O ( v , w ) = ∑ δ = − h v  + 1  h w  − 1   N δ  D δ  ( v , w )         ( 53 )   MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaieqacqWFpbWtcqGGOaakcqWG2bGDcqGGSaalcqWG3bWDcqGGPaqkcqGH9aqpdaaeWbqaaiabd6eaonaaBaaaleaaiiGacqGF0oazaeqaaOGaemiraq0aaSbaaSqaaiab+r7aKbqabaGccqGGOaakcqWG2bGDcqGGSaalcqWG3bWDcqGGPaqkaSqaaiab+r7aKjabg2da9iabgkHiTiabdIgaOnaaBaaameaacqWG2bGDaeqaaSGaey4kaSIaeGymaedabaGaemiAaG2aaSbaaWqaaiabdEha3bqabaWccqGHsislcqaIXaqma0GaeyyeIuoakiaaxMaacaWLjaGaeiikaGIaeGynauJaeG4mamJaeiykaKcaaa@5444@