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Articles 1 - 30 of 359
Full-Text Articles in Physical Sciences and Mathematics
Perceiving A Corridor With Ctfm Ultrasonic Sensing, S. M. Antoun, Phillip J. Mckerrow
Perceiving A Corridor With Ctfm Ultrasonic Sensing, S. M. Antoun, Phillip J. Mckerrow
Faculty of Informatics - Papers (Archive)
When deprived of sight humans adapt and use other senses for navigation. Most rely on touch (long cane), but some use auditory perception. We have observed a blind teenager echolocating using sounds (clicks) he makes with his mouth. More commonly, an ultrasonic sensor is used as a navigational aid to scan the path and environment. The echoes blind people perceive are interpreted by each individual to form an auditory scene where clear paths and obstacles are identified. With this information, the blind user threads his/her way safely through the space scanned. The work we describe here seeks to mimic a …
Substitute Three-Dimensional Perception Using Depth And Colour Sensors, Simon Meers, Koren Ward
Substitute Three-Dimensional Perception Using Depth And Colour Sensors, Simon Meers, Koren Ward
Faculty of Informatics - Papers (Archive)
The development of sensor-actuator systems that can provide the user with perception of the environment without any use of the eyes is a difficult task. Firstly, the sensors must work effectively under differing conditions. Secondly, the actuators (or auditory feedback) must present the environmental information to the user in a manner that is easy to understand. Thirdly, the whole system needs to be compact, efficient and robust to be practical for a blind person to use. This paper firstly reviews current research in the area of substitute vision systems and discusses their limitations. We then provide details of the substitute …
A Multi-Class Image Classification System Using Salient Features And Support Vector Machines, Wenbin Shao, Son Lam Phung, G. Naghdy
A Multi-Class Image Classification System Using Salient Features And Support Vector Machines, Wenbin Shao, Son Lam Phung, G. Naghdy
Faculty of Informatics - Papers (Archive)
This paper addresses the problem of automatic image annotation for semantic retrieval of images. We propose an image classification system that is capable of recognizing several image categories. The system is based on the support vector machine and a set of image features that includes MPEG-7 visual descriptors and a custom feature. The system is evaluated on a large dataset consisting of 14400 images in four categories - landscape, cityscape, vehicle and portrait. We find that the proposed edge direction histogram and the MPEG-7 edge histogram perform better than other features in this application. Experiment results indicate that the pair- …
Role Of Group A Streptococcus Htra In The Maturation Of Speb Protease, J. N. Cole, J. A. Aquilina, P. G. Hains, A. Henningham, K. S. Sriprakash, M. G. Caparon, V. Nizet, M. Kotb, S. J. Cordwell, S. P. Djordjevic, Mark J. Walker
Role Of Group A Streptococcus Htra In The Maturation Of Speb Protease, J. N. Cole, J. A. Aquilina, P. G. Hains, A. Henningham, K. S. Sriprakash, M. G. Caparon, V. Nizet, M. Kotb, S. J. Cordwell, S. P. Djordjevic, Mark J. Walker
Faculty of Science - Papers (Archive)
The serine protease HtrA (DegP) of the human pathogen Streptococcus pyogenes (group A Streptococcus; GAS) is localized to the ExPortal secretory microdomain and is reportedly essential for the maturation of cysteine protease SpeB. Here we utilize HSC5 (M5 serotype) and the in-frame isogenic mutant HSC5ΔhtrA to determine whether HtrA contributes to the maturation of other GAS virulence determinants. Mutanolysin cell wall extracts and secreted proteins were arrayed by 2-DE and identified by MALDI-TOF PMF analysis. HSC5ΔhtrA had elevated levels of cell wall-associated M protein, whilst the supernatant had higher concentrations of M protein fragments and a reduced amount of mature …
Changing Cultures Of Water In Eastern Australian Backyard Gardens, Lesley M. Head, Pat Muir
Changing Cultures Of Water In Eastern Australian Backyard Gardens, Lesley M. Head, Pat Muir
Faculty of Science - Papers (Archive)
Research into diverse cultural understandings of water provides important contributions to the pressing global issue of sustainable supply, particularly when combined with analysis of relationships between everyday household practice and larger sociotechnical networks of storage and distribution. Here we analyse semi-structured interviews with 298 people about their 241 backyards in the Australian east coast cities of Sydney and Wollongong, undertaken during the 2002-03 drought. Water emerged as an important issue in both consciousness and practice. In contrast to a number of other environmental issues which stimulate more polarised responses, a commitment to reducing water consumption was shared across the study …
Transition Analysis For Moderate Feedback Self-Mixing Interferometry, L. Wei, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo
Transition Analysis For Moderate Feedback Self-Mixing Interferometry, L. Wei, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo
Faculty of Informatics - Papers (Archive)
We present a theoretical analysis on the locations of transition points in moderate feedback self-mixing signal which is a fundamental issue to be addressed in preprocessing experimentally acquired data. Locations for the start and end points for upward and downward switchings are calculated based on the Lang-Kobayashi model and discussions are given, which provides guidance in achieving more accurate signal normalization.
