• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.967-972
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• 1995

원자력발전소 증기발생기 전열관의 레이저 용접을 위하여 광섬유 전송 레이저 용접광학계를 설계하고 분석하고 실제 레이저 용접에 활용코자 하였다. 이를 위해서 ㎾급 고출력 Nd:YAG 레이저의 출력변수에 맞춘 광성유 선정 및 sleeve 면에서의 용접 power density와 초점깊이를 고려한 광학계통 설계를 수행하였다. 레이저 출력변수가 150 mm.mrad이며 800$\mu\textrm{m}$의 광섬유를 사용하는 경우, 3회에 걸친 coupling으로도 광섬유 출사부의 F# 를 2.48 정도로 하는 것이 가능하며 이때 +- 0.5mm 정도의 초점깊이를 얻을 수 있었다.

• Korean Architects
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• s.619
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• pp.28-33
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• 2020

2017 경기도건축문화상 사용승인 부문 대상. '여주박물관 여마관'을 검색하면 나오면 수상기록이다. 검은 유리로 구성된 반듯한 건물과 남서쪽 모서리가 잘려나간 삼각면이 단정하면서 인상적이다. 검은 유리면은 하늘을, 삼각면은 남한강을 비추는 건물이 자연과 스스럼없이 어우러진다. 설계의 백미는 건물 안에 있다. 돌로 쌓은 층 위에 건물을 두고 건물 안 전면에 통유리를 설치해 남한강 상류와 파란 하늘이 바로 앞에 있는 듯 경이롭게 다가온다. 이곳을 설계한 이성관 건축사가 이곳을 설계한 나이는 68세였다. 현재는 72세, 현역이다. 지난 10월 8일 여주박물관 1층에서 이성관 건축사를 만났다.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.3
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• pp.18-24
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• 2011

In this paper, we present the load-deflection behavior of GRP pipes. GRP buried pipes are widely used in construction in the advantage of their superior mechanical and physical characteristics such as high chemical resistance, high corrosion resistance, right weight, smooth surface of the pipe, and cost effectiveness from soil-structure interaction. To design flexible pipes to be buried underground, it should be based on the ASTM D2412(2010). When applying ASTM D 2412(2010) to the design, pipe stiffness(PS) must be predetermined by the parallel-plate test which requires tedious and laborious working process. To overcome such problems, the finite element simulations for finding the load-deflection behavior of the GRP flexible pipes is installed at UTM testing machine. In the finite element simulations, basic data, such as the modulus of elasticity of the material and cross-sectional dimension, is used. From the investigation, we found that the difference between experimental result and analytical prediction is less than 15% when the pipe deflected 3% and 5% of its vertical diameter although the pipe material is not uniform across the cross-section.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.8
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• pp.633-643
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• 2015

In this study, we develop a highly efficient conical-air diffuser that generates fine bubble. By inserting a sufficient number of aerotropic microorganisms with dissolved oxygen from an air diffuser and minimizing the air-channel blockages within the air diffuser, we expect to improve the efficiency and durability of the decomposition process for organic waste. To upgrade the conventional air diffuser, we perform experiments and numerical analysis to develop a conical-type that generates fine bubble, and which is free from nozzle blockage. We complement the air-diffuser design by numerically analyzing the internal air-flow pattern within the diffuser. Then, by applying the diffuser to a mockup bioreactor, we experimentally and numerically study the bubble behavior observed in the diffuser and the 2-phase fluid flow in the bioreactor. The results obtained include statistics of the cord length and increased velocity, and we investigate the mechanisms of the fluid-flow characteristics including bubble clouds. Throughout the study, we systemize the design procedures for the design of efficient air diffusers, and we visualize the fluid-flow patterns caused by bubble generation within the mockup bioreactor. These results will provide a meaningful basis for further study as well as the detection of oxygen transfer and fluid-flow characteristics in real-scale bio-reactors using sets of air diffusers.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.171-174
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• 2004

본 논문은 Hspice 를 사용한 달팽이관 생역학의 능동적이며 선형적인 1 차 그리고 2 차원 모델링을 보여준다. Hspice 모델링의 장점은 달팽이관 생역학을 아날로그 IC 칩으로 구현할 수 있다는 점이다. 즉 Biochip 으로 설계하는데 활용된다. 본 논문은 달팽이관 생역학을 어떻게 전기회로 모델화한 뒤, 다시 어떻게 Hspice 코드로 표현하는 가를 보여준다. 달팽이관 회로가 Hspice 코드 실행을 위해 변형되어야만 하는 과정을 상세히 보여준다. 1 차원의 결과와 2 차원의 결과를 비교하고 있다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.1108-1113
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• 2005

