The adsorption of surfactants from dilute oil solutions on to solid surfaces is studied as a function of surface curvature and surface coverage. Coarse-grained molecular models, computer simulations, and umbrella sampling are used to compute the dependence of the free energy of adsorption on to a spherical colloid surface with radius R. It is shown that for fixed surface coverage, and with all ...

A wireless sensor network (WSN) is composed of a group of small power-constrained nodes with functions of sensing and communication, which can be scattered over a vast region for the purpose of detecting or monitoring some special events. The first challenge encountered in WSNs is how to cover a monitoring region perfectly. Coverage and connectivity are two of the most fundamental issues in WSN...

In this paper, we show that Krypton atoms form a commensurate solid (CS) phase with a fractional coverage of one krypton atom per every four carbons on zigzag carbon nanotubes. This is a unique phase, different from the √ 3×√3R30◦ CS monolayer formed on graphite, which has a lower coverage of one krypton atom per every six carbons. Our prediction disagreeswith experiments that observe in nanotu...

We consider Poisson random balls in R, with the pair (center, radius) given by a Poisson point process in Rd×(0,+∞). According to the intensity measure of the Poisson process, we investigate the eventuality of covering the whole space with the union of the balls. We exhibit a disjunction phenomenon between the coverage with large balls (low frequency) and the coverage with small balls (high fre...

Wireless sensor networks can be used to monitor the interested region by multi-hop communication. Coverage is a primary metric to evaluate the capacity of monitoring. In this paper, we focus on the coverage issue under border effects, where the sensor nodes are distributed in a circle-shaped region randomly. Under this scenario, the expected coverage of the sensor node and the total network cov...

We take some parts of a theoretical mobility model in a two-dimension grid proposed by Greenlaw and Kantabutra to be our model. The model has eight necessary factors that we commonly use in a mobile wireless network: sources or wireless signal providers, the directions that a source can move, users or mobile devices, the given directions which define a user’s movement, the given directions whic...

Keywords: Three-dimensional networks 3D networks Coverage and connectivity Polyhedron Node placement k-Coverage a b s t r a c t The increasing interest in using sensor networks in applications for underwater surveillance and oceanic studies underscores the importance of solving the coverage and connec-tivity issues in 3D wireless sensor networks (WSN). In particular, the problem of supporting f...

This paper studies the optimal number of UAVs to deploy for a given mission subjected to sensor or connectivity constraints. The relationship between the connectivity of the UAV and their sensing ratio (sensing or communication radius/search area radius) is determined by extensive Monte Carlo simulation. A general relationship between the sensing ratio, connectivity and the number of UAVs deplo...

In a wireless LAN, even if the coverage of the access point (AP) and the mobile terminals are the same, the hidden terminal problem can not be avoided. If the AP and all the mobile terminals have the same coverage with a radius R there will always be terminals in the coverage area of the AP which are hidden to one another. This paper introduces this phenomenon, that we refer to as the natural h...