Enhancing The Multicast Performance Of Structured P2p Overlay In Supporting Massively Multiplayer Online Games, Xinbo Jiang, Farzad Safaei, P. Boustead
Enhancing The Multicast Performance Of Structured P2p Overlay In Supporting Massively Multiplayer Online Games, Xinbo Jiang, Farzad Safaei, P. Boustead
Faculty of Informatics - Papers (Archive)
Scribe is a scalable application level multicast infrastructure. We have developed two techniques to improve the performance of Scribe in terms of latency and bandwidth distribution. The first technique identifies that the final hop of Scribe traffic path is largely selected without any proximity consideration and incurs the longest distance traveled. To overcome this, we introduce Proximity Neighbor Selection (PNS) into the final hop for latency improvement. The second technique builds a hierarchical two-level overlay. While PNS can be applied at both levels for latency performance, the bandwidth stress required by applications can now be distributed among the nodes in …
A Communications Policy Perspective On Ctc Sustainability In Regional Australia: Commercial Viability And Social Good, William Tibben
A Communications Policy Perspective On Ctc Sustainability In Regional Australia: Commercial Viability And Social Good, William Tibben
Faculty of Informatics - Papers (Archive)
Community Technology Centers (CTCs) seek to provide regional communities with access to information and communication technologies (ICTs) and broadband services. The focus of this paper is on developing sustainability in such CTCs in contexts that are often challenged by economic decline. An exploration of current communications policy is undertaken to better understand the provision of these equity initiatives. Using Australian legislation for telecommunications and broadcasting, the paper provides a framework to understand sustainability in CTCs. Out of this analysis a more detailed understanding of sustainability is advanced.
Can Superior Crm Capabilities Improve Performance In Banking, T. R. Coltman
Can Superior Crm Capabilities Improve Performance In Banking, T. R. Coltman
Faculty of Informatics - Papers (Archive)
The market enthusiasm generated around investment in customer relationship management (CRM) technology is in stark contrast to the nay-saying by many academic and business commentators. This raises an important research question concerning the extent to which banks should continue to invest in CRM technology. Drawing on field interviews and a survey of senior bank executives the results reveal that a superior CRM capability can deliver improved performance. The paper then demonstrates that in order to be most successful, CRM programs require a combination of technical, human and business capabilities.
