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Article
Publication date: 14 August 2018

Waqas Khalid and Zaza Nadja Lee Herbert-Hansen

This paper aims to investigate the application of unsupervised machine learning in the international location decision (ILD). This paper addresses the need for a fast…

691

Abstract

Purpose

This paper aims to investigate the application of unsupervised machine learning in the international location decision (ILD). This paper addresses the need for a fast, quantitative and dynamic location decision framework.

Design/methodology/approach

Unsupervised machine learning technique, i.e. k-means clustering, is used to carry out the analysis. In total, 24 different indicators of 94 countries, categorized into five groups, have been used in the analysis. After the clustering, the clusters have been compared and scored to select the feasible countries.

Findings

A new framework is developed based on k-means clustering that can be used in ILD. This method provides a quantitative output without personal subjectivity. The indicators can be easily added or extracted based on the preferences of the decision-makers. Hence, it was found out that the unsupervised machine learning, i.e. k-means clustering, is a fast and flexible decision support framework that can be used in ILD.

Research limitations/implications

Limitations include the generality of selected indicators and clustering algorithm used. The use of other methods and parameters may lead to alternate results.

Originality/value

The framework developed through the research intends to assist the decision-makers in deciding on the facility locations. The framework can be used in international and national domains. It provides a quantitative, fast and flexible way to shortlist the potential locations. Other methods can also be used to further decide on the specific location.

Details

Journal of Global Operations and Strategic Sourcing, vol. 11 no. 3
Type: Research Article
ISSN: 2398-5364

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Article
Publication date: 11 February 2019

Muhammad Waqas Khalid, Junaid Zahid, Muhammad Ahad, Aadil Hameed Shah and Fakhra Ashfaq

The purpose of this paper is to measure the unidimensional and multidimensional inequality in the case of Pakistan and compare their results at the provincial as well as regional…

377

Abstract

Purpose

The purpose of this paper is to measure the unidimensional and multidimensional inequality in the case of Pakistan and compare their results at the provincial as well as regional (urban and rural areas) level. The authors collected data from Pakistan Social and Living Standard Measurement and Household Integrated Economic Survey for fiscal years of 1998–1999 and 2013–2014.

Design/methodology/approach

The authors used Gini coefficient for unidimensional inequality and multidimensional indexing approach of Araar (2009) for multidimensional inequality.

Findings

The findings predicted that unidimensional inequality is relatively high in the urban area due to uneven dissemination of income, but multidimensional inequality is quite high in rural areas because of higher disparities among all dimensions. At the provincial level, Punjab has relatively high-income inequality followed by Sindh, KPK and Baluchistan.

Originality/value

This study is a pioneering effort to compare two time periods to explore unidimensional and multidimensional inequality in all provinces of Pakistan and their representative rural-urban regions by applying Araar and Duclos’s (2009) approach. Further, this study opens some new insights for policy makers.

Details

International Journal of Social Economics, vol. 46 no. 2
Type: Research Article
ISSN: 0306-8293

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Article
Publication date: 1 July 2020

Waqas Khalid, Simon Holst Albrechtsen, Kristoffer Vandrup Sigsgaard, Niels Henrik Mortensen, Kasper Barslund Hansen and Iman Soleymani

Current industry practices illustrate there is no standard method to estimate the number of hours worked on maintenance activities; instead, industry experts use experience to…

464

Abstract

Purpose

Current industry practices illustrate there is no standard method to estimate the number of hours worked on maintenance activities; instead, industry experts use experience to guess maintenance work hours. There is also a gap in the research literature on maintenance work hour estimation. This paper investigates the use of machine-learning algorithms to predict maintenance work hours and proposes a method that utilizes historical preventive maintenance order data to predict maintenance work hours.

Design/methodology/approach

The paper uses the design research methodology utilizing a case study to validate the proposed method.

Findings

The case study analysis confirms that the proposed method is applicable and has the potential to significantly improve work hour prediction accuracy, especially for medium- and long-term work orders. Moreover, the study finds that this method is more accurate and more efficient than conducting estimations based on experience.

Practical implications

The study has major implications for industrial applications. Maintenance-intensive industries such as oil and gas and chemical industries spend a huge portion of their operational expenditures (OPEX) on maintenance. This research will enable them to accurately predict work hour requirements that will help them to avoid unwanted downtime and costs and improve production planning and scheduling.

Originality/value

The proposed method provides new insights into maintenance theory and possesses a huge potential to improve the current maintenance planning practices in the industry.

