Klaipėdos universitetas

This paper addresses the issue of finding the most efficient estimator of the normal population mean when the population “Coefficient of Variation (C. V.)” is ‘Rather-Very-Large’ though unknown, using a small sample (sample-size ≤ 30). The paper proposes an “Efficient Iterative Estimation Algorithm exploiting sample “C. V.” for an efficient Normal Mean estimation”. The MSEs of the estimators per this strategy have very intricate algebraic expression depending on the unknown values of population parameters, and hence are not amenable to an analytical study determining the extent of gain in their relative efficiencies with respect to the Usual Unbiased Estimator X ̅(sample mean ~ Say ‘UUE’). Nevertheless, we examine these relative efficiencies of our estimators with respect to the Usual Unbiased Estimator, by means of an illustrative simulation empirical study. MATLAB 7.7.0.471 (R2008b) is used in programming this illustrative ‘Simulated Empirical Numerical Study’.

Ships are no Flying Dutchmen! They need a harbour. Therefore, the development of ship construction is pretty much connected with that of harbour construction, and beyond this, they influence the topography and infrastructure of a harbour. The transition between the Medieval period and the Early Modern Age is a period of great change in the development of larger ships, even in the Baltic. Furthermore, the internationalisation of Baltic trade took place. In Medieval times, ship construction followed conditions in the harbours. In the Early Modern Age, it was the other way round. Now, harbour construction, topography and infrastructure follow the development of ship construction. The paper focuses on the deep impact that larger multi-mast sailing ships had on the development of Baltic harbours.

The remains of a Medieval harbour were discovered in Puck in 1977. Preliminary research was conducted the next year by Wiesław Stępień. The site consists of a set of timber construction remains, located on the ground and strengthened with fascine, between which fragments of ceramics appear, especially in the area of the base of the pier. There are also a lot of pieces of simply processed trunks and branches stripped of bark nearby. Also, some scattered pieces of oak logs with yoke openings have been found lying distributed between the piles. Some help in attempting to reconstruct their arrangement comes from the mooring piles, which have a characteristic rectangular cross-section, and are still located on the sea bed. Pieces of five wrecks (one log boat, and four made from planks) have been found between the harbour constructions. Looking at the chronological arrangement of the site, created slowly on the basis of results obtained from dendrochronological analysis, and supplemented with radiological research, we can assume that the harbour was in use between the tenth and the 14th centuries.