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Assume that dataset has<jats:italic>M<\/jats:italic>labels. The first method creates<jats:italic>M<\/jats:italic>deep convolutional neural networks called<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\{\\text {DCNN}_i\\}_{i=1}^{M}$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msubsup><mml:mrow><mml:mo>{<\/mml:mo><mml:msub><mml:mtext>DCNN<\/mml:mtext><mml:mi>i<\/mml:mi><\/mml:msub><mml:mo>}<\/mml:mo><\/mml:mrow><mml:mrow><mml:mi>i<\/mml:mi><mml:mo>=<\/mml:mo><mml:mn>1<\/mml:mn><\/mml:mrow><mml:mi>M<\/mml:mi><\/mml:msubsup><\/mml:math><\/jats:alternatives><\/jats:inline-formula>. Each of the networks<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\text {DCNN}_i$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msub><mml:mtext>DCNN<\/mml:mtext><mml:mi>i<\/mml:mi><\/mml:msub><\/mml:math><\/jats:alternatives><\/jats:inline-formula>is composed of a convolutional neural network (<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\text {CNN}_i$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msub><mml:mtext>CNN<\/mml:mtext><mml:mi>i<\/mml:mi><\/mml:msub><\/mml:math><\/jats:alternatives><\/jats:inline-formula>) and a fully connected neural network (<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\text {FCNN}_i$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msub><mml:mtext>FCNN<\/mml:mtext><mml:mi>i<\/mml:mi><\/mml:msub><\/mml:math><\/jats:alternatives><\/jats:inline-formula>). In training, a set of projection matrices<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\{\\mathbf {P}_i\\}_{i=1}^M$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msubsup><mml:mrow><mml:mo>{<\/mml:mo><mml:msub><mml:mi>P<\/mml:mi><mml:mi>i<\/mml:mi><\/mml:msub><mml:mo>}<\/mml:mo><\/mml:mrow><mml:mrow><mml:mi>i<\/mml:mi><mml:mo>=<\/mml:mo><mml:mn>1<\/mml:mn><\/mml:mrow><mml:mi>M<\/mml:mi><\/mml:msubsup><\/mml:math><\/jats:alternatives><\/jats:inline-formula>are created and adaptively updated as representations for feature subspaces<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\{\\mathcal {S}_i\\}_{i=1}^M$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msubsup><mml:mrow><mml:mo>{<\/mml:mo><mml:msub><mml:mi>S<\/mml:mi><mml:mi>i<\/mml:mi><\/mml:msub><mml:mo>}<\/mml:mo><\/mml:mrow><mml:mrow><mml:mi>i<\/mml:mi><mml:mo>=<\/mml:mo><mml:mn>1<\/mml:mn><\/mml:mrow><mml:mi>M<\/mml:mi><\/mml:msubsup><\/mml:math><\/jats:alternatives><\/jats:inline-formula>. A rejection value is computed for each training based on its projections on feature subspaces. Each<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\text {FCNN}_i$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msub><mml:mtext>FCNN<\/mml:mtext><mml:mi>i<\/mml:mi><\/mml:msub><\/mml:math><\/jats:alternatives><\/jats:inline-formula>acts as a binary classifier with a cost function whose main parameter is rejection values. A threshold value<jats:inline-formula><jats:alternatives><jats:tex-math>$$t_i$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msub><mml:mi>t<\/mml:mi><mml:mi>i<\/mml:mi><\/mml:msub><\/mml:math><\/jats:alternatives><\/jats:inline-formula>is determined for<jats:inline-formula><jats:alternatives><jats:tex-math>$$i^{th}$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msup><mml:mi>i<\/mml:mi><mml:mrow><mml:mi>th<\/mml:mi><\/mml:mrow><\/mml:msup><\/mml:math><\/jats:alternatives><\/jats:inline-formula>network<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\text {DCNN}_i$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msub><mml:mtext>DCNN<\/mml:mtext><mml:mi>i<\/mml:mi><\/mml:msub><\/mml:math><\/jats:alternatives><\/jats:inline-formula>. A testing strategy utilizing<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\{t_i\\}_{i=1}^M$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msubsup><mml:mrow><mml:mo>{<\/mml:mo><mml:msub><mml:mi>t<\/mml:mi><mml:mi>i<\/mml:mi><\/mml:msub><mml:mo>}<\/mml:mo><\/mml:mrow><mml:mrow><mml:mi>i<\/mml:mi><mml:mo>=<\/mml:mo><mml:mn>1<\/mml:mn><\/mml:mrow><mml:mi>M<\/mml:mi><\/mml:msubsup><\/mml:math><\/jats:alternatives><\/jats:inline-formula>is also introduced. The second method creates a single DCNN and it computes a cost function whose parameters depend on subspace separations using the geodesic distance on the Grasmannian manifold of subspaces<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\mathcal {S}_i$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msub><mml:mi>S<\/mml:mi><mml:mi>i<\/mml:mi><\/mml:msub><\/mml:math><\/jats:alternatives><\/jats:inline-formula>and the sum of all remaining subspaces<jats:inline-formula><jats:alternatives><jats:tex-math>$$\\{\\mathcal {S}_j\\}_{j=1,j\\ne i}^M$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mml:msubsup><mml:mrow><mml:mo>{<\/mml:mo><mml:msub><mml:mi>S<\/mml:mi><mml:mi>j<\/mml:mi><\/mml:msub><mml:mo>}<\/mml:mo><\/mml:mrow><mml:mrow><mml:mi>j<\/mml:mi><mml:mo>=<\/mml:mo><mml:mn>1<\/mml:mn><mml:mo>,<\/mml:mo><mml:mi>j<\/mml:mi><mml:mo>\u2260<\/mml:mo><mml:mi>i<\/mml:mi><\/mml:mrow><mml:mi>M<\/mml:mi><\/mml:msubsup><\/mml:math><\/jats:alternatives><\/jats:inline-formula>. The proposed methods are tested using multiple network topologies. 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