49 resultados para permanent income inequality
Resumo:
Over time the demand for quantitative portfolio management has increased among financial institutions but there is still a lack of practical tools. In 2008 EDHEC Risk and Asset Management Research Centre conducted a survey of European investment practices. It revealed that the majority of asset or fund management companies, pension funds and institutional investors do not use more sophisticated models to compensate the flaws of the Markowitz mean-variance portfolio optimization. Furthermore, tactical asset allocation managers employ a variety of methods to estimate return and risk of assets, but also need sophisticated portfolio management models to outperform their benchmarks. Recent development in portfolio management suggests that new innovations are slowly gaining ground, but still need to be studied carefully. This thesis tries to provide a practical tactical asset allocation (TAA) application to the Black–Litterman (B–L) approach and unbiased evaluation of B–L models’ qualities. Mean-variance framework, issues related to asset allocation decisions and return forecasting are examined carefully to uncover issues effecting active portfolio management. European fixed income data is employed in an empirical study that tries to reveal whether a B–L model based TAA portfolio is able outperform its strategic benchmark. The tactical asset allocation utilizes Vector Autoregressive (VAR) model to create return forecasts from lagged values of asset classes as well as economic variables. Sample data (31.12.1999–31.12.2012) is divided into two. In-sample data is used for calibrating a strategic portfolio and the out-of-sample period is for testing the tactical portfolio against the strategic benchmark. Results show that B–L model based tactical asset allocation outperforms the benchmark portfolio in terms of risk-adjusted return and mean excess return. The VAR-model is able to pick up the change in investor sentiment and the B–L model adjusts portfolio weights in a controlled manner. TAA portfolio shows promise especially in moderately shifting allocation to more risky assets while market is turning bullish, but without overweighting investments with high beta. Based on findings in thesis, Black–Litterman model offers a good platform for active asset managers to quantify their views on investments and implement their strategies. B–L model shows potential and offers interesting research avenues. However, success of tactical asset allocation is still highly dependent on the quality of input estimates.
Resumo:
Axial-flux machines tend to have cooling difficulties since it is difficult to arrange continuous heat path between the stator stack and the frame. One important reason for this is that no shrink fitting of the stator is possible in an axial-flux machine. Using of liquid-cooled end shields does not alone solve this issue. Cooling of the rotor and the end windings may also be difficult at least in case of two-stator-single-rotor construction where air circulation in the rotor and in the end-winding areas may be difficult to arrange. If the rotor has significant losses air circulation via the rotor and behind the stator yokes should be arranged which, again, weakens the stator cooling. In this paper we study a novel way of using copper bars as extra heat transfer paths between the stator teeth and liquid cooling pools in the end shields. After this the end windings still suffer of low thermal conductivity and means for improving this by high-heat-conductance material was also studied. The design principle of each cooling system is presented in details. Thermal models based on Computational Fluid Dynamics (CFD) are used to analyse the temperature distribution in the machine. Measurement results are provided from different versions of the machine. The results show that significant improvements in the cooling can be gained by these steps.
Resumo:
The standard squirrel-cage induction machine has nearly reached its maximum efficiency. In order to further increase the energy efficiency of electrical machines, the use of permanent magnets in combination with the robust design and the line start capability of the induction machine is extensively investigated. Many experimental designs have been suggested in literature, but recently, these line-start permanent-magnet machines (LSPMMs) have become off-the-shelf products available in a power range up to 7.5 kW. The permanent magnet flux density is a function of the operating temperature. Consequently, the temperature will affect almost every electrical quantity of the machine, including current, torque, and efficiency. In this paper, the efficiency of an off-the-shelf 4-kW three-phase LSPMM is evaluated as a function of the temperature by both finite-element modeling and by practical measurements. In order to obtain stator, rotor, and permanent magnet temperatures, lumped thermal modeling is used.
Resumo:
Tässä tutkielmassa tarkastellaan kansainvälisessä yritystoiminnassa esiintyviä juridisen kaksinkertaisen verotuksen ongelmatilanteita suomalaisten yritysten näkökulmasta. Tutkielmassa pohditaan lisäksi yritysten omaa roolia osana kaksinkertaisen verotuksen tilanteita. Juridista kaksinkertaista verotusta muodostuu, kun sama yhtiö maksaa samasta tulosta veroa kahteen valtioon. Teoriaosio etenee verotusoikeuden määrittämisestä kaksinkertaisen verotuksen muodostumiseen. Kaksinkertainen verotus pyritään poistamaan poistomenetelmällä, joka on Suomessa tavallisesti hyvitysmenetelmä. Ongelmatilanne muodostuu, kun kaksinkertaista verotusta ei saada tehokkaasti poistettua tulon lähdevaltion ja yhtiön asuinvaltion välillä. Tämä tutkielma on laadullinen tutkimus ja tutkimusmenetelmänä on käytetty teemahaastattelua. Tutkimustulokset osoittavat, että kvalifikaatiokonflikteissa juridisen kaksinkertaisen verotuksen ongelmatilanne esiintyy pääsääntöisesti rojalti-liiketulo -luokitteluristiriidan seurauksena. Kiinteän toimipaikan kvalifikaatio on harvinaisempi ongelmatilanne. Hyvitysmenetelmän suurimmat ongelmat esiintyvät puolestaan pääliikkeen tappiollisen liiketoiminnan johdosta. Toinen hyvitysmenetelmän ongelmakohta esiintyy, kun lähdeveron alainen tulo huomioidaan bruttotulosta, mutta ulkomaisen tulon hyvitys suoritetaan nettotulosta. Haastatteluiden perusteella on selvää, että yritysten oma rooli kaksinkertaisen verotuksen ehkäisyssä on merkittävä. Yrityksen omia vaikutusmahdollisuuksia ovat muun muassa riittävä ennakointikyky, dokumentointi, selkeät sopimukset ja asiantuntijuus.