• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.191.2-191.2
• /
• 2010

The conventional method to assess turbine performance is its model testing which becomes costly and time consuming for several design alternatives in design optimization. Computational fluid dynamics (CFD) has become a cost effective tool for predicting detailed flow information in turbine space to enable the selection of best design. In the present paper, Francis turbine of commercial small hydropower plants which is under 70kw is investigated. Solutions are investigated with respect to the hydraulic characteristics against an outward angle of guide vane, the number of guide vane and head (inlet velocity). By suitable modification of the runner shape, low pressure zone on the leading edge can be reduced. If the entire runner is to be optimized in this manner, flow simulation tests have to be carried out on a series of different geometrical shape.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.10 no.6
• /
• pp.5-10
• /
• 1973

The exact shape of the ceater conductor of a snaked line antenna is not important in determining it's radiating properties. An analysis is therefore made by standard priciples of a snaked line antenna having a simple shape for the center conductor. The approach leads to an explicit formula for the structure attenuation constant in terms of its geometrical parameters. Experimental results support the theory.

• The Research Journal of the Costume Culture
• /
• v.6 no.4
• /
• pp.84-103
• /
• 1998

The purpose of this study si focused on Futurism style and contemporary fashion in the 20th century, by researching the Giacomo Balla, Fortunato Depero, Tullio Crali, Erenesto Thayate characteristics fashion design. The results of this study are following as : The general traits of Futurism style are classified with aesthetics, formative characteristics. First, aesthetic characteristics are based on H. Bergson's life-phylosophy and F. Nietzche's art theory. Second, formative characteristics is Dynamism. Futurism Dynamism are classified with psychological Dynamism and physical Dynamism. Futurism trends in the costume : first, dynamism in fashion design, second, asymmetrical balance, third, formativeness, forth, technology, fifth, anti-traditionalism. Dynamism are expressed textile, pattern and costuem shape in contemporary dress. Asymmetrical balance are expressed costume silhouette shape and framework through the geometrical asymmetrical balance. Formativeness are agree with Paco Rabanne's fashion design expressed body and movement and phychological world of human through the secondly fabric. Technology are expressed new mechanical dynamism in used technology art and new fashion material by metal. The last, anti-traditionalism is recognized new value and idea in fashion.

• International Journal of Automotive Technology
• /
• v.6 no.4
• /
• pp.305-314
• /
• 2005

Injection rate shape control is one feature of a diesel fuel injection system that is strongly desired at this time. In the conventional common rail system, it is difficult to control the injection rate since the fuel pressure is constant during the injection period, resulting in a nearly rectangular rate shape. In order to look into possible injection modulations, injectors equipped with standard and geometrically modified control valves were investigated in detail by means of computer modelling and simulation. Experiments were carried out to validate the feasibility of such a shaping. The results of this study show a noteworthy dependence of the fuel rate on geometrical modifications in the piloting stage of the injector.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.12
• /
• pp.174-181
• /
• 1999

This paper describes the effect of the stylus tip size on the shape error in surface topography measurement. To analyze the distortional effect of an actual surface geometry origination from the finite stylus size, the surface is modeled as a sinusoid and the stylus tip as a circle. The magnitude of this distortion is defined as the ration of standard deviation, and this is expressed as an analytic function of the stylus tip radius and the geometrical parameter of a sinusoid. In this paper, the spectrum analysis of the profile is applied to investigate the distortional effect due to the mechanical filtering of the stylus in the frequency domain. and, the cumulative power spectrum is proposed to assess the shape error of measured data according to the various stylus tip sizes. From these results, a new method to select proper stylus tip radius is proposed.

• Korean Institute of Interior Design Journal
• /
• no.14
• /
• pp.74-81
• /
• 1998

It is character of Minimalism that representation as a simple shape extremely & objective acess that start from movement of visual art and part of music that began mainly at New York City in America at the end of 1960 period. Then in processing of development of Modernism Art it can be said that Minimalism reach the top of Modernism with that it carried out such character of formed Purity Doctrine of Modernism Art extremely and realized self-restorational character of Minimalism at the pictures that Minimalism is characterized by objectional clearness conceptual strictness reality and simplicity at the picture and by simplicity singularity uninterality and enviromentality at the sculpture. If we analyze Minimalic character in Interior design dividing into the density of space the principle of compound performance of touch and detail those are moderated and simple space simple and repeated compounding of geometrical line and shape the pure techniques of expression and the simplity of pure srtuctural -beauty in detail.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1999.04a
• /
• pp.260-267
• /
• 1999

In this paper, We propose the initial shape finding and dynamic analysis of cable dome structure are presented. Cable dome that is consist of three component such as cable, strut and fabric membrane have complex structural characteristics. Main structural system of cable dome is cable-strut tensegric system, and fabric membrane element Is conceived as cladding roof material. One of the important problem of cable dome is shape finding of those subjected to cable and membrane forces, which stabilize the structures. And the other is structural response from external load effect such as snow and wind When cable dome are subjected to dynamic load such as wind load each structural component has many important problem because of their special structural characteristics. One problem is that geometrical nonlinearity should be considered in the dynamic analysis because large deformation is occurred from their flexible characteristic. The other problem is that wrinkling occurs occasionally because cable and membrane elements can not transmit compressive forces. So this paper describe the physical structural response of cable dome structure.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1999.04a
• /
• pp.151-158
• /
• 1999

The single layer latticed domes have various behaviors with each geometrical shape and scale, and they are affected by vertical component as well as horizontal component of the dynamic load. And they represent very different earthquake responses under each ground acceleration compared with another structural systems. Generally, all of the members of latticed domes undergo three dimensional deflections if they are subjected to arbitrary one dimensional horizontal load under earthquake motions. And their response characteristics are very different to their shapes, rise/span ratios, and damping mechanisms. In this study the .earthquake response behavior is verified according to the factor of each shape, rise/span ratio, ana damping ratio of latticed domes, which undergo horizontal and vertical earthquake motions by numerical approaches.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.11a
• /
• pp.43-46
• /
• 2000

Optical triangulation displacement sensors(0TDSs) are widely used for their simple struchlre, high resolution, and long operating range. However, there are several factors that must be taken into account in order to obtain high accuracy and reliability Measurement errors from inclinations a？ an object surface, prohe signal fluctuations generated by speckle effects. power vanation of a light source, electronic noises, and so on. Previous models of OTDSs can not show reasonable behavior as change of surface inclination and shape of light intensity distribution on the detector. In this paper, we propose a new and reasonable modeling for diffise-type OTDSs based on a geometrical optics. To verify propriety of new modeling, we take basic experiments. Shape of light intensity distribution is asymmetric in both simulation result and experimental result. Both simulation result and experimental result show same tendency of light intensity distribution movement as changing surface inclination

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.04a
• /
• pp.25-28
• /
• 2008

This study investigates the effect of geometrical shape of concert halls, with variation in the shape and location of diffusers. The acoustical characteristics both in the audience area and on the stage 1:50 scale models of shoebox and fan-shaped halls. It was found that the front side walls affect sound diffusion. The 1:50 scale model based on the Boston Symphony Hall was used for monaural impulse response measurements for calculation of RT, EDT, C80, G and ST1. In addition, calculating the numbers and amplitudes of reflection rays were applied to quantify diffusion phenomena.