Current practices in software development heavily emphasize the development of reusable and modular software, which allow software components to be developed and maintained independently. While a component-oriented approach offers a number of benefits, it presents several quality assurance challenges including validating the correctness of individual components as well as their integration. Des...

Achieving acceptable quality of service in highly dynamic computing environments requires not only adaptation and reconfiguration of individual components of the system, but also collaboration among these components. To address the integration and collaboration of adaptive computing components, we propose COCA, a contract-based collaborative adaptation infrastructure. COCA uses contract specifi...

In a web service composition, an electronic contract (e-contract) regulates how the services participating in the composition should behave, including the restrictions that these services must fulfill, such as real-time constraints. In this work we present a visual model that allows us to specify e-contracts in a user friendly way, including conditional behavior and realtime constraints. A case...

In this paper we present a framework to analyze conflicts of contracts written in structured English. A contract that has manually been rewritten in a structured English is automatically translated into a formal language using the Grammatical Framework (GF). In particular we use the contract language C L as a target formal language for this translation. In our framework C L specifications could...

A common problem in economic transactions is the presence of relevant aspects of the exchange that cannot be fully specified in the contract, for example, because they are observable but not verifiable by a third party (court). The existence of non-verifiable aspects (some qualitative features of the exchanged goods and services that cannot be verified in court), contractual complexities, lack ...

This chapter describes the application of contract-based design in Simulink to the development of a digital hydraulic controller. A semi-formal approach to the development is used, where contracts are used to aid the structuring of the system and for creating interface specifications for components that can later be used for testing. An analysis of the influence of the contracts on the developm...

Because software specifications often serve as a formal contract between the developer and the customer, systems have been proposed ([8], [2], [5]) that help the software client better understand specifications by automatically paraphrasing them in natural language. The REVIEW system [6] applies natural language generation within Metaview [7], a metasystem that facilitates the construction of C...

Modular static analysis requires treating some portion of the program opaquely. To enable such analysis, we introduce a notion of abstract reduction semantics. Opaque components are approximated by their specifications, which in turn are treated as abstract values during reduction. We demonstrate the technique by applying it to two kinds of specifications for higher-order languages: types and f...

When Web services are composed by linking service providers and requestors, the requestor’s requirements for a ”useful” service have to be matched against the service description offered by the provider. Among other things, service specifications (requirements or descriptions) may contain operation contracts specifying pre-conditions and effects of (required or provided) operations. In this pap...

All errors are my own responsibility. Abstract Motivated by economic models of sequential trade, empirical analyses of market dynamics in the U.S. equities market frequently estimate liquidity from regressions of price changes on transaction volumes, where the latter are signed (positive for buyer-initiated trades; negative for seller-initiated trades). This paper estimates these specifications...