Physical Sciences and Mathematics Commons^™

Smicts: A Simulation Based Approach To Understand And Manage Service Quality, Karthik Vilapakkam Nagarajan, Meena Chavan, Tamrad Woldu Tewoldeberhan, Peter James Vial, V. N. Srivalli

Faculty of Informatics - Papers (Archive)

In this paper a novel simulation framework SIMCTS (Simulation Modelling and Analysis of Customer Satisfaction Patterns for Telecommunication Service Providers) for ISP business process modelling is described. It is shown that simulation technology can tackle a wide range of operational challenges in telecommunication service industry. The lack of very specific building blocks for functional service quality simulation has made the development SIMCTS simulation framework an absolute necessity. The paper introduces service quality framework that could transform a conceptual service quality model in to computer simulation model using the available service quality data in a fast and a effective way. The …

Novel Two-Dimension Fbg Sensor Based On Rectangle Cantiliver Beam For Simultaneous Measurement Of Force And Temperature, Weigang Zhang, Guiyan Kai, Shuzhong Yuan, Xiaoyi Dong, Enbang Li, Jiangtao Xi, Joe F. Chicharo

Faculty of Informatics - Papers (Archive)

In this paper, for the first time to our knowledge, we report a novel FBG-type two-dimensional sensor that is able to simultaneously measure two-dimension (2-D) force and temperature, and the 2-D force sensing process can be tuned by applying rectangular cantilever beam (RCB). In the vertical directions of the RCB axis, the wavelengths shifts of two FBGs bonded to the surface of the RCB are quasi-linear with respect to the 2-D force and temperature, respectively. Two FBGs are experimentally demonstrated to have the 2-D force sensitivities of ~5.32 nm/N and 3.21 nm/N, a temperature sensitivity of ~0.095nm/°C between 0°C and …

Measuring The Linewidth Enhancement Factor Of Semiconductor Lasers Based On Weak Optical Feedback Effect, Yanguang Yu, Jiangtao Xi, Enbang Li, Joe F. Chicharo

Faculty of Informatics - Papers (Archive)

Semiconductor lasers are very different from other lasers because refraction variation can't be avoided when the gain is changed. Refraction variation can be introduced the theory of semiconductor laser by a dimensional parameter. This parameter is called linewidth enhancement factor (LEF). The value of LEF is very important for many aspects of laser behavior. The LEF characterizes the linewidth broadening and chirp due to fluctuation in the carrier density. A simple method to measure the linewidth enhancement factor of laser diodes is presented in this paper. The method uses the self-mixing effect at a weak feedback level. An optical beam …

Definition Of An Object-Oriented Modeling Language For Enterprise Architecture, Lam-Son Le, Alain Wegmann

Faculty of Informatics - Papers (Archive)

In enterprise architecture, the goal is to integrate business resources and IT resources in order to improve an enterprise's competitiveness. In an enterprise architecture project, the development team usually constructs a model that represents the enterprise: the enterprise model. In this paper, we present a modeling language for building such enterprise models. Our enterprise models are hierarchical object-oriented representations of the enterprises. This paper presents the foundations of our language (i.e. the Living System Theory and the RM-ODP standard), the definition of the language and ends by presenting an example of an enterprise model developed with our web-based CAD tool.

Multi-Attribute Decision Making Approach For Strategic Planning Of Dgs, Ashish Agalgaonkar, S. V. Kulkarni, S. A. Khaparde

Faculty of Informatics - Papers (Archive)

The distributed energy sources technology has progressed from isolated operation to hybrid and now to microgrid operation. The planning strategies initially considered cost-benefit analysis of distributed generation (DG). Later supporting advantages of the hybrid system including improvement of the efficiency were also considered for decision making. With increased complexities in DGs planning options along with multiple attributes to be accounted, more sophisticated techniques are needed to arrive at the correct decisions by decision makers. The analytical hierarchy process (AHP) is proposed to identify the relative significance of the chosen attributes. Proper integration of different attributes can be achieved by linear …

Multiple Distributed Generators For Distribution Feeder Voltage Support, M A. Kashem, Gerard Ledwich

