34,952 research outputs found
Improving Ontology Recommendation and Reuse in WebCORE by Collaborative Assessments
In this work, we present an extension of CORE [8], a tool for Collaborative Ontology Reuse and Evaluation. The system receives an informal description of a specific semantic domain and determines which ontologies from a repository are the most appropriate to describe the given domain. For this task, the environment is divided into three modules. The first component receives the problem description as a set of terms, and allows the user to refine and enlarge it using WordNet. The second module applies multiple automatic criteria to evaluate the ontologies of the repository, and determines which ones fit best the problem description. A ranked list of ontologies is returned for each criterion, and the lists are combined by means of rank fusion techniques. Finally, the third component uses manual user evaluations in order to incorporate a human, collaborative assessment of the ontologies. The new version of the system incorporates several novelties, such as its implementation as a web application; the incorporation of a NLP module to manage the problem definitions; modifications on the automatic ontology retrieval strategies; and a collaborative framework to find potential relevant terms according to previous user queries. Finally, we present some early experiments on ontology retrieval and evaluation, showing the benefits of our system
Broadband suppression of backscattering at optical frequencies using low permittivity dielectric spheres
The exact suppression of backscattering from rotationally symmetric objects
requires dual symmetric materials where . This prevents
their design at many frequency bands, including the optical one, because
magnetic materials are not available. Electromagnetically small non-magnetic
spheres of large permittivity offer an alternative. They can be tailored to
exhibit balanced electric and magnetic dipole polarizabilities, which result in
approximate zero backscattering. In this case, the effect is inherently
narrowband. Here, we put forward a different alternative that allows broadband
functionality: Electromagnetically large spheres made from low permittivity
materials. The effect occurs in a parameter regime that approaches the trivial
case, where approximate duality is met in a
weakly wavelength dependence fashion. Despite the low permittivity, the overall
scattering response of the spheres is still significant. Radiation patterns
from these spheres are shown to be highly directive across an octave spanning
band. The effect is analytically and numerically shown using the Mie
coefficients.Comment: 6 Figure
Local absorption of uncertainty in complex systems using resilient objects
Traditional approaches to managing uncertainties during product development often lead to increased complexity and resource consumption. This paper introduces the concept of ‘resilient objects’ as an alternative solution, designed to provide passive protection against disruptive events of different kinds, thereby reducing the necessity for complex margins at system interfaces. The paper illustrates the concept of resilient objects through practical examples, which demonstrate the objects’ ability to uphold system functionality even when faced with unexpected disruptive events. By embodying resilience locally in areas of the system that are most susceptible to uncertain conditions, resilient objects offer the potential to minimise interface margins and thus the need for excessive system over-design. The concept of resilient objects offers a new perspective on how to solve the trade-offs between resilience and complexity when addressing uncertainties in the dynamic landscape of product development
The Applied Nutrition Project of Eastern Kenya – An Initiative for Reducing Hunger and Malnutrition
Sustainable development is the only kind of development possible for help in the
third world. Due to various historical, political, geographic and climatic conditions the
divergence between those countries providing and those receiving help is so vast that donations
of labor an/or money is simply not enough. Rather, communities have to be
taught to support and develop themselves during the receipt of aid and especially after
the help pulls out. It is our goal in this article to summarize one such »sustainable development
« project. As volunteers for AMREF (African Medical and Research Foundation),
we worked with the remarkable Makueni Applied Nutrition Project in eastern
Kenya in the summer of 2001. Our job was to visit the various locations in this semiarid
and arid environment and to write a report on the situation of the diverse parts of
the project. The Applied Nutrition Project (ANP) started in 1984 and serves as an excellent
example of the significant help that can be provided to needy areas of the world with
a multifaceted approach
Optical Absorption Spectra of Ag11 Isomers by First-Principles Theoretical Spectroscopy with Time-dependent Density Functional Theory
The optical absorption spectrum of the three most stable isomers of the Ag11
system was calculated using the time-dependent density functional theory, with
the generalized gradient approximation for the exchange and correlation
potential, and a relativistic pseudopotential parametrization for the modelling
of the ion-electron interaction. The computational scheme is based on a real
space code, where the photoabsorption spectrum is calculated by using the
formalism developed by Casida. The significantly different spectra of the three
isomers permit the identification of the ground-state configuration
predominantly present in the laboratory beams in base to a comparison between
the calculated photoabsorption spectrum of the most stable configuration of
Ag11 and the measured spectra of medium-size silver clusters trapped in noble
gas Ar and Ne matrices at different temperatures. This assignment is confirmed
by the fact that this isomer has the lowest calculated energy.Comment: 6 pages, 3 color figures, submitted to Chem. Phys. Let
Recent Technological Developments on LGAD and iLGAD Detectors for Tracking and Timing Applications
This paper reports the last technological development on the Low Gain
Avalanche Detector (LGAD) and introduces a new architecture of these detectors
called inverse-LGAD (iLGAD). Both approaches are based on the standard
Avalanche Photo Diodes (APD) concept, commonly used in optical and X-ray
detection applications, including an internal multiplication of the charge
generated by radiation. The multiplication is inherent to the basic n++-p+-p
structure, where the doping profile of the p+ layer is optimized to achieve
high field and high impact ionization at the junction. The LGAD structures are
optimized for applications such as tracking or timing detectors for high energy
physics experiments or medical applications where time resolution lower than 30
ps is required. Detailed TCAD device simulations together with the electrical
and charge collection measurements are presented through this work.Comment: Keywords: silicon detectors, avalanche multiplication, timing
detectors, tracking detectors. 8 pages. 8 Figure
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