{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T03:55:21Z","timestamp":1775793321236,"version":"3.50.1"},"reference-count":63,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2018,8,21]],"date-time":"2018-08-21T00:00:00Z","timestamp":1534809600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key Research and Development Project","award":["2016YFC0502501"],"award-info":[{"award-number":["2016YFC0502501"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41771465"],"award-info":[{"award-number":["41771465"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Karst rocky desertification (KRD) has become the primary ecoenvironmental problem in the karst regions of southwest China. The rapid and efficient acquisition of exposed bedrock fractions (EBF) is crucial for the monitoring and assessment of KRD degree and distribution within the highly heterogeneous landscapes. Remote-sensing indices provide a useful method for the quick mapping of the EBF at large scales. The currently available rock indices, however, are faced with insensitivity to bedrock change characteristics, which greatly limits their performances and suitability. To address this problem, we proposed a novel karst bare-rock index (KBRI) that applies shortwave-infrared (SWIR) and near-infrared (NIR) bands from Landsat-8 OLI imagery to maximally distinguish between exposed bedrock and other land cover types in southwest China. A linear regression model was thus established between KBRI and the EBF derived from in situ measurements. The model developed here was then validated with an independent experiment and applied over a large geographic area to produce regional maps of EBF in southwest China. Experimental results showed good performance on root mean square error (5.59%), mean absolute error (4.63%), root mean absolute percentage error (13.59%), and coefficient of determination (0.72), respectively. The advantages of the proposed method are reflected in its simplicity and minimal requirements for auxiliary data while still achieving comparatively better accuracy than existing related indices. Thus, the KBRI has the great potential for the application in other regions around the world with the similar geological backgrounds, thereby helping to address the similar or other related environmental issues. Results of this study provide baseline data for the KRD assessment and karst-ecosystem management in southwest China.<\/jats:p>","DOI":"10.3390\/rs10091321","type":"journal-article","created":{"date-parts":[[2018,8,21]],"date-time":"2018-08-21T11:12:42Z","timestamp":1534849962000},"page":"1321","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":40,"title":["Analysis of Landsat-8 OLI Imagery for Estimating Exposed Bedrock Fractions in Typical Karst Regions of Southwest China Using a Karst Bare-Rock Index"],"prefix":"10.3390","volume":"10","author":[{"given":"Jie","family":"Pei","sequence":"first","affiliation":[{"name":"The State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, P.O. Box 9718, Datun Road, Chaoyang, Beijing 100101, China"},{"name":"University of Chinese Academy of Sciences, Yuquan Road 19, Shijingshan, Beijing 100049, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Li","family":"Wang","sequence":"additional","affiliation":[{"name":"The State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, P.O. Box 9718, Datun Road, Chaoyang, Beijing 100101, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ni","family":"Huang","sequence":"additional","affiliation":[{"name":"The State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, P.O. Box 9718, Datun Road, Chaoyang, Beijing 100101, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jing","family":"Geng","sequence":"additional","affiliation":[{"name":"University of Chinese Academy of Sciences, Yuquan Road 19, Shijingshan, Beijing 100049, China"},{"name":"Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jianhua","family":"Cao","sequence":"additional","affiliation":[{"name":"Key Laboratory of Karst Dynamics, Institute of Karst Geology, Chinese Academy of Geological Sciences, Qixing Road, Guilin 541004, China"},{"name":"International Research Center on Karst, UNESCO, Qixing Road, Guilin 541004, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5959-9351","authenticated-orcid":false,"given":"Zheng","family":"Niu","sequence":"additional","affiliation":[{"name":"The State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, P.O. Box 9718, Datun Road, Chaoyang, Beijing 100101, China"},{"name":"University of Chinese Academy of Sciences, Yuquan Road 19, Shijingshan, Beijing 100049, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,8,21]]},"reference":[{"key":"ref_1","first-page":"425","article-title":"Progress in the study on karst processes and carbon cycle","volume":"14","author":"Yuan","year":"1999","journal-title":"Adv. Earth Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1002\/ldr.592","article-title":"Karst rocky desertification in southwestern China: Geomorphology, landuse, impact and rehabilitation","volume":"15","author":"Wang","year":"2004","journal-title":"Land Degrad. Dev."},{"key":"ref_3","first-page":"81","article-title":"Rock desertification in the subtropical karst of south China","volume":"108","author":"Yuan","year":"1997","journal-title":"Z. Geomorphol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2115","DOI":"10.1080\/01431160903382892","article-title":"Spectral indices for estimating ecological indicators of karst rocky desertification","volume":"31","author":"Yue","year":"2010","journal-title":"Int. J. