• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.19 no.2
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• pp.109-116
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• 2023

This study presents a CRUD modelling to simulate the thermal resistance behavior of CRUD, deposited on the surface of a cladding tube of a fuel assembly. When heat produced from fuels transfers to a coolant through a cladding tube, the CRUD acting as an additional thermal resistance is expressed as two layers, i.e., a solid oxide layer and an imaginary fluid layer, which are added to the experimental tube's heat structure of the MARS-KS input data. The validation calculation for the experiments performed in UNIST-DISNY facility showed that the center and surface temperatures of the cladding tube increased as the porosity and the steam amount inside pores of the CRUD got higher. In addition, the temperature gradient in the imaginary fluid layer was calculated to be larger than that in the solid oxide part, indicating that the steam amount inside the layer acted more largely as thermal resistance. It was also evaluated through sensitivity calculations that the cladding tube temperature was more sensitive to the CRUD porosity and the steam amount in pores than to the inlet flow rate of the coolant.

• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.859-873
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• 2008

Job satisfaction impacts on the turnover intention of employee, which affects the turnover behavior. This paper concerns with the impact of job satisfaction on the turn over behavior. Since turnover intention is highly correlated with job satisfaction, salary, employment status and etc, we should pay careful attention for modelling of those variables as independent variables and the turnover behavior as a dependent variable in the empirical study for the impact of factors on turnover behavior. We detect significant variables which effect the turnover behavior using 2-stage logistic regression inserting the turnover intention, an independent variable, with the chance estimates derived from the instrumental variables in Graduates Occupational Mobility Survey.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.105-115
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• 2014

This paper aims to examine the mediating effects of psychological capital on the relationships between learning organization and innovative behavior. 310 sheets of questionnaires were gathered from the organizational members of the companies in 5 cities, including Seoul and Pohang and analysed using structural equation modelling technique. The results show followings: First, the human factor of learning organization has a significant influence to the innovative behavior and the psychological capital. Second, structural factor of learning organization has a significant influence to the psychological capital but does not have a significant influence to the innovative behavior. Third, the mediating effect of psychological capital has a significant partial effect between human factor of learning organization and innovative behavior, and full effect between structural factor of learning organization and innovative behavior. The results of this study implies that some guideline could be used in promoting learning organization and making implementing strategy.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.3
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• pp.110-116
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• 2020

Grains in the BaTiO₃, which is used for a dielectric layer in MLCC(Multi-Layer Ceramic Capacitor) are necessary to form core/shell structure for a stable TCC(Temperature Coefficient of Capacitance) behavior. The shell property has been deduced from the whole TCC behavior of core/shell structure due to its tiny size, ~ few ㎛. This study demonstrates the individual TCC behavior of the shell phase measured by micro-contact measurement in a temperature range between 35 and 135℃. Pt electrode pairs deposited on an enlarged core/shell structure in a diffusion couple sample made the measurement possible. As a result, the DPT (Diffusion Phase Transition) behavior of the shell phase was revealed as a different TCC behavior from that of the core: a broad peak with T_m at 65℃. This would be also useful experimental data for a modelling that depicts dielectric-temperature behavior of core/shell structure.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.496-510
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• 2007

This paper describes the use of a discrete mathematical model to represent the basic mechanisms of regulation of the bacteria E. coli in batch fermentation. The specific phenomena studied were the changes in metabolism and genetic regulation when the bacteria use three different carbon substrates (glucose, glycerol, and acetate). The model correctly predicts the behavior of E. coli vis-a-vis substrate mixtures. In a mixture of glucose, glycerol, and acetate, it prefers glucose, then glycerol, and finally acetate. The model included 67 nodes; 28 were genes, 20 enzymes, and 19 regulators/biochemical compounds. The model represents both the genetic regulation and metabolic networks in an integrated form, which is how they function biologically. This is one of the first attempts to include both of these networks in one model. Previously, discrete mathematical models were used only to describe genetic regulation networks. The study of the network dynamics generated 8 $(2^3)$ fixed points, one for each nutrient configuration (substrate mixture) in the medium. The fixed points of the discrete model reflect the phenotypes described. Gene expression and the patterns of the metabolic fluxes generated are described accurately. The activation of the gene regulation network depends basically on the presence of glucose and glycerol. The model predicts the behavior when mixed carbon sources are utilized as well as when there is no carbon source present. Fictitious jokers (Joker1, Joker2, and Repressor SdhC) had to be created to control 12 genes whose regulation mechanism is unknown, since glycerol and glucose do not act directly on the genes. The approach presented in this paper is particularly useful to investigate potential unknown gene regulation mechanisms; such a novel approach can also be used to describe other gene regulation situations such as the comparison between non-recombinant and recombinant yeast strain, producing recombinant proteins, presently under investigation in our group.

