Results 41 to 50 of about 203,934 (147)

Coordinating representation registers: linear algebra students' understanding of orthogonal Legendre polynomials in the inner product space ℙn in a technology-assisted learning environment

Annales de Didactique et de Sciences Cognitives, 2018
The purpose of this research study was to understand how linear algebra students in a university in the United States make sense of the orthogonal Legendre polynomials as vectors of the inner product space ℙn in a DGS (Dynamic Geometry Software)-MATLAB ...
Günhan Caglayan
doaj   +1 more source

Influence of Dissolved Oxygen on the Gassing Tendency of Biodegradable Insulating Liquids Under Thermal and Electrical Faults

High Voltage, EarlyView.
ABSTRACT Dissolved gas analysis (DGA), widely used for fault diagnosis, can be significantly influenced by the presence of oxygen. Oxygen not only accelerates fluid degradation but also alters the type and concentration of fault gases generated, potentially leading to misinterpretation of transformer conditions if conventional DGA models are applied ...
Moïse Agouassi, U. Mohan Rao, Issouf Fofana, Yazid Hadjadj, Fethi Maghnefi   +4 more
wiley   +1 more source

Fault Classification in Power Transformers Using Dissolved Gas Analysis and Optimized Machine Learning Algorithms

Machines
Power transformers are critical assets in electrical power systems, yet their fault diagnosis often relies on conventional dissolved gas analysis (DGA) methods such as the Duval Pentagon and Triangle, Key Gas, and Rogers Ratio methods.
Vuyani M. N. Dladla, Bonginkosi A. Thango   +1 more
doaj   +1 more source

Fault Prediction for Power Transformer Using Optical Spectrum of Transformer Oil and Data Mining Analysis

IEEE Access, 2020
Periodic preventive maintenance of power transformer should be conducted for its health monitoring and early fault detection. Transformer oil is a vital element where its contents and properties need to be monitored during the service life of a power ...
Nur Afini Fauzi, N. H. Nik Ali, Pin Jern Ker, Vimal Angela Thiviyanathan, Yang Sing Leong, Ahmed H. Sabry, MD. Zaini Bin Jamaludin, Chin Kim Lo, Looe Hui Mun   +8 more
doaj   +1 more source

The role of leadership on employee mental ill‐health through workplace disruption: A systematic review and meta‐analysis of longitudinal research

Journal of Occupational and Organizational Psychology, Volume 99, Issue 4, December 2026.
Abstract As socio‐global events more frequently disrupt workplaces, understanding leadership's dynamic and context‐sensitive role in shaping employee wellbeing during periods of uncertainty has become increasingly important. Drawing on the Conservation of Resources Theory, this study synthesized current longitudinal evidence on the association between ...
Jasmine K. Bhatia, Eyal Karin, Thomas Rigotti, Monique F. Crane   +3 more
wiley   +1 more source

duVal Allen, 1918

, 1918
Black-and-white photographic postcard with a portrait of duVal Allen in uniform, photographed during his World War I service as an ambulance driver in France.

core   +1 more source

A combined technique for power transformer fault diagnosis based on k‐means clustering and support vector machine

IET Nanodielectrics
This contribution presents a two‐step hybrid diagnostic approach, combining k‐means clustering for subset formation, followed by subset analysis conducted by human experts.
Arnaud Nanfak, Abdelmoumene Hechifa, Samuel Eke, Abdelaziz Lakehal, Charles Hubert Kom, Sherif S. M. Ghoneim   +5 more
doaj   +1 more source

Propagation of internal gravity waves: Optimal vertical discretisation and grid design based on numerical error analysis

Quarterly Journal of the Royal Meteorological Society, Volume 152, Issue 780, October 2026 Part A.
An energy‐conserving discrete framework for the vertical discretisation of stratified ocean models is developed using internal gravity‐wave theory. A β$$ \beta $$‐indexed family of schemes is analysed through perturbation theory, revealing optimal parameter choices and grid designs that reduce truncation errors significantly.
Gabriel Derrida, Laurent Debreu, Florian Lemarié, Jérome Chanut   +3 more
wiley   +1 more source

Intelligent Fault Detection of MV/HV Transformers Using Fuzzy Logic Based on DGA

Eng
Dissolved Gas Analysis (DGA) of power system transformers has emerged as one of the most effective transformer health diagnosing tools by analyzing the gases dissolved in the insulating oil.
Lone Larona Mogotsi, Akhtar Rasool, Edwin Matlotse, Sadaqat Ali, Ahmed Ali   +4 more
doaj   +1 more source

A Dynamic Adam Based Deep Neural Network for Fault Diagnosis of Oil-Immersed Power Transformers

Energies, 2019
This paper presents a Dynamic Adam and dropout based deep neural network (DADDNN) for fault diagnosis of oil-immersed power transformers. To solve the problem of incomplete extraction of hidden information with data driven, the gradient first-order ...
Minghui Ou, Hua Wei, Yiyi Zhang, Jiancheng Tan   +3 more
doaj   +1 more source