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Article
Publication date: 1 August 2005

S. Manseur, K. Attalah and Y. Cherruault

This paper aims at applying the proven Adomian and Alienor methods to solve the problem of optimal chemotherapy of HIV model.

308

Abstract

Purpose

This paper aims at applying the proven Adomian and Alienor methods to solve the problem of optimal chemotherapy of HIV model.

Design/methodology/approach

The combination of the Adomian decomposition method and the Alienor reduction method allows us to solve the control problem as if it were a classical one‐dimensional minimization problem. The methodology is applied to a HIV model and simulation results given.

Findings

A general abstract framework for the control of a non‐linear evolution system has been developed. It was shown that it is possible to control a system by using the powerful techniques of Adomian and Alienor, and produce results comparable with those obtained by classical methods where other cost functions are used.

Research limitations/implications

The benefit of this work is based on the CD4 healthy cells being maximized and the cost based on a drug dose being minimized. The new methodology could be used after further research for solving many control problems in biology and in other areas such as those involving industrial processes.

Practical implications

New methodology is cost‐effective in controlling the drug dose affecting rate of infection of cells by HIV virus.

Originality/value

New application of proven methodology will solve many control problems in biocybernetics/biomedicine/industry and other fields.

Details

Kybernetes, vol. 34 no. 7/8
Type: Research Article
ISSN: 0368-492X

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Article
Publication date: 5 May 2015

Witold Mazgaj and Adam Warzecha

The purpose of this paper is to present the differences in results of numerical calculations arising from different simplifications of the rotational magnetization model in…

73

Abstract

Purpose

The purpose of this paper is to present the differences in results of numerical calculations arising from different simplifications of the rotational magnetization model in typical dynamo sheets.

Design/methodology/approach

A comprehensive model of rotational magnetization processes in typical dynamo sheets should take into consideration the magnetic hysteresis and eddy current phenomena and also certain anisotropic properties. The chosen model of the rotational magnetization is briefly presented in this paper. A method of the inclusion of the rotational magnetization model into equations of the magnetic field distribution is described. The correctness of these equations has been verified experimentally. Numerical calculations of the rotational magnetization in two types of dynamo sheets were carried out for several simplifications of the described model.

Findings

Results of numerical calculations of the rotational magnetization with the omission of the hysteresis phenomenon or with the omission of eddy currents were compared with results obtained with the use of the comprehensive model of the rotational magnetization.

Practical implications

The paper presents comments and recommendations concerning the omission of both the hysteresis phenomenon and eddy currents in the analysis of the rotational magnetization in dynamo sheets and the impact of these simplifications on numerical calculation results.

Originality/value

The content of the paper refers to very important issues of modeling and calculations of the rotational magnetization in typical dynamo steel sheets.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 4 January 2011

Zi‐Qiang Zhu

Fractional slot permanent magnet (PM) brushless machines having concentrated non‐overlapping windings have been the subject of research over last few years. They have already been…

1536

Abstract

Purpose

Fractional slot permanent magnet (PM) brushless machines having concentrated non‐overlapping windings have been the subject of research over last few years. They have already been employed in the commercial hybrid electric vehicles (HEVs) due to high‐torque density, high efficiency, low‐torque ripple, good flux‐weakening and fault‐tolerance performance. The purpose of this paper is to overview recent development and research challenges in such machines in terms of various structural and design features for electric vehicle (EV)/HEV applications.

Design/methodology/approach

In the paper, fractional slot PM brushless machines are overviewed according to the following main and sub‐topics: first, machine topologies: slot and pole number combinations, all and alternate teeth wound (double‐ and single‐layer windings), unequal tooth structure, modular stator, interior magnet rotor; second, machine parameters and control performance: winding inductances, flux‐weakening capability, fault‐tolerant performance; and third, parasitic effects: cogging torque, iron loss, rotor eddy current loss, unbalanced magnetic force, acoustic noise and vibration.

