Radoslav Radonja - Academia.edu (original) (raw)

Papers by Radoslav Radonja

Sveučilište u Rijeci. Pomorski fakultet. Zavod za brodsko strojarstvo i energetiku., Nov 14, 2018

Pomorstvo: Scientific Journal of Maritime Research, Jun 30, 2010

TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation

Cruising tourism is becoming increasingly popular, the number of cruises having seen a continuous... more Cruising tourism is becoming increasingly popular, the number of cruises having seen a continuous increase since the 1970s. In Croatia as well there is an upward trend in the number of cruise passengers and ports. Of all Croatian ports, it is the port of Dubrovnik that has had the most calls by foreign cruisers. The paper analyses the available statistical data on the maritime cruise market in Europe with special reference to the Mediterranean countries. In the national context, a presentation of cruise traffic in the port of Dubrovnik is given. Although this type of tourism contributes to the development and improvement of the economy, it also has a negative impact on the environment through air pollution by CO2 emissions, subsequently affecting human health as well. The authors investigate the level of CO2 emissions in the area of the port of Dubrovnik. CO2 emissions were calculated based on cruiser activity, the calculations being based on CO2 emissions for three ship navigation modes-slow steaming on arrival and departure, manoeuvring on arrival and departure, and for a berthed ship. The aim of the research was to provide a better insight in the emission inventories in this area. This research can also be applied to other port areas.

Journal of Marine Science and Engineering, Mar 22, 2023

Pomorstvo

In this study, the environmental footprint within a designated area is determined by an inventory... more In this study, the environmental footprint within a designated area is determined by an inventory of air pollutants (including toxic and greenhouse gases) emissions generated. The designated area of concern is the port of Dubrovnik, a well-known cruise ship destination, where a major source of pollutant emissions is the diesel engines of the ships operating in the port. This research was undertaken for the port of Dubrovnik in connection with the development of the national strategy and the need for determining the inventory of air pollutants. It was conducted for the last pre – COVID- 19 year, 2019. In this paper, after a short introduction, the basic data of the port of Dubrovnik and the marine traffic (predominantly cruisers) in 2019 are provided, obtained from publicly available data. Next, the emission estimate methodology based on a bottom-up approach is described. The inventory analysis was undertaken from the port boundary to the PWD (pier/wharf/dock) and back. The basic equ...

Područje Jadranskog mora ima različite prednosti za špeditere (otpremnike) i brodovlasnike uzimaj... more Područje Jadranskog mora ima različite prednosti za špeditere (otpremnike) i brodovlasnike uzimajući u obzir prijevoz tereta i atraktivnost obale. Ono nudi veliki potencijal kompanijama za kružna putovanja i nautički turizam uzrokujući nagli rast pomorskog prijevoza u posljednjih deset godina, što je uzrokovalo povećanu zabrinutost za zdravlje i okoliš, namećući potragu za rješenjem koje bi uravnotežilo učinke onečišćenja i održivost u razvoju. Ovaj članak je pregled preliminarnih rezultata autora prikupljenih kroz nekoliko istraživanja u tijeku, koja su rezultirala prijedlogom ASAP projekta (Zaštita područja Jadranskog mora). Cilj je utvrditi skladište brodskih emisija za Jadransko more čiji nalazi će biti osnova za Registar emisija koji će biti ujedinjen u učinkoviti informacijski sustav za nadzor brodskih emisija i sprječavanje onečišćenja zraka (EMIS). Na osnovi rezultata, zainteresirane stranke imaju mogućnost zahtjeva zaštite IMO-a za to područje. Istraživanja autora usmjerena...

U doktorskom radu su znanstvenim metodama istražene i analizirane najvažnije karakteristike pomor... more U doktorskom radu su znanstvenim metodama istražene i analizirane najvažnije karakteristike pomorskog prometa u hrvatskom dijelu Jadrana, prikazani su najnoviji međunarodni ekološki zahtjevi s osnove sprječavanja onečišćenja okoliša i njihov utjecaj na brodare kroz osnovna načela cikličnih promjena na pomorskom tržištu sa smjernicama za njihovu prilagodbu (ekološka prihvatljivost broda kao osnovni preduvjet opstanka brodara na tržištu), te izrađen pregled globalno dostupnih metodologija procjene emisija i analizirane mogućnosti njihove primjene na promatranom području. Pri tom su holističkim pristupom problematici razmotreni različiti aspekti utjecaja emisija iz pomorskog prometa na čovjeka, okoliš i klimu. Uzimajući u obzir temeljne postavke strategije održivog razvoja i integriranog upravljanja priobalnim područjem postavljen je model Registra emisija koji uvažava specifičnosti pomorskog prometa u hrvatskom djelu Jadrana i omogućuje izradu početnog skladišta emisija (otiska) i nji...

