• Journal of Welding and Joining
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• 제32권2호
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• pp.37-42
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• 2014

In this study, non-load-carrying fillet welded joints fabricated using EH grade-steel are evaluated with the structural stress approach. The thickness effect was investigated by a study on welded steel joints with thickness ranging from 25 to 80mm. As-welded joint for main plate thickness of 25 to 80mm, the fatigue strength is reduced gradually. On the other hand, in case of main plate thickness of 25 to 80mm, the structural stress concentration factor increases gradually. As a result, for structural stress approach, thickness effect is not required for correction. Based on these results, a new evaluation fillet welded joint for fatigue design purposes has been proposed FAT 125.

• Structural Engineering and Mechanics
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• 제19권2호
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• pp.217-230
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• 2005

A steel silo traditionally consists of a cylindrical and a conical shell. In order to facilitate emptying operations, the cylinder is placed on local supports. This may lead to dangerous stress concentrations and eventually to local instability of the cylindrical wall. In this contribution, the locally supported cylinder is strengthened by means of ring stiffeners and longitudinal stiffeners and the effect of their dimensions on the buckling stress is investigated. This study leads to a number of diagrams, each of them representing the effect of one of the dimensions on the buckling stress. In each diagram, the failure pattern corresponding to the buckling stress is indicated.

• Coupled systems mechanics
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• 제8권2호
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• pp.169-184
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• 2019

This research work presents a study that aims to assess the dynamic structural behaviour and also investigate the human comfort levels of a reinforced concrete building, when subjected to nondeterministic wind dynamic loadings, considering the effect of masonry infills on the global stiffness of the structural model. In general, the masonry fills most of the empty areas within the structural frames of the buildings. Although these masonry infills present structural stiffness, the common practice of engineers is to adopt them as static loads, disregarding the effect of the masonry infills on the global stiffness of the structural system. This way, in this study a numerical model based on sixteen-storey reinforced concrete building with 48 m high and dimensions of $14.20m{\times}15m$ was analysed. This way, static, modal and dynamic analyses were carried out in order to simulate the structural model based on two different strategies: no masonry infills and masonry infills simulated by shell finite elements. In this investigation, the wind action is considered as a nondeterministic process with unstable properties and also random characteristics. The fluctuating parcel of the wind is decomposed into a finite number of harmonic functions proportional to the structure resonant frequency with phase angles randomly determined. The nondeterministic dynamic analysis clearly demonstrates the relevance of a more realistic numerical modelling of the masonry infills, due to the modifications on the global structural stiffness of the building. The maximum displacements and peak accelerations values were reduced when the effect of the masonry infills (structural stiffness) were considered in the dynamic analysis. Finally, it can be concluded that the human comfort evaluation of the sixteen-storey reinforced concrete building can be altered in a favourable way to design.

• Journal of the Korean Institute of Landscape Architecture
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• 제28권1호
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• pp.29-36
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• 2000

Leisure constraints mean the factor to constrain individual's leisure activity. Leisure constraints are composed of interpersonal constraints, interpersonal constraints and structural constraints. The purposes of this study are to show that intrapersonal leisure constraints have a strong effect on leisure preference, and leisure constraints are sequential and hierachical process. Intrapersonal constraints effect on leisure constraints in first step. And then interpersonal constraints and structural constraints effect on leisure participation. Those three leisure constraints are all linked together and come out step by step. Regarding adults as a population, who are more than 20-year-old and live in Seoul, 9 dongs were chose after dividing into upper and lower classes according to the value of their residence. The questionnaire consists of 4 parts: intrapersonal constraints, interpersonal constraints, structural constraints, and demographic characteristics. Results of this paper is that people who have strong intrapersonal constraints normally have problems caused from social structure. Intrapersonal constraints and structural constrains come out not seperately but together. Then, it can be said that structural constraints have an influence over intrapersonal constraints. So, it's necessary to solve structural problems to increase preferences and participations of them.

• Coupled systems mechanics
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• 제5권4호
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• pp.355-369
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• 2016

Changes in chemical structure have profound effects on the physical properties of epoxy-based materials, and eventually affect the durability of the entire system. Microscopic structural voids generally existing in the epoxy cross-linked networks have a detrimental influence on the epoxy mechanical properties, but the relation remains elusive, which is hindered by the complex structure of epoxy-based materials. In this paper, we investigate the effect of structural voids on the epoxy-based materials by using our developed mesoscale model equipped with the concept of multiscale modeling, and SU-8 photoresist is used as a representative of epoxy-based materials. Developed from the results of full atomistic simulations, the mesoscopic model is validated against experimental measurements, which is suitable to describe the elastic deformation of epoxy-based materials over several orders of magnitude in time- and length scales. After that, a certain quantity of the structure voids is incorporated in the mesoscale model. It is found that the existence of structural voids reduces the tensile stiffness of the mesoscale epoxy network, when compared with the case without any voids in the model. In addition, it is noticed that a certain number of the structural voids have an insignificant effect on the epoxy elastic properties, and the mesoscale model containing structural voids is close to those found in real systems.

