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Article
Publication date: 4 April 2008

T.Y. Qin, B.J. Zhu and N.A. Noda

This paper aims to calculate the mixed‐mode stress intensity factors (SIFs) of a 3D crack meeting the interface in a bimaterial under shear loading by a hypersingular…

Abstract

Purpose

This paper aims to calculate the mixed‐mode stress intensity factors (SIFs) of a 3D crack meeting the interface in a bimaterial under shear loading by a hypersingular integral equation (HIE) method, And further to assess the accuracy of numerical solutions for the mixed mode SIFs along the crack front.

Design/methodology/approach

A 3D crack modeling is reduced to solving a set of HIEs. Based on the analytical solutions of the singular stress field around the crack front, a numerical method for the HIEs is proposed by a finite‐part integral method, where the displacement discontinuities of the crack surface are approximated by the product of basic density functions and polynomials. Using FORTRAN program, numerical solutions of the mixed‐mode SIFs of some examples are presented.

Findings

The numerical method is proved to be an effective construction technique. The numerical results show that this numerical technique is successful, and the solution precision is satisfied.

Research limitations/implications

This work takes further steps to improve the fundamental systems of HIE for its application in the fields of arbitrary shape crack problems. Propose several techniques for numerical implementation, which could increase the efficiency and accuracy of computation.

Practical implications

Whenever there is a structure containing the 3D crack, the analysis method described in this paper can be utilized to find the critical configurations under which the structure may be most vulnerable. In such cases, the strength predictions would be safer if the crack could be taken into account.

Originality/value

This paper is the first to apply HIE method to analyzing the mixed‐mode crack meeting the interface in 3D dissimilar materials. Numerical solutions of the mixed‐mode SIFs can give the satisfied solution precision.

Details

Engineering Computations, vol. 25 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 13 November 2009

Chia‐Hau Chen, Chao‐Shi Chen, Ernian Pan, Han‐Chou Tseng and Pao‐Shan Yu

The purpose of this paper is to present special nine‐node quadrilateral elements to discretize the un‐cracked boundary and the inclined surface crack in a transversely…

Abstract

Purpose

The purpose of this paper is to present special nine‐node quadrilateral elements to discretize the un‐cracked boundary and the inclined surface crack in a transversely isotropic cuboid under a uniform vertical traction along its top and bottom surfaces by a three‐dimensional (3D) boundary element method (BEM) formulation. The mixed‐mode stress intensity factors (SIFs), KI, KII and KIII, are calculated.

Design/methodology/approach

A 3D dual‐BEM or single‐domain BEM is employed to solve the fracture problems in a linear anisotropic elastic cuboid. The transversely isotropic plane has an arbitrary orientation, and the crack surface is along an inclined plane. The mixed 3D SIFs are evaluated by using the asymptotical relation between the SIFs and the relative crack opening displacements.

Findings

Numerical results show clearly the influence of the material and crack orientations on the mixed‐mode SIFs. For comparison, the mode‐I SIF when a horizontal rectangular crack is embedded entirely within the cuboid is calculated also. It is observed that the SIF values along the crack front are larger when the crack is closer to the surface of the cuboid than those when the crack is far away from the surface.

Research limitations/implications

The FORTRAN program developed is limited to regular surface cracks which can be discretized by the quadrilateral shape function; it is not very efficient and suitable for irregular crack shapes.

Practical implications

The evaluation of the 3D mixed‐mode SIFs in the transversely isotropic material may have direct practical applications. The SIFs have been used in engineering design to obtain the safety factor of the elastic structures.

Originality/value

This is the first time that the special nine‐node quadrilateral shape function has been applied to the boundary containing the crack mouth. The numerical method developed can be applied to the SIF calculation in a finite transversely isotropic cuboid within an inclined surface crack. The computational approach and the results of SIFs are of great value for the modeling and design of anisotropic elastic structures.

Details

Engineering Computations, vol. 26 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

Content available
Article
Publication date: 15 June 2017

Ali Dadashi, Maxim A. Dulebenets, Mihalis M. Golias and Abdolreza Sheikholeslami

The paper aims to propose a new mathematical model for allocation and scheduling of vessels at multiple marine container terminals of the same port, considering the access…

1157

Abstract

Purpose

The paper aims to propose a new mathematical model for allocation and scheduling of vessels at multiple marine container terminals of the same port, considering the access channel depth variations by time of day.

