wireless sensor networks (wsns) have many applications in the areas of commercial, military and environmental requirements. regarding the deployment of low cost sensor nodes with restricted energy resources, these networks face a lot of security challenges. a basic approach for preparing a secure wireless communication in wsns, is to propose an efficient cryptographic key management protocol be...

We use the catalogue of 4315 extragalactic H I 21-cm emission line detections from HIPASS to calculate the most accurate measurement of the H I mass function (HIMF) of galaxies to date. The completeness of the HIPASS sample is well characterised, which enables an accurate calculation of space densities. The HIMF is fitted with a Schechter function with parameters: α = −1.37 ± 0.03 ± 0.05, log(M...

Microelectromechanical systems (MEMS) resonant sensors provide a high degree of accuracy for measuring the physical properties of chemical and biological samples. These sensors enable the investigation of cellular mass and growth, though previous sensor designs have been limited to the study of homogeneous cell populations. Population heterogeneity, as is generally encountered in primary cultur...

We demonstrate a silicon micro-opto-electro-mechanical sensor based on mass-loading of a chemo-selective polymer coated onto a microbridge. The sensor is probed optically using an on-chip waveguide Fabry-Pérot interferometer for high resolution displacement and resonant frequency measurement. The mechanical resonator is designed with paddles to simplify chemo-selective polymer deposition and to...

This work focuses on the proof-mass mechanical structural design improvement of a tri-axial piezoresistive accelerometer specifically designed for head injuries monitoring where medium-G impacts are common; for example, in sports such as racing cars or American Football. The device requires the highest sensitivity achievable with a single proof-mass approach, and a very low error (<1%) as the a...

The 12th IEEE International Conference on Mobile Ad hoc and Sensor Systems (IEEE MASS 2015) will be held in Dallas, Texas, USA, October 19 – 22, 2015. Wireless ad hoc communication, Internet of Things, and mobile computing have applications in a variety of environments, such as smart homes, hospitals, battlefields, and disaster-recovery operations. Wireless sensor and actuator networks are bein...

A rapid biosensor for the detection of bacterial growth was developed using micromechanical oscillators coated in common nutritive layers. The change in resonance frequency as a function of the increasing mass on a cantilever array forms the basis of the detection scheme. The calculated mass sensitivity according to the mechanical properties of the cantilever sensor is approximately 50 pg/Hz; t...

Measurements of an object's fundamental physical properties like mass, volume, and density can offer valuable insights into the composition and state of the object. However, many important biological samples reside in a liquid environment where it is difficult to accurately measure their physical properties. We show that by using a simple piece of glass tubing and some inexpensive off-the-shelf...