scholarly journals Spatial Representation of GPR Data—Accuracy of Asphalt Layers Thickness Mapping

2021 ◽  
Vol 13 (5) ◽  
pp. 864
Author(s):  
Šime Bezina ◽  
Ivica Stančerić ◽  
Josipa Domitrović ◽  
Tatjana Rukavina
Keyword(s):  
Layer Thickness ◽  
Relative Error ◽  
Spatial Representation ◽  
3D Model ◽  
3D Models ◽  
Average Relative Error ◽  
3D Gpr ◽  
Additional Processing ◽  
Ground Penetrating ◽  
Pavement Thickness

Information on pavement layer thickness is very important for determining bearing capacity, estimating remaining life and strengthening planning. Ground-penetrating radar (GPR) is a nondestructive testing (NDT) method used for determining the continuous pavement layer thickness in the travel direction. The data obtained with GPR in one survey line is suitable for the needs of repair and rehabilitation planning of roads and highways, but not for wider traffic areas such as airfield pavements. Spatial representation of pavement thickness is more useful for airfield pavements but requires a 3D model. In the absence of 3D GPR, a 3D model of pavement thickness can be created by additional processing of GPR data obtained from multiple survey lines. Five 3D models of asphalt pavements were created to determine how different numbers of survey lines affect their accuracy. The distance between survey lines ranges from 1 to 5 m. The accuracy of the 3D models is determined by comparing the asphalt layer thickness on the model with the values measured on 22 cores. The results, as expected, show that the highest accuracy is achieved for the 3D model created with a distance of 1 m between survey lines, with an average relative error of up to 1.5%. The lowest accuracy was obtained for the 3D model created with a distance of 4 m between the survey lines, with an average relative error of 7.4%.

scholarly journals Studying the Construction of Floor Mosaics in the Roman Villa of Pisões (Portugal) Using Noninvasive Methods: High-Resolution 3D GPR and Photogrammetry

2019 ◽  
Vol 11 (16) ◽  
pp. 1882 ◽  
Author(s):  
Bento Caldeira ◽  
Rui Jorge Oliveira ◽  
Teresa Teixidó ◽  
José Fernando Borges ◽  
Renato Henriques ◽  
...  
Keyword(s):  
High Resolution ◽  
Archaeological Site ◽  
3D Models ◽  
Noninvasive Methods ◽  
Noninvasive Sensors ◽  
Roman Villa ◽  
3D Gpr ◽  
Ground Penetrating ◽  
Structural Levels ◽  
Very High

Over the past decade, high-resolution noninvasive sensors have been widely used in explorations of the first few meters underground at archaeological sites. However, remote sensing actions aimed at the study of structural elements that require a very high resolution are rare. In this study, layer characterization of the floor mosaic substrate of the Pisões Roman archaeological site was carried out. This work was performed with two noninvasive techniques: 3D ground penetrating radar (3D GPR) operating with a 1.6 GHz central frequency antenna, which is a very high-resolution geophysical method, and photogrammetry with imagery obtained by an unmanned aerial vehicle (UAV), which is a very high-resolution optical method. The first method allows penetration up to 30–40 cm depth and 3D models can be obtained, and with the second method, very high detail surface images and digital surface models can be obtained. In this study, we analyze a combination of data from both sensors to study a portion of the floor mosaic of the Pisões Roman Villa (Beja, Portugal) to obtain evidence of the inner structure. In this context, we have detected the main structural levels of the Roman mosaic and some internal characteristics, such as etched guides, internal cracking, and detection of higher humidity areas. The methodology that we introduce in this work can be referenced for the documentation of ancient pavements and may be used prior to carrying out preservation activities. Additionally, we intend to show that a Roman mosaic, understood as an archaeological structure, does not consist of only beautiful superficial drawings defined by the tesserae, but these mosaics are much more complex elements that must be considered in their entirety for preservation.

