Search results for "Complement"

Le Geometrie dei numeri duali

I numeri duali furono introdotti per la prima volta da William Kingdon Clifford (1845-1879) nel 1873, come estensione dei quaternioni (biquaternioni), nell’ambito dello studio dei numeri ipercomplessi. In seguito, furono chiamati così da Eduard Study (1862-1930) [Study 1902], il quale ne fece poi oggetto di studio [Study 1903]. Già nel 1885 Arthur Buchheim (1859-1888) [Buchheim 1885], aveva rintracciato l’origine dei duali in Clifford e si era soffermato sulla (sostanziale) differenza tra l’introduzione dei biquaternioni in Hamilton e in Clifford. Nel 1906, in perfetto accordo alle teorie esposte da Study nel 1903, Joseph Grünwald (1876-1911), introdusse i numeri duali come u+vε, dove u e v…

Efficient numerical methods for pricing American options under stochastic volatility

2007

Five numerical methods for pricing American put options under Heston's stochastic volatility model are described and compared. The option prices are obtained as the solution of a two-dimensional parabolic partial differential inequality. A finite difference discretization on nonuniform grids leading to linear complementarity problems with M-matrices is proposed. The projected SOR, a projected multigrid method, an operator splitting method, a penalty method, and a componentwise splitting method are considered. The last one is a direct method while all other methods are iterative. The resulting systems of linear equations in the operator splitting method and in the penalty method are solved u…

Numerical Study of Two Sparse AMG-methods

2003

A sparse algebraic multigrid method is studied as a cheap and accurate way to compute approximations of Schur complements of matrices arising from the discretization of some symmetric and positive definite partial differential operators. The construction of such a multigrid is discussed and numerical experiments are used to verify the properties of the method.

Active macro-zone approach for incremental elastoplastic-contact analysis

2013

SUMMARY The symmetric boundary element method, based on the Galerkin hypotheses, has found an application in the nonlinear analysis of plasticity and in contact-detachment problems, but both dealt with separately. In this paper, we want to treat these complex phenomena together as a linear complementarity problem. A mixed variable multidomain approach is utilized in which the substructures are distinguished into macroelements, where elastic behavior is assumed, and bem-elements, where it is possible that plastic strains may occur. Elasticity equations are written for all the substructures, and regularity conditions in weighted (weak) form on the boundary sides and in the nodes (strong) betw…

An iterative method for pricing American options under jump-diffusion models

2011

We propose an iterative method for pricing American options under jump-diffusion models. A finite difference discretization is performed on the partial integro-differential equation, and the American option pricing problem is formulated as a linear complementarity problem (LCP). Jump-diffusion models include an integral term, which causes the resulting system to be dense. We propose an iteration to solve the LCPs efficiently and prove its convergence. Numerical examples with Kou@?s and Merton@?s jump-diffusion models show that the resulting iteration converges rapidly.

Saponins from the Roots of Nylandtia spinosa

2007

From the roots of Nylandtia spinosa, four new triterpene saponins, 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-galactopyranosyl-(1-->4)-[alpha- l-arabinopyranosyl-(1-->3)]-beta- d-xylopyranosyl-(1-->4)-[beta- d-apiofuranosyl-(1-->3)]-alpha- l-rhamnopyranosyl-(1-->2)-beta- d-fucopyranosyl ester ( 1), 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-galactopyranosyl-(1-->4)-[alpha- l-arabinopyranosyl-(1-->3)]-beta- d-xylopyranosyl-(1-->4)-alpha- l-rhamnopyranosyl-(1-->2)-beta- d-fucopyranosyl ester ( 2), 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-apiofuranosyl-(1-->4)-[beta- d-galactopyranosyl-(1-->2)]-beta- d-xylopyranosyl-(1-->4)-alpha- l-rhamnopyranosyl-(1-->2)-be…

Chess Thinking and Configural Concepts

2012

The purpose of this work is to connect chess and mathematics education. First, we introduce the idea of configural concepts in chess thinking and then we outline a scheme to show the phases of chess reasoning and how to apply this idea to some conflictual situations. We conclude this work proposing two research problems in introducing chess in mathematical classroom activities.

COULD STUDY AND PLAY OF CHESS IMPROVE SOCIAL INTERACTIONS? RE PORT OF AN ITALIAN CASE STUDY.

2012

Aim of this work is to improve the social interactions within a math classrooms (6 th grade), introducing a chess activity during the curricula hours. The theoretical framework upon which this research is based consists of: Vygotsky’s Theory of child developmen t (Vygotsky, 1986), the knowledge objectification theory (Radford, 2006) and theory of configural concepts (a personal review of Fischbein’s theory of figural concepts). We will discuss the results of an experimentation that has the purpose to create an appropriate environment wher e the students develop the abilities to solve and pose problems.

L’idea di iperspazio e l’evoluzione del pensiero geometrico al quadridimensionale

Attraverso un viaggio storico di quasi due secoli, lo scritto vuole analizzare le situazioni in cui lo studio della geometria iperdimensionale ha avuto la sua genesi e la sua evoluzione. Colui il quale approfondisce in modo analitico la questione è Ludwig Schläfli che con il suo Theorie der vielfachen Kontinuität, a partire dallo studio di un integrale, analizza lo spazio pluridimensionale senza cercare una immagine nel mondo circostante di ciò che descrive in modo molto sistematico attraverso i coefficienti che prendono il suo nome. L’aspetto divulgativo della questione viene affrontata a partire dagli anni ’70 del XIX secolo da Beltrami, Casorati e Stringham, da un punto di vista merament…

Occurrence of Mycotoxins in Botanical Dietary Supplement Infusion Beverages.

2019

The aim of the present work was to study the occurrence of mycotoxins [aflatoxins (1-4), 3-acetyldeoxyniavlenol (5), 15-acetyldeoxynivalenol (6), nivalenol (7), HT-2 (8), T-2 (9), ochratoxin A (10), zearalenone (11), enniatin A (12), enniatin A1 (13), enniatin B (14), enniatin B1 (15), and beauvericin (16)] present in potable products derived from herbal teas. Analysis was carried out by liquid chromatography coupled to ion-trap tandem mass spectrometry (LC-MS/MS-IT) after a dispersive liquid-liquid microextraction procedure (DLLME) was conducted. The DLLME method was applied to 52 commercial samples of chamomile, chamomile with anise, chamomile with honey, linden, pennyroyal mint, thyme, v…