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The paper reviews the existing methods for identifying QRS complexes. An attempt is made to make a well-defined classification of available algorithms in an approach to QRS detection. Emphasis is laid on the consideration of specific requirements for such algorithms by computer-aided real-time ECG systems. A task of choice of the most suitable method is formulated. An algorithm based on the well-known principles of frequency-time detection is proposed as an alternative solution of this task. The algorithm makes it possible to single out QRS complexes from real-time ECG and to effectively make a digital signal processing by available optimized libraries. The method initially used in the Matlab package has been integrated within the laboratory computerized ECG system.

The paper deals with the synthesis of algorithms for non-linear control of the degree of contrast of digital chest images by bringing the baseline histogram of brightness to the prearranged form and with practical analysis of the efficiency of the algorithms derived.

Results of the investigation of the interrelation between cosmonauts' erroneous actions and work and rest schedule intensity in fourteen long-duration Mir missions are presented in the paper. The statistical significance of this dependence has been established, and its nonlinear character has been revealed. An algorithm of short-range planning of crew operations has been developed based on determination of critical crew work loads deduced from increases in erroneous actions. Together with other methods the suggested approach may be used to raise cosmonauts' performance reliability.

Copyright of Automatic Welding / Avtomatitcheskaia Svarka is the property of International Association Welding (Paton Publishing House) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper shows how to improve the quality of diagnosing coronary heart disease (CHD). It proposes a mathematical model of coronary circulatory disorders, which is based on the definition of CHD as a cardiac abnormality caused by the imbalance of coronary blood flow and myocardial oxygen consumption, outlines an algorithm for construction of this model. With this model, a computer system has been designed for examining a patients with CHD, which permits the construction of a virtual model of coronary circulatory disorders.

The paper considers principles in the design of measuring impedance converters which can find medical and biological applications. The converters are noted for a wide range of amplitudes and frequencies of measuring currents with better metrological characteristics.

Despite the fact that the duration of cardiac cycle complexes is a main diagnostic index in interpretation of ECG, a unified common approach to constructing measuring algorithms is lacking now. The paper reviews the methods of detection and measurement of the onset and termination of cardiographic complexes. Their link with the general theory of assessment by using the Fischer mathematical statistic methods, the Winner filtration methods, the approximation methods by spline functions and Kalman's filters is considered. An attempt was made to describe the pattern of cardiac cycle pulses on the basis of physiological processes of cardiac electric activity.

The paper describes the method of image recognition in which a useful element of Bayes' approach, numerous alternatives, is united with the productive idea of heterogeneous sequential analysis--ordering of signs by their informative value for decision making. The idea of the method--a sequential Bayes' algorithm--consists in the following: the a priori probabilities are not determined before-hand but specified in turn, depending on the empirical material. The author proves that algorithms conforming to the Neumann-Pierson or Wald strategies, specifically, the heterogeneous sequential algorithm, are not to be referred to the Bayes' algorithms, as is usually done in analyses of clinical laboratory data. Ideologically the heterogeneous sequential algorithm was developed as a method for analysis of empirical data, whereas the Bayes' approach is a deductive method. Confusion of the Bayes' approach with the algorithms based on the probability ratios is methodologically unjustified at least because the Neumann-Pierson and Wald's approaches are the greatest statistical achievements of the twentieth century and have nothing to do with the Bayes' formula. The methodology of constructing the probability measure in the clinical laboratory signs space is described in detail, as are the new objects, interval and binary structures, which emerge in the course of this construction. These objects help improve the diagnostic significance of clinical laboratory information even in cases when the results of analyses are apparently normal. The sequential Bayes algorithm is compared with the traditional Bayes approach to certain clinical problems. The author concludes that the sequential Bayes algorithm is a serious alternative to algorithms for making multiple-alternative decisions in the solution of clinical tasks.

The paper proposes a mathematical model of development of a cell population with a changing proliferative activity. The model is based on the Markov branching process with cells of several types. A procedure for identifying the constructed model by experimental evidence is being developed. An example of model construction and assessment for cultured diploid fibroblasts is given.

