ABSTRACT. U ovom radu je prikazano jedno rešenje za prijem i obradu JSON komandi u programskoj podršci digitalnog televizijskog prijemnika. Cilj rada jeste omogućavanje komunikacije između korisničke aplikacije i modula za upravljanje funkcionalnostima digitalnog TV prijemnika. Dato rešenje se bazira na postojećim standardima digitalne televizije i standardima za komunikaciju.

ABSTRACT. U ovom radu je prikazano jedno rešenje implementacije Android 4K hibridnog OTT STB uređaja. Cilj ovog rada jeste proširenje mogućnosti koje pružaju OTT i hibridni STB uređaji u jednu celinu kao i mogućnost reprodukcije video sadržaja visoke rezolucije. Dato rešenje je implementirano modulima koji su obezbjedili funkcionalnost digitalne televizije i bazirano je na postojećim standardima iste kao i standardima za komunikaciju.

ABSTRACT. Današnji TV uređaji poseduju više načina za bežičnu komunikaciju kao što su Wi-Fi, Bluetooth i IR. Najčešće se koriste za pristup internetu sadržaju, kontroli ili prikazu informacija na dodatnom uređaju. Posmatrajući uređaj na kome se prikazuju dodatne informacije TV uređaja i imajući u vidi da se napaja najčešće iz ograničenog izvora električne energije, potrošnja mrežnih modula značajno utiče na životni vek dodatnog uređaja i predstavlja potencijalni problem. U ovom radu biće opisana generička programska podrška za bežično upravljanje pametnih televizora preko mobilnog uređaja baziranom na Android sistemu, sa akcentom na što manju potrošnju prilikom razmene poruka.

ABSTRACT. ADAS Grabber je jedinstvena platforma koja upotpunjuje dobro poznate načine testiranja u autoidustriji. Ovaj sistem je pogodan u razrađenim HIL testiranjima koje se odnose na deo sa mašinskom vizuelnom percepciom. Pored toga što je dodatak BBT sistema otvoren je još jedan put koji doprinosi lakšem ispitivanju veoma složenih sistema autoindustrije. ADAS Grabber je ispitni sistem koji je se lako prilagođava na razne vrste sistema sa mašinskom vizuelnom percepciom jer omogućava paralelan rad sa sistemom koji ispitujemo koji podržava od 1 do 9 kamera. Podrška reprodukcije i snimanja ispitnih vektora je omogućena putem brzog interfejsa PCIe. U sledećim verzijama ovog sistema korak dalje bi predstavljao itegraciju CAN magistrale putem koje bi ispitni sistem mogao da vrši validaciju ponašanja promene stanja vozila.

ABSTRACT. Efficient testing of digital audio systems requires an embedded device, reliable and precise tool as a standard piece of audio engineers workspace. In order to replace expensive solutions available on the market, RT-RK institute has developed a device by the name RT-AG (RT – Audio Grabber), with functionalities that satisfy current standards in audio consumer electronics. This paper describes a software of the device, with emphasis on recording and playing signals of new generation audio technologies.

ABSTRACT. Kao sto je slučaj sa softverom za desktop računare, embedded sistemi takođe imaju softver koji je podložan napadima i izmenama od strane neautorizovanih lica. U ovom radu biće ukratko objašnjena potreba za zaštitom sistema, kao i posledice slabo osmišljenih mehanizama zaštite. Dat je pregled elemenata kriptografije koji su najčešće u upotrebi, enkripcije/dekripcije, hash funkcija, digitalnog potpisa. Opisano je kako se kriptografske metode mogu upotrebiti u zaštiti softvera embedded sistema. Dat je primer primene predloženih metoda zaštite kod set-top-boks uređaja, u procesu sigurnog podizanja sistema i ažuriranja softvera.

ABSTRACT. Analysis of start-up transient of Half Wave Capacitive Divider Power Supply is presented, for entire range of initial phase. Duration of start-up transient is estimated, and approximate formula for its higher boundary is developed.

ABSTRACT. Precision full-wave rectifier with two current conveyors, two diodes and without any passive component is shown. The theory of the rectifier operation is described and analyzed. In the presented rectifier input signal can be only rectified, but at the same time it can also be rectified and amplified or rectified and attenuated. The current mode technique has been employed in order to provide the high-precision capability of the circuit. PSPICE program has been used to verify the proposed design of the current-mode precision full-wave rectifier. To evaluate the accuracy of the current-mode full-wave rectifier generalized frequency response concept is used.

ABSTRACT. This paper presents two hard switching boost DC/DC converters, one made with GaN FETs and SiC diodes and the other with MOSFETs and fest recovery epitaxial diodes (FRED). Both converters achieved 1200W of continuous output power operating at relatively high switching frequency of 167 kHz. Input voltages from 180 V to 240 V corresponding to the battery bank or photovoltaic power generation system, are boosted to 400V. The idea was to demonstrate the performance of GaN transistors in order to show their significant advantages over silicon MOSFETs.

