Modified Matrix Method Research Articles

METHODOLOGICAL AND PRACTICAL ASPECTS OF SUBSTANTIATING MANAGEMENT DECISIONS ON LABOR SAFETY BASED ON RISK ASSESSMENT

The article deals with the practical application of modern methods and approaches to the assessment of occupational risks based on the identification of hazards. Preventive measures and production methods should be chosen based on the results of hazard identification and risk assessment, which will ensure an increase in the level of safety and health of employees, as well as allow the integration of occupational risk management into other subsystems of the general enterprise management system at all hierarchical levels. Despite the fact that a lot of attention is paid to this issue, the problem of choosing a risk assessment method and its practical implementation remains relevant.
 An urgent issue in the process of assessing occupational risks and further planning preventive measures is the early identification of production factors that can become potential sources of danger. The analysis of the theory and practice of the formation of preventive measures at enterprises shows the effectiveness of the application of modifications of the matrix method of risk assessment, the application of which allows taking into account the peculiarities of occupational safety management at enterprises, taking into account the features of the used equipment, technological processes and other factors.
 As a result of the application of the modified matrix method, effective preventive measures were developed for production processes that had an unacceptable and medium level of risk. In addition, due to the implementation of additional preventive actions, the indicator of the probability of the occurrence of a dangerous event was reduced, which directly affected the overall assessment of the degree of risk.
 For the practical implementation of a scientific approach to management decision-making based on the results of professional risk assessment, a scheme is proposed that defines the stages of the process of preparation and management decision-making.
 In the case of submission of proposals and initiatives for the implementation of projects to improve operational efficiency, it is worth paying attention to the following areas: determine the priority areas for the implementation of the project; conduct an accounting and in-depth analysis of available resources, in particular, regarding potential locations, human potential, logistics and related business in the region; involve the experience and specialists available at the enterprise to determine possible risk factors.

High-order matrix method with delimited expansion domain

Motivated by the substantial instability of the fundamental and high-overtone quasinormal modes (QNMs), recent developments regarding the notion of black hole pseudospectrum call for numerical results with unprecedented precision. This work generalizes and improves the matrix method for black hole QNMs to higher orders, specifically aiming at a class of perturbations to the metric featured by discontinuity intimately associated with the QNM structural instability. The approach is based on the mock-Chebyshev grid, which guarantees its convergence in the degree of the interpolant. In practice, solving for black hole QNMs is a formidable task. The presence of discontinuity poses a further difficulty so that many well-known approaches cannot be employed straightforwardly. Compared with other viable methods, the modified matrix method is competent in speed and accuracy. Therefore, the method serves as a helpful gadget for relevant studies.

Matrix method for perturbed black hole metric with discontinuity

Recent studies based on the notion of black hole pseudospectrum indicated substantial instability of the fundamental and high-overtone quasinormal modes (QNMs). Besides its theoretical novelty, the details about the migration of the QNM spectrum due to specific perturbations may furnish valuable information on the properties of associated gravitational waves in a more realistic context. This work generalizes the matrix method for black hole QNMs to cope with a specific class of perturbations to the metric featured by discontinuity, which is known to be intimately connected with the QNM structural instability. In practice, the presence of discontinuity poses a difficulty so that many well-known approaches for QNMs cannot be straightforwardly applied. By comparing with other methods, we show that the modified matrix method is efficient, which can be used to solve for the low-lying modes with reasonable precision. Therefore, it might serve as an alternative gadget for relevant studies.

Propagation and control of shear waves in piezoelectric composite waveguides with metallized interfaces

This paper investigates coupled electro-elastic shear waves propagating along a piezoelectric finite width waveguide consisting of layers separated by metallized interfaces and arranged in a periodic way along the guide. The modified matrix method is applied to obtain the dispersion equation for a waveguide with straight walls. Bragg resonances and the presence of trapped modes and slow waves are revealed and analyzed for a periodic structure consisting of unit cells made up firstly from two different piezoelectric materials, and secondly from two identical piezoelectric materials. An analytical expression for the transmission coefficient for the waveguide with a defect layer is found that can be used to accurately detect and control the position of the passband within a stopband. This can be instrumental for constructing a tuneable waveguide made of layers of identical piezoelectric crystals separated by metallized interfaces.

