Analytical communication networks model for enterprise grid computing

This paper addresses the problem of performance analysis based on the communication modeling of large-scale heterogeneous distributed systems, with an emphasis on enterprise Grid computing systems. The study of communication layers is important, as the overall performance of a distributed system often critically hinges on the effectiveness of this part. We propose an analytical model that is based on probabilistic analysis and queuing networks. The proposed model considers the processor as well as network heterogeneity of the enterprise Grid system. The model is validated through comprehensive simulations, which demonstrate that the proposed model exhibits a good degree of accuracy for various system sizes, and under different working conditions.

Analytical modeling of communication latency in multi-cluster systems

This paper addresses the problem of performance modeling of large-scale distributed systems with emphasis on communication networks in heterogeneous multi-cluster systems. The study of interconnection networks is important because the overall performance of a distributed system is often critically hinged on the effectiveness of this part. We present an analytical model to predict message latency in multi-cluster systems in the presence of processor heterogeneity. The model is validated through comprehensive simulation, which demonstrates that the proposed model exhibits a good degree of accuracy for various system sizes and under different operating conditions.

Performance modeling and analysis of heterogeneous meta-computing systems interconnection networks

The overall performance of a distributed system often depends on the effectiveness of its interconnection network. Thus, the study of the communication networks for distributed systems is very important, which is the focus of this paper. In particular, we address the problem of interconnection networks performance modeling for heterogeneous meta-computing systems. We consider the meta-computing system as a typical multi-cluster system. Since the heterogeneity is becoming common in such systems, we take into account network as well as cluster size heterogeneity to propose the model. To this end, we present an analytical network model and validate the model through comprehensive simulation. The results of the simulation demonstrated that the proposed model exhibits a good degree of accuracy for various system organizations and under different working conditions.

A distributed gateway selection algorithm for UAV networks

In recent years, unmanned aerial vehicle (UAV) has been widely adopted in military and civilian applications. For small UAVs, cooperation based on communication networks can effectively expand their working area. Although the UAV networks are quite similar to the traditional mobile ad hoc networks, the special characteristics of the UAV application scenario have not been considered in the literature. In this paper, we propose a distributed gateway selection algorithm with dynamic network partition by taking into account the application characteristics of UAV networks. In the proposed algorithm, the influence of the asymmetry information phenomenon on UAVs' topology control is weakened by dividing the network into several subareas. During the operation of the network, the partition of the network can be adaptively adjusted to keep the whole network topology stable even though UAVs are moving rapidly. Meanwhile, the number of gateways can be completely controlled according to the system requirements. In particular, we define the stability of UAV networks, build a network partition model, and design a distributed gateway selection algorithm. Simulation results show using our proposed scheme that the faster the nodes move in the network, the more stable topology can be found, which is quite suitable for UAV applications.

Delay tolerant networks

The delay-tolerant networks (DTNs) are emerging research topics that have attracted keen research efforts from both academia and industry. Different from the traditional communication networks, DTNs consider an extreme network condition where a complete end-to-end path between the data source and destination may not exist, and the network is subject to dynamic node connections and unstable topologies. With the above features, DTNs find broad applications in the situations where legacynetworks cannot work effectively, such as data communications in rural areas, where stable communications infrastructure is not available or costly, and crucial areas, e.g., disaster rescue and battlefield communications. To summarize, the DTNs, as an important technology complementary to traditional networkings, can be widely applied to national welfare and the people’s livelihood.

Energy and communication infrastructure for disaster resilience in rural and regional Australia

Energy and communication infrastructure for disaster resilience in rural and regional Australia, Regional Studies. Australia's rural and regional areas are prone to frequent natural disasters with extensive socio-economic impacts. Resultant damage to large-grid energy and communication networks can lead to widespread, lengthy outages, signalling the need for alternative infrastructure developments to aid disaster risk reduction and resilience-building (DRRR). Distributed smart renewable energy micro-grid systems can mitigate adverse impacts through outage prevention and rapid service restoration, increase rural and regional resilience, and offer communities opportunities for socio-economic development. However, renewable energy and digital communications policy uncertainty currently adversely affects disaster preparedness and investment in alternative infrastructure, undermining rural and regional futures.

Multi-cluster computing interconnection network performance modeling and analysis

The overall performance of a distributed system is often depends on the effectiveness of its interconnection network. Thus, the study of the communication networks for distributed systems is very important, which is the focus of this paper. In particular, we address the problem of fat-tree based interconnection networks performance modeling for multi-user heterogeneous multi-cluster computing systems. To this end, we present an analytical model and validate the model through comprehensive simulation. The results of the simulation demonstrated that the proposed model exhibits a good degree of accuracy for various system organizations and under different working conditions.

