• Environmental Analysis Health and Toxicology
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• v.14 no.1_2
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• pp.45-54
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• 1999

Quantitative strucrure-activity relationships between the toxicity (LD$\_$50/) and molecular properties of amine and nitro compounds were tested. The all 19 compounds showed low correlations below 0.500 to their LD$\_$50/ values. When amine or nitro compounds were taken separately, the correlation between the calculated chemphysico parameters and LD$\_$50/ were also poor (r$^2$=0.4911, 3967 repectively). The overall relationships among the QSAR parameters were investigated. Molecular weight shows a high correlation with total surface area (r$^2$=0.9287); 0.9090 for zero-order connectivity and second-order connectivity : 0.8784 for bioconcentration factor and second-order connectivity. When amine compounds were taken to perform the statistical treatment, the relationships between parameters were as follows: 0.8436 for volume-negentropy; 0.8925 for volume-bioconcentration factor; 0.9929 for zero-order connectivity-Kow; zero-order connectivity-bioconcentration factor; 0.9141 for zero-order connectivity-solubility; 0.9718 for solubility-bioconcentration factor; 0.9894 for solubility-bioconcentration factor and 0.9319 for Kow-bioconcentration factor. On the other hand, nitro compounds showed different relationships as follows: 0.8952 for volume-I/O character; 0.9520 for volume-total surface area: 0.9351 for volume-molecular weight; 0.9351 for volume-MW; 0.9961 for Kow-Koc; 0.8455 for Kow-bioconcentration factor; 0.8879 for Koc-bioconcentration factor; 0.9987 for MW-total surface area respectively.

• Journal of Welding and Joining
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• v.15 no.4
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• pp.178-186
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• 1997

The purpose of this study is to evaluate the J-R curve characteristics for the 5083 aluminum alloy weldment by the load ratio analysis. The results of the load ratio analysis are compared with those of the J-R curve which are obtained by the ASTM unloading compliance method. The crack length calculated by the load ratio analysis is agrees well with the measured final crack length. The slope of the exponential J-R curve estimated by the load ratio analysis is slightly smaller than that by the ASTM unloading compliance method. The exponential correlation of the J-R curve for the 5083 aluminum alloy base metal by the load ratio analysis is J = 93.88 ${\Delta}{\alpha}^{0.375}$. That for the weld metal and HAZ is J = 69.87 ${\Delta}{\alpha}^{0.389}$ and J = 70.59 ${\Delta}{\alpha}^{0.359}$ respectively. The J-R curve obtained by the ASTM unloading compliance method is overpredicted and should be offsetted due to the initial negative crack. On the other hand, the load ratio analysis method can evaluate the J-R curve by only load displacement curve without particular crack measurement equipment.

• Publications of The Korean Astronomical Society
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• v.15 no.spc2
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• pp.1-13
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• 2000

Through the coupling between the near-earth space environment and the polar ionosphere via geomagnetic field lines, the variations occurred in the magnetosphere are transferred to the polar region. According to recent studies, however, the polar ionosphere reacts not only passively to such variations, but also plays active roles in modifying the near-earth space environment. So the study of the polar ionosphere in terms of geomagnetic disturbance becomes one of the major elements in space weather research. Although it is an indirect method, ground magnetic disturbance data can be used in estimating the ionospheric current distribution. By employing a realistic ionospheric conductivity model, it is further possible to obtain the distributions of electric potential, field-aligned current, Joule heating rate and energy injection rate associated with precipitating auroral particles and their energy spectra in a global scale with a high time resolution. Considering that the ground magnetic disturbances are recorded simultaneously over the entire polar region wherever magnetic station is located, we are able to separate temporal disturbances from spatial ones. On the other hand, satellite measurements are indispensible in the space weather research, since they provide us with in situ measurements. Unfortunately it is not easy to separate temporal variations from spatial ones specifically measured by a single satellite. To demonstrate the usefulness of ground magnetic disturbance data in space weather research, various ionospheric quantities are calculated through the KRM method, one of the magneto gram inversion methods. In particular, we attempt to show how these quantities depend on the ionospheric conductivity model employed.

• Journal of The Korean Astronomical Society
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• v.36 no.1
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• pp.21-31
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• 2003

ASTRO-F /FIS will carry out all sky survey in the wavelength from 50 to 200 ${\mu}m$. At far infrared, stars and galaxies may not be good calibration sources because the IR fluxes could be sensitive to the dust shell of stars and star formation activities of galaxies. On the other hand, asteroids could be good calibration sources at far infrared because of rather simple spectral energy distribution. Recent progresses in thermal models for asteroids enable us to calculate the far infrared flux fairly accurately. We have derived the Bond albedos and diameters for 559 asteroids based on the IRAS and ground based optical data. Using these thermal parameters and standard thermal model, we have calculated the spectral energy distributions of asteroids from 10 to 200 ${\mu}m$. We have found that more than $70\%$ of our sample asteroids have flux errors less than $10\%$ within the context of the best fitting thermal models. In order to assess flux uncertainties due to model parameters, we have computed SEDs by varing external parameters such as emissivity, beaming parameter and phase integral. We have found that about 100 asteroids can be modeled to be better than $5.8\%$ of flux uncertainties. The systematic effects due to uncertainties in phase integral are not so important.

