Dynamic Context-Aware Service Composition, Brokerage and Monitoring in Service-Oriented Computing

长期以来，服务组合一直是一个活跃的研究领域，它使服务代理能够生成适应其客户复杂需求的组合服务。众所周知的个体问题，如约束满足、上下文感知、数据集成和数据隐私，都在文献中找到了各种独立的解决方案。然而，从更广泛的角度来看，这些问题实际上是相互交织在一起的，它们的相互作用产生了单独的解决方案无法解决的其他问题。我们的解决方案为综合解决所有这些问题提供了坚实的理论基础。*《金融邮报》2017年3月的一篇文章报道称，由于国际电子商务未能征税，加拿大政府每年可能损失高达13亿美元的税收。这一问题源于这样一个事实，即不能期望参与国际电子商务的服务提供者意识到，也无权适用适用于他们所提供服务的每个客户的具体情况的所有国际限制/政策/条例。*此外，电子商务倾向于向能够负担得起与其他公司在线服务协作投资的较大公司创造更多业务量。具有上下文/约束感知的自动化服务组合可以帮助更专业和商业上没有关联的服务提供商接触到他们的客户。例如，在对一项交易适用国际政策之后，与当地服务的交易相比，与外国服务提供商的交易可能被证明更合适。因此，拥有约束/策略/上下文管理的集成解决方案将潜在地促进上下文专门化(例如本地)服务提供商的经济生存能力。*从不同的角度来看，上述问题都与组合服务上的集成数据模型的自动操纵有关。尽管有这些共同点，但这些问题并没有得到适当的综合解决方案。更具体地说，针对组合服务中的约束感知问题提供了各种解决方案。然而，它们都认为约束是整个组合服务固有的，而没有考虑它们可能应用于组合服务的哪一部分。此外，现有的解决方案中没有一个提供了考虑不同约束来源的集成解决方案，尤其是外部定义的约束。*该项目旨在为服务组合过程以及组合服务的执行开发一个新的集成约束/上下文感知模型。该模型基于可能世界语义的概念，其中计算上下文和约束是在多维上下文空间上建模的。

Service composition has long been an active research domain that enables a service broker to generate a composite service adapted to the complex needs of their clients. Well-known individual problems such as constraint satisfaction, context-awareness, data integration, and data privacy have all found various independent solutions in the literature. However, a broader look at the situation reveals that these problems are in fact interwoven and their interaction creates other problems that individual solutions cannot solve. Our solution proposes a sound theoretical basis to an integrated solution to all these problems as a whole. ******An article from the Financial Post reported in March 2017 that the Government of Canada is potentially losing up to 1.3B$ yearly in taxation revenue due to international e-commerce failing to charge taxes. This problem stems from the fact that service providers involved in international e-commerce cannot be expected to be aware, nor have authority to apply all international constraints/policies/regulations that apply to the specific context of every customer to which they provide a service. ******Furthermore, e-commerce has a tendency to create more business volume to larger companies that can afford investments in online service collaboration with other companies. Automated service composition augmented with context/constraint-awareness can help more specialized and commercially unconnected service providers to reach for their clientele. For example, a transaction with a local service may prove to be more appropriate compared with a transaction with a foreign service provider after international policies are applied to a transaction. Having an integrated solution for constraint/policy/context management would thus potentially foster the economic viability of contextually specialized (e.g. local) service providers.******The problems stated above are all related, from various perspectives, to the automated manipulation of an integrated data model over the composite service. Despite this common denominator, these problems have not met with an appropriately integrated solution. More specifically, various solutions were provided to the problem of constraint-awareness in composite services. However, they all consider constraints as being inherent to the whole composite service without consideration which part of the composite service they may apply. Also, none of the existing solutions provide an integrated solution considering different sources of constraints, especially externally-defined constraints. ******This project aims at the development of a new integrated constraint/contextual-aware model for the service composition process, as well as for the execution of composite services. This model is based on the notion of possible-worlds semantics, where the computational context and the constraints are modeled over a multidimensional context space.