Design/methodology/approach

This paper proposes a new mathematical model for allocation and scheduling of vessels at multiple marine container terminals of the same port, considering the access channel depth variations by time of day. The access channel serves as a gate for vessels entering or leaving the port. During low-depth tidal periods the vessels with deep drafts have to wait until the depth of the access channel reaches the required depth.

Findings

A number of numerical experiments are performed using the operational data collected from Port of Bandar Abbas (Iran). Results demonstrate that the suggested methodology is able to improve the existing port operations and significantly decrease delayed vessel departures.

Originality/value

The contribution of this study to the state of the art is a novel mathematical model for allocation and scheduling of vessels at multiple terminals of the same port, taking into consideration channel depth variations by time of day. To the best of the authors’ knowledge, this is the first continuous berth scheduling linear model that addresses the tidal effects on berth scheduling (both in terms of vessel arrival and departure at/from the berth) at multiple marine container terminals.

Details

Maritime Business Review, vol. 2 no. 2
Type: Research Article
ISSN: 2397-3757

Keywords

Open Access
Article
Publication date: 8 July 2020

Yang Li, Yaochen Qin, Liqun Ma and Ziwu Pan

The ecological environment of the Loess Plateau, China, is extremely fragile under the context of global warming. Over the past two decades, the vegetation of the Loess…

Abstract

Purpose

The ecological environment of the Loess Plateau, China, is extremely fragile under the context of global warming. Over the past two decades, the vegetation of the Loess Plateau has undergone great changes. This paper aims to clarify the response mechanisms of vegetation to climate change, to provide support for the restoration and environmental treatment of vegetation on the Loess Plateau.

Design/methodology/approach

The Savitsky–Golay (S-G) filtering algorithm was used to reconstruct time series of moderate resolution imaging spectroradiometer (MODIS) 13A2 data. Combined with trend analysis and partial correlation analysis, the influence of climate change on the phenology and enhanced vegetation index (EVI) during the growing season was described.

Findings

The S-G filtering algorithm is suitable for EVI reconstruction of the Loess Plateau. The date of start of growing season was found to gradually later along the Southeast–Northwest direction, whereas the date of the end of the growing season showed the opposite pattern and the length of the growing season gradually shortened. Vegetation EVI values decreased gradually from Southeast to Northwest. Vegetation changed significantly and showed clear differentiation according to different topographic factors. Vegetation correlated positively with precipitation from April to July and with temperature from August to November.

Originality/value

This study provides technical support for ecological environmental assessment, restoration of regional vegetation coverage and environmental governance of the Loess Plateau over the past two decades. It also provides theoretical support for the prediction model of vegetation phenology changes based on remote sensing data.

Details

International Journal of Climate Change Strategies and Management, vol. 12 no. 4
Type: Research Article
ISSN: 1756-8692

Keywords

Article
Publication date: 26 April 2022

Wei Jia and J. Alexander Nuetah

Market integration in China is still progressing, while the border effects of trade among regions still exist. The question of whether eliminating or weakening regional…

Abstract

Purpose

Market integration in China is still progressing, while the border effects of trade among regions still exist. The question of whether eliminating or weakening regional bias can promote of China's agricultural trade still remains an important issue. This paper analyzes the impact of regional bias on China's agricultural trade.

Design/methodology/approach

This paper constructs a pure exchange computable general equilibrium model of nine regions and three sectors, and analyzes the impact of regional bias on China's regional agricultural trade; Comparing the differences of regional bias on China's inter-regional and external agricultural trade, the paper especially analyzes the impact of the agricultural imports and exports in eight regions of China.

Findings

The results show that regional bias has had substantial impacts on China's agricultural trade. Elimination of regional bias would therefore increase China's agricultural exports and imports by factors of 1.32 and 1.63, respectively while its agricultural trade deficit would increase by 84%. Inter-regional agricultural trade in China would increase by 3.53 times. With the elimination of regional bias, the Northern coastal, Central and Northwestern regions would have the largest increase in inter-regional agricultural trade. Unlike the Northern coastal region, inter-regional agricultural import in the Central and Northwestern regions tends to be greater than inter-regional agricultural exports.

