• Geomechanics and Engineering
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• v.29 no.4
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• pp.471-486
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• 2022

The effect of segmental joints is one of main importance for the segmental lining design when tunnels are excavated by a mechanized process. In this paper, segmental tunnel linings are analyzed by two numerical methods, namely the Beam-Spring Method (BSM) and the Solid-Interface Method (SIM). For this purpose, the Tehran Subway Line 6 Tunnel is considered to be the reference case. Comprehensive 2D numerical simulations are performed considering the soil's calibrated plastic hardening model (PH). Also, an advanced 3D numerical model was used to obtain the stress relaxation value. The SIM numerical model is conducted to calculate the average rotational stiffness of the longitudinal joints considering the joints bending moment distribution and joints openings. Then, based on the BSM, a sensitivity analysis was performed to investigate the influence of the ground rigidity, depth to diameter ratios, slippage between the segment and ground, segment thickness, number of segments and pattern of joints. The findings indicate that when the longitudinal joints are flexible, the soil-segment interaction effect is significant. The joint rotational stiffness effect becomes remarkable with increasing the segment thickness, segment number, and tunnel depth. The pattern of longitudinal joints, in addition to the joint stiffness ratio and number of segments, also depends on the placement of longitudinal joints of the key segment in the tunnel crown (similar to patterns B and B').

• Journal of Korea Trade
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• v.27 no.1
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• pp.42-59
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• 2023

Purpose - As a leading source of foreign exchange and investment, tourism has grown in importance as a component of international trade. Accordingly, in recent decades much attention has been directed toward attracting foreign tourists and, in turn, positively affecting the recommendation intentions of foreign tourists. Despite such interests, there remains a dearth of empirical research on this issue. Moreover, prior research has focused primarily on the simple main effect of a certain factor on recommendation intentions. Therefore, the present study aims to (1) investigate the effect of overall satisfaction on the recommendation intentions of foreign tourists, and (2) examine the potential moderating effects of personal factors (i.e., age and destination image) on the association between overall satisfaction and recommendation intention. Design/methodology - Using a moderated moderation analysis of the data drawn from the 2018 International Visitor Survey conducted by the Korea Tourism Organization, this study proposes the three-way interaction effects of overall satisfaction, age, and destination image on recommendation intention. Findings - The findings of the study indicate that overall satisfaction is positively associated with recommendation intention and this relationship becomes stronger among younger tourists. The findings further indicate that the moderating effect of age on the relationship between overall satisfaction and recommendation intention depends on changes in the image of the destination. Specifically, the destination image exerts a positive moderating impact on the influence of age that moderates the overall satisfaction and recommendation intention relationship. Originality/value - Considering that the tourism economy has been severely affected by the current COVID-19 pandemic, this study contributes to a more accurate understanding of the factors affecting the recommendation intention, especially in times of crisis.

• Design & Manufacturing
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• v.17 no.2
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• pp.55-61
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• 2023

With femtosecond (fs) laser pulse irradiation on metals, various types of nano- and micro-scale structures can be naturally induced at the surface through laser-matter interaction. Two notable structures are laser-induced periodic surface structures (LIPSSs) and cone/spike structures, which are known to significantly modify the optical and physical properties of metal surfaces. In this work, we irradiate fs laser pulses onto various types of metals, cold-rolled steel, pickled & oiled steel, Fe-18Cr-8Ni alloy, Zn-Mg-Al alloy coated steel, and pure Cu which can be useful for precise molding and imprinting processes, and adjust the morphological profiles of LIPSSs and cone/spike structures for clear structural coloration and a larger range of surface wettability control, respectively, by changing the fluence of laser and the speed of raster scan. The periods of LIPSSs on metals used in our experiments are nearly independent of laser fluence. Accordingly, the structural coloration of the surface with LIPSSs can be optimized with the morphological profile of LIPSSs, controlled only by the speed of the raster scan once the laser fluence is determined for each metal sample. However, different from LIPSSs, we demonstrate that the morphological profiles of the cone/spike structures, including their size, shape, and density, can be manipulated with both the laser fluence and the raster scan speed to increase a change in the contact angle. By injection molding and imprinting processes, it is expected that fs laser-induced surface structures on metals can be replicated to the plastic surfaces and potentially beneficial to control the optical and wetting properties of the surface of injection molded and imprinted products.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.423-430
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• 2023

