Calin Neamtu

Dr. Calin Neamtu

Technical University of Cluj Napoca, Design Engineering and Robotics
orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

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

Representative Publications

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14 August 2022 in Applied Sciences
Verified
Journal Article
Open access
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Radu ComesRadu Comes
Radu Comes
Calin NeamtuCalin Neamtu
Calin Neamtu
CGCătălin Grec
Cătălin Grec
Zsolt BunaZsolt Buna
Zsolt Buna
CGCristian Gazdac
Cristian Gazdac
LMLiliana Daniela Mateescu-Suciu
Liliana Daniela Mateescu-Suciu
The most peculiar characteristic of a cultural heritage is represented by its uniqueness. To ensure that an object is preserved against environmental deterioration, vandal attacks, and accidents, modern Cultural Heritage documentation involves 3D scanning technologies. In the case of fragmented artefacts, the digitization process represents an essential prerequisite for facilitating an accurate 3D reconstruction. The aim of this research paper is to present a framework that enables an accurate digital reconstruction of fragmented or damaged artefacts using ornament stencils obtained from 3D scan data. The proposed framework has been applied for the richly adorned ornaments of the fragmented Dacian embossed disk from Piatra Roșie. The case study makes use of the 3D dataset acquired, using a structured light scanner to extract vector displacement maps, which are then applied to the 3D computer-aided design (CAD) model. The output of the framework includes a proposed digital reconstruction of the aurochs fragmented Dacian embossed disk, as well as the ornaments’ stencils database. The proposed framework addresses problems that are associated with 3D reconstruction processes, such as self-intersections, non-manifold geometry, 3D model topology, and file format interoperability. Finally, the resulting 3D reconstruction has been integrated within virtual reality (VR), augmented reality (AR), and mixed reality (MR) applications, as well as computer-aided manufacturing (CAM) based on additive manufacturing to facilitate the dissemination of the results.

22 April 2021 in Polymers
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Journal Article
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Paul BerePaul Bere
Paul Bere
Mircea Cristian DudescuMircea Cristian Dudescu
Mircea Cristian Dudescu
Calin NeamtuCalin Neamtu
Calin Neamtu
CCCătălin Cocian
Cătălin Cocian
Composite materials are very often used in the manufacture of lightweight parts in the automotive industry, manufacturing of cost-efficient elements implies proper technology combined with a structural optimization of the material structure. The paper presents the manufacturing process, experimental and numerical analyses of the mechanical behavior for two composite hoods with different design concepts and material layouts as body components of a small electric vehicle. The first model follows the black metal design and the second one is based on the composite design concept. Manufacturing steps and full details regarding the fabrication process are delivered in the paper. Static stiffness and strain values for lateral, longitudinal and torsional loading cases were investigated. The first composite hood is 254 times lighter than a similar steel hood and the second hood concept is 22% lighter than the first one. The improvement in terms of lateral stiffness for composite hoods about a similar steel hood is for the black metal design concept about 80% and 157% for the hood with a sandwich structure and modified backside frame. Transversal stiffness is few times higher for both composite hoods while the torsional stiffness has an increase of 62% compared to a similar steel hood.

27 September 2020 in Polymers
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Journal Article
Open access
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Paul BerePaul Bere
Paul Bere
Calin NeamtuCalin Neamtu
Calin Neamtu
RAZVAN UDROIURAZVAN UDROIU
RAZVAN UDROIU
Fibre-reinforced polymers (FRP) have attracted much interest within many industrial fields where the use of 3D printed molds can provide significant cost and time savings in the production of composite tooling. Within this paper, a novel method for the manufacture of complex-shaped FRP parts has been proposed. This paper features a new design of bike saddle, which was manufactured through the use of molds created by fused deposition modeling (FDM), of which two 3D printable materials were selected, polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS), and these molds were then chemically and thermally treated. The novel bike saddles were fabricated using carbon fiber-reinforced polymer (CFRP), by vacuum bag technology and oven curing, utilizing additive manufactured (AM) molds. Following manufacture the molded parts were subjected to a quality inspection, using non-contact three-dimensional (3D) scanning techniques, where the results were then statistically analyzed. The statistically analyzed results state that the main deviations between the CAD model and the manufactured CFRP parts were within the range of ±1 mm. Additionally, the weight of the upper part of the saddles was found to be 42 grams. The novel method is primarily intended to be used for customized products using CFRPs.

