• Journal of Korea Trade
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• v.27 no.5
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• pp.63-90
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• 2023

Purpose - This study aims to identify the relationship between logistics companies' Logistics 4.0 technology adoption with logistics innovation capability and logistics performance, and analyze the mediating effect of logistics innovation capability and the mediated moderation effect of firm size through logistics innovation capability. Design/methodology - Research models and hypotheses were established based on prior research related to Industry 4.0, Logistics 4.0, logistics technology, logistics performance, and firm size. The survey was conducted on the employees of logistics companies, and exploratory factor analysis, reliability analysis, confirmatory factor analysis, discriminant validity analysis, structural equation model analysis, mediation effect, moderation effect, and the mediated moderation effect analysis were performed. Findings - The adoption of Logistics 4.0 technology was found to significantly affect logistics innovation capability and logistics performance. Logistics innovation capability was found to significantly affect logistics performance. Moreover, logistics innovation capability was found to have a significant mediation effect on the relationship between Logistics 4.0 technology adoption and logistics performance. The moderation effect based on firm size was found to have a partial effect on logistics innovation capability and logistics performance, but the mediated moderation effect was not significant. Originality/value - This study is meaningful in that it empirically analyzed the relationship of Logistics 4.0 technology adoption with logistics innovation capability and logistics performance, the mediating effect of logistics innovation capability, the moderation effect of firm size, and the mediated moderation effect of firm size, which were not addressed in previous studies.

• Computers and Concrete
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• v.18 no.5
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• pp.937-950
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• 2016

This study applied autoclave expansion and heat curing to accelerate the hydration of concrete and investigated how these methods affect the expansion rate, crack pattern, aggregate size effect, and expansion of electric arc furnace oxidizing slag (EOS)-containing concrete. An expansion prediction model was simulated to estimate the expansion behavior over a long period and to establish usage guidelines for EOS aggregates. The results showed that the EOS content in concrete should range between 20% and 30% depending on the construction conditions, and that coarse aggregates with a diameter of ${\geq}4.75-mm$ are not applicable to construction engineering. By comparison, aggregates with a size of 1.18-0.03 mm resulted in higher expansion rates; these aggregates can be used depending on the construction conditions. On Day 21, the prediction model attained a coefficient of determination ($R^2$) of at least 0.9.

• Journal of the Korean Ceramic Society
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• v.33 no.5
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• pp.583-589
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• 1996

In this study a new analytical model which can describe the relationship between the bridging stress and microstructure has beenproposed in order to investigate the microstructural effect on the R-curve behavior in polycrystalline aluminas since the R-curve can be derived via the bridging stress function. In the currently developed model function the distribution of grain size is considered as a microstructural factor in modeling of bridging stress function and thus the bridging stress function including three constants PM, n, and Cx, can be established analytically and quantitatively. The results indicate that the n value is closely related to the grain size distribution thereby providing a reliability of the current model for the bridging stress analysis. Thus this model which explains the correlation of the bridging stress distribution and microstructual parame-ters is useful for the systematic interpretation of microfracture mechanism including the R-curve behavior in polycrystalline aluminas.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.1
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• pp.1-9
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• 2011

In order to investigate the cause and magnitude of scale effect occurring in the model experiments of fishing nets, five pairs of Nylon pyramid nets and one pair of PE ones in which all the two nets paired were equal each other in the factors determining their flow resistance, i. e., the ratio d/l of diameter d to length l of bars, the angle f between two adjacent bars, the attack angle q of nettings to the water flow, and the wall area S of nets, and different in the values of d and l were prepared. Then, the nets were attached to the circular steel frame alternately and their flow resistances with shapes in water were measured on the sea ascribing no turbulent flows by using the tension meter made of a block bearing for the experiment. All the Nylon nets were spreads out easily in water to form a circular cone at relatively low velocity of water and showed the resistance smaller a little in the nets with larger d and l than them with smaller d and l, because the filtration of water through meshes become easier in nets especially with larger l. But PE nettings were not spread out sufficiently on account of their small flexibility and showed higher resistance especially in them with thicker twines. Therefore, the difference in bar length or mesh size and flexibility of nettings between prototype and model nets are regarded to become factors ascribing scale effect. Especially the influence of the difference in mesh size may become large significantly in actual model experiments because the mesh size of model nets is decided at much larger value than that given by scale ratio and so the difference of mesh size between the two nets become much larger than that between nets used in this experiment.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.160-165
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• 2007

