• Journal of the Society of Naval Architects of Korea
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• v.31 no.3
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• pp.135-144
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• 1994

The coupled vibration of the deck house and stern structure, which was experienced on a 12,900 TDW Ro/Ro ship, has been studied. It was a large-scale vibration problem where the structure resonates with the propeller excitation at the first blade passing frequency. After discussing the structural characteristics of the ship, the vibration characteristics measured ducting the sea-trial are presented and compared with the analysis results which are based on a 3 dimensional finite element(FE) model. The FE model is also used to verify various reinforcement options and to predict their effectiveness. A substantial reduction or the vibration was confirmed during the sea-trial after installing a few selected reinforcement. The forced vibration response, which is computed using the FE model, is compared with the measured data. The change of the vibration characteristics according to loading conditions is also studied.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.386-403
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• 2021

Preannouncing a new product to its target audiences has been more and more prevalent in a wealth of industries, particularly industries that attach great importance to the speed of entry. Grounded in market signaling theory, the current research advances a theoretical model that takes full cognizance of the relation between preannounced information about an upcoming product and individual customers' behavioral intentions as well as significant moderating effects of prior product knowledge and new product innovativeness. In response, a web-based survey is conducted for data collection and the structural equation model is utilized for data analysis. Results of this study demonstrate that preannounced new product information attributes (i.e., quantity, clarity) may positively influence consumers' attitudes, in turn, lead to a favorable purchase intention. Moreover, the moderating effects of product knowledge and product innovativeness are also confirmed. Specifically, product knowledge moderates the quantity-attitude relation positively and moderates the clarity-attitude relation negatively, whereas product innovativeness does opposite. Both implications and limitations are also described.

• Wind and Structures
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• v.27 no.6
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• pp.399-416
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• 2018

In order to reveal the independent relationship between track irregularity and wind loads, the stochastic characteristics of train-bridge coupling systems subjected to wind loads were investigated by the multi-sample calculation. The vehicle was selected as 23 degrees of freedom dynamical model, and the bridge was described by three-dimensional finite element model. It was assumed that the wind loads were random processes with strong spatial correlation, while the track irregularities were stationary random ones. As a case study, a high-speed train running on a cable-stayed bridge subjected to wind loads was studied. The effect of rail irregularities was deemed to be independent of the effect of wind excitations on the coupling system in the same wind circumstance for the same project, leading to the conclusion that the effect of wind loads and moving vehicle could be calculated separately. The variance results of the stochastic responses of vehicle-bridge coupling system under the action of wind loads and rail irregularities together were equivalent to the sum of the variance of the responses induced by each excitation. Therefore, when one of the input excitations is different, only the effect of changed loads needs to be assessed. Moreover, the new calculated results were combined with the effect of unchanged loads to present the stochastic response of coupling system subjected to the different excitations, reducing the cost of computations. The stochastic characteristics, the CFD (cumulative distribution function) of the coupling system with different wind velocities, vehicle speed, and vehicle marshalling were studied likewise.

• Structural Engineering and Mechanics
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• v.68 no.5
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• pp.563-573
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• 2018

Temperature-induced responses, such as strains and displacements, are related to the boundary conditions. Therefore, it is required to determine the boundary conditions to establish a reliable bridge model for temperature-induced responses analysis. Particularly, bridge bearings usually present nonlinear behavior with an increase in load, and the nonlinear boundary conditions cause significant effect on temperature-induced responses. In this paper, the bridge nonlinear boundary conditions were simulated as bilinear translational or rotational springs, and the boundary parameters of the bilinear springs were identified based on the measured temperature-induced responses. First of all, the temperature-induced responses of a simply support beam with nonlinear translational and rotational springs subjected to various temperature loads were analyzed. The simulated temperature-induced strains and displacements were assumed as measured data. To identify the nonlinear translational and rotational boundary parameters of the bridge, the objective function based on the temperature-induced responses is then created, and the nonlinear boundary parameters were further identified by using the nonlinear least squares optimization algorithm. Then, a beam structure with nonlinear translational and rotational springs was simulated as a numerical example, and the nonlinear boundary parameters were identified based on the proposed method. The numerical results show that the proposed method can effectively identify the parameters of the nonlinear boundary conditions. Finally, the boundary parameters of a real arch bridge were identified based on the measured strain data and the proposed method. Since the bearings of the real bridge do not perform nonlinear behavior, only the linear boundary parameters of the bridge model were identified. Based on the bridge model and the identified boundary conditions, the temperature-induced strains were recalculated to compare with the measured strain data. The recalculated temperature-induced strains are in a good agreement with the real measured data.

• Journal of Korea Technology Innovation Society
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• v.21 no.4
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• pp.1536-1576
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• 2018

This study aims at investigating the path in which entrepreneurial orientation and absorptive capacity, which have a significant influence on the corporate performance of SMEs, are mediated through product innovation performance (product speed, product quality). For the empirical study, 233 questionnaires collected from 1775 SMEs including in Daejeon Techno Park start-ups were analyzed by using structural equation model. The empirical analysis shows that absorptive capacity and entrepreneurial orientation have a positive effect on performance through product innovation performance. Therefore, it is suggested that entrepreneurial orientation and absorptive capacity increase product innovation performance in terms of corporate strategy and external information utilization capability, and product innovation performance leads to performance. This paper suggests that entrepreneurial strategy and capacity to utilize external information are important for introducing high quality products faster than others in response to the external environment.