23 February 2024 in Journal on Computing and Cultural Heritage
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Journal Article
Open access
Calin NeamtuCalin Neamtu
Calin Neamtu
Radu ComesRadu Comes
Radu Comes
Dorin-Mircea PopoviciDorin-Mircea Popovici
Dorin-Mircea Popovici
Elena BautuElena Bautu
Elena Bautu
LMLiliana Daniela Mateescu-Suciu
Liliana Daniela Mateescu-Suciu
MPMatei-Ioan Popovici
Matei-Ioan Popovici
Cultural institutions are increasingly prioritizing the utilization of diverse mixed reality technologies to enrich the visitor experience during their physical exhibitions. These institutions are actively integrating virtual assets to enhance interactivity and facilitate immersive storytelling experiences. The use of extended reality technologies in cultural heritage dissemination has become a common solution to improve the perception on cultural heritage of their visitors. The objective of the proposed research is to conduct a comparative analysis of three distinct extended reality applications used in cultural heritage experiences. The proposed workflow integrates advanced 3D scanning technology and additive manufacturing techniques to produce tangible replicas which are further enhanced using extended reality technologies, such as augmented reality, desktop virtual reality, and immersive virtual reality. To evaluate the developed extended reality applications, we have conducted various System Usability Scale tools to assess applications’ usability while also trying to identify the most appropriate application that can be integrated within the museum exhibition. From a utility point of view, we found no notable differences in the user perceptions between proposed solutions, whereas from a usability and satisfaction point of view, the most preferred solution was the augmented reality one. The workflow is presented in sufficient detail to ensure the replication of the results.

29 December 2022 in Applied Sciences
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Journal Article
Open access
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Jacek KęsikJacek Kęsik
Jacek Kęsik
Kamil ŻyłaKamil Żyła
Kamil Żyła
Jerzy MontusiewiczJerzy Montusiewicz
Jerzy Montusiewicz
Marek MiloszMarek Milosz
Marek Milosz
Calin NeamtuCalin Neamtu
Calin Neamtu
MJMarta Juszczyk
Marta Juszczyk
Three dimensional digitization of cultural heritage resources gains a lot of attention from the European Union and the United Nations, which is clearly revealed in current strategic goals and financing perspectives. Existing methodological approaches to 3D scanning in a prevailing number of cases assume that the procedure of scanning is performed in places that are closed to tourists, at least for the time of scanning. However, closing an exhibition for tourists or moving an artifact to be scanned is not always possible. Thanks to the long-term experience of the authors with 3D scanning of cultural heritage, the special procedure was designed for small and medium size objects to overcome difficulties expected in such cases. The procedure has been successfully implemented during 3D scanning of objects exhibited in the Silk Road region (on the territory of modern Uzbekistan), as well as objects being parts of wooden sacral architecture of the Maramures region (in Romania). It was revealed that the proposed procedure was successfully allowed to counteract organizational problems during 3D scanning of heritage objects being under continuous display, and that the achieved results of scanning were nevertheless of good quality.

28 April 2022 in Applied Sciences
Verified
Journal Article
Open access
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Dorin-Mircea PopoviciDorin-Mircea Popovici
Dorin-Mircea Popovici
DIDorin Iordache
Dorin Iordache
Radu ComesRadu Comes
Radu Comes
Calin NeamtuCalin Neamtu
Calin Neamtu
Elena BautuElena Bautu
Elena Bautu
This paper is situated at the intersection of using Virtual Reality as a tool for cultural heritage preservation and using gesture interaction-based technology in order to achieve touchless, distant interaction of users with reconstructed artifacts. Various studies emphasize the positive effect on the cultural experience brought on by the use of Virtual Reality in a museum context. We build our approach on this idea, by modeling and reconstructing museum exhibits, both small artifacts and large architectural edifices. We propose and design navigation and interaction scenarios, at the same time taking into account present day limitations regarding social interaction, imposed during the COVID-19 pandemic. By considering the user in the center of the experience and focusing on enabling him/her to adjust the perspective on the visualized artifacts and to freely interact with them through natural gestures, we allow the user to immerse in the virtual environment and interact with the reconstructed artifacts by means of simple hand gestures, with no touch. Finally, we assess the usability and utility of the Virtual Reality system in a questionnaire-based study with 137 participants over a period of 6 months, whose results we discuss in the paper.