scholarly journals Distinguishing Drones from Birds in a UAV Searching Laser Scanner Based on Echo Depolarization Measurement

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5597
Author(s):  
Jacek Wojtanowski ◽  
Marek Zygmunt ◽  
Tadeusz Drozd ◽  
Marcin Jakubaszek ◽  
Marek Życzkowski ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Cross Polarization ◽  
Negative Consequences ◽  
Polarization Ratio ◽  
Monitoring Equipment ◽  
The Past ◽  
Novel Approach ◽  
Widespread Availability ◽  
Illegal Activities

Widespread availability of drones is associated with many new fascinating possibilities, which were reserved in the past for few. Unfortunately, this technology also has many negative consequences related to illegal activities (surveillance, smuggling). For this reason, particularly sensitive areas should be equipped with sensors capable of detecting the presence of even miniature drones from as far away as possible. A few techniques currently exist in this field; however, all have significant drawbacks. This study addresses a novel approach for small (<5 kg) drones detection technique based on a laser scanning and a method to discriminate UAVs from birds. The latter challenge is fundamental in minimizing the false alarm rate in each drone monitoring equipment. The paper describes the developed sensor and its performance in terms of drone vs. bird discrimination. The idea is based on simple cross-polarization ratio analysis of the optical echo received as a result of laser backscattering on the detected object. The obtained experimental results show that the proposed method does not always guarantee 100 percent discrimination efficiency, but provides certain confidence level distribution. Nevertheless, due to the hardware simplicity, this approach seems to be a valuable addition to the developed anti-drone laser scanner.

Mobile robot motion control and autonomous navigation in GPS-denied outdoor environments using 3D laser scanning

2019 ◽  
Vol 39 (3) ◽  
pp. 469-478
Author(s):  
Qifeng Yang ◽  
Daokui Qu ◽  
Fang Xu ◽  
Fengshan Zou ◽  
Guojian He ◽  
...  
Keyword(s):  
Mobile Robot ◽  
Motion Control ◽  
Autonomous Navigation ◽  
Laser Scanning ◽  
Large Scale ◽  
Laser Scanner ◽  
Geometric Feature ◽  
Content Type ◽  
Localization Accuracy ◽  
Novel Approach

Purpose This paper aims to propose a series of approaches to solve the problem of the mobile robot motion control and autonomous navigation in large-scale outdoor GPS-denied environments. Design/methodology/approach Based on the model of mobile robot with two driving wheels, a controller is designed and tested in obstacle-cluttered scenes in this paper. By using the priori “topology-geometry” map constructed based on the odometer data and the online matching algorithm of 3D-laser scanning points, a novel approach of outdoor localization with 3D-laser scanner is proposed to solve the problem of poor localization accuracy in GPS-denied environments. A path planning strategy based on geometric feature analysis and priority evaluation algorithm is also adopted to ensure the safety and reliability of mobile robot’s autonomous navigation and control. Findings A series of experiments are conducted with a self-designed mobile robot platform in large-scale outdoor environments, and the experimental results show the validity and effectiveness of the proposed approach. Originality/value The problem of motion control for a differential drive mobile robot is investigated in this paper first. At the same time, a novel approach of outdoor localization with 3D-laser scanner is proposed to solve the problem of poor localization accuracy in GPS-denied environments. A path planning strategy based on geometric feature analysis and priority evaluation algorithm is also adopted to ensure the safety and reliability of mobile robot’s autonomous navigation and control.

scholarly journals Applicability of the Functional Resonance Analysis Method in urban transport

2018 ◽  
Vol 231 ◽  
pp. 05006 ◽  
Author(s):  
Piotr Smoczyński ◽  
Adam Kadziński ◽  
Adrian Gill ◽  
Kobaszyńska-Twardowska Anna
Keyword(s):  
Urban Transportation ◽  
Urban Transport ◽  
Negative Consequences ◽  
Analysis Method ◽  
Resonance Analysis ◽  
The Past ◽  
Novel Approach ◽  
Scientific World ◽  
High Level ◽  
Resilience Mechanisms

