Digital Commons Network^™

Encouraging Physical Activity In Teens. Can Technology Help Reduce Barriers To Physical Activity In Adolescent Girls?, Tammy Toscos Phd, Anne Faber, Kay Connelly, Adity Mutsuddi Upoma

Health Services and Informatics Research

Physical activity levels of girls decline dramatically during adolescence and may be a contributor to the increasing number of obese teens in the United States. Research has shown that social support is positively correlated with physical activity levels in adolescents, particularly girls. We present the findings from a three week field study of a mobile phone application designed to create a support group for physical activity within an existing social network of adolescent girls. Our findings suggest design considerations for technologies that encourage physical activity for this user group.

Presented at 2008 Second International Conference on Pervasive Computing Technologies for …

Tunable True-Time Delay Unit Based On Opto-Vlsi Processing, Feng Xiao, Budi Juswardy, Kamal Alameh

Research outputs pre 2011

A novel tunable true-time delay unit is proposed and demonstrated. The unit is based on the use of an Opto-VLSI processor that dynamically selects a single waveband or multiple wavebands from an RF-modulated broadband optical signal and routes them to a high-dispersion fiber for arbitrary time delay synthesis. Experimental results demonstrate continuously tunable time delay of up to 4 ns.

Obstacle Detection And Spectral Discrimination Using Multi-Wavelength Motionless Wide Angle Laser Scanning, Kaveh Sahba, Kamal Alameh, Clifton Smith

Research outputs pre 2011

Static laser scanning over a wide angle is demonstrated by ranging to 20 laser beams generated by a novel cylindrical quasi-cavity waveguide, using laser triangulation. Baseline distances and outgoing angles unique to each laser beam are calculated by modelling the triangulation arrangement using a system of linear equations and plotting principal rays. The quasi-cavity waveguide, imaging lens and focal plane are also plotted. The system is calibrated by finding optimal values for uncertain instrumental parameters using constrained non-linear optimization. Distances calculated over 5m indoors result in accuracies above 93%. Discrete laser spectroscopy using 640nm and 785nm laser diodes is also …

A Tunable Multiwavelength Laser Employing A Semiconductor Optical Amplifier And An Opto-Vlsi Processor, Muhsen Aljada, Kamal Alameh, Yong T. Lee

Research outputs pre 2011

We propose and experimentally demonstrate a stable tunable multiwavelength laser employing a semiconductor optical amplifier (SOA) in conjunction with an opto-very-large-scale-integration (VLSI) processor. By uploading digital phase holograms onto the opto-VLSI processor, the amplified spontaneous emission of the SOA is arbitrarily sliced and injected back into the SOA to generate multiple lasing wavelengths with a linewidth of 0.5 nm. Experimental results demonstrate a tunable multiwavelength laser with a tuning range from 1528 to 1533 nm with power fluctuations of less than 0.5 dB.

Current Challenges Facing Information And Communications Technology: A Manifesto For Change, Donald Mcdermid

Research outputs pre 2011

A distinction is drawn concerning the true nature of Information and Communications Technology (ICT) which previously was seen as technology-focused or techno centric but actually concerns transformation and the management of change in business (socio-techno centric). Current issues and challenges in ICT are examined and future trends and directions highlighted. This leads to a manifesto for change outlining a coherent approach to transforming ICT into a resource which fully contributes to business. Finally given this manifesto, challenges for tertiary education are outlined.

Evaluation Of An Optical Image Sensor For Use In The Microphotonic Real-Time Vegetation Discrimination System, Arie Paap, Sreten Askraba, Kamal Alameh, John Rowe

Research outputs pre 2011

A comparison between the performance of a commercially available line scan camera and a linear sensor array employed in a micro-photonic real-time vegetation discrimination system for use in selective herbicide spraying systems is presented.

