Yan, Jun

Research Overview

- Service-oriented Computing and Web services
- Service-oriented software engineering
- Workflow Technology (Peer-to-Peer based workflow, decentralised workflow management)
- Service level agreement management
- Adaptive process management
- Internet computing and E-commerce

Available as Research Supervisor

Selected Publications

Journal Article

Year	Title
2019	Location Based Encryption Published In Lecture Notes in Computer Science Volume 11547 LNCS Pages 21 - 38 Altmetric
2015	Delta extraction in a limited collaborative environment Published In International Journal of Intelligent Information and Database Systems Volume 9 Pages 54 - 78 ISSN 1751-5858 Altmetric
2015	Using diffusion of innovation theory to understand the factors impacting patient acceptance and use of consumer e-health innovations: a case study in a primary care clinic Published In BMC Health Services Research Volume 15 Pages 1 - 15 ISSN 1472-6963 Altmetric
2015	Using grouping strategy and pattern discovery for delta extraction in a limited collaborative environment Published In International Journal of Business Intelligence and Data Mining Volume 10 Pages 378 - 405 ISSN 1743-8187 Altmetric
2014	Attribute-based data transfer with filtering scheme in cloud computing Published In The Computer Journal Volume 57 Pages 579 - 591 ISSN 1460-2067 Altmetric
2014	Quality-aware service selection for service-based systems based on iterative multi-attribute combinatorial auction Published In IEEE Transactions on Software Engineering Volume 40 Pages 192 - 215 ISSN 0098-5589 Altmetric
2014	Trust-oriented QoS-aware composite service selection based on genetic algorithms Published In Concurrency and Computation: Practice and Experience Volume 26 Pages 500 - 515 ISSN 1532-0634 Altmetric
2013	A decentralized service discovery approach on peer-to-peer network Published In IEEE Transactions on Services Computing Volume 6 Pages 64 - 75 ISSN 1939-1374 Altmetric
2013	Incremental service level agreements violation handling with time impact analysis Published In Journal of Systems and Software Volume 86 Pages 1530 - 1544 ISSN 0164-1212 Altmetric
2012	A cloud-based design of smart car information services Published In Journal of Internet Technology Volume 13 Pages 317 - 326 ISSN 1607-9264
2012	Attribute-based oblivious access control Published In The Computer Journal Volume 55 Pages 1202 - 1215 ISSN 1460-2067 Altmetric
2012	Computing resource prediction for MapReduce applications using decision tree Published In Lecture Notes in Computer Science Volume 7235 Pages 570 - 577 Altmetric
2012	Efficient oblivious transfers with access control Published In Computers and Mathematics with Applications Volume 63 Pages 827 - 837 ISSN 0898-1221 Altmetric
2012	Modelling and simulation of an adaptive neuro-fuzzy inference system (ANFIS) for mobile learning Published In IEEE Transactions on Learning Technologies Volume 5 Pages 226 - 237 ISSN 1939-1382 Altmetric
2012	New constructions of OSBE schemes and their applications in oblivious access control Published In International Journal of Information Security Volume 11 Pages 389 - 401 ISSN 1615-5262 Altmetric
2012	Patients perceptions of web self-service applications in primary healthcare Published In Studies in Health Technology and Informatics Volume 178 Pages 242 - 249 ISSN 1879-8365 Altmetric
2012	Privacy enhanced data outsourcing in the cloud Published In Journal of Network and Computer Applications Volume 35 Pages 1367 - 1373 ISSN 1084-8045 Altmetric
2012	Privacy preserving protocol for service aggregation in cloud computing Published In Software: Practice and Experience Volume 42 Pages 467 - 483 ISSN 0038-0644 Altmetric
2012	Privacy-preserving decentralized key-policy attribute-based encryption Published In IEEE Transactions on Parallel and Distributed Systems Volume 23 Pages 2150 - 2162 ISSN 1045-9219 Altmetric
2010	An extended dual concern model for partner selection in multi-agent systems Published In Systemics and Informatics World Network Volume 11 Pages 1 - 9
2010	An offer generation approach to SLA negotiation support in service oriented computing Published In Service Oriented Computing and Applications Volume 4 Pages 277 - 289 ISSN 1863-2386 Altmetric
2009	Lifetime service level agreement management with autonomous agents for services provision Published In Information Sciences Volume 179 Pages 2591 - 2605 ISSN 0020-0255 Altmetric
2007	A P2P based Service Flow System with Advanced Ontology-based Service Profiles Published In Advanced Engineering Informatics: the science of supporting knowledge-intensive activities Volume 21 Pages 221 - 229 ISSN 1474-0346 Altmetric
2007	An Extended Dual Concern Model for Partner Selection in Multi-Agent Systems Published In System and Information Sciences Notes Volume 1 Pages 153 - 158
2007	Autonomous service level agreement negotiation for service composition provisions Published In Future Generation Computer Systems: the international journal of grid computing: theory, methods and applications Volume 23 Pages 748 - 759 ISSN 0167-739X Altmetric
2007	Dynamic Service Composition Contracting based on Agent Coalition Published In System and Information Sciences Notes Volume 1 Pages 103 - 108

