• Title/Summary/Keyword: Natural Phenomena

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Biodegradable Inorganic-Organic Composite Artificial Bone Substitute -in vitro biocompatibility evaluation by cell culture- (유기질과 무기질 복합체를 이용한 체내흡수형 인공골재료에 관한 연구 -세포배양에 의한 생체적합성 평가-)

  • Ahn, Sue-Jin;Kim, Yo-Sook;Lee, Choon-Ki;Suh, Hwal
    • Journal of Biomedical Engineering Research
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    • v.16 no.3
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    • pp.331-336
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    • 1995
  • A composite material was produced as an artificial bone substitute which is gradually degrAded and replaced by the regenerated natural bones after implantation. To detect the effect of the material on the cell's activity, the composite specimens were placed in MEMs and incubated at $37^{\circ}C$ for one week. Human uterus cervical cancer origin HeLa 3 cells and mouse subcutaneous origin L929 cells were cul- tured in the specimen dissolved MEMs for 5 days to investigate cytotoxicity via cell growth rates. ${Na_2}^{51}CrO_4$ solution was added to the media, to label the HeLa 53 cells, and the released amount of $^{51}Cr$ was measured by a $\gamma$-counter. On the cell growth investigation, no significant cytotoxic phenomena were revealed in both HeLa S3 and L929 cell cultures. On the released 51CR from the incubated HeLa 53 cells, no significant cell degeneration was observed from the composite embedded MEMs.

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Theoretical Investigation on Implications of 'Community of Inquiry' for Science Education: Toward 'Community of Inquiry in Science Classroom' ('탐구공동체'의 과학 교육적 함의에 대한 이론적 고찰 : '과학 교실 탐구공동체'를 향해서)

  • Joung, Yong Jae
    • Journal of The Korean Association For Science Education
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    • v.34 no.3
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    • pp.303-319
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    • 2014
  • The purpose of this study is to investigate theoretically the meaning and features of the Community of Inquiry (CoI) based on the views of Peirce and Dewey, and to explore the implications of CoI in science education. The meaning and features of CoI are: (a) inquiry in CoI is initiated with faithful doubt; (b) inquiry in CoI finishes with faithful belief; (c) inquiry in CoI attempts to find out the best explanation and solution regarding the practical effects of objects; (d) as an ideal community, CoI is required to be one that inquires continuously without definite limits; (e) as an actual community, CoI requires its members' open communication to find the best explanation and solution. Based on these features of CoI, the Community of Inquiry in Science Classroom (CoI-SC), "the classroom community for the purpose of transforming the state of faithful doubt into the state of faithful belief, in relation to natural phenomena or objects, and where the members share objectives as participants continuously attempt to find out the best explanation and solution by open communication, considering fallibility and the practical effects of objects", was suggested. The condition for implementation of the CoI-SC, "'interest', 'openness', 'rigor', 'fallibilism', 'participation', 'inquiry without definite limits'", were also suggested. Finally, several suggestions for the science curriculum were given.

Flood Routing of Sequential Failure of Dams by Numerical Model (수치모형을 이용한 순차적 댐 붕괴 모의)

  • Park, Se Jin;Han, Kun Yeun;Choi, Hyun Gu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.5
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    • pp.1797-1807
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    • 2013
  • Dams always have the possibility of failure due to unexpected natural phenomena. In particular, dam failure can cause huge damage including damage for humans and properties when dam downstream regions are densely populated or have important national facilities. Although many studies have been conducted on the analysis of flood waves about single dam failure thus far, studies on the analysis of flood waves about the sequential failure of dams are lacking. Therefore, the purpose of this study was to calculate the peak discharge of sequential failure of dams through flood wave analysis of sequential failure of dams and this analysis techniques to predict flood wave propagation situation in downstream regions. To this end, failure flood wave analysis were conducted for Lawn Lake Dam which is a case of sequential failure of dams among actual failure cases using DAMBRK to test the suitability of the dam failure flood wave analysis model. Based on the results, flood wave analysis of sequential failure of dams were conducted for A dam in Korea assuming a virtual extreme flood to predict flood wave propagation situations and 2-dimensional flood wave analysis were conducted for major flooding points. Then, the 1, 2-dimensional flood wave analysis were compared and analyzed. The results showed goodness-of-fit values exceeding 90% and thus the accuracy of the 1-dimensional sequential failure of dams simulation could be identified. The results of this study are considered to be able to contribute to the provision of basic data for the establishment of disaster prevention measures for rivers related to sequential failure of dams.