The paper defines requirements for reference signals to check measuring the algorithms of automatic electrocardiographic systems. It proposes a reference signal which meets these requirements and gives a block diagram of a test bed.

The paper deals with the automatic processing of a Doppler ultrasonic signal and with the development of the respective software. It outlines the theory of Doppler gram synthesis and the recognition algorithms for typical elements, which are based on the developed theory, for averaged summary blood flow and spectral image of the signal.

The paper outlines the applicability of the sample recognition theory to process the data obtained with the use of multifiber optical catheters as part of information systems for diagnostics and visualization for microsurgery. A specific example of synthesizing the image assessment algorithm by employing the sample recognition theory is considered for the visualization system for a laser angioplastic unit.

This paper presents the method, algorithm and results of structural identification as a model of pilot's perception of perturbed angular motion of the cockpit and its transmission to the joystick as well as spectral density of the remnant corresponding to the transmission process. Assessments of scalar quasilinear and (more effective) multichannel models of pilot's functions are given. The assessments have been obtained for a single operator. They illustrate the potentials of this procedure.

The method of automatic registration and of the analysis of neutrophils' mobility with the use of the Image Analysis System is described in this paper. The authors developed an algorithm of cells identification which makes it possible to carry out cadre-by-cadre observing the shift of each cell's centre of gravity with the time interval between cadres more than 15 seconds. This algorithm also allows to measure areas, perimeters and orientation of cells and their changes. Looking after the shifts of the cells' centres of gravity allows to describe the cells' paths in the form of the following dependences: path-by-time, shift-by-time, angle of vector of shift alteration. Observing a great number of cells at the same time allows to get true statistical picture of neutrophils' activity and distribution of cells' activity in population of neutrophils during only some minutes of registration. It is shown that each cell in the population has its own constant velocity.

The paper is concerned with a program for data processing of dynamic scintigraphy of the skeleton and skeletal muscles using 99mTc-sodium 1-hydroxy-ethane-1, 1-diphosphonate. Employing gamma-chamber computer the program enables rapid and precise computation of the coefficient of RP elimination from the blood and the coefficients of RP accumulation by the bones and muscle tissue. Based on those coefficients one can make diagnosis and follow the time-course of pathological changes occurring in the skeleton during endocrine diseases.

Copyright of Refrigeration Engineering & Technology is the property of Odesa National University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recently we have seen the active penetration of computer algebra systems to the educational process because it allows to form an innovative learning technologies. Almost every branch of mathematics the Maple developed the separate specialized package commands. However, currently these technologies, despite its effectiveness and visibility, for various reasons, are still not common in the classroom. The purpose of this article is to review basic information about the capabilities of computer algebra to solve some common problems of the elementary number theory, and which can be used to solve educational problems. The paper describes the package description commands NumberTheory of the computer algebra system Maple. The methods of solving some common problems in the number theory in Maple. Using discussed the team package Maple a teacher can illustrate the problem solving in the classroom for the subject of the elementary number theory [ABSTRACT FROM AUTHOR]

The paper substantiates the conditions of seismic stability in the rock mass with cavities, on which protected objects are located, under constant seismic effects of mass explosions in quarries. Based on the ray-tracing method, a mathematical model of the interaction between longitudinal and transverse waves with a spherical cavity has been developed. An algorithm has been elaborated for determining the total static and dynamic loads along the spherical cavity perimeter from seismic explosion waves falling on the interface. The regularities of joint action of static loads have been determined, when located above the objects cavity, with allowance for the effect of the mass of cavity ceiling, the mass of the protected object above it and dynamic loads in the rock mass, and under the plane wave front fall on the cavity from different directions. The dependences of the change of total stresses referred to the incident wave stress at the interface of the rock mass and the cavity depending on the coordinate on its surface have been set. It has been established that the most dangerous points of cavity surface, in which destruction is likely to occur, are the cases when the seismic wave front falls on the cavity from the bottom directions typical for blasting operations in deep quarries. Under the arbitrary angles of the wave incidence on the cavity the stresses rearrange along the perimeter, which under different circumstances might lead to the mass breach and the fall of the protected objects, located above it, under the ground. [ABSTRACT FROM AUTHOR]

