PEMBELAJARAN BERTINGKAT PADA ARSITEKTUR JARINGAN SARAF FUNGSI RADIAL BASIS

Jaringan saraf tiruan (JST) adalah jaringan yang cara kerjanya meniru jaringan saraf manusia ditandai dengan sebuah set masukan dan sebuah set keluaran. Proses pembelajaran dalam jaringan akan mengekstraksi informasi dari berbagai macam input yang diberikan. Diantara masukan dan keluaran terdapat layer untuk memproses input yang dinamakan unit tersembunyi (hidden layer). Salah satu model JST adalah jaringan saraf fungsi radial basis (Radial Basis Function Neural Network = RBFNN) yaitu model jaringan saraf dengan satu unit dalam lapisan tersembunyi. Jumlah layer tunggal pada hidden layermenyebabkan permasalahan pembelajaran di RBFNN dapat dianggap sebagai suatu sistem linear. Pada RBFNN fungsi aktivasi yang digunakan adalah fungsi basis (Gaussian) dengan fungsi linear di lapisan output. Dikarenakan RBFNN adalah sistem linear sehingga teknik Orthogonal Least Squares (OLS) yang menerapkan konsep basis orthogonal dengan pendekatan terdekat ke solusi sebenarnya dapat menjadi salah satu algoritma pembelajaran pada RBFNN. Makalah ini membahas pembelajaran bertingkat sebagai cara optimasi pembelajaran pada RBFNN yang menggabungkan teknik linear yaitu Regularized Orthogonal Least Sqaures (ROLS) dan non linear yaitu algoritma genetik. Hasil ujicoba menunjukkan untuk semua data dengan persentase pembelajaran dan parameter algoritma genetik yang berbeda-beda mempunyai akurasi yang bervariasi pula. Akan tetapi rata-rata hasil ujicoba menghasilkan akurasi diatas 90% dan bahkan untuk beberapa percobaan akurasi bisa mencapai 100%.Kata kunci : jaringan saraf fungsi radial basis, optimasi pembelajaran, regularized orthogonal least sqaures,algoritma geneti

Adaptation of the Wound Healing Questionnaire universal-reporter outcome measure for use in global surgery trials (TALON-1 study): mixed-methods study and Rasch analysis

BackgroundThe Bluebelle Wound Healing Questionnaire (WHQ) is a universal-reporter outcome measure developed in the UK for remote detection of surgical-site infection after abdominal surgery. This study aimed to explore cross-cultural equivalence, acceptability, and content validity of the WHQ for use across low- and middle-income countries, and to make recommendations for its adaptation.MethodsThis was a mixed-methods study within a trial (SWAT) embedded in an international randomized trial, conducted according to best practice guidelines, and co-produced with community and patient partners (TALON-1). Structured interviews and focus groups were used to gather data regarding cross-cultural, cross-contextual equivalence of the individual items and scale, and conduct a translatability assessment. Translation was completed into five languages in accordance with Mapi recommendations. Next, data from a prospective cohort (SWAT) were interpreted using Rasch analysis to explore scaling and measurement properties of the WHQ. Finally, qualitative and quantitative data were triangulated using a modified, exploratory, instrumental design model.ResultsIn the qualitative phase, 10 structured interviews and six focus groups took place with a total of 47 investigators across six countries. Themes related to comprehension, response mapping, retrieval, and judgement were identified with rich cross-cultural insights. In the quantitative phase, an exploratory Rasch model was fitted to data from 537 patients (369 excluding extremes). Owing to the number of extreme (floor) values, the overall level of power was low. The single WHQ scale satisfied tests of unidimensionality, indicating validity of the ordinal total WHQ score. There was significant overall model misfit of five items (5, 9, 14, 15, 16) and local dependency in 11 item pairs. The person separation index was estimated as 0.48 suggesting weak discrimination between classes, whereas Cronbach's α was high at 0.86. Triangulation of qualitative data with the Rasch analysis supported recommendations for cross-cultural adaptation of the WHQ items 1 (redness), 3 (clear fluid), 7 (deep wound opening), 10 (pain), 11 (fever), 15 (antibiotics), 16 (debridement), 18 (drainage), and 19 (reoperation). Changes to three item response categories (1, not at all; 2, a little; 3, a lot) were adopted for symptom items 1 to 10, and two categories (0, no; 1, yes) for item 11 (fever).ConclusionThis study made recommendations for cross-cultural adaptation of the WHQ for use in global surgical research and practice, using co-produced mixed-methods data from three continents. Translations are now available for implementation into remote wound assessment pathways