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Djupsjöbacka, AndersORCID iD iconorcid.org/0000-0002-9971-2432
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Publications (10 of 67) Show all publications
Puerta, R., Joharifar, M., Schatz, R., Djupsjöbacka, A., Ostrovskis, A., Sun, Y.-T. -., . . . Pang, X. (2023). Coherent Joint Transmission with 1024-QAM for 6G Distributed-MIMO Networks with Analog Radio-over-LWIR FSO Fronthaul Links. In: 2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings (ACP/POEM): . Paper presented at 2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings (ACP/POEM).
Open this publication in new window or tab >>Coherent Joint Transmission with 1024-QAM for 6G Distributed-MIMO Networks with Analog Radio-over-LWIR FSO Fronthaul Links
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2023 (English)In: 2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings (ACP/POEM), 2023Conference paper, Published paper (Refereed)
Abstract [en]

Distributed-MIMO (D-MIMO) is a prospective solution for next-generation mobile networks to increase capacity and coverage. We experimentally validate 1024-QAM coherent joint transmissions in a two transmitter D-MIMO network including radio-over-LWIR FSO fronthaul links facilitating deployment and achieving diversity and power gains close to theoretical values.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:ri:diva-70046 (URN)10.1109/ACP/POEM59049.2023.10369145 (DOI)
Conference
2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings (ACP/POEM)
Note

This work is supported by the Swedish Foundation for Strategic Research (SM21-0047), EU H2020 cFLOW Project (828893), Swedish Research Council (VR) projects 2019–05197 and 2022–04798, VINNOVA funded project (2023–00659), COST Action CA19111 NEWFOCUS, and RRF project Latvian Quantum Technologies Initiative (2.3.1.1.i.0/1/22/I/CFLA/001).

Available from: 2024-01-17 Created: 2024-01-17 Last updated: 2024-01-17Bibliographically approved
Puerta, R., Joharifar, M., Han, M., Djupsjöbacka, A., Bobrovs, V., Popov, S., . . . Pang, X. (2023). Experimental Validation of Coherent Joint Transmission in a Distributed-MIMO System with Analog Fronthaul for 6G. In: 2023 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit): . Paper presented at 2023 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit) (pp. 585-590). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Experimental Validation of Coherent Joint Transmission in a Distributed-MIMO System with Analog Fronthaul for 6G
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2023 (English)In: 2023 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit), Institute of Electrical and Electronics Engineers (IEEE), 2023, p. 585-590Conference paper, Published paper (Refereed)
Abstract [en]

The sixth-generation (6G) mobile networks must increase coverage and improve spectral efficiency, especially for cell-edge users. Distributed multiple-input multiple-output (D-MIMO) networks can fulfill these requirements provided that transmission/reception points (TRxPs) of the network can be synchronized with sub-nanosecond precision, however, synchronization with current backhaul and fronthaul digital interfaces is challenging. For 6G new services and scenarios, analog radio-over-fiber (ARoF) is a prospective alternative for future mobile fronthaul where current solutions fall short to fulfill future demands on bandwidth, synchronization, and/or power consumption. This paper presents an experimental validation of coherent joint transmissions (CJTs) in a two TRxPs D-MIMO network where ARoF fronthaul links allow to meet the required level of synchronization. Results show that by means of CJT a combined diversity and power gain of +5 dB is realized in comparison with a single TRxP transmission.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:ri:diva-66228 (URN)10.1109/eucnc/6gsummit58263.2023.10188222 (DOI)
Conference
2023 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit)
Note

This project is financially supported by the Swedish Foundation for Strategic Research (project No. SM21-0047). Also, it is supported in part by the Swedish Research Council (VR) project 2019–05197 and Vinnova project 2022–02545 (A-FRONTHAUL).

Available from: 2023-09-08 Created: 2023-09-08 Last updated: 2023-09-08Bibliographically approved
Puerta, R., Han, M., Joharifar, M., Schatz, R., Sun, Y.-T. -., Fan, Y., . . . Pang, X. (2023). NR Conformance Testing of Analog Radio-over-LWIR FSO Fronthaul link for 6G Distributed MIMO Networks. In: Opt. Fiber Commun. Conf. Exhib., OFC - Proc.: . Paper presented at 2023 Optical Fiber Communications Conference and Exhibition, OFC 2023 - Proceedings. Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>NR Conformance Testing of Analog Radio-over-LWIR FSO Fronthaul link for 6G Distributed MIMO Networks
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2023 (English)In: Opt. Fiber Commun. Conf. Exhib., OFC - Proc., Institute of Electrical and Electronics Engineers Inc. , 2023Conference paper, Published paper (Refereed)
Abstract [en]

We experimentally test the compliance with 5G/NR 3GPP technical specifications of an analog radio-over-FSO link at 9 μm. The ACLR and EVM transmitter requirements are fulfilled validating the suitability of LWIR FSO for 6G fronthaul. © 2023 The Author(s).

