DIGITAL IMAGE ANALYSIS OF THE VISIBLE REGION THROUGH SIMULATION OF ROCK ART PAINTINGS

Non-destructive rock art recording techniques are getting special attention in the last years, opening new research lines in order to improve the level of documentation and understanding of our rich legacy. This paper applies the principal component analysis (PCA) technique in images that include wavelengths between 400-700 nm (visible range). Our approach is focused on determining the difference provided by the image processing of the visible region through four spectral images versus an image that encompasses the entire visible spectrum. The images were taken by means of optical filters that take specific wavelengths and exclude parts of the spectrum. Simulation of rock art is prepared in laboratory. For this purpose, three different pigments were made simulating the material composition of rock art paintings. The advantages of studying the visible spectrum in separate images are analysed. In addition, PCA is applied to each of the images to reduce redundant data. Finally, PCA is applied to the image that contains the entire visible spectrum and is compared with previous results. Through the results of the four visible spectral images one can begin to draw conclusions about constituent painting materials without using decorrelation techniques.

Download Full-text

ANÁLISIS DE COMPONENTES PRINCIPALES DE IMÁGENES MULTIESPECTRALES EN EL ÁMBITO DEL ARTE RUPESTRE

Proceedings - 1st Congress in Geomatics Engineering - CIGeo ◽

10.4995/cigeo2017.2017.6597 ◽

2017 ◽

Author(s):

Berta Carrión-Ruiz ◽

José Luis Lerma

Keyword(s):

Principal Component Analysis ◽

Near Infrared ◽

Rock Art ◽

Visible Region ◽

Principal Component ◽

Optical Filters ◽

Infrared Region ◽

Spectral Behaviour ◽

Near Infrared Region ◽

Art Analysis

This paper tackles principal component analysis (PCA) in images that include wavelengths between 380-1000 nm. Our approach is focussed on taking advantage of the potencial of ultraviolet and infrarred images, in combination with the visible ones, to improve documentation process and rock art analysis. In this way, we want to improve the discrimination between pigment and support rock, and analyse the spectral behaviour of rock art paintings in the ultraviolet and infrared regions. Three images were used, one image from the ultraviolet (UV) region, one from the visible region (VIS) and another one from the near infrared region (NIR). Optical filters coupled to the camera optics were used to take the images. These filters capture specific wavelengths excluding radiation that we are not interested in registering. Finally, PCA is applied to the acquired images. The results obtained demonstrate the PCA usefulness with imagery in this field and also it is possible to extract some conclusions about the correspondent paint pigments.http://dx.doi.org/10.4995/CIGeo2017.2017.6597

Download Full-text

Tunable Faraday rotation of ferromagnet thin film in whole visible region coupled with aluminum plasmonic arrays

Nanophotonics ◽

10.1515/nanoph-2021-0327 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Feifei Zhang ◽

Taisuke Atsumi ◽

Xiaolun Xu ◽

Shunsuke Murai ◽

Katsuhisa Tanaka

Keyword(s):

Faraday Rotation ◽

Noble Metals ◽

Spectral Response ◽

Visible Region ◽

Visible Spectrum ◽

Ferromagnetic Film ◽

Visible Range ◽

Plasmonic Nanostructures ◽

Blue Range ◽

Dielectric Environment

Abstract To date, the plasmonic nanostructure utilized for magneto-optical (MO) enhancement has been limited to noble metals with resulted enhancement in the green-red part of visible spectrum. In this study, we fabricated a diffractive hexagonal array composed of Al nanoparticles (NPs) with a thin 7.5 nm ferromagnetic film and pushed the enhanced Faraday rotation (FR) into the blue to green range of the visible light. The freedom and ability to control the working spectral region in the whole visible range from 400 to 800 nm were also demonstrated by changing the lattice constant and the dielectric environment of plasmonic nanostructures. Particularly, in the blue range we obtained the maximum FR 0.57° at 410 nm with a broad boosting region around 0.5° from 400 to 500 nm. Moreover, the largest FR 1.66° was shown at 638 nm by tuning the dielectric environment into a higher refractive index medium. The results of our investigation demonstrate the potential of Al-based magnetoplasmonic effect and offer opportunities to push the MO spectral response out of visible range into the ultraviolet-blue range.

Download Full-text

Multivariate micropollutants analysis in marine waters

Water Science & Technology ◽

10.2166/wst.1995.0701 ◽

1995 ◽

Vol 32 (9-10) ◽

pp. 341-348

Author(s):

V. Librando ◽

G. Magazzù ◽

A. Puglisi

Keyword(s):

Multivariate Data Analysis ◽

Partial Least Squares Regression ◽

Environmental Chemistry ◽

Sampling Site ◽

Principal Component ◽

Least Squares Regression ◽

Organic Micropollutants ◽

Suspended Material ◽

The Difference

The monitoring of water quality today provides a great quantity of data consisting of the values of the parameters measured as a function of time. In the marine environment, and especially in the suspended material, increasing importance is being given to the presence of organic micropollutants, particularly since some are known to be carcinogenic. As the number of measured parameters increases examining the data and their consequent interpretation becomes more difficult. To overcome such difficulties, numerous chemometric techniques have been introduced in environmental chemistry, such as Multivariate Data Analysis (MVDA), Principal Component Analysis (PCA) and Partial Least Squares Regression (PLSR). The use of the first technique in this work has been applied to the interpretation of the quality of Augusta bay, by measuring the concentration of numerous organic micropollutants, together with the classical water pollution parameters, in different sites and at different times. The MVDA has highlighted the difference between various sampling sites whose data were initially thought to be similar. Furthermore, it has allowed a choice of more significant parameters for future monitoring and more suitable sampling site locations.