Originality/value

This paper thus aims to fill existing gap in investigating the impacts of regional bias on China's agricultural trade. Firstly, the model proposed in this paper does not only consider the linkage between the agricultural and non-agricultural sectors, but also the inter-regional agricultural trade linkages of the different regions in China. Secondly, the authors decompose home bias into national and regional biases and assess how regional bias affects agricultural trade of the various regions of China.

Details

China Agricultural Economic Review, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1756-137X

Keywords

Article
Publication date: 13 July 2018

Nadjia Khatir and Safia Nait-bahloul

This study aims to evaluate a new fusion technique of visual and textual clusters of objects from a real multimedia data-driven collection to improve the performance of…

Abstract

Purpose

This study aims to evaluate a new fusion technique of visual and textual clusters of objects from a real multimedia data-driven collection to improve the performance of multimedia applications.

Design/methodology/approach

The authors focused on using multi-criteria for clustering texts and images. The algorithm consists of these steps: first is text representation using the statistical method of weighting, second is image representation using a bag of words feature descriptors methods and finally application of multi-criteria clustering.

Findings

As an application for event detection based on social multimedia data, in particular, Flickr platform. Several experiments were conducted to choose the appropriate parameters for a better scheme of clustering. The new approach achieves better performance when aggregate text clustering is done with image clustering for event detection.

Research limitations/implications

Further researches would be investigated on other social media platforms such as Facebook and Twitter for a generalization of the technique.

Originality/value

This study contributes to multimedia data mining through the new fusion technique of clustering. The technique has its root in such strong field as the field of multi-criteria clustering and decision-making support.

Details

Kybernetes, vol. 47 no. 10
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 29 April 2021

Chaochao Liu, Zhanwen Niu and Qinglin Li

Existing studies suggested that there is a nonlinear relationship between lean production adoption and organizational performance. Lean production adoption is a gradual…

Abstract

Purpose

Existing studies suggested that there is a nonlinear relationship between lean production adoption and organizational performance. Lean production adoption is a gradual process, and the application status of lean tools will affect enterprise performance. The existing literature has insufficiently explored the nonlinear relationship of the lean tools application status on operational performance and environmental performance using the same theoretical framework. A combination approach of interpretative structural modeling (ISM) and Bayesian networks was proposed in this paper, which was used to analyze the complex relationship between lean tools application status with operational and environmental performance.

Design/methodology/approach

ISM was used to analyze the inter-relationship of 17 lean tools identified from the lean literature and construct the lean tools structure model providing reference for building Bayesian network. By calculating the prior and conditional probabilities within the lean tools and between the lean tools with the operational and environmental performance, a Bayesian simulation model was constructed and used to analyze the performance outcomes under different lean tools application status.

Findings

The performance simulation result – representing by the probability of three performance levels as good, average and poor – shows inconsistent changes with the changing of lean tools application status. By comparing the changes of operational performance and environmental performance, it can be found that environmental performance is less sensitive to the change of lean tools application status than operational performance.

Originality/value

Using the integrated ISM–Bayesian network approach, the results indicated a nonlinear relationship between lean tools with operational and environmental performance and provided a reference for the exploration of the nonlinear relationship between lean tools and performance. This research further calls for exploring the S-curve relationship between lean tools and environmental performance.

Article
Publication date: 28 April 2014

Zongduo Wu, Zhi Zong and Lei Sun

– The purpose of this paper is to provide an improved Mie-Grüneisen mixture model to simulate underwater explosion (UNDEX).

362

Abstract

Purpose

The purpose of this paper is to provide an improved Mie-Grüneisen mixture model to simulate underwater explosion (UNDEX).

Design/methodology/approach

By using Mie-Grüneisen equations of state (EOS) to model explosive charge, liquid water and solid structure, the whole fluid field is considered as a multi-phases mixture under Mie-Grüneisen EOS. Then by introducing auxiliary variables in Eulerian model and using mass fraction to establish a diffusion balance, a new improved Mie-Grüneisen mixture model is presented here. For the new reconstructed mixture model, a second order MUSCL scheme with TVD limiter is employed to solve the multi-phase Riemann problem.

Findings

Numerical examples show that the results obtained by Mie-Grüneisen mixture model are quite closed to theoretical and empirical data. The model can be also used in 2-D fluid-structure problem of UNDEX effectively and it is proved that the deformation of structure can be clearly described by mass fraction.

