• Advances in materials Research
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• v.11 no.2
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• pp.91-109
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• 2022

This paper presents a closed-form higher-order analysis of interfacial shear stresses in RC continuous beams strengthened with bonded prestressed laminates. For retrofitting reinforced concrete continuous beams is to bond fiber reinforced prestressed composite plates to their tensile faces. An important failure mode of such plated beams is the debonding of the composite plates from the concrete due to high level of stress concentration in the adhesive at the ends of the composite plate. The model is based on equilibrium and deformations compatibility requirements in and all parts of the strengthened beam, where both the shear and normal stresses are assumed to be invariant across the adhesive layer thickness. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both the RC continuous beams strengthened with bonded prestressed laminates. The theoretical predictions are compared with other existing solutions. A parametric study has been conducted to investigate the sensitivity of interface behavior to parameters such as laminate stiffness and the thickness of the laminate where all were found to have a marked effect on the magnitude of maximum shear and normal stress in the composite member.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.32 no.2
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• pp.124-134
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• 2024

This study is based on the Expectation Confirmation Theory (ECT) and categorizes trust types in non-face-to-face boarding services into three dimensions: structural assurance, platform, and service provider. It analyzes the impact of these trust types on users' perceived usefulness, satisfaction, and continuous usage intentions. Using a structural equation model, the study found that the three dimensions of trust positively influence users' satisfaction and perception of usefulness, thereby promoting intentions for continuous use. However, perceived risk weakens the positive relationship between trust and continuous usage intentions. By exploring the moderating role of perceived risk in non-face-to-face boarding services, this study analyzes its impact on user behavior patterns, contributing to the optimization of service design and enhancement of user trust. This study promotes widespread acceptance and continuous use of the service, and is crucial for developing effective non-contact service strategies that meet the needs and expectations of Chinese travelers in the post-pandemic travel environment. The findings provide a new perspective and empirical evidence for understanding user attitudes and behaviors towards non-face-to-face services, holding significant theoretical and practical implications.

• Journal of Korean Society of Steel Construction
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• v.21 no.1
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• pp.37-44
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• 2009

A truss deck system that has replaced the slab form conventional method has become widely used in the construction of reinforced concrete structures as well as steel structures. The current commercial products, however, have some problems. The discontinuity between the lattice wires on the joint of the bottom wire induces vierendeel behavior, which increases the deflection of the system. In this research, a new truss deck system with continuous lattice wires on the level of the bottom wire was developed to reduce the system's vierendeel behavior and to improve its deformation capacity. To investigate the system's structural behavior, an experimental test and an analysis were performed. The main parameters of the test and analysis were the longitudinal shape and spacing of the lattices. To simulate the loading condition in the construction field, uniform construction loads were directly applied on the deck plates of the analysis model and the test specimens. The results of such analysis and test revealed that the longitudinal shape of the lattice wires is a major factor affecting the structural behavior of a steel wire truss deck. Thus, continuous lattice wires could result in decreased vierendeel behavior in the steel wire truss deck. It was also found that the truss deck system with lattices spaced longer than in the conventional products could be effectively used without increasing the member stresses.

• Journal of Korean Society of Steel Construction
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• v.11 no.2 s.39
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• pp.213-222
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• 1999

Elastic-plastic methods have been used for the better prediction of the actual behavior of continuous-composite plate girder bridges in the overload and maximum load analysis. The structural evaluation using ALFD(Alternate Load Factor Design) uses the elastic-plastic analysis. The plastic rotations that remain after the load is removed can be occurred by the yielding locations of the maximum moment section. This situation can occur due to the residual stresses even if the moment is below the theoretical yield moment. The local yielding causes positive automoments that assure elastic behavior under subsequent overloads. In this study, the automoments at the piers occurred due to the unit plastic rotations and other locations were calculated by the conjugate-beam method and three-moment equation, using the nine design span with progressively smaller pier sections. The automoments were determined by the developed computer programs in this study in which the moments and plastic rotations from the continuity and moment-inelastic rotation relationships must be equal. And also the ratings of 3-span continuous composite plate girder bridges with non-compact section were carried out according to the Korean Highway Bridge Specification.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.1
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• pp.75-89
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• 2014

In recent years, utilization of underground space has been increasing in various parts of the world. In particular, open-cut method is usually applied to the shallow depth excavation. However some problems such as extreme traffic congestion and unstability of adjacent structures etc. might occur. In order to cope with these problems, the M-CAM (Modified Cellular Arch Method) method was proposed to excavate soil tunnels at shallow depth with secured enough stability and minimized construction period. In this study, sensitivity analysis was performed to predict the influence of the size of CPW(Continuous Pile Wall) and ground conditions on the behavior of the tunnel. First of all, embedded depth and diameter (or thickness) of CPW, coefficient of lateral earth pressure, and ground conditions were selected as parameters that could affect tunnel stability. Meanwhile, FLAC 2D based on finite difference method was used for numerical analysis. As a result of this study, it was checked out that embedded depth among sizes of CPW had a greatest influence on the stability of a tunnel.

