• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.3
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• pp.293-301
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• 2008

The purpose of this study is price determination for KLIS (Korea Land Information System) which Korea government established. For this purpose, I analyzed cost accounting and made the KLIS selling price according to selling amount, recovery rate and information volume. In case of recovery rate, the cost was expensive but, in case of information volume the cost was cheap. So, the price determination for KLIS should be resonable according to information volume considering GIS revitalization.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.73-78
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• 2000

On this study, the fatigue crack propagation of super duplex stainless steel is investigated in conditions of various volume fraction of austenite phase by changing heat treatment temperature. And we analysed acoustic emission signals during the fatigue test by time-frequency analysis methods. As the temperature of heat treatment increased, volume fraction of austenite decreased and coarse grain was obtained. The specimen heat treated at $1200^{\circ}C$ had longer fatigue life and slower rate of crack growth. As a result of time-frequency analyze of acoustic emission signals during fatigue test, main frequency was $200{\sim}300kHz$ having no correlation with heat treatment and crack length, and 500kHz was obtained by dimple and separate of inclusion

• Korea-Australia Rheology Journal
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• v.17 no.4
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• pp.149-156
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• 2005

A simple constitutive model for viscoelastic suspensions is discussed in this paper. The model can be used to predict the rheological properties (relative viscosity and all stresses) for viscoelastic suspensions in shear and elongational flow, and the constitutive equations combine a 'viscoelastic' behaviour component and a 'Newtonian' behaviour component. As expected, the model gives a prediction of positive first normal stress difference and negative second normal stress difference; the dimensionless first normal stress difference strongly depends on the shear rate and decreases with the volume fraction of solid phase, but the dimensionless second normal stress difference (in magnitude) is nearly independent of the shear rate and increases with the volume fraction. The relative viscosities and all the stresses have been tested against available experimental measurements.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.3
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• pp.253-261
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• 2000

Head-out water immersion induces marked increase in the cardiac stroke volume. The present study was undertaken to characterize the stroke volume change by analyzing the aortic blood flow and left ventricular systolic time intervals. Ten men rested on a siting position in the air and in the water at $34.5^{circ}C$ for 30 min each. Their stroke volume, heart rate, ventricular systolic time intervals, and aortic blood flow indices were assessed by impedance cardiography. During immersion, the stroke volume increased 56%, with a slight (4%) decrease in heart rate, thus cardiac output increased ${\sim}50%.$ The slight increase in R-R interval was due to an equivalent increase in the systolic and diastolic time intervals. The ventricular ejection time was 20% increased, and this was mainly due to a decrease in pre-ejection period (28%). The mean arterial pressure increased 5 mmHg, indicating that the cardiac afterload was slightly elevated by immersion. The left ventricular end-diastolic volume index increased 24%, indicating that the cardiac preload was markedly elevated during immersion. The mean velocity and the indices of peak velocity and peak acceleration of aortic blood flow were all increased by ${\sim}30%,$ indicating that the left ventricular contractile force was enhanced by immersion. These results suggest that the increase in stroke volume during immersion is characterized by an increase in ventricular ejection time and aortic blood flow velocity, which may be primarily attributed to the increased cardiac preload and the muscle length-dependent increase in myocardial contractile force.

• Journal of Korean Neurosurgical Society
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• v.46 no.4
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• pp.378-384
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• 2009

Objective : In order to establish the role of Gamma Knife radiosurgery (GKS) in large intracranial arteriovenous malformations (AVMs), we analyzed clinical characteristics, radiological features, and radiosurgical outcomes. Methods : Between March 1992 and March 2005, 28 of 33 patients with large AVMs (> $10\;cm^3$ in nidus-volume) who were treated with GKS underwent single session radiosurgery (RS), and the other 5 patients underwent staged volumetric RS. Retrospectively collected data were available in 23 cases. We analyzed treatment outcomes in each subdivided groups and according to the AVM sizes. We compared the estimated volume, defined as primarily estimated nidus volume using MR images, with real target volume after excluding draining veins and feeding arteries embedded into the nidus. Results : Regarding those patients who underwent single session RS, 44.4% (8/18) had complete obliteration; regarding staged volumetric RS, the obliteration rate was 40% (2/5). The complete obliteration rate was 60% (6/10) in the smaller nidus group ($10-15\;cm^3$ size), and 25% (2/8) in the larger nidus group (over $15\;cm^3$ size). One case of cerebral edema and two cases (8.7%) of hemorrhage were seen during the latent period. The mean real target volume for 18 single sessions of RS was $17.1\;cm^3$ ($10.1-38.4\;cm^3$), in contrast with the mean estimated volume of $20.9\;cm^3$ ($12.0-45.0\;cm^3$). Conclusion : The radiosurgical treatment outcomes of large AVMs are generally poor. However, we presume that the recent development in planning software and imaging devices aid more accurate measurement of the nidus volume, therefore improving the treatment outcome.

