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Jovanovic I.,Serbian Mining and Metallurgy Institute | Miljanovic I.,University of Belgrade
Minerals Engineering | Year: 2015

Successful control of flotation plants in modern conditions represents a challenging and complex task that has yet to be accomplished. There have been multiple attempts, however, to find an appropriate control technique that would completely cover the dynamic, complex and poorly-defined flotation system. This paper presents a literature review of current theoretical and applied researches in the field of control of flotation plants with mechanical flotation cells. Significant aspects of the stratification of control levels are described in the paper, with emphasis on advanced techniques that include predictive and intelligent control methods. Traditional PID controllers are found not suitable for the comprehensive control of dynamic flotation systems, except, in part, for the lower hierarchy levels. In the area of advanced control, model predictive methods can improve flotation process performances, but as a rule, in a short period of time. Intelligent methods are playing a significant role in flotation process control, increasing its flexibility, although none of the available variations completely satisfy all the process control aspects. Bearing in mind the results achieved so far, further improvements are expected in the areas of overall control strategy, individual control components and repositioning of advanced control methods. © 2014 Elsevier Ltd. All rights reserved. Source

Jovanovic I.,Serbian Mining and Metallurgy Institute | Miljanovic I.,University of Belgrade | Jovanovic T.,JKP 3. Oktobar Bor
Minerals Engineering | Year: 2015

The modern modeling of flotation processes has been burdened for years with limitations of classical mathematics and modeling. The emergence of soft computing methods has also been looked upon in many of the industry's branches as promising, and up to a certain point, those expectations have been met. Today, these soft computing methods are used regularly in research, and in some cases, within different industrial practices. This paper gives a review regarding the most common soft computing methods and their use in flotation processes modeling. Artificial neural networks have received the widest application in this area, and are followed by fuzzy logic, genetic algorithms, support vector machines and learning decision trees. Over the last five years, the number of reported studies within this field, has steadily increased. And although several classes of flotation problems are being successfully modeled with soft computing methods, there still remain a number of unresolved issues and obstacles. This paper thus attempts to provide an explanation for the current state and use of soft computing methods, as well as to present some ideas on future initiatives and potential developments within the area. © 2015 Elsevier Ltd. Source

Brodic D.,University of Belgrade | Milivojevic D.R.,Serbian Mining and Metallurgy Institute
Information Technology and Control | Year: 2012

The paper presents a methodology for the estimation of the initial skew rate of text lines. Firstly, it splits text into groups according to the bounding boxes. Linked bounding boxes establish the bigger objects called connected components. After applying mathematical morphology operations, the enlarged group of the connected components is formed. The longest connected component is extracted by the longest common subsequence method. Inside the longest connected component, the gravity centers are determined for each bounding box. They represent the reference points, which are used for the calculation of the initial skew rate. Calculation is made by the moment based method. The comparative analysis of the origin and estimated skew rate is used to evaluate the algorithm. Hence, the proposed algorithm is examined with different printed text samples. It showed robustness for the skew estimation in the wide range of resolutions. Source

Brodic D.,University of Belgrade | Milivojevic Z.N.,Technical college Nis | Milivojevic D.R.,Serbian Mining and Metallurgy Institute
Elektronika ir Elektrotechnika | Year: 2012

The paper presents the approach to the algorithm for text line segmentation based on the anisotropic Gaussian kernel. As a result of this algorithm the growing region around text is exploited. Furthermore, anisotropic Gaussian kernel is rotated to improve text line segmentation process. Text objects orientation is evaluated by binary moments. For test purposes algorithm is evaluated under different text samples. From the obtained results comparative analysis between algorithm with anisotropic and oriented Gaussian kernel is made. At the end, benefits of the extended approach are revealed. Source

Zivkovic D.,University of Belgrade | Du Y.,Central South University | Talijan N.,University of Belgrade | Kostov A.,Serbian Mining and Metallurgy Institute | Balanovic L.,University of Belgrade
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2012

The results of the calculation of thermodynamic properties in liquid state for ternary Al-Ni-Zn alloys using the newest version of the general solution model for thermodynamic prediction are presented. Nine sections with different molar ratios of Ni to Zn, Zn to Al and Al to Ni were investigated in a temperature interval of 1800-2000 K. Partial and integral molar thermodynamic properties in liquid phase for the Al-Ni-Zn ternary system are determined and discussed. © 2012 The Nonferrous Metals Society of China. Source

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