• Journal of applied mathematics & informatics
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• v.3 no.2
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• pp.169-182
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• 1996

This paper presents the numerical experiment of a dis-cretized loaded cable with periodic forcing. There appeared to be var-ious type of nonlinear oscillations over a wide range of fequencies and amplitudes for the periodic forcing term. The same forcing term can give rise to large or small oscillation by solving initial value problem and observing the solutions after a long time.

• Journal of applied mathematics & informatics
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• v.9 no.2
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• pp.635-643
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• 2002

The asymptotic behaviour of the solutions of initial - boundary value problem for a class of nonlinear parabolic differential - functional equations is studied via the method of differential inequalities in order to obtain oscillation criterion for the solutions.

• Journal of applied mathematics & informatics
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• v.4 no.1
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• pp.47-62
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• 1997

This paper is concerned with investigating the global as-ymptotic behavior of the zero solution of the initial-boundary value problem for a nonlinear fourth order wave equation, Moreover an esti-mate of the rate of decay of the solutions is obtained.

• Steel and Composite Structures
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• v.29 no.2
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• pp.161-173
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• 2018

Point bending is often used for cambering and curving structural steel girders. An analytical solution, applicable in the elasto-plastic range only, that relates applied loads to the desired curve was recently developed for inducing horizontal curves using four-point bending. This solution does not account for initial residual stresses and geometric imperfections built-in hot-rolled sections. This paper presents results from a full-scale test on a hot-rolled steel section curved using four-point bending. In parallel, a numerical analysis, accounting for both initial geometric imperfections and initial residual stresses, was carried out. The models were validated against the experimental results and a good agreement for lateral offset and for strain in the elasto-plastic and post-plastic ranges was achieved. The results show that the effect of initial residual stresses on deformation and strain is minimal. Finally, residual stresses due to cold bending calculated from the numerical analysis were assessed and a revised stress value for the service load design of the curved girder is proposed.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.2
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• pp.200-206
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• 2000

Ninety nursery pigs were used in two metabolism experiments to determine the effects of roasting and extruding on the nutritional value of Williams 82 soybeans with (+K) and without (-K) gene expression for the Kunitz trypsin inhibitor. Treatments for both experiments were: 1) soybean meal; 2) +K roasted; 3) +K extruded; 4) -K roasted; and 5) -K extruded. Diets were the soybean preparations (96.5% of the diet) with only vitamins and minerals added as needed to meet or exceed NRC recommendations. Daily feed allowance was 5% of initial BW given as three equal meals. In Exp. 1, 50 weanling pigs (4.7 kg average BW and 21 d average age) were used. Apparent values for N digestibility (p<0.001), biological value (p<0.09), percentage N retention (p<0.05), GE digestibility (p<0.001) and percentage ME (p<0.001) were greater for pigs fed extruded soybeans than pigs fed roasted soybeans. Also, N digestibility (p<0.05), biological value (p<0.03) and percentage N retention (p<0.04) were greater for pigs fed -K soybeans than those fed +K soybeans. In Exp. 2, 40 pigs (9.7 kg average BW and 35 d average age) were allowed to adjust to the nursery environment before use in the experiment. In general, the pigs in Exp. 2 (i.e., the older pigs) had greater utilization of nutrients from all of the soybean products than the younger pigs used in Exp. 1. Digestibilities of DM, N and GE were greater (p<0.001) for pigs fed -K soybeans than those fed +K soybeans and extruded soybeans had greater digestibilities of DM, N and GE than roasted soybeans (p<0.001). Also, percentage N retention (p<0.01) and percentage ME (p<0.001) for pigs fed extruded soybeans were greater than for pigs fed roasted soybeans. In conclusion, extruded and -K soybeans were greater nutritional value than roasted and +K soybeans for 4.7 and 9.7 kg nursery pigs.

• Journal of the Korean Society for Heat Treatment
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• v.10 no.2
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• pp.121-127
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• 1997

In order to elucidate thermal stability of Fe-$Fe_2Ti$ eutectic structure, the initial several structures have been investigated in the changes of coarsening and spheroidization during prolonged annealing under the eutectic temperature. The results are as follows: 1) The rate constant of coarsening and spheroidization was formulated as $S^{-n}-S_0^{-n}=k{\cdot}t$, where S is the total area of the interface between ${\alpha}$ and C($Fe_2Ti$) per unit volume, $S_0$ is initial value and k is the rate constant. 2) The coarsening and spheroidization mechanism was described by Ostwald ripening and controlled by diffusion of Ti-atom in ${\alpha}$-phase. 3) The spheroidization rate constant in eutectic lamellar structures was depended upon annealing temperature and showed the Arrhenius relation. The activation energy for spheroidization of lamellar structure was 365 kJ/mole.

