Serbian Mining and Metallurgy Institute

Bor, Serbia

Serbian Mining and Metallurgy Institute

Bor, Serbia
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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.

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.

Bozic D.,Serbian Mining and Metallurgy Institute | Gorgievski M.,Serbian Mining and Metallurgy Institute | Stankovic V.,University of Belgrade | Strbac N.,University of Belgrade | And 2 more authors.
Ecological Engineering | Year: 2013

The adsorption of heavy metal ions from synthetic single ion solutions was performed by using beech sawdust. The pH value of water increases when rinsing the sawdust with distilled water. The maximum sawdust adsorption capacity was achieved at pH>4, while at pH<2 it gets zero. The adsorption capacity is almost equal for Cu2+ and Ni2+ (4-4.5mgg-1), while for Zn2+ ions it is 2mgg-1, thus exhibiting certain selectivity the first two against zinc ions. Obtained results showed that the adsorption kinetics follows the pseudo-second order reaction model. The adsorption equilibrium data show good fitting to the Langmuir equation. The adsorption occurs via an ion exchange mechanism, where mostly calcium from the sawdust cell structure was substituted by heavy metal ions. © 2013 Elsevier B.V.

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.

Serbula S.M.,University of Belgrade | Antonijevic M.M.,University of Belgrade | Milosevic N.M.,Serbian Mining and Metallurgy Institute | Milic S.M.,University of Belgrade | Ilic A.A.,University of Belgrade
Journal of Hazardous Materials | Year: 2010

Measurements of air quality in the territory of Bor (Serbia) were performed at the sampling sites in the urban-industrial, suburban and rural area during the 2003-2008 period. A high level of arsenic (As) concentration in suspended particulate matter (PM) is of a predominantly industrial origin. The major source of pollution is the copper smelter which is situated in the close vicinity of the urban area of Bor. The ambient level of PM and As is influenced by meteorological parameters as well as the remoteness from the copper smelter. Continual exceedances of the annual limit value (LV) for As (6ngm-3) were recorded at the sampling sites in the urban-industrial and suburban area. Maximum annual As concentrations were recorded at Town Park (46.5ngm-3) in 2004, Institute (95.4ngm-3) in 2004 and Jugopetrol (74.5ngm-3) in 2003. In the past 15 years not a single mean annual As concentration recorded at the sampling sites Town Park, Institute and Jugopetrol has been within the LV. When the average annual and maximum monthly As concentrations are compared, it can be concluded that the level of pollution is higher in the urban-industrial and suburban areas than in the rural area. © 2010 Elsevier B.V.

Brodic D.,University of Belgrade | Milivojevic D.R.,Serbian Mining and Metallurgy Institute | Milivojevic Z.N.,Technical College Nis
Sensors | Year: 2011

The paper introduces a testing framework for the evaluation and validation of text line segmentation algorithms. Text line segmentation represents the key action for correct optical character recognition. Many of the tests for the evaluation of text line segmentation algorithms deal with text databases as reference templates. Because of the mismatch, the reliable testing framework is required. Hence, a new approach to a comprehensive experimental framework for the evaluation of text line segmentation algorithms is proposed. It consists of synthetic multi-like text samples and real handwritten text as well. Although the tests are mutually independent, the results are cross-linked. The proposed method can be used for different types of scripts and languages. Furthermore, two different procedures for the evaluation of algorithm efficiency based on the obtained error type classification are proposed. The first is based on the segmentation line error description, while the second one incorporates well-known signal detection theory. Each of them has different capabilities and convenience, but they can be used as supplements to make the evaluation process efficient. Overall the proposed procedure based on the segmentation line error description has some advantages, characterized by five measures that describe measurement procedures. © 2011 by the authors; licensee MDPI, Basel, Switzerland.

Brodic D.,University of Belgrade | Milivojevic D.R.,Serbian Mining and Metallurgy Institute | Tasic V.,Serbian Mining and Metallurgy Institute
MIPRO 2011 - 34th International Convention on Information and Communication Technology, Electronics and Microelectronics - Proceedings | Year: 2011

Handwritten document images incorporate noise as binarization process by product. It causes some difficulties in text analysis process. To overcome this problem morphological preprocessing is performed. Hence, the basic and compound morphological operations are incorporated. Further, their effort to make document image noiseless is evaluated. Results are given and comparative analysis is made. From the obtained results, decision-making is performed and convenient preprocessing morphological operation is proposed. © 2011 MIPRO.

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.

Brodic D.,University of Belgrade | Milivojevic D.R.,Serbian Mining and Metallurgy Institute | Milivojevic Z.,Technical College Nis
Sensors | Year: 2010

Text line segmentation is an essential stage in off-line optical character recognition (OCR) systems. It is a key because inaccurately segmented text lines will lead to OCR failure. Text line segmentation of handwritten documents is a complex and diverse problem, complicated by the nature of handwriting. Hence, text line segmentation is a leading challenge in handwritten document image processing. Due to inconsistencies in measurement and evaluation of text segmentation algorithm quality, some basic set of measurement methods is required. Currently, there is no commonly accepted one and all algorithm evaluation is custom oriented. In this paper, a basic test framework for the evaluation of text feature extraction algorithms is proposed. This test framework consists of a few experiments primarily linked to text line segmentation, skew rate and reference text line evaluation. Although they are mutually independent, the results obtained are strongly cross linked. In the end, its suitability for different types of letters and languages as well as its adaptability are its main advantages. Thus, the paper presents an efficient evaluation method for text analysis algorithms. © 2010 by the authors.

Trumic B.,Serbian Mining and Metallurgy Institute | Stankovic D.,Serbian Mining and Metallurgy Institute | Ivanovic A.,Serbian Mining and Metallurgy Institute
Journal of Mining and Metallurgy, Section B: Metallurgy | Year: 2010

In order to form the necessary data base on platinum and platinum metals, certain tests were carried out on platinum samples of different purity of 99.5%, 99.9% and 99.99%. The degree of cold deformation, annealing temperature and chemical assays were tested as well as their impact on the mechanical properties of platinum. The Vickers hardness (HV) values were determined with different deformation degree, starting from annealing temperatures for platinum of different purity and tensile strength (Rm), flow limit (Rp0,2) and elongation (A) in the function of annealing temperatures and annealing time at a constant deformation degree.

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