Engineering Commons^™

Engineering Of A Single Alkaline Fuel Cell Part I: Construction Of A Test Bed, Jonathan Blackledge, James Brunton, Eugene Coyle, David Kennedy, Heinz Schmidt-Walter, Hans Kohnke, Gerhard Sauer, Steffen Schudt, James Hamilton

Articles

Fuel Cells offer a realistic, sustainable and clean alternative energy option for stationary and mobile applications. Hydrogen and fuel cell technologies are recognised by many as possible long term energy solutions, but to-date have failed to make an impact on the energy market. This is due to a number of key reasons, some of which include, efficiency, scale, accessories and power output. Applying fuel cells to small telecommunication components requires the applications of Micro and Nanotechnology, which have yet to be perfected to make them long lasting and cost effective. This paper outlines the reasons for commercialisation of fuel cells …

A Covert Encryption Method For Applications In Electronic Data Interchange, Jonathan Blackledge, Dmitry Dubovitskiy

Articles

A principal weakness of all encryption systems is that the output data can be ‘seen’ to be encrypted. In other words, encrypted data provides a ‘flag’ on the potential value of the information that has been encrypted. In this paper, we provide a new approach to ‘hiding’ encrypted data in a digital image.

In conventional (symmetric) encryption, the plaintext is usually represented as a binary stream and encrypted using an XOR type operation with a binary cipher. The algorithm used is ideally designed to: (i) generate a maximum entropy cipher so that there is no bias with regard to any …

Inverse Scattering Solutions With Applications To Electromagnetic Signal Processing, Jonathan Blackledge, Timo Hamalainen, Jyrki Joutsensalo

Articles

When a signal is recorded that has been physically generated by some scattering process (the interaction of electromagnetic, acoustic or elastic waves with inhomogeneous materials, for example), the ‘standard model’ for the signal (i.e. information content convolved with a characteristic Impulse Response Function) is usually based on a single scattering approximation. An additive noise term is introduced into the model to take into account a range of non-deterministic factors including multiple scattering that, along with electronic noise and other background noise sources, is assumed to be relatively weak. Thus, the standard model is based on a ‘weak field condition’ and …

Analyzing The Impact Of A Virtual Machine On A Host Machine, Greg Dorn, Chris Marberry, Scott Conrad, Philip Craiger

Publications

As virtualization becomes more prevalent in the enterprise and in personal computing, there is a great need to understand the technology as well as its ramifications for recovering digital evidence. This paper focuses on trace evidence related to the installation and execution of virtual machines (VMs) on a host machine. It provides useful information regarding the types and locations of files installed by VM applications, the processes created by running VMs and the structure and identity of VMs, ancillary files and associated artifacts.

Invited Article: Data Analysis Of The Floating Potential Measurement Unit Aboard The International Space Station, Aroh Barjatya, Charles M. Swenson, Donald C. Thompson, Kenneth H. Wright

Publications

We present data from the Floating Potential Measurement Unit (FPMU) that is deployed on the starboard truss of the International Space Station. The FPMU is a suite of instruments capable of redundant measurements of various plasma parameters. The instrument suite consists of a floating potential probe, a wide-sweeping spherical Langmuir probe, a narrow-sweeping cylindrical Langmuir probe, and a plasma impedance probe. This paper gives a brief overview of the instrumentation and the received data quality, and then presents the algorithm used to reduce I-V curves to plasma parameters. Several hours of data are presented from August 5, 2006 and March …

Preliminary Feasibility Of Dedicated Breast Ct With An Inverse Geometry, Taly Gilat-Schmidt

Biomedical Engineering Faculty Research and Publications

In this study we theoretically investigated the minimum scan time of an inverse-geometry dedicated breast CT system that provides sufficient sampling and dose equivalent to mammography without exceeding the limits of source power or detector count rate. The inverse geometry, which utilizes a large-area scanned source and a narrower photon-counting detector, is expected to have improved dose efficiency compared to cone-beam methods due to reduced scatter effects and improved detector efficiency. The analysis assumed the specifications of available inverse-geometry source and detector hardware (SBDX, NovaRay, Inc, Newark CA). The scan time was calculated for a 10, 14, and 18-cm diameter …

