{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T15:32:07Z","timestamp":1784907127186,"version":"3.55.0"},"reference-count":62,"publisher":"Springer Science and Business Media LLC","issue":"4","license":[{"start":{"date-parts":[[2017,7,11]],"date-time":"2017-07-11T00:00:00Z","timestamp":1499731200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/www.springer.com\/tdm"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Neural Comput &amp; Applic"],"published-print":{"date-parts":[[2019,4]]},"DOI":"10.1007\/s00521-017-3141-2","type":"journal-article","created":{"date-parts":[[2017,7,11]],"date-time":"2017-07-11T05:19:04Z","timestamp":1499750344000},"page":"1103-1116","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":52,"title":["Performance prediction of roadheaders using ensemble machine learning techniques"],"prefix":"10.1007","volume":"31","author":[{"given":"Sadi Evren","family":"Seker","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2043-6402","authenticated-orcid":false,"given":"Ibrahim","family":"Ocak","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2017,7,11]]},"reference":[{"issue":"11","key":"3141_CR1","first-page":"1264","volume":"46","author":"J Rostami","year":"1994","unstructured":"Rostami J, Ozdemir L, Neil DM (1994) Performance prediction: a key issue in mechanical hard rock mining. Min Eng 46(11):1264\u20131267","journal-title":"Min Eng"},{"key":"3141_CR2","doi-asserted-by":"publisher","first-page":"3","DOI":"10.1016\/j.tust.2014.07.003","volume":"44","author":"E Avunduk","year":"2014","unstructured":"Avunduk E, Tumac D, Atalay AK (2014) Prediction of roadheader performance by artificial neural network. Tunn Undergr Space Technol 44:3\u20139","journal-title":"Tunn Undergr Space Technol"},{"key":"3141_CR3","unstructured":"Farmer I, Garrity P (1987) Prediction of roadheader cutting performance from fracture toughness considerations. In: Proceedings of the 6th international congress on rock mechanics, vol 1, Montreal, Canada, pp 621\u2013624"},{"key":"3141_CR4","first-page":"66","volume":"19","author":"D Poole","year":"1987","unstructured":"Poole D (1987) The effectiveness of tunnelling machines. Tunn Tunn 19:66\u201367","journal-title":"Tunn Tunn"},{"key":"3141_CR5","first-page":"27","volume":"21","author":"KH Gehring","year":"1989","unstructured":"Gehring KH (1989) A cutting comparison. Tunn Tunn 21:27\u201330","journal-title":"Tunn Tunn"},{"issue":"2","key":"3141_CR6","doi-asserted-by":"publisher","first-page":"181","DOI":"10.1016\/j.tust.2009.11.002","volume":"25","author":"I Ocak","year":"2010","unstructured":"Ocak I, Bilgin N (2010) Comparative studies on the performance of a roadheader, impact hammer and drilling and blasting method in the excavation of metro station tunnels in Istanbul. Tunn Undergr Space Technol 25(2):181\u2013187","journal-title":"Tunn Undergr Space Technol"},{"key":"3141_CR7","unstructured":"http:\/\/www.belpacificinc.com"},{"key":"3141_CR8","first-page":"41","volume":"20","author":"N Bilgin","year":"1988","unstructured":"Bilgin N, Seyre T, Shahriar K (1988) Roadheader performance in \u0130stanbul, Golden Horn clean-up contributes valuable data. Tunn Tunn 20:41\u201344","journal-title":"Tunn Tunn"},{"issue":"10","key":"3141_CR9","first-page":"29","volume":"22","author":"N Bilgin","year":"1990","unstructured":"Bilgin N, Seyrek T, Erdinc E, Shahriar K (1990) Roadheaders glean valuable tips for Istanbul Metro. Tunn Tunn 22(10):29\u201332","journal-title":"Tunn Tunn"},{"issue":"6","key":"3141_CR10","doi-asserted-by":"publisher","first-page":"629","DOI":"10.1016\/j.tust.2004.04.004","volume":"19","author":"N