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Article
Publication date: 14 October 2020

Qiushuang Zhang, Xin Jin, Zhihua Liu, Zhijing Zhang, Yan Fang, Zhongqing Zhang and Yann Ledoux

The modern manufacturing industry has put forward higher requirements for the assembly accuracy of components with the development of the industrial technology. For…

Abstract

Purpose

The modern manufacturing industry has put forward higher requirements for the assembly accuracy of components with the development of the industrial technology. For precision assembly, the traditional assembly process study based on tolerance has had difficulty in meeting these requirements. Hence, the distribution of the form errors must be considered. The registration between the two mating surfaces with form errors determines the parts’ assembly position, and is the basis for the prediction and control of the assembly accuracy. This study aims to provide a new surfaces registration method which takes form errors into consideration.

Design/methodology/approach

This study presents a new registration approach based on the minimum potential energy. A unique set of contact points on mating surfaces that meet the actual conditions can be obtained and the spatial position of the assembled part is calculated.

Findings

The experimental results show that the calculated values are in good agreement with the experimental values. Furthermore, the root mean square error is within 2%, which proves the validity and accuracy of the approach.

Originality/value

This paper provides an effective and new method for precision assembly which takes form errors into consideration. The method can give the optimal solution of the contact points, which is more consistent with the actual assembly situation and provides a basis for predicting assembly accuracy.

Details

Assembly Automation, vol. 40 no. 6
Type: Research Article
ISSN: 0144-5154

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Book part
Publication date: 13 August 2020

Sam McLeod, Carey Curtis and John Stone

Modelling has been a mainstay of conventional planning support tools (PSTs) since the 1960s and is instrumental in transport and land use planning decision-making…

Abstract

Modelling has been a mainstay of conventional planning support tools (PSTs) since the 1960s and is instrumental in transport and land use planning decision-making. Numerous studies have been conducted to model the potential impacts of emerging vehicle automation and sharing technologies. A systematic review of recent modelling studies of autonomous and shared vehicles in the research literature examines the extent of their contribution to ‘smart’ mobility knowledge. The findings suggest a limited knowledge base from which to support future planning. PSTs that can offer more pluralistic, discursive, and transparent methods in order to understand and proactively shape a transition to a planned urban future are also needed.

Details

Shaping Smart Mobility Futures: Governance and Policy Instruments in times of Sustainability Transitions
Type: Book
ISBN: 978-1-83982-651-1

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Article
Publication date: 22 March 2013

S. Abbasbandy and H. Roohani Ghehsareh

In this paper, an analysis is performed to find the solution of a nonlinear ordinary differential equation that appears in a model for MHD viscous flow caused by a shrinking sheet.

Abstract

Purpose

In this paper, an analysis is performed to find the solution of a nonlinear ordinary differential equation that appears in a model for MHD viscous flow caused by a shrinking sheet.

Design/methodology/approach

The cases of two dimensional and axisymmetric shrinking have been discussed. When the sheet is shrinking in the x‐direction, the analytical solutions are obtained by the Hankel‐Padé method. Comparison to exact solutions reveals reliability and high accuracy of the procedure, even in the case of multiple solutions. The case of sheet shrinking in the y‐direction is also considered, with success.

Findings

When the sheet shrinks in the x‐direction, the analytical solutions are obtained by Hankel‐Padé method. Also, when the sheet shrinks in the y‐direction, the obtained results with Hankel‐Padé method are presented.

Practical implications

Comparison to exact solutions reveals reliability and high accuracy of the procedure and convincingly could be used to obtain multiple solutions for certain parameter domains of this case of the governing nonlinear problem.

Originality/value

The numerical solutions are given for both two‐dimensional and axisymmetric shrinking sheets by using Hankel‐Padé method. It is clear that the Hankel‐Padé method is, by far, more simple, straightforward and gives reasonable results for large Hartman numbers and suction parameters.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 23 no. 2
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 18 May 2021

Shah Khalid, Shengli Wu and Fang Zhang

How to provide the most useful papers for searchers is a key issue for academic search engines. A lot of research has been carried out to address this problem. However…

Abstract

Purpose

How to provide the most useful papers for searchers is a key issue for academic search engines. A lot of research has been carried out to address this problem. However, when evaluating the effectiveness of an academic search engine, most of the previous investigations assume that the only concern of the user is the relevancy of the paper to the query. The authors believe that the usefulness of a paper is determined not only by its relevance to the query but also by other aspects including its publication age and impact in the research community. This is vital, especially when a large number of papers are relevant to the query.

Design/methodology/approach

This paper proposes a group of metrics to measure the usefulness of a ranked list of papers. When defining these metrics, three factors, including relevance, publication age and impact, are considered at the same time. To accommodate this, the authors propose a framework to rank papers by a combination of their relevance, publication age and impact scores.

