Comparison of Different Neural Network Training Algorithms with Application to Face Recognition Problem

Research in the field of face recognition has been popular for several decades. With advances in technology,approaches to solving this problems haves changed. Main goal of this paper was to compare different training algorithms for neural networks and to apply them for face recognition as it is a nonlinear problem. Algorithm that we have used for face recognition problem was the Eigenface algorithm that belongs to the Principal Component Analysis (PCA) algorithms. Percentage of recognition for all the used training functions is above 90%

Neural Network Model Predictive Control of Nonlinear Systems Using Genetic Algorithms

In this paper the synthesis of the predictive controller for control of the nonlinear object is considered. It is supposed that the object model is not known. The method is based on a digital recurrent network (DRN) model of the system to be controlled, which is used for predicting the future behavior of the output variables. The cost function which minimizes the difference between the future object outputs and the desired values of the outputs is formulated. The function ga of the Matlab’s Genetic Algorithm Optimization Toolbox is used for obtaining the optimum values of the control signals. Controller synthesis is illustrated for plants often referred to in the literature. Results of simulations show effectiveness of the proposed control system

Trends of production and consumption of beech roundwood on the European market

By the development and analysis of the model of beech roundwood production and consumption trends in the most important European countries, Serbia and Europe altogether, for the period 1990-2000, the paper identifies the regularities in their trend, based on which the relations in the production and consumption trends are analyzed. Based on the elements obtained in this way, the paper points to the possibilities of selling beech wood offered by the European market

ANTIOXIDANT AND PRO-OXIDANT EFFECT OF ASCORBIC ACID

Free radicals attack proteins, lipids, enzymes and DNA causing pathological changes in organism. There are many mechanisms that organism uses to fight against free radicals. Ascorbic acid is one of the strongest reducers and eliminators of free radicals. It reduces stable oxygenic, azoth and thyol radicals and acts as a primary defense against water radicals in blood. When radicals are dissolved in water suspensions of erythrocytes and low density lipoproteins (LDL), ascorbic acid catches and eliminates free radicals before they arrive to the membrane and LDL molecules. Even though ascorbic acid is not capable of eliminating free radicals out of fluid medium, it acts as synergist to alpha-tocopherol in lipid section, contributes to the lessening of lipid tocoperoxil radicals, and above all, regenerates alpha-tocopherol. Ascorbic acid may act as pro-oxidant under in vitro conditions in the presence of metals; however, this effect is probably not important under in vivo conditions where metal ions, being sequestered, become second reducers

Non-wood forest products based enterprises’ cooperation and business networking forms in central Serbia

Collaboration between enterprises includes all activities, which are undertaken in order to achieve common goals and interests. Business networking involves the establishment of various forms of associations and business communities, with or without the creation of new economic entities. The aim of the paper was to study the forms of cooperation between non-wood forest products based small and medium enterprises, as well as to determine the attitudes of their representatives towards cooperation and business networking with other enterprises in Central Serbia. Research included 91 non-wood forest product based small and medium enterprises and 19 representatives of leading enterprises, which were selected based on specifically defined criteria. Both the methods of analysis and synthesis and comparative and statistical methods were applied in the paper. The results indicate that almost all analyzed enterprises cooperate with other enterprises. The most common form of cooperation is present “during selling” and “during purchase”. The majority of leading enterprises’ representatives are members of some of the existing associations of entrepreneurs. Based on the analysis, it was found that there is a need for development of cooperation between the analyzed enterprises. In accordance with that, proposals for the improvement of business networking were given. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Istraživanja klimatskih promena i njihovog uticaja na životnu sredinu - praćenje uticaja, adaptacija i ublažavanje”, podprojekat 43007/16-III: Socio-ekonomski razvoj, ublažavanje i adaptacija na klimatske promene i br. 37008-TR: Održivo gazdovanje ukupnim potencijalima šuma u Republici Srbij

An analysis of briquette value chain at the Limsko forest area

Value creation represents an increase in the value of assets in the manufacturing process. Business processes that lead to value creation can be presented as a value chain. For wood products, total value creation takes place in the complex processes of production and exchange between forestry and timber industry. The research on the use of biomass for energy purposes is increasing in recent decades. Within the research on value chain, in our country were, to less extent were represented those related to woody biomass products. In this sense, the aim of the research is to determine the organization of woody biomass products (briquettes) value chain and its analysis in the Limsko forest area. A “door-to-door” survey was used as a research technique. Data collection was conducted in the period from April to May of 2013. In total, 19 representatives of enterprises, which are participants in the woody biomass products value chain in the Limsko forest area were surveyed. Manufacturing enterprise, located in Nova Varoš, was analysed as the main participant in this chain. In addition, its suppliers (15), wholesaler (1), retailer (1), and consumer (1) were analysed. The manufacturing enterprise exclusively used raw material produced in sawmills. The results indicate that an increase in value occurs, primarily, during the transportation of raw materials from sawmill to the manufacturing enterprise. The next increase in value occurs during the storage of raw materials within the manufacturing enterprise and with the emergence of new stages in the production process, as well as during the transportation of products to the wholesaler, retailer and consumer

Neural network model predictive control of nonlinear systems using genetic algorithms

In this paper the synthesis of the predictive controller for control of the nonlinear object is considered. It is supposed that the object model is not known. The method is based on a digital recurrent network (DRN) model of the system to be controlled, which is used for predicting the future behavior of the output variables. The cost function which minimizes the difference between the future object outputs and the desired values of the outputs is formulated. The function ga of the Matlab's Genetic Algorithm Optimization Toolbox is used for obtaining the optimum values of the control signals. Controller synthesis is illustrated for plants often referred to in the literature. Results of simulations show effectiveness of the proposed control system. © 2006-2012 by CCC Publications

Organization of private forest sector in Timok forest area

<span>Today, private forest owners (PFOs) in Serbia cooperate in form of private forest owners associations (PFOAs). Currently, there are 20 PFOAs, of which 15 are in Timok region. Initiatives of PFOs from Timok forest area, animated the owners from other parts of the country and led to foundation of Serbian Federation of Forest Owners' Associations. Twelve of PFOAs from Timok forest area are the founders of Serbian private forest owners' umbrella organization. Restructuring of Public Enterprise (PE) "Srbijasume", which started in 2001, led to development of private small and medium forest enterprises, engaged as contractors of PE for harvesting, timber transport and construction of forest roads. The objectives of this paper are to elaborate if there are differences between PFOs in Serbia and Timok region and to analyze organization of private forest owners in Timok forest area. In order to reach these objectives, results of PRIFORT project were used. This project focused on four countries of Western Balkans region: Bosnia and Herzegovina, Croatia, Serbia and Macedonia. The aim of this project was to explore precondition for formation of PFOs in this region. Quantitative survey (n = 350) of randomly selected PFOs was conducted in nine municipalities in Serbia, of which two were in Timok region (n = 100). The results show that there are differences between PFOs in Serbia and Timok region in number of PFOs, size of private property and in additional incentives. These results also indicate that economic interest is a motive for establishment of PFOAs and that state support is very important for their development. Since a number of PFOs are entrepreneurs, it can be assumed that, further development of theirs organizations could lead to development of SMEs clusters. </span