scholarly journals Brief communication: 3D reconstruction of a collapsed rock pillar from web-retrieved images and terrestrial LiDAR data – The 2005 event of the West face of the Drus (Mont-Blanc massif)

2016 ◽  
Author(s):  
Antoine Guerin ◽  
Antonio Abellán ◽  
Battista Matasci ◽  
Michel Jaboyedoff ◽  
Marc-Henri Derron ◽  
...  
Keyword(s):  
Point Cloud ◽  
3D Model ◽  
Rock Avalanche ◽  
Lidar Data ◽  
The West ◽  
Terrestrial Lidar ◽  
The Face ◽  
The Difference ◽  
Historical Photographs ◽  
Mont Blanc Massif

Abstract. In June 2005, a series of major rockfall events completely wiped out the Bonatti Pillar located in the legendary Drus West face (Mont-Blanc massif, France). Terrestrial LiDAR scans of the face were acquired after this event but no pre-event point cloud is available. Thus, in order to reconstruct the volume and the shape of the collapsed blocks, a 3D model has been built using photogrammetry (SfM) based on 30 pictures collected on the Web. All these pictures were taken between September 2003 and May 2005. We then reconstructed the shape and volume of the fallen compartment by comparing the SfM model with terrestrial LiDAR data acquired in October 2005 and November 2011. The volume is calculated to 292’680 m3 (±5 %). This result is close to the value previously assessed by Ravanel and Deline (2008) for this same rock-avalanche (265’000 ± 10’000 m3). The difference between these two estimations can be explained by the rounded shape of the volume determined by photogrammetry, which may lead to a volume overestimation. However it is not excluded that the volume calculated by Ravanel and Deline (2008) is slightly underestimated, the thickness of the blocks having been assessed manually from historical photographs.

scholarly journals Brief communication: 3-D reconstruction of a collapsed rock pillar from Web-retrieved images and terrestrial lidar data – the 2005 event of the west face of the Drus (Mont Blanc massif)

2017 ◽  
Vol 17 (7) ◽  
pp. 1207-1220 ◽  
Author(s):  
Antoine Guerin ◽  
Antonio Abellán ◽  
Battista Matasci ◽  
Michel Jaboyedoff ◽  
Marc-Henri Derron ◽  
...  
Keyword(s):  
Structure From Motion ◽  
Point Cloud ◽  
Rock Avalanche ◽  
Lidar Data ◽  
The West ◽  
Terrestrial Lidar ◽  
The Difference ◽  
Historical Photographs ◽  
D Model ◽  
Mont Blanc Massif

Abstract. In June 2005, a series of major rockfall events completely wiped out the Bonatti Pillar located in the legendary Drus west face (Mont Blanc massif, France). Terrestrial lidar scans of the west face were acquired after this event, but no pre-event point cloud is available. Thus, in order to reconstruct the volume and the shape of the collapsed blocks, a 3-D model has been built using photogrammetry (structure-from-motion (SfM) algorithms) based on 30 pictures collected on the Web. All these pictures were taken between September 2003 and May 2005. We then reconstructed the shape and volume of the fallen compartment by comparing the SfM model with terrestrial lidar data acquired in October 2005 and November 2011. The volume is calculated to 292 680 m3 (±5.6 %). This result is close to the value previously assessed by Ravanel and Deline (2008) for this same rock avalanche (265 000 ± 10 000 m3). The difference between these two estimations can be explained by the rounded shape of the volume determined by photogrammetry, which may lead to a volume overestimation. However it is not excluded that the volume calculated by Ravanel and Deline (2008) is slightly underestimated, the thickness of the blocks having been assessed manually from historical photographs.

scholarly journals Different Paths for Developing Terrestrial LiDAR Data for Comparative Analyses of Topographic Surface Changes

2020 ◽  
Vol 10 (21) ◽  
pp. 7409 ◽  
Author(s):  
Waldemar Kociuba
Keyword(s):  
High Resolution ◽  
Point Cloud ◽  
Laser Scanning ◽  
Mineral Resources ◽  
Noise Removal ◽  
Airborne Lidar ◽  
Lidar Data ◽  
Differential Analysis ◽  
Terrestrial Lidar ◽  
Surface Changes

High resolution terrestrial laser scanning data (TLS; terrestrial LiDAR) provide an excellent background for quantitative resource estimation through the comparative analysis of topographic surface changes. However, unlike airborne LiDAR data, which is usually provided as classified and contains a class of ground points, raw TLS data include all of the points of the scanned space within the specified scanner range. In effect, utilizing the latter data to estimate the volume of the resource by the differential analysis of digital elevation models (DEMs) requires the data to be specially prepared, i.e., separating from the point cloud only the data that represent the relevant class. In the case of natural resources, e.g., mineral resources, the class is represented by ground points. This paper presents the results that were obtained by differential analysis of high resolution DEMs (DEM of difference (DoD) method) using TLS data that were processed both manually (operator noise removal) and with the use of the automatic Cloth Simulation Filter (CSF) algorithm. Three different time pairs of DoD data were analyzed for a potential gravel-cobble deposit area of 45,444 m2, which was located at the bottom of the mouth section of the Scott River in south-east Svalbard. It was found that the applied method of ground point classification had very little influence on the errors in the range of estimating volumetric parameters of the mineral resources and measurement uncertainty. Moreover, it was shown that the point cloud density had an influence on the CSF filtering efficiency and spatial distribution of errors.

