Results 261 to 270 of about 781,232 (282)

Detection of non-perfused zones in retinal images

[1991] Computer-Based Medical Systems@m_Proceedings of the Fourth Annual IEEE Symposium, 2002
An automatic analysis of angiographic retinal images is discussed. A detection method based on textural differences between perfused and nonperfused regions is described. The image is tessellated into a large number of primary regions using the positions of major vessels.
Jasiobedzki, Piotr, McLeod, David, Taylor, Chris J.   +2 more
openaire   +2 more sources

Pedestrian zone anomaly detection by non-parametric temporal modelling

2014 11th IEEE International Conference on Advanced Video and Signal Based Surveillance (AVSS), 2014
With the increasing focus on safety and security in public areas, anomaly detection in video surveillance systems has become increasingly more important. In this paper, we describe a method that models the temporal behavior and detects behavioral anomalies in the scene using probabilistic graphical models.
Ayse Elvan Gunduz, Tugba Taskaya Temizel, Alptekin Temizel   +2 more
openaire   +1 more source

Reformative Arithmetic for Non Detection Zone Islanding Detection Based on the Voltage Shift Technique

Applied Mechanics and Materials, 2013
The quick & exact anti-islanding is a mandatory feature for grid-connected distributed generation system. The conventional passivity detection method has the biggish blind section and lower reliability, especially when the grid-connected inverter export power and burthen power are balanceable; the islanding detection often is disabled. And that the
Ji Hong Zhang, Pei Hong Yang, Zhen Kui Wu   +2 more
openaire   +1 more source

A Novel Islanding Detection Method With Reduced Non-Detection Zones For Different Distributed Generation Units

2020 International Conference on Smart Grids and Energy Systems (SGES), 2020
In distribution system studies, Distributed Generation (DG) has become an important entity due to the power demand. The DG provides advantages such as improving the voltage profile, power loss reduction, increased power reliability, stability, and quality. The major issue that needs consideration is the islanded operation of the system.
Sowmya Ramachandradurai, Narayanan. K
openaire   +1 more source

Phase-locked loop effect on non-detection zone of unintentional islanding

2015 17th European Conference on Power Electronics and Applications (EPE'15 ECCE-Europe), 2015
The number of small power distributed generators connected to the low voltage distribution networks has increased the possibility of unintentional islanding operations. In this paper, the influence of the Synchronous Reference Frame — Phase Locked Loop (SRF-PLL) for single-phase and three-phase inverter, combined with the wider frequency and voltage ...
SGARBOSSA, RICCARDO, Santa, Luca Dalla, MATTAVELLI, PAOLO, PETUCCO, ANDREA, CAVAZZANA, FRANCESCO, Cerretti, Alberto   +5 more
openaire   +1 more source

Occurrence Probability and Prediction of Unintentional Islands Using Non Detection Zones

2019 IEEE Power & Energy Society General Meeting (PESGM), 2019
As a result of the increasing share of distributed generation in electric supply, the probability of unintentional electrical islands is also increasing. Unintentional islands occur when sub-grids with balanced active and reactive power are separated. Stable unintentional islands are hard to detect and pose a risk for normal grid operation as well as ...
Sebastian Palm, Peter Schegner
openaire   +1 more source

Analysis on non-detection zone of the islanding detection in photovoltaic grid-connected power system

2011 International Conference on Advanced Power System Automation and Protection, 2011
Until now, there is a great development in photovoltaic grid-connected power system. In addition, there is an ongoing research on the problems existed in the system. Islanding of photovoltaic grid-connected power system have adverse impact on power quality and utility equipments, affecting the performance of the utility even worse, it may damage people'
YuGuo Fan, Chen Li
openaire   +1 more source

Active Anti-Islanding technique with reduced Non-Detection Zone for Centralized Inverters

2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia), 2018
This paper presents an active anti-islanding scheme for grid-tied centralized inverters for large Photovoltaic (PV) power plants. The proposed technique involves appropriate reactive power injection into the grid which results in the positive/negative rate of change of frequency.
Prashant Jain, Vivek Agarwal, Bishnu Prasad Muni, Eswar Rao, Deepak Gehlot, S. Gautam Kumar   +5 more
openaire   +1 more source

Surface wave detectability of transition zone anisotropy induced by non-Newtonian mantle flow

2022
<p>Large-scale anisotropy inferred from long-period seismic tomography mainly results from the crystallographic preferred orientation (CPO) of olivine aggregates due to mantle deformation. In the 410-km transition zone, the inclusion of wadsleyite CPO diminishes the overall anisotropy.
John Keith Magali, Sébastien Merkel, Estelle Ledoux   +2 more
openaire   +2 more sources

Modeling and design of phase shift anti-islanding method using non-detection zone

Solar Energy, 2007
Abstract Islanding phenomenon of a grid-connected independent generator like a photovoltaic (PV) system occurs when a section of a utility system is disconnected from the main utility voltage source, but the independent generator continues to energize the utility lines in the isolated section. Since islanding causes a safety hazard to utility service
Byunggyu Yu, Mikihiko Matsui, Youngseok Jung, Gwonjong Yu   +3 more
openaire   +1 more source