Clustering of ECG segments for patients before sudden cardiac death based on Lagrange descriptors

Novel approach to clustering of ECG segments based on Lagrange descriptors is presented in this paper. The approach starts by extracting 2D features with the help of Lagrange descriptors. Then the features are transformed to latent vectors which are clustered using K-means algorithm. The object of the research is to visualize the dynamics of clusters of 2D features of segments of ECG before sudden cardiac death happens to a patient

Skeletinių kreivių panaudojimas su glodinimo procedūra trumpų laiko eilučių prognozei

An improved algebraic forecasting method with internal smoothing is proposed for short-term time series prediction. The concept of the H-rank is proposed for the detection of a base fragment of the sequence. Numerical experiments with artificially generated and real-world time series are used to illustrate the forecast method.Straipsnyje pateiktas patobulintas trumpų laiko eilučių prognozės metodas, identifikuojantis algebrinės sekos skeletinę kreivę. Prognozei pagerinti naudojama vidinio glodinimo procedūra. Eksperimentai atlikti su dirbtinai sugeneruota testine eilute ir realiais duomenimis

Special Multiplicative Operators for the Solution of ODE – Invariants and Representations

The generalized multiplicative operator of differentiation is introduced in this paper. It is shown that the generalized multiplicative operator can be expressed as a product of two noncommutative but multiplicative exponential operators, though the generalized multiplicative operator is not an exponential operator itself. The generalized multiplicative operator is effectively exploited for the construction of solutions to nonlinear ordinary differential equations through formal transformations of invariants and representations of initial conditions. The concept of the generalized multiplicative operator provides the insight into the algebraic structure of solutions to nonlinear ordinary differential equations which cannot be identified using conventional exponential operators

Special solutions of Huxley differential equation

The conditions when solutions of Huxley equation can be expressed in special form and the procedure of finding exact solutions are presented in this paper. Huxley equation is an evolution equation that describes the nerve propagation in biology. It is often useful to obtain a generalized solitary solution for fully understanding its physical meanings. It is shown that the solution produced by the Exp-function method may not hold for all initial conditions. It is proven that the analytical condition describing the existence of the produced solution in the space of initial conditions (or even in the space of the system's parameters) can not be derived by the Exp-function method because the question about the existence of that solution is omitted. The proposed operator method, on the contrary, brings the load of symbolic computations before the structure of the solution is identified. The method for the derivation of the solution is based on the concept of the rank of the Hankel matrix constructed from the sequence of coefficients representing formal solution in the series form. Moreover, the structure of the algebraic-analytic solution is generated automatically together with all conditions of the solution's existence. Computational experiments are used to illustrate the properties of derived analytical solutions

Distributed Parallel Computing for Visual Cryptography Algorithms

Proceedings of: Second International Workshop on Sustainable Ultrascale Computing Systems (NESUS 2015). Krakow (Poland), September 10-11, 2015.The recent activities to construct exascale and ultrascale distributed computational systems are opening a possibility to apply parallel and distributed computing techniques for applied problems which previously were considered as not solvable with the standard computational resources. In this paper we consider one global optimization problem where a set of feasible solutions is discrete and very large. There is no possibility to apply some apriori estimation techniques to exclude an essential part of these elements from the computational analysis, e.g. applying branch and bound type methods. Thus a full search is required in order to solve such global optimization problems. The considered problem describes visual cryptography algorithms. The main goal is to find optimal perfect gratings, which can guarantee high quality and security of the visual cryptography method. The full search parallel algorithm is based on master-slave paradigm. We present a library of C++ templates that allow the developer to implement parallel master-slave algorithms for his application without any parallel programming and knowledge of parallel programming API. These templates automatically give parallel solvers tailored for clusters of computers using MPI API and distributed computing applications using BOINC API. Results of some computational experiments are presented.The work presented in this paper has been partially supported by EU under the COST programme Action IC1305, ’Network for Sustainable Ultrascale Computing (NESUS)’

