Search results for " Mathematica"

Universal formulas for characteristic classes on the Hilbert schemes of points on surfaces

2007

This article can be seen as a sequel to the first author's article ``Chern classes of the tangent bundle on the Hilbert scheme of points on the affine plane'', where he calculates the total Chern class of the Hilbert schemes of points on the affine plane by proving a result on the existence of certain universal formulas expressing characteristic classes on the Hilbert schemes in term of Nakajima's creation operators. The purpose of this work is (at least) two-fold. First of all, we clarify the notion of ``universality'' of certain formulas about the cohomology of the Hilbert schemes by defining a universal algebra of creation operators. This helps us to reformulate and extend a lot of the f…

The use of history in mathematics education: The case of posthumous twins

2018

Se presenta un estudio exploratorio sobre un tipo particular de problemas verbales descriptivos de larga tradición e importancia en el desarrollo del pensamiento matemático: el problema de los gemelos póstumos. La metodología que sustenta el estudio tiene dos vertientes complementarias: el análisis histórico epistemológico y el análisis didáctico en los libros de texto y manuales escolares. Con énfasis en la resolución de problemas, se resalta la importancia de integrar la historia y epistemología de las ideas matemáticas en la investigación educativa, para provecho de estudiantes y profesores. An exploratory study is presented on a particular type of descriptive word problems of long tradi…

Ģeometrijas jautājumi

1932

Izdevumam nav titullapas. Lekciju nosaukuma varianti un gads norādīti sējuma sākumā, ierakstīti ar zīmuli.

Micropollutants throughout an integrated urban drainage model: Sensitivity and uncertainty analysis

2017

Abstract The paper presents the sensitivity and uncertainty analysis of an integrated urban drainage model which includes micropollutants. Specifically, a bespoke integrated model developed in previous studies has been modified in order to include the micropollutant assessment (namely, sulfamethoxazole – SMX). The model takes into account also the interactions between the three components of the system: sewer system (SS), wastewater treatment plant (WWTP) and receiving water body (RWB). The analysis has been applied to an experimental catchment nearby Palermo (Italy): the Nocella catchment. Overall, five scenarios, each characterized by different uncertainty combinations of sub-systems (i.e…

An interpretative and cognitive semiotic approach to the learning process of mathematical objects

2013

IDENTIFYING STUDENTS’ WAYS OF LEARNING OF MATHEMATICS AT UNIVERSITY LEVEL

2019

The Mathematics study course is one of the core subjects in study programs of Technical Universities. To acquire this course successfully it is necessary to have mathematics background of sufficiently high quality. The authors of this paper recognize the difficulties first year students face due of their insufficient mathematical knowledge.Today, universities emphasize independent study work by students and allocate special time slots for this. To be successful, students need to plan their study time, use appropriate learning methods, and have motivation. Because of the significance of students’ individual work, a questionnaire was developed to research how students plan their time and acti…

LDA+Uand tight-binding electronic structure of InN nanowires

2013

In this paper we employ a combined ab initio and tight-binding approach to obtain the electronic and optical properties of hydrogenated Indium nitride InN nanowires. We first discuss InN band structure for the wurtzite structure calculated at the LDA+U level and use this information to extract the parameters needed for an empirical tight-binging implementation. These parameters are then employed to calculate the electronic and optical properties of InN nanowires in a diameter range that would not be affordable by ab initio techniques. The reliability of the large nanowires results is assessed by explicitly comparing the electronic structure of a small diameter wire studied both at LDA+U and…

Toward a formalization of a two traders market with information exchange

2014

This paper shows that Hamiltonians and operators can also be put to good use even in contexts which are not purely physics based. Consider the world of finance. The work presented here {models a two traders system with information exchange with the help of four fundamental operators: cash and share operators; a portfolio operator and an operator reflecting the loss of information. An information Hamiltonian is considered and an additional Hamiltonian is presented which reflects the dynamics of selling/buying shares between traders. An important result of the paper is that when the information Hamiltonian is zero, portfolio operators commute with the Hamiltonian and this suggests that the dy…

Understanding the shortcomings of commodity-based technology in input-output models: an economic-circuit approach

2004

International audience; The Make-Use Model serves as a basis for most national accounting systems as the System of National Accounts (SNA) and is acknowledged as the most suitable model for interregional analysis. Two hypotheses are traditionally made featuring either industry-based technologies (IBT) or commodity-based technologies (CBT). While industry-based technologies can be easily interpreted in terms of a demand-driven economic circuit, it will be shown that: (1) commodity-based technologies cannot be interpreted as a demand-driven economic circuit because this involves computing the inverse of a matrix (the matrix of industry output proportions), which is either impossible or genera…

Precision luminosity measurements at LHCb

2014

Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy $\sqrt{s}$. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for $\sqrt{s}$ = 2.76, 7 and 8 TeV (proton-proton collisions) and for $\sqrt{s_{NN}}$ = 5 TeV (proton-lead collisions). Both the "van der Meer scan" and "beam-gas imaging" luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves sig…