• Korean journal of food and cookery science
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• v.5 no.1
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• pp.49-52
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• 1989

Stress relaxation tests with different percent deformation were performed for crude and refined starch gels of acorn. With no relation to percent deformation, refined starch gel had higher initial stress ($\sigma_e$) and lower equilibrium stress ($\sigma_e$) than crude starch gel. But the ratio of equilibrium stress to initial stress ($\sigma_e$/$\sigma_o$) was minimum at 60 percent deformation. The analysis of relaxation curves by successive residual method revealed that the rheological behavior of acorn starch gels could be expressed by generalized Maxwell model. The element numbers of models for crude and refined starch gel were 7-element and 5-element at 60 percent deformation, and 5-element and 3-element at 45 percent deformation, respectively.

• Structural Engineering and Mechanics
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• v.25 no.2
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• pp.147-160
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• 2007

In this paper, a dynamic analysis based on the fuzzy set theory is presented as a possible complementary tool to the classical stochastic methods for dynamic analyses. Material parameters of a structure are influenced by uncertainties and therefore they are considered to be fuzzy quantities with given distributions, that means fuzzy numbers with given membership functions. The fuzzy dynamic analysis is conducted with help of fuzzy arithmetic defined on the so-called ${\alpha}$-cuts. The results of the analysis are also obtained in the form of fuzzy numbers, which compared to the stochastic methods is less computationaly expensive while at the same time they still provide information about the distribution of a quantity. This method is demonstrated on an analysis of a two-dimensional frame subjected to possible seismic load, where the uncertain eigenmodes and eigenfrequencies are used in the modal analysis.

• Honam Mathematical Journal
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• v.41 no.1
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• pp.197-206
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• 2019

We consider the extended generalized Hecke groups ${\bar{H}}_{3,q}$ generated by $X(z)=-(z-1)^{-1}$, $Y(z)=-(z+{\lambda}_q)^{-1}$ with ${\lambda}_q=2\;cos({\frac{\pi}{q}})$ where $q{\geq}3$ an integer. In this work, we study the generalized Pell sequences in ${\bar{H}}_{3,q}$. Also, we show that the entries of the matrix representation of each element in the extended generalized Hecke Group ${\bar{H}}_{3,3}$ can be written by using Pell, Pell-Lucas and modified-Pell numbers.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.4
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• pp.355-361
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• 2004

The finite element method were used to determine the stress intensity factor of cracked plate. The stress method, displacement method and J Integral are most popular finte element method. ANSYS proposed another a kind of displacement method. In this paper, it was examined that the accuracy and utility of the ANSYS method could believable to determine the stress intensity factors of centered inclined crack. Generally, inclined crack has two portion of stress intensity factors, tensile mode F1 and shear mode F2. For the purpose of increasing the accuracy of stress intensity factors, examined the effect of the numbers of nodes and elements, crack tip element size and number of partition of the crack tip vicinity. It was found that the method proposed by ANSYS is useful and has high accuracy. Accuracy of calculated stress intensity factors was increased by increase of the number of nodes and elements, and at the small size of crack tip elements can get more highly accuracy.

• Journal of Advanced Marine Engineering and Technology
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• v.14 no.4
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• pp.46-56
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• 1990

Stress analysis of axi-symetric body with non-symetric loading and non-symetric given displacements is investigated in this paper using the finite element method. As the non-symetric load and non-symetric given displacements of axi-symetric body are generally periodic functions of angle .theta., the nodal forces and nodal displacements can be expanded in cosine and sine series, that is, Fourier series. Furthermore, using Euler's formula, the cosine and sine series can be converted into exponential series and it is prooved that the related calculus become more clear. Substituting the nodal displacements expanded in Fourier series into the strain components of cylindrical coordinates system, the element strains are expressed in series form and by the principal of virtual work, the element stiffness martix and element load vector are obtained for each order. It is also showed that if the non-symetric loads are even or odd functions of angle ${\theta}$ the stiffness matrix and load vector of the system are composed with only real numbers and relatively small capacity fo computer memory is enough for calculation.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.345-350
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• 2000

Adaptive finite element analysis, which its solution error meets with the user defined allowable error, is recently used far improving reliability of finite element analysis results. This adaptive analysis is composed of two procedures; one is the error estimation of an analysis result and another is the reconstruction of finite elements. In the rp-method, an element size is controlled by relocating of nodal positions(r-method) and the order of an element shape function is determined by the hierarchical polynomial(p-method) corresponding to the element solution error. In order to show the effectiveness and accuracy of the suggested rp-method, various numerical examples were analyzed and these analysis results were examined by comparing with those obtained by the existed methods. As a result of this study, following conclusions are obtained. (1) rp-method is more accurate and effective than the r- and p-method. (2) The solution convergency of the rp-method is controlled by means of the iterative calculation numbers of the r- and p- method each other.

