The purpose of this paper is to find the best solver for parallelizing particle methods based on solving Pressure Poisson Equation (PPE) by taking Moving Particle Semi-Implicit…
Abstract
Purpose
The purpose of this paper is to find the best solver for parallelizing particle methods based on solving Pressure Poisson Equation (PPE) by taking Moving Particle Semi-Implicit (MPS) method as an example because the solution for PPE is usually the most time-consuming part difficult to parallelize.
Design/methodology/approach
To find the best solver, the authors compare six Krylov solvers, namely, Conjugate Gradient method (CG), Scaled Conjugate Gradient method (SCG), Bi-Conjugate Gradient Stabilized (BiCGStab) method, Conjugate Gradient Squared (CGS) method with Symmetric Lanczos Algorithm (SLA) method and Incomplete Cholesky Conjugate Gradient method (ICCG) in terms of convergence, time consumption, parallel efficiency and memory consumption for the semi-implicit particle method. The MPS method is parallelized by the hybrid Open Multi-Processing (OpenMP)/Message Passing Interface (MPI) model. The dam-break flow and channel flow simulations are used to evaluate the performance of different solvers.
Findings
It is found that CG converges stably, runs fastest in the serial way, uses the least memory and has highest OpenMP parallel efficiency, but its MPI parallel efficiency is lower than SLA because SLA requires less synchronization than CG.
Originality/value
With all these criteria considered and weighed, the recommended parallel solver for the MPS method is CG.
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L. Dam and B.N. Petkova
Multinationals are increasingly pressured by stakeholders to commit to environmental sustainability that exceeds their own firm borders. As a result, multinationals have started…
Abstract
Purpose
Multinationals are increasingly pressured by stakeholders to commit to environmental sustainability that exceeds their own firm borders. As a result, multinationals have started to commit to environmental supply chain sustainability programs (ESCSPs). However, little is known about whether such commitment is rewarded or punished by financial markets, and if the stock price reaction differs depending on the type of firm that commits to such a program. This paper aims to discuss these issues.
Design/methodology/approach
The authors conduct an event study followed by two-equation Heckman modeling, using a sample of 66 multinationals that committed to the ESCSP of the Carbon Disclosure Project (CDP).
Findings
It was found that generally there is a marginally significant negative stock price reaction to announcement of participation in this ESCSP (i.e. −0.8 percent, p<0.10). However, the authors argue and show that firms in industries that have historically faced more pressure from consumers are less likely to announce their participation. If one corrects for this industry bias, then the negative stock price reaction is even more pronounced (i.e. −3.2 percent, p<0.05).
Research limitations/implications
Using objective data, the study provides insights into the shareholder wealth effects of firms that commit to the ESCSP of the CDP. As such, the sample does not cover firms that set up their own ESCSPs.
Practical implications
The paper is valuable for practitioners and investors who are interested in finding out if participation in ESCSPs is financially attractive, and for (governmental) policy makers who may want to be assured that there is sufficient incentive for firms to pursue environmental supply chain sustainability.
Originality/value
This is the first paper that captures how financial markets react to announcements of ESCSPs.
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Lorri J. Santamaría, Andrés P. Santamaría, Melinda Webber and Sharona Jayavant
This chapter features leadership practices sourced from more than 25 Māori (Indigenous) and non-Māori women in Aotearoa New Zealand (NZ) who are leaders of schools where…
Abstract
This chapter features leadership practices sourced from more than 25 Māori (Indigenous) and non-Māori women in Aotearoa New Zealand (NZ) who are leaders of schools where Māori-based best practices benefit Māori and other systemically underserved students (e.g., children in poverty, Pasifika [i.e., Samoan, Fijian, Cook Island, Tongan] descent). This study, by Auckland-based scholars of North American, Indigenous, and international descent (Māori, Latino, African American/American Indian [Choctaw], and East Indian immigrant) examines the expression of Applied Critical Leadership (ACL) in women leaders participating in Te Ara Hou or The Māori Achievement Collaboratives (MACS), an initiative aimed at challenging status quo leadership practices, which result in persistent inequitable educational outcomes for Māori learners. Based on an analysis of data, women leaders demonstrated leadership that mirrored and exemplified leadership practices suggested in ACL research. Qualitative stories evidenced from women leaders in MACS provided exemplars of authentic and appropriate pathways for implementing effective leadership practices aimed at promoting whānau (family), iwi (tribe), and hapū (subtribe) engagement, context-specific pedagogy, tikanga (cultural protocols), and whanaungatanga (relationships) within mainstream school contexts. These findings affirm and validate research on the benefits of critical and culturally appropriate leadership around the world in a number of diverse contexts.