• Journal of Korean Academy of Nursing
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• v.33 no.6
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• pp.686-692
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• 2003

Purpose: To assess the effect of handwashing improving program and MRSA carrier detection program on MRSA(methicillin resistant Staphylococcus aureus) infection rate in a intensive care unit. Method: The intervention was Nosocomial Infection(NI) control program consisted of hand washing improving program and identification and treatment of MRSA carrier. Data on the NI and MRSA infections were collected by an infection control nurse based on the definition of CDC. MRSA infection rates were calculated by the number of MRSA infection per 100 admissions or 1,000 patients-days. The difference of MRSA infection rates between pre and post intervention was tested by Chi-square at =.05. Result: MRSA infection rates 3.0% or 3.2 per 1,000 patient-days at the pre, 4.6% or 3.7 per 1,000 patient-days at the post, and the differences were not statistically significant (p=.411, p=.769 respectively). Conclusion: The handwashing improving program and MRSA carrier detection program was not effective in reducing the Nosocomial Infection(NI) or MRSA infection rates. It is recommended further studies with a longer intervention and follow-up period.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.433-438
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• 1998

Design lateral strength calculated by current seismic design code is prescribed to be much lower than the force level required for a structure to respond elastically during design level earthquake ground motion. Present procedures for calculating seismic design forces are based on the use of elastic spectra reduced by a strength reduction factor known as "response modification factor, R". This factor accounts for the inherent ductility, overstrength, redundancy, and damping of a structural system. This study considers ductility and overstrength of the wall-type structure for investigating R factor. This means that R factor is determined from the product of "ductility-based R factor($R_$\mu$$) and overstrength factor($R_s$). $R_$\mu$$ factor is calibrated to attain the targer ductility ratio (system ductility capacity) and produced in the from of $R_$\mu$$ spectra considering the influence of target ductility, natural period, and hysteretic model. On the other hand, $R_s$ is more difficult to quantify, since it depends on both material and system-dependent uncertain parameters. In this study Rs factor was determined from the result of push-over analysis.-over analysis.

• The Korean Journal of Ceramics
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• v.3 no.2
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• pp.73-81
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• 1997

In this paper, it is intended to present more reproducible and quantitative method for adhesion assemssement. In scratch test, micromechanical analysis on the stress state beneath the indenter was carried out considering the additional blister field. The interface adhesion was quantified as work of adhesion through Griffith energy approach on the basis of the analyzed stress state. The work of adhesion for DLC film/WC-Co substrate calculated through the proposed analysis shows the identical value regardless of distinctly different critical loads measured with the change of film thickness and scratching speed. On the other hand, uniaxial loading was imposed on DCL film/Al substrate, developing the transverse film cracks perpendicular to loading direction. Since this film cracking behavior depends on the relative magnitude of adhesion strength to film fracture strength, the quantification of adhesion strength was given a trial through the micromechanical analysis of adhesion-dependence of film cracking patterns. The interface shear strength can be quantified from the measurement of strain $\varepsilon$s and crack spacing $\lambda$ at the cessation of film cracking.

• Journal of Information Technology Applications and Management
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• v.19 no.2
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• pp.217-231
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• 2012

In the past, companies should make enormous facility investment and acquire a right to do business in order to join communication markets, but now they can do business without important facilities, such as communication networks. Such a movement to ease regulations about companies which want to newly join the communication industry is expected not only to change a competition frame of the mobile communication market but also to greatly affect the entire communication industry. Through this study aiming to look into a way to calculate a reasonable wholesale price related to the government's introduction of the Mobile Virtual Network Operator (MVNO) system, I came up with a following result. I applied the operating profit percentage and the ratio of operating gain to cost to the cost plus model and retail minus model, respectively, to calculate the wholesale price and found that when I calculated with the cost plus model applying the operating profit percentage, I could get the highest wholesale price. On the other hand, I got the lowest wholesale price with the retail minus model by applying the operating profit percentage. Division of expenses and calculation of profit percentage are important factors in calculating the wholesale price and such results are expected to help accurate calculation of the MVNO wholesale price.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.5
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• pp.379-383
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• 2002

Allelic diversity of 44 microsatellite marker loci originated from the coding regions of specific genes or the non-coding regions of barley genome was analyzed for 19 barley genotypes. Multi-allelic variation was observed at the most of marker loci except for HVM13, HVM15, HVM22, and HVM64. The number of different alleles ranged from 2 to 12 with a mean of 4.0 alleles per micro-satellite. Twenty-one alleles derived from 10 marker loci are specific for certain genotypes. The level of polymorphism (Polymorphic Information Content, PIC) based on the band pattern frequencies among genotypes was relatively high at the several loci such as HVM3, HVM5, HVM14, HVM36, HVM62 and HVM67. In the cluster analysis using genetic similarity matrix calculated from microsatellite-derived DNA profiles, two major groups were classified and the spike-row type was a major factor for clustering. Correlation between genetic similarity matrices based on microsatellite markers and pedigree data was highly significant ($r=0.57^{**}$), but these two parameters were moderately associated each other. On the other hand, RAPD-based genetic similarity matrix was more highly associated with microsatellite-based genetic similarity ($r=0.63^{**}$) than coefficient of parentage.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.49-63
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• 2008

The objectives of this research were to evaluate the pressurized/the main inlet water flowrate ratio which have been used as the most important parameter for operating the pump diffusion mixer until now, to suggest the alternative operating parameter and the relating criteria if the flowrate ratio was not inadequate. For the objectives of this research, computational fluid dynamics (CFD) simulation was conducted for 21 cases of flowrate ratio in full-scaled pump diffusion mixer. From the results of CFD simulation, the local velocity gradient values were calculated in each case in order to analyze the simulation results in more detail. For verifying CFD simulation, wet test was conducted. The wet test was to measure the factual coagulant dispersion distribution at a distance of 5.4m from deflector. From both results of CFD simulation and wet test, flowrate ratio was inadequate as operating parameter or criteria, on the other hand the pressurized/the main inlet velocity ratio(dimensionless) was useful in predicting the performance of pump diffusion mixer. Also, the injected coagulant could be dispersed evenly in overall cross section on the condition that pressurized/the main inlet velocity ratio(dimensionless) is over at least 20.