ABSTRACT. Rechargeable batteries are most important part in uninterruptible power supply system in telecommunication centers. Value of stored energy is reversible process, but capacity is highly dependent of charging and discharging process, temperature and other factors. Depending on application, rechargeable batteries can be connected in series, parallel or series/parallel string. With series connected battery string, higher voltage can be achieved, but unequal cell voltage balance can lead to accelerated aging of connected batteries. In parallel connected string, higher current capacity can be achieved, but due to unequal resistance of installations, internal discharging represents serious problem. Advantages of accurate charge equalization are very substantial and include reduced damage to battery cells in the stack, and dramatic increase in battery life. Realization of battery control system with bi-directional DC/DC converters is presented and described.

ABSTRACT. This paper proposes implementation of Recursive Least Square (RLS) method in a self-adaptive technique for Active Power Filter (APF) control. APF are used to reduce the Total Harmonic Distortion (THD) in power system. Namely, APF compensate higher harmonics present in the power grid. In order to compensate, the higher harmonics should be identified, at first. The real truth is that nonlinear loads mainly distort the current. Therefore the distortion current is to be measured and all harmonic components identified. RLS method uses values of the sampled current to calculate the needed compensation for APF. Then APF (in shunt configuration) add to the grid the required higher harmonic components of current diminishing distortion on the grid. Simulations by SystemC verify the effectiveness of the method.

ABSTRACT. In this paper artificial neural networks are used for identification of nonlinear loads on the network, as one of the methods for non-intrusive load monitoring. Specific parameters of a group of the nonlinear loads are first measured, and then a neural network is used in order to identify which load is active on the network. Performances of ELM algorithm are tested, in the sense of the activation function and number of hidden neurons. It is shown that the task of loads identification can be done successfully.

ABSTRACT. Conventional circuit breakers suffer from two main deficiencies: they are slow to operate and develop an electrical arc. These may be overcome by using solid-state switches which in turn introduce other problems, most significantly power dissipated while in the on-state. Ne¬ver¬theless, a number of solid state devices are candidates for implementation as low-voltage circuit breakers and there are several options based on the semiconductor material that may function as a high-power switches. This paper presents a unique, extensive and systematic eva¬luation of these options for suitability as solid state breakers. Voltage controlled devices are selected due to the simplicity of the controlling circuit and their resilience to dv/dt induced switching. Properties of fully solid-state circuit breakers are esta¬blished and systematic comparisons are made among switches built of silicon and several other wide band-gap (WBG) devices such as SiC MOS and GaN HEMT transistors. Using SPICE simulation of transistor models supplied by the device manufacturers, it is shown that solid state circuit breakers (SSCBs) based on WBG devices exhibit superior characteristics compared with silicon devices, with faster switching and higher voltage and current ratings.

ABSTRACT. Merenje vrednosti izolacione moći fasade vrši se pomoću izvora buke postavljenog pod uglom 45±5 stepeni, prema ISO 140-5. Zbog zavisnosti vrednosti izolacione moći fasade od ugla pod kojim zvučni talas pogađa fasadu, od interesa je ispitati raspodelu uglova incidencije buke na fasadu u realnosti. U ovom radu prikazan je način za određivanja i analizu incidentnih uglova buke na fasadi zgrada u urbanim uslovima. Kao alat za ovu svrhu korišćen je planarni neregularni mikrofonski niz sa 24 mikrofona, koji je dizajniran namenski za ovu aplikaciju. Lokalizacija zvučnih izvora u urbanim uslovima i raspodela uglova incidencije izvršena je pomoću nekoliko algoritama za obradu signala sa mikrofonskog niza.

ABSTRACT. Night clubs on the river are well known specificity of Belgrade, but also serious noise sources in the wide environment, especially during night. For noise prediction it is necessary to estimate data concerned their sound power. Choosing the correct standard for qualifying such acoustic sources can be a challenge. The decision must take into account a number of factors: type of noise source, avaliable equipment and testing environment, regulations, etc. This paper provides an overview of the existing standards for determining the sound power, but also a possibility of application of such standards in order to quantify the nightclubs on the river as a noise source. According to the specificity of the noise emitted by night clubs on the river and their dimensions, a sugesstions for determination of the sound power for two different approaches are proposed - measurement of sound pressure and sound intensity.

ABSTRACT. Zahtevi iz domena energetske efikasnosti uslovili su sve češće korišćenje dvostrukih masivnih zidova sa termoizolacionim slojem između njih. U literaturi postoji relativno malo podataka o laboratorijski izmerenim vrednostima izolacione moći takvih pregradnih zidova. Zbog toga se u praksi javljaju greške koje se naknadno veoma teško mogu korigovati. Merenja u novoizgrađenim zgradama pokazala su neočekivano male vrednosti izolacije takvih zidova, manje od očekivanih prema poznatoj teoriji o masivnim monolitnim pregradama. U ovom radu su analizirani rezultati laboratorijskih merenja standardnih konfiguracija dvostrukih zidova. Na osnovu toga su izvedeni zaljučci o uticaju pojedinih parametara takve konstrukcije na očekivane vrednosti zvučne izolacije i o mehnaizmima prenosa zvučne enegije kroz njih.

