SALES FORECAST MODELING BASED ON CORRELATION AND REGRESSION METHODS

The presented article explores the methods of correlation and regression analysis, developed its own algorithm for obtaining the initial data of interest, and also presents the calculation algo-rithm for the law of change in sales volumes. Based on the presented calculations, the errors of the correlation coefficients and the results of the regression analysis were calculated.

Designing problems of oil fields infrustructre in the Arctic under the climate change

Background. Designing problems of oil fields infrastructure in the Arctic under climate change, namely, applying of temperature coefficient when calculating bearing capacity, heaving of lightly loaded foundations, optimization of thermal stabilization solutions are presented in the article. Aim. To change the strategy for designing foundations on permafrost by choosing the worst soil conditions to the implementation of an invariant matrix for designing and construction of soil bases and foundations considering specifics of industrial facilities of oil and gas fields based on unified numerical calculations (regulations). Materials and methods. An overview of the current regulatory requirements to the design of foundations on permafrost is made. The analysis of forecast modeling of the temperature of soil bases of typical industrial facilities of oil and gas fields to justify design solutions and also the use of thermal stabilization systems is done. Results. It is proposed to develop a regional directory of weather stations with long observation period based on updated climate data to decrease the volume of designing work and the amount of mistakes in applying of thermal stabilization systems. It is necessary to create regional dynamic models of permafrost geosystems, implement forecast modeling of seasonal thawing potential depth and frozen ground temperature in natural landscapes on the base of geotechnical monitoring data and select adaptation methods to existing or expecting climate change trends. Conclusions. Regulations on designing and construction of soil bases and foundations on permafrost considering specifics of industrial facilities of oil and gas fields is an effective solution. It allows moving on the strategy implementation of uniform approaches to oil fields development on permafrost: from designing for every structure on the base of typical solutions and results of engineering surveys to invariant matrix of project solutions.

Use of Discrete-Time Forecast Modeling to Enhance Feedback Control and Physically Unrealizable Feedforward Control with Applications

When the manipulated variable (MV) has significantly large time delay in changing the control variable (CV), use of the currently measured CV in the feedback error can result in very deficient feedback control (FBC). However, control strategies that use forecast modeling to estimate future CV values and use them in the feedback error have the potential to control as well as a feedback controller with no MV deadtime using the measured value of CV. This work evaluates and compares FBC algorithms using discrete-time forecast modeling when MV has a large deadtime. When a feedforward control (FFC) law results in a physically unrealizable (PU) controller, the common approach is to use approximations to obtain a physically realizable feedforward controller. Using a discrete-time forecast modeling method, this work demonstrates an effective approach for PU FFC. The Smith Predictor is a popular control strategy when CV has measurement deadtime but not MV deadtime. The work demonstrates equivalency of this discrete-time forecast modeling approach to the Smith Predictor FBC approach. Thus, this work demonstrates effectiveness of the discrete-time forecast modeling approach for FBC with MV or DV deadtime and PU FFC.