Simple analytical models for the calculation of the electric field radiated by the base station antenna

This paper outlines four different models for the assessment of the electric field radiated by the base station antenna system, thus featuring the Free Space Model (FS), Perfect Ground Model (PG), Fresnel Reflection Coefficient Model (RC) and Modified Image Theory Model (MIT). The results obtained with these approaches are compared to the results computed via Numerical Electromagnetics Code (NEC). Several variables have been varied to examine the accuracy of each calculation model. The calculations have been undertaken for the far field only. As many European countries perform the field assessment using the FS model, the final goal of this work is to come up with the most convenient model for the field calculation

EVALUATION OF RESEARCH IN BAUXITE-BEARING AREA ON A LOCALITY „CRVENE STIJENE“ WITH EMPHASIS ON EXPLOITATION OF ASSOCIATED DEPOSITS

In this paper we present and elaborate one example when bauxite was the main target of investigation. During reprocessing and reinterpreting original input data from locality “Crvene stijene” near Jajce in Bosnia and Herzegovina, it was established that bauxite hanging wall and footwall rocks in fact present even more valuable mineral resources, dimension stone. This paper presents results of reprocessing and reinterpretation of original data with focus not only on primary resource, but on resources that are developed in footwall and hanging wall. Final goal of the research was to optimize the ratio between research and exploration cost and total profit by exploration of all available mineral resources in the area. For that purpose, new method of bauxite (primary resource) and associated deposits is developed and named “integrated approach”. Integrated, joint evaluation of bauxite and associated deposits (dimension stone), would give far greater significance to whole area. Finally, with this new method, the ratio between overall profit and cost will be maximized. </p

Ostvareni finansijski rezultat u proizvodnji jagode kratkog dana

In South-western Ontario's continental climate (short days, hot summers and very cold winters) the matted-row system was the dominant production system to grow short-day strawberries. Varieties-staggered production (planting a combination of early, mid and late-season varieties) provides strawberry harvest from five to seven weeks. Short-day strawberries are vegetative grown in the first year, and harvested for two consecutive years. The total cost of short-day strawberry production was 54,370 $CAD/ha. The production and harvest costs in the first and second years were 20,812$CAD/ha and 16,930 $CAD/ ha, respectively, and accounted for 69.42$CAD/ha (the first and second production years 41,330 $CAD/ha and 35,341$CAD/ha, respectively). The short-day strawberries in matted-row system, with average yield of 15,722 kg/ha, generated a net revenue of 22,300 $CAD/ha.U uslovima kontinentalne klime jugo-zapadnog Ontarija u kojima su leta kratka i vruća, a zime hladne, dominantno je gajenje jagode kratkog dana u redovima na otvorenom polju. U strukturi proizvodnje učestvuju rane, srednje i kasne sorte, što omogućava berbu od 5 do 7 nedelja. Ukupna eksploatacija jagodnjaka je dve godine. Troškovi zasnivanja i proizvodnje jagode kratkog dana u prvoj i drugoj godini posle sadnje iznose ukupno 54.370$CAD/ha. Troškovi nege i berbe u prvoj godini iznose 20.812 $CAD/ha, a troškovi nege i berbe u drugoj godini su 16.930$CAD/ha, pri čemu učestvuju sa 69,42 % u strukturi ukupnih troškova zasnivanja i redovne proizvodnje jagode. Najniža ulaganja su pri zasnivanju zasada sa učešćem od 8,13%, dok je udeo troškova sadnje i nege zasada u ukupnim ulaganjima 22,45%. Ukupan prihod u proizvodnji jagode kratkog dana je 76.671 $CAD/ha (41.330$CAD u prvoj godini i 35.341 $CAD/ha u drugoj godini). Prema tome, i pored visokih ulaganja po jedinici površine kod jagoda kratkog dana, uz prosečan prinos od 15.772 kg/ha, ostvaruje se profit od 22.301$CAD/ha