Faculty of Informatics - Papers (Archive)

Inclusion of voltage support distributed generation (VSDG) can reinforce the feeder voltage of distribution networks, especially in rural/remote areas where voltage dip and frequent blackouts are significant concerns for power utilities. However, installation of multiple distributed generators within a distribution grid system may introduce technical problems in network operation and control, including control interaction and/or voltage instability. This paper addresses the network issues that may occur during multiple VSDG inclusion in the network and presents analytical models and solutions to develop design criteria of VSDG installation in the networks. Voltage sensitivity of lines is investigated and the effect of DG …

The Arp Virtual Reality System In Addressing Security Threats And Disaster Scenarios, Yang-Wai Chow, Ronald Pose, Matthew Regan

Faculty of Informatics - Papers (Archive)

Nations, corporations and political organizations around the world today are forced to deal with an increasing number of security threats. As a result, various organizations must find ways to adequately equip and prepare themselves to handle numerous dangerous and life threatening circumstances. Virtual reality is an extremely important technology that can be used across a variety of different fields and for a number of diverse applications, ranging from simulation training to visualization tools, in order to prepare for and manage disaster situations. Head mounted display (HMD) virtual reality systems attempt visually to immerse the user in a virtual environment. However, …

An Ontology Based Approach For Health Information Discovery, Khin T. Win, Minjie Zhang

Faculty of Informatics - Papers (Archive)

The need of searching and retrieving relevant information has become important in the health care delivery. In this paper, we discuss how domain specific ontologies can support the information selection and introduce an ontology based approach for health information discovery in distributed environments. This research is the preliminary result of a health information retrieval project.

Assessing The Impact Of Increased Air Conditioner Load On Power Quality In Australia, Lianne Mollier, D A. Robinson, Sarath Perera, Victor J. Gosbell, Frank Bucca

Faculty of Informatics - Papers (Archive)

Measurements of performance of existing technology air conditioner systems with regards to their impact on power quality in LV distribution systems are presented. Three types of split-phase air conditioners are studied including direct on line starting, soft starter and inverter fed units. Results of testing and subsequent calculations illustrate that the direct on line and soft starter units do not meet compliance requirements of the relevant standard, and as penetration of air conditioners increases, voltage fluctuations may become a significant problem in some LV distribution systems in Australia.

Response Of Mains Connected Induction Motors To Low Frequency Voltage Fluctuations From A Flicker Perspective, Sankika Tennakoon, Sarath Perera, D A. Robinson

Faculty of Informatics - Papers (Archive)

In radial power systems flicker transfer from a higher voltage level (upstream) to a lower voltage level (downstream) is seen to be significantly affected by the downstream load composition. Industrial load bases containing mains connected induction motors are known to be effective in the flicker attenuation process compared to residential load bases containing passive loads. For better understanding of the flicker attenuation influenced by induction motors their dynamic behaviour has to be closely investigated under fluctuating supply conditions. This paper presents the methodology and results of investigations undertaken to examine the response of an induction motor to small perturbations in …

Power System Applications Of Superconducting Magnetic Energy Storage Systems, X D. Xue, Eric Kw Cheng, Danny Sutanto

Faculty of Informatics - Papers (Archive)

This study overviewed current researches on power system applications of SMES systems. Some key schematic diagrams of applications were given, too. Furthermore, the authors tried to present a few valuable suggestions for future studies of SMES applications to power systems.

Harmonic Allocation To Aggregated Regions Within A Transmission Network, Timothy J. Browne, Victor J. Gosbell, Sarath Perera

Faculty of Informatics - Papers (Archive)

Utilising the standard AS/NZS61000.3.6 to carry out a harmonic allocation to a load in a transmission system requires detailed knowledge of the location and magnitude of every future load. Given that the size of the load at a bus in a transmission system could conceivably be from zero up to around thirty percent of the fault level, such knowledge is unlikely to be available with any degree of certainty. This paper proposes an allocation policy which reduces the effect of load uncertainty, by allocating harmonic emission levels to areas comprising buses which are electrically close. Possible techniques are demonstrated using …

