Parametric invariant Random Matrix Model and the emergence of multifractality

We propose a random matrix modeling for the parametric evolution of eigenstates. The model is inspired by a large class of quantized chaotic systems. Its unique feature is having parametric invariance while still possessing the non-perturbative crossover that has been discussed by Wigner 50 years ago. Of particular interest is the emergence of an additional crossover to multifractality.Comment: 7 pages, 6 figures, expanded versio

Scaling properties of delay times in one-dimensional random media

The scaling properties of the inverse moments of Wigner delay times are investigated in finite one-dimensional (1D) random media with one channel attached to the boundary of the sample. We find that they follow a simple scaling law which is independent of the microscopic details of the random potential. Our theoretical considerations are confirmed numerically for systems as diverse as 1D disordered wires and optical lattices to microwave waveguides with correlated scatterers.Comment: 5 pages, 4 figures Submitted to Physical Review B Revision 2: 1) Theoretical curve fits added to Figures 1-4. 2) Scaling parameter added to inset of Figure 2. 3) Minor text changes to reflect referee comments. 4) Some extra refereces were adde

Expected exponential loss for gaze-based video and volume ground truth annotation

Many recent machine learning approaches used in medical imaging are highly reliant on large amounts of image and ground truth data. In the context of object segmentation, pixel-wise annotations are extremely expensive to collect, especially in video and 3D volumes. To reduce this annotation burden, we propose a novel framework to allow annotators to simply observe the object to segment and record where they have looked at with a \$200 eye gaze tracker. Our method then estimates pixel-wise probabilities for the presence of the object throughout the sequence from which we train a classifier in semi-supervised setting using a novel Expected Exponential loss function. We show that our framework provides superior performances on a wide range of medical image settings compared to existing strategies and that our method can be combined with current crowd-sourcing paradigms as well.Comment: 9 pages, 5 figues, MICCAI 2017 - LABELS Worksho

Scattering at the Anderson transition: Power--law banded random matrix model

We analyze the scattering properties of a periodic one-dimensional system at criticality represented by the so-called power-law banded random matrix model at the metal insulator transition. We focus on the scaling of Wigner delay times $\tau$ and resonance widths $\Gamma$. We found that the typical values of $\tau$ and $\Gamma$ (calculated as the geometric mean) scale with the system size $L$ as $\tau^{\tiny typ}\propto L^{D_1}$ and $\Gamma^{\tiny typ} \propto L^{-(2-D_2)}$, where $D_1$ is the information dimension and $D_2$ is the correlation dimension of eigenfunctions of the corresponding closed system.Comment: 6 pages, 8 figure

Mesoscopic mean-field theory for spin-boson chains in quantum optical systems

We present a theoretical description of a system of many spins strongly coupled to a bosonic chain. We rely on the use of a spin-wave theory describing the Gaussian fluctuations around the mean-field solution, and focus on spin-boson chains arising as a generalization of the Dicke Hamiltonian. Our model is motivated by experimental setups such as trapped ions, or atoms/qubits coupled to cavity arrays. This situation corresponds to the cooperative (E⊗β) Jahn-Teller distortion studied in solid-state physics. However, the ability to tune the parameters of the model in quantum optical setups opens up a variety of novel intriguing situations. The main focus of this paper is to review the spin-wave theoretical description of this problem as well as to test the validity of mean-field theory. Our main result is that deviations from mean-field effects are determined by the interplay between magnetic order and mesoscopic cooperativity effects, being the latter strongly size-dependent

SJM: Un simulador de jerarquías de memoria orientado a la docencia de arquitectura de computadores

El concepto de jerarquía de memoria de un computador es uno de los más importantes en el ámbito de la docencia en arquitectura de computadores. Habitualmente, los distintos aspectos de la estructura y el funcionamiento de la jerarquía de memoria (memoria cache, memoria virtual, algoritmos de reemplazo, tasas de fallos, etc.) se explican primero a los alumnos de manera teórica, y posteriormente se realizan prácticas basadas en programas que simulan dicha jerarquía. En este trabajo se presenta un nuevo simulador pedagógico, SJM, que permite modelar de forma amigable distintas jerarquías de memoria, modificar fácilmente sus características y obtener medidas de sus prestaciones, de cara a que los alumnos, mediante la evaluación de distintas configuraciones de la jerarquía de memoria, afiancen su comprensión de los distintos aspectos de ésta.Peer Reviewe

Lógica de gerenciamento e experiência sensível. Gerentes intermediários e funcionários juniores em um centro de distribuição.