ABSTRACT. Povećani zahtevi u pogledu termičke izolacije u zgradarsvu uslovili su sve veću upotrebu dvostrukih masivnih zidova sa iermoizolacionim materijalom u međuprostoru. Standard SRPS 12354-1 definiše prostupke proračuna zvučne izolacije od vazdušnog zvuka, ale ne obuhvata ovakve konstrukcije. Kod dvosrukih masivnih pregrada postoje dve paralelne putanje prolaska zvuka. Jedna je direktna putanja kroz pregradu, a druga predstavlja dodatnu bočnu putanju. Ta dodana bočna putanja dominatno određuje ukupna izolaciona svojstva dvostrukog zida. Kod dvostrukih masivnih pregrada izlaciona svojstava bočnih putanja su promenjena, obzirom da u njima učestvuju dve tanje pregrade. U radu prikazan je predlog jednog mogućeg pristupa za proračun dvostrukih pregrada po načelima metodologije definisane za jednostruke masivne pregrade iz standarda SRPS 12354-1. Na primeru uobičajenih konstrukcija koje se koriste danas u stanogradnji prikazane su vrednosti dobijene predloženim proračunom i upoređene sa rezultatima laboratorijskih merenja

ABSTRACT. Razvoj regulative za zvučnu zaštitu u zgradama doveo je u gotovo svim evropskim zemljama do uvođenja akustičke klasifikacione šeme. To podrazumeva da je definisana podela na klase zvučne izolacije prema kojoj se kategorišu zgrade u celini ili pojedinačni stanovi u njima, na sličan način kao u postojećem sistemu energetske efikasnosti. U procesu izrade nove regulative za zvučnu zaštitu u Srbiji planirano je da se uvede akustička klasifikacija stambenih zgrada i stanova i preispitaju minimalni zahtevi u pogledu zvučne izolacije koji se moraju postići. To otvara pitanje sudbine postojećih zgrada, ali i statusa do sada uobičajeno primenjivanih građevinskih sistema koji određuju nivo zvučne izolacije. U radu je prikazana analiza stanja zvučne izolacije na uzorku novoizgrađenih stambenih zgrada u širem okruženju Beograda. Na osnovu toga je izvršena procena efekata koje bi moguće podele na klase i pooštravanje minimalnih zahteva imali na uobičajene sisteme gradnje koji se danas primenjuju.

ABSTRACT. U radu su dati rezultati zvučne izolacione moći za jedan tip PVC prozora sa roletnom. Ispitivanja su izvršena u sladu sa serijom standarda SRPS EN ISO 10140. Rad je nastao kao logična posledica činjenice da je praktična klasifikacija ovakvog prozora diskutabilna s obzirom na to da se može desiti da rezultati pokažu da prozor sa podignutom roletnom pripada jednoj klasi prozora, a sa spuštenom drugoj. U praksi jako mali broj proizvođača vrši ispitivanja ovog tipa prozora zbog očekivano lošijih rezultata.

ABSTRACT. Zid izrađen uz poštovanje opštih pravila izgradnje je preduslov za dobijanje zadovoljavajuće zvučne izolacije. Ušteda na malteru i neadekvatno povezivanje konstruktivih elemenata zida svakako nisu poželjni. U radu je dat primer koliko mali otvori u zidu i adekvatno izvedno malterisanje utiču na zvučnu izolacionu moć zida od pune opeke i zida od bloka.

ABSTRACT. U ovom radu predstavljen je matematički postupak za određivanje funkcije gustine verovatnoće i funkcije raspodele verovatnoće greške pri detekciji signala u kanalu, gde pored termičkog šuma, istovremeno postoje promene anvelope signala usled višepropagacionog fedinga i efekat senke. Izvedeni su izrazi za ove veličene za različite modulacione formate i analiziran je uticaj dubine fedinga i inteziteta efekta senke na njihov oblik. Rezultati mogu biti od koristi kada se primenjuju Monte Karlo simulacije da bi se procenilo trajanje simulacije.

ABSTRACT. Najveći izazov pri implementaciji efikasnog postupka za lociranje mobilne stanice predstavlja negativan uticaj NLOS (Non-Line of Sight) propagacijskih uslova. U ovom radu je predloženo jedno od mogućih rješenja za potiskivanje NLOS grešaka pozicioniranja u ćelijskim radio mrežama, zasnovano na TOA (Time of Arrival) orjentisanom ML (Maximum Likelihood) estimatoru sa ugrađenim Levenberg-Marquardt algoritmom optimizacije. Pokazano je da na ovakav način projektovani estimator predstavlja ujedno i estimator minimalne varijanse u kombinovanom LOS/NLOS propagacionom okruženju.

ABSTRACT. Tradicionalne telekomunikacione mreže migrirale su prema ALL-IP višemedijskim mrežama i tako je protokol za pokretanje sesije (SIP - Session Initiation Protocol) dobio nezaobilaznu važnost. Performanse SIP signalizacije su važan faktor koji utiče na ukupni kvalitet usluge. U radu su definisane i izmjerene performanse pomoću Master Claw sistema u okviru IMS (IP Multimedia Subsystem) sistema MTEL-a.

