941 research outputs found
Enrollment Report - Fall 1990
The Enrollment Report provides administrative and delivery-site information on enrollment headcount and student credit hours, as well as the demographic characteristics of enrolled students. The purpose of this profile is to provide the undergraduate and graduate enrollments and student credit hour information by college or equivalent academic unit, class, gender and ethnicity
Informationsverarbeitung im Rahmen der JahresabschlussprĂźfung: Fachkonzeptuelles Modell eines integrierten Anwendungssystems zur UnterstĂźtzung der JahresabschlussprĂźfung
Gegenstand der vorliegenden Untersuchung ist es, die Jahresabschlussprßfung als Prozess der Informationsverarbeitung darzustellen und diesen Prozess zu analysieren. Es wird betrachtet, ob und auf welche Art und Weise durch zielorientierte Konstruktion eines Anwendungssystems zur Unterstßtzung der Abschlussprßfung die Effektivität und Effizienz des Prßfungsprozesses erhÜht werden kann. Dabei werden ausgehend von einer Informationsbedarfsanalyse sämtliche denkbaren MÜglichkeiten des Einsatzes prßfungsunterstßtzender Anwen-dungssysteme untersucht. Auf dieser Basis wird im Hauptteil der Untersuchung ein fachkonzeptuelles Modell eines prßfungsunterstßtzenden Anwendungssystems unter Zugrunde-legung der ARIS-Methode modelliert. Die Arbeit wurde im Jahre 2002 an der wirtschaftswissenschaftlichen Fakultät der TU Dresden als Dissertation angenommen
Dynamical Instabilities and Deterministic Chaos in Ballistic Electron Motion in Semiconductor Superlattices
We consider the motion of ballistic electrons within a superlattice miniband
under the influence of an alternating electric field. We show that the
interaction of electrons with the self-consistent electromagnetic field
generated by the electron current may lead to the transition from regular to
chaotic dynamics. We estimate the conditions for the experimental observation
of this deterministic chaos and discuss the similarities of the superlattice
system with the other condensed matter and quantum optical systems.Comment: 6 pages, RevTEX; 4 fig
Anisotropic permeability in deterministic lateral displacement arrays
We uncover anisotropic permeability in microfluidic deterministic lateral
displacement (DLD) arrays. A DLD array can achieve high-resolution bimodal
size-based separation of microparticles, including bioparticles, such as cells.
For an application with a given separation size, correct device operation
requires that the flow remains at a fixed angle to the obstacle array. We
demonstrate via experiments and lattice-Boltzmann simulations that subtle array
design features cause anisotropic permeability. Anisotropic permeability
indicates the microfluidic array's intrinsic tendency to induce an undesired
lateral pressure gradient. This can cause an inclined flow and therefore local
changes in the critical separation size. Thus, particle trajectories can become
unpredictable and the device useless for the desired separation task.
Anisotropy becomes severe for arrays with unequal axial and lateral gaps
between obstacle posts and highly asymmetric post shapes. Furthermore, of the
two equivalent array layouts employed with the DLD, the rotated-square layout
does not display intrinsic anisotropy. We therefore recommend this layout over
the easier-to-implement parallelogram layout. We provide additional guidelines
for avoiding adverse effects of anisotropy on the DLD.Comment: 13 pages, 10 figures, 1 table, DLD, particle separation,
microfluidics, anisotropic permeabilit
Can filesharers be triggered by economic incentives? Results of an experiment
Illegal filesharing on the internet leads to considerable financial losses for artists and copyright owners as well as producers and sellers of music. Thus far, measures to contain this phenomenon have been rather restrictive. However, there are still a considerable number of illegal systems, and users are able to decide quite freely between legal and illegal downloads because the latter are still difficult to sanction. Recent economic approaches account for the improved bargaining position of users. They are based on the idea of revenue-splitting between professional sellers and peers. In order to test such an innovative business model, the study reported in this article carried out an experiment with 100 undergraduate students, forming five small peer-to-peer networks.The networks were confronted with different economic conditions.The results indicate that even experienced filesharers hold favourable attitudes towards revenue-splitting.They seem to be willing to adjust their behaviour to different economic conditions
Breakdown of deterministic lateral displacement efficiency for non-dilute suspensions: a numerical study
We investigate the effect of particle volume fraction on the efficiency of
deterministic lateral displacement (DLD) devices. DLD is a popular passive
sorting technique for microfluidic applications. Yet, it has been designed for
treating dilute suspensions, and its efficiency for denser samples is not well
known. We perform 3D simulations based on the immersed-boundary,
lattice-Boltzmann and finite-element methods to model the flow of red blood
cells (RBCs) in different DLD devices. We quantify the DLD efficiency in terms
of appropriate "failure" probabilities and RBC counts in designated device
outlets. Our main result is that the displacement mode breaks down upon an
increase of RBC volume fraction, while the zigzag mode remains relatively
robust. This suggests that the separation of larger particles (such as white
blood cells) from a dense RBC background is simpler than separating smaller
particles (such as platelets) from the same background. The observed breakdown
stems from non-deterministic particle collisions interfering with the designed
deterministic nature of DLD devices. Therefore, we postulate that dense
suspension effects generally hamper efficient particle separation in devices
based on deterministic principles.Comment: 21 pages, 9 figure
Building Science Gateways for Analysing Molecular Docking Results Using a Generic Framework and Methodology
Molecular docking and virtual screening experiments require large computational and data resources and high-level user interfaces in the form of science gateways. While science gateways supporting such experiments are relatively common, there is a clearly identified need to design and implement more complex environments for further analysis of docking results. This paper describes a generic framework and a related methodology that supports the efficient development of such environments. The framework is modular enabling the reuse of already existing components. The methodology, which proposes three techniques that the development team can use, is agile and encourages active participation of end-users. Based on the framework and methodology, two prototype implementations of science-gateway-based docking environments are presented and evaluated. The first system recommends a receptor-ligand pair for the next docking experiment, and the second filters docking results based on ligand properties
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