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This chapter focuses on the importance of reflection for teacher growth. Through two case studies, life examples are given on the significance of embedding critical reflection…
Abstract
This chapter focuses on the importance of reflection for teacher growth. Through two case studies, life examples are given on the significance of embedding critical reflection already in initial teacher education. Teachers’ life stories were collected through in-depth “rivers of life” interviews. The interplay between teachers’ awareness of their life story and their subjective theories, and how this impacts on the teachers’ attitude and openness to change are illustrated. The findings indicate that reflecting on one’s life stories may play an important role in forming teachers’ beliefs and pedagogical practices and hence their attitudes to change. The findings also suggest that a culture fostering close reflective collaboration and collegial support plays an important part in developing teachers’ perspectives of their roles and that of their learners. The findings reveal that presuming a single work culture in a school may be an oversimplification as several subcultures may be at play in one institution and even within the same subject area. The findings should have implications for approaches and procedures in teacher education and for the induction of novice teachers. Although the case studies reported here are based on Icelandic data, they should offer insights and have relevance for teacher education and teacher growth not only in Iceland but also in other countries as well.
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Adetunji Kamoli, Razali Adul Hamid and Syamsul Hendra Bin Mahmud
Under-reporting of an occupational accident is commonly found at both organisational and individual levels. It interferes with the reality of health and safety in organisations…
Abstract
Under-reporting of an occupational accident is commonly found at both organisational and individual levels. It interferes with the reality of health and safety in organisations and countries. It also hinders the ability to identify trends, recognise priorities, improve strategies, and allocation of resources for accident prevention. This study examined the reasons for the under-reporting of occupational accidents at the organisation level in the Nigerian construction industry. A review of the literature was conducted on the under-reporting of occupational accidents. Thereafter, a field survey with questionnaires was distributed to solicit information from the Nigerian construction professionals in the Federal Capital Territory, Abuja, Nigeria. 300 questionnaires were distributed, and 235 responses were received and analysed with Microsoft Excel and SPSS software by applied relative importance index and ranked. The study found that among the top-ranked reasons for under-reporting of occupational accidents by the organisation is to maintain a reputation. It is therefore important to increase awareness on the reporting of occupational accidents and its importance in accident prevention programmes by the regulatory bodies. Also, more collaborative efforts, standards, and policies should be put in place by the governments for ensuring reporting and record-keeping of accidents in the Nigerian construction industry. Records of dangerous incidents are the key indicator for the organisation for the improvement in the prevention of hazards. The study, therefore, concludes that there should be proper recording and surveillance of occupational accidents, hazards, and their related background causes in reaction to quick and complex variations in work-life.
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Chunchen Xia, Zhixian Cao, Gareth Pender and Alistair Borthwick
The purpose of this paper is to present a fully conservative numerical algorithm for solving the coupled shallow water hydro-sediment-morphodynamic equations governing fluvial…
Abstract
Purpose
The purpose of this paper is to present a fully conservative numerical algorithm for solving the coupled shallow water hydro-sediment-morphodynamic equations governing fluvial processes, and also to clarify the performance of a conventional algorithm, which redistributes the variable water-sediment mixture density to the source terms of the governing equations and accordingly the hyperbolic operator is rendered similar to that of the conventional shallow water equations for clear water flows.
Design/methodology/approach
The coupled shallow water hydro-sediment-morphodynamic equations governing fluvial processes are arranged in full conservation form, and solved by a well-balanced weighted surface depth-gradient method along with a slope-limited centred scheme. The present algorithm is verified for a spectrum of test cases, which involve complex flows with shock waves and sediment transport processes with contact discontinuities over irregular topographies. The computational results of the conventional algorithm are compared with those of the present algorithm and evaluated by available referenced data.
Findings
The fully conservative numerical algorithm performs satisfactorily over the spectrum of test cases, and the conventional algorithm is confirmed to work similarly well.
Originality/value
A fully conservative numerical algorithm, without redistributing the water-sediment mixture density, is proposed for solving the coupled shallow water hydro-sediment-morphodynamic equations. It is clarified that the conventional algorithm, involving redistribution of the water-sediment mixture density, performs similarly well. Both algorithms are equally applicable to problems encountered in computational river modelling.
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Sanyam Sharma, Chimata Murali Krishna and Rajesh Singh
This paper aims to evaluate the theoretical performance of elliptical dam bearing (EDB). The objective of this paper is to study the influence of eccentricity ratio, dam…
Abstract
Purpose
This paper aims to evaluate the theoretical performance of elliptical dam bearing (EDB). The objective of this paper is to study the influence of eccentricity ratio, dam parameters and micropolarity parameters on the stability of EDB with respect to micropolar lubrication.
