scholarly journals Non-Linear Spectral Unmixing for the Estimation of the Distribution of Graphene Oxide Deposition on 3D Printed Composites

2020 ◽  
Vol 10 (21) ◽  
pp. 7792
Author(s):  
Giorgio Licciardi ◽  
Costantino Del Gaudio ◽  
Jocelyn Chanussot
Keyword(s):  
Graphene Oxide ◽  
Hyperspectral Imaging ◽  
Materials Science ◽  
Hyperspectral Image ◽  
Polymer Matrix Composites ◽  
Spectral Unmixing ◽  
Science Field ◽  
Hyperspectral Image Analysis ◽  
Custom Made ◽  
3D Printed

Hyperspectral analysis is a well-established technique that can be suitably implemented in several application fields, including materials science. This approach allows us to deal with data samples containing spatial and spectral information at very high resolution, thus enabling us to evaluate materials properties at a nanoscale level. As a proof of concept, hyperspectral imaging was here considered to investigate 3D printed polymer matrix composites, considering graphene oxide (GO) as a nanofiller. Commercial polycaprolactone and polylactic acid filaments were firstly treated with GO to be then printed into testing specimens. Raman analysis was performed to assess the GO distribution on samples surface by mapping different regions of interest and the collected data were the input of a custom-made algorithm for hyperspectral image analysis, tailored to detect the GO signature. Findings showed a valuable matching to Raman maps and were also characterized by the positive feature of avoiding to set specific conditions to perform the investigation as GO Raman distribution was carried out by fixing the wavenumber at 1580 cm−1, which is representative of the G band of the nanofiller. This occurrence might lead to an uneven intensity representation related to possible peak shifts which can bias the acquired results. Differently, hyperspectral imaging needs a minimal set of data input, i.e., the spectral signatures of neat materials, to directly identify the searched nanomaterial. More in-depth investigations need to be performed to fully validate the proposed approach, but the here presented results already show the potential and versatility of hyperspectral analysis in the materials science field.

scholarly journals Determining the composition of an object based on its hyperspectral image

2021 ◽  
Vol 45 (3) ◽  
pp. 394-398
Author(s):  
A.V. Demin ◽  
E.N. Sechak ◽  
S.P. Prisyazhnyuk
Keyword(s):  
Mathematical Model ◽  
Image Analysis ◽  
Hyperspectral Imaging ◽  
Spectral Range ◽  
Hyperspectral Image ◽  
Operating Conditions ◽  
Imaging Spectrometer ◽  
Percentage Content ◽  
Hyperspectral Image Analysis ◽  
Object Based

The article presents results of the development and research of a hyperspectral imaging spectrometer for analyzing borehole fluids in real operating conditions in the spectral range from 0.35 microns to 2.1 microns. A mathematical model and an algorithm for identifying the borehole fluid by composition and percentage content based on the results of hyperspectral image analysis are developed.

scholarly journals Estimation of the Number of Endmembers in Hyperspectral Images Using Agglomerative Clustering

2020 ◽  
Vol 12 (21) ◽  
pp. 3585
Author(s):  
José Prades ◽  
Gonzalo Safont ◽  
Addisson Salazar ◽  
Luis Vergara
Keyword(s):  
Independent Component Analysis ◽  
Hyperspectral Imaging ◽  
Hyperspectral Image ◽  
Spectral Unmixing ◽  
Independent Component ◽  
Hyperspectral Images ◽  
Agglomerative Clustering ◽  
Number Of Clusters ◽  
Knowing How ◽  
Pixel Matching

Many tasks in hyperspectral imaging, such as spectral unmixing and sub-pixel matching, require knowing how many substances or materials are present in the scene captured by a hyperspectral image. In this paper, we present an algorithm that estimates the number of materials in the scene using agglomerative clustering. The algorithm is based on the assumption that a valid clustering of the image has one cluster for each different material. After reducing the dimensionality of the hyperspectral image, the proposed method obtains an initial clustering using K-means. In this stage, cluster densities are estimated using Independent Component Analysis. Based on the K-means result, a model-based agglomerative clustering is performed, which provides a hierarchy of clusterings. Finally, a validation algorithm selects a clustering of the hierarchy; the number of clusters it contains is the estimated number of materials. Besides estimating the number of endmembers, the proposed method can approximately obtain the endmember (or spectrum) of each material by computing the centroid of its corresponding cluster. We have tested the proposed method using several hyperspectral images. The results show that the proposed method obtains approximately the number of materials that these images contain.

