• Structural Engineering and Mechanics
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• v.83 no.4
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• pp.415-433
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• 2022

Eighteen (18) (120×300×2200 mm) beams were prepared and tested to evaluate the shear strength of Glass Fiber Reinforced Concrete (GFRC) beams with no shear reinforcement, and evaluate the effectiveness of various innovative strengthening systems to increase the shear capacity of the GFRC beams. The test variables are the amount of discrete glass fiber (0.0, 0.6, and 1.2% by volume of concrete) and the type of longitudinal reinforcement bars (steel or GFRP), the strengthening systems (externally bonded (EB) sheet, side near-surface mounted (SNSM) bars, or the two together), strengthening material (GFRP or steel) links, different configurations of NSM GFRP bars (side bonded links, full wrapped stirrups, side C-shaped stirrups, and side bent bars), link spacing, link inclination angle, and the number of bent bars. The experimental results showed that adding the discrete glass fiber to the concrete by 0.6%, and 1.2% enhanced the shear strength by 18.5% and 28%, respectively in addition to enhancing the ductility. The results testified the efficiency of different strengthening systems, where it is enhanced the shear capacity by a ratio of 28.4% to 120%, and that is a significant improvement. Providing SNSM bent bars with strips as a new strengthening technique exhibited better shear performance in terms of crack propagation, and improved shear capacity and ductility compared to other strengthening techniques. Based on the experimental shear behavior, an analytical study, which allows the estimation of the shear capacity of the strengthened beams, was proposed, the results of the experimental and analytical study were comparable by a ratio of 0.91 to 1.15.

• Knowledge Management Research
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• v.24 no.1
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• pp.223-243
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• 2023

RPA is implemented through management policy and enforced in mandatory environments to enhance performance and efficiency in various fields. However, the success of RPA implementation depends on the level of active engagement from organization members, even in a mandatory setting. This study identifies perceived ease of use, usefulness, accountability, perceived risk, and self-efficacy as variables that influence conative use behavior, which consists of reflective secondary factors such as immersion, reinvention, and learning. Data was collected from 207 office workers in various industries who have experience with RPA to test the proposed research model. The structural equation was verified using SPSS 20.0 and SmartPLS 4.0, and the analysis showed that all the proposed variables had a significant impact on conative use behavior. Our research findings provide theoretical and practical implications in knowledge management, enabling companies that implement RPA to recognize and address factors that encourage their members to actively use RPA.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.1
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• pp.85-98
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• 2023

This study analyzes the importance and implementation of countermeasures to reduce safety accidents that may occur during fishing in coastal gillnet fishing. Safety accidents that may occur in coastal gillnet fishing were classified into 56 measurement items in six areas: slips and trips, contact with machinery, falls, struck by object, musculoskeletal symptoms, and electrical shock. 35 fishermen belonging to coastal gillnet associations in Tongyeong and Namhae were selected as samples, and the importance and implementation of the proposed measurement items were investigated in the field. In addition, the results were evaluated visually by IPA analysis. As a result of the analysis, the importance of struck by object was the highest, and the implementation of slips and trips was the highest. On the other hand, prevention of musculoskeletal damage was found to be the lowest in both importance and implementation. The area with the most significant difference in importance and implementation by the classified area for measurement items was struck by object, and the area with the minor difference was slips and trips. Among the measurement items, the importance is highly recognized, but there are items with low implementation. To improve their level of implementation, countermeasures such as continuous education, economic support, and structural change of fishing boats should be prepared; moreover, policy support activities for implementation should be carried out.

• Steel and Composite Structures
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• v.42 no.1
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• pp.1-22
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• 2022

