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Article
Publication date: 3 July 2024

Anis Abdelkefi, Amal Souissi and Imen Abdennadher

This paper aims at the analytical formulation of the electromagnetic features of flux switching permanent magnet (PM) machines with emphasis on the PM air gap flux density and…

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Abstract

Purpose

This paper aims at the analytical formulation of the electromagnetic features of flux switching permanent magnet (PM) machines with emphasis on the PM air gap flux density and armature magnetic reaction.

Design/methodology/approach

The PM air gap flux density is formulated considering three different analytical models. These differ by the incorporation of the air gap magnetic saliency level from the stator side. In addition, the armature magnetic reaction is investigated based on a simplified magnetic reluctance circuit that considers the flux switching permanent magnet machines magnetic circuit geometry specification. Then, the no- and on-load torque is predicted based on the two air gap flux densities.

Findings

It has been found that the PM air gap flux density considering the stator saliencies with trapezoidal magnetomotive force waveform presents the highest accuracy. Despite the simplicity of the magnetic equivalent circuit-based approach, the predicted air gap armature magnetic reaction is in good agreement with the finite element analysis (FEA) one. These lead to the analytical predictions of the no- and on-load torque which is characterized by an acceptable accuracy.

Research limitations/implications

This work should be extended to experimental validation of the FEA results regarding the torque production generation.

Originality/value

The paper proposes an improved design-oriented analytical approach with emphasis on the PM air gap flux density and the armature magnetic reaction of flux switching PM machines.

Details

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

Keywords

Article
Publication date: 9 July 2024

Zengrui Zheng, Kainan Su, Shifeng Lin, Zhiquan Fu and Chenguang Yang

Visual simultaneous localization and mapping (SLAM) has limitations such as sensitivity to lighting changes and lower measurement accuracy. The effective fusion of information…

Abstract

Purpose

Visual simultaneous localization and mapping (SLAM) has limitations such as sensitivity to lighting changes and lower measurement accuracy. The effective fusion of information from multiple modalities to address these limitations has emerged as a key research focus. This study aims to provide a comprehensive review of the development of vision-based SLAM (including visual SLAM) for navigation and pose estimation, with a specific focus on techniques for integrating multiple modalities.

Design/methodology/approach

This paper initially introduces the mathematical models and framework development of visual SLAM. Subsequently, this paper presents various methods for improving accuracy in visual SLAM by fusing different spatial and semantic features. This paper also examines the research advancements in vision-based SLAM with respect to multi-sensor fusion in both loosely coupled and tightly coupled approaches. Finally, this paper analyzes the limitations of current vision-based SLAM and provides predictions for future advancements.

Findings

The combination of vision-based SLAM and deep learning has significant potential for development. There are advantages and disadvantages to both loosely coupled and tightly coupled approaches in multi-sensor fusion, and the most suitable algorithm should be chosen based on the specific application scenario. In the future, vision-based SLAM is evolving toward better addressing challenges such as resource-limited platforms and long-term mapping.

Originality/value

This review introduces the development of vision-based SLAM and focuses on the advancements in multimodal fusion. It allows readers to quickly understand the progress and current status of research in this field.

Details

Robotic Intelligence and Automation, vol. 44 no. 4
Type: Research Article
ISSN: 2754-6969

Keywords

Article
Publication date: 4 July 2024

Emrah Cetin and Z.Q. Zhu

This study aims to obtain the minimum torque ripple at the maximum average torque for Flux-switching permanent magnet (FSPM) machines.

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Abstract

Purpose

This study aims to obtain the minimum torque ripple at the maximum average torque for Flux-switching permanent magnet (FSPM) machines.

Design/methodology/approach

This paper is about torque performance optimization of the FSPM machines. To achieve that, finite element analysis and genetic algorithm (GA) are used. Five different designs are simulated, optimized and compared on their air gap flux density, back electromotive force, cogging torque, average torque, torque density and torque ripple.

Findings

After the thousands of iterations, its proved that all proposed shaping techniques have potential for reducing torque ripple and cogging torque, with slightly reduced average torque. The best design is the joint stator and rotor shaping, Design V, which results in the lowest torque ripple and cogging torque. The techniques should be applicable to FSPMs with other stator slot/rotor pole number combinations.

