Deep learning architectures for the analysis and classification of brain tumors in MR images

The need to make timely and accurate diagnoses of brain diseases has posed challenges to computer-aided diagnosis systems. In this field, advances in deep learning techniques play an important role, as they carry out processes to extract relevant anatomical and functional characteristics of the tiss...

Full description

Autores:
Osorio-Barone, A.
Contreras Ortiz, Sonia Helena
Tipo de recurso:
Fecha de publicación:
2020
Institución:
Universidad Tecnológica de Bolívar
Repositorio:
Repositorio Institucional UTB
Idioma:
eng
OAI Identifier:
oai:repositorio.utb.edu.co:20.500.12585/9955
Acceso en línea:
https://hdl.handle.net/20.500.12585/9955
https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11583/115830B/Deep-learning-architectures-for-the-analysis-and-classification-of-brain/10.1117/12.2579618.short?SSO=1
Palabra clave:
Bioinformatics
Brain
Computer aided diagnosis
Convolutional neural networks
Image classification
Image enhancement
Learning systems
Magnetic resonance
Magnetic resonance imaging
Network architecture
Transfer learning
Tumors
LEMB
Rights
closedAccess
License
http://purl.org/coar/access_right/c_14cb
id UTB2_096684e6e2e43e8a9efaa5068ebfec7f
oai_identifier_str oai:repositorio.utb.edu.co:20.500.12585/9955
network_acronym_str UTB2
network_name_str Repositorio Institucional UTB
repository_id_str
dc.title.spa.fl_str_mv Deep learning architectures for the analysis and classification of brain tumors in MR images
title Deep learning architectures for the analysis and classification of brain tumors in MR images
spellingShingle Deep learning architectures for the analysis and classification of brain tumors in MR images
Bioinformatics
Brain
Computer aided diagnosis
Convolutional neural networks
Image classification
Image enhancement
Learning systems
Magnetic resonance
Magnetic resonance imaging
Network architecture
Transfer learning
Tumors
LEMB
title_short Deep learning architectures for the analysis and classification of brain tumors in MR images
title_full Deep learning architectures for the analysis and classification of brain tumors in MR images
title_fullStr Deep learning architectures for the analysis and classification of brain tumors in MR images
title_full_unstemmed Deep learning architectures for the analysis and classification of brain tumors in MR images
title_sort Deep learning architectures for the analysis and classification of brain tumors in MR images
dc.creator.fl_str_mv Osorio-Barone, A.
Contreras Ortiz, Sonia Helena
dc.contributor.author.none.fl_str_mv Osorio-Barone, A.
Contreras Ortiz, Sonia Helena
dc.subject.keywords.spa.fl_str_mv Bioinformatics
Brain
Computer aided diagnosis
Convolutional neural networks
Image classification
Image enhancement
Learning systems
Magnetic resonance
Magnetic resonance imaging
Network architecture
Transfer learning
Tumors
topic Bioinformatics
Brain
Computer aided diagnosis
Convolutional neural networks
Image classification
Image enhancement
Learning systems
Magnetic resonance
Magnetic resonance imaging
Network architecture
Transfer learning
Tumors
LEMB
dc.subject.armarc.none.fl_str_mv LEMB
description The need to make timely and accurate diagnoses of brain diseases has posed challenges to computer-aided diagnosis systems. In this field, advances in deep learning techniques play an important role, as they carry out processes to extract relevant anatomical and functional characteristics of the tissues to classify them. In this paper, the study of various architectures of convolutional neural networks (CNN) is presented, with the aim of classifying three types of brain tumors in high-contrast magnetic resonance (MR) images. The architectures of the present study were VGG16, ResNet50, Xception, whose implementations are defined in the Keras framework. The evaluation of these architectures were preceded by data augmentation techniques and transfer learning, which improved the effectiveness of the training process, thanks to the use of pre-trained models with the ImageNet dataset. The VGG16 architecture was the one with the best performance, with an accuracy of 98.04%, followed by ResNet50 with 94.89%, and finally, Xception with 92.18%.