Studies on the chlorella in Korea (한국 Chlorella에 대한 연구)

  • 이주식;심종호
    • Korean Journal of Microbiology
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    • v.1 no.1
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    • pp.38-44
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    • 1963
  • According to the experiment on pure-isolation and the related contaminants of Chlorella, the phenomena of the ecological distributions of Chlorella in Korea have been manifested in several areas and also the aim that in going to do culture, biological and physiological study of Chlorella is carried out. Contaminants very oftenly occupied on the colony of the strains taken in order to fulfil pure-isolation of Chlorella, but in accordance with being piled up the minute research on this subject, I can obtain the desirable results as follows: 1. For the pure-isolation, the duration chose the time from May to September 1957 so that may easily isolate from contaminant water with utilizing the antibiotic substances. 2. To take long time, 36-48 hours until growth of nascent through the non-sporulated, it originates from the difference of the cultured media. In addition to the above mention, the mechanism of growth until nascent through the sporulated must not always require the ligh. However the supply of metabolic energy depend upon its nutritional conditions per phase. 3. The culture of Chlorella should be based on the lower culturing except adding especial conditions such as reagent concentration of media, artifical shake of media and other facts due to the natural conditions. And also these strains grew not only in distilled water but 2% NaCl solution without any abnormality in cell it self. I, therefore, guess it is possible to culture in sea-water under phasic environment. 4. In the experiment of ammonia detection, it is caused by the sampling surroundings to contain the minute quantity of ammonia in strain No. M 918; that is the place to be plenty of Carbohydrate on behalf of protein. 5. To compare the absorption curve of chlorophyll of higher plant with that of Chlorella, the absorption zone made mostly the Same ones each other but a little absorption grade dose not clearly appear. The colony which formed giant type grows with intensive colour and green band on surrounding of the colony and after that it was changed into all the green colour and developed up to end. 6. At first phase for a week, the development of Chlorella suspends the normal condition as in vivo but after a few days, the colour of chlorophyll gradually changed into blue-yellow which secrete the mucous substances on the agar media. The cell was flew out the contained substances itself on leaving the cell wall only, or the various micro-organism diffused on the outer-region of the cell.

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Comparative Study of Earth Science Curriculum and Textbooks of Secondary School of South Korea and North Korea (남북한 중등학교 지구과학 교육과정 및 교과서 비교 연구)

  • Lee, Yang-Rak
    • Journal of the Korean earth science society
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    • v.21 no.1
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    • pp.1-12
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    • 2000
  • The earth science curriculum and textbooks of the secondary school in South Korea and North Korea were analysed comparatively with the modified TIMSS curriculum frameworks. In the secondary school of North Korea, earth science is not provided with separate subject, but partly taught in geography. Geography is taught by two hour per week in the first to fifth grade of secondary school. Especially the first and the fifth grade geography are deeply related to earth science. The major aim of earth science education in South Korea is to develop creative problem solver having with interest and curiosity in searching natural phenomena and with basic science concepts and inquiry process skills. But on the other hand the aim of geography education of North Korea is to cultivate communist revolutionists who are faithful to IL-Sung Kim and Jung-IL Kim. In both Koreas the category of 'earth feature' and 'earth process' are dealt a lot, but 'earth in the universe' is rarely taught in North Korea, which suggests that separate subject of astronomy is instructed in the North. Generally the scope and sequence of earth science of North Korea comes under those of middle school of South Korea. Especially discrepancy in level of meteorology and astronomy area between North and South Korea is great.

