Geographic routing with cooperative relaying and leapfrogging in wireless sensor networks

A novel geographic routing protocol for multi-hop wireless sensor networks is presented. It exploits the broadcast nature of the wireless channel to enable on-demand cooperative relaying and leapfrogging for circumventing weak radio links. In order to achieve energy efficiency, a metric is introduced for next-hop selection that takes into account information on the residual battery energy, the geographical position of the sensor nodes, and the channel quality of the involved radio links when available. Performance results show that the completely decentralized protocol offers significant benefits by reducing the number of (re)transmissions required to reach the destination. This translates into network-wide energy savings that extend the network lifetime.

Optimal multicast tree routing for cluster computing in hypercube interconnection networks

Cluster computation has been used in the applications that demand performance, reliability, and availability, such as cluster server groups, large-scale scientific computations, distributed databases, distributed media-on-demand servers and search engines etc. In those applications, multicast can play the vital roles for the information dissemination among groups of servers and users. This paper proposes a set of novel efficient fault-tolerant multicast routing algorithms on hypercube interconnection of cluster computers using multicast shared tree approach. We present some new algorithms for selecting an optimal core (root) and constructing the shared tree so as to minimize the average delay for multicast messages. Simulation results indicate that our algorithms are efficient in the senses of short end-to-end average delay, load balance and less resource utilizations over hypercube cluster interconnection networks.

Inverse opal gas sensors : Zn(II)-doped tin dioxide systems for low temperature detection of pollutant gases

Focusing here on the effects of zinc doping in a nanocrystalline matrix of tin dioxide, inverse opal prototype sensors are presented and extensively studied as superior candidates for gas sensing applications. Courtesy of factors including controlled porosity, enhanced surface to volume ratio and homogeneous dispersion of species in the crystalline lattice assured by the sol–gel technique, prototype sensors were prepared with high dopant ratios in a range of new compositions. Exploiting their high sensitivities to low-gas concentrations at low working temperatures, and thanks to the presented templated sol–gel approach, the prepared sensors open up new frontiers in compositional control over the sensing oxide materials, consequently widening the possibilities available in on-demand gas sensor synthesis.

A new screen face for public service broadcasting

The contemporary broadcasting industry is characterised by technological and social change, it is increasingly competitive, and the media industry is fragmenting. New services need not necessarily compete with existing free-to-air broadcasting but could act as further incentive for audiences to invest in new equipment. New equipment will be necessary in the future as set out under the Television Broadcasting Services (Digital Conversion) Act 2000 (Cth), before the planned switch-off of analogue broadcasts planned for this year but now likely to be 2013. By then, however, audiences might already have migrated to the online environment for television and radio content as well as other services. Those that produce and deliver programs via free-to-air broadcasting need to consider what audiences do with new media in order to engage them. This will be an ongoing process as technology and audience expectations continue to change. Against such a background, this article examines how Australia’s public broadcasters are responding to the new media environment. It will consider their interactive online programs and services with specific analysis of ABC’s new ‘iView’ and ‘ABC Fora’ which offer content on-demand. It will also examine SBS online initiatives. I wish to argue that the new media offer public broadcasters new prospects to provide forums and spaces for education, entertainment, public discussion and interaction online.

Experiments toward a practical implementation of an intelligent kanban system

This paper presents laboratory experiments to test a bottom up approach to production control and supply chain management. Built upon the successful traditional kanban (Card) system, the new intelligent system associates a kanban agent to each physical kanban. Instead of relying on demand forecast and planning, kanban agents reason about their own movements to adapt to changing demands. After previous simulations results of the intelligent system showed significant performance improvements over the traditional system, we further use the Auto-ID Laboratory at Cambridge University to test the feasibility of the idea in a realistic manufacturing environment. The results from the experiments demonstrated the superiority on several performance measures of the intelligent system compared to the traditional system used as a benchmark. Moreover, the implementation of the experiments exposed several real world constraints not shown in the simulation study and practical solutions were adopted to address these.

Biology and management of Murray cod reproduction within controlled environments

The emerging Murray cod aquaculture industry is currently restricted by a lack of consistent and year-round production of fingerlings. Biological information and reproductive technologies developed during this research have facilitated the development of indoor, environmentally-controlled breeding practices for this species, thereby enabling Murray cod juveniles to be produced on-demand.

Dielectrophoretically tuneable optical waveguides using nanoparticles in microfluidics

We present a tuneable optical waveguide using dielectrophoretically controlled nanoparticles in microfluidics. Silicon dioxide nanoparticles of different sizes in de-ionized water are channelled through a microfluidic system. An array of microelectrodes generates the dielectrophoretic force to funnel nanoparticles, forming narrowbands at the center of the microfluidics at different applied voltages and frequencies. It is observed that these narrowbands either scatter or guide the coupled light under selected conditions. The realization of such a system offers exciting possibilities for the development of a new class of optofluidics, which are tuned by the positioning of nanoparticles on demand.

Above the trust and security in cloud computing : a notion towards innovation

While the nascent Cloud Computing paradigm supported by virtualization has the upward new notion of edges, it lacks proper security and trust mechanisms. Edges are like on demand scalability and infinite resource provisioning as per the `pay-as-you-go' manner in favour of a single information owner (abbreviated as INO from now onwards) to multiple corporate INOs. While outsourcing information to a cloud storage controlled by a cloud service provider (abbreviated as CSP from now onwards) relives an information owner of tackling instantaneous oversight and management needs, a significant issue of retaining the control of that information to the information owner still needs to be solved. This paper perspicaciously delves into the facts of the Cloud Computing security issues and aims to explore and establish a secure channel for the INO to communicate with the CSP while maintaining trust and confidentiality. The objective of the paper is served by analyzing different protocols and proposing the one in commensurate with the requirement of the security property like information or data confidentiality along the line of security in Cloud Computing Environment (CCE). To the best of our knowledge, we are the first to derive a secure protocol by successively eliminating the dangling pitfalls that remain dormant and thereby hamper confidentiality and integrity of information that is worth exchanging between the INO and the CSP. Besides, conceptually, our derived protocol is compared with the SSL from the perspectives of work flow related activities along the line of secure trusted path for information confidentiality.