ABSTRACT. U ovom radu opisane su karakteristike TTEthernet mreža, kao i razlike u odnosu na standardne Ethernet mreže. Opisani su principi i uloge TT, RC, BE, te PCF tipova saobraćaja, gdje je fokus na TT komunikaciji jer je ona primarna u TTEthernet mrežama. Objašnjen je način na koji se vrši sinhronizacija između uređaja u mreži, koja generalno predstavlja jedan od najbitnijih aspekata u determinističkim mrežama. Opisani su principi kojima se postiže otpornost na greške kod TTEthernet mreža. Kroz opis karakteristika TTEthernet mreža navedene su njihove prednosti u bezbjednosno-kritičnim aplikacijama u odnosu na standardne Ethernet mreže.

ABSTRACT. U radu su analizirani kašnjenje, varijacija kašnjenja – džiter, paketski gubici i propusni opseg kao parametri kvaliteta servisa, a u formi četiri tipa degradacije kvaliteta video sadržaja. Izvršena je analiza uticaja definisanih nivoa degradacija na subjektivne impresije posmatrača predstavljene kroz prosečne (srednje) subjektivne ocene (Mean Opinion Score, MOS). Za analizu je korišćena ReTRiEVED baza sekvenci sa dostupnim subjektivnim impresijama kvaliteta. Za objektivnu procenu kvaliteta korišćene su tri mere sa potpunim referenciranjem na izvorni video sadržaj. Prikazani su stepeni slaganja subjektivnih i objektivnih skorova kvaliteta kroz dijagrame rasipanja i odgovarajuće kvantitativne mere (koeficijent linearne korelacije i korelaciju rangova). Na osnovu logističkih interpolacionih funkcija izvršeno je preslikavanje parametara kvaliteta servisa u zadovoljstvo korisnika. Pokazano je da džiter ima mnogo destruktivniji efekat od ostalih tipova degradacije signala.

ABSTRACT. This paper presents a part of the results obtained by the Process Control group of the Politehnica University of Timisoara, Romania, in the field of evolving Takagi-Sugeno-Kang fuzzy models. These results concern the development of Takagi-Sugeno-Kang fuzzy models by incremental online algorithms for the description of the dynamics or static behavior of three technical and non-technical system applications, namely magnetic levitation systems, Anti-lock Braking Systems and automated translation.

ABSTRACT. This paper presents a comparison of most frequently used criteria for optimizing distributed order PID and fractional PID controllers. The problem of interest is how to provide load disturbance rejection under constraints to performance and robustness. The comparison of optimal controllers via different optimization criteria has been performed for different non-integer processes. The optimal controllers are obtained via optimization by genetic algorithm.

ABSTRACT. In this paper for the class of linear singular impulsive dynamical systems we present solvability results. We define consistent initial conditions, tractability and regularity, we discuss existence and uniqueness of solutions, and we define equivalent statements for solvability definition of singular impulsive system. A linear singular impulsive system represents mixture of singular differential and singular difference and algebraic equations. In special case, for singular matrices being regular, results are standard as in case of linear impulsive systems. In case of continual or discrete dynamics being absent, results specialize to classical singular discrete, or singular continual systems, respectively. This class of system is here defined for the first time. This paper also considers wider class of general systems that includes both singular and standard impulsive systems.

ABSTRACT. It is well known that the PID controllers are used in most of industry applications (in more than 95% cases, according to relevant reports and analyses) and that these controllers are rarely without integral action. Also, Internal Model Control (IMC) based designs are well recognized and accepted inside control community thanks to their stability and performance robustness. Having in mind nonlinear and slowly varying dynamics of the industrial processes, in this paper we propose an Adaptive Internal Model-based Neural Controller with embedded Integral action (AIMNCI). The internal model of the controlled plant is implemented by the Fast Clustered Radial Basis Function Network (FCRBFN) provided with the Stochastic Gradient Descent (SGD) learning algorithm. Some illustrations and performance comparison between the proposed AIMNCI controller and others are given by two examples.

ABSTRACT. Acoustic signals are shown to be very informative for a wide variety of applications; however, they are highly susceptible to the surrounding noise. This paper proposes a new algorithm which uses cepstral coefficient extracted from acoustic recordings in order to detect whether the useful acoustic signal is contaminated with noise. Apart from noise detection, this algorithm also performs noise classification if the contamination is indeed present. The algorithm used for this purpose is a clustering scheme based on support vector machines and the performance of the algorithm is tested on nominal recordings taken from fan mills in thermal power plants in Serbia. The contamination has been performed using four different types of noise, and the algorithm has been tested for different values of signal-to-noise ratio.

