Description:
Funding details: Australian Research Council, ARC Funding text 1: Joarder Kamruzzaman received the BSc and MSc degrees in Electrical and Electronic Engineering from Bangladesh University of Engineering and Technology, Dhaka, and the PhD degree in Information Systems Engineering from Muroran Institute of Technology, Hokkaido, Japan. He is currently a Professor in the School of Science, Engineering and Information Technology, Federation University Australia. Previously, he served as the Director of the Centre for Multimedia Computing, Communications and Artificial Intelligence Research hosted first by Monash University and later by Federation University. His research interests include distributed computing, Internet of Things, machine learning and cyber security. He has published 260+ peer-reviewed publications which include over 80 journal papers, 170 conferences, 11 book chapters and two edited reference books. He is the recipient of Best Paper award in four international conferences: ICICS′15, Singapore; APCC′14, Thailand; IEEE WCNC′10, Sydney, Australia and in the IEEE-ICNNSP′03, Nanjing, China. He has received nearly A$2.3m competitive research funding, including prestigious ARC (Australian Research Council) grant and large CRC (Collaborative Research Centre) grant. He was the founding Program co-Chair of the first International Symposium on Dependability in Sensor, Cloud, and Big Data Systems and Applications (DependSys), China in 2015. He has served 32 conferences in leadership capacities including Program co-Chair, Publicity Chair, Track Chair and Session Chairs, and since 2012 as an Editor of the Elsevier Journal of Network and Computer Applications, and had served as the lead Guest of Elsevier Journal Future Generation Computer Systems.
Description:
With the increasing popularity of digital products, there is a strong desire to protect the rights of owners against illegal redistribution. Traditional encryption schemes alone do not provide a comprehensive solution to digital rights management, since they do not prevent users who are authorized to use a digital product for their own use from transferring the cleartext content to unauthorized users. However, traceability schemes can be used to trace the illegitimate redistributors effectively. Two types of traceability schemes have been proposed in the literature - traceability codes (TA codes), and codes with the identifiable parent properties (IPP codes). TA codes are special IPP codes, and many TA codes implement an efficient identification algorithm which can determine at least one redistributor. However, many IPP codes are not TA codes, in which case, no efficient identification algorithms are available. In this paper, we generalize the definition of TA codes to derive a new family of traceability codes that is much larger than the family of traditional TA codes. By using existing decoding algorithms with respect to the Lee distance, an efficient identification algorithm is proposed for generalized TA codes. Furthermore, we show that the identification algorithm of generalized TA codes can find more redistributors than those of traditional TA codes.
Description:
With the increasing popularity of digital products, there is a strong desire to protect the rights of owners against illegal redistribution. Traditional encryption schemes alone do not provide a comprehensive solution to digital rights management, since they do not prevent users who are authorized to use a digital product for their own use from transferring the cleartext content to unauthorized users. However, traceability schemes can be used to trace the illegitimate redistributors effectively. Two types of traceability schemes have been proposed in the literature - traceability codes (TA codes), and codes with the identifiable parent properties (IPP codes). TA codes are special IPP codes, and many TA codes implement an efficient identification algorithm which can determine at least one redistributor. However, many IPP codes are not TA codes, in which case, no efficient identification algorithms are available. In this paper, we generalize the definition of TA codes to derive a new family of traceability codes that is much larger than the family of traditional TA codes. By using existing decoding algorithms with respect to the Lee distance, an efficient identification algorithm is proposed for generalized TA codes. Furthermore, we show that the identification algorithm of generalized TA codes can find more redistributors than those of traditional TA codes.
Description:
Trade-off between energy-efficiency and reliability in wireless sensor networks is application dependent. Without the reliability, the extended lifetime of a network is of limited use. Due to the inherent correlation between reliability and congestion, it is necessary to reduce congestion to improve reliability. Existing congestion control algorithms in wireless sensor networks are reactive. They attempt to reduce the congestion only after its detection. In this paper, we present Location Aided Congestion Aware Routing (LACAR) protocol that proactively avoids congestion formation and improves data delivery success rate in data gathering wireless sensor networks. Location, energy and congestion information of neighbours together with the location information of the base station determine appropriate routes. Simulation results show that LACAR achieves high packet success rate in an energy-efficient way.
