• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.1
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• pp.117-124
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• 2009

The p-convergent boundary element method has been proposed to analyze two-dimensional potential problem on the basis of high order Legendre shape functions that have different property comparing with the shape functions in conventional boundary element method. The location of nodes corresponding to high order shape function are not defined along the boundary, called by nodeless node, similar to the p-convergent finite element method. As the order of shape function increases, the collocation point method is used to solve linear simultaneous equations. The collocation patterns of p-convergent boundary element method consist of non-symmetric hierarchial or symmetric non-hierarchical. As the order of shape function increases, the number of collocation point increases. The singular integral that appears in p-convergent boundary element has been calculated by special numeric quadrature technique and semi-analytical integration technique. The L-shape domain problem including singularity in the vicinity of reentrant comer is analyzed and the numerical results show that the relative error is smaller than $10^{-2}%$ range as compared with other results in literatures. In case of same condition, the symmetric p-collocation point pattern shows high accuracy of solution.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.153-165
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• 1994

In this study, we tested the influences of several ${\kappa}$ opioid ligands on the $[^3H]diprenorphine$ binding in rat and guinea pig cortex membrane preparations. Using paradigm to block ${\mu}\;and\;{\delta}$ opioid receptors with $DAMGO(1{\mu}M)$ and $DPDPE(1{\mu}M)$, $[^3H]diprenorphine$ labeled ${\kappa}$ sites. Competition analysis in both rat and guinea pig cortex has shown a single population of $[^3H]diprenorphine$ binding site with different Kd values, respectively. There is a significant difference in Ki values of (-) WIN44441 and (+)WIN44441 in both rat and guinea pig cortex. Bremazocine, (-)ethylketocyclazocine, (-)cyclazocine, nor-binaltorphimine effectively inhibited the $[^3H]diprenorphine$ binding with different Ki values in rat and guinea pig cortex. U-69,593, U-50,488H and dynorphine-A (1-8) did not inhibit the $[^3H]diprenorphine$ binding in rat but in guinea pig cortex. Nor-binaltorphimine was a ligand discriminate the ${\kappa}_1$, and ${\kappa}_2$ receptor most effectively. We, also, examined the influence of Na ion and $GTP{\gamma}S$, a nonhydrolyzable guanine nucleotide analog, on the inhibition of $[^3H]diprenorphine$ binding by diprenorphine, (-)ethyl-ketocyclazocine, U-69,593 and bremazocine. By the replacement of NaCl with N-methy-D-glucamine or addition of $GTP{\gamma}S$, Ki values of diprenorpnine were not changed and that of ethylketocyclazocine were changed significantly in both rat and guinea pig cortex. The Ki value of bremazocine was decreased by removal of Na ion, and increased by $GTP{\gamma}S$, however, was not changed by any one of either. These results suggest that there are 2 kinds of subtypes of ${\kappa}$ opioid receptor, ${\kappa}_1$, and ${\kappa}_2$, showing different Ki values for various ${\kappa}$ opioid ligands, also, bremazocine possess the antagonistic property at ${\kappa}_2$ site which is dominant subtype of K receptor in rat cortex.

• Journal of the Korean Magnetics Society
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• v.17 no.4
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• pp.172-177
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• 2007

In order to detect of the magnetic property in the cell unit, we studied the GMR-SV (giant magnetoresistance-spin valves) biosensor, which was depended on the micro patterned features according to two easy directions of longitudinal and transversal axes. Here, the multi layer structure was glass/NiO/NiFe/CoFe/Cu/CoFe/NiFe. The uniaxial anisotropy direction was applied to the patterned biosensor during the deposition and vacuum post-annealing at $200^{\circ}C$ under the magnitude of 300 Oe, respectively. Considering the magnetic shape anisotropy effect, the size of micro patterned biosensor was a $2{\times}5{\mu}m^2$ after the photo lithography process. By our experimental results, we confirmed that the best condition of GMR-SV biosensor should be the same direction of the axis sensing current and the easy axis of pinned NiO/NiFe/CoFe triple layer oriented to the width direction of device, and the direction of the easy axis of free CoFe/NiFe bilayer was according to the longitudinal direction of device.

