Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 23 of 23
Full-Text Articles in Engineering
Optical Cavity Design Of Integrated Microphotonic Wideband Adaptive Rf Signal Processor, Rong Zheng, Zhenglin Wang, Kamal Alameh
Optical Cavity Design Of Integrated Microphotonic Wideband Adaptive Rf Signal Processor, Rong Zheng, Zhenglin Wang, Kamal Alameh
Research outputs pre 2011
In this paper. we analyse the beam propagation within the optical cavities of all integrated MicroPhotonic adaptive RF signal processor, and optimize the optical beam diameter and incidence angle that maximize the number of taps to realise high-resolution R F processor. Simulation results show that for a 1m-diameter collimated Gallssioll beam, 16 taps per cavity can be achieved for a 20mm-long cavity, and that there is no need for a diffractive optical element (DOE) to re- collimate the Gaussian beam within the cavity. The tolerance of the MicrnPhotonic processor to changes in optical cavity length which degrade the beam overlapping …
Throughput And Delay Optimization In Wdm Fddi Optical Network, Muhsen Aljada, Kamal Alameh, Khalid Al-Begain
Throughput And Delay Optimization In Wdm Fddi Optical Network, Muhsen Aljada, Kamal Alameh, Khalid Al-Begain
Research outputs pre 2011
The rapidly growing Internet traffic are driving the demands for higher transmission capacity and higher processing speed, especially for the backbone networks. To support such bandwidth usage an optical Fiber Distributed Data Interface Wavelengtg Division Multiplexed (FDDI/WDM) network is proposed, wherein the wavelength channels are amplified using Erbium-Doped Fiber Amplifiers (EDFA's) to compensate for the losses over the optical fiber span. In this paper we investigate the network performance for both asynchronous and synchronous transmissions by measuring the amplified spontaneous emission (ASE) along the ring, the optical signal to noise ratio (OSNR) and the electrical SNR at different destinations. The …
Design Of Reconfigurable Optical Interconnects Employing Opto-Vlsi Processors, Roger Jeffery, Kamal Alameh, Mikhail Vasiliev
Design Of Reconfigurable Optical Interconnects Employing Opto-Vlsi Processors, Roger Jeffery, Kamal Alameh, Mikhail Vasiliev
Research outputs pre 2011
We investigate the design and performance of a reconfigurable optical interconnect structure based on vertical-cavity surface-emitting lasers (VCSEL), Opto-VLSI processors and photodetector arrays. We optimise a proof-of-concept 3-VCSEL-element structure that eliminates crosstalk caused by unwanted diffracted optical beams and show that a bit error role (BER) of 10'17 is feasible at 3.2 Gbps for each channel.
Dynamic Wavefront Generation Technology Using Optovlsi Processor, Zhenglin Wang, Kamal Alameh, Rong Zheng
Dynamic Wavefront Generation Technology Using Optovlsi Processor, Zhenglin Wang, Kamal Alameh, Rong Zheng
Research outputs pre 2011
In this paper we present a novel approach for dynamic wavefront generatio based on reconfigurable Opto-VLSI processing. Computer algorithms are developed to generate arbitrary quadric-phse lense and lenslet array with programmable focal lenght, beam steering and lens diameter by driving the Opto-VLSI processor with different computer generated phase holograms. Proff-of-concept experimental results show that multiple spheric and aspheric lens/lenslet wavefrongs can be generated with each lens independently addressed. The measured meaximum focal length tuning range is from +80mm to infinity and the beam scanning angular range is +7mrad, which are in excellent agreement with theory. Difference spatial profiles for wavefront …
Optical Interference Suppression Using Microphotonic Rf Filter Structure, Rong Zheng, Kamal E. Alameh, Zhenglin Wang
Optical Interference Suppression Using Microphotonic Rf Filter Structure, Rong Zheng, Kamal E. Alameh, Zhenglin Wang
Research outputs pre 2011
The impact of laser coherence noise on conventional photonic RF filters is investigated in this paper. In addition, a new microphotonic adaptive RF filter structure is proposed, which can simultaneously suppress the phased-induced intensity noise caused by optical interference. Results show that the coherence length of the laser light significantly degrades the RF frequency response of a photonic transversal RF filter, whereas the microphotonic RF filter has the capability of generating arbitrary transfer function with no phase-induced intensity noise
Image Segmentation Using Neuromorphic Integrate And Fire Cells, Gregory Crebbin
Image Segmentation Using Neuromorphic Integrate And Fire Cells, Gregory Crebbin
Research outputs pre 2011
This paper introduces an electronic circuit implementation of an integrate-and-fire cell. The cell generates output current pulses when the input light intensity exceeds a given threshold. A firing cell also transmits its firing pattern to neighbouring cells, thereby causing blocks of cells to fire in synchrony when their detectors receive similar input light intensities. The synchronicity and frequency of the pulses can be used to code an image into separate regions or objects. The actions of the cell are demonstrated with the simulation of a linear 8-cell array
Establishing Physical Survivability Of Large Networks Using Properties Of Two-Connected Graphs, Daryoush Habibi, Hoang N. Nguyen, Quoc Viet Phung, Kung-Meng Lo
