407 research outputs found
Effect of the Canting of Local Anisotropy Axes on Ground-State Properties of a Ferrimagnetic Chain with Regularly Alternating Ising and Heisenberg Spins
The effect of the canting of local anisotropy axes on the ground-state phase
diagram and magnetization of a ferrimagnetic chain with regularly alternating
Ising and Heisenberg spins is exactly examined in an arbitrarily oriented
magnetic field. It is shown that individual contributions of Ising and
Heisenberg spins to the total magnetization basically depend on the spatial
orientation of the magnetic field and the canting angle between two different
local anisotropy axes of the Ising spins.Comment: 3 pages, 3 figure
Pairwise thermal entanglement in Ising-XYZ diamond chain structure in an external magnetic field
Quantum entanglement is one of the most fascinating types of correlation that
can be shared only among quantum systems. The Heisenberg chain is one of the
simplest quantum chains which exhibits a reach entanglement feature, due to the
Heisenberg interaction is quantum coupling in the spin system. The two
particles were coupled trough XYZ coupling or simply called as two-qubit XYZ
spin, which are the responsible for the emergence of thermal entanglement.
These two-qubit operators are bonded to two nodal Ising spins, and this process
is repeated infinitely resulting in a diamond chain structure. We will discuss
two-qubit thermal entanglement effect on Ising-XYZ diamond chain structure. The
concurrence could be obtained straightforwardly in terms of two-qubit density
operator elements, using this result, we study the thermal entanglement, as
well as the threshold temperature where entangled state vanishes. The present
model displays a quite unusual concurrence behavior, such as, the boundary of
two entangled regions becomes a disentangled region, this is intrinsically
related to the XY-anisotropy in the Heisenberg coupling. Despite a similar
property had been found for only two-qubit, here we show in the case of a
diamond chain structure, which reasonably represents real materials.Comment: 6 pages, 7 figure
Music Learning Tools for Android Devices
In this paper, a musical learning application for
mobile devices is presented. The main objective is to design and develop an application capable of offering exercises to practice and improve a selection of music skills, to users interested
in music learning and training. The selected music skills are rhythm, melodic dictation and singing. The application includes an audio signal analysis system implemented making use of the
Goertzel algorithm which is employed in singing exercises to check if the user sings the right musical note. This application also includes a graphical interface to represent musical symbols.
A set of tests were conducted to check the usefulness of the application as musical learning tool. A group of users with different music knowledge have tested the system and reported
to have found it effective, easy and accessible.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Cultural diversity, educational achievements and school. Arguments from educational community
Questo studio costituisce la prima fase di un lavoro più ampio la cui i nalità
è quella di contribuire al miglioramento della scuola attraverso l’identii cazione,
elaborazione e dif usione di una casistica di buone pratiche scolastiche in contesti culturalmente
diversi. Questa ricerca incomincia revisionando il concetto di “successi educativi”
e “buone pratiche” da una doppia prospettiva: analizzando la letteratura specii ca
per quanto riguarda i contributi più signii cativi degli ultimi anni sul miglioramento
dell’ei cacia scolastica e, in aggiunta, analizzando le opinioni dei rappresentanti dei diversi
collettivi che hanno a che fare con la materia e denominati in questo studio, “esperti”
(docenti, assessori, famiglie, accademici, tecnici e agenti socioculturali). L’articolo si
focalizza sulla descrizione del supporto metodologico che ci ha permesso di portare avanti
questo processo di consultazione (il metodo Delphi) e sulla presentazione dei principali
risultati. In dei nitiva, presentiamo i punti d’accordo e le discrepanze trovate in riferimento
al concetto di “successo educativo”. Il processo Delphi sviluppato in questo lavoro
è stato iterattivo e interattivo. Nel processo si è garantito l’anonimato dei partecipanti,
la retro alimentazione costante e controllata e la presenza, nel risultato i nale, di tutte le
opinioni individuali. Lo strumento per la raccolta d’informazione è stato il questionario.
Nella prima fase di consulenza, ci sono state domande aperte che hanno permesso di
fare un’analisi qualitativa delle risposte. Partendo da questa analisi abbiamo elaborato
un secondo questionario di tipo scalare la cui analisi ha permesso di conoscere il grado di
consenso sulle questioni sottoposte a dibattito. La ricerca del consenso e la stabilità sono
stati i criteri che hanno guidato le analisi realizzate sull’informazione raccolta nelle due
fasi di consultazione e anche i criteri di saturazione di questa.h is paper is the i rst stage of a broader study that intents to improve schooling
ei cacy by identifying, describing and disseminating the best practices developed in
Spanish schools from diverse cultural backgrounds. It reviewed two main concepts –
“educational achievement” and “best school practices” – from a double perspective: i rst,
analyzing the most meaningful research contributions made in this area over the last ten
years; and second, taking into account the opinions of experts (teachers, educational advisors,
families, students, theorists, social players…) on these subjects. h e paper had two
main objectives: describing the methodological framework used in the expert consultation
process (the Delphi method) and presenting the main points of consensus and discrepancy regarding the concept of “educational achievement in culturally diverse educational contexts”.
h e Delphi consultation carried out was an iterative and interactive process. h e
process was coni dential and special care was taken to ensure continuous feedback and
representation of all individual opinions in the i nal results. Information was collected
using questionnaires. In the i rst consultation round, the questionnaire included openended
questions, whose responses were analyzed using a qualitative approach. A second
questionnaire was designed on the basis of this information. It provided quantitative
information that was useful to measure the level of agreement on the various issues discussed.
h e search for consensus and stability and information saturation were the basic
criteria that guided the analysis of information provided by the experts consulted
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