Digital Twin in the IoT Context: A Survey on Technical Features, Scenarios, and Architectural Models

In the paper

“If a robust and permanent link between the physical object, owned by a customer, and the logical one is possible, then the product could be tailored to a specific customer in terms of specialized features and/or additional functionalities [13].”

What the sources say

• ?Could not verify

  The Simulation and RPRV Facility Operational Experience sections discuss modifying flight-control software for a remotely piloted research vehicle. Searches for a permanent physical–logical link and customer-specific product features found no passage addressing the claim. (LLM, conf=0.76)

  cites [13] 13. Porter, Michael E., and James E. Heppelmann. "How smart, connected products are transforming companies." Harvard business review 93, no. 10 (2015): 96-114.Experimental — accuracy not yet measured

In the paper

“Management techniques for large virtualized infrastructure [163] could be usefully adopted in these cases.”

What the sources say

• ?Could not verify

  The Introduction and Section 2 describe digital twins as virtual models and discuss how they can be used, but do not address management techniques for large virtualized infrastructure. Searches for virtualized infrastructure, cloud management, and adopting such techniques for digital twins found no passage on that point. The paper’s discussion of virtual models alone does not verify what the citation is attached to. (LLM, conf=0.73)

  cites [163] 163. R. P. Esteves, L. Z. Granville and R. Boutaba, "On the management of virtual networks," in IEEE Communications Magazine, vol. 51, no. 7, pp. 80-88, July 2013. DOI: 10.1109/MCOM.2013.6553682. sourceExperimental — accuracy not yet measured

In the paper

“A large composition of Digital Twins could become the definition of a large system of systems, and hence reliable approaches to complexity are needed [158].”

What the sources say

• Partly supported

  Section 2.1 (page not provided) says large, dynamic ensembles of distributed components require approaches for managing complexity and building dependable systems. The paper addresses pervasive multi-agent systems, however, not Digital Twins or a claim that their composition constitutes a system of systems. (LLM, conf=0.86)

  cites [158] 158. E. Silva, T. Batista and F. Oquendo, "A mission-oriented approach for designing system-of-systems," 2015 10th System of Systems Engineering Conference (SoSE), San Antonio, TX, 2015, pp. 346-351. DOI: 10.1109/SYSOSE.2015.7151951. sourceExperimental — accuracy not yet measured

In the paper

“There is a long history of the computer augmentation of physical objects [177], [178].”

What the sources say

• Partly supported

  The section “Digital Twins in Engineering Practices, and Their Relevance for Data- and Model-Driven Healthcare” describes traditional computer-aided design models of physical artifacts and contrasts them with newer digital twins (page unavailable). That supports the existence of earlier computer modeling of physical objects, but the paper does not establish the claimed long history. (LLM, conf=0.78)

  cites [177] 177. J.W. Edwards, and D.A. Deets. "Development of a Remote Digital Augmentation System and Application to a Remotely Piloted Research Vehicle." 1975. NASA Technical report TN D-7941, [ONLINE] available at https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750012 221.pdf sourceExperimental — accuracy not yet measured
• Partly supported

  The Digital Twin section (page unavailable) dates the digital-twin concept to 2003 and describes it as linking physical objects with virtual objects and data. That supports a history of one form of computer augmentation, but does not establish the broader claim that computer augmentation of physical objects has a long history. (LLM, conf=0.78)

  cites [178] 178. J. Glos Williamson. "Digital augmentation of keepsake objects: a place for interaction of memory, story, and self." MS Thesis, School of Architecture and Planning, Massachusetts Institute of Technology, September 1997. [ONLINE] available at https://dspace.mit.edu/bitstream/handle/1721.1/61536/4123486 1-MIT.pdf?sequence=2 sourceExperimental — accuracy not yet measured

In the paper

“More recently, this trend has been applied in new domains or it has profited of improved technologies, e.g., in Big Data and Smart Manufacturing [179], and Augmented and Virtual Reality [180]).”

What the sources say

• Partly supported

  The Materials and Methods section lists Big Data among technologies planned for integration into digital assistive technology, supporting that part of the claim. Our copy does not describe an application in Smart Manufacturing. Augmented and Virtual Reality belongs to a separate citation in the citing sentence, so it is not judged here. (LLM, conf=0.85)

  cites [179] 179. Q. Qi and F. Tao, "Digital Twin and Big Data Towards Smart Manufacturing and Industry 4.0: 360 Degree Comparison," in IEEE Access, vol. 6, pp. 3585-3593, 2018. DOI: 10.1109/ACCESS.2018.2793265. sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [180] 180. D. Oliver, D, D. Adam, A.P. Hudson-Smith. "Living with a Digital Twin: Operational management and engagement using IoT and Mixed Realities at UCL's Here East Campus on the Queen Elizabeth Olympic Park". In: Proceedings of the 26th annual GIScience Research UK conference: GISRUK 2018. GIS Research UK (GISRUK): University of Leicester, UK. [ONLINE] available at http://discovery.ucl.ac.uk/10056521/1/Hudson- Smith_Final_Oliver_Dawkins_Digital_Twin_GISRUK_2018 %20%281%29_segment.pdf source

In the paper

“Physical objects interact with very complex environments and are immersed in them.They reflect the dynamics of the physical context in which they are operating [141].”

What the sources say

• Partly supported

  Section 2.3 describes autonomous vehicles operating amid dynamic logistics and production processes, and the Conclusion discusses interactions between people, machines, and products. But Section 3 says changes in the real world are reflected in the digital world; it does not say that physical objects themselves reflect the dynamics of a complex environment. (LLM, conf=0.77)

  cites [141] 141. N. Mohammadi and J. E. Taylor, "Smart city digital twins," 2017 IEEE Symposium Series on Computational Intelligence (SSCI), Honolulu, HI, 2017, pp. 1-5. DOI: 10.1109/SSCI.2017.8285439. sourceExperimental — accuracy not yet measured

In the paper

“Orchestration is an essential function [154] in order to govern the aggregations.”

What the sources say

• ?Could not verify

  Section 2 (GAMA Meta-Model; page unavailable) describes scheduling and nested agent populations, and §3.4 (Multi-Level modeling; page unavailable) gives an example of a building agent controlling its micro-agents. Neither passage says that orchestration is an essential function for governing aggregations. Searches for “orchestration” and governance of aggregations found no passage making that point. (LLM, conf=0.72)

  cites [154] 154. R Buyya, MA Rodriguez, AN Toosi and J. Park. "Cost-efficient orchestration of containers in clouds: a vision, architectural elements, and future directions". in 2nd Mathematics, Informatics, Science and Education International Conference (MISEIC) July 2018, Surabaya, Indonesia (Journal of Physics: Conference Series; Vol. 1108). Bristol ENG: IOS Press. DOI: https://doi.org/10.1088/1742-6596/1108/1/012001. sourceExperimental — accuracy not yet measured

In the paper

“The Digital Twin concept goes hand in hand with the ability to collect data and information by crawling and crowdsourcing social media [119].”

