La simulation numérique de la propagation des ondes électromagnétiques sur de longues distances et au-dessus de terrain a ces dernières années reçu une attention particulière du fait de son fort impact sur les systèmes radar et de télécommunications. Habituellement, il est considéré une modélisation bidimensionnelle pour traiter ces problématiques, cependant par une telle approche il est impossible de considérer les effets transverses au plan vertical passant par l'émetteur et le récepteur ainsi que la dépolarisation de l'onde. Pour pallier ces problèmes, une approche tridimensionnelle doit obligatoirement être considérée.<br /><br />La méthode de modélisation proposée est basée sur l'Equation Parabolique 3D (EP3D). Deux résolutions de celle-ci ont été considérées : nommées Split-Step Fourier (SSF) et Différences Finies (DF). La résolution SSF est basée sur une décomposition en un spectre angulaire d'ondes planes par l'intermédiaire d'une transformée de Fourier. La résolution de l'EP3D par DF développée utilise quant à elle un algorithme dit de Crank-Nicholson. Afin d'optimiser le temps de calcul et l'espace mémoire nécessaire, la méthode des directions alternées a été appliquée pour résoudre cette équation de propagation. Toutes deux ont été couplées avec la condition aux limites de Léontovich pour pouvoir prendre en compte le relief 3D.<br /><br />Ces deux méthodes ont été implémentées et validées sur différents cas tests canoniques. On a ainsi pu constater la capacité de ces méthodes à modéliser les phénomènes de réflexion, diffraction et réfraction. Celles-ci ont ensuite été appliquées au-dessus de scènes tridimensionnelles réalistes. Ces applications ont permis de comparer les deux méthodes développées ainsi que de mettre en relief les effets 3D dus au terrain et souligné les avantages d'une résolution tridimensionnelle.

A two-dimensional isotropic metamaterials formed by crossed split-ring resonators (CSRRs) are studied in this paper. The effective characteristic parameters of this media are determined by quasi-static Lorentz theory. The induced current distributions of a single CSRR at the resonant frequency are presented. Moreover, the dependence of the resonant frequency on the dimensions of single CSRR and the spaces of the array are also discussed. / Singapore-MIT Alliance (SMA)

<p>The shareholder is supposed to be indifferent if one share costs 100 SEK, or 10 shares cost 10 SEK each. In an efficient market, shares should be valued directly to new expectations as a result of the announcement of the reverse split. We investigate whether abnormal returns incur surrounding reverse split and if owner structure change.</p><p>One reason for the reverse share split is that most companies have plans to imple-ment other company’s specific events in order to survive rather than to change the price range to a more attractive level. We found a negative return in the ex-day at 8,1 per cent. When the ex-day is pure enough from other price driving information should the outcome be a reaction to how the market perceives changes in future divi-dends after the reverse split. In consideration of stock ownership of votes accounted for a reduction of individual owners, and increasing institutional owners, more in companies with low Market to Book. This may suggest that the institutional share-holders have increased their share of votes to increase their power in the companies.</p>

