Improvements of task scheduling and load balancing in cloud environment by swarm intelligence metaheuristics

Klaud racunarstvo pripada grupi novijih racunarskih paradigmi, koja se poput paradigme mrežnog racunarstva, bazira na grupisanju resursa i na korišcenju mrežnih i Internet tehnologija. U opštem smislu, klaud racunarstvo se odnosi na novi nacin isporuke racunarskih resursa u vidu usluge, gde se pod resursima podrazumeva gotovo sve, od podataka i softvera, do hardverskih komponenti, kao što su procesirajuci elementi, memorija i skladišta. Klaud racunarstvo je aktuelna i važna multidisciplinarna oblast, o cemu svedoci veliki broj objavljenih radova u vrhunskim me unarodnim casopisima i prikazanih na najznacajnijim svetskim skupovima. Na osnovu naucnih rezultata prikupljenih u objavljenim radovima iz ovog domena, može da se zakljuci da u klaud okruženju postoji veliki broj izazova i problema, za cije rešavanje mogu da se prona u bolje metode, tehnike i algoritmi. Jedan od najvažnijih izazova savremenog klaud okruženja je raspore ivanje zahteva krajnjih korisnika za izvršavanje na ogranicenom skupu raspoloživih resursa (virtuelnih mašina). Problem raspore ivanja na klaudu odnosi se na definisanje rasporeda izvršavanja zadataka na ogranicenom skupu raspoloživih resursa uzimajuci pritom u obzir potencijalna ogranicenja i funkciju cilja koju je potrebno optimizovati. Raspore ivanje poslova vrše algoritmi raspore ivanja, koji mogu da se podele na staticke i dinamicke. U slucaju statickog raspore ivanja, gde se poslovi ne mogu dinamicki prebacivati sa preopterecnih na manje opterecene virtuelne mašine, zadaci se raspore uju za izvršavanje na raspoložive virtuelne mašine pre pocetka izvršavanja. S druge strane, primenom metoda dinamickog raspore ivanja, koje je u literaturi poznato pod nazivom balansiranje opterecenja, vrši se preraspodela poslova izme u aktivnih virtuelnih mašina tokom samog izvršavanja programa raspore ivanja. Preraspodela se vrši tako što se zadaci sa virtuelnih mašina koje imaju vece opterecenje dinamicki prebacuju za izvršavanje na virtuelnim mašinama koje imaju manje opterecenje. Za potrebe dinamickog raspore ivanja koriste se uglavnom heuristicke i metaheuristicke optimizacione metode i algoritmi, koji postižu dobre rezultate. Problemi raspore ivanja poslova i balansiranja opterecenja na klaudu pripadaju grupi NP teških kombinatornih i/ili globalnih problema sa ili bez ogranicenja. Na osnovu publikovanih rezultata u relevantnim literaturnim izvorima, vidi se da su metaheuristike inteligencije rojeva, koje spadaju u grupu prirodom-inspirisanih algoritama, uspešno testirane na bencmark problemima i primenjivane na prakticnim NP teškim optimizacionim problemima (globalnim i kombinatornim) i da mogu da postignu bolje rezultate u smislu brzine konvergencije i kvaliteta rešenja, od drugih metoda, tehnika i algoritama. Polazeci od navedenog, u ovom radu je ispitivano da li je moguce dalje unaprediti rešavanja problema raspore ivanja poslova i balansiranja opterecenja na klaudu primenom metaheuristika inteligencije rojeva. Tokom sprovedenog istraživanja, unapre eno je i adaptirano više metaheuristika inteligencije rojeva za rešavanje problema raspore ivanja poslova i balansiranja opterecenja u klaud okruženju. U disertaciji su detaljno prikazane implementacije dva unapre ena algoritma rojeva - algoritma optimizacije monarh leptirovima i algoritma optimizacije jatom kitova. Za potrebe testiranja, rešavana su dva modela raspore ivanja poslova na klaudu. Prvi model, koji pripada grupi jednokriterijumske optimizacije, uzima u obzir minimizaciju vremena izvršavanja svih zadataka na klaudu, dok drugi, višekriterijumski model uzima u obzir minimizaciju vremena izvršavanja svih zadataka na klaudu i budžeta, tj. troškova za izvršavanje svih zahteva krajnjih korisnika. Simulacije su vršene u robusnom okruženju CloudSim simulatora i oba algoritma su testirana sa skupom veštackih podataka, generisanih u okviru CloudSim platforme, i realnih podataka, koji su preuzeti iz globalno dostupne bencmark baze. Osim testiranja za praktican izazov na klaudu, da bi se preciznije utvrdila unapre- enja modifikovanih metaheuristika u odnosu na osnovne verzije, obe metaheuristike su verifikovane i testiranjima na standardnim skupovima bencmark funkcija za globalnu optimizaciju bez ogranicenja. Upore ivanjem generisanih rezultata (kvalitet rešenja i brzina konvergencije) sa rezultatima najboljih poznatih metaheuristika i heuristika iz literature, koje su primenjivane na iste instance problema (na praktican problem raspore ivanja na klaudu i bencmark testove), dokazan je kvalitet implementiranih algoritama, cime je potvr ena i osnovna hipoteza ovog rada da se rešavanje izazova raspore ivanja poslova i balansiranja opterecenja u klaud okruženju mogu dalje unaprediti primenom metaheuristika inteligencije rojeva

