• The Journal of Korean Physical Therapy
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• v.25 no.5
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• pp.260-265
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• 2013

Purpose: This study was conducted in order to evaluate the quantitative effectiveness of region of interest (ROI) setting in MR-DTI analysis with and without fMRI activation results. Methods: Ten right-handed normal volunteers participated in this study. DTI and fMRI datasets for each subject were obtained using a 1.5T MRI system. For neural fiber tracking, ROIs were drawn using two methods: The drawing points were located in the fMRI activation areas or areas randomly selected by users. In this study, the neural fiber tract targeted the corticospinal tract (CST) Quantitative analyses were performed and compared. The pixel numbers passing through the fiber tract in the individual brain volume were counted. The ratios between the ROI pixel numbers and the extracted fiber pixel numbers, and the ratios between the fiber pixel numbers and the whole-brain pixel numbers were also calculated. Results: According to our results, extracted CST fiber tract in which the ROI was drawn with fMRI activation areas showed higher distribution than drawing the ROI by users' hands. In addition, the quantitatively measured values represented higher pixel distribution: The counted average pixel numbers were 4553.8 and 1943.3. The average ratios of the ROI areas were 33.87 and 22.52. The average percentages of the individual whole-brain volume numbers were 2.06 and 0.87. Conclusion: Results of this study appear to indicate that use of this method can allow for more objectives and significant for study of the recovery of neural fiber mechanisms and brain rehabilitation.

• Journal of Environmental Impact Assessment
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• v.21 no.5
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• pp.767-779
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• 2012

In case of executing surveys in marine ecosystems, the most important things are scientific selection measures of survey stations that can represent various ecosystems characteristics in subjected areas. The situations show a lot of differences that understand characteristics of marine ecosystems in targeted areas according to selection methods and positions in survey stations. Investigation ranges and station numbers in marine ecosystems are classified according to project characteristics and scales. But, currently a clear divisions or objective standards are not. Therefore, this study tried to provide selection measures of survey station in scientific and objective marine ecosystems through precise analysis among environmental impact statements of coastal development projects until now. In this study, impact scopes of marine ecosystems correspond to physical impact predictions by undertaking projects. Impact ranges were divided into three(physical impact ranges) coastal waters. In case of proposing numbers of survey stations according to this survey ranges, numbers of investigation stations due to minimum survey scopes in targeted projects applied 20~30% of all numbers in survey stations. Number of survey stations due to average investigation scopes within physical impact ranges applied 60~70% of all numbers in investigation stations. Numbers of survey stations due to maximum survey ranges within physical impact scopes applied 10~20% of all numbers in survey stations. So, improvement measures were deducted. Finally, according to prediction ranges in impact of various coastal development projects, several kinds of conclusions are suggested. And, it is thought to be able to use as fundamental database to select investigation stations in marine organisms through this study.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.21 no.2
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• pp.89-107
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• 2017

In this paper, we have proposed a modified Marker-And-Cell (MAC) method to investigate the problem of an unsteady 2-D incompressible flow with heat and mass transfer at low, moderate, and high Reynolds numbers with no-slip and slip boundary conditions. We have used this method to solve the governing equations along with the boundary conditions and thereby to compute the flow variables, viz. u-velocity, v-velocity, P, T, and C. We have used the staggered grid approach of this method to discretize the governing equations of the problem. A modified MAC algorithm was proposed and used to compute the numerical solutions of the flow variables for Reynolds numbers Re = 10, 500, and 50000 in consonance with low, moderate, and high Reynolds numbers. We have also used appropriate Prandtl (Pr) and Schmidt (Sc) numbers in consistence with relevancy of the physical problem considered. We have executed this modified MAC algorithm with the aid of a computer program developed and run in C compiler. We have also computed numerical solutions of local Nusselt (Nu) and Sherwood (Sh) numbers along the horizontal line through the geometric center at low, moderate, and high Reynolds numbers for fixed Pr = 6.62 and Sc = 340 for two grid systems at time t = 0.0001s. Our numerical solutions for u and v velocities along the vertical and horizontal line through the geometric center of the square cavity for Re = 100 has been compared with benchmark solutions available in the literature and it has been found that they are in good agreement. The present numerical results indicate that, as we move along the horizontal line through the geometric center of the domain, we observed that, the heat and mass transfer decreases up to the geometric center. It, then, increases symmetrically.

• Composites Research
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• v.17 no.6
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• pp.44-51
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• 2004

To determine the effect of numbers of nitrogen atom bonded at ethyl group included in main chain of linear amine curing agents of epoxy-cure systems on the thermal and mechanical properties, standard epoxy resin DGEBF was cured with DETA, TETA and TEPA in a stoichiometrically equivalent ratio. From this work, the effect of curing agents of the DGEBF/amine systems oil the thermal and mechanical properties was significantly influenced by numbers of nitrogen atom of curing agents. The results showed that heat of reaction increased, and maximum exothermic temperature decreased with the decrease of numbers of nitrogen atom. In case of cured systems, density and maximum conversion(%) had no relation to numbers of nitrogen atom, but flexural modulus and tensile modulus increased with the decrease of numbers of nitrogen atom in main chain. Thermal stability, shrinkage(%), Tg, tensile and flexural strength showed irregular tendency having nothing to do with numbers of nitrogem atom at a sight. This findings imply that the differences in the maximum conversion(%) about the chain length of curing agents affect the thermal and mechanical properties.