On Implementing Mpeg-21 Intellectual Property Management And Protection, N. P. Sheppard
On Implementing Mpeg-21 Intellectual Property Management And Protection, N. P. Sheppard
Faculty of Informatics - Papers (Archive)
The MPEG-21 Intellectual Property Management and Protection (&lquot;IPMP&rquot;) Components specify a framework for inter-operable and renewable digital rights management based on IPMP tools that implement proprietary digital rights management features. MPEG-21 defines the mechanism by which protected multimedia objects are associated with proprietary IPMP tools, but does not specify the interface through which IPMP tools and MPEG-21 terminals communicate. This paper describes an implementation of the IPMP components including an interface to IPMP tools based on the MPEG Rights Expression Language; dynamic construction of authorisation proofs that permit a principal to carry out an action; and a cryptographic architecture bound …
A Note On Überveillance / A Note On Uberveillance, M G. Michael, Katina Michael
A Note On Überveillance / A Note On Uberveillance, M G. Michael, Katina Michael
Faculty of Informatics - Papers (Archive)
The following note from the editors presents a summary of the term überveillance, as it was originally presented by the primary author in May 2006. Überveillance is an above and beyond, an exaggerated, an omnipresent 24/7 electronic surveillance. It is a surveillance that is not only “always on” but “always with you” (it is ubiquitous) because the technology that facilitates it, in its ultimate implementation, is embedded within the human body. The problem with this kind of bodily invasive surveillance is that omnipresence in the ‘material’ world will not always equate with omniscience, hence the real concern for misinformation, misinterpretation, …
Realising Wacnet Through A Zigbee-Based Architecture, A. Desmet, F. Naghdy, Monserrat Ros
Realising Wacnet Through A Zigbee-Based Architecture, A. Desmet, F. Naghdy, Monserrat Ros
Faculty of Informatics - Papers (Archive)
The development of a novel architecture called Wireless Ad-hoc Control Networks (WACNets) is reported. WACNet (Wireless Ad-hoc Control Network) is a novel concept developed by Intelligent Mechatronics Research Centre, University of Wollongong, towards providing a framework for highly distributed intelligent wireless control networks. A WACNet consists of intelligent nodes based on IEEE 1451 Smart Sensor with a wireless means of communication (BlueTooth). The focus in this paper is on designing a suitable wireless communication system for this network. In the earlier design. the wireless communications was developed based on Bluetooth and WiFi standards. While being successful, they showed some limitations …
Improving Inventory Control In A Small-To-Medium Retailer Using Rfid., D. Hamilton
Improving Inventory Control In A Small-To-Medium Retailer Using Rfid., D. Hamilton
Faculty of Informatics - Papers (Archive)
Small-to-medium retailers are organizations that have traditionally had problems with inaccurate inventory control systems. This paper documents a research project that is currently in progress, aiming to explore the use of RFID for improving inventory control in a small-to-medium retailer. The aim of this paper is to review literature related to the project to emphasise its significance. In the initial part of this paper, the purpose of inventory control and the basic principles of RFID technology will be outlined. The latter part of this paper examines literature that has been published in relation to RFID and inventory control, highlighting areas …
The Mpeg-7 Query Format: A New Standard In Progress For Multimedia Query By Content, Kevin Adistambha, M. Doeller, R. Tous, M. Gruhne, M. Sano, C. Tsinaraki, S. Christodoulakis, Kyoungro Yoon, C. H. Ritz, I. S. Burnett
The Mpeg-7 Query Format: A New Standard In Progress For Multimedia Query By Content, Kevin Adistambha, M. Doeller, R. Tous, M. Gruhne, M. Sano, C. Tsinaraki, S. Christodoulakis, Kyoungro Yoon, C. H. Ritz, I. S. Burnett
Faculty of Informatics - Papers (Archive)
ln recent years, the amount of Internet accessible digital audiovisual media files has vastly increased. Therefore the need to describe the media (by way of metadata) has also increased significantly. MPEG-7 (finalized in 2001) provides a comprehensive and rich metadata standard for the descr iption of multimedia content. Unfortunately, a standardized query format does not exist for MPEG-7, or other multimedia metadata. Such a standard would provide for communications between quer ying clients and databases, suppor ting cross-modal and cross-media retrieval. The ISO/IEC SC29WG11 committee decided therefore to contribute to this application space by adding such functionality as a new …
Reconfigurable Media Coding: Self-Describing Multimedia Bitstreams, Joseph Thomas-Kerr, J. Janneck, M. Mattavelli, I. Burnett, C. Ritz
Reconfigurable Media Coding: Self-Describing Multimedia Bitstreams, Joseph Thomas-Kerr, J. Janneck, M. Mattavelli, I. Burnett, C. Ritz
Faculty of Informatics - Papers (Archive)
The development of MP3 and JPEG sparked an explosion in digital content on the internet. These early encoding formats have since been joined by many others, including Quicktime, Ogg, MPEG-2 and MPEG-4, which poses an escalating challenge to vendors wishing to develop devices that interoperate with as much content as possible. This paper presents aspects of Reconfigurable Media Coding (RMC), a project currently mat. In other words, an RMC bitstream contains metadata to assemble a decoder from a fundamental building-blocks, as well as a schema that describes the syntax of the content data, and how it may be parsed. RMC …
The Bullwhip Effect In Complex Supply Chains, I. Alony, Albert Munoz Aneiros
The Bullwhip Effect In Complex Supply Chains, I. Alony, Albert Munoz Aneiros
Faculty of Informatics - Papers (Archive)
This paper reviews the various methods of modelling the dynamics of supply chains. We then present recently documented causes of the Bullwhip effect in production supply chains, and the methodologies used to describe and measure the importance of these causes. We examine the limitations of these methodologies and suggest a combined approach discrete event-continuous simulation modelling approach to further study this phenomenon in complex production supply chains.