Research limitations/implications

The FVM model based on mass fraction can only describe the motion of compressible material under impact. Material failure or large deformation needs a modification about the EOS or implementations of other models (i.e. FEM model).

Originality/value

An improved non-oscillation Mie-Grüneisen mixture model, which based on mass fraction, is given in the present paper. The present Mie-Grüneisen mixture model provides a simplified and efficient way to simulate UNDEX. The feasibility of this model to simulate the detonation impacts on different mediums, including water and other metal mediums, is tested and verified here. Then the model is applied to the simulation of underwater contact explosion problem. In the simulation, deformation of structure under explosion loads, as well as second shock wave, are studied here.

Details

Engineering Computations, vol. 31 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 2 November 2020

Ali Sarkeshikian, Mohhamadali Shafia, Amir Zakery and Alireza Aliahmadi

In the organizational technology acceptance (TA) decision-making process, stakeholders have many divergence opinions. Sometimes, an opposing stakeholder of a decision can…

Abstract

Purpose

In the organizational technology acceptance (TA) decision-making process, stakeholders have many divergence opinions. Sometimes, an opposing stakeholder of a decision can stop the whole process of decision-making. In such a case, consensus may take a long time followed by a high risk. The purpose of this study is twofold. First, to find the best model with the least prediction error for the simulation of the consensus process in TA decisions. Second, to investigate the time required for the consensus process to yield the TA decision in different scenarios and to propose solutions to reduce the required time in a case study.

Design/methodology/approach

This study uses real-world data containing 1,186 actual observations. Stakeholders are decision-maker agents, and the observations are derived from survey data and used for simulation. Data were obtained from 126 experts in the Iranian rail freight industry. Opinion dynamics theory was used for agent-based simulation of stakeholders’ behavior. The agents interacted over time and their effects on other agents’ opinions were investigated.

Findings

The results illustrate an appropriate opinion changing model, a data-gathering method and a simulation scenario for TA consensus. The suitable model was selected after examining the advantages and disadvantages of and comparing the prediction results for different models with the real database of opinions. To reduce the consensus process time, the results suggest gathering the team members and networking with some leaders as advocators. A large number of advocators with high acceptability and continuous exchanging messages with other agents can improve the acceptance rate and have the most significant impact on other stakeholders’ opinions.

Originality/value

To the best of the authors’ knowledge, previous studies simulate individual TA processes. However, there is a difference between the individual TA and the organizational TA. The organizational TA requires the simultaneous decision-making of different stakeholders. In this research, the organizational TA was investigated.

Article
Publication date: 9 June 2022

Roya Rahimi, Yilmaz Akgunduz and Anil Bilgihan

The current study investigates the impact of the COVID-19 pandemic on the mental health and career perspectives of the future workforce of the tourism and hospitality…

Abstract

Purpose

The current study investigates the impact of the COVID-19 pandemic on the mental health and career perspectives of the future workforce of the tourism and hospitality industry in the UK. The paper is based on theories of emotion and focuses on the interplay role of three factors of fear of COVID-19, depression, and future career anxiety.

Design/methodology/approach

The current research uses a mixed-method approach in two studies to answer the research questions. First, an online questionnaire was distributed among 197 current tourism and hospitality students in the UK. In the second phase through a qualitative approach and 17 semi-structured interviews, a more in-depth approach was taken to understand the impact of the COVID-19 pandemic and the future career perspectives of the respondents.

Findings

Findings reveal a high level of mental health disorders among respondents. The majority of respondents suffer from some sort of mental health conditions/disorders that affect their moods, thinking, and behaviors. The results further show that the fear of COVID-19 causes depression which results in career anxiety.

Practical implications

The findings suggest that the future tourism workforce in the UK is likely to suffer from some sort of mental health disorder that can influence their performances in the workplace. Companies are advised to make adjustments that help to protect the well-being and psychological health of their staff.

Originality/value

Previous studies used a snapshot in time only with a focus on the immediate and short-term effects of the pandemic. In the current study, by taking a long-term impact approach, the authors attempted to understand the psychological impact of the COVID-19 on the future workforce of the tourism industry in the UK and offered practical implications for stakeholders.

Details

Journal of Hospitality and Tourism Insights, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2514-9792

Keywords

1 – 10 of over 3000