Journal of Maritime & Transportation Science

A ship's propulsion system has a significant impact on the ship’s energy efficiency, environm... more A ship's propulsion system has a significant impact on the ship’s energy efficiency, environmental friendliness, reliability and safety. An indispensable part of a propulsion system with mechanical power transmission is a stern tube with bearings. During operation, the sliding bearings material is subjected to stresses caused by a force proportional to the total mass of the shaft and propeller. The reliability of stern tube bearings is particulary important for safety, and their durability has a significant impact on maintenance costs. Depending on the lubricant, there are bearings that are lubricated with oil or water. The permissible bearing load with hydrodynamic lubrication depends primarily on the material, the viscosity of the lubricant used and the shaft speed. Metals and their alloys with a low coefficient of friction are used for oil-lubricated bearings. Bearings lubricated with water are made of a special type of hardwood ("tree of life", lat. lignum vitae), ...

2019 International Symposium ELMAR, 2019

Shipping is a very significant source of air pollution, greatly contributing to the creation of g... more Shipping is a very significant source of air pollution, greatly contributing to the creation of greenhouse gases and influencing the climate change. Ships are responsible for roughly 3% of global CO2 and GHG emissions, emitting approximately 1 billion tonnes of CO2 and GHGs per year. Shipping emissions cause severe impacts on health and the environment. The article describes the methodology for estimating the atmospheric emissions of carbon dioxide (CO2) in international shipping in the Bay of Raša as a sensitive area and the respective results. The shipping emissions have been calculated on actual shipping activities for ships calling at the Port of Bršica in 2017. The aim of the research was to provide a better insight in the emission inventories in this area. Ship’s emissions were calculated by the ship activity-based method which involves the application of emission factors for each ship-activity (slow steaming on arrival and departure, manoeuvring on arrival and departure, and ...

Transport, 2020

The aim of this article is to enhance performance monitoring of a two-stroke electronically contr... more The aim of this article is to enhance performance monitoring of a two-stroke electronically controlled ship propulsion engine on the operating envelope. This is achieved by setting up a machine learning model capable of monitoring influential operating parameters and predicting the fuel consumption. Model is tested with different machine learning algorithms, namely linear regression, multilayer perceptron, Support Vector Machines (SVM) and Random Forests (RF). Upon verification of modelling framework and analysing the results in order to improve the prediction accuracy, the best algorithm is selected based on standard evaluation metrics, i.e. Root Mean Square Error (RMSE) and Relative Absolute Error (RAE). Experimental results show that, by taking an adequate combination and processing of relevant sensory data, SVM exhibit the lowest RMSE 7.1032 and RAE 0.5313%. RF achieve the lowest RMSE 22.6137 and RAE 3.8545% in a setting when minimal number of input variables is considered, i.e....

Svjetska financijska kriza uzrokovala je zastoj na po-morskom tržištu i prisilila brodare na prom... more Svjetska financijska kriza uzrokovala je zastoj na po-morskom tržištu i prisilila brodare na promjene u po-slovanju što je za posljedicu imalo smanjenu moguć-nost zapošljavanja do te mjere da su neke morali ili privremeno zaustaviti ili prodati svoja osnovna sred-stva za rad – brodove. Zastoju su znatno pridonijele i međunarodne konvencije o ekološkom zakonodavstvu koje pooštravaju kriterije u svezi prevencije onečišće-nja okoliša. Glavni cilj istraživanja jest određivanje smjernica koje će omogućiti prilagodbu poslovanja brodara budućim događanjima na pomorskom tržištu i novonastalim okolnostima, a uzimajući u obzir do-govorenu dinamiku provođenja novih ekoloških nor-mi, pravila i propisa. Pomorsko tržište, s obzirom na njegovu složenost u takvim okolnostima, zahtijeva po-zornu analizu iz koje će se sintetizirati novonastale specifičnosti, te induktivnom i deduktivnom metodom doći do prihvatljivog rješenja, pri čemu će metoda teo-rije sustava biti osnova sustavnog pristupa predmetu...

An Introduction to Marine Ecology, 2009

Educating marine engineers for their future job is quite a challenge for their professors respect... more Educating marine engineers for their future job is quite a challenge for their professors respecting the changes occurred in shipping in past few decades. In some cases the approach is still focused on teaching the facts in the same way they were taught long time ago. But today’s students have changed and so has technology. Advances in educational technology are transforming the learning and teaching processes. Consequently, the education system must adjust to better accommodate the way students learn. The method of teaching based on real practical problems (faults, failures) seems to be giving an opportunity for students to be creative, to understand a specific problem and find a solution for it. To understand the process of decision making or risk assessment presents a real challenge. The students have been working in several teams sharing the information among the members, discussing and competing. Collaborative communication and interpersonal skills of students were developed, a...