Application of 3D-printing technologies for production of master-model in engineering industry

2021 ◽  
Vol 0 (9) ◽  
pp. 17-21
Author(s):  
O. A. Dvoryankin ◽  
◽  
N. I. Baurova ◽  
Keyword(s):  
3D Printing ◽  
Layer Thickness ◽  
Ultimate Strength ◽  
3D Models ◽  
Engineering Industry ◽  
Master Model ◽  
Parameter Influence ◽  
Printing Parameter

Analysis of 3D-printing methods used in the molding production to manufacture master-models has been carried out. The technology was selected, which allowed one to make high-precision parts, combining the molding and the 3D-printing. Factors effecting on the quality of 3D-models printed by this technology were analyzed. Experimental studied for determination of the printing parameter influence (layer thickness, filling percentage, printing velocity) on ultimate strength of specimens made of ABS-plastic were carried out.

scholarly journals UNDERWATER PHOTOGRAMMETRY DIGITAL SURFACE MODEL (DSM) OF THE SUBMERGED SITE OF THE ANCIENT LIGHTHOUSE NEAR QAITBAY FORT IN ALEXANDRIA, EGYPT

2019 ◽  
Vol XLII-2/W10 ◽  
pp. 1-8 ◽  
Author(s):  
M. Abdelaziz ◽  
M. Elsayed
Keyword(s):  
3D Model ◽  
Low Cost ◽  
Data Gathering ◽  
Archaeological Site ◽  
3D Models ◽  
Surface Model ◽  
Digital Surface Model ◽  
Architectural Elements ◽  
3D Photogrammetry ◽  
First Time

<p><strong>Abstract.</strong> Underwater photogrammetry in archaeology in Egypt is a completely new experience applied for the first time on the submerged archaeological site of the lighthouse of Alexandria situated on the eastern extremity of the ancient island of Pharos at the foot of Qaitbay Fort at a depth of 2 to 9 metres. In 2009/2010, the CEAlex launched a 3D photogrammetry data-gathering programme for the virtual reassembly of broken artefacts. In 2013 and the beginning of 2014, with the support of the Honor Frost Foundation, methods were developed and refined to acquire manual photographic data of the entire underwater site of Qaitbay using a DSLR camera, simple and low cost materials to obtain a digital surface model (DSM) of the submerged site of the lighthouse, and also to create 3D models of the objects themselves, such as statues, bases of statues and architectural elements. In this paper we present the methodology used for underwater data acquisition, data processing and modelling in order to generate a DSM of the submerged site of Alexandria’s ancient lighthouse. Until 2016, only about 7200&amp;thinsp;m<sup>2</sup> of the submerged site, which exceeds more than 13000&amp;thinsp;m<sup>2</sup>, was covered. One of our main objectives in this project is to georeference the site since this would allow for a very precise 3D model and for correcting the orientation of the site as regards the real-world space.</p>

scholarly journals FROM ARCHIVE DOCUMENTATION TO ONLINE 3D MODEL VISUALIZATION OF NO LONGER EXISTING STRUCTURES: THE TURIN 1911 PROJECT

2020 ◽  
Vol XLIII-B2-2020 ◽  
pp. 837-844
Author(s):  
D. Einaudi ◽  
A. Spreafico ◽  
F. Chiabrando ◽  
C. Della Coletta
Keyword(s):  
Cultural Heritage ◽  
3D Model ◽  
3D Models ◽  
World's Fair ◽  
Existing Structures ◽  
Present Generation ◽  
Technical Issues ◽  
Digital Documentation ◽  
3D Documentation ◽  
Model Visualization

Abstract. Rebuilding the past of cultural heritage through digitization, archiving and visualization by means of digital technology is becoming an emerging issue to ensure the transmission of physical and digital documentation to future generations as evidence of culture, but also to enable present generation to enlarge, facilitate and cross relate data and information in new ways. In this global effort, the digital 3D documentation of no longer existing cultural heritage can be essential for the understanding of past events and nowadays, various digital techniques and tools are developing for multiple purposes.In the present research the entire workflow, starting from archive documentation collection and digitization to the 3D models metrically controlled creation and online sharing, is considered. The technical issues to obtain a detail 3D model are examined stressing limits and potentiality of 3D reconstruction of disappeared heritage and its visualization exploiting three complexes belonging to 1911 Turin World’s Fair.

scholarly journals Predicting Indoor Temperature Distribution Based on Contribution Ratio of Indoor Climate (CRI) and Mobile Sensors

Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 458
Author(s):  
Yanan Zhao ◽  
Zihan Zang ◽  
Weirong Zhang ◽  
Shen Wei ◽  
Yingli Xuan
Keyword(s):  
Temperature Distribution ◽  
Relative Error ◽  
Prediction Accuracy ◽  
Prediction Method ◽  
Mobile Sensors ◽  
Average Relative Error ◽  
Contribution Ratio ◽  
Mobile Sensor ◽  
Indoor Climate ◽  
Indoor Temperature