What the sources say

• Partly supported

  The Twitter service description (p. 4) supports the claim that data can be collected from social media: it describes retrieving tweets by user, content query, or stream. Our copy does not connect that capability to a Digital Twin or describe it as crowdsourcing. (LLM, conf=0.85)

  cites [119] 119. S. Bosse, and U. Engel, "Real-Time Human-In-The-Loop Simulation with Mobile Agents, Chat Bots, and Crowd Sensing for Smart Cities". Sensors, 19(20), p.4356. 2019 sourceExperimental — accuracy not yet measured

In the paper

“From the Definition of Composability in Software [146] and some implementations [147] up to the Software Component Model [148] [149] [150] efforts, software engineering shows a constant trend to create conditions and frameworks for supporting component integration and communication, e.g., also in specific fields like CPS [151].”

What the sources say

• Supported

  The citation is attached to the example of a framework in a specific cyber-physical field, rather than to the claim of a constant trend across software engineering. The Abstract and Section III, T-RECS DESIGN (pages unavailable), describe an electric-grid testbed that runs software agents, simulates the physical grid, and emulates communication among agents. (LLM, conf=0.88)

  cites [146] 146. R. Canetti, and M. Fischlin. "Universally composable commitments." In Annual International Cryptology Conference, pp. 19-40. Springer, Berlin, Heidelberg, 2001. source
• Partly supported

  The paper’s “Protocol hierarchy” section says its framework makes subprotocol composition easy to analyze and implement, so it supports an example of a composability framework. Its “Protocols” section defines composition for cryptographic protocols, not a general definition of software composability; it does not establish a constant trend across software engineering toward component integration and communication. No page number is available in our copy. (LLM, conf=0.81)

  cites [147] 147. D. Hofheinz and V. Shoup. "GNUC: A new universal composability framework." Journal of Cryptology 28, no. 3 (2015): pp 423-508. sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [148] 148. G. T. Heineman and W. T. Councill, Eds., Component-Based Software Engineering: Putting the Pieces Together. Reading, MA, USA: Addison-Wesley, 2001. source

In the paper

“This is a growing trend of AI that can also be applied to the Digital Twin concept [190].”

What the sources say

• Partly supported

  The Conclusion says the virtual-human systems use AI, and Selecting the Character Model describes 3-D digital twins made from a scanned human model (page numbers unavailable). This supports AI use with those digital characters, but the paper does not establish a growing AI trend or discuss applying AI to the broader Digital Twin concept. (LLM, conf=0.78)

  cites [190] 190. F. Tao, J. Cheng, Q. Qi, M. Zhang, H. Zhang, and F. Sui. (2017). ''Digital twin-driven product design, manufacturing and service with big data,'' Int. J. Adv. Manuf. Technol., Mar. 2017, DOI: 10.1007/s00170-017-0233-1 sourceExperimental — accuracy not yet measured

In the paper

“The Digital Twin concept has been developed in the manufacturing industry with specific goals and its importance is likely to increase in the future [194] [195] [196] [197] [198].”

What the sources say

• ?Could not verify

  The Introduction discusses IoT devices across several domains, and the Discussion & Future Work section evaluates IoT protocols, not Digital Twins. Searches for “Digital Twin” and its proposed manufacturing origins and future importance found no passage addressing the claim. Page numbers were not available in our copy. (LLM, conf=0.76)

  cites [194] 194. R. Rosen, G. V. Wichert, G. Lo, and K. D. Bettenhausen, "About the importance of autonomy and digital twins for the future of manufacturing" IFAC-Papersonline, vol. 48, no. 3, pp. 567-572, Aug. 2015. sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [195] 195. M. Castelluccio. "DIGITAL TWINS INVADE INDUSTRY." Strategic Finance, Mar. 2018, p. 63+. Academic OneFile. source
• ?Could not verify

  The Introduction and Architecture Overview describe virtual representations of physical objects in IoT systems, but do not discuss the Digital Twin concept’s development in manufacturing. The Conclusion discusses future needs for the paper’s interoperability architecture, not the future importance of Digital Twins. Searches for “Digital Twin” and manufacturing-related terms found no passage addressing the attributed claim; page numbers were unavailable in our copy. (LLM, conf=0.75)

  cites [196] 196. J. David, A. Lobov and M. Lanz, "Leveraging Digital Twins for Assisted Learning of Flexible Manufacturing Systems," 2018 IEEE 16th International Conference on Industrial Informatics (INDIN), Porto, 2018, pp. 529-535. DOI: 10.1109/INDIN.2018.8472083 sourceExperimental — accuracy not yet measured

In the paper

“The concept has also attracted the interest of governments with possible funding and industrial fallout [122].”

What the sources say

• Partly supported

  The Digital Twin section (page unavailable) says the term appeared in a NASA technology roadmap, which indicates interest from one government agency, and notes adoption by several corporations. The Introduction (page unavailable) describes possible commercial use of results from the crane platform. The paper does not establish interest from governments more broadly or link that interest to possible funding and industrial outcomes. (LLM, conf=0.76)

  cites [122] 122. A. Bolton, L. Butler, I. Dabson, M. Enzer, M. Evans, T. Fenemore, F. Harradence et al. "Gemini Principles." University of Cambridge, UK 2018 [ONLINE] available at: https://www.repository.cam.ac.uk/bitstream/handle/1810/2848 89/The%20Gemini%20Principles%202019.pdf?sequence=7] sourceExperimental — accuracy not yet measured

In the paper

“Possibilities range from personalization and customization to the definition of a compelling set of software functionalities that will complement and augment the product and will be the major added value of a physical product [188].”

What the sources say

• Partly supported

  Section 4.3 (p. 1) describes tailored customer solutions and a continuum in which services can become the main source of value rather than the physical product. Section 4.6 (p. 1) also gives an example of services embedded in a product. The copy does not identify software functionalities as the means of augmenting a product or as its major added value. (LLM, conf=0.85)

  cites [188] 188. T.S. Baines, H.W. Lightfoot, O. Benedettini O, J.M. Kay. "The servitization of manufacturing: A review of literature and reflection on future challenges". Journal of manufacturing technology management. 2009 Jun 5;20(5):547-67. sourceExperimental — accuracy not yet measured

In the paper

“With the advent of the IoT and the possibility of fully monitoring clinical patients with a wealth of body and environmental sensors and low-cost devices [260], there is the possibility to implement many different solutions to improve patients' quality of life without requiring their hospitalization.”

What the sources say

• ?Could not verify

  Split into 2 atoms — 0 confirmed, 0 partially supported, 0 disputed, 0 misattributed, 2 unverifiable. Expand the claim to see per-atom verdicts.

  cites [260] 260. R. Kumar and M. P. Rajasekaran, "An IoT based patient monitoring system using raspberry Pi," 2016 International Conference on Computing Technologies and Intelligent Data Engineering (ICCTIDE'16), Kovilpatti, 2016, pp. 1-4. sourceExperimental — accuracy not yet measured

In the paper

“The Digital Patient could also be useful for the implementation of the Virtual Patient framework [261], a software framework that simulates real life pathologies in such a realistic way that practitioners and students can exercise and improve their skills at dealing with different diseases.”

