• Title/Summary/Keyword: Natural Phenomena

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A Four-Node Assumed Strain Plate Element for Explicit Dynamic Transient Analysis (명시적인 동적 시간이력해석을 한 사절점 가변형도 평판요소)

  • 이상진
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.14 no.3
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    • pp.349-359
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    • 2001
  • An enhanced four-node plate element, which has been developed for explicit dynamic analysis of plate, is described in this paper. Reissner-Mind1in(RM) assumptions are adopted to consider transverse shear deformation effects in the present plate element. RM plate element produces a shear locking phenomena in thin plate so that the substitute natural strains based on assumed strain method are explicitly derived. The present plate element is applied into the explicit transient algorithm and the mass matrix of plate is formulated by using special lumping method proposed by Hinton et al. The performance of the element is verified with numerical examples.

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ANALYSIS OF A STATION BLACKOUT SCENARIO WITH AN ATLAS TEST

  • Kim, Yeon-Sik;Yu, Xin-Guo;Kang, Kyoung-Ho;Park, Hyun-Sik;Cho, Seok;Choi, Ki-Yong
    • Nuclear Engineering and Technology
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    • v.45 no.2
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    • pp.179-190
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    • 2013
  • A station blackout experiment called SBO-01 was performed at the ATLAS facility. From the SBO-01 test, the station blackout scenario can be characterized into two typical phases: A first phase characterized by decay heat removal through secondary safety valves until the SG dryouts, and a second phase characterized by an energy release through a blowdown of the primary system after the SG dryouts. During the second phase, some physical phenomena of the change over a pressurizer function, i.e., the pressurizer being full before the POSRV $1^{st}$ opening and then its function being taken by the RV, and the termination of normal natural circulation flow were identified. Finally, a core heatup occurred at a low core water level, although under a significant amount of PZR inventory, whose drainage seemed to be hindered owing to the pressurizer function by the RV. The transient of SBO-01 is well reproduced in the calculation using the MARS code.

An Experimental Study on the Characteristics of Evaporative Heat Transfer of Carbon Dioxide (이산화탄소의 증발열전달 특성에 관한 실험적 연구)

  • 조은석;윤석호;김민수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.1
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    • pp.38-45
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    • 2002
  • Evaporative heat transfer characteristics of carbon dioxide have been investi- gated by experiment. The experiments have been carried out for a seamless stainless steel tube of the outer diameter of 9.55 mm, the inner diameter of 7.75 mm and the length of 5.0 m. Direct heating method was used for supplying heat to the refrigerant where the test tube was uniformly heated by electric current which was applied to the tube wall. Experiments were conducted with$CO_2$of purity 99.99% at saturation temperatures of 0.0 to 10.5$^{\circ}C$, heat fluxes of 12 to 27kW/$m^2$s and mass fluxes of 212 to 530 kg/$m^2$s. The heat transfer coefficients of $CO_2$are decreased as the vapor quality increases and these phenomena are explained by dimensionless Weber and Bond numbers. The heat transfer coefficients of$CO_2$increase when the heat and mass fluxes increase, and the saturation temperature effects are minor in the test range of this study. The present experimental data are compared with six renowned correlations with root-mean-squared deviations ranging from 23.0 to 94.9% respectively.

Nonlinear Motion Responses for A Moored Ship beside Quay (안벽에 계류된 선박에 대한 비선형 운동응답)

  • Lee, Ho-Yooung;Lim, Choon-Gyu;Lew, Jae-Moon;Chun, In-Sik
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.172-178
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    • 2003
  • As a typoon gets into harbour, a moored ships shows erratic motions and even mooring line failures is occurred. Such troubles may be caused by harbour resonance phenomena, result in large motion amplitudes at law frequency, which is closed to the natural frequency of the moored ship. The nonlinear motions of a moored ship beside quay are simulated under external forces due to wave, current including mooring forces in time domain. The forces due to waves are obtained from source and dipole distribution method in the frequency domain. The current forces are calculated by using slow motion maneuvering equation in the horizontal plane. The wind forces are calculated from emperical formula of ABS and the mooring forces of ropes and fenders are modeled as linear spring.

