Engineering Commons^™

A Comparative Test Of Brillouin Amplification And Erbium-Doped Fiber Amplification For The Generation Of Millimeter Waves With Low Phase Noise Properties, Markus Junker, Max Ammann, Andreas Schwarzbacher, Jens Klinger, Kai-Utwe Lauterback, Thomas Schneider

Articles

Measurements of phase noise of a 40-GHz carrier signal are presented. The carrier is generated by the amplification of harmonics due to stimulated Brillouin scattering. An analogy to a generation of millimeter waves by an erbium-doped fiber instead of the Brillouin amplifier is investigated and discussed. In our setup, both show a comparable behavior in respect to their noise characteristics.

Compact Annular-Ring Embedded Circular Patch Antenna With Cross-Slot Ground Plane For Circular Polarisation, Xiulong Bao, Max Ammann

Articles

A dual-frequency dual-circularly polarised patch antenna with wide beamwidth is proposed. The two-layer structure comprises circular patches with offset circular slots connected to rectangular slots. They provide orthogonal perturbations realising RHCP and LHCP for the lower and upper bands, respectively. The wide beamwidth is realised by extending the substrate beyond the groundplane. Measurements show a maximum beamwidth of 180deg and gains of 3.9 and 0.5 dBic for zenith and 10deg elevation, respectively, for the upper band. The measured beamwidth for the low band is 130deg with a maximum gain of 3.9 and -0.7 dBic for zenith and 10deg elevation, respectively. …

Quarter-Wave Metal Plate Solar Antenna, S. Shynu, Max Ammann, Brian Norton

Articles

A novel design of a quarter-wave shorted trapezoidal metal plate solar antenna using high efficiency polycrystalline silicon solar cells is presented. Using the DC conductive parts of the cell as RF antenna elements as well as choosing the radiating element to be a small base trapezoid, better coupling between the the feed and shorting plates is ensured and 40.3% size reduction compared to a conventional shorted quarter-wave patch is obtained. The trapezoidal radiating element covers merely 2.7% of the total available illumination area of the solar cell, leaving its efficiency essentially unaffected. The proposed design strategy has been verified by …

Compact Concentric Annular-Ring Patch Antenna For Triple Frequency Operation, Xiulong Bao, Max Ammann

Articles

A novel single-layer, single-feed concentric annular-ring microstrip patch antenna providing triple-frequency operation is proposed and experimentally studied. This is achieved by embedding a small circular patch into a dual stub-loaded concentric annular-ring structure and by employing a cross-slot in the ground plane. The proposed technique can provide triple-band operation and reduce the antenna size by over 50% compared to the conventional annular-ring patch antenna for a given frequency. Experimental results show the proposed antenna to have impedance bandwidths of 6.38, 6.30 and 35% for the three bands, at 1.17, 1.428 and 1.9 GHz, respectively. The proposed structure is capable of …

From L-Shaped Planar Monopoles To A Novel Folded Antenna With Wide Bandwidth, Giuseppe Ruvio, Max Ammann

Articles

A novel folded monopole antenna is investigated numerically and experimentally. The proposed antenna comprises a short folded monopole suitably shaped at the base with two vertical grounding probes. This small antenna is shown to have a fractional impedance bandwidth up to 125% (1.6 GHz to 7.5 GHz) for a 10 dB return loss. An interesting compromise between impedance bandwidth and pattern control is found by tuning a double side bevel at the base of the monopole, the position of the feeding point and its distance from the ground plane. Measurements and simulations are in good agreement and show a dramatic …

All-Fiber Multimode-Interference-Based-Refractometer Sensor:Proposal And Design, Qian Wang, Gerald Farrell

Articles

A novel all-fiber refractometer sensor is proposed, which is based on multimode interference in the multimode fiber core section sandwiched between two single-mode fibers. A wide-angle beam propagation method in the cylindrical coordinate is employed as the modeling tool for simulation and design of the proposed refractometer sensor. The design for a refractometer is presented that shows that the refractometer would have an estimated resolution of 5.4×10−5 for refractive indices from 1.33 to 1.45 and of 3.3×10−5 for refractive indices from 1.38 to 1.45 through the choice of an appropriate length of the multimode fiber core section.

