A Secure and Efficient Communication in VANET

Recently, the demand for monitoring a certain object covering large and dynamic scopes such as wildfires, glaciers, and radioactive contaminations, called large-scale fluid objects (LFOs), is coming to the fore due to disasters and catastrophes that lately happened. This article provides an analytic comparison of such LFOs and typical individual mobile objects (IMOs), namely animals, humans, vehicles, etc., to figure out inherent characteristics of LFOs. Since energy-efficient monitoring of IMOs has been intensively researched so far, but such inherent properties of LFOs hinder the direct adaptation of legacy technologies for IMOs, this article surveys technological evolution and advances of LFOs along with ones of IMOs. Based on the communication cost perspective correlated to energy efficiency, three technological phases, namely concentration, integration, and abbreviation, are defined in this article. By reviewing various methods and strategies employed by existing works with the three phases, this article concludes that LFO monitoring should achieve not only decoupling from node density and network structure but also trading off quantitative reduction against qualitative loss as architectural principles of energy-efficient communication to break through inherent properties of LFOs. Future research challenges related to this topic are also discussed.

Download Full-text

PageRank Implemented with the MPI Paradigm Running on a Many-Core Neuromorphic Platform

Journal of Low Power Electronics and Applications ◽

10.3390/jlpea11020025 ◽

2021 ◽

Vol 11 (2) ◽

pp. 25

Author(s):

Evelina Forno ◽

Alessandro Salvato ◽

Enrico Macii ◽

Gianvito Urgese

Keyword(s):

Parallel Execution ◽

Spiking Neural Networks ◽

Massively Parallel ◽

Current Version ◽

Hardware Platform ◽

Pagerank Algorithm ◽

Programming Paradigm ◽

Neuromorphic Hardware ◽

Efficient Communication ◽

Many Core

SpiNNaker is a neuromorphic hardware platform, especially designed for the simulation of Spiking Neural Networks (SNNs). To this end, the platform features massively parallel computation and an efficient communication infrastructure based on the transmission of small packets. The effectiveness of SpiNNaker in the parallel execution of the PageRank (PR) algorithm has been tested by the realization of a custom SNN implementation. In this work, we propose a PageRank implementation fully realized with the MPI programming paradigm ported to the SpiNNaker platform. We compare the scalability of the proposed program with the equivalent SNN implementation, and we leverage the characteristics of the PageRank algorithm to benchmark our implementation of MPI on SpiNNaker when faced with massive communication requirements. Experimental results show that the algorithm exhibits favorable scaling for a mid-sized execution context, while highlighting that the performance of MPI-PageRank on SpiNNaker is bounded by memory size and speed limitations on the current version of the hardware.

Download Full-text

Indoor landmark-based path-finding utilising the expanded connectivity of an endpoint partition

Environment and Planning B Urban Analytics and City Science ◽

10.1177/0265813516670901 ◽

2016 ◽

Vol 45 (2) ◽

pp. 233-252

Author(s):

Pepijn Viaene ◽

Alain De Wulf ◽

Philippe De Maeyer

Keyword(s):

Visual Information ◽

Spatial Configuration ◽

Shortest Paths ◽

Minimal Amount ◽

Path Finding ◽

Breadth First Search ◽

Length Increase ◽

Efficient Communication ◽

Indoor Wayfinding

Landmarks are ideal wayfinding tools to guide a person from A to B as they allow fast reasoning and efficient communication. However, very few path-finding algorithms start from the availability of landmarks to generate a path. In this paper, which focuses on indoor wayfinding, a landmark-based path-finding algorithm is presented in which the endpoint partition is proposed as spatial model of the environment. In this model, the indoor environment is divided into convex sub-shapes, called e-spaces, that are stable with respect to the visual information provided by a person’s surroundings (e.g. walls, landmarks). The algorithm itself implements a breadth-first search on a graph in which mutually visible e-spaces suited for wayfinding are connected. The results of a case study, in which the calculated paths were compared with their corresponding shortest paths, show that the proposed algorithm is a valuable alternative for Dijkstra’s shortest path algorithm. It is able to calculate a path with a minimal amount of actions that are linked to landmarks, while the path length increase is comparable to the increase observed when applying other path algorithms that adhere to natural wayfinding behaviour. However, the practicability of the proposed algorithm is highly dependent on the availability of landmarks and on the spatial configuration of the building.

Download Full-text