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Search results for: super twisting algorithm
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Silence/noise detection for speech and music signals
PublicationThis paper introduces a novel off-line algorithm for silence/noise detection in noisy signals. The main concept of the proposed algorithm is to provide noise patterns for further signals processing i.e. noise reduction for speech enhancement. The algorithm is based on frequency domain characteristics of signals. The examples of different types of noisy signals are presented.
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Parallel Background Subtraction in Video Streams Using OpenCL on GPU Platforms
PublicationImplementation of the background subtraction algorithm using OpenCL platform is presented. The algorithm processes live stream of video frames from the surveillance camera in on-line mode. Processing is performed using a host machine and a parallel computing device. The work focuses on optimizing an OpenCL algorithm implementation for GPU devices by taking into account specific features of the GPU architecture, such as memory access,...
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A non-uniform real-time speech time-scale stretching method
PublicationAn algorithm for non-uniform real-time speech stretching is presented. It provides a combination of typical SOLA algorithm (Synchronous Overlap and Add ) with the vowels, consonants and silence detectors. Based on the information about the content and the estimated value of the rate of speech (ROS), the algorithm adapts the scaling factor value. The ability of real-time speech stretching and the resultant quality of voice were...
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Comparison of various speech time-scale modificartion methods
PublicationThe objective of this work is to investigate the influence of the different time-scale modification (TSM) methods on the quality of the speech stretched up using the designed non-uniform real-time speech time-scale modification algorithm (NU-RTSM). The algorithm provides a combination of the typical TSM algorithm with the vowels, consonants, stutter, transients and silence detectors. Based on the information about the content and...
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A low complexity double-talk detector based on the signal envelope
PublicationA new algorithm for double-talk detection, intended for use in the acoustic echo canceller for voice communication applications, is proposed. The communication system developed by the authors required the use of a double-talk detection algorithm with low complexity and good accuracy. The authors propose an approach to doubletalk detection based on the signal envelopes. For each of three signals: the far-end speech, the microphone...
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IPMSM rotor position estimator based on analysis of phase current derivatives
PublicationThis paper describes an algorithm for estimation of IPMSM angular rotor position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. The presented method is designed for medium- and high-speed range, since it is based on determination of the EMF vector. Algorithm is characterised by a very simple formulae. The calculation of rotor position is performed in every PWM...
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Transient detection for speech coding applications
PublicationSignal quality in speech codecs may be improved by selecting transients from speech signal and encoding them using a suitable method. This paper presents an algorithm for transient detection in speech signal. This algorithm operates in several frequency bands. Transient detection functions are calculated from energy measured in short frames of the signal. The final selection of transient frames is based on results of detection...
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Implementation of discrete convolution using polynomial residue representation
PublicationConvolution is one of the main algorithms performed in the digital signal processing. The algorithm is similar to polynomial multiplication and very intensive computationally. This paper presents a new convolution algorithm based on the Polynomial Residue Number System (PRNS). The use of the PRNS allows to decompose the computation problem and thereby reduce the number of multiplications. The algorithm has been implemented in Xilinx...
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Design and computational fluid dynamics analysis of the last stage of innovative gas-steam turbine
PublicationResearch regarding blade design and analysis of flow has been attracting interest for over a century. Meanwhile new concepts and design approaches were created and improved. Advancements in information technologies allowed to introduce computational fluid dynamics and computational flow mechanics. Currently a combination of mentioned methods is used for the design of turbine blades. These methods enabled us to improve flow efficiency...
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Detection of vehicles stopping in restricted zones in video from surveillance cameras
PublicationAn algorithm for detection of vehicles that stop in restricted areas, e.g. excluded by traffic rules, is proposed. Classic approaches based on object tracking are inefficient in high traffic scenes because of tracking errors caused by frequent object merging and splitting. The proposed algorithm uses the background subtraction results for detection of moving objects, then pixels belonging to moving objects are tested for stability....
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Modal parameters identification with Particle Swarm Optimization
PublicationThe paper presents method of the modal parameters identification based on the Particle Swarm Optimization (PSO) algorithm [1]. The basic PSO algorithm is modified in order to achieve fast convergence and low estimation error of identified parameters values. The procedure of identification as well as algorithm modifications are presented and some simple examples for the SISO systems are provided. Results are compared with the results...
