TY  - CONF
AU  - Mitrović, Aleksandra
AU  - Mitrović, Nenad
AU  - Kreculj, Dragan
AU  - Ratković Kovačević, Nada
AU  - Dihovicni, Djordje
AU  - Ilić, Ivana
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7742
AB  - Today, the waste material obtained by 3D printing operations presents significant challenges due to the increasing global adoption of this technology, leading to serious environmental implications. The generation of plastic waste from unsuccessful prints and end-of-life products is a growing concern, impacting the circular economy. With a 26% annual growth rate in additive manufacturing, the amount of waste is rapidly increasing, necessitating effective waste management strategies. However, 3D printing offers advantages in waste reduction compared to 
traditional manufacturing methods, with only 40% waste generation compared to subtractive technologies and much of the waste being recyclable. The challenges of waste material obtained by 3D printing are numerous and require a comprehensive approach to waste management and recycling. Moreover, leveraging the abundant opportunities for reusing materials and developing sustainable composite filaments, 3D printing can contribute to environmental sustainability and the principles of circular economy.
PB  - Conference of Academies for Applied Studies in Serbia (CAASS)
C3  - International Multidisciplinary Conference – Challenges of Contemporary Higher Education CCHE 2024
T1  - Challenges with Waste Material Obtained by 3D Printing
EP  - 421
SP  - 417
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7742
ER  - 

@conference{
author = "Mitrović, Aleksandra and Mitrović, Nenad and Kreculj, Dragan and Ratković Kovačević, Nada and Dihovicni, Djordje and Ilić, Ivana",
year = "2024",
abstract = "Today, the waste material obtained by 3D printing operations presents significant challenges due to the increasing global adoption of this technology, leading to serious environmental implications. The generation of plastic waste from unsuccessful prints and end-of-life products is a growing concern, impacting the circular economy. With a 26% annual growth rate in additive manufacturing, the amount of waste is rapidly increasing, necessitating effective waste management strategies. However, 3D printing offers advantages in waste reduction compared to 
traditional manufacturing methods, with only 40% waste generation compared to subtractive technologies and much of the waste being recyclable. The challenges of waste material obtained by 3D printing are numerous and require a comprehensive approach to waste management and recycling. Moreover, leveraging the abundant opportunities for reusing materials and developing sustainable composite filaments, 3D printing can contribute to environmental sustainability and the principles of circular economy.",
publisher = "Conference of Academies for Applied Studies in Serbia (CAASS)",
journal = "International Multidisciplinary Conference – Challenges of Contemporary Higher Education CCHE 2024",
title = "Challenges with Waste Material Obtained by 3D Printing",
pages = "421-417",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7742"
}

Mitrović, A., Mitrović, N., Kreculj, D., Ratković Kovačević, N., Dihovicni, D.,& Ilić, I.. (2024). Challenges with Waste Material Obtained by 3D Printing. in International Multidisciplinary Conference – Challenges of Contemporary Higher Education CCHE 2024
Conference of Academies for Applied Studies in Serbia (CAASS)., 417-421.
https://hdl.handle.net/21.15107/rcub_machinery_7742

Mitrović A, Mitrović N, Kreculj D, Ratković Kovačević N, Dihovicni D, Ilić I. Challenges with Waste Material Obtained by 3D Printing. in International Multidisciplinary Conference – Challenges of Contemporary Higher Education CCHE 2024. 2024;:417-421.
https://hdl.handle.net/21.15107/rcub_machinery_7742 .

Mitrović, Aleksandra, Mitrović, Nenad, Kreculj, Dragan, Ratković Kovačević, Nada, Dihovicni, Djordje, Ilić, Ivana, "Challenges with Waste Material Obtained by 3D Printing" in International Multidisciplinary Conference – Challenges of Contemporary Higher Education CCHE 2024 (2024):417-421,
https://hdl.handle.net/21.15107/rcub_machinery_7742 .