Findings

Many fractional slot PM machine topologies exist. Owing to rich mmf harmonics, fractional slot PM brushless machines exhibit relatively high rotor eddy current loss, potentially high unbalanced magnetic force and acoustic noise and vibration, while the reluctance torque component is relatively low or even negligible when an interior PM rotor is employed.

Originality/value

This is the first overview paper which systematically reviews the recent development and research challenges in fractional‐slot PM machines. It summarizes their various structural and design features for EV/HEV applications.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 20 August 2018

Athanasios Sarigiannidis, Minos Beniakar and Antonios Kladas

This paper aims to introduce a computationally efficient hybrid analytical–finite element (FE) methodology for loss evaluation in electric vehicle (EV) permanent magnet (PM…

112

Abstract

Purpose

This paper aims to introduce a computationally efficient hybrid analytical–finite element (FE) methodology for loss evaluation in electric vehicle (EV) permanent magnet (PM) traction motor applications. In this class of problems, eddy current losses in PMs and iron laminations constitute an important part of overall drive losses, representing a key design target.

Design/methodology/approach

Both surface mounted permanent magnet (SMPM) and double-layer interior permanent magnet (IPM) motor topologies are considered. The PM eddy losses are calculated by using analytical solutions and Fourier harmonic decomposition. The boundary conditions are based on slot opening magnetic field strength tangential component in the air gap in the SMPM topology case, whereas the numerically evaluated normal flux density variation on the surface of the outer PM is implemented in the IPM case. Combined analytical–loss evaluation technique has been verified by comparing its results to a transient magnetodynamic two-dimensional FE model ones.

Findings

The proposed loss evaluation technique calculated the total power losses for various operating conditions with low computational cost, illustrating the relative advantages and drawbacks of each motor topology along a typical EV operating cycle. The accuracy of the method was comparable to transient FE loss evaluation models, particularly around nominal speed.

Originality/value

The originality of this paper is based on the development of a fast and accurate PM eddy loss model for both SMPM and IPM motor topologies for traction applications, combining effectively both analytical and FE techniques.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Available. Open Access. Open Access
Article
Publication date: 23 March 2023

Ahmed Attalah Hassan Al-Fhdawi and Adel Mashaan Rabee

The purpose of this study was to determine the influence of environmental pH on production of biofilms and virulence genes expression in Pseudomonas aeruginosa.

974

Abstract

Purpose

The purpose of this study was to determine the influence of environmental pH on production of biofilms and virulence genes expression in Pseudomonas aeruginosa.

Design/methodology/approach

Among 303 clinical and environmental samples 109 (61 + 48) isolates were identified as clinical and environmental P. aeruginosa isolates, respectively. Clinical samples were obtained from patients in the Al-Yarmouk hospital in Baghdad city, Iraq. Waste water from Al-Yarmouk hospital was used from site before treatment unit to collect environmental samples. The ability of producing biofilm at various pH levels was examined by microtiter plate and the prevalence of Alg D, Psl A and Pel A was determined by quantitative real time-polymerase chain reaction (qRT-PCR).

Findings

This study showed that the ability of clinical and environmental isolates to biofilm development was observed in 86.9% and 85.42% of clinical and environmental isolates, respectively. As well as, the environmental P. aeruginosa isolates showed the highest biofilm production at pH 7. Clinical isolates showed the highest genes expression of Alg D, Psl A and Pel A as compared to environmental isolates with pH change. In general, both clinical and environmental isolates formed biofilm and carried AlgD, PslA and PelA genes. Also, alkaline pH was favored for biofilm production.

Originality/value

There are very few studies done to find out the influence of environmental pH on production of biofilms and virulence genes expression in Pseudomonas aeruginosa. This study is unique as it has highlighted the influence of environmental pH on the ability of clinical and environmental isolates to biofilm development and genes expression.

