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Enhancing Metaheuristic Optimization: A Novel Nature-Inspired Hybrid Approach Incorporating Selected Pseudorandom Number Generators
No full textIn this paper, a hybrid nature-inspired metaheuristic algorithm based on the Genetic Algorithm and the African Buffalo Optimization is proposed. The hybrid approach adaptively switches between the Genetic Algorithm and the African Buffalo Optimization during the optimization process, leveraging their respective strengths to improve performance. To improve randomness, the hybrid approach uses two high-quality pseudorandom number generators—the 64-bit and 32-bit versions of the SIMD-Oriented Fast Mersenne Twister. The effectiveness of the hybrid algorithm is evaluated on the NP-hard Container Relocation Problem, focusing on a test set of restricted Container Relocation Problems with higher complexity. The results show that the hybrid algorithm outperforms the individual Genetic Algorithm and the African Buffalo Optimization, which use standard pseudorandom number generators. The adaptive switch method allows the algorithm to adapt to different optimization problems and mitigate problems such as premature convergence and local optima. Moreover, the importance of pseudorandom number generator selection in metaheuristic algorithms is highlighted, as it directly affects the optimization results. The use of powerful pseudorandom number generators reduces the probability of premature convergence and local optima, leading to better optimization results. Overall, the research demonstrates the potential of hybrid metaheuristic approaches for solving complex optimization problems, which makes them relevant for scientific research and practical applications
Bounds for confluent Horn function Φ2 deduced by McKay Iν Bessel law
No full textThe main aim of this article is to derive by probabilistic method new functional and uniform bounds for Horn confluent hypergeometric Φ2 of two variables and the incomplete Lipschitz–Hankel integral, among others. The main mathematical tools are the representation theorems for the McKay Iν Bessel probability distribution's CDF and certain known and less known properties of cumulative distribution functions
Analysis of Zadar airport
No full textZračni promet kao jedna od grana prometa zadnjih godina bilježi veliki porast u odnosu na druge vrste prometa. U pružanju kvalitetnih, sigurnih i brzih usluga najvažniju ulogu imaju zračne luke u kojima se odvija proces prihvata i otpreme putnika, prtljage, tereta i pošte. Sve usluge koje se pružaju u zračnim lukama izuzetno su brze i bitne u vremenu, zbog toga infrastruktura i kapaciteti zračne luke imaju veliku ulogu u procesima tehnologije prihvata i otpreme. Temelj kvalitetnog procesa prihvata i otpreme putnika i prtljage obuhvaća registraciju putnika, provjeru dokumentacije, zaštitne preglede, ukrcaj putnika i prtljage, obavješćivanje posade, zatvaranje leta, aktivnosti pri dolasku ili odlasku zrakoplova. Zračna luka Zadar od svog otvaranja do danas bilježi stalan porast prometa i pruža svim putnicima vrhunsku uslugu i sigurnost. U cilju što boljeg, sigurnijeg i bržeg funkcioniranja Zračne luke Zadar javlja se i potreba za proširenjem postojećih kapaciteta kako bi se pravodobno i sigurno moglo što većem broju putnika pružiti kvalitetna i sigurna usluga. Analizom povijesnog razvoja Zračne luke Zadar od njezine izgradnje, potpune devastacije u Domovinskom ratu, obnove nakon razaranja pa do respektabilne zračne luke danas, obraditi će se svi aspekti koji pokazuju kako je potrebno planski i učinkovito donositi rješenja i ostvarivati buduće projekte za proširenje postojećih kapaciteta i na taj način osigurati kvalitetu usluga svim korisnicima zračne luke.Air traffic is one type of transportation that in the last few years marks huge growth in relation on other types of transportation. In giving the quality, safe and fast service , the most important role is on airports, in which services like reception and dispatch of passengers, luggage, cargo and mail is taking places. All services given in airport are quick and essential in time, because of that infrastructure and capacity of airports have great role in process of reception and dispatch. Foundation of quality process of reception and dispatch of passengers and luggage, includes registration of passengers, document verification, security check, embarkment of passengers, loading of luggage, informing the crew, closing the flight, and activity's on planes arrival and departure. Zadar airport from its beginnings till this day marks constant increase of traffic, and provides all its passengers excellent service and safety. In order to function better, safer and faster, Zadar airport needs to expand existing capacities, in order to be able to provide quality and safe service to as many passengers as possible in timely and safe manner. Analyzing the historical development of Zadar airport from its construction, complete devastation in Croatian war of independence, renovation after destruction, all the way to respectable airport it is today, all aspects will be processed that's show how it is necessary to plan and effectively bring solutions and implement future projects to expand existing capacities, and thus ensure the quality of services for all airports users
Intelligent anti-collision systems
No full textSmatra se kako je ljudski faktor i njegove pogreške tijekom procjene jedan od glavnih uzroka
nastanka nezgoda. Međunarodna pomorska organizacija navodi kako je ljudska pogreška
