Bogdan Pirvu

Dr. Bogdan Pirvu

Lucian Blaga University from Sibiu, Faculty of Engineering
orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 August 2017 in IOP Conference Series: Materials Science and Engineering
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Conference Paper
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BPBogdan Pirvu
Bogdan Pirvu
CZConstantin-Bala Zamfirescu
Constantin-Bala Zamfirescu
Manufacturing companies, independent of operation sector and size, must be able to produce lot size one products, just-in-time at a competitive cost. Coping with this high adaptability and short reaction times proves to be very challenging. New approaches must be taken into consideration for designing modular, intelligent and cooperative production systems which are easy to integrate with the entire factory. The coined term for this network of intelligent interacting artefacts system is cyber-physical systems (CPS). CPS is often used in the context of Industry 4.0-or what many consider the forth industrial revolution. The paper presents an overview of key technological and social requirements to map the Smart Factory vision into reality. Finally, global and Romanian specific challenges hindering the vision of a true Smart Factory to become reality are presented.

21 May 2021 in Sensors
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Journal Article
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RSRadu Sorostinean
Radu Sorostinean
Arpad GellertArpad Gellert
Arpad Gellert
BPBogdan Pirvu
Bogdan Pirvu
This paper presents different prediction methods based on decision tree and ensemble learning to suggest possible next assembly steps. The predictor is designed to be a component of a sensor-based assembly assistance system whose goal is to provide support via adaptive instructions, considering the assembly progress and, in the future, the estimation of user emotions during training. The assembly assistance station supports inexperienced manufacturing workers, but it can be useful in assisting experienced workers, too. The proposed predictors are evaluated on the data collected in experiments involving both trainees and manufacturing workers, as well as on a mixed dataset, and are compared with other existing predictors. The novelty of the paper is the decision tree-based prediction of the assembly states, in contrast with the previous algorithms which are stochastic-based or neural. The results show that ensemble learning with decision tree components is best suited for adaptive assembly support systems.

10 January 2022 in Sensors
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Journal Article
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Arpad GellertArpad Gellert
Arpad Gellert
RSRadu Sorostinean
Radu Sorostinean
BPBogdan Pirvu
Bogdan Pirvu
Manual work accounts for one of the largest workgroups in the European manufacturing sector, and improving the training capacity, quality, and speed brings significant competitive benefits to companies. In this context, this paper presents an informed tree search on top of a Markov chain that suggests possible next assembly steps as a key component of an innovative assembly training station for manual operations. The goal of the next step suggestions is to provide support to inexperienced workers or to assist experienced workers by providing choices for the next assembly step in an automated manner without the involvement of a human trainer on site. Data stemming from 179 experiment participants, 111 factory workers, and 68 students, were used to evaluate different prediction methods. From our analysis, Markov chains fail in new scenarios and, therefore, by using an informed tree search to predict the possible next assembly step in such situations, the prediction capability of the hybrid algorithm increases significantly while providing robust solutions to unseen scenarios. The proposed method proved to be the most efficient for next assembly step prediction among all the evaluated predictors and, thus, the most suitable method for an adaptive assembly support system such as for manual operations in industry.

6 April 2021 in Applied Sciences
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Journal Article
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Arpad GellertArpad Gellert
Arpad Gellert
Stefan-Alexandru PrecupStefan-Alexandru Precup
Stefan-Alexandru Precup
BPBogdan Pirvu
Bogdan Pirvu
Ugo FioreUgo Fiore
Ugo Fiore
CZConstantin-Bala Zamfirescu
Constantin-Bala Zamfirescu
Francesco PalmieriFrancesco Palmieri
Francesco Palmieri
Industrial assistive systems result from a multidisciplinary effort that integrates IoT (and Industrial IoT), Cognetics, and Artificial Intelligence. This paper evaluates the Prediction by Partial Matching algorithm as a component of an assembly assistance system that supports factory workers, by providing choices for the next manufacturing step. The evaluation of the proposed method was performed on datasets collected within an experiment involving trainees and experienced workers. The goal is to find out which method best suits the datasets in order to be integrated afterwards into our context-aware assistance system. The obtained results show that the Prediction by Partial Matching method presents a significant improvement with respect to the existing Markov predictors.

25 September 2022
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Book Chapter
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PTPrasad Talasila
Prasad Talasila
DCDaniel-Cristian Crăciunean
Daniel-Cristian Crăciunean
BPBogdan Pirvu
Bogdan Pirvu
Peter Gorm LarsenPeter Gorm Larsen
Peter Gorm Larsen
CZConstantin-Bala Zamfirescu
Constantin-Bala Zamfirescu
ASAlea Scovill
Alea Scovill

2 August 2022 in Mathematics
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Journal Article
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Arpad GellertArpad Gellert
Arpad Gellert
Stefan-Alexandru PrecupStefan-Alexandru Precup
Stefan-Alexandru Precup
Alexandru MateiAlexandru Matei
Alexandru Matei
BPBogdan Pirvu
Bogdan Pirvu
CZConstantin-Bala Zamfirescu
Constantin-Bala Zamfirescu
This paper presents a context-aware adaptive assembly assistance system meant to support factory workers by embedding predictive capabilities. The research is focused on the predictor which suggests the next assembly step. Hidden Markov models are analyzed for this purpose. Several prediction methods have been previously evaluated and the prediction by partial matching, which was the most efficient, is considered in this work as a component of a hybrid model together with an optimally configured hidden Markov model. The experimental results show that the hidden Markov model is a viable choice to predict the next assembly step, whereas the hybrid predictor is even better, outperforming in some cases all the other models. Nevertheless, an assembly assistance system meant to support factory workers needs to embed multiple models to exhibit valuable predictive capabilities.