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81.
82.
Diego Dermeval Jéssyka Vilela Ig Ibert Bittencourt Jaelson Castro Seiji Isotani Patrick Brito Alan Silva 《Requirements Engineering》2016,21(4):405-437
There is an increase use of ontology-driven approaches to support requirements engineering (RE) activities, such as elicitation, analysis, specification, validation and management of requirements. However, the RE community still lacks a comprehensive understanding of how ontologies are used in RE process. Thus, the main objective of this work is to investigate and better understand how ontologies support RE as well as identify to what extent they have been applied to this field. In order to meet our goal, we conducted a systematic literature review (SLR) to identify the primary studies on the use of ontologies in RE, following a predefined review protocol. We then identified the main RE phases addressed, the requirements modelling styles that have been used in conjunction with ontologies, the types of requirements that have been supported by the use of ontologies and the ontology languages that have been adopted. We also examined the types of contributions reported and looked for evidences of the benefits of ontology-driven RE. In summary, the main findings of this work are: (1) there are empirical evidences of the benefits of using ontologies in RE activities both in industry and academy, specially for reducing ambiguity, inconsistency and incompleteness of requirements; (2) the majority of studies only partially address the RE process; (3) there is a great diversity of RE modelling styles supported by ontologies; (4) most studies addressed only functional requirements; (5) several studies describe the use/development of tools to support different types of ontology-driven RE approaches; (6) about half of the studies followed W3C recommendations on ontology-related languages; and (7) a great variety of RE ontologies were identified; nevertheless, none of them has been broadly adopted by the community. Finally, we conclude this work by showing several promising research opportunities that are quite important and interesting but underexplored in current research and practice. 相似文献
83.
Recently the action systems formalism for parallel and distributed systems has been extended with the procedure mechanism.
This gives us a very general framework for describing different communication paradigms for action systems, e.g. remote procedure
calls. Action systems come with a design methodology based on the refinement calculus. Data refinement is a powerful technique
for refining action systems. In this paper we will develop a theory and proof rules for the refinement of action systems that
communicate via remote procedures based on the data refinement approach. The proof rules we develop are compositional so that
modular refinement of action systems is supported. As an example we will especially study the atomicity refinement of actions.
This is an important refinement strategy, as it potentially increases the degree of parallelism in an action system.
Received February 1999 / Accepted in revised form July 2000 相似文献
84.
Boulahya K Ruiz-González L Parras M González-Calbet JM Nickolsky MS Nicolopoulos S 《Ultramicroscopy》2007,107(6-7):445-452
Two complex perovskite-related structures were solved by ab initio from precession electron diffraction intensities. Structure models were firstly derived from HREM images and than have been confirmed independently using two and three-dimensional sets of precession intensities. Patterson techniques prove to be effective for ab initio structure resolution, specially in case of projections with no overlapping atoms. Quality of precession intensity data may be suitable enough to resolve unknown heavy oxide structures. 相似文献
85.
Clarisse Sieckenius de Souza Simone Diniz Junqueira Barbosa Raquel Oliveira Prates 《Knowledge》2001,14(8):461-465
Designing software involves good perception, good reasoning, and a talent to express oneself effectively through programming and interactive languages. Semiotic theories can help HCI designers increase their power to perceive, reason and communicate. By presenting some of the results we have reached with semiotic engineering over the last few years, we suggest that the main contributions of semiotic theory in supporting HCI design are: to provide designers with new perceptions on the process and product of HCI design; to bind together all the stages of software development and use, giving them a unique homogeneous treatment; and to pose innovative questions that extend the frontiers of HCI investigations. 相似文献
86.
Andrei?SharfEmail author Marina?Blumenkrants Ariel?Shamir Daniel?Cohen-Or 《The Visual computer》2006,22(9-11):835-844
Editing and manipulation of existing 3D geometric objects are a means to extend their repertoire and promote their availability. Traditionally, tools to compose or manipulate objects defined by 3D meshes are in the realm of artists and experts. In this paper, we introduce a simple and effective user interface for easy composition of 3D mesh-parts for non-professionals. Our technique borrows from the cut-and-paste paradigm where a user can cut parts out of existing objects and paste them onto others to create new designs. To assist the user attach objects to each other in a quick and simple manner, many applications in computer graphics support the notion of “snapping”. Similarly, our tool allows the user to loosely drag one mesh part onto another with an overlap, and lets the system snap them together in a graceful manner. Snapping is accomplished using our Soft-ICP algorithm which replaces the global transformation in the ICP algorithm with a set of point-wise locally supported transformations. The technique enhances registration with a set of rigid to elastic transformations that account for simultaneous global positioning and local blending of the objects. For completeness of our framework, we present an additional simple mesh-cutting tool, adapting the graph-cut algorithm to meshes. 相似文献
87.