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Spectrum-based modal parameters identification with Particle Swarm Optimization
PublicationThe paper presents the new method of the natural frequencies and damping identification based on the Artificial Intelligence (AI) Particle Swarm Optimization (PSO) algorithm. The identification is performed in the frequency domain. The algorithm performs two PSO-based steps and introduces some modifications in order to achieve quick convergence and low estimation error of the identified parameters’ values for multi-mode systems....
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Shared processor scheduling
PublicationWe study the shared processor scheduling problem with a single shared processor to maximize total weighted overlap, where an overlap for a job is the amount of time it is processed on its private and shared processor in parallel. A polynomial-time optimization algorithm has been given for the problem with equal weights in the literature. This paper extends that result by showing an (log)-time optimization algorithm for a class...
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Numerical solution of threshold problems in epidemics and population dynamics
PublicationA new algorithm is proposed for the numerical solution of threshold problems in epidemics and population dynamics. These problems are modeled by the delay-differential equations, where the delay function is unknown and has to be determined from the threshold conditions. The new algorithm is based on embedded pair of continuous Runge–Kutta method of order p = 4 and discrete Runge–Kutta method of order q = 3 which is used for the...
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Simulation model of IPMSM drive with rotor position estimator
PublicationThe paper presents a simulation model of electric drive consisting of: IPMSM motor, inverter and digital controller. The model was designed in Mathlab/Simulink. By modelling of the controller its discrete operation was taken into account in order to simulate precisely a specific sensorless control algorithm. A method for estimation of angular rotor position was proposed. Its mathematical algorithm was explained and errors were...
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The parallel environment for endoscopic image analysis
PublicationThe jPVM-oriented environment to support high performance computing required for the Endoscopy Recommender System (ERS) is defined. SPMD model of image matching is considered and its two implementations are proposed: Lexicographical Searching Algorithm (LSA) and Gradient Serching Algorithm (GSA). Three classes of experiments are considered and the relative degree of similarity and execution time of each algorithm are analysed....
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A New Three-Dimensional Space Vector Modulation for Multilevel Four-Leg Converters Based on the Shape Functions of Tetrahedral Element
PublicationThe paper proposes a new three-dimensional space vector pulse-width modulation (3D-SVPWM) algorithm for multilevel four-leg converters. The proposed PWM duty cycle calculation is based on the shape functions of the threedimensional tetrahedral finite elements. The algorithm ensures synthesis of accurate and undistorted output voltages even under significant imbalance or ripple in the DC-link voltages. At the same time, the algorithm...
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The effect of pre-hydrogen charging on corrosion behaviour of superduplex stainless steel welded joints
PublicationThe paper presents results of research undertaken to determine the influence of hydrogen on passivity and corrosion resistance of 2507 super duplex stainless steel welded joints. Butt welded joints were made with low heat input using flux corded arc welding (FCAW) method. Coupons of 5.0 x 5.0 mm were cut from the welded joints containing weld metal (WM), heat affected zone (HAZ) and parent metal (PM). Hydrogen was introduced...
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Efficiency evaluation of graduation process in Australian public universities
PublicationFirst-year attrition and on-time graduation are key challenges for contemporary universities, which determine their efficiency. Based on the benefit of the doubt approach, this study reports the efficiency of the graduation process in 37 Australian public universities. The super-efficiency model extended by restrictions on virtual weights is used. The proposed model considers the attrition rate and the on-time graduation rate separately...
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Computer-aided reconstruction of the railway track axis geometrical shape
PublicationIn the paper a method of the railway track axis geometrical shape identification in a horizontal plane, directly from the continuous satellite measurements, is presented. In this method, an algorithm for the design of railway track sections located in the horizontal arc is used. The algorithm uses an analytical description of the layout by means of suitable mathematical formulas. The design procedure has a universal character and...
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On Computational Aspects of Greedy Partitioning of Graphs
PublicationIn this paper we consider a problem of graph P-coloring consisting in partitioning the vertex set of a graph such that each of the resulting sets induces a graph in a given additive, hereditary class of graphs P. We focus on partitions generated by the greedy algorithm. In particular, we show that given a graph G and an integer k deciding if the greedy algorithm outputs a P-coloring with a least k colors is NP-complete for an infinite...