Analysis Of Strain And Intermixing In Single-Layer Ge/Si Quantum Dots Using Polarized Raman Spectroscopy, Anna Baranov, A. V. Federov, Tatiana Perova, R. A. Moore, V. Yam, D. Bouchier, V. Le Thanh, Kevin Berwick

Articles

The built-in strain and composition of as-grown and Si-capped single layers of Ge∕Si dots grown at various temperatures (460–800 °C) are studied by a comparative analysis of the Ge-Ge and Si-Ge modes in the polarized Raman spectra of the dots. A pronounced reduction of the strain and Ge content in the dots after deposition of the cap layer at low temperatures is observed, indicating that strain-induced Si diffusion from the cap layer is occurring. For large dots grown at 700–800 °C the observations are in agreement with a model of the Ge∕Si dot consisting of a Si-rich boundary region and …

Design Of One-Dimensional Composite Photonic Crystals With An Extended Photonic Band Gap, Vladimir Tolmachev, Kevin Berwick

Articles

A technique for photonic band gap (PBG) extension based on mixing photonic crystals with different lattice constants or filling factors is suggested. For the design of photonic crystals with maximal PBG extension the gap map imposition method is utilized. Gap maps for composite photonic crystals based on Si-air structures are calculated and used to predict optimal structures for fabrication.

Investigation On Annular-Ring Patch Antenna With Ebg Structure, Xiulong Bao, Giuseppe Ruvio, Max Ammann

Conference papers

An annular-ring loaded circular patch antenna with slot-ring array of EBG cells on the ground plane is presented. A comparison is made between the annular ring loaded patch on a conventional PEC groundplane and the same patch on a groundplane with a 2x2, a 4x4 and a 6x6 slot-ring EBG array. It was found that the annular-ring patch antenna with a 4 x 4 slot-ring array in the ground plane is superior in the overall performance (gain, impedance and axial-ratio bandwidth). The array of EBG was found to improve gain by 3.5dB and increase the bandwidth of input impedance by …

Generation Of High Quality Audio Natural Emotional Speech Corpus Using Task Based Mood Induction, Charlie Cullen, Brian Vaughan, Spyros Kousidis, Yi Wang, Ciaran Mcdonnell, Dermot Campbell

Conference papers

Detecting emotional dimensions [1] in speech is an area of great research interest, notably as a means of improving human computer interaction in areas such as speech synthesis [2]. In this paper, a method of obtaining high quality emotional audio speech assets is proposed. The methods of obtaining emotional content are subject to considerable debate, with distinctions between acted [3] and natural [4] speech being made based on the grounds of authenticity. Mood Induction Procedures (MIP’s) [5] are often employed to stimulate emotional dimensions in a controlled environment. This paper details experimental procedures based around MIP 4, using performance related …

B2b E-Marketplaces In The Airline Industry: A Study On Process Drivers And Performance Indicators, Claudia-Maria Wagner, Bernd Huber, Edward Sweeney

Practitioner Journals

No abstract provided.

Recruiting First Year Engineering Undergraduates, Eddie Conlon

Conference papers

This paper presents findings of three surveys conducted with first year students in the Faculty of Engineering in the Dublin Institute of Technology. It presents evidence on the reasons students study engineering, their sources of information on higher education programmes and the people who influence their decision to do engineering. It shows there are gaps in the students’ knowledge of their programmes and also between their expectations and their experience of their course. Some proposed areas of action are identified to increase both recruitment and retention. It is argued that projecting an image of engineering as a creative activity would …

Hand Posture Recognition In Sign Language Using Shape Distributions, Eamonn Young, Gary Clynch

Conference Papers

A shape distribution is a histogram used to uniquely identify different shapes. The histogram is produced by taking random distances on the surface of a shape or object. Theoretically, each shape or object should produce a unique histogram, as the distribution of distances for each shape should be different. Shape distributions have recently been implemented in a number of object recognition areas. They are an attractive method as they are inherently simple, fast and generic. This paper presents the results of research undertaken on the application of shape distributions for the purpose of sign language recognition. There are four main …

Rating Requirements Of A Unified Power Quality Conditioner (Upqc) For Voltage Ride Through Capability Enhancement, N. G. Jayanti, Malabika Basu, Michael Conlon, Kevin Gaughan

Conference papers

The problem of voltage ride through capability of fixed speed wind generation as a result of voltage sags is examined by means of a simulation study. The role of a Unified Power Quality Conditioner (UPQC), which provides both shunt and series compensation, in enhancing the ride through capability is investigated under both full and partial voltage restoration. Results of a study to identify the minimum rating requirements to ensure stability are presented.