• Advanced Composite Materials
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• 제17권4호
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• pp.343-358
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• 2008

This present study provides the structural design and analysis of main wing, horizontal tail and control surface of a small scale WIG (Wing-in-Ground Effect) craft which has been developed as a future high speed maritime transportation system of Korea. Weight saving as well as structural stability could be achieved by using the skin.spar.foam sandwich and carbon/epoxy composite material. Through sequential design modifications and numerical structural analysis using commercial FEM code PATRAN/NASTRAN, the final design structural features to meet the final design goal such as the system target weight, structural safety and stability were obtained. In addition, joint structures such as insert bolts for joining the wing with the fuselage and lugs for joining the control surface to the wing were designed by considering easy assembling as well as more than 20 years service life.

• Smart Structures and Systems
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• 제12권6호
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• pp.619-640
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• 2013

It is highly desirable to explore efficient algorithms for detecting structural damage of large size structural systems with limited input and output measurements. In this paper, a new structural damage detection algorithm based on substructure approach is proposed for large size structural systems with limited input and output measurements. Inter-connection effect between adjacent substructures is treated as 'additional unknown inputs' to substructures. Extended state vector of each substructure and its unknown excitations are estimated by sequential extended Kalman estimator and least-squares estimation, respectively. It is shown that the 'additional unknown inputs' can be estimated by the algorithm without the measurements on the substructure interface DOFs, which is superior to previous substructural identification approaches. Also, structural parameters and unknown excitation are estimated in a sequential manner, which simplifies the identification problem compared with other existing work. Structural damage can be detected from the degradation of the identified substructural element stiffness values. The performances of the proposed algorithm are demonstrated by several numerical examples and a lab experiment. Measurement noise effect is considered. Both the simulation results and experimental data validate that the proposed algorithm is viable for structural damage detection of large size structural systems with limited input and output measurements.

• Journal of the East Asian Society of Dietary Life
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• 제17권3호
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• pp.417-424
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• 2007

The purpose of this study was to measure the effects that service quality, perceived value and satisfaction have on loyalty in Namhaean area restaurants. A total of 273 questionnaires were completed. The structural equation model was used as an analysis method to measure the causal effects of service quality, perceived value, satisfaction and loyalty. The results demonstrated that the structural analysis result for the data was an excellent model fit. The effect of service quality on value, the effect of perceived sacrifice on value, the effect of service quality on satisfaction, the effect of value on satisfaction, and the effect of satisfaction on loyalty were statistically significant. Moreover service quality had an indirect effect on satisfaction through perceived value, and service quality also had an indirect effect on loyalty through perceived value and satisfaction. Perceived value had an indirect effect on loyalty, and an effect through satisfaction. Perceived sacrifice had an indirect effect on satisfaction through perceived value, and it also had an indirect effect on loyalty, and an effect through satisfaction. Further study is still required, and should be aimed at identifying the causal mechanisms of constructs, such that restaurant managers might be better prepared to offer value and satisfaction to their customers.

• Journal of Distribution Science
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• 제19권10호
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• pp.65-74
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• 2021

Purpose: The purpose of this study is to identify the maximum organizational effectiveness of compensation systems in the distribution industry. It is to identify the relationship between structural compensation and organizational effectiveness. It also aims to clarify whether distributive justice plays as a controlling variable between two variables. Research design, data and methodology: This study was conducted on distribution industry employees. The questionnaire was collected through self-subscription. A total of 209 questionnaires were collected during the month of April 2021, of which 203 were used as valid samples. Results: Structural compensation have been shown to have a positive impact on two sub-factors of organizational effectiveness. In the verification of the controlling effect of distributive justice, perceived fairness has a control effect on the relationship between extrinsic compensation and organizational effectiveness but it does not show a controlling effect on the relationship between intrinsic compensation and organizational effectiveness. Conclusions: Structural compensation has a positive effect on organizational effectiveness. The distribution industry should aware of the compensation and the perceived fairness. The fairness of distribution plays a role in identifying the recognition of compensation and organizational feasibility, identifying motivations of employees, and mediating proper strategies to enhance job satisfaction.

• Structural Engineering and Mechanics
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• 제32권3호
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• pp.459-475
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• 2009

This paper presents analytical methodologies for remaining life prediction of plain concrete structural components considering tension softening and size effects. Non-linear fracture mechanics principles (NLFM) have been used for crack growth analysis and remaining life prediction. Various tension softening models such as linear, bi-linear, tri-linear, exponential and power curve have been presented with appropriate expressions. Size effect has been accounted for by modifying the Paris law, leading to a size adjusted Paris law, which gives crack length increment per cycle as a power function of the amplitude of a size adjusted stress intensity factor (SIF). Details of tension softening effects and size effect in the computation of SIF and remaining life prediction have been presented. Numerical studies have been conducted on three point bending concrete beams under constant amplitude loading. The predicted remaining life values with the combination of tension softening & size effects are in close agreement with the corresponding experimental values available in the literature for all the tension softening models.