A new approach for efficiently achieving high availability in mobile computing

Recent advances m hardware technologies such as portable
computers and wireless communication networks have led to the emergence of mobile computing systems. Thus, availability and accessibility of the data and services become important issues of mobile computing systems. In this paper, we present a data replication and management scheme tailored for such environments In the proposed scheme data is replicated synchronously over stationary sites while for the mobile network, data is replicated asynchronously based on commonly visited sites for each user. The proposed scheme is compared with other techniques and is shown to require less communication cost for an operation as well as provide higher degree of data availability.

Analytical network modeling of heterogeneous large-scale cluster systems

The study of the communication networks for distributed systems is very important, since the overall performance of these systems is often depends on the effectiveness of its communication network. In this paper, we address the problem of networks modeling for heterogeneous large-scale cluster systems. We consider the large-scale cluster systems as a typical cluster of clusters system. Since the heterogeneity is becoming common in such systems, we take into account network as well as cluster size heterogeneity to propose the model. To this end, we present an analytical network model and validate the model through comprehensive simulation. The results of the simulation demonstrated that the proposed model exhibits a good degree of accuracy for various system organizations and under different working conditions.

Heteroglossic spaces : interrogating academic literacies in teacher education

This paper explores the challenges of implementing critical writing pedagogy in conditions of increasing cultural and textual uniformity of literacy and emphasises the need for a pedagogy that takes into account the heteroglossic nature of writing space and its relation to the multiple textual practices of students. In practical terms, we argue for such literacy practices in teacher education that would require students not only to understand the complexities of language and literacy but to actively engage them in a diverse range of textual practices that would both stretch their repertoires as language users and sensitise them to the cultural-semiotic diversity of contemporary classrooms. This task becomes more urgent in the current era of standards, accountability and classroom pedagogies that are not attuned to the particularities of students’ textual practices and the communication networks in which they participate.

Teacher education and critical inquiry : the use of activity theory in exploring alternative understandings of language and literacy

This paper explores the challenges of espousing a critical pedagogy within the managerial climate that presently shapes teacher education. It argues that current discourses of professionalism are incommensurate with a view of literacy as social practice and that they disregard complex semiotic ecologies in which both school and university students operate. Graduate teachers are constructed as the ‘providers’ of decontextualised literacy skills to school students whose existing communication networks are ignored. Rejecting this narrow view of professional practice, we draw on activity theory to analyse the social configuration of tertiary students’ identities and the textual resources that mediate their professional learning. This kind of research is needed to reveal the contradictions within and between activity systems in which tertiary students participate as well as to construct possible solutions to the contradictions identified.

Teacher education and critical inquiry : the use of activity theory in exploring alternative understandings of language and literacy

This article explores the challenges of espousing a critical pedagogy within the managerial climate that presently shapes teacher education. Current discourses of professionalism are incommensurate with an understanding of the way that literacy practices are grounded in the social worlds in which both school and university students operate. Such discourses construct graduate teachers as the providers of decontextualised literacy skills to school students whose existing communication networks are ignored. We argue that an alternative understanding of professional practice can be developed by focusing on the textual resources university students use to mediate their learning, and by locating their emerging professional identities within the activity systems and meaning-making practices in which they participate.

Agency-nursing work : perceptions and experiences of agency nurses

This paper explores agency-nursing work from the perspective of agency nurses to gain in-depth understanding of their clinical practice, their relationships with the employing agency, hospitals and permanent nurses, and their professional status. For this study, individual interviews were conducted with ten agency nurses who were registered with one of three nursing agencies in Melbourne, Australia. Five major themes emerged from interview data: orientation, allocation of agency nurses, reasons for doing agency-nursing work, experiences with hospital staff, and professionalism. The findings reveal that the primary reason for nurses engaging in agency-nursing work is for the flexibility it offers. While agency nurses described a commitment to professionalism, the findings emphasise the need to establish effective communication networks between agency nurses, nursing agencies and hospital institutions. Such communication between stakeholders is important to facilitate discussion of issues such as appropriate notification of shift availability, appropriate assignment of work and recognition of the agency nurse as a valuable member of the health care team. In particular, the findings highlight the importance of comprehensive orientation and education for agency nurses to shift the focus of their daily work from task completion to more comprehensive patient care.