Hiroyuki Okamura
Last Updated :2022/08/02
- Affiliations, Positions
- Graduate School of Advanced Science and Engineering, Professor
- E-mail
- okamu
hiroshima-u.ac.jp
- Self-introduction
- Reliability Engineering, Software Reliability, Stochastic Model
Basic Information
Major Professional Backgrounds
- 2007/04/01, 2010/03/31, Hiroshima University, Graduate School of Engineering, Associate Professor
- 2003/04/01, 2018/03/31, Hiroshima University, Graduate School of Engineering, Associate Professor
- 2003/04/01, 2007/03/31, Hiroshima University, Graduate School of Engineering, Assistant Professor
- 2001/04/01, 2003/03/31, Hiroshima University, Graduate School of Engineering, Assistant
- 1998/10/01, 2001/03/31, Hiroshima University, School of Engineering, Assistant
- 1997/04/01, 1998/09/30, CSK Corporation, Regular Employee
- 2018/04/01, 2020/03/31, Hiroshima University, Graduate School of Engineering, Professor
Educational Backgrounds
- Hiroshima University, Faculty of Engineering, Japan, 1991/04, 1995/03
- Hiroshima University, Graduate School, Division of Engineering, Japan, 1995/04, 1997/03
Academic Degrees
- Doctor of Engineering, Hiroshima University
- Master of Engineering, Hiroshima University
Research Fields
- Informatics;Principles of Informatics;Mathematical informatics
- Complex systems;Social / Safety system science;Social systems engineering / Safety system
Research Keywords
- Stochastic Model
- Performance Analysis
- Reliability Engineering
- Software Reliability Engineering
- Operations Research
Affiliated Academic Societies
- IEICE
- IPSJ
- ORSJ
- JSIAM
- IEEE
- ACM
- Reliability Engineering Association of Japan
Educational Activity
Course in Charge
- 2022, Undergraduate Education, Intensive, Basics of Data Engineering
- 2022, Undergraduate Education, 4Term, Numerical Computation
- 2022, Undergraduate Education, 2Term, Software Engineering
- 2022, Undergraduate Education, 2Term, Software Management
- 2022, Undergraduate Education, Intensive, Data Analysis for Medical and Welfare Policies
- 2022, Graduate Education (Master's Program) , 1Term, Special Exercises on Informatics and Data Science A
- 2022, Graduate Education (Master's Program) , 2Term, Special Exercises on Informatics and Data Science A
- 2022, Graduate Education (Master's Program) , 3Term, Special Exercises on Informatics and Data Science B
- 2022, Graduate Education (Master's Program) , 4Term, Special Exercises on Informatics and Data Science B
- 2022, Graduate Education (Master's Program) , Academic Year, Special Study on Informatics and Data Science
- 2022, Graduate Education (Doctoral Program) , Academic Year, Special Study on Informatics and Data Science
Research Activities
Academic Papers
- Optimal control of preventive maintenance schedule and safety stocks in an unreliable manufacturing environment, INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS, 74(1-3), 147-155, 20011201
- A structural approximation method to generate the optimal auto-sleep schedule for computer systems, COMPUTERS & MATHEMATICS WITH APPLICATIONS, 46(7), 1103-1110, 200310
- Phase type approximation for optimal auto-sleep scheduling, MATHEMATICAL AND COMPUTER MODELLING, 38(11-13), 1391-1398, 200312
- Rejuvenating communication network system under burst arrival circumstances, IEICE TRANSACTIONS ON COMMUNICATIONS, E88B(12), 4498-4506, 200512
- Distribution-free checkpoint placement algorithms based on min-max principle, IEEE TRANSACTIONS ON DEPENDABLE AND SECURE COMPUTING, 3(2), 130-140, 2006
- Discrete-time cost analysis for a telecommunication billing application with rejuvenation, COMPUTERS & MATHEMATICS WITH APPLICATIONS, 51(2), 335-344, 200601
- Gompertz software reliability model: Estimation algorithm and empirical validation, JOURNAL OF SYSTEMS AND SOFTWARE, 82(3), 535-543, 200903
- Software Reliability Modeling Based on Capture-Recapture Sampling, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E92A(7), 1615-1622, 200907
- Markovian Arrival Process Parameter Estimation With Group Data, IEEE-ACM TRANSACTIONS ON NETWORKING, 17(4), 1326-1339, 200908
- A Variational Bayesian Approach for Estimating Parameters of a Mixture of Erlang Distribution, COMMUNICATIONS IN STATISTICS-THEORY AND METHODS, 39(13), 2333-2350, 2010
- Comprehensive evaluation of aperiodic checkpointing and rejuvenation schemes in operational software system, JOURNAL OF SYSTEMS AND SOFTWARE, 83(9), 1591-1604, 201009
