In this study, the mechanical buckling of functionally graded material cylindrical shell that is embedded in an outer elastic medium and subjected to combined axial and radial compressive loads is ...investigated. The material properties are assumed to vary smoothly through the shell thickness according to a power law distribution of the volume fraction of constituent materials. Theoretical formulations are presented based on a higher-order shear deformation shell theory (HSDT) considering the transverse shear strains. Using the nonlinear strain–displacement relations of FGMs cylindrical shells, the governing equations are derived. The elastic foundation is modelled by two parameters Pasternak model, which is obtained by adding a shear layer to the Winkler model. The boundary condition is considered to be simply-supported. The novelty of the present work is to achieve the closed-form solutions for the critical mechanical buckling loads of the FGM cylindrical shells surrounded by elastic medium. The effects of shell geometry, the volume fraction exponent, and the foundation parameters on the critical buckling load are investigated. The numerical results reveal that the elastic foundation has significant effect on the critical buckling load.
Suction caissons are cylindrical-shaped foundation elements closed at the top and open at the bottom which are almost completely embedded with their cylindrical part in the soil. The main advantage ...of this foundation compared to other commonly used foundation concepts is its fast, ease, and almost noiseless installation, as well as the effortless removal at the end of the lifetime. Suction caissons supporting three- or four-legged jackets have been employed successfully in several recent offshore windfarm projects around the world. The study presented herein investigates the general suitability of suction caissons in the south china sea at three representative sites. The results show that suction caisson foundations are technically feasible. Sizes can be large and may vary between 13 m to 15 m in diameter and 10 m to 13 m in length, which, however, may reduce noticeably when considering load redistribution in the design, typically done in a FEED and detailed design. The main challenges of suction caisson application are the very soft soil conditions and possible liquefaction potential due to large earthquake events. Although technically feasible, the economic viability of suction caissons needs to be investigated on project-specific basis. For that purpose, the authors provide an overview of general aspects which need to be considered in such an evaluation. This study gives realistic case studies for research and industry in offshore wind farm development.
Objective Foundation pit retaining piles play a vital role in building construction. In order to ensure the safety and stability of foundation pit construction, it is necessary to make in-depth study ...on the stress distribution law of stratum support under the action of foundation pit retaining piles. Method The analysis model and theoretical calculation formula upon the stratum internal support under the action of retaining piles are put forward. Based on the solution method of the uniform stress in the half-arc plane of elasticity, the distribution law of soil internal support stress between piles is deduced and analyzed under different retaining pile distances. The mechanical mechanism of the soil arch between the piles and under the foundation pit retaining piles is revealed. The stratum support stress under the action of the retaining piles is calculated and analyzed with the example of Linjiazhuang Station on Jinan Metro Line 4. Result & Conclusion Under the pile side soil pressure, the support str
Deep learning (DL) research has made remarkable progress in recent years. Natural language processing and image generation have made the leap from computer science journals to open-source communities ...and commercial services. Pre-trained DL models built on massive datasets, also known as foundation models, such as the GPT-3 and BERT, have led the way in democratizing artificial intelligence (AI). However, their potential use as research tools has been overshadowed by fears of how this technology can be misused. Some have argued that AI threatens scholarship, suggesting they should not replace human collaborators. Others have argued that AI creates opportunities, suggesting that AI-human collaborations could speed up research. Taking a constructive stance, this editorial outlines ways to use foundation models to advance science. We argue that DL tools can be used to create realistic experiments and make specific types of quantitative studies feasible or safer with synthetic rather than real data. All in all, we posit that the use of generative AI and foundation models as a tool in information systems research is in very early stages. Still, if we proceed cautiously and develop clear guidelines for using foundation models and generative AI, their benefits for science and scholarship far outweigh their risks.
•The editorial discusses the opportunities and challenges of using foundation models.•Generative AI can be used to develop data or content for various forms of studies.•Generative AI content and data can be used to avoid privacy concerns.•A process for safely using generated content in research is proposed.
•A complete analytical model of beam resting on multi-layered elastic foundation is proposed for the first time.•The present model is developed based on the symplectic elasticity.•Generalized ...six-parameter foundation model is proposed for multi-layered foundation.•Layer-discretizing technique for higher accuracy in foundation response can be conducted based on the developed methodology in the model.
