database, and standard electronic catalogue. Also, it needed developing program to strengthen the competitiveness of forest product industries, expanding to outsourcing and affiliated companies.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.2
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• pp.101-113
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• 2018

This paper investigates the relationship between external search strategy and radical innovation performance. As the discrepancies that can exist among the varying sources of external knowledge is overlooked, the existing literature on the effect of external search strategy on radical innovation performance remains inconclusive. This study aims to reconcile such mixed findings by recognizing that external knowledge can be distinctive depending on the environment in which its source is embedded in; specifically, this paper examines the relationship between external search strategy and radical innovation performance by distinguishing external search from 'market' and 'non-market' relationships. We test our hypotheses with a sample of 431 firms from the manufacturing industries from the 2010 STEPI survey. Our empirical findings suggest that external search strategy from market relationships positively influences radical innovation performance, while the influence of external search strategy from non-market relationships is found to be not significant. Our research suggests that in order to improve radical innovation performance, firms must be able to maintain a cooperative relationship with other actors connected with market relationships and to effectively exploit the market knowledge obtained from these actors.

• School Mathematics
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• v.15 no.1
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• pp.159-177
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• 2013

This study is a case study of STEAM education. We have developed teaching and learning materials, suggested teaching method, and analysed the result for exploring the potential and effect of STEAM. The content of this study is based on the history of mathematics. Science (S) is related to the 24 divisions of the year, the height of the sun, the movement of heavenly bodies. Technology (T) is related to the exploration with graphic calculators. Engineering (E) is related to design sundial and research on the design principles. Art (A) is related to literature review about mathematical history, the understanding of the value of the mathematics. Mathematics (M) is related to the trigonometric functions. We have considered that Project-Based Learning is proper teaching and learning for STEAM education, we have designed the STEAM PBL and analysed the results focused on the developing integrative knowledge, mathematical attitude including mathematical value, the competencies of 21 century. The result of this study is as follows. We find that STEAM education activates students' collaboration, communication skills and improves representation and critical thinking skills. Also STEAM education makes positive changes of students' mathematical attitudes including the values of the mathematics.

• Journal of Life Science
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• v.31 no.9
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• pp.862-872
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• 2021

Recent studies on synthesis of metallic nanomaterials such as silver (Ag), gold (Au), platinum (Pt), cerium (Ce), zinc (Zn), and copper (Cu) nanoparticles (NPs) using plants and microbes are attracted researchers for their wide range of applications in the field of biomedical sciences. The plant contains abundant of bioactive contents such as flavonoids, alkaloids, saponins, steroids tannins and nutritionals components. Similarly, microbes produce bioactive metabolites, proteins and secretes valuable chemicals such as color pigments, antibiotics, and acids. Recently reported, biogenic synthesis of NPs in non-hazardous way and are promising candidates for biomedical applications such as antibacterial, antifungal, anti-cell proliferative and anti-plasmodia activity. All those activities are dose dependent, along with their shape and size also matters on potential of NPs. Microbes and plants are great source of metabolites, those useful in biomedical field, such metabolites or chemicals involved in synthesis of NPs in an ecofriendly way. NPs synthesized using microbes or plant materials are reveals more non-toxic, facile, and cost-effective compare to chemically synthesized NPs. In present review we are focusing on NPs synthesis using biological agents such as microbes (bacteria, fungi and algae) and plant, characterization using different techniques and their antibacterial applications on pathogenic Gram-positive and Gram-negative organisms.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.9
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• pp.1-16
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• 2019

This study was carried out to develop a physics education program for foreign students of university in Korea to improve their ability to major in the field and to prevent them from becoming dropout. The subjects of the study are five Chinese students attending a natural science and engineering college. Prior to the development of the physics education program, the researchers developed basic physics textbooks for the foreign students and questionaries for diagnosis and summative evaluation, and utilized them to apply a total of seven classes. After the application of the classes, the results of the student's diagnosis and summative evaluation, the teacher's diaries, the observer's diaries, and the transcripts were analyzed by triangulation method. In addition, Nvivo12 was used for the analysis of the teacher's and observer's diaries to help with qualitative analysis. The results of the study are as follows: First, the oder and contents of physics education program for students of the natural science and engineering college were presented in detail, and basic physics textbooks and tools for diagnosis and summative assessment were developed. Second, as a result of the analysis of the diagnosis and summative assessment results of the program, the students' basic physics achievement improved by an average of 40 points due to the application of the developed program. Third, as a result of the application of the program using Nvivo12, meaningful node and actual cases were extracted. There were 10 types of nodes created such as understanding of the students, teaching method, rate of the participation, level differences, language problems, relevance to majors, curriculum and methods of education in the country of origin, cooperative learning, and interest inducement. The researcher provided suggestions on physics education methods for students of science and engineering colleges in Korea based on the related cases.