• Journal of applied mathematics & informatics
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• v.41 no.1
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• pp.107-121
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• 2023

An epidemic infectious disease model consists of six compartments viz. Susceptible, Exposed, Infected, Quarantine, Recovered, and Virus with nonlinear saturation incidence rate is proposed to know the viral disease dynamics. There exist two biological equilibrium points for the model system. The system's local and global stability is done through Lyapunov's direct method about equilibrium points. The sensitivity analysis has been performed for the basic reproduction number and equilibrium points through the normalized forward sensitivity index. Sensitivity analysis shows that virus growth and quarantine rates are more sensitive parameters. In support of mathematical conclusions, numerical experimentation has been shown.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.1
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• pp.125-131
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• 2002

This paper was studied on the effect of temperature on corrosion of absorption refrigeration systems using $LiBr-H_2O$ working fluids. In the fresh water and 62 % lithium bromide solution at $70^{\circ}C$, polarization test of SS 400, Cu(C1220T-OL) and Al-Ni bronze was carried out. And polarization behavior, polarization resistance characteristics, corrosion rate(mmpy) and corrosion sensitivity of materials forming absorption refrigeration systems was considered. The main results are as following: (1) As the experimental temperature increase, the change of corrosion rate of Al-Ni bronze become duller than SS 400 and Cu in 62% lithium bromide solution. (2) According as corrosion environment is changed from fresh water to 62% lithium bromide solution, potential change of Cu and Al-Ni bronze become less noble than SS 400. (3) The corrosion sensitivity of Al-Ni bronze was duller than that of Cu and SS 400 in 62% LiBr solution.

• Journal of the Korean GEO-environmental Society
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• v.4 no.3
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• pp.69-77
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• 2003

This study was carried out to evaluate the WASP5 model parameters and to analyze the sensitivity of parameters in Daechung Reservoir. The values predicted by the model and tendency were very similar to the observed data at Daejeon intake, so it is possible to predict water quality of the Daejeon intake region in the future. Results from the sensitivity analysis showed that Chlorophyll-a was sensitive to variations in saturated growth rate of phytoplankton, endogenous respiration rate of phytoplankton, extinction coefficient and temperature. T-N was sensitive to mineralization rate of dissolved organic nitrogen and temperature. T-P was affected by T-P load, temperature, extinction coefficient, mineralization rate of dissolved organic phosphorus and saturated growth rate of phytoplankton. BOD was influenced by deoxygenation rate and temperature, and DO was influenced by temperature. Adequate input data was applied and assessed through the model sensitivity analysis. So it is possible to distinguish the input data which need careful attention when it has application to model.

• The Korean Journal of Emergency Medical Services
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• v.1 no.1
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• pp.20-27
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• 1997

This study of the positive rates of HBsAg, anti-HBs among 119 Emergency Medical Technicians and Rescuers who were working in Pohang, Kyoung-Buk, Korea was performed from March to June 1997 according to three methods of EIA, RPHA and PHA. The number of samples were 201. The results were as follows; The overall positive rate of HBs Ag by EIA and RPHA methods were 4.98%, 5.47%, the overall positive rate of anti-HBs by EIA and PHA methods were 58.71%, 63.68%. In detecting of HBs Ag, concurrence rate, sensitivity, specificity and predictability of PHA to EIA were 99.5%, 90.9%, 100% and 99.75% respectively. In detecting of anti-HBs, concurrence rate, sensitivity, specificity and predictability of PHA to EIA were 91.04%, 89%, 94.5% and 89.87% respectively. Based on this study, there were no significant diffrences in the positive rates of HBsAg and Anti-HBs in 119 Emergency Medical Technicians and Rescurers in Pohang, Korea as compared with the general population according to other studies. In terms of concurrence rate, sensitivity, specificity and the costs of RPHA with EIA for detecting HBsAg, RPHA is more cost effective than EIA for mass screening of HBsAg detection. Also, In terms of concurrence rate, sensitivity and specificity of PHA with EIA, PHA is more cost effective and less problems of procedure than the EIA for mass screening of Anti-HBs detection.

