Search results for "spektri"
showing 10 items of 61 documents
Discriminating Basal Cell Carcinoma and Bowen’s Disease with Novel Hyperspectral Imaging System and Convolutional Neural Networks
2022
Discovering knowledge in various applications with a novel hyperspectral imager
2013
Hyperspectral imaging system in the delineation of Ill-defined basal cell carcinomas : a pilot study
2019
Background Basal cell carcinoma (BCC) is the most common skin cancer in the Caucasian population. Eighty per cent of BCCs are located on the head and neck area. Clinically ill‐defined BCCs often represent histologically aggressive subtypes, and they can have subtle subclinical extensions leading to recurrence and the need for re‐excisions. Objectives The aim of this pilot study was to test the feasibility of a hyperspectral imaging system (HIS) in vivo in delineating the preoperatively lateral margins of ill‐defined BCCs on the head and neck area. Methods Ill‐defined BCCs were assessed clinically with a dermatoscope, photographed and imaged with HIS. This was followed by surgical procedures…
Spectral analysis and quantum chaos in two-dimensional nanostructures
2015
This thesis describes a study into the eigenvalues and eigenstates of twodimensional (2D) quantum systems. The research is summarized in four scientific publications by the author. The underlying motivation for this work is the grand question of quantum chaos: how does chaos, as known in classical mechanics, manifest in quantum mechanics? The search and analysis of these quantum fingerprints of chaos requires efficient numerical tools and methods, the development of which is given a special emphasis in this thesis. The first publication in this thesis concerns the eigenspectrum analysis of a nanoscale device. It is shown that a measured addition energy spectrum can be explained by a simple …
FTIR matrix isolation and theoretical studies of glycolic acid dimers
2018
Glycolic acid (GA) dimers were studied in low temperature argon matrices by means of FTIR spectroscopy. Experimentally, the dimers were produced when monomeric glycolic acid molecules were thermally mobilized upon annealing of argon matrices at 25–35 K. The experimental spectra observed upon annealing indicate the presence of three different dimer structures. Computationally, MP2 and DFT calculations were used to study the potential dimer species in order to scrutinize the possible dimer structures, their energetics and their spectral features. Altogether 27 local minima were found for dimer structures for the three lowest conformers of glycolic acid considered based on previous studies on …
Rapid Quantification of Microalgae Growth with Hyperspectral Camera and Vegetation Indices
2021
Spectral cameras are traditionally used in remote sensing of microalgae, but increasingly also in laboratory-scale applications, to study and monitor algae biomass in cultures. Practical and cost-efficient protocols for collecting and analyzing hyperspectral data are currently needed. The purpose of this study was to test a commercial, easy-to-use hyperspectral camera to monitor the growth of different algae strains in liquid samples. Indices calculated from wavebands from transmission imaging were compared against algae abundance and wet biomass obtained from an electronic cell counter, chlorophyll a concentration, and chlorophyll fluorescence. A ratio of selected wavebands containing near…
UV-säteilyn vaikutukset kasvuun sekä klorofyllin ja fenolisten yhdisteiden määrään rauduskoivun (Betula pendula) taimilla
2008
Assessment of microalgae species, biomass and distribution from spectral images using a convolution neural network
2021
Artikkeliin "Assessment of microalgae species, biomass and distribution from spectral images using a convolution neural network" liittyvä aineisto koostuu seuraavista osista: 1.Transmittanssi-hyperspektrikuvat levänäytteistä kuvattuina 24-kuoppalevyllä 2.Biomassamääritykset elektronisella solulaskurilla 3.Opetus- ja validointiaineisto konvoluutioneuroverkolle 4.Testiaineisto konvoluutioneuroverkolle 5.Opetus-, validointi- ja testiaineiston käsittelyyn käytetty Python koodi 6.Seitsemään eri malliin käytetty Python koodi ja mallit itsessään The data and code related to the article "Assessment of microalgae species, biomass and distribution from spectral images using a convolution neural netwo…
Minimal learning machine in anomaly detection from hyperspectral images
2020
Abstract. Anomaly detection from hyperspectral data needs computationally efficient methods to process the data when the data gathering platform is a drone or a cube satellite. In this study, we introduce a minimal learning machine for hyperspectral anomaly detection. Minimal learning machine is a novel distance-based classification algorithm, which is now modified to detect anomalies. Besides being computationally efficient, minimal learning machine is also easy to implement. Based on the results, we show that minimal learning machine is efficient in detecting global anomalies from the hyperspectral data with low false alarm rate.
Spectral imaging from UAVs under varying illumination conditions
2013
Abstract. Rapidly developing unmanned aerial vehicles (UAV) have provided the remote sensing community with a new rapidly deployable tool for small area monitoring. The progress of small payload UAVs has introduced greater demand for light weight aerial payloads. For applications requiring aerial images, a simple consumer camera provides acceptable data. For applications requiring more detailed spectral information about the surface, a new Fabry-Perot interferometer based spectral imaging technology has been developed. This new technology produces tens of successive images of the scene at different wavelength bands in very short time. These images can be assembled in spectral data cubes wit…