The Balance Sheet Channel

In this paper, we study the role of the credit channel of monetary policy in the context of a DSGE model. Through the use of a regulated banking sector subject to a regulatory capital constraint on lending, we provide alternative interpretations that can potentially explain differences in the implementation of monetary policy without appealing to ad-hoc central bank preferences. This is accomplished through the characterization of the external finance premium as a function of bank leverage and systemic aggregate risk.

New Numerical Method for Fermion Field Theory

A new deterministic, numerical method to solve fermion field theories is presented. This approach is based on finding solutions $Z[J]$ to the lattice functional equations for field theories in the presence of an external source $J$. Using Grassmann polynomial expansions for the generating functional $Z$, we calculate propagators for systems of interacting fermions. These calculations are straightforward to perform and are executed rapidly compared to Monte Carlo. The bulk of the computation involves a single matrix inversion. Because it is not based on a statistical technique, it does not have many of the difficulties often encountered when simulating fermions. Since no determinant is ever calculated, solutions to problems with dynamical fermions are handled more easily. This approach is very flexible, and can be taylored to specific problems based on convenience and computational constraints. We present simple examples to illustrate the method; more general schemes are desirable for more complicated systems.Comment: 24 pages, latex, figures separat

Counterpropagating dipole-mode vector soliton

We experimentally observe a counterpropagating dipole-mode vector soliton in a photorefractive SBN:60Ce crystal. We investigate the transient formation dynamics and show that the formation process differs significantly from the copropagating geometry. The experimental results are compared with fully anisotropic numerical simulations which show good qualitative agreement.Comment: 4 pages, 4 figure

Daily Stress Recognition from Mobile Phone Data, Weather Conditions and Individual Traits

Research has proven that stress reduces quality of life and causes many diseases. For this reason, several researchers devised stress detection systems based on physiological parameters. However, these systems require that obtrusive sensors are continuously carried by the user. In our paper, we propose an alternative approach providing evidence that daily stress can be reliably recognized based on behavioral metrics, derived from the user's mobile phone activity and from additional indicators, such as the weather conditions (data pertaining to transitory properties of the environment) and the personality traits (data concerning permanent dispositions of individuals). Our multifactorial statistical model, which is person-independent, obtains the accuracy score of 72.28% for a 2-class daily stress recognition problem. The model is efficient to implement for most of multimedia applications due to highly reduced low-dimensional feature space (32d). Moreover, we identify and discuss the indicators which have strong predictive power.Comment: ACM Multimedia 2014, November 3-7, 2014, Orlando, Florida, US

Locke and Hume’s philosophical theory of color is investigated through a case study of Esref Armagan, an artist born blind

This article investigates Locke and Hume’s philosophical theory of color, through a study of the fine art practice of Esref Armagan, a Turkish artist who was born blind. The philosophical theory of color is important to the cultural history of blindness, as it has been used to justify early curricula in schools for the blind. This study is based on the following research question: Can people who are born blind understand color in the fine arts? The study is part of a grounded methodology study of art practices and visual impairment, whose findings informed a participatory study of museum access. This article examines part of the study’s first phase, and focuses on the practice of the blind Turkish artist, Esref Armagan. Data was collected through a translated correspondence interview with Esref Armagan, and an examination of research articles focusing on Armagan’s drawing skills. The study’s data is analyzed using Anderson, Krathwohl, and Bloom’s (2001) learning hierarchy. It is found that Armagan has an extensive knowledge of color and other visual concepts, developed symbolically. What is more, not only does Armagan have a knowledge of color, but he can use this knowledge creatively in accordance with Anderson et al.’s (2001) highest level of learning (level 6). The article concludes that Locke and Hume’s philosophical theory of color can be challenged in the context of the creative fine arts, as Armagan could develop unique, creative images using color. Therefore, our application of the philosophical theory of color on the education of students with visual impairments, and the pedagogical and andragogical practice based on these theories, should be questioned

Radio Observations of HD 80606 Near Planetary Periastron

This paper reports Very Large Array observations at 325 and 1425 MHz (90cm and 20cm) during and near the periastron passage of HD 80606b on 2007 November 20. We obtain flux density limits (3-sigma) of 1.7 mJy and 48 microJy at 325 and 1425 MHz, respectively, equivalent to planetary luminosity limits of 2.3 x 10^{24} erg/s and 2.7 x 10^{23} erg/s. These are well above the Jovian value (at 40 MHz) of 2 x 10^{18} erg/s. The motivation for these observations was that the planetary magnetospheric emission is driven by a stellar wind-planetary magnetosphere interaction so that the planetary luminosity would be elevated. Near periastron, HD 80606b might be as much as 3000 times more luminous than Jupiter. Recent transit observations of HD 80606b provide stringent constraints on the planetary mass and radius, and, because of the planet's highly eccentric orbit, its rotation period is likely to be "pseudo-synchronized" to its orbital period, allowing a robust estimate of the former. We are able to make robust estimates of the emission frequency of the planetary magnetospheric emission and find it to be around 60--90 MHz. We compare HD 80606b to other high-eccentricity systems and assess the detection possibilities for both near-term and more distant future systems. Of the known high eccentricity planets, only HD 80606b is likely to be detectable, as HD 20782B b and HD 4113b are both likely to have weaker magnetic field strengths. Both the forthcoming "EVLA low band" system and the Low Frequency Array may be able to improve upon our limits for HD 80606b, and do so at a more optimum frequency. If the low-frequency component of the Square Kilometre Array (SKA-lo) and a future lunar radio array are able to approach their thermal noise limits, they should be able to detect an HD 80606b-like planet, unless the planet's luminosity increases by substantially less than a factor of 3000.Comment: 9 pages; accepted for publication in A

Refractometry of organosilica microspheres

The refractive index of novel organosilica (nano/micro)material is determined using two methods. The first method is based on analysis of optical extinction efficiency of organosilica beads versus wavelength, which is obtained by a standard laboratory spectrometer. The second method relies on the measurable trapping potential of these beads in the focused light beam (laser tweezers). Polystyrene beads were used to test these methods, and the determined dispersion curves of refractive index values have been found accurate. The refractive index of organosilica beads has been determined to range from 1.60-1.51 over the wavelength range of 300-1100 nm.Comment: 9 pages, 8 figure