• Steel and Composite Structures
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• 제6권5호
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• pp.367-386
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• 2006

This paper describes the results of a numerical investigation of the large deflection behaviour of steel beams under fire conditions, taking into consideration the effect of catenary action provided by the surrounding structures. The main focus is on the development, validation and application of a simplified calculation method that may be adopted in design calculations. Because no experimental result is available for validation of the simplified calculation method, the finite element program ABAQUS has been used to simulate the large deflection behaviour of a number of steel beams so as to provide alternative results for validation of the proposed method. Utilising catenary action has the potential of eliminating fire protection to all steel beams without causing structural failure in fire. However, practical application of catenary action will be restricted by concerns over large beam deflection causing integrity failure of the fire resistant compartment and additional cost of strengthening the connections and the surrounding structures to resist the catenary forces in the steel beams. This paper will provide a discussion on practical implications of utilising catenary action in steel beams as a means of eliminating fire protection. A number of examples will then be provided to illustrate the type of steel framed structure that could benefit the most from exploiting catenary action in fire resistant design.

• Structural Engineering and Mechanics
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• 제42권4호
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• pp.551-570
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• 2012

An experimental program was carried out to investigate the influence of fibre reinforcement on the mechanical behaviour of high strength reinforced concrete beams. Eighteen beams, loaded in four-point bending tests, were examined by applying monotonically increasing controlled displacements and recording the response in terms of load-deflection curves up to failure. The major test variables were the volume fraction of steel fibres and the transverse steel amount for two different values of shear span. The contribution of the stirrups to the shear strength was derived from the deformations of their vertical legs, measured by means of strain gauges. The structural response of the tested beams was analyzed to evaluate strength, stiffness, energy absorption capacity and failure mode. The experimental results and observed behaviour are in good agreement with those obtained by other authors, confirming that an adequate amount of steel fibres in the concrete can be an alternative solution for minimizing the density of transverse reinforcement. However, the paper shows that the use of different theoretical or semi-empirical models, available in literature, leads to different predictions of the ultimate load in the case of dominant shear failure mode.

• 한국컴퓨터정보학회논문지
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• 제3권4호
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• pp.145-153
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• 1998

전자문서관리는 정부와 기업 등 현대조직의 지나친 종이문서주의에서 발생한 비효율성을 극복하고 조직의 경쟁력을 제고시킬 수 있는 중요한 대안이다. 미국 등 선진국에 비하여 우리나라 정부나 기업은 오래된 관료문화로 인하여 전자문서관리에 대한 인식이 부족하고 그 활용에 따르는 여러 가지 장점을 무시해 왔다. 그러나 전자문서관리는 전자문서유통, 전자결재와 서명, 전자우편과 전자게시판, 전자정보 공개와 정보공유 및 공동활용 등을통하여 조직성과를 극대화할 수 있는 효과를 가지고 있다. 이 점에서 전자문서관리시스템의도입은 절실히 요청되고 있다. 그러나 전자문서관리시스템의 정착을 위해서는 관련법제도의정비, 직원의 의식과 행태의 개혁, 전자문서관리 시스템의 기술적 기반구축, 전자문서 작성기와 포맷의 표준화 등이 이루어져야 한다.

• Archives of Pharmacal Research
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• 제18권3호
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• pp.141-145
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• 1995

Omeprazole, a proton pump inhibitor, was given intravenously (iv), orally (po), intraperitoneally (ip), hepatoportalvenously (pv), and intrarectally (ir) to rats at a dose of 72mg/kg in order to investigate the bioavailability of the drug, The extent of bioavailabilities of omeprazole administered through pv, ip, po, and ir routes were 88.5, 79.4, 40,8, and 38.7%, respectively. Pharmacokinetic analysis in this study and literatures (Regardh et al., 1985 : Watanabe et al., 1994) implied significant dose-dependency in hepatic first-pass metabolism, clearance and distribution, and acidic degradation in gastric fluid. The high bioavailability from the pv administration (88.5%) means that only 11.5% of dose was extracted by the first-pass metabolism through the liver at this dose (72 mg/kg). The low bioavailability from the oral administration (40.8%) in spite of minor hepatic first-pass extraction indicates low transport of the drug from GI lumen to portal vein. From the literature (Pilbrant and Cederberg, 1985), acidic degradation in gastric fluid was considered to be the major cause of the low transport. Thus, enteric coating of oral preparations would enhance the oral bioavailability substantially. The bioavailability of the drug from the rectal route, in which acidic degradation and hepatic first-pass metabolism may not occur, was low (38.7%) but comparable to that from the oral route (40.8 %) indicating poor transport across the rectal membrane. In this case, addition of an appropriate absorption enhancer would improve the bioavailability. Rectal route seems to be an possible alternative to the conventional oral route for omeprazole administration.

• 한국환경과학회지
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• 제23권4호
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• pp.571-584
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• 2014

The present study aims to apply a surface image velocimetry(SIV) system to video images captured with CCTV and estimate the flood discharge. The CCTV was installed at the Hancheon Bridge of the Han Cheon in Jeju Island for disaster surveillance, and seven flood events occurred in 2012 were used. During the image analyses, input parameters, interrogation areas and searching areas were determined with proper calibration procedures. To check for accuracy and applicability of SIV, the velocities and flood discharges estimated by SIV were compared with the measured ones by an electromagnetic surface velocimeter, Kalisto. The comparison results showed fairly good agreements. The RMSE(Root Mean Square Error) values between two instruments showed a range of 4.13 and 14.2, and the determination coefficients reached 0.75 through 0.85. It means that the SIV could be used as a good alternative method for other traditional velocity measuring instruments in measuring flood discharges.

