TOWARDS MACHINE VISION BASED RAILWAY ASSETS PREDICTIVE MAINTENANCE

The main goal of this paper is to present novel technologies that can contribute to safety, competitiveness, efficiency and operational reliability of Railway infrastructure through the development of innovative solutions for measuring and monitoring of railway assets based on machine vision. Measuring the transversal position of the wheels on the rail, as well as identification of the defects of the wheel and the rail (such as deformation of rail head edge, lateral wear, worn wheels, cracks in wheel and rail, rolling contact fatigue, corrugation and other irregularities) can increase reliability and lower maintenance costs. Currently, there is a need on the market for the innovative solution, namely the on-board high-speed stereo camera system augmented with a system that projects custom pattern (fringe scanner system) for measuring the transversal position of the wheels on the rail, robust to environmental conditions and waste along the track that can provide reliable measurements of transversal position of the wheels up to 200 km/h. New trends in Precise Industrial 3D Metrology are showing that stereo vision is an absolute must have in modern specialized optical precision measuring systems for the three-dimensional coordinate measurement

Fotonaponski sistemi u urbanim sredinama povezani na distributivnu mrežu i primer njihove primene

U urbanim sredinama postoji veliki broj ravnih osunčanih površina na krovovima zgrada koje su pogodne za postavljanje fotonaponskih solarnih sistema i dobijanje obnovljive energije. Poslednjih 15 godina u urbanim sredinama širom Evrope sve je veća primena fotonaponskih (PV) sistema, koja je dovela do pozitivnih ekonomskih i ekoloških efekata proisteklih iz ovakvog načina dobijanja energije. Dogodile su se značajne promene u pristupu i načinu planiranja novih delova grada, važnoj ulozi eksperata, edukaciji stručnjaka, učešću javnosti i ulozi lokalnih vlasti u implementaciji ovih projekata. Implementacija PV sistema u projektovanju i izgradnji objekata postaje deo standardnih aktivnosti u razvoju gradova. Postoje i značajne prepreke za primenu ovih sistema, koje su evropske države prevazišle, a tiču se pre svega legislativnog okvira koji reguliše ovakvu vrstu projekata, a zatim i načina njihovog finansiranja. U saradnji Elektrotehničkog fakulteta u Beogradu i Instituta za arhitekturu i urbanizam Srbije izrađen je projekat Solarne fotonaponske elektrane u cilju promocije korišćenja čistih izvora energije u urbanim sredinama. U ovom radu je prikazano idejno rešenje fotonaponske elektrane na zgradi Gradske opštine Vračar. Planirano je da maksimalna snaga fotonaponske elektrane iznosi 11,5kW. Preko trofaznog invertora sistem je povezan sa elektrodistributivnom mrežom, kojoj bi predavao višak proizvedene električne energije. U ovom radu su objašnjeni praktični problemi vezani za projektovanje arhitektonskog izgleda i energetskih instalacija ovog objekta, kao i realni problemi sa kojim se ovakvi projekti mogu sresti. Osim toga, na osnovu inostranih iskustava u radu su date smernice za primenu ovakve vrste projekata kod nas.Urednik: Momir Đurovi

Primena fotonaponskih sistema u funkciji urbanog razvoja-svetska iskustva i lokalne mogućnosti

Poslednjih 15 godina u urbanim sredinama širom Evrope sve je veća primena fotonaponskih (PV) sistema. Implementacija PV sistema u projektovanju i izgradnji objekata postaje deo standardnih aktivnosti u razvojnim procesima gradova. Iako se ne može očekivati da primena ovih sistema bude na listi prioriteta urbanog razvoja, ipak, s druge strane može značajno doprineti rešavanju sistemskih energetskih problema u gradovima. Međutim, postoje i značajne prepreke za implementaciju ovih sistema, koje su evropske države prevazišle, a tiču se pre svega legislativnog okvira koji reguliše ovakvu vrstu projekata, a zatim i načina njihovog finansiranja. Kroz primere evropskih gradova i sdudije slučaja (case study) gradova Gelsenkirchena u Nemačkoj, Gleisdorfa u Austriji i Liona u Francuskoj, rad nastoji da ukaže na pozitivne ekonomske i ekološke efekte ovakvog načina dobijanja energije i ukaže na značajnije promene u pristupu i načinu planiranja novih delova grada, važnoj ulozi eksperata, edukaciji stručnjaka, učešću javnosti i ulozi lokalnih vlasti u implementaciji ovih projekata. Osim toga, na osnovu inostranih primera u radu su date smernice za implementaciju ovakve vrste projekata kod nas. Prikazan je projekat solarne fotonaponske elektrane urađen za Skupštinu opštine Vračar u Beogradu. Rad predlaže mere i akcije (od edukacije do finansiranja) koje bi pomogle u realizaciji ovakve vrste projekata u Srbiji

