adequate coverage is one of the main problems for distributed wireless sensor networks and the effectiveness of that highly depends on the sensor deployment scheme. given a finite number of sensors, optimizing the sensor deployment will provide sufficient sensor coverage and save power of sensors for movement to target location to adequate coverage. in this paper, we apply fuzzy logic system to...

Knowledge of the diffuse-field coherence between array sensors is a basic assumption for a wide range of array processing applications. Explicit relations previously existed only for omnidirectional and first-order directional sensors, or a restricted arrangement of differential patterns. We present a closed-form formulation of the theoretical coherence function between arbitrary directionally ...

Networks of wireless integrated sensors are often used to monitor parameters distributed in the environment. These parameters are related to a variety of applications such as security, patient monitoring, chemical and biological hazard detection. Some solutions rely on replaceable batteries with a limited life-time to provide long-term sensor operation. Others envision short transmission range ...

Ad-hoc networks of sensor nodes are in general semi-permanently deployed. However, the topology of such networks continuously changes over time, due to the power of some sensors wearing out to new sensors being inserted into the network, or even due to designers moving sensors around during a network re-design phase (for example, in response to a change in the requirements of the network). In t...

This paper outlines, presents, and discusses the development strategy, design, results and analysis for a neural network implementation of a control system for an artificial being in an environmental simulator. Limited visual sensors and aural sensors are provided by the simulation. The main goal of this project is a well documented, long living robot.

Digital photography has made immense progress over the past 15 years, particularly in increasing resolution and improving low-light performance. But continuing progress in these aspects of performance is not possible, because cameras are now approaching the limits imposed by the basic nature of light. This article looks at the physics that explains these limits. It shows how the fact that light...

We are facing an growing demand in deploying large scale sensor networks in the real world. However, there are still many obstacles before we can proceed. Security is a major concern as we need to be sure that the data we receive is authentic and confidential, and have not been tampered with. This is especially difficult because sensors have very limited resources and we cannot guarantee physic...

Polymer–derived ceramics (PDCs) constituted from silicon, carbon, nitrogen and oxygen embody not only remarkable resistance to creep, thermal shock and oxidation at very high temperatures, but also functional properties such as semiconductivity which extends up to 1350C. In this report we describe the extraordinary sensitivity of the electrical resistance of the PDCs to hydrogen, at temperature...

Conventional fiber Bragg grating sensors have a few limitations, such as limited interrogation resolution and speed and difficulty in separating different measurands. In this article, microwave photonic techniques applied to fiber Bragg grating sensors to improve the interrogation resolution and speed are discussed. Experimental results to validate the techniques are provided.

Conventional cameras have a rather limited field of view, which raises various problems like the necessity to control their orientation. Panoramic or omnidirectional image sensors solve this problem by using a curved mirror. In this work we address the modelling and design omnidirectional catadioptric sensors and show our experiences with semi-spherical mirrors.