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Investigation on the Properties of a Microcellular Light-Weighted Humidity Controlling Tile (마이크로셀룰라 경량 조습타일의 특성 고찰)

  • Song, In-Hyuck;Lee, Eun-Jung;Kim, Hai-Doo;Kim, Young-Wook;Yun, Dal-Woong
    • Journal of the Korean Ceramic Society
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    • v.48 no.5
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    • pp.404-411
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    • 2011
  • The humidity controlling ceramic materials was developed by applying the phenomena of dew condensation in the capillary. It is said that the humidity range which human feels comfortable is from 40 to 70% in relative humidity. In this study, the ceramic tile using natural soils such as diatomite for interior wall was investigated. In particular, we had introduced novel processing routes for fabricating microcellular ceramics tile using hollow microsphere as a pore former. The microcellular pores in the humidity controlling ceramic materials showed the superior properties such as light-weight, heat insulation. The cell density was ${\sim}1.0{\times}10^9$ cells/$cm^3$ and density of sample was 0.65 g/$cm^3$ in the case of 1.71 wt% hollow microsphere content. Also, it is observed that the BET surface area and the pore volume of the sintered diatomite tile have the values of 40.92 $m^2$/g and 0.173 $cm^3$/g.

Computer-aided approach of parameters influencing concrete service life and field validation

  • Papadakis, V.G.;Efstathiou, M.P.;Apostolopoulos, C.A.
    • Computers and Concrete
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    • v.4 no.1
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    • pp.1-18
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    • 2007
  • Over the past decades, an enormous amount of effort has been expended in laboratory and field studies on concrete durability estimation. The results of this research are still either widely scattered in the journal literature or mentioned briefly in the standard textbooks. Moreover, the theoretical approaches of deterioration mechanisms with a predictive character are limited to some complicated mathematical models not widespread in practice. A significant step forward could be the development of appropriate software for computer-based estimation of concrete service life, including reliable mathematical models and adequate experimental data. In the present work, the basis for the development of a computer estimation of the concrete service life is presented. After the definition of concrete mix design and structure characteristics, as well as the consideration regarding the environmental conditions where the structure will be found, the concrete service life can be reliably predicted using fundamental mathematical models that simulate the deterioration mechanisms. The prediction is focused on the basic deterioration phenomena of reinforced concrete, such as carbonation and chloride penetration, that initiate the reinforcing bars corrosion. Aspects on concrete strength and the production cost are also considered. Field observations and data collection from existing structures are compared with predictions of service life using the above model. A first attempt to develop a database of service lives of different types of reinforced concrete structure exposed to varying environments is finally included.

A Study on the Geometric Form of the Preliminary Plan "hanyang" in Early Chosun Dynasty (초기 한양도성계획의 도형적 해석에 관한 연구)

  • 정기호;김용기
    • Journal of the Korean Institute of Landscape Architecture
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    • v.22 no.4
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    • pp.119-132
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    • 1995
  • This study shows the characteristics of the early phenomena of the city plan Hanyang (old city Seoul). It consists of two steps. One is to search for the constructing principles of the geometric setting. And the other is to inquire and interpret the objects of beginning and ending points of that setting. The results based on geographic analysis and historical facts are as follows: 1) The city plan Hanyang shows a certain hierarchy:the major axis and the locations of the palace and the city set up in the prority. This priority made onto lower hierarchical plans such as the site plans of palaces and city wall. For example of the significant objects are Namdaemum (South Gate of the city wall) and Kwanghwamun (South Gate of the Palace). They are on the main axis, and became the basic points of the detailed city plans. 2) The palace palace on its major axis, right-angled minor axis, and 4 grade inclination to north. The four small city wall gates located on the base of four greater gates. 3) The geometric characteristics as constructing principle found on certain hierarchical order. Thus, the natural elements as mountains, had an important effect on the arrangement of major facilities and those main constructions made on lower - hierarchical settings. 4) These facts related closely to the philosophy of Jung, Do-Jon, the initiative planer of the Hanyang.