Gaussian Regression Process for Prediction of Compressive Strength of Thermally Activated Geopolymer Mortars

The primary objective of this research is the development of a prediction model of the compressive strength of geopolymer mortars made with fly ash and granular slag which hardened in different curing conditions. Data for the numerical analysis were obtained by experimental research; for this purpose 45 series of geopolymer mortars were made, 9 of which were cured in ambient conditions at a temperature of 22 °С, and the remaining were exposed to thermal activation for a duration of 24 h at the temperatures of 65 °С, 75 °С, 85 °С and 95 °С. Using machine learning, a Gaussian regression method was developed in which the curing temperature and the percentage mass content of fly ash and granular slag were used as input parameters, and the compressive strength as the output. Based on the results of the developed model, it can be concluded that the Gaussian regression process can be used as a reliable regression method for predicting the compressive strength of geopolymer mortars based on fly ash and granular slag

Possibilities of Application Photovoltaic Systems in Urban Areas - Case Studies

Poslednjih 15 godina u urbanim sredinama širom Evrope sve je veća primena fotonaponskih (PV) sistema. Implementacija PV sistema u projektovanju i izgradnji objekata postaje deo standardnih aktivnosti u razvoju gradova. Postoje i značajne prepreke za primenu ovih sistema, koje su evropske države prevazišle, a tiču se pre svega legislativnog okvira koji reguliše ovakvu vrstu projekata, a zatim i načina njihovog fi nansiranja. Kroz primere evropskih gradova i sdudije slučaja (case study) gradova Gelsenkirchena u Nemačkoj, Gleisdorfa u Austriji i Liona u Francuskoj, rad nastoji da ukaže na pozitivne ekonomske i ekološke efekte ovakvog načina dobijanja energije i ukaže na značajnije promene u pristupu i načinu planiranja novih delova grada, važnoj ulozi eksperata, edukaciji stručnjaka, učešću javnosti i ulozi lokalnih vlasti u implementaciji ovih projekata. Osim toga, na osnovu inostranih primera u radu su date smernice za primenu ovakve vrste projekata kod nas. Prikazan je projekat solarne fotonaponske elektrane urađen za Skupštinu opštine Vračar u Beogradu. Rad predlaže mere i akcije (od edukacije do fi nansiranja) koje bi pomogle u realizaciji ovakve vrste projekata u Srbiji.Photovoltaic systems have seen an expansion of their application in the past 15 years. Implementation of these systems becomes one of the standard activities in the urban design and development processes. On the other hand, there are considerable constraints for the application of photovoltaic systems, mainly in the legislative area, which regulates the implementation and fi nancing of these projects. These problems have been overcame succesfully by many European countries. This paper tries to point to some positive economic and ecological effects of these energy systems and present a change of the approach to design of new city districts. Some other issues, presented in this paper are the: importance and education of experts, participation of public and local government. The method of this paper is the presentation of positive examples of European cities and their case studies. Some of the cities are Gelsenkirchen (Germany), Gleisdorff (Austria), Lion (France). Based on those experiences, the paper proposes guidelines for the local application of these projects. An example of the solar photovoltaic plant for the Municipality of Vračar in Belgrade is presented in detail. The paper proposes measures and actions (from education to fi nancing) which would help in realizations of similar projects in Serbi

Lateral-Directional Aerodynamic Optimization of a Tandem Wing UAV Using CFD Analyses

