2,136 research outputs found
Controlling Excitations Inversion of a Cooper Pair Box Interacting with a Nanomechanical Resonator
We investigate the action of time dependent detunings upon the excitation
inversion of a Cooper pair box interacting with a nanomechanical resonator. The
method employs the Jaynes-Cummings model with damping, assuming different decay
rates of the Cooper pair box and various fixed and t-dependent detunings. It is
shown that while the presence of damping plus constant detunings destroy the
collapse/revival effects, convenient choices of time dependent detunings allow
one to reconstruct such events in a perfect way. It is also shown that the mean
excitation of the nanomechanical resonator is more robust against damping of
the Cooper pair box for convenient values of t-dependent detunings.Comment: 11 pages, 5 figure
Sustainable growth in complex networks
Based on the empirical analysis of the dependency network in 18 Java
projects, we develop a novel model of network growth which considers both: an
attachment mechanism and the addition of new nodes with a heterogeneous
distribution of their initial degree, . Empirically we find that the
cumulative degree distributions of initial degrees and of the final network,
follow power-law behaviors: , and
, respectively. For the total number of links as a
function of the network size, we find empirically ,
where is (at the beginning of the network evolution) between 1.25 and
2, while converging to for large . This indicates a transition from
a growth regime with increasing network density towards a sustainable regime,
which revents a collapse because of ever increasing dependencies. Our
theoretical framework is able to predict relations between the exponents
, , , which also link issues of software engineering and
developer activity. These relations are verified by means of computer
simulations and empirical investigations. They indicate that the growth of real
Open Source Software networks occurs on the edge between two regimes, which are
either dominated by the initial degree distribution of added nodes, or by the
preferential attachment mechanism. Hence, the heterogeneous degree distribution
of newly added nodes, found empirically, is essential to describe the laws of
sustainable growth in networks.Comment: 5 pages, 2 figures, 1 tabl
Application of Adult Learning Theory to Supplemental Instruction in Undergraduate Chemistry Classes
The Supplemental Instruction (SI) program relies on the foundations of adult education. In particular it depends heavily on peer support in difficult classes. The andragogical approach highlights the importance of addressing different learning styles and helps students to engage in collaborative learning and problem solving
Recommended from our members
The latest (version 4.3) Mars Climate Database
Introduction: The Mars Climate Database (MCD) is a database of meteorological fields derived from General Circulation Model (GCM) numerical simulations of the Martian atmosphere and validated using available observational data. The MCD includes complementary post-processing schemes such as high spatial resolution interpolation of environmental data and means of reconstructing the variability thereof. The GCM is developed at Laboratoire de Météorologie Dynamique du CNRS (Paris, France) [1,2] in collaboration with the Open University (UK), the Oxford University (UK) and the Instituto de Astrofisica de Andalucia (Spain) with support from the European Space Agency (ESA) and the Centre National
d'Etudes Spatiales (CNES)
Recommended from our members
Mars Climate Database version 5
The Mars Climate Database (MCD) is a database of meteorological fields derived from General Circulation Model (GCM) numerical simulations [2,4] of the Martian atmosphere and validated using available observational data. The MCD includes complementary post-processing schemes such as high
spatial resolution interpolation of environmental data and means of reconstructing the variability thereof. The GCM is developed at LMD (Laboratoire de Météorologie Dynamique, Paris, France) in collaboration with several teams in Europe: LATMOS (Laboratoire Atmosphères, Milieux, Observations
Spatiales, Paris, France), the Open University (UK), the Oxford University (UK) and the Instituto de Astrofisica de Andalucia (Spain) with support from the European Space Agency (ESA) and the Centre National d'Etudes Spatiales (CNES). The MCD is freely distributed and intended to be useful and used in the framework of engineering applications as well as in the context of scientific studies which require accurate knowledge of the state of the Martian atmosphere. The Mars Climate Database (MCD) has over the years been distributed to more than 150 teams around the world. With the many improvements implemented in the GCM over the last few years, a new series of reference simulations have been run and compiled in a new version (version 5) of the Mars Climate Database, released in the first half of 2012
Hiperplasia angiolinfoide con eosinofilia: a propósito de una localización atípica en músculo trapecio
La hiperplasia angiolinfoide con eosinofilia es una patología poco frecuente de presentación clínica
inespecífica que lleva a que rara vez se diagnostique antes del estudio histológico. Habitualmente afecta a piel y tejido
celular subcutáneo siendo rara la localización extracutánea. Presentamos un caso clínico de una tumoración en una
mujer de 46 años localizada a nivel del músculo trapecio; y revisamos las características histopatológicas y de tratamiento
de esta patología.Angiolymphoid hyperplasia with eosinophilia is an uncommon condition with non-specific clinical
symptoms that needs a histological study to have the diagnosis. Usually this lesion occurs in the skin and the subcutaneous
tissue, with extracutaneous affection being rare. We describe a tumour affecting the trapezius muscle in a 40-
year-old woman; and we review the histopathologic findings and the treatment of this pathology
Osteosarcoma perióstico: caso clínico
El osteosarcoma perióstico es un sarcoma raro que asienta en la superficie del hueso. Aunque algunos
autores lo incluyen en los osteosarcomas yuxtacorticales sus peculiaridades clínicas, radiológicas y anatomopatológicas
entre ellos que llevan a diferencias en el tratamiento y pronóstico le otorgan personalidad propia. Presentamos
un caso clínico de osteosarcoma perióstico en un varón de 18 años, a nivel de fémur. Se realiza una revisión de
la bibliografía, señalando las principales características de esta entidad.Periosteal osteosarcoma is a rare malignant neoplasm located on bone surface. Although some
authors include it among juxtacortical osteosarcoma, its clinical feature, imaging studies findings and histologic patterns
which lead to differences in the treatment and prognostic, give to it a peculiar identity. We report a case of an
18 years old man who had this tumour in his femur. We do a review of literature
- …