Bilgin","year":"2004","unstructured":"Bilgin N, Dincer T, Copur H, Erdogan M (2004) Some geological and geotechnical factors affecting the performance of a roadheader in an inclined tunnel. Tunn Undergr Space Technol 19(6):629\u2013636","journal-title":"Tunn Undergr Space Technol"},{"key":"3141_CR11","unstructured":"Copur H, Rostami J, Ozdemir L, Bilgin N (1997) Studies on performance prediction of roadheaders. In: Proceedings of the 4th international symposium on mine mechanization and automation, Brisbane, QLD, Australia, A4-1\u2013A4-7"},{"key":"3141_CR12","first-page":"38","volume":"50","author":"H Copur","year":"1998","unstructured":"Copur H, Ozdemir L, Rostami J (1998) Roadheader applications in mining and tunneling. Min Eng 50:38\u201342","journal-title":"Min Eng"},{"key":"3141_CR13","first-page":"36","volume":"31","author":"K Thuro","year":"1999","unstructured":"Thuro K, Plinninger RJ (1999) Predicting roadheader advance rates. Tunn Tunn 31:36\u201339","journal-title":"Tunn Tunn"},{"issue":"11","key":"3141_CR14","first-page":"633","volume":"104","author":"C Balci","year":"2004","unstructured":"Balci C, Demircin MA, Copur H, Tuncdemir H (2004) Estimation of optimum specific energy based on rock properties for assessment of roadheader performance. J S Afr Inst Min Metall 104(11):633\u2013642","journal-title":"J S Afr Inst Min Metall"},{"key":"3141_CR15","first-page":"355","volume":"111","author":"A Ebrahimabadi","year":"2011","unstructured":"Ebrahimabadi A, Goshtasbi K, Shahriar K, Seifabad CM (2011) A model to predict the performance of roadheaders based on the rock mass brittleness index. J S Afr Inst Min Metall 111:355\u2013364","journal-title":"J S Afr Inst Min Metall"},{"issue":"4","key":"3141_CR16","first-page":"1015","volume":"57","author":"A Ebrahimabadi","year":"2012","unstructured":"Ebrahimabadi A, Goshtasbi K, Shahriar K, Seifabad CM (2012) A universal model to predict roadheaders\u2019 cutting performance. Arch Min Sci 57(4):1015\u20131026","journal-title":"Arch Min Sci"},{"issue":"4","key":"3141_CR17","doi-asserted-by":"publisher","first-page":"207","DOI":"10.1007\/BF01045717","volume":"30","author":"Y Yang","year":"1997","unstructured":"Yang Y, Zhang Q (1997) A hierarchical analysis for rock engineering using artificial neural networks. Rock Mech Rock Eng 30(4):207\u2013222","journal-title":"Rock Mech Rock Eng"},{"issue":"1","key":"3141_CR18","first-page":"49","volume":"36","author":"M Shahin","year":"2001","unstructured":"Shahin M, Jaksa M, Maier H (2001) Artificial neural networks application in geotechnical engineering. Aust Geomech 36(1):49\u201362","journal-title":"Aust Geomech"},{"issue":"2","key":"3141_CR19","doi-asserted-by":"publisher","first-page":"269","DOI":"10.1016\/S1365-1609(00)00078-2","volume":"38","author":"VK Singh","year":"2001","unstructured":"Singh VK, Singh D, Singh PK (2001) Prediction of strength properties of some schistose rocks from petrographic properties using artificial neural networks. Int J Rock Mech Min Sci 38(2):269\u2013284","journal-title":"Int J Rock Mech Min Sci"},{"key":"3141_CR20","first-page":"19","volume":"43","author":"M Khandelwal","year":"2004","unstructured":"Khandelwal M, Roy MP, Singh PK (2004) Application of artificial neural network in mining industry. Ind Min Eng J 43:19\u201323","journal-title":"Ind Min Eng J"},{"issue":"2","key":"3141_CR21","doi-asserted-by":"publisher","first-page":"224","DOI":"10.1016\/j.ijrmms.2005.06.007","volume":"43","author":"H Sonmez","year":"2006","unstructured":"Sonmez