A Type Of Variation Of Hamilton Path Problem With Applications, Jitian Xiao, Jun Wang

Research outputs pre 2011

This paper describes a type of variation of the Hamilton path problem that can be applied to a type of applications. Unlike the original Hamilton path problem, the variation always has a solution. The problem of finding solutions to the variation of the Hamilton path problem is NP-complete. A heuristic for finding solutions to the problem is developed and analyzed. The heuristic is then applied to a real application scenario in the area of spatial cluster scheduling in spatial join processing. Experiments have demonstrated that the proposed method generates better cluster sequence than existing algorithms.

Photonic-Based Spectral Reflectance Sensor For Ground-Based Plant Detection And Weed Discrimination, Arie Paap, Sreten Askraba, Kamal Alameh, John Rowe

Research outputs pre 2011

A bench prototype photonic-based spectral reflectance sensor architecture for use in selective herbicide spraying systems performing non-contact spectral reflectance measurements of plants and soil is described and experimental data obtained with simulated farming vehicle traveling speeds of 7 and 22 km/h is presented. The sensor uses a three-wavelength laser diode module that sequentially emits identically-polarized laser light beams through a common aperture, along one optical path. Each laser beam enters a multi-spot beam generator which produces up to 14 parallel laser beams over a 210mm span. The intensity of the reflected light from each spot is detected by a high-speed …

Opto-Vlsi Based Broadband Reconfigurable Optical Add-Drop Multiplexer, Feng Xiao, Budi Juswardy, Kamal Alameh

Research outputs pre 2011

In this paper, a reconfigurable optical add/drop multiplexer (ROADM) structure using an Opto-VLSI processor, two arrayed waveguide grating de/multiplexers (AWGs) and a custom-made fiber array is described. The fiber array consist of N pairs of upper and lower fibers, where each pair could function as an add, a drop or a thru multiplexers depending on the hologram generated by the Opto-VLSI processor. Experimental results show that the proposed ROADM structure has an average insertion loss of 5.5 dB for all the functions and a uniformity of 0.3 dB over a wide wavelength range from 1524 nm to 1576 nm. A …

Opto-Vlsi-Based Reconfigurable Microwave Photonic Transversal Filter With Positive And Negative Coefficients, Feng Xiao, Budi Juswardy, Kamal Alameh

Research outputs pre 2011

A novel reconfigurable microwave photonic filter structure with positive and negative coefficients is proposed and demonstrated. The filter structure comprises two arrayed waveguide gratings, a custom-made fiber array, high-dispersion fibres, and a reconfigurable opto-VLSI processor. Positive and negative filter weights can flexibly be synthesised to realise arbitrary transfer functions. Experimental results are presented, which demonstrate the principle of the proposed filter structure.

Men Of Steel Or Plastic Cops: The Use Of Ethnography As A Transformative Agent, Christine Teague, David Leith

Research outputs pre 2011

The Perth urban rail system, like many other rail systems in Australia and overseas, is subject to crime and anti-social behaviour around the railway environs from a small minority of the travelling public. The transit officers, who form part of the security section of the Public Transport Authority, are the people employed to deal with these incidents, which can result in transit officers being injured. To fully understand the violence and antisocial behaviour that they deal with on a regular basis and develop strategies to reduce this risk of injury, it was necessary to enter their world. The researcher in …

Reconfigurable Multi-Passband Optical Filter Using Opto-Vlsi Processor, Muhsen Aljada, Kamal Alameh

Research outputs pre 2011

A reconfigurable multi-passband optical filter of 0.5 nm linewidth and a tuning range of 8 nm is demonstrated using an opto-VLSI processor. The wavelength tunability is performed using digital phase holograms uploaded on the opto-VLSI processor.