Diversity Performance Of Interleaved Spread Spectrum Ofdm Signals Over Frequency Selective Multipath Fading Channels, P. Tu, Xiaojing Huang, E. Dutkiewicz
Diversity Performance Of Interleaved Spread Spectrum Ofdm Signals Over Frequency Selective Multipath Fading Channels, P. Tu, Xiaojing Huang, E. Dutkiewicz
Faculty of Informatics - Papers (Archive)
In this paper we propose an interleaved spread spectrum orthogonal frequency division multiplexing (ISS-OFDM) system for achieving both frequency diversity and time diversity and investigate the system performance over frequency selective fading channels. The purpose is to exploit the diversity capability of OFDM systems, develop efficienct spectrum spreading technique and improve the system performance against frequency selective channel fading. At the transmitter, the ISS-OFDM signal is generated by employing spread spectrum modulation and interleaving techniques. At the receiver, the received signals are combined by using maximum ratio combining (MRC) technique. The simulation indicates that the ISS-OFDM system has improved performance …
Logistics Service Recovery And The Role Of Technology, A. Brinsmead
Logistics Service Recovery And The Role Of Technology, A. Brinsmead
Faculty of Informatics - Papers (Archive)
The logistics industry is becoming increasingly competitive, and supply chains becoming increasingly complex. Service failures are inevitable and part of the logistics landscape. Service recovery is relevant given the logistic industry’s trend toward a proactive approach to service failures. Furthermore, service recovery has the potential to become a source of organisational differentiation. Service failure management needs to be an integral part of the greater customer service program, rather than a reactive ad hoc process. Technology, already underpinning much of the industries capabilities, is seen as a likely enabler of sophisticated service recovery processes. The service recovery process is broken down …
Intelligent Multimedia Delivery? It’S A Question Of Semantics, Joseph Thomas-Kerr, I. Burnett, C. Ritz
Intelligent Multimedia Delivery? It’S A Question Of Semantics, Joseph Thomas-Kerr, I. Burnett, C. Ritz
Faculty of Informatics - Papers (Archive)
Intelligent multimedia delivery uses semantic information about content to enhance the delivery process. This paper proposes a model for intelligent multimedia delivery that advances the state of the art by incorporating a concept of semantic distortion into the delivery optimization process. Furthermore, the model combines format-independence with rate-distortion optimization to provide a flexible framework for intelligent delivery of multimedia in existing and future formats. The paper provides a review of the existing work covering components of the model: scalable coding formats, rate-distortion optimization, format-independent adaptation, and semantic adaptation. It then details the model, and identifies open problems and opportunities for …
Dynamic Bandwidth Mcids - A Cognitive Solution For Mcids Based Uwb Communications, J. Zhao, Xiaojing Huang, E. Dutkiewicz
Dynamic Bandwidth Mcids - A Cognitive Solution For Mcids Based Uwb Communications, J. Zhao, Xiaojing Huang, E. Dutkiewicz
Faculty of Informatics - Papers (Archive)
Dynamic bandwidth multicode interleaved direct sequence (MCIDS), an enhanced MCIDS based Ultra-wideband (UWB) application is proposed in this paper, featuring a cognitive transmission bandwidth adaptation without any adverse effect on the data rate. By introducing a specific lowpass filtering and down-sampling into the traditional MCIDS algorithm, this system can decrease the transmission bandwidth into part of its original bandwidth but still be able to recover all the transmitted data from the reduced bandwidth. This solution can efficiently improve the coexistence ability of UWB devices in a cognitive manner without increasing hardware complexity.