- A refined EM algorithm for PH distributions, PERFORMANCE EVALUATION, 68(10), 938-954, 201110
- Software Reliability Prediction Based on Least Squares Estimation, QUALITY TECHNOLOGY AND QUANTITATIVE MANAGEMENT, 9(3), 243-264, 201209
- Application of Markov Chain Monte Carlo Random Testing to Test Case Prioritization in Regression Testing, IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS, E95D(9), 2219-2226, 201209
- Enhancing Performance of Random Testing through Markov Chain Monte Carlo Methods, IEEE TRANSACTIONS ON COMPUTERS, 62(1), 186-192, 201301
- Dynamic software rejuvenation policies in a transaction-based system under Markovian arrival processes, PERFORMANCE EVALUATION, 70(3), 197-211, 201303
- Improvement of expectationmaximization algorithm for phase-type distributions with grouped and truncated data, APPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, 29(2), 141-156, 2013
- Performance evaluation of workload-based software rejuvenation scheme, IEICE Transactions on Information and Systems, E84D(10), 1368-1375, 20011001
- Discrete availability models to rejuvenate a telecommunication billing application, IEICETRANSACTIONSONCOMMUNICATIONS, E86B(10), 2931-2939, 20031001
- Fine-Grained Shock Models to Rejuvenate Software Systems, IEICE Transactions on Information and Systems, E86D(10), 2165-2171, 20031001
- Performance evaluation of power-aware communication network devices, EMBEDDEDANDUBIQUITOUSCOMPUTING-EUC2005, 3824, 245-254, 20050101
- Cost-effective analysis of software systems with periodic rejuvenation, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, E85A(12), 2923-2932, 20021201
- Dependability Analysis of a Transaction-Based Multi-Server System with Rejuvenation, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, E86A(8), 2081-2090, 20030801
- Optimal policies for a controlled queueing system with removable server under a random vacation circumstance, COMPUTERS & MATHEMATICS WITH APPLICATIONS, 39(1-2), 215-227, 200001
- Performance evaluation of workload-based software rejuvenation scheme, IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS, E84D(10), 1368-1375, 200110
- Cost-effective analysis of software systems with periodic rejuvenation, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E85A(12), 2923-2932, 200212
- Dependability analysis of a transaction-based multi-server system with rejuvenation, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E86A(8), 2081-2090, 200308
- Discrete availability models to rejuvenate a telecommunication billing application, IEICE TRANSACTIONS ON COMMUNICATIONS, E86B(10), 2931-2939, 200310
- Fine-grained shock models to rejuvenate software systems, IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS, E86D(10), 2165-2171, 200310
- Performance evaluation of power-aware communication network devices, EMBEDDED AND UBIQUITOUS COMPUTING - EUC 2005, 3824, 245-254, 2005
- NHPP-Based Software Reliability Models Using Equilibrium Distribution, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E95A(5), 894-902, 201205
- Software reliability growth models with normal failure time distributions, RELIABILITY ENGINEERING & SYSTEM SAFETY, 116, 135-141, 201308
- Optimal Trigger Time of Software Rejuvenation under Probabilistic Opportunities, IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS, E96D(9), 1933-1940, 201309
- Application of deterministic annealing EM algorithm to MAP/PH parameter estimation, TELECOMMUNICATION SYSTEMS, 54(1), 79-90, 201309
- Variational Bayes for Phase-Type Distribution, COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION, 43(8), 2031-2044, 20140914
- Transient Analysis of Software Rejuvenation Policies in Virtualized System: Phase-Type Expansion Approach, QUALITY TECHNOLOGY AND QUANTITATIVE MANAGEMENT, 11(3), 335-351, 201409
- Performance evaluation of snapshot isolation in distributed database system under failure-prone environment, JOURNAL OF SUPERCOMPUTING, 70(3), 1156-1179, 201412
- A Fast EM Algorithm for Fitting Marked Markovian Arrival Processes with a New Special Structure, Proceedings of 10th European Workshop on Performance Engineering (EPEW 2013), 119-133, 2013
- Aperiodic checkpoint placement algorithms -- survey and comparison --, Journal of Software Engineering and Applications, 6(4A), 41-53, 2013
- Estimating response time distribution of server application in software aging phenomenon,, Proceedings of IEEE 5th International Workshop on Software Aging and Rejuvenation (WoSAR-2013), 4, 2013
