Jean‐Paul Swan, Olivier Walti and Jean‐Fraçois Brudny
Electrical machines are more and more fed by static converters. These power supplies impose nonsinusoidal statoric waveform to the machines. In these conditions, behaviour of…
Abstract
Electrical machines are more and more fed by static converters. These power supplies impose nonsinusoidal statoric waveform to the machines. In these conditions, behaviour of magnetic material can be very different compared with sinusoidal ones. The characterization of magnetic material under non‐sinusoidal excitations is not clearly defined. At the present time, there is not any standard about operating test and specific parameters to be measured in order to get efficient knowledge of soft magnetic materials in distorted excitation mode. The aim of this paper is to present the effect of statoric connections on harmonic characterization parameters. The experimental results correspond to a Fe‐Si non oriented material excited by two different waveforms in a classical Epstein frame. The behaviour of the material is divided into two parts: the fundamental and the harmonic responses. The fundamental parameters are representative of the duty frequency of the machine, harmonic ones give information about additional losses; especially their harmonic distribution. They also allow us to estimate harmonic impact on the fundamental response.
Sidhartha Sahoo, Shriram Pandey and Sanjaya Mishra
The purpose of this study is to identify seminal research works on distance and online learning that have had significant impact on the domain.
Abstract
Purpose
The purpose of this study is to identify seminal research works on distance and online learning that have had significant impact on the domain.
Design/methodology/approach
The authors used the SCOPUS database for this study as the data source, and a well-defined search strategy retrieved the items for analysis. First, the authors identified the h-index (n = 207) of the discipline to determine the threshold for listing the top works. The authors critically analysed these classic publications using several bibliometric parameters to present the analysis. To understand the primary focus of the classic research works, the authors also carried out a keyword cluster analysis using VOSviewer.
Findings
While the USA produced maximum classic research, authors from Canada have maximum research visibility in terms of citations (n = 474.06). Canada also received the highest value of RCI (1.30), followed by Taiwan and Australia. The majority of the classics are published in 67 scientific journals. Of these, Computers and Education published the highest number with a quarter of the total citations (n = 19,403). Although e-learning was the nucleus of the research theme, the authors observed that students, learning systems, online learning, blended learning, learning management systems and computer-aided instructions dominated their influence in the research cluster.
Originality/value
To the best of the authors’ knowledge, this is the first of its kind work in the field of distance and online learning. Findings of this study would be useful to faculty, researchers and students in the discipline to focus on the seminal works and understand their implications better in the context of the growing significance of the discipline.