192 research outputs found
Curvature Dependence of Hydrophobic Hydration Dynamics
We investigate the curvature-dependence of water dynamics in the vicinity of
hydrophobic spherical solutes using molecular dynamics simulations. For both,
the lateral and perpendicular diffusivity as well as for H-bond kinetics of
water in the first hydration shell, we find a non-monotonic solute-size
dependence, exhibiting extrema close to the well-known structural crossover
length scale for hydrophobic hydration. Additionally, we find an apparently
anomalous diffusion for water moving parallel to the surface of small solutes,
which, however, can be explained by topology effects. The intimate connection
between solute curvature, water structure and dynamics has implications for our
understanding of hydration dynamics at heterogeneous biomolecular surfaces.Comment: 10 pages, 9 figure
Empirical-Rational Semantics of Agent Communication
The missing of an appropriate semantics of agent communication languages is one of the most challenging issues of contemporary AI. Although several approaches to this problem exist, none of them is really suitable for dealing with agent autonomy, which is a decisive property of artificial agents. This paper introduces an observation-based approach to the semantics of agent communication, which combines benefits of the two most influential traditional approaches to agent communication semantics, namely the mentalistic (agent-centric) and the objectivist (i.e., commitment- or protocol-oriented) approach. Our approach makes use of the fact that the most general meaning of agent utterances lays in their expectable consequences in terms of agent actions, and that communications result from hidden but nevertheless rational and to some extent reliable agent intentions. In this work, we present a formal framework which enables the empirical derivation of communication meanings from the observation of rational agent utterances, and introduce thereby a probabilistic and utility-oriented perspective of social commitments
Synchronisation of Bistatic Radar Systems
Abstract-Bistatic radar is gaining more and more interest over the last years. It offers more freedom to deploy the transmitter and the receiver, e. g. in a way to enhance the signature of stealthy targets. Furthermore the bi-or multistatic system can be realized without using expensive transmit/receive-modules. An additional feature of bistatic radar is that continuous wave signals can be used. A crucial problem associated with bi-and multistatic systems is the synchronisation of time and frequency at the transmitters and receivers for coherent signal processing and range measurement. Modern communications satellites and world wide accessible GPS signals allow to synchronise the time easily over a long period with a time difference of less than 1 ns. The required frequency stability depends on the baseline and may vary with application. Image generation with bistatic SAR systems requires a frequency coherence for at least the coherent integration time. For interferometric SAR systems this coherence has to be expanded over the whole processing time. The paper will concentrate on the problem of time and frequency synchronisation between a bistatic transmitter and receiver pair. Possible solutions for attaining the requirements of bistatic radar systems will be discussed
Vom gemischten Phasenraum zu ungeordneten Systemen
Im Rahmen dieser Dissertation werden Quantensignaturen generischer Hamilton-Systeme untersucht. Der klassische Phasenraum solcher Systeme zeichnet sich durch die Koexistenz von Bereichen regulärer und chaotischer Dynamik aus, wobei die Bereiche regulärer Dynamik in einer selbstähnlichen Weise angeordnet sind. Diese bemerkenswerte Struktur eines gemischten Phasenraums führt quantenmechanisch zu einer neuen Klasse von hierarchischen Eigenzuständen, die hier qualitativ und quantitativ behandelt wird. Die Konsequenzen dieser neuen Eigenzustände für offene Quantensysteme werden ebenfalls detailiert untersucht. Im zweiten Teil der Arbeit stehen ungeordnete eindimensionale und quasi-eindimensionale Systeme im Vordergrund. Insbesondere werden die Lokalisierungseigenschaften von Wellenfunktionen in solchen Proben bei Anlegen eines elektrischen Feldes und bei sukzessiver Brechung der Zeitumkehr durch Anlegen eines Magnetfelds untersucht
Sinn und Geschichte. Die filmische Selbstvergegenwärtigung der nationalsozialistischen 'Volksgemeinschaft'.
Der Kernteil der Arbeit analysiert drei 'nationale Großfilme'
(Goebbels) mit historischen Stoffen, die zugleich drei zentrale
Aspekte der nationalsozialistischen Sozialutopie 'Volksgemeinschaft'
repräsentieren: die Gesellschaftsbiologie (Robert Koch. Der Bekämpfer
des Todes, 1939), die Rassenutopie (Jud Süß, 1940) und die
Wehrgemeinschaft (Der große König, 1940). Die brillante Analyse
verbindet institutionsgeschichtliche, diskursanalytische und
systemtheoretische Zugriffe, um einen Beitrag zur Sozialgeschichte
kollektiver Selbstdarstellungen zu liefern. Sie macht damit moderne
Methoden der Geschichtswissenschaft auch für andere Kulturwissenschaften
- vor allem für die mentalitätsgeschichtlich orientierte
Literaturwissenschaft - fruchtbar. Letzlich hat die Arbeit einen
über das Dritte Reich weit hinausreichenden, säkularen Prozeß im
Blick, in dem das neuartige 'Aufschreibsystem' Film zum wichtigsten
Medium von Sinnstiftungen in der Massengesellschaft des 20.
Jahrhunderts wird
Bank stock performance and bank regulation around the globe.
We analyze the effect of bank capital, regulation, and supervision on the annual stock performance of global banks during the period of 1999–2012. We study a large comprehensive panel of international banks and find that higher Tier 1 capital decreases a bank's stock performance over the whole sample period. However, during turbulent times stocks of more highly capitalized banks perform significantly better. Additionally, we find strong evidence that banks that are more likely to receive government bailout during financial distress realize smaller stock performance. In contrast, we find no convincing evidence that banks that generate higher non-interest income have a higher performance
Micro simulated moving bed chromatography-mass spectrometry as a continuous on-line process analytical tool
Continuous manufacturing is becoming increasingly important in the (bio-)pharmaceutical industry, as more product can be produced in less time and at lower costs. In this context, there is a need for powerful continuous analytical tools. Many established off-line analytical methods, such as mass spectrometry (MS), are hardly considered for process analytical technology (PAT) applications in biopharmaceutical processes, as they are limited to at-line analysis due to the required sample preparation and the associated complexity, although they would provide a suitable technique for the assessment of a wide range of quality attributes. In this study, we investigated the applicability of a recently developed micro simulated moving bed chromatography system (µSMB) for continuous on-line sample preparation for MS. As a test case, we demonstrate the continuous on-line MS measurement of a protein solution (myoglobin) containing Tris buffer, which interferes with ESI-MS measurements, by continuously exchanging this buffer with a volatile ammonium acetate buffer suitable for MS measurements. The integration of the µSMB significantly increases MS sensitivity by removing over 98% of the buffer substances. Thus, this study demonstrates the feasibility of on-line µSMB-MS, providing a versatile PAT tool by combining the detection power of MS for various product attributes with all the advantages of continuous on-line analytics
Interaction is Meaning: A New Model for Communication in Open Systems
We propose a new model for agent communication in open systems that is based on the principle that the meaning of communicative acts lies in their experienced consequences. A formal framework for analysing such evolving semantics is defined. An extensive analysis of example interaction processes shows that our framework allows for an assessment of several properties of the communicative conventions governing a multiagent system. Among other advantages, our framework is capable of providing a very straightforward definition of communicative conflict. Also, it allows agents to reason about the e#ects of their communicative behaviour on the structure of communicative expectations as a whole when making decisions
- …