What the sources say

• ?Could not verify

  Section 4, “Digital as a Service” (page unavailable), describes a virtual digital infrastructure for smart-city systems, not a Digital Patient or a Virtual Patient framework. Searches for “Digital Patient Virtual Patient framework” and for patient pathology simulation found no passage addressing the claimed use or the framework’s description. (LLM, conf=0.76)

  cites [261] 261. A.A. Kononowicz, N. Zary, S. Edelbring, J. Corral, I. Hege. "Virtual patients-what are we talking about? A framework to classify the meanings of the term in healthcare education". BMC medical education. 2015 Dec;15(1): pp. 11. sourceExperimental — accuracy not yet measured

In the paper

“The Digital Twin concept is well aligned with the idea of Smart Cities as complex systems [263] that show real-time behavior as well as emerging ones in the long run.”

What the sources say

• Partly supported

  The paper describes smart-city infrastructure as a combination of legacy platforms, sensor streams, open data, and historical time series (A. Legacy IoT platforms are not neglected, p. 1), supporting the description of cities as complex systems. It does not describe long-run emergent behavior. The sentence’s Digital Twin alignment is the citing authors’ framing, not a point established by this source. (LLM, conf=0.78)

  cites [263] 263. M. Batty. "Cities and complexity: understanding cities with cellular automata, agent-based models, and fractals". The MIT press, Boston, USA, 2007 Sep 30. sourceExperimental — accuracy not yet measured

In the paper

“For instance, the IIOT Consortium is working on integrating in their standardization also the DT aspects [25].”

What the sources say

• ?Could not verify

  The Introduction discusses digital twins and a lack of suitable IoT standards, but does not mention an IIOT Consortium or its standardization work. Searches for the consortium and digital-twin standardization found no passage addressing the attributed claim. (LLM, conf=0.72)

  cites [25] 25. S. Malakuti, and S. Grüner, "Architectural aspects of digital twins in IIoT systems". In Proceedings of the 12th European Conference on Software Architecture: Companion Proceedings (pp. 1-2), 2018. sourceExperimental — accuracy not yet measured

In the paper

“Also, autonomics and self-management are well considered properties of the Digital Twins [194].”

What the sources say

• ?Could not verify

  The Introduction and Section III discuss managing IoT devices and a policy-based access-control framework, not properties of Digital Twins. Searches for “Digital Twins,” “autonomics,” and “self-management” found no passage in our copy addressing the attributed claim. (LLM, conf=0.77)

  cites [194] 194. R. Rosen, G. V. Wichert, G. Lo, and K. D. Bettenhausen, "About the importance of autonomy and digital twins for the future of manufacturing" IFAC-Papersonline, vol. 48, no. 3, pp. 567-572, Aug. 2015. sourceExperimental — accuracy not yet measured

In the paper

“It is able to support DT applications [221] and providing some basic functionalities needed in a DT platform as identity management [266], cloud resources management [267], and semantic approaches for data analysis [268].”

What the sources say

• ?Not checked — no full text of the sourcecites [221] 221. C.N. Verdouw, J.W. Kruize, J. Wolfert, and G. Chatzikostas,. "Digital Twins in Farm Management: Illustrated by cases from FIWARE Accelerators SmartAgriFood and Fractals". In 11th International European Forum (Igls-Forum) (161st EAAE Seminar) on System Dynamics and Innovation in Food Networks. 2017, February.
• Partly supported

  Section II describes FIWARE’s context broker, context history, and IoT device-management tools, supporting its use as an application platform. The paper demonstrates AI/IoT applications, not digital-twin (DT) applications, so it does not establish the DT-specific part of the claim. The separately cited identity-management, cloud-resource, and semantic-analysis functions are not attributed to this source. (LLM, conf=0.76)

  cites [266] 266. Á. Alonso et al., "An Identity Framework for Providing Access to FIWARE OAuth 2.0-Based Services According to the eIDAS European Regulation," in IEEE Access, vol. 7, pp. 88435- 88449, 2019. sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [267] 267. L. Moor, L. Bitter, M. D. Prado, N. Pazos and N. Ouerhani, "IoT meets distributed AI -Deployment scenarios of Bonseyes AI applications on FIWARE," 2019 IEEE 38th International Performance Computing and Communications Conference (IPCCC), London, United Kingdom, 2019, pp. 1-2. source

In the paper

“An interesting proposal, stressing out relevant properties of the Digital Twin like simulation and prediction, as well as collection of historical data in a context of advanced manufacturing comes from [206].”

What the sources say

• Partly supported

  The Middleware for Sensor Virtualization section describes PRESTO caching past sensor data and using predictive techniques; Testbeds and Experimental Resources discusses simulation for evaluating sensor-network middleware (pages not provided). These support the individual concepts, but our copy does not present them as a Digital Twin proposal in advanced manufacturing. (LLM, conf=0.83)

  cites [206] 206. B. Brenner and V. Hummel, "Digital twin as enabler for an innovative digital shopfloor management system in the ESB logistics learning factory at Reutlingen-University," Procedia Manuf., vol. 9, pp. 198-205, Jan. 2017. sourceExperimental — accuracy not yet measured

In the paper

“This trend is also strongly concerned with the usage of data in the context of industrial environments [274] and the integration of the platform and the Digital Twin solution within the IT infrastructure of the manufacturers [275].”

What the sources say

• ?Not checked — no full text of the sourcecites [274] 274. General Electric. "PREDIX The Industrial IoT Application Platform". White Paper from General Electric , 2017 [ONLINE] available at https://www.ge.com/digital/sites/default/files/download_assets/ Predix-The-Industrial-Internet-Platform-Brief.pdf source
• ?Could not verify

  The cited paper’s Section 6.1 discusses survey and sensor data used to create digital twins of people for smart-city simulations; Section 1.10 discusses data used in smart-city management. Neither addresses the industrial-environment data use attributed to this source. The separate claim about integration with manufacturers’ IT infrastructure is attached to citation [275], not this source. (LLM, conf=0.77)

  cites [275] 275. F. Luyckx. "Impact of the Digital Twin on the enterprise architecture". Blog entry of June 14 th 2018. [ONLINE] available at https://vnsg.nl/iMIS/VNSGWeb/Blogs/Impact_of_the_digital_ twin_on_the_enterprise_architecture.aspx sourceExperimental — accuracy not yet measured

In the paper

“The paradigms of Lambda computing [292] [293] and liquid software [294] are examples of the requested flexibility.”

What the sources say

• Supported

  The Introduction describes lambda architecture as combining batch and stream processing and providing flexible data provisioning based on user needs. The Lambda architecture section likewise says users can tailor analysis routines to their needs. This source is cited for the lambda paradigm, not for liquid software, which has a separate citation. (LLM, conf=0.91)

  cites [292] 292. M. Kiran, P. Murphy, I. Monga, J. Dugan and S. S. Baveja, "Lambda architecture for cost-effective batch and speed big data processing," 2015 IEEE International Conference on Big Data (Big Data), Santa Clara, CA, 2015, pp. 2785-2792. DOI: 10.1109/BigData.2015.7364082. source
• ?Not checked — no full text of the sourcecites [293] 293. M. Gribaudo, M. Iacono, and M. Kiran, "A performance modeling framework for lambda architecture based applications". in: Future Generation Computer Systems, 86 (2018): pp. 1032-1041. source
• ?Not checked — no full text of the sourcecites [294] 294. A. Gallidabino et al., "On the Architecture of Liquid Software: Technology Alternatives and Design Space," 2016 13th Working IEEE/IFIP Conference on Software Architecture (WICSA), Venice, 2016, pp. 122-127. DOI: 10.1109/WICSA.2016.14. source

In the paper

“All these platforms, especially the industrial ones, pay attention to the edge computing aspects and they support the possibility to execute and exploit the edge capabilities in order to better implement the Digital Twin concept, e.g., [287], [288] with examples of Smart City and Digital Twins.”