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Examining the Current Status Quo of Children's Science Exhibits and Exploring the Direction of Development in Children's Science Museum Exhibition (국내 어린이 중심 과학전시 현황 파악 및 발전방향 모색)

  • Jeong, Da-Hye;Park, Young-Shin
    • Journal of the Korean earth science society
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    • v.38 no.6
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    • pp.448-463
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    • 2017
  • The study aims to suggest the direction of improvement in presenting the exhibition space by examining the current status quo of children's science exhibitions in order to enhance the educational effectiveness Children's Science Museum. For this purpose, the children's science museum exhibition and exhibition space were categorized into three themes largely according to the exhibition contents, and an analysis framework was developed to analyze exhibition media and exhibition space. For the research subjects, we selected 7 exhibition halls targeted at children in Korea, collected data via video-taping, and analyzed based on the framework of analysis. When analyzing the display situation in which the exhibits have the contents of 'body', 'peripheral things', and 'natural phenomena', we found that the exhibits are composed of too difficult contents to understand, which do not fit the children's developmental level, and the major media used are observational and explaining media. Additionally, concerning the exhibition space, there is a tendency to rely on the installation elements and color effect. It is also difficult to deduce the contents of the exhibits and the entire story. We suggest that the entire exhibition planning be carefully made from the beginning to improve the current status and enhance the educational effectiveness of the Children's Science Museum with the help of experts.

Program Development on the Thermofluidodynamic Analysis of LNG Storage Tanks (LNG 저장탱크의 종합 열유동 해석프로그램 개발)

  • Kim Hoyeon;Choi Sunghee;Bak Young;Lee Junghwan;Yoon Ikkeun;Kim Donghyuk;Ha Jongmann;Joo Sangwoo
    • Journal of the Korean Institute of Gas
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    • v.5 no.2 s.14
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    • pp.52-61
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    • 2001
  • Cryogenic LNG(Liquefied Natural Gas) which is stored in the cylindrical storage tanks of $100,000m^3$ has very complex flow phenomena and the changes of thermal properties with exterior conditions and operation modes. These complex thermofluid behaviors are affected by the storage, exterior conditions of LNG, design specifications and heat transfer characteristics of tanks. Also, those have influence on the stable storage and supply of LNG in the storage tanks. Thus this study peformed the analysis on the 2-D heat transfer of the tank with exterior conditions, on the Cool Down Process in order to cool down the LNG Storage Tank at the initial normal state, and on the Filling Process considered for incoming and rising of LNG. The analysis on the Mixing LNG Storage was studied too. At last, the visualized program on the complex thermofluidodynamic analysis was developed on the basis of the above analyses. The development of this program becomes to be used to the basic design of the commercial tanks as well as to assure technical skill of the analysis on the thermal stability of the stored LNG in the LNG Storage Tank.

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The Study on living Art and Costumes Culture of the Middle-Age Europe (중세유럽의 생활미술과 복식문화에 관한 연구)

