• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.302-305
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• 2005

In this study, settlement characteristics of 38 CFRD was investigated from monitoring data and the method to estimate the dam settlements considering valley shape during constructions was proposed. The construction modulus of dam was found to be dependent on void ratios and valley shape factor. The construction modulus varied with valley shape and decreased with increasing void ratio. Also, the modulus was increased when the shape coefficient was less than 4. The settlement investigation results showed that the total settlement was proportional to the value of the settlement coefficient multiplied by the shape coefficient divided by void ratio.

• Journal of Mechanical Science and Technology
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• 제17권11호
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• pp.1665-1673
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• 2003

We propose an image-based three-dimensional shape determination system. The shape, and thus the three-dimensional coordinate information of the 3-D object, is determined solely from captured images of the 3-D object from a prescribed set of viewpoints. The approach is based on the shape-from-silhouette (SFS) technique, and the efficacy of the SFS method is tested using a sample data set. The extracted three-dimensional shape is modeled with polygons generated by a new iterative triangulation algorithm, and the polygon model can be exported to commercial software. The proposed system may be used to visualize the 3-D object efficiently, or to quickly generate initial CAD data for reverse engineering purposes, including three dimensional design applications such as 3-D animation and 3-D games.

• 소성∙가공
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• 제10권3호
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• pp.185-192
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• 2001

In order to obtain the optimal products in deep drawing process, elliptical deep drawing tests were carried out with several shape radii of the punch and die. As parameters on testing, shape radii of the punch and die were selected. In addition, the conventional shape radii have been determined by trial-and-error using industrial experience and post processing test, and only approximate shape radii of the punch and die have been presented. The optimal shape radii of the punch and die in elliptical deep drawing process with biaxisymmetric blank shape are proposed. In this study, we suggest the appropriate conditions to be applicable to the actual manufacturing processes through the experiment and finite element method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.672-678
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• 1993

The bead shape in high frequency electric resistance (HER) pipe welding gives important information ons judging current welding state. In most manufacturing process, the heat input is controlled by skilled operators observing color and bead shape. We proposed the bead shape monitoring system in HERW pipe process by using structured light beam. We reconstructs 3-D shape of bead from the measured data, and compare this shape with real 3-D shape obtained by coordinate-measuring machine. This experiment results show that the proposed system can monitor the bead shape with good accuracy.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1068-1071
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• 1996

Good shape on flat rolled product is necessary to meet today's customer quality requirement. To meet the increasing demand in quality of strip shape from downstream customers, POSCO has replaced the Automatic Shape Control(ASC) system with the existing one that had used noncontact type measuring system at No.2 Cold Rolling Mill, Pohang works in October, 1995. The strip shape is influenced by the profile, roll crown, bending control, skew control system, as well as work roll cooling system. We have used ASC to adjust those factors in Cold Rolling Mill that could get a satisfactory result, almost less than .+-.5 1-unit deviation from the target shape. However, the downstream customer(i.e. Continuos Annealing Line) wants a good shape not only at the moment of exit of roll bite, but after rolling without tension. In this investigation, the difference will be discussed and how deal with this problem.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.175.2-175
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• 2001

The strip profile and shape control is one of the most important technologies in Hot Rolling Mill System. Because the unbalance of strip´s shape and wave appearance between stands has a bad effect on Hot Rolling Mill System by making the inferior thickness, strip´s damage and so forth in factories. Many competition Plate Mill introduced shape control system, for example, pair cross-mill, work roll bender, which includes shape measuring instruments and shape control mathematical models. Shape meter, which is equipped for flatness, only does feedback control at the top of coil. And, for crown, we depend on initial setup value and there is no feedback control. Therefore we predict the shape of strip using rolling pressure, bender force and tension of inter-stand in ...

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.88-91
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• 2007

In the shape design optimization of an airfoil, the shape function has been used to find the optimal airfoil shape for given conditions. The parameters determining the airfoil shape are used in the shape design optimization as design variables. However, they usually don't have physical meaning. The PARSEC (Parametric Shapes) function is a recently proposed shape function and its parameters have the physical meaning. In this study the usefulness of the PARSEC is tested for the RAE2822 airfoil in the transonic flow region to reduce the shock strength and the result is compared with Hicks-Henne function. The optimized airfoils reduce the shock strength and they show similar result.

• 대한기계학회논문집A
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• 제26권12호
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• pp.2503-2510
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• 2002

Since the first shape-form-shading technique was developed by Horn in the early 1970s, many different approaches have been continuously emerging in the past three decades. Some of them improve existing techniques, while others are completely new approaches. Using the image reflectance equation, they estimate the 3-D shape of an object utilizing adequate constraints. Each algorithm applies different constraints such as brightness, smoothness, and integrability to solve the shape-from-shading problem. Especially for symmetric objects, a symmetry constraint is proposed to improve the performance of existing shape-from-shading algorithm in this paper. The symmetry constraint is imposed to a conventional algorithm and then the improvement in the performance of 3-D shape reconstruction is proved by quantitatively comparing the depth and gradient errors.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.349-352
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• 2001

Shape separation method - a separation process which utilizes the fact that particles of different shape behave differently in force fields- is regarded as an useful measure for recycling, mineral processing, upgrading powdered material and so on. In this study, a trial was given to shape separation method using fluid field to recover pure diatom skeleton - which is thought to have many uses in itself and potential for various applications -from low grade diatomaceous earth of southeastern part of the Korean Peninsula. The striking difference of shape between diatom skeleton and other minerals like clay and quartz made it natural to choose shape separation method. Considering the size of particles to be separated, among many possible methods of shape separation, hydrodynamic field using hydrocyclone was adopted. And it resulted in recovery of pure diatom skeleton with high purity

• 설비공학논문집
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• 제16권4호
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• pp.374-382
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• 2004

Diffuser design is crucial for water-chilled heat storage. Its impact on the system performance is more significant for the underground tank due to inherent limit on the aspect ratio and tank shape. The effect of diffuser shape on the performance of the water-chilled heat storage is numerically investigated. Three dimensional simulation has been conducted for fully incorporating the complex diffuser shape and the non-symmetric tank shape. Mixing at the inlet of the diffuser depends on the inlet Reynolds number, Froude number and the diffuser shape. Three types of the diffuser shape and the broad range of Reynolds number (Re=400, 800, 1200) and Froude number (Fr=0.5, 1.0, 2.0) are examined. The performance of the heat storage tank is evaluated by the thermocline thickness which is reverse to the degree of stratification. The radial regulated plate diffuser, which is the suggested diffuser shape in this study, shows the lowest thermocline thickness in the condition considered.