• KIEAE Journal
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• 제10권5호
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• pp.23-30
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• 2010

The residence means a given place. It is repeated that process of overcome, protection, assimilation and adaptation has applied to environmental condition. Architecture is part of environment and various. Thus there are lots of types. We need the place with uniqueness, and it is suitable for biological and humanistic environment. The living space turned to be meaningful place with design, and people start to live with nature together. Therefore design restructures whole environment and makes people to be closed with nature. We have to understand nature of environment to connect one place with the other place, and people start to put down roots certain place. Coping with social needs, we have to develop the architectural alternative which can be applied to natural condition. This study suggest sound high-density urban residential model as it function social mix.

• 한국통신학회논문지
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• 제29권9B호
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• pp.818-825
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• 2004

고가용정 (high availability) 이란 하드웨어, 소프트웨어, 네트워크 등에 문제가 발생하였을 때 지속적으로 서비스를 제공해주는 가술을 말한다. 고가용성은 정보화 시대의 도래, 전자 상거래의 발전 및 정보 및 멀티미디어 서비스 등의 컴퓨팅 환경의 변화에 따라 점차 중요시되고 있다 특히 하루 24시간 일년 내내 서비스를 제공해 주어야 하는 네트워크 컴퓨팅 부분에서 고가용성은 필수 불가결한 것으로 인식되고 있다. 이에 본 논문에서는 멀티미디어 관광 정보시스템 (Multimedia Tourism Information System)을 위해서 고가용정 (high-availability) 리녹스 (Linux) 서버에 대해서 분석 연구 하여, 대안을 제시 하고자 한다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권8호
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• pp.373-380
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• 2003

This paper consists of a study in post-assembly magnetization of LSPM (Line Start Permanent Magnet Motor). Recently, LSPM is noted as an alternative to the induction motor because it offers a very high efficiency and unity power factor, And it is necessary for permanent magnets to be magnetized by means of post-assembly magnetization in LSPMS because of the manufacturing cost involved. The manufacturing process is also simpler in post-assembly magnetization than in pre-assembly magnetization. Generally, permanent magnet motors are magnetized by their own stator coil or by magnetizing fixtures. However, the permanent magnet in a LSPM is scarcely magnetized by using them because of the eddy current of the rotor bar. Hence, it is necessary to design a magnetizing fixture that overcomes this problem. In this paper, the author analyses the post-assembly magnetization of a LSPM and proposes a method for designing the magnetizing fixture. The method that the author proposes is to make the number of coil turns greater in order to reduce the effect of the eddy current of the rotor bars.

• Advances in Energy Research
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• 제1권2호
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• pp.127-146
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• 2013

Torrefaction technologies convert assorted biomass feedstocks into energy-concentrated, carbon neutral fuel that is economically transported and easily ground for blending with fossil coals at numerous power plants around the world without needs to retrofit. Utilization of torrefied biomass in conventional electric generating units may be an increasingly attractive alternative for electricity generation as aging power plants in the world need to be upgraded or improved. This paper examines the economic feasibility of torrefaction in different scenarios by modeling torrefaction plants producing 136,078 t/year (150,000 ton/year) biocoal from wood and corn stover. The utilization of biocoal blends in existing coal-fired power plants is modeled to determine the demand for this fuel in the context of emerging policies regulating emissions from coal in the U.S. setting. Opportunities to co-locate torrefaction facilities adjacent to corn ethanol plants and coal-fired power plants are explored as means to improve economics for collaborating businesses. Life cycle analysis was conducted in parallel to this economic study and was used to determine environmental impacts of converting biomass to biocoal for blending in coal-fired power plants as well as the use of substantial flows of off-gasses produced in the torrefaction process. Sensitivity analysis of the financial rates of return of the different businesses has been performed to measure impacts of different factors, whether input prices, output prices, or policy measures that render costs or rewards for the businesses.

• 한국실내디자인학회논문집
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• 제29호
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• pp.103-111
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• 2001

The ideal housing in the 21st century means that it can provide people with the balanced life between nature and human life, while is possible through the systematic harmony of nature, environment, and human. As our society increasingly pays attention to the importance of environment, environment friendly houses and ecological dwellings are being built. If we add our own cultural environment attribute and historical identity to the ecological housing, we can create the most unique Korean ecological architecture. This study examines ecological interior expression methods from the traditional housing architecture which started out of nature, in order to find out an ecological approach in the interior design of the dwelling space. Based upon this examination, it mainly focuses on how these methods can be applied to a modern housing architecture. From an ecological perspective, the traditional house interior has two distinct characteristics; nature friendly and human friendly, because it considered nature and human harmoniously. The interior of the traditional housing can be divided into three types; nature friendly, health friendly, and human friendly. Finally, this study investigates the ecological value of the three types and application of them to modern housing. It will help to find out the harmonious way of building a house harmonizing both nature and human. Especially, considering that the nature is being destructed and the health of human is deteriorating due to the destruction of the nature, this study will show a feasible alternative to build the most Korean style of environmental architecture.