What the sources say

• Partly supported

  The Technical Approach (pp. 4–5) discusses edge computing devices and programmable edge gateways that can run dynamically deployed components. The FIWARE section (p. 3) gives a Smart City example. Our copy does not connect these capabilities to Digital Twins or establish that all the platforms, especially industrial ones, support edge execution for that purpose. (LLM, conf=0.88)

  cites [287] 287. J. Cheng, W. Chen, F. Tao, and C.-L. Lin, "Industrial IoT in 5G environment towards smart manufacturing," Journal of Industrial Information Integration, vol. 10, pp. 10-19, 2018. sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [288] 288. B. Varghese et al., "Realizing Edge Marketplaces: Challenges and Opportunities," in IEEE Cloud Computing, vol. 5, no. 6, pp. 9-20, Nov./Dec. 2018. DOI: 10.1109/MCC.2018.064181115. source

In the paper

“The vast literature mentioned in this section is conceptually aligned on an idea of the DT, but there is not a shared set of properties that can help to create common background, language, and a unifying framework for representing and discussing the DT.”

In the paper

“The available definitions converge at a high level in representing the DT as made out of two entities, a physical one and a logical one.”

In the paper

“These definitions are not operable ones, i.e., they don't define features that a DT must have.”

In the paper

“The definitions end up to focus on specific aspects of the problem domains, e.g., a DT is a representation of a manufactured product, or the DT is a 3D representation within the multimedia realm, and they lose generality.”

In the paper

“The vast literature mentioned in this section is conceptually aligned on an idea of the DT, but there is not a shared set of properties that can help to create common background, language, and a unifying framework for representing and discussing the DT.”

In the paper

“Many papers reference it as a major requirement, a few try to define it, e.g., [51].”

What the sources say

• ?Not checked — no full text of the sourcecites [51] 51. S. O. Erikstad, "Merging Physics, Big Data Analytics and Simulation for the Next-Generation Digital Twins." High- Performance Marine Vehicles (2017): 141-151. source

In the paper

“Actually, academia and industry have already started several specification and prototyping activities in order to demonstrate, develop and introduce platforms supporting the Digital Twin concept.”

In the paper

“Many well-known companies are involved in positioning their solutions or future products as leaders of the sector.”

In the paper

“DT is finding interest and an increasing application in several fields.”

In the paper

“The DT finds its usage and utility in each of the different phases of the life cycle and the software counterpart helps in improving and optimize the 'product' at each step.”

In the paper

“• Since the Digital Twin is framed in a lifecycle composed of different steps, it can encompass data and information that describe the 'history' of the physical object.”

In the paper

“• A Digital Twin strictly refers to a physical object;”

In the paper

“Another characterizing feature of the Digital Twin concept is the 'linkage' between logical and physical objects.”

In the paper

“The linkage is not necessarily real time, nor resilient or permanent.”

In the paper

“This flow of information creates a linkage between the physical and the logical objects.”

In the paper

“It is important to note that Grieves' definition of Digital Twin [6] does not apply to systems that show an Evolutionary Emergence, i.e., systems that exhibit a deliberate capability to learn and modify their behavior in order to adapt to changing conditions.”

What the sources say

• ?Not checked — no full text of the sourcecites [6] 6. M. Grieves, and J. Vickers. "Digital Twin: Mitigating unpredictable, undesirable emergent behavior in complex systems." in Transdisciplinary perspectives on complex systems, Berlin, Germany: Springer, 2017 pp. 85-113. [ONLINE] available :https://www.springerprofessional.de/en/digital-twin- mitigating-unpredictable-undesirable-emergent- behav/10588328 source

In the paper

“From the Production phase onwards, the information about or from the physical object(s) must be collected and provided to the logical object.”

In the paper

“• A Digital Twin contains all the information needed to fully characterize a physical object and its intended or predicted behavior; and”

In the paper

“In other words, a Digital Twin relates n products to a single software representation.”

In the paper

“There is special correlation between the concepts of Digital Twin and of Avatar within the Virtual Reality domain.”

In the paper

“From a practical perspective, the linkage between the physical and the logical object is effective if the refresh time of the status of logical object is lower than the average access time of applications using the logical object.”

In the paper

“These transformations imply the generation of a continuous flow of data that represent the modifications and the current status of the physical object.”

In the paper

“The intended goals of Multi-agent systems are very much aligned with those of the Digital Twin concept.”

In the paper

“If a user cannot distinguish a virtual product from a physical one, under appropriate simulation conditions, then a virtual representation of the physical object could be considered a Digital Twin [6].”

What the sources say

• ?Not checked — no full text of the sourcecites [6] 6. M. Grieves, and J. Vickers. "Digital Twin: Mitigating unpredictable, undesirable emergent behavior in complex systems." in Transdisciplinary perspectives on complex systems, Berlin, Germany: Springer, 2017 pp. 85-113. [ONLINE] available :https://www.springerprofessional.de/en/digital-twin- mitigating-unpredictable-undesirable-emergent- behav/10588328 source

In the paper

“For this, the Digital Twin concept has attracted a wide interest as a possible concept generally applicable in IoT and CPS (e.g., [39] 45]).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [39] 45]

In the paper

“Changes in the real world occur according to physical laws and the logical objects must evolve to reflect them.”

In the paper

“However, this cardinality may also be 1-to-N in case different replicas exists with respect to the asset.”

In the paper

“Initially, industries relay on proprietary interfaces and methods specific for their products, approaches and needs.”

In the paper

“These features are indeed very relevant for the Digital Twin evolution.”

In the paper

“These specific developments tend to segment the applicability of the solutions.”

In the paper

“Another emerging aspect of the DT is its software programmability.”

In the paper

“Multi-agent systems offer several interesting properties that a consolidated Digital Twin concept may embody:”

In the paper

“The Digital Twin solution must be integrated with existing systems for Enterprise Resource Planning (ERP), Manufacturing Execution Systems (MES) and Production Unit control and their related information flows by means of an Enterprise Service Bus [32].”

What the sources say

• ?Not checked — no full text of the sourcecites [32] 32. D. Schel C. Henkel D. Stock O. Meyer G. Rauhöft P. Einberger M. Stöhr M. A. Daxer J. Seidelmann "Manufacturing Service Bus: an Implementation" 11th CIRP Conference on Intelligent Computation in Manufacturing Engineering Jul. 2017: pp 179- 184. source

In the paper

“A timerelated representation is also needed in order to understand the past behavior of an object and to use the data to predict future modifications and actions.”

In the paper

“Virtualization has also been extensively applied to the IoT: a sensor can be virtualized in a cloud system and behave as the real one by running software functionalities that represent a specific 'smart object' [109].”

What the sources say

• ?Not checked — no full text of the sourcecites [109] 109. I. Khan, F. Belqasmi, R. Glitho, N. Crespi, M. Morrow and P. Polakos, "Wireless sensor network virtualization: A survey," in IEEE Communications Surveys & Tutorials, vol. 18, no. 1, pp. 553-576, Firstquarter 2016. DOI: 10.1109/COMST.2015.2412971. source

In the paper

“• Knowledge of the Physical World: it is a daunting task to determine and to describe the models, laws and effects of the real world in a logical object.”

