• Steel and Composite Structures
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• 재36권6호
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• pp.689-702
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• 2020

The current study deals with the size-dependent free vibration analysis of graphene nanoplatelets (GNPs) reinforced polymer nanocomposite plates resting on Pasternak elastic foundation containing different boundary conditions. Based on a four variable refined shear deformation plate theory, which considers shear deformation effect, in conjunction with the Eringen nonlocal elasticity theory, which contains size-dependency inside nanostructures, the equations of motion are established through Hamilton's principle. Moreover, the effective material properties are estimated via the Halpin-Tsai model as well as the rule of mixture. Galerkin's mathematical formulation is utilized to solve the equations of motion for the vibrational problem with different boundary conditions. Parametrical examples demonstrate the influences of nonlocal parameter, total number of layers, weight fraction and geometry of GNPs, elastic foundation parameter, and boundary conditions on the frequency characteristic of the GNPs reinforced nanoplates in detail.

• 한국염색가공학회지
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• 제21권3호
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• pp.26-36
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• 2009

The objective of this study is to investigate the elution characteristics of the partial dispositioned hollow nylon filament and the mechanical properties of the eluted fabrics according to the weight reduction conditions. For this purpose, the partial dispositioned nylon/PET composite filament, SDY 70d/48f was prepared, and warp beam was also prepared on the sizing machine using these yarns. Four kinds of woven fabrics were designed with different warp and weft densities and these fabrics specimens were eluted with weight reduction conditions of two kinds of NaOH concentration (30, 40g/l), three kinds of weight reduction temperature (50, 60, $85^{\circ}C$) and two kinds of weight reduction time (30, 60min). The eluting rates of these fabrics specimens were analysed with various weight reduction conditions. The eluting characteristics of these fabrics were discussed with the cross-section of nylon hollow filament measures by SEM. Finally, the mechanical properties of the partial dispositioned hollow nylon fabrics were measured and discussed with various weight reduction conditions.

• 한국안전학회지
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• 제28권4호
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• pp.8-13
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• 2013

Fatigue crack growth tests were conducted on urban railway wheel steel under mode I and mixed-mode conditions. Fatigue crack growth rates were evaluated in terms of equivalent stress intensity factor ranges, using both the extended and projected crack lengths. The equivalent stress intensity factor range with the growth rate results obtained under mode I loading conditions can be used to predict the crack growth rate under mixed-mode loading conditions. Extended crack length rather than projected crack length is appropriate for the prediction of the crack growth rate under the mixed-mode loading conditions.

• 산경연구논집
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• 제13권11호
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• pp.1-10
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• 2022

Purpose: This study measures the influence of facilitating conditions on employees' attitudes towards the adoption of big data analytics by selected medical aid organizations in Durban. In the health care sector, there are various sources of big data such as patients' medical records, medical examination results, and pharmacy prescriptions. Several organizations take the benefits of big data to improve their performance and productivity. Research design, data, and methodology: A survey research strategy was conducted on some selected medical aid organizations. A non-probability sampling and the purposive sampling technique were adopted in this study. The collected data was analysed using version 23 of Statistical Package for Social Science (SPSS) Results: the results show that the "facilitating conditions" have a positive influence on employees' attitudes in the adoption of big data analytics Conclusions: The findings of this study provide empirical and scientific contributions of the facilitating conditions issues regarding employee attitudes toward big data analytics adoption. The findings of this study will add to the body of knowledge in this field and raise awareness, which will spur further research, particularly in developing countries.

• Structural Engineering and Mechanics
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• 제4권2호
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• pp.191-202
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• 1996

This paper presents a construction of adaptive boundary element for the problem with mixed boundary conditions such as heat transfer between heated body surface and surrounding medium. The scheme is based on the sample point error analysis and on the extended error indicator, proposed earlier by the authors for the potential and elastostatic problems, and extended successfully to multidomain and thermoelastic analyses. Since the field variable is connected with its derivative on the boundary, their errors are also interconnected by the specified condition. The extended error indicator on each boundary element is modified to meet with the situation. Two numerical examples are shown to indicate the differences due to the prescribed boundary conditions.

