• Steel and Composite Structures
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• v.33 no.2
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• pp.261-275
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• 2019

The main objective of this paper is to study the axial buckling and post-buckling of geometrically imperfect single-layer graphene sheets (GSs) under in-plane loading in the theoretical framework of the nonlocal strain gradient theory. To begin with, a graphene sheet is modeled by a two-dimensional plate subjected to simply supported ends, and supposed to have a small initial curvature. Then according to the Hamilton's principle, the nonlinear governing equations are derived with the aid of the classical plate theory and the von-karman nonlinearity theory. Subsequently, for providing a more accurate physical assessment with respect to the influence of respective parameters on the mechanical performances, the approximate analytical solutions are acquired via using a two-step perturbation method. Finally, the authors perform a detailed parametric study based on the solutions, including geometric imperfection, nonlocal parameters, strain gradient parameters and wave mode numbers, and then reaching a significant conclusion that both the size-dependent effect and a geometrical imperfection can't be ignored in analyzing GSs.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.9
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• pp.159-169
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• 2019

This work presents the three-dimensional extended strain smoothing approach in the framework of finite element method, so-called smoothed finite element method (S-FEM) for quasi-incompressible hyperelastic materials undergoing the large deformations. The proposed method is known that the incompressible limits, such as over-estimation of stiffness and distorted mesh sensitivity, can be overcome in two dimensions. Therefore, in this paper, the idea of Cell-based, Edge-based and Node-based strain smoothing approaches is extended to three-dimensions. The construction of subcells and smoothing domains for each methods are explained. The smoothed strain-displacement matrix and the stiffness matrix are obtained on each smoothing domain in the same manner with two-dimensional S-FEM. Various numerical tests are studied to demonstrate the validity and accuracy of 3D-S-FEM. The obtained results are compared with analytical solutions to express the efficacy of the methods.

• Steel and Composite Structures
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• v.38 no.6
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• pp.717-737
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• 2021

A theoretical energy-based model to capture the mechanical response of thick woven composite laminates, which are used in such applications as maritime or aerospace, to high-velocity impact was developed. The dependences of the impact phenomenon on material and geometrical parameters were analysed making use of the Vaschy-Buckingham Theorem to provide a non-dimensional framework. The model was divided in three different stages splitting the physical interpretation of the perforation process: a first where different dissipative mechanisms such as compression or shear plugging were considered, a second where a transference of linear momentum was assumed and a third where only friction took place. The model was validated against experimental data along with a 3D finite element model. The numerical simulations were used to validate some of the new hypotheses assumed in the theoretical model to provide a more accurate explanation of the phenomena taking place during a high-velocity impact.

• Advances in aircraft and spacecraft science
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• v.9 no.5
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• pp.367-375
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• 2022

Modeling the properties of complex alloys such as nickel superalloys is an extremely challenging scientific and engineering task. The model should take into account a large number of uncorrelated factors, for many of which information may be missing or vague. The individual contribution of one or another chemical element out of a dozen possible ligants cannot be determined by traditional methods. Moreover, there are no general analytical models describing the influence of elements on the characteristics of alloys. Artificial neural networks are one of the few statistical modeling tools that can account for many implicit correlations and establish correspondences that cannot be identified by other more familiar mathematical methods. However, such networks require careful tuning to achieve high performance, which is time-consuming. Data preprocessing can make model training much easier and faster. This article focuses on combining physics-based deep network configuration and input data engineering to simulate the solvus temperature of nickel superalloys. The used deep artificial neural network shows good simulation results. Thus, this method of numerical simulation can be easily applied to such problems.

• Geomechanics and Engineering
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• v.35 no.1
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• pp.13-27
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• 2023

The model production for large-scale (lateral length ≥ 2.0 m) capillary barrier (CB) model tests is time and cost-intensive. To address these limitations, the framework of a small-scale CB (SSCB) model test under the lateral no-flow condition has been established. In this study, to validate the experimental methodology of the SSCB model test, a series of seepage analyses on the SSCB model test and engineered slopes in the same and additional test conditions was performed. First, the seepage behavior and diversion length (L_D) of the CB system were investigated under three rainfall conditions. In the seepage analysis for the engineered slopes with different slope angles and sand layer thicknesses, the L_D increased with the increase in the slope angle and sand layer thickness, although the increase rate of the L_D with the sand layer thickness exhibited an upper limit. The L_D values from the seepage analysis agreed well with the results estimated from the laboratory SSCB mode test. Therefore, it can be concluded that the experimental methodology of the SSCB model test is one of the promising alternatives to efficiently evaluate the water-shielding performance of the CB system for an engineered slope.

• Journal of Distribution Science
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• v.21 no.9
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• pp.93-102
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• 2023

Purpose: This study attempts to analyze the current status of the railway logistics business and to seek ways to improve it by using the business model as an analytical framework. It was intended to reflect practical implications that could be applied to the field, by dealing with issues at the industrial site related to each component in the business model. Research design, data and methodology: This study was conducted through literature review and field research. We analyzed academic papers and industrial reports on the development of the railway logistics industry and interviewed various stakeholders in the railway logistics industry. Results: This study determined the factors that could be eliminated, raised, reduced, or created from the customer and product perspective, infrastructure management perspective, and financial perspective. Conclusions: The growth of existing business can be achieved by lowering service prices, improving service quality, and securing large-scale transportation capacity. The additional transportation of high value goods and cold chain commodities will be promising business opportunities. Existing services can be provided to new customers (large pre-shippers, forwarding customers, etc.) in order to increase the size of sales Urban delivery services and comprehensive logistics services based on complex logistics centers may open an avenue for new market. A more timetable and track capacity need to be assigned to logistics, which significantly improve the flexibility and the competency of railway logistics.

• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.238-248
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• 2023

This study aims to examine the symbolism of the emblems of World Expositions by using Victor Turner's symbolic theory as a research method, and to reveal the symbolic types behind them by classifying the emblem designs of different periods and themes. The research object is 12 comprehensive World's Fair emblems from the 1939 New York World's Fair in the United States to the 2025 Osaka World's Fair in Japan, as identified by Bureau International des Expositions. The research method mainly adopts documentary research to collect historical information and theoretical frameworks related to the design of World's Fair emblems. In the analysis process, Victor Turner's symbolic sign theory is used as the main analytical framework to link the design elements of emblems to their relevance to specific societies and cultures in order to reveal the themes, values and ideas represented by the emblem symbolism. The results of the study show that the design of the Expo emblem uses different symbols, including material symbols, behavioral symbols, sensory symbols, natural symbols, social symbols and virtual symbols, to convey the core concepts, themes and values of the Expo. Through different types of symbols, the Expo emblem shows a wide range of concerns about technology and the future, mankind and the world, nature and ecology, and society and innovation. The symbolic design of the emblem plays an important role in conveying the core concept and theme of the Expo.

• Journal of Wellbeing Management and Applied Psychology
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• v.5 no.4
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• pp.11-17
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• 2022

Purpose: This study discusses how Indonesia's response to the Corona Virus Disease-19 pandemic based on the perspective of housing policy capacity which consists of resources, organizations, and networks, politics, systems, and finance. Research design, data and methodology: This study used a qualitative method through a literature review. Data collection techniques were carried out by searching various sources and literature related to housing capacity theory and various data on Indonesia's response to the Covid 19 pandemic. Based on a literature review, this study adapted and modified the five components of capacity, namely resource capacity, organizational and network capacity, political capacity, system capacity and financial capacity in Indonesia in responding to the Covid-19 pandemic. Data analysis used analytical themes which consist of understanding the data, generating initial codes, looking for themes, reviewing themes, defining and naming themes, producing of manuscripts. Results: The results show that the weakness of the system capacity greatly affects Indonesia's housing policy capacity in responding to the Covid-19 pandemic and on the other hand the five housing capacities are an integrated process within the housing policy framework in Indonesia, especially to overcome the Covid-19 pandemic. Conclusions: The findings of this study are the importance of building a system capacity that is directly integrated with housing policy and the strengthening of the resources capacity, organizations, and networks, politics, and finance in the context of Indonesia's housing policy, especially in dealing with the Covid-19 pandemic situation.

• Geomechanics and Engineering
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• v.37 no.2
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• pp.167-178
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• 2024

The natural frequency shift under cyclic environmental loads is a key issue in the design of monopile-based offshore wind power turbines because of their dynamic sensitivity. Existing evidence reveals that the natural frequency shift of the turbine system in sand is related to the varying foundation stiffness, which is caused by soil deformation around the monopile under cyclic loads. Therefore, it is an urgent need to investigate the effect of soil deformation on the system frequency. In the present paper, three generalized geometric models that can describe soil deformation under two-way cyclic loads are proposed. On this basis, the cycling-induced changes in soil parameters around the monopile are quantified. A theoretical approach considering three-spring foundation stiffness is employed to calculate the natural frequency during cycling. Further, a parametric study is conducted to describe and evaluate the frequency shift characteristics of the system under different conditions of sand relative density, pile slenderness ratio and pile-soil relative stiffness. The results indicate that the frequency shift trends are mainly affected by the pile-soil relative stiffness. Following the relevant conclusions, a design optimization is proposed to avoid resonance of the monopile-based wind turbines during their service life.

• The Journal of Industrial Distribution & Business
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• v.15 no.5
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• pp.29-37
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• 2024

Purpose: Numerous prior researchers have identified only that sustainable management of ESG factors promotes business value creation and shapes enhanced innovation performance. This study aims to determine the positive relationships between ESG management and economic development, focusing on the mutual benefits and risks and the various stakeholders involved in managing change. Research design, data and methodology: This study selected the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement as a key methodology. Literature search used the following databases: Web of Science, Scopus, and Google Scholar. The quality assessment criteria for selected prior studies ranged from issues like design, sample size and the representativeness of the subjects, validity of measurements, and analytical strength. Results: The findings of this study indicates that there are four critical solutions for economic development triggers using ESG strategy, such as (1) ESG and Innovation-Driven Growth, (2) ESG and Human Capital Development, (3) ESG and Operational Efficiency, (4) ESG and Market Opportunities. This study insists that public-private partnerships are critical for enhancing sustainable economic development and meeting the needs of society. Conclusions: It is, therefore, important for governments and policymakers to play a critical role in setting the proper framework that allows for the uptake of ESG and an enabling environment for sustainable economic development.