Engineering Commons^™

Ray-Trace Modelling Of Reflectors For Quantum Dot Solar Concentrators, Manus Kennedy, Sarah Mccormack, John Doran, Brian Norton

Conference Papers

Quantum Dot Solar Concentrators (QDSCs) are static, non-imaging concentrators which do not require expensive solar tracking and concentrate both direct and diffuse light. Optical efficiencies (ηopt) and concentration ratios (C) of a single plate QDSC were calculated by Monte-Carlo ray-trace modelling. Consideration of reflection, refraction, quantum dot (QD) photon emission and absorption and light attenuation in the device matrix were included in the analysis. In this paper, the effect of placing plane and diffuse reflectors at the rear surface was analyzed. Mirrors with a structured surface (saw-tooth shaped) were also modelled and the effect of each reflector type on C …

Enhancing Educational Programmes For Geomatics In Ireland, Frank Prendergast, William Prendergast, Avril Behan, Helen Murray

Conference Papers

The growing spatial information needs of society, the rapid development of new surveying technologies, and the global demand for appropriately qualified surveyors, have triggered a radical re-evaluation of Geomatics education in Europe. Although significant enhancements to DIT’s educational programmes have been made during the last decade, the provision of new opportunities for learners and innovative changes to existing paradigms of training and education are required. This paper addresses some of the issues confronting educators in DIT, and presents some of the strategies for their enhancement and implementation.

Modelling The Effect Of Device Geometry On Concentration Ratios Of Quantum Dot Solar Concentrators, Manus Kennedy, Sarah Mccormack, John Doran, Brian Norton

Conference Papers

Quantum dot solar concentrators (QDSCs) are static, nonimaging concentrators which concentrate both direct and diffuse light. Using Monte-Carlo ray-trace modelling, concentration ratios (C) were predicted for QDSCs of different 2-D geometries. The optimum shape and size were determined, for given system parameters, by calculating the relative cost per unit power output. Devices with different 3-D geometry were also compared. The thickness of the plate was varied and devices with tapered thickness were modelled to investigate the effect on C.

Investigation Of Macrobending Losses Of Standard Single Mode Fiber With Small Bend Radii, Pengfei Wang, Qian Wang, Gerald Farrell, Ginu Rajan, Thomas Freir, John Cassidy

Articles

An investigation of macrobending loss characteristics of a standard singlemode fiber (SMF28) for small bend radii is presented theoretically and experimentally, which includes the bend loss of the SMF28 with coating layers and the bare SMF28 after stripping the coating layers and chemical etching of partial cladding. The significant influence of reflection occurring at the interface between the cladding and coating layer or the cladding layer and air on the bend loss is investigated theoretically and experimentally.

Wideband Reconfigurable Rolled Planar Monopole Antenna, Giuseppe Ruvio, Max Ammann, Zhi Ning Chen

Articles

A novel technique to reconfigure the frequency range of a planar monopole antenna is presented. By adjusting the degree of spiral tightness, a shift of the well-matched operating frequency range is achieved. The proposed antenna is capable of covering the frequencies in the range from 2.9 to 15 GHz, depending on the degree of spiral tightness. The antenna yields a high-efficiency across the full operating bandwidth. Radiation patterns show good omni-directional features in all primary cuts and remain relatively stable with the change of antenna configuration, so that it is a remarkable candidate for indoor or mobile applications where a …

Macrobending Fiber Loss Filter, Ratiometric Wavelength Measurement And Application, Qian Wang, Ginu Rajan, Gerald Farrell, Pengfei Wang, Yuliya Semenova, Thomas Freir

Articles

A macrobending standard single-mode fibre (SMF28) is optimized as an edge filter, with the optimal bending radius and length determined according to the bend loss and polarization sensitivity of the bending fibre. An all-fibre ratiometric wavelength system is built and calibrated. The system's accuracy and resolution is discussed with the influence of noise of input signal and photodetectors. Finally, the ratiometric system is employed for the demodulation of FBG strain sensing.

A Method To Measure Reference Strain In Fbg Strain Sensor Interrogation System Involving Actuators, Ginu Rajan, Yuliya Semenova, Qian Wang, Gerald Farrell, Pengfei Wang

Articles

A method for reference strain measurement for FBG strain sensor in the testing stage while applying strain using actuators like piezo translators or micro screw is introduced. Unlike conventional methods of surface mounting, in our method the strain gauge is affixed directly to the optical fibre, which allows it to use with systems where the strain is applied directly using actuators while testing the FBG sensing system. Different bonding techniques were tested and a comparison with the results from calculated values are presented. Since the contact area between the fibre and strain gauge is very small a corrected gauge factor …

Enhancement Of Maximum Time Delay In One Fiber Segment Slow Light Systems Based On Stimulated Brillouin Scattering, Ronny Henker, Thomas Schneider, Markus Junker, Kai-Uwe Lauterbach, Max Ammann, Andreas Schwarzbacher

Conference papers

An effective method to enhance the time delay in SBS-based slow-light systems by decoupling the delay from the Brillouin gain is shown. A drastic improvement of the time delay in one fiber segment was achieved.

