Wyniki wyszukiwania - Biblioteka Nauki

1

Utilisation of free tacheometric stations in monitoring of monumental objects

100%

Malarski R. , Nagórski K.

Reports on Geodesy

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2011

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tom z. 1/90

271-278

EN

This paper presents results of investigations concerning utilisation of free tacheometric stations for: a) Determination of slip of objects located on escarpments, b) Investigations of deformations of bodies of monumental objects. The usefulness of the proposed technology of surveys for implementation of the above tasks has been proved. Results of investigations have been illustrated by results of surveys of displacements and deformations of the St.Ann’s Academic Church in Warszawa.

2

Method of network reliability analysis based on accuracy characteristics

100%

Łapiński S.

Reports on Geodesy

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2011

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tom z. 1/90

265-270

EN

Measurements of structures must be precise and accurate as they affect the quality of the final result of geodetic tasks. In some cases there is a risk of committing a gross error. Diagnostic analyses may allow such an observation in to the adjustment and estimation of unknown parameters. The paper presents results of network deformation and robustness analysis based on the characteristics of network accuracy and reliability. The maximum undetectable error that may occur in an individual observation constitutes the source of deformation. The method tested in the present paper is proposed in Prószyński and Parzyński (2009). The paper evaluates theoretical relationships and their utility for analyses of large geodetic networks. Additionally, the paper attempts to transfer the presented relationships to the case of free adjustment, which was not included in theoretical derivations in the paper mentioned above. The research has been conducted using a computer generated 2D linear-angular network. The analysis focuses on the results of network deformation, depending on the assumed reference system. Moreover, an attempt has been made to modify the proposed method of network reliability analysis for the case of free adjustment.

3

Wpływ liczby pobieranych próbek i ich usytuowania w okresie na błąd wyznaczania wartości skutecznej i średniej sygnału poliharmonicznego (Część II)

100%

Nowaczyk E. , Nowaczyk J.

Metrology and Measurement Systems

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2002

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tom Vol. 9, nr 4

413-432

PL

W przentowanej pracy podano zależności matematyczne określające wartość skuteczną sygnału wyliczaną na podstawie próbek pobranych przez przetwornik niesynchroniczny. Przedstawiono wyniki badań modelu takiego przetwornika w środowisku MATLAB-a. Uzyskane rezultaty ilustrują wpływ parametrów sygnału poliharmonicznego i sposobu przeprowadzania próbkowania na błąd wyznaczenia wartości skutecznej i średniej bezwzględnej tego sygnału. W artykule zamieszczono przesłanki odnośnie prawidłowego wyboru częstotliwości próbkowania, a także zalecenia stosowania filtrów antyaliasingowych w torze przetwarzania. Stanowia one zdaniem autorów skuteczne remedium na zmniejszenie błędów omawianych w pracy.

EN

The paper produces an analysis of the accuracy of determination of the root-mean-square (rms) and average value at asynchronous signal sampling. It is an enlargement of the publication [1]. Mathematical equations determining the rms value for pure sine-wave and polyharmonic signals have been presented. The calculation of the average value has been based on the analysis carried out in a general way in many literature items, such as [6]. For both calculated kinds of values, tests were carried out by creating a model of asynchronous converter in MATLAB's environment and applying at its input a pure sine-wave signal or polyharmonic signals of different forms; at the same time the sampling frequency and the number of samples taken were changed. The obtained simulation results, representing the determination of the root-mean-square or average value with regard to the conventional true value, for exemplifying signal forms, have been presented in illustrations. They illustrate the effect of the number of samples taken, of the relative sampling frequency, of the moment of the first sample, and for polyhannonic signals also of harmonic contents, their numbers and phase shift. The phenomenon of result waving and particularly big errors for some ,,unlucky" harmonic numbers have been shown. It was noticed that as the number of the samples taken increases, the intervals are being narrowed where the calculated root-mean-square or average value can be found. However, with an increase of the sampling frequency there is need for drawing a larger and larger number of samples, in order to obtain results not differing from each other more than it is admissible (when calculating the root-mean-square value this occurs for a relative sampling frequency greater than four). If a signal contains, apart from the fundamental frequency, also harmonics ones (and this is always the case in practice), then in selecting sampling frequencies the greatest harmonic numbers should be kept in mind, including also the sum or the difference of their numbers. Neglecting this recommendation that results from Shannon's theorem, may lead to the result waving at a very low frequency and simultaneously with high amplitude. The result of taking a greater number of samples for calculations may be more departing from the correct one than with their smaller number. Application of antialiasing filters in the conversion line was proposed. These filters, damping high frequency components and possible noise enable one to obtain greater repeatability of the results. For the sampling of signals of approximately constant frequency, such as those of the power-line, it was recommended to select a sampling frequency close to an odd multiple of the rated frequency value of the sampled signal, both when calculating the average and the rms value. The presented paper points to the error sources resulting from the way of drawing of samples by sampling converters. It also contains main lines directed at practicians, connected with making use of the obtained results when applying these converters in measurements and automation.