Originality/value

In this paper, rotor pole shaping by notching, chamfering and generic shaping, stator tooth shaping and joint shaping techniques are investigated for 12 s/10p FSPM machines. Rotor and stator flanks are optimized separately and jointly, by using finite element analysis and GA for optimization to achieve maximum average torque and minimum torque ripple. Five different design is implemented and compared, respectively.

Details

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

Keywords

Article
Publication date: 16 July 2024

Yung-Ming Cheng

The purpose of this study is to propose a research model based on the stimulus-organism-response (S-O-R) model to explore whether social media affordances and media richness as…

Abstract

Purpose

The purpose of this study is to propose a research model based on the stimulus-organism-response (S-O-R) model to explore whether social media affordances and media richness as environmental stimuli to learners’ involvement elicited by massive open online courses (MOOCs) can affect their learning persistence in MOOCs and, in turn, their learning outcomes in MOOCs. This study further examines whether demographic variables can moderate the relationship between learners’ learning persistence in MOOCs and their learning outcomes.

Design/methodology/approach

Sample data for this study were collected from learners who had experience in taking MOOCs provided by the MOOCs platform launched by a well-known university in Taiwan, and 396 usable questionnaires were analyzed using structural equation modeling.

Findings

This study proved that learners’ perceived social media affordances and media richness in MOOCs positively influenced their cognitive involvement and affective involvement elicited by MOOCs, which concurrently expounded their learning persistence in MOOCs and, in turn, uplifted their learning outcomes in MOOCs. The results support all proposed hypotheses and the research model, respectively, explains 70.5% and 61.8% of the variance in learners’ learning persistence in MOOCs and learning outcomes. Besides, this study showed that learners’ usage experience moderated the relationship between learners’ learning persistence in MOOCs and their learning outcomes.

Originality/value

This study uses the S-O-R model as a theoretical groundwork to construct learners’ learning outcomes in MOOCs as a series of the psychological process, which is affected by social media affordances and media richness. Noteworthily, while the S-O-R model has been extensively used in previous literature, little research uses the S-O-R model to explain the media antecedents of learners’ learning persistence and learning outcomes in MOOCs. Hence, this study enriches the research for understanding how learners value their learning gains via using media features to support them in MOOCs.

Details

Interactive Technology and Smart Education, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1741-5659

Keywords

Article
Publication date: 7 August 2024

Rajagopal and Ananya Rajagopal

The principal objective of the study is to analyze the influence of ethnicity, culture and collective intelligence in entrepreneurial creativity, innovation and marketing of…

Abstract

Purpose

The principal objective of the study is to analyze the influence of ethnicity, culture and collective intelligence in entrepreneurial creativity, innovation and marketing of artisanal beer in Mexico.

Design/methodology/approach

The qualitative data have been gathered by conducting four workshops with twelve respondents in each workshop across four states of Mexico comprising Mexico City, Puebla, Queretaro and Guadalajara. These workshops were held for four hours during the pre-lunch period over the weekends, which was participated by a mix of entrepreneurs and consumers.

Findings

Artisanal entrepreneurship is driven by the culture, ethnicity, collective intelligence and frugal innovations. Ethnic products generate patriotic feeling and consumption for a social cause to encourage artisans at the grassroots with the local tags. Results also indicate that social media and crowd cognition play an important role in developing creative artisanal beer.

Research limitations/implications

This study is founded on the theoretical maxims of social learning theory (SCT), social cognitive theory and theory of creativity. The contextual interpretation of SCT explains the socialization of concepts by modelling emotions and behavior to derive structural experiences as observed in artisanal entrepreneurship.

Practical implications

Entrepreneurs can develop brand emotions, boost anthropomorphic feelings and inculcate the sense of nationalism among consumers to market ethnic brands and develop social consciousness towards consumption of “Made in Mexico” products.

Social implications

Artisanal beer face major challenge of customer outreach by enhancing the brand proximity and ethnic values. Ethnic products hold a strong image in niche market and need to be stimulated by the experience sharing through social media and community interactions.

Originality/value

This research study significantly contributes to the existing literature on ethnic entrepreneurship and creativity using innovative research approach.

Details

Qualitative Research Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1443-9883

Keywords

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