• Korean Journal of Veterinary Research
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• v.9 no.2
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• pp.19-25
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• 1969

The effects of some chemicals for the germinative stimulation of Clostridium chauvoei spore studied. The results obtained were as follows: 1. Cooked meat medium (CMM) was superior to Liver-liver bouillon (LLB) for cultivation of the organisms. 2. Heating the organisms at $70^{\circ}C$ for 30 minutes prior to cultivation in CMM stimulated the germination rate. 3. The addition of 0.5mM L-alanine to CMM was found to be most effective for the rapid germination of the spores. 4. The addition of 0.2 mM D-alanine to CMM inhibited the germination of the spores even if the spores were heat treated. 5. The addition of 0.1mM manganese retarded the germination time, but the final germination rate was greater with 0.1mM manganese than with 0.5mM L-alanine. 6. The addition of both 0.5mM L-alanine and 0.1mM manganese stimulated the germination rate to 100 per cent. 7. The germination rate was greater with the addition of germination stimulants than without any stimulants. The germination rate was approximately 6 per cent greater with prior heat treatment than without heat treatment. 8. The optimum time for the harvest of vegetative forms of the organisms was 15 hours after cultivation in the media which contain suitable germination stimulants.

• Tunnel and Underground Space
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• v.20 no.2
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• pp.119-124
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• 2010

Hopkinson's effect tests were carried out for various strain rates on three different types of rock in both saturated and dry states in order to examine the effects of strain rate and water saturation on tensile strength. The tensile strength increased with the increase of the strain rate not only in dry state but also in saturated state. It was also especially recognizable that the dynamic tensile strength of rock in the dry state was proportional to approximately a one-third multiple of strain rate no matter what the type of rock. It was found that water saturation decreased tensile strength in the dry state of sandstone and tuff, both with high porosity, but no significant difference could be recognized between the dry and the saturated states of granite, which has a low porosity of 0.49%.

• Journal of the Korean Institute of Gas
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• v.8 no.2 s.23
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• pp.42-47
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• 2004

The axisymmetric methane-air counterflow flame in microgravity was simulated to investigate effects of the global strain rate on the flame structure. The flame shapes and profiles of temperature and the axial velocity for the mole fraction of methane in the methane-nitrogen fuel stream, Xm= 20, 50, $80\%$, and the global strain rate, ag= 20, 60, 90 $s^{-1}$ each mole fraction were compared. The profiles of the temperature and axial velocity of the axisymmetric simulations were in good agreement with those of OPPDIF, an one-dimensional flamelet code. It was confirmed that the flame is stretched more and the flame radius increases and the flame thickness decreases as the global strain rate increases.

• Journal of Information Technology Services
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• v.20 no.4
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• pp.23-33
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• 2021

The prolonged coronavirus 19 (COVID-19) has caused serious problems such as job losses and youth unemployment, but as the fourth industrial revolution and digital transformation accelerate, the importance of SW is highlighted and more qualified jobs are expected in the SW industry. However, domestic SW companies are having difficulties in not properly recognizing the value of SW products. Among many related issues, commercial SW maintenance-related issues are representative, and the main problem is the difference in the maintenance fee rates between domestic and foreign SW. In this study, the expected job creation effect when the SW maintenance rate is raised was analyzed using data related to the SW industry and commercial software. As a result of the analysis, the amount required to raise the commercial SW maintenance rate by 1% is 162 billion won. If all of these are used for employment, the expected new job creation effect is 3,240 jobs per year, and 15,451 jobs are created per year when calculated and estimated as the effect of increasing sales through the employment inducement coefficient. In addition, the amount required to raise the current average maintenance rate of 11.1% to 15% is 631.9 billion won, and it was possible to estimate the effect of creating jobs for 12,648 people based on the simple average wage and 60,259 people from the sales increase effect.

• Asia-Pacific Journal of Business
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• v.13 no.3
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• pp.343-359
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• 2022

We analyze the regional ripple effects of both the sale prices and cheonsei prices using the global VAR(GVAR) model. The interest rate shock causes the regional sale prices to fall. Moreover, the greatest responses to the shock are those of Gangnam-gu, etc. because of there were many transactions for investment purpose. When interest rate rose, the cheonsei price in Gangnam-gu reacted greatly. Conversely, if interest rates fall, the cheonsei demand to live in Gangnam-gu increases. Furthermore, the response of sale price to the interest rate shock are greater than those of the cheonsei prices. Whereas, a positive shock on the sale price in Gangnam-gu increases the sale price there. It also raises the sale prices of the surrounding area in a similar pattern. The shock on the sale price in Gangnam-gu also increases the cheonsei price in Gangnam-gu. In addition, an increase in the sale price in Gangnam-gu leads to increases of cheonsei prices in other regions. Therefore, the recent rise of the base rate can negatively affect the sale prices, and thus a decrease in the sale price spreads to the surrounding areas. Accordingly, it is time for policy alternatives to make a soft landing in sale prices.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.37.1-37.1
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• 2021

Observations suggest the star formation in nuclear rings of barred galaxies proceeds episodically in time and sometimes asymmetrically in space. Existing theories and numerical simulations suggest that the episodic star formation is perhaps due to either supernova feedback combined with fluid instabilities or time-varying mass inflow rate. However, it has been challenging to discern what dominates in shaping the star formation history because the effects of the inflow and feedback are blended in global simulations of nuclear rings. To understand their effects separately, we construct semi-global models of nuclear rings, which treat the mass inflow rate as a model parameter. By running simulations with the inflow rates kept constant or oscillating in time, we find that the star formation rate (SFR) of the rings varies coherently with the inflow rate, while the feedback is responsible only for stochastic fluctuations of the SFR within a factor of two. The feedback instead plays an important role in maintaining the vertical dynamical equilibrium and setting the depletion time. While the asymmetry in the inflow does not necessarily lead to the asymmetry in the star formation, we find that the rings undergo a transient period of lopsided star formation when the inflow rate of only one dust lane is suddenly increased.

