skip to main content
research-article

A survey on standards for real-time distribution middleware

Published:01 March 2014Publication History
Skip Abstract Section

Abstract

This survey covers distribution standards oriented to the development of distributed real-time systems. Currently, there are many distribution standards that provide a wide and different set of real-time facilities to control the temporal aspects of applications. Besides giving a general overview of these standards, we describe the real-time mechanisms proposed by each standard to manage both processor and network resources, discuss whether the available facilities are sufficient to guarantee determinism throughout the whole application, and identify a set of features and deployment options that would be desirable in any real-time distribution middleware regardless of its distribution model and standard. The survey identifies open issues and key challenges for future research.

References

  1. M. Aldea, G. Bernat, I. Broster, A. Burns, R. Dobrin, J. M. Drake, G. Fohler, P. Gai, M. González Harbour, G. Guidi, J. J. Gutiérrez, T. Lennvall, G. Lipari, J. M. Martínez, J. L. Medina, J. C. P. Gutiérrez, and M. Trimarchi. 2006. FSF: A real-time scheduling architecture framework. In Proceedings of the IEEE Real Time Technology and Applications Symposium. 113--124. Google ScholarGoogle ScholarDigital LibraryDigital Library
  2. Altran Praxis. 2011. SPARK—the SPADE Ada Kernel (including RavenSPARK), Edition 7.2.Google ScholarGoogle Scholar
  3. M. Amoretti, S. Caselli, and M. Reggiani. 2006. Designing distributed, component-based systems for industrial robotic applications. In Industrial Robotics: Programming, Simulation and Applications, Low Kin Huat (Ed.). ISBN: 3-86611-286-6, InTech, DOI:10.5772/4892.Google ScholarGoogle Scholar
  4. J. S. Anderson and E. D. Jensen. 2006. Distributed real-time specification for Java: A status report (digest). In Proceedings of the 4th International Workshop on Java Technologies for Real-Time and Embedded Systems (JTRES’06). ACM, New York, NY, 3--9. Google ScholarGoogle ScholarDigital LibraryDigital Library
  5. ARINC. ARINC Specification 653p1. 2006. Avionics application software standard interface (ARINC-653).Google ScholarGoogle Scholar
  6. ARINC. ARINC Specification 664p7. 2009. Aircraft data network, part 7—Avionics Full Duplex Switched Ethernet (AFDX) network.Google ScholarGoogle Scholar
  7. N. Audsley and A. Wellings. 2001. Issues with using Ravenscar and the Ada Distributed Systems Annex for high-integrity systems. Ada Letters XXI, 33--39. Google ScholarGoogle ScholarDigital LibraryDigital Library
  8. T. P. Baker, 1991. Stack-based scheduling for realtime processes. Real-Time Systems 3, 67--99. Google ScholarGoogle ScholarDigital LibraryDigital Library
  9. J. Bard and V. J. Kovarik. 2007. Software Defined Radio: The Software Communications Architecture. Wiley-Blackwell. ISBN: 0-47086-518-0.Google ScholarGoogle Scholar
  10. P. Basanta-Val, M. García-Valls, and I. Estévez-Ayres. 2010. An architecture for distributed real-time Java based on RMI and RTSJ. In Proceedings of the IEEE Conference on Emerging Technologies and Factory Automation (ETFA). 1--8.Google ScholarGoogle Scholar
  11. G. S. Blair, G. Coulson, A. Andersen, L. Blair, M. Clarke, F. Costa, H. Duran-Limon, T. Fitzpatrick, L. Johnston, R. Moreira, N. Parlavantzas, and K. Saikoski. 2001. The design and implementation of open ORB 2. In IEEE Distributed Systems Online, Vol. 2. Google ScholarGoogle ScholarDigital LibraryDigital Library
  12. G. Bollella and J. Gosling. 2000. The real-time specification for Java. IEEE Computer 33, 6, 47--54. Google ScholarGoogle ScholarDigital LibraryDigital Library
