Multi-Agent Deployment for Visibility Coverage in Polygonal Environments with Holes

This article presents a distributed algorithm for a group of robotic agents with omnidirectional vision to deploy into nonconvex polygonal environments with holes. Agents begin deployment from a common point, possess no prior knowledge of the environment, and operate only under line-of-sight sensing and communication. The objective of the deployment is for the agents to achieve full visibility coverage of the environment while maintaining line-of-sight connectivity with each other. This is achieved by incrementally partitioning the environment into distinct regions, each completely visible from some agent. Proofs are given of (i) convergence, (ii) upper bounds on the time and number of agents required, and (iii) bounds on the memory and communication complexity. Simulation results and description of robust extensions are also included

Video Art: Cultural Transformations

In the 1960s, there were efforts to move broadcast television in the direction of the experimental video art by altering television\u27s conventional format. Fred Barzyk, in his role as a producer and director at WGBH-TV in Boston, was uniquely positioned to act as a link between television and experimental video artists who normally would not have had access to the technology available at a major broadcast facility. As the leading innovator in the beginnings of video art, the Korean American Nam June Paik (1932-2006) deserves special mention. His work bridges the worlds of art, video technology, and television. The video works of Nan June Paik, Amy Greenfield, Peter Campus, Feng Meng Bo, Elizabeth Sussman and other video artists are considered in this essay as key contributors to the development of video art. The selection is based on my experience with the artists cited. Despite video art\u27s growing popularity among contemporary artists in the 1970s and beyond, the museums were slow to acknowledge this development. One of the problems was deciding where, among the existing museum collections, to locate video art. In its 50 some years of history, video art has enjoyed a remarkable success in its artistic innovations while undergoing changes in formats virtually at the speed of rapid advances in electronic visual technology. Ironically, the legacy of creative television set in motion by Barzyk and his generation has been largely coopted by the television broadcasting industry, which mainly serves as a platform for mass media advertising

Spartan Daily, September 19, 2000

Volume 115, Issue 13https://scholarworks.sjsu.edu/spartandaily/9581/thumbnail.jp

Art theft, art vandalism, and guardianship in U.S. art institutions.

Art crime scholars and art world professionals constantly grapple with determining the most effective methods by which to reduce and prevent victimization by art thieves and art vandals. Despite the numerous accounts of this form of criminality, there is a dearth of empirical studies focused on the security and care of art collections. Using Routine Activities Theory to guide the research, the present study explores the relationship between social and physical guardianship practices and the prevalence of art theft and art vandalism using questionnaire data collected from 111 American art museums and art galleries. The results indicate an overwhelming lack of statistically significant association between the majority of the guardianship measures and art theft and art vandalism victimization, a pattern consistent with the possibility that social and physical guardianship practices are not implemented until after an act of vandalism has already occurred

On realistic target coverage by autonomous drones

Low-cost mini-drones with advanced sensing and maneuverability enable a new class of intelligent sensing systems. To achieve the full potential of such drones, it is necessary to develop new enhanced formulations of both common and emerging sensing scenarios. Namely, several fundamental challenges in visual sensing are yet to be solved including (1) fitting sizable targets in camera frames; (2) positioning cameras at effective viewpoints matching target poses; and (3) accounting for occlusion by elements in the environment, including other targets. In this article, we introduce Argus, an autonomous system that utilizes drones to collect target information incrementally through a two-tier architecture. To tackle the stated challenges, Argus employs a novel geometric model that captures both target shapes and coverage constraints. Recognizing drones as the scarcest resource, Argus aims to minimize the number of drones required to cover a set of targets. We prove this problem is NP-hard, and even hard to approximate, before deriving a best-possible approximation algorithm along with a competitive sampling heuristic which runs up to 100× faster according to large-scale simulations. To test Argus in action, we demonstrate and analyze its performance on a prototype implementation. Finally, we present a number of extensions to accommodate more application requirements and highlight some open problems

VC-Dimension of Exterior Visibility

In this paper, we study the Vapnik-Chervonenkis (VC)-dimension of set systems arising in 2D polygonal and 3D polyhedral configurations where a subset consists of all points visible from one camera. In the past, it has been shown that the VC-dimension of planar visibility systems is bounded by 23 if the cameras are allowed to be anywhere inside a polygon without holes [1]. Here, we consider the case of exterior visibility, where the cameras lie on a constrained area outside the polygon and have to observe the entire boundary. We present results for the cases of cameras lying on a circle containing a polygon (VC-dimension= 2) or lying outside the convex hull of a polygon (VC-dimension= 5). The main result of this paper concerns the 3D case: We prove that the VC-dimension is unbounded if the cameras lie on a sphere containing the polyhedron, hence the term exterior visibility

Task-driven multi-formation control for coordinated UAV/UGV ISR missions

The report describes the development of a theoretical framework for coordination and control of combined teams of UAVs and UGVs for coordinated ISR missions. We consider the mission as a composition of an ordered sequence of subtasks, each to be performed by a different team. We design continuous cooperative controllers that enable each team to perform a given subtask and we develop a discrete strategy for interleaving the action of teams on different subtasks. The overall multi-agent coordination architecture is captured by a hybrid automaton, stability is studied using Lyapunov tools, and performance is evaluated through numerical simulations