• 제목/요약/키워드: Complex Phenomena

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Development of Two-Dimensional Near-field Integrated Performance Assessment Model for Near-surface LILW Disposal (중·저준위 방사성폐기물 천층처분시설 근계영역의 2차원 통합성능평가 모델 개발)

  • Bang, Je Heon;Park, Joo-Wan;Jung, Kang Il
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.4
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    • pp.315-334
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    • 2014
  • Wolsong Low- and Intermediate-level radioactive waste (LILW) disposal center has two different types of disposal facilities and interacts with the neighboring Wolsong nuclear power plant. These situations impose a high level of complexity which requires in-depth understanding of phenomena in the safety assessment of the disposal facility. In this context, multidimensional radionuclide transport model and hydraulic performance assessment model should be developed to identify more realistic performance of the complex system and reduce unnecessary conservatism in the conventional performance assessment models developed for the $1^{st}$ stage underground disposal. In addition, the advanced performance assessment model is required to calculate many cases to treat uncertainties or study parameter importance. To fulfill the requirements, this study introduces the development of two-dimensional integrated near-field performance assessment model combining near-field hydraulic performance assessment model and radionuclide transport model for the $2^{nd}$ stage near-surface disposal. The hydraulic and radionuclide transport behaviors were evaluated by PORFLOW and GoldSim. GoldSim radionuclide transport model was verified through benchmark calculations with PORFLOW radionuclide transport model. GoldSim model was shown to be computationally efficient and provided the better understanding of the radionuclide transport behavior than conventional model.

Analysis of Regional Relative Humidity Environment for Dehumidification System Efficiency of Suspension Bridge Cable (현수교 케이블 송기시스템 효율화를 위한 지역별 상대습도 환경 분석)

  • Seo, Dong-Woo;Kim, Ga Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.7
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    • pp.88-94
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    • 2018
  • This study examined the safety of a cable stayed bridge caused by damage to the cable system. Many cable-supported bridges, including cable-stayed bridges and suspension bridges, have been constructed on the Korean peninsula. This requires efficient maintenance and management because this structure has complex structural components and systems. This large structure also often faces risks either from manmade causes or natural phenomena. In 2015, the cables on one cable-stayed bridge in South Korea was struck by lightning, which led to a fire on the cables. These cables were damaged, which put the bridge at risk. This bridge was back in use after a few weeks of investigations and replacements of the cables but this was done at enormous social and economic expense. After this event, risk-based management for infrastructure is required by public demand. Therefore, this study examined the risks on the cable system due to potential damage. In this paper, a one cable-stayed bridge in South Korea was selected and its safety was investigated based on the damage scenarios of cable system for efficient and prompt management, and to support decision making. FEM analysis was conducted to evaluate the safety of the bridges after damage to the cable system.

Explore the Relationship Between Sports Culture and Social Change (스포츠문화와 사회변화의 관계 탐색)

  • Goo, Kang-Bon
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.4
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    • pp.1181-1187
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    • 2019
  • Today's sports, by themselves, express a wide variety of phenomena and reproduce or imply complex social symbols. The definition of sports being transformed in combination with ideology, which has become a central issue in each era, has become more diverse in recent years. Recently, with the 4th Industrial Revolution leading the social phenomenon, sports culture is producing a new phenomenon. In this era, we need the study in the question of how to understand and interpret sports culture is the right approach. The struggle for survival in each discipline was expressed as a reinterpretation of sports culture. This is to answer questions about how sports culture is consumed, spread and reinterpreted. The purpose of this study is to find out the direction and directing point of sports culture. Based on such problem recognition, five types of answers to what sports culture consumes were presented. Based on this, the fairness related to school sports, sports society-club(sports clubs), sports events, sports media, and sports was suggested as a medium for the spread of sports culture. We are accepting and transforming numerous scientific civilizations to improve sports culture and to promote consumers. However, there is a pity not to define such a thing. Efforts at a more fundamental level, such as cultural regulation and fundamental directions, need to be discussed. The framework of reinterpretation of sports culture should be constantly looking for directions and answers about what to do, not just the level of interpretation.

