Repository of the University of Rijeka, Faculty of Maritime Studies
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Radio Wave Energy Harvesting Model of a Maritime Automatic Identification System
No full textRadio waves, the spectrum of the electromagnetic waves, are all around us and in most cases have only one purpose. The maritime Automatic Identification System (AIS) uses Very High Frequency (VHF) radio waves for the purpose of data exchange between ships and shore stations. These data exchanges take place during certain time intervals, resulting in intermittent emission of electromagnetic waves. In the research presented in this paper, the objective was to add a new purpose for the AIS electromagnetic waves, i.e. to act as a power source for the RF energy harvester. After collecting the electromagnetic waves of the AIS system, the signals’ voltage is rectified, amplified and delivered to the load. In this paper, the process of radio wave energy harvesting is simulated in the Multisim software and analyzed in detail. The results of the analysis showed a multiple increase in the voltage value at the output of the RF energy harvester
Ungrounded system
No full textU završnom radu iznesen je pregled osnovnih značajki neuzemljenih električnih
sustava, njegove primjene te prednosti i mana korištenja takvih sustava. Objašnjeno je
ponašanje sustava u normalnim uvjetima i u uvjetima kvara. Poseban fokus stavljen je na
primjenu takvih sustava na brodovima i načine detekcije spoja s masom.In this work, an overview of the basic features of ungrounded electrical systems, its
application, and the advantages and disadvantages of using such systems was presented.
The behaviour of the system under normal conditions and under fault conditions is
explained. A special focus is placed on the application of such systems on ships and ways
of detecting the ground faults
Database security
No full textBaza podataka je najsloženiji oblik strukture i organizacije podataka te ju možemo definirati kao jedinicu u koju se skladište sve informacije i podatci u svrhu jednostavnog pristupanja i upravljanja istima. Zbog povećanja količine podataka s kojom raspolažu tvrtke i organizacije, raste i važnost očuvanja sigurnosti baza podataka kako bi se spriječio neovlašteni pristup od strane zlonamjernih korisnika. Ugrađivanje sigurnosnih elemenata u Sustave za upravljanje bazama podataka predstavlja važan način za povećanje njene sigurnosti. Razinu sigurnosti informacijskog sustava, tehnologije i informacija koje informacijski sustav sadrži određuje sigurnosna politika. U ovom završnom radu cilj je prikazati koje sigurnosne prijetnje postoje, te koji su mogući načini sprječavanja napada i zaštite podataka.Database is the most complex form of data structure and organization, which can be defined as a unit in which all information and data are stored for the purpose of easy access and management. Due to the increase in the amount of data that companies and organizations posses, it is important to maintain the security of databases in order to prevent unauthorized access by malicious users. Incorporating security elements into Database Management Systems is an important way to increase its security. The level of security of the information system, technology, and information that the information system contains is determined by the security policy. In this final paper, the aim is to present what security threats exist, as well as possible ways to prevent the attack on the database or how to protect data
The Analysis of the Deficiencies Resulting from Paris MoU PSC Inspections
No full textSubstandard ships pose a significant threat to human life and the environment. Therefore, detecting deficiencies and removing such vessels from service is necessary, which is one of the port state control (PSC) inspection tasks. In addition, the role of PSC inspection is to improve safety at sea and in ports. To be up to the task, the States jointly created several memoranda to fight against substandard ships. The most frequent deficiencies detected on ships during Paris Memorandum of Understanding (MoU) PSC inspections are analyzed in this paper. The analysis was made according to factors such as type of vessel, flag and the category to which deficiency belongs. Results revealed that most frequent deficiencies detected on ships, regardless of type or flag, come from International Safety Management (ISM) and fire protection. Furthermore, it is found that among the ten most frequent deficiencies, three are from the navigation safety category. Therefore, corrective actions to improve safety at sea are needed and presented
Container ship fleet route evaluation and similarity measure-ment between two shipping line ports
No full textThe characterization of ship routes and route similarity measurement based on Automatic Identification System (AIS) data are topics of various scientific interests. Common route research approaches use available AIS identifiers of ship types. However, assessing route and similarity profiles for individual fleets requires collecting data from secondary sources, dedicated software libraries or the creation of specific methods. Using an open-source approach, public AIS and ship data, we evaluate route characteristics for the container ships of a single fleet in a six-month period, calling on two selected ports of the shipping line on the USA East Coast. We evaluate the routes in terms of length, duration and speed, whereas for the similarity measurement we employ the discrete Fréchet distance (DFD). The voyage length, duration and average speed distributions were observed to be moderately positive (0.77), negative (−0.62), and highly positively skewed based on the adjusted Fisher– Pearson coefficient of skewness (1.23). The most similar voyages were from the same ships, with the lowest discrete Fréchet distance similarity value (0.9 NM), whereas 2 different ships had the most dissimilar voyages, with the highest DFD value (14.1 NM). The proposed methodology enables assessment of similarities between individual ships, or between fleets
Characteristics of air freight transport in integrated and multimodal transportation