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.earscirev.2014.01.005","article-title":"Rocky desertification in southwest china: Impacts, causes, and restoration","volume":"132","author":"Jiang","year":"2014","journal-title":"Earth Sci. Rev."},{"key":"ref_6","first-page":"101","article-title":"Concept deduction and its connotation of karst rocky desertification","volume":"21","author":"Wang","year":"2002","journal-title":"Carsologica Sin."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"5136","DOI":"10.1080\/01431161.2013.787500","article-title":"Development of new remote sensing methods for mapping green vegetation and exposed bedrock fractions within heterogeneous landscapes","volume":"34","author":"Yue","year":"2013","journal-title":"Int. J. Remote Sens."},{"key":"ref_8","first-page":"86","article-title":"Estimating ecological indicators of karst rocky desertification by linear spectral unmixing method","volume":"31","author":"Zhang","year":"2014","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1002\/ldr.2193","article-title":"Object-based mapping of karst rocky desertification using a support vector machine","volume":"26","author":"Xu","year":"2015","journal-title":"Land Degrad. Dev."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/S0034-4257(97)00104-1","article-title":"On the relation between NDVI, fractional vegetation cover, and leaf area index","volume":"62","author":"Carlson","year":"1997","journal-title":"Remote Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"768","DOI":"10.3390\/s90200768","article-title":"Comparison between fractional vegetation cover retrievals from vegetation indices and spectral mixture analysis: Case study of PROBA\/CHRIS data over an agricultural area","volume":"9","author":"Sobrino","year":"2009","journal-title":"Sensors"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1698","DOI":"10.1016\/j.agrformet.2011.07.004","article-title":"A comparison of methods for estimating fractional vegetation cover in arid regions","volume":"151","author":"Jiapaer","year":"2011","journal-title":"Agric. For. Meteorol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1080\/2150704X.2015.1070315","article-title":"Mapping karst rocky desertification using landsat 8 images","volume":"6","author":"Li","year":"2015","journal-title":"Remote Sens. Lett."},{"key":"ref_14","first-page":"105","article-title":"Quantifying the effectiveness of ecological restoration projects on long-term vegetation dynamics in the karst regions of southwest China","volume":"54","author":"Tong","year":"2017","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_15","first-page":"573","article-title":"Problems and development trends about researches on karst rocky desertification","volume":"22","author":"Wang","year":"2007","journal-title":"Adv. Earth Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1560","DOI":"10.1126\/science.1082750","article-title":"Climate-driven increases in global terrestrial net primary production from 1982 to 1999","volume":"300","author":"Nemani","year":"2003","journal-title":"Science"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1659\/mrd.857","article-title":"Mapping karst rock in southwest China","volume":"29","author":"Huang","year":"2009","journal-title":"Mt. Res. Dev."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1988","DOI":"10.1109\/LGRS.2015.2441962","article-title":"Spectral indices for estimating exposed carbonate rock fraction in karst areas of southwest China","volume":"12","author":"Xie","year":"2015","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"450","DOI":"10.1177\/0309133317714246","article-title":"The application of geospatial techniques in monitoring karst vegetation recovery in southwest China: A review","volume":"41","author":"Zhang","year":"2017","journal-title":"Prog. Phys. Geogr."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1007\/s10661-017-5976-5","article-title":"Using principal component analysis and annual seasonal trend analysis to assess karst rocky desertification in southwestern China","volume":"189","author":"Zhang","year":"2017","journal-title":"Environ. Monit. Assess."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1268","DOI":"10.1109\/TGRS.2003.813209","article-title":"Land cover conversion and degradation analyses through coupled soil-plant biophysical parameters derived from hyperspectral EO-1 Hyperion","volume":"41","author":"Huete","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"939","DOI":"10.1016\/j.rse.2007.07.005","article-title":"Spectral mixture analysis for mapping abundance of urban surface components from the Terra\/ASTER data","volume":"112","author":"Pu","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_23","first-page":"38","article-title":"Stratified spectral mixture analysis of medium resolution imagery for impervious surface mapping","volume":"60","author":"Sun","year":"2017","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_24","first-page":"266","article-title":"Uncertainty of remotely sensed extraction of information of karst rocky desertification","volume":"26","author":"Yue","year":"2011","journal-title":"Adv. Earth Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"8098","DOI":"10.1029\/JB091iB08p08098","article-title":"Spectral mixture modeling: A new analysis of rock and soil types at the Viking Lander I site","volume":"91","author":"Adams","year":"1986","journal-title":"J. Geophys. Res.