• Geomechanics and Engineering
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• v.8 no.3
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• pp.461-476
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• 2015

Rankine's theory of earth pressure cannot be directly employed to c-${\phi}$ soils backfill with a sloping ground subjected to complex loadings. In this paper, an analytical solution for active earth pressures on retaining structures of cohesive backfill with an inclined surface subjected to surcharge, pore water pressure and seismic loadings, are derived on the basis of the lower-bound theorem of limit analysis combined with Rankine's earth pressure theory and the Mohr-Coulomb yield criterion. The generalized active earth pressure coefficients (dimensionless total active thrusts) are presented for use in comprehensive design charts which eliminate the need for tedious and cumbersome graphical diagram process. Charts are developed for rigid earth retaining structures under complex environmental loadings such as the surcharge, pore water pressure and seismic inertia force. An example is presented to illustrate the practical application for the proposed coefficient charts.

• Journal of Environmental Impact Assessment
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• v.19 no.6
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• pp.547-552
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• 2010

The theory of island biogeography has influenced strongly on the conservation and management issues of species diversity in the islands. The theory has not limited to islands in the ocean, but expanded to isolated and fragmented areas in the forests and urban. This study has a rare opportunity to explore the species diversity and abundance of birds in the islands of Korea. A total of 151 islands in the west and south areas in the Korean peninsula were examined. The number of species and the area of islands were highly significant (P<0.000) and the number of species and the distance from the mainland showed not so strong relationship. This indicated that bird species diversity has more influenced by the size of the islands not the distance. This can be from the study species of birds that can fly long distance, and also natural characteristics of migratory and resident status. Species-area curve showed that the z-value was 0.21 indicating the area and the bird species are strongly correlated. The long-term monitoring of bird species presence in the islands should be followed for a proper management plan.

• Computers and Concrete
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• v.25 no.2
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• pp.155-166
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• 2020

In this work, the buckling and vibrational behavior of the composite beam armed with single-walled carbon nanotubes (SW-CNT) resting on Winkler-Pasternak elastic foundation are investigated. The CNT-RC beam is modeled by a novel integral first order shear deformation theory. The current theory contains three variables and uses the shear correction factors. The equivalent properties of the CNT-RC beam are computed using the mixture rule. The equations of motion are derived and resolved by Applying the Hamilton's principle and Navier solution on the current model. The accuracy of the current model is verified by comparison studies with others models found in the literature. Also, several parametric studies and their discussions are presented.

• Structural Engineering and Mechanics
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• v.50 no.5
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• pp.575-588
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• 2014

Gel materials have recently gained more attention due to its unique capability of large and reversible volumetric changes. This study explores the possibility of mimicking the pattern formation of certain natural fruits during their growing process and leaves during drying processes through the swelling and de-swelling of gel materials. This will hopefully provide certain technical explanations on the morphology of fruits and plants. We adopt the inhomogeneous field gel theory to predict the deformation configurations of gel structures to describe the morphology of natural fruits and plants. The growing processes of apple and capsicum are simulated by imposing appropriate boundary conditions and field loading via varying the chemical potential from their immature to mature stages. The drying processes of three types of leaves with different vein structures are also investigated. The simulations lead to promising results and demonstrate that pattern formation of fruits and plants may be described from mechanical perspective by the behavior of gel materials based on the inhomogeneous field theory.

• Journal of Korean Society of Rural Planning
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• v.27 no.2
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• pp.77-89
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• 2021

To predict the level of residents' participation in rural tourism project, we used agent-based model. The decision-making mechanism which calculates the utility related to attitude, subjective norm, perceived behavioral control of planned behavior theory was applied to the residents' decision to participate. As a result of the simulation over a period of 20 years, in the baseline scenario set similar to the general process of promoting rural projects, the proportion of indigenous people decreased and the participation rate decreased. In the scenarios with different learning frequencies in perceived behavioral control, overall participation rate decreased. Learning every five years had the effect of increasing the participation rate slightly. Participation rates increased significantly in the scenario that consider economic aspects and reputation in attitude and did not decline in the scenario where population composition was maintained. The virtuous cycle effect of subjective norm according to changes in participation rate due to influence of attitude and perceived behavioral control shows the dynamic relationship.

• Steel and Composite Structures
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• v.42 no.1
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• pp.75-90
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• 2022

The pointwise equilibrium polynomial (PEP) element considering local second-order effect has been widely used in direct analysis of many practical engineering structures. However, it was derived according to Euler-Bernoulli beam theory and therefore it cannot consider shear deformation, which may lead to inaccurate prediction for deep beams. In this paper, a novel beam-column element based on Timoshenko beam theory is proposed to overcome the drawback of PEP element. A fifth-order polynomial is adopted for the lateral deflection of the proposed element, while a quadric shear strain field based on equilibrium equation is assumed for transverse shear deformation. Further, an additional quadric function is adopted in this new element to account for member initial geometrical imperfection. In conjunction with a reliable and effective three-dimensional (3D) co-rotational technique, the proposed element can consider both member initial imperfection and transverse shear deformation for second-order direct analysis of frame structures. Some benchmark problems are provided to demonstrate the accuracy and high performance of the proposed element. The significant adverse influence on structural behaviors due to shear deformation and initial imperfection is also discussed.