H, Gokceoglu C, Kayabas A, Nefeslioglu HA (2006) Estimation of rock modulus: for intact rocks with an artificial neural network and for rock masses with a new empirical equation. Int J Rock Mech Min Sci 43(2):224\u2013235","journal-title":"Int J Rock Mech Min Sci"},{"issue":"5","key":"3141_CR22","doi-asserted-by":"publisher","first-page":"781","DOI":"10.1007\/s00603-007-0138-7","volume":"41","author":"I Yilmaz","year":"2008","unstructured":"Yilmaz I, Yuksek AG (2008) An example of artificial neural network application for indirect estimation of rock parameters. Rock Mech Rock Eng 41(5):781\u2013795","journal-title":"Rock Mech Rock Eng"},{"issue":"1","key":"3141_CR23","doi-asserted-by":"publisher","first-page":"41","DOI":"10.1016\/S1674-5264(09)60158-7","volume":"20","author":"S Dehghan","year":"2010","unstructured":"Dehghan S, Sattari G, Chehreh S, Aliabadi M (2010) Prediction of uniaxial compressive strength and modulus of elasticity for travertine samples using regression and artificial neural networks. Min Sci Technol (China) 20(1):41\u201346","journal-title":"Min Sci Technol (China)"},{"issue":"6","key":"3141_CR24","doi-asserted-by":"publisher","first-page":"1047","DOI":"10.1007\/s00603-012-0236-z","volume":"45","author":"I Ocak","year":"2012","unstructured":"Ocak I, Seker SE (2012) Estimation of elastic modulus of intact rocks by artificial neural network. Rock Mech Rock Eng 45(6):1047\u20131054","journal-title":"Rock Mech Rock Eng"},{"issue":"2","key":"3141_CR25","doi-asserted-by":"publisher","first-page":"799","DOI":"10.1007\/s00603-013-0415-6","volume":"47","author":"I Enayatollahi","year":"2013","unstructured":"Enayatollahi I, Bazzazi AA, Asadil A (2013) Comparison between neural networks and multiple regression analysis to predict rock fragmentation in open-pit mines. Rock Mech Rock Eng 47(2):799\u2013807","journal-title":"Rock Mech Rock Eng"},{"issue":"3","key":"3141_CR26","doi-asserted-by":"publisher","first-page":"259","DOI":"10.1016\/S0886-7798(00)00055-9","volume":"15","author":"MA Grima","year":"2000","unstructured":"Grima MA, Brunies PA, Verhoef PNW (2000) Modeling tunnel boring machine by neuro-fuzzy methods. Tunn Undergr Space Technol 15(3):259\u2013269","journal-title":"Tunn Undergr Space Technol"},{"issue":"6","key":"3141_CR27","doi-asserted-by":"publisher","first-page":"597","DOI":"10.1016\/j.tust.2004.02.128","volume":"19","author":"AG Benardos","year":"2004","unstructured":"Benardos AG, Kaliampakos DC (2004) Modelling TBM performance with artificial neural networks. Tunn Undergr Space Technol 19(6):597\u2013605","journal-title":"Tunn Undergr Space Technol"},{"issue":"1","key":"3141_CR28","doi-asserted-by":"publisher","first-page":"157","DOI":"10.1016\/j.ijrmms.2005.04.007","volume":"43","author":"S Kahraman","year":"2006","unstructured":"Kahraman S, Altun H, Tezekici BS, Fener M (2006) Sawability prediction of carbonate rocks from shear strength parameters using artificial neural networks. Int J Rock Mech Min Sci 43(1):157\u2013164","journal-title":"Int J Rock Mech Min Sci"},{"issue":"5","key":"3141_CR29","first-page":"727","volume":"20","author":"G Javad","year":"2010","unstructured":"Javad G, Narges T (2010) Application of artificial neural networks to the prediction of tunnel boring machine penetration rate. Min Sci Technol 20(5):727\u2013733","journal-title":"Min Sci Technol"},{"key":"3141_CR30","doi-asserted-by":"publisher","first-page":"481","DOI":"10.1016\/j.tust.2007.07.002","volume":"23","author":"J Ovidio","year":"2008","unstructured":"Ovidio J, Santos