• Structural Engineering and Mechanics
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• v.5 no.3
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• pp.239-256
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• 1997

The companion paper presents a new three-parameter model for the uniaxial rate-sensitive material response, which is based on a bilinear static stress-strain relationship with kinematic strain-hardening. This paper extends the proposed model to trilinear static stress-strain relationships for steel and concrete, and discusses the implementation of the new models within an incremental-iterative solution procedure. For steel, the three-parameter rate-function is employed with a trilinear static stress-strain relationship, which allows the utilisation of different levels of rate-sensitivity for the plastic plateau and strain-hardening ranges. For concrete, on the other hand, two trilinear stress-strain relationships are used for tension and compression, where rate-sensitivity is accounted for in the strain-softening range. Both models have been implemented within the nonlinear analysis program ADAPTIC, which is used herein to provide verification for the models, and to demonstrate their applicability to the rate-sensitive analysis of steel and reinforced concrete structures.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.6
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• pp.451-458
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• 2014

The purpose of this study is to compare the economics between a diesel propulsion vessel and a LNG fuel propulsion vessel through the analysis of the present value using the LCC(Life Cycle Cost) method. This study is also to judge the economics for long-term operation of a LNG fuel propulsion vessel as a result of analysis about the equivalent uniform annual cost. In particular, LCC method was strengthened by sensitivity analysis based on combined interest rate which is considering discount rate and inflation rate simultaneously.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.4
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• pp.161-172
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• 2020

The tensile property of A5082 and A6060 aluminium wrought alloys was investigated, in terms of the strain rate sensitivity on alloy conditions by heat treatment and bake hardenability on pre-strain prior to strain ageing. The tensile test was carried out in a range of strain rate of 4.17 × 10^-5 s^-1 ~ 4.17 × 10^-5 s^-1 in room temperature and the nominal range of pre-strain was 3.0 ~ 10.5%. The tensile deformation of A5082 alloys is characterized as typical case of dynamic strain ageing with negative strain rate sensitivity for all conditions, and the tensile strength indicates a similar level regardless of alloy conditions, except only in full annealed condition. The stress-relief annealing on A6060 alloys can induce practical decrease in strength level of over approximately 100 MPa without any ductility loss, compared to as-rolled condition, while a full annealed and aged condition leads remarkable strengthening effect with the decrease of tensile elongation. Additionally, the bake hardenability of A5082 alloy by strain ageing indicates a negative dependence upon the increase of pre-strain, while A6060 alloy exhibits a positive sign even in low level relatively compared with conventional SPCC.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.365-369
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• 2006

It is concentrated on a methodology to establish a scheme of investment on power distribution systems of components. This paper provides a methodology to estimate the scheme as using a customer interruption cost regarding reliability indices in power distribution systems. The proposed method basically uses the failure rate depending on time for explaining the deterioration of a component. Therefore, the theory of the sensitivity is used for deciding the precedence of the investment to consider an effect of each component's failure rate on the system reliability. After Estimating the sensitivity on component investment cost making incremental reliability level is produced by component's investment cost accumulated according to the precedence of the sensitivity. After that, the failure rate corresponding with reliability level on the curve of investment cost is used as producing the curve of customer interruption cost. Two curves have the crossing point that is proposed to acceptable reliability level for customer and utility. In this paper, the acceptable reliability level for customer with the utility is assessed to analyze customer interruption cost and sensitivity of reliability indices. In conclusion the result of investment based on this method is shown to the reliability level with two cost.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.491-495
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• 1997

In this paper, an effective mount design method using vector synthesis is presented for two mount systems. For designing mount stiffnesses effectively, we perform a sensitivity analysis, i.e, identify the contribution rate of an input component vector to the total output vector. Especially, we show that it is necessary to takea phase sensitivity into consideration in case of two mount systems, such as the excavator mount systems having engine mounts and cabin mounts. THe proposed method is testified is testified through an test bed.

• Journal of the Optical Society of Korea
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• v.14 no.1
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• pp.14-21
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• 2010

Fiber ring laser based intra-cavity absorption spectroscopic sensor has great potential for high sensitivity gas detection. Using the rate equations and propagation equations, we investigated theoretically factors that affect the sensitivity of such fiber ring laser sensors and determined the optimal design parameters and conditions for significant enhancement of the system sensitivity. Experiments have been conducted to determine the sensitivity enhancement performance. The results showed a factor of 25 ~ 30 in sensitivity enhancement in the experimental system, agreeing well with the theoretical expectations. Experiments on acetylene detection have also been carried out and the results showed that the ring cavity significantly increases the signal absorption and that high sensitivity can be obtained for gas detection.