We present the objectives, activities and some preliminary results of the FP7 STREP project INTrEPID (INTelligent systems for Energy Prosumer buildIngs at District level).

Real-time and embedded applications cover an extremely wide variety of domains, each with stringent requirements, including highly precise timing characteristics, small memory footprints, flexible sensor and actuator interfaces, and robust safety characteristics. Processing in such application domains often involves distributed processing in which communication and synchronization and their resulting integration present additional challenges. A major part of the cost of creating such real-time and embedded applications is spent in the often complex software development, integration, verification, and validation of the resulting systems. A vast majority of all microprocessors are now used for real-time and embedded applications, and higher-level programming languages and middleware are needed to develop software for these applications, timely and safely. The Java programming language has become an attractive choice because of its excellent software engineering characteristics. Yet, standard Java is unsuitable for developing hard real-time embedded systems, mainly due to underspecification of thread scheduling and the presence of garbage collection. These problems are addressed by the Real-Time Specification for Java. Interest in real-time Java in both the research community and the industry has increased significantly, because of its challenges and its potential impact on the development of embedded and real-time applications. The Workshop on Java Technologies for Real-Time and Embedded Systems (JTRES) is dedicated to research on Java for embedded real-time systems. JTRES 2011, the 9th workshop in the series, was organized in York, UK by the Real-time Systems Group of the University of York. This special issue of Concurrency and Computation: Practice and Experience brings four invited papers from the JTRES 2011. These papers have been expanded and carefully peer reviewed. The papers highlight topics of special interest: multiprocessor and distributed real-time Java, as well as verification of real-time Java programs. In Supporting lock-based multiprocessor resource sharing protocols in real-time programming languages 1, Lin, Wellings, and Burns survey currently available resource sharing protocols for multiprocessor applications. Because there are no obvious best solutions, the authors continue with the design for a framework where programmers may define and implement their own policies. This is illustrated and evaluated with Ada as base language. Shared memory solutions may become a bottleneck in multicore systems; this is one motivation for the paper by Meawad, Iyer, Schoeberl, and Vitek on Micro-transactions for concurrent data structures 2. In this paper, the authors demonstrate that it is feasible with suitable hardware support to build efficient and predictable transactional memories. Also, the hardware support is not very expensive as shown by a prototype implementation in the field-programmable gate array-based Java Optimized Processor system. For Java, garbage collection is another issue when moving to multiprocessors with shared memory. Although predictable real-time garbage collectors have been developed, the multiprocessor setting requires rethinking the problem as done in Design and analysis of a hard real-time garbage collector for a Java chip multi-processor 3, which summarizes key contributions from Puffitsch’ doctoral thesis. The experimental parts of this work once more uses extensions to the Java Optimized Processor system. A contribution within the area of verification is Haddad and Leavens’ Specifying subtypes in Safety Critical Java programs. 4. This paper addresses the intricate problem of specifying timing properties they conform with inheritance, where subtype methods use more time to execute because they extend corresponding supertype methods. This is done within the Java Modeling Language context. As editors, we thank the authors contributing to this special issue and also extend our gratitude to all the reviewers whose dedication ensured a good selection of articles and made this special issue possible.

The paper presents development and validation of a coal mill model to be used for improved mill control, which may lead to a better load following capability of power plants fired by pulverized coal. The model is relatively simple, yet it captures all significant mill dynamics. The model is validated using data from four mills of a similar type from two different manufacturers. In the validation, model parameters are estimated using an efficient evolutionary algorithm called Differential Evolution. The model parameters are similar for all four mills, indicating that the model structure can be trusted.

Jigsaw patterns, a graphical architecture description notation, will be presented in this paper. The jigsaw patterns shows components and connectors with their interfaces. Connectors are structures or objects implementing the interfaces. Components are structures interacting via the connectors. Each component and connector can be taken as a new system and decomposed. The semantics of the jigsaw patterns in terms of ML is also described. The application of this notation is illustrated by a case study \3D-Med" prototype system. The jigsaw patterns diiers from other architecture description languages (ADLs) and supporting tools in that it focuses on the overall system structure, how subsystems interface and how they decompose further. Other ADLs and tools supports mainly the description and analysis of style-based components and their connections.

