scholarly journals UAV Approach for Detecting Plastic Marine Debris on the Beach: A Case Study in the Po River Delta (Italy)

Drones ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 140
Author(s):  
Yuri Taddia ◽  
Corinne Corbau ◽  
Joana Buoninsegni ◽  
Umberto Simeoni ◽  
Alberto Pellegrinelli

Anthropogenic marine debris (AMD) represent a global threat for aquatic environments. It is important to locate and monitor the distribution and presence of macroplastics along beaches to prevent degradation into microplastics (MP), which are potentially more harmful and more difficult to remove. UAV imaging represents a quick method for acquiring pictures with a ground spatial resolution of a few centimeters. In this work, we investigate strategies for AMD mapping on beaches with different ground resolutions and with elevation and multispectral data in support of RGB orthomosaics. Operators with varying levels of expertise and knowledge of the coastal environment map the AMD on four to five transects manually, using a range of photogrammetric tools. The initial survey was repeated after one year; in both surveys, beach litter was collected and further analyzed in the laboratory. Operators assign three levels of confidence when recognizing and describing AMD. Preliminary validation of results shows that items identified with high confidence were almost always classified properly. Approaching the detected items in terms of surface instead of a simple count increased the percentage of mapped litter significantly when compared to those collected. Multispectral data in near-infrared (NIR) wavelengths and digital surface models (DSMs) did not significantly improve the efficiency of manual mapping, even if vegetation features were removed using NDVI maps. In conclusion, this research shows that a good solution for performing beach AMD mapping can be represented by using RGB imagery with a spatial resolution of about 200 pix/m for detecting macroplastics and, in particular, focusing on the largest items. From the point of view of assessing and monitoring potential sources of MP, this approach is not only feasible but also quick, practical, and sustainable.

2012 ◽  
pp. 66-80
Author(s):  
Michał Mrozowicki

Michel Butor, born in 1926, one of the leaders of the French New Novel movement, has written only four novels between 1954 and 1960. The most famous of them is La Modification (Second thoughts), published in 1957. The author of the paper analyzes two other Butor’s novels: L’Emploi du temps (Passing time) – 1956, and Degrés (Degrees) – 1960. The theme of absence is crucial in both of them. In the former, the novel, presented as the diary of Jacques Revel, a young Frenchman spending a year in Bleston (a fictitious English city vaguely similar to Manchester), describes the narrator’s struggle to survive in a double – spatial and temporal – labyrinth. The first of them, formed by Bleston’s streets, squares and parks, is symbolized by the City plan. During his one year sojourn in the city, using its plan, Revel learns patiently how to move in its different districts, and in its strange labyrinth – strange because devoid any centre – that at the end stops annoying him. The other, the temporal one, symbolized by the diary itself, the labyrinth of the human memory, discovered by the narrator rather lately, somewhere in the middle of the year passed in Bleston, becomes, by contrast, more and more dense and complex, which is reflected by an increasinly complex narration used to describe the past. However, at the moment Revel is leaving the city, he is still unable to recall and to describe the events of the 29th of February 1952. This gap, this absence, symbolizes his defeat as the narrator, and, in the same time, the human memory’s limits. In Degrees temporal and spatial structures are also very important. This time round, however, the problems of the narration itself, become predominant. Considered from this point of view, the novel announces Gerard Genette’s work Narrative Discourse and his theoretical discussion of two narratological categories: narrative voice and narrative mode. Having transgressed his narrative competences, Pierre Vernier, the narrator of the first and the second parts of the novel, who, taking as a starting point, a complete account of one hour at school, tries to describe the whole world and various aspects of the human civilization for the benefit of his nephew, Pierre Eller, must fail and disappear, as the narrator, from the third part, which is narrated by another narrator, less audacious and more credible.