Barbosa FR 《Applied optics》1983,22(23):3859-3863
Several orders of stimulated Raman scattering (SRS) in monomode and multimode fibers have been observed. The relatively low power in the visible used in the quasi-stationary regime permitted observation of sharply defined Stokes and anti-Stokes spectral lines without any continua. Results of pump-to-Stokes power conversion in a monomode fiber indicate a striking equivalence between pump power and fiber length. The dependence of multiple SRS generation/amplification with these parameters is investigated up to the limit of near total pump extinction. We propose a qualitative explanation of these facts, although a detailed theory of nonlinear behavior of fibers is wanting. Parametric four-photon mixing is again confirmed to account for the generation of stimulated anti-Stokes radiation in multimode fibers and its absolute absence in monomode fibers. 相似文献
88.
Quasi-elastic light scattering of carnauba wax in the liquid phase is obtained in a heterodyne setup, and dynamic processes are analyzed through electrophoresis. Nonspherical polar clusters are found, containing a net electrical charge. An applied square-wave electric field induces drift and rotation of these clusters.These effects are dependent on strength and frequency of the applied electric field. At 373 K and in the low frequency limit the local electric field strength is approximately 70 times the strength of the applied one. This enhancement is believed to be caused by collective orientation of the clusters. The electrophoretic mobility is 1.1 X 10(-12) m2/V sec in the high frequency limit and 7.4 X 10(-11) m2/V sec in the low frequency limit. The electric dipole moment is 6.3 X 10(-16) N(-1/2) m(-1/2) where N is the cluster density/cubic meter and the net charge is about one or two elementary charges. 相似文献
89.
Lakoumentas J Drakos J Karakantza M Sakellaropoulos G Megalooikonomou V Nikiforidis G 《Computer methods and programs in biomedicine》2012,108(1):158-167
Prognosis of B-Chronic Lymphocytic Leukemia (B-CLL) remains a challenging problem in medical research and practice. While the parameters obtained by flow cytometry analysis form the basis of the diagnosis of the disease, the question whether these parameters offer additional prognostic information still remains open. In this work, we attempt to provide computer-assisted support to the clinical experts of the field, by deploying a classification system for B-CLL multiparametric prognosis that combines various heterogeneous (clinical, laboratory and flow cytometry) parameters associated with the disease. For this purpose, we employ the na?ve-Bayes classifier and propose an algorithm that improves its performance. The algorithm discretizes the continuous classification attributes (candidate prognostic parameters) and selects the most useful subset of them to optimize the classification accuracy. Thus, in addition to the high classification accuracy achieved, the proposed approach also suggests the most informative parameters for the prognosis. The experimental results demonstrate that the inclusion of flow cytometry parameters in our system improves prognosis. 相似文献
90.
Sotirios Liaskos Shakil M. Khan Marin Litoiu Marina Daoud Jungblut Vyacheslav Rogozhkin John Mylopoulos 《Information Systems》2012
Customizing software to perfectly fit individual needs is becoming increasingly important in information systems engineering. Users want to be able to customize software behavior through reference to terms familiar to their diverse needs and experience. We present a requirements-driven approach to behavioral customization of software systems. Goal models are constructed to represent alternative behaviors that users can exhibit to achieve their goals. Customization information is then added to restrict the space of possibilities to those that fit specific users, contexts, or situations. Meanwhile, elements of the goal models are mapped to units of source code. This way, customization preferences posed at the requirements level are directly translated into system customizations. Our approach, which we apply to an on-line shopping cart system and an automated teller machine simulator, does not assume adoption of a particular development methodology, platform, or variability implementation technique and keeps the reasoning computation overhead from interfering with the execution of the configured application. 相似文献