  13. J. L. Campos, J. J. Gutiérrez, and M. G. Harbour. 2004. The chance for Ada to support distribution and real-time in embedded systems. In Reliable Software Technologies—Ada-Europe 2004, A. Llamosí and A. Strohmeier (Eds.). Lecture Notes in Computer Science, Vol. 3063. Springer, 91--105.Google ScholarGoogle Scholar
  14. J. L. Campos, J. J. Gutiérrez, and M. G. Harbour. 2006. Interchangeable scheduling policies in real-time middleware for distribution. In Proceedings of the 11th Ada-Europe International Conference on Reliable Software Technologies. Lecture Notes in Computer Science, Vol. 4006. Springer, 227--240. Google ScholarGoogle ScholarDigital LibraryDigital Library
  15. A. Corsaro and D. C. Schmidt. 2012. The data distribution service—the communication middleware fabric for scalable and extensible systems-of-systems. In System of Systems, Dr. Adrian V. Gheorghe (Ed.). ISBN: 978-953-51-0101-7, InTech, DOI:10.5772/30322.Google ScholarGoogle Scholar
  16. R. I. Davis and A. Burns. 2011. A survey of hard real-time scheduling for multiprocessor systems. ACM Computing Surveys 43, 4, 35:1--35:44. Google ScholarGoogle ScholarDigital LibraryDigital Library
  17. A. Dubey, G. Karsai, and N. Mahadevan. 2011. A component model for hard real-time systems: CCM with ARINC-653. Software: Practice and Experience (SPE) 41, 12, 1517--1550. DOI:10.1002/spe.1083. http://dx.doi.org/10.1002/spe.1083 Google ScholarGoogle ScholarDigital LibraryDigital Library
  18. M. Felser. 2001. Ethernet TCP/IP in automation: A short introduction to real-time requirements. In Proceedings of the 8th IEEE International Conference on Emerging Technologies and Factory Automation, Vol. 2. 501--504.Google ScholarGoogle ScholarCross RefCross Ref
  19. G. Fohler and G. C. Buttazzo. 2002. Introduction to the Special Issue on Flexible Scheduling, Vol. 22. Springer Netherlands. 10.1023/A:1013489610047. Google ScholarGoogle ScholarDigital LibraryDigital Library
  20. A. Foster and S. Aslam-Mir. 2005. Practical experiences using the OMG's Extensible Transport Framework (ETF) under a real-time Corba ORB to implement QoS sensitive custom transports for SDR. In Proceedings of the SDR Technical Conference and Product Exposition.Google ScholarGoogle Scholar
  21. E. Freeman, S. Hupfer, and K. Arnold. 1999. JavaSpaces: Principles, Patterns, and Practice. Addison-Wesley, Reading, MA. Google ScholarGoogle ScholarDigital LibraryDigital Library
  22. FRESCOR. Framework for Real-Time Embedded Systems Based on COntRacts. 2006. Project Web page. Retrieved September 2013 from http://www.frescor.orgGoogle ScholarGoogle Scholar
  23. M. Gillen, J. Loyall, K. Z. Haigh, R. Walsh, C. Partridge, G. Lauer, and T. Strayer. 2012. Information dissemination in disadvantaged wireless communications using a data dissemination service and content data network. In Proceedings of the SPIE Conference on Defense Transformation and Net-Centric Systems, Vol. 8405.Google ScholarGoogle Scholar
  24. A. Gokhale, K. Balasubramanian, A. S. Krishna, J. Balasubramanian, G. Edwards, G. Deng, E. Tukay, J. Parsons, and D. C. Schmidt. 2008. Model driven middleware: A new paradigm for developing distributed real-time and embedded systems. Science of Computer Programming 73, 1, 39--58. Google ScholarGoogle ScholarDigital LibraryDigital Library
  25. C. Grelck, J. Julku, and F. Penczek. 2012. Distributed S-Net: Cluster and grid computing without the hassle. In Proceedings of the 12th IEEE /ACM International Symposium on Cluster, Cloud and Grid Computing (CCGrid). 410--418. Google ScholarGoogle ScholarDigital LibraryDigital Library
  26. J. J. Gutiérrez and M. Harbour. 1999. Prioritizing remote procedure calls in Ada distributed systems. Ada Letters XIX, 67--72. Google ScholarGoogle ScholarDigital LibraryDigital Library
  27. J. J. Gutiérrez and M. Harbour. 2001. Towards a real-time distributed systems annex in Ada. Ada Letters XXI, 62--66. Google ScholarGoogle ScholarDigital LibraryDigital Library
