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NEC Laboratory for Analysis of System Dependability (LASD)

LASD in NEC Central Research Laboratories focuses on conducting research on modeling and analysis of dependable computing systems. Large-scale IT systems providing computing services become critical infrastructures as numerous organizations rely on such services. It is imperative to assure the high-availability of services in a consistent manner ranging from hardware, middleware, applications, operations and human factors. In order to assess the reliability, availability and performability resulting from various aspects of IT systems, we advance the modeling techniques such as fault tree, Markov models, non-Markovian models and stochastic Petri nets and their combinations. Using efficient model composition and solution techniques, qualitative and quantitative measures are computed efficiently and they are supplied to the continuous improvement of IT system design.

News

Projects

Candy

Candy is the component-based availability modeling framework for assessing the availability of IT systems from system specifications described by SysML. Candy enables system engineers to assess the availability of systems semi-automatically from their design of system administrative operations as well as fault-tolerant configurations.

SWIFT

Swift is an efficient fault tree analysis engine involving several logic reduction techniques and an improved Binary Decision Diagram algorithm. Swift is used for reliability analysis of IT systems from system configurations. Using Swift, engineers can easily evaluate system reliability and find out single point of failures and/or minimum cut sets causing system failures.

VM rejuvenation scheduling

Long running software sometime suffers from software aging which is a progressive degradation of software execution. Software rejuvenation clears software aging by proactively restarting the execution environment and improves the system availability. We develop analytic models for several rejuvenation strategies and determine the optimum rejuvenation schedule for achieving high-availability.

Design of disaster recovery operation

Disaster recovery solutions have been gaining more attention after the huge earthquake struck Japan in 2011. The risk of simultaneous failures of multiple IT components is not negligible and recovery operations should be designed in consideration with various failure scenarios. Our research focus on designing disaster recovery operations which meet the customer requirements for time-to-recover system while minimizing the associated cost.

Members

Fumio Machida

Fumio Machida is a researcher at LASD. Currently he is leading the project Candy in collaboration with Duke High Availability Assurance Lab. His research focuses on modeling and analysis of the system/data availability for designing, improving and assuring dependable ICT services.
Contact: f-machida at ab.jp.nec.com

Jianwen Xiang

Dr. Jianwen Xiang is a researcher at LASD. He is the developer of Swift. His research interests include system reliability engineering, formal methods, and ubiquitous computing.
Contact: j-xiang at ah.jp.nec.com

Kumiko Tadano

Kumiko Tadano is a researcher at LASD. She has research collaboration with SW Technologies Lab (STLab) in University of Florence. Her research interests include system availability modeling and analysis by taking into account human factors in operation of information systems.
Contact: k-tadano at bq.jp.nec.com