2019 International Symposium ELMAR, 2019

Shipping is a very significant source of air pollution, greatly contributing to the creation of g... more Shipping is a very significant source of air pollution, greatly contributing to the creation of greenhouse gases and influencing the climate change. Ships are responsible for roughly 3% of global CO2 and GHG emissions, emitting approximately 1 billion tonnes of CO2 and GHGs per year. Shipping emissions cause severe impacts on health and the environment. The article describes the methodology for estimating the atmospheric emissions of carbon dioxide (CO2) in international shipping in the Bay of Raša as a sensitive area and the respective results. The shipping emissions have been calculated on actual shipping activities for ships calling at the Port of Bršica in 2017. The aim of the research was to provide a better insight in the emission inventories in this area. Ship’s emissions were calculated by the ship activity-based method which involves the application of emission factors for each ship-activity (slow steaming on arrival and departure, manoeuvring on arrival and departure, and ...

U doktorskom radu su znanstvenim metodama istražene i analizirane najvažnije karakteristike pomor... more U doktorskom radu su znanstvenim metodama istražene i analizirane najvažnije karakteristike pomorskog prometa u hrvatskom dijelu Jadrana, prikazani

This paper provides an overview of preliminary results obtained from ongoing research on the Adri... more This paper provides an overview of preliminary results obtained from ongoing research on the Adriatic Sea Area (ASA), which has resulted in the proposal of the Adriatic Sea Area Protection (ASAP) project. The ASA offers several advantages for shippers and ship owners in terms of cargo transport and attractiveness of the coast. A rise in business for cruising companies and nautical tourism have also caused a rise in health and environmental concerns, thus prompting this proposal. Its goal is to establish ship emission inventory for the Adriatic Sea, whose findings will be the basis for the Emission Register, which will be incorporated into an effective Emission Monitoring Information System (EMIS). Interested parties will then have the possibility of requesting International Maritime Organization (IMO) protection of the area. Research is focused on the prevention of air pollution from ship emissions, concluding that effective solutions must be accomplished through Integrated Coastal ...

Sveučilište u Rijeci. Pomorski fakultet. Zavod za brodsko strojarstvo i energetiku., Nov 14, 2018

Pomorstvo: Scientific Journal of Maritime Research, Jun 30, 2010

TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation

Cruising tourism is becoming increasingly popular, the number of cruises having seen a continuous... more Cruising tourism is becoming increasingly popular, the number of cruises having seen a continuous increase since the 1970s. In Croatia as well there is an upward trend in the number of cruise passengers and ports. Of all Croatian ports, it is the port of Dubrovnik that has had the most calls by foreign cruisers. The paper analyses the available statistical data on the maritime cruise market in Europe with special reference to the Mediterranean countries. In the national context, a presentation of cruise traffic in the port of Dubrovnik is given. Although this type of tourism contributes to the development and improvement of the economy, it also has a negative impact on the environment through air pollution by CO2 emissions, subsequently affecting human health as well. The authors investigate the level of CO2 emissions in the area of the port of Dubrovnik. CO2 emissions were calculated based on cruiser activity, the calculations being based on CO2 emissions for three ship navigation modes-slow steaming on arrival and departure, manoeuvring on arrival and departure, and for a berthed ship. The aim of the research was to provide a better insight in the emission inventories in this area. This research can also be applied to other port areas.

Journal of Marine Science and Engineering, Mar 22, 2023

Pomorstvo

In this study, the environmental footprint within a designated area is determined by an inventory... more In this study, the environmental footprint within a designated area is determined by an inventory of air pollutants (including toxic and greenhouse gases) emissions generated. The designated area of concern is the port of Dubrovnik, a well-known cruise ship destination, where a major source of pollutant emissions is the diesel engines of the ships operating in the port. This research was undertaken for the port of Dubrovnik in connection with the development of the national strategy and the need for determining the inventory of air pollutants. It was conducted for the last pre – COVID- 19 year, 2019. In this paper, after a short introduction, the basic data of the port of Dubrovnik and the marine traffic (predominantly cruisers) in 2019 are provided, obtained from publicly available data. Next, the emission estimate methodology based on a bottom-up approach is described. The inventory analysis was undertaken from the port boundary to the PWD (pier/wharf/dock) and back. The basic equ...

