• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.158-166
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• 1997

This study presents the method to quantify the stand structure diversity or homogeneity. Gadow's dbh differentiation(Durchmesserdifferenzierung) is introduced which quantifies the horizontal stand structure by the ratio of the dbh between subject tree and neighbour trees. And new stand structure diversity index based on Lorenz curve, which is made by ratio of tree number and basal area or volume by dbh class, is presented. The horizontal stand structure index based on Lorenz curve has a value from 0 to 1 as Gadow's index, and approximates to 1 if the stand structure has high diversity. In the comparative analysis for performance, the new stand structure index based on Lorenz curve is considered to compare with the Gadow's index for describing the stand structure.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.2122-2130
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• 1993

A numerical and experimental study has been performed on the flow in a shallow rectangular tank accompanying a vortex shedding. The model is composed of a rectangular tank with a vertical plate with a length half the width of the tank. The tank is subject to a horizontal sinusoidal oscillation. The numerical analysis shows that the pattern of vortex shedding changes considerably when the Reynolds number $R_e$ is varied from 500 to 7500. It is symmetric for $R_e$ <1500 and asymmetric for $R_e$ > 1500. The kinetic energies of the right-hand and left-hand sides of the vertical plate are used to quantify the degree of the asymmetry. Experimental visualization is carried out at $R_e$ = 3876 and 52000. The development of the streamline pattern at $R_e$ = 3876 is in closer agreement with the numerical result at $R_e$ = 1000 than that at $R_e$ =3876. The asymmetric pattern is observed at $R_e$ = 52000.

• Environmental Engineering Research
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• v.14 no.1
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• pp.63-67
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• 2009

Escherichia coli K-12 (E. coli K-12) is a representative indicator globally used for distinguishing and monitoring dynamic fates of pathogenic microorganisms in the environment. This study investigated how to most critically quantify lacZ ($\beta$-galactosidase) gene in E. coli K-12 by two different real-time polymerase chain reaction (real-time PCR) in association with three different DNA extraction practices. Three DNA extractions, i.e., sodium dodecyl sulfate (SDS)/proteinase K, magnetic beads and guanidium thiocyanate (GTC)/silica matrix were each compared for extracting total genomic DNA from E. coli K-12. Among them, GTC/silica matrix and magnetic beads beating similarly worked out to have the highest (22-23 ng/${\mu}L$) concentration of DNA extracted, but employing SDS/proteinase K had the lowest (10 ng/${\mu}L$) concentration of DNA retrieved. There were no significant differences in the quantification of the copy numbers of lacZ gene between SYBR Green I qPCR and QProbe-qPCR. However, SYBR Green I qPCR obtained somewhat higher copy number as $1{\times}10^8$ copies. It was decided that GTC/silica matrix extraction or magnetic beads beating in combination with SYBR Green I qPCR can be preferably applied for more effectively quantifying specific gene from a pure culture of microorganism.

• Membrane and Water Treatment
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• v.3 no.3
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• pp.151-168
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• 2012

Gas sparging is one of the techniques used to control the concentration polarization during ultrafiltration. In this work, the effects of gas sparging in stratified flow regime were investigated during gel layer controlling cross flow ultrafiltration in a rectangular channel. Synthetic solution of pectin was used as the gel forming solute. The liquid and gas flow rates were selected such that a stratified flow regime was prevalent in the channel. A mass transfer model was developed for this system to quantify the effects of gas flow rates on mass transfer coefficient (Sherwood number). The results were compared with the case of no gas sparging. Gas sparging led to an increase of mass transfer coefficient by about 23% in this case. The limitation of the developed model was also evaluated and it was observed that beyond a gas flow rate of 20 l/h, the model was unable to explain the experimental observation, i.e., the decrease in permeate flux with flow rate.

• Proceedings of the Membrane Society of Korea Conference
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• 2002.05a
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• pp.81-85
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• 2002

Small angle light scattering and field emission scanning electron microscope have been used to quantify the kinetics of liquid-liquid separation behavior during water vapor(RH52%[$\pm$3%] at 27$^{\circ}C$) quenching (non-solvent induced phase separation, NIPS) of polysulfone/NMP/Alcohol and CPVC/THF/Alcohol, respectively. Time dependence of the position of the light scattering maximum was observed at polysufone dope solutions, confirming spinodal secomposition (SD). while CPVC dope solutions showed a decreased scattered light intensity with a increased q-valuel, indicating nucleation & growth (NG). For the each system, domain growth rate in the intermediate and late stage of phase separation decreased with increasing the number of carbon of alcohol used as additive (non-solvent). Also, in the early stage for SD, the scattering intensity with time was in accordance with Cahns linear theory of spinodal decomposition,[1-3] regardless of types of non-solvent additive.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.56.2-56.2
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• 2014

