Dragan Milicev

Automatic model transformations using extended UML object diagrams in modeling environments

One of the most important features of modeling tools is generation of output. The output may be documentation, source code, net list, or any other presentation of the system being constructed. The process of output generation may be considered as automatic creation of a target model from a model in the source modeling domain. This translation does not need to be accomplished in a single step. Instead, a tool may generate multiple intermediate models as other views to the system. These models may be used either as better descriptions of the system, or as a descent down the abstraction levels of the user-defined model, gradually leading to the desired implementation. If the modeling domains have their metamodels defined in terms of object-oriented concepts, the models consist of instances of the abstractions from the metamodels and links between them. A new technique for specifying the mapping between different modeling domains is proposed in the paper. It uses UML object diagrams that show the instances and links of the target model that should be created during automatic translations. The diagrams are extended with the proposed concepts of conditional, repetitive, parameterized, and polymorphic model creation, implemented by the standard UML extensibility mechanisms. Several examples from different engineering domains are provided, illustrating the applicability and benefits of the approach. The first experimental results show that the specifications may lead to better reuse and shorter production time when developing customized output generators.

On the Semantics of Associations and Association Ends in UML

Association is one of the key concepts in UML that is intensively used in conceptual modeling. Unfortunately, in spite of the fact that this concept is very old and is inherited from other successful modeling techniques, a fully unambiguous understanding of it, especially in correlation with other newer concepts connected with association ends, such as uniqueness, still does not exist. This paper describes a problem with one widely assumed interpretation of the uniqueness of association ends, the restrictive interpretation, and proposes an alternative, the intentional interpretation. Instead of restricting the association from having duplicate links, uniqueness of an association end in the intentional interpretation modifies the way in which the association end maps an object of the opposite class to a collection of objects of the class at that association end. If the association end is unique, the collection is a set obtained by projecting the collection of all linked objects. In that sense, the uniqueness of an association end modifies the view to the objects at that end, but does not constrain the underlying object structure. This paper demonstrates how the intentional interpretation improves expressiveness of the modeling language and has some other interesting advantages. Finally, this paper gives a completely formal definition of the concepts of association and association ends, along with the related notions of uniqueness, ordering, and multiplicity. The semantics of the UML actions on associations are also defined formally

A classification and comparison of Data Mining algorithms for Wireless Sensor Networks

With the technological developments, the Wireless Sensor Network (WSN) nodes are getting smaller, but WSNs are getting larger, currently containing thousands, possible millions of nodes in the future. Consequently, dealing with the shear volume of data produced by these networks poses a serious challenge, one logically approached through use of Data Mining techniques. This has inspired a body of research which aims to develop new, and adapt existing solutions for Distributed Data Mining (DDM), so that they can be efficiently used in WSN. This paper presents and overview of such approaches. A classification framework is proposed, and selected solutions form the current State-of-the-Art available in open literature are presented, and categorized.

Domain mapping using extended UML object diagrams

Many modeling domains can be meta modeled using the core UML structural concepts. When the user needs other specific forms generated from models in such domains, such as source code, model transformations should be defined. The author advocates a specification method for defining model translation that is visual, making specifications easier to create and modify.

Predicated software pipelining technique for loops with conditions

An effort to formalize the process of software pipelining loops with conditions is presented. A formal framework for scheduling such loops, based on representing sets of paths by matrices of predicates, has been proposed. Usual set operations and relationships may then be applied to such matrices. Operations of a loop body are placed into a single schedule with the flow of control implicitly encoded in predicate matrices. An algorithm that generates loop code from such an encoded schedule has been described. The framework is supported by a concrete proposed technique that iteratively parallelize loops, as well as with heuristics driven by data dependencies to efficiently shorten loop execution. Preliminary experimental results of our prototype implementation prove that the proposed framework, technique, and heuristics produce efficient code at acceptable cost.

A formal model of software pipelining loops with conditions

This paper addresses the problem of parallelizing loops with conditional branches in the context of software pipelining. A new formal approach to this problem is proposed in the form of Predicated Software Pipelining (PSP) model. The PSP model represents execution of a loop with conditional branches as transitions of a finite state machine. Each node of the state machine is composed of operations of one parallelized loop iteration. The rules for operation movements between nodes in the PSP model are described. The model represents a new theoretical framework for further investigation of inherent properties of these loops.

A Retrospective on User Interface Development Technology

The authors present a brief survey on the evolution of user interface (UI) development technology, especially over the past two decades, shaped by the desktop, Web, and mobile eras. From the technology mainstream, the authors describe form-oriented, template-based, object-oriented, hybrid, and declarative frameworks and address model-driven and generic approaches. The focus of this article is on a framework of UI development concerns and how these have been addressed in each analyzed technology or group of technologies. At the end, the authors summarize current issues and future directions of UI development in general.

Empirical analysis of GUI programming concerns

The focus of this paper is on identification of typical graphical user interface (GUI) programming concerns. As opposed to some other proposals available in the literature that indicate GUI programming concerns by simple intuition, we have conducted a systematic empirical analysis to derive our proposal. It included an analysis of an existing application programming interface (API), its use in industrial projects, and an analysis of the requirements and issues reported during software maintenance. In addition, we have evaluated more than 50 GUI frameworks and APIs and proved usefulness and generality of our classification of concerns. As an additional proof of applicability of the proposed classification, we have refactored the inheritance hierarchy of the selected GUI API using concern-oriented interfaces. We have implemented a supporting tool that complements the developed API and supports its concern-oriented use. The evaluation of the refactored API showed positive effects on API usability.

Socratenon-a Web-based training system with an intellect

The main goal of the project called Socratenon was to build a new Web-based training environment that would go beyond traditional ones. In the open literature, there are several solutions trying to accomplish the same to a certain degree. Some of them are nothing more but plain virtual textbooks that only flip pages on mouse-clicks. More sophisticated techniques include user modeling in order to personalize the content for the user, adaptive interfaces, intelligent agents for improved assistance and search, neural networks and case-based reasoning for building intelligent back-ends, etc. In general, many existing learning environments lack interaction, full utilization of Web resources is scarce, while solutions utilizing a combination of all above are practically non-existent or in development. This paper tries to merge the potential of the new Internet technologies and the latest developments in cognitive sciences, on the one hand, with the comfort of learning at the most suitable time and in the most suitable place, on the other hand. The project has been finalized, the package works, and its performance has been tested both objectively and subjectively; it demonstrates superiority over similar solutions from the open literature. Its complexity is such that it can fit even the widespread PC platforms, although it demonstrates the best performance on state-of-the-art corporate platforms.

An interactive tool for UML class model evolution in database applications

In the context of model-driven development of database applications with UML, the (usually relational) database schema is obtained automatically from the application’s structural (class) UML model. Changes in requirements often lead to modifications of the application’s structural model. Such changes, in turn, have to be propagated to the underlying database schema. Very often, especially when the system is in production with a large volume of users’ live data, the data is considered to be valuable enough to be preserved through these changes. This paper describes an approach to cope with the problem of model evolution with the ultimate requirement to preserve the data stored in the database. The algorithm interactively determines differences between structural UML models before and after the changes and resolves those differences into transformations in the relational database domain.