76 research outputs found
Indicators and methods for assessing the quality of logistic activity processes
Purpose: This article is aimed at identifying and evaluating the quality and safety indicators of processes in the logistics system and solving the problems of product control in the goods’ distribution process. Design/Methodology/Approach: In order to assess the risks and quality of control methods in the goods’ distribution processes, studies were carried out in the process of grain supply, on which the risk assessment was tested using the fault tree using a qualitative approach with a deductive logic, which allowed to identify events at the lower levels of the system. To evaluate the results when comparing various methods of monitoring the characteristics of products in the product distribution process certain statistical tools were used. The evaluation with comparative tests is required in order to determine the way of measuring products in the goods distribution logistics system. The study uses the methods of formalization, analysis, measurement, experimental and comparison. Findings: The considered risk assessment method and the given example allow us to recommend its use for the product distribution processes for various purposes. A technique is proposed for comparing various control methods based on statistical tools that can be recommended for various goods’ distribution operations. Practical implications: The results of the study can be applied in practice to improve the quality of goods’ distribution processes and reduce risks in the various supply chains. Originality/value: The main contribution of this study is to shift the emphasis on the assessment of processes in goods’ distribution to the positions of a risk-based approach and the use of various statistical tools in logistics’ activities.peer-reviewe
Critical behavior of 3D Z(N) lattice gauge theories at zero temperature
Three-dimensional lattice gauge theories at zero temperature are
studied for various values of . Using a modified phenomenological
renormalization group, we explore the critical behavior of the generalized
model for . Numerical computations are used to simulate
vector models for for lattices with linear extension up
to . We locate the critical points of phase transitions and establish
their scaling with . The values of the critical indices indicate that the
models with belong to the universality class of the three-dimensional
model. However, the exponent derived from the heat capacity is
consistent with the Ising universality class. We discuss a possible resolution
of this puzzle. We also demonstrate the existence of a rotationally symmetric
region within the ordered phase for all at least in the finite
volume.Comment: 25 pages, 4 figures, 8 table
«Green economy» : emerging national models, estimations, trends in EU and CIS
Green economy as a transitional phase to sustainable development has gained impetus after adoption of the 2030 sustainable development goals. The article contains analysis of the existing conceptual foundations of the green growth together with the assessment tools thereof on the one part and the results of the green economy models under gradual formation in the EU and the CIS on the other part. Such approach allowed the authors to set forth the most urgent lines of development of the statistical assessment tools for the green economy achievements with the purpose of its efficient implementation.peer-reviewe
Modeling of radiative - conductive heat transfer in compositing materials
A layer of composite material is investigated, which is heated one-sidedly with one-dimensional energy transfer accounting for thermal conductivity and radiation. A mathematical model is suggested for non-stationary coefficient thermophysical problem under radiative-conductive heat transfer in a material layer. Temperature dependencies of thermal capacity and thermal conductivity coefficient of composite radio-transparent material have been determined through numerical modeling by solving the coefficient reverse problem of thermal conductivity
THE ESTIMATION OF RISK FOR DEVELOPMENT OF DISEASES DUE TO WHOLE-BODY VIBRATION EXPOSURE IN THE WORKERS OF TURBINE SHOPS OF THERMAL POWER STATIONS
The estimation of risk for development of diseases due to whole body vibration exposure on the basis of spectral characteristics at the workplaces in turbine shops of thermal power stations was carried out. The highest average equivalent levels of whole-body vibration by speeding up of vibration and. vibration velocity were observed at the workplaces of turbine machinists of Kuznetsk Thermal Power Station and. the Western-Siberian Thermal Power Station; in the machinists-inspectors of turbine equipment the indicators were a little bit lower. At the workplaces of turbine machinists the highest levels of risk for backache in the lower part and autonomic sensory polyneuropathy syndromes development were registered at the Western-Siberian Thermal Power Station and the Southern-Kuzbass Thermal Power Station, little smaller indicators were observed at Tom-Usinsk Thermal Power Station and Kuznetsk Thermal Power Station
SPECTRAL CHARACTERISTICS OF NOISE IN THE WORKERS OF MAIN DEPARTMENTS OF THE ENTERPRISES OF ALUMINIUM AND THERMAL POWER INDUSTRIES
The study of the spectral characteristics of noise levels in the workers of main departments of the enterprises of aluminium and thermal power industries had shown that equivalent sound levels in electrolysis shops at the workplaces of those engaged in electrolysis and anodic production exceeded permissible indicators on 7,1 and 11,8 dBA; in boiler shops of a thermal power station at the workplaces of boiler machinists, machinists-inspectors of boiler equipment and mill machinists the excess in permissible indicators was 22,2 dBA, 21,4 dBA and 29,3 dBA accordingly. It was established that noise in boiler and turbine shops of a thermal power station was broadband and exceeded maximum permissible values in all parts of a spectrum. In the turbine shops of a thermal power station noise levels more often exceeded maximum permissible levels in low- and high-frequency parts of a spectrum
Phase transitions in strongly coupled 3d Z(N) lattice gauge theories at finite temperature
We perform an analytical and numerical study of the phase transitions in
three-dimensional Z(N) lattice gauge theories at finite temperature for N>4
exploiting equivalence of these models with a generalized version of the
two-dimensional vector Potts models in the limit of vanishing spatial coupling.