• Journal of Ocean Engineering and Technology
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• v.33 no.5
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• pp.486-494
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• 2019

Recently, the interest in marine leisure activities has been growing rapidly with the work-life balance trend. In response to this demand, the Korean government is supporting fostering and revitalizing the relevant industries and facilities. In particular, a marina has been making efforts to change itself into a resort with multiple amenities instead of a simple mooring facility. However, the facilities in a marina for the transport of marine leisure equipment mostly consist of cranes and boat-lifts using ropes, which can result in incidents such as damage and accidents during lifting or movement. This paper proposes the equipment and support system for the safe transportation of marine leisure ships. Aluminum transport equipment was designed by performing a structural analysis to achieve a lighter weight than the existing steel products. In addition, a safety support system with alarms for tilting or obstacles and a slope monitoring system was developed to enhance the safety during operation and transportation. The safety support system developed in this study was implemented and installed in the transport system, and verified through commissioning on land.

• Journal of the Korea Society of Computer and Information
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• v.26 no.3
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• pp.137-142
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• 2021

The goal of this study is to investigate how YouTube use motivation such as perceived usefulness and perceived enjoyment affect the compulsive YouTube usage and academic adjustment of college students. To this end, a research model was established and 113 response data obtained by conducting a questionnaire survey on college students in Seoul were used for structural model analysis. The results of this study can be summarized as following. First, perceived usefulness has a positive effect on academic adjustment. Second, compulsive YouTube usage has a negative effect on academic adjustment. Third, perceived enjoyment was identified as a factor that plays a role like pharmakon. The findings suggest the necessity of learning strategies that control the degree of perceived enjoyment as well as the instrumental use of perceived usefulness in order to improve the academic adjustment of college students.

• Fashion & Textile Research Journal
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• v.23 no.2
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• pp.200-211
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• 2021

This study examines the effects of fashion influencers' body types (realistic versus ideal body types) on self-expression, self-representation, and recommendation intentions, as mediated by familiarity toward influencers. Although fashion influencers lead to a positive consumer response compared to traditional advertisements, previous research on the effects of fashion influencers on consumers is limited. Thus, this study tests the role of consumers' socio-psychological aspects in understanding how and why fashion influencers affect consumers' behavioral intentions associated with self-expression, self-representation, and influencer recommendation. A total of 180 women in their 20s and 30s participated in the survey. The responses were collected after showing them stimuli featuring fashion influencers with either ideal or realistic body shapes. The data were analyzed using SPSS18.0 for descriptive statistics, and AMOS 18.0 for confirmatory factor analysis and structural equation modeling. The results showed that participants who were shown realistic body types perceived familiarity, which generated positive effects on self-expression, self-representation, and recommendation intentions. Hence, the effects of influencers' body types on recommendation intention are mediated by familiarity. Self-expression and self-representation intentions also increase influencer recommendation intention. Comparatively, participants who were shown ideal body types only induced higher self-representation intention, which increased their recommendation intention. The current findings can help fashion marketers select the appropriate influencers who fit their target customers as promotional models, as well as to induce changes in consumers' behavioral intention.

• Advances in concrete construction
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• v.13 no.5
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• pp.385-394
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• 2022

Recently, an increasing number of cutting-edged studies have shown that designing a smart active control for real-time implementation requires piles of hard-work criteria in the design process, including performance controllers to reduce the tracking errors and tolerance to external interference and measure system disturbed perturbations. This article proposes an effective artificial-intelligence method using these rigorous criteria, which can be translated into general control plants for the management of civil engineering installations. To facilitate the calculation, an efficient solution process based on linear matrix (LMI) inequality has been introduced to verify the relevance of the proposed method, and extensive simulators have been carried out for the numerical constructive model in the seismic stimulation of the active rigidity. Additionally, a fuzzy model of the neural network based system (NN) is developed using an interconnected method for LDI (linear differential) representation determined for arbitrary dynamics. This expression is constructed with a nonlinear sector which converts the nonlinear model into a multiple linear deformation of the linear model and a new state sufficient to guarantee the asymptomatic stability of the Lyapunov function of the linear matrix inequality. In the control design, we incorporated H Infinity optimized development algorithm and performance analysis stability. Finally, there is a numerical practical example with simulations to show the results. The implication results in the RMS response with as well as without tuned mass damper (TMD) of the benchmark building under the external excitation, the El-Centro Earthquake, in which it also showed the simulation using evolved bat algorithmic LMI fuzzy controllers in term of RMS in acceleration and displacement of the building.

• Steel and Composite Structures
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• v.41 no.5
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• pp.663-679
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• 2021

To elucidate the differences in the collapse behavior between a single-story beam-column assembly and multi-story frame, two 1/3-scale two-bay composite frames, including a single-story composite beam-column assembly and a three-story composite sub-frame, were designed and quasi-statically tested. The load-displacement responses, failure modes, and internal force development of the two frames were analyzed and compared in detail. Furthermore, the resistance mechanisms of the two specimens were explored, and the respective contributions of different load-resisting mechanisms to the total resistances were quantitatively separated to gain deeper insights. The experimental tests indicated that Vierendeel action was present in the two-dimensional multi-story frames, which led to an uneven internal force distribution among the three stories. The collapse resistance of TSDWA-3S in the flexural stage was not significantly increased by the structural redundancy provided by the additional story, as compared to that of TSDWA-1S. Although the development of the load response was similar in the two specimens at flexural stage, the collapse mechanisms of the multi-story composite frame were much more complicated than those of the single-story beam-column assembly, and the combined action between stories was critical in determining the internal force redistribution and rebalancing of the remaining structure.