- Estimating software reliability with static project data in incremental development processes, Proceedings of 2013 Joint Conference of the 23rd International Workshop on Software Measurement (IWSM-2013) and the 8th International Conference on Software Process and Product Measurement (MENSURA-2013), 219-224, 2013
- Generalized Cox proportional hazards regression-based software reliability modeling with metrics data, Proceedings of The 19th IEEE Pacific Rim International Symposium on Dependable Computing (PRDC 2013),, 328-337, 2013
- Modeling and analysis of multi-version concurrent control,, Proceedings of The 37th Annual International Computer Software and Applications Conference (COMPSAC 2013), 53-58, 2013
- NHPP-based software reliability model with mixed gamma distribution,, Advanced Science and Technology Letters, 19, 240-243, 2013
- Quantifying software test process and product reliability simultaneously,, Proceedings of The 24th International Symposium on Software Reliability Engineering (ISSRE 2013), 108-117, 2013
- Quantitative security evaluation for software system from vulnerability database, Journal of Software Engineering and Applications, 6(4A), 15-23, 2013
- Semi-parametric approach for software reliability evaluation using mixed gamma distributions, International Journal of Software Engineering and Its Applications, 7(4), 401-414, 2013
- Sensitivity analysis of reliability function for virtualized system,, Proceedings of the 8th International Conference on Mathematical Methods in Reliability, --Theory, Methods and Applications -- (MMR-2013), 229-232, 2013
- SRATS: Software reliability assessment tool on spreadsheet, Proceedings of The 24th International Symposium on Software Reliability Engineering (ISSRE 2013),, 100-117, 2013
- A novel framework of software reliability evaluation with software reliability growth models and software metrics, Proceedings of The 15th IEEE International Symposium on High Assurance Systems Engineering (HASE 2014), 97-104, 20140109
- Quantifying resiliency of virtualized system with software rejuvenation, Proceedings of The 2014 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering (QR2MSE 2014), 6 pages, 20140723
- Optimized patch applying schedule within multiplex software architecture, Proceedings of The 6th Asia-Pacific International Symposium on Advanced Reliability and Maintenance Modeling (APARM 2014), 311-318, 20140821
- Fine-grained software reliability estimation using software testing inputs, Proceedings of The 6th Asia-Pacific International Symposium on Advanced Reliability and Maintenance Modeling (APARM 2014), 365-372, 20140821
- Maximum penalized likelihood estimation for phase-type software reliability growth model, Proceedings of The 6th Asia-Pacific International Symposium on Advanced Reliability and Maintenance Modeling (APARM 2014), 373-380, 20140821
- Optimal reliability design for real-time systems with dynamic voltage and frequency scaling, Proceedings of The 20th IEEE Pacific Rim International Symposium on Dependable Computing (PRDC 2014), 213-222, 20141118
- Coarse-grained parallel uniformization for continuous-time Markov chains, Proceedings of The 20th IEEE Pacific Rim International Symposium on Dependable Computing (PRDC 2014), 116-124, 20141118
- Availability importance measures for virtualized system with live migration, Applied Mathematics, 6, 359-372, 20150201
- Network survivability modeling and analysis for power-aware MANETs by Markov regenerative processes, Telecommunication Systems Journal, 60, 471-484, 20150317
- Quantifying resiliency of virtualized system with software rejuvenation, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (A), E98-A(10), 2051-2059, 20151001
- Survivability analysis of VM-based intrusion tolerant systems, IEICE Transactions on Information and Systems (D), E98-D(12), 2082-2090, 20151201
- A Markov decision process approach to dynamic power management in a cluster system, IEEE Access, 3(1), 1-9, 20151217
- PH fitting algorithm and its application to reliability engineering, Journal of the Operations Research Society of Japan, 59(1), 72-109, 20160202
- Optimal planning for open source software updates, Proceedings of the Institution of Mechanical Engineerings, Part O: Journal of Risk and Reliability, 230(1), 44-53, 20160111