No full textZračni prijevoz tereta ima značajnu ulogu u globalnom transportnom sustavu. Kao dio prometnog sustava konstantno je podložan razvitku i prilagodbi suvremenim transportnim tehnologijama. Karakteristike zračnog prijevoza tereta omogućuju brz i siguran prijevoz gotovo svih vrsta tereta. Zrakoplovi za prijevoz tereta svojim tehničko-tehnološkim obilježjima omogućuju brzu i jednostavnu manipulaciju tereta te sa gotovo potpunom paletizacijom i kontejnerizacijom tereta predstavljaju odličan primjer integralnog prijevoza. Uključenost zračnog prijevoza u multimodalni transport nije u potpunosti definirana i može se proučavati sa različitih stajališta ovisno o načinu tumačenja same definicije.Air freight transport plays a significant role in the global transport system. As part of the transport system, it is constantly subject to development and adaptation to modern transport technologies. The characteristics of air freight transport enable the fast and safe transport of almost all types of cargo. Cargo aircraft, with their technical and technological features, enable quick and easy cargo handling and with almost complete palletization and containerization of cargo, represent an excellent example of integrated transport. The inclusion of air transport in multimodal transport is not fully defined and can be studied
from various standpoints depending on the interpretation of the definition itself
Influence of fuel quality on the operation of the marine steam generator
No full textU ovom završnom radu pod nazivom “UTJECAJ KVALITETE GORIVA NA RAD BRODSKOG GENERATORA PARE” opisane su opće stvari vezane uz goriva koje se koriste za brodske generatore pare, opisan je sustav gorača brodskog generatora pare na simulatoru Kongsberg MC-90, te kroz tablice i dijagrame prikazano je kako se ponašaju produkti izgaranja goriva prilikom promjene ogrjevne vrijednosti goriva na već navedenom simulatoru.In this final paper entitled " INFLUENCE OF FUEL QUALITY ON THE OPERATION OF THE MARINE STEAM GENERATOR" general matters related to the fuel oil used for marine steam generators are described, the burner system of the marine steam generator on the Kongsberg MC-90 simulator is described, and through tables and diagrams it is shown how the products of fuel combustion behave when the calorific value of the fuel is changed on the already mentioned simulator
Poboljšanje iskorištavanja pomorskih podataka putem naprednih tehnika strojnog učenja u analizi AIS podataka
No full textThis bachelor's thesis reviews the literature on the application of diverse machine learning (ML) methods in the maritime industry, specifically focusing on automatic identification system (AIS) data. The review explores a wide range of ML techniques, such as neural networks, reinforcement learning, classification, regression, and clustering, and their utilization to enhance maritime operations, efficiency, and safety. Demonstrating positive results, various studies highlight the effectiveness of these methods as well as several shortcomings that are sought to be corrected in further research. Furthermore, the thesis identifies potential future applications of ML in fleet management, vessel maintenance, and navigational safety analysis. In summary, the thesis presents practical insights through the application of selected ML methods to real AIS data, yielding meaningful results for the maritime industry.Ovaj završni rad pruža pregled literature o primjeni različitih metoda strojnog učenja u pomorstvu, fokusirajući se na podatke automatskog identifikacijskog sustava (AIS). Prikazane su različite primjene metoda strojnog učenja u područjima poput pomorske sigurnosti, praćenja brodova, optimizacije rute, detekcije anomalija i predikcije ponašanja brodova. Demonstrirajući pozitivne rezultate, različita istraživanja ističu učinkovitost tih metoda kao i nekolicinu nedostataka koji se nastoje ispraviti u daljnjim istraživanjima. Nadalje, rad identificira potencijalne buduće primjene metoda strojnog učenja u upravljanju flotom, održavanju brodova i analizi navigacijske sigurnosti. Ukratko, rad pruža praktične uvide kroz primjenu odabranih metoda na stvarnim AIS podacima, donoseći značajne rezultate za pomorsku industriju
Inert gas system on crude oil tankers with reference to ballast tanks
No full textSustav inertnog plina jedan je od ključnih sustava za operativnost broda, odnosno za pravilno izvođenje operacija sa teretom kod brodova za prijevoz sirove nafte radi niza faktora. Ovim radom obrađena je tema sustava inertnog plina na tankerima za prijevoz sirove nafte. Objašnjeni su razlozi inertiranja brodskih prostora, uključujući posebni osvrt na inertiranje balastnih prostora. Sukladno tome navedeni su zahtjevi, odnosno propisi vezani za sustav inertnog plina, metode inertiranja, a opisani su i pojedinačni dijelovi sustava (uređaji i oprema).Inert gas system is one of the key ship systems for operability, that is for the proper execution of cargo operations on crude oil transporting ships due to several factors. This paper deals with the topic of the inert system on crude oil tankers. Explanation of the reasons for the inerting of ship spaces is given, including a special reference to the inerting of ballast spaces. Accordingly, the requirements and regulations related to the inert gas system, and methods of inerting are listed, also, individual parts of the system (devices and equipment) are described
Mobile maze solving robot by following line
No full textDefiniranjem pojma labirinta postignuta je osnova rada, koja se nadograđuje teorijskim dijelom gdje su obuhvaćene tehnologije i algoritmi primijenjeni u izradi robota koji rješavaju labirinte kao i senzori koji se koriste u aplikacijama te vrste, zatim slijedi primjena u industriji i kao kraj praktična izvedba robota koji rješava labirint primjenom pravila lijeve ruke. Vrlo je važno naglasiti važnost prilagodljivosti robota različitim područjima primjene što otvara mnoge mogućnosti razvoja tehnologije u različitim smjerovima.By defining the concept of a maze, the basis of the work has been achieved, which is upgraded with a theoretical part where the technologies and algorithms applied in the creation of robots that solve labyrinths as well as sensors used in applications of this type are covered, followed by application in industry and, finally, the practical performance of a robot that solves maze using the left hand rule. It is very important to emphasize the importance of adaptability of robots to different areas of application, which opens many opportunities for technology development in different directions