  28. M. T. Higuera-Toledano. 2012. Adaptive distributed embedded and real-time Java systems based on RTSJ. In Proceedings of the 15th IEEE International Symposium on Object/Component/Service-Oriented Real-Time Distributed Computing Workshops (ISORCW). 164--171. Google ScholarGoogle ScholarDigital LibraryDigital Library
  29. J. Hugues, B. Zalila, L. Pautet, and F. Kordon. 2008. From the prototype to the final embedded system using the Ocarina AADL toolsuite. ACM Transactions in Embedded Computing Systems 7, 4, 1--25. Google ScholarGoogle ScholarDigital LibraryDigital Library
  30. IEEE: The Institute of Electrical and Electronics Engineers STD 802.1D. 2004. Media Access Control (MAC) bridges. http://www.ieee802.org/1/pages/802.1D.htmlGoogle ScholarGoogle Scholar
  31. IEEE: The Institute of Electrical and Electronics Engineers STD 802.1Q. 2006. Virtual bridged local area networks. Annex G. http://www.ieee802.org/1/pages/802.1Q.htmlGoogle ScholarGoogle Scholar
  32. IEEE: The Institute of Electrical and Electronics Engineers STD 802.1Qbb. 2011. Priority-based flow-control. http://www.ieee802.org/1/pages/802.1bb.htmlGoogle ScholarGoogle Scholar
  33. ISO/IEC. 2006. Taft, S. T., Duff, R. A., Brukardt, R., Ploedereder, E., and Leroy, P. 2006. Ada 2005 Reference Manual. Language and Standard Libraries—International Standard ISO/IEC 8652 (E) with Technical Corrigendum 1 and Amendment 1. Lecture Notes in Computer Science, Vol. 4348. Springer.Google ScholarGoogle Scholar
  34. ISO/IEC. 2012. Ada 2012 Reference Manual. Language and Standard Libraries—International Standard ISO/IEC 8652:2012(E).Google ScholarGoogle Scholar
  35. E. D. Jensen, C. D. Locke, and H. Tokuda. 1985. A time-driven scheduling model for real-time systems. In Proceedings of IEEE Real-Time Systems Symposium. 112--122.Google ScholarGoogle Scholar
  36. Y. Kermarrec. 1999. CORBA vs. Ada 95 DSA: A programmer's view. Ada Letters XIX, 39--46. Google ScholarGoogle ScholarDigital LibraryDigital Library
  37. K. H. Kim. 2000. Object-oriented real-time distributed programming and support middleware. In Proceedings of the 7th International Conference on Parallel and Distributed Systems (ICPADS). IEEE Computer Society, Washington, DC, 10--20. Google ScholarGoogle ScholarDigital LibraryDigital Library
  38. R. Klefstad, D. C. Schmidt, and C. O’Ryan. 2002. Towards highly configurable real-time object request brokers. In Proceedings of the 5th IEEE International Symposium on Object-Oriented Real-Time Distributed Computing (ISORC). 437--447. Google ScholarGoogle ScholarDigital LibraryDigital Library
  39. H. Kopetz. 2011. Real-Time Systems: Design Principles for Distributed Embedded Applications (2nd ed., XVIII). Springer. Google ScholarGoogle ScholarDigital LibraryDigital Library
  40. S. Lankes, A. Jabs, and T. Bemmerl. 2003. Integration of a CAN-based connection-oriented communication model into real-time Corba. In Proceedings of the 17th International Symposium on Parallel and Distributed Processing (IPDPS). IEEE Computer Society, Washington DC, 121--129. Google ScholarGoogle ScholarDigital LibraryDigital Library
  41. J. W. S. Liu. 2000. Real-Time Systems. Prentice Hall PTR, Upper Saddle River, NJ.Google ScholarGoogle Scholar
  42. C. L. Liu and J. W. Layland. 1973. Scheduling algorithms for multiprogramming in a hard-real-time environment. Journal of the ACM 20, 46--61. Google ScholarGoogle ScholarDigital LibraryDigital Library
  43. T. Losert, W. Huber, K. Hendling, and M. Jandl 2004. An extensible transport framework for Corba with emphasis on real-time capabilities. In Proceedings of the 2nd IEEE International Conference on Computational Cybernetics (ICCC). 155--161.Google ScholarGoogle ScholarCross RefCross Ref
  44. A. K. Mok. 1983. Fundamental Design Problems of Distributed Systems for the Hard Real-Time Environment. Ph.D. Dissertation. Massachusetts Institute of Technology.Google ScholarGoogle Scholar
