Search results for "reduction"
showing 10 items of 2058 documents
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 …
Vector anisotropic filter for multispectral image denoising
2015
In this paper, we propose an approach to extend the application of anisotropic Gaussian filtering for multi- spectral image denoising. We study the case of images corrupted with additive Gaussian noise and use sparse matrix transform for noise covariance matrix estimation. Specifically we show that if an image has a low local variability, we can make the assumption that in the noisy image, the local variability originates from the noise variance only. We apply the proposed approach for the denoising of multispectral images corrupted by noise and compare the proposed method with some existing methods. Results demonstrate an improvement in the denoising performance.
Evaluation of a Support Vector Machine Based Method for Crohn’s Disease Classification
2019
Crohn’s disease (CD) is a chronic, disabling inflammatory bowel disease that affects millions of people worldwide. CD diagnosis is a challenging issue that involves a combination of radiological, endoscopic, histological, and laboratory investigations. Medical imaging plays an important role in the clinical evaluation of CD. Enterography magnetic resonance imaging (E-MRI) has been proven to be a useful diagnostic tool for disease activity assessment. However, the manual classification process by expert radiologists is time-consuming and expensive. This paper proposes the evaluation of an automatic Support Vector Machine (SVM) based supervised learning method for CD classification. A real E-…
Older women's personal goals and exercise activity: an 8-year follow-up.
2013
This study investigated the associations of personal goals with exercise activity, as well as the relationships between exercise-related and other personal goals, among older women. Both cross-sectional and longitudinal designs were used with a sample of 308 women ages 66–79 at baseline. Women who reported exercise-related personal goals were 4 times as likely to report high exercise activity at baseline than those who did not report exercise-related goals. Longitudinal results were parallel. Goals related to cultural activities, as well as to busying oneself around the home, coincided with exercise-related goals, whereas goals related to own and other people’s health and independent living…
Las tecnologías de reproducción asistida y sus metáforas
2005
The enormous development -in both research and application- of assisted reproduction technologies has been accompanied by a lack of theoretical reflection on its power of change: the concept and treatment of the body, the concept of paternity or motherhood, etc.The metaphorical analysis allows us to deconstruct both dominant discourses: patriarchal and reductionist biomedical. We propose a transdisciplinary analysis which explains the interactions between the diverse discourses: biomedical, mass media, legal, symbolicpsycho-social, gender, historic- which make up the supply as well as the creation of demand of all these practices. The transdisciplinary analysis would help to reveal the biom…
Neurophilosophy in Zubiri’s perspective?
2016
The current intellectual situation is characterized by the vigour of neurophilosophy, founded on the new data of the neurosciences, in an attempt to replace traditional philosophical methods by the method of natural sciences. My aim is to show that Zubiri’s philosophy, which is also associated with the natural sciences, is a successful alternative to the pseudo-scientific and reductionist neurophilosophy, because his Noology is intrinsically connected to Neurobiology, especially through the concepts of formality and formalization, which are the basis for grounding a new conception of intelligence and reality.
Banal Sustainability : Renewing the Cultural Norm of Not Wasting Food
2022
Recently food waste has been raised as a major sustainability problem: roughly one third of the food produced globally ends up lost or wasted. This article investigates how people attach meaning to food waste reduction, based on eight individual interviews conducted with people met at a consumer education event in Helsinki in 2017. It is shown how the traditional cultural norm of not wasting food is reproduced in discourse on thrift and frugality and renewed by research-based arguments from circular economy discourse and environmental and sustainability discourse. It is proposed that the interplay of discourses merge into what Lars Kaijser calls banal sustainability: the complicated issue o…
Catalytic properties of Ag-PolyaminoβCD NPs for reduction of nitroarenes
2014
The reduction of nitroarenes is a key reaction involved in the synthesis of several compounds such as drugs, pesticides or dyes. During the last years Pd and Ag NPs have been used as catalysts to carry out this reaction with NaBH4. However several mechanistic aspects of the process are still unclear; in particular there is not agreement about the kinetic order of these reactions, whether 0-th or 1-st order in the substrate[1]. The aim of this work is to use a novel catalytic systems constituted by Ag-NPs coated with different polyamino-βCDs (Figure 1)[2], to carry out the reduction of some aromatic nitrocompounds using NaBH4 as the reducing agent, and to determine the kinetic features of th…
DNA oxidation products determined with repair endonucleases in mammalian cells: Types, basal levels and influence of cell proliferation
1999
Purified repair endonucleases such as Fpg protein, endonuclease III and IV allow a very sensitive quantification of various types of oxidative DNA modifications in mammalian cells. By means of these assays, the numbers of base modifications sensitive to Fpg protein, which include 8-hydroxyguanine (8-oxoG), were determined to be less than 0.3 per 10(6) bp in several types of untreated cultured mammalian cells and human lymphocytes and less than 10 per 10(6) bp in mitochondrial DNA from rat and porcine liver. Oxidative 5,6-dihydropyrimidine derivatives sensitive to endonuclease III and sites of base loss sensitive to endonuclease IV or exonuclease III were much less frequent than Fpg-sensitiv…
Role of glutathione in cell nucleus
2010
Cells with high proliferation rate have high glutathione levels. This typical feature of cancer cells is viewed usually as a defence mechanism against ionizing radiation or chemotherapy. Efforts have been made in order to decrease cellular glutathione levels in tumours as a necessary pre-treatment for cancer therapy. However, very few reports have considered cellular glutathione as a physiological tool for cells to proliferate and that most of this high glutathione levels were located in the nucleus. The role of nuclear glutathione in cell physiology has become more important in the last years. This review summarizes new findings that point to the nuclear reduced status as an environment th…