-Atmos."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1109\/79.974727","article-title":"Spectral unmixing","volume":"19","author":"Keshava","year":"2002","journal-title":"IEEE Signal Process. Mag."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1016\/0034-4257(94)90013-2","article-title":"How unique are spectral signatures?","volume":"49","author":"Price","year":"1994","journal-title":"Remote Sens. Environ."},{"key":"ref_28","unstructured":"Chang, C.I. (2003). Hyperspectral Imaging: Techniques for Spectral Detection and Classification, Plenum Publishing Co."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1062","DOI":"10.1109\/TGRS.2015.2473705","article-title":"Advancement of hyperspectral image processing and information extraction","volume":"20","author":"Zhang","year":"2016","journal-title":"J. Remote Sens."},{"key":"ref_30","first-page":"305","article-title":"Effective exploitation model of karst water in Xiaojiang basin, Luxi county, Yunnan","volume":"24","author":"Wang","year":"2005","journal-title":"Carsologica Sin."},{"key":"ref_31","first-page":"456","article-title":"Current status and treatment of rocky desertification in key eastern areas of the Nandong subterranean river system","volume":"33","author":"Qin","year":"2014","journal-title":"Carsologica Sin."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"881","DOI":"10.1007\/s12665-009-0083-8","article-title":"Relationships between rocky desertification and spatial pattern of land use in typical karst area, southwest China","volume":"59","author":"Jiang","year":"2009","journal-title":"Environ. Earth Sci."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Zhang, H.K., Roy, D.P., Yan, L., Li, Z., Huang, H., Vermote, E., Skakun, S., and Roger, J.C. (2018). Characterization of Sentinel-2a and Landsat-8 top of atmosphere, surface, and nadir brdf adjusted reflectance and NDVI differences. Remote Sens. Environ.","DOI":"10.1016\/j.rse.2018.04.031"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Tian, H., Wu, M., Wang, L., and Niu, Z. (2018). Mapping early, middle and late rice extent using Sentinel-1A and Landsat-8 data in the Poyang Lake Plain, China. Sensors, 18.","DOI":"10.3390\/s18010185"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"5077","DOI":"10.3390\/rs70505077","article-title":"Object-based flood mapping and affected rice field estimation with Landsat 8 OLI and MODIS data","volume":"7","author":"Dao","year":"2015","journal-title":"Remote Sens."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1247","DOI":"10.5194\/gmd-7-1247-2014","article-title":"Root mean square error (RMSE) or mean absolute error (MAE)?\u2014Arguments against avoiding RMSE in the literature","volume":"7","author":"Chai","year":"2014","journal-title":"Geosci. Model Dev."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/j.ocemod.2013.08.003","article-title":"Problems in RMSE-based wave model validations","volume":"72","author":"Mentaschi","year":"2013","journal-title":"Ocean Model."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1016\/j.neucom.2015.12.114","article-title":"Mean absolute percentage error for regression models","volume":"192","author":"Golden","year":"2016","journal-title":"Neurocomputing"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Tian, H., Li, W., Wu, M., Huang, N., Li, G., Li, X., and Niu, Z. (2017). Dynamic monitoring of the largest freshwater lake in China using a new water index derived from high spatiotemporal resolution Sentinel-1A data. Remote Sens., 9.","DOI":"10.3390\/rs9060521"},{"key":"ref_40","first-page":"112","article-title":"Restoration of missing information of mountain shadow on remote sensing images in peak cluster karst area based on kriging","volume":"32","author":"Yang","year":"2012","journal-title":"Remote Sens. Land Resour."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2957","DOI":"10.3390\/rs4102957","article-title":"Enhanced built-up and bareness index (EBBI) for mapping built-up and bare land in an urban area","volume":"4","author":"Assyakur","year":"2012","journal-title":"Remote Sens."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1080\/01431160304987","article-title":"Use of normalized difference built-up index in automatically mapping urban areas from TM imagery","volume":"24","author":"Zha","year":"2003","journal-title":"Int. J. Remote Sens."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"357","DOI":"10.3390\/rs8050357","article-title":"Assessing future vegetation trends and restoration prospects in the karst regions of southwest China","volume":"8","author":"Tong","year":"2016","journal-title":"Remote Sens."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1080\/02757259509532278","article-title":"Land degradation, soil erosion and desertification monitoring in mediterranean ecosystems","volume":"12","author":"Hill","year":"1995","journal-title":"Remote Sens. Rev."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"33540","DOI":"10.1117\/1.3216031","article-title":"Prediction and validation of foliage projective cover from Landsat-5 TM and Landsat-7 ETM+ imagery","volume":"3","author":"Armston","year":"2009","journal-title":"J. Appl. Remote Sens."