508 research outputs found
Framework for software architecture visualization assessment.
In order to assess software architecture visualisation strategies, we qualitatively characterize then construct an assessment framework with 7 key areas and 31 features. The framework is used for evaluation and comparison of various strategies from multiple stakeholder perspectives. Six existing software architecture visualisation tools and a seventh research tool were evaluated. All
tools exhibited shortcomings when evaluated in the framework
Untangling Fine-Grained Code Changes
After working for some time, developers commit their code changes to a
version control system. When doing so, they often bundle unrelated changes
(e.g., bug fix and refactoring) in a single commit, thus creating a so-called
tangled commit. Sharing tangled commits is problematic because it makes review,
reversion, and integration of these commits harder and historical analyses of
the project less reliable. Researchers have worked at untangling existing
commits, i.e., finding which part of a commit relates to which task. In this
paper, we contribute to this line of work in two ways: (1) A publicly available
dataset of untangled code changes, created with the help of two developers who
accurately split their code changes into self contained tasks over a period of
four months; (2) a novel approach, EpiceaUntangler, to help developers share
untangled commits (aka. atomic commits) by using fine-grained code change
information. EpiceaUntangler is based and tested on the publicly available
dataset, and further evaluated by deploying it to 7 developers, who used it for
2 weeks. We recorded a median success rate of 91% and average one of 75%, in
automatically creating clusters of untangled fine-grained code changes
From image to technology: a multidisciplinary approach for improving the quality of organic bread.
This study is part of a research programme devoted to improving the quality of organic bread. It aims to identify and test prototypes of breads approved by consumers. This is achieved by analysing consumer representations and preferences and placing them within the framework of technological, sensory and nutritional dimensions of the products. The multidisciplinary approach implements an original qualitative approach that combines three consumer focus groups made up of both loyal and occasional consumers, and confrontation sessions with the programme scientific partners. Four prototypes of organic breads have thus been formalised and subsequently tested on a sample of 120 consumers from two sites (Angers and Strasbourg). From an operational point of view, proposals for organic breads approved by consumers are formulated. In terms of methodology, the contributions of a multidisciplinary study are discussed
Mechanical tests and definition of new indexes of grape berry firmness. Evolution of berry skin hardness during alcoholic fermentation
The mechanical strength or firmness of a fruit is considered an important parameter to characterise its state of ripeness or conservation, as well as other parameters such as sugar level or color. The mechanical hardness of grapes influences the integrity and sanitary quality of the harvest. In this study, the mechanical characteristics of grapevine berries were studied at harvest time in order to determine their rheological properties (firmness and hardness of the berry skin) during alcoholic fermentation. Special indexes were defined measuring the energy needed to crush the berries to 50 % of their initial diameter, and applied successively to two different varieties. The entire berry firmness and the skin hardness were both different. Mechanical indexes linked to grape firmness were defined. Using these indexes, a significant effect on the firmness behavior due to variety was recorded: the skin of 'Grenache Noir' was found firmer and harder than 'Carignan Noir'. Furthermore, during the alcoholic fermentation, no change in skin hardness was observed for both varieties, despite changes in the composition of the must. These results give new information on mechanical properties of berries and could be used as an aid in the winemaking process. Indeed, they would probably help the winemaker to better choose the type of fermentation and maceration adapted to his grapes according to the type of wine he wishes to produce
Scissors resonance in the quasi-continuum of Th, Pa and U isotopes
The gamma-ray strength function in the quasi-continuum has been measured for
231-233Th, 232,233Pa and 237-239U using the Oslo method. All eight nuclei show
a pronounced increase in gamma strength at omega_SR approx 2.4 MeV, which is
interpreted as the low-energy M1 scissors resonance (SR). The total strength is
found to be B_SR = 9-11 mu_N^2 when integrated over the 1 - 4 MeV gamma-energy
region. The SR displays a double-hump structure that is theoretically not