Establishing Physical Survivability Of Large Networks Using Properties Of Two-Connected Graphs, Daryoush Habibi, Hoang N. Nguyen, Quoc Viet Phung, Kung-Meng Lo
Research outputs pre 2011
Establishing the physical survivability of large networks is not a trivial task. Some techniques for assessing physical survivability such as the cutset method can not deal with large size networks (S. Ramamurthy and B. Mukherjee), (W.N. Grover and J. Doucette, 2001). A fast technique for finding biconnected components of a graph and testing the network for node-/link-bridges, presented in (W.D. Grover, 2004), does not provide any further information, such as identifying the fundamental cycles within the network, which would significantly benefit the next phase of network design for protection using such techniques as shared backup path protection (SBPP), p-cycle, or …
An Analogue Recurrent Neural Networks For Trajectory Learning And Other Industrial Applications, Ganesh Kothapalli
An Analogue Recurrent Neural Networks For Trajectory Learning And Other Industrial Applications, Ganesh Kothapalli
Research outputs pre 2011
A real-time analogue recurrent neural network (RNN) can extract and learn the unknown dynamics (and features) of a typical control system such as a robot manipulator. The task at hand is a tracking problem in the presence of disturbances. With reference to the tasks assigned to an industrial robot, one important issue is to determine the motion of the joints and the effector of the robot. In order to model robot dynamics we use a neural network that can be implemented in hardware. The synaptic weights are modelled as variable gain cells that can be implemented with a few MOS …
K Pair Of Disjoint Paths Algorithm For Protection In Wdm Optical Networks, Quoc Viet Phung, Daryoush Habibi, Hoang N. Nguyen, Kungmang Lo
K Pair Of Disjoint Paths Algorithm For Protection In Wdm Optical Networks, Quoc Viet Phung, Daryoush Habibi, Hoang N. Nguyen, Kungmang Lo
Research outputs pre 2011
Survivable routing in wavelength division multiplexing (WDM) optical networks has been proven to be NP-hard problem. There is a trade-off between the computational time and the optimality of solutions in existing approaches to the problem. Existing heuristic approaches purely based the graph algorithms are efficient in computational time but do not offer optimal solutions and may fail in some cases even when a solution exists. Meanwhile, the integer linear programming (ILP) models offer optimal solutions but are intractable even with moderate scale networks. In this paper, we introduce a new algorithm for finding K pairs of disjoint paths which are …
Dynamic Wavelength Routing In All Optical Mesh Network, Kungmang Lo, Daryoush Habibi, Quoc Viet Phung, Hoang Nghia Nguyen
Dynamic Wavelength Routing In All Optical Mesh Network, Kungmang Lo, Daryoush Habibi, Quoc Viet Phung, Hoang Nghia Nguyen
Research outputs pre 2011
Wavelength-division multiplexing (WDM) offers the capability to handle the increasing demand of network traffic in a manner that takes advantage of already deployed optical fibers. Lightpaths are optical connections carried end-to-end over a wavelength on each intermediate link. Wavelengths are the main resource in WDM networks. Due to the inherent channel constraints, a dynamic control mechanism is required to efficiently utilize the resource to maximize lightpath connections. In this paper, we investigate a class of adaptive routing called dynamic wavelength routing (DWR), in which wavelength converters (WCs) are not utilized in the network. The objective is to maximize the wavelength …
Region Segmentation For Facial Image Compressing, Alexander Tropf, Douglas Chai
Region Segmentation For Facial Image Compressing, Alexander Tropf, Douglas Chai
Research outputs pre 2011
This paper addresses the segmentation of passport images in order to improve quality of significant regions and to further reduce redundancy of insignificant ones. The approach is to first segment a facial image into two major regions, namely background and foreground. Here a new technique using pixel difference is presented. To compress facial regions at better quality, a face segmentation algorithm is introduced that detects eyes and mouth in a face. Region of interest (ROI) coding is then used to obtain better quality for facial features. At the end, some strategies that make use of region segmentation are proposed in …
Broadband Static Micro-Delay Lines Generation For Oct, Kamal Alameh, David Sampson, Zhenglin Wang, Rong Zheng, Chung Poh
Broadband Static Micro-Delay Lines Generation For Oct, Kamal Alameh, David Sampson, Zhenglin Wang, Rong Zheng, Chung Poh
Research outputs pre 2011
In this paper we propose a novel technique to generate variable true time micro-delay for fibre-based optical coherent tomography (OCT) using two Opto-VLSI processors. The technique offers broadband high resolution scanning depth without moving parts. The beam steering and multicasting capabilities of the Opto-VLSI processors provide a valuable scanning tool allowing the delay generator to jump between nonadjacent depths and realising multiple delays simultaneously. Experimental results achieved maximum 500 nm delay with 3dB bandwidth is more than 55nm a centre wavelength 1550nm.