Rf-Sputtered Bi-Substituted Iron Garnet Composite Films For Visible-Range Magnetooptics, Mohammad Alam, Mikhail Vasiliev, Kamal Alameh, V. A. Kotov

Research outputs pre 2011

We report on the synthesis of new magneto-optical materials with excellent optical and magneto-optical properties for visible-range and near-infrared applications. Bi-substituted composite garnet films fabricated with excess bismuth oxidecontent using RF co-sputtering and oven-annealing processes have been found to possess simultaneously record MO quality and uniaxial magnetic anisotropy.

Opto-Vlsi-Based Reconfigurable Photonic Rf Filter, Feng Xiao, Mingya Shen, Budi Juswardy, Kamal Alameh

Research outputs pre 2011

Radio frequency (RF) signal processors based on photonics have several advantages, such as broadband capability, immunity to electromagnetic interference, flexibility, and light weight in comparison to all-electronics RF filters. It still requires innovative research and development to achieve high-resolution reconfigurable photonic RF signal processors featuring high selectivity, resolution, wide tunability, and fast reconfigurability. In this paper, we propose and experimentally demonstrate the concept of a reconfigurable photonic RF filter structure integrating an Amplified Spontaneous Emission (ASE) source, an Opto-VLSI processor that generates arbitrary phase-only steering and multicasting holograms for wavelength selection and attenuation, arrayed waveguide gratings (AWGs) for waveband multiplexing …

Adiabatically Induced Coherent Josephson Oscillations Of Ultracold Atoms In An Asymmetric Two-Dimensional Magnetic Lattice, Ahmed Abdelrahman, Peter Hannaford, Kamal Alameh

Research outputs pre 2011

We propose a new method to create an asymmetric two-dimensional magnetic lattice which exhibits magnetic band gap structure similar to semiconductor devices. The quantum device is assumed to host bound states of collective excitations formed in a magnetically trapped quantum degenerate gas of ultracold atoms such as a Bose-Einstein condensate (BEC) or a degenerate Fermi gas. A theoretical framework is established to describe possible realization of the exciton-Mott to discharging Josephson states oscillations in which the adiabatically controlled oscillations induce ac and dc Josephson atomic currents where this effect can be used to transfer n Josephson qubits across the asymmetric …

Multipartite Entanglement In A Discrete Magnetic Bands Magnetic Lattice, Ahmed Abdelrahman, Peter Hannaford, Mikhail Vasiliev, Kamal Alameh

Research outputs pre 2011

An asymmetric multi-quantum state magnetic lattice is proposed to host entangled system formed by using Bose Einstein Condensate. Discrete magnetic bands magnetic lattice is devised to locate a controllable long-range entanglement of a many qubits well separated in space. Confinement of the system may improve the condition for long-range entanglement.

A Novel Reconfigurable Optical Interconnect Architecture Using An Opto-Vlsi Processor And A 4-F Imaging System, Mingya Shen, Feng Xiao, Kamal Alameh

Research outputs pre 2011

A novel reconfigurable optical interconnect architecture for on-board high-speed data transmission is proposed and experimentally demonstrated. The interconnect architecture is based on the use of an Opto-VLSI processor in conjunction with a 4-f imaging system to achieve reconfigurable chip-to-chip or board-to-board data communications. By reconfiguring the phase hologram of an Opto-VLSI processor, optical data generated by a vertical Cavity Surface Emitting Laser (VCSEL) associated to a chip (or a board) is arbitrarily steered to the photodetector associated to another chip (or another board). Experimental results show that the optical interconnect losses range from 5.8dB to 9.6dB, and that the maximum …

Distributed Optical Fibre Smart Sensors For Structural Health Monitoring: A Smart Transducer Interface Module, Graham Wild, Steven Hinckley