Functional resonance is a novel approach of explaining how adverse events happen in complex socio-technical systems. It stresses the fact that such systems in most of the cases function without any negative consequences due to their internal adaptiveness, called resilience. Therefore, this approach is particularly suitable to domains with relatively high level of safety, where there is not much data on incidents and accidents form the past. It can also be used for describing other analyses domains in order to better understand their resilience mechanisms. The literature review performed with help of Scopus database shows clearly that the topic of functional resonance is getting more and more attention in the scientific world. The research aiming to develop the FRAM or using it as a tool for various kinds of safety analyses is being published in the best journals from a variety of disciplines, especially the Engineering. Transportation system was the domain of the research in four investigated papers; three times the aviation transport and once – maritime transport. There was no publication in the urban transportation, although the FRAM is applicable also in this domain.

scholarly journals Concrete Preliminary Damage Inspection by Classification of Terrestrial Laser Scanner Point Clouds through Systematic Threshold Definition

2019 ◽  
Vol 8 (12) ◽  
pp. 585 ◽  
Author(s):  
Zahra Hadavandsiri ◽  
Derek D. Lichti ◽  
Adam Jahraus ◽  
David Jarron
Keyword(s):  
Structural Damage ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Concrete Structures ◽  
Principal Component ◽  
Point Clouds ◽  
Novel Approach ◽  
Robust Version ◽  
Systematic Point ◽  
Damage In Concrete

This paper presents a novel approach for automatic, preliminary detection of damage in concrete structures using ground-based terrestrial laser scanners. The method is based on computation of defect-sensitive features such as the surface curvature, since the surface roughness changes strongly if an area is affected by damage. A robust version of principal component analysis (PCA) classification is proposed to distinguish between structural damage and outliers present in the laser scanning data. Numerical simulations were conducted to develop a systematic point-wise defect classifier that automatically diagnoses the location of superficial damage on the investigated region. The method provides a complete picture of the surface health of concrete structures. It has been tested on two real datasets: a concrete heritage aqueduct in Brooks, Alberta, Canada; and a civil pedestrian concrete structure. The experiment results demonstrate the validity and accuracy of the proposed systematic framework for detecting and localizing areas of damage as small as 1 cm or less.

Identifying Seismic Local Collapse Mechanisms in Unreinforced Masonry Buildings through 3D Laser Scanning

2014 ◽  
Vol 628 ◽  
pp. 79-84 ◽  
Author(s):  
Chiara Andreotti ◽  
Domenico Liberatore ◽  
Luigi Sorrentino
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Unreinforced Masonry ◽  
Earthquake Ground Motion ◽  
Collapse Mechanism ◽  
Masonry Buildings ◽  
Survey Techniques ◽  
The Past ◽  
Collapse Mechanisms ◽  
2009 L’Aquila Earthquake

The surveys following severe earthquakes show that existing unreinforced masonry buildings are highly vulnerable to local collapse mechanisms. However, their assessment is strongly sensitive to the choice of the mechanism, whose boundary conditions are largely unknown. In the past the mechanism has been selected based on the crack survey alone, because the survey of the deformations is very difficult if traditional tools are used. In the last years advanced survey techniques have been developed, the most powerful of whom resorts to laser scanning. A laser scanner allows the acquisitions of a very large amount of information: building overall dimensions and single elements detailed survey, detection of anomalies, and identification of very limited deformations undetectable with the naked eye. Moreover, contrary to traditional procedures, it allows the survey of the façades without any direct contact with the building, which could be damaged after an earthquake. A laser-scanner survey has been performed in the whole historical centre of Rovere, in the municipality of Rocca di Mezzo, affected by the 2009 L’Aquila earthquake. This survey has been used to study the façades of three different building units, recognising the collapse mechanism triggered by the earthquake ground motion. The mechanisms are fairly different from what suggested by the crack pattern alone and pertain to deformations that cannot be recognised in the photos. Moreover, the faithful geometric models that can be generated from laser scanning allow accounting for deformations and out-of-plumb. Thus, the acceleration activating the mechanism can be estimated much more accurately compared to a perfectly vertical and parallelepiped wall.