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2023
Keywords
Analog radio, Conformance testing, Distributed MIMO, MIMO networks, Technical specifications
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:ri:diva-66114 (URN)10.23919/OFC49934.2023.10117234 (DOI)2-s2.0-85161033979 (Scopus ID)
Conference
2023 Optical Fiber Communications Conference and Exhibition, OFC 2023 - Proceedings
Note

This work is financially supported by the Swedish Foundation for Strategic Research (project No. SM21-0047). Also, this work was supported in part by the EU H2020 cFLOW Project (828893), in part by the Swedish Research Council (VR) projects 2019-05197 and 2016-04510, in part by the by COST Action CA19111 NEWFOCUS, and in part by the ERDF-funded CARAT project (No. 1.1.1.2/VIAA/4/20/660).

Available from: 2023-09-08 Created: 2023-09-08 Last updated: 2024-02-01Bibliographically approved
Göreke, H., Djupsjöbacka, A., Schenkman, B., Andrén, B., Hermann, D. S. & Brunnström, K. (2023). Perceptual Judgments of Simulated Low Temperatures in LCD based Vehicle Displays. In: Digest of Technical Papers - SID International Symposium: . Paper presented at SID International Symposium Digest of Technical Papers, 2023. Los Angeles, USA. 21 May 2023 through 26 May 2023 (pp. 595-598). John Wiley and Sons Inc, 54(1)
Open this publication in new window or tab >>Perceptual Judgments of Simulated Low Temperatures in LCD based Vehicle Displays
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2023 (English)In: Digest of Technical Papers - SID International Symposium, John Wiley and Sons Inc , 2023, Vol. 54, no 1, p. 595-598Conference paper, Published paper (Refereed)
Abstract [en]

A well-known drawback with LCD-displays in cold is a slow pixel response leading to poor picture quality. Low temperatures can constitute a hazard in viewing important displays in cars. Perceptual experiments with 20 test-persons were conducted to find clear and acceptable ranges on screens simulating distortions in low temperatures. The results showed perception over clear and acceptable image quality was impaired beyond -20°C for the LCD-screen in the experiments. 

Place, publisher, year, edition, pages
John Wiley and Sons Inc, 2023
Keywords
CMS; Cold screen; LCD displays; LCD screens; Lows-temperatures; Perceptual judgements; Picture quality; Psychophysic; Vehicle display; Video quality; Liquid crystal displays
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:ri:diva-68033 (URN)10.1002/sdtp.16628 (DOI)2-s2.0-85175305976 (Scopus ID)
Conference
SID International Symposium Digest of Technical Papers, 2023. Los Angeles, USA. 21 May 2023 through 26 May 2023
Note

This research has been supported by the Sweden´s Innovation Agency (VINNOVA, dnr. 2020-05129 and 2021-02107) through the project SCREENS and Celtic-Next project IMMINENCE (C2020/2-2).

Available from: 2023-11-23 Created: 2023-11-23 Last updated: 2023-11-23Bibliographically approved
Brunnström, K., Djupsjöbacka, A., Ozolins, O., Billingham, J., Wistel, K. & Evans, N. (2023). Quality measurement methods for video assisting refereeing systems. Sports Engineering, 26(1), Article ID 17.
Open this publication in new window or tab >>Quality measurement methods for video assisting refereeing systems
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2023 (English)In: Sports Engineering, ISSN 1369-7072, E-ISSN 1460-2687, Vol. 26, no 1, article id 17Article in journal (Refereed) Published
Abstract [en]

Changes in the footballing world’s approach to technology and innovation, along with major advancements in broadcasting contributed to the decision by the International Football Association Board to introduce Video Assistant Referees in 2018. The change meant that under strict protocols referees could use video replays to review decisions in the event of a “clear and obvious error” or a “serious missed incident”. At the time of writing 48-Member Associations have introduced the Video Assistant Referees protocol in at least one of their tournaments and there are many technology providers who work with organisers to implement the Video Assistant Referees systems. To ensure that the use of Video Assistant Referees has a positive effect on the game, Fédération Internationale de Football Association collaborated with the RISE Research Institutes of Sweden to develop objective test methods that could be used to ensure that a system can provide an adequate solution. Each provider must be able to pass requirements that ensure that they can deal with the challenges of processing, coding, decoding, synchronising, and re-formatting of the broadcast feeds. This article will describe the development of the test methods and illustrate some initial results from a test event on Video Assistant Referees system candidates. The methods have shown to be robust and appropriate for their intended purpose and will be developed over the years to ensure the quality of Video Assistant Referees. The developed measurement methods are general and can be applied to other broadcast and video systems as well as to other sports. © 2023, The Author(s).