JR, Tarcisio BC (2008) Artificial neural networks analysis of Sao Paulo subway tunnel settlement data. Tunn Undergr Space Technol 23:481\u2013491","journal-title":"Tunn Undergr Space Technol"},{"issue":"05","key":"3141_CR31","doi-asserted-by":"publisher","first-page":"389","DOI":"10.1061\/(ASCE)1090-0241(1998)124:5(389)","volume":"124","author":"J Shi","year":"1998","unstructured":"Shi J, Ortigao JAR, Bai JJ (1998) Modular neural networks for predicting settlements during tunneling. J Getech Geoenviron Eng 124(05):389\u2013395","journal-title":"J Getech Geoenviron Eng"},{"key":"3141_CR32","unstructured":"Suwansawat S (2002) Earth pressure balance (EPB) shield tunneling in Bangkok: ground response and prediction of surface settlements using artificial neural networks. Ph.D. thesis, Massachusetts Institute of Technology, Cambridge, MA"},{"issue":"2","key":"3141_CR33","doi-asserted-by":"publisher","first-page":"133","DOI":"10.1016\/j.tust.2005.06.007","volume":"21","author":"S Suwansawat","year":"2006","unstructured":"Suwansawat S, Einstein HH (2006) Artificial neural networks for predicting the maximum surface settlement caused by EPB shield tunneling. Tunn Undergr Space Technol 21(2):133\u2013150","journal-title":"Tunn Undergr Space Technol"},{"key":"3141_CR34","unstructured":"Nellessen P (2007) Using neurofuzzy systems to predict settlements for slurry shield drives based on an evaluation of the process data synchronous to the advance. In: EURO: TUN thematic conference on computational methods in tunnelling, Vienna, Austria"},{"issue":"3","key":"3141_CR35","doi-asserted-by":"publisher","first-page":"1263","DOI":"10.1007\/s12665-012-2214-x","volume":"70","author":"I Ocak","year":"2013","unstructured":"Ocak I, Seker SE (2013) Calculation of surface settlements caused by EPBM tunneling using artificial neural network, SVM, and Gaussian processes. Environ Earth Sci 70(3):1263\u20131276","journal-title":"Environ Earth Sci"},{"issue":"5","key":"3141_CR36","doi-asserted-by":"publisher","first-page":"1246","DOI":"10.1007\/s12665-011-0940-0","volume":"64","author":"J Xu","year":"2011","unstructured":"Xu J, Xu Y (2011) Grey correlation-hierarchical analysis for metro-caused settlement. Environ Earth Sci 64(5):1246\u20131256","journal-title":"Environ Earth Sci"},{"key":"3141_CR37","doi-asserted-by":"publisher","first-page":"573","DOI":"10.1016\/j.jrmge.2015.06.008","volume":"7","author":"A Ebrahimabadi","year":"2015","unstructured":"Ebrahimabadi A, Azimipour M, Bahreini A (2015) Prediction of roadheaders\u2019 performance using artificial neural network approaches (MLP and KOSFM). J Rock Mech Geotech Eng 7:573\u2013583","journal-title":"J Rock Mech Geotech Eng"},{"key":"3141_CR38","doi-asserted-by":"publisher","first-page":"1823","DOI":"10.1007\/s00521-013-1434-7","volume":"24","author":"A Salsani","year":"2014","unstructured":"Salsani A, Daneshian J, Shariati S, Chamzini AY, Taheri M (2014) Predicting roadheader performance by using artificial neural network. Neural Comput Appl 24:1823\u20131831","journal-title":"Neural Comput Appl"},{"key":"3141_CR39","unstructured":"Shahriar K (1988) Investigation of effects of rocks excavability and geotechnical properties on roadheaders\u2019 excavation rate, ITU Institute of Science and Technology Ph.D. thesis, 241 pages"},{"key":"3141_CR40","unstructured":"Bilgin N, Yaz\u0131c\u0131 S, Eskikaya \u015e (1996) A model to predict the performance of roadheaders and impact hammers in tunnel drivages. In: Proceeding of \u201cEurock\u201996 ISRM international