Statistical Computation For Extreme Bridge Traffic Load Effects, Colin C. Caprani, E. J. O'Brien

Conference papers

The maintenance of highway infrastructure constitutes a major expenditure in many countries. This cost can be reduced significantly by minimizing the repair or replacement of highway bridges. In the assessment of existing bridges, the strength estimate tends to be more accurate than that of traffic loading, due to the more variable nature of loading. Recent advances in the statistical analysis of highway bridge traffic loading have resulted in more accurate forecasts of the actual loading to which a bridge is subject. While these advances require extensive numerical computation, they can significantly improve the accuracy of the calculation. This paper outlines …

Including Embodied Energy Considerations At The Conceptual Stage Of Building Design, Y. Yohanis, Brian Norton

Articles

Elevated operating temperatures reduce the solar to electrical conversion efficiency of building integrated photovoltaic devices (BIPV). Phase change materials (PCM) can be used to passively limit this temperature rise although their effectiveness is limited by their low thermal conductivities and by crystallization segregation during solidification. This paper presents an experimental evaluation of the effects of convection and crystalline segregation in a PCM as a function of efficiency of heat transfer within the finned PV/PCM system. The thermal performances of bulk PCM with crystallization segregation for different internal fin arrangements are presented. It is noted that the addition of internal fins …

A Critical Appraisal Of The Roles Of Public Sector Employees In The Provision Of Educational Buildings Under A Public Private Partnership (Ppp) In The Republic Of Ireland, Louis Gunnigan, David Eaton

Conference papers

Public-Private Partnership (PPP) has now become established as a key element in the Irish Government’s strategy in the provision of school buildings. Specific guidelines have been implemented to define the public sector role in a PPP in Ireland and these guidelines represent a significant change in role from those in the traditional schools procurement process. Through a literature review, this paper maps the PPP process and establishes the new tasks that public sector employees must carry out in the adoption of PPP. The new knowledge, skills and competence (KSC) required to carry out these tasks are noted. Whilst existing literature …

Towards An Inverse Constant Q Transform, Derry Fitzgerald, Matt Cranitch, Marcin T. Cychowski

Conference papers

The Constant Q transform has found use in the analysis of musical signals due to its logarithmic frequency resolution. Unfortunately, a considerable drawback of the Constant Q Transform is that there is no inverse transform. Here we show it is possible to obtain a good quality approximate inverse to the Constant Q transform provided that the signal to be inverted has a sparse representation in the Discrete Fourier transform domain. This inverse is obtained through the use of lo and l1 minimisation approaches to project the signal from the constant Q domain back to the Discrete Fourier Transform domain. Once …

Thermal Sprayed Surface Coatings And Optical Characterisation, Yueqiang Xue

Masters

This research work aims to establish the potential of defect detection of thermal sprayed surface coatings by using a newly developed optical non-destructive interferometric technique – Electronic Speckle Pattern Shearing Interferometry (ESPSI), rather than using mechanical destructive testing methods and other non-destructive methods. This technique has been used in many industries for non-destructive testing (NDT). However, it is innovative to use this technique for NDT of thermal sprayed metal alloy coatings, especially those that are produced by flame powder spraying process. Investigations were carried out by the SUPERJET spray process, which was the flame powder spray process utilised in this …

Attention Driven Reference Resolution In Multimodal Contexts, John D. Kelleher

Articles

In recent years a a number of psycholinguistic experiments have pointed to the interaction between language and vision. In particular, the interaction between visual attention and linguistic reference. In parallel with this, several theories of discourse have attempted to provide an account of the relationship between types of referential expressions on the one hand and the degree of mental activation on the other. Building on both of these traditions, this paper describes an attention based approach to visually situated reference resolution. The framework uses the relationship between referential form and preferred mode of interpretation as a basis for a weighted …

Serious Gordon: Using Serious Games To Teach Food Safety In The Kitchen., Brian Mac Namee, Pauline Rooney, Patrick Lindstrom, Andrew Ritchie, Frances Boylan, Greg Burke

Conference papers

This paper will describe the development of Serious Gordon, an interactive digital game developed to tech the basics of kitchen food safety to workers in industries dealing with food. The motivations driving the development of the game will be described as will the development process itself. An initial evaluation of the game, from both a technical and pedagogical point of view, will be presented as will conclusions on the viability of using a commercial game engine for the purpose of developing educational games.

The R-Cube: Reviewing, Reinforcing And Rewarding After Successful Module Completion, Ciaran O'Leary

Conference papers

Revisiting material previously presented and successfully assessed can lead to much frustration among teaching staff and students. Despite this, it is often a requirement due to the time lag between the point at which a student begins a module and the time when they successfully passed a prerequisite module. Also, students who successfully pass a module fit into a number of categories, from those who were successful in all components of the assessment to those who displayed the minimum level of competence required for satisfaction of the learning outcomes. We introduce a novel instructional model which we predict will be …

Structural Descriptions In Human-Assisted Robot Visual Learning, Geert-Jan Kruijff, John D. Kelleher, Gregor Berginc, Ales Leonardis

Conference papers

The paper presents an approach to using structural descriptions, obtained through a human-robot tutoring dialogue, as labels for the visual ob ject models a robot learns. The paper shows how structural descriptions can relate models for different aspects of one and the same object, and how relating descriptions for visual models and discourse referents enables incremental updating of model descriptions through dialogue (either robot- or human-initiated). The approach has been implemented in an integrated architecture for human-assisted robot visual learning.