scholarly journals VALIDATION OF EXTRACTED ENDMEMBERS FROM HYPERSPECTRAL IMAGES

2019 ◽  
Vol XLII-4/W18 ◽  
pp. 989-992
Author(s):  
A. Sharifi ◽  
M. Hosseingholizadeh
Keyword(s):  
Image Classification ◽  
Hyperspectral Image ◽  
Accuracy Assessment ◽  
Extraction Methods ◽  
Primary Objective ◽  
Spectral Unmixing ◽  
Endmember Extraction ◽  
Hyperspectral Image Classification ◽  
Hyperspectral Image Analysis ◽  
Maximum Angle

Abstract. An essential step in the characterization of surface materials using hyperspectral image analysis is image classification using endmembers. Spectral unmixing is the best method for hyperspectral image classification. This method assumes that the pixel-topixel variability in scene results from varying proportions of spectral endmembers. Spectral endmembers can be derived from the imagery or measurements in the laboratory or field. The primary objective of this paper was to assess the ability of extracted endmembers against some different solutions for extraction of endmembers for hyperspectral image classification. In this paper, we compared the Pixel Purity Index (PPI) and the Sequential Maximum Angle Convex Cone (SMACC) as two popular methods of endmember extraction with library and field spectral. We used spectral information divergence for detection desirable endmembers from field spectral. For accuracy assessment of spectral mixture analysis and production of endmember abundance images for each of methods, the linear spectral unmixing algorithm is used. After a comparison between the results of these methods, it has been verified that field spectral have a better classification result in comparing with other endmember extraction methods. Also, the PPI has reliable results as an automatic endmember extraction method in comparing.

Development of high-performance objective lens polepiece for ultrahigh resolution Analytical Electron Microscope

1993 ◽  
Vol 51 ◽  
pp. 254-255
Author(s):  
K. Fukushima ◽  
T. Kaneyama ◽  
F. Hosokawa ◽  
H. Tsuno ◽  
T. Honda ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Performance ◽  
Open Space ◽  
Materials Science ◽  
Objective Lens ◽  
Ultrahigh Resolution ◽  
Science Field ◽  
Specimen Holder ◽  
Analytical Electron ◽  
Analytical Electron Microscope

Recently, in the materials science field, the ultrahigh resolution analytical electron microscope (UHRAEM) has become a very important instrument to study extremely fine areas of the specimen. The requirements related to the performance of the UHRAEM are becoming gradually severer. Some basic characteristic features required of an objective lens are as follows, and the practical performance of the UHRAEM should be judged by totally evaluating them.1) Ultrahigh resolution to resolve ultrafine structure by atomic-level observation.2) Nanometer probe analysis to analyse the constituent elements in nm-areas of the specimen.3) Better performance of x-ray detection for EDS analysis, that is, higher take-off angle and larger detection solid angle.4) Higher specimen tilting angle to adjust the specimen orientation.To attain these requirements simultaneously, the objective lens polepiece must have smaller spherical and chromatic aberration coefficients and must keep enough open space around the specimen holder in it.

scholarly journals Trends in Deep Learning for Medical Hyperspectral Image Analysis

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Uzair Khan ◽  
Sidike Paheding ◽  
Colin Elkin ◽  
Vijay Devabhaktuni
Keyword(s):  
Image Analysis ◽  
Deep Learning ◽  
Hyperspectral Image ◽  
Hyperspectral Image Analysis

scholarly journals 3D Printed Clamps for In Vitro Tensile Tests of Human Gracilis and the Superficial Third of Quadriceps Tendons

2021 ◽  
Vol 11 (6) ◽  
pp. 2563
Author(s):  
Ivan Grgić ◽  
Vjekoslav Wertheimer ◽  
Mirko Karakašić ◽  
Željko Ivandić
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Tensile Tests ◽  
Biomechanical Properties ◽  
Testing Procedure ◽  
Laboratory Equipment ◽  
Fused Deposition ◽  
Custom Made ◽  
3D Printed

