• Earthquakes and Structures
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• v.11 no.4
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• pp.723-740
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• 2016

Reinforced concrete corbels are generally used to transfer loads within a structural system, such as buildings, bridges, and facilities in general. They commonly present low aspect ratio, requiring an accurate model for shear strength prediction in order to promote flexural behavior. The model described here, originally developed for walls, was adapted for corbels. The model is based on a reinforced concrete panel, described by constitutive laws for concrete and steel and applied in a fixed direction. Equilibrium in the orthogonal direction to the shearing force allows for the estimation of the shear stress versus strain response. The original model yielded conservative results with important scatter, thus various modifications were implemented in order to improve strength predictions: 1) recalibration of the strut (crack) direction, capturing the absence of transverse reinforcement and axial load in most corbels, 2) inclusion of main (boundary) reinforcement in the equilibrium equation, capturing its participation in the mechanism, and 3) decrease in aspect ratio by considering the width of the loading plate in the formulation. To analyze the behavior of the theoretical model, a database of 109 specimens available in the literature was collected. The model yielded an average model-to-test shear strength ratio of 0.98 and a coefficient of variation of 0.16, showing also that most test variables are well captured with the model, and providing better results than the original model. The model strength prediction is compared with other models in the literature, resulting in one of the most accurate estimates.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.1 no.1
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• pp.44-49
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• 1989

Cohesive sedimentation mechanism is affected by various physico-chemical factors. Thus, the field observations and the laboratory experiments for cohesive sediment have been reported for decades. Erosion and deposition test was carried out with cohesive sediment material sampled in the Keum River Estuary in this study. The change of the suspended cohesive sediment concentration was measured for various flow conditions, which have the purpose to determine the critical shear stress and the coefficients for erosion and deposition . The critical shear stress and the coefficient for erosion were determined in the flume test. The equilibrium concentration was determined for each shear stress and the relationship between the normalized equilibrium cocentration with the initial cocentration (Ceq/co) and the equivalent shear stress was obtained. The experimental results were compared with the other results and showed fairly well agreements with them.

• Korean journal of food and cookery science
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• v.5 no.1
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• pp.49-52
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• 1989

Stress relaxation tests with different percent deformation were performed for crude and refined starch gels of acorn. With no relation to percent deformation, refined starch gel had higher initial stress ($\sigma_e$) and lower equilibrium stress ($\sigma_e$) than crude starch gel. But the ratio of equilibrium stress to initial stress ($\sigma_e$/$\sigma_o$) was minimum at 60 percent deformation. The analysis of relaxation curves by successive residual method revealed that the rheological behavior of acorn starch gels could be expressed by generalized Maxwell model. The element numbers of models for crude and refined starch gel were 7-element and 5-element at 60 percent deformation, and 5-element and 3-element at 45 percent deformation, respectively.

• Journal of Korea Trade
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• v.25 no.4
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• pp.88-107
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• 2021

Purpose - Using a model that highlights Ricardian comparative advantage and Cournot competition, I derive theoretical predictions on how bilateral measures of trade intensity, specialization, and intra-industry are interrelated, and how Ricardian productivity differences affect these measures. We test the predictions using trade and production data, and confirm them. Design/methodology - A simple two-country general equilibrium model is constructed to derive theory-based bilateral indexes. We then test the relationships among them using panel data for 35 countries and 14 industries between 1996 and 2008. Findings - Bilateral trade intensity is increasing in specialization, as in the classical trade theory, and in intra-industry trade, as in the new trade theory. However, productivity differences positively affect specialization, and negatively affect intra-industry trade. These effects cancel each other; thus productivity differences have little impact on trade intensity. Originality/value - This paper provides a comprehensive conceptual framework for understanding the relationship among trade intensity, specialization, intra-industry trade, and productivity differences. We derive theory-consistent measures of specialization, intra-industry trade, and productivity differences. Moreover, we reevaluate the empirical relevance of these variables for the study of gravity equations. This paper is also an effort to capture oligopolistic competition in a general equilibrium framework, interests in which recently resurged.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1890-1901
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• 2022

We have assessed the applicability of the thermal-hydraulic system analysis code, SPACE, to a small modular reactor called SMART. For the assessment, the experimental data from a scale-down integral-test facility, SMART-ITL, were used. It was conformed that the SPACE code unrealistically calculates the safety injection flow rate through the CMT and SIT during a small-break loss-of-coolant experiment. This unrealistic behavior was due to the overprediction of interfacial heat transfer at the steam-water interface in a vertically stratified flow in the tanks. In this study, a special thermal-hydraulic component model has been developed to realistically calculate the interfacial heat transfer when a strong non-equilibrium two-phase flow is formed in the CMT or SIT. Additionally, we developed a special heat structure model, which analytically calculates the heat transfer from the hot steam to the cold tank wall. The combination of two models for the tank are called the special component model. We assessed it using the SMART-ITL passive safety injection system (PSIS) test data. The results showed that the special component model well predicts the transient behaviors of the CMT and SIT.