  • 이순홍
    • Journal of the Korean Society of Costume
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    • v.35
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    • pp.17-44
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    • 1997
  • Medieval European practical art and style of costume is studied through referring to the literatures. The type of clothing that was seen on tapestries arts and crafts paintings and wall paintings and appeared in the architecture such as church. There were symbolic aspects of color motifs at this period and some restraints for clothing according to the social class, It was a period that draped garments due to the War of Crusades is appeared. Be-cause the medieval taste and decorative character is not only 'formative art' but also the taste beyoud 'mode' and atomsphere of that times it could be seen the strong reflec-tion of customs in the clothing of that times which is shown in works of art. 1) The purpose of Christian art which was found in mosaics stained glasses wall pain-tings and statues of architecture was not just the revival of natural phenomena but visuali-zation of sacred and invisible things. It was valuable to understandin of the spiritual through the sense organ It was a monumental art that was combined with decorative func-tion and role of the Bible. It revealed what was about the religious spiritual miracle, 2) In the medieval European painting characteristic and beautiful creativity was the basis of an argument. Both "Worship of East-ern" that is painted ion a parchment and "Cor-onation of Charles VI" were described decor-ation motifs on the edge of buildings geo-metric patterns and others with outstanding skill. there were precise technologic skill of architect and glassmen and lots of patience of craftsmen. " The Labour of the Months" and the scene of"A Trial at the Court" is also de-scribed elaborately. 3) Tapestry was developed in France Ger-many Swiss at the 14th century. Religionary and historical themes unicorn lady bird flowering plants and others were major motifs. It was very important as decorative wall coverings and as practical door arch and bed hangings. It was made through patient hard work with simple technique and it was con-sidered as an art for practical use. Tapestry was what everyone wish to have. It is reckoned for the item of the best gift. The royalty and nobility ordered and used custom-made tapestries. Sometimes the subject of motifs consisted of series which were deeply related to living 4) Decorative arts and crafts was the art that used materials such as precious metals jewels and others and that accorded with the luxurious and gorgeous taste of the royalty and nobility. Christian considered splendid and beautiful color of light as a symbol of glory. They used also for church appliances, There were metal crafts wood crafts textile crafts and others, As was stated above the costume appeared on the arts and crafts for living revealed the process of changes saw how the politic econ-omic and social organizations were developed.and social organizations were developed.

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Application of Self-Adaptive Meta-Heuristic Optimization Algorithm for Muskingum Flood Routing (Muskingum 홍수추적을 위한 자가적응형 메타 휴리스틱 알고리즘의 적용)

  • Lee, Eui Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.7
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    • pp.29-37
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    • 2020
  • In the past, meta-heuristic optimization algorithms were developed to solve the problems caused by complex nonlinearities occurring in natural phenomena, and various studies have been conducted to examine the applicability of the developed algorithms. The self-adaptive vision correction algorithm (SAVCA) showed excellent performance in mathematics problems, but it did not apply to complex engineering problems. Therefore, it is necessary to review the application process of the SAVCA. The SAVCA, which was recently developed and showed excellent performance, was applied to the advanced Muskingum flood routing model (ANLMM-L) to examine the application and application process. First, initial solutions were generated by the SAVCA, and the fitness was then calculated by ANLMM-L. The new value selected by a local and global search was put into the SAVCA. A new solution was generated, and ANLMM-L was applied again to calculate the fitness. The final calculation was conducted by comparing and improving the results of the new solution and existing solutions. The sum of squares (SSQ) was used to calculate the error between the observed and calculated runoff, and the applied results were compared with the current models. SAVCA, which showed excellent performance in the Muskingum flood routing model, is expected to show excellent performance in a range of engineering problems.

Microcosm Studies of Nanomaterials in Water and Soil Ecosystems (수생태 및 토양생태계에서 나노물질의 마이크로코즘 연구)

  • Yoon, Sung-Ji;An, Youn-Joo
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.4
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    • pp.288-294
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    • 2012
  • The current growth of nano-industries has resulted in released nanoparticles entering into water and soil ecosystems via various direct or indirect routes. Physicochemical properties of nanoparticles differ from bulk materials, and nanomaterials influence the fates of nanoparticles and the interactions of living or non-living things in the environment. Microcosm analysis is a research methodology for revealing natural phenomena by mimicking part of an ecosystem under controlled conditions. Microcosm study allows for the integrated analysis of toxic effects and fates of nanoparticles in the ecosystem. Ecotoxicity studies of nanomaterials are steadily increasing, and microcosm studies of nanomaterials are currently beginning to surface. In this study, microcosm studies of nanomaterials in water and soil ecosystems were extensively investigated based on SCI(E) papers. We found that the microcosm studies have been reported in 12 instances, and mesocosm studies have been reported in only once until now. Advanced research was mostly evaluated at the microorganism level. But integrated analysis of nanotoxicity is required to research the interactions based of various species. Thus, our studies analysed the trend of microcosm studies on nanomaterials in water and soil ecosystems and suggested future directions of microcosm research of nanomaterials.