On The Accuracy Of Rfid Tag Estimation Functions, Dheeraj Klair, K. Chin, R. Raad
On The Accuracy Of Rfid Tag Estimation Functions, Dheeraj Klair, K. Chin, R. Raad
Faculty of Informatics - Papers (Archive)
Dynamic Framed Slotted Aloha (DFSA) based tag reading protocols rely on a tag estimation function to calculate the best frame size to use for a given tag set. An inaccurate estimate results in high identification delays and unnecessary energy wastage. This is particularly serious when DFSA based tag reading protocols are used in RFID-enhanced wireless sensor networks (WSNs), where nodes are battery constrained. To this end, this paper presents qualitative and quantitative analysis of five tag estimation functions using Monte Carlo simulations. We iteratively estimate a given set of tags and evaluate the mean error, variability, skew and Kurtosis of …
Peak-To-Average Power Ratio Performance Of Interleaved Spread Spectrum Ofdm Signals, P. Tu, Xiaojing Huang, E. Dutkiewicz
Peak-To-Average Power Ratio Performance Of Interleaved Spread Spectrum Ofdm Signals, P. Tu, Xiaojing Huang, E. Dutkiewicz
Faculty of Informatics - Papers (Archive)
In this paper we propose an interleaved spread spectrum orthogonal frequency division multiplexing (ISS-OFDM) transmission scheme and demonstrate its reduced peak-toaverage power ratio (PAR). The proposed ISS-OFDM signal is realized by two steps. The first step is to modulate the data symbol by complex exponential spreading and the second is to use an interleaving technique to spread the signal spectrum as well as reduce the signal peak-to-average power ratio. The distinctive features of the proposed method are that in the frequency domain the same data information is carried by a number of subbands to effectively spread the signal spectrum and …
Viability Of Concurrent Transmission And Reception For Uwb Radios Over Multipath Channels, Ricardo Gandia Sanchez, Xiaojing Huang, K. Chin
Viability Of Concurrent Transmission And Reception For Uwb Radios Over Multipath Channels, Ricardo Gandia Sanchez, Xiaojing Huang, K. Chin
Faculty of Informatics - Papers (Archive)
Multihop transmissions over wireless mesh networks present limited end-to-end (E2E) data rates, as every hop waits for an entire packet to arrive before starting retransmission. That is, the E2E data rate drops when every hop stores and then forwards packets, thus making such transmissions unsuitable for multimedia applications. In this work, in order to increase data rates, we present an ultra-wideband (UWB) radio transceiver capable of concurrently transmit and receive (cTxRx) packets. However, concurrently receiving and transmitting comes at the cost of a channel model with increased interference level. Herein, we explain a new interference model and propose a transceiver …
On The Characteristics Of Bgp Routes, J. Clement, K. Chin
On The Characteristics Of Bgp Routes, J. Clement, K. Chin
Faculty of Informatics - Papers (Archive)
This paper studies the characteristics of Border Gateway Protocol (BGP) routes. In particular, it identifies autonomous systems (ASs) that appear frequently in path vectors. In addition, it analyzes path vector lengths. Finally, it investigates the prevalence of inflated paths, commonly used by ASs for traffic engineering purposes.
