We propose the use of structured natural language (English) in specifying service choreographies, focusing on the what rather than the how of the required coordination of participant services in realising a business application scenario. The declarative approach we propose uses the OMG standard Semantics of Business Vocabulary and Rules (SBVR) as a modelling language. The service choreography approach has been proposed for describing the global orderings of the invocations on interfaces of participant services. We therefore extend SBVR with a notion of time which can capture the coordination of the participant services, in terms of the observable message exchanges between them. The extension is done using existing modelling constructs in SBVR, and hence respects the standard specification. The idea is that users -domain specialists rather than implementation specialists -can verify the requested service composition by directly reading the structured English used by SBVR. At the same time, the SBVR model can be represented in formal logic so it can be parsed and executed by a machine.

Abstract-We present a compilation tool SBVR2Alloy which is used to automatically generate as well as validate service choreographies specified in structured natural language. The proposed approach builds on a model transformation between Semantics of Business Vocabulary and Rules (SBVR), an OMG standard for specifying business models in structured English, and the Alloy Analyzer which is a SAT based constraint solver. In this way, declarative specifications can be enacted via a standard constraint solver and verified for realisability and conformance.

It is well known that solar simulator is a very important equipment in solar panels research and development (R&D). Solar simulator is mainly used to assess the efficiency of solar panels. However, the cost to acquire such system is expensive and prone to malfunction when used repeatedly. The cost to repair solar simulator when malfunction is also expensive and time consuming. As an alternative, low cost solar simulator has been built independently by a group of researcher from Faculty of Electrical Engineering Technology (FTKE), University of Malaysia, Perlis (UniMAP) using 88 GU-10 halogen bulbs. This paper presents the assessment of the in-house build low cost solar panel simulator. The simulator was tested in three separate experiments to plot the current-voltage (IV) curve. The IV curves obtained from these experiments were analysed to determine the irradiance input (in Wm −2) of the solar simulator. Results have shown that the in-house build solar simulator has an input of 350 ∼ 400 Wm −2 if solar panels are suspended 20 cm above the halogen bulbs.

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The service choreography approach has been proposed for describing the global ordering constraints on the observable message exchanges between participant services in service oriented architectures. Recent work advocates the use of structured natural language, in the form of Semantics of Business Vocabulary and Rules (SBVR), for specifying and validating choreographies. This paper addresses the verification of choreographies-whether the local behaviours of the individual participants conform to the global protocol prescribed by the choreography. We describe how declarative specifications of service choreographies can be verified using a trace-based model, namely an adaptation of Shields' vector languages. We also use the so-called blackboard rules, which draw upon the Bach coordination language, as a middleware that adds reactiveness to this declarative setting. Vector languages are to trace languages what matrices are to linear transformations; they afford a more concrete representation which has advantages when it comes to computation or manipulation.