Attributable to their complexity the problems of a beam resting on a multi-layered foundation (BMF) have not gain sufficient attention from researchers compared to those of a beam placing on a single-layered foundation (BSF). Although they are as significantly important in engineering disciplines, few scientific articles regarding BMF were published so far. Thus, this paper is aimed to establish an effective analytical approach to study a Timoshenko beam on a multi-layered elastic foundation. Comprehensive types of beam/foundation as well as a variety of load conditions are presented. The mathematical model of BMF is developed based on a symplectic dual equation, which is derived from the Hamiltonian principle associated with the Legendre transformation. The vertical deformations of the multi-layered foundation are assumed as the linear combination of the products of the vertical deformation at layer interface and the corresponding transverse distribution function. Variational method and iterative technique are utilized to formulate and solve for the distribution functions. Discretizing each layer in the foundation into sublayers is proposed to obtain more accurate deformation and stress responses. Compared to the finite element method, this article provides a highly reliable and effective analytical approach to investigate BMF problems.
Display omitted
•This paper explores the micro-foundations of global business incubation by examining how stakeholders influence the development of technology business incubation platforms in china and the UK.•We ...articulate how stakeholder engagement varies over time by engaging with entrepreneurs in the form of collaborative partnerships.•Different types of stakeholders play different roles in deploying three distinctive mechanisms—namely, initiating, orchestrating and partaking—during the developmental trajectory involved in the launch and development of entrepreneurial ventures.•From a micro-foundational perspective, we highlight the agency-orientated activities championed by entrepreneurial organizations situated in global strategic partnership contexts.
This paper explores the micro-foundations of global business incubation by examining how stakeholders influence the development of technology business incubation platforms and entrepreneurial activities in the context of strategic entrepreneurial partnerships. By drawing from stakeholder theory, we propose a conceptual framework that articulates how stakeholder engagement—including local governments, universities, and business support organizations—varies over time by engaging with entrepreneurs in the form of collaborative partnerships. This paper investigates two technology business incubators in China and the UK through a comparative lens and offers empirical evidence to support its theoretical argumentation. From a temporal perspective, we found that different types of stakeholders play different roles in deploying three distinctive mechanisms—namely, initiating, orchestrating and partaking—during the developmental trajectory involved in the launch and development of entrepreneurial ventures. Importantly, from a micro-foundational perspective, we highlight the agency-orientated activities championed by entrepreneurial organizations situated in global strategic partnership contexts.
Abstract Objective To make scientifically sound and practical recommendations for daily sleep duration across the life span. Methods The National Sleep Foundation convened a multidisciplinary expert ...panel (“Panel”) with broad representation from leading stakeholder organizations. The Panel evaluated the latest scientific evidence and participated in a formal consensus and voting process. Then, the RAND/UCLA Appropriateness Method was used to formulate sleep duration recommendations. Results The Panel made sleep duration recommendations for 9 age groups. Sleep duration ranges, expressed as hours of sleep per day, were designated as recommended, may be appropriate , or not recommended . Recommended sleep durations are as follows: 14-17 hours for newborns, 12-15 hours for infants, 11-14 hours for toddlers, 10-13 hours for preschoolers, 9-11 hours for school-aged children, and 8-10 hours for teenagers. Seven to 9 hours is recommended for young adults and adults, and 7-8 hours of sleep is recommended for older adults. The self-designated basis for duration selection and critical discussions are also provided. Conclusions Consensus for sleep duration recommendations was reached for specific age groupings. Consensus using a multidisciplinary expert Panel lends robust credibility to the results. Finally, limitations and caveats of these recommendations are discussed.
Due to the low precision in the prediction of foundation pit settlement of the traditional grey Verhulst model, the optimized discrete grey Verhulst model was selected as the preferred method in ...settlement prediction. In this work, a combination forecasting model was proposed based on the optimized grey discrete Verhulst model and BP neural network to better predict the foundation pit settlement. For application of the proposed models, the settlement of the foundation pit of a building in Longcheng Industrial Park in Shenzhen, China was predicted. The optimized discrete grey Verhulst model was established on reciprocal transformation of the original data sequence by discretization method. In the modified forecasting model, the predicted result of the optimized grey discrete Verhulst model was used as the input sample value of the BP neural network model and the measured value was used as the target sample value of the neural network model. Furthermore, the neural network was trained to target accuracy and made predict. The maximum number of epochs was 5 × 10
5
. The target error of training is set as 1E−6. The prediction results of these grey models were compared with the prediction results of Kalman filter model. And the two-way verification was carried out to verify that these grey models were suitable for the settlement prediction of the foundation pit. The predicted results of optimized grey discrete Verhulst–BP neural network model display that the average relative errors and mean square errors of the settlement predicted value of two monitoring points
CJ12
and
CJ23
were 0.0967%, 0.0002 and 0.0795%, 0.00006, respectively. The results revealed that the optimized grey discrete Verhulst–BP neural network model combined the advantages of the two models to achieve complementary advantages, which has higher prediction accuracy and stability. Comparison between the calculated results and the measured ones indicate that the proposed model could satisfactorily describe the settlement monitoring projects.
PDF