Yoshiharu Maeno

Dr. Yoshiharu Maeno is a director at LASD.
Contact: y-maeno at aj.jp.nec.com

Recent Selected Publications

  • F. Machida, J. Xiang, K. Tadano and S. Hosono, An asset-based development approach for availability and safety analysis on a flood alert system, In RADIANCE2015, 2015. [pdf]
  • J. Xiang, F. Machida, K. Tadano, Y. Maeno, An imperfect fault coverage model with coverage of irrelevant components, IEEE Transactions on Reliability, Vol. 64, No. 1, 2015.[link]
  • F. Machida, J. Xiang, K. Tadano and S. Hosono, An asset-based development approach for availability and safety analysis on a flood alert system, In RADIANCE2015, 2015. [pdf]
  • R. Matias Jr., A. Andrzejak, F. Machida, D. Elias and K. S. Trivedi, A Systematic Differential Analysis for Fast and Robust Detection of Software Aging, to be appeared in SRDS2014.
  • J. Xiang, F. Machida, K. Tadano and Y. Maeno, Analysis of Persistence of Relevance in Systems with Imperfect Fault Coverage, appeared in SafeComp2014.
  • R. Xia, F. Machida and K. S. Trivedi, A Markov Decision Process Approach for Optimal Data Backup Scheduling, In Proc. of 4th International Workshop on Dependability of Clouds, Data Centers and Virtual Machine Technology (DCDV), 2014. [pdf]
  • F. Machida, R. Mibu, J. Gokurakuji, K. Yanoo, K. Tadano, Y. Maeno and T. Sugawara, Server virtualized infrastructure for resilient voice communication service, In Proc. of IEEE/IFIP Network Operations and Management Symposium (NOMS2014), 2014. [pdf]
  • F. Machida, V. F. Nicola, K. S. Trivedi, Job completion time on a virtualized server with software rejuvenation, ACM Journal on Emerging Technologies in Computing Systems, Vol. 10, No. 1, 2014.[link]
  • R. Xia, X. Yin, J. Alonso, F. Machida and K. S. Trivedi, Performance and Availability Modeling of IT Systems with Data Backup and Restore, IEEE Tras. on Dependable and Secure Computing, 2013.[link]
  • F. Machida, J. Xiang, K. Tadano and Y. Maeno, Composing Hierarchical Stochastic Model from SysML for System Availability Analysis, In 24th Int'l Symp. on Software Reliability Engineering (ISSRE), 2013. [pdf]
  • L. Carnevali, M. Paolieri, K. Tadano and E. Vicario, Towards the quantitative evaluation of phased maintenance procedures using non-Markovian regenerative analysis, In Proc. of 10th European Workshop (EPEW), pp. 176-190, 2013.[link]
  • K. Tadano, J. Xiang, F. Machida and Y. Maeno, Identification of Smallest Unacceptable Combinations of Simultaneous Component Failures in Information Systems, Vol.E96-D, No.9, Sep. 2013.[link]
  • J. Xiang, F. Machida, K. Tadano, and Y. Maeno, Coverage of Irrelevant Components in Systems with Imperfect Fault Coverage, Vol.E96-A, No.7, Jul.2013.[link]
  • J. Xiang, F. Machida, K. Tadano, K. Yanoo, W. Sun, and Y. Maeno, A Static Analysis of Dynamic Fault Trees with Priority-AND Gates, In Proc. of 6th Latin-American Symp. on Dependable Computing (LADC), 2013. [pdf]
  • F. Machida, J. Xiang, K. Tadano and Y. Maeno, Software life-extension: a new countermeasure to software aging, In Proc. of 23rd Int'l Symp. on Software Reliability Engineering (ISSRE), 2012. [pdf]
  • K. Tadano, F. Machida, J. Xiang, and Y. Maeno, Identification of Minimal Unacceptable Combinations of Simultaneous Component Failures in Information Systems, In Proc. of 18th Pacific Rim Int. Symp. on Dependable Computing (PRDC), 2012. [pdf], [link]
  • X. Yin, J. Alonso, F. Machida, E. C. Andrade and K. S. Trivedi, Availability Modeling and Analysis for Data Backup and Restore operations, In Proc. of 31st Int. Symp. on Reliable Distributed Systems (SRDS), 2012. [pdf]
  • F. Machida, D. Kim, and K. S. Trivedi, Modeling and Analysis of Software Rejuvenation in a Server Virtualized System with Live VM migration, Performance Evaluation, 2012. [link]
  • F. Machida, J. Xiang, K. Tadano and Y. Maeno, Combined Server Rejuvenation in a Virtualized Data Center, In Proc. of 23rd Int'l Conf. on Autonomic and Trusted Computing (ATC), 2012. [pdf] [link]
  • R. S. Matos Jr., P. R. M. Maciel, F. Machida, D. Kim, K. S. Trivedi, Sensitivity Analysis of Server Virtualized System Availability, IEEE Trans. on Reliability, 2012. [link]
  • F. Machida, R. Mibu, J. Gokurakuji, K. Yanoo, K. Tadano, Y. Maeno and T. Sugawara, Server virtualized infrastructure for resilient voice communication service, In Proc. of IEEE/IFIP Network Operations and Management Symposium (NOMS2014), 2014. [pdf]
  • J. Xiang, K. Yanoo, Y. Maeno, K. Tadano, F. Machida, A. Kobayashi, T. Osaki, Efficient Analysis of Fault Trees with Voting Gates, In Proc. of 22nd Int'l Symp. on Software Reliability Engineering (ISSRE), 2011. [pdf] [link]
  • J. Xiang, K. Yanoo, Y. Maeno, and K. Tadano, Automatic Synthesis of Static Fault Trees from System Models, In Proc. of The 5th International Conference on Secure Software Integration and Reliability Improvement (SSIRI), 2011. [pdf] [link]
  • F. Machida, E. C. Andrade, D. Kim, and K. Trivedi, Candy: Component-based availability modeling framework for cloud service management using SysML, Proc. of Int. Symp. on reliable distributed systems (SRDS), 2011. [pdf] [link]
  • K. Tadano, J. Xiang, M. Kawato, Y. Maeno, Automatic Synthesis of SRN Models from System Operation Templates for Availability Analysis, In Proc. of 30th Int. Conf. on Computer Safety, Reliability and Security (SAFECOMP), 2011. [link]
  • J. Xiang, K. Yanoo, Formal Static Fault Tree Analysis, In Proc. of The 6th International Conference on Computer Engineering & Systems (ICCES), 2010 (Best Paper). [pdf] [link]

Opportunities

Jobs

LASD seeks specialists with both industrial and research experiences for conducting research to apply cutting-edge technology to practical dependable IT systems.

Internships

We are accepting international internship students pursuing advanced degrees in the areas of mathematics, analytics, and computer science with keen interest in LASD’s research projects.

Research collaborations

We are seeking for opportunities for global research collaboration with any individuals and research institutes in the areas such as dependability, reliability, availability, and safety of (hardware + software) systems.

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