Trunk muscle activation patterns in subjects with low back pain

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Theoretical analysis of the cumulative costs of different diesel bus alternatives for a public transport in the city of Belgrade

This paper includes comparative analysis of the environmental, energetic, and financial costs of different bus propulsion, possibly applied on the public transport in the city of Belgrade. It considers the modern diesel bus, the trolleybus, the natural gas bus with the spark ignition engine, the electric bus using LiFePO4 battery, and the electric bus with ultra-capacitor. The results are presented according to the real data and the real electro-energetic situation in Serbia, with the dominantly used lignite coal as primary fuel. This model gives the exact exhaust emission of electric vehicles at the thermal power plant, enables its comparison to the internal combustion engine vehicles. The result in analysis shows that the natural gas bus is the most cost efficient in economical way with overall exploitation price of $87 per 100 km. The trolleybus is more economical then the natural gas powered bus only at high departures rate, higher than 230 per workday

Competitiveness and Development of National Economy

This paper examines the relation between the two, may be the most pressing, phenomena of the world economy: competitiveness and development. Of course both can be interpreted in several ways, but the most operative way is to consider competitivenes by the methodology of the World Economic Forum's Global Competitiveness Index, and the development by the gross of domestic product per population. The intent is to determine what is the conection between these two indicators in general, and to pass the question in such a way, and to establish a methodology for further analysis of individual groups of countries considered in the report of the World Economic Forum's Global Competitiveness in the world. Therefore, we use correlation analysis between the observed indicators for the economy after 2005, since the above-mentioned study and implement competitiveness, with an accent on the last mid-term because of current events. The answer to the question: what is the relationship between these indicators in the timeline for all countries concerned is excpected. It is also important for the countries of the former Yugoslavia as a guide in the efforts to retrieve the position in the world economy

Characterization of infrared search and tracking systems for monitoring of movable objects

Предложена тема припада области инфрацрвене (ИЦ) оптоелектронске технике. Најсавременији приступ решавању проблема квалитетног надзора, ране детекције и праћење промена у оквиру посматране сцене, заснива се на термовизијским системима са панорамским приказом, ИРСТ (Infrared Search and Tracking) система у оквиру мрежноцентричног концепта, чијом применом се остварује правовремено уочавање циља и превентивни одзив самог система у зависности од његове намене, одговарајућим управљањем КИС надзора, на енергетски ефикасан начин...Suggested theme belongs to domain infrared (IR) optoelectronic technique. The most recent approach of solving the problem of quality monitoring, early detection and tracking changes of infrared search and tracking (IRST) systems with panoramic display

Practical research of the angle of thermodynamic losses when indicating pressure in the cylinder diesel engine

Vrlo važan literaturni izvor pri proučavanju radnih procesa u cilindrima motora, decenijama unazad, predstavlja članak Güntera Hohenberga 'Definition und Eigenschaften des termodinamischen Verlust-winkels von Kolbenmaschinen', objavljen 1976. godine u časopisu Automobil industrie, izdanje 4. Ovim člankom je teoretski i praktično (eksperimentalno) obrađena tema određivanja ugla termodinamičkih gubitaka na krivoj pritiska bez sagorevanja izmerenoj u cilindru motora. Posebna vrednost Hohenbergovih istraživanja je u eksperimentalnim rezultatima dobijenim osrednjavanjem izmerenih podataka na većem broju različitih motora. Pokazalo se da su ti eksperimentalni rezultati i te kako upotrebljivi za brzo, ali dosta tačno, određivanje ugla termodinamičkih gubitaka na krivoj pritiska bez sagorevanja,kod bilo kog motora. Dijagrami koje je predložio Hohenberg su od koristi i danas, bilo da se primenjuju direktno ili služe za poređenje sa rezultatima neke od savremenijih računskih metoda zasnovanih na termodinamičkoj analizi procesa u cilindru motora. Međutim, teoretski prilaz Hohenberga datom problemu kroz jednačine koje je postavio, daje dosta dobru predstavu o najuticajnijim faktorima na veličinu ugla termodinamičkih gubitaka, ali u sebi ima i dosta grešaka i grubih aproksimacija. Dobrim i lošim stranama ovog vrlo važnog literaturnog izvora kroz poređenje sa jednom od savremenih termodinamičkih metoda vezanim za problematiku određivanja ugla termodinamičkih gubitaka, posvećen je ovaj rad.Very important literary source for the study of work processes in the engine cylinders, for decades, has been an article by Günter Hohenberg 'Definition und Eigenschaften des termodinamischen Verlust-winkels von Kolbenmaschinen', published in 1976 in the magazine Automobil Industrie, Edition 4. This article theoretically and practically (experimentally) deals with the topic of determining the angle of thermodynamic losses on the pressure curve without combustion measured in the engine cylinder. The special value of this research is in the experimental results obtained by averaging the measured data on a large number of different engines. It has been shown that these experimental results are useful for a quick, but quite accurate, determining of the angle of thermodynamic losses on the pressure curve without combustion, with any engine. Diagrams proposed by Hohenberg are used today, whether they are applied directly or used for comparison with the results of some of the more modern computational methods based on thermodynamic analysis of the processes in the engine cylinder. However, the theoretical approach by Hohenberg to the given problem through the equations he set, gives a pretty good idea of the most influential factors on the size of the angle of thermodynamic losses, but it has a lot of mistakes and rough approximations. This work is dedicated to the good and bad sides of this very important literature source through a comparison with one of the modern thermodynamic methods related to the issue of determining the angle of thermodynamic losses

