Abstract not found

The Generic Modeling Environment (GME) is a configurable tool suite that facilitates the rapid creation of domainspecific model-integrated program synthesis environments. There are three characteristics of the GME that make it a valuable tool for the construction of domain-specific modeling environments. First, the GME provides generic modeling primitives that assist an environment designer in the specification of new graphical modeling environments. Second, these generic primitives are specialized to create the domain-specific modeling concepts through meta-modeling. The meta-models explicitly support composition enabling the creation of composite modeling languages supporting multiple paradigms. Third, several ideas from prototype-based programming languages have been integrated with the inherent model containment hierarchy, which gives the domain expert the ability to clone graphical models. This paper explores the details of these three ideas and their implications.

Digital signal processing (DSP) systems are widely used in communication, medical, sonar, radar, equipment health monitoring and many other applications. Frequently, the signal processing system has to meet real-time requirements and provide very large throughput. For example, modern automatic target recognition systems operate with a processing throughput in excess of 10 Gflop per second. In real-time vibration analysis used for turbine engine testing [1], the aggregate sustained computation rate is also in the Gflop range. The high performance requires the use of computing platforms that include the combination of dedicated hardware processors, and general-purpose computers forming a hybrid, parallel/distributed configuration. Complexity, heterogeneity of the computing environment, and real-time operation make the software development for digital signal processing difficult and expensive. The design of DSP systems is based on the available a priori information about the signal source and the noise in the environment. Necessarily, the performance of the implemented system largely depends on the environmental conditions as well as additional factors, such as the computational resources available to the task. In conventional design approaches, these conditions are typically set in design time by introducing various constraints, simplifications, and assumptions. The critical issue in this methodology is what happens if the design time assumptions do not hold? Stabilization of the environment is impossible in

Edward Lee and Stephen Neuendorffer EECS Department University of California at Berkeley Berkeley, CA 94720, U.S.A.

Modern computer systems routinely present information to the user as a combination of text and diagrammatic images, described as "graphical user interfaces". Practitioners and researchers in Human-Computer Interaction (HCI) generally believe that the value of these diagrammatic representations is derived from metaphorical reasoning; they communicate abstract information by depicting a physical situation from which the abstractions can be inferred. This assumption has been prevalent in HCI research for over 20 years, but has seldom been tested experimentally. This thesis analyses the reasons why diagrams are believed to assist with abstract reasoning. It then presents the results of a series of experiments testing the contribution of metaphor to comprehension, problem solving, explanation and memory tasks carried out using a range of different diagrams. The results indicate that explicit metaphors provide surprisingly little benefit for cognitive tasks using diagrams as an external re...

Actor-oriented components emphasize concurrency and temporal semantics and are used for modeling and designing embedded software and hardware. Actors interact with one another through ports via a messaging schema that can follow any of several concurrent semantics. Domainspecific actor-oriented languages and frameworks are common (Simulink, LabVIEW, SystemC, etc.). However, they lack many modularity and abstraction mechanisms that programmers have become accustomed to in object-oriented components, such as classes, inheritance, interfaces, and polymorphism, except as inherited from the host language. This paper shows a form that such mechanisms can take in actor-oriented components, gives a formal structure, and describes a prototype implementation. The mechanisms support actor-oriented class definitions, subclassing, inheritance, and overriding. The formal structure imposes structural constraints on a model (mainly the “derivation invariant”) that lead to a policy to govern inheritance. In particular, the structural constraints permit a disciplined form of multiple inheritance with unambiguous inheritance and overriding behavior. The policy is based formally on a generalized ultrametric space with some remarkable properties. In this space, inheritance is favored when actors are “closer” (in the generalized ultrametric), and we show that when inheritance can occur from multiple sources, one source is always unambiguously closer than the other.

Memorandum UCB/ERL M05/22 Earlier versions: • UCB/ERL M04/16 UCB/ERL M03/28 UCB/ERL M02/23 UCB/ERL M99/40 UCB/ERL M01/12

Among the most significant technological developments of the past 20 years are computer-based systems (CBSs), where functional, performance, and reliability requirements demand the tight integration of physical processes and information processing. Because complex component interactions exist in these systems, we must construct the software and its associated hardware such that they can evolve together. Model integrated computing (MIC) is an effective and efficient method for developing, maintaining, and evolving large-scale, domain-specific CBS applications. MIC is modelbased, allowing the synthesis of application programs from models created using customized, domain-specific, multi-aspect model integrated program synthesis (MIPS) environments. Integrated models explicitly represent dependencies and constraints among various design views. Because engineers can input design information at appropriate levels in the design hierarchy, and are freed from low-level implementation details, true end-user programmability is achieved. This paper discusses MIC technology and presents two large-scale MIC applications currently in use—the Saturn Site Production Flow (SSPF) system and the Integrated Test Information System (ITIS). The SSPF is a manufacturing execution system used by General Motors ’ Saturn division to model, monitor, and analyze throughput characteristics of the plant. SSPF has been deployed in two Saturn plants and has helped Saturn to increase throughput in the Spring Hill, TN plant by nearly 10%. The ITIS, used to support Department of Defense aerospace testing at Arnold Engineering Development Center, integrates diverse sets of information from distributed, heterogeneous data sources into a seamless real-time, on-demand data system. The ITIS allows for rapid generation and customization of test information systems that track changing user requirements, allowing secure, uniform access to search metadata and retrieve test data

The ability to adapt a software artifact is essential toward handling evolving stakeholder requirements. Adaptation is also vital in many areas where software is required to adjust to changing environment conditions (e.g., the growing presence of embedded systems). Current techniques for supporting adaptability and evolvability can be categorized as static (happening at compile-time or design-time), or dynamic (adaptation during the actual execution of the system). This paper describes a specialtopics software engineering course that uses Java as a foundation for teaching concepts of static and dynamic adaptation. The course surveys Java-related research in the areas of meta-programming and reflection, aspect-oriented software development, model-driven computing, and adaptive middleware. Key words: Java education, evolvable software, aspect-oriented software development, model-integrated computing, adaptive middleware ______________________________________________________________________ 1.

Versatile model-based design demands languages and tools which are suitable for the cre-ation, manipulation, transformation, and composition of domain-specific modeling languages and domain models. The Meta Object Facility (MOF) forms the cornerstone of the OMG’s Model Driven Architecture (MDA) as the standard metamodeling language for the specifica-tion of domain-specific languages. This thesis describes an implementation of MOF v1.4 as an alternative metamodeling language for the Generic Modeling Environment (GME), the flagship tool of Model Integrated Computing (MIC). This implementation utilizes model-to-model transformations specified with the Graph Rewriting and Transformation tool suite (GReAT) to translate between MOF and the UML-based GME metamodeling language. The technique described by this paper illustrates the role formally well-defined metamod-eling and metamodel-based model transformation approaches can play in interfacing MIC technology to new and evolving modeling standards.