2014 ◽  
pp. 156-163
Author(s):  
Simona Jişa

Jean Echenoz’s text presents Victoria’s story who runs away from Paris, believing that she has killed her lover. Her straying (that embraces the form of a relative deterritorialization in a Deleuzian sense) lasts one year and it is built up geographically upon a descent (more or less symbolical) to the South of France and, after that, she comes back to Paris and encloses the spatial and textual curl. From a spatial point of view, she turns into a heterotopia (Foucault) every place where she is located, fact that reflects her incapability of constituting a personal, intimate space. The railway stations, the trains, the hotels, the improvised houses of those with no fixed abode are turning, according to Marc Augé’s terminology, into a « non-lieux » that excludes human being. Her vagrancy is characterized through a continuous flight from police and people and through a continuous decrease of her standard of living and dignity. It’s not about a quest of oneself, but about a loss of oneself. Urged by a strong feeling of culpability, her vagrancy is a self-punishment that comes to an end when the concerns of her problems disappear and she finds out that her lover is alive.


1991 ◽  
Vol 148 ◽  
pp. 205-206 ◽  
Author(s):  
A. Krabbe ◽  
J. Storey ◽  
V. Rotaciuc ◽  
S. Drapatz ◽  
R. Genzel

Images with subarcsec spatial resolution in the light of near-infrared atomic (Bry) and molecular hydrogen H2 (S(1) v=1-0) emission lines were obtained for some extended, pointlike objects in the Large Magellanic Cloud (LMC) for the first time. We used the Max-Planck-Institut für extraterrestrische Physik (MPE) near-infrared array spectrometer FAST (image scale 0.8”/pix, spectral resolving power 950) at the ESO/MPI 2.2m telescope, La Silla. We present some results on the 30-Dor complex and N159A5.


2021 ◽  
Vol 13 (10) ◽  
pp. 5518
Author(s):  
Honglyun Park ◽  
Jaewan Choi

Worldview-3 satellite imagery provides panchromatic images with a high spatial resolution and visible near infrared (VNIR) and shortwave infrared (SWIR) bands with a low spatial resolution. These images can be used for various applications such as environmental analysis, urban monitoring and surveying for sustainability. In this study, mineral detection was performed using Worldview-3 satellite imagery. A pansharpening technique was applied to the spatial resolution of the panchromatic image to effectively utilize the VNIR and SWIR bands of Worldview-3 satellite imagery. The following representative similarity analysis techniques were implemented for the mineral detection: the spectral angle mapper (SAM), spectral information divergence (SID) and the normalized spectral similarity score (NS3). In addition, pixels that could be estimated to indicate minerals were calculated by applying an empirical threshold to each similarity analysis result. A majority voting technique was applied to the results of each similarity analysis and pixels estimated to indicate minerals were finally selected. The results of each similarity analysis were compared to evaluate the accuracy of the proposed methods. From that comparison, it could be confirmed that false negative and false positive rates decreased when the methods proposed in the present study were applied.


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shulei Li ◽  
Mingcheng Panmai ◽  
Shaolong Tie ◽  
Yi Xu ◽  
Jin Xiang ◽  
...  

Abstract Metasurfaces composed of regularly arranged and deliberately oriented metallic nanoparticles can be employed to manipulate the amplitude, phase and polarization of an incident electromagnetic wave. The metasurfaces operating in the visible to near infrared spectral range rely on the modern fabrication technologies which offer a spatial resolution beyond the optical diffraction limit. Although direct laser writing is an alternative to the fabrication of nanostructures, the achievement of regular nanostructures with deep-subwavelength periods by using this method remains a big challenge. Here, we proposed and demonstrated a novel strategy for regulating disordered plasmonic nanoparticles into nanogratings with deep-subwavelength periods and reshaped nanoparticles by using femtosecond laser pulses. The orientations of the nanogratings depend strongly on the polarization of the femtosecond laser light. Such nanogratings exhibit reflection and polarization control over the reflected light, enabling the realization of polarization sensitive optical memory and color display with high spatial resolution and good chromacity.