ABSTRACT. A mobile robot that determines the shape and size of an unknown workspace is presented in this paper. The robot is wheeled, and equipped with a controller and cliff sensors. The main goal of this paper is to demonstrate the potential use of neural networks for workspace mapping. A workspace can be a table or any other surface with cliff boundaries, assuming that the robot can reach all of its boundaries. The detection of the workspace cliff boundaries is accomplished using infrared sensors that are pointed downwards. The body of the robot is designed and manufactured using a 3D printer. Robot uses differential drive to move, and odometry for position sensing. The motion control algorithm is explained in details. Controller is based around Raspberry Pi 3. The description of the neural network that determines the shape and size of the workspace is presented, along with test results. The robot is tested for determining the size and shape of a rectangular workspace with the dimensions of 70 cm x 50 cm.

ABSTRACT. This paper describes the extension of the existing GCC profiling tools. The existing solution gives the possibility of obtaining data on code coverage only at the end of execution. Here is presented a software solution to the problem of obtaining these data during the execution of code in specific cases where the execution of code must not be terminated. The paper also covers forms of data presentation of the code coverage in a way that should facilitate their analysis in the part that relates to the new graphical tool for presenting collected data.

ABSTRACT. Permanentan razvoj MIPS arhitekture donosi pored novih instrukcija nove standarde koje treba da zadovolje programski prevodioci. Jedna od inovacija jeste FPXX konvencija, koja pomaže u migraciji od sistema sa 32-bitnim jedinicama za rad sa brojevima u pokrentom zarezu na one sa 64-bitnim jedinicama. Ovaj rad opisuje izmene načinjene u alatu za dinamičku analizu binarnog koda Velgrind, s ciljem dodavanja podrške za konvenciju FPXX.

ABSTRACT. U ovom radu je opisan postupak portovanja Tizen 2.3 wearable operativnog sistema za 32-bitnu MIPS procesorsku platformu. Tizen je operativni sistem namenjen širokom spektru uređaja koji promoviše ideju njihove integracije u jedinstven ekosistem koji pruža konzistentno korisničko iskustvo. MIPS predstavlja RISC procesorsku arhitekturu koja uz nisku potrošnju energije ostvaruje dobre performanse, sa posebno dominantnom pozicijom u sferi mrežnih uređaja. U radu su dati detaljniji opisi operativnog sistema i platforme, predstavljeni su razlozi koji su doveli do portovanja, opisane su faze rada i prikazani rezultati verifikacionih testova.

ABSTRACT. U ovom radu je opisana realizacija prilagođavanja programskog prevodioca LuaJIT arhitekturi MIPS64 sa i bez koprocesora (jedinice za operacije u aritmetici pokretnog zareza). Detaljno je opisan pristup, način i redosled prilagođavanja interpretera LuaJIT i prevodioca LuaJIT za arhitekturu MIPS64. Izvršen je paralelan prikaz realizacije rešenja u slučaju da arhitektura MIPS64 sadrži koprocesor i slučaj kada ga arhitektura MIPS64 ne poseduje.

ABSTRACT. Uvezivač predstavlja alat koji spaja objektne datoteke i od njih pravi izvršnu ili deljenu datoteku. Cilj ovog rada je realizacija podrške za uvezivanje programa za arhitekturu MIPS64 u okviru uvezivača GOLD. U radu je realizovana podrška za verzije binarne sprege programske podrške N32 i N64.

ABSTRACT. This paper describes an example of architecture of modules for machine perception of the environment in the system for driving assistance. There is shown some examples of advanced driving assistance that have been developed by the world's leading companies in this field. Also it shows the trends of development of similar systems in the world, and the realization of concrete platforms on which they are/will be implemented and developed algorithms for such purposes. Those algorithms are explained in the paper.

ABSTRACT. Settling time is one of the parameters most difficult to measure, especially for integrated PLLs, since many internal, low-frequency signals are usually not available to the user. This paper describes the method for accurate measurement of settling time of integrated frequency synthesizers using the waveform capturing capabilities of modern spectrum analyzers.

ABSTRACT. Power management is an important aspect of modern embedded system design. In order to evaluate effectiveness of power management techniques power profiling is used. Most model-based power profiling for low power systems so far has been focused on cycle-accurate models, which are not useful for online use. We present high-level model-based power profiling, for CC430 System on Chip (SoC) as an example. Three SoC components are modeled: CPU, AD converter and RF core. Models are constructed using finite state machines and linear regression. Presented model has less than 4% mean error on run tests.

ABSTRACT. This paper presents a lifesaving smart mechatronic system that prevents poisoning from high concentrations of Carbon Monoxide. This proposed system provides a technical solution to attenuate the dangers of gas used for heating space and water. It relies on sensor nodes, actuator nodes, a main control node, and a corresponding smartphone application allowing emergency communication and remote monitoring of the heated rooms. Sensor nodes composed of a gas sensor, a microcontroller, and an audiovisual alarm- as well as actuator nodes- which comprises a window actuator, a relay, and a microcontroller- are installed in rooms where heating is used. When the concentrations reach dangerous levels, the main control node, which consists of a microcontroller connected to a server, sends commands to the sensor nodes to turn an alarm on, and to the actuator node to automatically open the air vents and activate the fans to accelerate the renewal of air and decrease the concentration. Through a smartphone application, the suggested system notifies relative and/or emergency services. The paper presents the architecture and design of this scheme, details its components, and provides its cost analysis.