Description:
The function of any visual prosthetic will be to generate patterned stimulation of the visual cortex arising from either direct stimulation (e.g. using cortical implants) or more peripheral inputs (e.g. an artificial retina). Direct cortical stimulation may result in patterns containing relatively few elements (say 10-100) while an artificial retina may deliver more complex patterns. We propose that regardless of the site of intervention, a tactile copy of the input, delivered to the skin at the same time as it is sent to the visual cortex, will offer significant advantages, especially during early stages of testing and development in which the user must 'make sense' of the novel input. The advantages of such a display include: (1) exploitation of multisensory processes such as cross-calibration, learning to discriminate sub-threshold stimuli and perceptual redundancy, (2) a means of measuring strengths and weaknesses of the prosthetic's visual input and evaluation of improvements and (3) a way of quickly adapting the congenitally- or late-blind user to the prosthetic.
Description:
Cluster-based routing protocols for wireless sensor networks have proved to be a very popular and effective innovation. They are inherently energy efficient and scalable owing to the distributed nature and hierarchical organization of sensor nodes, as well as the use of cluster heads in data reception, aggregation and transmission. However, their reliability is very limited because of the potential for sudden break down and the traffic congestion in a cluster head. A wireless communication link is also vulnerable to interference and noise. In addition, to form an optimal cluster is a NP hard problem. These problems make it very challenging to improve the reliability and energy efficiency simultaneously. To address these issues, this thesis proposes a number of clusterbased routing protocols that consider many challenging issues, such as the cluster number determination, the inter-cluster communication cost, the link quality and traffic congestion during the node clustering phase. This thesis contributes four innovative methods that improve both the reliability and energy efficiency of a wireless sensor network simultaneously. The first of these contributions is an optimum backup clustering technique, which reduces the re-clustering overhead of the network and safeguard a cluster head node from sudden break down. The second method, reliable and energy efficient inter-cluster communication, reduces the chance of a cluster head breakdown by developing routing paths that consider the optimal inter-cluster communication cost. This method also considers data loss due to poor link quality and congestion at the CH node. The third method, optimum cluster number determination technique for uniform wireless sensor network, integrates the wireless link quality factor analytically for estimating the optimal cluster number to be used in any suitable clustering protocol. Finally, joint optimization of number and allocation of clusters is introduced, which calculates the optimum cluster number at the time of node clustering. This is applicable in a wireless sensor network with both uniform and non-uniform node distributions. The performance of all the proposed methods is evaluated along with the computational complexity analysis and message overhead. To check whether the method promotes a sustainable environment, performance analysis of the backup clustering scheme has been presented for a certain portion of sensor nodes equipped with a solar cell. Statistical tests confirm that the new clustering methods exhibit significant improvements in terms of both reliability and energy efficiency over the most popular contemporary clustering protocols (e.g. HEED and only one existing backup clustering technique) with the comparable computational complexity and message overhead.
Description:
When network resources are shared between Instantaneous Request (IR) and Book-Ahead (BA) connections, activation of future BA connections may cause preemption of on-going IR connections due to resource scarcity. Rerouting of preempted calls via alternative feasible paths is often considered as the final option to restore and maintain service continuity. Existing rerouting techniques, however, do not ensure acceptably low service disruption time and suffer from high failure rate and low network utilization. In this work, a new rerouting strategy is proposed that estimates the future resource scarcity, identifies the probable candidate connections for preemption and initiates the rerouting process in advance for those connections. Simulations on a widely used network topology suggest that the proposed rerouting scheme achieves a higher successful rerouting rate with lower service disruption time, while not compromising other network performance metrics like utilization and call blocking rate.
Description:
In this paper, we propose a method for indexing and retrieval of images based on shapes of objects. The concept of connectivity is introduced. 3D models are used to represent 2D images. 2D images are decomposed a priori using connectivity which is followed by 3D model construction. 3D model descriptors are obtained for 3D models and used to represent the underlying 2D shapes. We have used spherical harmonics descriptors as the 3D model descriptors. Difference between two images is computed as the Euclidean distance between their descriptors. Experiments are performed to test the effectiveness of spherical harmonics for retrieval of 2D images. The proposed method is compared with methods based on principal components analysis (PCA) and generic Fourier descriptors (GFD). It is found that the proposed method is effective. Item S8 within the MPEG-7 still images content set is used for performing experiments.
