Judul: Predicting the Number of Hotspots in Kalimantan Using Long Short Term Memory Model Based on Climate Indicators
Abstrak: Forest and land fires have become a concerning phenomenon in Indonesia. As mitigation, hotspots are used as an early stage to identify fires. In an effort to predict the number of hotspots, deep learning models such as Long Short-Term Memory (LSTM) can be used. The purpose of this research is to build the best LSTM model architecture to predict the number of hotspots in Kalimantan based on climate indicators. The model is trained using the glorot uniform method as a weight initiation method, Nadam optimizer with a learning rate of 0.001, and early stopping as model regularization on training data with a proportion of 80%. The results show that the best LSTM model in this research is a model with 2 LSTM layers and 4 dense layers trained to minimize the Root Mean Squared Error (RMSE) as a loss function. The model uses a window of size 12 and a hidden layer with 64 nodes. On testing data, the model is able to predict the number of hotspots with an explained variance score of 83.4%., Kebakaran hutan dan lahan sudah menjadi fenomena yang memprihatinkan di Indonesia. Sebagai mitigasi, titik panas (hotspot) digunakan sebagai tahap awal untuk mengidentifikasi kebakaran. Dalam upaya memprediksi jumlah hotspot, model deep learning seperti Long Short-Term Memory (LSTM) dapat digunakan. Tujuan penelitian ini adalah membangun arsitektur model LSTM terbaik untuk memprediksi jumlah hotspot di Kalimantan berdasarkan indikator iklim. Model dilatih menggunakan metode glorot uniform sebagai metode inisiasi bobot, optimizer Nadam dengan learning rate 0,001, dan early stopping sebagai regularisasi model pada data training dengan proporsi sebesar 80%. Hasil penelitian menunjukkan bahwa model LSTM yang terbaik pada penelitian ini adalah model dengan 2 layer LSTM dan 4 dense layer yang dilatih untuk meminimumkan Root Mean Squared Error (RMSE) sebagai loss function. Model tersebut menggunakan window berukuran 12 dan hidden layer dengan 64 node. Pada data testing, model mampu memprediksi jumlah hotspot dengan explained variance score sebesar 83,4%.
Keyword: hotspot, layer, LSTM, Weight, dense

Judul: Performance Comparison of Best Subset-Bayesian Model Averaging and Regularization Method in Predicting the Number of Hotspots in Kalimantan
Abstrak: Luas wilayah hutan di Kalimantan terus berkurang akibat terjadinya kebakaran hutan dan lahan (karhutla). Penelitian-penelitian sebelumnya menunjukkan bahwa pencegahan karhutla di Kalimantan dapat dilakukan dengan memprediksi jumlah hotspot menggunakan machine learning berdasarkan indikator iklim. Penelitian ini bertujuan untuk membangun model regresi regularisasi dan Bayesian Model Averaging (BMA) berbasis model regresi polinomial berdasarkan hasil best subset selection. Model terbaik pada penelitian ini dipilih berdasarkan metrik evaluasi RMSE dan R^2. Selain itu, pengaruh normalisasi dan standardisasi juga diukur terhadap model yang dibangun. Hasilnya diperoleh kombinasi enam variabel prediktor terbaik dan diperoleh model terbaik yaitu BMA yang merupakan gabungan dari enam model regresi polinomial. Selain itu, penerapan normalisasi dan standardisasi data mempengaruhi nilai parameter seluruh model, tetapi hanya sedikit mempengaruhi hasil pengujian model. Dengan demikian, model BMA dengan data asli lebih dipilih karena nilai koefisiennya lebih mendekati nol dengan performa yang tidak jauh berbeda., The area of forests in Kalimantan continues decreasing due to forest and land fires. Previous studies have shown that the prevention of forest and land fires in Kalimantan can be implemented by predicting the number of hotspots using machine learning based on climate indicators. This study aims to build regularized regression models and Bayesian Model Averaging (BMA) based on polynomial regression models based on best subset selection. The best model in this study is assessed by using the RMSE and R^2 evaluation metrics. In addition, the effect of normalization and standardization is also evaluated on the constructed models. The results shows that a combination of the six best predictor variables is the best and it also shows that the best model is BMA which is a combination of the six polynomial regression models. In addition, the application of data normalization and standardization affects the parameter values of all models, but slightly affects the model testing results. Therefore, the BMA model with original data is more preferable because its coefficients are much closer to zero with similar performance.
Keyword: Machine learning, hotspot, Bayesian Model Averaging, Regularisasi, Regresi Ridge, Regresi LASSO, Regresi Elastic Net

Judul: Synthesis of Apatite - Chitosan Composite Using Duck Eggshell and Chitosan with Temperature and pH Control
Abstrak: Composite of apatite-chitosan was prepared by using chitosan as polymer matrix. Calcium phosphate was prepared from CaO and (NH4)2HPO4, which the ratio Ca : P had to be 1.67. Chitosan is produced by deacetilase from biopolymer chitin. Duck eggshell (95% CaCO3) as starting material was converted to be calcium oxide (CaO) through calcinations with temperature 1000oC for 5 hours. In-situ and ex-situ methods were prepared from apatite and chitosan (dissolved with acetate acid 2%). Calcium phosphate prepared for bone implantation, but it is too fragile and brittle to be implant into the body. So addition of chitosan can decrease crystalinity and increase mechanic characteristic (tougher). Composite apatite-chitosan was resulted by fast precipitation. Fast precipitation was held in a breaker glass with nitrogen atmosphere, under controlled temperature at 37oC and pH 7, in order to increase amount of hydroxyapatite. Precipitation with CaO which was dropped by (NH4)2HPO4. Hydroxyapatite and chitosan were appearing at samples with in-situ and ex-situ methods which indicating by peak matching of XRD (closed lattice parameter, crystal size), overlapping at FTIR spectra and supporting by SEM picture (homogenous and agglomerated particle). However, it still needs further research to examine biocompatibility osteoconductive degree of sample by in-vivo and in-vitro test.
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