• Honam Mathematical Journal
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• v.32 no.4
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• pp.791-795
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• 2010

We study the consequences of Gross's conjecture for cyclic extensions of degree $l^2$ where l is prime, and deduce that the L-values at s = 0 satisfy certain congruence relations.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.20-26
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• 2015

Objectives: To evaluate the biodurability of Korean Chrysotile(KC), the changes in fibers numbers and changes in the element composition of fibers from the lung of Sprague-Dawley rats instilled KC(average size $4.74{\mu}m$, $59,043{\times}10^6$ fibers/mg) was estimated. Methods: Rats were administered 1 mg KC(low group) or 2 mg KC(high group) by a single intratracheal instillation. At each time point(5 days, 5 weeks, 10 weeks), the numbers of KC fibers and the changes of element composition(atomic %) of KC fibers from the lung of the rats were analyzed with transmission electron microscope equipped with energy dispersive X-ray spectrometer. Results: Over time, the number of fibers within the lungs of animals were reduced. The average length of the low and high group is significantly reduced from 5 days after administration. Over time, the fiber ratio of at least $5{\mu}m$ remaining in the lung tissue of the low concentration group was up but the high group was reduced. From day 5 after administration, the composition ratio(Mg) was significantly decreased in all groups. Conclusions: Size and composition of Korean Chrysotile in the lung tissue of rats was changed from 5 days.

• Applied Microscopy
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• v.44 no.1
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• pp.8-14
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• 2014

The auditory system of the Korean greater horseshoe bat (Rhinolophus ferrumequinum korai, RFK) is adapted to its own echolocation signal, which consist of constant frequency (CF) element and frequency modulated (FM) element. In contrast, the Japanese long-fingered bat (Miniopterus schreibersii fuliginosus, MSF) emits FM signals. In the present study, the characteristics of stereocilia in RFK (a CF/FM bat) and MSF (a FM bat) were studied in the apical turn of the cochlea where the lower frequencies are transduced. Stereocilia lengths and numbers were quantitatively measured in RFK by scanning electron microscopy and compared with those of MSF. Each inner hair cells (IHCs) of RFK possessed three rows of stereocilia, whereas MSF possessed five rows of stereocilia. Gradients in stereocilia lengths and numbers of stereocilia of the IHCs of RFK were found to be less pronounced and fewer, respectively, than those of MSF. Each outer hair cells (OHCs) possessed three rows of stereocilia in both species. OHCs stereocilia in RFK that distinguished it from MSF were a shorter length and a greater number of stereocilia. These features suggest that the apical cochleas of RFK are adapted for the processing of higher frequency echolocation calls rather than that of MSF.

• Structural Engineering and Mechanics
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• v.41 no.4
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• pp.509-525
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• 2012

In recent years, CFRP material usage in strengthening applications gradually became widespread. Especially, the studies on the strengthening of shear deficient reinforced concrete beams with CFRP strips are chosen as a subject to numerous experimental studies and research on this subject are increased rapidly. The most important variable, that is affected on the failure mode of CFRP strips and that is needed for determining the shear capacity of the strengthened reinforced concrete beams, is the strain distribution between CFRP strips and concrete. Numerous experimental studies are encountered in the literature about the determination of strain distribution between CFRP strips and concrete. However, these studies mainly focused on the CFRP strips under axial tension. There are very limited numbers of experimental and analytic studies examining the strain distribution between concrete and CFRP strips, which are under combined stresses due to the effects of shear force and bending moment. For this reason, existing experimental study in the literature is used as model for ANSYS finite element software. Nonlinear finite element analysis of RC beams strengthened against shear with CFRP strips under reverse cyclic loading is performed. The strain distributions between CFRP strips and concrete that is obtained from finite element analysis are compared with the results of experimental measurements. It is seen that the experimental results are consisted with the results derived from the finite element analysis and important findings on the strain distribution profile are reached by obtaining strain values of many points using finite element method.