• 한국전산유체공학회:학술대회논문집
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• 1998.05a
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• pp.67-74
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• 1998

Reducing drag of vehicles are the main concern for the body shape designers in order to lower fuel consumption rate and to aid the driving stability. The drag of bluff bodies like transportation vehicles is mostly pressure drag due to the flow separation, which can minimized by controlling the location and size of the separation bubble. In the present study, the TURBO-3D code is incorporated with optimal algorithm based on analytical approximation method to obtain optimal afterbody shape of the MIRA Model corresponding to the lowest drag coefficient. For this purpose three mutually independent afterbody angles are chosen as design variables, while the drag coefficient is chosen as an objective function. It is demonstrated in the present study that an optimal body shape having lowest drag coefficient which is about $6\%$ lower than that of the original shape has been successfully obtained within number of iterations of the optimal design loop.

• Journal of Welding and Joining
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• v.17 no.2
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• pp.84-90
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• 1999

The shape of weld nuggest in arc spot welding of 304 stainless steel was found by searching thermal history of a weld joint through a three-dimensional finite element model. The problem consists of one in which the finite element mesh is growing continuously in time in order to accomodate metal transfer in arc spot welding using element rebirth technique. The analysis was performed on the basis of experimental results. The finite element program MARC, along with a few user subroutines, was employed to obtain the numerical results. Temperature-dependent thermal properties, stir effect in weld pool, effect of phase transformation, and the convective and radiative boundary conditions are included in the model. Numerically predicted shape of weld nuggest is compared with the experimentally observed shape.

• Journal of information and communication convergence engineering
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• v.19 no.2
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• pp.73-78
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• 2021

As interest in beauty has increased, various studies have been conducted, and related companies have considered the anthropometric data handled between humans and interfaces as an important factor. However, owing to the nature of 3D human body scanners used to extract anthropometric data, it is difficult to accurately analyze a user's body shape until a service is provided because the user only scans and extracts data. To solve this problem, the body shape of several users was analyzed, and the collected anthropometric data were obtained using a 3D human body scanner. After processing the extracted data and the anthropometric data, a custom deep learning model was designed, the designed model was learned, and the user's body shape information was predicted to provide a service suitable for the body shape. Through this approach, it is expected that the user's body shape information can be predicted using a 3D human body scanner, based upon which a beauty service can be provide.

• Smart Structures and Systems
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• v.29 no.2
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• pp.311-319
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• 2022

A model of plastic deformation of the shape memory alloys which describes dislocation slip at the microlevel is developed. A condition similar to the Schmid law was adopted for the determination of dislocation slip onset. A description of the interaction of plastic deformation and martensitic transformations by taking into account the densities of deformation defects is proposed. It is shown that the model can correctly describe the effect of plastic strain on the shape memory effect. The proposed model is also capable of describing the two-way shape memory effect.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.5
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• pp.55-61
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• 2007

In this paper, we propose a three-dimensional(3D) active shape models for medical image segmentation. In order to build a 3D shape model, we need to generate a point distribution model(PDM) and select corresponding landmarks in all the training shapes. The manual determination method, two-dimensional(2D) method, and limited 3D method of landmark correspondences are time-consuming, tedious, and error-prone. In this paper, we generate a 3D statistical shape model using the 3D model generation method of a distance transform and a tetrahedron method for landmarking. After generating the 3D model, we extend the shape model training and gray-level model training of 2D active shape models(ASMs) and we use the integrated modeling process with scale and gray-level models for the appearance profile to represent the local structure. Experimental results are comparable to those of region-based, contour-based methods, and 2D ASMs.

• 한국전산유체공학회:학술대회논문집
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• 1995.10a
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• pp.49-54
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• 1995

A numerical analysis on the effect of the front shape on the aerodynamic characteristics of HST model is made, using FVM based general purpose 3D Navier-Stokes eq. solver, TURBO-3D program. Numerical solutions are compared with each case of different front shape for HST model. The result shows a good quantitative aerodynamic characteristic tendencies for variation of front shape of HST. Thus it may be used as a basis in the design of the shape of real HST.

• Transactions of Materials Processing
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• v.3 no.3
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• pp.302-319
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• 1994

A new approach to die shape optimal design in bimetal extrusion of rods is presented. In this approach, the design problem is formulated as a constrained optimization problem incorporated with the finite element model, and optimization of the die shape is conducted on the basis of the design sensitivities. The combinations of the core and sleeve materials.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.4
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• pp.75-82
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• 2018

BIM(Building Information Modeling) based design process can initiatively conduct a task through all phases from early design step to construction and maintenance step. Also BIM efficiently manage the building's energy by reflecting 3D design and construction life cycle. This paper proposes an efficient process to build AHU's BIM-based library. This study involves analyzing an AHU model for development of design module, and making the template model using the same 12 parts including the shapes of ducts, doors and frames. In consideration of each shape's direction and the status of existence, which are detailed shapes of parts upon making the template model, all the shapes of the AHU model can be expressed. By applying parametric modeling to the template model, a quick and precise modification and transformation can be conducted, thus the efficiency is enhanced. A user selects an AHU model from a 2D model selection program, and extracts shape information. The final AHU shape is completed through the automation work of unnecessary shape deletion by bringing the extracted shape information to the template model. This enables the user to build efficient AHU's BIM-based library, since the quick and precise modification and transformation of the template model are possibile, and all AHU model shapes can be expressed.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.857-862
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• 2009

In this study, the numerical study has carried out to analyze the leakage in a steam turbine labyrinth seal. We modified tooth shape of the labyrinth seal and finds out difference of leakage in this study. Original model is straight labyrinth seal and its modified model is slant labyrinth seal. The numerical analyses are implemented on two models. The numerical results show that each leakage of tooth shape are found 0.4781 kg/s and 0.4485 kg/s, respectively. Slant labyrinth seal seals in a steam better than straight labyrinth seal. Since, actual clearance of the stream function in the slant model is smaller than the straight model.

• Transactions of Materials Processing
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• v.20 no.5
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• pp.350-356
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• 2011

Shape memory alloys(SMAs) exhibit pseudoelastic behavior, characterized by the recovery of an original shape even after severe deformation, during loading and unloading within appropriate temperature regimes. The distinctive mechanical behavior is associated with stress-induced transformation of austenite to martensite during loading and reverse transformation to austenite upon unloading. To develop a material model for SMAs, it is imperative to consider the difference in moduli of active phases. For example, the Young’s modulus of the martensite is one-third to one half of that of the austenite. The model proposed herein is a modification of the one proposed recently by Ho[17]. The prediction of the behavior of SMAs during unloading before the onset of reverse transformation was improved by introducing a new internal state variable incorporating the variation of the elastic modulus.