Peer-to-peer lending is hypothesized to help equalize economic opportunities for the world's poor. We empirically investigate the "flat-world" hypothesis, the idea that globalization eventually leads to economic equality, using crowdfinancing data for over 660,000 loans in 220 nations and territories made between 2005 and 2013. Contrary to the flat-world hypothesis, we find that peer-to-peer le...

We introduce a concept of differential flatness for systems described by nonlinear partial differential equations. It generalizes the now classical notion of differential flatness for finite differential systems and its recent extensions to linear partial differential equations. We apply it to the motion planning of a very flexible rod, outside of the linear approximation range.

A number of perceptual features have been utilized for the characterization of the emotional state of a speaker. However, for automatic recognition suitable objective features are needed. We have examined several features of the speech signal in relation to accentuation and traces of event-related brain potentials (ERPs) during affective speech perception. Concerning the features of the speech ...

For discrete-time systems, flatness is usually defined by replacing the time-derivatives of well-known continuous-time definition forward-shifts. With this definition, class flat systems corresponds exactly to which can be linearized a endogenous dynamic feedback as it proposed in literature. Recently, verifiable necessary and sufficient differential-geometric conditions for property have been ...

We survey two approaches to flatness necessary and sufficient conditions and compare them on examples.

When Einstein was thinking about the theory of general relativity based on the elimination of especial relativity constraints (especially the geometric relationship of space and time), he understood the first limitation of especial relativity is ignoring changes over time. Because in especial relativity, only the curvature of the space was considered. Therefore, tensor calculations should be to...

We propose a scenario in which the cosmological domain wall and monopole problems are solved without any fine tuning of the initial conditions or parameters in the Lagrangian of an underlying filed theory. In this scenario domain walls sweep out (unwind) the monopoles from the early universe, then the fast primordial black holes perforate the domain walls, change their topology and destroy them...

This paper describes the application of diierential atness techniques from nonlinear control theory to mechanical (La-grangian) systems. Systems which are diierentially at have several useful properties which can be exploited to generate eeective control strategies for nonlinear systems. For the special case of mechanical control systems, much more geometric information is present and the purpo...

We characterize those small categories with the property that flat (contravariant) functors on them are coherently axiomatized in the language of presheaves on them. They are exactly the categories with the property that every finite diagram into them has a finite set of (weakly) initial cocones.