Toward a framework for cloud security

While the emergence of cloud computing has made it possible to rent information technology infrastructures on demand, it has also created new security challenges. The primary security concern is trusting data (or resources in general) on another organization’s system. This document seeks to examine the current state of security in cloud computing and presents a set of challenges to address the security needs of clouds. The end result is a framework to help the design and implementation of effective cloud security infrastructures.

A technology to expose a cluster as a service in a cloud

Clouds refer to computational resources (in particular, clusters) that are accessible as scalable, on demand, pay-as- you-go services provided in the Internet. However, clouds are in their infancy and lack a high level abstraction. Specifically, there is no effective discovery and selection service for clusters and offer little to no ease of use for clients. Here we show a technology that exposes clusters as Web services in the form of a Cluster as a Service for publishing via WSDL, discovering, selecting and using clusters.

A SOA-driven business intelligence architecture

A business intelligence architecture comprises of different unique components to collect, transform, analyze and present the structured and unstructured raw data in simple formats to assist decision makers in making timely decisions. The introduction of service-oriented architecture (SOA) enables reusable services which are accessible over a network on demand. However, there is still a lack of academic literatures on the business intelligence architecture with service-oriented concept. Based upon various references on BI architectures from major vendors, a novel BI architecture that is built on service-oriented concept is presented and described in this paper. The proposed service-oriented architecture enables enterprises to deploy a more agile, flexible, cheaper, reusable, reliable and responsive BI applications in supporting decision making process.

Toward higher level abstractions for cloud computing

The general idea of cloud computing is offering computational resources as scalable, on demand services accessible over the internet. However, this new realisation of on demand computing is hindered by the amount of user involvement. Currently, high level abstractions in cloud computing only exist in the form of services. In particular, there is no effective means to publish, discover and finally use required services in clouds. In response, we propose a user level abstraction on top of already available cloud abstraction layers, present its concept using the resources via web services (RVWS) framework and demonstrate its feasibility by simplifying the exposure and use of clusters, a commonly used resource in cloud computing.

Trust ticket deployment : a notion of a data owner's trust in cloud computing

While cloud computing (CC) is a scalable model of shared infrastructure and on-demand computing, it lacks a transparent trust and security mechanism. A data owner (DO) loses control over the data outsourced to a machine in the cloud controlled and operated by a cloud service provider (CSP). This machine is at a location unknown to a data owner. This loss of control over data is further intensified with the lack of managing users' access to the data from practical cloud computing perspectives. In this paper, we introduce a new mechanism of ensuring trust and security in Software as a Service (SaaS) CC. Trust Ticket, with the supporting protocols, is our mechanism that helps a data owner in establishing a link between a CSP and a registered user. In our mechanism, a user first gets registered with a DO before receiving a Trust Ticket and a secret key from that DO. Each Trust Ticket is unique and encrypted. On completing the registration of each user, the DO apprises the CSP of the Trust Ticket. Trust Ticket and secret key are respectively for the registered user's getting accepted to the CSP and having a view of the data owner's data upon a successful verification by the CSP. We have done our experiment in Java network programming by creating an emulated cloud computing framework under the VMware ESXi 4.1 hyper visor based platform. Using the framework, we have evaluated our algorithmic protocol for Trust Ticket. We have also compared our work with prior work. Overall performance of our work is better. We argue that our proposed algorithmic protocol for Trust Ticket deployment establishes a data owner's trust. This trust is established through a data owner's control over data and a registered user, because a registered user is linked with a CSP by a data owner through Trust Ticket.

A cooperative cache architecture in support of caching multimedia objects in MANETs

This paper presents a cooperative caching architecture suitable for continuous media (CM) proxy caching in MANET environments. The proposed scheme introduces an application manager component, which is interposed between traditional Internet CM applications and the network layer. The application manager transparently performs data location and service migration of active CM streaming sessions so as to exploit nearby data sources based on the dynamic topology of a MANET. We propose two data location schemes - Cache-State - a link-state based scheme and Reactive - an on-demand scheme. Since service migration can occur frequently, the application manager uses soft-state signaling techniques to communicate between remote application managers by translating hard-state application signaling, such as Real Time Streaming Protocol (RTSP) into soft-state messages. The proposed schemes are evaluated through simulation studies using the NS simulator. Simulation studies show that both Cache-State and Reactive schemes demonstrate significant QoS improvements and reduced bandwidth consumption.

Distributed query processing for mobile surveillance

Addressing core issues in mobile surveillance, we present an architecture for querying and retrieving distributed, semi-permanent multi-modal data through challenged networks with limited connectivity. The system provides a rich set of queries for spatio-temporal querying in a surveillance context, and uses the network availability to provide best quality of service. It incrementally and adaptively refines the query, using data already retrieved that exists on static platforms and on-demand data that it requests from mobile platforms. We demonstrate the system using a real surveillance system on a mobile 20 bus transport network coupled with static bus depot infrastructure. In addition, we show the robustness of the system in handling different conditions in the underlying infrastructure by running simulations on a real, but historic dataset collected in an offline manner.