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Multilevel inverter neutral-point voltage sensor diagnostic based on the Extended Kalman Filter
PublicationA new algorithm for neutral point voltage imbalance estimation in DC link of the three-level (3L) neutral point clamped (NPC) voltage source inverter (VSI) is proposed. Application of the proposed algorithm does not require any additional sensors. The unbalanced voltage calculation is based on the information derived from the inverter output measured currents and from the knowledge of the load model parameters. In order to estimate...
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Real‐Time PPG Signal Conditioning with Long Short‐Term Memory (LSTM) Network for Wearable Devices
PublicationThis paper presents an algorithm for real‐time detection of the heart rate measured on a person’s wrist using a wearable device with a photoplethysmographic (PPG) sensor and accelerometer. The proposed algorithm consists of an appropriately trained LSTM network and the Time‐Domain Heart Rate (TDHR) algorithm for peak detection in the PPG waveform. The Long Short‐Term Memory (LSTM) network uses the signals from the accelerometer...
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Continuum contact model for friction between graphene sheets that accounts for surface anisotropy and curvature
PublicationUnderstanding the interaction mechanics between graphene layers and co-axial carbon nanotubes (CNTs) is essential for modeling graphene and CNT-based nanoelectromechanical systems. This work proposes a new continuum contact model to study interlayer interactions between curved graphene sheets. The continuum model is calibrated and validated using molecular dynamics (MD) simulations. These are carried out employing the reactive...
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Dynamic OWL Ontology matching Using Lexical Wordnet-based Measures
PublicationOntologies are often used as a means of describing knowledge and the domain of operation of modern applications. S need arises for the ability to quickly match those ontologies to enable interoperability of such systems. This paper presents an extension to Noy and McGuiness ontology construction methodology which should improve ontology interoperability and a lexicon-based algorithm for merging and aligning of such ontologies stored...
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Automatic Reduction-Order Selection for Finite-Element Macromodels
PublicationAn automatic reduction-order selection algorithm for macromodels in finite-element analysis is presented. The algorithm is based on a goal-oriented a posteriori error estimator that operates on low-order reduced blocks of matrices, and hence, it can be evaluated extremely quickly.
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Sensorless IPMSM drive with rotor position estimator based on analysis of phase current derivatives
PublicationThis paper describes a sensorless Interior Permanent Magnet Synchronous Motor (IPMSM) drive designed for traction applications. Wide-speed sensorless operation is provided with the use of three methods of rotor position estimation designed for: a standstill, low- and high-speed range. The paper focuses on the high-speed estimation algorithm. The estimator uses the derivatives of motor phase currentsresulting from PWM modulation...
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Porównanie algorytmów MGA i NGA do projektowania i optymlizacji kombinacyjnych układów cyfrowych z algorytmem MLCEA.
PublicationW artykule zaprezentowano porównanie algorytmów ewolucyjnych do projektowania i optymalizacji kombinacyjnych układów cyfrowych. Porównano algorytmy MGA (Multiobjective Genetic Algorithm) i NGA (Genetic Algorithm with N-cardinality Reprezentation) z utworzonym algorytmem MLCEA (Multi-Layer Chromosome Evolutionary Algorithm), bazującym na reprezentacji osobników w postaci chromosomów wielowarstwowych. Otrzymane wyniki dla algorytmu...
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Reliable Greedy Multipoint Model-Order Reduction Techniques for Finite-Element Analysis
PublicationA new greedy multipoint model-order reduction algorithm for fast frequency-domain finite-element method simulations of electromagnetic problems is proposed. The location of the expansion points and the size of the projection basis are determined based on a rigorous error estimator. Compared to previous multipoint methods, the quality of the error estimator is significantly improved by ensuring the orthogonality of the projection...
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Music Recommendation Based on Multidimensional Description and Similarity Measures . Rekomendacja muzyki na podstawie wielowymiarowego wektora cech i miar podobieństwa
PublicationThis study aims to create an algorithm for assessing the degree to which songs belong to genres defined a priori. Such an algorithm is not aimed at providing unambiguous classification-labelling of songs, but at producing a multidimensional description encompassing all of the defined genres. The algorithm utilized data derived from the most relevant examples belonging to a particular genre of music. For this condition to be met,...
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Retrieval with Semantic Sieve
PublicationThe article presents an algorithm we called Semantic Sieve applied for refining search results in text documents repository. The algorithm calculates socalled conceptual directions that enables interaction with the user and allows to narrow the set of results to the most relevant ones. We present the system where the algorithm has been implemented. The system also offers in the presentation layer clustering of the results into...
