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Wyszukujesz frazę "Marszał, L." wg kryterium: Autor


Wyświetlanie 1-10 z 10
Tytuł:
Określenie wieku kozy (Cobitis taenia) i kozy złotawej (Sabanejewia aurata) z wykorzystaniem niektórych struktur twardych
Age Validation of Spined Loach (Cobitis taenia) and Golden Loach (Sabanejewia aurata) Using Some Calcinated Structures
Autorzy:
Lampart-Kałużniacka, M.
Pietraszewski, D.
Marszał, L.
Heese, T.
Przybylski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1819042.pdf
Data publikacji:
2013
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
określanie wieku kozy
struktury twarde
otolith growth
fin rays
population
fish
lake
temperature
precision
accuracy
biology
scales
Opis:
Age is one of the most important life history variables of fish used to estimate growth rate, mortality rate and production. Age determining is usually carried out by analyzing any of several calcified structures, such as scales, otoliths (more frequently) or fin rays (rather seldom). Scales are easy to collect and this is the reason why this structure has been widely used, but for several reasons annuli may be ambiguous to discern on scales, especially in the loaches. The material was collected in May 2010 in the Pilica River. A total of 29 fish individuals, including 16 spined loach and 13 golden loach, were examined. The range of total length (TL) of the fishes in the sample studied was 43–102 mm in the former and 35 do 70 mm in the latter species, respectively. The precision of ageing using the cross-sections of dorsal, caudal, anal, pectoral and ventral fins rays were compared with age determination on the basis of otoliths. The analysis of the annuli of the investigated structures revealed that individuals aged 2 to 5 years (golden loach) and aged 3 to 7 years (spined loach) occurred in the material (Table 1 and 2, respectively). The obtained results indicate that in natural water bodies older individuals than formerly presumed may occur. Microscopic slides of the cross sections of otoliths and fins are most reliable for ageing such structures. The anal fin (A) it the most reliable structure for ageing, i.e. the age obtained from the fin is least divergent from the age obtained from the otolith. While planning the investigations of the age structure of populations it is necessary to establish the periods of sampling in a way that will be most congruent with the period of annuli formation.
Źródło:
Rocznik Ochrona Środowiska; 2013, Tom 15, cz. 2; 1041-1052
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of maximum length sequence in silent sonar
Autorzy:
Marszal, J.
Salamon, R.
Kilian, L.
Powiązania:
https://bibliotekanauki.pl/articles/331898.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Silent sonars are designed to reduce the distance over which their sounding pulses can be detected by intercept sonars. In order to meet this objective, we can use periodical sounding signals that have low power, a very long duration and wide spectrum. If used in the silent sonar’s receiver, matched filtration ensures very good detection of motionless or slow moving targets. However, it is more difficult to detect echo signals of fast moving targets with Doppler effect causing significant error in target distance measurements. In an effort to find signals that can better resist Doppler effect, maximum length sequence was tested for its application in silent sonar. It has an elementary signal which includes linear frequency modulation. It was demonstrated that the signal produces much better results than those obtained with simple frequency modulation signals.
Źródło:
Hydroacoustics; 2012, 15; 143-152
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Autonomous hydroacoustic sound velocity profiler
Autorzy:
Jedel, A.
Marszal, J.
Ostrowski, Z.
Kilian, L.
Powiązania:
https://bibliotekanauki.pl/articles/332093.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
hydroacoustics
sound velocity profiler
Opis:
The paper presents the autonomous hydroacoustic sound velocity profiler collaborating with ordinary PC by small box included interface & battery charger. The measurement and calibration methods and block diagram of the meter are presented as well as principles of operation, data collection, selection and transmission. There are described three versions of this meter - dropped from "normal" ships, installed in the light hull of submarines and casings in the hulls of variable depth sonar antennas.
Źródło:
Hydroacoustics; 2003, 6; 261-266
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Signal processing in the hydroacoustic ships berthing aid system
Autorzy:
Marszal, J.
Salamon, R.
Kilian, L.
Raganowicz, A.
Szurowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/332707.pdf
Data publikacji:
1997
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The berthing of ships is an extremely complicated task that requires decisions on the movement of ships based on a large number of variabies: tide wind, visibility, speed, distance from jetty. Particular difficulties are related to the less maneuverable ships such as very large crude carriers. The presented hydroacoustic ships berthing aid system measures four distances of a ship to the jetty using the sonar echo method. The system computer calculates the bow and stern speed and distances to dolphins from the measured data. The results obtained are simultaneously presented on a large, high luminance display as well as printed out and recorded on computer discs. Additionally the dolphins displacements are measured and the data obtained together with its statistical parameters are recorded.
Źródło:
Hydroacoustics; 1997, 1; 237-242
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic control of the receiving beam horizontal cross-section in the side scan sonar
Autorzy:
Jedel, A.
Kilian, L.
Marszal, J.
Ostrowski, Z.
Salamon, R.