Design/methodology/approach
In this study, the modified Reynolds’ equation for dynamic state is solved using the finite element method and Galerkin technique. A MATLAB code is written to compute pressure and stability and also to analyse the characteristics. The stability parameters of an EDB are computed for selected values of eccentricity ratios at four levels in the range of 0.20 to 0.35 and for length-diameter ratio of 2.0.
Findings
The results from stability analysis reveal that micropolar lubricated EDB provides better stability at smaller material length due to increased effective viscosity. Hence, it is better to select the smaller characteristic length and higher dam width to achieve optimum performance of these bearings.
Originality/value
Very few researchers investigated the effects of working eccentricity, bearing dam and micropolar fluid parameters on the EDB in the past. It is important to study these aspects for optimum performance of bearings.
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Angélica Megda Silva, Denis Abessa, Paulo Augusto Zaitune Pamplin and Maria Beatriz Bohrer-Morel
The São Lourenço River (SLR) is used to supply potable waters for the cities of São Lourenço da Serra and Juquitiba, but receives the residues from the water treatment plants…
Abstract
Purpose
The São Lourenço River (SLR) is used to supply potable waters for the cities of São Lourenço da Serra and Juquitiba, but receives the residues from the water treatment plants (WTPs) and sewage treatment plants (STPs), respectively. The purpose of this paper is to evaluate the impacts of the discharges of Juquitiba’s WTP and STP on the quality of the SLR, by using an integrated approach based on different lines of evidence.
Design/methodology/approach
Six sampling sites were established along the river and comprised areas situated upstream and downstream of the discharges. Five sampling surveys were performed between 2004 and 2006 for collecting water and sediment samples for ecotoxicological assays. In two of these campaigns, benthic community structure and geochemistry (metals, nutrients and sediment texture) were also assessed.
Findings
Concentrations of P, Fe and Al in waters exceeded the national standards, but sediments were not considered to be contaminated by metals or nutrients. Water and sediments tended to exhibit marginal toxicities, excluding the sediments from JQT007 and JQT008 that were frequently toxic. Combination of geochemistry, toxicity and ecological indices indicated that some sites are not degraded, but in some stations the benthic alteration may be due to non-measured contaminants, especially in JQT007 and JQT008.
Practical implications
As the use of waters from SLR for public supply has increased, these results show that action should be taken in order to reverse the environmental degradation of SRL.
Originality/value
This research combined sediment and water quality assessments in order to provide a more suitable and reliable diagnostic of the environmental quality of the SLR.
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Ali Karakus, Tim Warburton, Mehmet Haluk Aksel and Cuneyt Sert
This study aims to focus on the development of a high-order discontinuous Galerkin method for the solution of unsteady, incompressible, multiphase flows with level set interface…
Abstract
Purpose
This study aims to focus on the development of a high-order discontinuous Galerkin method for the solution of unsteady, incompressible, multiphase flows with level set interface formulation.
Design/methodology/approach
Nodal discontinuous Galerkin discretization is used for incompressible Navier–Stokes, level set advection and reinitialization equations on adaptive unstructured elements. Implicit systems arising from the semi-explicit time discretization of the flow equations are solved with a p-multigrid preconditioned conjugate gradient method, which minimizes the memory requirements and increases overall run-time performance. Computations are localized mostly near the interface location to reduce computational cost without sacrificing the accuracy.
Findings
The proposed method allows to capture interface topology accurately in simulating wide range of flow regimes with high density/viscosity ratios and offers good mass conservation even in relatively coarse grids, while keeping the simplicity of the level set interface modeling. Efficiency, local high-order accuracy and mass conservation of the method are confirmed through distinct numerical test cases of sloshing, dam break and Rayleigh–Taylor instability.
Originality/value
A fully discontinuous Galerkin, high-order, adaptive method on unstructured grids is introduced where flow and interface equations are solved in discontinuous space.
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Yaw A. Debrah and Ian G. Smith
Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on…
Abstract
Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on work and employment in contemporary organizations. Covers the human resource management implications of organizational responses to globalization. Examines the theoretical, methodological, empirical and comparative issues pertaining to competitiveness and the management of human resources, the impact of organisational strategies and international production on the workplace, the organization of labour markets, human resource development, cultural change in organisations, trade union responses, and trans‐national corporations. Cites many case studies showing how globalization has brought a lot of opportunities together with much change both to the employee and the employer. Considers the threats to existing cultures, structures and systems.