Download Full-text

Distribution and Severity of Placental Lesions Caused by the Chlamydia abortus 1B Vaccine Strain in Vaccinated Ewes

Pathogens ◽

10.3390/pathogens10050543 ◽

2021 ◽

Vol 10 (5) ◽

pp. 543

Author(s):

Sergio Gastón Caspe ◽

Javier Palarea-Albaladejo ◽

Clare Underwood ◽

Morag Livingstone ◽

Sean Ranjan Wattegedera ◽

...

Keyword(s):

Disease Outbreaks ◽

Principal Component ◽

Placental Pathology ◽

Wild Type ◽

Cell Infiltrate ◽

Chlamydia Abortus ◽

Vaccine Type ◽

The Difference ◽

Enzootic Abortion Of Ewes

Chlamydia abortus infects livestock species worldwide and is the cause of enzootic abortion of ewes (EAE). In Europe, control of the disease is achieved using a live vaccine based on C. abortus 1B strain. Although the vaccine has been useful for controlling disease outbreaks, abortion events due to the vaccine have been reported. Recently, placental pathology resulting from a vaccine type strain (vt) infection has been reported and shown to be similar to that resulting from a natural wild-type (wt) infection. The aim of this study was to extend these observations by comparing the distribution and severity of the lesions, the composition of the predominating cell infiltrate, the amount of bacteria present and the role of the blood supply in infection. A novel system for grading the histological and pathological features present was developed and the resulting multi-parameter data were statistically transformed for exploration and visualisation through a tailored principal component analysis (PCA) to evaluate the difference between them. The analysis provided no evidence of meaningful differences between vt and wt strains in terms of the measured pathological parameters. The study also contributes a novel methodology for analysing the progression of infection in the placenta for other abortifacient pathogens.

Download Full-text

Possibility of Human Gender Recognition Using Raman Spectra of Teeth

Molecules ◽

10.3390/molecules26133983 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3983

Author(s):

Ozren Gamulin ◽

Marko Škrabić ◽

Kristina Serec ◽

Matej Par ◽

Marija Baković ◽

...

Keyword(s):

Raman Spectra ◽

Principal Component ◽

Support Vector ◽

Gender Recognition ◽

Proof Of Concept ◽

Male And Female ◽

Tooth Type ◽

Tooth Apex ◽

The Difference

Gender determination of the human remains can be very challenging, especially in the case of incomplete ones. Herein, we report a proof-of-concept experiment where the possibility of gender recognition using Raman spectroscopy of teeth is investigated. Raman spectra were recorded from male and female molars and premolars on two distinct sites, tooth apex and anatomical neck. Recorded spectra were sorted into suitable datasets and initially analyzed with principal component analysis, which showed a distinction between spectra of male and female teeth. Then, reduced datasets with scores of the first 20 principal components were formed and two classification algorithms, support vector machine and artificial neural networks, were applied to form classification models for gender recognition. The obtained results showed that gender recognition with Raman spectra of teeth is possible but strongly depends both on the tooth type and spectrum recording site. The difference in classification accuracy between different tooth types and recording sites are discussed in terms of the molecular structure difference caused by the influence of masticatory loading or gender-dependent life events.

Download Full-text

Spatial multiplexing holographic combiner for glasses-free augmented reality

Nanophotonics ◽

10.1515/nanoph-2020-0243 ◽

2020 ◽

Vol 9 (9) ◽

pp. 3003-3010

Author(s):

Jiacheng Shi ◽

Wen Qiao ◽

Jianyu Hua ◽

Ruibin Li ◽

Linsen Chen

Keyword(s):

Augmented Reality ◽

Large Scale ◽

Motion Parallax ◽

Visible Spectrum ◽

Physical World ◽

Spatial Multiplexing ◽

White Balance ◽

Full Color ◽

Entire Visible Spectrum ◽

3D Scene

AbstractGlasses-free augmented reality is of great interest by fusing virtual 3D images naturally with physical world without the aid of any wearable equipment. Here we propose a large-scale spatial multiplexing holographic see-through combiner for full-color 3D display. The pixelated metagratings with varied orientation and spatial frequency discretely reconstruct the propagating lightfield. The irradiance pattern of each view is tailored to form super Gaussian distribution with minimized crosstalk. What’s more, spatial multiplexing holographic combiner with customized aperture size is adopted for the white balance of virtually displayed full-color 3D scene. In a 32-inch prototype, 16 views form a smooth parallax with a viewing angle of 47°. A high transmission (>75%) over the entire visible spectrum range is achieved. We demonstrated that the displayed virtual 3D scene not only preserved natural motion parallax, but also mixed well with the natural objects. The potential applications of this study include education, communication, product design, advertisement, and head-up display.