Findings

The framework is evaluated with the ACL (Association for Computational Linguistics Anthology Network) dataset. It demonstrates that the proposed ranking algorithm is effective for improving usefulness when two or three aspects of academic papers are considered at the same time, while the relevance of the retrieved papers is slightly down compared with the relevance-only retrieval.

Originality/value

To the best of the authors’ knowledge, the proposed multi-objective academic search framework is the first of its kind that is proposed and evaluated with a group of new evaluation metrics.

Details

Data Technologies and Applications, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2514-9288

Keywords

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Article
Publication date: 25 February 2014

Xudong Chen, Na Hu, Xue Wang and Xiaofei Tang

The purpose of this study is to examine whether corporate tax avoidance behavior increases firm value in Chinese context. A large number of studies conduct their designs…

Abstract

Purpose

The purpose of this study is to examine whether corporate tax avoidance behavior increases firm value in Chinese context. A large number of studies conduct their designs on the consumption that tax avoidance represents wealth transfer from government to enterprises and therefore enhances firm value. This study argues that, contrast to developed countries, tax avoidance does not necessarily add value to opaque Chinese firms relative to transparent counterparts due to higher agency costs.

Design/methodology/approach

Using a large sample of Chinese listed-firms data for the period 2001-2009 and fixed effects regression model, this study examines the relation between tax avoidance and firm value. A series of robustness checks are conducted to alleviate the concern of endogeneity.

Findings

The authors find that tax avoidance behavior increases agency costs and reduces firm value. The authors further find that information transparency interacts with corporate tax avoidance, moderating the relation between tax avoidance and firm value. Investors in China react negatively to corporate tax avoidance behavior, but this negative reaction could be mitigated by information transparency. The results are robust to a series of alternative treatments, including varied measures, first-order differential approach and 2SLS.

Originality/value

The results suggest that tax avoidance does not necessarily increase firm value, part of gains are encroached by self-serving managers. Moreover, investors in China downplay the significance of tax avoidance, although corporate information transparency could soften their negative tone.

Details

Nankai Business Review International, vol. 5 no. 1
Type: Research Article
ISSN: 2040-8749

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Article
Publication date: 14 January 2021

Fatih Kızılaslan

The purpose of this paper is to investigate the stochastic comparisons of the parallel system with independent heterogeneous Gumbel components and series and parallel…

Abstract

Purpose

The purpose of this paper is to investigate the stochastic comparisons of the parallel system with independent heterogeneous Gumbel components and series and parallel systems with independent heterogeneous truncated Gumbel components in terms of various stochastic orderings.

Design/methodology/approach

The obtained results in this paper are obtained by using the vector majorization methods and results. First, the components of series and parallel systems are heterogeneous and having Gumbel or truncated Gumbel distributions. Second, multiple-outlier truncated Gumbel models are discussed for these systems. Then, the relationship between the systems having Gumbel components and Weibull components are considered. Finally, Monte Carlo simulations are performed to illustrate some obtained results.

Findings

The reversed hazard rate and likelihood ratio orderings are obtained for the parallel system of Gumbel components. Using these results, similar new results are derived for the series system of Weibull components. Stochastic comparisons for the series and parallel systems having truncated Gumbel components are established in terms of hazard rate, likelihood ratio and reversed hazard rate orderings. Some new results are also derived for the series and parallel systems of upper-truncated Weibull components.

Originality/value

To the best of our knowledge thus far, stochastic comparisons of series and parallel systems with Gumbel or truncated Gumble components have not been considered in the literature. Moreover, new results for Weibull and upper-truncated Weibull components are presented based on Gumbel case results.

Details

International Journal of Quality & Reliability Management, vol. 38 no. 8
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 22 November 2019

Minhyung Kang

Continuous knowledge sharing by active users, who are highly active in answering questions, is crucial to the sustenance of social question-and-answer (Q&A) sites. The…

Abstract

Purpose

Continuous knowledge sharing by active users, who are highly active in answering questions, is crucial to the sustenance of social question-and-answer (Q&A) sites. The purpose of this paper is to examine such knowledge sharing considering reason-based elaborate decision and habit-based automated cognitive processes.

Design/methodology/approach

To verify the research hypotheses, survey data on subjective intentions and web-crawled data on objective behavior are utilized. The sample size is 337 with the response rate of 27.2 percent. Negative binomial and hierarchical linear regressions are used given the skewed distribution of the dependent variable (i.e. the number of answers).

Findings

Both elaborate decision (linking satisfaction, intentions and continuance behavior) and automated cognitive processes (linking past and continuance behavior) are significant and substitutable.

