• Computers and Concrete
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• v.24 no.4
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• pp.347-367
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• 2019

This work investigates the effect of Winkler/Pasternak/Kerr foundation and porosity on dynamic behavior of FG plates using a simple quasi-3D hyperbolic theory. Four different patterns of porosity variations are considered in this study. The used quasi-3D hyperbolic theory is simple and easy to apply because it considers only four-unknown variables to determine the four coupled vibration responses (axial-shear-flexion-stretching). A detailed parametric study is established to evaluate the influences of gradient index, porosity parameter, stiffness of foundation parameters, mode numbers, and geometry on the natural frequencies of imperfect FG plates.

• Computers and Concrete
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• v.27 no.1
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• pp.73-83
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• 2021

In this article, the mechanical buckling analysis of simply-supported functionally graded plates is carried out using a higher shear deformation theory (HSDT) in conjunction with the stress function method. The proposed formulation is variationally consistent, does not use a shear correction factor and gives rise to a variation of transverse shear stress such that the transverse shear stresses vary parabolically through the thickness satisfying the surface conditions without stress of shear. The properties of the plate are supposed to vary across the thickness according to a simple power law variation in terms of volume fraction of the constituents of the material. Numerical results are obtained to study the influences of the power law index and the geometric ratio on the critical buckling load.

• International Journal of Computer Science & Network Security
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• v.21 no.2
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• pp.21-39
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• 2021

The acceptance of smartphone applications in the learning field is one of the most significant challenges for higher education institutions in Saudi Arabia. These institutions serve large and varied sectors of society and have a tremendous impact on the knowledge gained by student segments at various ages. M-learning is of great importance because it provides access to learning through a wide range of mobile networks and allows students to learn at any time and in any place. There is a lack of quality requirements for M-learning applications in Saudi societies partly because of mandates for high levels of privacy and gender segregation in education (Garg, 2013; Sarrab et al., 2014). According to the Saudi Arabian education ministry policy, gender segregation in education reflects the country's religious and traditional values (Ministry of Education, 2013, No. 155). The opportunity of many applications would help the Saudi target audience more easily accept M-learning applications and expand their knowledge while maintaining government policy related to religious values and gender segregation in the educational environment. In addition, students can share information through the online framework without breaking religious restrictions. This study uses a quantitative perspective to focus on defining the technical aspects and learning requirements for distributing knowledge among students within the digital environment. Additionally, the framework of the unified theory of acceptance and use of technology (UTAUT) is used to modify new constructs, called application quality requirements, that consist of quality requirements for systems, information, and interfaces.

• Steel and Composite Structures
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• v.38 no.1
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• pp.1-15
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• 2021

In this paper, a higher order shear deformation theory for bending analysis of functionally graded plates resting on Pasternak foundation and under various boundary conditions is exposed. The proposed theory is based on the assumption that porosities can be produced within functionally graded plate which may lead to decline in strength of materials. In this research a novel distribution of porosity according to the thickness of FG plate are supposing. Governing equations of the present theory are derived by employing the virtual work principle, and the closed-form solutions of functionally graded plates have been obtained using Navier solution. Numerical results for deflections and stresses of several types of boundary conditions are presented. The exactitude of the present study is confirmed by comparing the obtained results with those available in the literature. The effects of porosity parameter, slenderness ratio, foundation parameters, power law index and boundary condition types on the deflections and stresses are presented.

• Journal of applied mathematics & informatics
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• v.39 no.1_2
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• pp.13-29
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• 2021

For a graph G = (V, E), a vertex coloring (or, simply, a coloring) of G is a function C : V (G) → {1, 2, …, k} (using the non-negative integers {1, 2, …, k} as colors). We say that a coloring of a graph G is injective if for every vertex v ∈ V (G), all the neighbors of v are assigned with distinct colors. The injective chromatic number χi(G) of a graph G is the least k such that there is an injective k-coloring [6]. In this paper, we study a natural variation of the injective coloring problem: coloring the edges of a graph under the same constraints (alternatively, to investigate the injective chromatic number of line graphs), we define the k- injective edge coloring of a graph G as a mapping C : E(G) → {1, 2, …, k}, such that for every edge e ∈ E(G), all the neighbors edges of e are assigned with distinct colors. The injective chromatic index χ′in(G) of G is the least positive integer k such that G has k- injective edge coloring, exact values of the injective chromatic index of different families of graphs are obtained, some related results and bounds are established. Finally, we define the injective clique number ωin and state a conjecture, that, for any graph G, ωin ≤ χ′in(G) ≤ ωin + 2.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.254-260
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• 2022

The purpose of this study was to identify the obstacles facing gifted students with learning disabilities (GSLDs) from the point of view of their teachers in the Makkah region and to find suggested solutions to overcome these obstacles. The study covered Makkah, Jeddah and Taif and used semi-structured interviews which included open-ended questions. The study findings indicated that there were several educational obstacles including the absence of adapted courses or specialized teachers for GSLDs category and the insufficient time for the students to express their talents. According to the findings, there were also societal obstacles including the society's failure to expect the presence of talents along with disabilities, or its denial or rejection of their talents in addition to ridiculing them. The findings also confirmed the existence of administrative obstacles including the lack of community partnership. There were also family obstacles such as the family's lack of encouragement for the students, and ignorance of the nature of GSLDs. The study came up with a number of solutions and proposals related to awareness, educational institutions, education and competitions for talented people with learning disabilities.

