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This paper will show a new approach to the solution of SAT-problems. It has been based on the isomorphism between the Boolean algebras of finite sets and the Boolean algebras of logic functions depending on a finite number of binary variables. Ternary vectors are the main data structure representing sets of Boolean vectors. The respective set operations (mainly the complement and the intersection)...
With the evolution of Internet, the meaning and accessibility of text documents and electronic information has increased. The automatic text categorization methods became essential in the information organization and data mining process. A proper classification of e-documents, various Internet information, blogs, emails and digital libraries requires application of data mining and machine learning...
Document clustering, which is also refered to as text clustering, is a technique of unsupervised document organisation. Text clustering is used to group documents into subsets that consist of texts that are similar to each orher. These subsets are called clusters. Document clustering algorithms are widely used in web searching engines to produce results relevant to a query. An example of practical...
This work is concerned with the propagation of rapidly oscillating electromagnetic (EM) signal in a Lorentz dispersive medium. The problem considered here is 1-dimensional and its exact solution is described by a contour integral defined in a complex frequency plane. With the use of uniform asymptotic techniques, approximate representation for the total field consisting of the Sommerfeld and Brillouin...
The paper presents the implementation of the Elliptic Curves Cryptography (ECC) algorithms to ensure security in the distributed measurement system. The algorithms were deployed in the LabWindows/CVI environment and are a part of its cryptographic library. Their functionality is identical with the OpenSSL package. The effectiveness of implemented algorithms is presented with the comparison of the...
The paper presents optimized hardware structure applied to genome alignment search. The proposed methodology is based on dynamic programming. The authors show how starting from the original Smith-Waterman approach, the algorithm can be optimized and the evaluation process simplified and speeded-up. The main idea is based on the observations of growth trends in the adjacent cells of the systolic array,...
In this paper we present a MOSFET-only implementation of a wideband Gilbert Cell. The circuit uses a commongate topology for a wideband input match, capable to cover the Wireless Medical Telemetry Service (WMTS) frequency bands of 600 MHz and 1.4 GHz. In this circuit the load resistors are replaced by transistors in triode region, to reduce area and cost, and minimize the effects of process and supply...
In this paper a numerically efficient filter design method suitable for variable fractional delay (VFD) filter implementation is investigated. We propose to use a well known window method with an asymmetric window extracted from optimal filter designed beforehand. As we will demonstrate, such an approach, if additional gain correction is applied, allows for nearly optimal VFD filter design. Thus,...
Very often, we are interested in the shape of a signal or an envelope of the signal or its spectrum. Classical extreme analysis (CEA) produces too many minor details of a signal shape. This fact, in the context of telecommunications, does not allow us to ensure a significant coefficient of a signal compression. Another option for signal analysis, based on the Delta Modulation (DM), lacks sufficient...
A review of our today’s understanding of the ultimately broadband photonic Internet is presented. A simple calculation is presented showing the estimate of the throughput of the core photonic network branches. Optoelectronic components, circuits, systems and signals, together with analogous electronic entities and common software layers, are building blocks of the contemporary Internet. Participation...
This paper deals with the design of radar receive filters jointly optimized with respect to sidelobe energy and sidelobe peaks via Pareto-optimal theory. We prove that this criterion is tantamount to jointly minimizing two quadratic forms, so that the design can be analytically formulated in terms of a multi-objective optimization problem. In order to solve it, we resort to the scalarization technique,...
In recent years, speech recognition functionality is increasingly being added in embedded devices. Because of limited resources in these devices, there is a need to assess whether the defined speech recognition system is feasible within given constraints, as well as estimating how many resources the system needs. In this paper, an attempt has been taken to define a technique for estimating hardware...
The numerical modelling of the Raman polarization attraction and amplification process in the telecommunication band around 1550 nm is presented. The possibility of achieving both polarization pulling and amplification in Polarization Division Multiplexing transmission system by exploiting the polarization dependence of stimulated Raman scattering is investigated. The acceptable crosstalk for the...
We have designed, fabricated in 90 nm technology and tested a prototype ASIC for readout of semiconductor pixel detectors for X-ray imaging applications. The 4mm x 4mm readout IC is working in single photon counting mode and contains a pixel matrix of 1280 readout channels with dimensions of 100 µm × 100 µm each. We present the architecture, the measurement results of this IC and our conclusions....
The subject of the paper is the software simulator of baseband signals received in a radar. These synthetic signals are sent to the DSP unit responsible for target detection and estimation. The software has been developed in Warsaw University of Technology as a part of R&D project, and its main purpose is to allow flexible testing and validation of the algorithms running in DSP processors of the...
In this paper a scheme of utilizing shape independent basis functions for the hierarchical multiresolution image compression is shown. For a given image texture region segmentation method is used. Following polygonal approximation of created segments causes a degradation of their boundaries. Using NURBS and Bezier interpolation and approximation segments' boundaries are created, thus achieving an...
The wideband coherent pulse radar provides high resolution image of the target. A model of this image is composed of the complex envelope superposition of signals diffracted by the point scatterers. The values of complex envelope are distributed over the radar image coordinate plane in accordance with the point scatterer's positions and their reflection coefficients. The radar image model is combining...
In this paper idea of passive radar system based on popular wireless networks commonly named WIFI is presented. In such an networks many transmitters operates in the same channel using multiple access. Wireless networks operating on frequencies 2.4GHz and 5GHz are very common today (IEEE 802.11 a/b/g/n). Classic passive radar determines bistatic distance and velocity by using cross-ambiguity function...
In the paper, a concept of Additive Fuzzy Noise (AFN) channel is introduced. The theoretical equations are derived for Bit Error Rate (BER) and Symbol Error Rate (SER) with some digital modulation scheme in the AFN channel. Following modulations are considered: Phase Shift Keying (16PSK), Quadrature Amplitude Modulation (16QAM). The fuzzy approach to these modulations is presented. The BER and SER...
In this paper, we address the adaptive detection/classification of signals in a homogenous interference environment. We refer to a radar system equipped with a phased array antenna and account for both the presence of mutual coupling between radiating antennas and a possible coherent interferer impinging on the array mainbeam. To deal with this scenario, we adopt a two-stage detection/classification...
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