Summary and Future Works

This review has focused on the noble gas systematics of subduction zones. Although a considerable database has been accumulated on the noble gas (and major volatile) characteristics of both arc and back-arc regions, and these are summarized above, there are numerous topics which warrant further and more detailed attention. We suggest that the following list contains realistic objectives where advances can be made  

Although the helium database is significant for arcs and back-arcs, the same cannot be said for neon and argon—much less so for krypton and xenon. This is due to a combination of obtaining suitable samples (not overwhelmed by air contamination) and analytical limitations. We envisage that future refinements and developments in sample processing (e.g., laser ablation) and/or measurement capabilities will lead to improved and more complete noble gas datasets—which ideally will have complementary major volatile data. 

The volatile output and composition at fore-arcs and back arcs remains poorly constrained. Currently, we are unaware of any representative volatile flux measurements for fore-arcs. These measurements are critical to arrive at an accurate volatile mass balance of subduction zones, and to evaluate if volatiles are transferred beyond this region to the zone of magma generation and/or to the deeper mantle. 

Better constraints are required for the input parameters (particularly for the noble gases and nitrogen). Additional information on the volatile composition of both oceanic sediments and crustal basement is needed to improve estimates of mass balance at subduction zones. 

More data are required on possible elemental (and isotopic) fractionation of the major and noble gases particularly during both metamorphic devolatilization reactions but also during magma storage, crystallization and degassing. This will 

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The remainder of the paper is organized as follows. Section 2 summarizes some useful concepts on BDDs, Boolean functions and sets, image computations, FSMs and symbolic traversals. Section 3 describes the underline approach to decompose and manipulate BDDs, as described in [8]. Section 4 describes the parallel implementation. Section 5 shows experimental results. Section 6 closes the paper with a brief summary and future work. 

In the following section, we present the relevant parts of Mechatronic UML and give an overview of our synthesis approach. For the formalization of the approach, we give fundamental definitions for the input behavioral specifications in Section 3. In Section 4, we present the concept of composition rules which formalize interdependent concerns. These composition rules are applied within the automatic composition of protocol behavior, as defined by the synthesis algorithm in Section 5. As the effect of the application of a set of composition rules cannot be anticipated, the result of the synthesis can violate properties of the protocol behavior. Therefore, we present the check for role conformance in Section 6. Related work is discussed in Section 7 and at last we conclude with a summary and future work in Section 8. 

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