A pattern recognition approach to complex networks

Complex networks exist in many areas of science such as biology, neuroscience, engineering, and sociology. The growing development of this area has led to the introduction of several topological and dynamical measurements, which describe and quantify the structure of networks. Such characterization is essential not only for the modeling of real systems but also for the study of dynamic processes that may take place in them. However, it is not easy to use several measurements for the analysis of complex networks, due to the correlation between them and the difficulty of their visualization. To overcome these limitations, we propose an effective and comprehensive approach for the analysis of complex networks, which allows the visualization of several measurements in a few projections that contain the largest data variance and the classification of networks into three levels of detail, vertices, communities, and the global topology. We also demonstrate the efficiency and the universality of the proposed methods in a series of real-world networks in the three levels.

City-to-surf - a peer-to-peer model of on-line professional development: a collaborative mentoring model

This project explores the potential of electronic communications to support peer-to-peer interaction between separate whole-school communities as a means of providing both authentic, situated, professional development for teachers, concurrent with the development of enhanced student learning outcomes, and the intentional sharing of school 'culture'.  The intense use of telecommunications by both teacher and students in a 'many-to-many' manner provides rich opportunities for teachers to rethink their pedagogy, reconceptualise their classroom culture, and for students to see teachers as learners 'in situ'.  An extensive trial between two schools some 120km apart has demonstrated the basic functionality of the model.  This paper discusses the origins of the project, findings from the trial, and the nature of the changes to be made to the model to enhance its effects.

An efficient replicated data management approach for peer-to-peer systems

The availability of critical services and their data can be significantly increased by replicating them on multiple systems connected with each other, even in the face of system and network failures. In some platforms such as peer-to-peer (P2P) systems, their inherent characteristic mandates the employment of some form of replication to provide acceptable service to their users. However, the problem of how best to replicate data to build highly available peer-to-peer systems is still an open problem. In this paper, we propose an approach to address the data replication problem on P2P systems. 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.

Improving prediction interval quality : a genetic algorithm-based method applied to neural networks

The delta technique has been proposed in literature for constructing
prediction intervals for targets estimated by neural networks. Quality of constructed prediction intervals using this technique highly depends on neural network characteristics. Unfortunately, literature is void of information about how these dependences can be managed in order to optimize prediction intervals. This study attempts to optimize length and coverage probability of prediction intervals through modifying structure and parameters of the underlying neural networks. In an evolutionary optimization, genetic algorithm is applied for finding the optimal values of network size and training hyper-parameters. The applicability and efficiency of the proposed optimization technique is examined and demonstrated using a real case study. It is shown that application of the proposed optimization technique significantly improves quality of constructed prediction intervals in term of length and coverage probability.

Multi-level virtual ring : a foundation network architecture to support peer-to-peer application in wireless sensor network

Two main problems prevent the deployment of peer-to-peer application in a wireless sensor network: the index table, which should be distributed stored rather than uses a central server as the director; the unique node identifier, which cannot use the global addresses. This paper presents a multi-level virtual ring (MVR) structure to solve these two problems.

The index table in MVR is distributed stored by using the DHT technique. MVR is constructed decentralized and runs on mobile nodes themselves, requiring no central server or interruption. Naming system in MVR uses natural names rather than global addresses to identify sensor nodes. The MVR can route directly on the name identifiers of the sensor nodes without being aware the location. Some sensor nodes are selected as the backbone nodes by the backbone selection algorithm and are placed on the different levels of the virtual rings. MVR hashes nodes’ identifiers on the virtual ring, and stores them at the backbone nodes. Furthermore, MVR adopts cross-level routing to improve the routing efficiency.

Experiments using ns2 simulator for up to 200 nodes show that the storage and bandwidth requirements of MVR grow slowly with the size of the network. Furthermore, MVR has demonstrated as self-administrating, fault-tolerant, and resilient under the different workloads.

Establishing Competitive Domination Cycles for Peer-to-peer Game Combat

Games require balance to be fair and enjoyable. In two player combat settings balance can be achieved by ensuring that both units are equally capable. The possibility of alliances changes the nature of balance when additional players are introduced. One approach to achieving balance is to use a domination loop between agents in a rock, scissors, paper style approach. This paper investigates whether such loops exist within the existing rules of game combat. Search processes within the attribute space of the game units are used to identify loops within an existing game architecture. A dominance metric is used to identify cycles where the victory is achieved by a clear threshold. Cycles with up to 5 players are demonstrated, although larger cycles require more effort to find. Use of models of game play and attribute space search are recommended as a mechanism for balancing games of this format.

A control methodology for DFIG type wind turbines connected to distribution networks

This paper proposes a decentralised controller design for doubly-fed induction generators (DFIGs) to enhance dynamic performance of distribution networks. The change in the output power due to the variable nature of wind is considered as an uncertain term in the design algorithm. In addition, the interconnection effect of the other subsystems are considered in the design process. The H norm of the uncertain system is found out and simultaneous output-feedback linear controllers are designed based controller is verified on a 16 bus distribution test system for severe disturbances. Simulation results indicate that the designed controller is robust against uncertainties in operating conditions

Remixing to design learning: social media and peer-to-peer interaction

Social and participatory media offer opportunities to interact and share user-generated content. After some investigation and research, the authors are in their initial stages of using such media to provide a pathway for thinking about learning design in higher education. Using the concept of remixing, the authors aim to creatively blend and manipulate ideas to build a sustainable approach to course/program enhancement. Remixing is touted as one of the most important practices within the field of open educational resources, but it is not mainstream practice in educational thinking or design. This article highlights the authors’ approach and uses their pre-service teacher education program and their previous high school study as an example of remixing. The high school study involved the integration of social and participatory media into the face-to-face classroom; Author 1 was the practitioner researcher in the high school study. This article articulates the use of online social environments at the high school level to highlight concepts of sharing and remixing as a creative and social approach to designing learning in higher education. It also attempts to consider this within a course-wide approach.

Fog computing: a cloud to the ground support for smart things and machine-to-machine networks

Cloud services to smart things face latency and intermittent connectivity issues. Fog devices are positioned between cloud and smart devices. Their high speed Internet connection to the cloud, and physical proximity to users, enable real time applications and location based services, and mobility support. Cisco promoted fog computing concept in the areas of smart grid, connected vehicles and wireless sensor and actuator networks. This survey article expands this concept to the decentralized smart building control, recognizes cloudlets as special case of fog computing, and relates it to the software defined networks (SDN) scenarios. Our literature review identifies a handful number of articles. Cooperative data scheduling and adaptive traffic light problems in SDN based vehicular networks, and demand response management in macro station and micro-grid based smart grids are discussed. Security, privacy and trust issues, control information overhead and network control policies do not seem to be studied so far within the fog computing concept.