3,474 research outputs found
Audiovisual research collections and their preservation
The basic problem of primary audio and video research materials is clearly shown by the survey: A great and important part of the entire heritage is still outside archival custody in the narrower sense, scattered over many institutions in fairy small collections, and even in private hands. reservation following generally accepted standards can only be carried out effectively if collections represent critical mass. Specialised audiovisual archives will solve their problems, as they will sooner or later succeed in getting appropriate funding to achieve their aims. A very encouraging example is the case of the Netherlands. The larger audiovisual research archives will also manage, more or less autonomously, the transfer of contents in time. For a considerable part of the research collections, however, the concept of cooperative models and competence centres is the only viable model to successfullly safeguard their holdings. Their organisation and funding is a considerable challenge for the scientific community. TAPE has significantly raised awareness of the fact that, unless action is swiftly taken, the loss of audiovisual materials is inevitable. TAPE’s international and regional workshops were generally overbooked. While TAPE was already underway, several other projects for the promotion of archives have received grants from organisations other than the European Commission, inter alia support for the St. Petersburg Phonogram Archive, and the Folklore Archive in Tirana, obviously as a result of a better understanding of the need for audiovisual preservation. When the TAPE project started its partners assumed that cooperative projects would fail because of the notorious distrust of researchers, specifically in the post-communist countries. One of the most encouraging surprises was to learn that, at least in the most recent survey, it became apparent that this social obstacle is fading out. TAPE may have contributed to this important development
Parental Ethnic Identity and Educational Attainment of Second-Generation Immigrants
A lack of cultural integration is often blamed for hindering immigrant families' economic progression. This paper is a first attempt to explore whether immigrant parents' ethnic identity affects the next generation's human capital accumulation in the host country. Empirical results based on data from the German Socio-Economic Panel (GSOEP) indicate that maternal majority as well as paternal minority identity are positively related to the educational attainment of second-generation youth – even controlling for differences in ethnicity, family background and years-since-migration. Additional tests show that the effect of maternal majority identity can be explained by mothers' German language proficiency, while the beneficial effect of fathers' minority identity is not related to language skills and thus likely to stem from paternal minority identity per se.ethnic identity, second-generation immigrants, education
A Lagrangian approach to modeling heat flux driven close-contact melting
Close-contact melting refers to the process of a heat source melting its way
into a phase-change material. Of special interest is the close-contact melting
velocity, or more specifically the relative velocity between the heat source
and the phase-change material. In this work, we present a novel numerical
approach to simulate quasi-steady, heat flux driven close-contact melting. It
extends existing approaches found in the literature, and, for the first time,
allows to study the impact of a spatially varying heat flux distribution. We
will start by deriving the governing equations in a Lagrangian reference frame
fixed to the heat source. Exploiting the narrowness of the melt film enables us
to reduce the momentum balance to the Reynolds equation, which is coupled to
the energy balance via the velocity field. We particularize our derivation for
two simple, yet technically relevant geometries, namely a 3d circular disc and
a 2d planar heat source. An iterative solution procedure for the coupled system
is described in detail and discussed on the basis of a convergence study.
Furthermore, we present an extension to allow for rotational melting modes.
Various test cases demonstrate the proficiency of our method. In particular, we
will utilize the method to assess the efficiency of the close-contact melting
process and to quantify the model error introduced if convective losses are
neglected. Finally, we will draw conclusions and present an outlook to future
work
Constraints, Lazy Constraints, or Propagators in ASP Solving: An Empirical Analysis
Answer Set Programming (ASP) is a well-established declarative paradigm. One
of the successes of ASP is the availability of efficient systems.
State-of-the-art systems are based on the ground+solve approach. In some
applications this approach is infeasible because the grounding of one or few
constraints is expensive. In this paper, we systematically compare alternative
strategies to avoid the instantiation of problematic constraints, that are
based on custom extensions of the solver. Results on real and synthetic
benchmarks highlight some strengths and weaknesses of the different strategies.
(Under consideration for acceptance in TPLP, ICLP 2017 Special Issue.)Comment: Paper presented at the 33nd International Conference on Logic
Programming (ICLP 2017), Melbourne, Australia, August 28 to September 1,
2017. 16 page
Observation of anisotropic interlayer Raman modes in few-layer ReS2
ReS has recently emerged as a new member in the rapidly growing family of
two-dimensional materials. Unlike MoS or WSe, the optical and
electrical properties of ReS are not isotropic due to the reduced symmetry
of the crystal. Here, we present layer-dependent Raman measurements of ReS
samples ranging from monolayers to ten layers in the ultralow frequency regime.
We observe layer breathing and shear modes which allow for easy assignment of
the number of layers. Polarization-dependent measurements give further insight
into the crystal structure and reveal an energetic shift of the shear mode
which stems from the in-plane anisotropy of the shear modulus in this material
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