• Journal of environmental and Sanitary engineering
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• v.15 no.3
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• pp.24-30
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• 2000

In this study, to determine the optimum fermentation process for the feed production of food wastes and estimate the practical value of fermented feed using kudzu creeper and sawdust as bulking agent. This study considered initial C/N ratio control as the fermentation process variables. The result are summarized as follows. Minimum water contents of byproducts in the fermentation feed production showed 39%(kudzu), 37%(sawdust) at the C/N ratio 25 and 45%(kudzu, sawdust) at the C/N ratio 35. Temperature variations in the fermentation feed production at the C/N ratio 25 indicated $68^{\circ}C$(kudzu), $70^{\circ}C$(sawdust). Optimum condition of fermentation process of water content, C/N ratio and permeability (porous structure of the mixture). For optimum fermentation gravitationally dewatered garbage, the proper mixing ratios of kudzu(moisture contents : 17.3%) and sawdust(moisture contents : 13.2%) were 41% and 39%, respectively. Major biological reaction in the aerobic fermentation feed production occurred during 12~24hrs.

• Transactions of Materials Processing
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• v.28 no.6
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• pp.354-360
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• 2019

The plastic strain ratio is one of the factors that affect the deep drawability of metal sheets. The plastic strain ratio of fully annealed Cu sheet is low because its texture has {001}<100>. In order to improve the deep drawability of Cu sheet, it is necessary to increase the plastic strain ratio of Cu sheet. This study investigate the increase of plastic strain ratio of a Cu sheet after the first asymmetry rolling and annealing, and the second asymmetry rolling and annealing in air and Ar gas conditions. The average plastic strain ratio (R_m) was 0.951 and |ΔR| value was 1.27 in the initial Cu sheet. After the second 30.1% asymmetric rolling and annealing of Cu sheet at 1000℃ in air condition, the average plastic strain ratio (R_m) was 1.03 times higher. However, |ΔR| was 0.12 times lower than that of the initial specimen. After the second 18.8% asymmetric rolling and annealing of Cu sheet at 630℃ in Ar gas condition, the average plastic strain ratio (R_m) was 1.68 times higher and |ΔR| was 0.82 times lower than that of the initial specimen. These results are attributed to the change of the texture of Cu sheet due to the different annealing conditions.

• Journal of Environmental Science International
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• v.20 no.1
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• pp.25-34
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• 2011

The new empirical static model was constructed on the basis of dimension analysis to predict the pressure drop according to the operating conditions. The empirical static model consists of the initial pressure drop term (${\Delta}P_{initial}$) and the dust mass number term($N_{dust}=\frac{{\omega}_0{\nu}_f}{P_{pulse}t}$), and two parameters (dust deposit resistance and exponent of dust mass number) have been estimated from experimental data. The optimum injection distance was identified in the 64 experimental data at the fixed filtration velocity and pulse pressure. The dust deposit resistance ($K_d$), one of the empirical static model parameters got the minimum value at d=0.11m, at which the total pressure drop was minimized. The exponent of dust mass number was interpreted as the elasticity of pressure drop to the dust mass number. The elasticity of the unimodal behavior had also a maximum value at d=0.11m, at which the pressure drop increased most rapidly with the dust mass number. Additionally, the correlation coefficient for the new empirical static model was 0.914.

• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.2
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• pp.158-163
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• 1983

The purpose of this experiment was to find out fundamental data for the cultivation of sorghum-sudangrass hybrid. Leaf area index and dry matter accumulation were investigated with 3-levels of nitrogen application,15, 25, 35kg per 10a during the period of initial growth from the 8th leaf emergence to the late blooming stage. The results obtained were as follows: Leaf emergence increased as growth progressed and in the same pattern at all N-levels. After the heading stage, the value was 15 at all N-levels. Leaf area index (LAI) increased as growth progressed and rapidly till the booting stage. At 15kg N-level the values were larger till the ear formation stage, and at 35tg N-level the values were larger than other N-levels after the booting stage. At the late blooming stage LAI reached 8.13 at 35kg N-level. The value of dry matter accumulation was the highest at 35kg N-level at the late blooming stage, and as was the same in the value of crop growth rate (CGR). There was a tendency that before the booting stage the enlargement of leaf area contributed to dry matter accumulation and after the booting stage did the increase of net assimilation rate (NAR) .