5,453 research outputs found
Optimal algorithms for global optimization in case of unknown Lipschitz constant
We consider a family of function classes which
allow functions with several minima and which
demand only Lipschitz continuity for smoothness.
We present an algorithm almost optimal for each of
these classes
StemNet: An Evolving Service for Knowledge Networking in the Life Sciences
Up until now, crucial life science information resources, whether bibliographic or factual databases, are isolated from each other. Moreover, semantic metadata intended to structure their contents is supplied in a manual form only. In the StemNet project we aim at developing a framework for semantic interoperability for these resources. This will facilitate the extraction of relevant information from textual sources and the generation of semantic metadata in a fully automatic manner. In this way, (from a computational perspective) unstructured life science documents are linked to structured biological fact databases, in particular to the identifiers of genes, proteins, etc. Thus, life scientists will be able to seamlessly access information from a homogeneous platform, despite the fact that the original information was unlinked and scattered over the whole variety of heterogeneous life science information resources and, therefore, almost inaccessible for integrated systematic search by academic, clinical, or industrial users
Role of Chlamydia pneumoniae and Mycoplasma pneumoniae as Causative Agents of Community-Acquired Pneumonia in Hospitalised Children and Adolescents
The aim of the study presented here was to determine the prevalence of Chlamydia pneumoniae versus Mycoplasma pneumoniae infections in paediatric patients with community-acquired pneumonia. A total of 50 patients (mean age, 5.5 years; median, 3.9 years) with community-acquired pneumonia were enrolled. Four patients were found to have Chlamydia pneumoniae infection (1 culture positive, 1 PCR positive and 2 serology positive) and 16 patients had Mycoplasma pneumoniae infection (2 PCR positive, 4 PCR and serology positive, 10 serology positive), including three patients with coinfection. The rates of Mycoplasma pneumoniae infection were 22%, 35% and 40% in children aged 1-3, >3-7 and >7 years, respectively. Acute Chlamydia pneumoniae infection was substantially less common than Mycoplasma pneumoniae infection in our study cohor
Free Radicals in Superfluid Liquid Helium Nanodroplets: A Pyrolysis Source for the Production of Propargyl Radical
An effusive pyrolysis source is described for generating a continuous beam of
radicals under conditions appropriate for the helium droplet pick-up method.
Rotationally resolved spectra are reported for the vibrational mode of
the propargyl radical in helium droplets at 3322.15 cm. Stark spectra
are also recorded that allow for the first experimental determination of the
permanent electric dipole moment of propargyl, namely -0.150 D and -0.148 D for
ground and excited state, respectively, in good agreement with previously
reported ab initio results of -0.14 D [1]. The infrared spectrum of the
mode of propargyl-bromide is also reported. The future application of these
methods for the production of novel radical clusters is discussed
GREAT: the SOFIA high-frequency heterodyne instrument
We describe the design and construction of GREAT, the German REceiver for
Astronomy at Terahertz frequencies operated on the Stratospheric Observatory
for Infrared Astronomy (SOFIA). GREAT is a modular dual-color heterodyne
instrument for highresolution far-infrared (FIR) spectroscopy. Selected for
SOFIA's Early Science demonstration, the instrument has successfully performed
three Short and more than a dozen Basic Science flights since first light was
recorded on its April 1, 2011 commissioning flight.
We report on the in-flight performance and operation of the receiver that -
in various flight configurations, with three different detector channels -
observed in several science-defined frequency windows between 1.25 and 2.5 THz.
The receiver optics was verified to be diffraction-limited as designed, with
nominal efficiencies; receiver sensitivities are state-of-the-art, with
excellent system stability. The modular design allows for the continuous
integration of latest technologies; we briefly discuss additional channels
under development and ongoing improvements for Cycle 1 observations.
GREAT is a principal investigator instrument, developed by a consortium of
four German research institutes, available to the SOFIA users on a
collaborative basis
Tangible Interaction and Learning: The Case for a Hybrid Approach
Research involving tangible interaction and children has often focused on how tangibles might sup- port or improve learning compared to more traditional methods. In this paper, we review three of our research studies involving tangible computer programming that have addressed this question in a variety of learning environments with a diverse population of children. Through these studies, we identify situations in which tangible interaction seems to offer advantages for learning; how- ever, we have also identify situations in which tangible interaction proves less useful and an alternative interaction style provides a more appropriate medium for learning. Thus, we advocate for a hybrid approach—one that offers teachers and learners the flexibility to select the most appropriate interaction style to meet the needs of a specific situation
A Study of the Scope of the Declamation Program in South Dakota and its Values as Measured by Presently Enrolled College Students
¬The purpose of this study was to declamation program in South Dakota High School in an effort to determine the values, if any, of this program as measured by students presently enrolled in college. First and perhaps foremost, was a personal interest in the area of declamation. At the present time, the writer is actively engaged in the coaching of declamation on the junior and senior high school levels. Also, while working on the course work toward the degree of Master of Science in communication, she worked with undergraduate college students in the area of original oratory which frequently involved many of the same processes and techniques stressed in declamation. The second reason for the selection of this study by the writer was the extensiveness of the declamation program in this state. A third factor in prompting this study by the writer was interact expressed on the part of members of the speech Department of South Dakota State College aroused by an interview-type survey conducted by three students on the campus of that institution during the fall of 1961. Finally, the writer was interested in examining the declamation program in South Dakota because of the disagreement that seemed to be expressed by those individuals who were coaching and judging declaration contests concerning the merits of the program itself. Therefore, because of personal interest, the magnitude of the program, recommendations based on previous surveys, and the existing differences of opinion of instructors in the field of declamation, the writer felt prompted to select a study which would include a review of the declamation program together with an attempt to measure what values, If any, presently enrolled college students felt they had received from their experiences with declamation in schools in South Dakota
Complete conditions for legitimate Wigner distributions
Given a real-valued phase-space function, it is a nontrivial task to
determine whether it corresponds to a Wigner distribution for a physically
acceptable quantum state. This topic has been of fundamental interest for long,
and in a modern application, it can be related to the problem of entanglement
detection for multi-mode cases. In this paper, we present a hierarchy of
complete conditions for a physically realizable Wigner distribution. Our
derivation is based on the normally-ordered expansion, in terms of annihilation
andcreation operators, of the quasi-density operator corresponding to the
phase-space function in question. As a by-product, it is shown that the
phase-space distributions with elliptical symmetry can be readily diagonalized
in our representation, facilitating the test of physical realizability. We also
illustrate how the current formulation can be connected to the detection of
bipartite entanglement for continuous variables.Comment: 6 pages, published version with improved presentatio
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