Non-linear echo cancellation - a Bayesian approach

Echo cancellation literature is reviewed, then a Bayesian model is introduced and it is shown how how it can be used to model and fit nonlinear channels. An algorithm for cancellation of echo over a nonlinear channel is developed and tested. It is shown that this nonlinear algorithm converges for both linear and nonlinear channels and is superior to linear echo cancellation for canceling an echo through a nonlinear echo-path channel

Mathematica code for implementing the aggregate EMF

This report contains the Mathematica code, used to implement the aggregate EMF spectral density due to several nearby transmitters

Antraff traffic analysis software user manual, June 11, 2018

This manual describes how to use the Antraff traffic trace analysis software, and how to make use of the scripts and procedures associated with it

Matlab code for implementing SS-OFDM

This report contains the matlab code used to implement an SS-OFDM system

Estimation of relative intensity and relative finality of fBm

This mathematica notebook is based on the one called fBmShiftTransformation10b.nb, which was in turn based on animate/animate3.nb. Section 1 includes basic definitions, Section 2 defines a function which estimates exit probability, for a process with a given down-crossing, by simulation. Section 3 then estimates the last exit density, which is carried out in detail for the cases H=0.75, 0.5, 0.85, and 0.35. Relative finality is found by fitting to the simulations, and this is then used to estimate the last exit density

Social network behaviour inferred from O-D Pair traffic

Because traffic is predominantly formed by communication between users or between users and servers which communicate with users, network traffic inherently exhibits social networking behaviour; the extent of interaction between entities – as identified by their IP addresses – can be extracted from the data and analysed in a multiplicity of ways. In this paper, Anonymized Internet Trace Datasets obtained from the Center for Applied Internet Data Analysis (CAIDA) have been used to identify and estimate characteristics of the underlying social network from the overall traffic. The analysis methods used here fall into two groups, the first being based on frequency analysis and second method being based on the use of traffic matrices, with the latter analysis method being further sub-divided into groups based on the traffic mean, variance and co-variance. The frequency analysis of origin, destination and O-D Pair statistics exhibit heavy tailed behaviour. Because the large number of IP addresses contained in the CAIDA Datasets, only the most predominate IP Addresses are used when estimating all three sub-divided groups of traffic matrices. Principal Component Analysis and related methods are applied to identify key features of each type of traffic matrix. A new system called Antraff has been developed by the authors to carry out all the analysis procedures

Face-to-face and virtual mathematics enrichment for rural schools: intersection of teachers, students, technology and pedagogy

In this paper the authors report on the University of Southern Queensland’s (USQ) Mathematics Rural and Regional Communities (MRRC) project. This project is an extension to the Mathematics Enrichment Program (MEP), which has been running since 2007. Since the MEP’s inception, more than 500 students, 29 schools, 15 pre-service teachers (who are involved to gain practical teaching experience) and many volunteer university lecturers and other mathematics and education professionals have been involved. The MRRC project builds on USQ’s MEP to offer content in an online or virtual format. Through an interactive virtual environment, the MRRC project connects regional high schools to USQ’s two campuses to build the capacity of the teachers and students involved. The authors describe the overall aim and structure of the MRRC program, preliminary evaluations of the program, analysis of the virtual space and future plans for the program

Experiments and proofs in web-service security

Many web services have a subsystem for allowing users to register, authenticate, reset their password, and change personal details. It is important that such subsystems cannot be abused by attackers to gain access to the accounts of other users. We study a system which was initially prone to such attacks. Specific attacks are demonstrated and the system is then modified to prevent such attacks in future. The design achieved in this way is then analysed to show that it can't be broken in future unless users allow their email to he intercepted. This is achieved by formulating the requirement as a statement of the user's expectations of the system and then analysing the source code of the system to prove that it meets these requirements. The process of attack, correction, and formulation of security rules, and proof that rules hold, is proposed as a methodical security design philosophy

A social contract for cyberspace

The current standards for the Internet and its services and devices are set and developed by multiple standards organisations, and national governments. In this paper, we argue that a social contract is needed between these organisations, and the entities (individual users, organisations, devices, and service providers) which use the Internet to communicate. Criteria which a social contract should meet are proposed; fourteen major current cybersecurity or ethical issues are then discussed; the necessity and feasibility of a social contract are considered. A draft social contract is then proposed and solutions or strategies to address the fourteen issues identified previously, on the basis of this draft social contract, are presented