Chapter

Year	Title
2014	Patients’ adoption of the e-appointment scheduling service: A case study in primary healthcare Published In Investing in E-Health: People, Knowledge and Technology for a Healthy Future Publisher IOS Press Pages 176 - 181 Altmetric

Conference Paper

Year	Title
2018	The Influence Factors of Online Review Quality and Their Mechanism on Trust Intention Published In Proceedings: 2018 IEEE 15th International Conference on e-Business Engineering, ICEBE 2018 Pages 147 - 152 Altmetric
2017	The Effects of Consumer Perceived Different Service of Trusted Third Party on Trust Intention: An Empirical Study in Australia Published In Proceedings - 14th IEEE International Conference on E-Business Engineering, ICEBE 2017 - Including 13th Workshop on Service-Oriented Applications, Integration and Collaboration, SOAIC 207 Pages 62 - 69 Altmetric
2017	Towards Cost Reduction in Cloud-Based Workflow Management through Data Replication Published In 5th International Conference on Advanced Cloud and Big Data Pages 94 - 99 Altmetric
2016	Understanding the influence and service type of trusted third party on consumers’ online trust: evidence from Australian B2C marketplace Published In Proceedings of the 18th Annual International Conference on Electronic Commerce: e-Commerce in Smart connected World Pages 18-1 - 18-8 Altmetric
2015	Business rule driven composite service optimisation and selection Published In Proceedings - 2015 IEEE International Conference on Services Computing, SCC 2015 Pages 49 - 56 Altmetric
2014	Attribute based service customization and selection Published In 7th International Conference on Service-Oriented Computing and Applications (SOCA 2014) Pages 57 - 64 Altmetric
2014	Towards a trust model for trust establishment and management in business-to-consumer e-commerce Published In Proceedings - 2014 The 11th IEEE International Conference on Ubiquitous Intelligence and Computing and 2014 IEEE 11th International Conference on Autonomic and Trusted Computing and 2014 IEEE 14th International Conference on Scalable Computing and Comm... Pages 479 - 486 Altmetric
2012	Developing an online patient appointment scheduling system based on web services architecture Published In APAMI-2012: 7th Asia Pacific Association for Medical Informatics Conference Pages 1 - 6
2012	INSC: An iterative negotiation approach for service compositions Published In IEEE 9th International Conference on Services Computing (SCC 2012) Pages 170 - 177 Altmetric
2012	Towards modelling real time constraints Published In ICSOFT 2012: 7th International Conference on Software Paradigm Trends Pages 158 - 164
2011	A cloud based information integration platform for smart cars Published In 2nd International Conference on the Emerging Areas of Security-Enriched Urban Computing and Smart Grids, SUComS 2011 Pages 241 - 250 Altmetric
2011	A privacy policy framework for service aggregation with P3P Published In ICIW 2011: 6th International Conference on Internet and Web Applications and Services Pages 171 - 177
2011	Analyzing fault-impact region of composite service for supporting fault handling process Published In IEEE International Conference on Services Computing Pages 290 - 297 Altmetric
2011	Modeling mobile learning system using ANFIS Published In ICALT '11 Proceedings of the 2011 IEEE International Conference on Advanced Learning Technologies Pages 378 - 380 Altmetric
2011	Privacy-preserved access control for cloud computing Published In Proceeding of 2011 IEEE 10th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom) Pages 83 - 90 Altmetric
2011	Web service selection based on similarity evaluation Published In Proceedings 2011 IEEE International Conference on Services Computing-SCC 2011 Pages 323 - 329 Altmetric
2010	A framework for privacy policy management in service aggregation Published In International Conference on Computer Supported Cooperative Work in Design Pages 166 - 171 Altmetric
2010	A generic construction of dynamic single sign-on with strong security Published In International ICST Conference on Security and Privacy in Communication Networks Pages 181 - 198 Altmetric
2010	A network-aware virtual machine placement and migration approach in cloud computing Published In International Conference on Grid and Cooperative Computing, GCC 2010 Pages 87 - 92 Altmetric
