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Simulation of Soil Behavior due to Dam Break Using Moving Particle Simulation (댐 붕괴에 의한 토양 거동 시뮬레이션)

  • Kim, Kyung Sung;Park, Dong-Woo
    • Journal of Ocean Engineering and Technology
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    • v.31 no.6
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    • pp.388-396
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    • 2017
  • A Lagrangian approach based computational fluid dynamics (CFD) was used to simulate large and/or sharp deformations and fragmentations of interfaces, including free surfaces, through tracing each particle with physical quantities. According to the concept of the particle-based CFD method, it is possible to apply it to both fluid particles and solid particles such as sand, gravel, and rock. However, the presence of more than two different phases in the same domain can make it complicated to calculate the interaction between different phases. In order to solve multiphase problems, particle interaction models for multiphase problems, including surface tension, buoyancy-correction, and interface boundary condition models, were newly adopted into the moving particle semi-implicit (MPS) method. The newly developed MPS method was used to simulate a typical validation problem involving dam breaking. Because the soil and other particles, excluding the water, may have different viscosities, various viscosity coefficients were applied in the simulations for validation. The newly developed and validated MPS method was used to simulate the mobile beds induced by broken dam flows. The effects of the viscosity on soil particles were also investigated.

Contrast and geometric correction of non-standardized radiographs in digital subtraction radiography (디지털 공제술에서 비표준화 방사선사진의 대조도 및 기하학적 보정에 관한 연구)

  • Kim, Eun-Kyung
    • Journal of Periodontal and Implant Science
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    • v.28 no.4
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    • pp.797-809
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    • 1998
  • The purposes of this study were to develop the computer program for the contrast and geometric correction in digital subtration radiography with the IDL (Interactive Data Language) and compare the results with this program for the correction of the non-standardized radiographs to those of standardized radiographs and those with "Emago" software, the commercial program for the correction. The procedures were written for the contrast correction and subtraction with the geometric correction, using IDL. 32 pairs of periapical radiographs of premolar and molar portion of two dry human mandibles were taken at two different occasions with XCP film holder(nonstandardized films) and another 32 pairs with customized XCP film holder(standardized films). Subtraction of standardized film pairs was performed. Subtraction after the contrast and geometric correction of non-standardized films was performed using the newly developed program and Emago software. Standard deviations of grey levels of the subtracted images by the newly developed program were compared with those of the standardized group and Emago-corrected group. Standard deviations of grey levels of new program-corrected group were much smaller than those of the Emago-corrected group (p<0.001) and slightly larger than those of standardized group (p<0.05). However, the difference was very minute. This study indicates that the newly developed program written with IDL may substitute the mechanical standardization for digital subtraction radiography.

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Classroom Discourse Analysis between Teacher and Students in Science Classroom (과학 수업 시간에 발생하는 교사-학생 간 교실 담화 분석)

  • Han, Shin;Jung, Jinwoo
    • Journal of Science Education
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    • v.35 no.2
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    • pp.159-172
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    • 2011
  • The purpose of this study is to specify the quality of I-R-E pattern and question-answer affiliation between students and teacher, depending on teacher's career. This study analyzes 6 classroom discourse texts of 6th grade science class. The results of this study are as follows. First, in the case of a newly appointed teacher, I-R-E pattern is appeared repeatedly. Second, in the case of experienced teachers, expended I-R-E pattern is appeared compare with a newly appointed teacher. Third, in the case of a newly appointed teacher, independence relational structure is appeared more repeatedly than other structures. But, in the case of experienced teachers, all kinds of question-answer structures - independence, parallel, insertion, and reorganization relational structure - are appeared more evenly.

