• Journal of Preventive Medicine and Public Health
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• v.52 no.4
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• pp.234-241
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• 2019

Objectives: To identify simultaneous behavioral changes in alcohol consumption, smoking, and weight using a fixed-effect model and to characterize their associations with disease status. Methods: This study included 7 000 529 individuals who participated in the national biennial health-screening program every 2 years from 2009 to 2016 and were aged 40 or more. We reconstructed the data into an individual-level panel dataset with 4 waves. We used a fixed-effect model for smoking, heavy alcohol drinking, and overweight. The independent variables were sex, age, lifestyle factors, insurance contribution, employment status, and disease status. Results: Becoming a high-risk drinker and losing weight were associated with initiation or resumption of smoking. Initiation or resumption of smoking and weight gain were associated with non-high-risk drinkers becoming high-risk drinkers. Smoking cessation and becoming a high-risk drinker were associated with normal-weight participants becoming overweight. Participants with newly acquired diabetes mellitus, ischemic heart disease, stroke, and cancer tended to stop smoking, discontinue high-risk drinking, and return to a normal weight. Conclusions: These results obtained using a large-scale population-based database documented interactions among lifestyle factors over time.

• Structural Engineering and Mechanics
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• v.70 no.2
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• pp.221-231
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• 2019

This paper performs for the first time a simultaneous optimization for members sections along with semi-rigid beam-to-column connections for space steel frames with fixed, semi-rigid, and hinged bases using a biogeography-based optimization algorithm (BBO) and a genetic algorithm (GA). Furthermore, a member's sections optimization for a fully fixed space frame is carried out. A real and accurate simulation of semi-rigid connection behavior is considered in this study, where the semi-rigid base connections are simulated using Kanvinde and Grilli (2012) nonlinear model, which considers deformations in different base connection components under the applied loads, while beam-to-column connections are modeled using the familiar Frye and Morris (1975) nonlinear polynomial model. Moreover, the $P-{\Delta}$ effect and geometric nonlinearity are considered. AISC-LRFD (2016) specification constraints of the stress and displacement are considered as well as section size fitting constraints. The optimization is applied to two benchmark space frame examples to inspect the effect of semi-rigidity on frame weight and drift using BBO and GA algorithms.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.287-300
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• 2022

Unconventional structures are getting more popular in recent days. Large-span roofs are used for many structures, such as airports, stadiums, and conventional halls. Identifying the pressure distribution and wind load acting on those structures is essential. This paper offers a collaborative study of computational fluid dynamics (CFD) simulations and wind tunnel tests for assessing wind pressure distribution for a building with a combined slender curved roof. The hybrid turbulence model, Improved Delayed Detached Eddy Simulation (IDDES), simulates the open terrain turbulent flow field. The wind-induced local pressure coefficients on complex roof structures and the turbulent flow field around the structure were thus calculated based upon open terrain wind flow simulated with the FLUENT software. Local pressure measurements were investigated in a boundary layer wind tunnel simultaneous to the simulation to determine the pressure coefficient distributions. The results predicted by CFD were found to be consistent with the wind tunnel test results. The comparative study validated that the recommended IDDES model and the vortex method associated with CFD simulation are suitable tools for structural engineers to evaluate wind effects on long-span complex roofs and plan irregular buildings during the design stage.

• Steel and Composite Structures
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• v.45 no.3
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• pp.331-348
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• 2022

The main goal of this article is to develop the finite element formulation based on the nonlocal strain gradient and the refined higher-order deformation theory employing a new function f(z) to investigate the static bending and free vibration of functionally graded porous (FGP) nanobeams. The proposed model considers the simultaneous effects of two parameters: nonlocal and strain gradient coefficients. The nanobeam is made by FGP material that exists in un-even and logarithmic-uneven distribution. The governing equation of the nanobeam is established based on Hamilton's principle. The authors use a 2-node beam element, each node with 8 degrees of freedom (DOFs) approximated by the C¹ and C² continuous Hermit functions to obtain the elemental stiffness matrix and mass matrix. The accuracy of the proposed model is tested by comparison with the results of reputable published works. From here, the influences of the parameters: nonlocal elasticity, strain gradient, porosity, and boundary conditions are studied.

• Steel and Composite Structures
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• v.50 no.1
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• pp.63-75
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• 2024

In this paper, the modified couple stress theory (MCST) and first order shear deformation theory (FSDT) are employed to investigate the free vibration and bending analyses of a three-layered micro-shell sandwiched by piezoelectric layers subjected to an applied voltage and reinforced graphene nanoplatelets (GPLs) under external and internal pressure. The micro-shell is resting on an elastic foundation modeled as Pasternak model. The mixture's rule and Halpin-Tsai model are utilized to compute the effective mechanical properties. By applying Hamilton's principle, the motion equations and associated boundary conditions are derived. Static/ dynamic results are obtained using Navier's method. The results are validated with the previously published works. The numerical results are presented to study and discuss the influences of various parameters on the natural frequencies and deflection of the micro-shell, such as applied voltage, thickness of the piezoelectric layer to radius, length to radius ratio, volume fraction and various distribution pattern of the GPLs, thickness-to-length scale parameter, and foundation coefficients for the both external and internal pressure. The main novelty of this work is simultaneous effect of graphene nanoplatelets as reinforcement and piezoelectric layers on the bending and vibration characteristics of the sandwich micro shell.