publishDate 2020
dc.date.issued.none.fl_str_mv 2020-11-03
dc.date.accessioned.none.fl_str_mv 2021-02-08T16:37:43Z
dc.date.available.none.fl_str_mv 2021-02-08T16:37:43Z
dc.date.submitted.none.fl_str_mv 2021-02-08
dc.type.coarversion.fl_str_mv http://purl.org/coar/version/c_970fb48d4fbd8a85
dc.type.driver.spa.fl_str_mv info:eu-repo/semantics/lecture
dc.type.hasversion.spa.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.spa.spa.fl_str_mv http://purl.org/coar/resource_type/c_8544
status_str publishedVersion
dc.identifier.citation.spa.fl_str_mv A. Osorio-Barone and S. H. Contreras-Ortiz "Deep learning architectures for the analysis and classification of brain tumors in MR images", Proc. SPIE 11583, 16th International Symposium on Medical Information Processing and Analysis, 115830B (3 November 2020); https://doi.org/10.1117/12.2579618
dc.identifier.uri.none.fl_str_mv https://hdl.handle.net/20.500.12585/9955
dc.identifier.url.none.fl_str_mv https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11583/115830B/Deep-learning-architectures-for-the-analysis-and-classification-of-brain/10.1117/12.2579618.short?SSO=1
dc.identifier.doi.none.fl_str_mv 10.1117/12.2579618
dc.identifier.instname.spa.fl_str_mv Universidad Tecnológica de Bolívar
dc.identifier.reponame.spa.fl_str_mv Repositorio Universidad Tecnológica de Bolívar
identifier_str_mv A. Osorio-Barone and S. H. Contreras-Ortiz "Deep learning architectures for the analysis and classification of brain tumors in MR images", Proc. SPIE 11583, 16th International Symposium on Medical Information Processing and Analysis, 115830B (3 November 2020); https://doi.org/10.1117/12.2579618
10.1117/12.2579618
Universidad Tecnológica de Bolívar
Repositorio Universidad Tecnológica de Bolívar
url https://hdl.handle.net/20.500.12585/9955
https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11583/115830B/Deep-learning-architectures-for-the-analysis-and-classification-of-brain/10.1117/12.2579618.short?SSO=1
dc.language.iso.spa.fl_str_mv eng
language eng
dc.rights.coar.fl_str_mv http://purl.org/coar/access_right/c_14cb
dc.rights.accessrights.spa.fl_str_mv info:eu-repo/semantics/closedAccess
eu_rights_str_mv closedAccess
rights_invalid_str_mv http://purl.org/coar/access_right/c_14cb
dc.format.mimetype.spa.fl_str_mv application/pdf
dc.publisher.place.spa.fl_str_mv Cartagena de Indias
dc.source.spa.fl_str_mv Proceedings Volume 11583, 16th International Symposium on Medical Information Processing and Analysis; 115830B (2020)
institution Universidad Tecnológica de Bolívar
bitstream.url.fl_str_mv https://repositorio.utb.edu.co/bitstream/20.500.12585/9955/2/license.txt
https://repositorio.utb.edu.co/bitstream/20.500.12585/9955/1/123.pdf