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Task Allocation and Scalability Evaluation for Real-Time Multimedia Processing in a Cluster Envirinment
PublicationAn allocation algorithm for stream processing tasks is proposed (Modified best Fit Descendent, MBFD). A comparison with another solution (BFD) is provided. Tests of the algorithms in an HPC environment are descrobed and the results are presented. A proper scalability metric is proposed and used for the evaluation of the allocation algorithm.
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Estimation of interior-permanent-magnet-synchronous-motor rotor position by analysis of phase-current derivatives
PublicationThis paper describes an algorithm for estimation of IPMSM rotor angular position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. The presented method is designed for medium- and high-speed range, since it is based on determination of the EMF vector. Calculation of the motor position is performed in every PWM cycle. The standard SV-PWM method is used to determine...
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A method for counting people attending large public events
PublicationThe algorithm for people counting in crowded scenes, based on the idea of virtual gate which uses optical flow method is presented. The concept and practical application of the developed algorithm under real conditions is depicted. The aim of the work is to estimate the number of people passing through entrances of a large sport hall. The most challenging problem was the unpredicted behavior of people while entering the building....
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Improved method for real-time speech stretching
Publicationn algorithm for real-time speech stretching is presented. It was designed to modify input signal dependently on its content and on its relation with the historical input data. The proposed algorithm is a combination of speech signal analysis algorithms, i.e. voice, vowels/consonants, stuttering detection and SOLA (Synchronous-Overlap-and-Add) based speech stretching algorithm. This approach enables stretching input speech signal...
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Detection of moving objects in images combined from video and thermal cameras
PublicationAn algorithm for detection of moving objects in video streams from the monitoring cameras is presented. A system composed of a standard video camera and a thermal camera, mounted in close proximity to each other, is used for object detection. First, a background subtraction is performed in both video streams separately, using the popular Gaussian Mixture Models method. For the next processing stage, the authors propose an algorithm...
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Solution of the dike-break problem using finite volume method and splitting technique
PublicationIn the paper the finite volume method (FVM) is presented for the solution of two-dimensional shallow water equations. These equations are frequently used to simulate the dam-break and dike-break induced flows. The applied numerical algorithm of FVM is based on the wave-propagation algorithm which ensures a stable solution and simultaneously minimizes the numerical errors. The dimensional decomposition according to the coordinate...
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Partial dominated schedules and minimizing the total completion time of deteriorating jobs
PublicationA problem of scheduling deteriorating jobs on a single processor is considered. The processing time of a job is given by a function pi=ai+bisi, where si is the starting time of the job, ai>=0, bi>=0, for i=1,...,n. Jobs are non-preemptive and independent and there are neither ready times nor deadlines. The goal is to minimize the total weighted completion time. We show how to employ the concept of non-dominated schedules to construct...
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Music genre classification applied to bass enhancement for mobile technology
PublicationThe aim of this paper is to present a novel approach to the Virtual Bass Synthesis (VBS) algorithms applied to portable computers. The proposed algorithm is related to intelligent, rule-based setting of synthesis parameters according to music genre of an audio excerpt. The classification of music genres is automatically executed employing MPEG 7 parameters and the Principal Component Analysis method applied to reduce information...
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Drum Replacement Using Wavelet Filtering Podmienianie próbek perkusyjnych przy zastosowaniu filtracji falkowej
PublicationThe paper presents the solution that can be used to unify snare drum sound within a chosen fragment. The algorithm is based on the wavelet transformation and allows replacement of sub-bands of particular sounds, which are outside a certain range. Five experienced sound engineers put the algorithm under the test using
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Nowy wewnątrzbudynkowy algorytm wyznaczania położenia obiektów
PublicationW referacie zaprezentowano nowy wewnątrzbudynkowy algorytm wyznaczania położenia obiektów WAP. W algorytmie tym uwzględnia się właściwości środowiska propagacyjnego, dzięki czemu dokładność estymat położenia obiektów wyznaczonych algorytmem WAP jest większa niż wyznaczonych znanymi algorytmami Chana oraz Foy’a. W referacie przedstawiono wyniki analizy porównawczej tych trzech algorytmów z użyciem rzeczywistych pomiarów odległości...