2010	Constructing an authentication token to access external services in service aggregation Published In IEEE International Conference on Services Computing Pages 321 - 328 Altmetric
2010	Design an automatic appointment system to improve patient access to primary health care Published In Australasian Workshop on Health Informatics and Knowledge Management Pages 17 - 22
2010	Developing a socio-technical approach supporting communication process analysis in healthcare information system development Published In 18th Annual Health Informatics Conference, HIC 2010
2010	Dynamic trust model for federated identity management Published In International Conference on Network and System Security Pages 55 - 61 Altmetric
2010	Enhanced learner model for adaptive mobile learning Published In International Conference on Information Integration and Web-based Applications & Services Pages 781 - 784 Altmetric
2009	A machine learning based framework for adaptive mobile learning Published In International Conference on Web-based Learning Pages 34 - 43 Altmetric
2009	An e-learning system architecture based on web services and intelligent agents Published In International Conference on Hybrid Intelligent Systems - Volume 2 Pages 173 - 177 Altmetric
2009	Dynamic service selection for service composition with time constraints Published In Australian Software Engineering Conference Pages 183 - 190 Altmetric
2009	Learner profile design for personalized e-learning systems Published In International Conference on Computational Intelligence and Software Engineering Pages 1 - 4 Altmetric
2009	ServiceTrust: supporting reputation-oriented service selection Published In International Conference on Service-Oriented Computing Pages 269 - 284 Altmetric
2009	Towards dynamic formation of temporal constraints for the service level agreements negotiation Published In IEEE International Conference on Service-Oriented Computing and Applications (SOCA 2009) Pages 72 - 79 Altmetric
2009	Verification of composite services with temporal consistency checking and temporal satisfaction estimation Published In International Conference on Web Information Systems Engineering Pages 343 - 350 Altmetric
2008	A practical geographic ontology for spatial web services Published In IEEE International Conference on Services Computing Pages 579 - 580 Altmetric
2008	Adaptation of web service composition based on workflow patterns Published In International Conference on Service-Oriented Computing Pages 22 - 37
2008	Chord4S: a P2P-based decentralised service discovery approach Published In IEEE International Conference on Services Computing Pages 221 - 228 Altmetric
2008	Towards QoS-based web services discovery Published In International Conference on Service-Oriented Computing Pages 200 - 210 Altmetric
2007	An agent-based decentralised process management framework for web service composition Published In International Conference on Scalable Information Systems Pages 1 - 4
2007	An agent-based framework for service level agreement management Published In International Conference on Computer Supported Cooperative Work in Design Pages 412 - 417 Altmetric
2007	Location-based services in emergency management- from government to citizens: global case studies Published In Research Network for a Secure Australia Security Technology Conference Pages 190 - 201
2007	Towards Collaborative Service Level Agreement Negotiation Published In the 4th International Conference on Grid Service Engineering and Management Pages 123 - 134

Available as Research Supervisor

Advisees

Graduate Advising Relationship

Degree	Research Title	Advisee
Doctor of Philosophy (Integrated)	Integrated and Adaptive Data Management Strategies for Scientific Workflows in Multi-Cloud Environments	Xie, Fei
Doctor of Philosophy (Integrated)	A three-dimensional integrated trust model for trust formation in b2c e-commerce	Cao, Cong

Located In Facility

Building 3 Room 217

Orcid Id

http://orcid.org/0000-0002-6474-1049 (confirmed)

Research Overview

- Service-oriented Computing and Web services
- Service-oriented software engineering
- Workflow Technology (Peer-to-Peer based workflow, decentralised workflow management)
- Service level agreement management
- Adaptive process management
- Internet computing and E-commerce