This dissertation discusses the formulation of a nonlinear storytelling board that preserves the contextual perspective of characters. Storytelling encompasses the director's creative intention by leveraging the interaction of various elements to construct a logical narrative that explores cause and effect. Its primary objective is to enhance viewers' empathy. Consequently, there is a pressing need for comprehensive research on differentiating storytelling from storyboarding. Moreover, the integrated approach to storytelling and storyboarding holds scholarly value in understanding the process of narrative composition and visualization. Thus, a study proposes a method for constructing nonlinear storytelling boards considering the discrete camera perspective and contextual scene continuity, ultimately contributing to visual complexity and correlation comprehension. This approach enables a careful and simultaneous consideration of the correlations that deepen cognition, including the physical, emotional, and event rhythms mentioned in Karen Perlman's theory.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.253-258
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• 2023

In comics, panels serve a variety of dramatic purposes, including controlling the flow of the story through the size, placement, and order of panels; directing the eye to where characters or specific actions take place; expressing the passage or sequence of time; and using backgrounds, lighting, and color to emphasize emotion and convey mood. When applied to VR animation, these comic panels can give users a more immersive experience of the cartoon world in the VR space. In the VR animation "Mescaformhill: Missing Five," produced in 2022, the comic panels directing is very important to guide the viewer's attention, and in the VR space, the camera angle can be freely changed to realize various visual effects, and the physical interaction brings the comic panels directing to life. This can open up new ways of storytelling in VR animation and contribute to its successful expansion into new mediums.

• The Journal of Information Systems
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• v.32 no.1
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• pp.23-51
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• 2023

Purpose: Live commerce is a new type of electronic commerce in combination with live streaming services. It is expected to increase virtual presence in the context of online shopping by overcoming a lack of social interactions between sellers and buyers which have been raised as a limitation in electronic commerce. Drawing on the studies of communication media, this study examines how live commerce contributes to the increase of virtual presence which consists of telepresence and social presence. Telepresence refers to a buyer's perception that he or she is present at the physical shopping mall during live shopping streaming whereas social presence refers to a buyer's perception of social interaction with a seller which is human warm, social, sensitive, and personal. In this study, we verify key determinants of virtual presence and its consequences. More specifically, this study proposes virtual presence contributes to the increase of buyers' trust in products and further purchase intentions. Furthermore, we verify influential factors of virtual presence from the technical and influencer perspectives of live commerce. Design/methodology/approach: To test the proposed hypotheses, the partial least squares (PLS) analysis is conducted with a total of 250 data collected on users with experience in the TaoBao live streaming shopping platform. Findings: The results show that first, telepresence and social presence are increased by visibility, media richness and attractiveness in the context of live shopping streaming. Second, buyers' trust in product trust and purchase intentions are positively influenced by telepresence and social presence. Finally, buyers' trust in product has a direct, positve effect on their purchase intentions. Overall, the findings offer new insights into the studies of electronic commerce by introducting the concepts of virtual presence and media richness from the literature of communication media in the field of live commerce.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1A
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• pp.45-52
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• 2010

This study pointed on the dynamic impact of AGT (Automated Guide-way Transit) bridge, due to concrete rail prominence. An experiment was done with 30 m P.S.C. bridge in AGT test line in Kyungsan. An artificial prominence with 10 mm hight, was installed at the mid span of concrete rail. And computer simulation was executed for the artificial prominence. As an experiment result, in the case of with prominence, bridge acceleration responses are increased 50% at the speed range of 20 km/h-60 km/h, and bridge displacement responses increased slightly. With these results, the prominence of concrete rail can be induce excess impact and vibration. And the computer program simulated much the same as experiments. So this program can be used for AGT bridge design and formulate the standard of concrete rail management.

• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.120-129
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• 1995

Since the rate and completeness of combustion in direct injection engines were controlled by the characteristics of gas flow fields and sprays, an understanding of those was essential to the design of the direct injection engines. In this study the numerical simulations of swirl effects on the characteristics of gas flow fields and sprays were performed using the spray model that could predict the interactions between gas fields and spray droplets. The governing equations were discretized by the finite volume method and the modified k- e model which included the compressibility effects due to the compression/expansion of piston was used. The results of numerical calculation of the spray characteristics in the quiescent environment were compared with the experimental data. There were good agreements between the results of calculation and the experimental data, except in the early stages of spray. In the motoring condition, the results showed that a substantial air entrainment into the spray volume was emerged and hence the squish motion was relatively unimportant during fuel injection periods. As the swirl ratio increased, the evaporation rate was increased due to the wide dispersion of the spray droplets and the strong interaction between spray droplets and gas fields.

• Korean Journal of Exercise Nutrition
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• v.13 no.1
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• pp.75-81
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• 2009

This study aims to find out the effect of ingestion of 3 mg·kg^-1 caffeine on fluid-electrolyte balance and Tty change during exercise under heat environment of 30~32℃ (40-50% humidity). Five trained males who routinely trained for approximately 60 min·d^-1, 3-6 d·wk^-1 (age; 28.20±3.56yrs, height; 174.56±5.46 cm, body mass; 76.13±9.02 kg, body fat(%); 14.24±3.99, VO₂max; 54.00±4.30 mL·kg^-1·min^-1, exercise career; 4.20±1.95yrs) performed 40min of treadmill running in heat chamber. The study was a double-blind, randomized, crossover design. Body mass change following exercise was higher for the PLAC (Placebo) and CAFF (Caffeine) in comparison to the CON (Control), there was no significant difference between the CAFF, PLAC, CON (p= .997). The U_sg not significant differences (p= .731) and Osm_urine not significant differences between the CAFF, PLAC, CON (p= .901). There also were not significant between the CAFF, PLAC, CON for [Na⁺]_urine and [K⁺]_urine (p= .928, p= .469). In the case of Tty, although the increase rate of Tty was the highest for the CAFF on exercise early, exercise the second half in comparison to the CON and PLAC, there was not significant interaction effect between the CAFF, PLAC, and CON of Tty (p= .067), In conclusion, it was confirmed that the 3 mg·kg^-1 caffeine ingestion prior to exercising in heat environment does not impart negative effect on body fluid, electrolyte balance and changes in Tty.

• The Journal of Information Systems
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• v.32 no.4
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• pp.1-28
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• 2023

Purpose Recently, organizations have been allocating significant financial resources toward the implementation of new technologies and stringent information security (IS) policies in order to enhance IS. However, the potential for IS threats from internal sources within organizations remains high. This study proposes a mechanism whereby the organization's IS environment (organizational justice) enhances employees' perception of IS value congruence and encourages their voice behavior. Furthermore, this study validates that an individual's susceptibility to interpersonal influence can reinforce the relationship between the aforementioned factors and voice behavior. Design/methodology/approach We utilized AMOS 22.0 and Process 3.1 to validate the research model and hypotheses. The data was gathered from 435 employees employed in South Korean firms that implemented IS policies in their work. Structural equation modeling was employed to examine the relationship between organizational justice, value congruence, and voice behavior, and the interaction effect was confirmed by incorporating model 1 of Process 3.1 for the hypothesis pertaining to susceptibility to interpersonal influence. Findings The findings of this study indicate that organizational justice has a positive impact on voice behavior, which is further enhanced by value congruence. Furthermore, the influence of organizational justice and value congruence on voice behavior is moderated by susceptibility to information influence, while susceptibility to normative influence only moderates the effect of organizational justice. These results provide valuable insights for organizations in developing customized information systems strategies that effectively promote employees' voice behaviors.