Research outputs pre 2011

In this paper, we present a smart transducer interface module (STIM) for distributed optical fibre smart sensors. The STIM is a general purpose interface that has been designed to be used with intensiometric optical fibre sensors. The interface is made up of 2 optical fibre PIN receivers, a differential amplifier and a digital signal processor. The two received signals are differentially amplified to increase sensitivity and the signal-to-noise ratio. A DSP evaluation board is used as the intelligence of the STIM, which has onboard ADC. The STIM was successfully used as an embedded system monitoring both temperature and strain, and …

Rf Magnetron Sputtered (Bidy)3(Fega)5o12:Bi2o3 Composite Garnet-Oxide Materials Possessing Record Magneto-Optic Quality In The Visible Spectral Region, Mikhail Vasiliev, Mohammad Alam, V.A. Kotov, Kamal Alameh, V.I. Belotelov, V.I. Burkov, A.K. Zvezdin

Research outputs pre 2011

Bismuth-substituted iron garnets are considered to be the most promising magneto-optical materials because of their excellent optical transparency and very high magneto-optical figures of merit in the near-infrared spectral region. However, the practical application of garnets in the visible and short-wavelength infrared parts of spectrum is currently limited, due to their very high optical absorption (especially in sputtered films) in these spectral regions. In this paper, we identify the likely source of excess absorption observed in sputtered garnet films in comparison with epitaxial layers and demonstrate (Bi,Dy)(3)(Fe,Ga)(5)O(12): Bi(2)O(3) composites possessing record MO quality in the visible region.

An Opto-Vlsi-Based Reconfigurable Optical Add-Drop Multiplexer Employing An Off-Axis 4-F Imaging System, Mingya Shen, Feng Xiao, Selam Ahderom, Kamal Alameh

Research outputs pre 2011

A novel reconfigurable optical add-drop multiplexer (ROADM) structure is proposed and demonstrated experimentally. The ROADM structure employs two arrayed waveguide gratings (AWGs), an array of optical fiber pairs, an array of 4-f imaging microlenses that are offset in relation to the axis of symmetry of the fiber pairs, and a reconfigurable Opto-VLSI processor that switches various wavelength channels between the fiber pairs to achieve add or drop multiplexing. Experimental results are shown, which demonstrate the principle of add/drop multiplexing with crosstalk of less than -27dB and insertion loss of less than 8dB over the Cband for drop and through operation …

Performance Of Mobile Camera On Colour 2d Barcode, Siong K. Ong, Douglas Chai, Keng T. Tan

Research outputs pre 2011

In recent years, colour 2D barcodes have emerged to increase the data capacity of the 2D barcode. Similarly, camera-equipped mobile phones have became more popular and their camera could act as an input device for a barcode decoder. In this paper, three Windows Mobile (WM) operated mobile phones are used to test their camera performance in reading the colour 2D barcodes. From the results, recommendations are put forward to those who are developing colour 2D barcode reader for mobile phones.

Novel Colour Selection Scheme For 2d Barcode, Hiroko Kato, Keng T. Tan, Douglas Chai

Research outputs pre 2011

The use of colours in 2D barcodes is challenging. This is even more so in barcodes for mobile devices. Although 2D barcodes are fast becoming the ubiquitous tool for mobile computing, most implementations considered monochromatic 2D barcodes. A few colour 2D barcodes are emerging but these implementations only utilises a limited number of colours. In this paper, we present the challenges faced by the use of colours in 2D barcodes for mobile devices. We also introduce a novel colour selection scheme for 2D barcode, which is implemented in our novel colour 2D barcode - the MMCCTM. Our novel selection scheme …

Multicast Encryption Infrastructure For Security In Sensor Networks, Richard R. Brooks, Brijesh Pillai, Matthew Pirretti, Michele C. Weigle

Computer Science Faculty Publications

Designing secure sensor networks is difficult. We propose an approach that uses multicast communications and requires fewer encryptions than pairwise communications. The network is partitioned into multicast regions; each region is managed by a sensor node chosen to act as a keyserver. The keyservers solicit nodes in their neighborhood to join the local multicast tree. The keyserver generates a binary tree of keys to maintain communication within the multicast region using a shared key. Our approach supports a distributed key agreement protocol that identifies the compromised keys and supports membership changes with minimum system overhead. We evaluate the overhead of …