Place, publisher, year, edition, pages
Springer Science and Business Media Deutschland GmbH, 2023
Keywords
Broadcast, Football, Latency, Measurements, Synchronicity, Video assistant referee (VAR), Video quality, Measurement methods, Quality measurements, Technology providers, Test method, Use of video, Video assistant referee, Sports
National Category
Engineering and Technology
Identifiers
urn:nbn:se:ri:diva-64303 (URN)10.1007/s12283-023-00408-6 (DOI)2-s2.0-85150219324 (Scopus ID)
Note

 Article; Correspondence Address: Brunnström, K.; RISE Research Institutes of Sweden ABSweden; email: kjell.brunnstrom@ri.se; Funding details: VINNOVA, 2021-02107, C2020/2-2; Funding text 1: Open access funding provided by RISE Research Institutes of Sweden. This project was funded as a development project together with FIFA during 2018–2020. RISE has received grants from FIFA during the development project. The research was also partly supported by internal funding of RISE.; Funding text 2: We acknowledge the invaluable help and assistance from Börje Andrén, Pär Johansson, Andreas Langell, Benny Norling, and Anders Gavler for the successful completion of the project. This research has been partly supported by the Sweden´s Innovation Agency (VINNOVA, dnr. 2021-02107) through the Celtic-Next project IMMINENCE (C2020/2-2) and RISE internal funding.; Funding text 3: We acknowledge the invaluable help and assistance from Börje Andrén, Pär Johansson, Andreas Langell, Benny Norling, and Anders Gavler for the successful completion of the project. This research has been partly supported by the Sweden´s Innovation Agency (VINNOVA, dnr. 2021-02107) through the Celtic-Next project IMMINENCE (C2020/2-2) and RISE internal funding.

Available from: 2023-05-08 Created: 2023-05-08 Last updated: 2023-12-04Bibliographically approved
Brunnström, K., Djupsjöbacka, A., Billingham, J., Wistel, K., Andrén, B., Ozolins, O. & Evans, N. (2023). Video expert assessment of high quality video for Video Assistant Referee (VAR): A comparative study. Multimedia tools and applications
Open this publication in new window or tab >>Video expert assessment of high quality video for Video Assistant Referee (VAR): A comparative study
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2023 (English)In: Multimedia tools and applications, ISSN 1380-7501, E-ISSN 1573-7721Article in journal (Refereed) Epub ahead of print
Abstract [en]

The International Football Association Board decided to introduce Video Assistant Referee (VAR) in 2018. This led to the need to develop methods for quality control of the VAR-systems. This article focuses on the important aspect to evaluate the video quality. Video Quality assessment has matured in the sense that there are standardized, commercial products and established open-source solutions to measure it with objective methods. Previous research has primarily focused on the end-user quality assessment. How to assess the video in the contribution phase of the chain is less studied. The novelties of this study are two-fold: 1) The user study is specifically targeting video experts i.e., to assess the perceived quality of video professionals working with video production. 2) Six video quality models have been independently benchmarked against the user data and evaluated to show which of the models could provide the best predictions of perceived quality. The independent evaluation is important to get unbiased results as shown by the Video Quality Experts Group. An experiment was performed involving 25 video experts in which they rated the perceived quality. The video formats tested were High-Definition TV both progressive and interlaced as well as a quarters size format that was scaled down half the size in both width and height. The videos were encoded with both H.264 and Motion JPEG for the full size but only H.264 for the quarter size. Bitrates ranged from 80 Mbit/s down to 10 Mbit/s. We could see that for H.264 that the quality was overall very good but dropped somewhat for 10 Mbit/s. For Motion JPEG the quality dropped over the whole range. For the interlaced format the degradation that was based on a simple deinterlacing method did receive overall low ratings. For the quarter size three different scaling algorithms were evaluated. Lanczos performed the best and Bilinear the worst. The performance of six different video quality models were evaluated for 1080p and 1080i. The Video Quality Metric for Variable Frame Delay had the best performance for both formats, followed by Video Multimethod Assessment Fusion method and the Video Quality Metric General model. 