Details

Arab Gulf Journal of Scientific Research, vol. 42 no. 2
Type: Research Article
ISSN: 1985-9899

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Article
Publication date: 13 August 2018

Elsa Fourie

The purpose of this paper is to identify limitations in managing the implementation of effective teaching and learning in township ECD centres.

1090

Abstract

Purpose

The purpose of this paper is to identify limitations in managing the implementation of effective teaching and learning in township ECD centres.

Design/methodology/approach

This research was grounded in a community-based participatory research approach. A qualitative research design was utilised because phenomena could be studied in terms of the meanings of people. Elements of grounded theory, situational analysis and community-based participatory research were blended. The qualitative research design involved semi-structured face-to-face interviews with teachers in township ECD centres.

Findings

The findings from this research made it evident that principals of ECD centres were often absent; had not been trained to manage an ECD centre; had limited skills to manage finances; did not communicate with parents or teachers; and did not motivate teachers to achieve goals or to improve their qualifications.

Practical implications

Challenges that could impede the effective implementation of an intervention programme should be identified and addressed. Principals of ECD centres should be empowered to manage their centres effectively. A training programme aimed at empowering principals of ECD centres has been developed and will be implemented after consultation with the gatekeeper and principals of the ECD centres.

Originality/value

The findings of this research could be used by principals and researchers to reflect on management practices in ECD centres. A challenge for principals is to acknowledge the principles of effective management and to close the gap between current practices and effective management practices. Interventions from academics are essential to enhance the quality of teaching and learning in ECD centres.

Details

International Journal of Educational Management, vol. 32 no. 6
Type: Research Article
ISSN: 0951-354X

Keywords

Available. Open Access. Open Access
Article
Publication date: 28 September 2023

Hani Atwa, Anas Alfadani, Joud Damanhori, Mohamed Seifalyazal, Mohamed Shehata and Asmaa Abdel Nasser

Patient safety focuses on minimizing risks that might occur to patients during provision of healthcare. The purpose of this study was to explore healthcare practitioners’…

947

Abstract

Purpose

Patient safety focuses on minimizing risks that might occur to patients during provision of healthcare. The purpose of this study was to explore healthcare practitioners’ attitudes towards patient safety inside different hospital settings in Jeddah, Kingdom of Saudi Arabia.

Design/methodology/approach

A descriptive, cross-sectional study was conducted on a sample of healthcare practitioners in main hospitals in Jeddah. Two main hospitals (one governmental and one private) were selected from each region of Jeddah (east, west, north and south), with a total number of eight out of thirty hospitals. Data were collected through the Attitudes to Patient Safety Questionnaire III that was distributed online. The questionnaire used a 5-point scale. Descriptive statistics were used. Comparisons were made by independent t-test and ANOVA. The statistical significance level was set at p < 0.05.

Findings

The study included 341 healthcare practitioners of different sexes and specialties in eight major governmental and private hospitals in Jeddah. “Working hours as error cause” subscale had the highest mean score (4.03 ± 0.89), while “Professional incompetence as error cause” had the lowest mean score (3.49 ± 0.97). The total questionnaire had a moderate average score (3.74 ± 0.63). Weak correlations between the average score of the questionnaire and sex, occupation and workplace were found (−0.119, −0.018 and −0.088, respectively).

Practical implications

Hospitals need to develop targeted interventions, including continuing professional development programs, to enhance patient safety culture and practices. Moreover, patient safety training is required at the undergraduate education level, which necessitates health professions education institutions to give more attention to patient safety education in their curricula.

Originality/value

The study contributed to the existing literature on patient safety culture in hospital settings in Jeddah, Saudi Arabia. The insights generated by the study can inform targeted interventions to enhance patient safety culture in hospitals and improve patient outcomes.

