Wang Zhizhong, Han Chao, Guosheng Huang, Han Bin and Han Bin
The deposition of particles onto a substrate during the cold spraying (CS) process relies on severe plastic deformation, so there are various micro-defects induced by insufficient…
Abstract
Purpose
The deposition of particles onto a substrate during the cold spraying (CS) process relies on severe plastic deformation, so there are various micro-defects induced by insufficient deformation and severe crushing. To solve the problems, many post-treat techniques have been used to improving the quality by eliminating the micro-defects. This paper aims to help scholars and engineers in this field a better and systematic understand of CS technology by summarizing the post-treatment technologies that have been investigated recently years.
Design/methodology/approach
This review summarizes the types of micro-defects and introduces the effect of micro-defects on the properties of CS coating/additive manufactured, illustrates the post-treatment technologies and its effect on the microstructure and performances, and finally outlooks the future development trends of post-treatments for CS.
Findings
There are significant discoveries in post-treatment technology to change the performance of cold spray deposits. There are also many limitations for post-treatment methods, including improved performance and limitations of use. Thus, there is still a strong requirement for further improvement. Hybrid post-treatment may be a more ideal method, as it can eliminate more defects than a single method. The proposed ultrasonic impact treatment could be an alternative method, as it can densify and flatten the CS deposits.
Originality/value
It is the first time to reveal the influence factors on the performances of CS deposits from the perspective of microdefects, and proposed corresponding well targeted post-treatment methods, which is more instructive for improving the performances of CS deposits.
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Many analysis and design problems in engineering and science involve uncertainty to varying degrees. This paper is concerned with the structural vibration problem involving…
Abstract
Purpose
Many analysis and design problems in engineering and science involve uncertainty to varying degrees. This paper is concerned with the structural vibration problem involving uncertain material or geometric parameters, specified as fuzzy parameters. The requirement is to propagate the parameter uncertainty to the eigenvalues of the structure, specified as fuzzy eigenvalues. However, the usual approach is to transform the fuzzy problem into several interval eigenvalue problems by using the α-cuts method. Solving the interval problem as a generalized interval eigenvalue problem in interval mathematics will produce conservative bounds on the eigenvalues. The purpose of this paper is to investigate strategies to efficiently solve the fuzzy eigenvalue problem.
Design/methodology/approach
Based on the fundamental perturbation principle and vertex theory, an efficient perturbation method is proposed, that gives the exact extrema of the first-order deviation of the structural eigenvalue. The fuzzy eigenvalue approach has also been improved by reusing the interval analysis results from previous α-cuts.
Findings
The proposed method was demonstrated on a simple cantilever beam with a pinned support, and produced very accurate fuzzy eigenvalues. The approach was also demonstrated on the model of a highway bridge with a large number of degrees of freedom.
Originality/value
This proposed Vertex-Perturbation method is more efficient than the standard perturbation method, and more general than interval arithmetic methods requiring the non-negative decomposition of the mass and stiffness matrices. The new increment method produces highly accurate solutions, even when the membership function for the fuzzy eigenvalues is complex.
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K. Primrose and C. Qiu
This paper reviews aspects of the current status of process sensing using electrical impedance process tomography. This new sensor technology offers a unique insight into a wide…
Abstract
This paper reviews aspects of the current status of process sensing using electrical impedance process tomography. This new sensor technology offers a unique insight into a wide range of industrial processes. Applications include a range of processes that feature complex flows and multiple component interactions. The paper provides an overview of hardware and software technology in terms of an instrument currently targeted at pilot trials through a consultancy service. Finally a case study is used to illustrate a typical application in which a detailed insight into an otherwise intractable process has been obtained.
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This research draws on qualitative interviews with primarily lower socioeconomic status (SES) public library internet users to illuminate their perceptions of economic benefits…
Abstract
This research draws on qualitative interviews with primarily lower socioeconomic status (SES) public library internet users to illuminate their perceptions of economic benefits afforded by the internet. This powerful evidence challenges utopian new technological theories. The results from this study allow for the comparison of perspectives from Millennials, Generation Xers, Boomers, and the Silent generation. These results suggest a disconnect between the cultural mythology around the internet as an all-powerful tool and the lived experiences of lower SES respondents. Lower SES participants primarily use the internet to train and educate themselves in areas where they would like to work in the process of applying for jobs using the internet. Participants recognized marginal benefits such as socialization and less burdensome job application processes. However, they struggled to identify significant job-related benefits when comparing applying for jobs online as opposed to applying for jobs in person. With the exception of millennials, all generational groups believed in the economic promise of the internet to make their lives easier given enough time. Millennials, however, challenged the techno-utopianism expressed by other generations. Only millennials recognized the realities of digital inequalities that make techno-utopian outcomes unattainable given broader economic realities for low-SES individuals.