In the paper

“IIoT and Industry 4.0 are beneficiaries of many of the possibilities offered by the Digital Twin and they are also well intertwined with IoT, and CPS technologies [37] [38].”

What the sources say

• ?Not checked — no full text of the sourcecites [37] 37. E. Negri, L. Fumagalli, and M. Macchi. "A review of the roles of digital twin in cps-based production systems." Procedia Manufacturing 11 (2017): 939-948. source
• ?Not checked — no full text of the sourcecites [38] 38. B. Ashtari Talkhestani, T. Jung, B. Lindemann, N. Sahlab, N. Jazdi, W. Schloegl, and M. Weyrich,. "An architecture of an Intelligent Digital Twin in a Cyber-Physical Production System". Automatisierungstechnik 2019, 67(9), 762-782. https://doi.org/10.1515/auto-2019-0039 source

In the paper

“In fact, physical objects can change over time in terms of status, behavior and response to events.”

In the paper

“Objects with limited processing and storage power can also be virtualized and represented in the 'cloud', and subsequently replicated several times, freeing the original object to support the processing required to serve all the possible applications.”

In the paper

“Virtual Reality can also be used to visualize the Digital Twins in order to better understanding its features [35] or for more complex tasks [36].”

What the sources say

• ?Not checked — no full text of the sourcecites [35] 35. G. Schroeder, C. Steinmetz, C. E. Pereira, I. Muller, N. Garcia, D. Espindola, and R. Rodrigues. "Visualising the Digital Twin using web services and augmented reality." In Proc. IEEE 14th International Conference on Industrial Informatics (INDIN), Poitiers, France, pp. 522-527. IEEE, 2016 source
• ?Not checked — no full text of the sourcecites [36] 36. M. Kritzler, M. Funk, F. Michahelles, and W. Rohde.. The virtual twin: controlling smart factories using a spatially-correct augmented reality representation. In Proceedings of the Seventh International Conference on the Internet of Things (IoT '17), 2017, ACM, New York, NY, USA, Article 38, 2 pages. DOI: https://doi.org/10.1145/3131542.3140274 source

In the paper

“In order to fully exploit the DT it is important to have DT's Application Programming Interfaces (APIs) [23], and models for programming the objects [24].”

What the sources say

• ?Not checked — no full text of the sourcecites [23] 23. J. Scheibmeir and Y. Malaiya, "An API Development Model for Digital Twins," 2019 IEEE 19th International Conference on Software Quality, Reliability and Security Companion (QRS- C), Sofia, Bulgaria, 2019, pp. 518-519. doi: 10.1109/QRS- C.2019.00103 source
• ?Not checked — no full text of the sourcecites [24] 24. A. Burghardt, D. Szybicki, P. Gierlak, K. Kurc, P. Pietruś, and R. Cygan, "Programming of Industrial Robots Using Virtual Reality and Digital Twins". Applied Sciences, 10(2), p.486, 2020 source

In the paper

“In addition, physical objects need to be exactly located in space and tracked in order to accurately embody them.”

In the paper

“For example, the Industrial Internet of Thing Consortium is addressing the manufacturing community with its architecture and APIs [25][26].”

What the sources say

• ?Not checked — no full text of the sourcecites [25] 25. S. Malakuti, and S. Grüner, "Architectural aspects of digital twins in IIoT systems". In Proceedings of the 12th European Conference on Software Architecture: Companion Proceedings (pp. 1-2), 2018. source
• ?Not checked — no full text of the sourcecites [26] 26. V. Souza, R. Cruz, W. Silva, S. Lins and V. Lucena, "A Digital Twin Architecture Based on the Industrial Internet of Things Technologies," 2019 IEEE International Conference on Consumer Electronics (ICCE), Las Vegas, NV, USA, 2019, pp. 1-2. doi: 10.1109/ICCE.2019.8662081 source

In the paper

“This reduces the need to always build expensive prototypes and mockups, thereby offering significant cost savings during product development and testing [19].”

What the sources say

• ?Not checked — no full text of the sourcecites [19] 19. E. M. Kraft, "The air force digital thread/digital twin-life cycle integration and use of computational and experimental knowledge." In 54th AIAA Aerospace Sciences Meeting, San Diego, California, USA, January 2016, p. 0897. source

In the paper

“However, the concept of the Digital Twin, as it is currently evolving, also inherits some features from other research and technological efforts.”

In the paper

“This linkage between the physical and the logical object is also a key element for introducing new capabilities and thus new business opportunities for the industry.”

In the paper

“These data must promptly be mirrored by the logical object.”

In the paper

“• Siloing/Programming: if proprietary and closed interfaces are used, it will be extremely difficult to create ecosystems of Digital Twins capable of working together and being interoperable.”

In the paper

“In addition, the simulation capabilities related to the Digital Twin concept are very useful for planning and projecting products [33][34].”

What the sources say

• ?Not checked — no full text of the sourcecites [33] 33. M. Schluse and J. Rossmann, "From simulation to experimentable digital twins: Simulation-based development and operation of complex technical systems," 2016 IEEE International Symposium on Systems Engineering (ISSE), Edinburgh, 2016, pp. 1-6. DOI: 10.1109/SysEng.2016.7753162 source
• ?Not checked — no full text of the sourcecites [34] 34. B. Schleich, N. Anwer, L. Mathieu, S. Wartzack, "Shaping the digital twin for design and production engineering", CIRP Annals, Volume 66, Issue 1, 2017, pp 141-144, ISSN 0007- 8506, https://doi.org/10.1016/j.cirp.2017.04.040. source

In the paper

“Replicas can also cooperate to share data and information about the physical object quickly and efficiently.”

In the paper

“Other domains, e.g., e-health or cultural heritage, not necessarily fit in the product and its life cycle perspective.”

In the paper

“In addition, different replicas, each devoted to a single application or domain of applications, can be instantiated and fed by a master logical object or by the physical object itself.”

In the paper

“Each replica can be tailored to the needs of the requesting application.”

In the paper

“The physical object could provide relevant status information, and the logical object could provide relevant updates and adjustments to the physical one to improve its functioning.”

In the paper

“A physical object can be virtualized and replicated several times in a virtualization space.”

In the paper

“In addition, a logical object may also mediate and represent the change status requested by applications.”

In the paper

“The notion of self-organizing (self-X) systems is also influencing the definition of the DT [175][176].”

What the sources say

• ?Not checked — no full text of the sourcecites [175] 175. K. Ding, F.T. Chan, X. Zhang, G. Zhou, F. Zhang. "Defining a digital twin-based cyber-physical production system for autonomous manufacturing in smart shop floors". International Journal of Production Research. 2019 Oct 18;57(20):6315-34. source
• ?Not checked — no full text of the sourcecites [176] 176. C. Liu, P. Jiang, W. Jiang. "Web-based digital twin modeling and remote control of cyber-physical production systems". Robotics and Computer-Integrated Manufacturing. 2020 Aug 1;64:101956. source

In the paper

“Multi tenancy is in fact demonstrated in the vIoT testbed [174].”