Floating slopes method application on the coal deposit Kongora

Izrada geološkog i ekonomskog modela ležišta u trodimenzionalnom okruženju, uz popratne baze podataka i proračune ekonomskih vrijednosti ležišta predstavlja temelj za primjenu suvremenih metoda u rudarstvu. Suvremene metode, kao što su: Lerchs-Grossmann-ova (LG) metoda, metoda pomičnog stošca i metoda dinamičkog programiranja, poslužile su kao izvrstan predložak za izradu programa optimalizacije kontura površinskih kopova. Računalna tehnika omogućila je iznalaženje optimalne konture kopa preko algoritama ugrađenih u profesionalne i namjenske programe. Brzina i jednostavnost rada te dobivanje pouzdanih izlaznih rezultata omogućili su široku primjenu suvremenih metoda, ugrađenih u puno računalnih programa.Temeljem osnovnih kriterija suvremenih metoda (optimalnost, stabilnost i kompatibilnost kosina) autori su predložili metodu optimalizacije kontura površinskog kopa koja je nazvana metoda pomičnih kosina (MPK).Ovaj rad je objedinio rezultate primjene MPK na ležištu ugljena "Kongora".Developing three-dimensional geological and economical models of deposits in combination with deposits economical values calculations, represents a fundament for application of contemporary methods in the mining engineering. It is proved that contemporary methods, such as Lerchs-Grossman\u27s method, Method of floating cone and Dynamic programming, are excellent models for generating the algorithm for contour optimization of an open pit mine. The exploration of the optimal pit contour can be a relatively simple and fast process if specialized mining software is utilized. The simplicity, quickness and reliable results offer a wide range of contemporary methods applications built in many mining computing programs. Based on available contemporary methods and their elementary criteria (optimality, stability and slope stability), authors suggest an innovative method of open pit contour optimization, named "Floating Slopes Method (FSM) ". This paper presents synthesis of results of FSM application on the coal deposit "Kongora"

NEW REGULATORY FRAMEWORK OF STUDENT WORK IN THE REPUBLIC OF CROATIA

U radu autori analiziraju osnovne postavke Zakona o obavljanju studenskih poslova, koji je stupio na snagu početkom studenoga 2018. godine. Uz prikaz ranijih pravnih rješenja, autori daju uvid u regulaciju obuhvata osoba koje mogu obavljati studenske poslove. Analiziraju se novi uvjeti za obavljanje studentskoga posla te sadržaj ugovora o obavljanju studentskoga posla. Raspravlja se o pravima i obvezama studenata kao i posrednika, te se daje osvrt na minimalnu naknadu za studentski rad.In this paper, the authors analyze the basic requirements of the Law on Performing Student Activities, which came into force at the beginning of November 2018. With an overview of earlier legal solutions, the authors give insights into the regulation of the scope of persons who can perform student work. New conditions for performing student work and contents of the contract on performing student work are analyzed. The rights and obligations of students and mediators are discussed, and a review of the minimum fee for student work is given

A novel laboratory set-up for investigation of intelligent automatic control in complex HVAC systems

U radu je prikazano novo laboratorijsko postorojenje za analizu rada klimatizacionog sistema, koje je smešteno u Laboratoriji za automatsko upravljanje na Mašinskom fakultetu Univerziteta u Beogradu. Nova KGH laboratorija je projektovana u cilju ispitivanja različitih složenih režima rada, uz obezbeđenje željenih uslova komfora. Poseban akcenat je stavljen na uticaj režima rada na potrošnju energije. Laboratorijsko postrojenje je projektovano da radi u složenim dinamičkim uslovima, kada se unutrašnji i spoljni parametri sredine znatno menjaju tokom vremena. U cilju minimizovanja potrošnje energije razvijeni su novi upravljački softveri i različiti algoritmi upravljanja klima komore.This paper presents a new laboratory set-up for the air-conditioning operation analysis in the Laboratory for Automatic Control at the Faculty of Mechanical Engineering, University of Belgrade. The new HVAC laboratory is designed to investigate different complex HVAC system working regimes and to provide desired space comfort. The emphasis is specially given to an impact on energy consumption. The laboratory set-up is designed to operate in the complex, dynamic regimes, when indoor environment parameters are intensively changed, together with a change of outdoor conditions. In order to minimize energy consumption, a new software and various automatic control algorithms are designed for automatic control of the air handlig unit

A novel laboratory set-up for investigation of intelligent automatic control in complex HVAC systems

U radu je prikazano novo laboratorijsko postorojenje za analizu rada klimatizacionog sistema, koje je smešteno u Laboratoriji za automatsko upravljanje na Mašinskom fakultetu Univerziteta u Beogradu. Nova KGH laboratorija je projektovana u cilju ispitivanja različitih složenih režima rada, uz obezbeđenje željenih uslova komfora. Poseban akcenat je stavljen na uticaj režima rada na potrošnju energije. Laboratorijsko postrojenje je projektovano da radi u složenim dinamičkim uslovima, kada se unutrašnji i spoljni parametri sredine znatno menjaju tokom vremena. U cilju minimizovanja potrošnje energije razvijeni su novi upravljački softveri i različiti algoritmi upravljanja klima komore.This paper presents a new laboratory set-up for the air-conditioning operation analysis in the Laboratory for Automatic Control at the Faculty of Mechanical Engineering, University of Belgrade. The new HVAC laboratory is designed to investigate different complex HVAC system working regimes and to provide desired space comfort. The emphasis is specially given to an impact on energy consumption. The laboratory set-up is designed to operate in the complex, dynamic regimes, when indoor environment parameters are intensively changed, together with a change of outdoor conditions. In order to minimize energy consumption, a new software and various automatic control algorithms are designed for automatic control of the air handlig unit

