scholarly journals The Use of Surface Laser Scanning for Creation of a Three-dimensional Digital Model of Monument

2015 ◽  
Vol 100 ◽  
pp. 1625-1633 ◽  
Author(s):  
Irina Kuznetsova ◽  
Darya Kuznetsova ◽  
Xeniya Rakova
2016 ◽  
Vol 22 ◽  
pp. 133-156 ◽  
Author(s):  
Charlotte A. Brassey

AbstractBody mass is a key parameter for understanding the physiology, biomechanics, and ecology of an organism. Within paleontology, body mass is a fundamental prerequisite for many studies considering body-size evolution, survivorship patterns, and the occurrence of dwarfism and gigantism. The conventional method for estimating fossil body mass relies on allometric scaling relationships derived from skeletal metrics of extant taxa, but the recent application of three-dimensional imaging techniques to paleontology (e.g., surface laser scanning, computed tomography, and photogrammetry) has allowed for the rapid digitization of fossil specimens. Volumetric body-mass estimation methods based on whole articulated skeletons are therefore becoming increasingly popular. Volume-based approaches offer several advantages, including the ability to reconstruct body-mass distribution around the body, and their relative insensitivity to particularly robust or gracile elements, i.e., the so-called ‘one bone effect.’ Yet their application to the fossil record will always be limited by the paucity of well-preserved specimens. Furthermore, uncertainties with regards to skeletal articulation, body density, and soft-tissue distribution must be acknowledged and their effects quantified. Future work should focus on extant taxa to improve our understanding of body composition and increase confidence in volumetric model input parameters.


Author(s):  
C. Balletti ◽  
F. Guerra ◽  
A. Lorenzon

Abstract. The Venetian galea (galley), dominating the Mediterranean Sea for almost 1000 years, is one of the most emblematic and fascinating objects in the history and culture of the Serenissima Republic of San Marco, the official name of ancient Venice. This boat has changed according to the needs and developments that have taken place over the centuries, proving versatile and powerful in military and commercial use.Unfortunately, no complete specimen has been received, and everything that can be known about galleys derives from paintings made in different eras, in models and in some original parts, kept inside the Naval Historical Museum of Venice.Another source are some manuscripts, where part of the traditional shipbuilding knowledge is handed down. To understand a galley it is necessary to understand which techniques were used by the proti (directors of the ancient shipyard) which differ substantially from the current design.These techniques were the synthesis of knowledge handed down from person to person and which did not make use of design drawings such as are used today. To obtain the reconstruction of a galley, lacking complete original drawings, we collected and analyzed different documentation that testified the ancient forms.The presented work aims to reconstruct a digital model of a galea starting from the photogrammetric and laser scanning survey of a wooden model of the hull of half of a 25-bench galley of the mid-seventeenth century. The surveyed maquette and brought back to the real scale was integrated by some artifacts present at the Naval History Museum of Venice, surveyed with photogrammetric techniques and laser scanning too.In this way a hypothetical configuration was reconstructed (by synthesis of collected and historical data) which shows the shape that this boat could reasonably have had. The result is a digital model, then printed to the scale, obtained by three-dimensional modeling starting from the point clouds of the maquette and the original artifacts. This final model has been compared with all the iconographic and documentary sources for its historical validation.The results obtained were used for a set-up aimed at enhancing the museum, because it was intended for a large audience.


2011 ◽  
Vol 6 ◽  
pp. 338-345
Author(s):  
Francesco Guerra ◽  
Paolo Vernier

Actually geometrics’ science offers new opportunities and interesting applications in the field of Cultural Heritage. These applications are strictly related to preservation, restoration but even to cataloging and reproducing a monument that no longer has its original integrity.  The possibility of obtaining 3D data, of such a model close to reality, enables us to realize studies that sometimes are too complex or impossible. The paper will describe the study of a monumental arch, the Arco dei Gavi, built in Verona during the I sec. A.C., that was destroyed in 1805 by the Napoleonic army, and its wooden model that was realized in 1813 and it has a very important role concerning the monument’s reconstruction. The purpose is to realize two threedimensional models which can be comparable to each other, two models with recognizable differences, similarities and discontinuities about shapes and single elements that compose the monument. It should also be noted that some original parts of the monument have not been relocated but are badly preserved in a museum: the 3D digital model helps to identify these parts in their original location. The main steps of the work can be summarized in: collecting the historical documentation of Arco dei Gavi and its representations; identifying proper instruments (laser scanning and photogrammetric hardware and software); surveying the Arch and its wooden model; identifying a unique and shared reference system; comparing both digital models related to the same scale; choosing a three-dimensional representation to emphasize the results; reallocation of outstanding pieces (virtual anastylosis).