ABSTRACT. This paper presents novel technique for counting people passing through the door. Finding acceptable solution for the presented problem is of great importance, hence the information about the number of people located in the specific area may be significant for different emergency situations, such as entry control, marketing research, office security, building management and road traffic monitoring. Multiple solutions available on the market, based on different technologies, provide acceptable results only under certain lighting conditions, with limited accuracy, high costs and computational power. In this paper we present hardware solution based on mm-Wave radar technology and dedicated algorithm implemented on custom digital signal processing (DSP) platform. Performed measurements and testing results have proven that presented approach is very reliable, even in situations when multiple persons are passing through the door simultaneously, in different directions and in very short time intervals.

ABSTRACT. Mobile robots are used in various applications, some of which have specific requirements, like precise localization. An odometry may be used for localization, or as a supporting system for improving accuracy of a global localization system. This often requires a lot of computing power and therefore not suitable for embedded systems. Although there are a lot of small computers available, suitable for mobile robots, with enough processing power for ordinary odometry algorithms, rarely a suitable interface for reading a high pulse train signal of the high resolution incremental encoder is available. In this paper we will present one efficient solution, tested through experiments, for bridging Raspberry Pi 3 and magnetic incremental rotary encoders.

ABSTRACT. The article presents the mathematical modelling and simulation models of a MEMS electromagnetic scanning system, with the aim to discuss sources of nonlinear behavior and to compare voltage vs. current control modes. The electromagnetic (EM) actuators develop high forces at any scale, and can be used at both resonance or far from it. This study completes previous design and manufacturing work of the electro-mechanical structure and its electric supply circuits. A nonlinear mathematical model for a general case, with the main actuator connected to a second elastic system carrying the mirror, and the particular mathematical model for infinite contact impedance between the actuator and the mirror support, allowing use of a single degree of freedom model for the mechanical part, are presented. The models are simplified for current control strategy discussion, and their SIMULINK implementation is included altogether with the results of simulations that confirm the advantages of the current control.

ABSTRACT. Ultrasonic sandwich transducer, also known as a Langevin’s transducer, is a half-wave resonant structure that oscillates in thickness direction. In this paper, new Matlab/Simulink model of a prestressed unsymmetrical ultrasonic sandwich transducer is presented. The sandwich transducer is modeled by applying three-dimensional (3D) Matlab/Simulink models of piezoceramic rings and metal endings, which are derived based on the piezoceramic ring model recently proposed by the authors. By cascade connecting the piezoceramic rings model with metal endings model, a complete model of ultrasonic Langevin’s transducer is obtained. Using this model one may determine any transducer transfer function, whereat is taken into the account the external medium influence, as well as the influence of the thickness and radial modes of each transducer component. The comparisons between experimental and theoretical results are quite good and validate the new design approach.

ABSTRACT. Karakteristike zvučnog polja u zatvorenom prostoru posledica su apsorpcionih, refleksionih i difuznih karakteristika samih površina za zadatu geometriju prostorije. Problem predikcije karakteristika akustičkog odziva odnosi se na problem što boljeg opisivanja procesa koji se odvijaju na površinama. Efikasnost materijala koji se apliciraju na pojedinim površinama zavisi direktno od načina na koji površine bivaju pogođene zvučnom enerijom. U ovom radu na bazi rejtrejsing simulacije zvučnog polja analizirana je raspodela incidentne energije po površinama prostorije kao i njena ugaona raspodela. Analizom su obuhvaćene prostorije različitih geometrijskih oblika, a simulacija je izvršena za različite kombinacije apsorpcionih i difuznih karakteristika unutrašnih površina. Poznavanje ovih karakteristika omogućava optimalniji raspored raspoloživog materijala kao i analizu izolacionih svojstava u zadatim uslovima.

ABSTRACT. U ovom radu su analizirani važeći kriterijumi koji se koriste kod definisanja nivoa zvuka alarmnih signala u zoni pokrivanja elektronskih sirena za javno uzbunjivanje. Na bazi detaljnijeg uvida u karaktersitike buke u naseljima, koristeći dostupne podatke iz literature, kao i podatke iz sopstvenih obimnih merenja, a imajući u vidu psihoakustičke karakteristike čula sluha, predložene su minimalne vrednosti nivoa alarmnih signala u odnosu na nivo buke u zoni pokrivaja sirena.

ABSTRACT. U radu smo prikazali merenje karakteristika usmerenosti violine. Merenje smo obavili u audio studiju Visoke škole elektrotehnike i računarstva mernim uređajem NTI XL2 sa ugrađenim mernim mikrofonom M4260. Violinu je svirao instrumentalista postavljen na rotaciono postolje. Brzina obrtanja postolja je 10 obrtaja u minuti. Karakteristike usmerenosti smo izmerili u horiznontalnoj ravni. Širina izabranog frekvencijskog opsega je tercnooktavna. Rezultate merenja smo prikazali tabelarno i grafički.

