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Full-Text Articles in Physical Sciences and Mathematics
Background Radio Frequency Interference Measurements For Wireless Devices In The Electricity Supply Industry, D A. Robinson, Tadeusz A. Wysocki, Victor W. Smith, Keni Popovski
Background Radio Frequency Interference Measurements For Wireless Devices In The Electricity Supply Industry, D A. Robinson, Tadeusz A. Wysocki, Victor W. Smith, Keni Popovski
Faculty of Informatics - Papers (Archive)
Incorporation of radio controller units into heavy equipment used in the electricity industry provides numerous advantages including: improved electrical isolation between plant and operator, ability to incorporate an additional remote operator, and reductions in vehicle wiring and hydraulic hoses for equipment control. However, secure operation of vehicles and plant incorporating radio control rely on establishing suitable levels of immunity to possible radio frequency interference. Interference levels in close proximity to high voltage power lines are of special concern to the electricity industry. This paper reports on a preliminary investigation into quantifying the levels of background radio interference at such locations …
A Secure Multicast Architecture And Protocol For Mospf, Junqi Zhang, Yi Mu, Vijay Varadharajan
A Secure Multicast Architecture And Protocol For Mospf, Junqi Zhang, Yi Mu, Vijay Varadharajan
Faculty of Informatics - Papers (Archive)
Multicast Open Shortest Path First (MOSPF) is an en hancement to unicast routing protocol OSPF. It has been widely used in many multicast applications for years. How ever, its security is still a major concern in some applica tions. Much work has been done on data protection, but only a few works have been done on member access con trol mechanisms. In this paper, we present a new secure multicast architecture and protocol for MOSPF from the perspective of member access control. Our new model in cludes a variant of previous access control mechanism and a novel distributed encryption scheme. …
Exploring End-User Perceptions Towards Mandated Deployment Of Pda-Based Health Information Systems Within Ambulatory Care, Jason P. Sargent, Lois Burgess, Joan Cooper, Carole Alcock, Damien Ryan
Exploring End-User Perceptions Towards Mandated Deployment Of Pda-Based Health Information Systems Within Ambulatory Care, Jason P. Sargent, Lois Burgess, Joan Cooper, Carole Alcock, Damien Ryan
Faculty of Informatics - Papers (Archive)
The impact of many well intentioned technology integration projects has not always been viewed favourably. In fact, many projects are destined to fail from the outset by not considering fundamental IT system inves tment risks (technical failure, data failure, user failure, organizational failure) [Lyytinen & Hirschiem, 1987]. With any new technology ‘an element of uncertainty exists in the minds of decision makers with respect to the successful adoption of them’ [Bagozzi et al, 1992]. Uncertainty towards adopting new technologies is not solely the domain of decision makers. Apart from chief technology and information officers, system administrators and help desk personnel, …
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
Faculty of Informatics - Papers (Archive)
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 …
Equivalences Between Pure Type Systems And Systems Of Illative Combinatory Logic, Martin Bunder, Willibrordus Dekkers
Equivalences Between Pure Type Systems And Systems Of Illative Combinatory Logic, Martin Bunder, Willibrordus Dekkers
Faculty of Informatics - Papers (Archive)
Pure Type Systems, PTSs, were introduced as a generalization of the type systems of Barendregt’s lambda cube and were designed to provide a foundation for actual proof assistants which will verify proofs. Systems of illative combinatory logic or lambda calculus, ICLs, were introduced by Curry and Church as a foundation for logic and mathematics. In an earlier paper we considered two changes to the rules of the PTSs which made these rules more like ICL rules. This led to four kinds of PTSs. Most importantly PTSs are about statements of the form M : A, where M is a term …
A Simple Element Inverse Jacket Transform Coding, Moon Ho Lee, Kenneth Finlayson
A Simple Element Inverse Jacket Transform Coding, Moon Ho Lee, Kenneth Finlayson
Faculty of Informatics - Papers (Archive)
Jacket transforms are a class of transforms which are simple to calculate, easily inverted and are size-flexible. Previously reported jacket transforms were generalizations of the well-known Walsh-Hadamard transform (WHT) and the center-weighted Hadamard transform (CWHT). In this paper we present a new class of jacket transform not derived from either the WHT or the CWHT. This class of transform can be applied to any even length vector, and is applicable to finite fields and is useful for constructing error control codes.