Analysis And Suppression Of Chatter In Robotic Machining Process, Zengxi Pan, H. Zhang
Analysis And Suppression Of Chatter In Robotic Machining Process, Zengxi Pan, H. Zhang
Faculty of Informatics - Papers (Archive)
One of the most challenging issues in robotic machining process is to know the vibration/chatter characteristics. To reduce the trial and error frustration, this paper presents the underline mechanism and theoretical analysis to provide physical understanding for the onset of chatter problem and principles to prevent that. First, the cutting force model and robot structure model are established for a systematic analysis of chatter mechanism. Completely different from common woes of regenerative chatter in conventional CNC machine paradigm, another type of chatter, namely, mode-coupling chatter was identified as the dominant source of vibrations in robotic machining, largely due to the …
Displacement Estimation Based On Model Calibration In Weak Feedback Optical Self-Mixing System, L. Wei, Jiangtao Xi, J. Chicharo
Displacement Estimation Based On Model Calibration In Weak Feedback Optical Self-Mixing System, L. Wei, Jiangtao Xi, J. Chicharo
Faculty of Informatics - Papers (Archive)
This paper presents a novel method to estimate displacement of a moving object based on model calibration in a weak feedback laser diode self-mixing system. A hybrid genetic algorithm is employed to locate the global minimum for the cost function which is constructed as the discrepancy between theoretically calculated system output and the experimental data. In turn, displacement measurement is achieved by identifying the optimal parameters for the system model. The proposed method is tested by both simulation and experimental setup with measuring accuracy better than 25nm.
Mac Design And Analysis For Wireless Sensor Networks With Co-Operative Localisation, M. Rengasamy, E. Dutkiewicz, M. Hedley
Mac Design And Analysis For Wireless Sensor Networks With Co-Operative Localisation, M. Rengasamy, E. Dutkiewicz, M. Hedley
Faculty of Informatics - Papers (Archive)
Abstract—Co-operative localisation in wireless sensor networks (WSNs) is a method in which wireless sensor nodes interact with each other as peers to determine their physical position. In such networks it is crucial for communication between nodes to be contention free to meet the strict timing requirements. Medium Access Control (MAC) protocols provide the strongest influence over contention control in WSNs. The focus of this work is the design and analysis of a WSN MAC protocol suitable for supporting co-operative localisation. This paper presents a design overview of the MAC protocol and details its control structure. Preliminary simulation results are also …
Location-Based Drm Using Wifi Access Points, Martin Jan Surminen, Nicholas Paul Sheppard, Reihaneh Safavi-Naini
Location-Based Drm Using Wifi Access Points, Martin Jan Surminen, Nicholas Paul Sheppard, Reihaneh Safavi-Naini
Faculty of Informatics - Papers (Archive)
Location-based Digital Rights Management (DRM) refers to a system allowing the owner of an electronic file to specify not only the actions a user is allowed to perform regarding the content, but also restrict the actions to a specified geographical area. A method for retrieving location information is required. One such method is to place wireless accesspoints in areas of interest, requiring a device to be in the vicinity of the correct accesspoint(s) in order to access a file.
Diversity Performance Of Precoded Ofdm With Mmse Equalization, Xiaojing Huang
Diversity Performance Of Precoded Ofdm With Mmse Equalization, Xiaojing Huang
Faculty of Informatics - Papers (Archive)
Two sets of bit error rate (BER) lower bounds for precoded orthogonal frequency division multiplexing (OFDM) systems using minimum mean square error (MMSE) equalization over frequency-selective multipath fading channels are evaluated by Monte Carlo method in this paper. The first set represents the best performance under different data group sizes used for precoding, whereas the second set represents the best performance under different channel multipath diversity orders. These performance bounds can serve as the guidelines for system designers to decide proper data group sizes for precoded OFDM systems in order to achieve better trade-off between system performance and complexity. Numerical …
On Indoor Multi-Hopping Capacity Of Wireless Ad-Hoc Mesh Networks, Mehran Abolhasan, Jerry Chun-Ping Wang, D. R. Franklin
On Indoor Multi-Hopping Capacity Of Wireless Ad-Hoc Mesh Networks, Mehran Abolhasan, Jerry Chun-Ping Wang, D. R. Franklin
Faculty of Informatics - Papers (Archive)
The capacity and multi-hopping performance of ad hoc mesh networks in dynamic environment still remains an open research issue. Previous theoretical studies suggest that they do not scale in densely distributed networks. However, a study has shown that scalability and hence the multihopping capacity of mesh network is not only bound by the number of nodes in the network but also the number of hops [3]. In this paper we investigate the performance of multihop ad hoc mesh networks, using both simulation studies and an experimental test-bed, and monitor the performance of the network as the number of hops in …