• Asian Journal of Business Environment
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• v.14 no.3
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• pp.23-35
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• 2024

Purpose: The study focuses on the impact of Foreign Direct Investment (FDI), trade openness, and energy consumption on carbon dioxide emissions in the Ivory Coast. It aims to quantitatively evaluate the effects of FDI, energy consumption, and trade openness on CO₂ emissions in Ivory Coast. Research design, data, and methodology: The research uses an econometric framework and the Autoregressive Distributed Lag (ARDL) model to analyze time-series data from 1980 to 2021 between these factors. Results: The analysis revealed that FDI significantly impacts the carbon dioxide emissions, FDI showed a negative impact on carbon emissions in the long-run equilibrium term. Also, energy consumption impacted CO₂ emissions in the long-run equilibrium term. Conclusion: To mitigate the upsurge of CO₂ emissions in the Ivorian context, concrete policy, including enactment and adherence to strict environmental regulations, adoption and prioritization of eco-friendly products and technologies, and investment in renewable energy infrastructure are recommended. The study contributes to the global discussion on sustainable development by offering a model for similar assessments in other emerging nations facing simultaneous economic growth and environmental conservation challenges.

• Structural Engineering and Mechanics
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• v.91 no.2
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• pp.123-133
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• 2024

The assessment of seismic behavior and seismic performance of ageing Sarıyar concrete gravity dam constructed on Sakarya River in Türkiye is the main focus of this paper. For this purpose, the impact of sediment domain, ageing of concrete material under the impact of chemical and mechanical actions, and dam-water-sediment interaction are included in the two-dimensional (2D) finite element (FE) model developed in FORTRAN 90 environment. In the FE model, the dam and age dependent sediment domains are modeled by solid elements, while reservoir domain is modeled by Lagrangian fluid elements. The radiation of reflected waves to the unbounded water domain is modeled by infinite Lagrangian fluid elements, while unbounded sediment domain is modeled by infinite solid elements. The coupled system was assumed to be under the simultaneous impact of Vertical (V) and Horizontal (H) ingredients of 1976 Koyna earthquake and the coupled system was analyzed in Laplace domain by direct method. Due to the deterioration of the concrete, the H and V displacement responses together with the fundamental period of the body, elongate throughout the lifetime and this reduce the seismic safety of the dam. It was deduced that the ageing dam body will not experience major damages under the Koyna earthquake both at the earlier and later ages. Furthermore, at the heel of the dam, the hydrodynamic pressure responses are decreased by rising the sediment domain depth.

• Journal of Radiation Industry
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• v.17 no.4
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• pp.437-442
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• 2023

This study conducted a comparative analysis of dose evaluations for ingestion of animal products based on data from nuclear power plants in the Republic of Korea, using methodologies from the Republic of Korea, 'IAEA TRS-472', and 'CSA N288.1:14'. The research focused on tritium, the most significant constituent among the gaseous and liquid radioactive emissions. The combined evaluation of tritium, in the form of tritiated water (HTO) and organically bound tritium (OBT), yielded results of 1.143 μSv y^-1 for the Republic of Korea, 0.965μSv y^-1 for 'TRS-472', and 0.886μSv y^-1 for 'N288.1:14'. Despite the Republic of Korea's guidelines not considering OBT, the evaluation results for the Republic of Korea were higher compared to other methodologies. This discrepancy was attributed to the unique approach of not considering the moisture content per individual in the calculations of plant and feed concentration in the Republic of Korea and the simultaneous consideration of specific-activity model and transfer model. The study highlights the necessity of developing dose evaluation models tailored to regional characteristics and underscores the importance of including OBT in these evaluations.

• Smart Structures and Systems
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• v.33 no.5
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• pp.375-383
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• 2024

Infrastructure facilities contain various pipe systems, which can be considerably damaged by external loads such as earthquakes. Therefore, structural health monitoring (SHM) and safety assessment of pipes are crucial. Digital twin technology for SHM of pipes is important in the industry. This study proposes a digital twin system that estimates the behavior, stress, and external load of real-scale pipes in real time under simultaneous seismic and external loads using a minimum number of sensors. Vibration tests were performed to construct the digital twin system, and a numerical model was developed that considered the dynamic characteristics of a target pipe. Moreover, a reduced-order modeling technique of a numerical model was applied to enhance its real-time performance. The digital twin system successfully estimated the response of the pipe at all points. Verification of the digital twin system was performed by comparing it with the experimental parameters of a real-scale pipe. The proposed digital twin system can help enhance SHM and system's maintenance.

• Wind and Structures
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• v.4 no.5
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• pp.399-412
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• 2001

Simultaneous pressure and force measurements have been conducted on a stationary box deck section model for two configurations (namely without and with New Jersey traffic barriers) at various angles of incidence. The mean and fluctuating aerodynamic coefficients and pressure coefficients were derived, together with their spectra and with the coherence functions between the pressures and the total aerodynamic forces. The mean aerodynamic coefficients derived from force measurements are first compared with those derived from the integration of the pressures on the deck surface. Correlation between forces and local pressures are determined in order to gain insight on the wind excitation mechanism. The influence of the angle of incidence on the pressure distribution and on the fluctuating forces is also analysed. It is evidenced how particular deck section areas are more responsible for the aerodynamic excitation of the deck.