The consolidation of microscopy technology into a university research support facility: Reflections on the 1980's and projections for the 1990's at the university of iowa

1993 ◽  
Vol 51 ◽  
pp. 476-477
Author(s):  
Kenneth C. Moore
Keyword(s):  
Laser Scanning ◽  
Freeze Fracture ◽  
Freeze Substitution ◽  
Research Support ◽  
University Of Iowa ◽  
Staff Members ◽  
The Past ◽  
Research Grade ◽  
The University ◽  
Support Facility

The University of Iowa Central Electron Microscopy Research Facility(CEMRF) was established in 1981 to support all faculty, staff and students needing this technology. Initially the CEMRF was operated with one TEM, one SEM, three staff members and supported about 30 projects a year. During the past twelve years, the facility has replaced all instrumentation pre-dating 1981, and now includes 2 TEM's, 2 SEM's, 2 EDS systems, cryo-transfer specimen holders for both TEM and SEM, 2 parafin microtomes, 4 ultamicrotomes including cryoultramicrotomy, a Laser Scanning Confocal microscope, a research grade light microscope, an Ion Mill, film and print processing equipment, a rapid cryo-freezer, freeze substitution apparatus, a freeze-fracture/etching system, vacuum evaporators, sputter coaters, a plasma asher, and is currently evaluating scanning probe microscopes for acquisition. The facility presently consists of 10 staff members and supports over 150 projects annually from 44 departments in 5 Colleges and 10 industrial laboratories. One of the unique strengths of the CEMRF is that both Biomedical and Physical scientists use the facility.

Fenny Roshayanti: A Biography of Science Educator for Our Time

2019 ◽  
Author(s):  
Adib Rifqi Setiawan
Keyword(s):  
Sampling Technique ◽  
Science Educator ◽  
Data Sources ◽  
Negative Consequences ◽  
Academic Advisor ◽  
External Audit ◽  
Narrative Approaches ◽  
The Past ◽  
Science Technology ◽  
And Mathematics

STEAM is an acronym for Science, Technology, Engineering, Art, Mathematics. STEAM defined as the integration of science, technology, engineering, art, and mathematics into a new cross-disciplinary subject in schools. The concept of integrating subjects in Indonesian schools, generally is not new and has not been very successful in the past. Some people consider STEAM as an opportunity while others view it as having problems. Fenny Roshayanti is science educator and researcher that consider STEAM as an opportunity. She has involved the study of STEAM, as an author, educator, academic advisor, and seminar speaker. This article examines what it has been and continues work from Fenny Roshayanti in the science education. Our exploration uses qualitative methods of narrative approaches in the form of biographical studies. Participants as data sources were selected using a purposive sampling technique which was collected based on retrospective interview and naturalistic observation. Data's validity, reliability, and objectivity checked by using external audit techniques. This work explores the powerful of female’s personal style in developing a form of social influence based on her forms of capital as well as address the positive and negative consequences that may follow while implement and research STEAM in teaching classroom.