https://repositorio.utb.edu.co/bitstream/20.500.12585/9955/3/123.pdf.txt
https://repositorio.utb.edu.co/bitstream/20.500.12585/9955/4/123.pdf.jpg
bitstream.checksum.fl_str_mv e20ad307a1c5f3f25af9304a7a7c86b6
b345a48d565b0cd2d23d56700a322fd8
5489dd7b9335f8e0d85b5ee7e28a9c09
bc6160faadc0ddfc012b69057ef67461
bitstream.checksumAlgorithm.fl_str_mv MD5
MD5
MD5
MD5
repository.name.fl_str_mv Repositorio Institucional UTB
repository.mail.fl_str_mv repositorioutb@utb.edu.co
_version_ 1808397596986703872
spelling Osorio-Barone, A.9dc91c41-f76a-4994-838c-fa39f38e1beeContreras Ortiz, Sonia Helena690f7c84-d6e0-464a-b059-47146b2f92f52021-02-08T16:37:43Z2021-02-08T16:37:43Z2020-11-032021-02-08A. Osorio-Barone and S. H. Contreras-Ortiz "Deep learning architectures for the analysis and classification of brain tumors in MR images", Proc. SPIE 11583, 16th International Symposium on Medical Information Processing and Analysis, 115830B (3 November 2020); https://doi.org/10.1117/12.2579618https://hdl.handle.net/20.500.12585/9955https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11583/115830B/Deep-learning-architectures-for-the-analysis-and-classification-of-brain/10.1117/12.2579618.short?SSO=110.1117/12.2579618Universidad Tecnológica de BolívarRepositorio Universidad Tecnológica de BolívarThe need to make timely and accurate diagnoses of brain diseases has posed challenges to computer-aided diagnosis systems. In this field, advances in deep learning techniques play an important role, as they carry out processes to extract relevant anatomical and functional characteristics of the tissues to classify them. In this paper, the study of various architectures of convolutional neural networks (CNN) is presented, with the aim of classifying three types of brain tumors in high-contrast magnetic resonance (MR) images. The architectures of the present study were VGG16, ResNet50, Xception, whose implementations are defined in the Keras framework. The evaluation of these architectures were preceded by data augmentation techniques and transfer learning, which improved the effectiveness of the training process, thanks to the use of pre-trained models with the ImageNet dataset. The VGG16 architecture was the one with the best performance, with an accuracy of 98.04%, followed by ResNet50 with 94.89%, and finally, Xception with 92.18%.application/pdfengProceedings Volume 11583, 16th International Symposium on Medical Information Processing and Analysis; 115830B (2020)Deep learning architectures for the analysis and classification of brain tumors in MR imagesinfo:eu-repo/semantics/lectureinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_8544http://purl.org/coar/version/c_970fb48d4fbd8a85BioinformaticsBrainComputer