  45. MultiPARTES. Multi-Cores Partitioning for Trusted Embedded Systems (2011--2014). Project Web page. Retrieved September 2013 from http://www.multipartes.euGoogle ScholarGoogle Scholar
  46. L. Neumeyer, B. Robbins, A. Nair, and A. Kesari. 2010. S4: Distributed stream computing platform. In Proceedings of the IEEE International Conference on Data Mining (ICDM). 170--177. Google ScholarGoogle ScholarDigital LibraryDigital Library
  47. K. Nichols, S. Blake, F. Baker, and D. Black. 1998. Definition of the differentiated services field (DS field) in the Ipv4 and Ipv6 headers.Google ScholarGoogle Scholar
  48. OMG. 2004. Extensible transport framework.Google ScholarGoogle Scholar
  49. OMG. 2005. Realtime Corba Specification. v1.2. http://www.omg.org/spec/RT/1.2/Google ScholarGoogle Scholar
  50. OMG. 2007. Data Distribution Service for Real-Time Systems. v1.2. http://www.omg.org/spec/DDS/1.2/Google ScholarGoogle Scholar
  51. OMG. 2009. The Real-Time Publish-Subscribe Wire Protocol. DDS interoperability wire protocol specification. v2.1. http://www.omg.org/spec/DDSI/2.1/Google ScholarGoogle Scholar
  52. OMG. 2011. Corba Core Specification. v3.2. http://www.omg.org/spec/CORBA/3.2/Google ScholarGoogle Scholar
  53. OMG. 2012. Extensible and Dynamic Topic Types for DDS. v1.0. http://www.omg.org/spec/DDS-XTypes/1.0/Google ScholarGoogle Scholar
  54. C. O’Ryan, F. Kuhns, D. C. Schmidt, O. Othman, and J. Parsons. 2000. The design and performance of a pluggable protocols framework for real-time distributed object computing middleware. In Proceedings of the IFIP/ACM International Conference on Distributed Systems Platforms. Springer-Verlag, New York, 372--395. Google ScholarGoogle ScholarDigital LibraryDigital Library
  55. L. Pautet and S. Tardieu. 2000. Glade: A framework for building large object-oriented real-time distributed systems. In Proceedings of ISORC. 244--251. Google ScholarGoogle ScholarDigital LibraryDigital Library
  56. P. Pedreiras, R. Leite, and L. Almeida. 2003. Characterizing the real-time behavior of prioritized Switched-Ethernet. In Proceedings of the 2nd Workshop on Real-Time LANs in the Internet Age (RTLIA).Google ScholarGoogle Scholar
  57. S. Perathoner, E. Wandeler, L. Thiele, A. Hamann, S. Schliecker, R. Henia, R. Racu, R. Ernst, and M. G. Harbour. 2007. Influence of different system abstractions on the performance analysis of distributed real-time systems. In Proceedings of the 7th ACM & IEEE International Conference on Embedded Software (EMSOFT’’07). ACM, New York, NY, 193--202. Google ScholarGoogle ScholarDigital LibraryDigital Library
  58. H. Pérez and J. J. Gutiérrez. 2009. Experience in integrating interchangeable scheduling policies into a distribution middleware for Ada. In Proceedings of the ACM SIGAda Annual International Conference on Ada and Related Technologies, ACM, New York, 73--78. Google ScholarGoogle ScholarDigital LibraryDigital Library
  59. H. Pérez and J. J. Gutiérrez. 2012. On the schedulability of a data-centric real-time distribution middleware. Computer Standards and Interfaces 34, 1, 203--211. Google ScholarGoogle ScholarDigital LibraryDigital Library
  60. H. Pérez and J. J. Gutiérrez. 2013. Experience with the integration of distribution middleware into partitioned systems. In Proceedings of the 17th Ada-Europe International Conference on Reliable Software Technologies. Lecture Notes in Computer Science, Vol. 7896. Springer, 1--16.Google ScholarGoogle Scholar
  61. H. Pérez, J. J. Gutiérrez, and M. Harbour. 2012. Adapting the end-to-end flow model for distributed Ada to the Ravenscar profile. Ada Letters 33, 1, 53--63. Google ScholarGoogle ScholarDigital LibraryDigital Library
