Judul: Prediksi Awal Musim Hujan di Wilayah Waingapu Menggunakan Jaringan Syaraf Tiruan Backpropagation
Abstrak: Curah hujan merupakan faktor utama dari iklim. Kondisi iklim yang tidak menentu dapat menjadi penyebab kegagalan dalam bertani. Hal ini, membuat para petani sulit dalam memprediksi waktu yang pas untuk bercocok tanam. Oleh karena itu, diperlukan berbagai informasi hasil prediksi iklim sehingga lebih bermanfaat dalam bidang pertanian. Salah satunya adalah dengan memprediksi awal musim hujan (AMH) untuk menekan risiko gagal panen. Penelitian ini bertujuan menentukan awal musim hujan berdasarkan data curah hujan harian di wilayah Waingapu berdasarkan teori Liebmann, menentukan korelasi dalam penentuan prediktor JST antara awal musim hujan dengan peubah indeks iklim global, dan menerapkan metode jaringan syaraf tiruan (JST) untuk memprediksi awal musim hujan. Data indeks iklim global yang digunakan adalah data Southern Oscillation Index (SOI) dan SST Nino 3. Hasil perhitungan menggunakan teori Liebmann AMH terjadi antara bulan September sampai Desember. Prediktor yang digunakan adalah bulan Juli, Agustus dari data SOI dan bulan Juli, Agustus dari data SST Nino 3.4. Hasil penelitian prediksi ini memperoleh model terbaik dengan nilai 𝑅������2 sebesar 0.69 dan nilai RMSE sebesar 25.39.
Keyword: awal musim hujan, jaringan syaraf tiruan, SOI, SST Nino 3.4

Judul: Pemodelan Jaringan Syaraf Tiruan untuk Memprediksi Awal Musim Hujan Berdasarkan Suhu Muka Laut
Abstrak: Anjatan-Indramayu is the one of agriculture regions in Indonesia. The success or failure of the harvest each year depends on water availability in the region. Therefore we need an accurate method to predict the beginning of rainy season. The method used to predict in this research is artificial neural network (ANN) backpropagation. Result of ANN prediction accuracy is measured by R2 and RMSE. This research uses ECHAM4p5_CA sea surface temperature (SST) is one of the sea surface temperature models with the months of June, July and August. The domain of SST is selected based on the correlation of 5% and 10% for each of the month June, July, and August. This research uses ANN architecture with two parameters: neuron hidden (NH) and learning rate (LR). The number of hidden neurons used in this research are 5, 10, 20, and 40, and the learning rates are 0.3, 0.1, and 0.01. The best prediction result correlation of 5% using the ANN is for June with R2 is 51% and RMSE 3.03 at NH 10 and LR 0.01, July with R2 is 48% and RMSE 3.39 at NH 20 and LR 0.1, and August with R2 is 75% and RMSE 2.51 at NH 40 and LR 0.01. The best prediction result correlation of 10% using the ANN is for June with R2 is 44% and RMSE 3.32 at NH 5 and LR 0.3, July with R2 is 42% and RMSE 3.42 at NH 10 and LR 0.1, and August with R2 is 71% and RMSE 3.37 at NH 20 and LR 0.01. The conclusion from this research is the neuron hidden and learning rate with different values affect R2 and RMSE.
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Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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