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A Study on Confucian Philosophies and Taoist Docrine in the Landscape Style of Palaces in Chosun Dynasty (조선조 궁궐조경양식에 나타난 유가.도가적 사상)

  • 진상철;최기수
    • Journal of the Korean Institute of Landscape Architecture
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    • v.22 no.4
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    • pp.81-93
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    • 1995
  • Landscape Style would take various influences in general. In that of Korean Palaces religious thinking has been caused he most important factor. This conceptual attitude has been derived from Confucian philosophies and the doctrines of Taoism, the realm of ideas that had constituted the schema of culture through long times in the Orient. This paper has dealt with the influences of one's outlook on the universe, antropocentricism, and on the relationships of man and nature in those two major teachings upon the landscape style of palaces in Chosun Dynasty. The Confucian philosophies and the doctrines of Taoism in Taosim in palaces would be summarized as followings: 1. The composition of exterior spaces had been understood as a place for moral training and political morality in the world view of Confucious. 2. The view point on court circle with plants and trees had directed to the influences of beauty upon the human spirit, and it is clear in naming attitude. 3. The composition type of void and solid in palaces would focused on the completion of Confucian thoughts totally, and the method of a unit space is same. 4. The double symbolic ideas could be find out in the components of exterior space; one is Confucian in phenomena, the other is Taoism in meaning. This can be cleared in Pangji(方池), layout of natural features, and in planting methods. As a conclusion, the common spiritual base in landscape architecture of Korean old palaces can be understood as two major thinkings; Confucian philosophies and the doctrines of Taoism.

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Qualitative Research on Fashion Product Shopping and Retail Therapy (패션제품 쇼핑을 통한 리테일 테라피 효과에 대한 질적 연구)

  • Ahn, Ga Young;Lee, Yuri
    • Journal of the Korean Society of Clothing and Textiles
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    • v.42 no.3
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    • pp.411-427
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    • 2018
  • This study is to understand the inner psychological state of consumers who pursue a retail therapy effect through fashion product shopping. Qualitative research on the whole process from the point of time of occurrence of shopping motivation to the end of shopping motivation was performed. The researcher became a virtual shopping partner during shopping and conducted a natural conversation interview using a mobile instant messenger program (Kakao Talk). After shopping, participants were asked to write a diary on that day. Collected data were analyzed by applying the grounded theory approach suggested by Strauss and Corbin (1998). Casual Condition, represented everyday stress and Contextual Condition indicated the self-healing consumption trend. Main Phenomena showed a mood change during the fashion shopping process. The sense of emancipation from the place, the satisfaction from the maintenance of social relations, and the sense of accomplishment through purchases were revealed. Intervening Condition showed the consideration in the process of shopping for fashion products, such as providing a try-on experience, price promotion, and involvement of a companion. Action Interaction Strategy was the shopping behavior for the positive emotion increase and negative emotion decrease. Consequence represented a retail therapy in shopping for fashion products.

PC-KIMMO-based Description of Mongolian Morphology

  • Jaimai, Purev;Zundui, Tsolmon;Chagnaa, Altangerel;Ock, Cheol-Young
    • Journal of Information Processing Systems
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    • v.1 no.1 s.1
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    • pp.41-48
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    • 2005
  • This paper presents the development of a morphological processor for the Mongolian language, based on the two-level morphological model which was introduced by Koskenniemi. The aim of the study is to provide Mongolian syntactic parsers with more effective information on word structure of Mongolian words. First hand written rules that are the core of this model are compiled into finite-state transducers by a rule tool. Output of the compiler was edited to clarity by hand whenever necessary. The rules file and lexicon presented in the paper describe the morphology of Mongolian nouns, adjectives and verbs. Although the rules illustrated are not sufficient for accounting all the processes of Mongolian lexical phonology, other necessary rules can be easily added when new words are supplemented to the lexicon file. The theoretical consideration of the paper is concluded in representation of the morphological phenomena of Mongolian by the general, language-independent framework of the two-level morphological model.