  62. H. Pérez, J. J. Gutiérrez, D. Sangorrín, and M. Harbour. 2008. Real-time distribution middleware from the Ada perspective. In Proceedings of the 13th Ada-Europe International Conference on Reliable Software Technologies, F. Kordon and T. Vardanega (Eds.). Lecture Notes in Computer Science, Vol. 5026. Springer, 268--281. Google ScholarGoogle ScholarDigital LibraryDigital Library
  63. M. Perrotin, E. Conquet, P. Dissaux, T. Tsiodras, and J. Hugues. 2010. The TASTE toolset: Turning human designed heterogeneous systems into computer built homogeneous software. In Proceedings of the European Congress on Embedded Real-Time Software (ERTS’10). Toulouse, France.Google ScholarGoogle Scholar
  64. I. Pyarali, M. Spivak, R. Cytron, and D. C. Schmidt. 2001. Evaluating and optimizing thread pool strategies for real-time CORBA. In Proceedings of the 2001 ACM SIGPLAN Workshop on Optimization of Middleware and Distributed Systems. ACM, New York, NY, 214--222. Google ScholarGoogle ScholarDigital LibraryDigital Library
  65. R. Rekik and S. Hasnaoui. 2009. Application of a can bus transport for DDS middleware. In Proceedings of the 2nd International Conference on the Applications of Digital Information and Web Technologies (ICADIWT). 766--771.Google ScholarGoogle Scholar
  66. R. Rouvoy, P. Barone, Y. Ding, F. Eliassen, S. Hallsteinsen, J. Lorenzo, A. Mamelli, and U. Scholz. 2009. MUSIC: Middleware support for self-adaptation in ubiquitous and service-oriented environments. In Software Engineering for Self-Adaptive Systems. Lecture Notes in Computer Science, Vol. 5525. Springer-Verlag, Berlin, Heidelberg, 164--182. Google ScholarGoogle ScholarDigital LibraryDigital Library
  67. M. Ryll and S Ratchev. 2008. Application of the data distribution service for flexible manufacturing automation. International Journal of Aerospace and Mechanical Engineering 2, 3, 193--200.Google ScholarGoogle Scholar
  68. D. C. Schmidt. 1998. Evaluating architectures for multithreaded object request brokers. Communications of the ACM 41, 10, 54--60. Google ScholarGoogle ScholarDigital LibraryDigital Library
  69. D. C. Schmidt. 2005. TAO Developer's Guide: Building a Standard in Performance. Object Computing, Inc.Google ScholarGoogle Scholar
  70. D. C. Schmidt, A. Corsaro, and H. V. Hag. 2008. Addressing the challenges of tactical information management in net-centric systems with DDS. Journal of Defense Software Engineering, 24--29.Google ScholarGoogle Scholar
  71. D. C. Schmidt and C. D. Cranor. 1996. Pattern Languages of Program Design 2. Addison-Wesley Longman, Boston, MA, 437--459. Google ScholarGoogle ScholarDigital LibraryDigital Library
  72. D. C. Schmidt, D. L. Levine, and S. Mungee. 1998. The design of the TAO real-time object request broker. Computer Communications 21, 4, 294--324. Google ScholarGoogle ScholarDigital LibraryDigital Library
  73. D. C. Schmidt, S. Mungee, S. Flores-Gaitan, and A. Gokhale. 2001. Software architectures for reducing priority inversion and non-determinism in real-time object request brokers. Journal of Real-Time Systems 21, 2, 77--125. Google ScholarGoogle ScholarDigital LibraryDigital Library
  74. L. Sha, T. Abdelzaher, K. Arzén, A. Cervin, T. Baker, A. Burns, G. Buttazzo, M. Caccamo, J. Lehoczky, andA. Mok. 2004. Real time scheduling theory: A historical perspective. Journal of Real-Time Systems 28, 2--3, 101--155. DOI:10.1023/B:TIME.0000045315.61234.1e. Google ScholarGoogle ScholarDigital LibraryDigital Library
  75. L. Sha, R. Rajkumar, and J. P. Lehoczky. 1990. Priority inheritance protocols: An approach to real-time synchronization. IEEE Transactions on Computers 39, 9, 1175--1185. Google ScholarGoogle ScholarDigital LibraryDigital Library
  76. Sun Microsystems. 2000. JSR-50: Distributed Real-Time Specification. http://jcp.org/en/jsr/detail?id=50Google ScholarGoogle Scholar
  77. Sun Microsystems. 2002. JavaTM Message Service Specification. v1.1. http://www.oracle.com/technetwork/java/docs-136352.htmlGoogle ScholarGoogle Scholar
