133,185 research outputs found

    Using patterns in the automatic marking of ER-Diagrams

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    This paper illustrates how the notion of pattern can be used in the automatic analysis and synthesis of diagrams, applied particularly to the automatic marking of ER-diagrams. The paper describes how diagram patterns fit into a general framework for diagram interpretation and provides examples of how patterns can be exploited in other fields. Diagram patterns are defined and specified within the area of ER-diagrams. The paper also shows how patterns are being exploited in a revision tool for understanding ER-diagrams

    Automatic assessment of sequence diagrams

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    In previous work we showed how student-produced entity-relationship diagrams (ERDs) could be automatically marked with good accuracy when compared with human markers. In this paper we report how effective the same techniques are when applied to syntactically similar UML sequence diagrams and discuss some issues that arise which did not occur with ERDs. We have found that, on a corpus of 100 student-drawn sequence diagrams, the automatic marking technique is more reliable that human markers. In addition, an analysis of this corpus revealed significant syntax errors in student-drawn sequence diagrams. We used the information obtained from the analysis to build a tool that not only detects syntax errors but also provides feedback in diagrammatic form. The tool has been extended to incorporate the automatic marker to provide a revision tool for learning how to model with sequence diagrams

    eulerForce: Force-directed Layout for Euler Diagrams

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    Euler diagrams use closed curves to represent sets and their relationships. They facilitate set analysis, as humans tend to perceive distinct regions when closed curves are drawn on a plane. However, current automatic methods often produce diagrams with irregular, non-smooth curves that are not easily distinguishable. Other methods restrict the shape of the curve to for instance a circle, but such methods cannot draw an Euler diagram with exactly the required curve intersections for any set relations. In this paper, we present eulerForce, as the first method to adopt a force-directed approach to improve the layout and the curves of Euler diagrams generated by current methods. The layouts are improved in quick time. Our evaluation of eulerForce indicates the benefits of a force-directed approach to generate comprehensible Euler diagrams for any set relations in relatively fast time

    Automatic code generation from UML diagrams: the state-of-the-art

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    The emergence of the Unified Modeling Language (UML) as the de-facto standard for modeling software systems has encouraged the development of automated software tools that facilitate automatic code generation. UML diagrams are used to diagrammatically model and specify the static structure as well as the dynamic behavior of object-oriented systems and the software tools then go ahead and automatically produce code from the given diagrams. In the last two decades substantial work has been done in this area of automatic code generation. This paper is aimed at identifying and classifying this work pertaining to automatic code generation from UML diagrams, restricting the search neither to a specific context nor to a particular programming language. A Systematic literature review (SLR) using the keywords “automatic code generation”, “MDE”, “code generation” and “UML” is used to identify 40 research papers published during the years 2000–2016 which are broadly classified into three groups: Approaches, Frameworks and Tools. For each paper, an analysis is made of the achievements and the gaps, the UML diagrams used the programming languages and the platform. This analysis helps to answer the main questions that the paper addresses including what techniques or implementation methods have been used for automatic code generation from UML Diagrams, what are the achievements and gaps in the field of automatic code generation from UML diagrams, which UML diagram is most used for automatic code generation from UML diagrams, which programming language source code is mostly automatically generated from the design models and which is the most used target platform? The answers provided in this paper will assist researchers, practitioners and developers to know the current state-of-the-art in automatic code generation from UML diagrams.Keywords: Automatic Code Generation (ACG); Unified Modeling Language (UML); Model Driven Engineering (MDE

    Оптимизация структуры средств автоматизации судовых электроэнергетических систем

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    Проведен анализ структурных схем устройств автоматической точной синхронизации генераторов, распределения активной и реактивной нагрузок между параллельно работающими генераторами. Разработана оптимизированная структура контроллера автоматизации для судовых электроэнергетических систем. Выполнен абстрактный синтез цифрового автомата системы управления контроллером автоматизации.The analysis of the block-diagrams of diesel-generators automatic precise synchronization, active and reactive load sharing devices is carried out. The block-diagram of the optimized automatic controller is developed. Abstract synthesis of the automata for automatic controller control system is made

    Sufficient Criteria for Consistent Behavior Modeling with Refined Activity Diagrams: Long Version

