Personne :
Zhang, Hai

En cours de chargement...
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Adresse électronique
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Structures organisationnelles
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Université Laval. Laboratoire de vision et systèmes numériques
Identifiant Canadiana

Résultats de recherche

Voici les éléments 1 - 5 sur 5
  • Publication
    Non-destructive imaging of marqueteries based on a new infrared-terahertz fusion technique
    (Pergamon, 2022-06-25) Avdelidis, Nicolas P.; Hu, Jue; Zhang, Hai; Gargiulo, Gianfranco; Maldague, X.; Sfarra, Stefano; Zhang, Mingli; Yang, Dazhi
    Detection of subsurface defects has hitherto been regarded as an important element in the course of preserving cultural heritage. To do so, non-destructive imaging approaches for viewing and determining the location of splitting inside the sample under test are required, which constitute the subject of the present study. Both active thermography and terahertz imaging have demonstrated their potential in providing non-destructive inspection on cultural heritage objects. Conventionally, active thermography has been used to retrieve details on the defects as well as morphological data from the surface and subsurface, whereas pulsed terahertz imaging has been applied to record the internal material distribution. Here, the feature extraction, selection and fusion framework is extended to design a fusion process to merge the information obtained by both active thermography and terahertz imaging; in this way, the technique naturally inherits the strengths of both aforementioned imaging technologies. The fusion technique is able to produce images with high-contrast defect information located at different depths. To demonstrate the efficacy of the suggested technique, an experiment has been conducted on an ancient marquetry.
  • Publication
    Novel infrared-terahertz fusion 3D non-invasive imaging of plant fibre-reinforced polymer composites
    (Barking Elsevier Applied Science, 2022-05-14) Hu, Jue; Zhang, Hai; Maldague, X.; Santulli, Carlo; Sfarra, Stefano; Tian, Guiyun
    The reinforcement of polymer composites using plant fibres has received vast and growing attention for investigation owing to their capability to serve as semi-structural materials, especially as a substitute for fiberglass. However, in this type of research, the structural complexity, due to geometrical mismatches and inherent variability to the properties of vegetable fibres and plant fibre composites would benefit from more effective noninvasive inspection techniques. In this work, a novel infrared-terahertz fused approach was proposed, and a new unsupervised deep residual fusion algorithm was developed in order to combine the outputs from two different physical mechanisms. Specifically, infrared imaging provided the details of the defects and the morphological information from the surface and subsurface, while terahertz imaging recorded the distribution of the fibres and the resin. Finally, the fused infrared-terahertz slices were reconstructed into a form of 3D exhibition for inspection and evaluation of two plant fibre-reinforced polymer composites in first time using multiphysical imaging and fusion.
  • Publication
    Autonomous high resolution inspection of kiss-bonds skins of carbon nanotube reinforced nanocomposites using novel dynamic line-scan thermography approach
    (Elsevier Applied Science Publishers, 2020-03-06) Zhang, Hai; Verberne, Pieter; Maldague, X.; Meguid, Shaker A.; Ibarra Castanedo, Clemente
    In addition to being a serious threat to aircraft safety, kiss-bonding is also difficult to detect using conventional non-destructive testing techniques. It is the objective of this study to develop an autonomous high resolution technique to detect kiss-bonds and disbonds between carbon nanotube (CNT) skins and the host substrate of large-scale nanocomposite structures. The newly developed automated dynamic line-scan thermography (LST) approach is capable of speedy detection (up to 50 mm/s) of contact kiss-bonds as well as disbonds in laminated CNT-reinforced nanocomposite.
  • Publication
    Inspecting historical vaulted ceilings by means of physical and chemical analyses : an integrated approach combining active infrared thermography and reflectance spectroscopy
    (INCOSE, 2020-03-01) Zhang, Hai; Cheilakou, Eleni; Maldague, X.; Theodorakeas, Panagiotis; Ibarra Castanedo, Clemente; Sfarra, Stefano; Koui, Maria
    The present study discusses the experimental physicochemical results obtained from the historical vaulted ceilings of an ancient church located in central Italy. Infrared thermography (IRT) in the active configuration was used to map subsurface defects caused by a seismic event and to discover buried structures, while the visible and near-infrared (VIS-NIR) fibre optics diffuse reflectance spectroscopy (FORS) technique was applied to identify the pigments of wall paintings decorating the vault. Historical photographs are useful to readers in order to clarify the state of conservation before and after the earthquake that took place in 2009. The combination of the experimental results can be useful in restoration processes.
  • Publication
    Using through-transmission mid-wave infrared vision and air-coupled ultrasound for artwork inspection : a case study on mock-ups of Portrait of the Painter's Mother
    (INCOSE, 2020-03-01) Zhang, Hai; Maldague, X.; Osman, Ahmad; Ibarra Castanedo, Clemente; Sfarra, Stefano
    The conservation of artworks is playing an increasingly important role in society today. Non-destructive investigation can provide the potential to identify deterioration as early as possible. In this research, transmission mid-wave infrared (MWIR) vision and air-coupled ultrasound (ACU) were used to investigate two paintings on canvas made from different textile support materials. An X-ray technique was used in the work for validation. It was found that the transmission mode can probe deeper and the differences in absorption due to the different textile support materials can be distinguished. This paper summarises advantages of the transmission inspection mode and compares and analyses images from the two techniques from a physical point of view.