Development of 3D Dynamic Numerical Simulation Method on a Soil-Pile System (지반-말뚝 시스템에 대한 3차원 동적 수치 모델링 기법 개발)

  • Kim, Seong-Hwan;Na, Seon-Hong;Han, Jin-Tae;Kim, Sung-Ryul;Sun, Chang-Guk;Kim, Myoung-Mo
    • Journal of the Korean Geotechnical Society
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    • v.27 no.5
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    • pp.85-92
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    • 2011
  • The dynamic behavior of piles becomes very complex due to soil-pile dynamic interaction, soil non-linearity, resonance phenomena of soil-pile system and so on. Therefore, the proper numerical simulation of the pile behavior needs much effort and calculation time. In this research, a new modeling method, which can be applied to the conventional finite difference analysis program FLAC 3D, was developed to reduce the calculation time. The soil domain in this method is divided into a near-field region and a far-field region, which is not influenced by the soil-pile dynamic interaction. Then, the ground motion of the far-field is applied to the boundaries of the near-field instead of modeling the far-field region as finite meshes. In addition, the soil non-linearity behavior is modeled by using the hysteretic damping model, which determines the soil tangent modulus as a function of shear strain and the interface element was applied to simulate the separation and slip between the soil and pile. The proposed method reduced the calculation time by as much as one third compared with a usual modeling method and maintained the accuracy of the calculated results. The calculated results by the proposed method showed a good agreement with the prototype pile behavior, which was obtained by applying a similitude law to the 1-g shaking table test results.

A Study on the Estiblishment of Space Planning on Myeon Center according to Regional Characteristics (지역특성에 따른 면소재지 공간계획수립에 관한 연구)

  • Yoon, Junsang;Kim, Sungrok
    • Journal of Agricultural Extension & Community Development
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    • v.20 no.2
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    • pp.407-429
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    • 2013
  • Although rural areas account for more than 80% of the total land area of South Korea, most of them are deteriorated and living environment is inconvenient. In addition, the migration of young generation to urban areas and ageing have reduced the population and caused not only cavitation phenomena of villages but also stagnant communities. As for one of the rural areas, the seat of Myeon Office located in Oesan-myeon, Buyeo-gun, Chungcheongnam-do, this study presented not a plan only for strengthening hub functions but the methodology of the complex development plan in consideration of the regional characteristics in the comprehensive improvement project in seat of Myeon Office. From the perspective of enhancing the function of the seat of Myeon Office, it is inevitable to establish plans based on hardware. However, empowerment of the residents in the targeted areas also works as an important factor. In other words, each project promoted by the plan will be mainly operated by the local residents. Therefore, it is necessary to establish a management system of this. The success or failure of the established plan is based on the accurate survey of the issues of the targeted areas and demand, and this depends on participation and positive response of the residents of the targeted areas. That is, the method as a 'local community network' is required in order to increase the effect of resident participation in the planning area.

Exploring the Relationships between Inquiry Problems and Scientific Reasoning in the Program Emphasized Construction of Problem: Focus on Inquiry About Osmosis (문제의 구성을 강조한 프로그램에서 나타난 탐구 문제와 과학적 추론의 관련성 탐색 -삼투 현상 탐구 활동을 중심으로-)