understood. Our results are compared with data from (gamma, gamma') experiments
and theoretical sum-rule estimates for a nuclear rigid-body moment of inertia.Comment: 11 pages, 9 figure
Phase detection based on a single parity check code for low SNR applications
The improvement of carrier phase synchronization through the use of channel decoding information has been recently
widely studied. However, an initial synchronization step is necessary prior to the first decoding iteration. When the phase to
estimate is not constant (due to frequency error or phase noise), this first step is problematic on relatively long coded
words. In this paper we propose to add a short single parity-check code to the transmission scheme for the synchronization
purpose. The proposed phase detector is based on the soft symbol decoding of the additional code. Our simulation
results show that the proposed synchronization scheme outperforms the classical non data-aided and decision directed
algorithms for continuous transmissions with 8PSK modulation, in presence of phase noise. It allows indeed to reduce
the phase jitter in considerable proportions. Requiring few additional complexity, it seems well adapted to satellite
continuous transmissions.De nombreuses études ont récemment montré l'avantage que l'on peut tirer du décodage canal pour
l'amélioration de la synchronisation de phase porteuse à faible rapport signal à bruit. Lorsque la phase à
estimer varie au cours du temps (erreur de fréquence, bruit de phase), l'estimation de la phase avant
la première étape de décodage pose toutefois problème lorsque les mots de code sont longs. Nous proposons
ici un algorithme de synchronisation fondé sur l'introduction d'un code de parité simple et court. Nous
montrons que pour une transmission continue et une modulation MDP8, le détecteur proposé permet de
réduire sensiblement la gigue de phase à très faible point de fonctionnement et en présence de bruit de
phase, par rapport aux algorithmes classiques. De faible complexité, il apparait notamment bien adapté au
contexte des télécommunications par satellite
Investigation of the 238U(d, p) surrogate reaction via the simultaneous measurement of γ -decay and fission probabilities
We investigated the 238U(d,p) reaction as a surrogate for the n + 238U reaction. For this purpose we measured
for the first time the γ -decay and fission probabilities of 239U∗ simultaneously and compared them to the
corresponding neutron-induced data. We present the details of the procedure to infer the decay probabilities, as
well as a thorough uncertainty analysis, including parameter correlations. Calculations based on the continuumdiscretized
coupled-channels method and the distorted-wave Born approximation (DWBA) were used to correct
our data from detected protons originating from elastic and inelastic deuteron breakup. In the region where fission
and γ emission compete, the corrected fission probability is in agreement with neutron-induced data, whereas
the γ -decay probability is much higher than the neutron-induced data. We have performed calculations of the
decay probabilities with the statistical model and of the average angular momentum populated in the 238U(d,p)
reaction with the DWBA to interpret these resultsComisión Europea 26949
Insulator-Metal Transition in One Dimension Induced by Long-Range Electronic Interactions
The effects of a long range electronic potential on a one dimensional
commensurate Charge Density Wave (CDW) state are investigated. Using numerical
techniques it is shown that a transition to a metallic ground state is reached
as the range of the electron-electron repulsion increases. In this metallic
state, the optical conductivity exhibits a large Drude weight. Possible
interpretations of our results are discussed.Comment: 5 pages, Revtex, minor misprints corrected and a reference to earlier
work by V. Emery and C. Noguera adde
Charge gap in the one--dimensional dimerized Hubbard model at quarter-filling
We propose a quantitative estimate of the charge gap that opens in the
one-dimensional dimerized Hubbard model at quarter-filling due to dimerization,
which makes the system effectively half--filled, and to repulsion, which
induces umklapp scattering processes. Our estimate is expected to be valid for
any value of the repulsion and of the parameter describing the dimerization. It
is based on analytical results obtained in various limits (weak coupling,
strong coupling, large dimerization) and on numerical results obtained by exact
diagonalization of small clusters. We consider two models of dimerization:
alternating hopping integrals and alternating on--site energies. The former
should be appropriate for the Bechgaard salts, the latter for compounds where
the stacks are made of alternating and molecules. % and ( denotes , , ...).Comment: 33 pages, RevTeX 3.0, figures on reques
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