The acoustic vector sensor (AVS) is used to measure the acoustic intensity, which gives the direction-ofarrival (DOA) of an acoustic source. However, while estimating the DOA from the measured acoustic intensity the finite microphone separation (d) in a practical AVS causes angular bias. Also, in the presence of noise there exists a trade off between the bias (strictly increasing function of d) and variance (strictly decreasing function of d) of the DOA estimate. In this paper, we propose a novel method for mitigating the angular bias caused due to finite microphone separation in an AVS. We have reduced the variance by increasing the microphone separation and then removed the bias with the proposed bias model. Our approach employs the finite element method (FEM) and curves fitting to model the angular bias in terms of microphone separations and frequency of a narrowband signal. Further, the bias correction algorithm based on the intensity spectrum has been proposed to improve the DOA estimation accuracy of a broadband signal. Simulation results demonstrate that the proposed bias correction scheme significantly reduces the angular bias and improves the root mean square angular error (RMSAE) in the presence of noise. Experiments have been performed in an acoustic full anechoic room to corroborate the effect of microphone separation on DOA estimation and the efficacy of the bias correction method.

In case of the private procurement auctions the entrepreneurs are not forced to limit themselves to the standard auction rules, and in practice one can observe many hybrid or quasi-auction mechanisms spontaneously introduced. The paper analyzes two of them, which start as a first-price sealed-bid auction, followed by a run-off in a form of an English auction, and which differ by the transparency of rules concerning the initiation of the second stage. The focus of the paper is on the analysis of the price and allocative efficiency of these mechanisms, in order to determine whether they can serve as an alternative to the standard auction rules. Theoretical analyses are followed by the laboratory experiments, which demonstrate that the mechanisms under study are characterized by both high price and allocative efficiency, and therefore could be considered an interesting substitute of the standard auction rules.

The literature on exchange rate forecasting is vast. Many researchers have tested whether implications of theoretical economic models or the use of advanced econometric techniques can help explain future movements in exchange rates. The results of the empirical studies for major world currencies show that forecasts from a naive random walk tend to be comparable or even better than forecasts from more sophisticated models. In the case of the Polish zloty, the discussion in the literature on exchange rate forecasting is scarce. This article fills this gap by testing whether non-linear time series models are able to generate forecasts for the nominal exchange rate of the Polish zloty that are more accurate than forecasts from a random walk. Our results confirm the main findings from the literature, namely that it is difficult to outperform a naive random walk in exchange rate forecasting contest.

The i 982 UN Convention on the law of the sea came into force on i 6 November i 994. international Tribunal for the Law of the Sea established on the basis of this convention. The Tribune's official languages are English and French. On 18 October 1996, the Tribunal began its activities in Hamburg. The Tribunal is made up of 21 independent judges elected for 9 years. While performing their duties, Tribunal members enjoy diplomatic immunity. The judges choose from their own number a president, Vice-president and Secretary for a term of 5 years. Beginning from the first judgement issued on 4 December 1997 relating to the "Saiga ", the Tribunal of the Law of the Sea has considered to date ten cases, most of which concerned the immediate freeing of ships and temporary funds.

In the research on historic, composed green areas various computer technologies are applied, including among others reconstruction ideograms and virtual spatial models. They are created on the basis of historical cartographic materials, among which Prussian maps Urmesstichblatts and Messtischblatts deserve special attention as they provide extraordinarily useful and often otherwise unavailable information concerning the system of spatial composition.

The article presents a method of procedure on the example of selected research objects. Such studies are extremely useful in the process of research, analyses and documentation of the authentic state of historical sites. Moreover, they provide a significant material for further analyses concerning revalorisation and creation of the cultural landscape.