What the sources say

• ?Not checked — no full text of the sourcecites [174] 174. M. Ahmad, J. S. Alowibdi and M. U. Ilyas, "vIoT: A first step towards a shared, multi-tenant IoT Infrastructure architecture," 2017 IEEE International Conference on Communications Workshops (ICC Workshops), Paris, 2017, pp. 308-313. source

In the paper

“By means of APIs, a set of physical objects, through their logical object counterparts, can be made interoperable within a complex environment in order to cooperate and achieve specific business results [181].”

What the sources say

• ?Not checked — no full text of the sourcecites [181] 181. K. Borodulin, G. Radchenko, A. Shestakov, L. Sokolinsky, A. Tchernykh, and R. Prodan, "Towards Digital Twins Cloud Platform," in Proceedings of the 10th International Conference on Utility and Cloud Computing -UCC '17, pp. 209-210, 2017. source

In the paper

“Recent techniques for rapid recovery and restoration of virtual machines [167] [168] [169] can be adopted to provide these required capabilities.”

What the sources say

• ?Not checked — no full text of the sourcecites [167] 167. B. Egger, E. Gustafsson, C. Jo, and J. Son, "Efficiently restoring virtual machines," Int. J. Parallel Programm., vol. 43, no. 3, pp. 421-439, 2015. source
• ?Not checked — no full text of the sourcecites [168] 168. L. Cui, Z. Hao, Y. Peng and X. Yun, "Piccolo: A Fast and Efficient Rollback System for Virtual Machine Clusters," in IEEE Transactions on Parallel and Distributed Systems, vol. 28, no. 8, pp. 2328-2341, 1 Aug. 2017. DOI: 10.1109/TPDS.2017.2668403. source
• ?Not checked — no full text of the sourcecites [169] 169. Y. Yamato, Y. Nishizawa, S. Nagao and K. Sato, "Fast and Reliable Restoration Method of Virtual Resources on OpenStack," in IEEE Transactions on Cloud Computing, vol. 6, no. 2, pp. 572-583, 1 April-June 2018. DOI: 10.1109/TCC.2015.2481392. source

In the paper

“The issue of entanglement and the fast data acquisition is an important one for the DT as well as for IoT systems.”

In the paper

“The quantity of historical information, for certain objects, increases over time and there are also new findings and new contextualization of them.”

In the paper

“For some physical objects, real-time processing, communication and storage capabilities could be required in order to properly keep track of the events and changes in status, while for other objects daily updates or even longer periods may be acceptable.”

In the paper

“While all of these mechanisms ensure the high persistency of objects and memory in large distributed systems, they do introduce the issues of managing different copies and their consistency.”

In the paper

“Typically, the intended direction of communication is from physical to logical.”

In the paper

“The efforts related to virtualization also offer mechanisms and technologies for supporting the composability property of the Digital Twin: microservices [152] and containers [153] are possible candidates for supporting the integration and composition of several logical objects.”

What the sources say

• ?Not checked — no full text of the sourcecites [152] 152. K. Bakshi, "Microservices-based software architecture and approaches," 2017 IEEE Aerospace Conference, Big Sky, MT, 2017, pp. 1-8. DOI: 10.1109/AERO.2017.7943959. source
• ?Not checked — no full text of the sourcecites [153] 153. B. Burns and D. Oppenheimer, "Design Patterns for Container- Based Distributed Systems," Proc. 8 th USENIX Workshop Hot Topics in Cloud Computing (HotCloud 16), 2016; [ONLINE] available at https://www.usenix.org/system/files/conference/hotcloud16/hot cloud16_burns.pdf.

In the paper

“For some objects, a very short interval for synchronization may be a stringent requirement for the use of the Digital Twin approach, e.g., medical applications, robotics, Industrial Internet applications and the like.”

In the paper

“However, for physical objects that are instrumented, there could be a great value in supporting bidirectional communication.”

In the paper

“'Objects with memory' [145] is a technology that tackles the issue to save the history of the 'old things' in the context of IoT.”

What the sources say

• ?Not checked — no full text of the sourcecites [145] 145. R. Barthel, K.L. Mackley, A. Hudson-Smith, A. Karpovich, M. De Jode, C. Speed. "An internet of old things as an augmented memory system". Personal and ubiquitous computing. 2013 Feb 1;17(2):321-33. source

In the paper

“This should not come as a surprise; in fact, smart manufacturing is moving from the design of logical objects to the actual implementation of several physical objects that can be coupled with one or more corresponding logical object(s).”

In the paper

“Replicability is assured by the ability of software environments to virtualize components.”

In the paper

“For instance, a smart city application has been prototyped exploiting these concepts [166].”

What the sources say

• ?Not checked — no full text of the sourcecites [166] 166. B. Rusti, H. Stefanescu, M. Iordache, J. Ghenta, C. Brezeanu and C. Patachia, "Deploying Smart City components for 5G network slicing," 2019 European Conference on Networks and Communications (EuCNC), Valencia, Spain, 2019, pp. 149-154. source

In the paper

“Different studies and experiments have addressed the need for composition/aggregation of objects within the IoT context, for instance the EU project iCore has provided and experimented the possibility to virtualize and aggregate different objects [161].”

What the sources say

• ?Not checked — no full text of the sourcecites [161] 161. R. Giaffreda. "iCore: A cognitive management framework for the Internet of Things". The Future Internet Assembly 2013 May 7 (pp. 350-352). Springer, Berlin, Heidelberg. source

In the paper

“The DT is able to support the transformation of physical objects (atoms) into software entities (bits).”

In the paper

“The logical object within the DT is the main enabling factor for this property, it has to be persistent and resilient in order to be always available.”

In the paper

“In this case, communication can occur by means of other objects that are capable of directly observing and determining the status of a physical object and then feed that information to the logical object of the observed physical entity.”

In the paper

“For instance, the status of an object can be monitored by means of a camera and/or sensor, with any relevant information extracted from the multimedia flow and passed to the logical object.”

In the paper

“A single virtualized instance (i.e., a logical object) can have enough processing power in the cloud to reply to multiple and real-time requests.”

In the paper

“As seen, the logical object can be used to represent the physical object in time and space.”

In the paper

“The logical replica makes this information available to the applications and services.”

In the paper

“If the DT concept will be implemented in several application domains then these properties can result a valid means to reason about the DT and its features.”

In the paper

“The most tangible value of a large Digital Twin implementation may reside in the possibility to observe, analyze and understand real-world interactions and impacts on different objects at a very granular level.”

In the paper

“A temperature value could refer to a specific object, and/or to an entire environment.”

In the paper

“Wherever the unpredictability of behavior and complexity in interactions and in the change of states are relevant, Digital Twin modeling could be a viable option for attacking some control problems.”

In the paper

“Servitization is a term and a set of technical definitions and methods that are very interesting to a broad industry and business community [187].”

What the sources say

• ?Not checked — no full text of the sourcecites [187] 187. C. Kowalkowski, H. Gebauer B. Kamp, G. Parry. "Servitization and deservitization: Overview, concepts, and definitions". Industrial Marketing Management. 2017 Jan 1;60: pp 4-10. source

In the paper

“Some of the properties discussed herein are foundational for a Digital Twin, i.e., without them there is no a real DT implementation; while others extend and increase the intrinsic value of the Digital Twin relation.”