Place, publisher, year, edition, pages
Springer, 2023
Keywords
Digital television; High definition television; Sports; Value engineering; Contribution; Objective video quality; PSNR; SSIM; Subjective video quality; Video assistant referee; Video quality; VIF; VMAF; VQM general; VQM_VFD; Quality control
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:ri:diva-69335 (URN)10.1007/s11042-023-17741-4 (DOI)2-s2.0-85180664528 (Scopus ID)
Note

This work was funded by Fédération Internationale de Football Association (FIFA) and Sweden´s Innovation Agency (VINNOVA, dnr. 2021-02107) through the Celtic-Next project IMMINENCE (C2020/2-2), which is hereby gratefully acknowledged.

Available from: 2024-01-15 Created: 2024-01-15 Last updated: 2024-01-17Bibliographically approved
Brunnström, K., Djupsjöbacka, A., Billingham, J., Wistel, K., Andrén, B., Ozolins, O. & Evans, N. (2023). Video quality of video professionals for Video Assisted Referee (VAR). Paper presented at IS and T International Symposium on Electronic Imaging: Human Vision and Electronic Imaging, HVEI 2023. San Francisco, USA. 15 January 2023 through 19 January 2023. IS and T International Symposium on Electronic Imaging Science and Technology, 35(10), Article ID 259.
Open this publication in new window or tab >>Video quality of video professionals for Video Assisted Referee (VAR)
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2023 (English)In: IS and T International Symposium on Electronic Imaging Science and Technology, ISSN 2470-1173, Vol. 35, no 10, article id 259Article in journal (Refereed) Published
Abstract [en]

Changes in the footballing world’s approach to technology and innovation contributed to the decision by the International Football Association Board to introduce Video Assistant Referees (VAR). The change meant that under strict protocols referees could use video replays to review decisions in the event of a "clear and obvious error" or a "serious missed incident". This led to the need by Fédération Internationale de Football Association (FIFA) to develop methods for quality control of the VAR-systems, which was done in collaboration with RISE Research Institutes of Sweden AB. One of the important aspects is the video quality. The novelty of this study is that it has performed a user study specifically targeting video experts i.e., to measure the perceived quality of video professionals working with video production as their main occupation. An experiment was performed involving 25 video experts. In addition, six video quality models have been benchmarked against the user data and evaluated to show which of the models could provide the best predictions of perceived quality for this application. Video Quality Metric for variable frame delay (VQM_VFD) had the best performance for both formats, followed by Video Multimethod Assessment Fusion (VMAF) and VQM General model.

Place, publisher, year, edition, pages
Society for Imaging Science and Technology, 2023
Keywords
Sports; Value engineering; Federation internationale de football associations; Perceived quality; Quality modeling; Quality of videos; Research institutes; User data; User study; Video production; Video quality; Video quality metric; Quality control
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:ri:diva-66714 (URN)10.2352/EI.2023.35.10.HVEI-259 (DOI)2-s2.0-85169574220 (Scopus ID)
Conference
IS and T International Symposium on Electronic Imaging: Human Vision and Electronic Imaging, HVEI 2023. San Francisco, USA. 15 January 2023 through 19 January 2023
Note

This work was mainly funded by Fédération Internationale de Football Association (FIFA) and partly supported by the Sweden´s Innovation Agency (VINNOVA, dnr. 2021-02107) through the Celtic-Next project IMMINENCE (C2020/2-2) as well as RISE internal funding. 

Available from: 2023-09-20 Created: 2023-09-20 Last updated: 2023-12-04Bibliographically approved
Puerta, R., Ozolins, O., Djupsjöbacka, A., Bobrovs, V., Popov, S. & Pang, X. (2022). 5G/NR Conformance Testing of Analog Radio-overfiber Fronthaul Links. In: 2022 IEEE International Topical Meeting on Microwave Photonics, MWP 2022 - Proceedings: . Paper presented at 2022 IEEE International Topical Meeting on Microwave Photonics, MWP 2022, 3 October 2022 through 7 October 2022. Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>5G/NR Conformance Testing of Analog Radio-overfiber Fronthaul Links
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2022 (English)In: 2022 IEEE International Topical Meeting on Microwave Photonics, MWP 2022 - Proceedings, Institute of Electrical and Electronics Engineers Inc. , 2022Conference paper, Published paper (Refereed)
Abstract [en]