Optical Phase Shifting With Acousto-Optic Devices, Enbang Li, Jianquan Yao, Daoyin Yu, Jiangtao Xi, Joe F. Chicharo
Optical Phase Shifting With Acousto-Optic Devices, Enbang Li, Jianquan Yao, Daoyin Yu, Jiangtao Xi, Joe F. Chicharo
Faculty of Informatics - Papers (Archive)
A novel optical phase-shifting method based on a well-known acousto-optic interaction is proposed. By using a pair of acousto-optic modulators (AOMs) and properly aligning them, we construct an optical phase shifter that can directly control the phase of a collimated beam. The proposed phase shifter is insensitive to the polarization of the incident beam when polarization-insensitive AOMs are used, and no calibration is necessary. The proposed approach is confirmed with experimental results.
Effects Of Fiber Cladding On Uv Beams And Fringe Patterns In Side-Exposure Fbg Writing, Enbang Li, Jiangtao Xi, Joe F. Chicharo, Yanguang Yu, Jianquan Yao
Effects Of Fiber Cladding On Uv Beams And Fringe Patterns In Side-Exposure Fbg Writing, Enbang Li, Jiangtao Xi, Joe F. Chicharo, Yanguang Yu, Jianquan Yao
Faculty of Informatics - Papers (Archive)
The so-called side-exposure method has been widely used in the fabrication of fiber Bragg gratings (FBGs). The effects of the fiber cladding on the wavefronts of the UV writing beams and the interference fringes formed inside the fiber have been addressed in this study. The wavefronts of the UV beams have been analyzed and it has been demonstrated that the existence of the fiber cladding significantly alters the wavefronts of the UV beams in one plane and makes them highly astigmatic. Based on the calculated wavefront radii of the UV beams, a model has been established for prediction of the …
Multi-Channel Fbg Sensing System Using A Dense Wavelength Division Demultiplexing Module, Enbang Li, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo, Jianquan Yao
Multi-Channel Fbg Sensing System Using A Dense Wavelength Division Demultiplexing Module, Enbang Li, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo, Jianquan Yao
Faculty of Informatics - Papers (Archive)
Fiber Bragg grating (FBG) sensing is gaining attention in both scientific research areas and engineering applications thanks to its distinguishing advantages including wavelength multiplexing capability, miniature size, high sensitivity, immunity from electro-magnetic interference, etc. FBG sensing is based on the detection of the shifted Bragg wavelength of the light reflected by a fiber grating which is sensitive to various physical parameters such as strain and temperature. One of the challenging tasks in FBG sensing is to determine the Bragg wavelength shift, which can be done by using an optical spectrum analyzer (OSA). An OSA is suitable for laboratory tests, but …
Performance Comparison Of Sequences Designed From The Hall Difference Set And Orthogonal Gold Sequences Of Length 32, Jennifer Seberry, Beata J. Wysocki, Tadeusz A. Wysocki
Performance Comparison Of Sequences Designed From The Hall Difference Set And Orthogonal Gold Sequences Of Length 32, Jennifer Seberry, Beata J. Wysocki, Tadeusz A. Wysocki
Faculty of Informatics - Papers (Archive)
In the paper we perform a performance comparison between two sets of orthogonal spreading sequences i.e. sequences based on the Hadamard matrix of order 32 constructed using the Hall difference set and orthogonal Gold sequences of length 32. Both considered sets of sequences are characterised by low peaks in the aperiodic cross-correlation functions and have also good aperiodic auto-correlation properties.
