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This paper presents technical requirements for acceptance of track works according to European standard EN 13231-1, which was adopted as Serbian standard in 2014. The standard applies to track with standard gauge (1435 mm) layed in ballast bed. Requirements for acceptance of works should be applied for laying of the new track, as well as for reconstruction, renewal and maintenance of the existing track. Paper points out that, despite of established legal framework in the Republic of Serbia, national technical regulations are still not harmonised with the requirements of the standard. The special importance is drawn to establishment of the procedures for measuring the relevant parameters and controling the track condition, as well as procedures for documenting measurement results and performed controls. In addition, paper shows prescribed tolerances for track geometry parameters and track superstructure elements according to EN 13321-1. Acceptance deadline has special importance and it should be defined in the contract between Infrastructure Manager and Contractor.

This paper presents the application of cognitive radio technology in vehicular ad-hoc networks aimed to improve the communications between vehicles themselves as well as between vehicles and roadside infrastructure. Due to dynamic approach of spectrum access, cognitive radio is a technology that enables more efficient usage of radio-frequency spectrum. We review actual approaches and discuss research challenges related to the use of cognitive radio technology in vehicular ad hoc networks with emphasis on architecture, spectrum management as well as QoS optimization. The researching on cognitive radio application in vehicular networks is still developing and there are not many experimental platforms due to their complex setups. Some related research projects and cognitive radio realizations are provided in this paper.

The problem of public transit network design belongs to the class of NP hard combinatorial optimization problem. Since optimal solution of this problem is difficult to discover, many heuristic algorithms have been proposed in the literature. By applying various heuristic algorithms to one problem instance, various solutions could be generated. We assume, in this paper, that decisions related to public transit network choice should be made in the presence of trade-offs between two or more conflicting objectives (usually, the passengers' and operator's interests are in conflict). In this paper, we propose the model for public transit network choice. The proposed model is based on the Data Envelopment Analysis (DEA). The proposed model is tested on the one of the best known benchmark examples for the transit network design problem.

This paper presents the design and implementation of the smart web sensors. The paper briefly describes the concept of automatic configuration based on electronic specifications in industrial measurement and control systems as well as in distributed systems based on the OGC SWE family of standards. The model for the implementation of Plug and Play sensor in accordance with the IEEE 1451 family of standards is analyzed in detail. Special attention is paid to the network connectivity of analog sensors in accordance with IEEE 1451.4. The practical implementation of the 1451.4 compatible network processor for RTD temperature sensors and adequate software support for 1451.4 TEDS generation, are included in the paper.

The paper shows the configuration of a new educational machine based on hybrid kinematics mechanism. The concept of a three-axis O-X hybrid mechanism is described, consisting of a single serial translational axis and a two-axis parallel mechanism that can operate in two variants, with extended form O and crossed form X-joints of the parallel mechanism. The virtual prototype of the machine was configured in a CAD/CAM environment, where simulations of the mechanism's operation were performed. A programming system for machine has been prepared that also enables program verification. An open architecture control system based on the LinuxCNC platform has been configured for control of the machine. The trial work of the machine was performed in order to verify the realized prototype and control.

In this paper was presented the technical procedure implemented for the fault diagnostics of the thyristor bridge in an АС/DC converter. During the development of the new generation of digital controllers for AC/DC converters, it was required for these devices to have a possibility for a real-time detection of the thyristor converter fault. Thyristor bridge fault should be detected without the need for the state monitoring of the particular power semiconductor switches or rapid fuses. Thyristor bridge fault was identified using the measurement of the line-frequency second harmonic in the rectifier output current signal. Output voltage and current waveforms were presented, as well as the current spectra, in the cases of the thyristor bridge operation without one switch. The operation principle was described for a protection from an asymmetric operation of a thyristor bridge. A negative influence of high-order harmonics was analysed on the particular rectifier components, both in the cases of the output voltage control, as well as for operation in the current limit mode.

Laser techniques have become irreplaceable in solving a wide variety of conservation problems. For the last thirty years, lasers have been used in the diagnostic process, in the process of removing undesirable layers, as well as in repairing damages of cultural heritage objects. Because of the complexity of artifacts, traditional cleaning methods in many cases have partial success. Laser cleaning shows certain advantages such as: high selectivity, precision, efficiency and reliability in application in different types of materials. There are also certain risks for cleaning objects, and the studies of process optimization are the subject of a number researches. This paper presents the methodology and results of the application of infrared thermography for the continuous monitoring of temperature distribution on the surface of metal objects during laser irradiation. A large number of experiments were performed using Nd: YAG laser for cleaning. The obtained results were verified by the results of the numerical simulation of heat propagation in the base material. It has been shown that infrared thermography can eliminate damage to the base material, which is of special importance in the laser cleaning of priceless value artifact.

In this paper the model that solves the problem of exceeding time limit in the system of express parcel shipping in the Post of Serbia is described. The existing principle of the organization of the area serving is explained, as well as the problem of exceeding time limit that appears and leads to the delay of the service to the user. Two approaches for problem solving are suggested. The reengineering of the existing business processes is carried out to some extent through these two approaches, and will be presented by BPMN notation. The first approach is based on the use of the fuzzy set theory, i.e. fuzzy logical systems, while the other one is based on the use of algorithm 'zoning-routing'.

In this paper, for the universal machine tool for turning and function of the thrust of the cutting speed for blasting area efficiency and stability of the tool and sectional filings. These dependencies were used to determine the main characteristics of the optimal and maximum operating power equipment. Based on this, an analysis of the increase in operating power equipment in typical cases in order to adapt to the new needs of exploitation properties and improve productivity.Using the previous analysis, it was determined the best solution in terms of the rational design of machines, by ensuring the simultaneous use of the main features on the basis of the increase in speed with the use of tools and higher stability. In order to better display problems, an analysis of the appropriate diagrams P-V and V-D.On a typical example of the manufacturing practice at the end of the work, we demonstrate improvement of exploitation characteristics of a universal machine through appropriate calculations in terms of new needs adjustment feature, where it is expected that the reconstruction of the smallest machines. U radu je za univerzalnu mašinu alatku za obradu struganjem određena zavisnost pogonske snage od brzine rezanja za eksploatacijsku oblast iskorištenja postojanosti alatke i preseka stugotine. Ove zavisnosti su iskorišćene za utvrđivanje glavnih optimalnih karakteristika i maksimalne pogonske snage mašine. Na bazi ovoga, izvršena je analiza povećanja pogonske snage mašine za karakteristične slučajeve u cilju prilagođavanja eksploatacionih karakteristika novim potrebama odnosno poboljšanja proizvodnosti. Koristeći prethodnu analizu, određeno je najpovoljnije rešenje sa aspekta racionalnog projektovanja mašine, pri čemu je obezbeđeno istovremeno iskorišćenje glavnih karakteristika na bazi povećanja broja obrta, a uz primenu alata veće postojanosti. Radi potpunijeg prikaza problema, izvršena je analiza u pogodnim dijagramima P-V odnosno V-D. Na karakterističnom primeru iz proizvodne prakse, na kraju rada, dat je prikaz poboljšanja eksploatacijskih karakteristika jednog univerzalnog struga kroz odgovarajuće proračune sa aspekta prilagođavanja karakteristika novim potrebama, pri čemu se očekuje da će rekonstrukcija mašina biti najmanja.