Foreseen requirements and use cases of future beyond fifth-generation (B5G) and sixth-generation (6G) mobile networks have shown that current mobile networks implementations must be reconsidered. Analog radio-over-fiber (ARoF) is a prospective solution for future mobile fronthaul of certain applications where current solutions fall short to fulfill future demands on bandwidth and power consumption. This paper provides a complete New-Radio (NR) conformance testing of ARoF fronthaul links in full accordance with the 3rd Generation Partnership Project (3GPP) technical specifications. We experimentally verified that the adjacent channel leakage power ratio (ACLR) and the error vector magnitude (EVM) transmitter requirements are fulfilled validating ARoF links as a suitable solution for next-generation mobile fronthaul. Wireless transmissions results are also provided.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2022
Keywords
3GPP, 6G, Analog radio-over-fiber, Beyond 5G, Fronthaul links, Mobile networks, New Radio, 5G mobile communication systems, Radio links, Wireless networks, 3rd generation, 3rd generation partnership project, Analog radio, Conformance testing, Fronthaul link, Radio-over-fibers, Radio-over-fiber
National Category
Communication Systems
Identifiers
urn:nbn:se:ri:diva-64010 (URN)10.1109/MWP54208.2022.9997749 (DOI)2-s2.0-85146440212 (Scopus ID)9781665421218 (ISBN)
Conference
2022 IEEE International Topical Meeting on Microwave Photonics, MWP 2022, 3 October 2022 through 7 October 2022
Note

Funding details: 1.1.1.2/VIAA/4/20/660; Funding details: Stiftelsen för Strategisk Forskning, SSF, SM21-0047; Funding details: Vetenskapsrådet, VR, 2019-05197; Funding text 1: ACKNOWLEDGMENT This project is financially supported by the Swedish Foundation for Strategic Research (project No. SM21-0047). Also, it is supported in part by the Swedish Research Council (VR) project 2019-05197, and in part by the ERDF-funded CARAT project (No. 1.1.1.2/VIAA/4/20/660).

Available from: 2023-02-22 Created: 2023-02-22 Last updated: 2023-06-02Bibliographically approved
Brunnström, K., Djupsjöbacka, A. & Andrén, B. (2021). Objective video quality assessment methods for Video assistant refereeing (VAR) Systems.
Open this publication in new window or tab >>Objective video quality assessment methods for Video assistant refereeing (VAR) Systems
2021 (English)Report (Other academic)
Abstract [en]

This report describes the work and conclusions drawn after phase 4 in the project “Assessment methods for Video assistant refereeing (VAR) System”.

The performance of six different video quality models have been evaluated, that were identified during phase 1, against the subjective video quality database that was created during phase 3. The results are slightly different for 1080p compared to 1080i. For 1080p the models VQM_VFD, SSIM and VMAF performs the best with Pearson Correlation Coefficients (PCC) above 0.9. For 1080i the PCC drops a bit overall and then VMAF and VQM_VFD are close in performance and performing the best. The overall performance for both formats VMAF an VQM_VFD stands out as the best models. In this comparison VQM_VFD has the added advantage to also be able to perform its own registration i.e. to fix any misalignment between the reference video and the distorted one.

Publisher
p. 14
Series
RISE Rapport ; 2021:30
National Category
Signal Processing
Identifiers
urn:nbn:se:ri:diva-52578 (URN)10.23699/0x71-2570 (DOI)978-91-89385-15-3 (ISBN)
Available from: 2021-03-09 Created: 2021-03-09 Last updated: 2023-05-25Bibliographically approved
Brunnström, K., Djupsjöbacka, A. & Andrén, B. (2021). Objective video quality assessment methods for Video assistant refereeing (VAR) System: Phase 4 report on synchronizationand latency measurements. Kista
Open this publication in new window or tab >>Objective video quality assessment methods for Video assistant refereeing (VAR) System: Phase 4 report on synchronizationand latency measurements
2021 (English)Report (Other academic)
Abstract [en]

This report describes the work and conclusions drawn after phase 4 for the synchronization and latencymeasurements in the project “Assessment methods for Video Assistant Refereeing (VAR) System”.In phase 4, we have focused on up-dating the software so that it automatically detects: p (progressive),i (interlaced), and PsF (progressive segmented frame) formats and analyse the different video types. Wehave also the performed a field-test with an OB-van at an arena.

Place, publisher, year, edition, pages
Kista: , 2021. p. 13
Series
RISE Rapport ; 2021:30
Keywords
Fotboll, Video Assistant Referee (VAR), Latency, Synchronicity
National Category
Communication Systems Media Engineering Telecommunications
Identifiers
urn:nbn:se:ri:diva-59807 (URN)10.23699/0x71-2570 (DOI)978-91-89385-15-3 (ISBN)
Available from: 2022-07-15 Created: 2022-07-15 Last updated: 2023-05-25Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-9971-2432

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