• Journal of the Korean Ceramic Society
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• v.23 no.5
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• pp.35-40
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• 1986

The early hydration of tri-calcium silicate $(C_3S)$ with different cooling conditions was studied by varing water/solid ratio and atmosphere. The cooling condition and water/solid ratio affected to the second peak of heat liberation but it had no correlation to the induction period. The $Ca^{2+}$ concentration in the aqueous solution was maximized at the starting point of the second peak of heat liberation but in the $CO_2$ exsistence the $Ca^{2+}$ concentration was low and $SiO_2$ con-centration was increased. The hydration rate of $C_3S$ was so accelerated that the induction period could not appear in the $CO_2$ exsistence.

• Journal of Biosystems Engineering
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• v.41 no.3
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• pp.184-192
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• 2016

Purpose: To solve the decay phenomenon of Hanfu apples that occurs during storage and obtain the best environmental parameters for preserving Hanfu apples using Fluent. Methods: Preservation storage was designed by analyzing the characteristics of Hanfu-apple storage and the natural environment in northeast China. The boundary conditions and simulation of a preservation model were established. Results: Compared with the initial values, the hardness decreased by $1.95kg/cm^2$, the sugar-acid ratio decreased by 20.43, and weight-loss rate was 3.98%. Conclusion: The results for the temperature field and velocity field of the empty storage were analyzed using Fluent. Hanfu apples can maintain good quality during the period of storage, according to our analysis of the Hanfu-apple hardness, weight loss, and change in the sugar-acid ratio during the 90-day preservation period.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.2
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• pp.155-163
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• 1999

In this study, single cylinder engines with different tumble ratio were made to find out in-cylinder fluid motion and flame propagation. Tumble ratio derived from the steady state flow rig test. Flame propagation speed was obtained using cylinder head gasket ionization probe and the piston ionization probe. And the combustion pressure in cylinder was measured to analyze the combustion characteristics. In case of high tumble engine, BSFC and BSHC were decreased and BSNOx was increased at part load test. Also BMEP and combustion peak pressure was increased at full load test. Tumble flow motion had an great effects on initial burning period rather than main burning period in part load test.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.44-52
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• 2002

To understand the relationship among different quantitative traits, correlation studies were performed by utilizing eighty-eight inbred strains of silkworm, Bombyx mori L. on twelve economic characters. Analysis resulted in correlation of 5th instar period with total larval period (r ＝ 0.7882), cocoon weight with shell weight (r ＝ 0.8326), shell weight with shell ratio (r ＝ 0.5067), shell ratio with raw silk ％ (r ＝ 0.7570), raw silk ％ with filament length (r ＝ 0.3490), filament size (denier) with reelability (r ＝ 0.3193) and boil-off loss % (r ＝ 0.2792). Negative correlation was observed among filament length with filament size (r ＝ 0.7582) and reelability with boil-off loss % (r ＝ -0.3236). Correlation of different quantitative characters for quality silk production is discussed.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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• pp.25-32
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• 1998

Most recent seismic design codes include Response Modification Factor(RMF) for determining equivalent lateral forces. The RMF is used to reduce the linear elastic design spectrum to account for the energy dissipation capacity, overstrength and damping of the structure. In this study the RMF is defined as the ratio of the absolute maximum linear elastic base shear to the absolute maximum nonlinear base shear of a structure subject to the same earthquake accelerogram. This study investigates the effect of hysteretic model, as well as target ductility ratio and natural period on duct based RMF using nonlinear dynamic analyses of the SDOF systems. Special emphasis is given to the effects of the hysteretic characteristics such as strength deterioration and stiffness degradation. Results indicate that RMFs are dependent on ductility, period and hysteretic model.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.475-478
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• 2005

