We applied the concept of source-sink dynamics to investigate a recent (1999-2013) increase in the occurrence of the siphonophore Muggiaea atlantica in Scottish coastal waters. Our aim was to determine whether this change represented the establishment of resident populations (i.e. "sources"), or transient populations reliant on immigration (i.e. "sinks"). First, we show that local production wa...

In rotor walk on a finite directed graph, the exits from each vertex follow a prescribed periodic sequence. Here we consider the case of rotor walk where a particle starts from a designated source vertex and continues until it hits a designated target set, at which point the walk is restarted from the source. We show that the sequence of successively hit targets, which is easily seen to be even...

After a PV system is installed, periodic analysis is necessary to track how measured performance meets expectations. IEC 61724-3 outlines methods to quantify long term performance of PV systems. Applying these methods can be challenging due to the large quantity and possible quality control issues with measured data. In this paper, the methods outlined in IEC 617243 are applied to data collecte...

We present a finite element method for the numerical solution of diffusion problems on rough surfaces. The problem is transformed to an elliptic homogenization problem in a two dimensional parameter domain with a rapidly oscillating diffusion tensor and source term. The finite element method is based on the heterogeneous multiscale methods of E and Engquist [Commun. Math. Sci., 1 (2003), pp. 87...

We present a computational approach for the WKB approximation of the wave function of an electron moving in a periodic one-dimensional crystal lattice by means of a nonstrictly hyperbolic system whose flux function stems from the Bloch spectrum of the Schrödinger operator. This second part focuses on the handling of the source terms which originate from slowly-varying exterior potentials. Physi...

We extend the Bayesian method of Gregory and Loredo (1992) for the detection of a periodic signal of unknown shape and period, to the case where the noise sampling distribution is independent Gaussian. The analysis readily handles nonuniformily sampled data and allows for an unknown noise variance. The method is applied to the radio astronomy data for the interesting X-ray binary system LS I +6...

Introduction: Ionizing radiations are the hazardous agents in the workplace and all forms of ionizing radiation produce some type of injuries. Awareness of application of protection guidelines and knowledge of the principles of radiation protection can play an important role in health of employees. Survey of radiation employee’s levels of awareness and practical behavior is essential and ...