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    In use case-driven approaches to requirements modeling, UML activity diagrams are a wide-spread means for refining the functional view of use cases. Early consistency validation of activity diagrams is therefore desirable but difficult due to the semi-formal nature of activity diagrams. In this paper, we specify well-structured activity diagrams and define activities more precisely by pre- and post- conditions. They can be modeled by interrelated pairs of object diagrams based on a domain class diagram. This activity refinement is based on the theory of graph transformation and paves the ground for a consistency analysis of the required system behavior. A formal semantics for activity diagrams refined by pre- and post-conditions allows us to establish sufficient criteria for consistency. The semi-automatic checking of these criteria is supported by a tool for graph transformation

    Visualizing Set Relations and Cardinalities Using Venn and Euler Diagrams

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    In medicine, genetics, criminology and various other areas, Venn and Euler diagrams are used to visualize data set relations and their cardinalities. The data sets are represented by closed curves and the data set relationships are depicted by the overlaps between these curves. Both the sets and their intersections are easily visible as the closed curves are preattentively processed and form common regions that have a strong perceptual grouping effect. Besides set relations such as intersection, containment and disjointness, the cardinality of the sets and their intersections can also be depicted in the same diagram (referred to as area-proportional) through the size of the curves and their overlaps. Size is a preattentive feature and so similarities, differences and trends are easily identified. Thus, such diagrams facilitate data analysis and reasoning about the sets. However, drawing these diagrams manually is difficult, often impossible, and current automatic drawing methods do not always produce appropriate diagrams. This dissertation presents novel automatic drawing methods for different types of Euler diagrams and a user study of how such diagrams can help probabilistic judgement. The main drawing algorithms are: eulerForce, which uses a force-directed approach to lay out Euler diagrams; eulerAPE, which draws area-proportional Venn diagrams with ellipses. The user study evaluated the effectiveness of area- proportional Euler diagrams, glyph representations, Euler diagrams with glyphs and text+visualization formats for Bayesian reasoning, and a method eulerGlyphs was devised to automatically and accurately draw the assessed visualizations for any Bayesian problem. Additionally, analytic algorithms that instantaneously compute the overlapping areas of three general intersecting ellipses are provided, together with an evaluation of the effectiveness of ellipses in drawing accurate area-proportional Venn diagrams for 3-set data and the characteristics of the data that can be depicted accurately with ellipses

    The role of labels in the automatic assessment of graph-based diagrams

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    The ability to draw diagrams in free-form is rarely found in e-assessment systems. This paper examines one crucial area which needs to be well understood if automatic marking of diagrams is to be feasible: the analysis of labels. Graph-based diagrams include geometrical elements of differing shapes connected by lines to carry the semantics of the domain being modelled. Some diagrams also use the relative location of elements to express information. Labels play a central role in providing meaning both as identifiers, distinguishing between geometric elements, and the values of attributes of elements. Such information is central to the process of comparing two diagrams when marking student-drawn diagrams. Student-drawn diagrams likely to contain errors – they are imprecise. The aim, therefore, is, in the presence of imprecision, to match a student diagram with a model solution and award a mark which is close to that which an expert human would give. This paper explores the specific problem of determining the similarity of labels in diagrams which has been successfully employed in marking student diagrams in a formative environment

    Computational Particle Physics for Event Generators and Data Analysis

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    High-energy physics data analysis relies heavily on the comparison between experimental and simulated data as stressed lately by the Higgs search at LHC and the recent identification of a Higgs-like new boson. The first link in the full simulation chain is the event generation both for background and for expected signals. Nowadays event generators are based on the automatic computation of matrix element or amplitude for each process of interest. Moreover, recent analysis techniques based on the matrix element likelihood method assign probabilities for every event to belong to any of a given set of possible processes. This method originally used for the top mass measurement, although computing intensive, has shown its power at LHC to extract the new boson signal from the background. Serving both needs, the automatic calculation of matrix element is therefore more than ever of prime importance for particle physics. Initiated in the eighties, the techniques have matured for the lowest order calculations (tree-level), but become complex and CPU time consuming when higher order calculations involving loop diagrams are necessary like for QCD processes at LHC. New calculation techniques for next-to-leading order (NLO) have surfaced making possible the generation of processes with many final state particles (up to 6). If NLO calculations are in many cases under control, although not yet fully automatic, even higher precision calculations involving processes at 2-loops or more remain a big challenge. After a short introduction to particle physics and to the related theoretical framework, we will review some of the computing techniques that have been developed to make these calculations automatic. The main available packages and some of the most important applications for simulation and data analysis, in particular at LHC will also be summarized.Comment: 19 pages, 11 figures, Proceedings of CCP (Conference on Computational Physics) Oct. 2012, Osaka (Japan) in IOP Journal of Physics: Conference Serie
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