2021 ◽  
Author(s):  
Noha M. Elkersh ◽  
Rania A.Fahmy ◽  
Mohamed K. Zayet ◽  
Yousria S. Gaweesh

Abstract Background Digital workflow has invaded the different dental specialities. It includes some steps, the first of them is the scan process and dental modelling. Many methods are available for digital model fabrication. Therefore, the aim of this in vivo study to assess and compare the accuracy of 3-dimensional (3D) digital dental models obtained from scanning of conventional impressions versus models from digital impressions. Materials and Methods Three-dimensional digital model files were obtained in vivo from three different methods including scanning of impressions by both Cone beam computed tomography (CBCT) machine (Veraview x800, JMorita) and desktop scanner (Smart optics, Vinyl Open Air). The same volunteers have received digital impressions by an intraoral scanner (CS3600). Six linear measurements were measured in each Stereolithography (STL) model and compared with direct calliper measurements. Additionally, STL files from the three systems were paired and superimposed using a best-fit algorithm in a 3D modelling software. Mean deviations between the STL shells were calculated by the software and color maps were obtained for visual analysis. Intra-class correlation coefficient (ICC) was calculated to determine the intra-examiner reliability. Paired t-test, ANOVA with repeated measures and Post Hoc test (Bonferroni adjusted) were used in the statistical analysis. Significance of the obtained results was judged at the 5% level. Results The linear measurements and 3D deviation analysis revealed significant differences in some measurements but were considered clinically accepted. Digital models obtained from laser scanning of the impressions revealed the least mean differences from the gold standard ranging from (-0.24 to 0.01 mm), while CBCT scanning of the impressions mean differences ranged from (0.16 to -0.04 mm). IOS revealed the highest mean differences ranging from (0.11 to 0.33 mm). Conclusion Scanning the impression with a desktop scanner provided the highest accuracy in full arch scans followed by scanning with CBCT but with decreased surface texture of the 3D mesh. While intraoral scanners showed the least accuracy for full arch scans up till now and need further improvement in their technology. All techniques can be applied in clinical practice providing the use of high quality machines.


Author(s):  
J. Holy ◽  
G. Schatten

One of the classic limitations of light microscopy has been the fact that three dimensional biological events could only be visualized in two dimensions. Recently, this shortcoming has been overcome by combining the technologies of laser scanning confocal microscopy (LSCM) and computer processing of microscopical data by volume rendering methods. We have employed these techniques to examine morphogenetic events characterizing early development of sea urchin embryos. Specifically, the fourth cleavage division was examined because it is at this point that the first morphological signs of cell differentiation appear, manifested in the production of macromeres and micromeres by unequally dividing vegetal blastomeres.The mitotic spindle within vegetal blastomeres undergoing unequal cleavage are highly polarized and develop specialized, flattened asters toward the micromere pole. In order to reconstruct the three-dimensional features of these spindles, both isolated spindles and intact, extracted embryos were fluorescently labeled with antibodies directed against either centrosomes or tubulin.


Author(s):  
Hakan Ancin

This paper presents methods for performing detailed quantitative automated three dimensional (3-D) analysis of cell populations in thick tissue sections while preserving the relative 3-D locations of cells. Specifically, the method disambiguates overlapping clusters of cells, and accurately measures the volume, 3-D location, and shape parameters for each cell. Finally, the entire population of cells is analyzed to detect patterns and groupings with respect to various combinations of cell properties. All of the above is accomplished with zero subjective bias.In this method, a laser-scanning confocal light microscope (LSCM) is used to collect optical sections through the entire thickness (100 - 500μm) of fluorescently-labelled tissue slices. The acquired stack of optical slices is first subjected to axial deblurring using the expectation maximization (EM) algorithm. The resulting isotropic 3-D image is segmented using a spatially-adaptive Poisson based image segmentation algorithm with region-dependent smoothing parameters. Extracting the voxels that were labelled as "foreground" into an active voxel data structure results in a large data reduction.