TY  - JOUR
AU  - Škatarić, Dobrila
AU  - Ratković-Kovačević, Nada
PY  - 2010
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1039
AB  - U radu je predstavljeno nekoliko tehnika za redukciju reda sistema, poznatih iz literature, koje su sve zasnovane na uravnoteženju sistema uz primenu metode singularnih perturbacija. Ove tehnike imaju istu robusnost tačnosti izračunatu u skladu sa H∞ normom sistema redukovanog reda kao i dve tehnike poznate pod nazivom direktno odsecanje i metod balansirane rezidualizacije. Modifikacija ovih tehnika zadržava tačnu vrednost pojačanja jednosmernog signala kakva je kod originalnog sistema i daje aproksimaciju od veoma dobre do odlične tačnosti na nižim i srednjim učestanostima. Efikasnost prikazanih tehnika za redukciju reda modela data je na realnom primeru.
AB  - This paper presents several techniques for system order reduction, known from literature, all of them based on system balancing by employing the method of singular perturbation. These techniques have the same robustness accuracy evaluated with respect to the H∞ norm of the reducedorder system like two techniques known as the direct truncation and the balancing residualization method. A modification of these techniques preserves the exact DC gain as the original system, and produces from very good to excellent accuracy at low and medium frequencies. To illustrate the efficiency of the order-reduction techniques here presented, a real simulation example is given.
PB  - Univerzitet u Beogradu - Mašinski fakultet, Beograd
T2  - FME Transactions
T1  - Redukcija reda sistema kroz uravnoteženje sa gledišta metode singularnih perturbacija
T1  - The system order reduction via balancing in view of the method of singular perturbation
EP  - 187
IS  - 4
SP  - 181
VL  - 38
UR  - https://hdl.handle.net/21.15107/rcub_machinery_1039
ER  - 

@article{
author = "Škatarić, Dobrila and Ratković-Kovačević, Nada",
year = "2010",
abstract = "U radu je predstavljeno nekoliko tehnika za redukciju reda sistema, poznatih iz literature, koje su sve zasnovane na uravnoteženju sistema uz primenu metode singularnih perturbacija. Ove tehnike imaju istu robusnost tačnosti izračunatu u skladu sa H∞ normom sistema redukovanog reda kao i dve tehnike poznate pod nazivom direktno odsecanje i metod balansirane rezidualizacije. Modifikacija ovih tehnika zadržava tačnu vrednost pojačanja jednosmernog signala kakva je kod originalnog sistema i daje aproksimaciju od veoma dobre do odlične tačnosti na nižim i srednjim učestanostima. Efikasnost prikazanih tehnika za redukciju reda modela data je na realnom primeru., This paper presents several techniques for system order reduction, known from literature, all of them based on system balancing by employing the method of singular perturbation. These techniques have the same robustness accuracy evaluated with respect to the H∞ norm of the reducedorder system like two techniques known as the direct truncation and the balancing residualization method. A modification of these techniques preserves the exact DC gain as the original system, and produces from very good to excellent accuracy at low and medium frequencies. To illustrate the efficiency of the order-reduction techniques here presented, a real simulation example is given.",
publisher = "Univerzitet u Beogradu - Mašinski fakultet, Beograd",
journal = "FME Transactions",
title = "Redukcija reda sistema kroz uravnoteženje sa gledišta metode singularnih perturbacija, The system order reduction via balancing in view of the method of singular perturbation",
pages = "187-181",
number = "4",
volume = "38",
url = "https://hdl.handle.net/21.15107/rcub_machinery_1039"
}

Škatarić, D.,& Ratković-Kovačević, N.. (2010). Redukcija reda sistema kroz uravnoteženje sa gledišta metode singularnih perturbacija. in FME Transactions
Univerzitet u Beogradu - Mašinski fakultet, Beograd., 38(4), 181-187.
https://hdl.handle.net/21.15107/rcub_machinery_1039

Škatarić D, Ratković-Kovačević N. Redukcija reda sistema kroz uravnoteženje sa gledišta metode singularnih perturbacija. in FME Transactions. 2010;38(4):181-187.
https://hdl.handle.net/21.15107/rcub_machinery_1039 .