aided diagnosisConvolutional neural networksImage classificationImage enhancementLearning systemsMagnetic resonanceMagnetic resonance imagingNetwork architectureTransfer learningTumorsLEMBinfo:eu-repo/semantics/closedAccesshttp://purl.org/coar/access_right/c_14cbCartagena de IndiasPúblico generalWorld Health Organization—Cancer. Cited 2169 times. Accessed: 2020-07-14 https://www.who.int/health-topics/cancer#tab=tab_1Gladson, C.L., Prayson, R.A., Liu, W.M. The pathobiology of glioma tumors (Open Access) (2010) Annual Review of Pathology: Mechanisms of Disease, 5, pp. 33-50. Cited 142 times. doi: 10.1146/annurev-pathol-121808-102109Shimon, I., Melmed, S. Pituitary Tumor Pathogenesis (1997) Journal of Clinical Endocrinology and Metabolism, 82 (6), pp. 1675-1681. Cited 145 times. http://jcem.endojournals.org doi: 10.1210/jc.82.6.1675Afshar, P., Plataniotis, K.N., Mohammadi, A. Capsule Networks for Brain Tumor Classification Based on MRI Images and Coarse Tumor Boundaries (2019) ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings, 2019-May, art. no. 8683759, pp. 1368-1372. Cited 38 times. ISBN: 978-147998131-1 doi: 10.1109/ICASSP.2019.8683759Cheng, J., Huang, W., Cao, S., Yang, R., Yang, W., Yun, Z., Wang, Z., (...), Feng, Q. Enhanced performance of brain tumor classification via tumor region augmentation and partition (Open Access) (2015) PLoS ONE, 10 (10), art. no. e0140381. Cited 119 times. http://www.plosone.org/article/fetchObject.action?uri=info:doi/10.1371/journal.pone.0140381&representation=PDF doi: 10.1371/journal.pone.0140381Rehman, A., Naz, S., Razzak, M.I., Akram, F., Imran, M. A Deep Learning-Based Framework for Automatic Brain Tumors Classification Using Transfer Learning (2020) Circuits, Systems, and Signal Processing, 39 (2), pp. 757-775. Cited 26 times. http://www.springer.com/sgw/cda/frontpage/0,11855,5-40109-70-1176077-0,00.html doi: 10.1007/s00034-019-01246-3Saxena, P., Maheshwari, A., Maheshwari, S. (2019) Predictive Modeling of Brain Tumor: A Deep Learning Approach. Cited 3 times. arXiv preprintDong, H., Yang, G., Liu, F., Mo, Y., Guo, Y. Automatic brain tumor detection and segmentation using U-net based fully convolutional networks (Open Access) (2017) Communications in Computer and Information Science, 723, pp. 506-517. Cited 207 times. http://www.springer.com/series/7899 ISBN: 978-331960963-8 doi: 10.1007/978-3-319-60964-5_44Simonyan, K., Zisserman, A. (2014) Very Deep Convolutional Networks for Large-Scale Image Recognition. Cited 20079 times. arXiv preprintChollet, F. Xception: Deep learning with depthwise separable convolutions (Open Access) (2017) Proceedings - 30th IEEE Conference on Computer Vision and Pattern Recognition, CVPR 2017, 