• Structural Engineering and Mechanics
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• v.83 no.5
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• pp.617-625
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• 2022

A novel three variable refined plate theory (TVRPT) is developed in this article for laminated composite plates for the first time. The theory takes into account the nonlinear variation of transverse shear deformations, and satisfies the boundary conditions of zero traction on the plate surfaces without considering the "shear correction factor". The important characteristic of this new kinematic is that the unknowns numbers is only 3 as is employed in "classical plate theory" (CPT). The numerical results of the current theory are compared with 3D-elasticity solutions and the calculations of "first order theories" and other higher order models found in the literature.

• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.169-186
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• 2023

The research aimed to identify the effectiveness of an educational program using 3D glasses as a technological innovation on academic achievement and attitude towards elearning in science in the preparatory stage. The research relied on the analytical descriptive approach and the semi-experimental approach. The research tools were the achievement test and the scale of attitude towards e-learning. An educational program was designed and produced using 3D glasses. The study sample consisted of 60 students from the second grade in the preparatory stage at the Rural Jeddah School. The research concluded to the following results: There was a satistically sigificant difference at the level of sig. (0.05) among the -mean scores of the experiemtal and control group students in the post assessment atthe level of achievement in favor of the experiemental group and therewas a satistically sigificant difference at the level of sig. (0.05) among mean scores of the experiemtal and control group students in the post assessment at the level of attitude towards e-learning in favor of the experiemental group. And it was found that the positive effect of the 3D educational program for improving the level of achievement and the attitude towards e-learning for the students. The program allowed the experimental group students to practice self-learning, interaction, and achievement according to the individual differences among them.

• International Journal of High-Rise Buildings
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• v.13 no.1
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• pp.11-32
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• 2024

In recent years, urban landscapes across the globe have undergone a remarkable transformation marked by a substantial surge in skyscraper development. This paper offers a comprehensive overview of the contemporary evolution of tall buildings, with a particular emphasis on the Middle East. It surveys tall building development in the ten "tallest cities" across the Middle East, including Dubai, Doha, Abu Dhabi, Sharjah, Riyadh, Manama, Tel Aviv, Kuwait, Mecca, and Jeddah, while listing the tallest ten buildings in each city. The focus sharpens on Dubai, UAE, serving as a compelling case study that vividly illustrates the city's swift metamorphosis from a low-rise to a high-rise urban center. Through meticulous examination, the study aims to unveil the key drivers propelling the construction of the world's tallest buildings, asserting that globalization factors play a pivotal role in fostering this transformative shift. The impetus behind this surge is rooted in the aspiration to project a modern and progressive image on the global stage. With Dubai at the forefront, cities in the Middle East strategically endeavor to reshape their international image and reclaim historical grandeur through ambitious skyscraper projects.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.1
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• pp.63-69
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• 2023

Methods: Patients who underwent cholecystectomy were classified into two groups according to their GBWT status (GBWT+ vs. GBWT-). Results: Among 1,211 patients who underwent cholecystectomy, GBWT+ was seen in 177 (14.6%). The GBWT+ group was significantly older with more males, higher ASA score, higher alkaline phosphatase level, higher international normalized ratio, and lower albumin level than the GBWT- group. On ultrasound, GBWT+ patients had larger stone size, more pericholecystic fluid, more common bile duct stone, and more biliary pancreatitis. Compared with the GBWT- group, the GBWT+ group had more urgent surgeries (12.4% vs. 3.2%, p = 0.001), higher conversion rate (4.5% vs. 0.3%, p = 0.001), prolonged operative time (67 ± 38 vs. 54 ± 29 min; p = 0.001), more bleeding (3.4% vs. 0.5%, p = 0.002), and more need of drain (21.5% vs. 10.5%, p = 0.001). By multivariate analysis, factors associated with increased length of hospital stay were GBWT+ (HR: 1.97, 95% CI: 1.19-3.25, p = 0.008), urgent surgery (HR: 10.2, 95% CI: 4.07-25.92, p = 0.001), prolonged surgery (HR: 1.01, 95% CI: 1.0-1.02, p = 0.001), and postoperative drain (HR: 11.3, 95% CI: 6.40-20.0, p = 0.001). Conclusions: Variables such as GBWT ≥ 5 mm, urgent prolonged operation, and postoperative drains are independent predictors of extended hospital stay. GBWT+ patients are twice likely to stay in hospital for more than 72 hours and more prone to develop complications than GBWT- patients.