5 resultados para efficiency of markets
em AMS Tesi di Dottorato - Alm@DL - Università di Bologna
Resumo:
In this work we studied the efficiency of the benchmarks used in the asset management industry. In chapter 2 we analyzed the efficiency of the benchmark used for the government bond markets. We found that for the Emerging Market Bonds an equally weighted index for the country weights is probably the more suited because guarantees maximum diversification of country risk but for the Eurozone government bond market we found a GDP weighted index is better because the most important matter is to avoid a higher weight for highly indebted countries. In chapter 3 we analyzed the efficiency of a Derivatives Index to invest in the European corporate bond market instead of a Cash Index. We can state that the two indexes are similar in terms of returns, but that the Derivatives Index is less risky because it has a lower volatility, has values of skewness and kurtosis closer to those of a normal distribution and is a more liquid instrument, as the autocorrelation is not significant. In chapter 4 it is analyzed the impact of fallen angels on the corporate bond portfolios. Our analysis investigated the impact of the month-end rebalancing of the ML Emu Non Financial Corporate Index for the exit of downgraded bond (the event). We can conclude a flexible approach to the month-end rebalancing is better in order to avoid a loss of valued due to the benchmark construction rules. In chapter 5 we did a comparison between the equally weighted and capitalization weighted method for the European equity market. The benefit which results from reweighting the portfolio into equal weights can be attributed to the fact that EW portfolios implicitly follow a contrarian investment strategy, because they mechanically rebalance away from stocks that increase in price.
Resumo:
As land is developed, the impervious surfaces that are created increase the amount of runoff during rainfall events, disrupting the natural hydrologic cycle, with an increment in volume of runoff and in pollutant loadings. Pollutants deposited or derived from an activity on the land surface will likely end up in stormwater runoff in some concentration, such as nutrients, sediment, heavy metals, hydrocarbons, gasoline additives, pathogens, deicers, herbicides and pesticides. Several of these pollutants are particulate-bound, so it appears clear that sediment removal can provide significant water-quality improvements and it appears to be important the knowledge of the ability of stromwater treatment devices to retain particulate matter. For this reason three different units which remove sediments have been tested through laboratory. In particular a roadside gully pot has been tested under steady hydraulic conditions, varying the characteristics of the influent solids (diameter, particle size distribution and specific gravity). The efficiency in terms of particles retained has been evaluated as a function of influent flow rate and particles characteristics; results have been compared to efficiency evaluated applying an overflow rate model. Furthermore the role of particles settling velocity in efficiency determination has been investigated. After the experimental runs on the gully pot, a standard full-scale model of an hydrodynamic separator (HS) has been tested under unsteady influent flow rate condition, and constant solid concentration at the input. The results presented in this study illustrate that particle separation efficiency of the unit is predominately influenced by operating flow rate, which strongly affects the particles and hydraulic residence time of the system. The efficiency data have been compared to results obtained from a modified overflow rate model; moreover the residence time distribution has been experimentally determined through tracer analyses for several steady flow rates. Finally three testing experiments have been performed for two different configurations of a full-scale model of a clarifier (linear and crenulated) under unsteady influent flow rate condition, and constant solid concentration at the input. The results illustrate that particle separation efficiency of the unit is predominately influenced by the configuration of the unit itself. Turbidity measures have been used to compare turbidity with the suspended sediments concentration, in order to find a correlation between these two values, which can allow to have a measure of the sediments concentration simply installing a turbidity probe.
Resumo:
Microcredit has been a tool to alleviate poverty since long. This research is aimed to observe the efficiency of microcredit in the field of social exclusion. The development of questionnaires and use of existing tools was used to observe the tangible and intangible intertwining of microcredit and by doing so the effort was concentrated to observe whether microcredit has a direct effect on social exclusion or not. Bangladesh was chosen for the field study and 85 samples were taken for the analysis. It is a time period research and one year time was set to receive the sample and working on the statistical analysis. The tangible aspect was based on a World Bank questionnaire and the social capital questionnaire was developed through different well observed tools. The borrowers of Grameen Bank in Bangladesh, is the research sample whish shows a strong correlation between their tangible activity and social life. There are significant changes in tangible aspect and social participation observed from the research. Strong correlation between the two aspects was also found taking into account that the borrowers themselves have a vibrant social life in the village.
Resumo:
The diameters of traditional dish concentrators can reach several tens of meters, the construction of monolithic mirrors being difficult at these scales: cheap flat reflecting facets mounted on a common frame generally reproduce a paraboloidal surface. When a standard imaging mirror is coupled with a PV dense array, problems arise since the solar image focused is intrinsically circular. Moreover, the corresponding irradiance distribution is bell-shaped in contrast with the requirement of having all the cells under the same illumination. Mismatch losses occur when interconnected cells experience different conditions, in particular in series connections. In this PhD Thesis, we aim at solving these issues by a multidisciplinary approach, exploiting optical concepts and applications developed specifically for astronomical use, where the improvement of the image quality is a very important issue. The strategy we propose is to boost the spot uniformity acting uniquely on the primary reflector and avoiding the big mirrors segmentation into numerous smaller elements that need to be accurately mounted and aligned. In the proposed method, the shape of the mirrors is analytically described by the Zernike polynomials and its optimization is numerically obtained to give a non-imaging optics able to produce a quasi-square spot, spatially uniform and with prescribed concentration level. The freeform primary optics leads to a substantial gain in efficiency without secondary optics. Simple electrical schemes for the receiver are also required. The concept has been investigated theoretically modeling an example of CPV dense array application, including the development of non-optical aspects as the design of the detector and of the supporting mechanics. For the method proposed and the specific CPV system described, a patent application has been filed in Italy with the number TO2014A000016. The patent has been developed thanks to the collaboration between the University of Bologna and INAF (National Institute for Astrophysics).
Resumo:
Sweet sorghum, a C4 crop of tropical origin, is gaining momentum as a multipurpose feedstock to tackle the growing environmental, food and energy security demands. Under temperate climates sweet sorghum is considered as a potential bioethanol feedstock, however, being a relatively new crop in such areas its physiological and metabolic adaptability has to be evaluated; especially to the more frequent and severe drought spells occurring throughout the growing season and to the cold temperatures during the establishment period of the crop. The objective of this thesis was to evaluate some adaptive photosynthetic traits of sweet sorghum to drought and cold stress, both under field and controlled conditions. To meet such goal, a series of experiments were carried out. A new cold-tolerant sweet sorghum genotype was sown in rhizotrons of 1 m3 in order to evaluate its tolerance to progressive drought until plant death at young and mature stages. Young plants were able to retain high photosynthetic rate for 10 days longer than mature plants. Such response was associated to the efficient PSII down-regulation capacity mediated by light energy dissipation, closure of reaction centers (JIP-test parameters), and accumulation of glucose and sucrose. On the other hand, when sweet sorghum plants went into blooming stage, neither energy dissipation nor sugar accumulation counteracted the negative effect of drought. Two hybrids with contrastable cold tolerance, selected from an early sowing field trial were subjected to chilling temperatures under controlled growth conditions to evaluate in deep their physiological and metabolic cold adaptation mechanisms. The hybrid which poorly performed under field conditions (ICSSH31), showed earlier metabolic changes (Chl a + b, xanthophyll cycle) and greater inhibition of enzymatic activity (Rubisco and PEPcase activity) than the cold tolerant hybrid (Bulldozer). Important insights on the potential adaptability of sweet sorghum to temperate climates are given.