Selected Publications

Journal Article

Year	Title
2019	Location Based Encryption Published In Lecture Notes in Computer Science Volume 11547 LNCS Pages 21 - 38 Altmetric
2015	Delta extraction in a limited collaborative environment Published In International Journal of Intelligent Information and Database Systems Volume 9 Pages 54 - 78 ISSN 1751-5858 Altmetric
2015	Using diffusion of innovation theory to understand the factors impacting patient acceptance and use of consumer e-health innovations: a case study in a primary care clinic Published In BMC Health Services Research Volume 15 Pages 1 - 15 ISSN 1472-6963 Altmetric
2015	Using grouping strategy and pattern discovery for delta extraction in a limited collaborative environment Published In International Journal of Business Intelligence and Data Mining Volume 10 Pages 378 - 405 ISSN 1743-8187 Altmetric
2014	Attribute-based data transfer with filtering scheme in cloud computing Published In The Computer Journal Volume 57 Pages 579 - 591 ISSN 1460-2067 Altmetric
2014	Quality-aware service selection for service-based systems based on iterative multi-attribute combinatorial auction Published In IEEE Transactions on Software Engineering Volume 40 Pages 192 - 215 ISSN 0098-5589 Altmetric
2014	Trust-oriented QoS-aware composite service selection based on genetic algorithms Published In Concurrency and Computation: Practice and Experience Volume 26 Pages 500 - 515 ISSN 1532-0634 Altmetric
2013	A decentralized service discovery approach on peer-to-peer network Published In IEEE Transactions on Services Computing Volume 6 Pages 64 - 75 ISSN 1939-1374 Altmetric
2013	Incremental service level agreements violation handling with time impact analysis Published In Journal of Systems and Software Volume 86 Pages 1530 - 1544 ISSN 0164-1212 Altmetric
2012	A cloud-based design of smart car information services Published In Journal of Internet Technology Volume 13 Pages 317 - 326 ISSN 1607-9264
2012	Attribute-based oblivious access control Published In The Computer Journal Volume 55 Pages 1202 - 1215 ISSN 1460-2067 Altmetric
2012	Computing resource prediction for MapReduce applications using decision tree Published In Lecture Notes in Computer Science Volume 7235 Pages 570 - 577 Altmetric
2012	Efficient oblivious transfers with access control Published In Computers and Mathematics with Applications Volume 63 Pages 827 - 837 ISSN 0898-1221 Altmetric
2012	Modelling and simulation of an adaptive neuro-fuzzy inference system (ANFIS) for mobile learning Published In IEEE Transactions on Learning Technologies Volume 5 Pages 226 - 237 ISSN 1939-1382 Altmetric
2012	New constructions of OSBE schemes and their applications in oblivious access control Published In International Journal of Information Security Volume 11 Pages 389 - 401 ISSN 1615-5262 Altmetric
2012	Patients perceptions of web self-service applications in primary healthcare Published In Studies in Health Technology and Informatics Volume 178 Pages 242 - 249 ISSN 1879-8365 Altmetric
2012	Privacy enhanced data outsourcing in the cloud Published In Journal of Network and Computer Applications Volume 35 Pages 1367 - 1373 ISSN 1084-8045 Altmetric
2012	Privacy preserving protocol for service aggregation in cloud computing Published In Software: Practice and Experience Volume 42 Pages 467 - 483 ISSN 0038-0644 Altmetric
2012	Privacy-preserving decentralized key-policy attribute-based encryption Published In IEEE Transactions on Parallel and Distributed Systems Volume 23 Pages 2150 - 2162 ISSN 1045-9219 Altmetric
2010	An extended dual concern model for partner selection in multi-agent systems Published In Systemics and Informatics World Network Volume 11 Pages 1 - 9
2010	An offer generation approach to SLA negotiation support in service oriented computing Published In Service Oriented Computing and Applications Volume 4 Pages 277 - 289 ISSN 1863-2386 Altmetric
2009	Lifetime service level agreement management with autonomous agents for services provision Published In Information Sciences Volume 179 Pages 2591 - 2605 ISSN 0020-0255 Altmetric
2007	A P2P based Service Flow System with Advanced Ontology-based Service Profiles Published In Advanced Engineering Informatics: the science of supporting knowledge-intensive activities Volume 21 Pages 221 - 229 ISSN 1474-0346 Altmetric
2007	An Extended Dual Concern Model for Partner Selection in Multi-Agent Systems Published In System and Information Sciences Notes Volume 1 Pages 153 - 158
2007	Autonomous service level agreement negotiation for service composition provisions Published In Future Generation Computer Systems: the international journal of grid computing: theory, methods and applications Volume 23 Pages 748 - 759 ISSN 0167-739X Altmetric
2007	Dynamic Service Composition Contracting based on Agent Coalition Published In System and Information Sciences Notes Volume 1 Pages 103 - 108

