Wyniki wyszukiwania - BazTech

1

Orthogonal Harmonic Signals of the Generalized Class

Balashov Vitaliy, Oreshkov Vasyl, Barba Iryna, Iegupova Olena

Journal of Telecommunications and Information Technology

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2021

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nr 1

64--70

EN

Telecommunications transmission technologies with OFDM rely on orthogonal harmonic signal (OHS) systems. The criteria applicable to synthesizing OHS systems of the generalized class, including both classical signals and signals whose duration exceeds the orthogonality interval, have been considered. The problems of minimizing the effective width of the spectrum of the generalized class OHS have been solved. Estimates of the efficiency of the generalized class OHS have been given.

2

Zastosowanie transformaty Fouriera w badaniu prototypowego modułu suszącego linii otrzymywania paliwa z recyklingu odpadów

Ulbrich D., Kowalczyk J., Selech J., Włodarczyk K.

Mechanik

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2016

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R. 89, nr 7

858--859

PL

W artykule przedstawiono wyniki analizy i badań rozpoznawczych nt. możliwości zastosowania transformaty Fouriera w badaniu prototypowego modułu suszącego linii otrzymywania paliwa z recyklingu odpadów w czasie jego pracy. Transformata Fouriera została wykorzystana w badaniu powłok prewencyjnych, które były zastosowane do ochrony elementów prototypowej linii.

3

A new approach to homology modeling

He Y., Scheraga H. A., Rackovsky S.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2014

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Vol. 18, No 3

211--128

EN

The need to interpret experimental results led to, first, an all-atom f orce field, followed by a coarse-grained one. As an aid to these force fields, a new approac h is introduced here to predict protein structure based on the physical properties of th e amino acids. This approach includes three key components: Kidera factors describing the ph ysical properties, Fourier transformation and UNRES coarse-grained force field simulations. Different from traditional homology modeling methods which are based on evolution, this approach is phys ics-based, and does not have the same weaknesses as the traditional homology modeling method s. Our results show that this approach can produce above average prediction results, and can be used as a useful tool for protein structure prediction.

4

Fast multidimensional Bernstein-Lagrange algorithms

Kapusta J., Smarzewski R.

Annales Universitatis Mariae Curie-Skłodowska. Sectio AI, Informatica

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2012

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Vol. 12, no. 2

7--18

EN

In this paper we present two fast algorithms for the Bézier curves and surfaces of an arbitrary dimension. The first algorithm evaluates the Bernstein-Bézier curves and surfaces at a set of specific points by using the fast Bernstein-Lagrange transformation. The second algorithm is an inversion of the first one. Both algorithms reduce the initial problem to computation of some discrete Fourier transformations in the case of geometrical subdivisions of the d-dimensional cube. Their orders of computational complexity are proportional to those of corresponding d-dimensional FFT-algorithm, i.e. to O (N logN) + O (dN), where N denotes the order of the Bernstein-Bézier curves.

5

Equicontinuity and Convergent Sequences in the Spaces O′C and OM

Kisyński J.

Bulletin of the Polish Academy of Sciences. Mathematics

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2011

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Vol. 59, no 3

223--235

EN

Characterizations of equicontinuity and convergent sequences are given for the space O′C(Rn) of rapidly decreasing distributions and the space OM(Rn) of slowly increasing infinitely differentiable functions.

6

Estimation of parameters of forms of bending oscillations of a body by results of vibrating tests with application of the theory of optimum filtration and linear regression models

Lyapshin K., Vuchetich I.

Transport Problems

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2010

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T. 5, z. 2

13-19

EN

Three different passenger car bodies' vibration tests were carried out. During the tests simultaneously were register accelerations, body middle displacements and strength from vibrator to a body. On processing of testing signal was decrease its sampling frequency and used nonrecursive filter with Fourier transformation. Signal parameter estimation for first self frequency of bending vibration determination was carried out with four linear regression models according to quadratic mean criteria with pass from discrete to continuous model. Was carried out each model estimation results analyses and did conclusions about processing methods error and noise attend in measurement system.

7

Dyskretna transformata Fouriera okna czasowego skonstruowanego za pomocą funkcji gamma

Zapała W.

Zeszyty Naukowe. Górnictwo / Politechnika Śląska

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2004

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z. 260

535-542

PL

W referacie przedstawiono dyskretne okno czasowe bez listków bocznych w dziedzinie częstotliwości. Okno skonstruowano za pomocą funkcji gamma. Wyznaczono dyskretną transformatę Fouriera dla tego okna czasowego, a następnie przedstawiono jego charakterystyki częstotliwościowe.

EN

Discrete time window without side lobes in frequency domain has been presented in the paper. The window has been constructed basing on gamma function. Discrete Fourier transformation of this window has been determined and next its frequency characteristics have been presented.

8

Comparative investigations of similarity measure exploited in medical images preselection

Wróbel K., Porwik P.