Decision Aided Joint Compensation Of Clipping Noise And Nonlinearity For Mimo-Ofdm Systems, Shouyi Yang, Jiangtao Xi, Xiaomin Mu

Faculty of Informatics - Papers (Archive)

In this paper, we propose a new iterative approach to compensate the nonlinearity and clipping noise in multi-input multi-output orthogonal frequency division multiplexing (MlMO-OFDM) system with nonlinear channel. 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 this improved decision observations are employed to achieve the clipping noise compensation. The effectiveness of the proposed approach has been verified by computer simulations.

Mathematical Modelling In Nanotechnology, Ngamta Thamwattana, James M. Hill

Faculty of Informatics - Papers (Archive)

The interaction of nano particles with conventional materials dramatically changes all the physical parameters, which usually characterize the bulk material. The nano particles constitute highly reactive isolated sites to the extent that it leads to a change in the electronic structure of the nano composite, and accordingly all the physical properties, such as thermal, mechanical and electrical properties become different from those of the bulk material. To successfully exploit nano composites as components and devices, this fundamental shift of physical properties must be properly understood and accurately modelled. While experimentation is crucial, a theoretical understanding is also necessary and with …

An Adaptive Scalable Multiuser-Ofdm System For Multimedia Transmission Over Fading Channels, Ahmed Muthana M. Nadhim, Jianhua He, Jiangtao Xi, Zongkai Yang

Faculty of Informatics - Papers (Archive)

In this paper, an adaptive scalable multiuser-OFDM system was proposed for multimedia transmission over fading channels. The proposed adaptive algorithm can adapt according to the channel status information of each user's channel status. This algorithm dynamically changes according to the user's channel changes; this can keep fixed QoS at the physical layer. Another predefined QoS for different sessions and services to be provided for different users. This QoS can be guaranteed by multimedia scalability. Scalability can adapt to the service requirements, in terms of transmission data rate and bandwidth. As a result, a robust multimedia transmission scheme is achieved by …

Signal Processing Methods Implemented In A Novel Fbg Sensing System For Vibration/Dynamic Strain Measurement, Xingyuan Xu, Enbang Li, Jiangtao Xi, Joe F. Chicharo

Faculty of Informatics - Papers (Archive)

We have demonstrated a novel Fiber Bragg Grating sensing system based on a Fabry-Perot tunable filter for measuring dynamic processes. This system is very suitable for multipoint vibration or dynamic strain detection. However, in some conditions, the response time of Fabry-Perot tunable filter will influence the sensitivity of the sensor that the sensitivity is not kept constant. Therefore, post-processing for the measured vibration signal is necessary to solve this problem. In this paper, the demodulation technique of this system is briefly described and two signal processing methods are introduced to deal with the measured signal to obtain stable measurement of …

Generic Construction Of (Identity-Based) Perfect Concurrent Signatures, Sherman S. M. Chow, Willy Susilo

Faculty of Informatics - Papers (Archive)

The notion of concurrent signatures was recently introduced by Chen, Kudla and Paterson. In concurrent signature schemes, two entities can produce two signatures that are not binding, until one of the parties releases an extra piece of information (namely the keystone). Subsequently, it was noted that the concurrent signature scheme proposed in the seminal paper cannot provide perfect ambiguity. Then, the notion of perfect concurrent signatures was introduced. In this paper, we define the notion of identity-based (or ID-based) perfect concurrent signature schemes. We provide the first generic construction of (ID-based) perfect concurrent signature schemes from ring signature schemes. …

Cancelable Key-Based Fingerprint Templates, Russell Ang, Reihaneh Safavi-Naini, Luke F. Mcaven

Faculty of Informatics - Papers (Archive)

Biometric based authentication can provide strong security guarantee about the identity of users. Security of biometric data is particularly important as compromise of the data will be permanent. Cancelable biometrics store a non-invertible transformed version of the biometric data and so if the storage is compromised the biometric data remains safe. Cancelable biometrics also provide a higher level of privacy by allowing many templates for the same biometric data and hence non-linkability of user's data stored in different databases. We define how to measure the success of a particular transformation and matching algorithm for fingerprints. We consider a key-dependent geometric …

