• Structural Engineering and Mechanics
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• 제66권4호
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• pp.477-485
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• 2018

This study aims to investigate the influence of individual and hybrid fiber on the local bond-slip behavior of medium and high strength concrete after exposure to different high temperatures. Tests were conducted on local pullout specimens (150 mm cubes) with a reinforcing bar embedded in the center section. The embedment lengths in the pullout specimens were three times the bar diameter. The parameters investigated include concrete type (control group: ordinary concrete; experimental group: fiber concrete), concrete strength, fiber type and targeted temperature. The test results showed that the ultimate bond stress in the local bond stress versus slip curve of the high strength fiber reinforced concrete was higher than that of the medium strength fiber reinforced concrete. In addition, the use of hybrid combinations of steel fiber and polypropylene fiber can enhance the residual bond strength ratio of high strength concrete.

• 경영과학
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• 제29권3호
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• pp.67-80
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• 2012

This study analyzes the relationship among environment uncertainty, local infrastructure, flexible-open firm culture, operations performance and marketing performance focus on SMEs. This research has revealed that the relation among firm size, firm type, firm culture, operations performance and marketing performance as well. The findings show that firm has its culture which is preparing environment uncertainty and local infrastructure influence on forming firm culture. Change-oriented and leaning-oriented firm cultures affect operations performance and marketing performance. In conclusion, this study suggests implication and limitations for further research.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1096-1101
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• 2004

Generally, the buckling of thin-walled structures has studied for rectangular sections or circular sections. Rectangular sections have small stiffness and circular sections have large stiffness when they are compared with rectangular sections for local buckling. But both of them have similar stiffness to column buckling. Therefore in this paper, we are going to analyze the local buckling for the box section with rounded comer and compare with rectangular section. Also we confirm that the rounded comer section has larger local buckling strength than rectangular section.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.112-117
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• 2000

A numerical study on natural convection in a vertical square cavity filled with a porous medium is carried out with Brinkman-Forchheimer-extended Darcy flow model, and the validity of local thermodynamic equilibrium assumption is studied. The local thermodynamic equilibrium refers to the state in which a single temperature can be used to describe a heat transfer process in a multiphase system. With this assumption, the analysis is greatly simplified because only one equation is needed to describe the heat transfer process. But prior to using this assumption, it is necessary to know in what conditions the assumption can be used. The numerical results of this study reveal that large temperature difference between fluid phase and solid phase exists near wall region, paticularily when the convection becomes dominant over conduction. And the influence of flow parameters such as fluid Rayleigh number, fluid Prandtl number, dimensionless particle diameter and conductivity ratio are investigated.

• Steel and Composite Structures
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• 제37권2호
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• pp.151-173
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• 2020

This paper aims to probabilistically evaluate performance of two types of I beam to box column (IBBC) connection. With the objective of considering the variability of seismic loading demand, statistical features of the inter-story drift ratio corresponding to the second, fifth and eleventh story of a 12-story steel special moment resisting frames are extracted through incremental dynamic analysis at global collapse state. Variability of geometrical variables and material strength are also taken into account. All of these random variables are exported as inputs to a probabilistic finite element model which simulates the connection. At the end, cumulative distribution functions of local seismic demand for each component of each connection are provided using histogram sampling. Through a parametric study on probabilistic local seismic demand, the influence of some geometrical random variables on the performance of IBBC connections is demonstrated. Furthermore, the probabilistic study revealed that IBBC connection with widened flange has a better performance than the un-widened flange. Also, a design procedure is proposed for WF connections to achieve a same connection performance in different stories.

• 한국초전도ㆍ저온공학회논문지
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• 제21권2호
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• pp.1-9
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• 2019

Practical superconducting wires are designed with a composite structure to meet the desired engineering characteristics by expert selection of materials and design of the architecture. In practice, the local strain exerted on the superconducting component influences the electromagnetic properties. Here, recent progress in methods used to measure the local strain in practical superconducting wires and conductors using quantum beam techniques is introduced. Recent topics on the strain dependence of critical current are reviewed for three major practical wires: $Nb_3Sn$, BSCCO-2223 and REBCO tapes.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.403-410
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• 2004

In the conventional reinforced-concrete bridge deck, concrete and steels are likely to be deteriorated and corroded under the influence of noxious environment. To cope with these problems caused in the conventional reinforced-concrete bridge deck, pultruded composite bridge deck, called Delta Deck, is developed. In this paper, local deflection and fatigue characteristics of Delta Deck for DB24 truck load are evaluated through analysis and experiments.