Journal of Medical Informatics & Technologies

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2004

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Vol. 8

II25--31

EN

Nowadays, the most significant impact of digital image processing in the area of applications are real–world problems. Many new technological trends in medicine and digital processing have been implemented. Several factors indicate such development. A major one is the perpetually declining cost of the computer equipment required. Both processing unit and capacity of storage devices continue to become less expensive year by year. Another factor is the increasing availability of equipment for digitising and displaying images. In modern image processing, images have to be compared each other because such approach allows us to automate of retrieval process. Computer image retrieving is today especially important in medical diagnostics [1,7] or in preliminary images selection [8,9]. Today, in the digital image processing are used techniques and methods which have well known mathematical backgrounds. It can be observed, that in the area of digital signal processing, the Hough and well known the Fourier transform are exploited very often. These transforms are frequently use in image retrieving and can be implemented as computer applications. In many cases the mentioned methods give promising results in images classification or preselection [1,2,4,5,11]. Special properties of such transforms can be used in statistical or comparative goals, especially when searched information has graphic form. Taking into account the mentioned applications, transforms as methods of preliminary medical images selection have been investigated. From this reason pictures, analysing in the paper, to medical images have been limited.

9

Novel Fourier approach to digital holography

Paśko S., Jóźwicki R.

Opto-Electronics Review

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2002

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Vol. 10, No. 2

89-95

EN

A complete simulation procedure of the holographic process using Fourier approach is proposed. The algorithm elaborated allows determining the field distributions in the object and hologram Fresnel regions. To show some advantages of the method proposed one-dimensional computer simulations for a simple amplitude object case using Fresnel and Fourier holographic configurations are presented. The usefulness of the algorithm for image reconstruction from a hologram registered by CCD camera is demonstrated.

10

Near-surface inhomogeneities in the magnetotelluric field. Magnetic polarization

Miecznik J.

Acta Geophysica Polonica

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2002

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Vol. 50, nr 2

259-278

EN

Near-surface inhomogeneities cause the so-called static shift of amplitude magnetoelectric sounding curves for the magnetic polarization mode, and thus disturb the quantitative interpretation of magnetotelluric data. A number of possible methods for removing the static shift are presented in the geophysical literature; however, they all require data from other geophysical methods. Having known the electromagnetic field distribution in the given geoelectric cross-section, one can determine quantitative relationships between specific resistivities of the near-surface layer and calculated apparent resistivities. This is also an efficient way of removing static shift effects. The presented geoelectric model comprises a non-homogeneous near-surface layer resting over a 1D horizontally layered earth with arbitrary number of layers and the insulating base. The electromagnetic field distribution in such a model was calculated by means of the Fourier transformation with Dirichlet's boundary conditions. A plane electromagnetic wave with normal incidence was the source of electromagnetic field. The solutions are analytic expressions for the electric field at the Earth's surface. Moreover, asymptotic expressions for high-frequency and low-frequency field variations were calculated. In a high-frequency range, the impedance behaves as in the case of a uniform half-space. In a low-frequency range, the impedance depends most of all on the longitudinal conductivity of the layered earth.

11

Fast Fourier transform square-wave voltammetry detection of phenothiazines in cappilary electrophoresis

Magnuszewska J., Krogulec T., Baranski A. S.

Chemia Analityczna

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2000

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Vol. 45, No. 2

189-203

EN

A new detection technique called the fast F9urier transform square-wave voltammetry (FFT SWV) is based on measurements of ultramicroelectrode admittance as a function of potential. The response time of the detector (ultramicroelectrode) is less than 1 s, which makes the method suitable for most applications involving flowing electrolytes. The response is generated by a variety of processes involving the analyte, such as: reduction or oxidation, adsorption or desorption, surface transformation, inhibition of oxygen or hydrogen adsorption and changes in the solution resistance. Proper electrochemical conditioning of the ultramicroelectrode made of a noble metal (e.g. Au or Pt) provides a stable response for several hours. The new detection technique was tested under capillary elec-trophoresis and flow-injection conditions for the determination of ten phenothiazine derivatives. The detection limit was 2-5 * 10-7 mol 1-1 in CE and about 1 x 10-8 mol 1-1 in flow injection detections.

PL

Nowa technika detekcji wykorzystująca woltamperometrię fali prostokątnej z szybką transformacją Fouriera (FFT SWV) jest podstawą pomiarów admitancji ultramikro-elektrod w funkcji potencjału. Czas odpowiedzi detektora (ultramikroelektroda) poniżej l s umożliwia zastosowanie tej techniki w układach przepływowych. Odpowiedź dętektora może być wywołana przez różne procesy takie jak utlenienie lub redukcja analitu, jego adsorpcję lub desorpcję, procesy przekształceń powierzchniowych, inhibitowanie adsorpcji tlenu lub wodoru a także zmiany rezystancji roztworu. Odpowiednie elektrochemiczne kondycjonowanie ultramikroelektrod z metali szlachetnych (Au lub Pr) prowadzi do otrzymania stabilnej odpowiedzi przez wiele godzin. Ta nowa technika została przetestowana w warunkach elektroforezy kapilarnej i wstrzykowej analizy przepływowej przy oznaczaniu dziesięciu pochodnych fenotiazyny. Limit detekcji dla tych związków wynosi 2-5 x 10(-7) mol 1(-1) w warunkach elektroforezy kapilarnej i około 1 x 10(-8) mol 1(-1) podczas oznaczeń w warunkach wstrzykowej analizy przepływowej.