We consider a generalization of the classical Art Gallery Problem, where instead of a light source, the guards, called k-transmitters, model a wireless device with a signal that can pass through at most k walls. We show it is NP-hard to compute a minimum cover of point 2transmitters, point k-transmitters, and edge 2-transmitters in a simple polygon. The point 2transmitter result extends to orth...

The paper describes a 3D acoustic imaging system that uses a 2D receiver array and a 2D transmitter array. For many years, high quality acoustic imaging has been achieved by using synthetic transmit aperture (STA) technique [1][2]. Normally, STA uses an array of receivers and a small number of transmitters to produce an image. However, the conventional arrangement of transmitters in a same hori...

We investigated the levels of radio frequency electromagnetic fields (RF EMFs) emitted from marine ship transmitters. In this study, we recorded the radio frequency (RF) electric field (EF) levels emitted from transmitters from a marine vessel focusing on the areas normally occupied by crew members and passengers. Previous studies considered radiation hazard safety assessment for marine vessels...

We consider a visible light positioning system in which receiver performs position estimation based on signals emitted from number of emitting diode (LED) transmitters. Each LED transmitter can be malicious and transmit at an unknown power level with certain probability. A maximum likelihood (ML) estimator is derived the knowledge probabilities that transmitters malicious. In addition, presence...

In this paper we focus on approximate solutions to solve a new class of Art Gallery Problems inspired by wireless localization. Instead of the usual guards we consider wireless devices whose signal can cross a certain number, k, of walls. These devices are called k-transmitters. We propose an algorithm for constructing the visibility region of a k-transmitter located on a point of a simple poly...