The study of optical phenomena related to the strong electromagnetic response of noble metals (silver (Ag) and gold (Au) being most popular) over the last couple of decades has led to the emergence of a fast growing research area called plasmonics named after 'surface plasmons' which are electron density waves that propagate along the interface of a metal and a dielectric medium. Surface plasmons are formed by the coupling of light to the electrons on the metal surface subject to the fulfillment of certain physical conditions and they are bound to the metal surface. Depending on whether the metallic medium is a continuous film or a structure having dimensions less than or comparable to the wavelength of the exciting light, propagating or localized surface plasmons can be excited. The structure can be either a hole or an arbitrary pattern in a metal film, or a metallic particle. An array of subwavelength structures can behave as an effective homogeneous medium to incident light and this is the basis of a new class of media known as metamaterials. Metallic metamaterials enable one to engineer the electromagnetic response to  incident light and provide unconventional optical properties like negative refractive index as one prominent example. Metamaterials exhibiting negative index (also called negative index materials (NIMs)) open the door for super resolution imaging  and development of invisibility cloaks. However, the only problem affecting the utilization of plasmonic media to their fullest potential is the intrinsic loss of the metal, and it becomes a major issue especially at visible-near infrared (NIR) frequencies. The frequency of the surface plasmon is the same as that of the exciting light but its wavelength could be as short as that of X-rays. This property allows light of a given optical frequency to be conned into very small volumes via subwave lengthmetallic structures, that can be used to develop ecient sensors, solar cells, antennas and ultrasensitive molecular detectors to name a few applications. Also, interaction of surface plasmons excited in two or more metallic subwavelength structures in close proximity inuences the far-eld optical properties of the overall coupled system. Some eects of plasmonic interaction in certain coupled particles include polarization conversion, optical activity and transmission spectra mimicking electromagnetically-induced transparency (EIT) as observed in gas based atomicsy stems. In this thesis, we mainly focus on the optical properties of square arrays of certain plasmonic structures popularly researched in the last decade. The structures considered are as follows: (1) subwavelength holes of a composite hole-shape providing superior near-eld enhancement such as two intersecting circles (called' double hole') in an optically thick Au/Ag lm, (2) double layer shnets, (3) subwavelength U-shaped particles and (4) rectangular bars. The entire work is based on electromagnetic simulations using time and frequency domain methods. Au/Ag lms with periodic subwavelength holes provide extraordinarily high transmission of light at certain wavelengths much larger than the dimension of the perforations or holes. The spectral positions of the maxima depend on the shape of the hole and the intra-hole medium, thereby making such lms function as a refractive index sensor in the transmission mode. The sensing performance of the double-hole geometry is analyzed in detail and compared to rectangular holes. Fishnet metamaterials are highly preferred when it comes to constructing a NIM at optical frequencies. A shnet design that theoretically oers a negative refractive index with least losses at telecommunication wavelengths (1.4 1.5 microns) is presented. U-shaped subwavelength metallic particles, in particular single-slit split-ring resonators (SSRRs), provide a large negative response to the magnetic eld of light at a specic resonance frequency. The spectral positions of the structural resonances of the U-shaped particle can be found from its array far field transmission spectrum at normal incidence. An effort is made to clarify our understanding of these resonances with the help of localized surface plasmon modes excited in the overall particle. From an application point of view, it is found that a planar square array of SSRRs eectively functions as an optical half-wave waveplate at the main resonance frequency by creating a polarization in transmission that is orthogonal to that of incident light. A similar waveplate eect can be obtained purely by exploiting the near-eld interaction of dierently oriented neighbouring SSRRs. The physical reasons behind polarization conversion in dierent SSRR-array systems are discussed. A rectangular metallic bar having its dipolar resonance in the visible-NIR is called a nanoantenna, owing to its physical length in the order of nanometers. The excitation of localized surface plasmons, metal dispersion and the geometry of the rectangular nanoantenna make an analytical estimation of the physical length of the antenna from the desired dipolar resonance dicult. A practical map of simulated resonance values corresponding to a variation in geometrical parameters of Au bar is presented. A square array of a coupled plasmonic system comprising of three nanoantennas provides a net transmission response that mimicks the EIT effect. The high transmission spectral window possesses a peculiar dispersion profile that enables light with frequencies in that region to be slowed down. Two popular designs of such plasmonic EIT systems are numerically characterized and compared. / <p>QC 20121017</p>

Den här uppsatsen behandlar företag som är listade på Stockholmsbörsen som gjorde omvänd split mellan 1995 och 2004. Företagen är testade för abnormal avkastning kring tillkännagivandet av den omvända spliten, samt förändringar i köp-sälj ratio, handels volym och antalet handelsdagar där ingen handel skedde i aktien. Inga abnormala avkastningar eller signifikanta förändringar i köp-sälj ration eller handelsvolymen kunde hittas. Däremot så visar förändringen i antalet handelsdagar utan handel i aktien en försämring och antalet handelsdagar minskade i de aktier som genomgått en omvänd split. Detta medför att likviditeten minskade för de företag som genomförde en omvänd split. / This paper addresses reverse splits for firms trading on the Stockholm stock exchange between 1995 and 2004. The related sample are tested for abnormal returns surrounding the announcement day of the reverse split, as well as any changes in bid-ask spread, trading volume and the number of non-trading days. No findings of abnormal returns or significant changes in either bid-ask spread or trading volume could be found, while the number of non-trading days for the whole sample increased. This may suggest that the marketability decreased for the reverse splitting firms.

In this thesis, the effects of split canard on the aerodynamic characteristics of missiles at high angles of attack are numerically investigated. Moreover, an enhanced semi-empirical engineering-level method is developed for prediction of normal force and pitching moment of split canard mounted missiles. In order to analyze the effects of split canard, a generic test case model is created by mounting a split canard to a generic test case model, NASA Dual Control Missile (NDCM), which was previously modeled and analyzed for the validation of CFD modeling. After obtaining a generic missile model with split canard, the effects of split canard on the aerodynamic characteristics of this missile in case of no control, pitch control, yaw control, and roll control deflections are numerically investigated. It is seen that the split canard decreases the local angle of attack of existing canard, increases the normal force and the maneuverability of the missile, and reduces the induced rolling moment at high angles of attack. Five different aerodynamic design parameters are determined for split canard and the effects of each parameter on missile aerodynamics are numerically investigated. It is seen that the roll orientation, deflection angle, size of the split canards have strong effects on missile&rsquo / s aerodynamic performance whereas longitudinal position of the split canards only affects the pitching moment of the missile. Finally, an enhanced semi-empirical engineering-level method, CFD-CBU, is developed for split canard mounted missiles in order to predict the normal force and the pitching moment coefficients. The developed method is validated with NDCM test case model. After this validation, the method is applied to the split canard mounted generic missile in case of no control deflection and pitch control deflection. The results of this method are compared with CFD results and it is seen that the results are in good agreement with each other.

