We describe an approach to the specification and implementation of consistency constraints in object-oriented database systems, adopting the programming-by-contract paradigm developed for object-oriented programming. We also investigate how consistency constraints specified in programming-by-contract can be transformed into production rules of an active, object-oriented database system.

Personal e-health systems are the next generation of e-health applications and their goal is to assist patients in managing their disease and to help both patients and healthy people maintain behaviours that promote health. To do this, e-health systems collect, process, store and communicate the individual’s personal data. This paper presents an analysis of personal e-health systems and identif...

In 2003, trading of commodity futures shifted from single commodity, regional exchanges to national exchanges that trade multiple commodities. This paper examines price discovery and hedging effectiveness of commodity futures after this change and concludes that,on average, futures prices do discover information relatively efficiently,but helps to manage risk less efficiently. The paper uses th...

This paper describes the negotiation component of E-Alliance, a software infrastructure defined for supporting negotiation activities in concurrent inter-organizational alliances. The E-Alliance’s main intent is to preserve the autonomy of organizations grouped in an alliance. The purpose of this work is to offer support for small and medium enterprises which cannot or do not want to fulfill a ...

The traceability question is addressed through the development of a framework to go from requirements to aspects using the Design by Contract methodology. It is demonstrated that by starting at the requirements stage, and specifying an early aspect in the same semiformal language as the system’s existing requirements, we have the basis from which to design the aspects at the implementational st...

This paper studies a contract design problem in a setting where time clauses are important. A principal hires an agent to complete a project within a …xed time horizon and prefers to have the project done as early as possible. The agent whose e¤ort is not contractible has a tendency to shirk and to delay exerting e¤ort. We show that in the principal’s optimal contract, deadlines and payment sch...

The proposed Competitive Contract Net Protocol has been designed to facilitate a flexible cooperation in competitive multi-agent environments and to support automated or semi-automated negotiations in competitive domains. The protocol is based on FIPA standards. The protocol covers not only the phase of contracting the commitments, but also allows for a decommitment negotiation and contract ter...

Recent studies show that the democratic peace correlation is not significant once the potentially confounding variable that can cause both democracy and peace, contract-intensive economy, is considered; this pattern holds in analyses of wars, fatal militarized interstate conflicts (Mousseau 2009), and interstate crises (Mousseau et al. 2013). These studies rescind the primary evidence for democ...

To study the recessive drain of college teachers is meaningful in practice. This paper, in perspective of psychological contract, analyzes the characteristics of psychological contracts of college teachers, the relationship between psychological contract breaches and recessive drain of college teachers, and the influencing factors of contract breaches, advancing relevant countermeasures for dea...

This research analyzed the effect of knowledge workers’ psychological contract on organizational commitment and work satisfaction. Data was collected thru a questionnaire survey given to 517 randomly selected Chinese knowledge workers in two state-owned engineering research institutions. The questionnaire contained items about the demographic profile of the respondents, psychological contract, ...