Područje Jadranskog mora ima različite prednosti za špeditere (otpremnike) i brodovlasnike uzimaj... more Područje Jadranskog mora ima različite prednosti za špeditere (otpremnike) i brodovlasnike uzimajući u obzir prijevoz tereta i atraktivnost obale. Ono nudi veliki potencijal kompanijama za kružna putovanja i nautički turizam uzrokujući nagli rast pomorskog prijevoza u posljednjih deset godina, što je uzrokovalo povećanu zabrinutost za zdravlje i okoliš, namećući potragu za rješenjem koje bi uravnotežilo učinke onečišćenja i održivost u razvoju. Ovaj članak je pregled preliminarnih rezultata autora prikupljenih kroz nekoliko istraživanja u tijeku, koja su rezultirala prijedlogom ASAP projekta (Zaštita područja Jadranskog mora). Cilj je utvrditi skladište brodskih emisija za Jadransko more čiji nalazi će biti osnova za Registar emisija koji će biti ujedinjen u učinkoviti informacijski sustav za nadzor brodskih emisija i sprječavanje onečišćenja zraka (EMIS). Na osnovi rezultata, zainteresirane stranke imaju mogućnost zahtjeva zaštite IMO-a za to područje. Istraživanja autora usmjerena...

U doktorskom radu su znanstvenim metodama istražene i analizirane najvažnije karakteristike pomor... more U doktorskom radu su znanstvenim metodama istražene i analizirane najvažnije karakteristike pomorskog prometa u hrvatskom dijelu Jadrana, prikazani su najnoviji međunarodni ekološki zahtjevi s osnove sprječavanja onečišćenja okoliša i njihov utjecaj na brodare kroz osnovna načela cikličnih promjena na pomorskom tržištu sa smjernicama za njihovu prilagodbu (ekološka prihvatljivost broda kao osnovni preduvjet opstanka brodara na tržištu), te izrađen pregled globalno dostupnih metodologija procjene emisija i analizirane mogućnosti njihove primjene na promatranom području. Pri tom su holističkim pristupom problematici razmotreni različiti aspekti utjecaja emisija iz pomorskog prometa na čovjeka, okoliš i klimu. Uzimajući u obzir temeljne postavke strategije održivog razvoja i integriranog upravljanja priobalnim područjem postavljen je model Registra emisija koji uvažava specifičnosti pomorskog prometa u hrvatskom djelu Jadrana i omogućuje izradu početnog skladišta emisija (otiska) i nji...

Journal of Maritime & Transportation Science

A ship's propulsion system has a significant impact on the ship’s energy efficiency, environm... more A ship's propulsion system has a significant impact on the ship’s energy efficiency, environmental friendliness, reliability and safety. An indispensable part of a propulsion system with mechanical power transmission is a stern tube with bearings. During operation, the sliding bearings material is subjected to stresses caused by a force proportional to the total mass of the shaft and propeller. The reliability of stern tube bearings is particulary important for safety, and their durability has a significant impact on maintenance costs. Depending on the lubricant, there are bearings that are lubricated with oil or water. The permissible bearing load with hydrodynamic lubrication depends primarily on the material, the viscosity of the lubricant used and the shaft speed. Metals and their alloys with a low coefficient of friction are used for oil-lubricated bearings. Bearings lubricated with water are made of a special type of hardwood ("tree of life", lat. lignum vitae), ...

2019 International Symposium ELMAR, 2019

Shipping is a very significant source of air pollution, greatly contributing to the creation of g... more Shipping is a very significant source of air pollution, greatly contributing to the creation of greenhouse gases and influencing the climate change. Ships are responsible for roughly 3% of global CO2 and GHG emissions, emitting approximately 1 billion tonnes of CO2 and GHGs per year. Shipping emissions cause severe impacts on health and the environment. The article describes the methodology for estimating the atmospheric emissions of carbon dioxide (CO2) in international shipping in the Bay of Raša as a sensitive area and the respective results. The shipping emissions have been calculated on actual shipping activities for ships calling at the Port of Bršica in 2017. The aim of the research was to provide a better insight in the emission inventories in this area. Ship’s emissions were calculated by the ship activity-based method which involves the application of emission factors for each ship-activity (slow steaming on arrival and departure, manoeuvring on arrival and departure, and ...