• Korean Journal of Plant Resources
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• v.18 no.1
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• pp.161-168
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• 2005

Tuber yield and content of general component and diosgenin which is a main bioactive property were investigated in order to determine the growth characteristics of round typed yam(Dioscorea opposita L.) and the potential of artificial culture at Suwon, Korea. Tubers of round yam were initiated to form at 60 days after planting and then enlargement of tubers lasted by 160 days after planting. Compared to short typed yam(108g), tuber weight of round yam was higher(127g) on the basis of dry weight at 200 days after planting. In comparison of general component between round yam and short yam, protein of round yam$(3.62\%)$ was higher than short yam$(2.10\%)$. Water content in round yam$(64.5\%)$ was lower in short yam$(79.4\%)$, indicating a higher dry weight ratio of round yam. Hardness of round yam was 2787.6 while short yam showed about two times higher hardness(4946.9). Lightness was higher in round yam(77.4). In tuber extracts analysis, diosgenin content was respectively $3.32\%$ in round yam and $2.61\%$ in short yam.

• Journal of Technology Innovation
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• v.22 no.1
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• pp.149-175
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• 2014

This study analyzed the effect of corporate innovation strategies on patent production and ultimately on technological change and new product development of firms in South Korea. The intent was to derive efficient strategies for enhancing technological performance of the firms. For the empirical analysis, three sources of data were combined: four waves of the Human Capital Corporate Panel Survey (HCCP) data collected by the Korea Research Institute for Vocational Education and Training (KRIVET), corporate financial data obtained from the Korea Information Service (KIS), and corporate patent data provided by the Korean Intellectual Property Office (KIPO). The patent production function was estimated by zero-inflated negative binomial (ZINB) regression. The technological performance function was estimated by two-stage regression, taking into account the endogeneity of patent production. An ordered logit model was applied for the second stage regression. Empirical results confirmed the critical role of corporate innovation strategies in patent production and in facilitating technological change and new product development of the firms. In patent production, the firms' R&D investment and human resources were key determinants. Higher R&D intensity led to more patents, yet with decreasing marginal productivity. A larger stock of registered patents also led to a larger flow of new patent production. Firms were more prolific in patent production when they had high-quality personnel, intensely investing in human resource development, and adopting market-leading or fast-follower strategy as compared to stability strategy. In technological performance, the firms' human resources played a key role in accelerating technological change and new product development. R&D intensity expedited new product development of the firm. Firms adopting market-leading or fast-follower strategy were at an advantage than those with stability strategy in technological performance. Firms prolific in patent production were also advanced in terms of technological change and new product development. However, the nexus between patent production and technological performance measures was substantially reduced when controlling for the endogeneity of patent production. These results suggest that firms need to strengthen the linkage between patent production and technological performance, and take strategies that address each firm's capacities and needs.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.503-519
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• 2014

This study was conducted to investigate ginger growth and its nutrient uptake depending on changes of soil properties as affected by applications of green manure crop and/or charcoal in continuous cropping system. The green manure crops applied were barley and hairy vetch, and charcoal was additionally treated in selected plots as a soil conditioner. Experimental plots were prepared as Plot 1 (control), Plot 2 (barley of 8kg $10a^{-1}$), Plot 3 (hairy vetch of 12kg $10a^{-1}$), Plot 4 (charcoal of 1,000kg $10a^{-1}$ and barley 8kg $10a^{-1}$), and Plot 5 (charcoal of 1,000kg $10a^{-1}$ and hairy vetch of 12kg $10a^{-1}$) with two different soil conditions (high clay content, HCC and low clay content, LCC). When comparing selected chemical properties of soils before and after cultivating ginger plant, soil pH decreased from 6.9~8.1 to 6.8~7.6, and electrical conductivity (EC) also declined from $0.45{\sim}1.25dSm^{-1}$ to $0.30{\sim}0.61dSm^{-1}$. However, the content of soil organic matter (SOM) and total nitrogen (T-N) increased. Thus, the soil chemical properties were improved with the applications of green manures and charcoal. Also, macro- and micro-nutrient contents of ginger plants in the different plots were various between normal and diseased plants grown in soils with HCC and LCC. In particular, the concentration of manganese (Mn) was 3~4 folds higher in the diseased plant than in the normal plants. Ginger growth status and yield was relatively improved with the applications of green manures and charcoal as comparing with control plot. Especially in the Plot 4 with LCC, the ginger plant was not infected by root-rot disease.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.273-280
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• 2019

