High-performance multifunctional graphene yarns: toward wearable all-carbon energy storage textiles

The successful commercialization of smart wearable garments is hindered by the lack of fully integrated carbon-based energy storage devices into smart wearables. Since electrodes are the active components that determine the performance of energy storage systems, it is important to rationally design and engineer hierarchical architectures atboth the nano- and macroscale that can enjoy all of the necessary requirements for a perfect electrode. Here we demonstrate a large-scale flexible fabrication of highly porous high-performance multifunctional graphene oxide (GO) and rGO fibers and yarns by taking advantage of the intrinsic soft self-assembly behavior of ultralarge graphene oxide liquid crystalline dispersions. The produced yarns, which are the only practical form of these architectures for real-life device applications, were found to be mechanically robust (Young's modulus in excess of 29 GPa) and exhibited high native electrical conductivity (2508 ± 632 S m(-1)) and exceptionally high specific surface area (2605 m(2) g(-1) before reduction and 2210 m(2) g(-1) after reduction). Furthermore, the highly porous nature of these architectures enabled us to translate the superior electrochemical properties of individual graphene sheets into practical everyday use devices with complex geometrical architectures. The as-prepared final architectures exhibited an open network structure with a continuous ion transport network, resulting in unrivaled charge storage capacity (409 F g(-1) at 1 A g(-1)) and rate capability (56 F g(-1) at 100 A g(-1)) while maintaining their strong flexible nature.

A computation trust model with trust network in multi-agent systems

Trust is a fundamental issue in multi-agent systems, especially when they are applied in e-commence. The computational models of trust play an important role in determining who and how to interact in open and dynamic environments. To this end, a computation trust model is proposed in which the confidence information based on direct prior interactions with the target agent and the reputation information from trust network are used. In this way, agents can autonomously deal with deception and identify trustworthy parties in multi-agent systems. The ontological property of trust is also considered in the model. A case study is provided to show the effectiveness of the proposed model.

Information theory based detection against network behavior mimicking DDoS attacks

DDoS is a spy-on-spy game between attackers and detectors. Attackers are mimicking network traffic patterns to disable the detection algorithms which are based on these features. It is an open problem of discriminating the mimicking DDoS attacks from massive legitimate network accessing. We observed that the zombies use controlled function(s) to pump attack packages to the victim, therefore, the attack flows to the victim are always share some properties, e.g. packages distribution behaviors, which are not possessed by legitimate flows in a short time period. Based on this observation, once there appear suspicious flows to a server, we start to calculate the distance of the package distribution behavior among the suspicious flows. If the distance is less than a given threshold, then it is a DDoS attack, otherwise, it is a legitimate accessing. Our analysis and the preliminary experiments indicate that the proposed method- can discriminate mimicking flooding attacks from legitimate accessing efficiently and effectively.

Architecture of fiber network : from understanding to engineering of molecular gels

A new approach of engineering of molecular gels was established on the basis of a nucleation-initiated network formation mechanism. A variety of gel network structures can be obtained by regulating the starting temperature of the sol−gel transition. This enables us to tune the network from the spherulitic domains pattern to the extensively interconnected fibrillar network. As the consequence of fibrous network structure turning, desirable rheological and other in-use properties of the materials can be obtained accordingly. This approach of micro-/nanostructural fabrication may open up a new route for micro-/nanofunctional materials engineering in general.

Quality control of sensor network data

A wireless sensor network (WSN) is a group of sensors that are geographically distributed and interconnected by wireless networks. Sensors gather information about the state of physical world. Then, after processing forward them to the main destination. To be able to provide this service, there are many aspects of communication techniques that need to be explored. Supporting quality of service (QoS) will be of critical importance for pervasive WSNs that serve as the network infrastructure of diverse applications. To illustrate new research and development interests in this field, this paper examines and discusses the requirements, critical challenges, and open research issues on QoS management in WSNs. A brief overview of recent progress is given.