• KSTLE International Journal
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• 제10권1_2호
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• pp.6-12
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• 2009

In this study, the effect of oil supply conditions on the dynamic performance of a hydrodynamic journal bearing is analyzed numerically. Axial length, circumferential length and location of oil grooves are considered as oil supply conditions. The perturbation equations of the perturbed film contents are obtained by applying Elrod's universal equation implementing JFO film rupture / reformation boundary conditions to Lund's infinitesimal perturbation method. The dynamic coefficients of a hydrodynamic journal bearing are calculated by solving the perturbation equations, and the linear stability analysis is carried out by using those for a variety of oil supply conditions.

• Journal of applied mathematics & informatics
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• 제28권3_4호
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• pp.597-610
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• 2010

For a class of nonlinear bilevel programming problems in which the follower's problem is linear, the paper develops a genetic algorithm based on the optimality conditions of linear programming. At first, we denote an individual by selecting a base of the follower's linear programming, and use the optimality conditions given in the simplex method to denote the follower's solution functions. Then, the follower's problem and variables are replaced by these optimality conditions and the solution functions, which makes the original bilevel programming become a single-level one only including the leader's variables. At last, the single-level problem is solved by using some classical optimization techniques, and its objective value is regarded as the fitness of the individual. The numerical results illustrate that the proposed algorithm is efficient and stable.

• Structural Engineering and Mechanics
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• 제10권2호
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• pp.93-110
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• 2000

An alternative interpretation of the completeness requirements for the higher order elements is presented. Apart from the familiar condition, $\sum_iN_i=1$, some additional conditions to be satisfied by the shape functions of higher order elements are identified. Elements with their geometry in the natural form, i.e., without any geometrical distortion, satisfy most of these additional conditions inherently. However, the geometrically distorted elements satisfy only fewer conditions. The practical implications of the satisfaction or non-satisfaction of these additional conditions are investigated with respect to a 3-node bar element, and 8- and 9-node quadrilateral elements. The results suggest that non-satisfaction of these additional conditions results in poorer performance of the element when the element is geometrically distorted. Based on the new interpretation of completeness requirements, a 3-node element and an 8-node rectangular element that are insensitive to mid-node distortion under a quadratic displacement field have been developed.

• Nonlinear Functional Analysis and Applications
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• 제29권2호
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• pp.461-475
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• 2024

The concept of an extension α-F-contraction and it's modified counterpart represents an advancement in the theory of metric space contractions. Through our study of the contraction principles and it's relationship to extension and modified extension, we found different conditions somewhat lengthy. In our paper, we create a development of the conditions for the extension of α-F-contraction and a modified α-F-contraction by reducing the conditions and make them easier. Our propose conditions are notably simple and effective. They serve as the foundation for proving theorems and solving examples that belong to our study. Moreover, they have remarkable significance in the condition of mathematical analysis and problem-solving. Thus, we find that these new conditions that we mention in the definitions achieve what is require and through them, we choose λ = 1 and we choose λ ∈ (0, 1) to clarify our ideas.

• Current Photovoltaic Research
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• 제6권2호
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• pp.62-67
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• 2018

Multi-wire busbar-type bifacial n-type Si solar cells have been used for the fabrication of monofacial and bifacial photovoltaic (PV) module, where bifacial module was equipped with transparent backsheet while monofacial module was prepared using white backsheet. The comparison of six-day accumulated power production obtained from outdoor test under gray cement ground conditions using 60cell monofacial and bifacial PV modules suggested the bifacial gain of over 20% could be achieved. Furthermore, the outdoor evaluation tests of bifacial modules with different ground conditions such as cement (reference), green paint, white paint and green artificial grass, were performed. It turned out white paint showed the best albedo and thus the highest power production, while green paint and artificial grass showed less power generation than cement ground.