BACKGROUND: The reclaimed lands for agricultural use managed by the Korean government is consisted of 17,145 hectares of lands under construction and 13,384 hectares of completed lands. In order to utilize these reclaimed lands as competitive agricultural complexes, the government is preparing to develop comprehensive development plans for multiple purposes. For rational land-use planning and soil management, information of the soil chemical properties is necessary. METHODS AND RESULTS: From 2013 to 2016, soil samples were collected from 85 representative sampling sites of the reclaimed lands and analyzed for soil chemical properties including electric conductivity (EC), pH, soil organic matter (SOM), and nutrients. The annual mean soil EC ranged from 5.1 to 8.3 dS m^-1 and have continued to decrease over the years (estimation equation with EC as dependent and year as independent variable was y =0.0736x² - 1.4985x + 9.8305, R² = 0.9753). The pH ranged from 7.3 to 7.6, which was higher than the optimum range (5.5~7.0) for agricultural soils. Soil organic matter (8 to 11 g kg^-1) was lower level than the optimum range (20~30 kg^-1). Available silicate (Av.SiO₂) ranged from 169 to 229 mg kg^-1, which was close to the minimum content (≥157 mg kg^-1) for rice paddy field. Available phosphate (Av.P₂O₅) content (24~39 mg kg^-1) was lower than the optimum range (80~120 mg kg^-1) for rice paddy field. CONCLUSION: For efficient agricultural use of reclaimed lands under government management, our results suggest that the application of organic matter and supplying deficient nutrients as well as desalinization is required.

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.172-180
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• 2007

A new diagnostics of plasma electron temperature and plasma density is introduced with the observation of the light emission along the tube of external electrode fluorescent lamps. With two different methods operating an external electrode fluorescent lamp of outer diameter 4.0 mm and length 860 mm for the back-light source of 37-inch LCD-TVs, the lighting modes and the plasma properties are investigated. In the center balance operation, the light-emission propagates simultaneously from both sides of the high voltage electrodes to the center of the lamp, while in conventional operation the light-emission propagates from the one end of a high voltage to the other ground electrode. In the operation value of luminance $10,000{\sim}15,000cd/m^2$, the electron plasma thermal energy $(kT_e)$ is about $1.3{\sim}2.7eV$ with the electron density $(n_e)$ is about $(1.6{\sim}3.6){\times}10^{16}m^{-3}$.

• Korean Journal of Materials Research
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• v.2 no.1
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• pp.65-75
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• 1992

0.4wt%C steel added with V and/or Nb were forged and followed by air cooling. The structure-property relationships were examined and multiple regression analysis was conducted to quantify the magnitudes of effects of microalloying elements on the properties of the steels. All material's tensile strength are greater than $70kg/\textrm{mm}^2$, so they are equal to or superior to Q/T material's(S45C). Their impact energies are less than 40J, so they are 50% of Q/T material's. Increasing the content of V from 0.10 to 0.15 wt% had brought improvement in UTS about 20% but with some sacrifice of impact energy. These were the results from the precipitation strengthening by fine dispersion of VC in ferrite, increment of pearlite volume fraction and decrement of pearlite interlamellar spacings. However, increasing the content of Nb from 0.05 to 0.l0wt % slightly improved UTS and impact energy. NbC precipitates were more effective in suppression of austenite grain coarsening than VC precipitates. Combined additions of V+Nb were more effective to bring impact toughness than sole addition. Optimum combination of strength and toughness was accomplished wish 0.4C-1. 19Mn-0.05S-0.12V-0.07Nb steel.

• Natural Product Sciences
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• v.15 no.3
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• pp.144-150
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• 2009

Gradient centrifugal partition chromatography (GCPC) method was developed and applied to isolate 3,5-dimethoxyphenanthrene-2,7-diol (DMP) and batatasin-I (BA-I) from the dichloromethane soluble extract of Dioscorea opposita. In this method, the lower phase of n-hexane-methanol-water system (HMW, 10 : 9 : 1, v/v) was used as a mobile phase A (MpA) and water was used as a mobile phase B (MpB). This gradient CPC method is comparable to that of reversed-phase HPLC method in that the stationary upper-phase of HMW (10 : 9 : 1 v/v) works as if it were reversed-phase silica gel due to its hydrophobic property, while the lower phase (MpA) and water (MpB) functioned as hydrophilic mobile phases. The initial condition of the mobile phase was 20% MpA/80% MpB and maintained for 150 min to obtain DMP (1.2 mg), and then MpA was increased up to 50% to elute BA-I (1.7 mg). The purities of DMP and BA-I were 94.1% and 98.3% with the recovery yields of 83% and 86%, respectively. Similar results were obtained by linear-gradient CPC. The CPC peak fractions were identified by comparing their retention time to those of authentic samples of DMP and BA-I and their spectroscopic data ($^1$H NMR and $^{13}$C NMR) to those of literature values.