• Hwankyungkyoyuk
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• v.21 no.4
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• pp.94-110
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• 2008

Recently environmental problem becomes such a big issue all over the world that the necessity and importance of the environmental education in school has been simultaneously emphasized. While diverse methods for the environmental education have been researched, this paper, especially focused on a teaching-learning model called GBS (Goal-based scenario), aims to provide a new learner-centered approach for the environmental education. For this purpose, this paper first briefly presents two theoretical backgrounds of GBS (i.e., constructivism and Schank's dynamic memory theory), which is followed by specific and concrete strategies and methods of how to apply GBS in class for the teacher. GBS(Goal-Based Scenario) is a learner-centered model in which learners are presented with a reality-based scenario (or task or problem) and go through several stages of 'missions' to get to a final solution of the given scenario. GBS, while completely resonant with other constructivist learning models in terms of learner-centered approaches, is distinctive from others, when it supplies more specific, structured guides of learning, called 'missions', to the students throughout the whole learning process. In a words, GBS ought to be recognized as an unique learner-centered model compromising the contradictory concepts of 'learner control' and 'structure and specifics' in learning environments still without any damage of constructivist learning principles.

• Asia-Pacific Journal of Business
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• v.14 no.1
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• pp.59-71
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• 2023

Purpose - The purpose of this study is to investigate the effect of corporate social responsibility (CSR) on firm performance in China, plus the moderating effects of advertising intensity and environmental pollution. Design/methodology/approach - We analyzed our dataset that consists of 188 public Chinese firms drawn from the Shanghai and Shenzhen exchanges during 2010-2020. Findings - Based on the stakeholder theory and signaling theory, we proposed the positive relationship between the CSR level and the firm performance. Further, we configured consumers and the government as major stakeholders in China, suggesting positive moderating effects of advertising intensity and environmental pollution, respectively. Research implications or originality - The results show that the CSR level increases the firm performance. The advertising intensity positively moderates the relationship between the CSR level and the firm performance, but there was no significant moderating effects of environmental pollution. The findings confirm the importance of consumers for the CSR stakeholders. While the Chinese government strongly reinforces environmental regulation, CSR itself does not seem to be the fine-aligned action prioritized for mitigating environmental pollution.

• The Journal of Information Systems
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• v.26 no.2
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• pp.43-62
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• 2017

Purpose This study provided empirical support for the model that explain the formation of privacy concerns in the perspective of Information Boundary Theory. This study investigated an integrated model suggesting that privacy concerns are formed by the individual's disposition to value privacy, privacy awareness, awareness of privacy policy, and government legislation. The Information Boundary Theory suggests that the boundaries of information space dependends on the individual's personal characteristics and environmental factors of e-commerce. When receiving a request for personal information from e-commerce websites, an individual assesses the risk depending on the risk-control assessment, the perception of intrusion give rise to privacy concerns. Design/methodology/approach This study empirically tested the hypotheses with the data collected in a survey that included the items measuring the constructs in the model. The survey was aimed at university students. and a causal modeling statistical technique(PLS) is used for data analysis in this research. Findings The results of the survey indicated significant relationships among environmental factors of e-commerce websites, individual's personal privacy characteristics and privacy concerns. Both individual's awareness of institutional privacy assurance on e-commerce and the privacy characteristics affect the risk-control assessment towards information disclosure, which becomes an essential components of privacy concerns.

• Journal of Mechanical Science and Technology
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• v.19 no.2
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• pp.589-604
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• 2005

To overcome the drawback of currently available curved beam theories having non-symmetric thin-walled cross sections, a curved beam theory based on centroid-shear center formulation is presented for the spatially coupled free vibration and elastic analysis. For this, the displacement field is expressed by introducing displacement parameters defined at the centroid and shear center axes, respectively. Next the elastic strain and kinetic energies considering the thickness-curvature effect and the rotary inertia of curved beam are rigorously derived by degenerating the energies of the elastic continuum to those of curved beam. And then the equilibrium equations and the boundary conditions are consistently derived for curved beams having non-symmetric thin-walled cross section. It is emphasized that for curved beams with L- or T-shaped sections, this thin-walled curved beam theory can be easily reduced to the solid beam theory by simply putting the sectional properties associated with warping to zero. In order to illustrate the validity and the accuracy of this study, FE solutions using the Hermitian curved beam elements are presented and compared with the results by previous research and ABAQUS's shell elements.