• Journal for History of Mathematics
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• v.20 no.4
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• pp.71-84
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• 2007

J. Bernoulli first discovered the method which one can produce those formulae for the sum $S_n(k)=\sum_{{\iota}=1}^n\;{\iota}^k$ for any natural numbers k. After then, there has been increasing interest in Bernoulli and Euler numbers associated with Riemann zeta functions. Recently, Kim have been studied extended q-Bernoulli numbers and q-Euler numbers associated with p-adic q-integral on $\mathbb{Z}_p$, and sums of powers of consecutive q-integers, etc. In this paper, we investigate for the historical background and evolution process of the sums of powers of consecutive q-integers and discuss for Euler zeta functions subjects which are studying related to these areas in the recent.

• Journal of Advanced Navigation Technology
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• v.11 no.2
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• pp.177-186
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• 2007

In this paper, the optimal position offset of optical phase conjugator (OPC) and the optimal dispersion offsets of fiber sections, which are alternating with the method for the symmetry of optical power and chromatic dispersion with respect to OPC, are numerically investigated as afunction of the WDM channel numbers. The WDM channel numbers are assumed to be 8, 12, 16, 20 and 24. The bit-rate of each channel is assumed to be 40 Gbps for all cases. It is confirmed that the optimal position offset of OPC and optimal dispersion offset of fiber section are gradually increased as the WDM channel numbers are gradually increased. But, the optimal dispersion values of fiber sections per OPC position offset of 1 km are independent on WDM channel numbers, because the optimal position offset of OPC and optimal dispersion offset of fiber section are simultaneously increased as the WDM channel numbers are increased. It is also confirmed that the applying of these optimal parameter values is efficient to WDM system with many channels rather than WDM with small channels.

• Korean Journal of Plant Taxonomy
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• v.48 no.4
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• pp.260-277
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• 2018

The evolution of chromosome numbers and the karyotype structure is a prominent feature of plant genomes contributing to or at least accompanying plant diversification and eventually leading to speciation. Polyploidy, the multiplication of whole chromosome sets, is widespread and ploidy-level variation is frequent at all taxonomic levels, including species and populations, in angiosperms. Analyses of chromosome numbers and ploidy levels of 252 taxa of Korean non-commelinid monocots indicated that diploids (ca. 44%) and tetraploids (ca. 14%) prevail, with fewer triploids (ca. 6%), pentaploids (ca. 2%), and hexaploids (ca. 4%) being found. The range of genome sizes of the analyzed taxa (0.3-44.5 pg/1C) falls well within that reported in the Plant DNA C-values database (0.061-152.33 pg/1C). Analyses of karyotype features in angiosperm often involve, in addition to chromosome numbers and genome sizes, mapping of selected repetitive DNAs in chromosomes. All of these data when interpreted in a phylogenetic context allow for the addressing of evolutionary questions concerning the large-scale evolution of the genomes as well as the evolution of individual repeat types, especially ribosomal DNAs (5S and 35S rDNAs), and other tandem and dispersed repeats that can be identified in any plant genome at a relatively low cost using next-generation sequencing technologies. The present work investigates chromosome numbers (n or 2n), base chromosome numbers (x), ploidy levels, rDNA loci numbers, and genome size data to gain insight into the incidence, evolution and significance of polyploidy in Korean monocots.

• Bulletin of the Korean Mathematical Society
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• v.20 no.1
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• pp.55-63
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• 1983

• Proceedings of the Korean Society of Computational and Applied Mathematics Conference
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• 2002.09a
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• pp.13.1-13
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• 2002

• The Journal of Internal Korean Medicine
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• v.19 no.2
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• pp.185-207
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• 1998

In order to study the immunohistochemical effects of Opae-san on gastric ulcer induced by HCl-aspirin in rats, experiments were done by oral administration and measure histological features of ulcer lesion, scaning electron microscopic appearance, the changes of numbers of parietal cells, chief cells, gastrin and somatostatin-immunoreactive cells. The obtained results are as follows: 1. Ulcerative lesions were numerously detected in control groups especially in junction of cardiac-fundic gastric mucosa and histologically very severe injury to gastric epithelium were observed too but in the Opae-san administrated groups, no gross lesion of ulcer were detected and histologically minor injury of gastric mucosa were observed. Most slight injuries to gastric mucosa were observed in 5 days after treatment. 2. The numbers of parietal cells were remarkably increased in control group but in Opae-san administrated groups appeared significant decrease compared to control groups. Most remarkably decrease of the numbers of parietal cells compared to control groups were observed in 5 days after treatment. 3. The numbers of chief cells were remarkably decreased in control group but in Opae-san administrated groups appeared significant increase compared to control groups. Most remarkably increase of the numbers of chief cells compared to control groups were observed in 5 days after treatment. 4. The numbers of gastrin-immunoreactive cells were remarkably decreased in control group but in Opae-san administrated groups appeared significant increase compared to control groups. Most remarkably decrease of the numbers of gastrin-immunoreactive cells compared to control groups were observed in 5 days after treatment. 5. The numbers of somatostatin-immunoreactive cells were remarkably decreased in control group but in Opae-san administrated groups appeared significant increase compared to control groups. Most remarkably decrease of the numbers of somatostatin-immunoreactive cells compared to control groups were observed in 5 days after treatment. 6. Scaning electron microscopically, severe denude and degeneration of gastric mucosa were observed in control groups but in Opae-san administrated groups the lesions were remarkably decreased compared to control groups.