symposium, Torino, Balkema"},{"key":"3141_CR41","unstructured":"Westfalia Becorit Industrietechnik GmbH (1993) L\u00fcttich E5\/E9 Project"},{"key":"3141_CR42","unstructured":"Fowell RJ, Richardson G, Gollick MJ (1994) Prediction of boom tunnelling machine excavation rates. In: Proceedings of the 1st North American rock mechanics symposium, Balkema, pp 243\u2013250"},{"key":"3141_CR43","unstructured":"Dunn PG, Howarth DF, Schmidt SPJ, Bryan IJ (1997) A review of non-explosive excavation projects for the Australian metalliferous mining industry, pp 1\u201313"},{"key":"3141_CR44","first-page":"183","volume":"26","author":"H Schneider","year":"1998","unstructured":"Schneider H (1998) Criteria for selecting a boom-type roadheader. Min Mag 26:183\u2013188","journal-title":"Min Mag"},{"key":"3141_CR45","unstructured":"Bauer R (2002) Hard rock roadheaders. In: Colorado school of mines short course notes (unpublished)"},{"key":"3141_CR46","unstructured":"Tumac D (2014) The investigation into Roadheader performance prediction in Ku\u00e7uksu sewage tunnel, ITU Institute of Science and Technology M.Sc. thesis"},{"key":"3141_CR47","unstructured":"Keles S (2005) Cutting performance assessment of a medium weight roadheader at Cayirhan coal mine, masters\u2019 thesis of the graduate school of natural and applied sciences of middle east technical university"},{"key":"3141_CR48","unstructured":"Ocak I, Eyigun Y, Cinar M, Nahya T (2007) Investigation into roadheader excavation performance and pick consumption used in Kadkoy-Kartal metro tunnels. In: Proceedings of the 2nd symposium on underground excavations for transportation, Istanbul, pp 199\u2013206 (in Turkish)"},{"key":"3141_CR49","doi-asserted-by":"publisher","first-page":"38","DOI":"10.1016\/j.tust.2013.09.009","volume":"40","author":"R Comakli","year":"2014","unstructured":"Comakli R, Kahraman S, Balci C (2014) Performance prediction of roadheaders in metallic ore excavation. Tunn Undergr Space Technol 40:38\u201345","journal-title":"Tunn Undergr Space Technol"},{"key":"3141_CR50","isbn-type":"print","doi-asserted-by":"publisher","DOI":"10.1002\/9781118350270","volume-title":"Practical tunnel construction","author":"GB Hemphill","year":"2012","unstructured":"Hemphill GB (2012) Practical tunnel construction. Wiley, Hoboken. ISBN: 978-1-118-33000-5","ISBN":"https:\/\/id.crossref.org\/isbn\/9781118330005"},{"key":"3141_CR51","volume-title":"Rock characterization testing and monitoring, suggested methods","author":"ISRM","year":"1981","unstructured":"ISRM (1981) Rock characterization testing and monitoring, suggested methods. Pergamon Press, Oxford"},{"key":"3141_CR52","first-page":"17","volume":"1","author":"DU Deere","year":"1964","unstructured":"Deere DU (1964) Technical description of rock cores for engineering purposes. Rock Mech Eng Geol 1:17\u201322","journal-title":"Rock Mech Eng Geol"},{"issue":"5","key":"3141_CR53","first-page":"1188","volume":"11","author":"SS Keerthi","year":"1999","unstructured":"Keerthi SS, Bhattacharyya C, Murthy KRK, Shevade SK (1999) Improvements to the SMO algorithm for SVM regression. IEEE Trans Neural Netw 11(5):1188\u20131193","journal-title":"IEEE Trans Neural Netw"},{"issue":"1","key":"3141_CR54","doi-asserted-by":"publisher","first-page":"5","DOI":"10.1023\/A:1010933404324","volume":"45","author":"L Breiman","year":"2001","unstructured":"Breiman L (2001) Random forests. Mach Learn 45(1):5\u201332","journal-title":"Mach Learn"},{"issue":"1","key":"3141_CR55","first-page":"49","volume":"24","author":"L Breiman","year":"1996","unstructured":"Breiman L (1996) Stacked