Nowadays the demand of the wireless application has grown from day to day life. The Demand of wireless applications has put a many of constraints on the use of available radio spectrum which is a limited and precious resource. The static spectrum assignment leads to underutilization of the spectrum as a great portion of the licensed spectrum is not efficiently utilized. Cognitive radio (CR) is ...

Abstract—Circular synthetic aperture radar (CSAR) imaging based on compressive sensing with random step frequency (RSF) as transmitted signal is introduced. CSAR is capable of obtaining both two-dimensional high resolution image and three-dimensional image due to a circular collection trajectory. RSF signal shares good characteristics of noise signals including “thumbtack-shape” ambiguity funct...

Cognitive radio networks sense spectrum occupancy and manage themselves to operate in unused bands without disturbing licensed users. The detection capability of a radio system can be enhanced if the sensing process is performed jointly by a group of nodes so that the effects of wireless fading and shadowing can be minimized. However, taking a collaborative approach poses new security threats t...

In the last two decades, a significant number of innovative sensing systems based on optical fiber sensors have been exploited in the engineering community due to their inherent distinctive advantages such as small size, light weight, immunity to electromagnetic interference (EMI) and corrosion, and embedding capability. A lot of optical fiber sensor-based monitoring systems have been developed...

We present a novel fiber-based near-field optical head consisting of a straw-shaped writing probe and a flat gap sensing probe. The straw-shaped probe with a C-aperture on the end face exhibits enhanced transmission by a factor of 3 orders of magnitude over a conventional fiber probe due to a hybrid effect that excites both propagation modes and surface plasmon waves. In the gap sensing probe, ...

Compressive sensing (CS) is a promising technology for realizing energy-efficient wireless sensors for long-term health monitoring. In this paper, we propose a datadriven CS framework that learns signal characteristics and individual variability from patients’ data to significantly enhance CS performance and noise resilience. This is accomplished by a co-training approach that optimizes both th...

System power models are important for power management and optimization on smartphones. However, existing approaches for power modeling have several limitations. Some require external power meters, which is not convenient for people to use. Other approaches either rely on the battery current sensing capability, which is not available on many smartphones, or take a long time to generate the powe...

In today’s scenario the introduction of new wireless applications and services and its increasing demand is creating issues in the allocation of the available radio spectrum which is limited and precious resource. As spectrum utilization depends strongly on time and place, a fixed spectrum assignment leads to under utilization of spectrum. Cognitive radio is a new technology which provides a dy...

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...

The growth of monoclinic Ga2O3 nanowires, nano-ribbons and nano-sheets has been investigated. Results indicate that high quality single crystal nanowires can be grown at 900°C using an Au catalyst, while single crystal nano-ribbons and nano-sheets require no metal catalyst for growth. Since bulk Ga2O3 is a promising material for high temperature sensing, Ga2O3 nanowires and nano-ribbons may pro...