A system for short term natural gas consumption forecasting with forecasting horizon h = 1,2,...,48 hours was developed for the company Energetika Ljubljana, d.o.o.. The system was designed as an extension of the existing forecasting system into near forecasting horizons (1-24 hours). The system has been installed on the server of the company and generates daily forecasts of the next 48 hours of natural gas consumption based on past consumption, weather forecasts, and population dynamics. The forecasts delivered by the system are in company Energetika Ljubljana, d.o.o., the basis for the optimization of the entire system of natural gas distribution and district heating.
F.15 Development of a new information system/databases
COBISS.SI-ID: 12703259This work considers the dynamics of various dripping regimes, observed in laser droplet sequence generation in dependence on detachment pulse power. The process of droplets generation was observed by using a high-speed infrared camera. Sequences of snapshots from the camera were then transformed into scalar time series which were used for dripping dynamics analysis and characterization. The focus was on time series analysis of characteristic examples of spontaneous, mixed and forced dripping. Analysis of selected time series was performed by using methods of nonlinear time series analysis, recurrence plots and time-frequency analysis by means of instantaneous frequency. Results of analysis indicate that laser droplet sequence generation should be considered a deterministic low-dimensional dynamical system. Based on Lyapunov exponents and 0-1 test for chaos it was concluded that time series of spontaneous and forced dripping regimes originate from chaotic dynamical system. This result was subsequently confirmed by means of recurrence plots and their quantification analysis. Additionally, the transition between spontaneous and forced dripping was characterized as an intermittent chaos-chaos transition with a non-stationary dripping regime in between. Finally, selected dripping regimes were also characterized in time-frequency space where empirical mode decomposition and instantaneous frequency were used.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 12568091Band sawing is one of the most efficient methods for which in general it is known that uneven tool wear, chatter and cutting blade defects can affect cutting performance significantly. A data acquisition system was arranged on an industrial band saw machine in order to characterize the band sawing process based on measurements of forces. In this paper, the cutting force signals are analyzed in order to demonstrate important relations to workpiece and cutting blade properties. It is shown that cutting forces contain information about inhomogeneity of a cut workpiece. Signals of cutting forces also reveal important properties of blade geometry that is related to uneven blade wear. Discontinuities such as blade welding are clearly evident in force signals and it is shown that unevenness of blade backing geometry can cause a significant variation in forces due to wedging between the workpiece and a blade support. An original method for blade shape extraction from force signals is presented in detail. Paper also reports on chatter phenomena observed at specific cutting conditions. Possible solutions to the addressed problems and phenomena are discussed in the conclusion.
F.13 Development of new production methods and tools or processes
COBISS.SI-ID: 12251419A two-dimensional pattern represents a fingerprint of the process that generated it. It is therefore expected that the information about the production process can be extracted from the pattern. In this paper, a non-parametric statistical method for modelling chaotic two-dimensional patterns and the estimation of the characteristic parameters is proposed. It is based on the joint probability density function of samples taken from known two-dimensional patterns representing a database. A new pattern with an unknown production process is reproduced by comparing parts of the new pattern with samples taken from the database. Because the samples in the database also include information about the production process, relevant parameters and the type of production process can be estimated simultaneously with the reproduction of patterns.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 31432797The progress of synthetic biology allows one to design artificial repressors that inhibit selected genes. Combination of repressors enables construction of NOR logical gates that could form the foundation for information processing within cells. The theoretical potentials and limitations of constructing NOR gates were analyzed. They could be experimentally realized in bacterial cells. The number of required artificial repressors was analysed and temporal simulations of an example function were performed.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 8956756