• Computers and Concrete
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• 제4권4호
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• pp.259-272
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• 2007

A method based on the lower-bound theorem of limit analysis is presented for the capacity assessment of nodal zones in strut-and-tie models. The idealized geometry of the nodal zones is formed by the intersection of effective widths of the framing struts and ties. The stress distribution is estimated by dividing the nodal zones into constant stress triangles separated by lines of stress discontinuity. The strength adequacy is verified by comparing the biaxial stress field in each triangle with the corresponding failure criteria. The approach has been implemented in a computer-based strut-and-tie tool called CAST (Computer-Aided Strut-and-Tie). An application example is also presented to illustrate the approach.

• 한국강구조학회 논문집
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• 제15권5호통권66호
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• pp.531-539
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• 2003

노스리지 지진 발생시 구조체 손상이 발생했던 현장용접 모멘트골조와 달리 기둥-보 브라켓형식의 모멘트골조에는 지진의 영향을 조정하고 감소시키는 도구(tool)가 바로 보에 이음부(splice)이다. 지진발생 중에 보의 이음부는 연성의 퓨즈(fuse)로서 작용할 수 있고, 골조에 발생할 수 있는 흼모멘트를 포함한 힘의 크기를 제한할 수 있다. 국내에서는 모멘트 골조의 대부분이 기둥-보 브라켓 형식으로 이루어진다. 본 논문에서는 이음하지 않은 H형강보를 제작하여 단순가력 실험을 수행하였고, 고력볼트를 이용하여 전강도설계된 실물실험체와 플랜지볼트 열수를 각각 75%, 50% 및 0%로 줄여서 이음부를 제작한 H형강 보를 단순가력 실험을 수행하였다. 이들 실험을 통해 기둥-보 브라켓형식의 모멘트 골조에서 보의 이음부(Beam Splice)가 악보(Week Beam)의 임계위치(Critical Point)로서 작용할 수 있는 가능성을 타진하고자 하는 연구에 기초자료를 제공하는 것이 본 연구의 목적이다.

• 풍력에너지저널
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• 제13권3호
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• pp.5-12
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• 2022

A methodology of wind turbine blade design has been established with PROPID code, which is an aerodynamic blade design tool developed by UIUC. PROPID code can design and analyze a wind turbine blade in a steady state flow. The methodology of wind turbine blade design includes an initial blade concept design, airfoil selection, basic design, and detailed design steps. Inverse design and performance analysis of the 2.3 MW U113 wind turbine blade was performed to verify the wind turbine blade design methodology. The differences in calculated power between PROPID code and GH Bladed code are under 1.0% in all wind conditions. Both blade shape design and performance analysis results using PROPID code are accurate. The aerodynamic characteristics of a U113 blade were investigated by computational fluid dynamics. Separation flow was captured by a Reynolds-averaged Navier-Stokes steady flow simulation using ANSYS CFX code. The numerical aerodynamic analysis methodology was verified by comparing the analysis results through CFD with BEMT-based program GH Bladed code results. Therefore, the blade design methodology will be applied to develop a super-capacity 20 MW wind turbine blade in the future.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.178-183
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• 2004

The main objective of the present study is to analyze the feasibility of fuel cell powered vehicle, which leads to carry out system design and performance analysis. The major design concepts which include battery, driving motor, and fuel cell module are analyzed and discussed for the future development. The traction power of fuel cell vehicle is calculated according to the driving courses specified. Further, the fuel cell stack is analyzed to determine the capacity of stack as a function of velocity for the appropriate power required.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.448-451
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• 2005

This paper presents the methodology to analyze flow duration characteristics and performance prediction for small hydro power(SHP) plants and its application. The flow duration curvecan be decided by using monthly rainfall data at the most of the SHP sites with no useful hydrological data. It was proved that the monthly rainfall data can be characterized by using the cumulative density function of Weibull distribution and Thiessen method were adopted to decide flow duration curve at SHP plants. And, the performance prediction has been studied and development. One SHP plant was selected and performance characteristics was analyzed by using the developed technique. Primary design specfications such as design flowrate, plant capacity, operational rate and annual electricity production for the SHP plant were estimated. It was found that the methodology developed in this study can be a useful tool to predict the performance of SHP plants and candidate sites in Korea.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.894-898
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• 2006

A model, which can analyze the hydrological performance for small hydropower(SHP) plants having no flow duration characteristics has been studied and developed. System performance of existing SHP plant under operating was analyzed by using the developed model. The annual operational rate of SHP plant showed that the data were in good agreement with predicted results from the model. Based on these results, several SHP sites to be exploited were selected and the performance characteristics were analyzed by using the developed model. Also, primary design values such as design flow rate, plant capacity, and operational rate were suggested. As a result, it was found that the methodology used in this study is useful tool to predict the hydrological system performances of SHP sites.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1294-1295
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• 2011

This paper describes a conceptual design of 10 MW class gearless type superconducting synchronous generator for wind turbine. The main benefits of gearless type generator are decrease of the process of maintenance and loss caused by drive-train. The designed generator improves efficiency of high-capacity wind turbine by applying superconducting coil making high magnetic field. Conventional wind turbines were investigated for up-scaling of generator and the generator had been designed with estimated design parameters using a finite elements method analysis tool.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2006년도 추계학술발표대회 논문집
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• pp.193-196
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• 2006

The meaning of the color which has from modern interior space has played important role, i.e. color itself Is the concept creation tool as well as the unique expression sphere in field of interior space far away from fixed idea relevant to the existing color which was only simple decoration or secondary element in space. Thus, this current work expresses that the color is related with decoration effect as well as basic designed-conceptual work process including the space is formed. Furthermore, through the side-composition with color, It activates the various space aspect perceptually, which created the colorful environment in using lightning, reflection of glass and penetrated nature etc. The keyword on color concept is as like various aspects, third dimension, non-materiality and symbolical meaning. In addition, it provides the color space equipped with functionality and artistry capable to arouse the diverse sensual capacity to space users on default of color image language.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.245-250
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• 1999

In order to design micro-fan appropriately, flow chacracteristics and mechanics should be carefully considered. The present work concerns with design procedure for a micro-fan using NACA(National Advisory Committee for Aeronautics) airfoil series. The generation of fan profiles is carried out automatically by defining related parameters, which is also converted to CAD/CAM data automatically. The optimal parting surface for the mold of micro-fan is also calculated by analyzing the geometric data numerically. As a consequence, the high capacity micro-fan can be developed successfully with a high-quality and an improved efficiency.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.742-747
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• 2005

A model, which can analyze the hydrological performance for small hydropower(SHP) plants having no flow duration characteristics has been studied and developed. System performance of existing SHP plant under operating was analyzed by using the developed model. The annual operational rate of SHP plant showed that the data were in good agreement with predicted results from the model. Based on these results, several SHP sites to be exploited were selected and the performance characteristics were analyzed by using the developed model. Also, primary design values such as design flow rate, plant capacity, and operational rate were suggested. As a result, it was found that the methodology used in this study is useful tool to predict the hydrological system performances of SHP sites.