Influence of disturbances in the process of fuel injection on the working processes in the cylinder diesel engine

Neujednačenost radnih procesa u cilindrima dizel-motora se može desiti iz više razloga. Dva najuticajnija faktora na ovu pojavu, a koji se odnose na poremećaje u procesu ubrizgavanja goriva, su: poremećaji u pogledu trenutnog položaja (ugla obrtanja) kolenastog vratila kada započinje ubrizgavanje goriva u nekom od cilindara, tzv. ugao predubrizgavanja, i poremećaji u količini goriva koja se isporučuje pojedinim cilindrima tokom jednog radnog ciklusa, tzv. ciklusna količina goriva. Navedeni poremećaji su daleko izraženiji kod klasičnih, mehaničkih sistema za ubrizgavanje goriva (pumpa visokog pritiska, pumpa-brizgač, itd.), i vrlo često se ne mogu preduprediti pri vanmotorskim ispitivanjima i podešavanjima sistema ubrizgavanja goriva. Simulacija opisanih poremaćaja u realnim uslovima rada dizel-motora, i proširivanje saznanja o njihovom pojedinačnom i zajedničkom uticaju na radne procese u cilindrima, nije nimalo jednostavna. Međutim, danas postoje komercijalni programi koji imaju ugrađene module zasnovane na proverenim jednačinama termodinamike, teorije sagorevanja i teorije strujanja, koje omogućavaju da se ova simulacija izvrši primenom računara. Jedan od takvih programa je program BOOST AVL. Rezultati simulacija dobijeni primenom ovog i sličnih programa mogu biti i pouzdaniji od simulacija u realnim uslovima rada motora, pošto je kod mehaničkih sistema ubrizgavanja goriva, vrlo teško kvantifikovati stepen poremećaja koji se želi simulirati. Dobijeni rezultati mogu biti iskorišćeni za razvijanje metoda identifikacije uticaja opisanih poremećaja na srednji indikatorski pritisak svakog cilindra, pa i celog motora, tačniju procenu mehaničkih gubitaka (stepena mehaničke korisnosti), itd.Unevenness of working processes in diesel engine cylinders can happen for several reasons. The two most influential factors to this phenomenon, which are related to disturbances in the fuel injection process are: disturbances in terms of the current position (rotation angle) of the crankshaft when the fuel injection in one of the cylinders starts, so-called pre-injection angle, and disturbances in the quantity of fuel that is supplied to individual cylinders during one work cycle, the so-called cycle amounts of fuel. These disturbances are more prominent in classical, mechanical fuel injection systems (high-pressure pump, pump-injector, etc.), and very often can not be prevented during the out engine testing and the fuel injection system adjustments. The simulation of disturbances described under real operating conditions of diesel engines, and expanding the knowledge of their individual and joined impact on the working processes in cylinders, is not at all simple. However, today there are commercial software which have built-in modules based on the proven equations of thermodynamics, combustion theory and the theory of flow, which makes it possible to carry out these simulations by using a computer. One such software is AVL BOOST. The simulation results obtained using this and similar software can be more reliable than simulations in real conditions of the engine, because in the mechanical fuel injection system it is very difficult to quantify the degree of the disturbance which is to be simulated. The given results can be used to develop methods of identifying the impact of described disturbances on the mean indicated pressure of each cylinder, as well as the entire engine, a more accurate assessment of mechanical losses (degree of mechanical utility), etc

Mobile Commerce and Consumers’ Online Purchase Orientation in Poland, Croatia and Serbia