Results of studying the dimensional accuracy of the bases of complete removable prostheses made using 3D printing and traditional technologies

2020 ◽  
pp. 34-39
Author(s):  
Vokulova Yu.A. Vokulova ◽  
E.N. Zhulev
Keyword(s):  
3D Printing ◽  
Traditional Method ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Digital Technologies ◽  
Dimensional Accuracy ◽  
3D Printer ◽  
Significance Level ◽  
Average Value ◽  
The Difference

This article presents the results of studying the dimensional accuracy of the bases of complete removable prostheses made using a 3D printer and the traditional method. Bases of complete removable prostheses were made using an intraoral laser scanner iTero Cadent (USA) and a 3D printer Asiga Max UV (Australia). To study the dimensional accuracy of the bases of complete removable prostheses, we used the DentalCAD 2.2 Valletta software. The Nonparametric Wilcoxon W-test was used for statistical analysis of the obtained data. We found that the average value of the difference with the standard for bases made using digital technologies is 0.08744±0.0484 mm. The average value of the difference with the standard for bases made by the traditional method is 0.5654±0.1611 mm. Based on these data, we concluded that the bases of complete removable prostheses made using modern digital technologies (intraoral laser scanning and 3D printer) have a higher dimensional accuracy compared to the bases of complete removable prostheses made using the traditional method with a significance level of p<0.05 (Wilcoxon's W-test=0, p=0.031). Keywords: digital technologies in dentistry, digital impressions, intraoral scanner, 3D printing, ExoCAD, complete removable dentures.

Extraordinary circumstances: Covid-19 – Italian Serie A scenario

2021 ◽  
pp. 175433712110192
Author(s):  
Milan Radojicic ◽  
Aleksandar Djokovic ◽  
Nikola Cvetkovic
Keyword(s):  
Cluster Analysis ◽  
Hierarchical Cluster Analysis ◽  
Hierarchical Cluster ◽  
Round Robin ◽  
The Past ◽  
Novel Approach ◽  
Round Robin Tournaments

Unpredictable and uncontrollable situations have happened throughout history. Inevitably, such situations have an impact on various spheres of life. The coronavirus disease 2019 has affected many of them, including sports. The ban on social gatherings has caused the cancellation of many sports competitions. This paper proposes a methodology based on hierarchical cluster analysis (HCA) that can be applied when a need occurs to end an interrupted tournament and the conditions for playing the remaining matches are far from ideal. The proposed methodology is based on how to conclude the season for Serie A, a top-division football league in Italy. The analysis showed that it is reasonable to play 14 instead of the 124 remaining matches of the 2019–2020 season to conclude the championship. The proposed methodology was tested on the past 10 seasons of the Serie A, and its effectiveness was confirmed. This novel approach can be used in any other sport where round-robin tournaments exist.

scholarly journals Estimation of Vegetation-Induced Flow Resistance for Hydraulic Computations Using Airborne Laser Scanning Data

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1864
Author(s):  
Peter Mewis
Keyword(s):  
Laser Scanning ◽  
Flow Resistance ◽  
Laser Scanner ◽  
Airborne Laser Scanning ◽  
Density Parameter ◽  
Vegetation Density ◽  
Airborne Laser Scanner ◽  
Airborne Laser ◽  
Bed Roughness ◽  
Available Information

The effect of vegetation in hydraulic computations can be significant. This effect is important for flood computations. Today, the necessary terrain information for flood computations is obtained by airborne laser scanning techniques. The quality and density of the airborne laser scanning information allows for more extensive use of these data in flow computations. In this paper, known methods are improved and combined into a new simple and objective procedure to estimate the hydraulic resistance of vegetation on the flow in the field. State-of-the-art airborne laser scanner information is explored to estimate the vegetation density. The laser scanning information provides the base for the calculation of the vegetation density parameter ωp using the Beer–Lambert law. In a second step, the vegetation density is employed in a flow model to appropriately account for vegetation resistance. The use of this vegetation parameter is superior to the common method of accounting for the vegetation resistance in the bed resistance parameter for bed roughness. The proposed procedure utilizes newly available information and is demonstrated in an example. The obtained values fit very well with the values obtained in the literature. Moreover, the obtained information is very detailed. In the results, the effect of vegetation is estimated objectively without the assignment of typical values. Moreover, a more structured flow field is computed with the flood around denser vegetation, such as groups of bushes. A further thorough study based on observed flow resistance is needed.

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