4

Acoustic sniper localization

100%

Danicki E.

Archives of Acoustics

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2005

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tom Vol. 30, No. 2

233-245

EN

Acoustic signals of small arm's fire, the muzzle blast and the shock wave generated by a supersonic bullet in air, are difficult to mask and can be exploited for localization of the hidden sniper. This paper presents the system of acoustic measurements, based on a number of both directional and omnidirectional microphones detecting the shock wave only, yielding exact solution for the sniper direction in spite of certain errors in the directional measurements. The system has a self-correcting ability concerning the sound directional measurements which contributes to the system technical feasibility. Auxiliary muzzle blast measurements would yield the sniper position.

5

Results of Geodetic Measurements in Czech Part of the Sneznik- Network - analysis 1992-1999

80%

Svabensky O. , Weigel J. , Bures J. , Svec M.

Reports on Geodesy

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2000

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tom z. 7/53

51-58

EN

ln a 1992 one of the first local geodynamic networks in Czech republic was established in czech-polish cooperation - the Sneźnik network. The network was designed as a model for testing of methodical and technological procedures for repeated satellite and classical geodetic measurements. Since 1992 several campaigns of GPS, EDM, levelling, gravimetric, astronomical and other measurements bad been carried out in the network within previous projects., Brno University of Technology had organized observation activities and carried out the measurements and processing of all campaigns in Czech part of the network. In years 1996 - 1998 the works in scope of the research project oriented on problems of the common processing of GPS and terrestrial measurements were carried out here in cooperation of TU Brno and Research Institute of Geodesy, Topography and Cartography Zdiby - Geodetic Observatory Pecny. This contribution gives overall history of measurements and describes the time evolution of the network points positions in time span of 8 years, estimated on ground of GPS data.

6

Evaluation of quality measurement

80%

Obmaščik M. , Bátora B. , Štekláč D. , Jurenová J.

Przegląd Mechaniczny

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2007

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tom nr 9 supl.

36-40

EN

Importance of knowledge, scientific and research activity for social development. The role of metrology, metrological assignment of correctness, uniformity and accuracy of measurement. Elimination and correction of systematic errors, determination of uncertainty of measurement of evaluated parameter for selected probability.

PL

Znaczenie wiedzy, nauki oraz badawczej aktywności dla społecznego rozwoju. Rola metrologii, oceny poprawności i wyznaczania dokładności pomiaru. Eliminacja i korekcja błędów systematycznych, wyznaczanie niepewności pomiaru mierzonego parametru dla wybranego poziomu ufności.

7

Performance assessment of "Field programmable analog arrays"

80%

Baccigalupi A. , Liccardo A.

Metrology and Measurement Systems

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2007

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tom Vol. 14, nr 4

563-575

EN

Field Programmable Analog Arrays (FPAAs) are reconfigurable analog modules introduced on the electronic market in the last decade. Their operation and, in particular, their programmability is achieved owing to the use of switched capacitors technology. At least in principle, they seem to be a very attractive and powerful tool to design analog circuits whose parameters have to be tuned to signal variations as in carrying out sensor conditioning systems. But the aim of exploiting their possibilities in the field of metrology requires complete characterization and performance assessment of the involved building blocks. With this goal, in the paper, the metrological characterization of the most commonly blocks to be used in analog conditioning circuits, such as amplifiers and filters, is performed. These blocks have been characterized in terms of both frequency response and step response and the obtained experimental results have been compared with those expected from theoretic analysis. Concluding remarks are then deduced to furnish practical hints in the use of FPAAs in measurement applications.

