• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.891-897
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• 2006

The volume control method which utilize a pressure node added into a finite shell element can overcome the drawbacks of conventional load control method and displacement control method. In this study, an improved volume control method is introduced for effective analysis of path-dependant behaviors of RC structures subjected to cyclic loading. RC shell structures including RC hollow columns are anlayized by discretizing the structures with layered shell elements and by applying in-plane two dimensional constitutive equations for concrete layers and reinforcement layers of the shell elements. The so-called path dependant volume control method is verified by comparing analysis results with other data including experimental results.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.195-202
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• 1999

In this Paper, a so-called volume-control method for nonlinear failure analysis of reinforced concrete cylindrical structures is proposed. The pressure node which defines uniform change of pressure on finite element is added into layered shell element utilizing in-plane constitutive models of reinforced concrete and layered formulation. With the pressure node formulation, one can control the change in volume enclosed by the cylindrical structures and determine the required change in pressure. An algorith of volume-control method is employed and failure analyses for RC cylindrical structures are carried out using proposed method.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.275-280
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• 2004

Shape optimization was performed to obtain the precise shape of cutouts including the internal shape of cutouts in laminated composite plates by three dimensional modeling using solid element. The volume control of the growth-strain method was implemented and the distributed parameter chosen as Tsai-Hill fracture index for shape optimization. The volume control of the growth-strain method makes Tsai-Hill failure index at each element uniform in laminated composites under the initial volume. Then shapes optimized by Tsai-Hill failure index were compared with those of the initial shapes for the various load conditions and cutouts. The following conclusions were obtained in this study. (1) It was found that growth-strain method was applied efficiently to shape optimization of three dimensional cutouts in a laminate composite, (2) The optimal shapes of the various load conditions and cutouts were obtained, (3) The maximum Tsal-Hill failure index was reduced up to 67% when shape optimization was peformed under the initial volume by volume control of growth-strain method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.585-590
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• 2003

To overcome the drawbacks of conventional load control method and displacement control method, the so-called volume control method was developed by utilizing a pressure node added into a finite shell element. In this study, an improved volume control method which can analyze path-dependant behaviors of RC shell structures subjected to cyclic loading effectively is developed. RC shell structures are discretized with layered shell elements and in-plane two dimensional constitutive equations for concrete and reinforcements are implemented for each layer of the shell elements. Validity of the so-called path dependant volume control method is also verified by comparing analysis results with other data including experimental results.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.277-282
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• 2003

The growth-strain method was applied to cutout optimization in laminated composite plates. Since the growth-strain method optimizes a shape by generating the bulk strain to make the distributed parameter uniform, the distributed parameter was chosen as Tsai-Hill value. In this study, of particular interest is to see whether the growth-strain method developed for shape optimization in isotropic media would work for laminated composite Plates. In volume control of the growth-strain method, it makes Tsai-Hill value at each element uniform in laminated composite plates under the predetermined volume. The shapes optimized by Tsai-Hill fracture index were compared with those of the initial shapes for the various load conditions and predetermined volumes of laminated composite plates. As a result, it was verified that volume control of the growth-strain method worked very well for cutout optimization in laminated composite plates.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.461-464
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• 2003

A new control volume finite element method is proposed for three dimensional analysis of polymer flow. Tetrahedral finite element is employed and co-located interpolation procedure for pressure and velocity is implemented. Inclusion of pressure gradient term in the velocity shape functions prevents the checkerboard pressure field from being developed. Vectorial nature of pressure gradient is considered in the velocity shape function so that velocity profile in the limit of very small Reynolds number becomes physically meaningful. The proposed method was verified through three dimensional simulation of pipe flow problem for Newtonian and power-law fluid. Calculated pressure and velocity field showed an excellent agreement with analytic solutions for pressure and velocity. Driven-cavity problem, which is reported to yield checkerboard pressure filed when conventional finite element method is applied, could be solved without yielding checkerboard pressure field when the proposed control volume finite element method was applied. The proposed method could be successfully applied to the three dimensional mold filling problem.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.12
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• pp.628-637
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• 2017

This study was conducted to present an effective control method for the common duct system to uniformly discharge volume flow rate exhausted from the kitchen and bathroom of each household in an apartment regardless of the position of household. Since the common duct system is installed vertically and the ventilator is installed in the terminal, the static pressure of each household decreases when vertical height increases. Therefore, the volume flow rate exhausted from each household is different. In order to improve such a phenomenon, a constant air volume damper shall be installed in a branch duct coupled with a common vertical duct system. The selected ventilator should also be able to handle the maximum volume flow rate considering diversity factor. Therefore, a uniform volume flow rate must be exhausted from all households where the hood is operated. This paper mainly focuses on suggestion of an optimum exhaust control method by comparing exhaust performance of each household according to the presence or absence of a constant air volume damper.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.4
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• pp.16-22
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• 2004

Shape optimization was performed to obtain the precise shape of cutouts including the internal shape of cutouts in laminated composite plates by three dimensional modeling using solid element. The volume control of the growth-strain method was implemented and the distributed parameter chosen as Tsai-Hill fracture index for shape optimization. The volume control of the growth-strain method makes Tsai-Hill failure index at each element uniform in laminated composites under the initial volume. Then shapes optimized by Tsai-Hill failure index were compared with those of the initial shapes for the various load conditions and cutouts. The following conclusions were obtained in this study (1) It was found that growth-strain method was applied efficiently to shape optimization of three dimensional cutouts in a laminated composite plate, (2) The optimal shapes on the various load conditions and cutouts were obtained, (3) The maximum Tsai-Hill failure index was reduced up to 67% when shape optimization was performed under the initial volume by volume control of growth-strain method.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.577-582
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• 2000

The pseudo-volume control method is developed for the failure analysis of RC slabs, by adding pressure node into layered shell element utilizing in-plane constitutive models of reinforced concrete and layered formulation. For the failure analysis of RC slabs n this paper, geometric nonliearity is also considered in the analysis. The validity of the pseudo-volume control method is verified by comparing analysis results and existing experimental results.

• Journal of The Korean Society of Integrative Medicine
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• v.3 no.3
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• pp.89-94
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• 2015

Purpose : This study was analyzed to researched the improvement of the posture and breathing ability on correction method of posture and breathing exercise in Forward Head Posture(FHP) Method : Eighten forward head posture subjects participated in this study. The control group applied to correction method of posture and the experiment group applied to correction method of posture with breathing exercises. Results : The results showed significant improvement in Craniovertebra-Angle on each two group(P<0.05). All the other result showed non-significant in respiratory(Tidal volume, Expiratory residual volume, Inspiratory residual volume) But value of result is slightly improved in after exercise. Conclusion : CVA angle is increased in each group but not increased between experiment group and control group. Total Volume(TV), Inspiratory Reserve Volume(IRV) and Expiratory Reserve Volume(ERV) are a little increased.