In practical building control, quickly obtaining detailed indoor temperature distribution is necessary for providing satisfying personal comfort and improving building energy efficiency. The aim of this study is to propose a fast prediction method for indoor temperature distribution without knowing the thermal boundary conditions in practical applications. In this method, the index of contribution ratio of indoor climate (CRI), which represents the independent contribution of each heat source to the temperature distribution, has been combined with the air temperature collected by one mobile sensor at the height of the working area. Based on a typical office model, the effectiveness of using mobile sensors was discussed, and the influence of its acquisition height and acquisition distance on the prediction accuracy was analyzed as well. The results showed that the proposed prediction method was effective. When the sensors fixed on the wall were used to predict the indoor temperature distribution, the maximum average relative error was 27.7%, whereas when the mobile sensor was used to replace the fixed sensors, the maximum average relative error was 4.8%. This indicates that using mobile sensors with flexible acquisition location can help promote both reliability and accuracy of temperature prediction. In the human activity area, data from a set of mobile sensors were used to predict the temperature distribution at four heights. The prediction accuracy was 2.1%, 2.1%, 2.3%, and 2.7%, respectively. However, the influence of acquisition distance of mobile sensors on prediction accuracy cannot be ignored. The distance should be large enough to disperse the distribution of the acquisition points. Due to the influence of airflow, some distance between the acquisition points and the room boundaries should be given.

scholarly journals VERIFICATION OF POTENCY OF AERIAL DIGITAL OBLIQUE CAMERAS FOR AERIAL PHOTOGRAMMETRY IN JAPAN

2016 ◽  
Vol XLI-B1 ◽  
pp. 63-68 ◽  
Author(s):  
Ryuji Nakada ◽  
Masanori Takigawa ◽  
Tomowo Ohga ◽  
Noritsuna Fujii
Keyword(s):  
3D Model ◽  
3D Models ◽  
Aerial Photographs ◽  
Digital Cameras ◽  
Digital Mapping ◽  
Aerial Photogrammetry ◽  
Public Survey ◽  
Survey Accuracy ◽  
Left And Right ◽  
Simultaneous Adjustment

Digital oblique aerial camera (hereinafter called “oblique cameras”) is an assembly of medium format digital cameras capable of shooting digital aerial photographs in five directions i.e. nadir view and oblique views (forward and backward, left and right views) simultaneously and it is used for shooting digital aerial photographs efficiently for generating 3D models in a wide area. &lt;br&gt;&lt;br&gt; For aerial photogrammetry of public survey in Japan, it is required to use large format cameras, like DMC and UltraCam series, to ensure aerial photogrammetric accuracy. &lt;br&gt;&lt;br&gt; Although oblique cameras are intended to generate 3D models, digital aerial photographs in 5 directions taken with them should not be limited to 3D model production but they may also be allowed for digital mapping and photomaps of required public survey accuracy in Japan. &lt;br&gt;&lt;br&gt; In order to verify the potency of using oblique cameras for aerial photogrammetry (simultaneous adjustment, digital mapping and photomaps), (1) a viewer was developed to interpret digital aerial photographs taken with oblique cameras, (2) digital aerial photographs were shot with an oblique camera owned by us, a Penta DigiCAM of IGI mbH, and (3) accuracy of 3D measurements was verified.

Low Cost Methods Used to Create 3D Models

2017 ◽  
Author(s):  
Agnieszka Chmurzynska ◽  
Karolina Hejbudzka ◽  
Andrzej Dumalski
Keyword(s):  
Laser Scanning ◽  
3D Model ◽  
Low Cost ◽  
3D Models ◽  
3D Modelling ◽  
Kinect Sensor ◽  
Applied Technology ◽  
Gaming Environment

During the last years the softwares and applications that can produce 3D models using low-cost methods have become very popular. What is more, they can be successfully competitive with the classical methods. The most wellknown and applied technology used to create 3D models has been laser scanning so far. However it is still expensive because of the price of the device and software. That is why the universality and accessibility of this method is very limited. Hence, the new low cost methods of obtaining the data needed to generate 3D models appeare on the market and creating 3D models have become much easier and accessible to a wider group of people. Because of their advantages they can be competitive with the laser scanning. One of the methods uses digital photos to create 3D models. Available software allows us to create a model and object geometry. Also very popular in the gaming environment device – Kinect Sensor can be successfully used as a different method to create 3D models. This article presents basic issues of 3D modelling and application of various devices, which are commonly used in our life and they can be used to generate a 3D model as well. Their results are compared with the model derived from the laser scanning. The acquired results with graphic presentations and possible ways of applications are also presented in this paper.

