As Cognitive Radio Networks (CRN) gain in popularity as an extremely promising wireless technology that can alleviate the apparent spectrum scarcity and support innovative wireless applications; they will become bigger targets for hackers. Moreover, they will also be exposed to diverse security threats especially at the PHY-layer spectrum sensing module. Hence, security consideration is central...

The aim of this thesis was to design and implement an adaptive medium access control (MAC) protocol for a cognitive radio network (CRN) testbed. The implementation was realized on Wireless open-Access Research Platform (WARPv2). The proposed MAC protocol was based on time division multiple access (TDMA) that works closely with the underlying orthogonal frequency division multiplexing (OFDM) bas...

Various primary user (PU) radios have been allocated into fixed frequency bands in the whole spectrum. A cognitive radio network (CRN) should be able to perform the wideband spectrum sensing (WSS) to detect temporarily unoccupied frequency bands. We summarize four occupancy features for the frequency bands. 1. The occupancy is sparse; 2. The frequency band allocation information is fixed and co...

The cognitive radio network (CRN) is a promising solution to the problem of spectrum scarcity. To achieve efficient spectrum utilization, cognitive radio requires a robust spectrum sensing and spectrum sharing scheme. Therefore, spectrum sharing scheme plays a key role in achieving the optimal utilization of the available spectrum. The spectrum sharing in CRN is more challenging than traditiona...

Nanocomposite thin film coatings of MoS2-added CrN/TiAlN tribological multilayers were prepared by reactive co-sputtering of Ti/Al 50/50 at.%, pure chromium and MoS2 targets of the independently d.c. driven unbalanced magnetrons. Nano-scaled tri-layer system with periodic thickness in a range of 4-10 nm of CrN, TiAlN and MoS2 compound layer with a broad interface, in which the composition is co...

We study time-bounded probabilistic reachability for Chemical Reaction Networks (CRNs) using the Linear Noise Approximation (LNA). The LNA approximates the discrete stochastic semantics of a CRN in terms of a continuous space Gaussian process. We consider reachability regions expressed as intersections of finitely many linear inequalities over the species of a CRN. This restriction allows us to...

Chromosomal DNA degradation is critical for cell death execution and is a hallmark of apoptosis, yet little is known about how this process is executed. Using an RNAi-based functional genomic approach, we have identified seven additional cell death-related nucleases (crn genes), which along with two known nucleases (CPS-6 and NUC-1) comprise at least two independent pathways that contribute to ...

The crooked neck (crn) gene of Drosophila encodes a protein of 702 amino acids and contains 16 tandemly arranged copies of a 34-amino-acid repeat that is similar to the tetratrico peptide repeat (TPR). Multiple copies of the TPR motif have also been found in a family of yeast genes, including several members that are necessary for cell division. TPR-containing proteins encoded by the yeast gene...

In this report, we propose a technique using negotiation based on multi-agent system (MAS) in the context of cognitive radio network (CRN). The agents are particularly suited to provide responsive solutions to complex problems such as the negotiation of the spectrum in CRN. We have implemented our proposed solution with JADE (Java Agent Development Framework) and we have also evaluate the propo...

We investigate the parallel assembly of two-dimensional, geometrically-closed modular target structures out of homogeneous sets of macroscopic components of varying anisotropy. The yield predicted by a chemical reaction network (CRN)-based model is quantitatively shown to reproduce experimental results over a large set of conditions. Scaling laws for parallel assembling systems are then derived...