• Journal of radiological science and technology
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• v.46 no.6
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• pp.493-499
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• 2023

This study developed education contents of measuring spatial dose with virtual reality simulation and applied to students majoring radiological science. The virtual reality(VR) contents with measuring spatial dose rate in the radiation controlled area was developed based on the simulation from pilot study. In this simulation, the tube voltage and tube current can be set from 60 to 120 kVp in 10 kVp steps and 10 to 40 mAs in 10 mAs increments, and the distance from source can be set from 30 to 400 cm continuously. Iron and lead shields can be placed between the source and the detector, and shielding thickness can be set by 1 mm increments ranging from 1 to 20 mm. We surveyed to students for evaluating improvement of understanding spatial dose rate between before and after education by VR simulation. The survey was conducted with 5 questions(X-ray exposure factors, effects by distance from the source, effects from using shield, depending on material and thickness of shield, concept and measuring of spatial dose rate) and all answers showed significant improvement. Therefore, this VR simulation content will be well used in education for spatial dose rate and radiation safety environments.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.5
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• pp.53-61
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• 1995

Analyses of subsurface drainage effects of farmland with respect to pipe and envelop material are made by the laboratory experiments using soil box to give basic information for the subsurface drainage system planning and design. Three different diameter PVC perforated pipes and a mesh pipe are used with envelop materials such as sand, rice bran, and crushed stone. Steady state subsurface drainage flow rate increased as envelop material changed from sand to rice bran and crushed stone. This indicates that as the hydraulic conductivity of the envelop material increases, the drainage flow rate increases. On the other hand, for a given envelop material, the mesh pipe which has the largest openning area shows the largest flow rate while small diameter PVC pipes show small flow rates. This tells that as the openning area and pipe diameter increase, the flow rate increases, too. Therefore, selection of pipe and envelop material should be made in accordance with the design drainage flow rate. Unsteady state subsurface drainage flow rate with respect to time differs for different envelop material. In case the sand was used as an envelop material, the small diameter PVC pipes show larger flow rates than the large diameter PVC pipe and mesh pipe. When the rice bran was used, the mesh pipe shows the largest flow rate, while small diameter pipes show smaller flow rates. In case the crushed stone was used as an envelop material, the large diameter PVC pipe and mesh pipe show larger flow rates, while small diameter pipes show a little bit smaller flow rates. However, the variation of flow rates among different pipes is the smallest when the crushed stone is used. The flow rate curve with respect to the pipe changes little for the crushed stone envelop which has a large hydraulic conductivity, while that changes much for the sand and rice bran envelops. However, it is difficult to draw a consistent relationship between the drainage flow rate and pipe for all the envelop materials. Since the subsurface drainage experiments are made only under the restricted laboratory condition in this study, further study including field experiment is required.

• Journal of Environmental Science International
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• v.17 no.7
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• pp.817-826
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• 2008

Using high voltage electric fields induced by high voltage AC (10-12 kV/cm, 20 kHz) and pulsed (20-30 kV/cm, 40 Hz) electric field generator as a semipermanent and environment-friendly disinfecting apparatus, the disinfection effect of coliform group in the effluent of sewage plant was investigated. The effects of electric field strength, treatment time, discharge area of a discharge tube, water quality factors (electric conductivity, pH and SS) on its death rate were examined. The death rate of coliform group was increased with increasing electric field strength and treatment time. For AC and pulsed electric field generator, the critical electric field strength was 6 kV/cm and 2 kV/cm, respectively, and the critical treatment time was 5 min and 2 min, respectively, regardless of electric field strength. Comparing the death rate of coliform group by AC and pulsed electric fields used in this study, its death rate was higher for the latter than the former, but did not increase linearly with increasing electric field strength. The results obtained for the effects of discharge area, electric conductivity, pH and SS on the death rate of coliform group using AC electric field (12 kV/cm, 20 kHz) were as follows: its death rate showed the trend to increase linearly with increasing discharge area; for the effect of electric conductivity, its death rate was increased with increasing electric conductivity, regardless of ionic species, increased with increasing cationic valency, but was similar between the same cationic valency; the pH $5{\sim}9$ used in this study did not affect its death rate; its death rate was decreased with increasing SS concentration.

• Journal of Sasang Constitutional Medicine
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• v.28 no.2
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• pp.123-131
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• 2016

Objectives We observed what effects of Paced Breathing(PB) in specific respiration rate have on heart rate variability (HRV) according to Sasang Constitution.Methods HRV of 72 healthy participants in sitting position was recorded while they carried out usual breathing, 0.2Hz, 0.1Hz, and 0.05Hz PB each 5 minutes in consecutive order. Five minute of relaxation was permitted between each breathing. Finally, HRV indices were statictically analyzed of 32 participants (SOEUM: 11, SOYANG: 10, TAEEUM: 11) after data out of accord with respiration rate or outliers were excluded.Results and Conclusions According to respiration rates, there was no statistical significance of HRV among Sasang Constitution. Regardless of Sasang Constituion, 0.2Hz PB increased mean heart rate and decreased natural logarithmic low frequency(lnLF) oscillation of HRV without the change of natural logarithmic high frequency(lnHF), while 0.1Hz PB increased lnLF and standard deviation of N-N interval(SDNN), and slightly decreased lnHF without the change of mean heart rate. 0.05 Hz PB also showed the same effect as 0.1Hz PB, but was impracticable.