3D Model-Based Semantic Categorization of Still Image 2D Objects

2011 ◽  
Vol 2 (4) ◽  
pp. 19-37
Author(s):  
Raluca-Diana Petre ◽  
Titus Zaharia
Keyword(s):  
3D Model ◽  
3D Models ◽  
Multimedia Databases ◽  
Indexing Methods ◽  
Still Image ◽  
Shape Indexing ◽  
Indexing And Retrieval ◽  
Video Indexing And Retrieval ◽  
Matching Techniques ◽  
Image Object

Automatic classification and interpretation of objects present in 2D images is a key issue for various computer vision applications. In particular, when considering image/video, indexing, and retrieval applications, automatically labeling in a semantically pertinent manner/huge multimedia databases still remains a challenge. This paper examines the issue of still image object categorization. The objective is to associate semantic labels to the 2D objects present in natural images. The principle of the proposed approach consists of exploiting categorized 3D model repositories to identify unknown 2D objects, based on 2D/3D matching techniques. The authors use 2D/3D shape indexing methods, where 3D models are described through a set of 2D views. Experimental results, carried out on both MPEG-7 and Princeton 3D models databases, show recognition rates of up to 89.2%.

Channel design for 3D models with applications in powder-bed additive manufacturing

2019 ◽  
Vol 25 (9) ◽  
pp. 1536-1544
Author(s):  
Xiangzhi Wei ◽  
Xianda Li ◽  
Shanshan Wen ◽  
Yu Zheng ◽  
Yaobin Tian
Keyword(s):  
Additive Manufacturing ◽  
3D Model ◽  
3D Models ◽  
Linear Constraints ◽  
Channel Design ◽  
Channel Network ◽  
Content Type ◽  
Powder Bed ◽  
Shortest Network ◽  
Manufacturing Techniques

Purpose For any 3D model with chambers to be fabricated in powder-bed additive manufacturing processes such as SLM and SLS, powders are trapped in the chambers of the finished model. This paper aims to design a shortest network with the least number of outlets for efficiently leaking the trapped powders. Design/methodology/approach This paper proposes a nonlinear objective with linear constraints for solving the channel design problem and a particle swarm optimization algorithm to solve the nonlinear system. Findings Structural optimization for the channel network leads to fairly short channels in the interior of the 3D models and very few outlets on the model surface, which achieves the cleaning of the powders while causing almost the least changes to the model. Originality/value This paper reveals the NP-harness of computing the shortest channel network with the least number of outlets. The proposed approach helps the design of lightweight models using the powder-bed additive manufacturing techniques.

Implementation of Reliability-Based Backcalculation Analysis

2005 ◽  
Vol 1905 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Sameh Zaghloul ◽  
Khaled Helali ◽  
Riaz Ahmed ◽  
Zubair Ahmed ◽  
Andris A. Jumikis
Keyword(s):  
Layer Thickness ◽  
Pavement Design ◽  
Reliability Factor ◽  
Structural Capacity ◽  
Degree Of Certainty ◽  
Essential Input ◽  
Pilot Implementation ◽  
Ground Penetrating ◽  
Normal Variability

The reliability concept provides a means of incorporating some degree of certainty into the pavement design process to ensure that the outcomes of the process will provide acceptable levels of service until the end of the intended design life. Pavement structural performance and rehabilitation design are highly dependent on the in situ layer properties. Pavement layer thickness is an essential input in backcalculation analysis performed with measured surface deflections to evaluate the in situ structural capacity of a pavement. Inaccurate thickness information may lead to significant errors in the backcalculated layer moduli and, hence, in the rehabilitation design. Because pavement layer thickness has some degree of variability (normal variability), it is important to consider this variability in the backcalculation analysis and rehabilitation design. A procedure was developed to implement the reliability concept in backcalculation analysis to account for the normal variability in layer thickness within structurally homogeneous sections. This procedure was developed on the basis of in situ layer information obtained from a ground-penetrating radar study performed for the New Jersey Department of Transportation. This paper provides an overview of the procedure, along with the results of the pilot implementation of the procedure. This reliability procedure complements the reliability factor of the 1993 AASHTO pavement design guide, as the latter reliability factor does not account for the in situ layer thickness.

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