Studying Modern Arabic Literature

2015 ◽  
Keyword(s):  
Twentieth Century ◽  
Arab World ◽  
Public Intellectual ◽  
Arabic Literature ◽  
Global Culture ◽  
The West ◽  
Teaching And Research ◽  
The Face ◽  
The 1960S ◽  
Modern Arabic

This book is devoted to the life and academic legacy of Mustafa Badawi who transformed the study of modern Arabic literature in the second half of the twentieth century. Prior to the 1960s the study of Arabic literature, both classical and modern, had barely been emancipated from the academic approaches of orientalism. The appointment of Badawi as Oxford University's first lecturer in modern Arabic literature changed the face of this subject as Badawi showed, through his teaching and research, that Arabic literature was making vibrant contributions to global culture and thought. Part biography, part collection of critical essays, this book celebrates Badawi's immense contribution to the field and explores his role as a public intellectual in the Arab world and the west.

THE WEST SALT CREEK ROCK AVALANCHE, SAG POND, AND OUTBURST FLOOD: MORPHOLOGICAL AND SEDIMENTOLOGICAL SIGNATURES FROM A SERIES OF EXTRAORDINARY EVENTS

2017 ◽  
Author(s):  
Jeffrey A. Coe ◽  
◽  
Erin K. Bessette-Kirton ◽  
Rex L. Baum ◽  
Joel B. Smith ◽  
...  
Keyword(s):  
Rock Avalanche ◽  
Outburst Flood ◽  
The West ◽  
Salt Creek

The Difference in Facial Movement Between the Medial and the Lateral Midface: A 3D Skin Surface Vector Analysis

2021 ◽  
Author(s):  
David L Freytag ◽  
Michael G Alfertshofer ◽  
Konstantin Frank ◽  
Dmitry V Melnikov ◽  
Nicholas Moellhoff ◽  
...  
Keyword(s):  
3D Imaging ◽  
Functional Anatomy ◽  
Skin Surface ◽  
Facial Movements ◽  
Anatomic Location ◽  
Objective Evidence ◽  
The Face ◽  
Functional Boundary ◽  
The Mean ◽  
The Difference

Abstract Background Our understanding of the functional anatomy of the face is constantly improving. To date, it is unclear whether the anatomic location of the line of ligaments has any functional importance during normal facial movements such as smiling. Objectives It is the objective of the present study to identify differences in facial movements between the medial and lateral midface by means of skin vector displacement analyses derived from 3D imaging and to further ascertain whether the line of ligaments has both a structural and functional significance in these movements. Methods The study sample consisted of 21 healthy volunteers (9 females & 12 males) of Caucasian ethnic background with a mean age of 30.6 (8.3) years and a mean BMI of 22.57 (2.5) kg/m 2. 3D images of the volunteers’ faces in repose and during smiling (Duchenne type) were taken. 3D imaging-based skin vector displacement analyses were conducted. Results The mean horizontal skin displacement was 0.08 (2.0) mm in the medial midface (lateral movement) and was -0.08 (1.96) mm in the lateral midface (medial movement) (p = 0.711). The mean vertical skin displacement (cranial movement of skin toward the forehead/temple) was 6.68 (2.4) mm in the medial midface whereas it was 5.20 (2.07) mm in the lateral midface (p = 0.003). Conclusions The results of this study provide objective evidence for an antagonistic skin movement between the medial and the lateral midface. The functional boundary identified by 3D imaging corresponds to the anatomic location of the line of ligaments.

scholarly journals The Value of a Decrease in Temperature by One Degree Celsius of the Regional Microclimate—The Cooling Effect of the Paddy Field

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 353
Author(s):  
Ya-Wen Chiueh ◽  
Chih-Hung Tan ◽  
Hsiang-Yi Hsu
Keyword(s):  
Land Use ◽  
Surface Temperature ◽  
Paddy Field ◽  
Research Area ◽  
Paddy Fields ◽  
Cooling Effect ◽  
Field Temperature ◽  
Bare Land ◽  
The Face ◽  
The Difference