uzročnik više od 80% nesreća na moru. Upravo se s povećanjem brzine broda smanjuje
mogućnost upravljanja njime. Navedeno je izravno povezano s manevarskim solucijama. Stoga,
potrebno je da se donose razumne odluke tijekom plovidbe te da se u obzir uzimaju svi
relevantni parametri, a sve u cilju otklona nastanka sudara.It is considered that the human factor and its errors during assessment is one of the main causes of accidents. The International Maritime Organization states that human error is the cause of more than 80% of accidents at sea. It is precisely as the speed of the ship increases that the ability to control it decreases. The above is directly related to maneuver solutions. Therefore, it is necessary to make reasonable decisions during navigation and to take into account all relevant parameters, all with the aim of eliminating collisions
The Impact of Slow Steaming on Fuel Consumption and CO2 Emissions of a Container Ship
No full textModern marine propulsion systems must be reliable, energy efficient, environmentally friendly, and economical. Efforts to reduce fuel costs and carbon dioxide (CO2) emissions per nautical mile have a significant impact on the choice of propulsion system. Considering that there is no alternative for maritime transport, various technical and technological solutions are being considered that aim to improve efficiency and reduce the negative impact on the environment. One of the ways to achieve this goal is slow steaming, which reduces fuel consumption and CO2 emissions. The designed speed of the vessel has a significant impact on the efficiency of slow steaming. Slow steaming is particularly suitable for large container ships with a design speed of more than 20 knots. In this paper, the effects of slow steaming are analyzed using the example of a container ship with diesel-engine propulsion. Propulsion systems with low-speed and medium-speed marine diesel engines with mechanical power transmission are investigated. Data on the required engine power and propeller speed were used for the study, obtained from calculations during testing of the ship’s hull model. The effects of speed reduction on specific fuel consumption and emission reduction were analyzed using numerical models of two-stroke and four- stroke diesel engines. The models were calibrated and validated using data provided by the engine manufacturers. The paper analyses four different cases where one or two low-speed diesel engines, or three or four medium-speed diesel engines, are used for propulsion. The analysis concludes that slow steaming can effectively reduce fuel consumption and CO2 emissions, but the choice of the optimal propulsion system is highly dependent on maritime market conditions in maritime transportation. The choice of propulsion system affects the potential of slow steaming
The influence of geomagnetic effects on the GPS position determination during a geomagnetic storm on september 8. 2017
No full textCilj ovog rada je određivanje utjecaja geomagnetskih učinaka na određivanje položaja
sustavom GPS (engl. Global Positioning System - GPS) tijekom geomagnetske oluje 8. Rujna
2017. godine. Unutar rada ispituje se globalni učinak geomagnetske oluje na geomagnetsko polje
što za rezultat ima degradaciju položajnih koordinata opservacijskih stanica. Stanice se nalaze na
raznim geografskim širinama radi kvalitetnijeg prikaza cijelog procesa.
Temelj istraživanja je teorijska osnova koja obuhvaća utjecaj svemirskog vremena na
propagaciju GPS signala koja je neophodna za praktično istraživanje te je navedena na početku
rada. Ona obuhvaća glavna svojstva navigacijskog sustava GPS, strukture i dinamike magnetskog
polja, kako Sunca tako i Zemlje i svemirsko vrijeme, koje obuhvaća interakciju magnetskog polja
Sunca i Zemlje te njihov utjecaj na GPS signal. Istraživanje obuhvaća ispitivanje stanja svemirskog
vremena kroz geomagnetske pokazatelje i geomagnetsko polje te njihov utjecaj na odstupanje
položajnih koordinata. Određeno je razdoblje od pet dana promatranja zbog što kvalitetnijeg uvida
u cijelu dinamiku procesa. Također, određeno je područje istraživanja koje obuhvaća različite
geografske širine (od polova prema ekvatoru) u blizini nultog meridijana. Prvo se pristupilo
ispitivanju geomagnetskih pokazatelja koji ukazuju na dinamično napredovanje geomagnetske
oluje. Zatim se pristupilo ispitivanju komponenti magnetskog polja promatranih stanica
magnetskih opservatorija s ciljem određivanja u kojoj mjeri je stvoren geomagnetski poremećaj
na različitim geografskim širinama. Ispitivanja odstupanja položajnih koordinata su također vršena
na opservacijskim stanicama koje se također nalaze na različitim geografskim širinama i u blizini
stanica magnetskih opservatorija. Na posljetku korelacijskom analizom je utvrđen utjecaj
geomagnetskih učinaka na određivanje položaja sustavom GPS tijekom geomagnetske oluje za
promatrano područje u promatranom periodu. Tijekom istraživanja koristile su se razne statističke
metoda s ciljem kvalitetnog i logičkog zaključivanja.The aim of this paper is to determine the impact of geomagnetic effects on positioning with
the Global Positioning System during the geomagnetic storm on September 8, 2017. The paper
examines the global effect of a geomagnetic storm on the geomagnetic field, which results in the
degradation of the positional coordinates of the observation stations. The stations are located at
various latitudes for a better representation of the entire process.
