5,295 research outputs found
The role of coordination analysis in software integration projects
Available for individual study only.What sort of component coordination strategies emerge in a software integration process? How can such strategies be discovered and further analysed? How close are they to the coordination component of the envisaged architectural model which was supposed to guide the integration process? This paper introduces a framework in which such questions can be discussed and illustrates its use by describing part of a real case-study. The approach is based on a methodology which enables semi-automatic discovery of coordination patterns from source code, combining generalized slicing techniques and graph manipulationThis research was partially supported by Fct in the context of the Mondrian project, under contract PTDC/EIA-CCO/108302/200
A "diamond-ring" star: the unusual morphologic structure of a young (multiple?) object
We have observed IRAS06468-0325 obtaining optical and infrared images through
IJHKs and L' filters, K-band low-resolution spectroscopy, together with
millimetre line observations of CO and CS. IRAS06468-0325 has a very unusual
and enigmatic morphology with two components: a bright, close to point-like
source (the diamond) and a sharp-edge ring-like structure (the ring). The
source is not detected in the optical, at wavelengths shorter than the I-band.
The diamond is seen in all the imaging bands observed. The ring-like structure
in IRAS06468-0325 is clearly seen in the I, J, H, and Ks. It is not detected in
the L'-band image. Infrared colours of the diamond are compatible with excess
circumstellar emission and a young stellar nature. A strongly non-gaussian and
moderately bright CO(1-0) and {13}CO(2-1) lines are seen towards
IRAS06468-0325, at v_{LSR} of 30.5 km s{-1} (corresponding to a kinematic
distance of 3 kpc). Very weak C{18}O(2-1) and CS(2-1) lines were detected.
K-band spectra of the diamond and of the ring are similar both in the slope of
the continuum and in the presence of lines supporting the idea that the ring is
reflected light from the diamond. With the current data, a few different
scenarios are possible to explain the morphology of this object. However, the
available data seem to favour that the morphology of IRAS06468-0325 correspond
to a young stellar multiple system in a transient stage where a binary
co-exists with a circumbinary disc, similar to the case of GG Tau. In this
case, the sharpness of the well-defined ring may be due to tidal truncation
from dynamic interactions between components in a binary or multiple stellar
system. IRAS06468-0325 may be an important rare case that illustrates a
short-lived stage of the process of binary or multiple star formation.Comment: 7 pages, 6 figure
On the reconfiguration of software connectors
Software connectors encapsulate interaction patterns between services in complex, distributed service-oriented applications. Such patterns evolve over time, in response to faults, changes in the expected QoS levels, emergent requirements or the re-assessment of contextual conditions. This paper builds up on a model for connector reconfiguration to introduce notions of reconfiguration equivalence and refinement allowing for reasoning about them. This paves the way towards a (still missing) calculus of connector reconfigurations.FC
On the specification of a component repository
The lack of a commonly accepted definition of a software component, the proliferation of competing `standards' and component frameworks, is here to stay, raising the fundamental question in component based development of how to cope in practice with heterogeneity. This paper reports on the design of a Component Repository aimed to give at least a partial answer to the above question. The repository was fully specified in Vdm and a working prototype is currently being used in an industrial environment
Reconfiguration mechanisms for service coordination
Serie : Lecture notes in computer science, ISSN 0302-9743, vol. 7843Models for exogenous coordination provide powerful glue- code, in the form of software connectors, to express interaction protocols between services in distributed applications. Connector reconfiguration mechanisms play, in this setting, a major role to deal with change and adaptation of interaction protocols. This paper introduces a model for connector reconfiguration, based on a collection of primitives as well as a language to specify connectors and their reconfigurations.Fundação para a Ciência e a Tecnologia (FCT
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