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1007\/s10661-010-1772-1","article-title":"Detecting vegetation cover change on the summit of cadillac mountain using multi-temporal remote sensing datasets: 1979, 2001, and 2007","volume":"180","author":"Kim","year":"2011","journal-title":"Environ. Monit. Assess."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1002\/ldr.1102","article-title":"Assessing spatial-temporal evolution processes of karst rocky desertification land: Indications for restoration strategies","volume":"24","author":"Bai","year":"2013","journal-title":"Land Degrad. Dev."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1016\/0034-4257(88)90106-X","article-title":"A soil-adjusted vegetation index (SAVI)","volume":"25","author":"Huete","year":"1988","journal-title":"Remote Sens. Environ."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Li, H., Wang, C., Zhong, C., Su, A., Xiong, C., Wang, J., and Liu, J. (2017). Mapping urban bare land automatically from landsat imagery with a simple index. Remote Sens., 9.","DOI":"10.3390\/rs9030249"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1016\/j.rse.2003.12.013","article-title":"Hyperspectral vegetation indices and novel algorithms for predicting green lai of crop canopies: Modeling and validation in the context of precision agriculture","volume":"90","author":"Haboudane","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_51","first-page":"55","article-title":"Analysis of spectral absorption features in hyperspectral imagery","volume":"5","author":"Meer","year":"2004","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"3361","DOI":"10.1080\/014311697216928","article-title":"Weathering process effects on spectral reflectance of rocks in a semi-arid environment","volume":"18","author":"Younis","year":"1997","journal-title":"Int. J. Remote Sens."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"11105","DOI":"10.3390\/rs70911105","article-title":"Interannual variations in growing-season NDVI and its correlation with climate variables in the southwestern karst region of China","volume":"7","author":"Hou","year":"2015","journal-title":"Remote Sens."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"2817","DOI":"10.1080\/01431160110076162","article-title":"A method for the segmentation of very high spatial resolution images of forested landscapes","volume":"23","author":"Pekkarinen","year":"2002","journal-title":"Int. J. Remote Sens."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1016\/j.scitotenv.2013.04.048","article-title":"Mining spatial information to investigate the evolution of karst rocky desertification and its human driving forces in Changshun, China","volume":"458\u2013460","author":"Xu","year":"2013","journal-title":"Sci. Total Environ."},{"key":"ref_56","first-page":"123","article-title":"Evolution characteristics of karst rocky desertification in Guangxi based on MODIS NDVI","volume":"22","author":"Jing","year":"2015","journal-title":"Res. Soil Water Conserv."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"631","DOI":"10.1007\/s12665-013-2460-6","article-title":"Comparative studies of the distribution characteristics of rocky desertification and land use\/land cover classes in typical areas of Guizhou province, China","volume":"71","author":"Ying","year":"2014","journal-title":"Environ. Earth Sci."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/j.ecoleng.2013.01.002","article-title":"Effectiveness of ecological restoration projects in a karst region of southwest China assessed using vegetation succession mapping","volume":"54","author":"Qi","year":"2013","journal-title":"Ecol. Eng."},{"key":"ref_59","doi-asserted-by":"crossref","unstructured":"Padarian, J., Minasny, B., and Mcbratney, A.B. (2015). Using Google\u2019s Cloud-Based Platform for Digital Soil Mapping, Pergamon Press, Inc.","DOI":"10.1016\/j.cageo.2015.06.023"},{"key":"ref_60","unstructured":"Lillesand, T.M., Kiefer, R.W., and Chipman, J.W. (2004). Remote Sensing and Image Interpretation, Wiley. [5th ed.]."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"823","DOI":"10.1080\/01431160600746456","article-title":"A survey of image classification methods and techniques for improving classification performance","volume":"28","author":"Lu","year":"2007","journal-title":"Int. J. Remote Sens."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1080\/10106040701337410","article-title":"Mapping dominant vegetation communities at meili snow mountain, Yunnan province, China using satellite imagery and plant community data","volume":"23","author":"Zhang","year":"2008","journal-title":"Geocarto Int."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1111\/j.1749-8198.2008.00200.x","article-title":"Remote sensing of mountain environments","volume":"3","author":"Weiss","year":"2009","journal-title":"Geogr. Compass"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/9\/1321\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:19:53Z","timestamp":1760195993000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/9\/1321"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,8,21]]},"references-count":63,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2018,9]]}},"alternative-id":["rs10091321"],"URL":"https:\/\/doi.org\/10.3390\/rs10091321","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,8,21]]}}}