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A Marketing Strategy of the Apartment Brand for the Newly Jointed Apartment Construction Company (후발 건설업체의 브랜드 마케팅 전략)

  • Yang Soo-Young;Kim Kyung-Rai;Shin Dong-Woo
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.543-548
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    • 2002
  • The brand value of apartment which affects not only sale percent and profit but also the worth of real estate is rising as an important point of apartment competition. But now the apartment brand market is occupied by some large-sized construction companies with strong recognition. So it's difficult for newly joined construction companies to enter the apartment market and the companies that made inroads into the market don't have the brand effects because of consumers' ignorance. Therefore, through the analysis of example from construction and industrial companies, I suggest the marketing strategy which consists of target market, positioning strategy, brand naming strategy, PR strategy and distinct strategy.

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An Experimental Study on Recycled Aggregate Concrete for Artificial Fishing Reefs (인공어초 개발을 위한 재생골재 콘크리트의 실험적 연구)

  • 홍종현;김문훈;우광성
    • Journal of Ocean Engineering and Technology
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    • v.17 no.4
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    • pp.16-22
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    • 2003
  • The mechanical characteristics of newly recycled aggregate concrete on the basis of the proposed mix design model have been studied to develop the precast artificial fishing reefs. In the first task, the experimental test for the recycled aggregates taken from Jeju Island has been carried out to verify the material properties in terms of specific gravity, percentage of solids, absorption and abrasion of coarse aggregates. In the second task, the experimental parameters of newly recycled aggregate concrete are investigated to meet with the requirements of guidelines with respect to slump, unit weight, pH, ultrasonic velocity, void ratio, and compressive strength which are made of sea-shore sand ad slag cement. The natural aggregate and polypropylene fiber are added to newly recycled aggregate concrete to improve the compressive strength and quality. The optimal mix proportions for compressive strength are W/C=30%, S/a=15%, NA/G=50% in porous concrete case, W/C=40%, S/a=45% in plain concrete case, and W/C=40%, S/a-45%, PF=1.0kg/㎥ in fiber reinforced concrete case.

Development of Outage Cost Impact Index Function of Electricity Energy and Outage Cost Assessment using WOROCAIS (전력에너지 공급지장비의 충격도지수 함수개발 및 WOROCAIS를 이용한 이의 추정에 관한 연구)

  • Lim, Jin-Taek;Choi, Jae-Seok;Jeon, Dong-Hoon;Seo, Chul-Soo;Lee, Jae-Gul
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.8
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    • pp.1066-1073
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    • 2013
  • This paper illustrates newly an outage cost impact index function(OCIIF). The assessment of the OCIIF is described using the Web Based Online Real-time Outage Cost Assessment and Information System(WOROCAIS) for power system outage cost assessment in Korea. The proposed OCIIF is not absolute but relative outage cost impact index function in view point of outage time using web based survey method for outage cost assessment. While conventional methodology does not consider short time outage cost assessment, the proposed OCIIF reflects short time outage. SCOF(Sector Customer Outage Function) in stead of the traditional SCDF(Sector Customer Damage Function) is defined and proposed newly in this paper. Based the SCOF, AVLL(Average Value of Loss Load) is newly proposed. The OCIIF is demonstrated by WOROCAIS in case study around 2,000 sample data surveyed by KEPCO in South Korea in recent.

Textural Properties of Processed Foods Produced from Newly Developed Non-Glutinous Rice Cultivars

  • Ha, Mi-Sun;Roh, Yi-Woo;Hong, Kwon-Pyo;Kang, Yoon-Suk;Jung, Dong-Chae;Kim, Kwang-Ho;Park, Sang-Kyu;Ha, Sang-Do;Bae, Dong-Ho
    • Food Science and Biotechnology
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    • v.16 no.5
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    • pp.789-795
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    • 2007
  • This study was undertaken to investigate the producibility of processed foods utilizing 6 newly developed non-glutinous rice cultivars. First, cooked rice, cake, cookies, bread, and slender rice cake sticks were prepared with the newly developed cultivars; then their physicochemical and textural properties were evaluated. The rice samples had similar pasting temperatures and peak times, but different viscosities and other pasting properties. The textural analysis results suggested that 'Chucheong' was appropriate for cooked rice due to its low amylose content; hardness, and springiness; 'Ilphumbyeo' for rice cakes due to its high amylose content, moderate cohesiveness and adhesiveness, and low hardness; 'Ilphumbyeo' for cookies due to its high amount of protein, and low cohesiveness and adhesiveness; 'Ilphumbyeo' for bread due to its high amylose content, moderate hardness, and low consistency; and 'Ilphumbyeo' for the slender rice cake sticks due to its low hardness, moderate breakdown, paste viscosity, and setback.