In this investigation, visitors to an art and design exhibition have used an interactive computer program to express the qualities they consider important for an art or design object (artefact). They have then used the program with their individually selected qualities to assess the artefacts. In this article, we present the experiment and its results. They indicate that with such a setting it is relatively easy to reach a degree of consensus about criteria. Such an interactive program can therefore be very useful, for instance when choosing among design proposals or when selecting artefacts for exhibitions, because they make the assessments open to a larger audience such that their basis can be discussed.

This chapter presents the modelling solution to the CoCoME example, the Trading System in rCOS, that is a Relational Calculus of Object and Component Systems developed at UNU-IIST. We give a model of requirements based on an abstraction of the use cases described in the description document of the example by the organisers in Chapter 3. We then use the refinement calculus of rCOS to derive design models that are in the same level of abstraction of the informal models given in the description. We make modifications to the models given in description document that we think either they improve the models.

We present a specification oriented real-time semantics for real-time programs consisting of communicating sequential processes running on a shared processor configuration. The semantics, which is given in Duration Calculus [7], separates properties of a (compiled) program from properties attributable to a scheduling strategy. This gives a clear division of concerns when a given program under a given scheduling strategy has to be proven correct wrt. hard real-time constraints.

In this paper we investigate the use of action systems with differential actions in the specification of hybrid systems. As the main contribution we generalize the definition of a differential action, allowing the use of arbitrary relations over model variables and their time derivatives in modelling continuous-time dynamics. The generalized differential action has an intuitively appealing predicate transformer semantics, which we show to be both conjunctive and monotonic. In addition, we show that differential actions blend smoothly with conventional actions in action systems even under parallel composition. Moreover, as the strength of the action system formalism is the support for stepwise development by refinement, we investigate refinement involving a differential action. We show that, due to the predicate transformer semantics, standard action refinement techniques apply also to the differential action, thus, allowing stepwise development of hybrid systems.

In this roadmap, we survey techniques for handling different functional and extra-functional properties of component and system behavior. A conclusion is that techniques exist for handling such properties, but that further work is needed to improve the theory of specifying and composing components, and to develop tool support.

A research project on development of autonomous machines for agricultural operations is currently inprogress. The goal has been to develop and demonstrate the benefits from using an autonomous platform and informationsystem for crop surveillance. The unit should navigate and operate autonomously in the field while carrying out cropanalysis tasks with computer-vision. A key component, which is being developed as a simulation prototype, is an integratedmanagement system, which involves planning and activation of a job and generation of sampling points and routes.An overall system architecture has been specified in the object-oriented Unified Modeling Language (UML) and is used todevelop a computerized simulation of the operation of the system. As the basis for the planning, the system interfaces to aprototype farm management information system. The planning domain of jobs in the field is modeled in relation to suchobjects as field, crop, machines, etc., and the attributes of these objects. The attributes specify the kind of data relevant tothe decision-making processes involved in the planning and the implementation of the jobs.The route planning system interfaces to the overall management system and relays concrete sequences of way-points tothe vehicle-level controller. It includes a new algorithm prescribing an optimal sampling and a corresponding efficient routeplan for the movements of the unit in the field. The planning algorithm has been designed on the basis of an evaluation ofthe spatial and temporal variability of weed occurrence and weed intensity.The management tasks related to the use of autonomous platform units have been identified. A hierarchical managementsystem, including specific plans for sampling points and routes aimed at weed mapping is demonstrated. Furthermore, themanagement system and its database provides the baseline for further enhancements, like inclusion of explicit schedulingmodels or specific decision support models for evaluating acquired information from the field.

We show h o w UML class diagrams can be used to document design by reenement in the early design stages. This is illustrated by an example from the area of embedded real-time and hybrid systems. A precise semantics is given for the UML class diagrams by translation to the Z schema calculus .

The Provably Correct Systems project [5, 6] developed links between layers of formal specifications for real-time systems. These layers cover requirements capture, design, programming and code generation. In this paper we trace real-time constraints through the layers in order to inspect their changing forms. They originate in constraints on continuous dynamical models of physical phenomena. However, in a digital system it is desirable to abstract the complexities of these models to simple clocks, and further to events in a reactive system. This paradigm is the main topic of this paper. We illustrate the different forms of timing constraints in duration calculus, a real-time interval logic.

Differential equations are used in control theory to describe a system and its behaviour. They define explicitly the relationships between continuous variables during the evolution of the system. In this paper, we introduce the use of differential equations as primitive actions. The semantics is given with the weakest liberal precondition predicate transformer.