  • Baek, Jongho
    • Journal of The Korean Association For Science Education
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    • v.40 no.1
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    • pp.77-87
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    • 2020
  • Scientific inquiry has emphasized its importance in various aspects of science learning and has been performed according to various methods and purposes. Among the various aspects of science learning, it is emphasized to develop core competencies with science, such as scientific thinking. Therefore, it is necessary to support students to be able to formulate scientific reasoning properly. This study attempts to explore problem-finding and scientific reasoning in the process of performing scientific inquiry. This study also aims to reveal what factors influence this complex process. For this purpose, this study analyzed the inquiry process and results performed by two groups of college students who conducted the inquiry related to osmosis. To analyze, research plans, presentations, and group interviews were used. As a result, it was found that participants used various scientific reasoning, such as deductive, inductive, and abductive reasoning, in the process of problem finding for their inquiry about osmosis. In the process of inquiry and reasoning complexly, anomalous data, which appear regularly, and the characteristics of experimental instruments influenced their reasoning. Various reasons were produced for the purpose of constructing the best explanation about the phenomena observed by participants themselves. Finally, based on the results of this study, several implications for the development context of programs using scientific inquiry are discussed.

Combination of Different Numerical Methods for Efficient Thermal Stress Analysis of Casting Process (주조공정에서의 효율적인 열응력 해석을 위한 이종해석기법의 연계)

  • Kwak, Si-Young;Lim, Chae-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.8
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    • pp.1051-1057
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    • 2010
  • This paper proposes a method that involves a combination of FDM and FEM for analyzing casting process. At present, many numerical analysis methods such as FDM, FEM, and BEM are used for solving engineering problems. For a given problem, a specific method that is suited to the problem is adopted; in general, FDM or FVM is favored for problems related to fluid flow or heat transfer, and FEM is adopted in stress analysis. However, there is an increasing need for using a combined method for complex and coupled phenomena analysis. Hence, we proposed a method in which FDM and FEM are coupled in three-dimensional space, and we applied this method to analyze casting process. In the proposed method, solidification and heat transfer was analyzed by using FDM. The field data such as temperature distribution were converted into a format suitable for FEM analysis that was used for calculating thermal stress distribution. Using the proposed method, we efficiently analyzed the analysis process from the viewpoints of work and time.

A Study on the Periodic Characteristics of Wonsam in the Joseon Dynasty (조선시대 원삼의 시기별 특성에 관한 연구)

  • Lim, Hyunjoo;Cho, Hyosook
    • Journal of the Korean Society of Costume
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    • v.63 no.2
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    • pp.29-44
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    • 2013
  • This study is about the periodic characteristics of Wonsam in the Joseon Dynasty. Wonsam include the Danryeong-shaped Wonsam in the beginning, the compound Wonsam in a period of transition and the stereotyped Wonsam in the late Joseon Dynasty. The formative characteristics of Wonsam are divided into four stages. The first stage of the Wonsam is from the 15th to 16th century. The shape of Wonsam began to form and it was similar to one of Danryeong during this time. The formative characteristics of the first Wonsam included collars that looked like one of Danryeong, side pleats(called Moo) with multiple inner folds, straight cylinder-shaped sleeves, and a belt tied with the Wonsam. There were various fabrics that were used for the Wonsam from this stage. Second stage of the Wonsam is from the early 17th to mid 17th century. This period marked the beginning of the transition of the Wonsam and it served as a stepping-stone to the development stage in the Joseon Dynasty. The characteristics of the transitional Wonsam were a complex combination of the Danryeong and Wonsam. During this period, the Wonsam went through many changes and forms in a short period of time. Third stage of the Wonsam is from the mid 17th to early 19th century. The Wonsam was developed at this stage. The developed Wonsam went through a period of transition equipped with a stable form. The formative characteristics of Wonsam during this period included collars that faced each other, big and wide sleeves with multicolored stripes, Hansam, curve-edged side seam and the side pleats(Moo) with multiple inner folds had disappeared. It was a turning point from the single-layered clothes to double layered clothes and from dark blue to green color appeared at this time. The fabric patterns of this stage tended to consist of more simplified silk pattern. The fourth stage of the Wonsam is from the late 19th to 20th century. The Wonsam was expanded at this stage. The formative characteristics and fabrics were typically used for the standard Wonsam and were divided into two types; as a ceremonial robe used in courts and a wedding ceremonial robe for the common people. Phenomena such as sewing of double-layered clothes as one and straight-edged side seam during the late Joseon period developed into simpler and more practical fashion culture.