You've Got Mail: Accountability And End User Attitudes To Email Management, Mark Brogan, Susan Vreugdenburg

Research outputs pre 2011

In a pioneering ethnographic study of end user responses to the problem of ‘information overload’ Whittaker and Sidner (1996) found that the design of systems primarily as methods of asynchronous communication, posed significant information management problems for users. In another contemporaneous study, David Bearman (1993) extended understanding of the implications of end user email management behavior by identifying significant accountability implications for organizations arising from the use of email. Recent case studies in the United States and Australia (Leopold, 2008; Raleigh Chronicle, 2008; Strutt, and Taylor, 2007) have once again focused attention on the accountability consequences for Government of email …

A Novel Wide-Angle Laser Triangulation Method For Obstacle Detection, Kaveh Sahba, Kamal Alameh, Clifton Smith

Research outputs pre 2011

Indoor active triangulation to laser spots generated by quasi-cylindrical cavity is demonstrated. Principal ray trajectory is modeled using a system of linear equations and fundamental ray geometry. Each ray’s unique outgoing angle and baseline is calculated and used to derive the range to the corresponding spot. Above 98% accuracy is achieved over an approximate range of 5m, demonstrating a novel motionless laser scanning technique with a wide scanned angle and no moving parts.

Pax7 Is Requisite For Maintenance Of A Subpopulation Of Superior Collicular Neurons And Shows A Diverging Expression Pattern To Pax3 During Superioir Collicular Development, Jennifer Thompson, Andreas Zembrzycki, Ahmed Mansouri, Melanie Ziman

Research outputs pre 2011

Pax7 encodes a transcription factor well-established as an important determinant of mesencephalic identity and superior collicular development. Pax7 mutant mice, however, present with no obvious morphological impairments to the superior colliculus. This finding is paradoxical and has been attributed to functional redundancy afforded by its paralogue Pax3. Here we utilise Pax7 mutant mice to investigate the precise role of this important developmental regulator during superior collicular development and neuronal specification/differentiation. We also assess its spatiotemporal relationship with Pax3 during embryonic development. Analysis of the superior colliculus of Pax7 mutant and wildtype mice at a variety of developmental timepoints revealed that …

Analysis Of Information Remaining On Hand Held Devices For Sale On The Second Hand Market, Andrew Jones, Craig Valli, Iain Sutherland

Research outputs pre 2011

The ownership and use of mobile phones, Personal Digital Assistants and other hand held devices is now ubiquitous both for home and business use. The majority of these devices have a high initial cost, a relatively short period before they become obsolescent and a relatively low second hand value. As a result of this, when the devices are replaced, there are indications that they tend to be discarded. As technology has continued to develop, it has led to an increasing diversity in the number and type of devices that are available, and the processing power and the storage capacity of …

A Novel Mobile Wimax Solution For Higher Throughput, Iftekhar Ahmad, Daryoush Habibi

Research outputs pre 2011

The IEEE 802.16 standard, also known as WiMAX, has emerged as an exciting technology for broadband wireless communications with potentials to offer high throughput and support high bandwidth demanding applications. WiMAX, however, has yet to prove its effectiveness when the end terminals are not fixed and have the capacity to move from one place to another at different speeds. Recent studies suggest that while WiMAX (802.16e) has the potential to deliver a data rate up to 75 Mb/s for fixed wireless communications, it fails drastically for mobile wireless communications, often providing a data rate less than 1 Mb/s when the …

A Proactive Forward Error Control Scheme For Mobile Wimax Communication, Iftekhar Ahmad, Daryoush Habibi

Research outputs pre 2011

The IEEE 802.16 standard, also known as WiMAX, has yet to prove its effectiveness when the end terminals are not static and free to move at vehicular speeds. High bit error rate caused by multipath fading at high vehicular speeds, is the key reason for low throughput at high speeds. Standard error control mechanisms like transmission control protocol (TCP) and forward error correction (FEC) have limited impact on the overall throughput at vehicular speeds. In this paper, we propose a proactive FEC scheme that adjusts the FEC code size based on the estimated bit error rate at various vehicular speeds. …

Source Localisation In Wireless Sensor Networks Based On Optimised Maximum Likelihood, Mohammed Rahman, Daryoush Habibi, Iftekhar Ahmad

