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- Dead-time compensator (3)
- ISE (2)
- Integral of Absolute Error (2)
- Performance Index (2)
- Smith predictor (2)
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- Optimum Control System. (1)
- 1D Photonic С rystal (1)
- 2.4 to 9 GHz antenna pattern stability monopole antennas planar monopole reconfigurable radio software defined radio ultrawide impedance bandwidth wideband antenna (1)
- 2.45 GHz 5.8 GHz ISM bands antenna gain horizontal slots hybrid inverted-L antenna impedance bandwidth lower edge frequency mobile applications (1)
- 800 MHz to 10.5 GHz (1)
- Affine blending systems (1)
- All optical matrix switch (1)
- Bevelling (1)
- Bispectrum (1)
- Broadband monopoles compact configuration impedance optimisation planar monopole radiation pattern radiation properties roll monopole thick cylindrical monopole thin-wire monopole (1)
- CALL TSM computer assisted language learning foreign language learning programme speech-adaptive time-scale modification tutor model variable time-scaling method (1)
- Cholesteric mirror (1)
- Communication (1)
- Control design (1)
- Control systems (1)
- Controls (1)
- Drum Transcription (1)
- E-commerce (1)
- EM coupling broadband properties circular annular monopole circular annular planar monopole electromagnetic coupling impedance bandwidth parametric effects planar radiator probe-fed strip radiation patterns (1)
- Electron beams (1)
- FTIR (1)
- First-order-plus-dead-time model (1)
- Fluorine (1)
- Frequency domain (1)
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Articles 1 - 24 of 24
Full-Text Articles in Engineering
Identification And Pid Control Of Time-Delayed Processes, Tony Kealy
Identification And Pid Control Of Time-Delayed Processes, Tony Kealy
Masters
This research was conducted primarily to investigate a selection of known methods for the identification of a mathematical model for processes with an inherent time delay, and subsequently, use the parameters of the identified model to regulate the processes via the PI/PID control strategy. The research examines the level of difficulty in performing or sanctioning different system identification methods in order to re-tune the controller. The process model identification methods are carried out on both simulated and real processes in the first part of the research. The selected parametric identification methods are chosen because they encompass open- and closed- loop …
The Estimation And Control Of A Laboratory Heating And Ventilation System, Robin P. Mooney
The Estimation And Control Of A Laboratory Heating And Ventilation System, Robin P. Mooney
Masters in Advanced Engineering
This dissertation is concerned with the estimation and control of a laboratory heating and ventilation system (Instrutek VVS-400). The system is a 2x2 multi-input multi-output process (MIMO). It has been shown that simple techniques such as the ultimate cycle method do not provide adequate control of the process. The system was interfaced with a PC using Matlab/Simulink via a data acquisition package (Humusoft). Continuous time process identification techniques were applied to the flow and temperature processes. The alternative tangent and point method was used to model the processes, and their interaction, using a first order lag plus delay model. Models …
Comparison Of Process Identification Techniqies In The Time- And Frequency-Domains, Tony Kealy, Aidan O'Dwyer
Comparison Of Process Identification Techniqies In The Time- And Frequency-Domains, Tony Kealy, Aidan O'Dwyer
Conference papers
This paper describes ten methods to identify a mathematical model for a real process with a time delay. The process is the Process Trainer, PT326 from Feedback Instruments Limited. Six of the methods use step response data and one of the methods uses impulse response data for identification. Two of the methods use frequency response data and the final method uses information from relay-based experiments. The best results are obtained using a combined analytical and gradient method [6] in the frequency-domain and, in the time-domain, using the two-point algorithm [1] and a method proposed by Suganda et al. [5].