Download Full-text

Pandemic of Childhood Myopia. Could New Indoor LED Lighting Be Part of the Solution?

Energies ◽

10.3390/en14133827 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3827

Author(s):

David Baeza Moyano ◽

Roberto Alonso González-Lezcano

Keyword(s):

Technological Progress ◽

Visible Spectrum ◽

Visible Range ◽

Natural Light ◽

Genetic Origin ◽

Led Lighting ◽

Health Authorities ◽

The World ◽

Children’S Work ◽

Possible Cause

The existence of a growing myopia pandemic is an unquestionable fact for health authorities around the world. Different possible causes have been put forward over the years, such as a possible genetic origin, the current excess of children’s close-up work compared to previous stages in history, insufficient natural light, or a multifactorial cause. Scientists are looking for different possible solutions to alleviate it, such as a reduction of time or a greater distance for children’s work, the use of drugs, optometric correction methods, surgical procedures, and spending more time outdoors. There is a growing number of articles suggesting insufficient natural light as a possible cause of the increasing levels of childhood myopia around the globe. Technological progress in the world of lighting is making it possible to have more monochromatic LED emission peaks, and because of this, it is possible to create spectral distributions of visible light that increasingly resemble natural light in the visible range. The possibility of creating indoor luminaires that emit throughout the visible spectrum from purple to infrared can now be a reality that could offer a new avenue of research to fight this pandemic.

Download Full-text

Changes in Phenols, Polysaccharides and Volatile Profiles of Noni (Morinda citrifolia L.) Juice during Fermentation

Molecules ◽

10.3390/molecules26092604 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2604

Author(s):

Zhulin Wang ◽

Rong Dou ◽

Ruili Yang ◽

Kun Cai ◽

Congfa Li ◽

...

Keyword(s):

Octanoic Acid ◽

Solid Phase ◽

Principal Component ◽

Hexanoic Acid ◽

Morinda Citrifolia ◽

Gas Chromatography Mass Spectrometry ◽

Aroma Characteristics ◽

Volatile Profiles ◽

The Difference ◽

Aroma Components

The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.

Download Full-text

Rhodanine-based dyes absorbing in the entire visible spectrum

Organic Chemistry Frontiers ◽

10.1039/c6qo00760k ◽

2017 ◽

Vol 4 (6) ◽

pp. 1024-1028 ◽

Cited By ~ 3

Author(s):

Rafael Sandoval-Torrientes ◽

Joaquín Calbo ◽

David García-Fresnadillo ◽

José Santos ◽

Enrique Ortí ◽

...

Keyword(s):

Optical Properties ◽

Dft Calculations ◽

Electrochemical Characterizations ◽

Visible Spectrum ◽

Electronic And Optical Properties ◽

Entire Visible Spectrum

A series of new broad-absorbing rhodanine-fluorene dyes conjugated with triarylamines are presented. Spectroscopic and electrochemical characterizations, along with theoretical DFT calculations, unveil the electronic and optical properties of the dyes.

Download Full-text

Analyzing Satellite Ocean Color Match-Up Protocols Using the Satellite Validation Navy Tool (SAVANT) at MOBY and Two AERONET-OC Sites

Remote Sensing ◽

10.3390/rs13142673 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2673

Author(s):

Adam Lawson ◽

Jennifer Bowers ◽

Sherwin Ladner ◽

Richard Crout ◽

Christopher Wood ◽

...

Keyword(s):

Infrared Imaging ◽

Ocean Color ◽

Visible Spectrum ◽

Ground Truth ◽

Naval Research ◽

Satellite Validation ◽

The Difference ◽

Stability And Accuracy ◽

Satellite Ocean Color

The satellite validation navy tool (SAVANT) was developed by the Naval Research Laboratory to help facilitate the assessment of the stability and accuracy of ocean color satellites, using numerous ground truth (in situ) platforms around the globe and support methods for match-up protocols. The effects of varying spatial constraints with permissive and strict protocols on match-up uncertainty are evaluated, in an attempt to establish an optimal satellite ocean color calibration and validation (cal/val) match-up protocol. This allows users to evaluate the accuracy of ocean color sensors compared to specific ground truth sites that provide continuous data. Various match-up constraints may be adjusted, allowing for varied evaluations of their effects on match-up data. The results include the following: (a) the difference between aerosol robotic network ocean color (AERONET-OC) and marine optical Buoy (MOBY) evaluations; (b) the differences across the visible spectrum for various water types; (c) spatial differences and the size of satellite area chosen for comparison; and (d) temporal differences in optically complex water. The match-up uncertainty analysis was performed using Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) SNPP data at the AERONET-OC sites and the MOBY site. It was found that the more permissive constraint sets allow for a higher number of match-ups and a more comprehensive representation of the conditions, while the restrictive constraints provide better statistical match-ups between in situ and satellite sensors.

Download Full-text