ABSTRACT. Pouzdana detekcija i otklanjanje kvarova na motociklima predstavlja put ka bezbednosti učesnika u saobraćaju. Motocikl je sačinjen od velikog broja delova koji potencijalno mogu imati kvar, i kao takav predstavlja složen i zahtevan sistem za analizu. U ovom radu prikazana je metoda za neinvazivnu detekciju kvarova na motociklu, nezavisno od tipa motocikla. Analizirana je mogućnost detekcije nebalansiranosti usisnih grana motora sa unutrašnjim sagorevanjem pomoću merenja intenziteta zvuka koji emituje motocikl. Kao merni alat u istraživanju korišćena je intenzitetska sonda sa dva mikrofona. U radu su prikazane prednosti merenja intenziteta u odnosu na druge akustičke metode u ovoj situaciji. Rezultat detekcije pomoću intenzitetske sonde upoređen je sa drugim tehnikama za određivanje ovog kvara.

ABSTRACT. U ovom radu su prikazani rezultati analize mogućnosti objektivne ocene kvaliteta sistema za ozvučavanje. Analiza je zasnovana na merenju uticaja koji jedan takav sistem ima na dinamičke osobine reprodukovanih signala. U literaturi se mogu naći podaci o dinamičkim osobinama muzičkih signala različitih žanrova, gde je pokazano da razlike u muzičkim stilovima rezultuju različitim statističkim parametrima (funkcija raspodele amplituda, dinamički opseg i dr.). Za potrebe ovog rada urađen je eksperiment u kome su test signali propušteni kroz različite sisteme za ozvučavanje sa ciljem da se na osnovu promena njihovih dinamičkih parametara dođe do određenih zaključaka koji bi poslužili za karakterizaciju tih sistema. Dobijeni rezultati su diskutovani sa stanovišta eventualnog kvantifikovanja razlika u kvalitetu sistema za ozvučavanje.

ABSTRACT. The Directive 2013/35/EU of The European Parliament and Council entered into force on the 1-st July 2016. It is focused on the minimum health and safety requirements regarding the exposure of workers to electromagnetic fields. The issue is up-to-date and challenging, a plain argument being the dynamic of the European legislation in the field: the presently repealed Directive 2004/40/EC had been elaborated just only 9 years before. There is a large concern between employers, stakeholders and authorities regarding the effective application of the associated settlements. How could be decided that we have to deal or not with a dangerous situation? For the very beginning, it is the responsibility of the employer, but in the second phase, a state protection authority should check the orderliness and the conformation to the imposed limits. There are high expectations regarding quasiaccurate but financially affordable methods for exposure evaluation. There are many international agencies and organizations involved in establishing exposure restrictions on scientific basis: World Health Organization (WHO), International Commission on Non-Ionizing Radiation Protection (ICNIRP), International Agency for Research on Cancer (IARC) and Institute of Electrical and Electronics Engineers (IEEE).Obviously, the 2013/35 Directive is not concentrated on the long-term effects of the existence of electromagnetic fields. Even if direct biophysical effects and indirect effects have been studied and demonstrated, there is not a generally accepted, scientifically proved relationship between normally encountered electromagnetic fields (EMF) and human health risks. The cautious approach should be that is better to prevent than to cure and, undoubtedly, all the workers in the European Union must be protected against the possible risks arising from different time varying electromagnetic fields. In this presentation we provide an overview of the main methods for assessing the answer of the human body versus the aggression performed by thelow frequency electric and magnetic fields on living; it is mainly about axial and respective circular current densities induced inside the body.It will be a talk on limits, advantages and accuracies of the direct measurements, phantom approaches and modeling and simulations based on computational electromagnetic, about the various methods and techniques implemented by dedicated software aiming to approximate solutions for Maxwell’s partial differential equations.

ABSTRACT. Since its introduction, nearly 70 years ago, Monte Carlo (MC) has become an important tool in many fields and applications [1] as well as useful method when the uncertainty propagation equation cannot be applied. MC is a technique that handles nonnormal distributions, complex algorithms and correlations between input variables for the considered model. In this case a distribution has to be determined for each variable, the data are generated for each one, and they are used as input for the model to produce output. Since 2011 this method is recommended by the BIPM for evaluation of measurement data [2] and it can be say that it revolutionizes the determination of measurement uncertainty. The availability of MC calculation tools may remove the need for special knowledge in the construction of measurement models in all fields of engineering, science and environment analysis. The conventional uncertainty analysis called as GUM approach requires approximation at each step of procedure causing serious doubts on the validity of the results. The first part of this paper deals with the GUM method [3] applied for the estimation of power factor value uncertainty. The pf value is achieved with the use of wattmeter PX110 that enables to simultaneous measurements of voltage, current and active power. The pf is a function of three correlated input variables (V, I and P). The second part presents the application of MC simulation with the use of popular spreadsheet. The comparison of the results obtained with the both methods is also described.

ABSTRACT. This paper describes the measuring circuit which model is represented by a dynamic element of the first order. The difference between determining the end of the transient for the element of the automatic control system and one for the instrument's measuring circuit. The most common criteria of the end of the transient in the measuring circuit are considered using different types of information. The standardized interval criterion is shown to be widely used. The dependence of the critical value of the maximum time constant of the measuring circuit is found.

