Search results for "algebra"
showing 10 items of 4129 documents
Primitive rispetto all’ oscillazione
2002
We study the real valued functions having a primitive with respect to the oscillation or a primitive with respect to the oscillation up to anegligible set.
A Note on the Density of Rational Functions in A ∞(Ω)
2018
We present a sufficient condition to ensure the density of the set of rational functions with prescribed poles in the algebra A ∞ (Ω).
Artificial neural network applied to the discrimination of antibacterial activity by topological methods
2000
Abstract A new topological method that makes it possible to discriminate the active and inactive molecules on the basis of their chemical structures is applied in the present study to the antibacterial agents. This method uses neural networks in which training algorithms are used as well as different concepts and methods of artificial intelligence with a suitable set of topological descriptors. It is possible to obtain a QSAR interpretation of the information contained in the network after the training has been carried out.
ChemInform Abstract: Topologically Complex Molecules Obtained by Transition Metal Templation: It Is the Presentation that Determines the Synthesis St…
2013
Topological constructions made from closed curves range from simple links to intricate knots and started to capture the chemists' attention in the early sixties. These mathematical objects result from particular embeddings of a single or a set of closed curves in the three-dimensional space that show an infinite variety of presentations. Simple catenanes, higher order interlocked macrocycles, and molecular knots can be synthesized via the metal template approach, just as simple macrocycles. However, this requires that rigid presentations with appropriate geometrical characteristics be identified prior to molecular design, and those selected for the metal-templated synthesis of some of these…
An Introduction to Computational Complexity
2016
This chapter is not strictly about algebra. However, this chapter offers a set of mathematical and computational instruments that will allow us to introduce several concepts in the following chapters. Moreover, the contents of this chapter are related to algebra as they are ancillary concepts that help (and in some cases allow) the understanding of algebra.
Effect of soil permanent grass cover on growth, yield and water status of rainfed olive trees in Sicily
2017
The study was carried out in an olive grove located along the hills of northern Sicily where soil had been managed for decades by chemical weeding. Starting in 2008, one portion of the grove was left non-weeded, and the permanent grass cover was managed by mowing 2-3 times per year in winter and spring. In 2011, 2012 and 2013, yield, average drupe weight, percentage of drupe black color (veraison), trunk circumference, shoot elongation, and leaf relative water content (RWC) were determined on 34 adult trees of the cultivar 'Biancolilla' with uniform size and age. In 2013, soil organic matter content and leaf nutrient concentrations were also determined in the two portions of the grove. As e…
Hierarchical and non-hierarchical clustering methods to study students algebraic thinking in solving an open-ended questionnaire
2017
The problem of taking a data set and separating it into subgroups, where the members of each subgroup are more similar to each other than they are to members outside the subgroup, has been extensively studied in science and mathematics education research. Student responses to written questions and multiple-choice tests have been characterised and studied using several qualitative and/or quantitative analysis methods. However, there are inherent difficulties in the categorisation of student responses in the case of open-ended questionnaires. Very often, researcher bias means that the categories picked out tend to find the groups of students that the researcher is seeking out. In our contribu…
Non-stationary dynamic analysis of random structures via virtual distortion method
2009
Shall We (Math and) Dance?
2019
Can we use mathematics, and in particular the abstract branch of category theory, to describe some basics of dance, and to highlight structural similarities between music and dance? We first summarize recent studies between mathematics and dance, and between music and categories. Then, we extend this formalism and diagrammatic thinking style to dance.
A New Simple Friction Model for S. I. Engine
2009
Internal combustion engine modeling is nowadays a widely employed tool for modern engine development. Zero and mono dimensional models of the intake and exhaust systems, combined with multi-zone combustion models, proved to be reliable enough for the accurate evaluation of in-cylinder pressure, which in turn allow the estimation of the engine performance in terms of indicated mean effective pressure (IMEP). In order to evaluate the net engine output, both the torque dissipation due to friction and the energy drawn by accessories must be taken into consideration, hence a model for the friction mean effective pressure (FMEP) evaluation is needed. One of the most used models accounts for engin…