Škatarić, Dobrila, Ratković-Kovačević, Nada, "Redukcija reda sistema kroz uravnoteženje sa gledišta metode singularnih perturbacija" in FME Transactions, 38, no. 4 (2010):181-187,
https://hdl.handle.net/21.15107/rcub_machinery_1039 .

TY  - JOUR
AU  - Ratković-Kovačević, Nada
AU  - Škatarić, Dobrila
PY  - 2010
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1098
AB  - A new approach in multimodeling strategy is proposed. Multimodel strategies in which control agents use different simplified models of the same system are being developed using balancing transformation and the corresponding order reduction concepts. Traditionally, the multimodeling concept was studied using the ideas of multitime scales (singular perturbations) and weak subsystem coupling. For all reduced-order models obtained, a Linear Quadratic Gaussian (LQG) control problem was solved. Different order reduction techniques were compared based on the values of the optimized criteria for the closed-loop case where the full-order balanced model utilizes regulators calculated to be the optimal for various reduced-order models. The results obtained were demonstrated on a real-world example: a multiarea power system consisting of two identical areas, that is, two identical power plants.
PB  - Hindawi Ltd, London
T2  - Mathematical Problems in Engineering
T1  - Multimodeling Control via System Balancing
VL  - 2010
DO  - 10.1155/2010/841830
ER  - 

@article{
author = "Ratković-Kovačević, Nada and Škatarić, Dobrila",
year = "2010",
abstract = "A new approach in multimodeling strategy is proposed. Multimodel strategies in which control agents use different simplified models of the same system are being developed using balancing transformation and the corresponding order reduction concepts. Traditionally, the multimodeling concept was studied using the ideas of multitime scales (singular perturbations) and weak subsystem coupling. For all reduced-order models obtained, a Linear Quadratic Gaussian (LQG) control problem was solved. Different order reduction techniques were compared based on the values of the optimized criteria for the closed-loop case where the full-order balanced model utilizes regulators calculated to be the optimal for various reduced-order models. The results obtained were demonstrated on a real-world example: a multiarea power system consisting of two identical areas, that is, two identical power plants.",
publisher = "Hindawi Ltd, London",
journal = "Mathematical Problems in Engineering",
title = "Multimodeling Control via System Balancing",
volume = "2010",
doi = "10.1155/2010/841830"
}

Ratković-Kovačević, N.,& Škatarić, D.. (2010). Multimodeling Control via System Balancing. in Mathematical Problems in Engineering
Hindawi Ltd, London., 2010.
https://doi.org/10.1155/2010/841830

Ratković-Kovačević N, Škatarić D. Multimodeling Control via System Balancing. in Mathematical Problems in Engineering. 2010;2010.
doi:10.1155/2010/841830 .

Ratković-Kovačević, Nada, Škatarić, Dobrila, "Multimodeling Control via System Balancing" in Mathematical Problems in Engineering, 2010 (2010),
https://doi.org/10.1155/2010/841830 . .

TY  - CONF
AU  - Škatarić, Dobrila
AU  - Ratković-Kovačević, Nada
PY  - 2006
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/562
AB  - Several techniques for system order reduction are presented here, known from literature, all of them based on system balancing and some of them employing the method of singular perturbation. These techniques are compared with the two techniques known as the direct truncation and the balancing residualization method for efficiency in approximating the model in two cases: when the system is in the open loop and when the system is working in the closed loop with negative unity gain. All of these techniques for order reduction have the same robustness accuracy evaluated with respect to the H-infinity norm of the reduced-order system. A modification of these techniques preserves the exact DC gain as the original system, and produce from very good to excellent accuracy at low and medium frequencies. To illustrate the efficiency of the order-reduction techniques here presented, a real simulation example is given. The closed loop case simulation shows that high frequency dynamics of the original system can be of more importance for more accurate approximation of the system behaviour in the closed loop even if the high frequency modes appear to be of less significance in the open loop.
C3  - WMSCI 2006 - The 10th World Multi-Conference on Systemics, Cybernetics and Informatics, Jointly with
T1  - Robust order reduction using system balancing with respect of the method of singular perturbation
EP  - 358
SP  - 353
VL  - 3
UR  - https://hdl.handle.net/21.15107/rcub_machinery_562
ER  - 