Description:
The vibrations induced by machine faults help in diagnosis and prognosis of the machine. It is crucial for the fault diagnostic system to extract resonant frequency band which carries useful information about the defect frequencies and contains maximum signal to noise ratio. The spectral orientation of the resonant frequency band varies with the variation in machine dynamics. The existing techniques which employ wavelet transformation to exploit the signal energy distribution among different frequency sub-bands, are based on fixed decomposition level and do not optimize the wavelet parameters according to varying machine dynamics. The proposed study develops a novel technique: Adaptive Wavelet Decomposition and Resonance Frequency Estimation (AWRE) which estimates the positioning of the resonant frequency band based on adaptive selection of the wavelet decomposition levels. The results for the simulated as well as actual vibration data demonstrate that the proposed technique estimates the bandwidth of the resonant frequency band quite effectively.
Description:
Vibration signals used for abnormality detection in machine health monitoring (MHM) suffer from significant variation with fault severity. This variation causes overlap among the features belonging to different types of faults resulting in severe degradation of fault detection accuracy. This paper identifies a new problem due to severity variant features and proposes a novel adaptive training set and feature selection (ATSFS) scheme based upon the orientation of the test data. In order to build ATSFS and validate its performance, training and testing data are obtained from different severity levels. To capture the non-stationary behavior of vibration signal, robust tools such as wavelet transform (WT) for time-frequency analysis are employed. Simulation studies show that ATSFS attains high classification accuracy even if training and testing data belong to different severity levels.
Description:
Increase in the number of coexisting networks in Industrial, Scientific and Medical (ISM) band cause interferences and demands for intelligent interference avoidance schemes. This paper proposes a novel Diversified Adaptive Frequency Rolling (DAFR) technique for frequency hopping in Bluetooth piconets which has the tendency to mitigate both the self and static interferences and ensures sufficient frequency diversity. Simulation studies validate the prospects for the proposed scheme to be used for frequency hopping networks against already existing techniques, Adaptive Frequency Hopping (AFH) and Adaptive Frequency Rolling (AFR).
Description:
The wireless networked sensors embedded with everyday objects will become an integral part of Future Internet, where the interaction among people, computer and those objects will shift the current Internet to a new paradigm, namely the Internet of Things. The terabyte torrent of data generated by billions of sensors belonging to a large number of distributed heterogeneous sensor networks in Future Internet will only be valuable if they can be effectively used on purpose, which leads to the necessity of an Internet scale query processing framework. In this paper, firstly, we focus on the distinct challenges present in Internet scale query processing over distributed sensor networks. Then, we propose a flexible and scalable system architecture capable of handling the complex scenario that might arise from the integration of a large number of such networks in Future Internet. Finally, we discuss the overall query processing methodology over such system and present some directions on the possible solutions to a number of identified research challenges. The outcome of this paper would foster the sensor network research in Future Internet domain
Description:
The quick market growth and ubiquitous acceptance of VoIP are primarily due to cheap service. VoIP services can be availed in mobile devices at a very low cost by employing IEEE 802.11 to provide last mile coverage. But call capacity is very low in these networks and call jitter occurs if voice quality requirements are not precisely met. We present a VoIP call capacity model for 802.11 networks which considers the most important real world factors like power capture and imperfect channel. Incorporating multiple channels can increase call capacity while multihop network can provide considerably large coverage. Our capacity model incorporates the effects of both multiple channels and multihop networks. We also consider the availability of multiple radio interfaces and conference call scenarios for ubiquitous applications of our model. To ensure voice quality, in addition to contention analysis, we also model the queue considering collision domain at each hop and formulate call capacity by estimating precise impairment budget over multihop.
Description:
WSNs generates a large amount of data in the form of stream and mining knowledge from the stream of data can be extremely useful. Association rules mining, from the sensor data, has been studied in recent literature. However, sensor association rules mining often produces a huge number of rules, but most of them either are redundant or fail to reflect the true correlation relationship among data objects. In this paper, we address this problem and propose mining of a new type of sensor behavioral pattern called associated-correlated sensor patterns. The proposed behavioral patterns capture not only association-like co-occurrences but also the substantial temporal correlations implied by such co-occurrences in the sensor data. Here, we also use a prefix tree-based structure called associated-correlated sensor pattern-tree (ACSP-tree), which facilitates frequent pattern (FP) growth-based mining technique to generate all associated-correlated patterns from WSN data with only one scan over the sensor database. Extensive performance study shows that our approach is time and memory efficient in finding associated-correlated patterns than the existing most efficient algorithms.