Dual Frequency Dual Circularly-Polarised Patch Antenna With Wide Beamwidth, Xiulong Bao, Max Ammann

Conference papers

A novel probe-fed single-layer annular-ring patch antenna for dual-frequency circular polarization is evaluated numerically and experimentally verified. The proposed antenna consists of a small circular patch surrounded by two concentric annular-rings, which is loaded by an unequal lateral cross-slot ground plane. The circularly-polarized frequency ratio of the two resonant modes is tunable to a small value, suitable for wireless communications systems. The patch size of the proposed antenna is reduced by about 53% compared to the conventional circular patch at a given frequency. The radiation characteristics of the novel antenna are also presented.

Groundplane Dependent Performance Of Printed Antenna For Mb-Ofdm-Uwb, Sergio Curto, Matthias John, Max Ammann

Conference papers

A printed ultra wideband (UWB) antenna suitable for multiband orthogonal frequency division multiplexing (MB-OFDM) UWB is presented in this paper. The proposed antenna covers a wide band from 3.1 GHz to 11.2 GHz. Good performance and low cost production was obtained using FR-4 substrate. An examination of the effects of ground plane dimensions on antenna properties such as gain, bandwidth and radiation pattern is made.

Inset-Fed Mircrostrip Patch Antenna With Integrated Polycrystalline Photovoltaic Solar Cell, S. Shynu, Maria Roo Ons, Max Ammann, Sarah Gallagher, Brian Norton

Conference papers

A novel method of integrating microstrip patch antennas and polycrystalline silicon solar cells for application in autonomous communication systems is presented. The DC and RF functions are intimately linked, by using the silver DC bus bars of the solar cell as the ground plane of the microstrip patch. The performance of the solar antenna is compared with standard microstrip patch. Detailed studies of the effect of the solar cell on the microstrip antenna are then carried out. The effects of solar cell integration, DC loading and variation in incident photon intensity of the silicon layer on the performance of the …

Thermal Effectiveness Characteristics Of Low Approach Indirect Evaporative Cooling Systems In Buildings, Ben Costelloe, Donal Finn

Articles

Meteorological enthalpy analysis of temperate and maritime climates above latitude 45°N suggests that the water-side evaporative cooling technique has considerable unrealised potential with contemporary “high temperature” building cooling systems—such as chilled ceilings and displacement ventilation. As low approach conditions are the key to exploiting the cooling potential of the ambient air, thermal performance at such conditions needs to be investigated. To address the research issues, an industrial scale test rig, based on a low approach open cooling tower and plate heat exchanger and designed to maximise evaporative cooling potential, has been constructed. The thermal effectiveness of such systems (as a …

A Combinatorial Approach Of Real Ga & Fuzzy To Atc Enhancement, Hossein Farahmand, Masoud Rashidinejad, Ali Akbar Gharaveici

Turkish Journal of Electrical Engineering and Computer Sciences

Under new de-regulated environment an open access to transmission system seems to be desired. Transmission system operators (TSOs) are encouraged to use the existing facilities more efficiently. This paper focuses on study of the best location for SVC as a FACTS device to improve voltage profile as well as maximum available transfer capacity (ATC) in order to achieve lower prices. Real genetic algorithm (RGA) is used for optimization technique and analytical hierarchy process (AHP) associated with fuzzy sets to obtain priority vector for each alternative to evaluate the GA fitness. The effectiveness of the proposed methodology is shown through case …

Modelling A Deposition Process In Collective Construction, Robert L. Stewart, R. Andrew Russell, Lindsay Kleeman

Turkish Journal of Electrical Engineering and Computer Sciences

During collective construction tasks, swarm robots coordinate their actions in space and time to build structures that conform to some given design or specification. In this paper, a simulation model and a mathematical model (based on a Markov chain) are introduced to describe the deposition process of a previously detailed robotic swarm system that uses templates and feedback to facilitate construction. The models are based on the behaviour and geometry of real robots and predict the dynamics observed during practical trials as well as explaining the occurrence of different spatial patterns of building blocks. Furthermore, the models provide an insight …

Orthogonal Linear Regression In Roentgen Stereophotogrammetry, Patrick Atkinson, Jesse V. Benny, Brian J. Mccartin

Mechanical Engineering Publications

Rooted in aerial reconnaissance, mathematical photogrammetry has evolved into a mainstay of biomedical image processing. The present paper develops an algorithm for Roentgen stereophotogrammetry, a method of imaging musculoskeletal systems both static and dynamic, which incorporates a number of novel features employing techniques from projective geometry, orthogonal regression and least squares approximation. Theoretical and numerical evidence is presented of the efficacy of the proposed procedure.

Preparing A Property Statement For A Property Company: The Key Stages., Myles Keaveney

Articles

No abstract provided.