At the beginning of the paper, the theoretical basis is stated, which includes the influence of
space weather on the propagation of the GPS signal, which is the foundation of the research and
is necessary for practical research. It includes the main properties of the GPS navigation system,
structure and dynamics of the magnetic field of both the Sun and the Earth, and space weather,
which includes the interaction of the Sun's and Earth's magnetic fields and their influence on the
GPS signal. The research includes monitoring of geomagnetic indicators, the geomagnetic field
and their influence on the positioning error in a certain observed period. A period of five days of
observation was determined for the purpose of better insight into the entire dynamics of the
process. A research area covering different latitudes (from the poles to the equator) near the prime
meridian has also been determined The first step was to examine the geomagnetic indicators that
indicate the dynamic progress of the geomagnetic storm. Then the examination of the components
of the magnetic field of the observed magnetic observatories was started with the aim of
determining to what extent a geomagnetic disturbance was created at different latitudes. An
overview of the position error of observation stations, which are also located at different latitudes
and are near the magnetic observatories, was made. Finally, through a correlation analysis, the
influence of geomagnetic effects on determining the position with the GPS system during a
geomagnetic storm for the observed area in the observed period was determined. During the
research, various statistical methods were used with the aim of qualitative and logical reasoning
E - Loran
No full textKako se elektronička navigacija razvijala kroz radio i radarsku navigaciju, novi način određivanja položaja našao se u hiperboličkoj navigaciji. Hiperbolička navigacija koristi krivulje zvane hiperbole koje spajaju mjesta jednake udaljenosti od žarišta kako bi se u njihovom presjecištu pronašla pozicija broda. Kroz povijest su se razvijali razni hiperbolički uređaji kao što su Consol, Decca, Gee, Loran-A, Loran-C, Chayka te kao napredna verzija Loran-C sustava, E-Loran. Satelitska navigacija je uslijedila nakon hiperboličkih sustava. Prvi satelitski sustavi funkcionirali su na temelju Dopplerovog efekta te je njihova primjena bila isključivo predviđena za vojne usluge. Globalni sustav za određivanje položaja (GPS) je od 2007. godine potpuno funkcionalan i dostupan čak i za civilnu upotrebu. GPS usprkos činjenici da je najsofisticiraniji sustav za pronalazak položaja na zemlji posjeduje određene mane koje znaju uzrokovati razne probleme. Osim što se ti problemi očituju izravno na korisnika već i neizravno stvaraju probleme za ekonomiju i gospodarstvo. E-Loran kao glavna tema ovoga rada se u nekoliko navrata u zadnjih 20 godina nudio kao rješenje upravo u trenucima kada oslanjanje na GPS nije moguće. Trenutna alternativa za GPS ne postoji, a pomutnje zbog interferencije i dalje ostaju problematika. Svojstva e-Loran signala upućuju na potrebu da se provedu testiranja, jer snažni i teško ometajući signali mogu biti jako dobra zamjena kada je to neophodno. Kako je to sustav koji je korišten još 1940-ih pod nazivom Loran-A i kasnije Loran-C uz sav napredak tehnologije koji je do sada postignut nova nadograđena verzija može biti preciznija i pouzdanija. Kako se satelitska navigacija počela sve više razvijati praksa korištenja hiperboličke navigacije počela se manje koristiti. Upravo to je razlog zbog kojeg nije iskorišten puni potencijal hiperboličkih uređaja i zahtjeva provedbu dodatnih istraživanja.How electronic navigation developed through radio and radar navigation, a new way of determining position was found in hyperbolic navigation. Hyperbolic navigation uses curves called hyperbolas that connect places of equal distance from the focal points to find the position of a ship at their intersection. Various hyperbolic devices were developed throughout history, such as Consol, Decca, Gee, Loran-A, Loran-C, Chayka, and an advanced version of the Loran-C system, E-Loran. Satellite navigation followed the hyperbolic systems. The first satellite systems were based on the Doppler effect and were intended exclusively for military use. Global Positioning System (GPS) has been fully functional since 2007 and available even for civilian use. Despite being the most sophisticated system for locating positions on Earth, GPS has certain drawbacks that can cause various problems. In addition to the problems that directly affect the user, they also indirectly create