Search results for "Extraction"
showing 10 items of 2072 documents
Classification based on Iterative Object Symmetry Transform
2004
The paper shows an application of a new operator named the iterated object transform (IOT) for cell classification. The IOT has the ability to grasp the internal structure of a digital object and this feature can be usefully applied to discriminate structured images. This is the case of cells representing chondrocytes in bone tissue, giarda protozoan, and myeloid leukaemia. A tree classifier allows us to discriminate the three classes with a good accuracy.
Finding essential features for tracking starfish in a video sequence
2004
The paper introduces a software system for detecting and tracking starfish in an underwater video sequence. The target of such a system is to help biologists in giving an estimate of the number of starfish present in a particular area of the sea-bottom. The nature of the input images is characterised by a low signal/noise ratio and by the presence of noisy background represented by pebbles; this makes the detection a non-trivial task. The procedure we use is a chain of several steps that starts from the extraction of the area of interest and ends with a classifier and a tracker providing the necessary information for counting the starfish present in the scene. © 2003 IEEE.
An improved MSD-based method for PD defects classification
2006
The new proposed method of pattern recognition is based on the application of Multi-resolution Signal Decomposition (MSD) technique of wavelet transform. This technique has showed off interesting properties in capturing the embedded horizontal, vertical and diagonal variations within an image obtained from the PD pattern in a separable form. This feature was exploited to identify in the PD pattern's MSD, relative at various family of partial discharge sources, some detail images typical of a single discharge phenomenon. The classification of a generic PD phenomenon is feasible through a comparison between its detail images and the detail images typical of a single discharge phenomenon. Test…
Shape-Based Features for Cat Ganglion Retinal Cells Classification
2002
This article presents a quantitative and objective approach to cat ganglion cell characterization and classification. The combination of several biologically relevant features such as diameter, eccentricity, fractal dimension, influence histogram, influence area, convex hull area, and convex hull diameter are derived from geometrical transforms and then processed by three different clustering methods (Ward’s hierarchical scheme, K-means and genetic algorithm), whose results are then combined by a voting strategy. These experiments indicate the superiority of some features and also suggest some possible biological implications.
Unsupervised change detection with kernels
2012
In this paper an unsupervised approach to change detection relying on kernels is introduced. Kernel based clustering is used to partition a selected subset of pixels representing both changed and unchanged areas. Once the optimal clustering is obtained the estimated representatives (centroids) of each group are used to assign the class membership to all others pixels composing the multitemporal scenes. Different approaches of considering the multitemporal information are considered with accent on the computation of the difference image directly in the feature spaces. For this purpose a difference kernel approach is successfully adopted. Finally an effective way to cope with the estimation o…
On-line high-pressure extraction-high-performance liquid chromatography
1983
Abstract A coupling unit is described that allows on-line operation of a high-pressure extraction apparatus with a high-performance liquid chromatograph. The unit consists of two high-pressure sample-injection valves, connected in series. The first valve operates as a switching valve to the loop and controls the release of pressure along a packed microbore column. Two short, packed microbore columns are positioned between the first and second valve, sampling the extracted compounds over a desired period and simultaneously operating as sample loop for the second valve; the latter is the injector for the high-performance liquid chromatographic column. The unit was tested by continuous extract…
The impact of feature extraction on the performance of a classifier : kNN, Naïve Bayes and C4.5
2005
"The curse of dimensionality" is pertinent to many learning algorithms, and it denotes the drastic raise of computational complexity and the classification error in high dimensions. In this paper, different feature extraction techniques as means of (1) dimensionality reduction, and (2) constructive induction are analyzed with respect to the performance of a classifier. Three commonly used classifiers are taken for the analysis: kNN, Naïve Bayes and C4.5 decision tree. One of the main goals of this paper is to show the importance of the use of class information in feature extraction for classification and (in)appropriateness of random projection or conventional PCA to feature extraction for …
Volumetric changes in alveolar ridge preservation with a compromised buccal wall: a systematic review and meta-analysis.
2020
Background Many studies have addressed socket preservation, though fewer publications considering buccal wall loss can be found, since the literature typically considers sockets with four walls. A systematic review was made on the influence of type II buccal bone defects, according to Elian’s Classification, in socket grafting materials upon volumetric changes in width and height. Material and Methods An electronic and manual literature search was conducted in accordance to PRISMA statement. The search strategy was restricted to randomized controlled trials (RCTs) and controlled clinical trials (CCTs) describing post-extraction sockets with loss of buccal wall in which alveolar ridge preser…
The effect of pre-anaesthetic assessment clinic: a systematic review of randomised and non-randomised prospective controlled studies
2021
ABSTRACTObjectivesThe aim of this systematic review was to examine the effectiveness of pre-anaesthetic assessment clinics (PACs) implemented to improve quality and patient safety in perioperative care.DesignSystematic review.Data sourcesThe electronic databases CINAHL Plus with Full Text (EBSCOhost), Medline, and Embase (OvidSP) were systematically searched from 1st April, 1996 to 4th February, 2021.Eligibility criteriaThe main inclusion criterion was that the study, using empirical quantitative methods, addressed the effectiveness of PACs.Data extraction and synthesisTitles, abstracts, and full texts were screened in duplicate by two authors. Risk of bias assessment, using the Joanna Brig…
Surfactant-based enrichment of rare earth elements from NdFeB magnet e-waste: Optimisation of cloud formation and rare earths extraction
2023
Appropriate waste and resource management are essential for a sustainable circular economy with reduced environmental impact. With critical resources, e-waste may serve as indirect raw material. For example, with NdFeB permanent magnets, Neodymium (Nd) and the co-present Dysprosium (Dy) are critical rare earth elements (REEs). However, there exists no economically viable technology for recycling them from electronic waste (e-waste). Here, a method is presented based on cloud point extraction (CPE). The work involves basic complexation chemistry in a cloud medium with pure REE salts, as well as, with real NdFeB-magnets (nearly 28% REE content by weight) from an old hard disk drive (5.2 g mag…