Details

Journal of Quality in Maintenance Engineering, vol. 27 no. 2
Type: Research Article
ISSN: 1355-2511

Keywords

Available. Open Access. Open Access
Article
Publication date: 15 March 2022

Jingrui Ge, Kristoffer Vandrup Sigsgaard, Julie Krogh Agergaard, Niels Henrik Mortensen, Waqas Khalid and Kasper Barslund Hansen

This paper proposes a heuristic, data-driven approach to the rapid performance evaluation of periodic maintenance on complex production plants. Through grouping, maintenance…

1548

Abstract

Purpose

This paper proposes a heuristic, data-driven approach to the rapid performance evaluation of periodic maintenance on complex production plants. Through grouping, maintenance interval (MI)-based evaluation and performance assessment, potential nonvalue-adding maintenance elements can be identified in the current maintenance structure. The framework reduces management complexity and supports the decision-making process for further maintenance improvement.

Design/methodology/approach

The evaluation framework follows a prescriptive research approach. The framework is structured in three steps, which are further illustrated in the case study. The case study utilizes real-life data to verify the feasibility and effectiveness of the proposed framework.

Findings

Through a case study conducted on 9,538 pieces of equipment from eight offshore oil and gas production platforms, the results show considerable potential for maintenance performance improvement, including up to a 23% reduction in periodic maintenance hours.

Research limitations/implications

The problem of performance evaluation under limited data availability has barely been addressed in the literature on the plant level. The proposed framework aims to provide a quantitative approach to reducing the structural complexity of the periodic maintenance evaluation process and can help maintenance professionals prioritize the focus on maintenance improvement among current strategies.

Originality/value

The proposed framework is especially suitable for initial performance assessment in systems with a complex structure, limited maintenance records and imperfect data, as it reduces management complexity and supports the decision-making process for further maintenance improvement. A similar application has not been identified in the literature.

Details

International Journal of Quality & Reliability Management, vol. 40 no. 3
Type: Research Article
ISSN: 0265-671X

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Article
Publication date: 25 March 2021

Kristoffer Vandrup Sigsgaard, Iman Soleymani, Niels Henrik Mortensen, Waqas Khalid and Kasper Barslund Hansen

This paper aims to investigate how the product architecture and service architecture methodology can be applied in strategic maintenance optimization to reduce the…

243

Abstract

Purpose

This paper aims to investigate how the product architecture and service architecture methodology can be applied in strategic maintenance optimization to reduce the non-value-adding variance of maintenance, decrease the complexity and ensure alignment in maintenance practices in asset-intensive companies. The proposed maintenance architecture model will make it possible to make data-driven decisions regarding how the equipment should be grouped and maintained.

Design/methodology/approach

The research approach is considered exploratory, and the main research strategy is a case study. The maintenance architecture model is developed based on the product architecture methodology and then tested in three different cases in the oil and gas sector.

Findings

Through the maintenance architecture model, it is possible to pair a quantitative data-driven approach with qualitative understanding of dependencies between equipment, maintenance actions and maintenance work management processes, enabling a more holistic and top-down data-driven approach to improving maintenance, than what currently exists in literature.

Originality/value

The proposed model provides a contribution to the understanding of maintenance and is positioned at a detailed level, different from other maintenance improvement models. This model is focused on the main drivers of maintenance that can be utilized at the strategic level compared to optimization of maintenance for individual pieces of equipment.

Details

Journal of Quality in Maintenance Engineering, vol. 28 no. 2
Type: Research Article
ISSN: 1355-2511

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Article
Publication date: 14 June 2019

B. Mahanthesh, Amala S., Gireesha B.J. and I.L. Animasaun

The study of novel exponential heat source (EHS) phenomena across a flowing fluid with the suspension of nanoparticles over a rotating plate in the presence of Hall current and…

73

Abstract

Purpose

The study of novel exponential heat source (EHS) phenomena across a flowing fluid with the suspension of nanoparticles over a rotating plate in the presence of Hall current and chemical reaction has been an open question. Therefore, the purpose of this paper is to investigate the impact of EHS in the transport of nanofluid under the influence of strong magnetic dipole (Hall effect), chemical reaction and temperature-dependent heat source (THS) effects. The Khanafer-Vafai-Lightstone model is used for nanofluid and the thermophysical properties of nanofluid are calculated from mixture theory and phenomenological laws. The simulation of the flow is also carried out using the appropriate values of the empirical shape factor for five different particle shapes (i.e. sphere, hexahedron, tetrahedron, column and lamina).

