Oblique generalizations of the Walsh basis

An approach to building generalized oblique discrete Walsh basis is suggested. Methods that allow forming transformation matrices based on oblique discrete Walsh functions are developed. Some properties of the suggested oblique discrete Walsh transformations and their applications to synthesizing algorithms of parametric estimation of polynomial trend models of digital signals are considered. © 2010 Allerton Press, Inc

Algorithms of parametric estimation of polynomial trend models of time series on discrete transforms

A forecasting of economic and financial indicators is the actual problem of strategic management. A time series forecasting often uses simple econometric models. The trend and seasonal trend models are among the popular models for forecasting. In some cases researchers need to analyze vector time series. The traditional algorithms of estimating time series models may be associated with a sufficiently high computational complexity. We propose the applications of oblique discrete Walsh transform to the synthesis of estimation algorithms of polynomial trend models' parameters of time series. Algorithms evaluate polynomial models that not above the third degree in a non-orthogonal basis of discrete exponential functions and orthogonal basis of discrete Chebyshev polynomials. The advantage of these algorithms is the computational efficiency, which associated with a significant reduction of the multiplicative complexity of algorithms in comparing with direct estimation of polynomial trend models

Short-Term Fuzzy Forecasting of Brent Oil Prices

© 2015, Asian Social Science. All rights reserved. Oil prices movements is very important macroeconomic factor for decision making. The accuracy of results for different types of oil brands depends on models and algorithms. This paper evaluates the effectiveness of using fuzzy sets to forecast daily Brent oil prices. It also contains possible modifications of the proposed method and in comparison with basic methods. The results suggest that Brent oil prices series have short memory because using information about last 2-days prices shows better forecast accuracy. Forecasting based on fixed universe of discourse shows better efficiency and it also proves that oil prices series has short memory. Adding the probability of switching between linguistic terms in defuzzification function could be used to improve accuracy of predictions. Also the approach can take into consideration expert’s opinion about direction of future variation. The effective expert’s work can reduce errors of forecast from 1.5% till 0.76%. But this modification can be used if experts correctly guess the direction of the change in trend in eight out of ten cases and more. The reasonable obtained results can be used by analysts dealing with the prediction of oil prices

Algorithms of quasi evaluation of polynomial trend of the digital signals based on oblique discrete walsh transformations

© 2016 IEEE.In this article, we consider applications of oblique discrete Walsh transformation algorithms at synthesizing a quasi-evaluation of polynomial trend models of digital signals. We consider peculiarities of computational complexity of the proposed algorithms and statistical properties of the estimated parameters of the polynomial trend in degree higher than the third level. The advantages of these algorithms are low multiplicative complexity and relative simplicity of the hardware implementation of binary arithmetic means

CYTOKINE STATUS IN PATIENTS WITH URTICARIA

Research objective. The present research evaluates some indicators of cytokine status in patients with urticaria for evaluation of the clinical course. Material and methods. 93 patients with urticaria at the age from 14 to 88 years were examined. The severity of the clinical course was assessed according to the Urticaria activity score-7. The determination of total IgE and IL-4, IL-6 and IL-10 was performed by ELISA. The digital material is processed by the method of variational statistics. Results. In patients with urticaria in cytokine status, there is an increase in anti-(IL-4, IL-6) and proinflammatory (IL-10) cytokines against a background of hyperproduction of total IgE. Conclusion: In patients with chronic urticaria there is a predominance of IL-6 production against the background of hyperproduction of total IgE and IL-10, causing a pronounced secondary immunological failure and decompensatory form

Multi-operator colligations and multivariate characteristic functions

In the spectral theory of non-self-adjoint operators there is a well-known operation of product of operator colligations. Many similar operations appear in the theory of infinite-dimensional groups as multiplications of double cosets. We construct characteristic functions for such double cosets and get semigroups of matrix-valued functions in matrix balls.Comment: 15p