In cold-formed steel (CFS) structures, such as trusses, transmission towers and portal frames, the use of back-to-back built-up CFS unequal angle sections are becoming increasingly popular. In such an arrangement, intermediate welds or screw fasteners are required at discrete points along the length, preventing the angle sections from buckling independently. Limited research is available in the literature on axial strength of back-to-back built-up CFS unequal angle sections. The issue is addressed herein. This paper presents an experimental investigation reported by the authors on back-to-back built-up CFS unequal angle sections with intermediate stiffeners under axial compression. The load-axial shortening behaviour along with the deformed shapes at failure are reported. A nonlinear finite element (FE) model was then developed, which includes material non-linearity, geometric imperfections and modelling of intermediate fasteners. The FE model was validated against the experimental test results, which showed good agreement, both in terms of failure loads and deformed shapes at failure. The validated finite element model was then used for the purpose of a parametric study comprising 96 models to investigate the effect of longer to shorter leg ratios, stiffener provided in the longer leg, thicknesses and lengths on axial strength of back-to-back built-up CFS unequal angle sections. Four different thicknesses and seven different lengths (stub to slender columns) with three overall widths to the overall depth (B/D) ratios were investigated in the parametric study. Axial strengths obtained from the experimental tests and FE analyses were used to assess the performance of the current design guidelines as per the Direct Strength Method (DSM); obtained comparisons show that the current DSM is conservative by only 7% and 5% on average, while predicting the axial strengths of back-to-back built-up CFS unequal angle sections with and without the stiffener, respectively.

• International Area Studies Review
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• v.15 no.1
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• pp.135-169
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• 2011

This study is for analyzing the management performances of Korean tourism firms, operating as preparing strategically against FTA which is one of the most importantly external environment in international management since in the middle of 1990s. The main purpose is to test empirically some relations between the management performances and the levels of ownership-specifics advantages of Korean tourism ones. To be exact, the dependent variables of management performances are classified with sales, profits and management satisfaction, while the independent ones of the competitive advantages are sorted with the 5 following factors like marketing, product development, service supply, finance and organization culture. The survey of Korean tourism enterprises engaging in management activities in Korea is implemented by collecting questionnaires. And for testing the hypothesis, the analyzing tools are being used for correlation, reliability, validity, multi regression and the path analysis of structural equation modeling. As a result, Marketing is certified as only common factor to influence three dependent variables of sales, profit and management satisfaction positively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.198-208
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• 2023

In order to enhance competitiveness in the industry, financial companies are building a high level of customer satisfaction and repurchase intention by further strengthening not only the technical quality of the platform business but also the customer-oriented service quality. Theoretically, it is time for a theoretical review of whether the expansion of service quality using platform business in the financial industry is directly linked to the performance of financial companies, such as satisfaction and repurchase intention of existing customers. Based on the rapid growth of mobile and the main activities of financial platform companies above, This study attempted to test a significant impact on customer satisfaction and reuse intention on information services and system services, which are service quality of mobile financial platforms. Even if a number of financial companies compete with each other, they could survive by dividing the market, In the digital environment, customers have free access, so the winner can monopolize the market. It is an environment in which customers can move to platform companies that provide better services. The contents presented through the results in this study will be able to be used strategically in terms of the implementation and operation of the financial platform. In addition, it served as an opportunity to find independent variables that affect customer satisfaction and reuse intention, which are financial platform service quality, and suggested the possibility of continuous development of the platform in the future. In summary, the service quality of financial platforms can further expand users by emphasizing user visibility in terms of information services and utilizing user-centered financial platforms that increase customer satisfaction and reliability by strengthening the responsiveness and ease of system services. This study is of important value and is believed to have laid an important foundation for future research.

• Journal of the Korea Society of Computer and Information
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• v.29 no.7
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• pp.53-71
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• 2024

Generative Artificial Intelligence (AI) has become the focus of societal attention due to its wide range of applications and profound impact. This paper constructs a comprehensive theoretical model based on the Unified Theory of Acceptance and Use of Technology 2 (UTAUT2), integrating variables such as Personal Innovativeness and Perceived Risk to study the key factors influencing enterprises' adoption of Generative AI. We employed Structural Equation Modeling (SEM) to verify the hypothesized paths and used the Bootstrapping method to test the mediating effect of Behavioral Intention. Additionally, we explored the moderating effect of Perceived Risk through Hierarchical Regression Analysis. The results indicate that Performance Expectancy, Effort Expectancy, Social Influence, Price Value, and Personal Innovativeness have significant positive impacts on Behavioral Intention. Behavioral Intention plays a significant mediating role between these factors and Use Behavior, while Perceived Risk negatively moderates the relationship between Behavioral Intention and Use Behavior. This study provides theoretical and empirical support for how enterprises can effectively adopt Generative AI, offering important practical implications.