2020 ◽  
Vol 118 (1) ◽  
pp. 106
Author(s):  
Lei Zhang ◽  
Jianliang Zhang ◽  
Kexin Jiao ◽  
Guoli Jia ◽  
Jian Gong ◽  
...  

The three-dimensional (3D) model of erosion state of blast furnace (BF) hearth was obtained by using 3D laser scanning method. The thickness of refractory lining can be measured anywhere and the erosion curves were extracted both in the circumferential and height directions to analyze the erosion characteristics. The results show that the most eroded positions located below 20# tuyere with an elevation of 7700 mm and below 24#–25# tuyere with an elevation of 8100 mm, the residual thickness here is only 295 mm. In the circumferential directions, the serious eroded areas located between every two tapholes while the taphole areas were protected well by the bonding material. In the height directions, the severe erosion areas located between the elevation of 7600 mm to 8200 mm. According to the calculation, the minimum depth to ensure the deadman floats in the hearth is 2581 mm, corresponding to the elevation of 7619 mm. It can be considered that during the blast furnace production process, the deadman has been sinking to the bottom of BF hearth and the erosion areas gradually formed at the root of deadman.


2015 ◽  
Vol 6 (1) ◽  
pp. 19-29 ◽  
Author(s):  
G. Bitelli ◽  
P. Conte ◽  
T. Csoknyai ◽  
E. Mandanici

The management of an urban context in a Smart City perspective requires the development of innovative projects, with new applications in multidisciplinary research areas. They can be related to many aspects of city life and urban management: fuel consumption monitoring, energy efficiency issues, environment, social organization, traffic, urban transformations, etc. Geomatics, the modern discipline of gathering, storing, processing, and delivering digital spatially referenced information, can play a fundamental role in many of these areas, providing new efficient and productive methods for a precise mapping of different phenomena by traditional cartographic representation or by new methods of data visualization and manipulation (e.g. three-dimensional modelling, data fusion, etc.). The technologies involved are based on airborne or satellite remote sensing (in visible, near infrared, thermal bands), laser scanning, digital photogrammetry, satellite positioning and, first of all, appropriate sensor integration (online or offline). The aim of this work is to present and analyse some new opportunities offered by Geomatics technologies for a Smart City management, with a specific interest towards the energy sector related to buildings. Reducing consumption and CO2 emissions is a primary objective to be pursued for a sustainable development and, in this direction, an accurate knowledge of energy consumptions and waste for heating of single houses, blocks or districts is needed. A synoptic information regarding a city or a portion of a city can be acquired through sensors on board of airplanes or satellite platforms, operating in the thermal band. A problem to be investigated at the scale A problem to be investigated at the scale of the whole urban context is the Urban Heat Island (UHI), a phenomenon known and studied in the last decades. UHI is related not only to sensible heat released by anthropic activities, but also to land use variations and evapotranspiration reduction. The availability of thermal satellite sensors is fundamental to carry out multi-temporal studies in order to evaluate the dynamic behaviour of the UHI for a city. Working with a greater detail, districts or single buildings can be analysed by specifically designed airborne surveys. The activity has been recently carried out in the EnergyCity project, developed in the framework of the Central Europe programme established by UE. As demonstrated by the project, such data can be successfully integrated in a GIS storing all relevant data about buildings and energy supply, in order to create a powerful geospatial database for a Decision Support System assisting to reduce energy losses and CO2 emissions. Today, aerial thermal mapping could be furthermore integrated by terrestrial 3D surveys realized with Mobile Mapping Systems through multisensor platforms comprising thermal camera/s, laser scanning, GPS, inertial systems, etc. In this way the product can be a true 3D thermal model with good geometric properties, enlarging the possibilities in respect to conventional qualitative 2D images with simple colour palettes. Finally, some applications in the energy sector could benefit from the availability of a true 3D City Model, where the buildings are carefully described through three-dimensional elements. The processing of airborne LiDAR datasets for automated and semi-automated extraction of 3D buildings can provide such new generation of 3D city models.


Sign in / Sign up

Export Citation Format

Share Document