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

scholarly journals Detecting Bacterial Biofilms Using Fluorescence Hyperspectral Imaging and Various Discriminant Analyses

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2213
Author(s):  
Ahyeong Lee ◽  
Saetbyeol Park ◽  
Jinyoung Yoo ◽  
Jungsook Kang ◽  
Jongguk Lim ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Hyperspectral Imaging ◽  
Food Processing ◽  
Nearest Neighbor ◽  
Hyperspectral Image ◽  
Uv Light ◽  
Hyperspectral Images ◽  
K Nearest Neighbor ◽  
E Coli ◽  
Discriminant Analyses

Biofilms formed on the surface of agro-food processing facilities can cause food poisoning by providing an environment in which bacteria can be cultured. Therefore, hygiene management through initial detection is important. This study aimed to assess the feasibility of detecting Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium) on the surface of food processing facilities by using fluorescence hyperspectral imaging. E. coli and S. typhimurium were cultured on high-density polyethylene and stainless steel coupons, which are the main materials used in food processing facilities. We obtained fluorescence hyperspectral images for the range of 420–730 nm by emitting UV light from a 365 nm UV light source. The images were used to perform discriminant analyses (linear discriminant analysis, k-nearest neighbor analysis, and partial-least squares discriminant analysis) to identify and classify coupons on which bacteria could be cultured. The discriminant performances of specificity and sensitivity for E. coli (1–4 log CFU·cm−2) and S. typhimurium (1–6 log CFU·cm−2) were over 90% for most machine learning models used, and the highest performances were generally obtained from the k-nearest neighbor (k-NN) model. The application of the learning model to the hyperspectral image confirmed that the biofilm detection was well performed. This result indicates the possibility of rapidly inspecting biofilms using fluorescence hyperspectral images.

scholarly journals Recurrent contracted sockets treated with personalized, three-dimensionally printed conformers and buccal grafts

2021 ◽  
pp. 112067212110000
Author(s):  
Annabel LW Groot ◽  
Jelmer S Remmers ◽  
Roel JHM Kloos ◽  
Peerooz Saeed ◽  
Dyonne T Hartong
Keyword(s):  
Three Dimensional ◽  
Case Series ◽  
Secondary Outcome ◽  
Retrospective Case ◽  
Upper Eyelid ◽  
Ocular Prosthesis ◽  
Buccal Mucosal Graft ◽  
Custom Made ◽  
3D Printed

Purpose: Recurrent contracted sockets are complex situations where previous surgeries have failed, disabling the wear of an ocular prosthesis. A combined method of surgery and long-term fixation using custom-made, three-dimensional (3D) printed conformers is evaluated. Methods: Retrospective case series of nine patients with recurrent excessive socket contraction and inability to wear a prosthesis, caused by chemical burns ( n = 3), fireworks ( n = 3), trauma ( n = 2) and enucleation and radiotherapy at childhood due to optic nerve glioma ( n = 1) with three average previous socket surgeries (range 2–6). Treatment consisted of a buccal mucosal graft and personalized 3D-printed conformer designed to be fixated to the periosteum and tarsal plates for minimal 2 months. Primary outcome was the retention of an ocular prosthesis. Secondary outcome was the need for additional surgeries. Results: Outcomes were measured at final follow-up between 7 and 36 months postoperatively (mean 20 months). Eight cases were able to wear an ocular prosthesis after 2 months. Three cases initially treated for only the upper or only the lower fornix needed subsequent surgery for the opposite fornix for functional reasons. Two cases had later surgery for cosmetic improvement of upper eyelid position. Despite pre-existing lid abnormalities (scar, entropion, lash deficiency), cosmetic outcome was judged highly acceptable in six cases because of symmetric contour and volume, and reasonably acceptable in the remaining two. Conclusions: Buccal mucosal transplant fixated with a personalized 3D-designed conformer enables retention of a well-fitted ocular prosthesis in previously failed socket surgeries. Initial treatment of both upper and lower fornices is recommended to avoid subsequent surgeries for functional reasons.

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