Search results for "Image Analysi"

How and why does willow biochar increase a clay soil water retention capacity?

2018

Addition of biochar into a soil changes its water retention properties by modifying soil textural and structural properties. In addition, internal micrometer-scale porosity that is able to directly store readily plant available water affects soil water retention properties. This study shows how precise knowledge of the internal micrometer-scale pore size distribution of biochar can deepen the understanding of the biochar-water interactions in soils. The micrometer-scale porosity of willow biochar was quantitatively and qualitatively characterized using X-ray tomography, 3D image analysis and Helium ion microscopy. The effect of biochar application on clay soil water retention was studied by…

Predicting stiffness and strength of birch pulp:Polylactic acid composites

2016

This paper studies failure of birch pulp–polylactic acid composites. Stiffness and strength are calculated using the theory of short fibre composites and the results are compared to experimental data. The results differed from the experimental values by 0–6%. With less aligned fibres the short fibre theory is not feasible. The performance of the 40 wt% birch pulp – polylactic acid composite is predicted with X-ray microtomography based finite element modelling, and the results are compared with experiments. Stiffness results differed from experiments by 1–17% . By adding into the models a third material phase representing the interface between the fibres and the matrix, the stress–strain c…

Exploiting historical rainfall and landslide data in a spatial database for the derivation of critical rainfall thresholds

2017

Critical rainfall thresholds for landslides are powerful tools for preventing landslide hazard. The thresholds are commonly estimated empirically starting from rainfall events that triggered landslides in the past. The creation of the appropriate rainfall–landslide database is one of the main efforts in this approach. In fact, an accurate agreement between the landslide and rainfall information, in terms of location and timing, is essential in order to correctly estimate the rainfall–landslide relationships. A further issue is taking into account the average moisture conditions prior the triggering event, which reasonably may be crucial in determining the sufficient amount of precipitation.…

Image classification based on 2D feature motifs

2013

The classification of raw data often involves the problem of selecting the appropriate set of features to represent the input data. In general, various features can be extracted from the input dataset, but only some of them are actually relevant for the classification process. Since relevant features are often unknown in real-world problems, many candidate features are usually introduced. This degrades both the speed and the predictive accuracy of the classifier due to the presence of redundancy in the candidate feature set. In this paper, we study the capability of a special class of motifs previously introduced in the literature, i.e. 2D irredundant motifs, when they are exploited as feat…

Algorithms and software for biological multiscale image analysis

2013

A new approach for geological faults detection

2004

This paper will introduce a new approach, mainly based on wavelets transform and mathematical morphology, for the detection of geological faults in satellite and aerial photos. This can be useful for territorial analysis, digital cartography and the use of geographical information systems. The proposed method is fast enough and unsupervised. Different techniques will be compared and some examples on real data will be presented to indicate the applicability of these methods.

Comparative Study of Feature classification Methods for Mass Lesion Recognition in Digitized Mammograms

2007

In this work a comparison of different classification methods for the identification of mass lesions in digitized mammograms is performed. These methods, used in order to develop Computer Aided Detection (CAD) systems, have been implemented in the framework of the MAGIC-5 Collaboration. The system for identification of mass lesions is based on a three-step procedure: a) preprocessing and segmentation, b) region of interest (ROI) searching, c) feature extraction and classification. It was tested on a very large mammographic database (3369 mammographic images from 967 patients). Each ROI is characterized by eight features extracted from a co-occurrence matrix containing spatial statistics inf…

Development and characterisation of polymer composite materials with bio-inspired functions

2018

Promocijas darbs ir izstrādāts disertācijas veidā fizikas nozarē materiālu fizikas apakšnozarē. Pētījums tika veikts LU Materiālu mehānikas institūtā. Darbs saistīts ar aktuālu un jaunu pētījumu virzienu: bioinspirēto funkciju tālāku attīstīšanu slodzi nesošos kompozītos. Tās ir mehānisku triecienu vizuālās indikācijas un polimēru matricas vaskulārās pašdziedināšanas funkcijas. Šīs funkcijas tika nodrošinātas, izveidojot viedus slāņus un iebūvējot tos kompozītā. Pētījumā tika noskaidrotas piemērotās pārbaužu secības, attīstītas kvantitatīvas metodes un mehānisks modelis, lai novērtētu jauno funkciju efektivitāti kompozītos. Ir pierādīta funkciju augstā efektivitāte un spēja uzlabot slodzi n…

Wavelets Image Analysis for Friction Stir Processed TiNi Functional Behavior Characterization

2015

Abstract A key topic regarding Ti Ni Shape Memory materials concerns the possibility to attain welded junctions that preserves the shape memory properties of material. Other research topic for SMAs regards the retention of the shape memory effect cyclic stability; in fact, good shape memory properties frequently decrease during SME cycling of material. A method able to improve the cyclic stability of TiNi shape memory effect is the grain refinement. Considering these above mentioned research topics, a solid state welding process, as the Friction Stir Welding, is thus attractive for SMA joining and it exhibits potentials for achieving welded joints affected by microstructural changes that pr…

Digital image analysis technique for measuring railway track defects and ballast gradation

2018

Abstract In order to guarantee safety and driving comfort and to maintain an efficient railway infrastructure, the first step is to carefully monitor the track geometry and wear level of the materials constituting the superstructure. To that end diagnostic trains are widely used on main lines, in that they can detect several geometric track parameters and rail wear, but under no circumstances they can yet detect ballast gradation. Due to the practical implications for the planning of maintenance operations on the railway network, this article presents a “DIP” digital image processing technique for measuring the transverse profile and corrugations of the rails as well as ballast gradation. T…