{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T12:28:54Z","timestamp":1786624134797,"version":"build-2736575974"},"reference-count":63,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T00:00:00Z","timestamp":1786579200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Motivated by the increasing security requirements of next-generation satellite-terrestrial communication systems and the emergence of Open Radio Access Network (O-RAN) architectures, this paper presents a secrecy analysis of a novel reconfigurable intelligent surface (RIS)-assisted mixed free-space optical (FSO) and radio frequency (RF) satellite downlink transmission system within an O-RAN-enabled non-terrestrial network (NTN) framework. The inherent broadcast nature of RF transmissions presents significant eavesdropping risks, which serves as the primary impetus for this study. We analyze the combined effects of imperfect channel state information (CSI) and random link blockage within such integrated networks. The impact of discrete phase shift constraints at the RIS is also investigated. Closed-form expressions are derived for three key performance metrics: connection outage probability (COP), secrecy outage probability (SOP), and the probability of positive secrecy capacity (PPSC). Through high signal-to-noise ratio (SNR) asymptotic analysis, corresponding asymptotic expressions are obtained, and all analytical results are validated via extensive Monte Carlo simulations. Our findings demonstrate that: (i) Link blockage probability and channel estimation accuracy jointly govern the secrecy performance floor. (ii) Increasing the number of RIS elements enhances physical-layer security by driving both the COP and SOP toward their theoretical lower bounds. (iii) Improving channel estimation accuracy diminishes the eavesdropper\u2019s channel advantage and improves the overall system security. These results offer valuable insights for designing secure mixed FSO\/RF satellite-terrestrial systems within O-RAN-enabled NTN architectures that effectively balance connectivity and confidentiality.<\/jats:p>","DOI":"10.3390\/e28080907","type":"journal-article","created":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T11:33:46Z","timestamp":1786620826000},"page":"907","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Secrecy Performance of O-RAN-Enabled RIS-Assisted FSO\/RF Satellite Downlinks"],"prefix":"10.3390","volume":"28","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-3511-5834","authenticated-orcid":false,"given":"Yuhang","family":"Li","sequence":"first","affiliation":[{"name":"School of Electronics, Peking University, Beijing 100871, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-5526-8319","authenticated-orcid":false,"given":"Xifan","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Electronics, Peking University, Beijing 100871, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-5733-2643","authenticated-orcid":false,"given":"Jiale","family":"Shi","sequence":"additional","affiliation":[{"name":"School of Electronics, Peking University, Beijing 100871, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7136-3402","authenticated-orcid":false,"given":"Guocheng","family":"Lv","sequence":"additional","affiliation":[{"name":"School of Electronics, Peking University, Beijing 100871, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ye","family":"Jin","sequence":"additional","affiliation":[{"name":"School of Electronics, Peking University, Beijing 100871, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1536","DOI":"10.1109\/COMST.2024.3449430","article-title":"Multi-satellite MIMO systems for direct satellite-to-device communications: A survey","volume":"27","author":"Bakhsh","year":"2025","journal-title":"IEEE Commun. Surv. Tut."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"17334","DOI":"10.1109\/JIOT.2022.3157673","article-title":"NOMA-based cognitive satellite terrestrial relay network: Secrecy performance under channel estimation errors and hardware impairments","volume":"9","author":"Guo","year":"2022","journal-title":"IEEE Internet Things J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2187","DOI":"10.1109\/TVT.2021.3122029","article-title":"NOMA-based overlay cognitive integrated satellite-terrestrial relay networks with secondary network selection","volume":"71","author":"Liu","year":"2021","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2413","DOI":"10.1109\/TCOMM.2021.3049364","article-title":"Uplink massive access in mixed RF\/FSO satellite-aerial-terrestrial networks","volume":"69","author":"Huang","year":"2021","journal-title":"IEEE Trans. Commun."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1109\/JSYST.2020.2967836","article-title":"Performance analysis of hardware-impaired overlay cognitive satellite-terrestrial networks with adaptive relaying protocol","volume":"15","author":"Singh","year":"2021","journal-title":"IEEE Syst. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3487","DOI":"10.1109\/TWC.2018.2815021","article-title":"Maximum secrecy throughput of MIMOME FSO communications with outage constraints","volume":"17","author":"Monteiro","year":"2018","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"4654","DOI":"10.1109\/COMST.2026.3658670","article-title":"Pivotal AI paradigms for satellite communication security: From machine learning to large language models","volume":"28","author":"Tan","year":"2026","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1376","DOI":"10.1109\/COMST.2023.3239220","article-title":"Understanding O-RAN: Architecture, interfaces, algorithms, security, and research challenges","volume":"25","author":"Polese","year":"2023","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_9","unstructured":"Hogan, H. (2013). Data demands drive free-space optics. Photon. Spectra, 38\u201342."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2813","DOI":"10.1109\/TWC.2007.06109","article-title":"BER performance of free space optical transmission with spatial diversity","volume":"6","author":"Navidpour","year":"2007","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1602","DOI":"10.1109\/COMST.2022.3175509","article-title":"Link-layer retransmission-based error-control protocols in FSO communications: A survey","volume":"24","author":"Le","year":"2022","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"714","DOI":"10.1109\/TWC.2015.2477400","article-title":"Generalized performance analysis of mixed RF\/FSO cooperative systems","volume":"15","author":"Uysal","year":"2016","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"28605","DOI":"10.1109\/JIOT.2024.3405973","article-title":"RIS-assisted hybrid FSO\/THz system with diversity combining schemes: A performance analysis","volume":"11","author":"Vishwakarma","year":"2024","journal-title":"IEEE Internet Things J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2914","DOI":"10.1109\/TVT.2021.3139885","article-title":"Performance analysis of the hybrid satellite-terrestrial relay network with opportunistic scheduling over generalized fading channels","volume":"71","author":"Zhao","year":"2022","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Wang, X., He, J., Xu, G., Chen, J., and Gao, Y. (2024). Secrecy performance of a non-orthogonal multiple access-based space\u2013air\u2013ground integrated network system with stochastic geometry distribution of terrestrial terminals and fog absorption in optical link. Aerospace, 11.","DOI":"10.3390\/aerospace11040306"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"704","DOI":"10.1109\/TBC.2022.3152053","article-title":"Enhanced 5G mobile broadcasting service with shape-adaptive RIS","volume":"68","author":"Qi","year":"2022","journal-title":"IEEE Trans. Broadcast."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1490","DOI":"10.1109\/JLT.2017.2687863","article-title":"Effect of RF interference on the security-reliability tradeoff analysis of multiuser mixed RF\/FSO relay networks with power allocation","volume":"35","author":"Salhab","year":"2017","journal-title":"J. Light. Technol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3913","DOI":"10.1109\/JIOT.2025.3639045","article-title":"RIS-empowered rate-splitting multiple access toward 6G and beyond wireless communication networks: A comprehensive survey","volume":"13","author":"Khoshafa","year":"2026","journal-title":"IEEE Internet Things J."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1035","DOI":"10.1109\/COMST.2022.3155305","article-title":"A survey on channel estimation and practical passive beamforming design for intelligent reflecting surface aided wireless communications","volume":"24","author":"Zheng","year":"2022","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4157","DOI":"10.1109\/TWC.2019.2922609","article-title":"Reconfigurable intelligent surfaces for energy efficiency in wireless communication","volume":"18","author":"Huang","year":"2019","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"520","DOI":"10.1109\/LWC.2023.3334275","article-title":"Secure beamforming design for RIS-assisted integrated sensing and communication systems","volume":"13","author":"Jiang","year":"2024","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"6781","DOI":"10.1109\/TCOMM.2021.3100860","article-title":"RIS-assisted multi-user MISO communications exploiting statistical CSI","volume":"69","author":"Gan","year":"2021","journal-title":"IEEE Trans. Commun."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"11521","DOI":"10.1109\/TWC.2024.3382750","article-title":"A new model of beyond diagonal reconfigurable intelligent surfaces (BD-RIS) for the corresponding quantization and optimization","volume":"23","author":"Sun","year":"2024","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Verma, S., Rodrigues, T.K., Kato, N., Ariyoshi, M., and Hasegawa, Y. (2025, January 8\u201312). Mitigating multi-layer jamming attacks in satellite-air-ground integrated networks. Proceedings of the GLOBECOM 2025\u20132025 IEEE Global Communications Conference, Taipei, Taiwan.","DOI":"10.1109\/GLOBECOM59602.2025.11432509"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1999","DOI":"10.1109\/LCOMM.2022.3186651","article-title":"Secrecy rate analysis of randomized radiation for intelligent reflecting surface-aided communication systems","volume":"26","author":"You","year":"2022","journal-title":"IEEE Commun. Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1104","DOI":"10.1109\/TBC.2024.3394293","article-title":"Enhancing 5G broadcast services in large-scale IoV networks using reliable RIS relaying","volume":"70","author":"Huang","year":"2024","journal-title":"IEEE Trans. Broadcast."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1235","DOI":"10.1109\/LWC.2020.2986750","article-title":"Multiuser scheduling for asymmetric FSO\/RF links in satellite-UAV-terrestrial networks","volume":"9","author":"Kong","year":"2020","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Lu, S., Xu, G., Qu, L., Zhang, Q., and Song, Z. (2022, January 1\u20133). Performance analysis of RIS-assisted RF\/FSO system for hybrid satellite-terrestrial relay network with decode-and-forward protocol. Proceedings of the 14th International Conference on Wireless Communications and Signal Processing (WCSP 2022), Online.","DOI":"10.1109\/WCSP55476.2022.10039373"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"31407","DOI":"10.1109\/JIOT.2024.3419264","article-title":"Joint UAV trajectory and power allocation with hybrid FSO\/RF for secure space\u2013air\u2013ground communications","volume":"11","author":"Zhang","year":"2024","journal-title":"IEEE Internet Things J."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"6384","DOI":"10.1109\/TCOMM.2018.2865944","article-title":"Secrecy outage analysis of mixed RF-FSO downlink SWIPT systems","volume":"66","author":"Lei","year":"2018","journal-title":"IEEE Trans. Commun."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"12427","DOI":"10.1109\/TVT.2018.2877136","article-title":"Physical-layer security for mixed \u03b7-\u03bc and M-distribution dual-hop RF\/FSO systems","volume":"67","author":"Yang","year":"2018","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_32","first-page":"1","article-title":"Secure transmission for energy efficient parallel mixed FSO\/RF system in presence of independent eavesdroppers","volume":"14","author":"Pattanayak","year":"2022","journal-title":"IEEE Photon. J."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"22932","DOI":"10.1109\/ACCESS.2026.3658255","article-title":"Performance analysis of artificial noise-aided physical layer security for mixed FSO-RF non-terrestrial networks","volume":"14","author":"Nguyen","year":"2026","journal-title":"IEEE Access"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1676","DOI":"10.1109\/TIV.2022.3225466","article-title":"Secrecy performance for RIS-based integrated satellite vehicle networks with a UAV relay and MRC eavesdropping","volume":"8","author":"Zhou","year":"2023","journal-title":"IEEE Trans. Intell. Veh."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1798","DOI":"10.1109\/TWC.2023.3292073","article-title":"Uplink secrecy performance of RIS-based RF\/FSO three-dimension heterogeneous networks","volume":"23","author":"Wang","year":"2024","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2958","DOI":"10.1109\/TVT.2024.3472219","article-title":"Performance analysis of RIS-aided FSO\/RF hybrid satellite-terrestrial network with imperfect CSI","volume":"74","author":"Sun","year":"2025","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"4461","DOI":"10.1109\/TCOMM.2020.2985028","article-title":"On secure mixed RF-FSO systems with TAS and imperfect CSI","volume":"68","author":"Lei","year":"2020","journal-title":"IEEE Trans. Commun."},{"key":"ref_38","first-page":"623","article-title":"Mixed FSO\/active IRS-aided MISO NOMA communication with imperfect CSI and SIC","volume":"12","author":"Mondal","year":"2025","journal-title":"IEEE Internet Things J."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"9237","DOI":"10.1109\/TVT.2023.3252083","article-title":"Error probability analysis of intelligent reflecting surface-enabled non-orthogonal multiple access systems","volume":"72","author":"Pawar","year":"2023","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2464","DOI":"10.1109\/LCOMM.2020.3011843","article-title":"Performance analysis of intelligent reflecting surface aided communication systems","volume":"24","author":"Tao","year":"2020","journal-title":"IEEE Commun. Lett."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Girdher, A., Bansal, A., Bhatnagar, M.R., and Dubey, A. (2022, January 2\u20134). IRS-assisted mixed FSO-RF communication system with on-off controlling. Proceedings of the ANTS, Malaga, Spain.","DOI":"10.1109\/ANTS56424.2022.10227769"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2156","DOI":"10.1109\/COMST.2024.3487112","article-title":"RIS-assisted physical layer security in emerging RF and optical wireless communications systems: A comprehensive survey","volume":"27","author":"Khoshafa","year":"2025","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1049\/cmu2.12830","article-title":"Physical layer security in satellite communication: State-of-the-art and open problems","volume":"19","author":"Abdelsalam","year":"2025","journal-title":"IET Commun."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"840","DOI":"10.1109\/OJCOMS.2025.3526215","article-title":"Intelligent control in 6G open RAN: Security risk or opportunity?","volume":"6","author":"Soltani","year":"2025","journal-title":"IEEE Open J. Commun. Soc."