Information Fusion For Visual Reference Resolution In Dynamic Situated Dialogue., Geert-Jan Kruijff, John D. Kelleher, Nick Hawes

Conference papers

Human-Robot Interaction (HRI) invariably involves dialogue about objects in the environment in which the agents are situated. The paper focuses on the issue of resolving discourse references to such visual objects. The paper addresses the problem using strategies for intra-modal fusion (identifying that different occurrences concern the same object), and inter-modal fusion, (relating object references across different modalities). Core to these strategies are sensori-motoric coordination, and ontology-based mediation between content in different modalities. The approach has been fully implemented, and is illustrated with several working examples

Spatial Prepositions In Context: The Semantics Of Near In The Presence Of Distractor Objects., Fintan Costello, John D. Kelleher

Conference papers

The paper examines how people’s judgements of proximity between two objects are influenced by the presence of a third object. In an experiment participants were presented with images containing three shapes in different relative positions, and asked to rate the acceptability of a locative expression such as ‘the circle is near the triangle’ as descriptions of those images. The results showed an interaction between the relative positions of objects and the linguistic roles that those objects play in the locative expression: proximity was a decreasing function of the distance between the object in the head position in the expression and …

Music Transcription Within Irish Traditional Music, Mikel Gainza

Doctoral

Transcribing Irish traditional music is an open-field of research. The oral transmission of the music between generations explains the lack of transcription until recent times. The music can be played solo, which permits the player to exploit the variety of ornamentation types, in unison, and also with the accompaniment of a harmonic instrument. Different signal processing applications for transcribing Irish traditional music are presented in this thesis, including onset, ornamentation and pitch detection. An onset detection system which focuses on the characteristics of the tin whistle within Irish traditional music is first presented. The tin whistle is a good example …

Design, Modelling And Simulation Of An Innovative Trefoil Rotary Kiln Pilot Plant, Mick Mckeever

Doctoral

This work investigates the contribution modelling makes when integrated into the pilot plant development stage of a new synthetic aggregate manufacturing process. The pilot plant is based around a novel rotary kiln, unique in design from standard kilns. The kiln has a trefoil cross sectional profile and a low thermal mass. A dynamic simulation model of the kiln was built to simulate the thermal behaviour of the pilot plant and the movement of the pelletised aggregate as it travels through the kiln drum.

As part of the preliminary work, a measurement and data acquisition subsystem was commissioned to allow data …

Development Of A Micro-Shot Peening Process And Testing Of Micro-Shot Peened Engineering Materials, James Vahey

Masters

A precision, air blast, shot peening machine was designed and developed and used to carry out peening operations on engineering materials and components. The machine was designed to allow all the variables of the peening process to be controlled and adjusted. The micro-shot peening process was applied to a series of standard High Speed Steel twist drills, carbide inserts for milling cutters, turning tools and EPDM material. The drills were used under controlled CNC conditions to machine mild steel plates. The useful cutting life of the drills was monitored. The surface finish and the dimensional accuracy of the holes were …

Wideband Dual Polarized Directional Base Station Antenna, Francisco L. Lerma

Masters

The thesis presents a study of different microwave radiators for wireless applications in the frequency range of 2.2 – 2.5GHz. The performance of microstrip patch antennas and dual polarized dipole antennas were evaluated numerically and experimentally verified. A single microstrip patch and a four- element microstrip array were simulated, fabricated and tested. Simulation was carried out by the finite integration time domain (FITD) method. Polarization diversity is realised using crossed dipoles printed elements. For the crossed dipole elements, two different feed arrangements were studied. Parameters such as return loss, isolation, radiation pattern, gain and bandwidth were measured and found to …

An Investigation Into The Behaviour Of Sheet Metal Workpieces When Subjected To Simultaneous Double Bending, Arthur Henry

Masters

Simultaneous double bending, where two 90° bends are formed in a single workpiece, in close proximity to each other and in alternate directions, are common in the metal forming industry, especially so in small production batches where press brakes and their associated tooling is extensively used. This bending process, resulting in what is commonly called a ‘joggle’ bend, is executed using specially shaped forming dies. The geometry of these dies determines the geometry of the bend and also the amount of sliding and /or stretching that takes place in the workpiece during the forming process. This in turn determines the …