8

Metody manometryczna i barometryczna pomiaru ciśnienia statycznego powietrza wentylacyjnego w wyrobiskach górniczych

80%

Bystroń H.

Przegląd Górniczy

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2000

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tom T. 56, nr 12

1-16

PL

Powietrze wentylacyjne traktuje się jako niezamglony roztwór powietrza suchego i pary wodnej, a jego przepływ wyrobiskiem górniczym - jako stacjonarny ruch turbulentny. Przedstawianie metody manometrycznej wychodzi z określonych postaci równania ruchu, które całkuje się wzdłuż osi wyrobiska górniczego lub osi przewodu pomiarowego - od przekroju dopływowego do przekroju wypływowego tego wyrobiska. Przekształcając wyniki całkowania, otrzymano dwa wzory określające dyssypację energii mechanicznej w wyrobisku: w pierwszym występuje ciśnienie mano-metryczne zmierzone w przekroju dopływowym wyrobiska, w drugim -w jego przekroju wypływowym. W metodzie barometrycznej - opartej na barometrach kontrolnym i wędrownym - wyprowadzono wzór określający skorygowane ciśnienie statyczne w wyrobisku górniczym. Podano wzory określające dyssypacje energii mechanicznej w wyrobisku oraz inne wielkości dotyczące wyrobiska i oczka podsystemu wentylacji. Na przykładzie podsystemów wentylacji kopalń " Pokój " i " Halemba" zilustrowano wzory dotyczące metod manometrycznej i barometrycznej oraz związki między tymi metodami. Omówiono małe zaburzenia, pulsacje (fluktuacje) i wibracje ciśnienia powietrza wentylacyjnego. Przedstawiono dodatkowe kwestie oraz wnioski.

EN

Ventilation air is treated as a non-hazy solution of dry air and water vapour and its flow through a mining working - as stationary turbulent motion. Presentation of the manometric method comes from the particular form of the motion equation integrated along the axis of mining working or measurement duct from the inflow-cross-section up to the outflow cross-section of this working. Transforming the results of integration two formulas determining mechanical energy dissipation in working have been obtained: in the first one appears the manometric pressure measured at the inflow cross-section of working, in the second one at its outflow cross-section. In the barometric method -based on control and travelling barometers - a formula determining corrected static pressure in mining working is derived. The formulas are given determining dissipation of mechanical energy in working and other values referred to working and ventilation subsystem. Taking ventilation subsystems of "Pokój" and "Halemba" colliers as examples formulas referring to manometric and barometric methods as well as connections between them are illustrated. Small disturbances, pulsations (fluctuations) and vibrations of ventilation air are discussed. Additional issues conclusions are presented.

9

Georeferencja wprost

80%

Feczan P. , Kurczyński Z.

Geodeta : magazyn geoinformacyjny

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2010

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tom nr 1

8-13

10

Short time algorithm of power waveforms fundamental harmonic estimation with use of prony's methods

80%

Zygarlicki J. , Mroczka J.

Metrology and Measurement Systems

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2011

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tom Vol. 18, nr 3

371-378

EN

This paper presents an example of practical use of Prony's method for monitoring of power waveform fundamental harmonic fluctuations, which is required for the analysis of window synchronizations in frequency analyses in power monitoring systems. The example presented offers verification of the authors' theoretical considerations published earlier in articles about Prony's method and its opportunities for practical use for real life signals. The investigations shown are based on the least squares Prony's method, which, in connection with digital filtrations, enables estimations of fundamental frequency at the rate of even tens of times per one fundamental harmonic period.

11

First results of GPS measurement campaigns in Tatra mountains

80%

Czarnecki K. , Mojzes M. , Papco J. , Walo J.

Reports on Geodesy

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2003

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tom z. 1/64

41-46

12

Porównanie optyczno-elektronicznych metod pomiaru granulacji

80%

Kamiński S. , Kamińska D.

