Extremal problems for multiple time delay hyperbolic systems are presented. The optimal boundary control problems for hyperbolic systems in which multiple time delays appear both in the state equations and in theNeumann boundary conditions are solved. The time horizon is fixed. Making use of Dubovicki-Milutin scheme, necessary and sufficient conditions of optimality for the Neumann problem with the quadratic performance functionals and constrained control are derived.

Fluid motions are responsible for most of the transport and mixing that take place in the environment, in industrial processes and vehicles, and within living organisms.

Shifting living conditions, environmental change, and population migrations are all necessitating changes in how we manage the space in which we live. Does our living have a future?

Analytic philosophy is sometimes understood in opposition to continental tradition. In this article, I would like to show that a Lviv‑Warsaw School shared many fundamental traits with analytic orientation. In afterwar Poland, this tradition clashed with the dialectical materialism that lacks strong scientific tradition but had the full support of the communist party. This situation produced a unique scenario in which the methodology of science could strive as a mainstream area. A crucial role was attributed to the theory of history.

We investigated sediments of three Sphagnum peatland-lake ecosystems located in Tuchola forest, both in moraine (Małe Leniwe near Rekowo) and outwash plain (Dury and Rybie Oko) landscape. Geological cross-sections were studied for each basin. Characteristic feature of these ecosystems is the presence of floating mats encroaching the lakes and deposition of highly hydrated sediments below the floating mat. Principal conditions favouring the development of peatland-lake ecosystems are (1) location of the lake in a sandy, non-calcareous catchment overgrown by coniferous forest, (2) steep ness of the lake basin, what prevents emerged macrophytes succession and (3) the depth of the basin significantly exceeding 10 m to avoid complete in filling of the lake basin. The developmental pathway in the Dury I basin indicates a shift in lake environment from neutral to acid one. After initial development of Charophytes, Potamogeton and Najas expanded, which later on, were succeeded by Sphagnum due to acidification of the lake water. Initial stages of the development of the lakes were determined mainly by allogenic factors, whereas in later stages autogenic factors (development of floating mat and peat acidifying the lake water) played fundamental role.

The Reserve Dury, Tuchola Pinewoods, Poland, includes five depressions with no outflow filled up with biogenie sediments. They undergo terrestrialization processes to a high degree. In four of the basins there are still some open water areas surrounded by floating mire with raised and transitional bog plants. For the needs of protection service officers some palynological and geological research were carried out. All the geological cores were described in detail following the Troels-Smith system. The deepest core Dury I was selected for pollen analysis. Ten Local Pollen Assemblage Zones (L PAZ) show the history ofregional and local plant communities. On the basis of two air photographs, modem dynamics of floating mire in four basins were evaluated. The results allow us to correlate the geological layers, to describe the Late Glacial and Holocene succession of plant cover at Dury I site, and to show the stages of filling-in of basins with lacustrine sediments and peat.

Abstract Various optimization problems for linear parabolic systems with multiple constant time lags are considered. In this paper, we consider an optimal distributed control problem for a linear complex parabolic system in which different multiple constant time lags appear both in the state equation and in the Neumann boundary condition. Sufficient conditions for the existence of a unique solution of the parabolic time lag equation with the Neumann boundary condition are proved. The time horizon T is fixed. Making use of the Lions scheme [13], necessary and sufficient conditions of optimality for the Neumann problem with the quadratic performance functional with pointwise observation of the state and constrained control are derived. The example of application is also provided.

Abstract Various optimization problems for linear parabolic systems with multiple constant time delays are considered. In this paper, we consider an optimal distributed control problem for a linear parabolic system in which multiple constant time delays appear in the Neumann boundary condition. Sufficient conditions for the existence of a unique solution of the parabolic equation with the Neumann boundary condition involving multiple time delays are proved. The time horizon T is fixed. Making use of the Lions scheme [13], necessary and sufficient conditions of optimality for the Neumann problem with the quadratic cost function with pointwise observation of the state and constrained control are derived.

Intensywność zakwitów glonów w Bałtyku wzrasta. Choć słowo ,,zakwit" kojarzy się z czymś pięknym, zjawisko nie należy do przyjemnych. Panuje powszechne przekonanie, że winien temu jest człowiek, lecz to chyba nie jest cała prawda.

An increase of water retention in the programmes of small retention in the country to the year 2015 is estimated at 1141 million m3. It means annual mean increase of retention capacity by c. 60 million m3. Accomplishment of relevant actions in the years 1997–2007 allowed collecting 57 million m3 in lakes, c. 56 million m3 in artificial reservoirs, 18.5 million m3 in fishponds, c. 10.5 million m3 with the channel retention and over 2 million m3 in other investments. It makes total increase of water retention by 142 million m3 which is 12.4% of target retention and the mean annual increment of c. 13 million m3. The paper presents volumes of retained water, sources and structure of financing, mean unit costs of retention increments and the increase of retention capacity in particular voivodships (acc. to new administration division) in the years 1998–2007.

Białowieża in Poland is a very famous region in Europe (because of its primeval forest and bison population), but its environmental history is poorly known. This article shows the results of palynological analysis, macrofossil analysis and geological settings of two mires in the Białowieża Forest. The pollen diagrams show changes of the vegetation cover from the younger part of the Late Glacial until the present time. The relative time scale is based on palynostratigraphy and comparison to published results of other sites from the adjacent regions. During the Late Glacial two stages of the vegetation succession were revealed: steppe and forest during the Alleröd period and tundra-like vegetation during the Younger Dryas. The Holocene history consists of five stages of plant cover development. The special features of the Białowieża Forest are conditioned by two main factors: low degree of anthropogenic impact and influences of continental climate and boreal zone, stronger than in the other regions of Poland.

A sea floor investigation was performed in the fiord of Hornsund by means of the seismoacoustic profiling, echosounding and core sampling. The main seismoacoustic sea floor units were recognized (the methods used according to Kowalewski et al. 1987a) and characterized on the basis of their relations to geomorphology and geological evolution. The bathymetrical sketch and the resulting geomorphological description of the bottom were prepared. The surface of the sea bottom and the surface of the bedrock displayed an irregular high relief with large sills dividing the fiord sea floor into several basins. Four main types of the sills were distinguished: burried sills, accumulative sills, rock sills and rock-accumulative sills. Within the internal Basins I and II there were thick (up to 170 m) covers of the glaciomarine ice-front deposit with changing thin ( 1 -5 m) blanket of the glaciomarine muds at the bottom surface. The Basin III had a cover of the glacial and glaciomarine deposits of variable lithology, genesis and age. The most external Basin IV had a cover o f glaciomarine muds up to 4 0 - 5 0 m thick, deposited on the tills. Four main glacial episodes were recognized, most probably referring to the stadials of Lisbetdalen, Slaklidalen, Revdalen and to the Little Ice Age.

The results of the detailed seismoacoustic profilling (CSP, boomar) are presented. The investigation has been carried out in February 1985 and 1988 during two Geodynamical Expeditions organized by the Institute of Geophysics of the Polish Academy of Sciences. The boomar penetration of the caldera floor went down to 150 msec. Four seismoacoustic units of volcanic formations have been determined. The unit A corresponds to pre-caldera series and occurred only in the border part of the flooded caldera. The unit contains mainly pyroclastic rocks (consolidated agglomerates and tuffs) and probably some intercalations of lavas. The units B, C and D fill up the caldera bottom and correspond to post-caldera series. The units are composed of pyroclastic rocks, containing also materials redeposited by lahars, glaciers, landwaters and by wind. The units C and D (the youngest one) were certainly deposited under water. All the units are cut by numerous faults, vents and other types of intrusions. The larger faults, en echelon type, are situated around the bottom and form a ring-fracture. Caldera was formed by succesive stages of collapsing. This process is not finished yet and volcanic activity is still alive (especially in the western part of the flooded caldera).

On the ground of results obtained by the seismoacoustic profiling carried out in 1985 and primary examination of core samples the following main seismoacoustic units are distinguished and characterized: unit A — bedrock, unit B — till and/or compacted glaciomarine deposit, unit C — glaciomarine ice-front deposit, unit D — glaciomarine mud. These results enabled to present the distribution of seismoacoustic units along the fiord and its extension on the shelf, as well as to determine a relation of bottom structures to Late Vistulian(?) deglaciation and the action of Holocene tributary glaciers, probably during the Little Ice Age. The position of marginal structures corresponding to local retreat stages of the glacier front is also presented.