Research limitations/implications

By measuring both subjective intentions and objective behavior, it verifies a detailed mechanism linking continuance intentions, past behavior and continuous knowledge sharing. The significant influence of automated cognitive processes implies that online knowledge sharing is habitual for active users.

Practical implications

Understanding that online knowledge sharing is habitual is imperative to maintaining continuous knowledge sharing by active users. Knowledge sharing trends should be monitored to check if the frequency of sharing decreases. Social Q&A sites should intervene to restore knowledge sharing behavior through personalized incentives.

Originality/value

This is the first study utilizing both subjective intentions and objective behavior data in the context of online knowledge sharing. It also introduces habit-based automated cognitive processes to this context. This approach extends the current understanding of continuous online knowledge sharing behavior.

Details

Aslib Journal of Information Management, vol. 72 no. 2
Type: Research Article
ISSN: 2050-3806

Keywords

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Article
Publication date: 1 February 2021

Xiaoying Li, Heng Li, Martin Skitmore and Fan Wang

Neglecting to wear a safety helmet can result in serious injuries at construction sites, but the cause of such unsafe behavior has not been fully understood. Therefore…

Abstract

Purpose

Neglecting to wear a safety helmet can result in serious injuries at construction sites, but the cause of such unsafe behavior has not been fully understood. Therefore, the purpose of this paper is to provide a means of systematically understanding on the causes of non-helmet use behaviors at construction sites.

Design/methodology/approach

This paper utilizes the system dynamics (SD) modeling to portray the construction system works at project, management and individual levels to understand the relative importance of safety climate and productivity pressures. A real-time helmet use behavior tracking system (the Eye on Project (EOP)) is developed to provide an objective record of helmet use practices. Using the data collected from the EOP, the proposed SD model can be calibrated to simulate the influence of safety climate and productivity pressures on the non-helmet use behaviors of construction workers.

Findings

The data collected from 91 responses through the questionnaire survey were utilized to develop the SD model, which consists of two balancing loops and two reinforced loops. The mean absolute percentage error is further used to evaluate the model. The results show that a positive safety climate significantly reduced the rate of non-helmet use behavior.

Originality/value

This study divided the primary contributors of non-helmet use behavior into three levels for the SD model development. The SD model can be used to develop policies for mitigating helmet misuse, which in turn improves the safety performance of construction sites.

Details

Engineering, Construction and Architectural Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0969-9988

Keywords

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Article
Publication date: 19 July 2011

Behrouz Raftari and Ahmet Yildirim

The purpose of this paper is to introduce a new version of the homotopy perturbation method (HPM) for solving the magnetohydrodynamic viscous flow due to a shrinking sheet.

Abstract

Purpose

The purpose of this paper is to introduce a new version of the homotopy perturbation method (HPM) for solving the magnetohydrodynamic viscous flow due to a shrinking sheet.

Design/methodology/approach

Three terms from HPM solution are used.

Findings

The results show that this method is very effective and simple and can be applied to other nonlinear problems.

Research limitations/implications

Comparison between the HPM and homotopy analysis methods for the studied problem shows a remarkable agreement and reveals that the HPM needs less work.

Practical implications

It is suggested that this method should be called HPM with auxiliary parameters. This paper uses two auxiliary parameters, three or more auxiliary parameters could be used for accuracy consideration.

Originality/value

In this paper, a two‐parameter HPM is applied which is useful for finding an approximate analytical solution of MHD viscous flow due to a shrinking sheet.

Details

Engineering Computations, vol. 28 no. 5
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 4 March 2019

Yu Qiu, Baoquan Li, Wuxi Shi and Yimei Chen

The purpose of this paper is to present a visual servo tracking strategy for the wheeled mobile robot, where the unknown feature depth information can be identified…

Abstract

Purpose

The purpose of this paper is to present a visual servo tracking strategy for the wheeled mobile robot, where the unknown feature depth information can be identified simultaneously in the visual servoing process.

Design/methodology/approach

By using reference, desired and current images, system errors are constructed by measurable signals that are obtained by decomposing Euclidean homographies. Subsequently, by taking the advantage of the concurrent learning framework, both historical and current system data are used to construct an adaptive updating mechanism for recovering the unknown feature depth. Then, the kinematic controller is designed for the mobile robot to achieve the visual servo trajectory tracking task. Lyapunov techniques and LaSalle’s invariance principle are used to prove that system errors and the depth estimation error converge to zero synchronously.

Findings

The concurrent learning-based visual servo tracking and identification technology is found to be reliable, accurate and efficient with both simulation and comparative experimental results. Both trajectory tracking and depth estimation errors converge to zero successfully.

Originality/value

On the basis of the concurrent learning framework, an adaptive control strategy is developed for the mobile robot to successfully identify the unknown scene depth while accomplishing the visual servo trajectory tracking task.

Details

Assembly Automation, vol. 39 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

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