More than a simple ideology, Management is a rationality since have overpassed the sphere of the direction of the work and have converted in a mentality. It will be displayed some examples in which is possible to notice that the managerial logic appears embodied in the middle management and when be reproduced with total conviction its rhetoric, they get big dosses of satisfaction. Suffering of these people, is caused by the opposite phenomenon: the disability to obey the mentioned their premises thanks to the requirements that the logic of the management impose to them. The subordinate personnel, by their way understand that rationality like a fatality and by these, without realizing it, reproduce it with resignation, and to protect their selves from the requirements that are imposed to them, been happy knowing that can “escape” daily when their working day ends.Más que una simple ideología, el management es una racionalidad pues ha sobrepasado la esfera de la dirección del trabajo y se ha convertido en una mentalidad. Se mostrarán algunos ejemplos en los cuales se observa que la lógica managerial aparece encarnada en los mandos medios y que cuando reproducen con total convicción y coherencia sus retóricas, obtienen grandes dosis de satisfacción. El sufrimiento de ellos, es causado por el fenómeno opuesto: la incapacidad de obedecer sus premisas gracias a las exigencias que la lógica del management les impone. El personal subalterno, por su parte entiende tal racionalidad como una fatalidad y, sin mucho darse cuenta, la reproduce con resignación y, para protegerse de las exigencias que le impone, se contenta creyendo que puede “escapársele” diariamente, cuando su jornada termina.Mais do que apenas uma ideologia, a administração é uma racionalidade porque foi além da esfera da direção do trabalho e se tornou uma mentalidade. Alguns exemplos serão mostrados nos quais se observa que a lógica gerencial aparece incorporada na gerência intermediária e que, quando ela reproduz sua retórica com total convicção e coerência, obtém grandes doses de satisfação. O sofrimento é causado pelo fenômeno oposto: a incapacidade de obedecer a suas premissas, graças às exigências que a lógica gerencial impõe. Os funcionários juniores, por sua vez, entendem essa racionalidade como uma fatalidade e, sem perceber, a reproduzem com resignação e, para se protegerem das exigências impostas, contentam-se em acreditar que podem "escapar" diariamente, quando termina o dia

Sociología y Antropología en la formación del administrador

El propósito es presentar a los estudiantes y a los formadores en administración una sucinta introducción a dos disciplinas científicas y sus correspondientes métodos. Se trata de la Antropología y la Sociología, las cuales han privilegiado a la Etnografía y la Etnología para llevar a cabo la explicación de sus respectivos problemas de estudio. El texto, netamente descriptivo, invita a una reflexión dirigida a la acción administrativa con la intención de que, por una parte ésta se enriquezca con la sensibilidad y el rigor científico de estas disciplinas y estos métodos; por otra parte, a estar muy atentos a los aspectos éticos que rodean la toma de decisiones por parte del profesional de la Administración.El propósito es presentar a los estudiantes y a los formadores en administración una sucinta introducción a dos disciplinas científicas y sus correspondientes métodos. Se trata de la Antropología y la Sociología, las cuales han privilegiado a la Etnografía y la Etnología para llevar a cabo la explicación de sus respectivos problemas de estudio. El texto, netamente descriptivo, invita a una reflexión dirigida a la acción administrativa con la intención de que, por una parte ésta se enriquezca con la sensibilidad y el rigor científico de estas disciplinas y estos métodos; por otra parte, a estar muy atentos a los aspectos éticos que rodean la toma de decisiones por parte del profesional de la Administración