@conference{
author = "Škatarić, Dobrila and Ratković-Kovačević, Nada",
year = "2006",
abstract = "Several techniques for system order reduction are presented here, known from literature, all of them based on system balancing and some of them employing the method of singular perturbation. These techniques are compared with the two techniques known as the direct truncation and the balancing residualization method for efficiency in approximating the model in two cases: when the system is in the open loop and when the system is working in the closed loop with negative unity gain. All of these techniques for order reduction have the same robustness accuracy evaluated with respect to the H-infinity norm of the reduced-order system. A modification of these techniques preserves the exact DC gain as the original system, and produce from very good to excellent accuracy at low and medium frequencies. To illustrate the efficiency of the order-reduction techniques here presented, a real simulation example is given. The closed loop case simulation shows that high frequency dynamics of the original system can be of more importance for more accurate approximation of the system behaviour in the closed loop even if the high frequency modes appear to be of less significance in the open loop.",
journal = "WMSCI 2006 - The 10th World Multi-Conference on Systemics, Cybernetics and Informatics, Jointly with",
title = "Robust order reduction using system balancing with respect of the method of singular perturbation",
pages = "358-353",
volume = "3",
url = "https://hdl.handle.net/21.15107/rcub_machinery_562"
}

Škatarić, D.,& Ratković-Kovačević, N.. (2006). Robust order reduction using system balancing with respect of the method of singular perturbation. in WMSCI 2006 - The 10th World Multi-Conference on Systemics, Cybernetics and Informatics, Jointly with, 3, 353-358.
https://hdl.handle.net/21.15107/rcub_machinery_562

Škatarić D, Ratković-Kovačević N. Robust order reduction using system balancing with respect of the method of singular perturbation. in WMSCI 2006 - The 10th World Multi-Conference on Systemics, Cybernetics and Informatics, Jointly with. 2006;3:353-358.
https://hdl.handle.net/21.15107/rcub_machinery_562 .

Škatarić, Dobrila, Ratković-Kovačević, Nada, "Robust order reduction using system balancing with respect of the method of singular perturbation" in WMSCI 2006 - The 10th World Multi-Conference on Systemics, Cybernetics and Informatics, Jointly with, 3 (2006):353-358,
https://hdl.handle.net/21.15107/rcub_machinery_562 .

TY  - JOUR
AU  - Škatarić, Dobrila
AU  - Ratković-Kovačević, Nada
PY  - 2006
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/603
AB  - Matematičko modelovanje realnih fizičkih sistema sa dovoljnom tačnošću ali i jednostavnošću za razne primene predmet je proučavanja dugi niz godina. Posebno su od interesa pojednostavljeni matematički modeli za dinamičke analize i sinteze upravljačkih algoritama. U radu će biti prikazano nekoliko poznatih tehnika za snižavanje reda sistema, koje su zasnovane na balansiranju sistema uz primenu metode singularnih perturbacija. Ove tehnike imaju istu tačnost i robusnost procenjenu prema H∞ normi sistema sniženog reda kao i metoda direktnog odsecanja i metoda balansiranja rezidualizovanog modela sistema. Prikazana je i modifikacija tehnike koja obezbeđuje tačnu vrednost pojačanja konstantnog ulaza kao kod originalnog modela sistema. Testirane tehnike daju odličnu tačnost na nižim i srednjim učestanostima. Za ilustraciju efikasnosti prikazanih metoda za snižavanje reda sistema izabrani su realni primeri iz procesne i vazduhoplovne industrije.
AB  - The mathematical modeling of real world systems has been treated from different viewpoint. Usually, two opposite demands have to be fulfilled: the model must be accurate but simple for dynamic analysis and control synthesis. This paper presents several techniques for system order reduction, all of them based on system balancing by employing the method of singular perturbation. These techniques have the same robustness accuracy evaluated with respect to the H∞ norm of the reduced-order system as the two techniques known as the direct truncation and balancing residualization methods. A modification of techniques is described that preserves the exact DC gain as the original system, and produce very good to excellent accuracy at low and medium frequencies. To illustrate the efficiency of the order reduction techniques here presented, a real simulation examples from process and airspace industry are presented.
PB  - Savez inženjera i tehničara Srbije, Beograd
T2  - Tehnika - Mašinstvo
T1  - Prikaz metode redukcije matematičkih modela složenih sistema procesnog upravljanja
T1  - The method for mathematical model reduction of the process control systems
EP  - 9
IS  - 2
SP  - 1
VL  - 55
UR  - https://hdl.handle.net/21.15107/rcub_machinery_603
ER  - 