This paper presents the second stage of a tandem fixed-wing unmanned aerial vehicle (UAV) aerodynamic development. In the initial stage, the UAV was optimized by analyzing its characteristics only in symmetrical flight conditions. Posted requirements were that both wings should produce relevant positive lift, the initial stall must occur on the front wing first, the center of pressure should be close to the center of gravity, and longitudinal static stability should be in the optimum range. Computational fluid dynamic (CFD) analyses were performed, where the applied calculation model was derived from the authors’ previous successful projects. The eighth version TW V8 has satisfied all longitudinal requirements. Lateral-directional CFD analyses of V8 showed that the ratio of the lateral and directional stability at the nominal cruising regime was optimal, but both lateral and directional static stabilities were too high. On further development versions, the lower vertical tail was eliminated, a negative dihedral was implemented on the front wing, and four inverted blended winglets were added. Version TW V14 has largely improved lateral and directional stability characteristics, while their optimum ratio at the cruising regime was preserved. Longitudinal characteristics were also well preserved. Maximum lift coefficient and lift-to-drag ratio were increased, compared to the V8

Prevalencija i molekularna karakterizacija enterotoksin-produkujućih sojeva S. aureus izolovanih iz vimena krava u Srbiji

Staphylococcus aureus is known worldwide as a frequent cause of mastitis in dairy cattle. Due to the production of heath resistant enterotoxins, this pathogen is also a major cause of food poisoning among humans, with symptoms of often severe vomiting and diarrhea. The aim of our study was to determine the prevalence of enterotoxinproducing strains of S. aureus originating from samples of cows with subclinical and clinical mastitis in the Republic of Serbia. Furthermore, we analyzed the type of staphylococcal enterotoxin they produce and phylogenetic relatedness among the S. aureus isolates recovered from milk in this study. Production of staphylococcal enterotoxins A, B, C, D and E was determined by commercial immunoenzyme assay VIDAS® SET2, and presence of corresponding genes encoding enterotoxin synthesis in positive isolates confirmed by Polymerase Chain Reaction. Enterotoxin production was determined in 5 out of 75 (6.67%) isolates of S. aureus and all of them produced staphylococcal enterotoxins C. After analyzing the nucleotide sequence of the gene encoding the synthesis of staphylococcal protein A, S. aureus isolates were assigned into 2 phylogenetic groups, including 7 clusters. All S. aureus isolates with the presence of sec gene formed one cluster even dough they originated from milk samples from different farms.Širom sveta S. aureus poznat je kao čest uzročnik mastitisa krava. Takođe predstavlja i glavni uzrok trovanja hranom nakon konzumiranja hrane kontaminirane njegovim enterotoksinima. Cilj ovog istraživanja bio je da se ispita prevalencija enterotoksinprodukujućih sojeva S. aureus poreklom iz vimena krava sa subkliničkim i kliničkim mastitisom u Srbiji, da se odredi tip enterotoksina koji produkuju i da se odredi filogenetska srodnost ovih izolata. Za određivanje sposobnosti sinteze stafilokoknih enterotoksina A, B, C, D i E korišćen je VIDAS® SET2 immunoenzimski test i utvrđeno je da 5 od 75 (6,67%) izolata S. aureus sintetiše enterotoksine. Lančanom reakcijom polimeraze na prisustvo odgovarajućih gena, utvrđeno je da svih 5 izolata poseduju gen za sintezu enterotoksina C. Analizom nukleotidnih sekvenci gena za sintezu stafilokoknog proteina A, izolati S. aureus grupisani su filogenetski u 2 grupe, odnosno u 7 klastera. Svi izolati S. aureus kod kojih je dokazano prisustvo gena za sintezu enterotoksina spadaju u isti klaster

