Digital Commons Network^™

Textual Case-Based Reasoning For Spam Filtering: A Comparison Of Feature-Based And Feature-Free Approaches, Sarah Jane Delany, Derek Bridge

Articles

Spam filtering is a text classification task to which Case-Based Reasoning (CBR) has been successfully applied. We describe the ECUE system, which classifies emails using a feature-based form of textual CBR. Then, we describe an alternative way to compute the distances between cases in a feature-free fashion, using a distance measure based on text compression. This distance measure has the advantages of having no set-up costs and being resilient to concept drift. We report an empirical comparison, which shows the feature-free approach to be more accurate than the feature-based system. These results are fairly robust over different compression algorithms in …

The Effect Of Physiological Cyclic Stretch On The Cell Morphology, Cell Orientation And Protein Expression Of Endothelial Cells, V. Barron, Claire Brougham, K. Coghlan, C. Stenson-Cox, D. O'Mahoney, P.E. Mchugh

Articles

In vivo, endothelial cells are constantly exposed to pulsatile shear and tensile stresses. The main aim of this study was to design and build a physiological simulator, which reproduced homogenous strain profiles of the tensile strain experienced in vivo, and to investigate the effect of this cyclic tensile strain on the cell morphology, cell orientation and protein expression of endothelial cells. The biological response of human umbilical vein endothelial cells to a uniaxial cyclic stretch, in this newly developed simulator, was examined experimentally using immunohistostaining and confocal imaging and it was

found that the cells elongated and oriented at 58.9± …

Preliminary Results For A Monocular Marker-Free Gait Measurement System, Jane Courtney, Annraoi Depaor

Articles

This paper presents results from a novel monocular marker-free gait measurement system. The system was designed for physical and occupational therapists to monitor the progress of patients through therapy. It is based on a novel human motion capture method derived from model-based tracking. Testing is performed on two monocular, sagittal-view, sample gait videos – one with both the environment and the subject’s appearance and movement restricted and one in a natural environment with unrestricted clothing and motion. Results of the modelling, tracking and analysis stages are presented along with standard gait graphs and parameters.

Integrated Antenna For Multiband Multi-National Wireless Combined With Gsm1800/Pcs1900/Imt2000 + Extension, Matthias John, Max Ammann

Articles

A printed triple-band monopole antenna appropriate for use as a terminal antenna in modern wireless multiband systems is proposed. The impedance bandwidth of each band has been optimised using a quasi-Newton technique and the bandwidth includes virtually all wireless bands. Various parameter sweeps are presented which improve our understanding of the antenna, in particular, the effect of groundplane-size and branch-off point on impedance bandwidth and radiation pattern.

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.

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 …

Voice Activated Command And Control With Speech Recognition Over Wifi, Brian Nolan, Tony Ayres

Articles

This paper presents work conducted to date on the development of a voice activated command and control framework specifically for the control of remote devices in a ubiquitous computing environment. The prototype device is a Java controlled Lego Mindstorm robot. The research considers three different scenario configurations. A recognition grammar for command and control of the robot has been created and implemented in Java, in part in the recognition engine and in part on the robot. The physical topology involves Java at each node endpoint, that is, at the handheld PC (iPaq), the PC workstation, the Linux server and onboard …

Why Renewables Need Nuclear?: A Brief Narrative, John Ratcliffe, Ruth Saurin

Articles

No abstract provided.

Effect Of Step Sintering On Breakdown Voltage Of Varistors Prepared From Nanomaterials, Suresh Pillai, Declan Mccormack, John Kelly, Ramesh Raghavendra

Articles

No abstract provided.

Synthesis Of High-Temperature Stable Anatase Tio2 Photocatalyst, Suresh Pillai, Declan Mccormack, Michael Seery, Pradeepan Periyat, Steven Hinder, John Colreavy, Reenamol George, Hugh Hayden

Articles

In the absence of a dopant or precursor odification, anatase to rutile transformation in synthetic TiO2 sually ccurs at a temperature of 600 700 °C. Conventionally, metal oxide dopants (e.g., Al2O3 nd SiO2 are used o tune the anatase to rutile transformation. A simple methodology is reported here to extend the anatase utile transformation by employing various concentrations of urea. XRD and Raman spectroscopy were used uring thermal treatment. A significantly higher anatase phase (97%) as been obtained at 800 C with use of a 1:1 Ti(OPr)4 urea composition and 11% anatase composition is etained even after calcining …

Geographic Variation Of Solar Water Heater Performance In Europe, Y. Yohanis, O. Popel, S. Frid, Brian Norton

Articles

Solar water heater (SWH) performance has been analysed using the ‘number of days’ method for 147 different sites in all European countries. The total number of days that the temperature of delivered solar heated water reaches or exceeds specified demand temperatures is correlated with solar radiation on a horizontal surface for summer, warm half-year, and whole year periods. Maps are presented and discussed showing the contours for the number of days that an illustrative SWH met different hot water demand temperatures. Correlations between number of days water is provided at a specified temperature and solar fractions for the same periods …

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 …

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 …

Planar Antennas, Zhi Ning Cheng, Max Ammann, Xianming Qing, Xuan Hui Wu, T. S.P. See, A. Cai

Articles

This article reviews the state of the art in broadband antennas for emerging UWB applications and addresses the important issues of the broadband antenna design for UWB applications. First, a variety of planar monopoles with finite ground planes are reviewed. Next, the roll antennas with enhanced radiation performance are outlined. After that, the planar antennas printed on PCBs are described. A directional antipodal Vivaldi antenna is also presented for UWB applications. Last, a UWB antenna for wearable applications is exemplified

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 …

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.

Process Modeling For Simulation, John Ryan, Cathal Heavey

Articles

This paper discusses shortfalls in relation to the requirements gathering phases of simulation. While many developments have taken place around supporting the model coding task of simulation, there are few tools available to assist in the requirements gathering phase. This is surprising as it has been reported by several researchers that the requirements phase can absorb twice as much resources as the coding phase. There are numerous process modeling tools available (over 100) that can and have been used to support the requirements phase of simulation. This paper provides a selective review of some of the most important in relation …

Photopolymer Diffractive Optical Elements In Electronic Speckle Pattern Shearing Interferometry, Emilia Mihaylova, Izabela Naydenova, Barry Duignan, Suzanne Martin, Vincent Toal

Articles

In this paper we present an electronic speckle pattern shearing interferometer using a photopolymer diffractive optical element in the form of a holographic grating, in combination with a ground glass to shear the images. The sheared images on the ground glass are further imaged onto a CCD camera. The distance between the grating and the ground glass can be used to control the shear and to vary the sensitivity of the system. The direction of sensitivity is easily controlled by rotation of the diffraction grating around its normal. Introducing photopolymer holographic gratings in ESPSI gives the advantage of using high …

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 …