This paper is concerned with the determination of the auditory filter shape using the notched noise method with noise bands symmetrically located above and below a probe frequency of 10 kHz. Unlike in the classical experiments conducted with the use of Patterson method the levels as well as power spectrum densities of the lower and upper component bands of the notched noise masker were not the same and were set such as to produce the same amount of masking at the 10-kHz frequency. The experiment consisted of three conditions in which the following values were determined: (I) the detection threshold for a 10-kHz probe tone in the presence of a noise masker presented below the tone’s frequency; (II) the level of a noise masker presented above the 10-kHz probe tone frequency, at which the masker just masked the probe tone, (III) the detection threshold for a probe tone in the presence of a notched-noise masker. The data show a considerable amount of variability across the subjects, however, the resulting frequency characteristics of the auditory filters are consistent with those presented in the literature so that the Equivalent Rectangular Bandwidth is less than 11% of their centre frequency.

Leaded and unleaded petrol samples as well as diesel oil samples were analysed lo determine Cd. Cr. Cu, Ni, Pb, Zn and As concentrations. In order lo obtain low detection limits new method of samples preparation was used. The fuel samples were dissolved in hydroraffinate which was the crude oil fraction obtained as a result of atmospheric distillation in the range of I 50---250°C. The obtained data on the metal concentrations in the investigated fuels allow determining the following emission factors of traffic fuels consumption processes [mg/kg fuel]: leaded and unleaded petrol - Cr - 0,5; Cu - 0,3; Ni - 0.5; Pb - 50 (leaded): Pb - 5 (unleaded); diesel fuel - Cd - 0,05: Cu - 0,3: Ni - 0.5. It was found in the investigations that traffic fuels consumption is not the source of Zn and As emission. The same refers to Cd emission in case of leaded and unleaded petrol consumption. On the basis of the identified emission factors Pb emission from traffic in Poland for years 1980---1999 as well as Cd, Cr, Cu and Ni emission for I 999 were assessed. The following emission in 1999 was determined as a result of the assessment [Mg]: Cd - 0,3: Cr - 2,9: Cu - 3,5 and Ni - 5,9. Emission of Pbu, was 237.6 Mg and Pb1.,w 79,2 Mg. These emissions were also compared with the total metal emissions in Poland.

Zmieniające się warunki życia, przekształcenia środowiska i migracje ludności wymuszają zmiany w gospodarce przestrzennej. Czy nasza przestrzeń ma przyszłość?

A new method of noise generation based on software implementation of a 7-bit LFSR based on a common polynomial PRBS7 using microcontrollers equipped with internal ADCs and DACs and a microcontroller noise generator structure are proposed in the paper. Two software applications implementing the method: written in ANSI C and based on the LUT technique and written in AVR Assembler are also proposed. In the method the ADC results are used to reseed the LFSR after its each full work cycle, what improves randomness of generated data, which results in a greater similarity of the generated random signal to white noise, what was confirmed by the results of experimental research. The noise generator uses only the internal devices of the microcontroller, hence the proposed solution does not introduce hardware redundancy to the system.

In this paper the method of fast impedance spectroscopy of technical objects with high impedance (|Zx| ≥1 GΩ) is evaluated by means of simulation and a practical experiment. The method is based on excitation of an object with a sinc signal and sampling the response signals proportional to current flowing through and voltage across the measured impedance. The object’s impedance spectrum is obtained with the use of continuous Fourier transform on the basis of linear approximations between samples in two acquisition sections, connected with the duration of the sinc signal. The method is first evaluated in MATLAB by means of simulation. An influence of the sinc signal duration and the number of samples on impedance modulus and argument measurement errors is explored. The method is then practically verified in a constructed laboratory impedance spectroscopy measurement system. The obtained acceleration of impedance spectroscopy in the low frequency range (below 1 Hz) and the decrease of the number of acquired samples enable to recommend the worked out method for implementation in portable impedance analyzers destined for operation in the field.