regressions. Mach Learn 24(1):49\u201384","journal-title":"Mach Learn"},{"issue":"2","key":"3141_CR56","first-page":"123","volume":"24","author":"L Breiman","year":"1996","unstructured":"Breiman L (1996) Bagging predictors. Mach Learn 24(2):123\u2013140","journal-title":"Mach Learn"},{"key":"3141_CR57","unstructured":"Ho TK (1995) Random decision forests. In: Proceedings of the 3rd international conference on document analysis and recognition, pp 278\u2013282"},{"issue":"7","key":"3141_CR58","doi-asserted-by":"publisher","first-page":"1545","DOI":"10.1162\/neco.1997.9.7.1545","volume":"9","author":"Y Amit","year":"1997","unstructured":"Amit Y, Geman D (1997) Shape quantization and recognition with randomized trees. Neural Comput 9(7):1545\u20131588","journal-title":"Neural Comput"},{"issue":"3","key":"3141_CR59","doi-asserted-by":"publisher","first-page":"322","DOI":"10.1016\/j.rse.2005.05.008","volume":"97","author":"M Xu","year":"2005","unstructured":"Xu M, Watanachaturaporn P, Varshney PK, Arora MK (2005) Decision tree regression for soft classification of remote sensing data. Remote Sens Environ 97(3):322\u2013336","journal-title":"Remote Sens Environ"},{"key":"3141_CR60","volume-title":"Ensemble methods: foundations and algorithms","author":"Z Zhi-Hua","year":"2012","unstructured":"Zhi-Hua Z (2012) Ensemble methods: foundations and algorithms. Chapman and Hall\/CRC, Boca Raton"},{"key":"3141_CR61","doi-asserted-by":"publisher","first-page":"29","DOI":"10.1016\/j.chemolab.2005.09.003","volume":"81","author":"B Uestuen","year":"2006","unstructured":"Uestuen B, Melssen W, Buydens L (2006) Facilitating the application of support vector regression by using a universal Pearson VII function based kernel. Chemometr Intell Lab Syst 81:29\u201340","journal-title":"Chemometr Intell Lab Syst"},{"issue":"1","key":"3141_CR62","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1023\/A:1007421302149","volume":"32","author":"E Frank","year":"1998","unstructured":"Frank E, Wang Y, Inglis S, Holmes G, Witten IH (1998) Using model trees for classification. Mach Learn 32(1):63\u201376","journal-title":"Mach Learn"}],"container-title":["Neural Computing and Applications"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/link.springer.com\/content\/pdf\/10.1007\/s00521-017-3141-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/link.springer.com\/article\/10.1007\/s00521-017-3141-2\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/link.springer.com\/content\/pdf\/10.1007\/s00521-017-3141-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,12,20]],"date-time":"2019-12-20T13:06:36Z","timestamp":1576847196000},"score":1,"resource":{"primary":{"URL":"http:\/\/link.springer.com\/10.1007\/s00521-017-3141-2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,7,11]]},"references-count":62,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2019,4]]}},"alternative-id":["3141"],"URL":"https:\/\/doi.org\/10.1007\/s00521-017-3141-2","relation":{},"ISSN":["0941-0643","1433-3058"],"issn-type":[{"value":"0941-0643","type":"print"},{"value":"1433-3058","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,7,11]]},"assertion":[{"value":"30 June 2016","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"27 June 2017","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"11 July 2017","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Compliance with ethical standards"}},{"value":"The authors declare that they have no conflict of interest.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Conflict of interest"}}]}}