A Novel Microphotonic Structure For Optical Header Recognition, Muhsen Aljada, Kamal Alameh, Adam Osseiran, Khalid Al-Begain
A Novel Microphotonic Structure For Optical Header Recognition, Muhsen Aljada, Kamal Alameh, Adam Osseiran, Khalid Al-Begain
Research outputs pre 2011
In this paper, we propose and demonstrate a new MicroPhotonic structure for optical packet header recognition based on the integration of an optical cavity, optical components and a photoreceiver array. The structure is inherently immune to optical interference thereby routing an optical header within optical cavities to different photo receiver elements to generate the autocorrelation function, and hence the recognition of the header using simple microelectronic circuits. The proof-of-concept of the proposed MicroPhotonic optical header recognition structure is analysed and experimentally demonstrated, and results show excellent agreement between measurements and theory.
Parametric Fault Modelling For Photonics System, Muhsen Aljada, Adam Osseiran, Kamal Alameh
Parametric Fault Modelling For Photonics System, Muhsen Aljada, Adam Osseiran, Kamal Alameh
Research outputs pre 2011
In this paper we investigate the impact of the most probable parametric faults generated by mal-functioning components in phonetic systems. We demonstrate, using the example of a MicroPholonic header correlator, the effectiveness of mixed-signals testing techniques for fault detection in photonic systems.
Optimisation Of Opto-Ulsi Processor Performance Using Closed-Loop Feedback, Chung Poh, Kamal Alameh, Rong Zheng
Optimisation Of Opto-Ulsi Processor Performance Using Closed-Loop Feedback, Chung Poh, Kamal Alameh, Rong Zheng
Research outputs pre 2011
In this paper, an algorithm based on multi-variable Newton-Raphson method is developed to optimise the steering efficiency of a I-D Opto-USLI processor. The algorithm enables the evaluation of the phase-voltage relationship of the Opto-ULSI processor using realtime power measurements. The optimisation algorithm reported in the paper is crucial for reconfigurable photonic systems such as optical add drop multiplexers, optical switches, tunable optical filters and WDM equalizers.
Dynamic Opto-Vlsi Lens And Lens-Let Generation With Programmable Focal Length, Zhenglin Wang, Kamal Alameh, Rong Zheng, Salem Adherom
Dynamic Opto-Vlsi Lens And Lens-Let Generation With Programmable Focal Length, Zhenglin Wang, Kamal Alameh, Rong Zheng, Salem Adherom
Research outputs pre 2011
In this paper we present and demonstrate a dynamic lens and lens array generation method with programmable focal length based on an Opto-VLSI processor. The Opto-VLSI is driven by computer generated algorithm to generate a discrete Fresnel lens phase hologram. By optimizing the phase hologram, lenses and lens arrays of different focal lengths ranging from 300mm to infinity can be realized. The optical axis of each lens element can be independently addressed to simultaneously focus and steer an optical beam within an angular range of ±0.5°.
Dynamic Spot Generation Using Opto-Vlsi Processing, Zhenglin Wang, Rong Zheng, Kamal Alameh
Dynamic Spot Generation Using Opto-Vlsi Processing, Zhenglin Wang, Rong Zheng, Kamal Alameh
Research outputs pre 2011
In this paper we demonstrate the capability of OptoVLSI processors to generate arbitrary optical power distribution for adaptive optical beam splitting and dynamic optical spot generation. By using the multicasting capability of Opto-VLSI processors, an input optical signal can be dynamically split into N spots array, and the output power of each spot can be independently configured. Experimental results of multiple beam splitting show that dynamic optical multicasting can be achieved with more than 20dB dynamic range. Special patterns are also generated by optimising the phase hologram of the Opto-VLSI processor to place the output beam spots at appropriate positions.
