<p>We address the problem of reconstructing a set of <i>K</i> binary patterns <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\varvec{\Xi }= (\varvec{\xi }^1,..., \varvec{\xi }^K) \in \{-1, +1 \}^{N \times K}\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mrow> <mi mathvariant="bold">Ξ</mi> </mrow> <mo>=</mo> <mrow> <mo stretchy="false">(</mo> <msup> <mrow> <mi mathvariant="bold-italic">ξ</mi> </mrow> <mn>1</mn> </msup> <mo>,</mo> <mo>.</mo> <mo>.</mo> <mo>.</mo> <mo>,</mo> <msup> <mrow> <mi mathvariant="bold-italic">ξ</mi> </mrow> <mi>K</mi> </msup> <mo stretchy="false">)</mo> </mrow> <mo>∈</mo> <msup> <mrow> <mo stretchy="false">{</mo> <mo>-</mo> <mn>1</mn> <mo>,</mo> <mo>+</mo> <mn>1</mn> <mo stretchy="false">}</mo> </mrow> <mrow> <mi>N</mi> <mo>×</mo> <mi>K</mi> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>, starting from their covariance matrix <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\varvec{\Xi }\varvec{\Xi }^T\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mrow> <mi mathvariant="bold">Ξ</mi> </mrow> <msup> <mrow> <mi mathvariant="bold">Ξ</mi> </mrow> <mi>T</mi> </msup> </mrow> </math></EquationSource> </InlineEquation> and from a set of mixtures of the form <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\varvec{\sigma }_M= \text {sign}(\sum _{\mu \in \mathcal {S}_M \subseteq \{1,..., K\}} \varvec{\xi }^{\mu })\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mrow> <mi mathvariant="bold-italic">σ</mi> </mrow> <mi>M</mi> </msub> <mo>=</mo> <mtext>sign</mtext> <mrow> <mo stretchy="false">(</mo> <msub> <mo>∑</mo> <mrow> <mi>μ</mi> <mo>∈</mo> <msub> <mi mathvariant="script">S</mi> <mi>M</mi> </msub> <mo>⊆</mo> <mrow> <mo stretchy="false">{</mo> <mn>1</mn> <mo>,</mo> <mo>.</mo> <mo>.</mo> <mo>.</mo> <mo>,</mo> <mi>K</mi> <mo stretchy="false">}</mo> </mrow> </mrow> </msub> <msup> <mrow> <mi mathvariant="bold-italic">ξ</mi> </mrow> <mi>μ</mi> </msup> <mo stretchy="false">)</mo> </mrow> </mrow> </math></EquationSource> </InlineEquation>, with <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\left\lvert S_M\right\rvert =M\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mfenced close="|" open="|"> <msub> <mi>S</mi> <mi>M</mi> </msub> </mfenced> <mo>=</mo> <mi>M</mi> </mrow> </math></EquationSource> </InlineEquation>. To this aim, we engage a modular Hebbian network, specified by the interaction matrix <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\varvec{J}^H = \frac{1}{N}\varvec{\Xi }\varvec{\Xi }^T\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msup> <mrow> <mi mathvariant="bold-italic">J</mi> </mrow> <mi>H</mi> </msup> <mo>=</mo> <mfrac> <mn>1</mn> <mi>N</mi> </mfrac> <mrow> <mi mathvariant="bold">Ξ</mi> </mrow> <msup> <mrow> <mi mathvariant="bold">Ξ</mi> </mrow> <mi>T</mi> </msup> </mrow> </math></EquationSource> </InlineEquation>, where <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\({\varvec{\sigma }_M}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mrow> <mi mathvariant="bold-italic">σ</mi> </mrow> <mi>M</mi> </msub> </math></EquationSource> </InlineEquation> is taken as the initial state, repeated in each of the constituting <i>L</i> modules and the stable state resulting from a Gibbs evolution rule is taken as an <i>L</i>-tuple of candidate patterns. Finally, by properly handling <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(\varvec{J}^H\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mrow> <mi mathvariant="bold-italic">J</mi> </mrow> <mi>H</mi> </msup> </math></EquationSource> </InlineEquation> we can derive the projector matrix <InlineEquation ID="IEq8"> <EquationSource Format="TEX">\(\varvec{J}^K = \varvec{\Xi }(\varvec{\Xi }^T \varvec{\Xi })^{-1} \varvec{\Xi }^T\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msup> <mrow> <mi mathvariant="bold-italic">J</mi> </mrow> <mi>K</mi> </msup> <mo>=</mo> <mrow> <mi mathvariant="bold">Ξ</mi> </mrow> <msup> <mrow> <mo stretchy="false">(</mo> <msup> <mrow> <mi mathvariant="bold">Ξ</mi> </mrow> <mi>T</mi> </msup> <mrow> <mi mathvariant="bold">Ξ</mi> </mrow> <mo stretchy="false">)</mo> </mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> <msup> <mrow> <mi mathvariant="bold">Ξ</mi> </mrow> <mi>T</mi> </msup> </mrow> </math></EquationSource> </InlineEquation> by which we can determine whether these candidate patterns are a good estimate for the ground patterns.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Pattern disentanglement and reconstruction by modular Hebbian networks

  • Elena Agliari,
  • Shahed Akter,
  • Andrea Alessandrelli,
  • Alberto Fachechi

摘要

We address the problem of reconstructing a set of K binary patterns \(\varvec{\Xi }= (\varvec{\xi }^1,..., \varvec{\xi }^K) \in \{-1, +1 \}^{N \times K}\) Ξ = ( ξ 1 , . . . , ξ K ) { - 1 , + 1 } N × K , starting from their covariance matrix \(\varvec{\Xi }\varvec{\Xi }^T\) Ξ Ξ T and from a set of mixtures of the form \(\varvec{\sigma }_M= \text {sign}(\sum _{\mu \in \mathcal {S}_M \subseteq \{1,..., K\}} \varvec{\xi }^{\mu })\) σ M = sign ( μ S M { 1 , . . . , K } ξ μ ) , with \(\left\lvert S_M\right\rvert =M\) S M = M . To this aim, we engage a modular Hebbian network, specified by the interaction matrix \(\varvec{J}^H = \frac{1}{N}\varvec{\Xi }\varvec{\Xi }^T\) J H = 1 N Ξ Ξ T , where \({\varvec{\sigma }_M}\) σ M is taken as the initial state, repeated in each of the constituting L modules and the stable state resulting from a Gibbs evolution rule is taken as an L-tuple of candidate patterns. Finally, by properly handling \(\varvec{J}^H\) J H we can derive the projector matrix \(\varvec{J}^K = \varvec{\Xi }(\varvec{\Xi }^T \varvec{\Xi })^{-1} \varvec{\Xi }^T\) J K = Ξ ( Ξ T Ξ ) - 1 Ξ T by which we can determine whether these candidate patterns are a good estimate for the ground patterns.