A Generic Pattern-based Design for Distributed Collaborative Editors

With the advent of information sharing technologies, users can share and collaborate in performing common tasks through the use of distributed collaborative applications. Specifically, Distributed Collaborative Editors (DCE) are more and more used in many fields including healthcare, education, software engineering, military, etc. However, all proposed DCE frameworks focused on coordination algorithms, i.e. how to ensure data convergence, while very little attention was given to addressing the design of DCE which shall be the fundamental step for DCE frameworks construction. In this article, we analyze and design DCE as the structure of five layers comprising classifiers, relations among them, and their main properties. We contribute in two areas. First, we define a generic DCE architecture that captures organization, business and software aspects of DCE. Secondly, we propose a pattern-based design that emphasizes good design principles for the business core of DCE. This design will allow DCE researchers and developers to converge towards the same generic framework while improving the quality and performance of proposed DCE applications and tools.

Persistent Multi-Agent Search and Tracking with Flight Endurance Constraints

A large group of small, limited endurance autonomous vehicles working cooperatively may be more effective in target search and track operations when compared with a long endurance vehicle. For a persistent search and track task, a need exists for coordination algorithms that account for limited agent endurance. This paper presents a multi-agent persistent search and track algorithm incorporating endurance constraints in a high-level algorithm that deploys and recovers vehicles from a stationary base station. Agents are assigned to search, track, return, and deploy modes using on-board sensor and battery measurements. Simulations and experiments show the relationship between the number of agents, battery capacity, search performance, and target tracking performance. The measures used to quantify these relationships include spatiotemporal coverage, target tracking effectiveness, and the usage of available aircraft. Hardware experiments demonstrate the effectiveness of the approach.