Aggregate processes in field calculus

Engineering distributed applications and services in emerging and open computing scenarios like the Internet of Things, cyber-physical systems and pervasive computing, calls for identifying proper abstractions to smoothly capture collective behaviour, adaptivity, and dynamic injection and execution of concurrent distributed activities. Accordingly, we introduce a notion of \u201caggregate process\u201d as a concurrent field computation whose execution and interactions are sustained by a dynamic team of devices, and whose spatial region can opportunistically vary over time. We formalise this notion by extending the Field Calculus with a new primitive construct, spawn, used to instantiate a set of field computations and regulate key aspects of their life-cycle. By virtue of an open-source implementation in the ScaFi framework, we show basic programming examples and benefits via two case studies of mobile ad-hoc networks and drone swarm scenarios, evaluated by simulation

Bistatic sonobuoy deployment strategies for detecting stationary and mobile underwater targets

The article of record as published may be found at https://doi.org/10.1002/nav.21807The problem of determining effective allocation schemes of underwater sensors for surveillance, search, detection, and tracking purposes is a fundamental research area in military operations research. Among the various sensor types, multistatic sonobuoy systems are a promising development in submerged target detection systems. These systems consist of sources (active sensors) and receivers (passive sensors), which need not be collocated. A multistatic sonobuoy system consisting of a single source and receiver is called a bistatic system. The sensing zone of this fundamental system is defined by Cassini ovals. The unique properties and unusual geometrical profile of these ovals distinguish the bistatic sensor allocation problem from conventional sonar placement problems. This study is aimed at supporting deci- sion makers in making the best use of bistatic sonobuoys to detect stationary and mobile targets transiting through an area of interest. We use integral geometry and geometric probability concepts to derive analytic expressions for the optimal source and receiver separation distances to maximize the detection probability of a submerged target. We corroborate our analytic results using Monte Carlo simulation. Our approach constitutes a valuable “back of the envelope” method for the important and difficult problem of analyzing bistatic sonar performance.Office of Naval ResearchTrkiye Bilimsel ve Teknolojik Aratirma Kurum