This paper finds that the long-term co-movement among commodities is driven by economic relations, such as, production, substitution or complementary relationships. These economic linkages imply that expected commodity prices, which are determined by convenience yields and risk premia among other factors, tend to move with each other. This source of co-movement is not captured by traditional co...

BACKGROUND Guidance on designing cost-effective examinations and on interpretation of expert observations has been available since the late 1990s in the form of a model framework called Case Assessment and Interpretation (CAI) (Cook et al., 1998a,b; Jackson and Jones, 2009). The underlying principles of the guidance were subsequently encoded in a published standard written by the Association of...

We investigate fully automatic recognition of singer traits, i. e., gender, age, height and ‘race’ of the main performing artist(s) in recorded popular music. Monaural source separation techniques are combined to simultaneously enhance harmonic parts and extract the leading voice. For evaluation the UltraStar database of 581 pop music songs with 516 distinct singers is chosen. Extensive test ru...

This paper presents the Virtual Science Hub platform. It is an open source platform that combines a social network, an elearning authoring tool, a videoconference service and a learning object repository for science teaching enrichment. These four main functionalities fit very well together. The platform was released in April 2012 and since then it has not stopped growing. Finally we present th...

In this paper, we are concerned with a class of multi-dimensional balance laws with a non-local dissipative source which arise as simplified models for the hydrodynamics of radiating gases. At first we introduce the energy method in the setting of smooth perturbations and study the stability of constants states. Precisely, we employ Fourier space analysis to quantify the energy dissipation rate...

Type and range of entrainment of glycolytic oscillations by a periodic source of substrate are determined experimentally in yeast extracts. Subharmonic entrainment proves the nonlinear nature of the glycolytic oscillator Random variation of the substrate input yields sustained oscillations of irregular waveform and stable period. The results agree with the predictions of an allosteric model for...

Abstract. We consider a second-order equation of Duffing type. Bounds for the derivative of the restoring force are given which ensure the existence and uniqueness of a periodic solution. Furthermore, the unique periodic solution is asymptotically stable with sharp rate of exponential decay. In particular, for a restoring term independent of the variable t, a necessary and sufficient condition ...

To examine levels, health risks, sources, and spatial distributions of potentially toxic elements in settled dust over Beijing urban area, 62 samples were collected mostly from residential building outdoor surfaces, and their <63 μm fractions were measured for 12 potentially toxic elements. The results show that V, Cr, Mn, Co, Ni, and Ba in dust are from predominantly natural sources, whereas C...