Based on the combined surface and volume RWG (Rao-Wilton-Glisson) basis functions, a simulator of a patch antenna on a finite dielectric substrate using the Method of Moments (MoM) has been implemented in Matlab. The metal surface is divided into planar triangular elements whereas the (inhomogeneous) dielectric volume is divided into tetrahedral elements. The structure under study is comprised of a typical patch antenna consisting of a single patch above a finite ground plane, and a probe feed. The performance of the solver is studied for different mesh configurations. The results obtained are tested by comparison with the commercial ANSOFT HFSS v8.5 and WIPL-D simulators. The former uses a large number of finite elements (up to 30,000) and adaptive mesh refinement, thus providing the reliable data for comparison. Behavior of the most sensitive characteristic ¡V antenna input impedance ¡V is tested, close to the first resonant frequency. The error in the resonant frequency is estimated at different values of the relative dielectric constant ƒÕr, which ranges from 1 to 20. The reported results show reasonable agreement. However, the solver needs to be further improved.

Power-poles are one of the common massive conducting structures in cities and countryside. To fulfill the remarkable increased electric power demand nowadays, the number and the size of power-poles are also growing over the past few decades.  The influence of power-pole on electromagnetic  wave  propagation  is  a  potential  noise  source  for  nearby  radio  devices  like radars.   This master thesis project is aiming to analysis the interference of a case where an Amplitude Modulated (AM) signal emitted. We consider here the Stockholm Arlanda Airport’s Very High Frequency (VHF) Omnidirectional Range (VOR) radar scattering by a power-pole 2.6km away.A Method of Moment technique is used to solve the scattering problem.  We modeled the power-pole on a blueprint from Svenska Kraftnät. It is meshed in small triangles by AutoCAD and  GMSH  software,  and  on  that  mesh  the  Rao-Wilton-Glisson  (RWG)  basis  function  are formed.  A MoM code developed by Makarov determines the bi-static scattering pattern of the power-pole.  Four main models have been considered, a one-side power-pole model and the same model with the ground plane, as well as two sides power-pole model and the model with the ground plane.  We have assumed that the incident field on the power-pole is a plane wave and that the ground is an infinite PEC surface.  The result is presented by the Interference to Signal ratio (ISR) of an airplane receiver when it is flying toward the airport for landing.By the end of the project, we have shown for the considered model that a    50    15dB level of interference is estimated for the interference to signal ratio.  This result then suggests that a power-pole may have a little signal interference towards the VOR system radar wave emit awayfrom 2.6km. / Kraftstolpar är vanligt förekommande stora ledande strukturerna i stadsnära regioner.  Städer och regioner uppvisar idag en kraftigt ökad efterfrågan på elektricitet, vilket ställer krav på ett kraftnät som klarar av större effekt. Ett sätt att öka effekten är att introducera fler kraftledningar, och där med också öka antalet kraftledningsstolpar.  Kraftledningsstolparna kan påverka den elektromagnetiska vågutbredning och är en potentiell bruskälla för närliggande radioenheter som t.ex.  radar/signal-anläggningar.  Detta examensarbete syftar till att analysera eventuella störningar vid användandet av en amplitudmodulerad (AM) signal. Vi betraktar här Stockholm Arlanda Airport’s Very High Frequency (VHF) Omnidirectional Range (VOR) radarspridning med en kraftstolpe 2,6 km bort.I detta fall används Method of Moment (MoM)-tekniken för att lösa spridningsproblemet. Vi modellerade kraftstolpen baserad på data från Svenska Kraftnät.  Stolpen modelleras med små  sammankopplade  trianglar  med  hjälp  av  programvaran  AutoCAD  och  GMSH,  och  på det nätverket bildas Rao-Wilton-Glisson (RWG) -basisfunktionen.  En MoM-kod utvecklad av Makarov bestämmer det bi-statiska spridningsmönstret för kraftstolpen.  Fyra huvudmodeller har beaktats, en en-sidig modell av en kraftstolpe med och utan jordplan, liksom en två-sidig modell med och utan jordplan. Vi har antagit att det mot kraftstoplen infallande fältet är en plan våg och att marken är en oändlig prefekt ledande-yta. Resultatet presenteras som en kvot mellan störning i förhållande till signalen (ISR) hos en flygmottagare när den flyger mot flygplatsen för landning.Beräkningarna i projektet visar att för de betraktade modellerna har vi en ISR på -50±15dB. Detta resultat antyder att en kraftstolpe på ett avstånd 2,6 km från VOR-systemet har en lågstörning på VOR-systemets amplitudmodulerade signal.

Previous research has indicated that aggression is generally detrimental to performance in the occupational domain (Campbell, 1990; James et al., 2005; Sackett, 2002; Viswesvaran et al., 1999). In certain athletic contexts, however, aggression may serve to enhance performance at the team level. For this analysis, team-level aggression is hypothesized to be positively related to team performance in basketball. Aggression in this context is defined as "the desire to inflict harm on another individual, group, or entity" (James, 2005, p.71). Both implicit (CRT-A) and explicit (NEO-PI-R) aggression were measured, and team performance was represented primarily by team scores. The data demonstrate that team-level implicit aggression is significantly and positively related to team performance, however team-level explicit aggression does not have a significant relationship with team performance.

Humanitarian clearance of minefields is most often carried out by hand, conventionally using a a metal detector and a probe. Detection is a very slow process, as every piece of detected metal must treated as if it were a landmine and carefully probed and excavated, while many of them are not. The process can be safely sped up by use of Ground-Penetrating Radar (GPR) to image the subsurface, to verify metal detection results and safely ignore any objects which could not possibly be a landmine. In this thesis, we explore the possibility of using Full Wave Inversion (FWI) to improve GPR imaging for landmine detection. Posing the imaging task as FWI means solving the large-scale, non-linear and ill-posed optimisation problem of determining the physical parameters of the subsurface (such as electrical permittivity) which would best reproduce the data. This thesis begins by giving an overview of all the mathematical and implementational aspects of FWI, so as to provide an informative text for both mathematicians (perhaps already familiar with other inverse problems) wanting to contribute to the mine detection problem, as well as a wider engineering audience (perhaps already working on GPR or mine detection) interested in the mathematical study of inverse problems and FWI.We present the first numerical 3D FWI results for GPR, and consider only surface measurements from small-scale arrays as these are suitable for our application. The FWI problem requires an accurate forward model to simulate GPR data, for which we use a hybrid finite-element boundary-integral solver utilising first order curl-conforming N\'d\'{e}lec (edge) elements. We present a novel `line search' type algorithm which prioritises inversion of some target parameters in a region of interest (ROI), with the update outside of the area defined implicitly as a function of the target parameters. This is particularly applicable to the mine detection problem, in which we wish to know more about some detected metallic objects, but are not interested in the surrounding medium. We may need to resolve the surrounding area though, in order to account for the target being obscured and multiple scattering in a highly cluttered subsurface. We focus particularly on spatial sensitivity of the inverse problem, using both a singular value decomposition to analyse the Jacobian matrix, as well as an asymptotic expansion involving polarization tensors describing the perturbation of electric field due to small objects. The latter allows us to extend the current theory of sensitivity in for acoustic FWI, based on the Born approximation, to better understand how polarization plays a role in the 3D electromagnetic inverse problem. Based on this asymptotic approximation, we derive a novel approximation to the diagonals of the Hessian matrix which can be used to pre-condition the GPR FWI problem.