• The Journal of Fisheries Business Administration
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• v.40 no.1
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• pp.153-172
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• 2009

Developing foreign fishing ground executed in various uncertainty such as fishing price, oil price, exchange rate. But traditional economic evaluation method, CVP(Cost-Volume-Profit) analysis doesn't consider uncertainty of foreign fishing ground. So we need new approach about economic evaluation that can take into account uncertainty. This study focus on the economic evaluation about experimental survey of tuna fishing grounds in the north pacific ocean by sensitive analysis and simulation. The results of the economic evaluation can be summarized as follows. First, when we take it for granted that the other uncertainty factors except for each fishing price, oil price, and exchange rate are constant. CVP gross sales has positive relation to the increasing rate of oil price, exchange rate(W/$) and negative relation to the increasing rate of fishing price and exchange rate(W/${\yen}$). Second, when we are supposing that fishing price, oil price, and exchange rate are followed. the probability of less than CVP gross sales is A ship(48.87%), B ship(49.64%), C ship(50.55%). Consequently, the economic evaluation by sensitive analysis and simulation is more useful tool than CVP(Cost-Volume-Profit) analysis under uncertainty.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1191-1196
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• 2009

The T-s chart of air displays graphically the thermophysical properties, so it is very conveniently used in various thermal systems. In previous study, the software analyzing 31 kinds of values in water system and 32 kinds of values in air-conditioning system were developed. In this study, the software drawing 13 kinds of quantity of state on air properties as ideal gas and analyzing 25 kinds of values in any air system was developed. The 13 kinds of quantity of state on air properties are temperature, pressure, specific volume, specific internal energy, specific enthalpy, specific entropy, specific exergy, exergy ratio, density, isobaric specific heat, isochoric specific heat, ratio of specific heat, and velocity of sound, and the 25 kinds of values including 13 kinds are mass flow rate, volume flow rate, internal energy flow rate, enthalpy flow rate, entropy flow rate, exergy flow rate, heat flow rate, power output, power efficiency, reversible work, lost work, and relative humidity. The developed software can draw any range of chart and analysis any state or process on air system. Also, this supports various document-editing functions such as power point. We wish to this chart is a help to design, analysis, and education in air system field.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.75
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• pp.95-116
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• 2017

The global financial crisis has slowed overall growth in the global economy. In addition, uncertainty is increasing in the world economy due to the Trade protectionism, sluggish world trade, and a rise in the rate of interest caused by expansion of fiscal spending by major countries. In this study, we analyzed various factors affecting the container import and export volume, which has a high correlation with export and import of commodities in international trade. In particular, we will examine how exchange rate fluctuations and domestic and overseas economic conditions affect container imports and exports. For the empirical analysis, monthly time series data were used from January 2000 to January 2017. We use the Error Correction Model (VECM) for the empirical analysis and the GARCH model for the exchange rate fluctuation. As a result, container export and import volume had a negative relationship with exchange rate and exchange rate volatility, which had a positive effect on domestic and international economic conditions. However, the effects are different before and after the financial crisis.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.83-89
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• 2008

The Effect of Space Velocity(SV) on NOx conversion rate was performed to develop NOx reduction after-treatment system. SV is calculated from engine exhaust gas volume and SCR catalyst volume. Found the Urea injection duty of maximum efficiency for NOx conversion if increase SV, NOx Conversion rate is down. Especially, when SV is more than $110,000h^{-1}$, NOx conversion rate decrease suddenly. Same case, if SV is lower than $40,000h^{-1}$, NOx conversion rate is down. Also, the characterization of Urea-SCR system was performed. Three candidate injectors for injecting Urea were tested in terms of 속 injection rate and NOx reduction rate. The performances of SCR catalytic converter on temperature were investigated. The performance of Urea-SCR system was estimated in the NEDC test cycle with and without EGR. It was found that nozzle type injector had high NOx conversion rate. SCR catalytic converter had the highest efficiency at the temperature of $350^{\circ}C$. EGR+Urea-SCR system achieved NOx reduction efficiency of 73% through the NEDC test cycle.

• Tribology and Lubricants
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• v.21 no.4
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• pp.159-164
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• 2005

An experimental study was conducted to evaluate characteristic variation of diluted engine oils in which contains diesel fuels and its tribological effects on engine components. In this study, diluted engine oils with $10\%,\;15\%,\;and\;20\%$ of initial fuel content rate have been used for measuring the viscosity reduction rate, blow-by gas increment rate, main gallery pressure reduction rate, and fuel content rate in engine oils. These parameters are strongly related to the tribological characteristics of key engine components. The kinematic viscosity of engine oils in which is contained by diesel fuels from $10\%\;to\;20\%$ in oils is decreasing to approximately $54\%$ of initial diluted fuel-oil volume ratios. The experimental results show that the distillated engine oil decrease the viscosity of engine oil and its oil film stiffness, and increase the wear rate of rubbing parts of engine components. Thus we recommend that the containing volume rate of fuels in engine oils should be restricted to $3\~4\%$ for a sophisticated Diesel engine and $5\~7\%$ for a standard one.