• Journal of Ocean Engineering and Technology
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• v.13 no.4 s.35
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• pp.55-62
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• 1999

Cold rolled steel has much plastic strain in the material surface produced by manufacturing process. The strain causes the variation of surface residual stress, in which influences the fatigue behavior under repeated loading. As experimental results, it was confirmed that the behavior of residual stress ${\sigma}_r$, with cycle N consisted of three stages except stress amplitude near fatigue limit in SPCC steel. On the first stage compressive residual stress decreased rapidly, on the second stage gradually, and on the last stage slightly. The relation between ${\sigma}_r$, and log N appeared linear behavior except the early part of cycle ratio $N/N_f$. The average gradient of ${\sigma}_r$, with respect to log N seemed to take a constant value without initial cycle ratio. On the other hand, the $N_f$ line was regressed by the first-order polynomial equation on ${\sigma}_r-log\;N_f$ diagram. Therefore, this study showed that both the gradient of ${\sigma}_r$, with respect to log N and the $N_f$ line was useful in predicting the cycle ratio $N/N_f$.

• Structural Engineering and Mechanics
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• v.1 no.1
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• pp.1-16
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• 1993

The behavior of shear-wall dominant, low-rise, multistory reinforced concrete building structures is investigated. Because there are no beams or columns and the slab and wall thicknesses are approximately equal, available codes give little information relative to design for gravity and lateral loads. Items which effect the analysis of shear-wall dominant building structures, i.e., material nonlinearity including rotating crack capability, 3-D behavior, slab-wall interaction, floor flexibilities, stress concentrations around openings, the location and the amount of main discrete reinforcement are investigated. For this purpose 2 and 5 story building structures are modelled. To see the importance of 3-D modelling, the same structures are modelled by both 2-D and 3-D models. Loads are applied first the vertical then lateral loads which are static equivalent earthquake loads. The 3-D models of the structures are loaded in both in the longitudinal and transverse directions. A nonlinear isoparametric plate element with arbitrarily places edge nodes is adapted in order to consider the amount and location of the main reinforcement. Finally the importance of 3-D effects including the T-C coupling between walls are indicated.

• Structural Engineering and Mechanics
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• v.64 no.1
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• pp.11-21
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• 2017

It has been observed in the past that, the reinforced concrete (RC) bridge columns are very often subjected to torsional moment in addition to flexure and shear during seismic vibration. Ignoring torsion in the design can trigger unexpected shear failure of the columns (Farhey et al. 1993). Performance based seismic design is a popular design philosophy which calls for accurate prediction of the hysteresis behavior of structural elements to ensure safe and economical design under earthquake loading. However, very few investigations in the past focused on the development of analytical models to accurately predict the response of RC members under cyclic torsion. Previously developed hysteresis models are not readily applicable for torsional loading owing to significant pinching and stiffness degradation associated with torsion (Wang et al. 2014). The present study proposes an improved polygonal hysteresis model which can accurately predict the hysteretic behavior of RC circular and square columns under torsion. The primary curve is obtained from mechanics based softened truss model for torsion. The proposed model is validated with test data of two circular and two square columns. A good correlation is observed between the predicted and measured torque-twist behavior and dissipated energy.

• The Journal of Information Systems
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• v.25 no.4
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• pp.63-85
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• 2016

Purpose While the popularity of C2C auction platforms such as eBay is gradually decreased, this domain is still undermined to explain online bidding behaviors. Online bidders sometimes engage in impulsive bidding due to some of the online auction characteristics. Therefore, this study develops and tests a model of the impulsive bidding exhibited by online bidders in C2C auction platforms. Based on S-O-R framework, our model posits that both perceived time-pressure and competition intensity affect cognitive absorption which ultimately influences the impulsive bidding. Design/methodology/approach This study collected survey data from 214 C2C auction participants, who have prior experience on impulsive bidding and tested both measurement model and structural model by using CB-SEM (covariate-based structural equation modelling) technique. In this study, by using AMOS 20.0, we tested the measurement model for its overall fit, item reliability, and validity and further conducted the structural model to test our proposed hypotheses. Findings Based on our results, we found that perceived tim-pressure and competition intensity were positively related to cognitive absorption. We also found that the cognitive absorption was positively associated with impulsive bidding behavior. In this study, by developing our research model in S-O-R framework, we provide an alternative theoretical mechanism to describe online impulsive bidding behavior.

• Korean Journal of Child Studies
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• v.25 no.5
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• pp.1-9
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• 2004

This study addressed ways in which poverty factors are associated with child physical aggression and how these relationships are moderated by parenting behavior. Using a longitudinal approach, parental poverty status was measured when children were 5 months; the Parenting Behaviour Questionnaire (Boivin et al., 2000) was administered when children were 17 months; and mothers reported child physical aggression behaviors when the children were 60 months. Using structure equation modeling analyses, the results of this study confirmed that parenting behavior is a mediator of the linkage between poverty and child physical aggression, showing the urgent need for early intervention for impoverished children.