The article presents results of the influence of the GMDH (Group Method of Data Handling) neural network input data preparation method on the results of predicting corrections for the Polish timescale UTC(PL). Prediction of corrections was carried out using two methods, time series analysis and regression. As appropriate to these methods, the input data was prepared based on two time series, ts1 and ts2. The implemented research concerned the designation of the prediction errors on certain days of the forecast and the influence of the quantity of data on the prediction error. The obtained results indicate that in the case of the GMDH neural network the best quality of forecasting for UTC(PL) can be obtained using the time-series analysis method. The prediction errors obtained did not exceed the value of ± 8 ns, which confirms the possibility of maintaining the Polish timescale at a high level of compliance with the UTC.
The paper presents the problem of position control of DC motor with rated voltage 24 V loaded by flywheel. The fractional order PD controller implemented in National Instruments NI ELVIS II programmed in LabView is used for controlling. The simple method for determining stability regions in the controller parameters space is given. Knowledge of these regions permits tuning of the controller and ensures required the phase margin of the system.
In this paper an artificial neural network, which realizes a nonlinear adaptive control algorithm, has been applied in a control system of variable speed generating system. The speed is adjusted automatically as a function of load power demand. The controller employs a single layer neural network to estimate the unknown plant nonlinearities online. Optimization of the controller is difficult because the plant is nonlinear and no stationary. Furthermore, it deals with the situation where the plant becomes uncontrollable without any restrictive assumptions. In contrast to previous work [1] on the same subject, the number of neural networks has been reduced to only one network. The number of the neurons in a network structure as well as choosing certain design parameters was specified a priori. The computer test results have been presented to show performance of proposed neural controller.
The economic downturn in Europe and in the world, has affected the traditional branches of industry in a particular way. Development plans of domestic coke plants in terms of main production assets for the next years have been presented. Taking into account the current market situation, the coke plants strategy should aim at risk minimization through application of already known technologies. On the other hand, investments in scope of new and innovative technologies which are connected with a high level of variability, should be seen as an opportunity. Thus, evaluation of investment projects should be done in a different way than so far. The traditional discount analysis, because of its static nature, does not take into account variability and options included in projects with many decision moments - it can prove to be not sufficient. A tool which helps the decision makers in such situations, is the real options analysis. The article presents the findings of the research-development project on coal blend pre-drying implementation, realized by Zdzieszowice Coke Plant and ICHPW in Zabrze. The results achieved so far, as well as the concerns resulting from the project, have been discussed in this article. Further project development plans, aiming at the construction of a semi industrial research installation for analysing the impact of pre-drying on the coke making process have been presented. The article describes premises for the application of real options analysis as a tool to evaluate projects, the results of which are uncertain. The origin and structure of real options as well as the conditions of their application compared to traditional, discount based project evaluation methods, have been presented. The origin and characteristic parameters of real options have been discussed. In the next part, by applying the NPV and real options method, the research-development undertaking of coal blend pre-drying implementation on two coke batteries, has been evaluated. In order to assess the real option's value of the project, which is a classic European call option, the Black-Scholes formula has been used. The achieved results have been compared as well as the flexibility rate of the analyzed research-development project has been defined.