CULTURAL COUNCIL AND PUBLIC INSTITUTIONS IN CULTURE - NEW LEGAL FRAMEWORK OF MANAGEMENT AND FINANCING

U ovom radu analizira se adekvatnost postojećeg pravnog okvira u području kulture odnosno uređenja statusa, upravljanja i financiranja javnih ustanova u kulturi, posebice onih koje nisu regulirane posebnim zakonima. Namjera je bila u ovom radu ukazati na moguće nedostatke u postojećoj regulativi i samoregulativi, te predložiti potencijalna unaprjeđenja pravne regulative, sve u cilju uspostavljanja modernog normativnog okvira za poboljšanje uvjeta upravljanja i financiranja javnih ustanova u kulturi u Republici Hrvatskoj. Posebno se ukazuje na poziciju i ovlasti kulturnih vijeća kao tijela koja imaju važnu ulogu o odlučivanju o dodjeli financijskih proračunskih sredstava kulturnim projektima, kao primjer suvremene kulturne politike. Međutim, u njihovu radu postoji mogućnost nastanka sukoba interesa s obzirom na disproporciju njihova statusa u kulturnom području, te je nužno stvoriti odgovarajuća legislativna rješenja koja će otkloniti mogućnost zloupotreba pozicija odnosno interesnog subjektivnog postupanja kod raspolaganja javnim sredstvima za javne potrebe u kulturi. Osnivanjem kulturnih vijeća, kulturna politika Republike Hrvatske prati načela suvremene kulturne politike pri čemu se odlučivanje i suodlučivanje o pitanjima o kulturi decentralizira i usmjerava na razine jedinica lokalne i regionalne uprave: županije, gradove ili općine, uz uvođenje različitih modaliteta sudioničkog upravljanja, uključujući osnivanje kulturnih vijeća. U ovom radu ukazujemo na određene zakonske manjkavosti i u tom smislu potrebu daljnjeg noveliranja propisa, te navodimo rješenja koja se nadovezuju na zakonske odredbe, a trebaju biti sadržana u aktima o osnivanju, statutima i drugim općim aktima samih ustanova u kulturi.This paper analyzes the adequacy of the existing legal framework in the field of culture, i.e. the regulation of the status, management, and financing of public cultural institutions, especially those that are not regulated by special laws. The intention of this paper was to point out possible shortcomings in the existing regulation and self-regulation and to propose potential improvements to the legal regulation, all with the aim of establishing a modern normative framework for improving the conditions of management and financing of public cultural institutions in the Republic of Croatia. The position and powers of cultural councils as bodies that have an important role in deciding on the allocation of financial budget resources to cultural projects, as an example of contemporary cultural policy, are particularly pointed out. However, in their work, there is a possibility of a conflict of interest due to the disproportion of their status in the cultural field, and it is necessary to create appropriate legislative solutions that will eliminate the possibility of abuse of positions, i.e. interest-based subjective treatment when disposing of public funds for public needs in culture. By establishing cultural councils, the cultural policy of the Republic of Croatia follows the principles of contemporary cultural policy, whereby decision-making and co-decision-making on cultural issues are decentralized and directed to the levels of local and regional administration units: counties, cities, or municipalities, with the introduction of various modalities of participatory management, including the establishment of cultural Council. In this paper, we point out certain legal deficiencies and, in this sense, the need for further amendments to the regulations, and we list solutions that follow from the legal provisions and should be contained in the founding acts, statutes and other general documents of the cultural institutions themselves

SHAPING AND REDESTINATION OF EXCAVATED AREAS IN THE COURSE OF THE EXPLOITATION OF CRUSHED STONE

Potrebe za tehničkim građevnim kamenom u izgradnji porušene zemlje sve su veće. Otvaranje novih kamenoloma podređeno je strogim ekološkim normama. Upitna je lokacija aktiviranja i koncept izvođenja rudarskih radova. Otkopane prostore valja tako oblikovati da se najpovoljnije uklapaju u neposredni i širi okoliš, a završno prenamjeniti u cilju gospodarskog, športsko-rekreacijskog ili nekog drugog korištenja. Na prirodnom modelu (kamenolom »Široki Čeac« Novalja, otok Pag) uvažene su specifičnosti lokaliteta i kraja, te data primjerena rješenja uz naglašenu mogućnost deponiranja komunalnog otpada.In the construction of devastated and demolished country the want for crushed stone is ever more greater. The opening of new quarryes is subject to strict ecological norms. The location of activity as well as the concept of the mining works represent a matter of consideration. Excavated areas should be shaped in a way to be integrated into immediate and wider environment most conveniently and then be redestinated with the purpose of the economic, sporting-recreation or some other usage. On the existing model in nature (»Široki Čelac« quarry, Novalja on the island of Pag), the specific characteristics of the locality and region have been respected. There have been also given adequate solutions for a possible deposit of communal waste