The abrupt depreciation of the zloty during the subprime crisis and fastrising prices are serious problems, because Poland, having to fulfil five Maastricht criteria, makes the dependence of her domestic inflation on price increases in the EU countries the central point of the discussion about the optimal monetary and fiscal policy rules for the next few years. The primary objective of the paper is to test out some hypotheses about the main sources of the volatility of the Polish zloty / euro exchange rate and inflation in Poland. Because several competing theoretical models describing inflationary processes are widely used, special attention is paid to their empirical verification. The working-hypotheses allowing for the country-specific features of the consumer and producer price inflation are formulated and verified in the paper.

This paper addresses the issue of obtaining maximum likelihood estimates of parameters for structural VAR models with a mixture of distributions. Hence the problem does not have a closed form solution, numerical optimization procedures need to be used. A Monte Carlo experiment is designed to compare the performance of four maximization algorithms and two estimation strategies. It is shown that the EM algorithm outperforms the general maximization algorithms such as BFGS, NEWTON and BHHH. Moreover, simplification of the problem introduced in the two steps quasi ML method does not worsen small sample properties of the estimators and therefore may be recommended in the empirical analysis.

The s-period ahead Value-at-Risk (VaR) for a portfolio of dimension n is considered and its Bayesian analysis is discussed. The VaR assessment can be based either on the n-variate predictive distribution of future returns on individual assets, or on the univariate Bayesian model for the portfolio value (or the return on portfolio). In both cases Bayesian VaR takes into account parameter uncertainty and non-linear relationship between ordinary and logarithmic returns. In the case of a large portfolio, the applicability of the n-variate approach to Bayesian VaR depends on the form of the statistical model for asset prices. We use the n-variate type I MSF-SBEKK(1,1) volatility model proposed specially to cope with large n. We compare empirical results obtained using this multivariate approach and the much simpler univariate approach based on modelling volatility of the value of a given portfolio.

In the design of asphalt mixtures for paving, the choice of components has a remarkable importance,as requirements of quality and durability must be assured in use, guaranteeing adequate standardsof safety and comfort.

In this paper, an approach of analysis on the aggregate materials using fractal geometry is proposed. Following an analytical and an experimental approach, it was possible to find a correlation betweencharacteristics of the asphalt concrete (specific gravity and porosity) and the fractal dimension ofthe aggregate mixtures.

The studies revealed that this approach allows to draw the optimal fractal dimension and, conse-quently, it can be used to choose an appropriate aggregate gradation for the specific application;once the appropriate initial physical parameters are finalized.

This fractal approach could be employed for predicting the porosity of mixed asphalt concretes,given as input the fractal characteristics of the aggregate mixtures of the concrete materials.

The selection of a contractor is one of the most important among decisions made by the ownerof a construction. The application of the prequalification procedure enables the selection of themost competent tenderers. Various mathematical models are helpful in carrying out prequalificationprocedure. In the paper, some selected mathematical models are briefly characterized and modelbased on the theory of fuzzy sets is offered. The applied model takes into consideration theowner’s various objectives, as well as different evaluation criteria. The results of the sensitivityanalysis of the model are also presented. Part of a computer software applying an earlier presentedprequalification mathematical model is described.

Th This paper presents a simple method of evaluating the load resistance and stiffness of corrugatedsheets locally loaded with suspended technical fixtures. As a part of this research, parametricnumerical analyses of corrugated sheets of different span, and with differently located concentratedforces, were carried out. Stress distributions in the individual folds in the elastic range and inthe ultimate limit state were identified. On their basis, equivalent concentrated load factors forthe individual folds in the sheet were determined. The load factors enable analyses of the loadresistance and stiffness of corrugated sheets loaded with concentrated forces, which can be helpfulin design practice.

This study deals with the behavior of composite blends constituted of rigid and impervious grainsincluded in saturated clay paste of kaolin, considered as permeable and deformable. Permeabilitytests performed during standard oedometr tests (before each load step) highlight the key role ofthe original and actual state of the clay paste, and show the existence of a threshold of sandgrain concentration above which a structuring effect influences its permeability. In the light ofthese experiments some usual homogenization methods (with simplifying assumptions to make theproblem manageable) are considered in order to model the mixture permeability. Qualitative andquantitative comparisons with experimental data point out their respective domain of interest andlimitations of such approaches.