In this limit the Polyakov loops play the role of Z(N) spins. The effective
couplings of these two-dimensional spin models are calculated explicitly. It is
argued that the effective spin models have two phase transitions of BKT type.
This is confirmed by large-scale Monte Carlo simulations. Using a cluster
algorithm we locate the position of the critical points and study the critical
behavior across both phase transitions in details. In particular, we determine
various critical indices, compute the helicity modulus, the average action and
the specific heat. A scaling formula for the critical points with N is
proposed.Comment: 28 pages, 12 figures, 12 tables; version to appear on Phys. Rev.
Determination of the probability of the damage to the health of workers in aluminium production due to the exposure to toxic substances
In the electrolytic aluminium production fluorides in the form of hydrogen fluoride and solid fluorides, alumina-containing dust, carbon monoxide, resinous substances and benz(a)pyrene are released into the air of the working zone representing a hazard to the workers' health. The paper presents the results of the researches of the working conditions of the workers employed in the electrolytic aluminium production. The concentrations of toxic substances in the air of working areas of those engaged in anode works and electrolysis, and crane operators are given; on their basis the risks of occupational diseases (fluorosis), of acute toxic effects, of chronic intoxication, and of cancer are calculated. The average-shift concentrations of hydrogen fluoride in the air of working areas of those engaged in electrolysis are 0.40-0.46 MPC, soluble fluorine salts - 0.31-0.38 MPC, insoluble fluorine salts -0.08-0.09 MPC. In the air of the working areas of those engaged in anode works MPC excess is noted for the aerosols of mostly fibrogenic action - in 1.25 times, for resinous substances - in 1.10 times. In the air of the working areas of those engaged in electrolysis MPC excess for resinous substances is registered in 1.06 times. The average-shift concentration of insoluble fluorine salts, and carbon monoxide in the air of the working areas of those engaged in anode works and electrolysis and crane operators are within the MPC. The risk of occupational disease development (fluorosis) due to the air pollution of the working zone in the aluminium production for the workers of the major occupational groups is ranging from 0.045 to 0.0482. Hydrogen fluoride is the most hazardous contaminant in air of the working zone contributing more than 55 % to the risk of fluorosis. The risk of acute toxic effects for the workers of the major occupational groups associated with the achievement of the concentrations of the contaminants in the air of the working areas of their maximum values are ranging from 0.181 to 0.230
LEDs based upon AlGaInP heterostructures with multiple quantum wells: comparison of fast neutrons and gammaquanta irradiation
The paper presents the research results of watt and volt characteristics of LEDs based upon AlGaInP heterostructures with multiple quantum wells in the active region. The research is completed for LEDs (emission wavelengths 624 nm and 590 nm) under irradiation by fast neutron and gamma-quanta in passive powering mode. Watt-voltage characteristics in the average and high electron injection areas are described as a power function of the operating voltage. It has been revealed that the LEDs transition from average electron injection area to high electron injection area occurs by overcoming the transition area. It disappears as it get closer to the limit result of the irradiation LEDs that is low electron injection mode in the entire supply voltage range. It has been established that the gamma radiation facilitates initial defects restructuring only 42% compared to 100% when irradiation is performed by fast neutrons. Ratio between measured on the boundary between low and average electron injection areas current value and the contribution magnitude of the first stage LEDs emissive power reducing is established. It is allows to predict LEDs resistance to irradiation by fast neutrons and gamma rays
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