Analytical Ise Calculation And Optimum Control System Design, Tony Kealy, Aidan O'Dwyer
Analytical Ise Calculation And Optimum Control System Design, Tony Kealy, Aidan O'Dwyer
Conference papers
Abstract – In control system theory, a performance index is a quantitative measure of the performance of a system and is chosen so that emphasis is given to the important system parameters. In this paper, the authors demonstrate two methods to determine analytically the Integral of the Square of the Error (ISE) performance index value for a first-order-plus-dead-time (FOPDT) process model under PI control. The ability of proportional/integral (PI) and proportional/integral/derivative (PID) controllers to compensate most practical industrial processes has led to their wide acceptance in industrial applications. The most direct way to set up PI/PID controller parameters is the …
An Investigation Into Non-Verbal Sound-Based Modes Of Human-To-Computer Communication With Rehabilitation Applications, Ted Burke
Conference Papers
During the course of our work in the National Rehabilitation Hospital in Ireland we have encountered patients who, while unable to speak, are capable of making reproducible utterances. We present techniques used to harness such utterances, in addition to whistling, as a means of communication and control. A simple technique for identifying the phonemes /o/ and /s/ (in single-symbol ARPAbet notation) is presented with applications. The use of pitch variation as a means of controlling a continuously variable parameter is described with two applications - a microcontroller based light dimmer switch and a computer program which facilitates mouse pointer control. …
Circular Annular Planar Monopoles With Em Coupling, Z. N. Chen, Max Ammann, M.Y. W. Chia, T.S. P. See
Circular Annular Planar Monopoles With Em Coupling, Z. N. Chen, Max Ammann, M.Y. W. Chia, T.S. P. See
Articles
A circular annular planar monopole with electromagnetic coupling shows broadband properties. The planar radiator is electromagnetically coupled with a probe-fed strip, and separated from it by a thin dielectric sheet. The parametric effects on the bandwidth are examined experimentally. The measurements demonstrate that the proposed monopoles have the merit of broad impedance bandwidths in the order of 100% for VSWR=2:1 and of 4:1 for VSWR=3:1 and acceptable radiation patterns across the bandwidths.
Drum Transcription In The Presence Of Pitched Instruments Using Prior Subspace Analysis, Derry Fitzgerald, Robert Lawlor, Eugene Coyle
Drum Transcription In The Presence Of Pitched Instruments Using Prior Subspace Analysis, Derry Fitzgerald, Robert Lawlor, Eugene Coyle
Conference papers
This paper demonstrates the use of Prior Subspace Analysis (PSA) as a method for transcribing drums in the presence of pitched instruments. PSA uses prior subspaces that represent the sources to be transcribed to overcome some of the problems associated with other subspace methods such as Independent Subspace Analysis (ISA) or sub-band ISA. The use of prior knowledge results in improved robustness for transcription purposes and enables the method to work more readily in the presence of pitched instruments than other subspace methods. The system presented in this paper attempts to extend the use of PSA to transcribe drum sounds …
Optical Switches Using Electro-Optical Effects In Liquid Crystals, Yuliya Semenova, S. Dovgalets, Yuri Panarin, Gerald Farrell
Optical Switches Using Electro-Optical Effects In Liquid Crystals, Yuliya Semenova, S. Dovgalets, Yuri Panarin, Gerald Farrell
Articles
A simple displacement sensor based on a bent singlemode-multimode-singlemode (SMS) fiber structure is proposed and experimentally investigated. The sensor offers a wider displacement range, not limited by the risk of fiber breakage, as well as a three-fold increase in displacement sensitivity by comparison with a straight SMS structure sensor. This sensor can be interrogated by either an optical spectral analyzer (OSA) or a ratiometric interrogation system: (1) if interrogated by an OSA assuming a resolution of 1 pm, it has a sensitivity of 28.2 nm for a displacement measurement range from 0 to 280 μm; (2) if interrogated by a …
Design Criteria And Optical Characteristics Of One-Dimensional Photonic Crystals Based On Periodically Grooved Silicon, Vladimir Tolmachev, Tatiana Perova, Kevin Berwick
Design Criteria And Optical Characteristics Of One-Dimensional Photonic Crystals Based On Periodically Grooved Silicon, Vladimir Tolmachev, Tatiana Perova, Kevin Berwick
Articles
Photonic bandgap (PBG) regions have been calculated for periodically grooved Si structures, acting as a one-dimensional photonic crystal. The wavelength range of the PBG as a function of the ratio (DSi/A) is presented, where DSi is the width of the Si walls and A is the grooved silicon lattice constant. The influence of the parameter DSi, the refractive index of the space between the Si walls and the number of structure periods, m, on the forming of PBG regions is discussed. A good correlation between the calculated and the experimentally observed …
Study Of Structure And Quality Of Different Silicon Oxides Using Ftir And Raman Microscopy, C. Moore, T. S. Perova, B. Kennedy, Kevin Berwick, I. I. Shaganov, R. A. Moore
Study Of Structure And Quality Of Different Silicon Oxides Using Ftir And Raman Microscopy, C. Moore, T. S. Perova, B. Kennedy, Kevin Berwick, I. I. Shaganov, R. A. Moore
Articles
In this work, SiO2 and fluorine and phosphorous doped SiO2 thin films are investigated using FTIR and Raman techniques. FTIR spectroscopy was performed at normal and oblique incidence of the probe beam in transmission and reflection modes. The effect of polarisation and angle of incidence of the probe beam is examined for the case of reflection mode. Infrared spectra taken from doped oxides show that the structure changes with the passage of time. Alternate methods to calculate the thickness of the doped film are therefore discussed. Infrared spectra of electron beam evaporated oxides give valuable information on their …
An Outline And Further Development Of Smith Predictor Based Methods For The Compensation Of Processes With Time Delay, Pauline Sourdille, Aidan O'Dwyer
An Outline And Further Development Of Smith Predictor Based Methods For The Compensation Of Processes With Time Delay, Pauline Sourdille, Aidan O'Dwyer
Conference papers
An extensive literature review is presented and a new modified Smith predictor is subsequently presented.