Multi-Frequency And Multiple Phase-Shift Sinusoidal Fringe Projection For 3d Profilometry, Enbang Li, X. Peng, Jiangtao Xi, Joe F. Chicharo, Jianquan Yao, D.W. Zhang

Faculty of Informatics - Papers (Archive)

In this paper, we report on a laser fringe projection set-up, which can generate fringe patterns with multiple frequencies and phase shifts. Stationary fringe patterns with sinusoidal intensity distributions are produced by the interference of two laser beams, which are frequency modulated by a pair of acousto-optic modulators (AOMs). The AOMs are driven by two RF signals with the same frequency but a phase delay between them. By changing the RF frequency and the phase delay, the fringe spatial frequency and phase shift can be electronically controlled, which allows high-speed switching from one frequency or phase to another thus makes …

Short E-Cash, Man Ho Au, Sherman S. M. Chow, Willy Susilo

Faculty of Informatics - Papers (Archive)

We present a bandwidth-efficient off-line anonymous e-cash scheme with traceable coins. Once a user double-spends, his identity can be revealed and all his coins in the system can be traced, without resorting to TTP. For a security level comparable with 1024-bit standard RSA signature, the payment transcript size is only 512 bytes. Security of the proposed scheme is proven under the q-strong Diffie-Hellman assumption and the decisional linear assumption, in the random oracle model. The transcript size of our scheme can be further reduced to 192 bytes if external Diffie-Hellman assumption is made. Finally, we propose a variant such …

The Character Of Free Topological Groups I, Peter R. Nickolas, Mikhail Tkachenko

Faculty of Informatics - Papers (Archive)

A systematic analysis is made of the character of the free and free abelian topological groups on uniform spaces and on topological spaces. In the case of the free abelian topological group on a uniform space, expressions are given for the character in terms of simple cardinal invariants of the family of uniformly continuous pseudometrics of the given uniform space and of the uniformity itself. From these results, others follow on the basis of various topological assumptions. Amongst these: (i) if X is a compact Hausdorff space, then the character of the free abelian topological group on X lies between …

Teaching Automated Test Case Generation, Tsong Yueh Chen, Fei-Ching Kuo, Zhiquan Zhou

Faculty of Informatics - Papers (Archive)

Software testing is a major approach to software quality assurance, but it is relatively neglected in universities' computing curricula. For students majoring in computer science or software engineering, several basic testing methods need to be taught. These testing methods generate test cases based on either specifications or program code. When introducing the testing methods based on program code, it is not easy to let the students experience automated test case generation due to the lack of supporting tools and limited teaching hours. In this paper we report our experience in teaching this topic with limited resources. The evaluation result indicates …

Security Analysis Of Michael: The Ieee 802.11i Message Integrity Code, Jianyong Huang, Jennifer Seberry, Willy Susilo, Martin W. Bunder

Faculty of Informatics - Papers (Archive)

The latest IEEE 802.11i uses a keyed hash function, called Michael, as the message integrity code. This paper describes some properties and weaknesses of Michael. We provide a necessary and sufficient condition for finding collisions of Michael. Our observation reveals that the collision status of Michael only depends on the second last block message and the output of the block function in the third last round. We show that Michael is not collision-free by providing a method to find collisions of this keyed hash function. Moreover, we develop a method to find fixed points of Michael. If the output …

A Comparative Analysis Of The Use Of The Web For Destination Marketing By Regional Tourism Organisations In Chile And The Asia Pacific, Lois Burgess, Joan Cooper, Narciso Cerpa, Jason P. Sargent

Faculty of Informatics - Papers (Archive)

With reports of travel purchases and reservations being one of the fastest growing segments of the Internet community (eMarketer, 2002), it is no surprise that the number of tourism operators on the Web has increased considerably over the past few years. In recent years, Australia and Chile have developed strong social and economic ties. With the introduction of direct air links between Australia and Chile in July 2002, the number of Australian business people and tourists visiting Chile and neighbouring countries increased significantly. This isn’t surprising considering approximately 35,000 Chileans live in Australia (DFAT, 2005). This paper presents the results …