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Katherine M. Johnson, Richard M. Simon, Jessica L. Liddell and Sarah Kington
There has been substantial interest in US cesarean rates, which increased from 5% of deliveries in the 1970s to nearly one-third of births by the mid-2000s. Explanations typically…
Abstract
There has been substantial interest in US cesarean rates, which increased from 5% of deliveries in the 1970s to nearly one-third of births by the mid-2000s. Explanations typically emphasize individual risk factors (e.g., advanced maternal age, increased BMI, and greater desire for control over delivery) of women giving birth, or address institutional factors, such as the medicalization of childbirth and the culture of liability leading physicians to practice defensive medicine. We focus here on another non-medical explanation – childbirth education (CBE). CBE is an important, underexplored mechanism that can shape women’s expectations about labor and birth and potentially lead them to expect, or desire, a cesarean delivery as a normalized outcome. We analyze data from three waves (2002, 2006, 2013) of the Listening to Mothers national survey on US women’s childbearing experiences (n = 3,985). Using logistic regression analysis, we examined both mode of delivery (vaginal versus cesarean), and attitudes about future request for elective cesarean among both primiparous and multiparous women. Despite previous research suggesting that CBE increased the likelihood of vaginal delivery, we find that CBE attendance was not associated with likelihood of vaginal delivery among either primiparous or multiparous women. However, both primiparous and multiparous women who attended CBE classes were significantly more likely to say they would request a future, elective cesarean. Furthermore, these effects were in the opposite direction of effects for natural birth attitudes. Our findings suggest that contemporary CBE classes may be a form of “anticipatory socialization”, potentially priming women’s acceptance of medicalized childbirth.
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Self-Service Technology (SST) is a disruptive technology that has reshaped customer interactions, increased efficiency, and enabled data-driven decision-making. Its impact…
Abstract
Self-Service Technology (SST) is a disruptive technology that has reshaped customer interactions, increased efficiency, and enabled data-driven decision-making. Its impact continues to evolve as technology advances and customer expectations change, making it a key consideration for businesses in a dynamic landscape. This chapter delves into critical findings regarding the adoption and implications of SST in tourism and hospitality. The relevant studies are sourced from the Scopus database. A mixed literature review methodology was employed to review papers. The literature review findings show facets of SST adoption, shedding light on the intricate relationships between consumer readiness variables, context-specific influences, preferred SST features, and psychological attributes. The study reveals consumer preferences, including convenience, ease of use, and speed of service, as primary drivers of the adoption of SST. The bibliometric analysis reveals the scope for developing SST literature in tourism and hospitality. Collaborations among scholars, research and funding institutions could help provide the impetus. Research in SST security, sustainability, and resilience could help enhance the SST literature. Comparative studies evaluating SST's social and economic implications are also suggested.
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Hong Long and Haibin Duan
The purpose of this paper is to present and implement a task allocation method based on game theory for reconnaissance mission planning of UAVs and USVs system.
Abstract
Purpose
The purpose of this paper is to present and implement a task allocation method based on game theory for reconnaissance mission planning of UAVs and USVs system.
Design/methodology/approach
In this paper, the decision-making framework via game theory of mission planning is constructed. The mission planning of UAVs–USVs is transformed into a potential game optimization problem by introducing a minimum weight vertex cover model. The modified population-based game-theoretic optimizer (MPGTO) is used to improve the efficiency of solving this complex multi-constraint assignment problem.
Findings
Several simulations are carried out to exhibit that the proposed algorithm obtains the superiority on quality and efficiency of mission planning solutions to some existing approaches.
Research limitations/implications
Several simulations are carried out to exhibit that the proposed algorithm obtains the superiority on quality and efficiency of mission planning solutions to some existing approaches.