Improvement on Performance Simulation Using Component Maps of Aircraft Gas Turbine Obtained from System Identification (시스템 식별로 구한 구성품 성능선도를 이용한 개선된 가스터빈 성능해석 연구)

  • Kong, Chang-Duk;Kho, Seong-Hee;Ki, Ja-Young
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.6
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    • pp.96-103
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    • 2004
  • Sought a set of component performance lines from experiment data or some data supplied in the engine manufacturer to improve the traditional scaling method and suggested a map scaling method that construct component performance lines newly using polynomial equations of MATLAB program. In this study, applied technique that is proposed newly to PT6A-62 that verified technique that is proposed newly using experiment data of small. size turboshaft engine, and is actuality aircraft engine. In identification of the component maps of the turboprop engine, the simulated performance using the proposed scaling method was compared with the real engine performance data and the performance using the traditional scaling method.

A Bibliographical Study on 4 Newly Found Jeolla-do Editions of Bumoeunjungkyeongeonhae (새로 발견된 호남판(湖南板) <부모은중경언해(父母恩重經諺解)> 4종의 서지적(書誌的) 연구(硏究))

  • Song, Il-Gie;Park, Min-Hee
    • Journal of Korean Library and Information Science Society
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    • v.41 no.2
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    • pp.209-228
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    • 2010
  • The purpose of this paper is to introduce 4 different Jeolla-do editions of Bumoeunjungkyeongeonhae(父母恩重經諺解) which were newly found recently. Editions of Eunjungkyeong(恩重經) translated in Korean reach 36 editions including these 4 editions. Among 36 editions, 14 editions were published in Jeolla-do. 3 editions of these newly found editions have attachments of 'Sipbeopgyesong(十法界頌)' and 'Sippaljiok(十八地獄)'. The feature of these attachments' form was started since 1563 edition of Songgwangsa in Jeolla-do. In particular, 1628 edition of Baegamsa and 1653 edition of Naejangsa have same attachments. Therefore it is presumed that these 2 editions were copied and engraved based on Songgwangsa edition.

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Long-term Monitoring of Expansion of Cement Concrete Pavement Affected by Alkali-Aggregate Reaction (알칼리-골재 반응에 의한 콘크리트 포장 팽창 장기 모니터링)

  • Hong, Seung-Ho;Shim, Young-Hwan
    • International Journal of Highway Engineering
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    • v.17 no.2
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    • pp.13-20
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    • 2015
  • PURPOSES: This paper describes the expansion caused by the alkali-aggregate reaction (AAR) in concrete pavement currently in service. It also discusses the effects of joints installed to release the stress induced by the AAR expansion. METHODS: The expansion effect on concrete pavement was verified by a visual inspection and long-term measurement of the joint width of a cut-section. The behaviors of 16 newly installed joints were monitored as part of the investigation and long-term monitoring was carried out for three years after cutting. RESULTS: The behavior of a bridge was affected when AAR occurred in the connected pavement. The newly installed joints shrank in the longitudinal direction of the bridge after cutting. The width of the joints decreased over the six months after cutting. A large portion of the joint width (8.5cm) was found to have closed nine months after cutting. It had ultimately shrunk by about 92 percent when the final measurement was taken. CONCLUSIONS : The expansion of the pavement due to AAR was quantitatively described by visual inspection and the long-term monitoring of the newly cut joints. However, the width of the new joints decreased over the six to nine months after cutting. Additional research should be conducted to determine a means of controlling the expansion due to AAR in the pavement.