Design/methodology/approach

Using Laplace transform technique, exact solutions are presented for the governing nonlinear equations. Graphical illustrations are pointed out to represent the impact of involved parameters in a comprehensive way. The numeric data of the density, thermal conductivity, dynamic viscosity, specific heat, Prandtl number and Nusselt number for 20 different nanofluids are presented.

Findings

It is established that the nanofluid enhances the heat transfer rate of the working fluids; the nanoparticles also cause an increase of viscous. The impact of EHS advances the heat transfer characteristics significantly than usual thermal-based heat source (THS).

Originality/value

The effectiveness of EHS phenomena in the dynamics of nanofluid over a rotating plate with Hall current, chemical reaction and THS effects is first time investigated.

Details

Multidiscipline Modeling in Materials and Structures, vol. 15 no. 4
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 28 June 2019

Muhammad Waqas, M. Mudassar Gulzar, Waqar Azeem Khan, Muhammad Ijaz Khan and Niaz B. Khan

This paper aims to elaborate the characteristics of magneto-Maxwell nanoliquid toward moving radiated surface. Flow analysis subject to Darcy–Forchheimer concept is studied…

61

Abstract

Purpose

This paper aims to elaborate the characteristics of magneto-Maxwell nanoliquid toward moving radiated surface. Flow analysis subject to Darcy–Forchheimer concept is studied. Newtonian heat/mass conditions and heat source aspects are taken into account for modeling. Apposite transformations are introduced for non-dimensionalization process.

Design/methodology/approach

Optimal homotopy analysis method is implemented to compute convergent solutions of nonlinear ordinary differential equations.

Findings

Temperature field increments when thermophoresis, heat generation and Brownian movement parameters are increased, whereas reverse situation is noticed for larger Prandtl number. The results also witness that concentration distribution has opposite characteristics for larger thermophoresis and Brownian movement parameters. Furthermore, the presented analysis reduces to traditional Darcy relation in the absence of local inertia coefficient.

Originality/value

As per the authors’ knowledge, no such analysis has been yet reported.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 6 August 2020

Iqra Shahzadi and Nabeela Kausar

The formulation of nonlinear convective non-Newtonian material is reported in this communication. Aspects of thermal radiation and heat source are taken into account for heat…

71

Abstract

Purpose

The formulation of nonlinear convective non-Newtonian material is reported in this communication. Aspects of thermal radiation and heat source are taken into account for heat transport analysis. The novel stratifications (thermal and solutal) and convective conditions are considered simultaneously. The boundary-layer concept is implemented to simplify the complex mathematical expressions.

Design/methodology/approach

The well-known optimal homotopy scheme develops the computations. Optimal values regarding nonzero auxiliary variables are calculated and examined.

Findings

Nonlinear convective flow; Thixotropic non-Newtonian material; Thermal radiation; Heat source; Stratifications and convective conditions; Buongiorno model.

Originality/value

To the best of authors’ knowledge, no such analysis has yet been reported.

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Article
Publication date: 6 August 2019

Muhammad Waqas, Muhammad Mudassar Gulzar, Zeeshan Asghar, Z. Ali, Waqar Azeem Khan and Abdul Sattar Dogonchi

The purpose of this study is to elaborate mixed convection impact in stratified nanofluid flow by convectively heated moving surface. Rheological relations of second-grade fluid…

75

Abstract

Purpose

The purpose of this study is to elaborate mixed convection impact in stratified nanofluid flow by convectively heated moving surface. Rheological relations of second-grade fluid are used for formulation. Magnetic field, heat absorption/generation and convective conditions are considered for modeling.

Design/methodology/approach

Convergent solutions are achieved using homotopy procedure.

Findings

The authors found opposing behavior for radiation and thermal stratification variables against thermal field.

Originality/value

No such analysis has yet been reported.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 6 August 2019

Tasawar Hayat, Ikram Ullah, Muhammad Waqas and Ahmed Alsaedi

The purpose of this study is to study the impacts of exponential space-dependent heat source (ESHS) and thermal radiation in Marangoni convective flow of Cross fluid. The…

97

Abstract

Purpose

The purpose of this study is to study the impacts of exponential space-dependent heat source (ESHS) and thermal radiation in Marangoni convective flow of Cross fluid. The passively controlled model is developed to exhibit the nanoparticles’ concentration on the surface.

Design/methodology/approach

The resulting problem under consideration is tackled by using the shooting approach.

Findings

Temperature field augments with enhancement of the thermophoretic, exponential-based space heat source (ESHS) and radiation parameters, whereas it decays with the increase of the Marangoni ratio parameter.

Originality/value

To the best of the authors’ knowledge, no such analysis has yet been reported.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

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