2017 ◽  
Vol 14 (3) ◽  
pp. 228-240 ◽  
Author(s):  
Riana Rahmawati ◽  
Beata Bajorek

Objectives This study aimed to explore perspectives about hypertension from patients who do not take anti-hypertensive medications. Factors that shape their perspectives as well as patients’ expectations were also canvassed. Method Individual, face-to-face interviews were conducted with 30 people (≥45 years old) living in rural villages, diagnosed with hypertension, who had not taken any anti-hypertensive medications for at least one year. Interviews were audiotaped, transcribed verbatim and thematically analysed. Results Four themes emerged: (1) alternative medicines for managing high blood pressure; (2) accessing health care services; (3) the need for anti-hypertensive medications; and (4) existing support and patients’ expectations. Reluctance to take anti-hypertensive medications was influenced by patients’ beliefs in personal health threats and the effectiveness of anti-hypertensive medications, high self-efficacy for taking alternative medicines, the lack of recommendation regarding hypertension treatment, and barriers to accessing supplies of medicines. Conclusion Despite their awareness of being diagnosed with hypertension, patients undervalued visiting a health professional to control their high blood pressure. Health strategies need to consider patients’ beliefs, concerns and expectations. Providing an accessible, affordable and adequate supply of hypertension medication is also key to any programs designed to optimise hypertension management.


2021 ◽  
Author(s):  
Daisuke Kimura ◽  
Ikuo Fukuda ◽  
Takeshi Fujita ◽  
Reiichi Murakami ◽  
Norio Nakamura ◽  
...  

Abstract A pleuroperitoneal communication is a serious complication for patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Video-assisted thoracoscopic surgery is performed using indocyanine green adsorbed to human serum albumin fluorescence to identify the communication because human serum albumin reinforces fluorescence images. A patient diagnosed with a pleuroperitoneal communication was referred to our department and underwent surgery. To detect the communication, a dialysate mixture that contained indocyanine green and human serum albumin was injected from the CAPD catheter. Real-time fluorescence images were able to clearly show a bleb-like lesion with a near-infrared spectroscopy camera, and the site was repaired. The patient had no recurrence at one-year follow-up. This method might be good method for pleuroperitoneal communication surgery.


Solid Earth ◽  
2016 ◽  
Vol 7 (2) ◽  
pp. 323-340 ◽  
Author(s):  
Sascha Schneiderwind ◽  
Jack Mason ◽  
Thomas Wiatr ◽  
Ioannis Papanikolaou ◽  
Klaus Reicherter

Abstract. Two normal faults on the island of Crete and mainland Greece were studied to test an innovative workflow with the goal of obtaining a more objective palaeoseismic trench log, and a 3-D view of the sedimentary architecture within the trench walls. Sedimentary feature geometries in palaeoseismic trenches are related to palaeoearthquake magnitudes which are used in seismic hazard assessments. If the geometry of these sedimentary features can be more representatively measured, seismic hazard assessments can be improved. In this study more representative measurements of sedimentary features are achieved by combining classical palaeoseismic trenching techniques with multispectral approaches. A conventional trench log was firstly compared to results of ISO (iterative self-organising) cluster analysis of a true colour photomosaic representing the spectrum of visible light. Photomosaic acquisition disadvantages (e.g. illumination) were addressed by complementing the data set with active near-infrared backscatter signal image from t-LiDAR measurements. The multispectral analysis shows that distinct layers can be identified and it compares well with the conventional trench log. According to this, a distinction of adjacent stratigraphic units was enabled by their particular multispectral composition signature. Based on the trench log, a 3-D interpretation of attached 2-D ground-penetrating radar (GPR) profiles collected on the vertical trench wall was then possible. This is highly beneficial for measuring representative layer thicknesses, displacements, and geometries at depth within the trench wall. Thus, misinterpretation due to cutting effects is minimised. This manuscript combines multiparametric approaches and shows (i) how a 3-D visualisation of palaeoseismic trench stratigraphy and logging can be accomplished by combining t-LiDAR and GPR techniques, and (ii) how a multispectral digital analysis can offer additional advantages to interpret palaeoseismic and stratigraphic data. The multispectral data sets are stored allowing unbiased input for future (re)investigations.


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