Agent-Based Coalitions In Dynamic Supply Chains, Chattrakul Sombattheera, Aditya K. Ghose
Agent-Based Coalitions In Dynamic Supply Chains, Chattrakul Sombattheera, Aditya K. Ghose
Faculty of Informatics - Papers (Archive)
Coalition formation is an important issue in multi-agent systems. Recent work in the area has focused on reducing the complexity of forming coalitions, i.e., each agent deliberately searches for potential coalition members before negotiating with them. We propose a framework for coalition formation of agents in a dynamic supply chain environment. The framework is composed of a negotiation protocol and a decision mechanism. The negotiation protocol allows thorough communication among agents across sectors (buyers, sellers, logistic providers). With the decision mechanism, agents take two steps to form coalitions: i) agents in each sector form loosely-coupled coalitions in order to decrease …
Secure Key Extraction In Computer Networks, Willy Susilo, Yi Mu, Xinyi Huang
Secure Key Extraction In Computer Networks, Willy Susilo, Yi Mu, Xinyi Huang
Faculty of Informatics - Papers (Archive)
Security of computer networks normally relies on a trusted authority who is responsible for setting up the system and distributing cryptographic keys. If the trusted authority is compromised due to an attack, then the security of the entire system will be compromised. In this paper, we will look into this issue in terms of identity-based (or ID-based) cryptography. Since the introduction of identity-based (or ID-based) cryptography in 1984 by Shamir, IDbased cryptography has attracted many research due to its simplicity. However, ID-based cryptography suffers from several drawbacks, namely the requirement of having a secure channel during the key extraction and …
Decision Aided Compensation Of Residual Frequency Offset For Mimo-Ofdm Systems With Nonlinear Channel, Shouyi Yang, Jiangtao Xi, Fang Wang, Xiaomin Mu, Hideo Kobayashi
Decision Aided Compensation Of Residual Frequency Offset For Mimo-Ofdm Systems With Nonlinear Channel, Shouyi Yang, Jiangtao Xi, Fang Wang, Xiaomin Mu, Hideo Kobayashi
Faculty of Informatics - Papers (Archive)
In this paper, we propose a new approach to compensate the residual frequency offset (RFO) in multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) system with nonlinear channel working in the burst mode. The proposed approach consists of two stages. Firstly a decision aided method is proposed to eliminate the nonlinearity introduced by high power transmit amplifier (HPA). Then a new decision aided approach is employed to achieve the RFO compensation on the nonlinearity-free symbols. The effectiveness of the proposed approach has been verified by computer simulations.
Estimating The Parameters Of Semiconductor Lasers Based On Weak Optical Feedback Interferometry, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo, Thierry Bosch
Estimating The Parameters Of Semiconductor Lasers Based On Weak Optical Feedback Interferometry, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo, Thierry Bosch
Faculty of Informatics - Papers (Archive)
The paper presents a new approach for measuring the linewidth enhancement factor (LEF) of semiconductor lasers (SL) and the optical feedback level factor C in SLs. The proposed approach is based on the analysis of self-mixing signals observed in self-mixing optical feedback interferometry. Unlike existing approaches, the approach tries to estimate the parameters LEF and C by a gradient-based optimization algorithm that achieves best data-to-theoretical model fitting. The effectiveness and accuracy of the method have been confirmed and tested by theoretical analysis and computer simulations.
Face Recognition With Ctfm Sonar, Kok Kai Yoong, Phillip J. Mckerrow
Face Recognition With Ctfm Sonar, Kok Kai Yoong, Phillip J. Mckerrow
Faculty of Informatics - Papers (Archive)
The use of biometrics, such as iris, thumbprints, voice, face, etc, for authentication have become commonplace. In this research, we are attempting to classify human faces using CTFM (Continuously Transmitted Frequency Modulated) sonar in place of the normally used computer vision. However, for this preliminary paper, the main objectives are to find out the range relationships between human facial features and how they are represented in echoes, and to test the quality of echo features for three faces from a single orientation. The tested features are features that were effective in past research into classifying objects from ultrasonic echoes. We …