Analytical Ise Calculation And Optimum Control System Design, Tony Kealy, Aidan O'Dwyer
Analytical Ise Calculation And Optimum Control System Design, Tony Kealy, Aidan O'Dwyer
Conference papers
In control system theory, a performance index is a quantitative measure of the performance of a system and is chosen so that emphasis is given to the important system parameters. In this paper, the authors demonstrate two methods to determine analytically the ISE performance index value for a FOPDT process model under PI control. The ability of proportional/integral (PI) and proportional/integral/derivative (PID) controllers to compensate most practical industrial processes has led to their wide acceptance in industrial applications. The most direct way to set up PI/PID controller parameters is the use of tuning rules. The second part of this paper …
System Identification Using Higher Order Spectra, Aidan O'Dwyer
System Identification Using Higher Order Spectra, Aidan O'Dwyer
Conference papers
This communication will explore the use of particular types of frequency domain concepts, labelled higher order spectra, to help determine the frequency response of a process. This will allow the identification of the parameters of a single input, single output (SISO) model for a process (which includes a time delay), in both open loop and closed loop environments.
On Stability Of Affine Blending Systems, Ruiyao Gao, Aidan O'Dwyer, Seamus Mcloone, Eugene Coyle
On Stability Of Affine Blending Systems, Ruiyao Gao, Aidan O'Dwyer, Seamus Mcloone, Eugene Coyle
Conference papers
This paper presents a novel approach to stability analysis of affine blending systems. The analysis is based on Quadratic Lyapunov functions. The approach considers the nonlinear offset term in affine blending systems as non-vanishing perturbations added to the corresponding nominal linear blending systems. The affine blending systems will be bounded if the corresponding linear blending system is exponentially stable. The bound is determined by an ultimate limit, which is proportional to the maximum of the offset terms of each affine system.
New Modified Smith Predictor Designs, Pauline Sourdille, Aidan O'Dwyer
New Modified Smith Predictor Designs, Pauline Sourdille, Aidan O'Dwyer
Conference papers
By combining several existing modified Smith predictor structures, presented in a literature review, a generalised form of the Smith predictor is proposed. From this structure, excellent servo and regulator responses can be obtained by specifying three controller dynamic elements. Two new modified Smith predictor structures are presented with their associated tuning rules. The results of the simulations indicate that the two new designs give better overall responses than the original Smith predictor.
Pid Compensation Of Time Delayed Processes 1998-2002: A Survey, Aidan O'Dwyer
Pid Compensation Of Time Delayed Processes 1998-2002: A Survey, Aidan O'Dwyer
Conference papers
A time delay may be defined as the time interval between the start of an event at one point in a system and its resulting action at another point in the system. Delays are also known as transport lags or dead times; they arise in physical, chemical, biological and economic systems, as well as in the process of measurement and computation. Methods for the compensation of time delayed processes may be broadly divided into proportional integral derivative (PID) based controllers, in which the controller parameters are adapted to the controller structure, and structurally optimised controllers, in which the controller structure …
Quality Challenges In E-Commerce Websites, Ronan Fitzpatrick
Quality Challenges In E-Commerce Websites, Ronan Fitzpatrick
Conference papers
No abstract provided.