  78. Sun Microsystems. 2004. Java Remote Method Invocation (RMI). http://www.oracle.com/technetwork/java/javase/tech/index-jsp-136424.htmlGoogle ScholarGoogle Scholar
  79. Sun Microsystems. 2012. Distributed Real-Time Specification (Early draft) http://jcp.org/en/egc/download/drtsj.pdf?id=50&fileId=5028Google ScholarGoogle Scholar
  80. D. Tejera, A. Alonso, and M. A. de Miguel. 2007. RMI-HRT: Remote method invocation—hard real time. In Proceedings of the 5th International Workshop on Java Technologies for Real-Time and Embedded Systems (JTRES’07). ACM, New York, NY, 113--120. Google ScholarGoogle ScholarDigital LibraryDigital Library
  81. The Open Group. 1997. DCE: Remote Procedure Calls. v1.2.2. https://www2.opengroup.org/ogsys/jsp/publications/PublicationDetails.jsp?catalogno=t151xGoogle ScholarGoogle Scholar
  82. The Open Group. 1998. POSIX .13 IEEE Std. 1003.13-1998. Information Technology—Standardized Application Environment Profile—POSIX Realtime Application Support (AEP). DOI:10.1109/IEEESTD.1999.90558Google ScholarGoogle Scholar
  83. The Open Group. 2010. Safety Critical Specification for Java. Draft Version 0.78. http://jcp.org/en/jsr/detail?id=302Google ScholarGoogle Scholar
  84. S. Urueña and J. Zamorano. 2007. Building high-integrity distributed systems with Ravenscar restrictions. Ada Letters XXVII 2, 29--36. Google ScholarGoogle ScholarDigital LibraryDigital Library
  85. T. Vergnaud, J. Hugues, L. Pautet, and F. Kordon. 2004. PolyORB: A schizophrenic middleware to build versatile reliable distributed applications. In Proceedings of Ada-Europe (2004-05-04), A. Llamosí and A. Strohmeier (Eds.). Lecture Notes in Computer Science, Vol. 3063. Springer, 106--119.Google ScholarGoogle Scholar
  86. J. Vila-Carbó, J. Tur-Masanet, and E. Hernández-Orallo. 2008. An evaluation of Switched Ethernet and Linux traffic control for real-time transmission. In Proceedings of the ETFA, 400--407.Google ScholarGoogle Scholar
  87. C. Zhang and V. Tsaoussidis. 2001. TCP-real: Improving real-time capabilities of TCP over heterogeneous networks. In Proceedings of the 11th International Workshop on Network and Operating Systems Support for Digital Audio and Video (NOSSDAV’01). ACM, New York, NY, 189--198. Google ScholarGoogle ScholarDigital LibraryDigital Library

Index Terms

  1. A survey on standards for real-time distribution middleware

          Recommendations

          Comments

          Login options

          Check if you have access through your login credentials or your institution to get full access on this article.

          Sign in

          Full Access

          • Published in

            cover image ACM Computing Surveys
            ACM Computing Surveys  Volume 46, Issue 4
            April 2014
            463 pages
            ISSN:0360-0300
            EISSN:1557-7341
            DOI:10.1145/2597757
            Issue’s Table of Contents

            Copyright © 2014 ACM

            Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than the author(s) must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from [email protected].

            Publisher

            Association for Computing Machinery

            New York, NY, United States

            Publication History

            • Published: 1 March 2014
            • Accepted: 1 September 2013
            • Revised: 1 January 2013
            • Received: 1 October 2012
            Published in csur Volume 46, Issue 4

            Permissions

            Request permissions about this article.

            Request Permissions

            Check for updates

            Qualifiers

            • research-article
            • Research
            • Refereed

          PDF Format

          View or Download as a PDF file.

          PDF

          eReader

          View online with eReader.

          eReader