Determining the source time function using the modified matrix method

The modified matrix method of construction of wavefield on the free surface of an anisotropic medium is proposed. The earthquake source represented by a randomly oriented force or a seismic moment tensor is placed on an arbitrary boundary of a layered anisotropic medium. The theory of the matrix propagator in a homogeneous anisotropic medium by introducing a “wave propagator” is presented. It is shown that the matrix propagator can be represented by a “wave propagator” in each layer for anisotropic layered medium. The matrix propagator P(z, z0=0) acts on the free surface of the layered medium and generates stress-displacement vector at depth z. The displacement field on the free surface of an anisotropic medium is obtained from the received system of equations considering the radiation condition and that the free surface is stressless. The new method determining source time function in anisotropic medium for three different types of seismic source is validated.

Occupational Safety and Calculation of Risks for all Employees

Occupational health and safety (OHS) is important for any organization, as it is a key aspect determining its success. In terms of new OHS approaches to risk management considering workers' age in both manufacturing and non-manufacturing sectors, it is essential to implement new preventative measures allowing the acceptance of adequate risk considering the active age of the employees.The abovementioned reasons led to the creation of a risk assessment tool that focuses on elderly workers. The risk assessment tool is based on a combination of a questionnaire and a matrix method. The matrix meth-od is extended by a coefficient considering the worker's age. The abovementioned reasons led to the creation of a risk assessment tool that focuses on elderly workers. The risk assessment tool is based on a combination of a questionnaire and a matrix method. The matrix method is extended by a coefficient considering the worker's age. The utilization of the modified matrix method is not limited by the company's size or scope of activities, thus making the method very practical and widely utilizable.Defining the coefficients that would take the employee's age into account proved to be a demanding task. Its solution was based on the changes in the functional capacity.

Calculation of equilibrium binding constants and cooperativity of Cu(II) mixed solvated complexes formation

A new extension of matrix approach is proposed to calculate the equilibrium constants of coordinated solvent substitution in a metal ion first salvation shell in the mixed solvent system. The proposed method allows reducing the number of independent variables, necessary to calculate the fractions of species in solution. The equilibrium model of MeCN substitution with DMF and DMSO in the presence of Cu(II) ion for the assessment of structure of intermediate species is presented and verified. The distribution diagrams of Cu(II) species in mixed organic solvents have been analyzed using the modified matrix method. The intrinsic equilibrium constants K of the first solvent molecule replacement in the Cu(II) coordination shell and the correction for the mutual influence between the solvent molecules as ligands in the successive complex formation (cooperativity parameter w) in acetonitrile solution have been calculated from the fitting procedure. It is shown that anticooperative substitution of MeCN by donor ligands in the first coordination shell of the Cu(II) ion is always governed by the change of coordination number during the stepwise process.

New method for ion mobility determination by stability threshold measurement in gas filled radio frequency quadrupoles

A new method is proposed for determining ion mobility by use of a RF-only quadrupole equipped with a longitudinal electrical field along its axis (RFQLEF). This method is based on measuring the transmission threshold for the ions of interest as a function of the RF voltage and frequency. The method is based on the analysis of the equation of the motion of ions under the RF-only quadrupolar electrical field and the friction force due to collisions of the ions with the buffer gas molecules. The stability diagram for this equation was found numerically by a modified matrix method. According to the stability diagram the threshold values of the RF voltage and frequency determine the mobility coefficient for the ions of interest. Mobility coefficients for electrosprayed ions of several substances (bradykinin 2+, gramicidin S 2+ and 1+, multicharged ions of apomyoglobin and cytochrome c) were measured and compared with literature values. © 1998 John Wiley & Sons, Ltd.

Simulating the effect of network changes in power system load flows

Power system load flow solutions, with particular reference to removal of branches for security evaluation, are discussed. The equivalence between two proposed techniques (compensation method and inversion of a modified matrix method) which allow simple modification of the load flow problem in order to evaluate single and double line outages is demonstrated.