problems for the economy. E-Loran, the main topic of this paper, has been offered several times in the last 20 years as a solution precisely when relying on GPS is not possible. Currently, there is no alternative to GPS, and interference disruptions continue to be problematic. The properties of the E-Loran signal suggest the need for testing because strong and highly interfering signals can be a very good replacement when necessary. As a system that was used as early as the 1940s under the name Loran-A and later Loran-C, with all the technological advancements achieved so far, a new upgraded version can be more precise and reliable. As satellite navigation began to develop more and more, the practice of using hyperbolic navigation began to decline. This is precisely why the full potential of hyperbolic devices has not been exploited and requires additional research
Fire protection of ships carrying radioactive cargo
No full textU ovom radu bit će riječi o osnovama zračenja, instrumentima za praćenje istog te o osobnoj zaštiti od zračenja. Govorit će se o IMDG Kodeksu te o karakteristikama specifičnih radioaktivnih tereta, njihovom pakiranju, označavanju te krcanju i slaganju u brodski prostor. Također bit će navedena specifična dokumentacija koja mora pratiti ovakvu vrstu tereta, te pojedine vrste brodova koji mogu prevoziti radioaktivni teret.
Na kraju će biti riječi o protupožarnoj zaštiti tereta, ljudi, imovine i okoliša te o vodiču medicinske prve pomoći za opasne tvari kojeg je potrebno primijeniti unesrećenima u slučaju izloženosti radioaktivnom materijalu.This paper will discuss the background of radiation, monitoring instruments and personal protection against radiation. The IMDG Code will be discussed, as well as the characteristics of specific radioactive cargoes, their packaging, labelling, loading and stacking onto the ship's space. Specific documentation that must accompany this type of cargo will be listed, also the types of vessels used for the transportation of radioactive cargo.
In the end, there will be a discussion about the fire protection of cargo, people, property and the environment, as well as the medical first aid guide for dangerous goods, which must be applied to the injured in the case of exposure to radioactive material
Motor control center
No full textU ovom završnom radu pisano je o principu, izvedbi i načinu rada razdjelnika elektromotornog pogona ( eng. MOTOR CONTROL CENTER, MCC ). Pisano je i o komponentama te sadržaju kabineta kao cjelina i raščlamba svih elemenata te cjeline. Definirani su pojmovi: MCC, elektromotor, automatika, te pravila registra vezana uz izradu, instalaciju i rad razdjelnika elektromotornog pogona. Također se navodi upravljanje elektromotorima preko frekventnog pretvarača, automatizaciji brodskih elemenata i grubi radovi u pripremi za instalaciju MCC-a.In this final paper, it was written about the principle, performance and mode of operation of the cabinet for controlling the electric motor (MOTOR CONTROL CENTER, MCC). It is also written about the components and contents of the cabinet as a whole and a breakdown of all the elements of that whole. The following terms are defined: MCC, electric motor, automation, and registry rules related to the manufacture, installation and operation of the electric motor control cabinet. It also mentions the control of electric motors via a frequency converter, the automation of ship elements and rough work in preparation for the installation of the MCC
The influence of exhaust valve burnout on main engine operation
No full textRad daje kratki opis ispušnog ventila dvotaktnog sporookretnog dizelskog brodskog motora, opisuje njegovu ulogu, princip rada te osnovne dijelove. Cilj ovog rada je istražiti utjecaj različitih postotaka nagorenosti ispušnog ventila na rad glavnog motora i njegovih
osnovnih parametara. U radu su dane tablice s vrijednostima dobivenih uz pomoć simulacija različitih stanja nagorenosti ispušnog ventila. Na temelju dobivenih vrijednosti izrađeni su dijagrami koji prikazuju utjecaj nagorenosti ventila na rad glavnog motora.The paper gives an insight into the two-stroke slow-speed diesel marine engine exhaust valve, it's task, how it works and the basic parts. The purpose of this paper is to investigate the influence of different percentages of exhaust valve burnout on the operation of the main engine and its basic parameters. The paper presents tables with values obtained by simulation, at different conditions of the exhaust valve. Based on the obtained values, flow charts are drawn to show the impact of burnt exhaust valves on the main engine operation