Hierarchical workflow management in wireless sensor network

To build the service-oriented applications in a wireless sensor network (WSN), the workflow can be utilized to compose a set of atomic services and execute the corresponding pre-designed processes. In general, WSN applications rely closely on the sensor data which are usually inaccurate or even incomplete in the resource-constrained WSN. Then, the erroneous sensor data will affect the execution of atomic services and furthermore the workflows, which form an important part in the bottom-to-up dynamics of WSN applications. In order to alleviate this issue, it is necessary to manage the workflow hierarchically. However, the hierarchical workflow management remains an open and challenging problem. In this paper, by adopting the Bloom filter as an effective connection between the sensor node layer and the upper application layer, a hierarchical workflow management approach is proposed to ensure the QoS of workflow-based WSN application . The case study and experimental evaluations demonstrate the capability of the proposed approach.

Principal led school improvement and teacher capacity building in the Barwon South Network : final report, May 2013

The period of interest for this report is the beginning of 2011 to the end of 2012. The period commenced when the Regional Network Leader of the Barwon South Network of schools in the Barwon South Region of the Department of Education and Early Childhood contacted the School of Education at Deakin University, Waurn Ponds Campus Geelong. The Regional Network Leader outlined a desire to engage with Deakin University to research a short-term-cycle model of school improvement to be implemented in the region. While the model was expected to be taken on by all schools in the region the research was limited to the 23 schools in the Barwon South Network with four schools to be investigated more closely for each of two years (2001 & 2012) – eight focus schools in total.

Many positive outcomes flowed from the implementation of short-term-cycle school improvement plans and their associated practices but there was wide variation in the nature and degrees of success and of the perception of the process. The research team asked the following questions of the data:

1. What aspects of the School Improvement Plan (SIP) approach were important for initiating and supporting worthwhile change?
2. What might we take from this, to provide guidance on how best to support change in teaching and learning processes in schools?

The School Improvement Plan (SIP) worked in a range of ways. At one level it was strongly focused on school leadership, and a need to improve principals’ capacity to initiate worthwhile teaching and learning processes in their schools. Underlying this intent, one might think an assumption is operation is that the leadership process involves top down decision-making and a willingness to hold staff accountable for the quality of their practice.

The second strong focus was on the translation into practice and the consequent effect on student learning, involving an emphasis on data and evidence led practice. Hence, along with the leadership focus there was a demand for the process of school improvement to reach down into students and classrooms. Thus, the SIP process inevitably involved a chain of decision-making by which student learning quality drove the intervention, and teachers responsible for this had a common view. The model therefore should not be seen as an intervention only on the principal, but rather on the school decision-making system and focus. Even though it was the principal receiving the SIP planning template, and reporting to the network, the reporting was required to include description of the operation of the school processes, of classroom processes, and of student learning. This of course placed significant constraints on principals, which may help explain the variation in responses and outcomes described above.

The findings from this study are based on multiple data sources: analysis of both open and closed survey questions which all teachers in the 23 schools in the network were invited to complete; interviews with principals, teachers and leaders in the eight case study schools; some interviews with students in the case study schools; and interviews with leaders who worked in the regional network office; and field notes from network meetings including the celebrations days. Celebrations days occurred each school term when groups of principals came together to share and celebrate the improvements and processes happening in their schools. Many of the themes emerging from the analysis of the different data sources were similar or overlapping, providing some confidence in the evidence-base for the findings.

The study, conducted over two years of data collection and analysis, has demonstrated a range of positive outcomes in at the case study schools relating to school communication and collaboration processes, professional learning of principals, leadership teams and classroom teachers. There was evidence in the survey responses and field notes from ‘celebration days’ that these outcomes were also represented in other schools in the network. The key points of change concerned the leadership processes of planning for improvement, and the rigorous attention to student data in framing teaching and learning processes. This latter point of change had the effect of basing SIP processes on a platform of evidence-based change. The research uncovered considerable anecdotal and observational evidence of improvements in student learning, in teacher accounts in interview, and presentations of student work. Interviews with students, although not as representative as the team would have liked, showed evidence of student awareness of learning goals, a key driver in the SIP improvement model. It was, however, not possible over this timescale to collect objective comparative evidence of enhanced learning outcomes.