As an innovative approach to retail, mobile commerce develops rapidly during last decade. It brings new challenges and opportunities in front of retailers who have to adapt their business strategies to new generation shoppers. With a good understanding of the shoppers’ online purchase intention, retailers are able to develop effective online strategies to attract new and keep loyal web-shopping customers. The purpose of this paper is to explain the online shopping orientation in the context of country of origin. There is a limited number of such research in Central and Eastern Europe, so there is a lack of knowledge about young consumers from this region and their attitude as mobile technology users. The article is based on the research conducted in Poland, Croatia and Serbia where 454 young non randomly selected respondents answered online survey questions. The research hypotheses were tested using correlation and non-parametric statistics. Differences between observed countries suggest that there is a necessity to adapt approach concerning online retailing even at the market with similar characteristics. Therefore, creators of marketing and sales strategies of online and omnichannel companies should consider this fact when planning business strategies. This work is licensed under a&nbsp;Creative Commons Attribution-NonCommercial 4.0 International License.</p

Practical research of the angle of thermodynamic losses when indicating pressure in the cylinder diesel engine

Vrlo važan literaturni izvor pri proučavanju radnih procesa u cilindrima motora, decenijama unazad, predstavlja članak Güntera Hohenberga 'Definition und Eigenschaften des termodinamischen Verlust-winkels von Kolbenmaschinen', objavljen 1976. godine u časopisu Automobil industrie, izdanje 4. Ovim člankom je teoretski i praktično (eksperimentalno) obrađena tema određivanja ugla termodinamičkih gubitaka na krivoj pritiska bez sagorevanja izmerenoj u cilindru motora. Posebna vrednost Hohenbergovih istraživanja je u eksperimentalnim rezultatima dobijenim osrednjavanjem izmerenih podataka na većem broju različitih motora. Pokazalo se da su ti eksperimentalni rezultati i te kako upotrebljivi za brzo, ali dosta tačno, određivanje ugla termodinamičkih gubitaka na krivoj pritiska bez sagorevanja,kod bilo kog motora. Dijagrami koje je predložio Hohenberg su od koristi i danas, bilo da se primenjuju direktno ili služe za poređenje sa rezultatima neke od savremenijih računskih metoda zasnovanih na termodinamičkoj analizi procesa u cilindru motora. Međutim, teoretski prilaz Hohenberga datom problemu kroz jednačine koje je postavio, daje dosta dobru predstavu o najuticajnijim faktorima na veličinu ugla termodinamičkih gubitaka, ali u sebi ima i dosta grešaka i grubih aproksimacija. Dobrim i lošim stranama ovog vrlo važnog literaturnog izvora kroz poređenje sa jednom od savremenih termodinamičkih metoda vezanim za problematiku određivanja ugla termodinamičkih gubitaka, posvećen je ovaj rad.Very important literary source for the study of work processes in the engine cylinders, for decades, has been an article by Günter Hohenberg 'Definition und Eigenschaften des termodinamischen Verlust-winkels von Kolbenmaschinen', published in 1976 in the magazine Automobil Industrie, Edition 4. This article theoretically and practically (experimentally) deals with the topic of determining the angle of thermodynamic losses on the pressure curve without combustion measured in the engine cylinder. The special value of this research is in the experimental results obtained by averaging the measured data on a large number of different engines. It has been shown that these experimental results are useful for a quick, but quite accurate, determining of the angle of thermodynamic losses on the pressure curve without combustion, with any engine. Diagrams proposed by Hohenberg are used today, whether they are applied directly or used for comparison with the results of some of the more modern computational methods based on thermodynamic analysis of the processes in the engine cylinder. However, the theoretical approach by Hohenberg to the given problem through the equations he set, gives a pretty good idea of the most influential factors on the size of the angle of thermodynamic losses, but it has a lot of mistakes and rough approximations. This work is dedicated to the good and bad sides of this very important literature source through a comparison with one of the modern thermodynamic methods related to the issue of determining the angle of thermodynamic losses

An Adaptive Neuro-Fuzzy Inference System in Assessment of Technical Losses in Distribution Networks

The losses in distribution networks have always been key elements in predicting investment, planning work, evaluating the efficiency and effectiveness of a network. This paper elaborates on the use of fuzzy logic systems in analyzing the data from a particular substation area predicting losses in the low voltage network. The data collected from the field were obtained from the Automatic Meter Reading (AMR) and Automatic Meter Management (AMM) systems. The AMR system is fully implemented in EPHZHB and integrated within the network infrastructure at secondary level substations 35/10kV and 10(20)/0.4 kV. The AMM system is partially implemented in the areas of electrical energy consumers; precisely, in accounting meters. Daily information gathered from these systems is of great value for the calculation of technical and non-technical losses. Fuzzy logic in combination with the Artificial Neural Networks implemented via the Adaptive Neuro-Fuzzy Inference System (ANFIS) is used. Finally, FIS Sugeno, FIS Mamdani and ANFIS are compared with the measured data from smart meters and presented with their errors and graphs