In the paper

“The first group includes the following properties: Reflection or Mirroring, Virtualization, and Entanglement, along with Representativeness and Contextualization in space and time.”

In the paper

“Memorization guarantees that a Digital Twin can be represented and controlled along a large part or the entire life cycle, while Augmentation ensures that it can become a programmable object.”

In the paper

“Servitization is a property that ensures the usability and the effectiveness of a DT with respect to its usage by final or intermediate customers.”

In the paper

“In addition, the implementation of the Digital Twin concept suffers from the lack of an established set of platforms, modelling and development tools that can scale up to very complex representations.”

In the paper

“Also NASA is using the DT for its own developments [192].”

What the sources say

• ?Not checked — no full text of the sourcecites [192] 192. E. Glaessgen, D. Stargel. "The digital twin paradigm for future NASA and US Air Force vehicles". 53rd AIAA/ASME/ASCE/AHS/ASC structures, structural dynamics and materials conference 20th AIAA/ASME/AHS adaptive structures conference 14th AIAA 2012 Apr 16 (p. 1818). source

In the paper

“This is an important signal of the need to create large, continuously running complex systems devoted to the prediction of Digital Twins' behavior in particular situations or environments [33][191].”

What the sources say

• ?Not checked — no full text of the sourcecites [33] 33. M. Schluse and J. Rossmann, "From simulation to experimentable digital twins: Simulation-based development and operation of complex technical systems," 2016 IEEE International Symposium on Systems Engineering (ISSE), Edinburgh, 2016, pp. 1-6. DOI: 10.1109/SysEng.2016.7753162 source
• ?Not checked — no full text of the sourcecites [191] 191. T. Gabor, L. Belzner, M. Kiermeier, M. T. Beck and A. Neitz, "A Simulation-Based Architecture for Smart Cyber-Physical Systems," 2016 IEEE International Conference on Autonomic Computing (ICAC), Wurzburg, 2016, pp. 374-379. DOI: 10.1109/ICAC.2016.29. source

In the paper

“In [189], an analysis of some current industrial initiative is provided as well as a general overview of the 'Servitization of the Digital Twin'.”

What the sources say

• ?Not checked — no full text of the sourcecites [189] 189. Q. Qi, F. Tao, Y. Zuo, D. Zhao. "Digital twin service towards smart manufacturing". Procedia Cirp. 2018 Jan 1;72:237-42. source

In the paper

“Another important issue is related to when applying the DT approach.In fact, many problems can be solved without introducing the Digital Twin concept.”

In the paper

“For instance, in [33] Digital Twins are embedded in Virtual Testbeds in order to execute several experiments.”

What the sources say

• ?Not checked — no full text of the sourcecites [33] 33. M. Schluse and J. Rossmann, "From simulation to experimentable digital twins: Simulation-based development and operation of complex technical systems," 2016 IEEE International Symposium on Systems Engineering (ISSE), Edinburgh, 2016, pp. 1-6. DOI: 10.1109/SysEng.2016.7753162 source

In the paper

“There are a few typical scenarios for the usage of the Digital Twin that can be inferred from the state of the art:”

In the paper

“In [193], a survey on current efforts within the IoT field to use simulation techniques and in particular the DT is given.”

What the sources say

• ?Not checked — no full text of the sourcecites [193] 193. T. Jung, N. Jazdi and M. Weyrich, "A survey on dynamic simulation of automation systems and components in the Internet of Things," 2017 22nd IEEE International Conference on Emerging Technologies and Factory Automation (ETFA), Limassol, 2017, pp. 1-4. source

In the paper

“Others are considered useful and they have been mentioned or introduced in some experiments or implementations.”

In the paper

“Predictability is an important property that ensures that the behavior of the Digital Twin within its operational contexts can be studied and predicted.”

In the paper

“Having more detailed information by means of a set of DTs could enable the provision of better models, applications, and solutions to the people involved.”

In the paper

“In this area, the EU project iCore has provided some practical implementations and a seminal architecture [161].”

What the sources say

• ?Not checked — no full text of the sourcecites [161] 161. R. Giaffreda. "iCore: A cognitive management framework for the Internet of Things". The Future Internet Assembly 2013 May 7 (pp. 350-352). Springer, Berlin, Heidelberg. source

In the paper

“• Prediction and simulation of the behavior of an aggregated set of Digital Twins in order to understand, control, govern, and orchestrate the behavior of a complex system.This is supported by the collection of historical data that show the past behavior of the physical object;”

In the paper

“Such a system could also offer the possibility to predict and actually simulate objects' behavior under different conditions.”

In the paper

“A permanent linkage between the customer and the producer is then established by means of the ownership of the servitized product.”

In the paper

“Ownership may pass from one object to the other.”

In the paper

“Composability and Accountability/Manageability introduce the ability to interact between different logical objects, softwarized objects, and to compose them into larger aggregations.”

In the paper

“The complexity of the models increases in relation to the number of involved objects, and so very large systems' modeling could require a huge effort.”

In the paper

“For example, the reference [183] proposes a data management model for the data produced by DTs in the maritime industry.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [183] 183. Ø.J. Rødseth, A.J. Berre. 'From digital twin to maritime data space: Transparent ownership and use of ship information. 13th Int. Symp. Integr. Ship's Inf. Syst. Mar. Traffic Eng. Conf.(ISIS-MTE), Berlin, Germany 2018 Sep.

In the paper

“The concept is also appealing for other application domains, and, along with the extensions, 'interpretations', and consolidation discussed in Section II, it has been studied and partially applied by several research efforts and in different industrial contexts.”

In the paper

“• Servitization of a physical product and its augmentation in terms of new functions and interaction with the customers.”

In the paper

“In this case, the Digital Twin is a means for offering high level of Servitization [186] of a physical object.”

What the sources say

• ?Not checked — no full text of the sourcecites [186] 186. S. Vandermerwe J. Rada. "Servitization of business: adding value by adding services". European management journal. 1988 Dec 1;6(4): pp 314-24. source

In the paper

“Ownership could also be useful to understand the story beyond a physical object, a used car, and to fully represent the status of the artifact.”

In the paper

“Clearly, large IoT systems, such as manufacturing or smart cities, could especially benefit from the unique properties of the DT concept.”

In the paper

“The DT has been implemented in different applications in several fields (see Table 1 for a recap of some of the application areas addressed by this survey) and, most likely, it will receive attention from other sectors.”

In the paper

“Their replication can create a set of logical objects that refer to the physical one, but they not necessarily share the same ownership.”

In the paper

“The DT, as many IoT systems, produce a large quantity of data.”

In the paper

“Having a large-scale platform would reduce the time required for implementing solutions, so that programmers could focus more on representing the Digital Twins than on developing a solution for supporting that representation.”

In the paper

“Many 'simple' IoT implementation could use these data to offer very effective services for traffic detection and prevention.”

In the paper

“In the long term, Servitization could lead to a new kind of economy no longer based on the ownership of things, but based on a pay per usage philosophy.The Digital Twin concept is a major enabler for this kind of change.”

In the paper

“Ownership introduces the ability to correctly manage Intellectual Properties Rights issues and associated responsibilities of the logical objects.”

In the paper

“In addition, some logical objects can offer different capabilities of interaction or better ways to exploit the features of the physical object and, consequently, they can have different constraints in ownership.”