Resynthesis Methods For Sound Source Separation Using Shifted Non-Negative Factorisation Models, Derry Fitzgerald, Matt Cranitch

Conference papers

Recently, techniques such as shifted 2D non-negative matrix factorisation and shifted 2D non-negative tensor factorisations have been proposed as methods for separating harmonic musical instruments from single and multi-channel mixtures. However, these methods require the use of a Constant Q transform, for which no true inverse exists. This has adverse effects on the quality of the resynthesis of the separated sources. In this paper, a number of different resynthesis methods are investigated in order to determine the best approach to resynthesis

Towards A Personal Automatic Music Playlist Generation Alogorithm: The Need For Contextual Information, Gordon Reynolds, Dan Barry, Ted Burke, Eugene Coyle

Conference papers

Large music collections afford the listener flexibility in the form of choice, which enables the listener to choose the appropriate piece of music to enhance or complement their listening scenario on-demand. However, bundled with such a large music collection is the daunting task of manually searching through each entry in the collection to find the appropriate song required by the listener. This often leaves the listener frustrated when trying to select songs from a large music collection. In this paper, an overview of existing methods for automatically generating a playlist is discussed. This discussion outlines advantages and disadvantages associated with …

A Brief Introduction To Speech Synthesis And Voice Modification, Alan O'Cinneide, David Dorran, Mikel Gainza

Conference papers

For both engineers and linguists, the computer synthesis of natural speech is an objective that would provide many useful applications to human-computer interaction, including the realm of electro-acoustic music. The purpose of this paper is to introduce the area of speech synthesis by providing an overview of the three main methods of computer speech synthesis; namely concatenative, articulatory and formant syntheses. Some aspects of the current state of the technology are illuminated and the final section will explain the author’s motivation and current research approach to the field of voice modification.

Time Signature Detection By Using A Multi Resolution Audio Similarity Matrix, Mikel Gainza, Eugene Coyle

Conference papers

A method that estimates the time signature of a piece of music is presented. The approach exploits the repetitative structure of most music, where the same musical bar is repeated in different parts of a piece. The method utilised a multi-resolution audio similarity matrix approach, which allows comparisons between longer audio segments (bars) by combining comparisons of shorter segments (fraction of a note). The time signature method only depends on musical structure, and does not depend on the presence of percussive instruments or strong musical accents.

Blind Source Separation And Automatic Transcription Of Music Using Tensor Decompositions, Derry Fitzgerald

Conference papers

Recent advances in the use of tensor decompositions for the analysis of music are described. In particular, the use of such decompositions for sound source separation and the automatic transcription of music are explored.

Route Disruption Analysis, Adam Kirk, Mei Chen

Kentucky Transportation Center Research Report

In today’s society, transportation has become a vital component of our economy, our national defense, our emergency response systems, and our day-to-day life. Disruption of major highway systems can have serious social, health, economic, security, and environmental consequences. Disruption of highway systems can result from natural or man-made causes, and it may be intentional or unintentional. Examples of the wide-ranging causes of highway disruption include weather, natural disasters, vehicle crashes, hazardous material spills, barge impacts with bridge piers, and acts of terrorism. Disruption of key transportation chokepoints, such as bridges or tunnels, could have disastrous impacts on Kentucky. With this …

Kentucky Traffic Collision Facts 2007 Report, Kentucky Transportation Center, Kentucky State Police

Kentucky Transportation Center Research Report

KENTUCKY’S TRAFFIC COLLISION FACTS report for 2007 is based on collision reports submitted to the Kentucky State Police Records Branch. As required by Kentucky Revised Statutes 189.635, “every law enforcement agency whose officers investigate a vehicle accident of which a report must be made...shall file a report of the accident...within ten days after investigation of the accident upon forms supplied by the bureau.” The stated purpose of this requirement is to utilize data on traffic collisions for such purposes as will improve the traffic safety program in the Commonwealth. Data contained in this report are based solely on the observations …

Test 1897: John Deere 7930 Ivt Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA

The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data.

EXPLANATION OF THE TEST PROCEDURES

Purpose

The purpose of …

Tractor Test 1917: Farmtrac 675 Also 8075, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

A Simple Laboratory Experiment For The Measurement Of Single Phase Permeability, Ali R. Zand, Yuri Sikorski, Matthew S. Sanders, Homayun K. Navaz

Mechanical Engineering Publications

A simple experiment for measuring single-phase permeability of fully saturated porous medium is introduced. The experiment utilizes radial flow of a non-volatile wetting fluid through a porous medium such as ceramic tile, concrete or sand. The radial position of flow front is measured as a function of time and the collected data are analyzed using Darcy's Law to determine the permeability. In addition, the phenomenon of the multiphase flow through the medium with a broad pore size distribution is demonstrated.

Iii Finishing, Lapping, Honing And Polishing: Processes, Characterisation And Novel Techniques-Experimental Research On Ultra-Smooth Surface Polishing Based On Two-Dimensional Vibration Of Liquid, Zhong Ning Guo, X. Z. Huang, Z. G. Huang, Z. Q. Yu, T. M. Yue, Wing Bun Lee

Faculty Publications

No abstract provided.

In-Situ Optimized Pwas Phased Arrays For Lamb Wave Structural Health Monitoring, Lingyu Yu, Victor Giurgiutiu

Faculty Publications

No abstract provided.

Nebraska Summary: S641 Massey Ferguson 7465, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S644 Challenger Mt525b, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …