Samuel Ratnajeevan Herbert Hoole

Samuel Ratnajeevan Herbert Hoole
Michigan State University | MSU · Department of Electrical and Computer Engineering

D.Sc. (Eng.) London, Ph.D. Carnegie Mellon, M.Sc. Distinction London, B.Sc. Eng. Hons,. Ceylon, IEEE Fellow, Chartered Engineer (Sri Lanka)

About

320
Publications
48,603
Reads
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2,126
Citations
Introduction
1. I have worked full time at University of Ceylon Katubedde Campus (now University of Moratuwa), Engineering Services and Management Consultants (Singapore), Ibadan Polytechnic (Nigeria), PA Consulting Services (US office), Drexel University, Harvey Mudd College (and while on leave from there at ENSIEG France, National University of Singapore, Institute of Fundamental Studies, Open University of Sri Lanka and University of Ruhuna in Sri Lanka), University of Peradeniya, Rensselaer Polytechnic Institute, University of Jaffna. 2. I am now at Michigan State University. Professorial Rank: I became Assistant Professor at Drexel in Sept. 1984, Associate Professor at Harvey Mudd College in July 1987 and was promoted to Professor in Jan. 1992. 2. I have consulted for several companies -- IBM, JPL, Aerojet Electrosystems, NASA, PA Consulting Services, Qualcomm, etc.
Additional affiliations
August 2011 - present
Michigan State University
Position
  • Professor of Electrical and Computer Engineering
September 2010 - August 2011
University of Jaffna
Position
  • UGC Coordinator for the New Faculty of Engineering
December 1999 - December 2010
University of Peradeniya
Position
  • Professor (Full)
Description
  • Legal successor to the University of Ceylon
Education
July 1991 - July 1993
University of London
Field of study
  • Computational Electromagnetics
January 1982 - December 1982
Carnegie Mellon University
Field of study
  • Electromagnetic Field Computation
October 1976 - October 1997
University of London (Joint Imperial and Queen Mary Colleges)
Field of study
  • Electrical Machines and Power Systems

Publications

Publications (320)
Article
Full-text available
The current Russian war against Ukraine is of global concern. It builds on the annexation of Crimea in 2014 and subsequently the war in the Donbas region of Ukraine, and has become a large-scale Russian invasion of Ukraine from three directions, Crimea in the south, Russia in the east, and Belarus in the north. Despite the geopolitical background t...
Patent
Full-text available
A defect detection system uses dedicated, simultaneously operating finite element optimization and mesh generation. Using an Eddy-current based probe, the system can detect and model surface and sub-surface defects.
Article
Full-text available
A computational technique is presented in this paper which improves finite element method (FEM) in solving inverse problems. Subregion method is used to select and isolate the area of interest where design parameters for defect shape are updated. An elastic mesh generator is developed in this paper to generate optimal meshes in the selected area to...
Article
Full-text available
Eddy Current Testing (ECT) plays a key role in detecting cracks and defects in conductors. The present study examines for the first time how subregion method, as an effective mathematical and computational technique, can be admixed with Finite Element Method (FEM) to study multiple defects parameters for ECT issues. Separating defect region from th...
Conference Paper
Full-text available
A novel study of using Subregion Finite Element Method (Subregion FEM) is presented. The idea of minimizing processing time and saving memory especially for large-scale problems are two major challenges that researchers and engineers are facing. The importance of developing efficient computational techniques becomes more important when the inverse...
Conference Paper
A novel study of using Subregi on Elastic Finite Element Method is presented. The idea of minimizing processing time and saving memory especially for large scale an d complicated practical pr oblems is one of the major problems that researches and engi neers are facing. A practical example of detecting hidden cracks in infield military vehicle...
Poster
A novel study of using Subregi on Elastic Finite Element Method is presented. The idea of minimizing processing time and saving memory especially for large scale an d complicated practical pr oblems is one of the major problems that researches and engi neers are facing. A practical example of detecting hidden cracks in infield military vehicle...
Article
Full-text available
According to PNG Power Limited (PPL), Papua New Guinea’s peak power demand is expected to increase from 210 MW in 2012 to 347 MW in 2026. Under the current state of the power sector in Papua New Guinea (PNG), it is critical to implement measures to cope with the increasing power demand to promote investment, economic growth, and ultimately to achie...
Article
Full-text available
An electric storm is a source of electrostatic charge that can induce high current and electric potential on a surface of an aircraft through direct effects. It can also be a source of radiated electromagnetic pulses on an aircraft in flight through indirect effects. Both direct and indirect effects can have adverse effects on flight safety. Thus,...
Article
Full-text available
In this paper, a single neuron neural network beamformer is proposed. A perceptron model is designed to optimize the complex weights of a dipole array antenna to steer the beam to desired directions. The objective is to reduce the complexity by using a single neuron neural network and utilize it for adaptive beamforming in array antennas. The selec...
Conference Paper
Multipath reflections are prevalent in underground mine wireless communication systems and are less constructive when an omnidirectional antenna is used. This phenomenon can be significantly controlled by eliminating the source of all multipaths with a single beam. The single beam must be rotatable towards the desired user to be of any use. The sin...
Conference Paper
This paper presents for the first time an assessment of the impact of direct cloud-to-cloud (CC) and intra-cloud (IC) lightning flash on a commercial and a military aircraft. In contrast to cloud-to-ground (CG) lightning strikes to aircraft, where measurements of CG flash measurements may be extended to aircraft strikes, CC and IC flashes are not s...
Conference Paper
Array antennas have a nonlinear, complex relationship between the antenna beams generated and the array input functions that generate the steerable beams. In this paper we demonstrate the use of a simple, computationally less intensive Perceptron Neural Network with non-linear sigmoid activation function to do the synthesis of the desired antenna b...
Conference Paper
Eddy Current Testing (ECT) plays a key role in detecting cracks and corrosion in conductors and ferromagnetic materials. A computational model for ECT is valuable for optimizing the parameters of the test procedure and maximize the detection probability of defects. Finite Element Method (FEM) is widely used in industry for developing simulation mod...
Poster
Eddy Current Testing (ECT) plays a key role in detecting cracks and corrosion in conductors and ferromagnetic materials. A computational model for ECT is valuable for optimizing the parameters of the test procedure and maximize the detection probability of defects. Finite Element Method (FEM) is widely used in industry for developing simulation mod...
Article
Full-text available
Papua New Guinea (PNG) is blessed with numerous energy resources, including oil, gas, wind, solar, tidal and biomass. Renewable energy resources have taken centre stage as PNG along with other countries seek to push for 32% of its national power demand to be met by renewable energy sources by the year 2030. In addition, PNG has an ambitious program...
Article
Cognitive Radio is a promising technique that allows the use of underused television spectrum to reach to remote, rural communication network users. In order to develop non-interfering, broad band communication link scattered users, there is a need for robust, narrow beam antennas with minimum of side lobes. In this paper we report the flexibility...
Conference Paper
Full-text available
In finite element optimization, the computational load limits the size of problem that can be solved. Finite element computation involves the solution of large matrix equations. Then optimization requires several such equations to be solved. Parallelization has been the preferred route to overcome this problem but was again limited by the cost of c...
Article
Full-text available
This paper examines the postwar Sri Lankan conditions among Sri Lanka Muslims, also known as Moors. The article will attempt to argue that state concessions to Muslim political leaders who supported the successive Sri Lanka's ruling classes from independence through the defeat of the Liberation Tigers of Tamil Eelam (LTTE) in 2009, have meant an is...
Article
Full-text available
In finite element optimization, the computational load is a limiting issue. Parallelization has been the preferred route to overcome this problem but was again limited by the cost of computers and the number of processors available. The graphics processing unit (GPU) on a PC provides a means of implementing the massive computations on numerous para...