한국정부가 제조물책임법을 2002년 7월에 도입한 이래, 많은 제조업체가 설계해석 툴의 도입을 검토하고 있다. 또한, 원청업체의 요청에 의해 설계해석 툴을 도입하기도 한다. 일반적으로 설계 해석 툴들은 엄청나게 복잡하고 방대한 지식을 포함하고 있기 때문에, 이 툴을 사용하는 해석 전문가 역시 전문가는 설계 및 분야에 관한 방대한 지식을 터득해야 한다. 따라서, 중소기업에 이런 툴을 도입하기 위해서는, 도입비용 뿐 아니라, 운용 인력 확보에도 상당한 애로를 겪고 있다. 본 연구에서는, 신축관을 설계하는 업체를 대상으로 하여, 신축관의 특성을 이해하기만 하면 해석이 가능한 시스템을 구축하여, 해석 툴의 사용자 범위를 확대하고자 한다. 이 목표를 달성하기 위하여, MS-Excel, MDT, ANSYS를 통합하였으며, 이 연구결과로, 특별한 교육을 받지 않은 설계자도 이 통합 시스템을 운용할 수 있고, 설계 및 검증 시간을 획기적으로 단축할 수 있음을 확인하였다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.684-689
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• 1998

전기출력 150 MWe(열출력 392 MWth)의 U-Zr 이원합금핵연료 사용 소형노심인 액채금속로 KALIMER 98.03 설계 노심에 대하여 열수력 특성을 분석하고, 그 결과를 97.07 설계 노심의 열수력 설계특성과 비교.분석하였다. 분석을 위해서 냉각재 유량배분 계산에 ORFCE-F, 유량배분에 따를 온도계산에는 ORFCE-T를 사용하였는데, 이들은 현재 KALIMER 개발의 개념설계 초기 단계에서 사용하고 있는 모듈이다. 열수력 특성 분석은 먼저 각 집합체의 출력과 핵연료봉의 최고 선출력에 따라 유량그룹을 설정하고, 각 집합체의 최고온도 연료봉에 대하여 냉각재 온도, 피복관 중심온도, 핵연료 중심온도 등을 계산하는 방식으로 수행한다 열수력 특성분석 결과 98.03 설계 노심이 97.07 설계 노심에 비해 노심내 출력분포가 더욱 평탄화 되어, 노심 유량영역은 16개에서 11개로 감소되었고, 그에 따를 온도계산에서도 피복관 중심에서의 2$\sigma$ 온도가 6$65^{\circ}C$에서 628$^{\circ}C$로 낮아지는 둥 매우 향상된 설계임을 알 수 있었다.

• Journal of Korea Water Resources Association
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• v.47 no.9
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• pp.777-787
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• 2014

Stormwater pipe systems are most commonly used to discharge rainwater from the urban catchment covered by the impervious area. To design stormwater pipe and rainwater pumping station, frequency analysis is implemented using historical rainfall and the design rainfall is timely distributed using theoretical shape such as Huff distribution. This method cannot consider the rainfall intensity variation caused by climate change which is type of uncertainty. Therefore, in this study, runoff from Gasan1 stormwater pumping stations catchment is calculated using design rainfall distributed by the 2nd quartile distribution method and the historical rainfall events. From the analysis, the nodal flooding in the urban catchment is likely caused by the high peak rainfall event rather than the large amount of rainfall. The linear regression analysis is implemented. As a result, when several storms have the same amount of rainfall, the nodal flooding in the stormwater pipe systems could be caused by the high peak of storm events. Since as the storm duration become short, the peak rainfall become high, the nodal flooding likely become severe with the short storm duration. The uncertainty in the peak data of design rainfall is analyzed and this uncertainty has to be consider in the stormwater pipe design process.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.1
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• pp.75-80
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• 1997

In other to construct a subway, we have to consider the position of the subway and acquisition of a topography, profile-map, cross-map, underground facilities map. All information of underground is demanded accurate location in other to prevent of accident of underground in subway construction. We must think about water lines, sewer lines, electronic lines, telephone lines, all urban gas-line because these are needed construction the subway. And attributes of underground facilities recorded on topography are characteristics. length, width. number, position, and depth of the lines. We have to record these attributes because these are very important to design map on subway construction. If we develop GIS (Geographic Information System) to use the exact in-formation of the underground facilities, we can be management safely and prevent very dangerous accident as fast as possible. In this study, attribute informations are linked geographic informations about underground facilities and we can develop Underground Facilities Management System(UFMS) to analysis dangerous region through dangerous degreed and predict accident range with these informations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.6
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• pp.1375-1383
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• 1994

The water distribution system problem consists of finding a minimum cost system design subject to hydraulic and operational constraints. Since the municipal water distribution system problem is nonconvex with multiple local minima, classical optimization methods find a local optimum. An outer flow search - inner optimization procedure is proposed for choosing a better local minimum for the water distribution systems. The pipe network is judiciously subjected to the outer search scheme which chooses alternative flow configurations to find an optimal flow division among pipes. Because the problem is nonconvex, a global search scheme called Stochastic Probing method is employed to permit a local optimum seeking method to migrate among various local minima. A local minimizer is employed for the design of least cost diameters for pipes in the network. The algorithm can also be employed for optimal design of parallel expansion of existing networks. In this paper one municipal water distribution system is considered. The optimal solutions thus found have significantly smaller costs than the ones reported previously by other researchers.