In the face of climate change, extreme climates are becoming more frequent. There were severe droughts in Taiwan in 2020, 2014–2015, and 2002. In these years, the paddy fields were kept fallow to save water and transfer agricultural water to non-agricultural use. On the other hand, with global warming, the existence of paddy fields may be one of the natural solutions to regional temperature mitigation. This study used remote sensing to quantify the difference in temperature between paddy fields and urban areas. The result of overall surface temperature deductive analysis revealed that the temperature in the whole Taoyuan research area was 1.2 °C higher in 2002 than in 2003 because of fallowing of the paddy field, while in the Hsinchu research area, it was 1.5 °C higher in 2002 than in 2003, due to the same reason described above. In terms of the difference in land use, for the Hsinchu research area, the surface temperature deductive result showed that the average paddy field temperature in 2002 was 22.3 °C (sample area average), which was 7.7 °C lower than that of the building and road point and 4.3 °C lower than that of the bare land point. The average paddy field temperature in 2003 was 19.2 °C (sample area average), which was 10.1 °C lower than that of the building and road point and 8.3 °C lower than that of the bare land point. Then this study evaluated the economic valuation of the paddy field cooling effect using the contingent valuation method. Through the paddy field cooling effect and in the face of worsening extreme global climate, the willingness to pay (WTP) of the respondents in Taiwan for a decrease of 1 °C with regard to the regional microclimate was evaluated. It was found that people in Taiwan are willing to pay an extra 8.89 USD/per kg rice/year for the paddy for a decrease in temperature by 1 °C in the regional microclimate due to the paddy field. Furthermore, this study applied the benefits transfer method to evaluate the value of a decrease of 1 °C in the regional microclimate in Taiwan. The value of a decrease of 1 °C in the regional microclimate in Taiwan is 9,693,144,279 USD/year. In this regard, the economic value of 1 °C must not be underestimated. In conclusion, more caution is needed while making decisions to change the land use of paddy fields to other land uses.

Associated change in plantar temperature and sweating after transthoracic endoscopic T2–3 sympathectomy for palmar hyperhidrosis

2001 ◽  
Vol 95 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Han-Jung Chen ◽  
Cheng-Loong Liang ◽  
Kang Lu
Keyword(s):  
Skin Temperature ◽  
Temperature Change ◽  
The Body ◽  
Palmar Hyperhidrosis ◽  
Compensatory Sweating ◽  
Content Type ◽  
Postoperative Changes ◽  
The Face ◽  
The Difference ◽  
Fine Print

Object. Transthoracic endoscopic T2–3 sympathectomy is currently the treatment of choice for palmar hyperhidrosis. Compensatory sweating of the face, trunk, thigh, and sole of the foot was found in more than 50% of patients who underwent this procedure. The authors conducted this study to investigate the associated intraoperative changes in plantar skin temperature and postoperative plantar sweating. Methods. One hundred patients with palmar hyperhidrosis underwent bilateral transthoracic endoscopic T2–3 sympathectomy. There were 60 female and 40 male patients who ranged in age from 13 to 40 years (mean age 21.6 years). Characteristics studied included changes in palmar and plantar skin temperature measured intraoperatively, as well as pre- and postoperative changes in plantar sweating and sympathetic skin responses (SSRs). In 59 patients (59%) elevation of plantar temperature was demonstrated at the end of the surgical procedure. In this group, plantar sweating was found to be exacerbated in three patients (5%); plantar sweating was improved in 52 patients (88.1%); and no change was demonstrated in four patients (6.8%). In the other group of patients in whom no temperature change occurred, increased plantar sweating was demonstrated in three patients (7.3%); plantar sweating was improved in 20 patients (48.8%); and no change was shown in 18 patients (43.9%). The difference between temperature and sweating change was significant (p = 0.001). Compared with the presympathectomy rate, the rate of absent SSR also significantly increased after sympathectomy: from 20 to 76% after electrical stimulation and 36 to 64% after deep inspiration stimulation, respectively (p < 0.05). Conclusions. In contrast to compensatory sweating in other parts of the body after T2–3 sympathetomy, improvement in plantar sweating was shown in 72% and worsened symptoms in 6% of patients. The intraoperative plantar skin temperature change and perioperative SSR demonstrated a correlation between these changes.

3D Model Registration Based on Feature Extraction

2011 ◽  
Vol 299-300 ◽  
pp. 1091-1094 ◽  
Author(s):  
Jiang Zhu ◽  
Yuichi Takekuma ◽  
Tomohisa Tanaka ◽  
Yoshio Saito
Keyword(s):  
Feature Extraction ◽  
Point Cloud ◽  
3D Model ◽  
Point Cloud Data ◽  
Coordinate Systems ◽  
High Precision Measurement ◽  
Registration Method ◽  
Cloud Data ◽  
Cad System ◽  
Complicated Model

Currently, design and processing of complicated model are enabled by the progress of the CAD/CAM system. In shape measurement, high precision measurement is performed using CMM. In order to evaluate the machined part, the designed model made by CAD system the point cloud data provided by the measurement system are analyzed and compared. Usually, the designed CAD model and measured point cloud data are made in the different coordinate systems, it is necessary to register those models in the same coordinate system for evaluation. In this research, a 3D model registration method based on feature extraction and iterative closest point (ICP) algorithm is proposed. It could efficiently and accurately register two models in different coordinate systems, and effectively avoid the problem of localized solution.

Full-Waveform Terrestrial Lidar Data Classification Using Raw Samples of Digitized Waveform

2021 ◽  
Author(s):  
Mohammad Pashaei ◽  
Michael J. Starek ◽  
Philippe Tissot ◽  
Jacob Berryhill
Keyword(s):  
Data Classification ◽  
Lidar Data ◽  
Terrestrial Lidar ◽  
Full Waveform
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