Research outputs pre 2011

Maximum likelihood (ML) is a popular and effective estimator for a wide range of diverse applications and currently affords the most accurate estimation for source localisation in wireless sensor networks (WSN). ML however has two major shortcomings namely, that it is a biased estimator and is also highly sensitive to parameter perturbations. An Optimisation to ML (OML) algorithm was introduced that minimises the sum-of-squares bias and exhibits superior performance to ML in statistical estimation, particularly with finite datasets. This paper proposes a new model for acoustic source localisation in WSN, based upon the OML estimation process. In addition to the …

An Improved Fec Scheme For Mobile Wireless Communication At Vehicular Speeds, Iftekhar Ahmad, Daryoush Habibi, Ziaur Rahman

Research outputs pre 2011

WiMAX has emerged as a promising wireless communication technology with potential to deliver high throughput and guaranteed quality of service to the end applications. Recent studies suggest that while WiMAX (802.16e) is capable of delivering a data rate of up to 75 Mbps for fixed wireless communications, data rate decreases drastically for mobile wireless communications, often providing a data rate less than 1 Mb/s when the mobile nodes travel at vehicular speeds. High bit error rate caused at high vehicular speeds is the key reason for low throughput. In noisy mobile communication environments, standard error control mechanisms like the transmission …

Fast Evaluation Of The Square Root And Other Nonlinear Functions In Fpga, Stefan Lachowicz, Hans-Joerg Pfleiderer

Research outputs pre 2011

The paper presents a novel method of evaluating the square root function in FPGA. The method uses a linear approximation subsystem with a reduced size of a look-up table. The reduction in the size of the lookup table is twofold. Firstly, a simple linear approximation subsystem uses the lookup table only for the node points. Secondly, a concept of a variable step look-up table is introduced, where the node points are not uniformly spaced, but the spacing is determined by how close to the linear function the approximated function is. The proposed method of evaluating nonlinear function and specifically the …

Performance Evaluation Of Ieee 802.15.4 For Mobile Sensor Network, Kartinah Zen, Daryoush Habibi, Alexander Rassau, Iftekhar Ahmad

Research outputs pre 2011

The IEEE 802.15.4 standard medium access control (MAC) protocol for low rate wireless personal area networks (LRWPAN) is design mainly for static sensor networks and its capability to support mobile sensor networks has not yet been established. To the best knowledge of authors, this is the first paper that evaluates the suitability of IEEE 802.15.4 MAC in mobile sensor networks environment. We evaluate the performance based on node's speed and beacon order, and observe the effect on energy usage, packet delivery ratio and time required to associate with its coordinator. From the experiment we observe that the moving nodes experienced …

Improving Mobile Sensor Connectivity Time In The Ieee 802.15.4 Networks, Kartinah Zen, Daryoush Habibi, Iftekhar Ahmad

Research outputs pre 2011

In the IEEE 802.15.4 medium access control (MAC) protocol for wireless sensor networks, a sensor node needs to associate with a coordinator before it starts sending or receiving data. The sensor node will mostly choose the nearest coordinator to associate with. However, this method is not suitable for a constantly moving sensor node because it will end up switching coordinators too often due to short connectivity time. The IEEE 802.15.4 has a simplistic and inadequate method of choosing a coordinator in this context. In this paper, we introduce a method to increase the mobile sensor node connectivity time with its …

Soft Computing In The Forecasting Of The Stock Exchange Of Thailand, Suchira Chaigusin, Chaiyaporn Chirathamjaree, Judith Clayden

Research outputs pre 2011

Stock markets are affected by many uncertainties and interrelated economic and political factors at both local and global levels; determining the set of relevant factors for making accurate predictions is a complicated task. This paper analyzes relevant literature on the Stock Exchange of Thailand (SET), according to the categories of techniques used. The research proposes an approach of soft computing on the SET forecasting and exposes the main driving indicators, from the literature, including Dow Jones, Nikkei index, Hang Seng index, Minimum Loan Rate, the value of the Thai baht and the gold price.