• 천문학논총
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• 제30권2호
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• pp.451-452
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• 2015

We performed statistical analysis for a nearby (0.01 < z < 0.05) volume limited ($M_r$ < -19) sample of galaxies via visual inspection and the definition of galaxy pair systems based on the Sloan Digital Sky Survey Data Release 7 in order to confirm the effects of galaxy interaction on AGN activities. We found that local environmental effects such as galaxy interaction have an influence on the enhancement of the frequency and the strength of the AGN activity. This article is the summary of the paper which will be submitted soon.

• 한국콘텐츠학회논문지
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• 제14권10호
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• pp.279-286
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• 2014

최근 농산물 전자상거래의 거래액은 지속적으로 상승하고 있으나 농산물을 취급하는 전문몰의 거래액은 감소하고 있는 실정이다. 농산물의 다양한 유통구조에 따라 판매 가격의 차이가 발생하고 있고, 이러한 차이가 소비자들의 구매결정에 영향을 미치고 있다. 본 연구에서는 지방자치단체 농산물 쇼핑몰의 운영 개선 방안을 도출하고자, 영향요인을 품질, 배송, 가격으로 하여 만족과 재구매의도에 미치는 영향에 관하여 검증하고자 하였다. 검증 결과 품질, 배송, 가격이 만족에 유의한 정(+)의 영향을 미치고, 가격과 만족이 재구매 의도에 유의한 정(+)의 영향을 미치지만, 품질과 배송은 재구매의도에 유의한 정(+)의 영향을 미치지 못하는 것으로 나타났다. 영향요인으로 제시한 변수 중 가격에 가장 민감하게 반응하는 것으로 나타나다. 지자체 쇼핑몰의 운영 개선 방안으로 (1) 정확한 제품 정보의 전달, (2) 지속적인 운영 관리, (3) 다양한 이벤트 실시, (4) 소비자에게 다양한 혜택 제공, (5) 다양한 제품 구성, (6) 적절한 판매 방법의 선택, (7) 삼품 검색의 용이성 제공이 필요하며, 상대적으로 다양한 혜택 제공과 검색 용이성이 중요한 것으로 사료된다.

• 한국콘텐츠학회논문지
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• 제16권4호
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• pp.594-603
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• 2016

본 연구는 철도역세권을 단순한 개발과 계획적 측면에서만 접근하지 않고, 실제 개발에 따른 도입 기능 및 프로그램이 지역의 발전과 주민 삶의 질에 어떠한 영향을 미치며, 궁극적으로 철도역세권 복합화를 통한 지역 활성화 방안에 대해 정책적 시사점을 제시해 보고자 하였다. 연구 방법은 역세권 주변 실거주민들을 대상으로 철도역세권 복합개발이 지역 활성화에 미치는 요소와 구조를 PLS 구조방정식을 활용해 실증 분석하였다. 분석 결과, 지역경제 활성화에는 마케팅 지원, 환승시스템 지원, 설계 및 디자인 지원, 복합용도 개발 지원, 법 제도 개선 등의 소프트웨어 요소들과 교통 기능, 정보교류 기능, 상업업무 기능, 주거 기능, 어메니티 기능 등의 하드웨어 요소들이 유효한 영향을 미치는 것으로 나타났다. 그리고 지역주민 삶의 질 측면에서는 하드웨어적 요소가 유효한 영향을 미치는 것으로 분석되었으나 소프트웨어적 요소나 네트워크적 요소는 유효한 영향을 미치지 못하는 것으로 나타났다. 이에 비해 네트워크 요소는 지역경제 활성화와 주민 삶의 질에 크게 기여하지 못하는 것으로 나타나 이에 관한 정책적 보완이 필요하다.