The paper focuses on new steganographic algorithm development. Proposed algorithm is stable to compression, including high rate compression, and based on singular vectors insensitive of image matrix blocks which corresponding to maximal singular values. Algorithm is polynomial of degree 2. The results of numerical experiments confirm the efficiency of the proposed algorithm. [ABSTRACT FROM AUTHOR]

The paper is devoted to the theoretical substantiation and approaches to the determination of the main parameters of circulation of the internal organs on the basis of the results of indirect radionuclide angiography. Formulas for the calculation of circulation mean time, blood flow volumetric rate and its fraction of the cardiac output were given. Using algorithms, cited in the paper, one could prepare programs for the processing of radionuclide angiography data on computers.

Copyright of Electrical Engineering & Electromechanics is the property of National Technical University, Kharkiv Polytechnic Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Algorithms of synchronized pulsewidth modulation (PWM), based on special space-vector-based control scheme (with the use of minimal number of voltage space vectors), have been applied for synchronous control of four neutral-point-clamped (NPC) inverters feeding six-phase (dual three-phase) drive on the base of asymmetrical open-end windings induction motor. It allows providing continuous synchronization and symmetry of the phase voltage of system during the whole control range for any ratio of voltage magnitudes of DC-sources, and for any configuration of DC-sources. Therefore, in this case four inverters of the system can be supplied by reduced number of insulated DC-sources (by one, or by two, or by three DC-sources instead of four DC-sources for standard system topology based on four two-level inverters). MATLAB- based simulations show behaviour of the system at steady-state control modes. References 11, table 1, figures 6. [ABSTRACT FROM AUTHOR]

The article describes the information technology for recognition of the number on the hot metal transfer ladle. Processing stages have been identified and described: preliminary processing, localization and number identification. The filtration and incomplete thresholding by means of global binarization with an automatic choice of a threshold have been analyzed. Localization is executed by a single linkage (the nearest neighbour) method with the modified windowing search algorithm. After localization area has been identified, a segment is generated. Identification is accomplished by means of a unique method, which is based on an indistinct representation of images and their comparison with indistinct standards. Combining in a characteristic point the segment which is being analyzed with a prototype segment kernels are formed. Those are then fractured into blocks. Based on these blocks two fuzzy sets are obtained -- one for the segment that is being analyzed and one for the prototype. For these sets the relative Hamming distance is then calculated. The calculated value shows the degree of similarity of the segments. During the tests it was proved that the Hamming distance for the segments with identical numbers is 0,01÷0,16, whereas for the segments with numbers of different ladles it is 0,26÷0,49, which is enough for a successful identification of a ladle by the image of its number. [ABSTRACT FROM AUTHOR]

A couple of decades ago, data rates on the network were measured in kilobytes per second, and even then, online game developers had some problems with the packet loss and transmission delays. Now the transfer rate is hundreds of times higher, and the problem of delay compensation is even more relevant. For many dynamic online games, a transmission delay of as little as 20 ms can be quite noticeable, negatively affecting the gameplay and emotions of the game, which can repel players. The problem is exacerbated by the fact that along with the need to compensate for the time of delivery of packets, on the client side there are other non-network factors that are beyond the control of developers, which make the total delay 5-10 ms longer. Because of this, the desire to get rid of network delays as much and as well as possible becomes a necessity, and developers are forced to look for optimal ways to solve this problem. The problem statement is as follows: to review the causes of delays in online games and possible solutions, as well as the advantages and disadvantages of certain approaches. The problem is considered at the 4 levels of the TCP / IP network model, as well as at the application level. The approaches are given for the most commonly used protocols for each layer, but basic ideas can be easily transferred to other implementations. The main causes of delays under consideration: propagation delay, router queue delay, transmission delay, and processing delays. This article shows the impact of network delays on the online games and the ways to compensate for them, along with the theory of data transmission protocols in the network and the ways to solve the problems that arise in the development of algorithms. Recommendations for solving the compensation problem can be taken into account when designing and launching online shooters, strategies, etc. Thanks to the given receptions it is possible to minimize the general delay on the transfer of packets in a network, thanks to which the game on the client looks as if the player plays in the Single Player mode. [ABSTRACT FROM AUTHOR]