Details

Arab Gulf Journal of Scientific Research, vol. 42 no. 3
Type: Research Article
ISSN: 1985-9899

Keywords

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Article
Publication date: 29 November 2024

Gwia Kim, Byoungho Ellie Jin and Heekyeong Jo

We aim to investigate the impact of different story types on small fashion business brand trust and purchase intention, guided by signaling theory. We investigate two potential…

221

Abstract

Purpose

We aim to investigate the impact of different story types on small fashion business brand trust and purchase intention, guided by signaling theory. We investigate two potential moderators – product aesthetic judgment (i.e. consumers’ responses to the aesthetic aspects of a product) and underdog positioning (i.e. brand’s positioning as a loser that is not a leader in the marketplace and has only a small market share but puts efforts into creating valuable products) – that may influence consumers’ responses to a story.

Design/methodology/approach

We developed video stimuli that tell business stories to empirically compare two story types bringing brand trust: identity-focused and product-focused stories. We conducted two experimental studies and tested six hypotheses with 302 datasets. Study 1 compared eco-friendly storytelling with product-focused storytelling, considering perceived product aesthetic judgment as the moderator. Study 2 repeated the experiment with a founder story and a product-focused story, considering the perceived underdog as the moderator.

Findings

The findings suggest that the influence of eco-friendly storytelling, compared to product-focused storytelling, on higher purchase intention is fully mediated by brand trust. Consumers’ perceived product aesthetic judgments toward an eco-friendly product can positively moderate the storytelling effect and brand trust. However, founder storytelling did not bring higher brand trust and, consequently, had no significant impact on purchase intention. Similarly, the perceived underdog did not moderate this relationship.

Originality/value

The study is novel as it is one of the first to compare story types based on story contents, whereas previous studies have focused on story delivery. Especially, we explored which story types and contents effectively build brand trust for small businesses, a critical factor for their success. Based on the extant literature, we categorized story types into identity-focused stories and product-focused stories based on contents. We hypothesized and concluded that an identity-focused story can be more effective in eliciting consumer responses. Furthermore, we confirm the critical role of brand trust as a mediator in bringing about purchase intention through eco-friendly storytelling.

Details

Journal of Fashion Marketing and Management: An International Journal, vol. 29 no. 2
Type: Research Article
ISSN: 1361-2026

Keywords

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Article
Publication date: 27 March 2023

Plato L. Smith II

The purpose of this project was to develop research support services that address local and external research data management (RDM) support drivers within the existing…

162

Abstract

Purpose

The purpose of this project was to develop research support services that address local and external research data management (RDM) support drivers within the existing organizational culture at the University of Florida. The goal was to prompt organization change to support a campus-wide electronic lab notebook.

Design/methodology/approach

This project used a mixed-methods research approach to cultivate an organizational change program that support technological infrastructure to benefit researchers. The mixed-methods research involved participation action research integrated with a stakeholder approach.

Findings

The development of the grant proposal which was unfunded led to development of continued project goals. This project confirmed the development for support for an institution-wide electronic research notebook (ERN) solution requires adherence to the summary of five key actions for developing RDM services. Failure to complete all of the key actions engenders fragmentation culture.

Research limitations/implications

This project includes implications for institutions to develop grant proposals with integrated budgets for research support services of funded projects; and to use the summary of key actions for developing RDM services articulated by Jones et al. (2013) in “How to Develop RDM Services – a guide for HEIs.” Both are need to support findable, accessible, interoperable and reusable data for researchers.

Practical implications

This project has practical implications for higher education institutions interested in leveraging socio-technical processes to advance the role of libraries as collaborator, partner and stakeholder in developing institution-wide adoption, support and training for ERN as a research support service to RDM.

Social implications

This paper contributes to the body of developing literature on ERN as support services to RDM lead by academic research libraries.

Originality/value

This project contributed to the change in organization culture resulting in the successful collaboration between the Research Office and College of Medicine to support an institution-wide ERN technological infrastructure for one year as a pilot at a large academic research institution in the southeast USA.

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