Determining the optimum orientation of a greenhouse on the basis of the total solar radiation availability

This paper presents an approach to determining the optimum orientation of a greenhouse for year round applications for different climatic conditions. The most commonly used uneven-span single shape of greenhouse in east-west and north-south orientation have been selected for comparison. Total solar radiation input to each wall, included surfaces and roofs, is computed for both solar greenhouse orientation and compared for each month of the year at different latitudes at the northern hemisphere. Experimental validation is carried out for the measured global solar radiation data for horizontal surface and south wall at (44° N and 20° E), Belgrade, Serbia. The predicted and measured values are in close agreement. Results shows that east-west orientation of uneven-span solar greenhouse is the best suited during each months for all analyzed latitudes

Revision of bryophyte specimens from Montenegro

More than hundred specimens of problematic or taxonomically re-evaluated taxa were revised in the Bryophyte Herbarium of the Hungarian Natural History Museum, Budapest (BP) and in the herbarium of P. Erzberger, Botanic Garden and Botanical Museum Berlin Dahlem (B). As result two species (Lophozia silvicola, Ulota intermedia) can be added to the Montenegrin bryophyte flora and one species (Brachythecium tenuicale) should be deleted. The recent distribution of several taxa of conservation interest was clarified, e. g. rarities like Neckera pumila, Ulota bruchii or genera potentially threatened due to climate change like Philonotis and Timmia. The results are important contributions to the preparation of an updated checklist and red list of the Montenegrin bryoflora

Trends in the Development of Machinery and Associated Technology

ABSTRACT This paper shows the analysis of using different kernel function for development of optimal Support Vector Machine (SVM) model which could be applied for prediction of wear rate of casting parts. Development of SVM model is designed with the three kernel functions: Radial Basis Kernel Function (RBF), Exponential Radial Basis Kernel Function (ERBF) and Polynomial Kernel Function (POLY). For the development of Improved Support Vector Machine (ISVM) model mixture of kernels RBF+POLY from the real operating conditions. In order to select the optimal model the statistical indicators for all models are presented. Results show that the ISVM using ERBF+POLY mixed kernel function show the best results for the practical purposes. The proposed ISVM model with a mixture of kernels is able to accurately predict the wear rate of casting parts. Keywords: Support Vector Machine, Kernel functions, wear rate INTRODUCTION SVM is based on statistical learning theory and is a new achievement in the field of data-driven modelling and has been successfully implemented in classification, regression and function estimatio

Flexible GPS/GPRS based System for Parameters Monitoring in the District Heating System

Energy consumption for heating purposes accounts for a significant part of the budgets of individual and collective users. This increases the importance of issues related to the monitoring of heating energy flows, analysis of flow parameters, verification of fees and, in the first place, minimization of energy consumption. The goal of this paper is to develop, by employing Global Positioning System receivers, measurement techniques that are suited to the continuous monitoring of the heating substation parameters. This paper presents the design and implementation of GPS/GPRS (Global Positioning System/General Packet Radio Service) system for low power data acquisition using MSP430 Texas Instruments microcontroller for monitoring of the heating substation parameters. The system is implemented in heating stations for a temperature and pressure monitoring. It contains GPS/GPRS gateway and 8 analog sensor inputs. Acquisition module and the server base station are suitable for industrial applications, home applications and for other appliances. The proposed measurement procedures, which are different from commercially available measurement units, are based on general-purpose acquisition hardware and processing software, thus guaranteeing the possibility of being easily reconfigured and reprogrammed according to the specific requirements of different possible fields of application and to their future developments

Improvement of study programs for bachelor’s and master’s studies in Mechatronics in response to the requirements of Industry 4.0

This study was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, and these results are parts of the Grant No. 451-03-68/2022-14/200132 with University of Kragujevac - Faculty of Technical Sciences in Čacak.Development in information technology has resulted in revolutionizing all aspects of life and this revolution has been realized as Industry 4.0. A main approach that universities' educational systems may take towards Industry 4.0 is educating students who have the right skill set for reacting to the changes in their working environment, adapting their performance, and learning to cope with technological development. This paper presents the results of the project "Improvement of study programs for bachelor's and master's studies in Mechatronics in response to the requirements of Industry 4.0", which was funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia as a part of program activity "Development of higher education" and performed in the 2020/21 academic year.Publishe

Integrisan proces proizvodnje abrazivnih reznih elemenata bagera u rudarskoj industriji

The paper presents an integrated production process for excavator cutting elements in the mining industry based on modern software systems for the optimization and management of casting process parameters through simulations. The concept involves the virtual manufacture, practical implementation of the established technological process and quality control of final castings i.e. excavator cutting elements. The presented production methodology reduces the time required to develop and manufacture the new product compared to the traditional methods of prototype testing.Publishe

Laboratorijska elektro-pneumatski upravljana postavka

Studying the dynamic behaviour of objects or systems in response to conditions cannot always be easily or safely applied in real life. Computer simulations in engineering are very important as it solves real-world problems safely and efficiently. It provides an important method of analysis which is easily verified, communicated, and understood. Across industries and disciplines, simulation modelling provides valuable solutions by giving clear insights into complex systems. A system presented in this paper is a pneumatic sheet metal bending laboratory setup. An electro-pneumatic motion control of this system is modelled and simulated in FluidSim software. This system is also physically built using main pneumatic and electrical components with PLC. Described laboratory setup in this paper was used in the education of students and significant enchantment in the understanding of how similar systems work was noticed.Publishe

Razvoj laboratorijskog sistema za merenje karakteristika fotonaponskotermičkog panela

The emissions of harmful gases into the atmosphere, air pollution and global warming can be greatly reduced by increasing the use of renewable energy sources such as solar energy to heat domestic hot water, space heating and generating electricity. This paper describes the systems of combined (hybrid) PV/T panels that can simultaneously generate both heat and electricity, as well as the characteristics of the PV/T panel. A prototype of the laboratory setting for the examination of these systems along with the used components is also shown. The temperature, fluid flow rate values, obtained heat and electric gain are also presented. Deficiencies and proposed changes in the laboratory setup and used equipment were laid out, in order to improve the accuracy of the measurements.Publishe