• Fashion & Textile Research Journal
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• v.24 no.3
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• pp.303-314
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• 2022

This study examined the impact of the social features (identification, interaction, information value) and technical features (visibility affordance, metavoicing affordance, social connecting affordance) in live commerce on consumers' attachment, which in turn affects consumers' continued intent to watch live commerce and intent to purchase from the platform. Consumers' attachment was represented by emotional attachment to the live shopping streamer and functional dependence on live commerce. Furthermore, this study investigated the effect of attachment on continuous watching intention and purchase intention. Using a web-based survey and consumers in their 20s and 30s (average age: 30.32) as a sample, this study collected 274 usable responses. The results showed that among the live commerce social system constructs, identification and interaction positively affected emotional attachment to the live commerce streamer. Among the live commerce technical system constructs, visibility affordance and social connecting affordance positively influenced functional dependence on live commerce. Both emotional attachment to the live streamer and functional dependence on live commerce were positively related to a continued intent to watch, which influenced the intent to purchase. This study empirically investigated live commerce based on the socio-technical systems framework and confirmed that both social and technical factors have a significant effect on consumers. This study also identified the impact of live commerce on consumers' attitudes through attachment theory. In addition, it has proved the antecedents and effect of continuous watching of live commerce on purchase behavior by focusing on continuous watching intention where less attention was paid in live commerce research.

• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.80-91
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• 2019

This study investigated the factors affecting the satisfaction and the continuous behavior intention of university students on MOOC. Adopting a questionnaire, the study collected data from 177 students enrolled in K-MOOC classes as an extracurriculum in the university in metropolitan area. Results indicated the following. First, the university students' satisfaction and continuous use intention on K-MOOC are higher during the semester than in vacation. Second, the perceived ease of use, usefulness, and task-technology fit influence the users'satisfaction on K-MOOC. Meanwhile, the perceived ease of use, task-technology, and user satisfaction likewise influence the users'continuous behavior intention. Hence, the study proposes that the subject matter on K-MOOC and the amount of educational content be made diversified, and the period of K-MOOC be made similar with that of the regular semester. The platform should also be stabilized, and the adequacy in mobile environment be improved. To further activate K-MOOC utilization in the university, the depth of contents and interaction between professors and students also need to be considered.

• Journal of Mechanical Science and Technology
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• v.20 no.7
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• pp.941-949
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• 2006

Nonlinear behavior analysis was used to verify whether a one-way clutch is effective for reducing the torsional vibration of a paired spur gear system under periodic excitation. The dynamic responses were studied over a wide frequency range by speed sweeping to check the nonlinear behavior using numerical integration. The gear system with a one-way clutch showed typical nonlinear behavior. The oscillating component of the dynamic transmission error was reduced over the entire frequency range compared to a system without a one-way clutch. The one-way clutch also eliminated unsteady continuous jump phenomena over multiple solution bands, and prevented double-side contact, even with very small backlash. Installing a one-way clutch on both sides of the gear system was more effective at mitigating the negative effects of external periodic excitation and various parameter changes than a conventional gear system without a one-way clutch.

• Culinary science and hospitality research
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• v.14 no.3
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• pp.45-57
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• 2008

The purpose of this study is to initiate a systematic approach to maximize profits through continuous development of menu and build a strong image of Western restaurants located inside hotels by identifying their guests' knowledge and concern and menu selection behavior in well being trend. Findings from the analysis are as follows. First, among the Western menu selection behavior, organic grain and seafood, seasonal event menu, less spicy and more natural cooking methods are favored as the most important consideration. Second, customers' knowledge and concern in well being trend and menu selection behavior were found to be statistically significant. Third, customers' awareness in health and obesity were found to be statistically significant to the concern in well being trend. Fourth, demographical characteristics of customers such as gender, marital status, age, income level and education were tested for their relationships with knowledge and concern in well being trend.

• Journal of Korean society of Dental Hygiene
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• v.11 no.1
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• pp.39-47
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• 2011

Objectives : The purpose of this study was to obtain data that can be utilized in the planning of oral health education, by surveying the correlation between oral health knowledge, attitudes, and behavior among elementary school students. Methods : A questionnaire was administered to 227 students in the 5th and 6th grades in Hongseong-gun. The obtained data were analyzed with the SPSS 14.0 program. Results : Knowledge of oral health was very high. Correct attitudes and positive behavior were indicated. There was a significant difference in oral health behavior according to school year(p<0.05). Positive correlation was significantly observed among oral health knowledge, attitudes, and behavior(p<0.01). Especially, attitudes and behavior were highly correlated(r=0.583). Conclusions : Children's knowledge, attitudes, and behavior toward oral health were mutually influenced. Thus, oral health education should be carried out with the goal of causing changes in the attitudes and behavior of students, as opposed to delivering simple knowledge. Through continuous oral health education, correct oral health knowledge and behavior can be developed. Thus oral health education was expected to promote healthy habit for oral health.