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Struminsky, K., Kruglik, S., Vetrov, D.P., and Oseledets, I. (2016, January 13\u201315). A new approach for sparse Bayesian channel estimation in SCMA uplink systems. Proceedings of the 8th International Conference on Wireless Communications and Signal Processing (WCSP 2016), Yangzhou, China.","DOI":"10.1109\/WCSP.2016.7752678"},{"key":"ref_46","unstructured":"Prudnikov, A.P., Brychkov, Y.A., and Marichev, O.I. (1986). Integrals and Series, Gordon and Breach Science Publishers."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"3961","DOI":"10.1109\/TVT.2021.3066219","article-title":"Secure outage analysis of FSO communications over arbitrarily correlated M\u00e1laga turbulence channels","volume":"70","author":"Ai","year":"2021","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1109\/TCOMM.2010.110910.090207","article-title":"On the diversity gain in dynamic decode-and-forward channels with imperfect CSIT","volume":"59","author":"Zhang","year":"2011","journal-title":"IEEE Trans. Commun."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"2285","DOI":"10.1109\/LCOMM.2020.3004413","article-title":"Outage performance for satellite-assisted cooperative NOMA systems with coordinated direct and relay transmission","volume":"24","author":"Li","year":"2020","journal-title":"IEEE Commun. Lett."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1109\/TWC.2015.2467386","article-title":"Performance analysis of free-space optical links over M\u00e1laga (M) turbulence channels with pointing errors","volume":"15","author":"Ansari","year":"2016","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1637","DOI":"10.1109\/TWC.2019.2894823","article-title":"Multicast precoding for multigateway multibeam satellite systems with feeder link interference","volume":"18","author":"Wang","year":"2019","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"3735","DOI":"10.1109\/TIV.2023.3264212","article-title":"STAR-RIS empowered cognitive non-terrestrial vehicle network with NOMA","volume":"8","author":"Guo","year":"2023","journal-title":"IEEE Trans. Intell. Veh."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1273","DOI":"10.1109\/TCOMM.2010.04.090177","article-title":"On the diversity gain in cooperative relaying channels with imperfect CSIT","volume":"58","author":"Zhang","year":"2010","journal-title":"IEEE Trans. Commun."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1109\/TBC.2023.3323929","article-title":"Resource efficient full-duplex mode of transmissions under imperfect CSI","volume":"70","author":"Teklu","year":"2024","journal-title":"IEEE Trans. Broadcast."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1488","DOI":"10.1109\/LCOMM.2019.2924214","article-title":"Secrecy rate maximization for intelligent reflecting surface assisted multi-antenna communications","volume":"23","author":"Shen","year":"2019","journal-title":"IEEE Commun. Lett."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"982","DOI":"10.1049\/iet-com.2010.0224","article-title":"Accurate closed-form approximations to generalised-K sum distributions and applications in the performance analysis of equal-gain combining receivers","volume":"5","author":"Peppas","year":"2011","journal-title":"IET Commun."},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Odeyemi, K.O., and Owolawi, P.A. (2022). A mixed FSO\/RF integrated satellite high altitude platform relaying networks for multiple terrestrial users with presence of eavesdropper: A secrecy performance. Photonics, 9.","DOI":"10.3390\/photonics9010032"},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Mathai, A.M., Saxena, R.K., and Haubold, H.J. (2009). The H-Function: Theory and Applications, Springer.","DOI":"10.1007\/978-1-4419-0916-9"},{"key":"ref_59","unstructured":"Gradshteyn, I.S., and Ryzhik, I.M. (2014). Table of Integrals, Series, and Products, Academic Press."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1007\/BF03049732","article-title":"An integral involving generalized function of two variables","volume":"75","author":"Mittal","year":"1972","journal-title":"Proc. Indian Acad. Sci.-Sec. A"},{"key":"ref_61","doi-asserted-by":"crossref","unstructured":"Kilbas, A.A. (2004). H-Transforms: Theory and Applications, CRC Press.","DOI":"10.1201\/9780203487372"},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"603","DOI":"10.23919\/JCN.2022.000029","article-title":"Performance analysis of wireless network aided by discrete-phase-shifter IRS","volume":"24","author":"Dong","year":"2022","journal-title":"J. Commun. Netw."},{"key":"ref_63","unstructured":"3GPP (2022). Study on Channel Model for Frequencies from 0.5 to 100 GHz, 3rd Generation Partnership Project (3GPP). Technical Report (TR) 38.901, V17.0.0."}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/28\/8\/907\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T11:37:06Z","timestamp":1786621026000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/28\/8\/907"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,13]]},"references-count":63,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["e28080907"],"URL":"https:\/\/doi.org\/10.3390\/e28080907","relation":{},"ISSN":["1099-4300"],"issn-type":[{"value":"1099-4300","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,13]]}}}