Powiązania:
https://bibliotekanauki.pl/articles/332725.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
A decade old side scan sonars are now being modernised by way of dynamically controlling the width of the receiving beam in the horizontal cross-section. The result is a quasi-constant linear resolution of the sonar (replacing constant angular resolution), when it picks up echo signals as it moves further away from the targets. The advantage of the treatment is that the ship using the side scan sonar can increase its speed without risking the loss of near targets’ echo. The articles describes how the system of dynamic control was implemented. Special TVG systems were introduced to control dynamic signal gain from several separate sections of the sonar’s acoustic array, which was divided symmetrically into unequal sections. The location of these systems in the sonar’s receiver is presented. Examples are given of curves that control TVG and of the effects of dynamic horizontal stabilisation of the sonar’s linear resolution as it receives signals.
Źródło:
Hydroacoustics; 2005, 8; 69-76
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrographic echosounder for sounding inland waters
Autorzy:
Jedel, A.
Kilian, L.
Marszal, J.
Ostrowski, Z.
Wojan, Z.
Zachariasz, K.
Powiązania:
https://bibliotekanauki.pl/articles/332033.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
This article describes a new echosounder model designed specifically for institutions responsible for the management of inland waterways, artificial and natural reservoirs, and marine coastal waters. The basic requirement related to the need of sounding shallow waters is measuring the smallest possible depths. Using separate transducers (sending and receiving) and attenuating them, and introducing a high dynamic range TVG circuit allowed the measurement of depths from 20cm at a maximum range of 100m. Water temperature is measured in order to include sound velocity corrections. The echosounder is manufactured using modern technology, with a PC 104 computer, robust FLASH memory emulating a hard disk, 8 inch color LCD panel, thermal printer with paper band for instant profile printouts, and a floppy disk drive for permanent storage. The echosounder interfaces to GPS.
Źródło:
Hydroacoustics; 2004, 7; 89-96
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time variable gain for long range sonar with chirp sounding signal
Autorzy:
Marszal, J.
Ostrowski, Z.
Schmidt, J.
Kilian, L.
Jedel, A.
Schmidt, A.
Powiązania:
https://bibliotekanauki.pl/articles/332524.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The main purpose of applying Time Variable Gain (TVG) in active sonars with digital signal processing is to reduce dynamic range of echo signal and adapt it to the dynamic range of the analogue to digital conversion. With high transmission losses level, the dynamic range of the input signal in long range sonars can be very high and even exceed 200 dB. When chirp sounding signals with matched filtration are used, sonars can reach very long ranges. The article presents optimisation of TVG control for long range sonars. It also looks at the influence of chirp sounding signal compression, the result of digital matched filtration, for the TVG controlling. The examples of obtained results are presented.
Źródło:
Hydroacoustics; 2007, 10; 117-122
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Workstation for training ASW helicopter navigators and analysing real flight data
Autorzy:
Raganowicz, A.
Kilian, L.
Marszal, J.
Schmidt, A.
Sidorko, T.
Rudnicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/332784.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
helicopter navigators
real flight data
aviation
Opis:
The article presents a training and diagnostic workstation designed for Polish Navy ASW helicopter navigators. Installed at the helicopter base, the workstation is used for training and instruction in operating the device and analysing information gathered by navigators during the flight using the ASW onboard sonar, sonobuoy receiver and magnetometer. The workstation allows instructors to task two operators and monitor their performance under conditions resembling those onboard a plane. The tasks involve the operation of the consoles and collecting information during tactical situations, diagnosing damage and analysing flight data in office environment. The objective is to ensure proper helicopter navigator training and experience given the limited possibility of training flights.
Źródło:
Hydroacoustics; 2009, 12; 181-188
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multibeam sonar with hexagonal array
Autorzy:
Salamon, R.
Marszal, J.
Kilian, L.
Jedel, A.
Ostrowski, Z.
Raganowicz, A.
Rudnicki, M.
Wofan, Z.
Zachariasz, K.
Powiązania:
https://bibliotekanauki.pl/articles/332250.pdf
Data publikacji:
1999
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper presents a multi-beam digital sonar that was designed for monitoring and fish stock assessment in in/and waters. The sonar can also be used as a bottom profiler in lakes, rivers and shallow sea areas. The hexagonal piezoelectric transducer array co-operates with a commutator set. The 32 -channel digital beamformer creates 30 narrow receiving beams in every 60o sector of simultaneous observation. The six sectors cover the whole 360o angle range of the sonar. The beamformer digital signal processing is based on second order sampling of echo signals and the phase-shifting principle of beam deflection. The sonar block diagram, beamformer algorithms, as well as transducers designs are discussed.
Źródło:
Hydroacoustics; 1999, 2; 133-138
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modernization of ASW sonar SQS-56 at Gdansk University of Technology
Autorzy:
Marszal, J.
Schmidt, J.
Salamon, R.
Kilian, L.
Raganowicz, A.
Zachariasz, K.
Ostrowski, Z.
Jedel, A.
Rudnicki, M.
Sidorko, T.
Powiązania:
https://bibliotekanauki.pl/articles/331991.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The fast development of electronic technology and digital signal processing methods makes electronic devices, including sonar systems ones, obsolete very quickly. On the other hand the ships mechanical components including mechanical parts of sonars are operational for a few dozens of years. It makes good opportunity to modernize these devices by using modern electronic devices and new digital signal processing methods with application of existing antenna and mechanical systems. The paper presents the modernization of ASW sonar SQS-56 on the Polish frigate ORP “Kościusko”. The aim of modernization, the new parameters of the sonar and block diagram after modernization are presented.
Źródło:
Hydroacoustics; 2010, 13; 191-196
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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