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1 – 8 of 8M.S. Daoussa Haggar and M. Mbehou
This paper focuses on the unconditionally optimal error estimates of a linearized second-order scheme for a nonlocal nonlinear parabolic problem. The first step of the scheme is…
Abstract
Purpose
This paper focuses on the unconditionally optimal error estimates of a linearized second-order scheme for a nonlocal nonlinear parabolic problem. The first step of the scheme is based on Crank–Nicholson method while the second step is the second-order BDF method.
Design/methodology/approach
A rigorous error analysis is done, and optimal L2 error estimates are derived using the error splitting technique. Some numerical simulations are presented to confirm the study’s theoretical analysis.
Findings
Optimal L2 error estimates and energy norm.
Originality/value
The goal of this research article is to present and establish the unconditionally optimal error estimates of a linearized second-order BDF finite element scheme for the reaction-diffusion problem. An optimal error estimate for the proposed methods is derived by using the temporal-spatial error splitting techniques, which split the error between the exact solution and the numerical solution into two parts, that is, the temporal error and the spatial error. Since the spatial error is not dependent on the time step, the boundedness of the numerical solution in L∞-norm follows an inverse inequality immediately without any restriction on the grid mesh.
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Samuel Kvasnicka, Thomas Bauernfeind, Paul Baumgartner and Riccardo Torchio
The purpose of this paper is to show that the computation of time-periodic signals for coupled antenna-circuit problems can be substantially accelerated by means of the single…
Abstract
Purpose
The purpose of this paper is to show that the computation of time-periodic signals for coupled antenna-circuit problems can be substantially accelerated by means of the single shooting method. This allows an efficient analysis of nonlinearly loaded coupled loop antennas for near field communication (NFC) applications.
Design/methodology/approach
For the modelling of electrically small coupled field-circuit problems, the partial element equivalent circuit (PEEC) method shows to be very efficient. For analysing the circuit-like description of the coupled problem, this paper developed a generalised modified nodal analysis (MNA) and applied it to specific NFC problems.
Findings
It is shown that the periodic steady state (PSS) solution of the resulting differential-algebraic system can be computed very time efficiently by the single shooting method. A speedup of roughly 114 to conventional transient approaches can be achieved.
Practical implications
The proposed approach appears to be an efficient alternative for the computation of time PSS solutions for nonlinear circuit problems coupled with discretised conductive structures, where the homogeneous solution is not of interest.
Originality/value
The present paper explores the implementation and application of the shooting method for nonlinearly loaded coupled antenna-circuit problems based on the PEEC method and shows the efficiency of this approach.
Details
Keywords
- Circuit analysis
- Transient analysis
- Time-domain modelling
- Equivalent circuit model
- Computational electromagnetics
- Field circuit models
- Near field communication
- Nonlinear resistive loads
- Full-wave rectifier
- Partial element equivalent circuit method
- Modified nodal analysis
- Differential-algebraic equation
- Backward differentiation formula
- Single shooting method
Jameela Mukhaimer, Maha Omar Mihdawi, Rana Al-Ghatam, Fairouz Alhourani and Francis Opinion
This study sought to understand the physical, educational and operational needs faced by healthcare workers (HCWs) (including physicians, nurses and allied health workers) during…
Abstract
Purpose
This study sought to understand the physical, educational and operational needs faced by healthcare workers (HCWs) (including physicians, nurses and allied health workers) during the COVID-19 pandemic.
Design/methodology/approach
A descriptive cross-sectional design was undertaken. HCWs working in hospitals, health centers, testing and quarantine areas in the Kingdom of Bahrain were invited to complete the online survey questionnaire developed by authors containing three domains: physical, educational, and perceived knowledge, and operational needs.
Findings
A convenient sample (N = 627) of volunteered participants responded to the online survey. The biggest challenges that HCWs were exposed to are physical needs (experiencing dry hands, difficulty breathing while on a mask, feeling hot and sweaty, and less fluid and food intake) which were reported as the higher level, followed by operational needs (limited communication due to Personal Protective Equipment - PPE - use, longer working hours, and preparation time to get ready for duty). Other challenges pertained to education and knowledge (the presence of multiple sources of information confused them during the care practices). Females faced more challenges than males, and Bahraini HCWs handled challenges more than non-Bahrainis. A negative relationship was found between age and years of experience with the challenges of the HCWs.
Originality/value
During the COVID-19 pandemic, health systems face rapidly increasing demands. HCWs face several challenges while providing patient care, particularly physical needs. This study provides adequate data for healthcare administrators to maintain a safe working environment during pandemics.
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Laszlo Hetey, Eddy Neefs, Ian Thomas, Joe Zender, Ann-Carine Vandaele, Sophie Berkenbosch, Bojan Ristic, Sabrina Bonnewijn, Sofie Delanoye, Mark Leese, Jon Mason and Manish Patel
This paper aims to describe the development of a knowledge management system (KMS) for the Nadir and Occultation for Mars Discovery (NOMAD) instrument on board the ESA/Roscosmos…
Abstract
Purpose
This paper aims to describe the development of a knowledge management system (KMS) for the Nadir and Occultation for Mars Discovery (NOMAD) instrument on board the ESA/Roscosmos 2016 ExoMars Trace Gas Orbiter (TGO) spacecraft. The KMS collects knowledge acquired during the engineering process that involved over 30 project partners. In addition to the documentation and technical data (explicit knowledge), a dedicated effort was made to collect the gained experience (tacit knowledge) that is crucial for the operational phase of the TGO mission and also for future projects. The system is now in service and provides valuable information for the scientists and engineers working with NOMAD.
Design/methodology/approach
The NOMAD KMS was built around six areas: official documentation, technical specifications and test results, lessons learned, management data (proposals, deliverables, progress reports and minutes of meetings), picture files and movie files. Today, the KMS contains 110 GB of data spread over 11,000 documents and more than 13,000 media files. A computer-aided design (CAD) library contains a model of the full instrument as well as exported sub-parts in different formats. A context search engine for both documents and media files was implemented.
Findings
The conceived KMS design is basic, flexible and very robust. It can be adapted to future projects of a similar size.
Practical implications
The paper provides practical guidelines on how to retain the knowledge from a larger aerospace project. The KMS tool presented here works offline, requires no maintenance and conforms to data protection standards.
Originality/value
This paper shows how knowledge management requirements for space missions can be fulfilled. The paper demonstrates how to transform the large collection of project data into a useful tool and how to address usability aspects.
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Adelaide Sheik, Deidre van Rooyen and Micaela Mazzei
Social innovation (SI) acknowledges socio-economic challenges as opportunities to make communities more sustainable and cohesive through inclusive grassroots practices. The…
Abstract
Purpose
Social innovation (SI) acknowledges socio-economic challenges as opportunities to make communities more sustainable and cohesive through inclusive grassroots practices. The question remains, however, as to whether and how socially innovative practices can be effectively supported in developing inclusive economies. Drawing on the findings from two South African in-depth case studies, This paper aims to discuss how social innovation ventures may be supported to drive inclusiveness.
Design/methodology/approach
This paper purposively sampled two social enterprises (SEs) and conducted in-depth case studies through interviews and secondary data review.
Findings
The SEs selected promoted digital, economic and social inclusion. Despite the diversity of the two organisations, they shared similar challenges in undertaking their practices mostly deriving from South Africa’s lack of legal recognition and policy framework for social purpose-driven businesses.
Originality/value
Applying Moulaert et al.’s (2007) SI classification criteria to the case studies in focus, this paper seeks to extend our understanding of the challenges that innovative SE organisations face in tackling exclusion and contributing to build inclusive economies in the South African context.
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