• Journal of applied mathematics & informatics
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• 제35권1_2호
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• pp.11-24
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• 2017

Using variational methods, we study the existence and multiplicity of weak solutions for some p(x)-Laplacian-like problems. First, without assuming any asymptotic condition neither at zero nor at infinity, we prove the existence of a non-zero solution for our problem. Next, we obtain the existence of two solutions, assuming only the classical Ambrosetti-Rabinowitz condition. Finally, we present a three solutions existence result under appropriate condition on the potential F.

• Journal of Mechanical Science and Technology
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• 제15권3호
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• pp.309-319
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• 2001

This paper demonstrates the development of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include design and fabrication of the etched planar waveguide Bragg grating optical temperature sensor. The typical bandwidth and reflectivity of the surface etched grating has been ∼0.2nm and ∼9%, respectively, at a wavelength of ∼1552nm. The temperature-induced wavelength change is found to be slightly non-linear over ∼200$^{\circ}C$ temperature range. Typically, the temperature-induced fractional Bragg wavelength shift measured in this experiment is 0.0132nm/$^{\circ}C$ with linear curve fit. Theoretical models with nonlinear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

• 대한수학회보
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• 제53권5호
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• pp.1439-1446
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• 2016

The execution complexities of the major time memory data tradeoff methods are analyzed in this paper. The multi-target tradeoffs covered are the classical Hellman, distinguished point, and fuzzy rainbow methods, both in their non-perfect and perfect table versions for the latter two methods. We show that their computational complexities are identical to those of the corresponding single-target methods executed under certain matching parameters and conclude that the perfect table fuzzy rainbow tradeoff method is most preferable.

• 대한수학회지
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• 제54권5호
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• pp.1573-1594
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• 2017

This paper deals with the existence and energy estimates of solutions for a class of degenerate nonlocal problems involving sub-linear nonlinearities, while the nonlinear part of the problem admits some hypotheses on the behavior at origin or perturbation property. In particular, for a precise localization of the parameter, the existence of a non-zero solution is established requiring the sublinearity of nonlinear part at origin and infinity. We also consider the existence of solutions for our problem under algebraic conditions with the classical Ambrosetti-Rabinowitz. In what follows, by combining two algebraic conditions on the nonlinear term which guarantees the existence of two solutions as well as applying the mountain pass theorem given by Pucci and Serrin, we establish the existence of the third solution for our problem. Moreover, concrete examples of applications are provided.

• Journal of Mechanical Science and Technology
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• 제14권5호
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• pp.477-482
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• 2000

This study discusses a non-contact optical technique (electronic speckle pattern interferometry) that is well suited for thermal deformation measurement without any surface preparation and compensating process. Fiber reinforced plastics ($[0]_{16},\;[0/90]_{8S}$) were analyzed by ESPI to determine their thermal expansion coefficients. The thermal expansion coefficient of the transverse direction of a uniaxial composite is evaluated as $48.78{\times}10^{-6}(1/^{\circ}C)$. Also, the thermal expansion coefficient of the cross-ply laminate $[0/90]_{8S}$ is numerically estimated as $3.23{\times}10^{-6}(1/^{\circ}C)$ that is compared with that measured by ESPI.

• Preventive Nutrition and Food Science
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• 제6권2호
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• pp.133-135
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• 2001

The edible part of cucurbita moschata Duch, which is commonly used as a Korean traditional medicine as well as a popular food source, was studied to isolate anti-complementary substance. Extracts of Cucurbita moschata Duch showed significant anti-complementary activities on the classical pathway of the complement system. Especially, the ripe Cucurbita moschata Duch had more activity than that of the complement system. Especially, the ripe Cucurbita moschata Duch had more activity than that of the green one in terms of the overall anti-complementary activity. Among the extracts of various organic solvents of the ripe Cucurbita moschata Duch, chloroform and ethyl-acetate extracts, which are non-polar solvent extracts, showed the strongest activities. These results suggest that the major difference in the solvent extraction for the anti-complementary substances depends on the change in the chemical composition such as the fatty acid with the degree of ripening.

• 한국분말재료학회지
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• 제13권6호
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• pp.450-454
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• 2006

Wear of steel plate was measured during unlubricated sliding against TiC composites. These composites consist of round TiC grains and steel matrix. TiC grain itself exhibits low surface roughness and round shape, which does not bring its counterpart into severe damage from friction. In our work a classical experimental design was applied to find out a dominant factor in counterpart wear. The analysis of the data showed that only the applied load has a significant effect on the counterpart wear. Wear rate of counterpart increased non-linearly with applied load. Amount of wear was discrepant from expectation of being in proportion to the load by analogy with friction force. Our experimental result from treating matrix variously revealed bimodal wear behavior between the composites and counterpart where a mode seems to result from the special lubricant characteristic of TiC grains, and the other is caused by metal-to-metal contact. The two wear mechanisms were discussed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.577-583
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• 1994

The purpose of this paper is to study the force control law which can be implemented on a non-modified robot system. The external force control algorithm proposed in this paper can be designed by means of a classical and modern control law. We showed the validation and the possibility of muti-dimensional force control idea through the simulation and experiments. Also, the Iterative learning control is studied for compensating errors due to thr disturbances and nonlinear effects. The previous information(control input, error) was used to determine the control input of next trial. The experimental result show the vaidity of this algorithm.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.802-807
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• 2003

The purpose of this paper is to investigate the free vibration characteristics of tapered beams with translational and rotational springs and tip masses at the ends. The beam model is based on the classical Bernoulli-Euler beam theory. The governing differential equation for the free vibrations of linearly tapered beams is solved numerically using the corresponding boundary conditions. Numerical results are compared with existing solutions by other methods for cases in which they are available. The lowest three natural frequencies are calculated over a wide range of non-dimensional system parameters: the translational spring parameter, the rotational spring parameter, the mass ratio and the dimensionless mass moment of inertia.

• 대한기계학회논문집B
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• 제25권5호
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• pp.680-687
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• 2001

In this study, spin-up flows in a rectangular container are analysed both numerically and experimentally. In the numerical computation, we use two Ekman pumping models, the classical leading order and the first order. We also compared our results with those obtained for the case without a pumping model. Effect of two parameters, Reynolds number and the Rossby number on the flow evolution is studied. The first order and the leading order Ekman pumping models are in good agreement with the experimental result compared with the non-Ekman pumping model. Attention is given to the merging of two cyclonic vortices.