Exploiting features of high density wireless sensor networks represents a challenging issue. In this work, the training of a sensor network which consists of anonymous and asynchronous sensors, randomly and massively distributed in a circular area around a more powerful device, called actor, is considered. The aim is to partition the network area in concentric coronas and sectors, centered at t...

Recent advances in hardware technology facilitate applications requiring a large number of sensor devices, where each sensor device has computational, storage, and communication capabilities. However these sensors are subject to certain constraints such as limited power, high communication cost, low computation capability, presence of noise in readings and low bandwidth. Since sensor devices ar...

WSN are ad-hoc mobile networks in which sensors have limited resources and communication capabilities. These reasons poses lots of technical challenges on sensor deployment scheme because it affect the cost and detection capability. The objective of this paper is to deploy sensors (indoor environment) in sensing field to ensure both sensing coverage and network connectivity with a minimum cover...

Estimating camera position and posture can be applied to the fields of augmented reality and robot navigation. In these fields, to obtain absolute position and posture of the camera, sensor-based methods using GPS and magnetic sensors and vision-based methods using input images from the camera have been investigated. However, sensor-based methods are difficult to synchronize the camera and sens...

We focus on the problem of energy-efficient convergecast in sensor networks. This problem identifies the energy-latency tradeoff during convergecast. Whenever a group of sensors communicate an event of interest, the latency involved in delivering such messages to the base station should be minimized. Since the sensors are constrained by limited power and are mostly idle, it is important that th...

Nanowire field-effect transistors (NW-FETs) are emerging as powerful sensors for detection of chemical/biological species with various attractive features including high sensitivity and direct electrical readout. Yet to date there have been limited systematic studies addressing how the fundamental factors of devices affect their sensitivity. Here we demonstrate that the sensitivity of NW-FET se...

This paper reviews CMOS (complementary metal-oxide-semiconductor) MEMS (micro-electro-mechanical systems) fabrication technologies and enabled micro devices of various sensors and actuators. The technologies are classified based on the sequence of the fabrication of CMOS circuitry and MEMS elements, while SOI (silicon-on-insulator) CMOS MEMS are introduced separately. Introduction of associated...

Wireless sensor network consisting of a large number of small sensors with low-power can be an effective tool for the collection and integration of data in a variety of environments. Here data exchange between the sensors and base station need to be designed to conserve the limited energy resources of the sensors. Grouping the sensors into clusters has been recognized as an efficient approach f...

gas sensitive metal oxide layers used in fabrication of resistive gas sensors are prepared by different deposition techniques. the technical data reported on some basic and practically important specifications of these devices, although fabricated based on the same gas sensitive oxide, are anomalously different. the influence of the fabrication technique used for the deposition of the gas sensi...