Article
Full-text available
In finite element optimization, the computational load is a limiting issue. Parallelization has been the preferred route to overcome this problem but was again limited by the cost of computers and the number of processors available. The graphics processing unit (GPU) on a PC provides a means of implementing the massive computations on numerous pa...
Article
Full-text available
This work presents a self-consistent and self-contained model to study and analyse aircraft-lightning electrodynamics. An aircraft-circuit-model-based estimation of lightning currents is reported when the aircraft is struck by cloud-to-ground (CG) and ground-to-cloud (GC) lightning flashes. A distributed transmission line model for the aircraft and...
Article
Full-text available
In nondestructive defect characterization, the genetic algorithm matches measurements to computations through finite element optimization of a parametrically described defect. This poses a huge computational load. A published element-by-element (EbE) conjugate gradients (CG) method for the graphics processing unit (GPU) parallelizes the matrix solu...
Article
Full-text available
This paper presents a computational investigation of the validity of eddy current testing (ECT) for defects embedded in steel using parametrically designed defects. Of particular focus is the depths at which defects can be detected through ECT. Building on this we characterize interior defects by parametrically describing them and then examining th...
Conference Paper
Full-text available
When a steel plate in an army ground vehicle is found to be defective, usually by eddy current testing (ECT), it is taken out of service for repairing without determining if the defect warrants withdrawal or not, whereas the defect might be minor and withdrawal wasteful. In building on our previous work we detect the optimal position to place the E...
Article
Full-text available
In finite element optimization, the computational load is a limiting issue. Parallelization has been the preferred route to overcome this problem but was again limited by the cost of computers and the number of processors available. The graphics processing unit (GPU) on a PC provides a means of implementing the massive computations on numerous para...
Article
Full-text available
In this paper we apply a detailed electrostatic model of an aircraft to be used in an experimentally validated, new electric-charge-based circuit model for studying aircraft-lightning electrodynamics. The model is used to evaluate the electrodynamics of an aircraft under a thundercloud. As commercial and military aircraft continue to be subject to...
Article
Full-text available
In finite element optimization, the computational load is a limiting issue. Parallelization has been the preferred route to overcome this problem but was again limited by the cost of computers and the number of processors available. The graphics processing unit (GPU) on a PC provides a means of implementing the massive computations on numerous para...
Article
Full-text available
Finite element mesh generators exist in the public domain, a few even based on a parametric device description. The typical mesh generator requires some man-machine interaction to define the points and boundary conditions. and does not work for nonstop optimization iterations for which we need a mesh dynamically evolving through the iterations with...
Article
Full-text available
In this paper we review a new electric charge based circuit model for studying aircraft-lightning electrodynamics and its application to an aircraft taking off or landing. As commercial and military aircraft continue to be subject to direct lightning flashes, there is a great need to characterize correctly the electrical currents and electric poten...
Article
This paper reviews the use of Artificial Neural Networks in lightning related problems, and especially in locating the lightning using a signal sensor with a three element antenna and signal processor. A model to correctly represent both lighting return stroke currents and the radiated lightning electromagnetic pulses (LEMP) is presented with caref...
Article
The two common types of lightning flashes that interact with both land systems and airborne systems are the cloud to ground (CG), or downward flashes, and the ground to cloud (GC), or upward flashes. In this paper we report on the direct effect of lightning strike on an aircraft when subject to both GC and CG flashes. The paper utilizes the transmi...
Article
Full-text available
Knowledge based expert systems play a major role in engineering design and optimization. This symbolic knowledge representation has made possible the representation of a broader range of engineering knowledge in order to provide computer based software tools for both analysis and design. This paper reviews existing works in electromagnetic knowledg...
Article
Full-text available
The teaching of ethics to engineering students is now mandated. Courses are centered round professional codes like the IEEE’s, not acknowledging that we operate in a grey area between the honest and the practical. This paper presents a new honest way in which ethics was taught at Michigan State University (MSU) and lessons from that experience. Doi...
Conference Paper
The paper will address the issues of a reliable model of lightning return stroke, and the extension of the model to arcs in electric power systems and aircraft. The lightning return stroke has been modeled using approximate representations of the electromagnetic wave which characterizes it: the electric circuit model and the waveguide model. It is...