Chapter

Year	Title
2014	Patients’ adoption of the e-appointment scheduling service: A case study in primary healthcare Published In Investing in E-Health: People, Knowledge and Technology for a Healthy Future Publisher IOS Press Pages 176 - 181 Altmetric

Conference Paper

Year	Title
2018	The Influence Factors of Online Review Quality and Their Mechanism on Trust Intention Published In Proceedings: 2018 IEEE 15th International Conference on e-Business Engineering, ICEBE 2018 Pages 147 - 152 Altmetric
2017	The Effects of Consumer Perceived Different Service of Trusted Third Party on Trust Intention: An Empirical Study in Australia Published In Proceedings - 14th IEEE International Conference on E-Business Engineering, ICEBE 2017 - Including 13th Workshop on Service-Oriented Applications, Integration and Collaboration, SOAIC 207 Pages 62 - 69 Altmetric
2017	Towards Cost Reduction in Cloud-Based Workflow Management through Data Replication Published In 5th International Conference on Advanced Cloud and Big Data Pages 94 - 99 Altmetric
2016	Understanding the influence and service type of trusted third party on consumers’ online trust: evidence from Australian B2C marketplace Published In Proceedings of the 18th Annual International Conference on Electronic Commerce: e-Commerce in Smart connected World Pages 18-1 - 18-8 Altmetric
2015	Business rule driven composite service optimisation and selection Published In Proceedings - 2015 IEEE International Conference on Services Computing, SCC 2015 Pages 49 - 56 Altmetric
2014	Attribute based service customization and selection Published In 7th International Conference on Service-Oriented Computing and Applications (SOCA 2014) Pages 57 - 64 Altmetric
2014	Towards a trust model for trust establishment and management in business-to-consumer e-commerce Published In Proceedings - 2014 The 11th IEEE International Conference on Ubiquitous Intelligence and Computing and 2014 IEEE 11th International Conference on Autonomic and Trusted Computing and 2014 IEEE 14th International Conference on Scalable Computing and Comm... Pages 479 - 486 Altmetric
2012	Developing an online patient appointment scheduling system based on web services architecture Published In APAMI-2012: 7th Asia Pacific Association for Medical Informatics Conference Pages 1 - 6
2012	INSC: An iterative negotiation approach for service compositions Published In IEEE 9th International Conference on Services Computing (SCC 2012) Pages 170 - 177 Altmetric
2012	Towards modelling real time constraints Published In ICSOFT 2012: 7th International Conference on Software Paradigm Trends Pages 158 - 164
2011	A cloud based information integration platform for smart cars Published In 2nd International Conference on the Emerging Areas of Security-Enriched Urban Computing and Smart Grids, SUComS 2011 Pages 241 - 250 Altmetric
2011	A privacy policy framework for service aggregation with P3P Published In ICIW 2011: 6th International Conference on Internet and Web Applications and Services Pages 171 - 177
2011	Analyzing fault-impact region of composite service for supporting fault handling process Published In IEEE International Conference on Services Computing Pages 290 - 297 Altmetric
2011	Modeling mobile learning system using ANFIS Published In ICALT '11 Proceedings of the 2011 IEEE International Conference on Advanced Learning Technologies Pages 378 - 380 Altmetric
2011	Privacy-preserved access control for cloud computing Published In Proceeding of 2011 IEEE 10th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom) Pages 83 - 90 Altmetric
2011	Web service selection based on similarity evaluation Published In Proceedings 2011 IEEE International Conference on Services Computing-SCC 2011 Pages 323 - 329 Altmetric
2010	A framework for privacy policy management in service aggregation Published In International Conference on Computer Supported Cooperative Work in Design Pages 166 - 171 Altmetric
2010	A generic construction of dynamic single sign-on with strong security Published In International ICST Conference on Security and Privacy in Communication Networks Pages 181 - 198 Altmetric
2010	A network-aware virtual machine placement and migration approach in cloud computing Published In International Conference on Grid and Cooperative Computing, GCC 2010 Pages 87 - 92 Altmetric
2010	Constructing an authentication token to access external services in service aggregation Published In IEEE International Conference on Services Computing Pages 321 - 328 Altmetric