A Generalized Algorithm For The Generation Of Correlated Rayleigh Fading Envelopes In Wireless Channels, Le Chung Tran, Tadeusz A. Wysocki, Alfred Mertins, Jennifer R. Seberry

Faculty of Informatics - Papers (Archive)

Although generation of correlated Rayleigh fading envelopes has been intensively considered in the literature, all conventional methods have their own shortcomings, which seriously impede their applicability. In this paper, a very general, straightforward algorithm for the generation of an arbitrary number of Rayleigh envelopes with any desired, equal or unequal power, in wireless channels either with or without Doppler frequency shifts, is proposed. The proposed algorithm can be applied to the case of spatial correlation, such as with multiple antennas in Multiple Input Multiple Output (MIMO) systems, or spectral correlation between the random processes like in Orthogonal Frequency Division …

Transcoding Of Narrowband To Wideband Speech, Christian H. Ritz, Nick Harders, Joseph Hermann, Matthew J. Baker

Faculty of Informatics - Papers (Archive)

Transcoding is required to facilitate the communication of compressed speech between networks that have adopted opposing speech coding standards. The traditional transcoding technique of tandem conversion by decoding from the old standard and then re-encoding with the new standard suffers from unacceptable delay and complexity. For real time applications, delay and complexity can be reduced by performing transcoding in the bit stream domain. This paper describes techniques for transcoding between narrowband and wideband speech coding standards. In particular, an examination of the performance of bit stream mapping approaches to transcoding from the ITU-T G.729 narrowband speech coder to the ITU-T …

A Data-Fitting Approach For Displacements And Vibration Measurement Using Self-Mixing Interferometers, Yi Zhang, Jiangtao Xi, Joe F. Chicharo, Yanguang Yu

Faculty of Informatics - Papers (Archive)

This paper presents a signal processing approach for vibration measurement using self-mixing interferometer (SMI). Compared to existing approaches, the proposed approach is able to achieve an accuracy of λ/40 which significantly exceeds the accuracy limit associated with conventional simple SMI systems λ/4.

On An Infinite Integral Arising In The Numerical Integration Of Stochastic Differential Equations, David M. Stump, James M. Hill

Faculty of Informatics - Papers (Archive)

We study a stochastic integral that arises during the implementation of the Milstein method for the numerical integration of systems of stochastic differential equations. The distribution of the integral can be written as the inverse Fourier transform of a characteristic function with essential singularities. This leads to a generalized integral that can be expressed as an infinite series involving the derivatives of Meixner polynomials. The generating function of the polynomials in combination with the Mittag–Leffler expansion theorem is used to obtain a novel series representation for the integral and the motivating problem in particular. This new form is rapidly convergent …

Web Globalization: A Methodology For Developing Usable Websites For The Global Market, Ghassan Al Qaimari

Faculty of Informatics - Papers (Archive)

In today’s global economy, with the appearance of the Internet and the fast evolution of technology, the frontiers of local markets have been fading and blending with global markets. These markets with no boundaries have lead many companies, organizations, educational institutions, and digital libraries to develop their own websites, and to find ways to make them usable and accessible and their products saleable to customers outside their traditional markets. Going global can help corporations lower the cost of entry to international trade, increase sales, create global demands, and establish a reliable, professional and international image online.

This means that website …

Two Sides Of Market Orientation And The Link To Performance, Tim Coltman, Timothy M. Devinney

Faculty of Informatics - Papers (Archive)

The impact of a market-oriented strategy on business performance remains an open question. One of the reasons for this is that virtually all the work conducted in marketing has viewed market orientation as a reflective unidimensional structure. In this study we demonstrate that two measures of market orientation (i.e., reactive and proactive) are related, but essentially separate constructs. The results show that proactive market orientation has a significant and positive mediating effect between
resources and performance while reactive market orientation appears to be losing its effectiveness.