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Norha M. Villegas, PhD

Context Management and Self-Adaptivity for
Situation-Aware Smart Software Systems

Norha Milena Villegas Machado
University of Victoria


Our society is increasingly demanding situation-aware smarter software (SASS) systems, whose goals change over time and depend on context situations. A system with such properties must sense their dynamic environment and respond to changes quickly, accurately, and reliably, that is, to be context-aware and self-adaptive. 

The problem addressed in this dissertation is the dynamic management of context information, with the goal of improving the relevance of SASS systems' context-aware capabilities with respect to changes in their requirements and execution environment. Therefore, this dissertation focuses on the investigation of dynamic context management and self-adaptivity to: (i) improve context-awareness and exploit context information to enhance quality of user experience in SASS systems, and (ii) improve the dynamic capabilities of self-adaptivity in SASS systems. 

Context-awareness and self-adaptivity pose significant challenges for the engineering of SASS systems. Regarding context-awareness, the first challenge addressed in this dissertation is the impossibility of fully specifying environmental entities and the corresponding monitoring requirements at design-time. The second challenge arises from the continuous evolution of monitoring requirements due to changes in the system caused by self-adaptation. As a result, context monitoring strategies must be modeled and managed in such a way that they support the addition and deletion of context types and monitoring conditions at runtime. For this, the user must be integrated into the dynamic context management process. Concerning self-adaptivity, the third challenge is to control the dynamicity of adaptation goals, adaptation mechanisms, and monitoring infrastructures, and the way they affect each other in the adaptation process. This is to preserve the effectiveness of context monitoring requirements and thus self-adaptation. The fourth challenge, related also to self-adaptivity, concerns the assessment of adaptation mechanisms at runtime to prevent undesirable system states as a result of self-adaptation.

Given these challenges, to improve context-awareness we made three contributions. First, we proposed the personal context sphere concept to empower users to control the life cycle of personal context information in user-centric SASS systems. Second, we proposed the SmarterContext ontology to model context information and its monitoring requirements supporting changes in these models at runtime. Third, we proposed an explicit context processing engine to discover implicit contextual facts from context information specified in changing context models.

To improve self-adaptivity we made three contributions. First, we proposed a
framework for the identification of adaptation properties and goals, which is useful to evaluate self-adaptivity and to derive monitoring requirements mapped to adaptation goals. Second, we proposed a reference model for designing highly dynamic self-adaptive systems, for which the continuous pertinence between monitoring mechanisms and both changing system goals and context situations is a major concern. Third, we proposed a model with explicit validation and verification (V&V) tasks for self-adaptive software, where dynamic context monitoring plays a major role. 

The seventh contribution of this dissertation, the implementation of SmarterContext infrastructure, addresses both context-awareness and self-adaptivity.

To evaluate our contributions, qualitatively and quantitatively, we conducted several comprehensive literature reviews, a case study on user-centric situation-aware online shopping, and a case study on dynamic governance of service-oriented applications.


Book Chapters

  • Villegas and Müller. The SmarterContext Ontology and its Application to the Smart Internet: A Smarter Commerce Case Study. The Personal Web, LNCS, Springer, 2013. In press.
  • Villegas, Tamura, Müller, et al.: DYNAMICO: A Reference Model for Governing Control Objectives and Context Relevance in Self-Adaptive Software Systems, volume 7475 of LNCS, pages 265-293. Springer, 2013.
  • Tamura, Villegas, Müller, et al.: Towards Practical Runtime Verification and Validation of Self-Adaptive Software Systems, volume 7475 of LNCS, pages 108-132. Springer, 2013.
  • de Lemos, Giese, Müller, Shaw, Andersson, Litoiu, Schmerl, Tamura, Villegas, et al.: Software Engineering for Self-Adaptive Systems: A second Research Roadmap, volume 7475, pages 1-32. Springer, 2013.
  • Villegas and Müller: Managing Dynamic Context to Optimize Smart Interactions and Services, pages 289-318. Springer-Verlag, Berlin, Heidelberg, 2010.

Conference Proceedings
  • Ebrahimi, Villegas, Müller, and Thomo: SmarterDeals: A Context-aware Deal Recommendation System based on the SmarterContext Engine. In Proceedings 2012 Conference of the Center for Advanced Studies on Collaborative Research (CASCON 2012), pages 116-130, Riverton, NJ, USA, 2012. IBM Corp.
  • Muñoz, Tamura, Villegas, and Müller. Surprise: User-controlled Granular Privacy and Security for Personal Data in SmarterContext. In Proceedings 2012 Conference of the Center for Advanced Studies on Collaborative Research (CASCON 2012), pages 131-145, Riverton, NJ, USA, 2012. IBM Corp.
  • Villegas, Müller, et al.: A Framework for Evaluating Quality-driven Self-Adaptive Software Systems. In Proceedings 6th International ICSE Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS 2011), pages 80-89, New York, NY, USA, 2011. ACM.
  • Frîncu, Villegas, Petcu, Müller, and Rouvoy: Self-Healing Distributed Scheduling Platform. In Proceedings 11th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGRID 2011), pages 225-234, Washington, DC, USA, 2011. IEEE Computer Society.
  • Villegas, Müller, et al.: A Dynamic Context Management Infrastructure for Supporting User-driven Web Integration in the Personal Web. In Proceedings 2011 Conference of the Center for Advanced Studies on Collaborative Research (CASCON 2011), pages 200-214, Markham, ON, Canada, 2011. IBM Corp.
Workshop Proceedings
  • N. M. Villegas and H. A. Müller. Context-driven adaptive monitoring for supporting SOA governance. In: Proceedings 4th InternationalWorkshop on a Research Agenda for Maintenance and Evolution of Service-Oriented Systems (MESOA 2010), Carnegie Mellon University Software Engineering Institute, 2010.
  • N. M. Villegas, H. A. Müller, and G. Tamura. Optimizing Run-Time SO Governance through Context-Driven SLAs and Dynamic Monitoring. In: 2011 IEEE International Workshop on the Maintenance and Evolution of Service-Oriented and Cloud-Based Systems (MESOCA 2011), pp. 1-10, IEEE, 2011.

Norha M. Villegas, PhD
Download my CV here

Norha and Gabriel at Mt. Washington, Feb 2013

CASCON 2012 Best Paper Award

S. Ebrahimi, N.M. Villegas, H.A. Müller, A. Thomo:  SmarterDeals: A Context-aware Deal Recommendation System based on the SmarterContext Engine. In Proceedings 22nd Conf. of the Center for Advanced Studies on Collaborative Research 2012), pp. 113-127, ACM Press, Markham, Ontario, Nov 2012.

IBM Canada CAS Research Project of the Year 2011 Award: 
Dynamic Context to Optimize Smart Interactions and Smart Services
H.A. Müller, N.M. Villegas J.C. Munoz, A. Lau, J. Lo, J. Ng, Nov 2011.