2017-January, pp. 1800-1807. Cited 1791 times. ISBN: 978-153860457-1 doi: 10.1109/CVPR.2017.195He, K., Zhang, X., Ren, S., Sun, J. Deep residual learning for image recognition (Open Access) (2016) Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 2016-December, art. no. 7780459, pp. 770-778. Cited 37128 times. ISBN: 978-146738850-4 doi: 10.1109/CVPR.2016.90http://purl.org/coar/resource_type/c_c94fLICENSElicense.txtlicense.txttext/plain; charset=utf-83182https://repositorio.utb.edu.co/bitstream/20.500.12585/9955/2/license.txte20ad307a1c5f3f25af9304a7a7c86b6MD52ORIGINAL123.pdf123.pdfAbstractapplication/pdf66472https://repositorio.utb.edu.co/bitstream/20.500.12585/9955/1/123.pdfb345a48d565b0cd2d23d56700a322fd8MD51TEXT123.pdf.txt123.pdf.txtExtracted texttext/plain1171https://repositorio.utb.edu.co/bitstream/20.500.12585/9955/3/123.pdf.txt5489dd7b9335f8e0d85b5ee7e28a9c09MD53THUMBNAIL123.pdf.jpg123.pdf.jpgGenerated Thumbnailimage/jpeg51945https://repositorio.utb.edu.co/bitstream/20.500.12585/9955/4/123.pdf.jpgbc6160faadc0ddfc012b69057ef67461MD5420.500.12585/9955oai:repositorio.utb.edu.co:20.500.12585/99552023-05-25 15:48:03.736Repositorio Institucional UTBrepositorioutb@utb.edu.coQXV0b3Jpem8gKGF1dG9yaXphbW9zKSBhIGxhIEJpYmxpb3RlY2EgZGUgbGEgSW5zdGl0dWNpw7NuIHBhcmEgcXVlIGluY2x1eWEgdW5hIGNvcGlhLCBpbmRleGUgeSBkaXZ1bGd1ZSBlbiBlbCBSZXBvc2l0b3JpbyBJbnN0aXR1Y2lvbmFsLCBsYSBvYnJhIG1lbmNpb25hZGEgY29uIGVsIGZpbiBkZSBmYWNpbGl0YXIgbG9zIHByb2Nlc29zIGRlIHZpc2liaWxpZGFkIGUgaW1wYWN0byBkZSBsYSBtaXNtYSwgY29uZm9ybWUgYSBsb3MgZGVyZWNob3MgcGF0cmltb25pYWxlcyBxdWUgbWUobm9zKSBjb3JyZXNwb25kZShuKSB5IHF1ZSBpbmNsdXllbjogbGEgcmVwcm9kdWNjacOzbiwgY29tdW5pY2FjacOzbiBww7pibGljYSwgZGlzdHJpYnVjacOzbiBhbCBww7pibGljbywgdHJhbnNmb3JtYWNpw7NuLCBkZSBjb25mb3JtaWRhZCBjb24gbGEgbm9ybWF0aXZpZGFkIHZpZ2VudGUgc29icmUgZGVyZWNob3MgZGUgYXV0b3IgeSBkZXJlY2hvcyBjb25leG9zIHJlZmVyaWRvcyBlbiBhcnQuIDIsIDEyLCAzMCAobW9kaWZpY2FkbyBwb3IgZWwgYXJ0IDUgZGUgbGEgbGV5IDE1MjAvMjAxMiksIHkgNzIgZGUgbGEgbGV5IDIzIGRlIGRlIDE5ODIsIExleSA0NCBkZSAxOTkzLCBhcnQuIDQgeSAxMSBEZWNpc2nDs24gQW5kaW5hIDM1MSBkZSAxOTkzIGFydC4gMTEsIERlY3JldG8gNDYwIGRlIDE5OTUsIENpcmN1bGFyIE5vIDA2LzIwMDIgZGUgbGEgRGlyZWNjacOzbiBOYWNpb25hbCBkZSBEZXJlY2hvcyBkZSBhdXRvciwgYXJ0LiAxNSBMZXkgMTUyMCBkZSAyMDEyLCBsYSBMZXkgMTkxNSBkZSAyMDE4IHkgZGVtw6FzIG5vcm1hcyBzb2JyZSBsYSBtYXRlcmlhLgoKQWwgcmVzcGVjdG8gY29tbyBBdXRvcihlcykgbWFuaWZlc3RhbW9zIGNvbm9jZXIgcXVlOgoKLSBMYSBhdXRvcml6YWNpw7NuIGVzIGRlIGNhcsOhY3RlciBubyBleGNsdXNpdmEgeSBsaW1pdGFkYSwgZXN0byBpbXBsaWNhIHF1ZSBsYSBsaWNlbmNpYSB0aWVuZSB1bmEgdmlnZW5jaWEsIHF1ZSBubyBlcyBwZXJwZXR1YSB5IHF1ZSBlbCBhdXRvciBwdWVkZSBwdWJsaWNhciBvIGRpZnVuZGlyIHN1IG9icmEgZW4gY3VhbHF1aWVyIG90cm8gbWVkaW8sIGFzw60gY29tbyBsbGV2YXIgYSBjYWJvIGN1YWxxdWllciB0aXBvIGRlIGFjY2nDs24gc29icmUgZWwgZG9jdW1lbnRvLgoKLSBMYSBhdXRvcml6YWNpw7NuIHRlbmRyw6EgdW5hIHZpZ2VuY2lhIGRlIGNpbmNvIGHDsW9zIGEgcGFydGlyIGRlbCBtb21lbnRvIGRlIGxhIGluY2x1c2nDs24gZGUgbGEgb2JyYSBlbiBlbCByZXBvc2l0b3JpbywgcHJvcnJvZ2FibGUgaW5kZWZpbmlkYW1lbnRlIHBvciBlbCB0aWVtcG8gZGUgZHVyYWNpw7NuIGRlIGxvcyBkZXJlY2hvcyBwYXRyaW1vbmlhbGVzIGRlbCBhdXRvciB5IHBvZHLDoSBkYXJzZSBwb3IgdGVybWluYWRhIHVuYSB2ZXogZWwgYXV0b3IgbG8gbWFuaWZpZXN0ZSBwb3IgZXNjcml0byBhIGxhIGluc3RpdHVjacOzbiwgY29uIGxhIHNhbHZlZGFkIGRlIHF1ZSBsYSBvYnJhIGVzIGRpZnVuZGlkYSBnbG9iYWxtZW50ZSB5IGNvc2VjaGFkYSBwb3IgZGlmZXJlbnRlcyBidXNjYWRvcmVzIHkvbyByZXBvc2l0b3Jpb3MgZW4gSW50ZXJuZXQgbG8gcXVlIG5vIGdhcmFudGl6YSBxdWUgbGEgb2JyYSBwdWVkYSBzZXIgcmV0aXJhZGEgZGUgbWFuZXJhIGlubWVkaWF0YSBkZSBvdHJvcyBzaXN0ZW1hcyBkZSBpbmZvcm1hY2nDs24gZW4gbG9zIHF1ZSBzZSBoYXlhIGluZGV4YWRvLCBkaWZlcmVudGVzIGFsIHJlcG9zaXRvcmlvIGluc3RpdHVjaW9uYWwgZGUgbGEgSW5zdGl0dWNpw7NuLCBkZSBtYW5lcmEgcXVlIGVsIGF1dG9yKHJlcykgdGVuZHLDoW4gcXVlIHNvbGljaXRhciBsYSByZXRpcmFkYSBkZSBzdSBvYnJhIGRpcmVjdGFtZW50ZSBhIG90cm9zIHNpc3RlbWFzIGRlIGluZm9ybWFjacOzbiBkaXN0aW50b3MgYWwgZGUgbGEgSW5zdGl0dWNpw7NuIHNpIGRlc2VhIHF1ZSBzdSBvYnJhIHNlYSByZXRpcmFkYSBkZSBpbm1lZGlhdG8uCgotIExhIGF1dG9yaXphY2nDs24gZGUgcHVibGljYWNpw7NuIGNvbXByZW5kZSBlbCBmb3JtYXRvIG9yaWdpbmFsIGRlIGxhIG9icmEgeSB0b2RvcyBsb3MgZGVtw6FzIHF1ZSBzZSByZXF1aWVyYSBwYXJhIHN1IHB1YmxpY2FjacOzbiBlbiBlbCByZXBvc2l0b3Jpby4gSWd1YWxtZW50ZSwgbGEgYXV0b3JpemFjacOzbiBwZXJtaXRlIGEgbGEgaW5zdGl0dWNpw7NuIGVsIGNhbWJpbyBkZSBzb3BvcnRlIGRlIGxhIG9icmEgY29uIGZpbmVzIGRlIHByZXNlcnZhY2nDs24gKGltcHJlc28sIGVsZWN0csOzbmljbywgZGlnaXRhbCwgSW50ZXJuZXQsIGludHJhbmV0LCBvIGN1YWxxdWllciBvdHJvIGZvcm1hdG8gY29ub2NpZG8gbyBwb3IgY29ub2NlcikuCgotIExhIGF1dG9yaXphY2nDs24gZXMgZ3JhdHVpdGEgeSBzZSByZW51bmNpYSBhIHJlY2liaXIgY3VhbHF1aWVyIHJlbXVuZXJhY2nDs24gcG9yIGxvcyB1c29zIGRlIGxhIG9icmEsIGRlIGFjdWVyZG8gY29uIGxhIGxpY2VuY2lhIGVzdGFibGVjaWRhIGVuIGVzdGEgYXV0b3JpemFjacOzbi4KCi0gQWwgZmlybWFyIGVzdGEgYXV0b3JpemFjacOzbiwgc2UgbWFuaWZpZXN0YSBxdWUgbGEgb2JyYSBlcyBvcmlnaW5hbCB5IG5vIGV4aXN0ZSBlbiBlbGxhIG5pbmd1bmEgdmlvbGFjacOzbiBhIGxvcyBkZXJlY2hvcyBkZSBhdXRvciBkZSB0ZXJjZXJvcy4gRW4gY2FzbyBkZSBxdWUgZWwgdHJhYmFqbyBoYXlhIHNpZG8gZmluYW5jaWFkbyBwb3IgdGVyY2Vyb3MgZWwgbyBsb3MgYXV0b3JlcyBhc3VtZW4gbGEgcmVzcG9uc2FiaWxpZGFkIGRlbCBjdW1wbGltaWVudG8gZGUgbG9zIGFjdWVyZG9zIGVzdGFibGVjaWRvcyBzb2JyZSBsb3MgZGVyZWNob3MgcGF0cmltb25pYWxlcyBkZSBsYSBvYnJhIGNvbiBkaWNobyB0ZXJjZXJvLgoKLSBGcmVudGUgYSBjdWFscXVpZXIgcmVjbGFtYWNpw7NuIHBvciB0ZXJjZXJvcywgZWwgbyBsb3MgYXV0b3JlcyBzZXLDoW4gcmVzcG9uc2FibGVzLCBlbiBuaW5nw7puIGNhc28gbGEgcmVzcG9uc2FiaWxpZGFkIHNlcsOhIGFzdW1pZGEgcG9yIGxhIGluc3RpdHVjacOzbi4KCi0gQ29uIGxhIGF1dG9yaXphY2nDs24sIGxhIGluc3RpdHVjacOzbiBwdWVkZSBkaWZ1bmRpciBsYSBvYnJhIGVuIMOtbmRpY2VzLCBidXNjYWRvcmVzIHkgb3Ryb3Mgc2lzdGVtYXMgZGUgaW5mb3JtYWNpw7NuIHF1ZSBmYXZvcmV6Y2FuIHN1IHZpc2liaWxpZGFkCgo=