Computers2015, 4(2), 87-112; doi:10.3390/computers4020087 (registering DOI) - published 17 April 2015 Show/Hide Abstract
Abstract: Nodes in mobile ad hoc networks (MANETs) are mandated to utilize their limited energy resources in forwarding routing control and data packets for other nodes. Since a MANET lacks a centralized administration and control, a node may decide to act selfishly, either by refusing to respond to route requests from other nodes or deceitfully by responding to some route requests, but dropping the corresponding data packets that are presented for forwarding. A significant increase in the presence of these misbehaving nodes in a MANET can subsequently degrade network performance. In this paper, we propose a dynamic reputation management system for detecting and isolating misbehaving nodes in MANETs. Our model employs a novel direct monitoring technique to evaluate the reputation of a node in the network, which ensures that nodes that expend their energy in transmitting data and routing control packets for others are allowed to carry out their network activities while the misbehaving nodes are detected and isolated from the network. Simulation results show that our model is effective at curbing and mitigating the effects of misbehaving nodes in the network.
Abstract: Embedded systems show the tendency of becoming more and more connected. This fact combined with the trend towards the Internet of Things, from which measuring instruments are not immune (e.g., smart meters), lets one assume that security in measuring instruments will inevitably play an important role soon. Additionally, measuring instruments have adopted general-purpose operating systems to offer the user a broader functionality that is not necessarily restricted towards measurement alone. In this paper, a flexible software system architecture is presented that addresses these challenges within the framework of essential requirements laid down in the Measuring Instruments Directive of the European Union. This system architecture tries to eliminate the risks general-purpose operating systems have by wrapping them, together with dedicated applications, in secure sandboxes, while supervising the communication between the essential parts and the outside world.
Abstract: Liquid foams are used in areas such as mineral separation, oil recovery, food and beverage production, sanitation and fire fighting. To improve the quality of products and the efficiency of processes in these areas, foam scientists wish to understand and control foam behaviour. To this end, foam scientists have used foam simulations to model foam behaviour; however, analysing these simulations presents difficult challenges. We describe the main foam research challenges and present the design of FoamVis, the only existing visualization, exploration and analysis application created to address them. We describe FoamVis’ main features, together with relevant design and implementation notes. Our goal is to provide a global overview and individual feature implementation details that would allow a visualization scientist to extend the FoamVis system with new algorithms and adapt it to new requirements. The result is a detailed presentation of the software that is not provided in previous visualization research papers.
Abstract: Research software often consists of individual, isolated prototype applications. Small proof of concept applications are usually enough for demonstrating new algorithms. However, the unification of new research algorithms into a cohesive software framework has advantages. Adding new features to an existing pipeline reduces implementation overhead. The researcher is more able to compare and contrast existing or previous work with new research. Utilizing previously implemented techniques, researchers are able to combine visualization options in new ways that typical research prototypes cannot. The software application can be made available to the domain expert for evaluation and future use. These goals are in part realized by utilizing recent advancements in game design technology and by leveraging features available with recent graphics hardware. Described is the design of a feature-rich flow visualization software framework in more detail than a typical research paper. In contrast to most research prototypes, the system we present handles real-world simulation datasets by interfacing directly with the commercial package called tecplot. We present a description of our system in detail, whereas previously published work focuses on the research contribution. The effectiveness and scalability of the approach is also discussed.
Abstract: Distributed constraint satisfaction problems (DisCSPs) are among the widely endeavored problems using agent-based simulation. Fernandez et al. formulated sensor and mobile tracking problem as a DisCSP, known as SensorDCSP In this paper, we adopt a customized ERE (environment, reactive rules and entities) algorithm for the SensorDCSP, which is otherwise proven as a computationally intractable problem. An amalgamation of the autonomy-oriented computing (AOC)-based algorithm (ERE) and genetic algorithm (GA) provides an early solution of the modeled DisCSP. Incorporation of GA into ERE facilitates auto-tuning of the simulation parameters, thereby leading to an early solution of constraint satisfaction. This study further contributes towards a model, built up in the NetLogo simulation environment, to infer the efficacy of the proposed approach.