• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.460-462
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• 2005

Asymmetrical rolling was performed with different working roll speeds of upper and lower rolls. In order to promote the shear deformation during asymmetrical rolling, various deformation parameters of initial sheet thickness, rolling reduction, roll speed ratio and roll radius are considered. The evolution of texture during asymmetrical rolling was shown by the calculation of orientation distribution function (ODF). The effect of deformation parameters on shea. deformation were investigated by simulations with the finite element method (FEM). Asymmetrical rolling gave rise to the development of pronounced strain gradients throughout the thickness layers which resulted in the formation of strong texture gradients in the sheet.

• Journal of Plant Biology
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• v.26 no.3
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• pp.131-139
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• 1983

Temperature response of amoebae of thermotactic mutants have been investigated. Amoebae of the mutant strain HO 428 showed positive thermotaxs which is strong at lower temperaturs and drops sharply above the growth temperature of amoebae. The temperature response of HO 428 amoebae was not affected by the length of amoebae on the grdients. HO 596 amoebae seemed to have both positive and negative thermotactic responses shortly after food depletion. Longer exposure of these amoebae on the thermal gradients induced a stronger negative response at lower temperatures and an apparent positive response at higher temperatures. A similar changes could be observed in HO 1445 amoebae. Based on the steady positive thermotactic response by HO 428 amoebae and the mode of change in termperature response at higher temperatures, 24$^{\circ}C$ and $25^{\circ}C$, by HO 596 amoebae, a model for the temperature response of vegetative Dictyostelium discoideum amoebae, strain HL 50, has been proposed. The main features of the model are: a positive response at the thermal gradients with midpoint temperatures lower than the growth temperatures of amoebae and a negative response above it.

• Korean Journal of Materials Research
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• v.11 no.9
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• pp.721-726
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• 2001

Directional solidification experiments have been carried out at the solidification rates from 0.5 to 50$\mu\textrm{m}$/s in Mar M-247LC superalloy in which several important liquid properties were estimated by analyzing the interface stability and temperature gradient at the solid/liquid interface. The diffusion coefficient in the liquid was estimated by employing the constitutional supercooling criterion. The temperature gradients changed with solidification rates and latent heat of solidification. The thermal conductivities of solid and liquid could be estimated by heat flux balance at the solid liquid interface.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.1
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• pp.157-173
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• 2015

In the present study, the existing equivalent stain method is improved to make up for its weaknesses. The improved inherent strain model is built considering more sophisticated three dimensional constraints which are embodied by six cubic elements attached on three sides of a core cubic element. From a few case studies, it is found that the inherent strain is mainly affected by the changes in restraints induced by changes of temperature-dependent material properties of the restraining elements. On the other hand, the degree of restraints is identified to be little influential to the inherent strain. Thus, the effect of temperature gradients over plate thickness and plate transverse direction normal to welding is reflected in the calculation of the inherent strain chart. The welding deformation can be calculated by an elastic FE analysis using the inherent strain values taken from the inherent strain chart.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.11
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• pp.773-780
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• 2010

The dispersion of plume which is emitted from a chimney is governed by a lot of factors： wind, local terrain, turbulence intensity of atmosphere, and temperature, etc. In this study, we numerically investigate the plume dispersions for various altitudinal temperature gradients and wind speeds. The normal atmosphere has the temperature decrease of $0.6^{\circ}C/100m$, however, actually the real atmosphere has the various altitudinal temperature profiles according to the meteorological factors. A previous study focused on this atmospheric temperature gradient which induces a large scale vertical flow motion in the atmosphere thus makes a peculiar plume dispersion characteristics. In this paper, the effects of the atmospheric temperature gradient as well as the wind speed are investigated concurrently. The results for the developing processes in the atmosphere and the affluent's concentrations at the ambient and ground level are compared under the various altitudinal temperature gradients and wind speeds.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1131-1134
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• 2009

Preparation of graded materials displaying gradients of desired properties is one of the important issues and less-developed areas in materials chemistry. For the first time we demonstrate facile control of porosity and length in the pores of AAO template in lateral directions by controlled dipping method. To demonstrate the versatility of the proposed method, laterally graded silica nanotubes are also prepared by using the laterally graded AAO templates. The method demonstrated here will open numerous possibilities for obtaining a variety of graded materials with lateral gradients of catalytic, electrochemical, mechanical and optical properties on the nanoscale.

• Structural Engineering and Mechanics
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• v.58 no.4
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• pp.627-639
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• 2016

The analysis of thermally induced stresses in engineering structures is a very important and necessary task with respect to design and modeling of pressurized containers, heat exchangers, aircrafts segments, etc. to prevent them from failure and improve working conditions. So, the purpose of this study is to investigate elasto-plastic thermal stresses and deformations in a thin annular plate embedded into rigid container. To this end, analytical research devoted to mathematically and physically rigorous stress/strain analysis is performed. In order to evaluate the effect of logarithmic thermal gradients, commonly applied to structures which incorporate thin plate geometries, different thermal parameters such as temperature mismatch and varying constraint temperature were introduced into the model of elastic perfectly-plastic annular plate obeying the von Mises yield criterion with its associated flow rule. The results obtained may be used in sensitive to temperature differences aircraft structures where the thermal effects on equipment must be kept in mind.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.3
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• pp.83-89
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• 2008

This paper introduces a visual object classification algorithm based on statistical information. Objects are characterized through the Histogram of Oriented Gradients (HOG) method and classification is performed using Multiclass AdaBoost. Salient features of an object's appearance are detected by HOG blocks Blocks of different sizes are tested to define the most suitable configuration. To select the most informative blocks for classification a multiclass AdaBoostSVM algorithm is applied. The proposed method has a high speed processing and classification rate. Results of the evaluation based on example of hand gesture recognition are presented.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.663-666
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• 1985

Whatever a surgeon choose aortic prosthesis in aortic stenosis, it will always provoke some degree of obstruction to flow due to its smaller effective orifice area to tissue annulus. Occasionally, we meet small aortic annulus to his or her body surface area in aortic valve replacement. The small annulus remains a problem in that both tissue and mechanical prosthesis have significant pressure gradients between LV and aorta in resting or exercising states. In these circumstances, diverse surgical procedures, such as tilting disc prosthesis, supraannular position of aortic prosthesis, and enlargement of aortic root [including aortoventriculoplasty, translocation of aortic valve, & double outlet of LV by valved conduit], were applied. We experienced one case of aortic stenosis with small aortic annulus. Systolic pressure gradients between LV & aorta were 90 mmHg. Diameter of annulus was 19 mm. So we performed patch enlargement of aortic root by Manouguian and AVR with St. Jude medical valve 23 mm.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.2
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• pp.55-61
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• 2011

This study analyzed on the characteristics of temperature distribution in an active regeneration DPF using computer simulation. In order to verify the boundary condition of analysis, results of temperature distribution in DPF are compared between experimental and computer simulation. Using this boundary condition, temperature distribution and filter's durability in DPF analyzed according to various operating conditions. The results of computational analysis are agreed well with experimental ones from the tendency of temperature distribution of axis and radius direction. The temperature increases and the axial temperature gradients in DPF according to velocity of exhaust gas are lowered as the high velocity of exhaust gas. But the temperature gradients of radius direction at exit side in DPF are grown as the high velocity of exhaust gas. The results according to inlet temperature of exhaust gas show that the increase ratios of temperature in DPF are grown as the high temperature of exhaust gas.