1,721,431 research outputs found
The Aladin abstract machine
Full text linkThe Aladin Abstract Machine (AAM) provides a completely abstract definition of a functional language. There are no primitives built into Aladin, instead primitives are in tended to be programmed in any language, functional or imperative and imported in to the AAM. In this report we develop an efficient operational semantics for the AAM using the original denotational semantics as our starting point. We then use this semantics to develop an implementation of Aladin, using the Java language, with the ability to write programs in an Aladin scripting language that we develop, and primitives written in C/C++, Java and Ginger
The ALADIN System and its canonical model configurations AROME CY41T1 and ALARO CY40T1
Full text linkThe ALADIN System is a numerical weather prediction (NWP) system developed by
the international ALADIN consortium for operational weather forecasting and
research purposes. It is based on a code that is shared with the global model
IFS of the ECMWF and the ARPEGE model of Météo-France. Today, this system
can be used to provide a multitude of high-resolution limited-area model
(LAM) configurations. A few configurations are thoroughly validated and
prepared to be used for the operational weather forecasting in the 16 partner
institutes of this consortium. These configurations are called the ALADIN
canonical model configurations (CMCs). There are currently three CMCs: the
ALADIN baseline CMC, the AROME CMC and the ALARO CMC. Other configurations
are possible for research, such as process studies and climate simulations.
The purpose of this paper is (i) to define the ALADIN System in relation to
the global counterparts IFS and ARPEGE, (ii) to explain the notion of the
CMCs, (iii) to document their most recent versions, and (iv) to illustrate
the process of the validation and the porting of these configurations to the
operational forecast suites of the partner institutes of the ALADIN
consortium.
This paper is restricted to the forecast model only; data assimilation
techniques and postprocessing techniques are part of the ALADIN System but
they are not discussed here
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Finite elements used in the vertical discretization of the fully compressible core of the ALADIN system
Full text linkThe finite-element method with B splines is used for definition of vertical operators in the nonhydrostatic fully compressible dynamical core of the ALADIN system. It represents a generalization of the same method used in the hydrostatic dynamical core shared by the ALADIN system and the global forecast system ARPEGE/IFS. The method is shown to be robust enough in idealized academic tests and real simulations. Its theoretical superiority is shown when compared with the finite-difference method
The Aladin Laser - From Development Challenges to Early In-Orbit Operations
No full textThe Aladin instrument is the sole payload on board the European Space Agency’s Aeolus satellite. The purpose of the mission is to measure wind velocities through the Earth’s atmosphere using the Doppler effect in order to provide inputs to numerical weather prediction models and to better understand atmospheric dynamics. To this end, the instrument has two high intensity, Q-switched lasers that emit 20ns pulses at a wavelength of 355nm, with a pulse repetition frequency of 50Hz. The development of these lasers proved to be somewhat longer and more challenging than was first anticipated, with several technology hurdles to be overcome before they could be integrated and tested on the Aladin instrument. This paper will present these, along with the solutions that were eventually implemented for the flight built instrument along with the on-ground verifications which were undertaken to demonstrate fitness for launch.
The Aeolus satellite was launched into a sun-synchronous, 320km orbit, from the Guiana Space Center, Kourou, French Guiana, on 22nd August 2018 on an Arianespace Vega rocket. The Aladin instrument, including the FM-A laser transmitter, was switched on 10 days later on 2nd September. The switch-on was successfully performed utilising several discrete energy steps, with intermittent assessments of the laser beam using the imaging mode of the Aladin spectrometers, in order to reduce the risk of laser damage. Full energy operation commenced on 4th September. This, along with an assessment of the early operations of the Aladin laser transmitter during the 3 month in-orbit commissioning phase and the subsequent early in-orbit operations will be described
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Historical observation impact assessments for EUMETNET using the ALADIN/HU limited area model
Full text linkTwo historical Observing System Experiment (OSE) studies using the ALADIN limited area model and its assimilation system are described. The first study, using an OSE scenario that minimizes the impacts of observations through the lateral boundary conditions, demonstrated the importance of each assimilated terrestrial (radiosonde, aircraft, and wind profiler) observations on the analyses and short-range forecasts of the ALADIN/HU model and proved evidence, that the role of conventional observations cannot be even partly taken over by satellite measurements without degradation of the forecast quality. The second study demonstrated that the assimilation of radiosonde observations remains indispensable even with a progressively increasing amount of aircraft measurements
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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