Prijevoz živih životinja željeznicom

The paper deals with the conditions and terms and methods of carriage of live animals in railway traffic. Live animals can be accepted for carriage in cages or without them, only with appropriate accompanying veterinary/sanitary papers. Transport must be organized in conformance with respective rules and precaution measures in order to have animals reach destination unharmed and alive. During transport adequate care is taken about fodder and water, airing and cleanliness of wagons, while at the end of carriage wagons are obligatorily disinfected.</p

Unusual Shipments in Air Transport

The article lists the unusual shipments in air transport.Over 2% of the annual cargo air transportation are the unusualshipments. Good co-ordination of the reception and deliveryprocesses of unusual shipments is one of the importantfactors in providing good and fast service knowing the basicregulations in air traffic

Razgradnja starih automobila

There are more than 100 million cars driving on the roadsof Europe, and as many as 40 million only in Germany. Theaverage driving life of an automobile is 13 years. In Gemwnyabout 2.8 million cars are discarded annually, and in Europemore than 10 million passenger cars.In taking care of the old cars, the question is whether toseparate the precious metals from the catalytic converters, as itis known that the car manufacturers have had to install catalyticconverters in the cars in the EC countries starting from JS'April 1993, in order to reduce the harmful exhaust emissions.Collecting of catalytic converters and retrieving of preciousmetals has first started in Europe in 1971. By the year 1994 thequota was estimated at about 450 kg of platinum and 90 kg ofrhodium, and these numbers are expected to increase gradually.A car is not a homogeneous thing. By disassembling it, themetal elements reach the foreseen quota of reusability. There isa greater problem with non-metals, one part of which ends upat the dumping place. The car users take out from the old carpartly the propelling fluid and the cars are disassembled intosingle parts that are being sold directly or recycled. Takingcare of cars has not been organized up to now. The owner hadto pay taxes for that, according to the car type.The system of providing for the cars in the future should bea network one. A network system achieves in cooperation withthe existing car owners a regionally demarcated disassemblingnetwork. The network system takes over, apart from networkdistribution, also the future coordi1wtion net and forms a connectingpoint for the car manufacturers and the recycling ofsecondary raw materials

Smanjenje štetnosti ispušnih plinova dizelskog motora

The paper deals with some possibilities of reduction of Diesel engine exhaust emission hazards. For purposes of purification of exhaust emissions, the in-built filters can be provided, like ceramic filters for sooth and water filters for gases. The oxidation catalyst may also be provided in addition to filters. Hybrid systems have been tested in "Golf' automobiles i.e. the combination of internal combustion engine and electric drive. This vehicle has been named "Eco Golf'. A mixture of Diesel fuel and n-butanol in the ratio of 60:40 has been used as the alternative fuel introducing the reduction of NOx by 8% and of particles by 36%. All limit values of Diesel engine exhaust gas components have been given in ECE R49 test.</p

Aspects of Reducing Polluting Impact of Shipyards on the Kvarner Bay

Four shipyards are located in the area of the Kvamer Bay,and they normally, at more or less regular intervals pe!form thecleaning of ship hulls. Due to the lack of necessary financialmeans, these processes usually mean applying of solid abrasiveswhich, due to their characteristics cause significant environmentalpollution.This paper presents the impact of individual shipyards, withregard to the extent of given se1vice - the treated area in squaredmetres, on the global pollution of the Kvamer Bay as well aspreventive and recovery measures that are feasible on a locallevel with the aim of reducing pollution

Demand Elasticity on the Transport Market

The elasticity of demand for traffic se1vices is the adaptationof traffic supply to traffic demand. The elasticity of suchdemand is low which is specific of the transport market, especiallyfrom the aspect of designing traffic demand.The essence of the problem of low elasticity can be noticedin three basic properties:First, in the change of place which determines the traffic demandor traffic relation.Second is the continuity of the need to transport goods andpassengers.Third, the needs for transport may vmy according to thechanges in society and economy, and they also change thesources of traffic demand. Therefore, the elasticity of demandfor traffic se1vices is relatively low

Okoliš i automobil

Constant increase of the number of automobiles causes demand for individual materials to get on the rise, thus giving an impulse to the development of recycling logistics. Used automobiles get disassembled and individual parts which can be used as raw materials or additives get recycled. Automobile tires can be reclaimed or vulcanized. In July 1978 the environmental-friendly "Blauer Engel" or "Blue Angel" symbol was first introduced for reclaimed tires. Later, emblems were introduced for other recycled automobile pans. The awarding of the emblem is being controlled and approved by authorized institutes, because the emblem rightfully designates traffic safety.</p

Ergonomic System, a Factor in the Improved Traffic Productivity

Considering the fact that noise is mostly caused by the trafficflow with all its characteristics, and in the production systemby machines, devices, and tools, it is necessary to implementmeasures for its prevention.Noise has to be eliminated on humanitarian grounds, andthen also with the aim of greater productivity and efficiency.However, regardless of the fact that, according to the analyses,by reducing noise the efficiency is increased and the costs(both fued and variable) reduced, these should not be the onlyreasons for its elimination; it should also be in the function ofthe organisation of the work place. Led by a human, ratherthan economic tendency, full satisfaction, good health, andmost of all increase in the productivity will be achieved throughsafety and protection

Automobilske gume i njihovo održavanje

The development of the automobile industry has invigorated the development and advancement of the tire manufacturers. Considering the fact that the tire is a major factor of traffic safety it should be secured proper maintenance and inspection.</p