In the paper

“On the other side, a poor description can be detrimental for the entire system and it can generate inadequate data and results.”

In the paper

“Actually, a sensor can represent an object, or some properties of an object in its environment, or direct properties of the environment in which the object is embedded.”

In the paper

“The augmentation property also aims at increasing the number of functions that a logical object can provide [186].”

What the sources say

• ?Not checked — no full text of the sourcecites [186] 186. S. Vandermerwe J. Rada. "Servitization of business: adding value by adding services". European management journal. 1988 Dec 1;6(4): pp 314-24. source

In the paper

“Obviously, there is a great interest in the manufacturing community for the concrete implementation of strategies and processes related to the Servitization of products and their DT.”

In the paper

“The industry is particularly interested in changes of ownership and its management for business reasons [184][185].”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [184] 184. J.G. Berti, L.S. Deluca, "Digital agreement management on digital twin ownership change inventors"; United States patent application US 16/392,426. 2019 Aug 15. [online] https://patentimages.storage.googleapis.com/6c/8a/26/9e9ed9f 1d6a043/US20190251575A1.pdf latest accessed: Feb, 22 nd 2020
• ?Not checked — no full text of the sourcecites [185] 185. C. Altun, B. Tavli and H. Yanikomeroglu, "Liberalization of Digital Twins of IoT-Enabled Home Appliances via Blockchains and Absolute Ownership Rights," in IEEE Communications Magazine, vol. 57, no. 12, pp. 65-71, December 2019. source

In the paper

“The possibility of defining platform mechanisms to support the creation of services is also discussed in [182].”

What the sources say

• ?Not checked — no full text of the sourcecites [182] 182. T. Niemirepo, M. Sihvonen, V. Jordan and J. Heinilä, "Service Platform for Automated IoT Service Provisioning," 2015 9th International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing, Blumenau, 2015, pp. 325- 329. source

In the paper

“With these properties, a Digital Twin system offers the ability to represent the current status of the physical object, and can be considered as a basic implementation of the concept.”

In the paper

“Some properties are generally considered valid, e.g., Identity, Representation in [51], Identity, Communication and others in [56], Entanglement is substantially addressed by the definition of Tactile Internet [15], and extensively used in the practice of the implementation of the DT.”

What the sources say

• ?Not checked — no full text of the sourcecites [51] 51. S. O. Erikstad, "Merging Physics, Big Data Analytics and Simulation for the Next-Generation Digital Twins." High- Performance Marine Vehicles (2017): 141-151. source
• ?Not checked — no full text of the sourcecites [56] 56. A. El Saddik,. "Digital Twins: the convergence of multimedia technologies." IEEE MultiMedia, v. 25, n. 2, Apr.-Jun. 2018, pg. 87-92. DOI: https://doi.ieeecomputersociety.org/10.1109/MMUL.2018.023 121167 source
• ?Not checked — no full text of the sourcecites [15] 15. M. Simsek, A. Aijaz, M. Dohler, J. Sachs and G. Fettweis, "5G- Enabled Tactile Internet," in IEEE Journal on Selected Areas in Communications, vol. 34, no. 3, pp. 460-473, March 2016. doi: 10.1109/JSAC.2016.2525398

In the paper

“These capabilities are instrumental to the ability to create a large number of new services and functionalities on the entire Digital Twin.”

In the paper

“Industries and especially manufacturing are extremely interested in Servitization.”

In the paper

“• Design and consolidation of products, i.e., where the Digital Twin is used to help in the design and the production phases of complex products and then used as a means to collect and check the operation of the product in order to identify variations or unexpected behavior;”

In the paper

“Thanks to strong entanglement, these functions can be used to control and to operate on the physical side of the Digital Twin.”

In the paper

“Some industries are interested in the concept and looking for potential applications [199], or checking the costs and applicability of the concept [200], or considering how to cope with data collection and usage [201].”

What the sources say

• ?Not checked — no full text of the sourcecites [199] 199. M. Zborowski. "Finding Meaning, Application for the Much- Discussed "Digital Twin"". Journal of Petroleum Technology. 2018 Jun 1;70(06):26-32. doi:10.2118/0618-0026-JPT source
• ?Not checked — no full text of the sourcecites [200] 200. T.D. West, M. Blackburn. "Is Digital Thread/Digital Twin Affordable? A Systemic Assessment of the Cost of DoD's Latest Manhattan Project". Procedia computer science. 2017 Jan 1;114: pp 47-56. source
• ?Not checked — no full text of the sourcecites [201] 201. T. H.-J. Uhlemann, C. Schock, C. Lehmann, S. Freiberger, and R. Steinhilper, ''The digital twin: Demonstrating the potential of real time data acquisition in production systems,'' Procedia Manuf., vol. 9, pp. 113-120, Jan. 2017, ISSN 2351-9789, DOI: https://doi.org/10.1016/j.promfg.2017.04.043. source

In the paper

“They ensure that the logical object fully represents and behaves like the physical object within one or more specific operational contexts.”

In the paper

“The replication of a set of objects' behaviors in a well-formed software environment can help to determine its faults and/or possible improvements.”

In the paper

“However, the Digital Twin representation could be used in order to provide more granular information.For instance, which cars are involved in a traffic jam, where each of them is heading, how much a single vehicle is polluting the environment, etc.”

In the paper

“In certain cases, it may be very difficult to associate some data, e.g., those collected by a sensor, to a specific physical object.”

In the paper

“DT will benefit from this interoperability effort.”

In the paper

“In this case, the Digital Twin acts as an agent that actively seeks information about its physical counterpart.”

In the paper

“The properties of the DT seem to fit in the need to control small contexts and environments and to be able to scale up to understanding and controlling the macro-behavior of the entire city.”

In the paper

“The different DTs will also behave in such a way to create relationships between them in order to identify common properties, e.g., the same subject, or the same owner, or the same usage of colors or other techniques.”

In the paper

“For instance, CoAP [241] and MQTT [242] are largely used depending on applications needs.”

What the sources say

• ?Not checked — no full text of the sourcecites [241] 241. K. Lee and S. Seol, "Applying CoAP for real-time device control over public networks," 2018 International Conference on Electronics, Information, and Communication (ICEIC), Honolulu, HI, 2018, pp. 1-2. source
• ?Not checked — no full text of the sourcecites [242] 242. P. Bellavista, L. Foschini, N. Ghiselli and A. Reale, "MQTT- based Middleware for Container Support in Fog Computing Environments," 2019 IEEE Symposium on Computers and Communications (ISCC), Barcelona, Spain, 2019, pp. 1-7.

In the paper

“This means that current IoT solutions could be integrated to provide a view on a large system as a Digital Twin.”

In the paper

“However, a wealth of information could even be inferred by the continuous access and crawling of information available on the internet like general wikis, specialized data bases, or even information extracted from Social Media and Networks.”

In the paper

“Self-organization is a fundamental function to be guaranteed in these kinds of systems.”

In the paper

“In each moment of a product's life cycle, producers and customers could have a clear idea of its functioning.”

In the paper

“First of all, it implies a higher control level and an improved ability to manage the characteristics of a product (on a large scale) in its daily operation.”

In the paper

“This ensures a high level of composability and the programmability.”

In the paper

“This search for relationships will create a network that could be evaluated by historians and experts in order to figure out new associations between different artifacts.”

In the paper