Analysis of binary trading patterns in Xetra

This paper proposes the Shannon entropy as an appropriate one-dimensional measure of behavioural trading patterns in financial markets. The concept is applied to the illustrative example of algorithmic vs. non-algorithmic trading and empirical data from Deutsche Börse's electronic cash equity trading system, Xetra. The results reveal pronounced differences between algorithmic and non-algorithmic traders. In particular, trading patterns of algorithmic traders exhibit a medium degree of regularity while non-algorithmic trading tends towards either very regular or very irregular trading patterns. JEL Classification: C40, D0, G14, G15, G2

Low Energy Dynamics in Ultradegenerate QCD Matter

We study the low energy behavior of QCD Green functions in the limit that the baryon chemical potential is much larger than the QCD scale parameter $\Lambda_QCD$. We show that there is a systematic low energy expansion in powers of $(\omega/m)^{1/3}$, where $\omega$ is the energy and $m$ is the screening scale. This expansion is valid even if the effective quark-gluon coupling $g$ is not small. The expansion is purely perturbative in the magnetic regime $|\vec{k}| \gg k_0$. If the external momenta and energies satisfy $k_0 \sim |\vec{k}|$, planar, abelian ladder diagrams involving the full quark propagator have to be resummed but the corresponding Dyson-Schwinger equations are closed.Comment: 4 pages, published versio

Factors Determining the Operational Self-Sufficiency Among Microfinance Institutions

This paper is to determine factors best describing a microfinance institution’s (MFI’s) operational selfsufficiency (OSS). The OSS is  defined as the ratio of an MFI’s operating revenues to it operating expenses including the financial costs and impairment losses on  loans. The outreach of an MFI, the writeoff ratio and regional differences are found significant in determining the OSS of MFIs. Surprisingly, neither an MFI’s depositors-to-borrowers ratio nor its deposits-to-loan portfolio ratio was found to be significant to explain an MFI’s OSS. There was no significant difference in the OSS in 2006 - before the worldwide financial crisis - and in 2008

Neutrino Emission from Ungapped Quark Matter

We study neutrino emission from a normal, ungapped, quark phase in the core of a compact star. Neutrino emission from non-interacting quark matter leads to an emissivity that scales as $\epsilon\sim T^7$. We show that the emissivity is enhanced by a combination of Fermi liquid and non-Fermi liquid effects. Fermi liquid effects lead to an emissivity that scales as $\epsilon\sim \alpha_s T^6$, as originally shown by Iwamoto. We demonstrate that non-Fermi liquid effects further enhance the rate, leading to $\epsilon\sim \alpha_s^3 T^6\log(m/T)^2$, where $m$ is the electric screening scale and $m\gg T$ under the conditions found in compact stars. We show, however, that combined with non-Fermi liquid effects in the specific heat the enhancement in the emissivity only leads to a modest reduction in the temperature of the star at late times. Our results confirm existing bounds on the presence of ungapped quark matter in compact stars. We also discuss neutrino emission from superconducting phases with ungapped fermionic excitations.Comment: minor corrections, published versio

Gegenständliche Modellierung virtueller Informationswelten

"In diesem Beitrag stellen wir ein Konzept greifbarer, gegenständlicher Benutzungsschnittstellen vor. Es werden Übergänge zwischen dem Modellieren im Realen und dem Erstellen virtueller Modelle geschaffen. Synchron zum gegenständlichen Modell entsteht ein virtuelles Abbild, das für Simulation, Animation und für Hilfen genutzt werden kann. Intuitive, spielerische und vorbegriffliche Herangehensweisen werden auf diese Weise mit abstraktem, analytischem Vorgehen verbunden. Es werden Anwendungsbeispiele gegeben und ein Projekt näher erläutert, in dem Förderbandanlagen synchron im Gegenständlichen und Virtuellen modelliert werden. Dabei wird das Programmieren durch Vormachen eingesetzt: Durch Bewegen von Gegenständen durch das Modell werden Regeln für Steuerungen von Förderbändern generiert. Anschließend stellen wir dar, wie gegenständliche Modellumgebungen, die durch ein synchronisiertes Computermodell unterstützt werden, die Zusammenarbeit fördern, indem sie auf natürliche Weise einen gemeinsamen Interaktionsraum herstellen, dessen zentrale Eigenschaften erläutert werden." (Autorenreferat)"In this text we present a concept of graspable computer-interfaces. It links modeling in physical reality with building virtual models. Synchronous to the graspable model a virtual twin-model is generated. The latter can be used for simulation, animation and giving help on the subject. Thus we connect intuitive, game-like and preconceptual approaches with abstract and analytic ways of thinking. We present some application areas, focusing on a project for the modeling of conveyor systems. We explain Programming by Demonstration: manually demonstrating the movement of objects through the scene we generate rules for programmable controls for the conveyor system. Then we focus on how working in computer supported concrete environments fosters group work and communication because it provides a shared workspace in a natural way." (author's abstract

Monitoring Traffic and Emissions by Floating Car Data

Intelligent traffic management is widely acknowledged as a means to optimise the utilisation of existing infrastructure capacities. A major requirement for intelligent traffic management is the collection of high quality data on traffic conditions in order to generate accurate real-time traffic information. The approach to be described here generates this information by a fleet of taxis equipped with GPS which act as Floating-Car-Data (FCD) provider for a number of metropolitan areas. The first part of this paper describes the methodology of setting up this data base. The information collected enables various applications such as real-time traffic monitoring, time-dynamic routing and fleet management. The second part of the paper proposes a framework for using these data additionally to include environmental effects into intelligent traffic management systems. To this end, a mapping between travel times and traffic flows is proposed. Some challenges related to the computation of emissions from velocity profiles are discussed. Equipped with these ingredients, an environmentally friendly intelligent traffic management might be in reach