A Robust Qr Based Detector For V Blast And Its Efficient Hardware Implementation, Fariborz Sobhanmanesh, Saeid Nooshabadi, Daryoush Habibi
A Robust Qr Based Detector For V Blast And Its Efficient Hardware Implementation, Fariborz Sobhanmanesh, Saeid Nooshabadi, Daryoush Habibi
Research outputs pre 2011
The use of multiple antennas at both transmitting and receiving sides of a communication channel has increased the spectral efficiency to near the Shannon bound. However algorithmic complexity in the realization of the receiver is a major problem for its hardware implementation. In this paper we investigate a near optimal algorithm for V-BLAST detection in MIMO wireless communication systems based on QR factorization, offering remarkable reduction in the hardware complexity. Specifically, we analyze some hardware implementation aspects of the selected algorithm through MATLAB simulations and demonstrate its robustness. This technique can be used in an efficient fixed point VLSI implementation …
Vlsi Implementation Of A Skin Detector Based On A Neural Network, Farid Boussaid, Abdesselam Bouzerdoum, Douglas Chai
Vlsi Implementation Of A Skin Detector Based On A Neural Network, Farid Boussaid, Abdesselam Bouzerdoum, Douglas Chai
Research outputs pre 2011
This paper describes the VLSI implementation of a skin detector based on a neural network. The proposed skin detector uses a multilayer perception with three inputs, one hidden layer, one output neuron and a saturating linear activation function to simplify the hardware implementation. The skin detector achieves a classification accuracy of 88.76%. To reduce mismatch associated errors, a single skin detection processing unit is used to classify all pixels of the input RGB image. The current-mode fully analog skin detection processing circuitry only performs computations during the read-out phase, enabling real-time processing. Fully programmable, the proposed skin detection processing circuitry …
A Shared Backup Path Protection Scheme For Optical Mesh Networks, Hoang N. Nguyen, Daryoush Habibi, Quoc Viet Phung, Kungmang Lo
A Shared Backup Path Protection Scheme For Optical Mesh Networks, Hoang N. Nguyen, Daryoush Habibi, Quoc Viet Phung, Kungmang Lo
Research outputs pre 2011
We propose a new heuristic ILP model for share backup path protection (SBPP) scheme of mesh networks, which used the sets of disjoint-joint primary-backup path candidates of using path-pair candidates. The solution of the model is near optimal and provides all the routing details of demands as well as the sharing information between backup paths, and also simplifies the wavelength assignment problem if the wavelength continuity is a consideration. The new entities are introduced into this model that allow to control the resource utilization as well as congestion level of the network for optimization purposes and the pre-processing of data …
Optimised Nano-Engineered 1-D Magnetophotonic Crystals For Integrated-Optical Modulators, Mikhail Vasiliev, Kamal Alameh, Vladimir Belotelov, Vyacheslav Kotov, Anotoly Zvezdin
Optimised Nano-Engineered 1-D Magnetophotonic Crystals For Integrated-Optical Modulators, Mikhail Vasiliev, Kamal Alameh, Vladimir Belotelov, Vyacheslav Kotov, Anotoly Zvezdin
Research outputs pre 2011
The optimization of multilayer ID megnetophotonic crystals with mulitple nano-engineered defects enables novel practical photonics applications. The properties of several optimized structures suitable for infrared intensity modulators are discussed. A novel approach to the design of integrated multi-channel WDM/DWDM transmission loss equalizers is proposed. We also show the effect of material absorption on the spectral properties of magnetic phtonic crystals, which is a factor of primary importance for the design of short-wavelenght infrared modulators.
Dynamic P-Cycles Selection In Optical Wdm Mesh Networks, Kungmang Lo, Daryoush Habibi, Quoc Viet Phung, Hoang Nguyen, Byungkyu Kang
Dynamic P-Cycles Selection In Optical Wdm Mesh Networks, Kungmang Lo, Daryoush Habibi, Quoc Viet Phung, Hoang Nguyen, Byungkyu Kang
Research outputs pre 2011
P-cycles have been recognized as a useful protection scheme in WDM mesh networks. This is a type of shared link protection that not only retains the mesh-like capacity efficiency, but also achieves the ring-like protection switching speed. However, finding the optimal set of p-cycles for protecting traffic demands is not a simple task and is an NP-hard problem. A general approach is to determine a set of candidate p-cycles and then determine optimal or near-optimal solutions by using integer linear programming (ILP) models or heuristics. In a dense mesh network, however, the number of candidate cycles is huge, and increases …
Capacity Utilization Versus Congestion Levels In Wavelength Routing For Large Scale Wdm Networks, Quoc Viet Phung, Daryoush Habibi, Hoang N. Nguyen, Kungmang Lo
Capacity Utilization Versus Congestion Levels In Wavelength Routing For Large Scale Wdm Networks, Quoc Viet Phung, Daryoush Habibi, Hoang N. Nguyen, Kungmang Lo
Research outputs pre 2011
Wavelength routing (WR) has been a key issue in WDM optical networks which carry huge amount of traffic aggregated from Internet protocol (IP), asynchronous transfer mode (ATM) and SDH/SONET layers. The problem, however, has been proved NP-hard. The time complexity and the optimality of solutions are two conflicting metrics. In addition, for optimization purposes, capacity utilization and network congestion level can be compromised to reduce the blocking probability of future connections. In this paper, we propose a heuristic approach for WR in large scale networks based on a balanced model developed for the capacity utilization and the congestion level. This …