@article{
author = "Škatarić, Dobrila and Ratković-Kovačević, Nada",
year = "2006",
abstract = "Matematičko modelovanje realnih fizičkih sistema sa dovoljnom tačnošću ali i jednostavnošću za razne primene predmet je proučavanja dugi niz godina. Posebno su od interesa pojednostavljeni matematički modeli za dinamičke analize i sinteze upravljačkih algoritama. U radu će biti prikazano nekoliko poznatih tehnika za snižavanje reda sistema, koje su zasnovane na balansiranju sistema uz primenu metode singularnih perturbacija. Ove tehnike imaju istu tačnost i robusnost procenjenu prema H∞ normi sistema sniženog reda kao i metoda direktnog odsecanja i metoda balansiranja rezidualizovanog modela sistema. Prikazana je i modifikacija tehnike koja obezbeđuje tačnu vrednost pojačanja konstantnog ulaza kao kod originalnog modela sistema. Testirane tehnike daju odličnu tačnost na nižim i srednjim učestanostima. Za ilustraciju efikasnosti prikazanih metoda za snižavanje reda sistema izabrani su realni primeri iz procesne i vazduhoplovne industrije., The mathematical modeling of real world systems has been treated from different viewpoint. Usually, two opposite demands have to be fulfilled: the model must be accurate but simple for dynamic analysis and control synthesis. This paper presents several techniques for system order reduction, all of them based on system balancing by employing the method of singular perturbation. These techniques have the same robustness accuracy evaluated with respect to the H∞ norm of the reduced-order system as the two techniques known as the direct truncation and balancing residualization methods. A modification of techniques is described that preserves the exact DC gain as the original system, and produce very good to excellent accuracy at low and medium frequencies. To illustrate the efficiency of the order reduction techniques here presented, a real simulation examples from process and airspace industry are presented.",
publisher = "Savez inženjera i tehničara Srbije, Beograd",
journal = "Tehnika - Mašinstvo",
title = "Prikaz metode redukcije matematičkih modela složenih sistema procesnog upravljanja, The method for mathematical model reduction of the process control systems",
pages = "9-1",
number = "2",
volume = "55",
url = "https://hdl.handle.net/21.15107/rcub_machinery_603"
}

Škatarić, D.,& Ratković-Kovačević, N.. (2006). Prikaz metode redukcije matematičkih modela složenih sistema procesnog upravljanja. in Tehnika - Mašinstvo
Savez inženjera i tehničara Srbije, Beograd., 55(2), 1-9.
https://hdl.handle.net/21.15107/rcub_machinery_603

Škatarić D, Ratković-Kovačević N. Prikaz metode redukcije matematičkih modela složenih sistema procesnog upravljanja. in Tehnika - Mašinstvo. 2006;55(2):1-9.
https://hdl.handle.net/21.15107/rcub_machinery_603 .

Škatarić, Dobrila, Ratković-Kovačević, Nada, "Prikaz metode redukcije matematičkih modela složenih sistema procesnog upravljanja" in Tehnika - Mašinstvo, 55, no. 2 (2006):1-9,
https://hdl.handle.net/21.15107/rcub_machinery_603 .