Catalytic Alkylation of Brown Coal and Peat

The alcohol alkylation of low-grade metamorphic coal and peat in the presence of mineral and organic acids was studied using FTIR, NMR, and GC-MS. The impact of the reaction conditions on the yield of extractable matter was investigated experimentally, and relevant regression equations were obtained. Changes in the group and individual compositions of the wax fractions of bitumen in the process of brown coal and peat alkylation were studied. It was found that the esters of alkylated coal waxes consisted of native esters of fatty acids, and alkyl esters of these acids formed as a result of the alkylation reaction. Esterification and transesterification were predominant in the reactions of the bitumen fraction components. The positive effect of alcohol alkylation on the increase of the bitumen yield was found

Network Modelling of Functioning System of the Process Module of Oil-Contaminated Wastewater Treatment

Abstract The article discusses network modeling of oil-contaminated waste water treatment at the stage of the process module functioning of water jet cleaning of waste water in the oil fields and petrochemical industries. Based on the review of the main modeling methods of discrete-continuous chemical processes, expediency of using the theory of Petri nets (PN) for modeling the process of wastewater treatment in the oil fields and petrochemical industries is substantiated. It is proposed to use a modification of Petri nets which is focused on modeling and analysis of discrete-continuous chemical processes by prioritizing transitions, timing marks in positions and transitions. A model in the form of modified Petri nets (MPN) is designed. A software package to control the process for wastewater treatment is designed by means of SCADA TRACE MODE

Control of Ni/Ce1-xMxOy catalyst properties via the selection of dopant M = Gd, La, Mg Part 1. Physicochemical characteristics

To elucidate the role of support composition in autothermal reforming of ethanol (ATR of C2H5OH), a series of Ni catalysts (Ni content 2–15 wt.%) supported on different ceria-based oxides (Ce1-xGdxOy, Ce1-xLaxOy and Ce1-xMgxOy; x = 0.1–0.9) were prepared. The synthetized materials were tested in ATR of ethanol at 200–700 °C. It was established that supports themselves show catalytic activity in ATR of C2H5OH and provide 10–15% yield of H2 at 700 °C. Upon the increase of Ni content from 2 to 15 wt.% the temperature of 100% ethanol conversion decreases from 700 tо 300 °С, hydrogen yield increases from 25 to 60%, the inhibition of С2-С3 by-products formation, as well as the promotion of decomposition of acetaldehyde occur. The enhancement of catalyst performance in ATR of C2H5OH has been observed in the next series of supports: Ce1-xMgxOy < Ce1-xGdxOy < Ce1-xLaxOy and with a decrease of x to an optimal value that correlates with the improvement of Ni active component reducibility. At 600 °C on 10Ni/Ce0.8La0.2O1.9 catalyst the H2 yield of 50% was achieved at C2H5OH conversion of 100%. Stable and high performance of developed catalysts in ATR of C2H5OH indicates the promise of their use in the production of hydrogen

Control of Ni/Ce1-xMxOy Catalyst Properties Via the Selection of Dopant M = Gd, La, Mg. Part 2. Catalytic Activity

To elucidate the role of support composition in autothermal reforming of ethanol (ATR of C2H5OH), a series of Ni catalysts (Ni content 2–15 wt.%) supported on different ceria-based oxides (Ce1-xGdxOy, Ce1-xLaxOy and Ce1-xMgxOy; x = 0.1–0.9) were prepared. The synthetized materials were tested in ATR of ethanol at 200–700 °C. It was established that supports themselves show catalytic activity in ATR of C2H5OH and provide 10–15% yield of H2 at 700 °C. Upon the increase of Ni content from 2 to 15 wt.% the temperature of 100% ethanol conversion decreases from 700 tо 300 °С, hydrogen yield increases from 25 to 60%, the inhibition of С2-С3 by-products formation, as well as the promotion of decomposition of acetaldehyde occur. The enhancement of catalyst performance in ATR of C2H5OH has been observed in the next series of supports: Ce1-xMgxOy < Ce1-xGdxOy < Ce1-xLaxOy and with a decrease of x to an optimal value that correlates with the improvement of Ni active component reducibility. At 600 °C on 10Ni/Ce0.8La0.2O1.9 catalyst the H2 yield of 50% was achieved at C2H5OH conversion of 100%. Stable and high performance of developed catalysts in ATR of C2H5OH indicates the promise of their use in the production of hydrogen