The purpose of this master’s thesis is to explain and analyze whether today’s existing regulations provide sufficient guidance on how to apply the Profit Split Method (PSM) in practice. Since the enterprises’ profits arising from intra-group transactions increases, the tax base for any government also becomes larger and more important. This issue will likely become even more problematic as the globalization branches out and the majority of the global trade is undertaken between associated enterprises. In order to satisfy all parts and serve the dual objective of securing an appropriate tax base in each jurisdiction and avoiding double taxation, one ambition of the OECD is to harmonize the transfer pricing rules and make them become more uniform. An area in which this goal can be accomplish is at an international level such as the OECD; an important developer in the field of transfer pricing. Different transfer pricing methods has been developed which can be applied by both taxpayers and tax authorities to determine a correct transfer price. Six of these methods has gained international acceptance, although to a more or less extent among various countries, and one of these methods is the PSM. In the years between 1979 and 1995, the OECD had a reluctant standpoint of accepting the application of any transfer pricing method based on profits, such as the PSM. This hesitant viewpoint changed in the existing TPG which explicitly stipulates that the PSM could provide a transfer pricing estimation in accordance with the ALP, which should be accepted in exceptional cases. There are certain situations where a PSM possibly will provide the most appropriate arm’s length result. Since the principle of economics can create complex business environments of both vertical and horizontal integration, contributions of valuable intangibles on both sides of the cross-border transaction, the PSM might be the only method which can be employed. A relevant issue which need to be enlightened is whether the existing guidance provided by the OECD and USA is sufficient from a practitioners and tax administration point of view, or is more guidance needed to better understand the issues surrounding the concept of the PSM. The fact that OECD insist of using comparables to the highest extent as possible when employing the PSM entails practical problems, since it is rather a rule than an exception that reliable comparables cannot be found when valuable intangibles are involved. The Arthur of this master’s thesis has identified three key conclusions which might facilitate how PSM issues can be handled in the future and improve the existing PSM guidance. These conclusions are the need for a uniform PSM interpretation, the need for additional flexibility and acceptance, and the need for additional TPG guidance.

The thesis aims to understand how learning processes are affected when an organization split into two separate organizations. The study is designed as a single case, covering a new government agency’s takeover of a core activity from another agency and the use of a purchase-provider split between the agencies, providing the new agency with IT-services. The findings revealed a difference in productive system and knowledge types between core- and IT-activities. The core activity was found to be dominated by explicit knowledge while the IT-activity seemed to be dominated by a mix of explicit and tacit knowledge. In order to bridge the gap between these two contexts needs, the organization of service management played a crucial part in boosting knowledge sharing and organizational learning within and between the two agencies, using a middle-up-down management style. Furthermore, the learning environment for managers in the core activities became restricted, using instrumental management strategies and focusing mainly on explicit knowledge, resulting in a lack of trust towards the providing agency.  However, the skill to perform on the operational level was maintained due to preserved relationships. Finally, the competence to order software requirement was found to be a collective competence evolving in the interaction between users and software developers. In order to be successful, a purchase-provider split needs to consider learning processes to a larger extent and the fact that requirement competence is a shared knowledge between purchaser and provider. Moreover, to make a purchaser-provider split successful over long term, new management strategies seem to be required based, on communicative rationality and not merely strategic rationality.

This study combines Optical Plankton Counter data on zooplankton abundance and Acoustic Doppler Current Profiler data on water currents to test hypotheses about spatial zooplankton distributions near a major point of land affecting local wind and water current patterns. Data were collected by repeatedly sampling a 2 km linear transect in the South Arm of Lake Opeongo, Ontario, Canada during July, 2008. Moving Split Window techniques were used to identify breakpoints in both zooplankton biomass concentration and a measure of water turbulence, and confirmed an effect of the topographic feature on local zooplankton distributions. Using additional data collected in 2001 and 2003, zooplankton abundance distributions were also tested under three wind speed ranges predicted from physical principles to correspond to varying stability of the water column. Significant differences were found in the variability and patch sizes of the distributions, indicating the importance of wind speeds on zooplankton patchiness.

This study combines Optical Plankton Counter data on zooplankton abundance and Acoustic Doppler Current Profiler data on water currents to test hypotheses about spatial zooplankton distributions near a major point of land affecting local wind and water current patterns. Data were collected by repeatedly sampling a 2 km linear transect in the South Arm of Lake Opeongo, Ontario, Canada during July, 2008. Moving Split Window techniques were used to identify breakpoints in both zooplankton biomass concentration and a measure of water turbulence, and confirmed an effect of the topographic feature on local zooplankton distributions. Using additional data collected in 2001 and 2003, zooplankton abundance distributions were also tested under three wind speed ranges predicted from physical principles to correspond to varying stability of the water column. Significant differences were found in the variability and patch sizes of the distributions, indicating the importance of wind speeds on zooplankton patchiness.