ABSTRACT. In this paper, we consider a method for measuring frequency, based on the determination of voltage transitions through zero (zero crossing technique). A brief description of this measurement method is given, as well as its modification, based on the linearization of the signal near zero. The use of this modification significantly improves the accuracy of frequency measurement. The analysis of the influence of the non-identity of the applied analog-to-digital converter (ADC) on the frequency measurements error was performed. The influence of additive, multiplicative error components, errors caused by the nonlinearity of the ADC conversion function and the error components caused by the quantization error is considered. It was shown that additive and multiplicative error components do not significantly influence the error of frequency measurements. Analytical relations that allow one to estimate the measurement error of the frequency from the ADC quantization error and the nonlinearity of the ADC conversion function were obtained. The reliability of the obtained results was confirmed by applying mathematical modeling (with the software Simulink 8).

ABSTRACT. In this paper, it is shown optimization in stochastic approach for THD factor measurement. There are two THD factor definitions. By one definition, THD factor is the true RMS of all harmonics higher than the first divided with the amplitude of the first harmonic. This is THD fundamental definition. THD root mean square definition is the true RMS of all harmonics higher than the first divided with true RMS of all harmonics, including first. Due to high precision and flexibility of the stochastic method, it is possible to measure THD factor directly, but it is also possible to optimize measurement by measuring first harmonic and true RMS of analog difference between analog signal and its first harmonic.

ABSTRACT. The aim of this paper is to present a detailed description of one simple experimental setup for measurement of the magnetomechanical effect of the cylindrical shaft made of commercial steel. This setup contains mechanical parts that allow generation of static torsional stress to the shaft. It also contains a large solenoid that produces an alternating magnetic field for axial magnetisation of the shaft, which is placed in the center of this solenoid. Another smaller solenoid is also placed inside the large solenoid and around the shaft to detect changes of the magnetic flux in the shaft under applied torque. The paper also presents initial measurement results obtained with this experimental setup, as well as proper discussion of these results.

ABSTRACT. In the era of battery operated devices, in particular booming wearables and Internet-of-Things (IoT) objects, ultra-low energy consumption is becoming the most important challenge in the electronic design. Supply-voltage scaling is an efficient way to reduce energy by lowering the operating voltage. The reported Minimum Energy Point(MEP), in i.e. modern CMOS 65nm, can be as low as 0.35V. To achieve such low voltage operation, sub-threshold circuit design needs to be considered. Swiss watch microelectronics was exploring this approach since 1970. An overview of the principles and challenges of today’s sub-threshold design will be given in this paper. The paper depicts also the 50 years of the Swiss “Quest for the Holy Grail” in ultra low-power wearable electronics, started with the world’s first electronic quartz wrist watch BETA1(1967) developed by the Centre Electronique Horloger (CEH) in Neuchâtel, toward autonomous, batteryless IoT objects of tomorrow.

ABSTRACT. Microhardness test is the most commonly used method for assessing the mechanical properties of thin films. This testing method uses controlled contact at a single point of an indenter and chosen material which induces the plastic deformation in material under indenter. The measured hardness is considered as the composite hardness, because the substrate participates in the plastic deformation caused by indentation. This research has been carried out in order to analyze and compare the hardness response of different composite systems consist of monolayer electrodeposited copper thin film on brass and steel alloys as the substrates. The influence of the electrodeposition parameters and of the substrate on the hardness and interlayer adhesion were investigated by Vickers microhardness testing for different load.

ABSTRACT. After a review of a deterministic model of time response of microfluidic adsorption-based chemical and biological sensors, we present an approximate model for efficient analysis of stochastic response, which takes into account a random AD process coupled with convection and diffusion of target substance particles. Subsequently, we present the results obtained by the comparison of the two response models (deterministic and stochastic) used for sensors with different micro/nanoscale active surfaces, and intended for detection of substances present in different concentrations. In this way we can distinguish the cases in which the use of the deterministic model is justified from those in which the use of the stochastic model is necessary. The presented findings enable more accurate interpretation of measurement results obtained by using sensors with micro/nanoscale active surface, as well as optimization of their design.

ABSTRACT. U ovom radu ispitivane su karakteristike višeslojnih dielektričnih HfO2/Al2O3 struktura na silicijumu kao potencijale komponente za primenu u fleš memorijama. Snimane su visokofrekventne CV krive nakon primene serije pozitivnih ili negativnih napona kojima se simulira rad memorije, tj. zapis i brisanje informacije. Pokazano je postojanje memorijskih svojstva i značajan memorijski prozor, ali su neophodna dalja istraživanja u pogledu realizacije efikasnijih i pouzdanijih struktura.

ABSTRACT. Podpovršinski defekti, simulirani u aluminijumskoj test pločici, ispitani su metodom impulsne termografije. Pri ispitivanjima je korišćena savremena termovizijska kamera FLIR SC7200 sa hlađenim detektorom. Radi poređenja kvaliteta generisanih termograma, podpovršinski defekti snimani su pri različitim vremenima integracije