Aparatura Badawcza i Dydaktyczna

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2007

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tom T. 12, nr 2-3

85-93

PL

W niniejszej pracy opisano urządzenie laboratoryjne pod nazwą Infrared Particle Sizer, dalej zwane IPS, które może być stosowane do szybkich pomiarów granulacji w czasie procesu produkcyjnego. Metodę pomiaru wykorzystywaną w analizatorze IPS porównano z innymi metodami optyczno-elektronicznymi. Przytoczone przykłady zastosowań prowadzą do wniosku, że urządzenie IPS ma dobre parametry techniczne i pozwala na rzeczywisty pomiar rozmiarów cząstek w szerokim zakresie. Dotyczy to cząstek materiałów nieorganicznych i organicznych.

EN

In this article the laboratory instrument called Infrared Particles Sizer (IPS) is described. The instrument can be applied to fast measurement of granulation, needed in production process. Measurement method that is used in IPS analyser is compared to other optical-electronic methods. Mentioned examples of application allow to draw conclusion that IPS instrument has good technical parameters and gives actual results of particles sizes in wide measuring range. This concerns organic and inorganic substances.

13

Badanie wpływu właściowości elektromagnetycznych drutów oporowych na obwód

80%

Niedbała R. , Wesołowski M. , Kucharski D.

Zeszyty Naukowe. Elektryka / Politechnika Łódzka

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2012

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tom z. 124

185-193

PL

Druty i taśmy wykonywane ze stopów oporowych (chromonikieliny, ferrochromale itp.)używane są nie tylko na elementy grzejne, lecz także na boczniki, rezystory regulowane itp. Obliczane są jako elementy rezystancyjne w całym zakresie temperaturowym. Tymczasem wpływ przenikalności magnetycznej w niskich temperaturach może być przyczyną powstających błędów tak ilościowych, jak i jakościowych. Przeprowadzone badania tych drutów zasilanych z idealnie sinusoidalnych źródeł już przy częstotliwości sieciowej zaczynają wykazywać odstępstwa od charakteru rezystancyjnego. Przesunięcie fazowe wraz z nieliniowością przebiegów pogłębia się przy rzeczywistych źródłach napięciowych. W referacie podano wyniki badań drutu kanthalowego, powszechnie używanego i uważanego za najlepszy średniotemperaturowy materiał oporowy. Przedstawione charakterystyki determinują zakres poprawności stosowanych obliczeń.

EN

Wires and strips made from high-resistivity are used not only as heating elements, but as shunts, adjustable resistors, etc additionally. During the calculations, they are treated as resistance elements in all temperature range. Meanwhile, the influence of magnetic permeability in low temperatures can result a quantitative and qualitative calculation errors. The measurements of such wires, powered by sinusoidal voltage sources, showed that even at 50 Hz frequency, electrical parameters deviates from resistive. In the article some measurement results of kanthal wires, considered to be the best medium - temperature heating material, were discussed. The presented characteristics, determinates the range of accuracy of calculations.

14

Budowa stanowiska pomiarowego do badania zmiennych rozpływów w rozgałęzieniach

80%

Cierniak W. , Gorgoń J. , Mnich K.

Prace Instytutu Mechaniki Górotworu PAN

|

2006

|

tom Vol. 8, no. 1-4

89--92

PL

W pracy zostały przedstawione dwa układy sterowania. Jeden z nich służy do synchronicznego sterowania dwoma pompami ze zmiennymi w czasie strumieniami za pomocą komputera i programu służącego do sterowania jedną pompą. Drugi służy do sterowania urządzeniem służącym do wytwarzania elastycznych modeli elementów układu krwionośnego.

EN

The article describes two computer controlled systems. First was designed to synchronously control two pumps, producing variable in time fluxes. It was realized by computer and a program which was controlling one of pumps. Second system was used to control a mechanism to producing the elastic latex models of blood- system elements.

15

Measurements of 3D turbulence structure in a compound channel

80%

Czernuszenko W. , Kozioł A. , Rowiński P. M.