Practical implications
The proposed framework and algorithm are expected to be applied to complex real scenarios with uncertain targets and heterogeneity.
Originality/value
The decision framework via game theory is proposed for the mission planning problem of UAVs–USVs and a MPGTO with swarm evolution, and the adaptive iteration mechanism is presented for ensuring the efficiency and quality of the solution.
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The aim of this study is to offer valuable insights to businesses and facilitate better understanding on transformer-based models (TBMs), which are among the widely employed…
Abstract
Purpose
The aim of this study is to offer valuable insights to businesses and facilitate better understanding on transformer-based models (TBMs), which are among the widely employed generative artificial intelligence (GAI) models, garnering substantial attention due to their ability to process and generate complex data.
Design/methodology/approach
Existing studies on TBMs tend to be limited in scope, either focusing on specific fields or being highly technical. To bridge this gap, this study conducts robust bibliometric analysis to explore the trends across journals, authors, affiliations, countries and research trajectories using science mapping techniques – co-citation, co-words and strategic diagram analysis.
Findings
Identified research gaps encompass the evolution of new closed and open-source TBMs; limited exploration across industries like education and disciplines like marketing; a lack of in-depth exploration on TBMs' adoption in the health sector; scarcity of research on TBMs' ethical considerations and potential TBMs' performance research in diverse applications, like image processing.
Originality/value
The study offers an updated TBMs landscape and proposes a theoretical framework for TBMs' adoption in organizations. Implications for managers and researchers along with suggested research questions to guide future investigations are provided.
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Guodong Sa, Haodong Bai, Zhenyu Liu, Xiaojian Liu and Jianrong Tan
The assembly simulation in tolerance analysis is one of the most important steps for the tolerance design of mechanical products. However, most assembly simulation methods are…
Abstract
Purpose
The assembly simulation in tolerance analysis is one of the most important steps for the tolerance design of mechanical products. However, most assembly simulation methods are based on the rigid body assumption, and those assembly simulation methods considering deformation have a poor efficiency. This paper aims to propose a novel efficient and precise tolerance analysis method based on stable contact to improve the efficiency and reliability of assembly deformation simulation.
Design/methodology/approach
The proposed method comprehensively considers the initial rigid assembly state, the assembly deformation and the stability examination of assembly simulation to improve the reliability of tolerance analysis results. The assembly deformation of mating surfaces was first calculated based on the boundary element method with optimal initial assembly state, then the stability of assembly simulation results was assessed by the density-based spatial clustering of applications with noise algorithm to improve the reliability of tolerance analysis. Finally, combining the small displacement torsor theory, the tolerance scheme was statistically analyzed based on sufficient samples.
Findings
A case study of a guide rail model demonstrated the efficiency and effectiveness of the proposed method.
Research limitations/implications
The present study only considered the form error when generating the skin model shape, and the waviness and the roughness of the matching surface were not considered.
Originality/value
To the best of the authors’ knowledge, the proposed method is original in the assembly simulation considering stable contact, which can effectively ensure the reliability of the assembly simulation while taking into account the computational efficiency.
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The purpose of this paper is to demonstrate the application of the control chart procedure to monitor the characteristics whose profile over time resembles a set of connected line…
Abstract
Purpose
The purpose of this paper is to demonstrate the application of the control chart procedure to monitor the characteristics whose profile over time resembles a set of connected line segments.
Design/methodology/approach
Fit a regression spline model by taking the subgroup average of the characteristic as response variable and time as the explanatory variable. Then monitor the response variable using the regression spline control chart with the fitted model as center line and upper and lower control limits at three standard deviation units of the response variable above and below the center line.
Findings
The proposed chart is successfully deployed to monitor the daily response time profile of a client server of an application support process. The chart ensured the stability of the process as well as detected the assignable cause leading to the slowing down of the server performance.
Practical implications
The methodology can be used to monitor any characteristics whose performance profile over time resembles a set of connected line segments. Some of the examples are the consumption profile of utility providers like power distribution companies, usage profiles of telecom networks, loading profile of airline check-in process, e-commerce websites, etc.
Originality/value
To the best of the author’s knowledge, construction of control charts using regression spline is new. The usage of the control chart to monitor the performance characteristics which exhibits a nonlinear profile over time is also rare.