Description:
In a decentralized sensor network, localization process relies on the integrity of participating sensors. Existence of malicious beacon nodes in the vicinity of non-beacon nodes affects this process. This paper presents a trilateration-based secure localization technique, which is capable of estimating the location of a sensor with high accuracy so long four neighbouring beacon nodes are benign, irrespective of the number of neighbouring liars and without assuming any trust model. In realistic scenarios of wireless environment where transmitted signals attenuate randomly due to fading, the liar-tolerance level of this attack-resistant technique has to be relaxed accordingly. Superiority of this technique against the state-of-the-art has been established with extensive simulation results in terms of location estimation accuracy and liar-filtering probability.
Description:
VoIP offers cheap voice communication which instigated its quick market growth. IEEE 802.11 WLANs offer cheap wireless coverage which can be used to provide VoIP service in mobile devices. But call capacity of such networks is very low compared to wired networks. To increase voice capacity in WLANs incorporation of power capture, increased data rate, and use of multiple channels are of great importance. Moreover, these networks should be carefully designed considering voice quality requirements to avoid call jitter and call drops. We propose an analytical model to estimate VoIP call capacity for multichannel WLANs with consideration for power capture, imperfect channel, and multiple network interfaces. We employed ITU-T E-model to assess voice quality which is used as the limiting factor to ensure that voice quality does not degrade in such networks. The model will be extremely helpful to network designers in planning single channel or multi-channel WLANs.
Description:
Obstacles present in the line of sight transmission path of a wireless signal severely attenuates the received signal power. Extreme fluctuations of the received signal power caused by shadowing can create "blind spots". Blind spots are areas within the cellular coverage area from where no communication is possible to the base station (BS). For single path packet based services link failures results in total loss of communication. The problem of link failure and blind spots can almost be eliminated in the recently proposed multipath cellular architecture (MCA) which provisions up to three different communication links from the mobile node (MN) to three adjacent BSs through overlapped coverage. Voice and/or multimedia packet delivery can thus benefit by establishing communication from the best interface in terms of received signal power. In this paper, we evaluate the performance of the multi-path MCA model in reducing link failure and blind spot communication problems in presence of multiple obstacles and shadow fading. Obstacle mobility model is utilized as the preferred user mobility model. Video transmission performance improves significantly in terms of reduced packet loss and improved reproduced signal quality at the receiver for the multipath MCA model compared to the existing single path cellular network architecture
Description:
A combination of qualitative and quantitative research methods were utilised to collect information from across the Great South Coast(GSC) region Victoria which included (5 municipalities:- Warrnambool City and the Shires of Corangamite, Glenelg, Moyne and Southern Grampians) and were aimed at information regarding telecommunications and broadband access and services, barriers and usage at local levels. Data collection methods included key stakeholder interviews, the online survey, case studies and spatial mapping of the responses and feedback garnered mainly from the surveys. Anticipated NBN access infrastructure has also been mapped.The adopted consultation and research methodology was designed to assess demand and support from business operators, local residents and other stakeholders for next generation broadband for the GSC region. The online survey was a major instrument for gathering data in the period to July 2011. The largest contributions to the 598 valid responses came from Warrnambool (n=166), Hamilton (n=94), Camperdown (n=29) and Portland (n=23). Summary available online. Qualitative data may be available by contacting CeCC.
Description:
A combination of qualitative and quantitative research methods were utilised to collect information from across the Great South Coast(GSC) region Victoria which included (5 municipalities:- Warrnambool City and the Shires of Corangamite, Glenelg, Moyne and Southern Grampians) and were aimed at information regarding telecommunications and broadband access and services, barriers and usage at local levels. Data collection methods included key stakeholder interviews, the online survey, case studies and spatial mapping of the responses and feedback garnered mainly from the surveys. Anticipated NBN access infrastructure has also been mapped.The adopted consultation and research methodology was designed to assess demand and support from business operators, local residents and other stakeholders for next generation broadband for the GSC region. The online survey was a major instrument for gathering data in the period to July 2011. The largest contributions to the 598 valid responses came from Warrnambool (n=166), Hamilton (n=94), Camperdown (n=29) and Portland (n=23). Summary available online. Qualitative data may be available by contacting CeCC.