- Analysis of optimal restart policies for software systems, Journal of Japan Industrial Management Association, 66(4E), 416-425, 20160305
- A note on variational Bayes approach for software reliability growth model with normal distribution, Proceedings of the 9th International Conference on Mathematical Methods in Reliability, Theory, Methods and Applications (MMR-2015), 41-48, 20150601
- A note on optimal allocation of testing-resources with architecture-based software reliability model, Proceedings of 2015 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering (QR2MSE 2015), 1, 8-13, 20150721
- Fine-grained software reliability estimation using software testing inputs, Proceedings of 2015 IEEE International Conference on Software Quality, Reliability and Security (QRS 2015), 85-92, 20150803
- Optimal power-aware design in a cluster system: Markov decision process approach, Proceedings of the 12th IEEE International Conference on Advanced and Trusted Computing (ATC 2015), 527-532, 20150810
- mapfit: An R-based tool for PH/MAP parameter estimation, The 14th International Conference on Quantitative Evaluation of Systems (QEST2015), Lecture Notes in Computer Science, 9295, 105-112, 20150901
- Towards comprehensive software reliability evaluation in open source software, Proceedings of the 24th International Symposium on Software Reliability Engineering (ISSRE 2015), 121-129, 20151102
- Survivability quantification of wireless ad hoc network taking account of border effects, Proceedings of the 21st IEEE Pacific Rim International Symposium on Dependable Computing (PRDC 2015), 149-158, 20151118
- Component importance measures for real-time computing systems in the presence of common-cause failures, Proceedings of the 21st IEEE Pacific Rim International Symposium on Dependable Computing (PRDC 2015), 301-310, 20151118
- Phase-type software reliability model: parameter estimation algorithms with grouped data, ANNALS OF OPERATIONS RESEARCH, 244(1), 177-208, 201609
- Dynamic software availability model with rejuvenation, Journal of the Operations Research Society of Japan, 59(4), 270-290, 20161031
- Optimistic and pessimistic maintenance policies, Proceedings of the 2nd International Conference on Mathematical Techniques in Engineering Applications (ICMTEA 2016), 20160429
- Mean Time to Security Failure of VM-Based Intrusion Tolerant Systems, Proceedings of the 15th International Workshop on Assurance in Distributed Systems and Networks (ADSN2016), 20160627
- Failure-correlated opportunity-based age replacement policies, Proceedings of the 7th Asia-Pacific International Symposium on Advanced Reliability and Maintenance Modeling (APARM 2016), 73-80, 20160824
- Performance comparison of algorithms for computing parametric sensitivity functions in continuous-time Markov chains, Proceedings of the 7th Asia-Pacific International Symposium on Advanced Reliability and Maintenance Modeling (APARM 2016), 415-422, 20160824
- Markov-based component importance analysis of real-time computing systems in a warm standby configuration, Proceedings of the 7th Asia-Pacific International Symposium on Advanced Reliability and Maintenance Modeling (APARM 2016), 613-620, 20160824
- Performance evaluation of VM-Based intrusion tolerant systems with Poisson arrivals, Proceedings of the 4th International Symposium on Computing and Networking (CANDAR 2016), 20161122
- A phase expansion approach for transient analysis of software rejuvenation model, Proceedings of the 8th International Workshop on Software Aging and Rejuvenation (WoSAR 2016), 20161023
- Dynamic Power Management With Optimal Time-Out Policies, IEEE SYSTEMS JOURNAL, 11(2), 962-972, 201706
- A Comprehensive Evaluation of Software Rejuvenation Policies for Transaction Systems With Markovian Arrivals, IEEE TRANSACTIONS ON RELIABILITY, 66(4), 1157-1177, 201712
- Moment-based approach for some age-based replacement problems, JOURNAL OF INDUSTRIAL AND PRODUCTION ENGINEERING, 34(8), 558-567, 2017
- Component Importance Analysis of Mobile Cloud Computing Systemin the Presence of Common-Cause Failures, IEEE ACCESS, 6, 18630-18642, 2018
- Reliability importance of components in a real-time computing system with standby redundancy schemes, International Journal of Mathematical, Engineering and Management Sciences, 3(2), 64-89, 201806