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Innovative system for energy collection and management integrated within a photovoltaic module
PublicationThe dynamic development of battery technology and design based on the flow of lithium ions, mainly driven by the needs of the automotive industry, leads to the conclusion that these batteries are becoming a more viable alternative to traditional lead-acid batteries. Their use is driven by the ability to quickly charge and discharge, a higher durability, maintenance-free operation, much smaller dimensions and lighter weight. The...
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IMPACT-TOUGHNESS INVESTIGATIONS OF DUPLEX STAINLESS STEELS
PublicationDuplex stainless steels are very attractive constructional materials for use in aggressive environments because of their several advantages over austenitic stainless steels. Duplex steels have excellent pitting and crevice corrosion resistance, are highly resistant to chloride stress-corrosion cracking and are about twice as strong as common austenitic steels. Better properties are associated with their microstructures consisting...
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Computationally-efficient design optimisation of antennas by accelerated gradient search with sensitivity and design change monitoring
PublicationElectromagnetic (EM) simulation tools are of primary importance in the design of contemporary antennas. The necessity of accurate performance evaluation of complex structures is a reason why the final tuning of antenna dimensions, aimed at improvement of electrical and field characteristics, needs to be based on EM analysis. Design automation is highly desirable and can be achieved by coupling EM solvers with numerical optimisation...
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Collective filter evaluation of an FSD filter-based resampling algorithm. [online] W: Online Symposium for Electronics Engineers. Techonline Bedford, Massachusetts, USA. [Dostęp: 15 stycznia**2002]. Dostępny w World Wide Web: http://www.techonline.com/community/ed_resource/feature_article/14917/[6 s. 5 rys.] Badanie algorytmu zmiany szybkości próbkowania realizowanego w oparciu o filtry FSD za pośrednictwem analizy filtru zbiorczego.
PublicationW pracy przedstawiono koncepcję filtru zbiorczego dla potrzeb oceny jakościalgorytmu zmiany szybkości próbkowania realizowanego w oparciu o filtry u-łamkowo-opóźniające (FSD). W przypadku takiego algorytmu przepróbkowania dowyznaczania każdej próbki wyjściowej potrzebny jest filtr FSD o innm opóź-nieniu ułamkowym. Z kolei jakość takiego filtru zależy właśnie od jego opóź-nienia, co stwarza problemy w ocenie jakości samego...
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Collaborative Exploration of Trees by Energy-Constrained Mobile Robots
PublicationWe study the problem of exploration of a tree by mobile agents (robots) that have limited energy. The energy constraint bounds the number of edges that can be traversed by a single agent. We use a team of agents to collectively explore the tree and the objective is to minimize the size of this team. The agents start at a single node, the designated root of the tree and the height of the tree is assumed to be less than the energy...
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Simulation of Wave Propagation in Media Described by Fractional-Order Models
PublicationIn this paper, algorithms for simulation of the wave propagation in electromagnetic media described by fractional-order (FO) models (FOMs) are presented. Initially, fractional calculus and FO Maxwell's equations are introduced. The problem of the wave propagation is formulated for media described by FOMs. Then, algorithms for simulation of the non-monochromatic wave propagation are presented which employ computations in the time...
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Optimised Robust Placement of Hard Quality Sensors for Robust Monitoring of Quality in Drinking Water Distribution Systems
PublicationA problem of optimised robust placement of the hard quality sensors in Drinking Water Distribution Systems under several water demand scenarios for robust quality monitoring is formulated. Numerical algorithms to solve the problem are derived. The optimality is meant as achieving at the same time a desired trade off between the sensor capital and maintenance costs and resulting robust estimation accuracy of the monitoring algorithm...
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Improving Re-rankCCP with Rules Quality Measures
PublicationRecommender Systems are software tools and techniques which aim at suggesting new items that may possibly be of interest to a user. Context-Aware Recommender Systems exploit contextual information to provide more adequate recommendations. In this paper we described a modification of an existing contextual post-filtering algorithm which uses rules-like user representation called Contextual Conditional Preferences. We extended the...
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Deep neural network architecture search using network morphism
PublicationThe paper presents the results of the research on neural architecture search (NAS) algorithm. We utilized the hill climbing algorithm to search for well-performing structures of deep convolutional neural network. Moreover, we used the function preserving transformations which enabled the effective operation of the algorithm in a short period of time. The network obtained with the advantage of NAS was validated on skin lesion classification...