Towards language-to-language transformation

This paper proposes a simplicity-oriented approach and framework for language-to-language transformation of, in particular, graphical languages. Key to simplicity is the decomposition of the transformation specification into sub-rule systems that separately specify purpose-specific aspects. We illustrate this approach by employing a variation of Plotkin’s Structural Operational Semantics (SOS) for pattern-based transformations of typed graphs in order to address the aspect ‘computation’ in a graph rewriting fashion. Key to our approach are two generalizations of Plotkin’s structural rules: the use of graph patterns as the matching concept in the rules, and the introduction of node and edge types. Types do not only allow one to easily distinguish between different kinds of dependencies, like control, data, and priority, but may also be used to define a hierarchical layering structure. The resulting Type-based Structural Operational Semantics (TSOS) supports a well-structured and intuitive specification and realization of semantically involved language-to-language transformations adequate for the generation of purpose-specific views or input formats for certain tools, like, e.g., model checkers. A comparison with the general-purpose transformation frameworks ATL and Groove, illustrates along the educational setting of our graphical WebStory language that TSOS provides quite a flexible format for the definition of a family of purpose-specific transformation languages that are easy to use and come with clear guarantees.

Stand-alone backup power system for electrical appliances with solar PV and grid options

<span style="font-size: 9pt; font-family: 'Times New Roman', serif;">For a portable backup power system, there is an essential need to contribute to increasing the energy conversion efficiency between the source and the electrical household appliances to overcome the recent issues of global warming. This paper proposes a Backup power system (BPS) compatible with the capability to match with two primary power sources; Grid-Connected power as an AC and solar-PV as a DC power source. This system composes of a rechargeable battery bank of about 300V, while the voltage matching concept keeps maintaining the battery fully charged as long as the source power is available. Matlab-based simulation has performed to prove the concept of the adopted voltage-matching. A relay switch circuit controlled by the main power source is used to change-over the load/appliances between direct link through bypassing the main power and the storage battery power when both options of main power are unavailable. The result shows the excellent utilization of the traditional BPS losses, the proposed topology can achieve about 99% power efficiency as compared with the traditional one.</span>

Matching in the Description Logic FL0 with respect to General TBoxes

Matching concept descriptions against concept patterns was introduced as a new inference task in Description Logics two decades ago, motivated by applications in the Classic system. Shortly afterwards, a polynomial-time matching algorithm was developed for the DL FL0. However, this algorithm cannot deal with general TBoxes (i.e., finite sets of general concept inclusions). Here we show that matching in FL0 w.r.t. general TBoxes is in ExpTime, which is the best possible complexity for this problem since already subsumption w.r.t. general TBoxes is ExpTime-hard in FL0. We also show that, w.r.t. a restricted form of TBoxes, the complexity of matching in FL0 can be lowered to PSpace.