Application of drone in agriculture

The paper analyzes the possibility and necessity of applying special types of robots (mini unmanned aircraft with different constructions with the UAV tag) in agriculture (agrodrone). Year 2015 was declared (Fortune Magazine, 2016) as the year of increase and widespread application of drone aircraft in all areas of human activity, particularly in agriculture and forestry (75% usage). This is important for large areas of farms, whe re the mini aircraft have numerous useful functions and a very cost-effective application. Agro drone flight (flight time of 45 min, and the flight altitude of 1 m to 120 m) can be used to analyze more functional parameters on about 120 ha of crops, and all data can be sent to multiple locations (Audit Information Centre, mobile phones users and the like). Today some types of agro drones have a relative price of 2000 USD, if the users (farmers) assemble the drone themselves after purchasing it in parts. However the price of these mini aircraft can be up to 250,000 US$ for specific models used by the military, when equipped with special infrared cameras, sensors and HD video tech nology, which is controlled by an operator (pilot) from the surface. Usage of agro drones may be expensive at first, but research shows that many data collected (for example, identifying the species of insects and plant diseases, irrigation, yield asse ssment or monitoring the movement of animals on farms), help farmers to regain inve sted funds, sometimes for only one year. Farmers can use these aircraft in order to establish a rational and precise use of pesticides, herbicides, mineral fertilizers, all based on data obtained from the agro drone, used for precision agriculture systems. In this sense, the farmers have significant financial benefits, since one drone flight has an operational cost of a water bottle, and the data collected has great value. There are anecdotes about farmers in the US who first buy an agro drone and afterwards a hunting dog. The paper presents some structures of agro drones as well as ideas for their possi ble future application in agriculture of the R. of Serbia

The effect of light/dark cycle changes on vascular permeability, inflammation and visual cycle in streptoyotocin-induced diabezic retinophaty in rats

Introduction: Diabetic retinopathy (DR) is not cured efficiently and changes of lifestyle measures may alleviate its course. The aim of our study was to investigate the effects of shortened daily photoperiod on inflammation and visual cycle in rat retina and retinal pigment epithelium (RPE) in DR. Methodology: Male Wistar rats were divided into the following groups: 1. control; 2. diabetic group (DM) treated with a single intraperitoneal injection of streptozotocin (100 mg/kg); 3. group exposed to light/dark cycle 6/18h for 3 months (6/18); 4. diabetic group exposed to light/dark cycle 6/18h (DM+6/18). Retinal blood vessel permeability was estimated immunohistochemically based on lectin staining, while the expression of genes involved in the visual cycle (SOX9, LRAT, RPE65, OTX2), and inflammation (IL-1, TNF-α) was determined by qRT-PCR in the retina and RPE. Results: Shortened photoperiod reduced neovascularisation and the expression of IL-1 and TNF-α in both retina and RPE. The expression of IL-1 and TNF-α genes in the retina was significantly higher in DM vs. control group (P=0.001). In contrast, retinal IL-1 and TNF-α expressions were significantly lower in DM+6/18 vs. DM group (P=0.001). The expression of IL-1 and TNF-α in RPE was significantly higher in DM vs. control group, however the expression of these genes was significantly lower in DM+6/18 vs. DM group (PIL-1=0.008 and PTNF-α=0.002). The expression of visual cycle genes was significantly up-regulated in RPE in DM+6/18 vs. DM group (P=0.001). Conclusion: Shortened daily photoperiod reduces blood vessel permeability in DR via its anti-inflammatory effect associated with accelerated visual cycle in the retina.Poster Session: Neuroimmunoendocrine Interaction

Distribution of Eurasian minnows ( Phoxinus

The Eurasian minnows of the genus Phoxinus are small cyprinid species, widely distributed across Europe and Asia. Currently, there are at least 15 species in Phoxinus, with preliminary data suggesting more to be described. Despite the discernible increase in research integrating molecular phylogenetic approaches with traditional taxonomy and systematics, inter- and intraspecific relationships in the genus Phoxinus are still poorly known. The aims of this research were to: (i) compile data on the distribution of Phoxinus species in Croatia and Bosnia and Herzegovina from the sampling conducted by authors from 2006 to 2016 and from literature sources, and (ii) provide a detailed insight on distribution ranges of genetic clades and species of Phoxinus in the western Balkans. Additional 118 localities in Croatia and 8 locations in Bosnia and Herzegovina were added to already known 160 localities from the literature data. Molecular analyses of mitochondrial DNA indicate: (i) the presence of Phoxinus marsilii in Croatia (Drava drainage, the Papuk Mountain), around 260 km south of its known distribution range in Hungary, and (ii) an exceptional genetic variability of P. lumaireul in the Western Balkans