Magnetoresistance of Bi Nanowires Grown by On-Film Formation of Nanowires for In-situ Self-assembled Interconnection

  • Ham, Jin-Hee;Kang, Joo-Hoon;Noh, Jin-Seo;Lee, Woo-Young
    • Proceedings of the Korean Magnestics Society Conference
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    • 2010.06a
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    • pp.79-79
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    • 2010
  • Semimetallic bismuth (Bi) has been extensively investigated over the last decade since it exhibits very intriguing transport properties due to their highly anisotropic Fermi surface, low carrier concentration, long carrier mean free path l, and small effective carrier mass $m^*$. In particular, the great interest in Bi nanowires lies in the development of nanowire fabrication methods and the opportunity for exploring novel low-dimensional phenomena as well as practical application such as thermoelectricity[1]. In this work, we introduce a self-assembled interconnection of nanostructures produced by an on-film formation of nanowires (OFF-ON) method in order to form a highly ohmic Bi nanobridge. A Bi thin film was first deposited on a thermally oxidized Si (100) substrate at a rate of $40\;{\AA}/s$ by radio frequency (RF) sputtering at 300 K. The sputter system was kept in an ultra high vacuum (UHV) of $10^{-6}$ Torr before deposition, and sputtering was performed under an Ar gas pressure of 2m Torr for 180s. For the lateral growth of Bi nanowires, we sputtered a thin Cr (or $SiO_2$) layer on top of the Bi film. The Bi thin films were subsequently put into a custom-made vacuum furnace for thermal annealing to grow Bi nanowires by the OFF-ON method. After thermal annealing, the Bi nanowires cannot be pushed out from the topside of the Bi films due to the Cr (or $SiO_2$) layer. Instead, Bi nanowires grow laterally as a mean s of releasing the compressive stress. We fabricated a self-assembled Bi nanobridge (d=192 nm) device in-situ using OFF-ON through annealing at $250^{\circ}C$ for 10hours. From I-V measurements taken on the Bi nanobridge device, contacts to the nanobridge were found highly ohmic. The quality of the Bi nanobridge was also proved by the high MR of 123% obtained from transverse MR measurements. These results manifest the possibility of self-assembled nanowire interconnection between various nanostructures for a variety of applications and provide a simple device fabrication method to investigate transport properties on nanowires without complex patterning and etching processes.

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A Study on the Makeup Trend of Digital Communication Environment (디지털 커뮤니케이션 환경의 메이크업 트렌드 연구)

  • Barng, Kee-Jung
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.37 no.1
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    • pp.23-36
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    • 2011
  • The purpose of this study is to make theoretical examinations into the makeup trend shown in digital communication environment and thereby determine potential associations of makeup trend with digital communication environment and characterize said trend, so that it can provide reference materials required for follow-up studies. This study comes to the following findings: First, it is found that there are sociocultural characteristics of digital communication environment, such as interactivity, technology-orientedness, sentiment-orientedness and mixture of time and space. Secondly, it is found that trends developed in makeup fall categorically into interactivity, virtuality, amusement and mobility. Thirdly, it is found that each type of digital communication adopts a mixture and juxtaposition of contemporary styles or categories with traditional ones through eclectic combination based on open-minded and horizontal ideas. Fourthly, it is found that a trend from digital communication environment doesn't coincide perfectly with any makeup trend, but the former trend works interactively and organically with the latter trend on the basis of homogeneity and similarity within a general framework that represents external esthetics of human being. With the creation of digital communication environment, our contemporary society forms as the complex phenomena of digital society in a combination and destruction of different categories beyond any certain international boundary, so that a hybrid tendency appears in contemporary makeup trend as well. Based on these findings, this study has its implications in the sense that it gives a new viewpoint based on design, formative characteristics and expression styles of makeup, and also provides useful reference materials for related industrial sectors.