Archives of Hydro-Engineering and Environmental Mechanics

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2007

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tom Vol. 54, nr 1

55-73

EN

The paper describes some turbulence measurements carried out in an experimental compound channel with flood plains. The surface of the main channel bed was smooth and made of concrete, whereas the floodplains and sloping banks were covered by cement mortar composed with terrazzo. Instantaneous velocities were measured be means of a three-component acoustic Doppler velocity meter (ADV) manufactured by Sontek Inc. This article presents the results of measurements of primary velocity, the distribution of turbulent intensities, Reynolds stresses, autocorrelation functions, turbulent scales, as well as the energy spectra.

16

Levels of electromagnetic fields from rail vehicles in the context of formal requirements

80%

Miszkiewicz A. , Tchórzewski K.

Problemy Kolejnictwa

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2020

|

tom Z. 187

109--116

EN

The article discusses the issue of electromagnetic field levels emitted from rail vehicles with regard to civil protection. The article presents the lack of legal solutions, limits and research methods in the railway industry in Poland. It also depicts the initial results of measurements from rail vehicles. Based on the findings, taking into consideration the measurement results and suppression of electromagnetic waves in free space, electromagnetic fields may reach substantial levels which can affect people’s health and life. The authors of the article conclude that the problem should not be ignored and requires further research, bearing in mind the progressing saturation of all rail vehicles with devices and electronic systems which will serve as sources of electromagnetic fields.

17

Evaluating the eﬃciency of low pressure part of steam turbines based on probing measurements

80%

Gardzilewicz A.

Transactions of the Institute of Fluid-Flow Machinery

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2017

|

tom nr 135

41--56

EN

A methodology oﬂow pressure part turbine eﬃciency evaluation based on measurements of the steam ﬂow parameters in the interspaces between neighbouring stages is described. Specially manufactured probes have been applied carry out such measurements. The eﬃciencies of the stages operating in the superheated steam zone result directly from experimental values of pressures, temperatures, and ﬂow angles. To complete the eﬃciency evaluation for the stages operating in the wet steam region, a relevant estimation of blading system losses has been proposed and validated. This evaluation of losses is compatible with the measurement results. Adaptation of a comparative error analysis makes it possible to show the advantages of the methodology over the thermal balance applied during performance tests. The low pressure turbine eﬃciency evaluation methodology has been applied to numerous steam turbine power units of 200–500 MW output.

18

Nowe ujęcie matematycznego zapisu zarysu okrągłości przy podparciu dwupryzmowym

80%

Nozdrzykowski K.

Pomiary Automatyka Kontrola

|

2007

|

tom R. 53, nr 12

70-72

PL

W artykule przedstawiono nowe ujęcie matematycznego zapisu zarysu okrągłości odpowiadające pomiarom cylindrycznych elementów maszyn podpartych w dwóch pryzmach. W oparciu o opracowany schemat pomia-rów odniesieniowych, uwzględniający związki kątowe pomiędzy promie-niem zarysów okrągłości wyprowadzone zostały wzory mające zastoso-wanie w symulacyjnych obliczeniach mierzonej odchyłki okrągłości Dz3 oraz wartości współczynnika wykrywalności kn3.

EN

In the paper was shown a new approach to mathematical description of roundness shape corresponding to measurements of cylindrical machinery parts supported onto two prisms. Basing on reference measurement schema, taking in regard angular relations between radius of roundness shape, the formulae used in simulating computations of measured roundness deviation Dz3 as well as detectability coefficient kn3 were presented.

19

Pomiar zza węgła

80%

Fuhrland M.

Geodeta : magazyn geoinformacyjny

|

2006

|

tom nr 1

54-56

20

The system of automatic laser plumb-line for monitoring a heavy dam wall

80%

Bryś H. , Ćmielewski K. , Gołuch P. , Kowalski K.

Reports on Geodesy

|

2011

|

tom z. 1/90

41-49

EN

While carrying out and exploiting dams we can notice displacements and stable or elastic deformations of the object itself, the area of placement, slopes, slopes of valleys, mazer bottom and even into its geometry is only possible to state with help of systematically performed geodesy measurement of deformations and dislocations.