2010	Design an automatic appointment system to improve patient access to primary health care Published In Australasian Workshop on Health Informatics and Knowledge Management Pages 17 - 22
2010	Developing a socio-technical approach supporting communication process analysis in healthcare information system development Published In 18th Annual Health Informatics Conference, HIC 2010
2010	Dynamic trust model for federated identity management Published In International Conference on Network and System Security Pages 55 - 61 Altmetric
2010	Enhanced learner model for adaptive mobile learning Published In International Conference on Information Integration and Web-based Applications & Services Pages 781 - 784 Altmetric
2009	A machine learning based framework for adaptive mobile learning Published In International Conference on Web-based Learning Pages 34 - 43 Altmetric
2009	An e-learning system architecture based on web services and intelligent agents Published In International Conference on Hybrid Intelligent Systems - Volume 2 Pages 173 - 177 Altmetric
2009	Dynamic service selection for service composition with time constraints Published In Australian Software Engineering Conference Pages 183 - 190 Altmetric
2009	Learner profile design for personalized e-learning systems Published In International Conference on Computational Intelligence and Software Engineering Pages 1 - 4 Altmetric
2009	ServiceTrust: supporting reputation-oriented service selection Published In International Conference on Service-Oriented Computing Pages 269 - 284 Altmetric
2009	Towards dynamic formation of temporal constraints for the service level agreements negotiation Published In IEEE International Conference on Service-Oriented Computing and Applications (SOCA 2009) Pages 72 - 79 Altmetric
2009	Verification of composite services with temporal consistency checking and temporal satisfaction estimation Published In International Conference on Web Information Systems Engineering Pages 343 - 350 Altmetric
2008	A practical geographic ontology for spatial web services Published In IEEE International Conference on Services Computing Pages 579 - 580 Altmetric
2008	Adaptation of web service composition based on workflow patterns Published In International Conference on Service-Oriented Computing Pages 22 - 37
2008	Chord4S: a P2P-based decentralised service discovery approach Published In IEEE International Conference on Services Computing Pages 221 - 228 Altmetric
2008	Towards QoS-based web services discovery Published In International Conference on Service-Oriented Computing Pages 200 - 210 Altmetric
2007	An agent-based decentralised process management framework for web service composition Published In International Conference on Scalable Information Systems Pages 1 - 4
2007	An agent-based framework for service level agreement management Published In International Conference on Computer Supported Cooperative Work in Design Pages 412 - 417 Altmetric
2007	Location-based services in emergency management- from government to citizens: global case studies Published In Research Network for a Secure Australia Security Technology Conference Pages 190 - 201
2007	Towards Collaborative Service Level Agreement Negotiation Published In the 4th International Conference on Grid Service Engineering and Management Pages 123 - 134

Advisees

Graduate Advising Relationship

Degree	Research Title	Advisee
Doctor of Philosophy (Integrated)	Integrated and Adaptive Data Management Strategies for Scientific Workflows in Multi-Cloud Environments	Xie, Fei
Doctor of Philosophy (Integrated)	A three-dimensional integrated trust model for trust formation in b2c e-commerce	Cao, Cong

Located In Facility

Building 3 Room 217

Orcid Id

http://orcid.org/0000-0002-6474-1049 (confirmed)

Yan, Jun Associate Professor

Associate Professor

Overview

Research Overview

Available as Research Supervisor

Publications

Selected Publications

Journal Article

Chapter

Conference Paper

Supervision

Available as Research Supervisor

Advisees

Graduate Advising Relationship

Contact

Located In Facility

Identity

Orcid Id

Overview

Research Overview

Publications

Selected Publications

Journal Article

Chapter

Conference Paper

Supervision

Advisees

Graduate Advising Relationship

Contact

Located In Facility

Identity

Orcid Id

Visualisations