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.117-123
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• 2009

This study is to investigate the characteristics of scour around pipeline in current and hydraulic model tests were performed. All the model test are 45 cases, which were conducted with velocities of 0.2 m/s to 0.5 m/s and pipe diameters of 45, 60, 90 mm. The developments of scour around pipeline were observed and equilibrium scour depths were recorded due to variation of pipe diameter and current velocity. According to the results, the equilibrium scour depth was proportional to current velocity and pipe diameter. The effect of diameter of pipeline on the equilibrium scour depth was bigger than current velocity. The correlations of relative scour depth and dimensionless number such as a Reynolds number, Shields number, and Froude number were analyzed. The Froude number and the relative scour depth had a high correlation of 0.900.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.893-900
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• 1997

In this study, vapor-liquid equilibria of a binary system, which consists of glycerol and water, are measured using a vaporrecirculating modified Othmer still at various subatmospheric pressures. The constituent components of the binary system considered in this study exhibit a large difference in the boiling temperatures. Since it is generally observed that the properties of a mixture greatly differ from those of the pure components, the phase equilibrium characteristics of a mixture can not be predicted from the properties of the pure components. Furthermore, an abrupt increase in the boiling temperature occurs as the concentration of the higher boiling component exceeds a certain value. Therefore, it is essential to acquire realistic phase equilibrium data of the mixture for industrial applications. Using the UNIQUAC model, the experimental vapor-liquid equilibrium data are correlated with good accuracy. The thermodynamic consistency test is also performed to ensure soundness of the data.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.4
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• pp.142-147
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• 2007

When the aircraft is developed, several flight tests are performed including stability and controllability, performance and systems, above all the most important part of the flight test is stability test. Stability test is divided into two parts, static stability and dynamic stability. Static stability of the aircraft is typically defined in terms of its initial tendency to return to equilibrium after a disturbance and not included time concept. One of static stability, longitudinal static stability, was addressed here. The longitudinal static stability was studied from the basic theory to the flight test method and also explained data reduction method throughout the flight test. Finally showed how to meet the specifications such as ROC, FAR and MIL-specifications.

• The Journal of Fisheries Business Administration
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• v.44 no.1
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• pp.71-79
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• 2013

This study is aimed to estimate market integration of wild caught fish species on the Korean market, using both multivariate and bivariate cointegration analysis. For the analysis of market integration between wild caught fish species, major four fish species those are most popular fish in the market and caught by the large purse seine fishery-chub mackerel, jack mackerel, hairtail and spanish mackerel-were selected as analytical target fish species. And their real monthly price data from January 2000 to December 2011 were used in the analysis. The results of the multivariate cointegration test for four wild caught fish species showed that there would be long-term equilibrium relationships among prices of four wild caught fish species, and consequently, the markets for wild caught fish species were estimated to be integrated. The results of exclusion test and bivariate cointegration test also supported that there would be a clear evidence to suggest that all target wild caught fish species were cointegrated each other.

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.731-732
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• 2003

Mutagen X (MX), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone is one of the most potent directing acting mutagen ever tested in SAL TA100 assay. Although MX analogues have been synthesized, tested for mutagenicity and modeled by structure-activity relationship (SAR) methods, the mechanism of interaction of these compounds with DNA to produce their remarkable mutagenic potency remains unresolved. MX exists as an equilibrium mixture of both ring and open form in water. This equilibrium is very fast for Ames test. Because the mixture is not separable by experimental methods, it is not clear which one is really responsible for the observed mutagenicity. There have been many debates that which one is really responsible for the observed mutagenicity. We used ab initio methods for the MX analogues. It seems both ring and open form could react with DNA bases as electrophiles. However, every open form has consistently lower LUMO energy than corresponding ring form. It is reasonable to assume that the major reaction will go through via open form for MX analogues. This suggest that the open form is more likely really mutagenic.