Simple and flexible random key pre-distribution schemes for wireless sensor networks using deployment knowledge

Sensor nodes are tiny, low-power and battery constrained electromechanical devices that are usually deployed for sensing some type of data in different types of areas. Because of their memory and computational restrictions, public key cryptography (PKC) systems are not suited for sensor nodes to provide security. Instead, private key cryptography is preferred to be used with sensor networks and there has been considerable work in this area, but there still exist problems with private key cryptography because of memory restrictions of sensor nodes. Number of keys that can be deployed into a sensor node is determined by the available memory of that node which is limited even private key cryptographic techniques are applied. So, new key distribution mechanisms are required to decrease number of pairwise keys that are deployed into a sensor node. Random key pre-distribution mechanisms have been proposed to overcome memory restrictions of sensor nodes. These mechanisms are widely accepted for sensor network security. Simply, these schemes try do decrease the number of keys to be deployed in each sensor node in a sensor network and provide reasonable security for the sensor network. Random key pre-distribution schemes proposed until now have some deficiencies. Some of these schemes are too complicated and too difficult to be applied. Schemes that seem deployable involve unrealistic assumptions when real world scenarios are considered. In this thesis, we propose random key pre-distribution mechanisms that are simple and easily deployable. In this thesis, we first developed a generalized random key pre-distribution scheme. Then we proposed three random key pre-distribution mechanisms based on this generalized scheme and we provided their simulation results and their comparison to well-known random key pre-distribution schemes in the literature. Our generalized scheme allows different systems to be derived according to deployment needs. It offers simple, easily deployable distribution mechanisms and provides reasonable connectivity and resiliency with respect to its simplicity

An algorithm for constructing various kinds of nanojunctions using zig-zag and armchair nanotubes

A method for generating various forms of junctions involving armchair and zig-zag nanotubes, firstly introduced by Zsoldos et al., is developed to cover all types of armchair and zig-zag nanotubes in a systematical way. This method can also be used to produce nanogears and toothed canals. The method is explained and flowcharts are included to aid in programming into a code

Molecular Mechanics and Molecular Dynamics Simulations of Carbon Based Nanogears

A system containing two nanogears and two nanotubes acting as shafts is designed. Then, it is checked to see whether it is a stable one by means of the molecular mechanics simulation. After it was ensured that the system was suitable for consideration, molecular dynamics were applied but from the results it was observed that the selected potential was not appropriate by itself alone and reconsideration showed that improvements were to be made. This resulted in introduction of an additional potential and the simulations yielded more realistic results. As the outcome, acceleration is observed on the rotor nanogear causing the rotor nanogear to rotate faster than the motor nanogear driving it but both the snapshots of the system and the angular velocity progress showed that the rotor nanogear eventually slows down and waits until the next effective tooth of the motor nanogear comes into the vicinity, making the designed system a candidate to be used in future applications

Carbon Nanobuggy is Ready for a Test Drive!

A nanostructure made of carbon atoms, resembling a real world buggy car has been designed respecting the sp2 bonding of the carbons as present in graphene and derived systems. The components of the carbon nanobuggy (nanotubes, nanotori, nanojunctions and nanogears) had been observed and tested for their stability in previous works, endorsing the stability and the plausibility of the nanobuggy itself. The resulting nanobuggy is optimized using MM+ force field

Structural properties of carbon nanogears

Structural stabilities of different types of carbon nanogears have been tested against temperature by means of a molecular dynamics procedure. Effects of periodic boundary conditions were also examined. It has been found that although the two types of nanogears (armchair and zigzag CNT yielding) investigated look similar in configuration, when tested against high temperatures, bond breakings and deformations occur at different regions

Structural and Thermal Properties of Indium Phosphide Nanoparticles: Molecular Dynamics Simulations

Structural and thermal properties of Indium Phosphide spherical nanoparticles at various sizes have been investigated via classical molecular dynamics simulations using an atomistic potential energy function. The initial configurations of the nanoparticles were chosen as spheres generated from the zinc blende crystalline structure. To investigate the relation between the size and the heat capacity, the simulations were realized at temperatures in the range of 1-1300 K under both equilibrium and non-equilibrated criteria. Structural phase transition from zinc blende to rock salt phase has been observed

Simple and flexible random key predistribution schemes for wireless sensor networks using deployment knowledge

Sensor nodes are tiny, low-power, computationally limited and battery constrained electromechanical devices that are usually deployed for sensing some type of data in the field. Random key predistribution mechanisms have been proposed to provide security for wireless sensor networks. In the literature, there are well known random key predistribution schemes. Some of these schemes are secure, but quite complex to apply, while some other are easily applicable but they do not offer reasonable security. In this paper, we propose random key predistribution schemes for wireless sensor networks that provide varying ranges of security and that are easily applicable due to their simplicity. In this respect, our schemes serve as a tradeoff. Moreover, our proposed schemes show a good extensibility property. We assume prior deployment knowledge. We examine performance of our schemes and compare them with well known random key predistribution schemes

Relationship of Meteorological and Air Pollution Parameters with Pneumonia in Elderly Patients

Background and Purpose. In this study, we aimed to evaluate the relationship between pneumonia and meteorological parameters (temperature, humidity, precipitation, airborne particles, sulfur dioxide (SO2), carbon monoxide (CO), nitrogen dioxide (NO2), nitrite oxide (NO), and nitric oxide (NOX)) in patients with the diagnosis of pneumonia in the emergency department. Methods. Our study was performed retrospectively with patients over 65 years of age who were diagnosed with pneumonia. The meteorological variables in the days of diagnosing pneumonia were compared with the meteorological variables in the days without diagnosis of pneumonia. he sociodemographic characteristics, complete blood count of the patients, and meteorological parameters (temperature, humidity, precipitation, airborne particles, SO2, CO, NO2, NO, and NOX) were investigated. Results. When the temperature was high and low, the number of days consulted due to pneumonia was related to low air temperature (p < 0.05). During the periods when PM 10, NO, NO2, NOX, and CO levels were high, the number of days referred for pneumonia was increased (p < 0.05). Conclusion. As a result, climatic (temperature, humidity, pressure levels, rain, etc.) and environmental factors (airborne particles, CO, NO, and NOX) were found to he effective in the number of patients admitted to the hospital due to pnewnonia