• Composites Research
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• v.37 no.3
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• pp.155-161
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• 2024

Boron nitride nanotubes and carbon nanotubes are the most representative one-dimensional nanostructures, and have received great attention as reinforcement for multifunctional composites for their excellent physical properties. The two nanotubes have similar excellent mechanical stiffness, strength, and heat conduction properties. Therefore, the reinforcing effect of these two nanotubes is greatly influenced by the properties of their interface with the polymer matrix. In this paper, recent comparative studies on the reinforcing effect of boron nitride nanotubes and carbon nanotubes through experimental pull-out test and in-silico simulation are summarized. In addition, the conflicting aspect of the two different nanotubes with structural defects in their side wall is discussed on the viscoelastic damping performance of nanocomposites.

• Steel and Composite Structures
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• v.51 no.5
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• pp.509-527
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• 2024

Bonding carbon fiber-reinforced polymer (CFRP) laminates have been extensively employed in the restoration of steel constructions. In addition to the mechanical properties of the CFRP, the bond strength (P_U) between the CFRP and steel is often important in the eventual strengthened performance. Nonetheless, the bond behavior of the CFRP-steel (CS) interface is exceedingly complicated, with multiple failure causes, giving the P_U challenging to forecast, and the CFRP-enhanced steel structure is unsteady. In just this case, appropriate methods were established by hybridized Random Forests (RF) and support vector regression (SVR) approaches on assembled CS single-shear experiment data to foresee the P_U of CS, in which a recently established optimization algorithm named Aquila optimizer (AO) was used to tune the RF and SVR hyperparameters. In summary, the practical novelty of the article lies in its development of a reliable and efficient method for predicting bond strength at the CS interface, which has significant implications for structural rehabilitation, design optimization, risk mitigation, cost savings, and decision support in engineering practice. Moreover, the Fourier Amplitude Sensitivity Test was performed to depict each parameter's impact on the target. The order of parameter importance was t_c> L_c > E_A > t_A > E_c > b_c > f_c > f_A from largest to smallest by 0.9345 > 0.8562 > 0.79354 > 0.7289 > 0.6531 > 0.5718 > 0.4307 > 0.3657. In three training, testing, and all data phases, the superiority of AO - RF with respect to AO - SVR and MARS was obvious. In the training stage, the values of R² and VAF were slightly similar with a tiny superiority of AO - RF compared to AO - SVR with R² equal to 0.9977 and VAF equal to 99.772, but large differences with results of MARS.

• Development and Reproduction
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• v.27 no.4
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• pp.213-220
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• 2023

Previously, we showed that a chronic-low-dose nonylphenol (NP) exposure resulted in histological changes with sexually dimorphic pattern in rat adrenal glands. We hypothesized that such structural changes are closely related to the hormonal secretory patterns. To test this hypothesis, we developed the short-term adrenal incubation method, and measured the levels of catecholamines and cortical steroids using the high-performance liquid chromatography with electrochemical detection (HPLC-ECD) and specific enzyme-linked immunosorbent assay, respectively. The norepinephrine (NE) levels in media from NP-treated female adrenal, except 100 pM NP, were significantly increased [control (CTL) vs 1 nM NP, p<0.001; vs 10 nM NP, p<0.05; vs 100 nM NP, p<0.001; vs 1 µM NP, p<0.01]. The NE secretion from male adrenal was higher when treated with 100 nM and 1 µM NP (CTL vs 100 nM NP, p<0.05; vs 1 µM NP, p<0.05, respectively). The aldosterone level in the female adrenal media treated with 100 pM NP was significantly decreased, on the other hand, that of media treated with 10 nM NP was significantly increased (CTL vs 100 pM NP, p<0.05; vs 10 nM NP, p<0.01). In male adrenal media, the aldosterone levels of 10 nM, 100 nM and 1 µM NP-treated media were significantly declined (CTL vs 10 nM NP, p<0.001; vs 100 nM NP, p<0.001; vs 1 µM NP, p<0.001). These results showed the NP treatment altered secretory pattern of aldosterone from adrenals of both sexes, showing sexual dimorphism. It may be helpful for understanding possible adrenal pathophysiology, and endocrine disrupting chemicals-related sexually dimorphic phenomena in adrenals.