We present an extensive study of the environment of galaxies with bars in the low-redshift Uni-verse, using a volume-limited sample of over 30,000 galaxies drawn from the Sloan Digital Sky Survey, with visually-determined morphological classifications and bar identifications. We use four different statistics to quantify the environment of our galaxies: the projected two-point cross-correlation function with respect to a spectroscopic sample of reference galaxies, the background-subtracted number count of galaxies in a deep photometric sample in the vicinity of our galaxies, the overdensity of the local environment estimated at ~3 Mpc scale from the three-dimensional reconstruction of the cosmic density field of the local Universe, and the membership of our galaxies in the SDSS galaxy groups to segregate central to satellite systems. We find a weak, but significant trend for early-type galaxies with a bar to be more strongly clustered on scales from a few 100 kpc to 1 Mpc, when compared to early-type galaxies without a bar. For late-type galaxies, we find less neighbours within ~50 kpc around the barred late-types when compared to the unbarred late-types. For late-type galaxies we also detect a decrease of the bar fraction for dark matter dominated systems, and finally we find no obvious correlation between the overdensity and the fraction of barred galaxies in our sample.

• Journal of Biomedical Engineering Research
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• v.23 no.3
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• pp.207-216
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• 2002

This Paper describes a quantitative analysis of Postural balance training using virtual bicycle system. We have used a virtual bicycle system that combines virtual reality technology with a bicycle . In this experiment, 20 normal adults were tested to investigate the influencing factors on Postural balance. Several factors including cycling time. cycling velocity. number of times of Path deviation, center of Pressure(COP) . and weight shift were extracted and evaluated to quantify the extent of control. Also, To improve the effect of balance training, we investigated the usefulness of visual feedback information by weight shift The results showed that the system was effective Postural balance rehabilitation training device and. in addition. the analysis method might have a wider applicability to the rehabilitation field.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.6
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• pp.738-745
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• 2012

Aircraft battle damage repair(ABDR) is emergency repair method for the damaged aircraft in battle field. The main purpose of the ABDR is to increase the readiness of fighter aircraft during wartime. While many studies have been conducted to develop ABDR method, few efforts have focused on evaluation of damage and determination of the size of hole caused by enemy's anti-aircraft artillery attack. The aim of this study is essentially to quantify damage of aircraft wing attacked by anti-aircraft artillery. The computer simulations was performed to accomplish this goal. A number of simulations have been carried out to compare size of damages under various attack conditions. In conclusion, it was revealed that the size of damage varied depending on the type and direction of cannonball. Furthermore, in this paper, the proper path sizes are suggested for different damage conditions.

• Osong Public Health and Research Perspectives
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• v.8 no.6
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• pp.389-396
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• 2017

Objectives: To circumvent the limitations of the current golden standard method, colony-forming unit (CFU) assay, for viability of Bacille Calmette-$Gu{\acute{e}}rin$ (BCG) vaccines, we developed a new method to rapidly and accurately determine the potency of BCG vaccines. Methods: Based on flow cytometry (FACS) and fluorescein diacetate (FDA) as the most appropriate fluorescent staining reagent, 17 lots of BCG vaccines for percutaneous administration and 5 lots of BCG vaccines for intradermal administration were analyzed in this study. The percentage of viable cells measured by flow cytometry along with the total number of organisms in BCG vaccines, as determined on a cell counter, was used to quantify the number of viable cells. Results: Pearson correlation coefficients of FACS and CFU assays for percutaneous and intradermal BCG vaccines were 0.6962 and 0.7428, respectively, indicating a high correlation. The coefficient of variation value of the FACS assay was less than 7%, which was 11 times lower than that of the CFU assay. Conclusion: This study contributes to the evaluation of new potency test method for FACS-based determination of viable cells in BCG vaccines. Accordingly, quality control of BCG vaccines can be significantly improved.

• Journal of Preventive Medicine and Public Health
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• v.55 no.5
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• pp.485-491
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• 2022

Objectives: Tuberculosis (TB) is a major public health concern worldwide. Social contact patterns can affect the epidemiology and risk of airborne diseases such as TB. This study was designed to investigate the social contact patterns associated with TB. Methods: In this case-control study, groups of participants with and without TB were matched by age and sex. Participants reported the nature, location, frequency, and average duration of social contacts over 1 month. The duration and number of social and spatial contacts were compared between groups using the chi-square test and the t-test. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to quantify the relationship between social contact time and TB status. Data were analyzed using Stata version 11 statistical software. A p-value of <0.05 was considered to indicate statistical significance. Results: In this study, 80 patients with TB and 172 control participants were included, and a total of 3545 social contacts were registered. Social contact with family members (OR, 1.72; 95% CI, 1.10 to 2.40), contact with a person with TB (OR, 1.53; 95% CI, 1.16 to 2.01), and contact at the participant's home (OR, 1.42; 95% CI, 1.19 to 1.82) were significantly associated with TB status. Conclusions: The duration of long-term social contact, rather than the number of contacts, may be the main contact-related factor associated with TB transmission in this population. The focus of contact-tracing efforts should be on finding and treating both family members and long-term contacts in non-household settings.