• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.307-313
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• 2001

In this Paper, friction welding optimization for 1Cr0.5Mo-STS304($\Phi$14mm), AE applications for the weld quality evaluation and the applications of various life prediction methods such as LMP(Larson-Miller Parameter) and ISM(initial strain method) were investigated : the creep behaviors of those steels and the friction welded joints under static load were examined by ISM combined with LMP at 400, 500, 550 and $600^{\circ}C$, and the relationship between these two kinds of phenomena was studied. The real-time predicting equations of elevated-temperature creep life(fracture time) under any creep stress at any elevated- temperature could be developed by LMP and LMP-ISM, It was confirmed that the life prediction equations by LMP and LMP-ISM are effective only up to 10$^2$hrs and can not be used for long times of 10$^3$-10$^{6}$ hrs, but by ISM it can be used for long times creep prediction of more than 10$^4$hrs with most reliability.

• Journal of Welding and Joining
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• v.24 no.1
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• pp.77-87
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• 2006

Considering ferrite grain size in the base metal, the prediction model for $A_{c3}$ temperature and prior austenite grain size at just above $A_{c3}$ temperature was proposed. In order to predict $A_{c3}$ temperature, the Avrami equation was modified with the variation of ferrite grain size, and its kinetic parameters were measured from non-isothermal data during continuous heating. From calculation using a proposed model, $A_{c3}$ temperatures increased with increasing ferrite grain size and heating rate. Meanwhile, by converting the phase transformation kinetic model that predicts the ferrite grain size from austenite grain size during cooling, a prediction model for prior austenite grain size at just above the $A_{c3}$ temperature during heating was developed.

• Journal of Power System Engineering
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• v.6 no.2
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• pp.40-47
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• 2002

In this paper, friction welding optimization for 1Cr0.5Mo-STS304 (${\phi}14\;mm$), AE applications for the weld quality evaluation and the applications of various life prediction methods such as LMP (Larson-Miller Parameter) and ISM (initial strain method) were investigated : The creep behaviors of those steels and the friction welded joints under static load were examined by ISM combined with LMP at 400, 500, 550 and $600^{\circ}C$, and the relationship between these two kinds of phenomena was studied. The real-time predicting equations of elevated-temperature creep life (rupture time) under any creep stress at any elevated-temperature could be developed by LMP and LMP-ISM. It was confirmed that the life prediction equations by LMP and LMP-ISM are effective only up to 102 h and can not be used for long times of 103-106 h, but by ISM it can be used for long times creep prediction of more than 104 h with most reliability.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.2 s.17
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• pp.5-12
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• 2004

The erosion wear of gun barrel occurs due to heat and chemical reactions. The high pressure and temperature in chamber increase the erosion wear. It is known that the metal phase transfer is the primary wear factor in a gun barrel under high temperature. In this paper, the tool of wear prediction in high pressure gun tube has been developed. The program developed has three modules such as DIRECT(interior ballistics analysis module), INVERSE(gun design module), and WEAR(wear prediction module). The prediction of wear was compared with the experimental data which was collected in the field unit. The prediction results shows good trend with the collected data.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.258-263
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• 2001

In this paper, the real-time prediction of high temperature creep life was carried out for the friction welded joints of dissimilar heat resistintg steels (CulCr0.5Zr-STS316L). Various life prediction methods such as LMP (Larson-Miller Parameter) and ISM (initial strain method) were applied. The creep behaviors of those steels and the welds under static load were examined by ISM combined with LMP at 300, 400 and 50$0^{\circ}C$, and the relationship between these two methods was investigated. A real-time creep life (tsub/r/, hr) prediction equation by initial strain ($\varepsilon_0$, %) under any creep stress ($\sigma$, MP$\alpha$) at any high temperature (T, K) was developed

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.11
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• pp.759-766
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• 2012

To estimate the cooling load for the following day, outdoor temperature and humidity are needed in hourly base. But the meteorological administration forecasts only maximum and minimum temperature. New methodology is proposed for predicting hourly outdoor temperature and humidity by using the forecasted maximum and minimum temperature. The correlations for normalized outdoor temperature and specific humidity has been derived from the weather data for five years at Seoul, Daejeon and Pusan. The correlations for normalized temperature are independent of date, while the correlations for specific humidity are linearly dependent on date. The predicted results show fairly good agreement with the measured data. The prediction program is also developed for hourly outdoor dry bulb temperature, specific humidity, dew point, relative humidity, enthalpy and specific volume.

• Ocean and Polar Research
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• v.23 no.2
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• pp.181-188
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• 2001

We describe here the Korea ocean prediction system that closely resembles operational numerical weather prediction systems. This prediction system will be served for real-time forecasts. The core of the system is a three-dimensional primitive equation numerical circulation model, based on ${\sigma}$-coordinate. Remotely sensed multi-channel sea surface temperature (MCSST) is imposed at the surface. Residual subsurface temperature is assimilated through the relationship between vertical temperature structure function and residual of sea surface height (RSSH) using an optimal interpolation scheme. A unified grid system, named as [K-E-Y], that covers the entire seas around Korea is used. We present and compare hindcasting results during 1990-1999 from a model forced by MCSST without incorporating RSSH data assimilation and the one with both MCSST and RSSH assimilated. The data assimilation is applied only in the East Sea, hence the comparison focuses principally on the mesoscale features prevalent in the East Sea. It is shown that the model with the data assimilation exhibits considerable skill in simulating both the permanent and transient mesoscale features in the East Sea.

• Journal of the korean Society of Automotive Engineers
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• v.7 no.3
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• pp.83-93
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• 1985

The prediction of emission concentrations in a 4cycle spark ignition engine was made by considering nonuniform model with thermodynamics, chemical equilibrium and kinetic mechanism of nitric oxide. Calculation of this model shows that a temperature difference of the order of 500K can be established across he cylinder. Results of the kinetic calculation of nitric oxide show that the temperature gradient across the cylinder has a profound effect on the nitric oxide formation. The predicted values for nitric oxide, carbon dioxide and carbon monoxide agree with measured ones for a variety of equivalence ratio.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.353-356
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• 2006

In this paper, the prediction method of internal temperature for reinforced concrete columns under high temperature is presented. Finite element method is employed to facilitate thermal analysis for any position of column. And the effect of the heat of vaporization is applied. To demonstrate the validity of this numerical procedure, the prediction by the proposed algorithm is compared with the test results from this study. The proposed algorithm is in good agreement with experimental results.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.437-439
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• 2005

Freshness of stored soybean curd as sensitivity ($R_{gas}/R_{air}$) was evaluated at 48-50 hr intervals using electronic nose at regular sequential square-wave temperatures between $4\;-\;10^{\circ}C$. Obtained kinetic data from apparent first principal component score $(PC1)_{app}$ and storage time were used for prediction of freshness. Percentage difference between predicted and actual values of stored soybean curd was less than 8.9% under fluctuating temperature condition.