Generalized solitary waves in nonintegrable KdV equations

The generalization of the classical Korteweg-de-Vries (KdV) solitary wave solution is presented in this paper. The amplitude and the propagation speed of generalized KdV solitary waves vary in time. Generating partial differential equations and conditions of existence of the generalized KdV solitary waves are derived using the inverse balancing method. Computational experiments illustrate the variety of new solitary solutions and their generating equations

Investigation of 5-Year Interconnections between Local Earth Magnetic Field Fluctuations and Acute Myocardial Infarction in Lithuania

The impact of the local Earth magnetic field (LEMF) on cardiovascular events has been studied recently. Data gathered during past years encouraged us to conduct this epidemiological analysis evaluating the association between changes in LEMF and hospital admissions due to AMI in Lithuania between August 2014 and September 2019. This study is unique due to its coverage of all Lithuanian patients. The frequency of morbidity of AMI was compared with the intensity of the LEMF and correlation coefficient was evaluated. The LEMF was measured by the Global Coherence Monitoring Network magnetometer located in Lithuania. LEMF was measured by pikotesla square (pT²). The LEMF was analized in five frequency ranges [Hz], generally called between Schumann resonance, which overlap with the human brain activity waves on electroencefalogram (EEG) frequency ranges (here, they are named as SDelta (0-3.5Hz), STheta (3.5-7Hz), SAlpha (7-15Hz), SBeta (15-32Hz) and SGamma (32-65Hz) to distinguish from the EEG bands). Significant correlations between weekly admissions of AMI cases and the weekly LEMF strength in five frequency ranges and in total range was found. A clear negative correlation was observed between cases of AMI in female group and LEMF frequency ranges SDelta (0-3.5Hz), STheta (3.5-7Hz), SAlpha (7-15Hz), SBeta (15-32Hz) and in total range. In the second half of the year the number of AMI is lower, therefore negative correlations between SDelta (0-3.5Hz), STheta (3.5-7Hz), SAlpha (7-15Hz) and SBeta (15-32Hz) ranges are stronger than in the first one. This is particularly noticeable in 2016 and 2018 years

GIS-based landform classification of Bronze Age archaeological sites on Crete Island

Various physical attributes of the Earth's surface are factors that influence local topography and indirectly influence human behaviour in terms of habitation locations. The determination of geomorphological setting plays an important role in archaeological landscape research. Several landform types can be distinguished by characteristic geomorphic attributes that portray the landscape surrounding a settlement and influence its ability to sustain a population. Geomorphometric landform information, derived from digital elevation models (DEMs), such as the ASTER Global DEM, can provide useful insights into the processes shaping landscapes. This work examines the influence of landform classification on the settlement locations of Bronze Age (Minoan) Crete, focusing on the districts of Phaistos, Kavousi and Vrokastro. The landform classification was based on the topographic position index (TPI) and deviation from mean elevation (DEV) analysis to highlight slope steepness of various landform classes, characterizing the surrounding landscape environment of the settlements locations. The outcomes indicate no interrelationship between the settlement locations and topography during the Early Minoan period, but a significant interrelationship exists during the later Minoan periods with the presence of more organised societies. The landform classification can provide insights into factors favouring human habitation and can contribute to archaeological predictive modelling

Experimental verification on applying indirect inverse substructuring analysis to identify coupling dynamic stiffness of mechanical assembly via planar surface

To broaden the engineering application of inverse substructuring analysis, the mechanical assembly via planar surface is experimentally studied. Specifically, the first and the second schemes of indirect inverse substructuring analysis are applied to identify the coupling dynamic stiffness of the assembly. The experimental model of the assembly is designed, and the surface is then discretized equivalently into point-to-point connections for testing the frequency response functions (FRFs) involved in the schemes. Experimental results show that, applying both of the schemes are feasible for the identification, and the identified stiffnesses approach to be stable as the number of discretized points increases