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Table 1 Table of Notations

From: An explainable CNN approach for medical codes prediction from clinical text

Notation

Description

\({\mathcal {L}}\)

The set of ICD-9 codes

\(y_{i,\ell }\in \ {0,\ 1}\)

The true value of the label task for instance i and \(\ell \in {\mathcal {L}}\), 1 indicates the label is true for instance i

\(d_e\)

The size of the input embedding

\(d_c\)

The size of the convolution output, a.k.a. the number of convolution filters

\({\mathbf {X}}=[{\mathbf {x}}_1,{\mathbf {x}}_2,\ldots ,{\mathbf {x}}_N]\)

The matrix of a document instance, where \({\mathbf {N}}\) is the length of the document and \({\mathbf {x}}_i\) is the vector representation of the word

\({\mathbf {W}}_c\in {\mathbb {R}}^{k\times d_e\times d_c}\)

Convolution filters, where k is the width of filter window

\({\mathbf {H}}\in {\mathbb {R}}^{d_c\times N}\)

Convolutional representation of the document

\(*\)

Convolution operator

g

An element-wise nonlinear transformation

\({\mathbf {b}}_c\in {\mathbb {R}}^{d_c}\)

The bias in convolutional operation

\({\mathbf {u}}_\ell \in {\mathbb {R}}^{d_c}\)

Attention parameter vector for label \(\ell\)

\(\varvec{\alpha }_\ell \in {\mathbb {R}}^N\)

Attention result vector for label \(\ell\)

\(b_\ell\)

Scalar offset in linear layer for label \(\ell\)

\(\varvec{\beta }_\ell \in {\mathbb {R}}^{d_c}\)

Vector of prediction weights

\(\sigma\)

Sigmoid function

\({\text { SoftMax }}()\)

\({\text{SoftMax}}({\mathbf{x}}) = \frac{{\exp ({\mathbf{x}})}}{{\sum\nolimits_{i} {\exp (x_{i} )} }}\), where \({\text{exp }}({\mathbf {x}})\) is the element-wise exponentiation of the vector \({\mathbf {x}}\)