Speech-Adaptive Time-Scale Modification For Computer Assisted Language Learning, Olivia Donnellan, Elmar Jung, Eugene Coyle
Speech-Adaptive Time-Scale Modification For Computer Assisted Language Learning, Olivia Donnellan, Elmar Jung, Eugene Coyle
Conference papers
In traditional foreign language learning programmes students are offered a tutor model characterised by slow, deliberate speech. This is insufficient to prepare them to cope with native, colloquial speech. By applying a timescale modification (TSM) algorithm to natural-speed, native speech, students have access to a more desirable, natural speech corpus which permits them to practise essential listening skills in a more focussed manner. This paper presents a method which allows slowing down speech without compromising the quality, pitch or naturalness of the slowed speech by applying different scaling factors to different types of speech segments. The new method is compared …
A Wide-Band Shorted Planar Monopole With Bevel, Max Ammann, Zhi Ning Chen
A Wide-Band Shorted Planar Monopole With Bevel, Max Ammann, Zhi Ning Chen
Articles
A new wide-band shorted planar monopole with a bevel is presented. The numerical simulations and measurements demonstrate that the impedance bandwidth of a wide-band planar square monopole is shown to increase dramatically by combining bevelling and a shorting technique. The radiation pattern stability is also discussed.
Optimization And Comparison Of Broadband Monopoles, Z. N. Chen, M.Y. W. Chia, Max Ammann
Optimization And Comparison Of Broadband Monopoles, Z. N. Chen, M.Y. W. Chia, Max Ammann
Articles
The impedance and radiation properties of four broadband monopoles are compared and the parameters of a new roll monopole are optimised experimentally and numerically. The performances of the roll monopole with various numbers of roll turns are discussed and optimised numerically. The measurements and simulations show that, compared with conventional broadband monopoles, the roll monopole
Modified Planar Inverted-L Antenna, Jonathan Evans, Max Ammann
Modified Planar Inverted-L Antenna, Jonathan Evans, Max Ammann
Conference papers
A hybrid inverted-L antenna (HIL) has been shown to reduce the physical height of a square planar monopole antenna, while retaining a relatively wide impedance bandwidth and good radiation pattern characteristics. The introduction of horizontal slots in the vertical edges of the antenna cause the surface current to meander, resulting in a decrease in the lower edge frequency of the impedance bandwidth. The impact of different sizes and arrangements of slots on impedance and radiation pattern bandwidth, gain and surface current distribution is simulated using transmission line modelling (TLM). Simulated results for impedance bandwidth are verified with measurements. With other …
Improved Pattern Stability For Monopole Antennas With Ultrawideband Impedance Characteristics, Max Ammann
Improved Pattern Stability For Monopole Antennas With Ultrawideband Impedance Characteristics, Max Ammann
Conference papers
The requirement of future software defined and reconfigurable radio networks to operate in multiple, wide-ranging, frequency bands places heavy demands on antenna designs. Rather than using antennas tuned at the time of manufacture to operate in certain predefined frequency bands under predefined radio systems, which limits the possibilities of implementing new radio systems on a reconfigurable terminal, a wideband antenna is proposed. The use of a single antenna which can operate over many octaves is very desirable for future wireless communications systems. We discuss the characteristics of the planar monopole, an antenna with wideband properties. The addition of a second …
Comparison Of Process Identification Techniques In The Time And Frequency Domains, Tony Kealy, Aidan O'Dwyer
Comparison Of Process Identification Techniques In The Time And Frequency Domains, Tony Kealy, Aidan O'Dwyer
Conference papers
This paper describes ten methods to identify a mathematical model for a real process with a time delay. The process is the Process Trainer, PT326 from Feedback Instruments Limited. Six of the methods use step response data and one of the methods uses impulse response data for identification. Two of the methods use frequency response data and the final method uses information from relay-based experiments. The best results are obtained using a combined analytical and gradient method [6] in the frequency-domain and, in the time-domain, using the two-point algorithm [1] and a method proposed by Suganda et al. [5].
A New Modified Smith Predictor Design, Pauline Sourdille, Aidan O'Dwyer
A New Modified Smith Predictor Design, Pauline Sourdille, Aidan O'Dwyer
Conference papers
A new modified Smith predictor structure is presented with its associated tuning rules.