A number of features of the short-term-cycle SIP were identified that supported positive change across the network. These were: 1) the support structures represented by the network leader and support personnel within schools, 2) the nature of the SIP model – focusing strongly on change leadership but within a collaborative structure that combined top-down and bottom-up elements, 3) the focus on data-led planning and implementation that helped drill down to explicit elements of classroom practice, and 4) the accountability regimes represented by network leader presence, and the celebration days in which principals became effectively accountable to their peers. We found that in the second year of the project, momentum was lost in the case study schools, as the network was dismantled. This raised issues also for the conduct of research in situations of systemic change.

Alongside the finding of evidence of positive outcomes in the case study schools overall, was the finding that the SIP processes and outcomes varied considerably across schools. A number of contextual factors were identified that led to this variation, including school histories of reform, principal management style, and school size and structure that made the short-term-cycle model unmanageable. In some cases there was overt resistance to the SIP model, at least in some part, and this led to an element of performativity in which the language of the SIP was conscripted to other purposes. The study found that even with functioning schools the SIP was understood differently and the processes performed differently, raising the question of whether in the study we are dealing with one SIP or many. The final take home message from the research is that schools are complex institutions, and models of school improvement need to involve both strong principled features, and flexibility in local application, if all schools’ interests in improving teaching and learning processes and outcomes are to be served.

A block-aware hybrid data dissemination with hotspot elimination in wireless sensor network

As a significant milestone in the data dissemination of wireless sensor networks (WSNs), the comb-needle (CN) model was developed to dynamically balance the sensor data pushing and pulling during hybrid data dissemination. Unfortunately, the hybrid push-pull data dissemination strategy may overload some sensor nodes and form the hotspots that consume energy significantly. This usually leads to the collapse of the network at a very early stage. In the past decade, although many energy-aware dynamic data dissemination methods have been proposed to alleviate the hotspots issue, the block characteristic of sensor nodes has been overlooked and how to offload traffic from hot blocks with low energy through long-distance hybrid dissemination remains an open problem. In this paper, we developed a block-aware data dissemination model to balance the inter-block energy and eliminate the spreading of intra-block hotspots. Through the clustering mechanism based on geography and energy, "similar" large-scale sensor nodes can be efficiently grouped into specific blocks to form the global block information (GBI). Based on GBI, the long-distance block-cross hybrid algorithms are further developed by effectively aggregating inter-block and intra-block data disseminations. Extensive experimental results demonstrate the capability and the efficiency of the proposed approach. © 2014 Elsevier Ltd.

Intelligent cuckoo search optimized traffic signal controllers for multi-intersection network

Traffic congestion in urban roads is one of the biggest challenges of 21 century. Despite a myriad of research work in the last two decades, optimization of traffic signals in network level is still an open research problem. This paper for the first time employs advanced cuckoo search optimization algorithm for optimally tuning parameters of intelligent controllers. Neural Network (NN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) are two intelligent controllers implemented in this study. For the sake of comparison, we also implement Q-learning and fixed-time controllers as benchmarks. Comprehensive simulation scenarios are designed and executed for a traffic network composed of nine four-way intersections. Obtained results for a few scenarios demonstrate the optimality of trained intelligent controllers using the cuckoo search method. The average performance of NN, ANFIS, and Q-learning controllers against the fixed-time controller are 44%, 39%, and 35%, respectively.

Novel approach to big data collaboration with network operators network function virtualisation (NFV)

The intersection of network function virtualisation (NFV) technologies and big data has the potential of revolutionising today's telecommunication networks from deployment to operations resulting in significant reductions in capital expenditure (CAPEX) and operational expenditure, as well as cloud vendor and additional revenue growths for the operators. One of the contributions of this article is the comparisons of the requirements for big data and network virtualisation and the formulation of the key performance indicators for the distributed big data NFVs at the operator's infrastructures. Big data and virtualisation are highly interdependent and their intersections and dependencies are analysed and the potential optimisation gains resulted from open interfaces between big data and carrier networks NFV functional blocks for an adaptive environment are then discussed. Another contribution of this article is a comprehensive discussion on open interface recommendations which enables global collaborative and scalable virtualised big data applications.