- A pull-type security patch management of an intrusion tolerant system under a periodic vulnerability checking strategy, Proceedings of 42nd IEEE International Conference on Computers, Software and Applications, 201807
- A comprehensive evaluation of software reliability modeling based on Marshall-Olkin type fault-detection time distributions, Proceedings of the 24th Asia-Pacific Software Engineering Conference (APSEC 2017), 486-494, 201712
- Software reliability modeling and analysis via kernel-based approach, Proceedings of the 22nd International Conference on Engineering of Complex Computer Systems (ICECCS 2017), 154-157, 201711
- A generalized bivariate modeling framework of fault detection and correction processes, Proceedings of the 26th International Symposium on Software Reliability Engineering (ISSRE 2017), 35-45, 201710
- A statistical framework on software aging modeling with continuous-time hidden Markov model, Proceedings of the 36th International Symposium on Reliable Distributed Systems (SRDS 2017), 114-123, 201709
- A note on computation of quasi-stationary distribution in continuous-time Markov chains, Proceedings of the 10th International Conference on Mathematical Methods in Reliability, Theory, Methods and Applications (MMR-2017), 201707
- Optimizing Testing-Resource Allocation Using Architecture-Based Software Reliability Model, JOURNAL OF OPTIMIZATION, 2018
- Optimal periodic software rejuvenation policies based on interval reliability criteria, RELIABILITY ENGINEERING & SYSTEM SAFETY, 180, 463-475, 201812
- Parameter Estimation of M-t/M/1/K Queueing Systems With Utilization Data, IEEE ACCESS, 7, 42664-42671, 2019
- Optimal security patch application timing for an intrusion tolerant system, Proceedings of 8th Asia-Pacific International Symposium on Advanced Reliability and Maintenance Modeling, vol. II, 855-859, 2018
- A note on availability importance measures of components in smart grid, Proceedings of 8th Asia-Pacific International Symposium on Advanced Reliability and Maintenance Modeling, vol. I, 75-79, 2018
- Parametric Uncertainty Propagation through Dependability Models, Proceedings of Latin-American Symposium on Dependable Computing, 10-18, 2018
- Software Test-Run Reliability Modeling with Non-homogeneous Binomial Processes, Proceedings of 23rd IEEE Pacific Rim International Symposium on Dependable Computing, 145-154, 2018
- Gompertz software reliability model: Estimation algorithm and empirical validation, JOURNAL OF SYSTEMS AND SOFTWARE, 82(3), 535-543, 2009
- Comprehensive evaluation of aperiodic checkpointing and rejuvenation schemes in operational software system, JOURNAL OF SYSTEMS AND SOFTWARE, 83(9), 1591-1604, 2010
- Software Reliability Prediction Based on Least Squares Estimation, QUALITY TECHNOLOGY AND QUANTITATIVE MANAGEMENT, 9(3), 243-264, 2012
- Application of Markov Chain Monte Carlo Random Testing to Test Case Prioritization in Regression Testing, IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS, E95D(9), 2219-2226, 2012
- Dynamic software rejuvenation policies in a transaction-based system under Markovian arrival processes, PERFORMANCE EVALUATION, 70(3), 197-211, 2013
- Optimal Trigger Time of Software Rejuvenation under Probabilistic Opportunities, IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS, E96D(9), 1933-1940, 2013
- Generalized-Gamma Software Reliability Model, Technical report of IEICE. SS, 103(318), 9-14, 20030912
Publications such as books
- 2016/04/14, Principles of Performance and Reliability Modeling and Evaluation, Fitting phase-type distributions and Markovian arrival processes: Algorithms and tools, Springer, 2016, 4, Scholarly Book, Joint work, 英語, H. Okamura and T. Dohi, 49-75, Chapter 3
- 2016/12, Advances in Reliability and System Engineering, Connectivity-based survivability analysis with border effects for wireless ad hoc network, Springer, 2016, 12, Scholarly Book, Joint work, 英語, Z. Yi, T. Dohi and H. Okamura, 53-86
- 2017/05, Mathematics Applied to Engineering, Quantitative security evaluation of an intrusion tolerant system, Elsevier, 2017, 5, Scholarly Book, Joint work, H. Okamura, T. Dohi, 21-54
- 2017/08, Reliability Modeling with Applications, Confidence intervals in optimal checkpoint placement, World Scientific, 2017, 8, Scholarly Book, Joint work, S. Tokumoto, T. Dohi, H. Okamura, W. Y. Yun, 79-99
Awards
- 2004/02, "The IEEE Reliability Society Japan Chapter, Outstanding Young Scientist Award", IEEE Reliability Society Japan Chapter