Article
Full-text available
In light of the new capability to fork an already parallelized kernel on a GPU, this paper shows how the use of the parallelization capabilities of a PC’s Graphics Processing Unit (GPU) makes the finite element design of coupled problems (such as the electroheat shape optimization problems we work with) realistic and practicable in terms of computa...
Article
Full-text available
This paper presents for the first time a case for the importance of ground to cloud (i.e. upward leader) lightning flash parameters for safety testing of aircraft-lightning interaction, protection of wind turbines, as well as the importance of cloud to ground radiated electric fields for indirect lightning-aircraft interaction and generation of ele...
Article
This paper presents an electromagnetic signal processor of the electric field radiated (and received) by a three-element antenna array as a mobile station receiver. It can increase power reception in the direction of the desired signal and minimize it in the direction of interference. Statistical brute force estimation of the position of a wireless...
Article
Teaching practical design to students requires first a numerical course such as on finite elements and then a course on optimization. However, because of curricular constraints, it is very difficult to get students to take two courses. This paper describes a new semester's course at Michigan State University that accomplishes this through flip teac...
Conference Paper
Full-text available
GPU-based finite element computation offers massive parallelization. It is briefly reviewed to give due credit. Element-by-element processing by Gauss iterations we show is faster than CG (speedup of 80 at 100002 matrix) and growing linearly without limit with variables. We obtain saturating ICCG speedup of 147 on the GPU, well above the 39 reporte...
Article
Full-text available
The FORTRAN programming language was used in early days of writing finite element field computation to write programs. Much of those codes were developed in an ad hoc way. Today, modern software developers face problems in understanding, modifying and utilizing those codes. As modern software engineers are very concerned with object oriented design...
Conference Paper
Modeling and determining propagation characteristics of Waveguides and transmission lines is very important for quick analysis in designing microwave circuits. In this research, full wave finite difference frequency domain (FDFD) will be presented to analyze different magnetically isotropic and non-isotropic circular cylindrical guiding structures....
Article
In the nondestructive evaluation (NDE) of steel plates, besides the detection of cracks, what is also important is their characterization. Characterization is necessary for determining whether any discovered crack demands withdrawal of the part from service. In eddy current crack identification the response of a part to a coil is compared to the r...
Article
Full-text available
The computational algorithms for device synthesis and nondestructive evaluation (NDE) are often the same. In both we have a goal – a particular field configuration yielding the design performance in synthesis or to match exterior measurements in NDE. The geometry of the design or the postulated interior defect is then computed. Several optimizatio...
Article
Teaching practical design to students requires first a numerical course such on as finite elements and then a course on optimization. However because of curricular constraints, it is very difficult to get students to take two courses. This paper describes a new semester’s course at Michigan State University that accomplishes this through flip teach...
Article
Full-text available
Purpose – As commercial and military aircraft continue to be subject to direct lightning flashes, there is a great need to characterize correctly the electrical currents and electric potential fluctuations on an aircraft to determine alternative design approaches to minimizing the severity of the lightning-aircraft dynamics. Moreover, with the incr...
Article
Full-text available
This paper describes the Sri Lankan system of degrees in computing in the context of the new joint ACM/IEEE Computing curricula in the five areas of computer science, computer engineering, information technology, information systems and software engineering. The University Grants Commission regulates the administration and admission of all universi...
Article
Full-text available
This paper reviews mathematical optimization in synthesis and nondestructive evaluation (NDE) by the finite element method in magnetics because background work has been inadequately attributed in the literature. The review identifies the earliest papers and reports new work in nondestructive evaluation and GPU-based matrix solution to save time and...
Article
Full-text available
Purpose Inverting electroheat problems involves synthesizing the electromagnetic arrangement of coils and geometries to realize a desired heat distribution. To this end two finite element problems need to be solved, first for the magnetic fields and the joule heat that the associated eddy currents generate and then, based on these heat sources, the...