The Use Of Neural Networks In The Prediction Of The Stock Exchange Of Thailand (Set) Index, Suchira Chaigusin, Chaiyaporn Chirathamjaree, Judith Clayden

Research outputs pre 2011

Prediction of stock prices is an issue of interest to financial markets. Many prediction techniques have been reported in stock forecasting. Neural networks are viewed as one of the more suitable techniques. In this study, an experiment on the forecasting of the Stock Exchange of Thailand (SET) was conducted by using feedforward backpropagation neural networks. In the experiment, many combinations of parameters were investigated to identify the right set of parameters for the neural network models in the forecasting of SET. Several global and local factors influencing the Thai stock market were used in developing the models, including the Dow …

Towards Automated Test Sequence Generation, Usman Farooq, Chiou Peng Lam, Huaizhong Li

Research outputs pre 2011

The article presents a novel control-flow based test sequence generation technique using UML 2.0 activity diagram, which is a behavioral type of UML diagram. Like other model-based techniques, this technique can be used in the earlier phases of the development process owing to the availability of the design models of the system. The activity diagram model is seamlessly converted into a colored Petri net. We proposed a technique that enables the automatic generation of test sequences according to a given coverage criteria from the execution of the colored Petri nets model. Two types of structural coverage criteria for AD based …

Supporting Component Selection With A Suite Of Classifiers, Valerie Maxville, Chiou Peng Lam, J Armarego

Research outputs pre 2011

Software selection involves the assimilation of information and results for each candidate to enable a comparison for decisions to be made. The processes and tools developed assist with software selection to enhance quality, documentation and repeatability. The CdCE process aims to retain and document the information used in selection to assist decisions and to document them for reference as the system evolves. This paper describes the CdCE process and our approach to assist the shortlisting of candidates through a suite of classifiers. The application of the suite is illustrated using a selection and evaluation case study. Applying this approach helps …

Morphology Independent Dynamic Locomotion Control For Virtual Characters, Adrian Boeing

Research outputs pre 2011

Physically based animation of virtual characters is an attractive technology for computer games. It enables characters to dynamically react to interactions with the environment. Existing dynamic simulation controllers are often complex to understand and manipulate, and so are of limited use for animators. This paper presents an extended spline-based control strategy similar to splines used in standard keyframe animation techniques. Unlike existing dynamic control strategies, this allows animators to modify the control system parameters in a manner similar to traditional kinematic animation techniques. A genetic algorithm is employed to produce the initial control parameters for the desired gait, and extend …

Mutation Analysis For The Evaluation Of Ad Models, Usman Farooq, Chiou Peng Lam

Research outputs pre 2011

UML has became the industry standard for analysis and design modeling. Model is a key artifact in Model Driven Architect (MDA) and considered as an only concrete artifact available at earlier development stages. Error detection at earlier development stages can save enormous amount of cost and time. The article presents a novel mutation analysis technique for UML 2.0 Activity Diagram (AD). Based on the AD oriented fault types, a number of mutation operators are defined. The technique focuses on the key features of AD and enhances the confidence in design correctness by showing the absence of control-flow and concurrency related …

Optimized Wlan Mac Protocol For Multimedia Applications, Hushairi Zen, Daryoush Habibi, Alexander Rassau, Iftekhar Ahmad

Research outputs pre 2011

In this paper we propose an optimized WLAN MAC protocol for multimedia applications. The proposed MAC protocol consist of 3 main optimizing architectures, traffic segregation, specific service interval (SI) for voice and video traffic and smaller contention window (CW). Traffic segregation segregates real-time traffic from best-effort traffic while specific service interval provides voice and video traffic with the SI based on its mean arrival rate. In the contention time frame, the CW is made smaller to reduce delay and increase throughput. Ns2 is used as a simulating tool to compare the results of our proposed protocol with the legacy 802.11 …