This study was performed to evaluate about load bearing capacity of continuos IPC Girder Bridge under and after Construction. This is Ichi-1 Bridge that is 2-40m span continuous bridge on a extension road through the Ichun and the Naesa. The result of static loading test to use a 25ton truck after construction, deflection ratio is 0.64 that is $35\%$ and average of response ratio is 0.48$\~$0.89 that is less than theoretical value. The result of dynamic loading test, the number of proper vibrations is 3.06Hz that is like theoretical value 3.61Hz, the modulus of impact is 0.235 that is bigger than specification 0.19. the load bearing capacity is minimum DB-40 that is so big value. In the result, continuos IPC Girder Bridge is safe in short period. we will evaluate long period behavior of continuos IPC Girder Bridge.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.4
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• pp.186-193
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• 2011

Purpose: This study was performed to find correlations between Edema Index and Heart Rate Variability(HRV) conducted in early postpartum period. Methods: 17 postpartum women were participated in this study which was conducted with Inbody 720(Biospace Co. Ltd.) and SA-6000(Medicore Co. Ltd.). Edema Index(Extra Cellular Water/Total Body Water) was calculated after body composition analysis and HRV result(TP, VLF, LF, HF, HF norm, LF norm, LF/HF ratio) was analysed within a week after delivery. Results: There was no significant correlations between Edema Index and HRV results in time domain analysis. also Edema Index and TP, LF, HF, LF/HF ratio have no significant correlations in frequency domain analysis. but only VLF data has significance compared with Edema Index. Conclusions: It can be suggested that VLF results analysed by HRV can be useful reference estimating postpartum edema especially occurs in early postpartum period.

• Journal of Nutrition and Health
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• v.22 no.4
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• pp.247-256
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• 1989

Growing male rats were allowed to have food from two dishes containing isocaloric, isoprotein 15% or 70% carbohydrate diet for 4, 8, 12 or 24 hours a day at the beginning of the dark period. Four hours of feeding were not enough to grow though the first 4 hours of intake were significantly higher than other periods. 4-hour and 8-hour feeding groups consumed significantly less carbohydrate calorie than 12-hour and ad libitum feeding groups, which hence, showed lower ratio of carbohydrate to protein in the total food consumed. The fasting brain tryptophan and serotonin levels among groups were not significantly different. It appears therefore that the manipulation of the feeding period could be valuable in suppression of carbohydrate appetitie, especially carbohydrate carving.

• Earthquakes and Structures
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• v.16 no.1
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• pp.69-82
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• 2019

As the residual displacement and/or drift demands are commonly used for seismic assessment of buildings, the estimation of these values play a very critical role through earthquake design philosophy. The residual displacement estimation of fixed base structures has been the topic of numerous researches up to now, but the effect of soil flexibility is almost always omitted. In this study, residual displacement demands are investigated for SDOF systems with period range of 0.1-3.0 s for near-field and far-field ground motions for both fixed and interacting cases. The elastoplastic model is used to represent non-degrading structures. Based on time history analyses, a new simple yet effective equation is proposed for residual displacement demand of any system whether fixed base or interacting as a function of structural period, lateral strength ratio and spectral displacement.

• Earthquakes and Structures
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• v.22 no.4
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• pp.373-386
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• 2022

The development of performance-based design methodologies requires a reasonable definition of a displacement-response spectrum. Although ground motions are known to be significantly affected by the resonant-like amplification behavior caused by multiple wave reflections within the surface soil, such a soil-resonance effect is seldom explicitly considered in current-displacement spectral models. In this study, an analytical approach is developed for the construction of displacement-response spectra by considering the soil-resonance effect. For this purpose, a simple and rational equation is proposed for the response spectral ratio at the site fundamental period (SRTg) to represent the soil-resonance effect based on wave multiple reflection theory. In addition, a bilinear model is adopted to construct the soil displacement-response spectra. The proposed model is verified by comparing its results with those obtained from actual observations and SHAKE analyses. The results show that the proposed model can lead to very good estimations of SRTg for harmonic incident seismic waves and lead to reasonable estimations of SRTg and soil displacement-response spectra for earthquakes with a relatively large magnitude, which are generally considered for seismic design, particularly in high-seismicity regions.