Transport, 2020

The aim of this article is to enhance performance monitoring of a two-stroke electronically contr... more The aim of this article is to enhance performance monitoring of a two-stroke electronically controlled ship propulsion engine on the operating envelope. This is achieved by setting up a machine learning model capable of monitoring influential operating parameters and predicting the fuel consumption. Model is tested with different machine learning algorithms, namely linear regression, multilayer perceptron, Support Vector Machines (SVM) and Random Forests (RF). Upon verification of modelling framework and analysing the results in order to improve the prediction accuracy, the best algorithm is selected based on standard evaluation metrics, i.e. Root Mean Square Error (RMSE) and Relative Absolute Error (RAE). Experimental results show that, by taking an adequate combination and processing of relevant sensory data, SVM exhibit the lowest RMSE 7.1032 and RAE 0.5313%. RF achieve the lowest RMSE 22.6137 and RAE 3.8545% in a setting when minimal number of input variables is considered, i.e....

Svjetska financijska kriza uzrokovala je zastoj na po-morskom tržištu i prisilila brodare na prom... more Svjetska financijska kriza uzrokovala je zastoj na po-morskom tržištu i prisilila brodare na promjene u po-slovanju što je za posljedicu imalo smanjenu moguć-nost zapošljavanja do te mjere da su neke morali ili privremeno zaustaviti ili prodati svoja osnovna sred-stva za rad – brodove. Zastoju su znatno pridonijele i međunarodne konvencije o ekološkom zakonodavstvu koje pooštravaju kriterije u svezi prevencije onečišće-nja okoliša. Glavni cilj istraživanja jest određivanje smjernica koje će omogućiti prilagodbu poslovanja brodara budućim događanjima na pomorskom tržištu i novonastalim okolnostima, a uzimajući u obzir do-govorenu dinamiku provođenja novih ekoloških nor-mi, pravila i propisa. Pomorsko tržište, s obzirom na njegovu složenost u takvim okolnostima, zahtijeva po-zornu analizu iz koje će se sintetizirati novonastale specifičnosti, te induktivnom i deduktivnom metodom doći do prihvatljivog rješenja, pri čemu će metoda teo-rije sustava biti osnova sustavnog pristupa predmetu...

An Introduction to Marine Ecology, 2009

Educating marine engineers for their future job is quite a challenge for their professors respect... more Educating marine engineers for their future job is quite a challenge for their professors respecting the changes occurred in shipping in past few decades. In some cases the approach is still focused on teaching the facts in the same way they were taught long time ago. But today’s students have changed and so has technology. Advances in educational technology are transforming the learning and teaching processes. Consequently, the education system must adjust to better accommodate the way students learn. The method of teaching based on real practical problems (faults, failures) seems to be giving an opportunity for students to be creative, to understand a specific problem and find a solution for it. To understand the process of decision making or risk assessment presents a real challenge. The students have been working in several teams sharing the information among the members, discussing and competing. Collaborative communication and interpersonal skills of students were developed, a...

2019 International Symposium ELMAR, 2019

Shipping is a very significant source of air pollution, greatly contributing to the creation of g... more Shipping is a very significant source of air pollution, greatly contributing to the creation of greenhouse gases and influencing the climate change. Ships are responsible for roughly 3% of global CO2 and GHG emissions, emitting approximately 1 billion tonnes of CO2 and GHGs per year. Shipping emissions cause severe impacts on health and the environment. The article describes the methodology for estimating the atmospheric emissions of carbon dioxide (CO2) in international shipping in the Bay of Raša as a sensitive area and the respective results. The shipping emissions have been calculated on actual shipping activities for ships calling at the Port of Bršica in 2017. The aim of the research was to provide a better insight in the emission inventories in this area. Ship’s emissions were calculated by the ship activity-based method which involves the application of emission factors for each ship-activity (slow steaming on arrival and departure, manoeuvring on arrival and departure, and ...

U doktorskom radu su znanstvenim metodama istražene i analizirane najvažnije karakteristike pomor... more U doktorskom radu su znanstvenim metodama istražene i analizirane najvažnije karakteristike pomorskog prometa u hrvatskom dijelu Jadrana, prikazani

This paper provides an overview of preliminary results obtained from ongoing research on the Adri... more This paper provides an overview of preliminary results obtained from ongoing research on the Adriatic Sea Area (ASA), which has resulted in the proposal of the Adriatic Sea Area Protection (ASAP) project. The ASA offers several advantages for shippers and ship owners in terms of cargo transport and attractiveness of the coast. A rise in business for cruising companies and nautical tourism have also caused a rise in health and environmental concerns, thus prompting this proposal. Its goal is to establish ship emission inventory for the Adriatic Sea, whose findings will be the basis for the Emission Register, which will be incorporated into an effective Emission Monitoring Information System (EMIS). Interested parties will then have the possibility of requesting International Maritime Organization (IMO) protection of the area. Research is focused on the prevention of air pollution from ship emissions, concluding that effective solutions must be accomplished through Integrated Coastal ...