Dispersion parameters for the number of piglets born alive were estimated using a repeatability and random regression model. Six sow breeds/lines were included in the analysis: Swedish Landrace, Large White and both crossbred lines between them, German Landrace and their cross with Large White. Fixed part of the model included sow genotype, mating season as month-year interaction, parity and weaning to conception interval as class effects. The age at farrowing was modelled as a quadratic regression nested within parity. The previous lactation length was fitted as a linear regression. Random regressions for parity on Legendre polynomials were included for direct additive genetic, permanent environmental, and common litter environmental effects. Orthogonal Legendre polynomials from the linear to the cubic power were fitted. In the repeatability model estimate of heritability was 0.07, permanent environmental effect as ratio was 0.04, and common litter environmental effect as ratio was 0.01. Estimates of genetic parameters with the random regression model were generally higher than in the repeatability model, except for the common litter environmental effect. Estimates of heritability ranged from 0.06 to 0.10. Permanent environmental effect as a ratio increased along a trajectory from 0.03 to 0.11. Magnitudes of common litter effect were small (around 0.01). The eigenvalues of covariance functions showed that between 7 and 8 % of genetic variability was explained by individual genetic curves of sows. This proportion was mainly covered by linear and quadratic coefficients. Results suggest that the random regression model could be used for genetic analysis of litter size.

• Computers and Concrete
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• v.11 no.5
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• pp.365-382
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• 2013

Although shear reinforcement in beams typically consists of steel bars bent in the form of stirrups or hoops, the addition of deformed steel fibres to the concrete has been shown to enhance shear resistance and ductility in reinforced concrete beams. This paper presents a model that can be used to predict the shear strength of fibrous concrete rectangular members without stirrups. The model is an extension of the plasticity-based crack sliding model originally developed for plain concrete beams. The crack sliding model has been improved in order to take into account several aspects: the arch effect for deep beams, the post-cracking tensile strength of steel fibre reinforced concrete and its ability to control sliding along shear cracks, and the mitigation of the shear size effect due to presence of fibres. The results obtained by the model have been validated by a large set of experimental tests taken from literature, compared with several models proposed in literature, and numerical analyses are carried out showing the influence of fibres on the beam failure mode.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.4
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• pp.271-277
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• 2017

In this paper, the amplitude and frequency dependent dynamic characteristics of the equivalent stiffness of a rubber bushing are investigated. A new mathematical model is proposed to explain the large deformation and size effect of a rubber bushing. The proposed model consists of elastic, viscous, and frictional stress components and the equivalent strain. The proposed model is verified using experimental results. The comparison shows that the proposed model can accurately predict the equivalent stiffness values of a rubber bushing under various magnitudes and frequencies. The developed model could be used to predict the dynamic equivalent stiffness of a rubber bushing in automotive engineering.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.2
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• pp.195-204
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• 2017

Predicting the failure life of automated manufacturing systems can reduce overall downtime, maintenance costs, and total plant operation costs. Therefore, there is a growing interest in fatigue failure mechanisms as the safety or service life assessment of manufacturing systems becomes an important issue. In particular, fretting fatigue is caused by repeated tangential stresses that are generated by friction during small amplitude oscillatory movements or sliding between two surfaces pressed together in intimate contact. Previous studies in fretting fatigue have observed size effects related to contact width such that a critical contact width exists where there is drastic change in the fretting fatigue life. However, most of them are the two-dimensional finite element analyses based on the plane strain assumption. The purpose of this study is to investigate the contact size effects on the three-dimensional finite element model of a finite width of a flat specimen and a cylindrical pad exposed to fretting fatigue. The contact size effects were analyzed by means of the stress and strain averages at the element integration points of three-dimensional finite element model. This study shows that the fretting fatigue life of manufacturing systems can be predicted by three-dimensional finite element analysis based on SWT critical plane model.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.2
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• pp.350-366
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• 2024

This study aimed to clarify the continuance intention of users of size recommendation services. The expectation-confirmation model framed the analysis of the 180 data points collected. The analysis determined the mediating effects of perceived usefulness and satisfaction on the relationship between expectation-confirmation and continuance intention. The moderated mediation effect of familiarity was also analyzed, and a path analysis was conducted using PROCESS macro. Results showed that expectation-confirmation had a significant effect on perceived usefulness, satisfaction, and continuance intention. Findings indicated that perceived usefulness affected satisfaction and continuance intention and confirmed that satisfaction affected continuance intention. In the relationship between expectation-confirmation and continuance intention, mediation analysis verified the mediation and double mediation of perceived usefulness and satisfaction. In the group with an above-average familiarity value, moderation analysis confirmed a moderating effect between perceived usefulness and satisfaction. Above-average familiarity values also confirmed that the moderating effect on continuance intention was significant.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.3
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• pp.485-500
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• 2024

This study was conducted to examine the effects of consumer evaluations on size recommendation services based on body information on consumer responses and the moderating effect of the level of information search. To analyze the research model, a total of 200 data were collected from August 18 to 24, 2022, targeting consumers who had experience with using size recommendation services based on body information. As a result of the research model analysis, it was confirmed that the compatibility, reliability, and convenience of the size recommendation services based on body information influenced attitude, which, in turn, influenced usage intention. In addition, In the case of the group subject to a low level of information search, the path through which compatibility and reliability influenced attitude was significant, but that of convenience was not. In the group featuring a high level of information search, the path through which reliability and convenience influenced attitude was significant, but that of compatibility was not. This study is meaningful in that it expanded research related to size recommendation services to the field of consumer behavior.