Search

Your search keyword '"Woodhead, Ian"' showing total 115 results
Start Over Author "Woodhead, Ian"
115 results on '"Woodhead, Ian"'

8. Contrast Capability of the NRI Lens

Author

Eccleston, Kimberley W., primary, Zhou, Yiwen, additional, Tan, Adrian E.-C., additional, Platt, Ian G., additional, Bateman, Christopher, additional, and Woodhead, Ian M., additional

Published
2021
Full Text
View/download PDF

12. A technique for evaluation of CCD video-camera noise

Author

Irie, Kenji, McKinnon, Alan E., Unsworth, Keith, and Woodhead, Ian M.

Subjects
Charge coupled devices -- Properties, Video cameras -- Properties, Noise control -- Methods, Image processing -- Methods, Business, Computers, Electronics, Electronics and electrical industries
Abstract

This paper presents a technique to identify and measure the prominent sources of sensor noise in commercially available charge-coupled device (CCD) video cameras by analysis of the output images. Noise fundamentally limits the distinguishable content in an image and can significantly reduce the robustness of an image processing application. Although sources of image sensor noise are well documented, there has been little work on the development of techniques to identify and quantify the types of noise present in CCD video-camera images. A comprehensive noise model for CCD cameras was used to evaluate the technique on a commercially available CCD video camera. Index Terms--Charge-coupled devices (CCDs), image processing, noise measurement, video signal processing.

Published
2008

14. Non-Invasive Groundwater Velocity Measurements Using a Novel Electromagnetic Flowmeter.

Author

Mitchell, Ben, Zhou, Yiwen, Hayes, Michael P., Heffernan, Bill, Platt, Ian, Bailey, Joseph, Hunze, Arvid, Gao, Ke, Long, Nick, and Woodhead, Ian

Subjects
GROUNDWATER flow, VELOCITY measurements, FARADAY'S law, NATURAL resources, MAGNETIC field measurements, DEIONIZATION of water, MAGNETIC fields
Abstract

Tracing groundwater flow is of vital importance for managing water resources and understanding the natural water cycle. However, it is a challenge to make accurate measurements of groundwater flow due to its extremely low velocity. A new electromagnetic flowmeter has been developed to conduct non-invasive groundwater flow velocity measurements. In the setup, a customized trapezoidal current source was connected to a 1 m $\times $ 1 m square coil to generate a strong vertical magnetic field. Two electrodes were used to sense the potential difference caused by water flowing through the magnetic field. A simulation has been developed based on Faraday’s law to evaluate the flow signal under an idealized condition. Two different lab environments have been built for testing the device: an artificial mini-aquifer and a rolling gantry. The measurements show that the flow signal, in practice, generated by the slow-moving water was orders of magnitude smaller than the inductive and capacitive interferences in the system. A linear signal processing model has been developed, allowing the flow signal to be extracted from the measured results. The results show good agreement with simulation and a strong correlation between the flow speed and the processed flow signal, having an $R^{2}$ coefficient of 0.94. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

23. Microwaves - Modeling and Experiments with Apples

Author

Jawad, Hawraa, Lanteri, Jérôme, Migliaccio, Claire, Pichot, Christian, Platt, Ian G., Tan, Adrian E.-C., Eccleston, Kimberley W., Woodhead, Ian M., Laboratoire d'Electronique, Antennes et Télécommunications (LEAT), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Lincoln Agritech Ltd, and IEEE

Subjects
Microwave modeling, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Nondestructive control, Quality of fruit
Abstract

International audience; The influence on the complex permittivity of cultivars (varieties), maturation, quality indices (e.g. soluble solids content), moisture or temperature can be used for sensing and monitoring for developing new generation of sensors for a nondestructive control of agricultural products for improving quality. The main application concerns here apples. The study includes modeling, simulations and measurements of the scattered field in far and near-field zones (excluding the interactive zone) regions of apples to check the feasibility of monitoring apple growth, maturation, quality indices and defects.

Published
2018

36. Pseudo-3-D Moment Method for Rapid Calculation of Electric Field Distribution in a Low-Loss Inhomogeneous Dielectric

Author

Woodhead, Ian M., Buchan, Graeme D., and Kulasiri, Don

Subjects
Dielectrics -- Research, Antennas (Electronics) -- Research, Business, Computers, Electronics, Electronics and electrical industries
Abstract

Numerous applications of dielectric modeling require computation of the distribution of the total electric field in an inhomogeneous dielectric, in response to an applied electric field. An integral equation method would normally use an electric field volume integral technique using the moment method and hence compute the field in three-dimensional (3-D) space. For those instances where the third dimension of the region is assumed to be invariant, such as when determining the spatial sensitivity of a time-domain reflectometry sensor, the heavy resource use of calculating the additional dimension is an unnecessary burden. The new method reported in this paper sums the field contributions from the invariant third dimension at each stage of a two-dimensional (2-D) calculation, reducing the order of the model matrix by 2[n.sup.2] where n is the number of cells in each dimension. Thus, by accepting a small loss in accuracy of less than 3%, this procedure reduces the required memory resource by more than 2[n.sup.2], and execution time is dramatically improved. Assuming an essentially lossless permittivity, we use the calculated electric field distribution from a parallel transmission line to calculate the line's propagation velocity and demonstrate favorable comparison with measured values. Index Terms--Dielectric bodies, method of moments, nonhomogeneous media.

Published
2001

Catalog

Books, media, physical & digital resources
See catalog results