Judul: Aplikasi  Algoritma Pohon Keputusan Pembelajar Mesin (Decision Tree of Machine  Learning) dalam Deteksi Agroforestri Kakao: Studi Kasus Kecamatan Baebunta  dan Baebunta Selatan, Luwu Utara
Abstrak: Tulisan ini menjelaskan tentang pembangunan algoritma pohon keputusan dari pembelajar mesin menggunakan data penginderaan jauh dan data geospasial untuk mengidentifikasi tanaman kakao agroforestri dan kakao monokultur. Tujuan dari penelitian ini adalah untuk menentukan peubah, atribut, dan parameter dalam mengidentifikasi agroforestri kakao dan kakao monokultur menggunakan citra SPOT 7 dengan fitur indeks vegetasi dan parameter geo-sosio-biofisik menggunakan mesin pembelajaran pohon keputusan. Penelitian ini menemukan bahwa peubah yang paling berpengaruh adalah NDVI dan elevasi. Penelitian ini juga menemukan bahwa parameter yang paling berpengaruh adalah Information Gain dengan kombinasi tanpa pemangkasan (pruning), tanpa pra-pangkas (pre pruning), kedalaman pohon 51, pra-pangkas alternatif (pre-pruning alternative) 21, ukuran daun 21, dan jenis sampel yang digunakan adalah Random Sampling. Kajian ini menghasilkan nilai Overall Accuracy (OA) sebesar 93,56% dan Kappa Accuracy (KA) sebesar 92,9%. ATHALLAH SYAFIQ PADANTYA. Application of the Decision Tree of Machine Learning Algorithm in the Detection of Cocoa Agroforestry: a Case Study of Baebunta and South Baebunta Districts, North Luwu. Supervised by I NENGAH SURATI JAYA. This paper describes the development of a decision tree of machine learning algorithm using remote sensing data and geospatial data to identify agroforestry and monoculture cocoa plants. The purpose of this research is to determine variables, attributes, and parameters in identifying cocoa agroforestry and cocoa monoculture using SPOT 7 with vegetation index features and geo-socio-biophysical parameters using machine learning decision tree. This study found that the most influential variables were NDVI and elevation. This study also found that the most influential parameter was Information Gain with a combination of no pruning, no pre-pruning, tree depth of 51, pre-pruning alternative of 21, leaf size of 21, and the type of sample which is random sampling. This study resulted an Overall Accuracy (OA) value of 93,56% and a Kappa Accuracy (KA) value of 92,9%.
Keyword: indeks vegetasi, geo-sosio-biofisik, pohon keputusan, mesin pembelajar

Judul: Developing a Decision Tree Algorithm for Cocoa Agroforestry  Detection in Three Typologies: Case Studies in Masamba District
Abstrak: Tulisan ini menerangkan tentang pembangunan algoritma klasifikasi machine learning pohon keputusan dalam mengidektifikasi agroforestri kakao dan kakao monokultur pada tiga tipologi menggunakan data penginderaan jauh dan data geospasial. Tujuan dari penelitian ini adalah untuk menemukan peubah (atribut) serta parameter algoritma pohon keputusan dalam mendeteksi kakao khususnya agroforestri berbasis citra resolusi tinggi SPOT 6/7. Kajian ini menguji peubah sosio-biogeofisik dan peubah spektral yang diturunkan dari citra SPOT SPOT 6/7. Penelitian ini menemukan bahwa peubah paling berpengaruh adalah NDVI untuk tipologi 1 dan 2, serta elevasi untuk tipologi 3. Penelitian ini juga menemukan bahwa kriteria dari algoritma pohon keputusan terbaik adalah information gain untuk tipologi 1 dan 2, serta gini index untuk tipologi 3. Kombinasi tersebut menghasilkan kappa accuracy (KA) sebesar 97,30%, 98,80%, dan 99,21% untuk tiap tipologi., This paper describes the development of a decision tree machine learning classification algorithm to identify cocoa agroforestry and cocoa monocultures in three typologies using remote sensing data and geospatial data. The objective of this study was to find variables (attributes) and parameters of the decision tree algorithm in detecting cocoa, especially agroforestry, based on SPOT 6/7 high resolution imagery. This study examines the socio-biogeophysical variables and spectral variables derived from SPOT SPOT 6/7 images. This study found that the most influential variables were NDVI for typology 1 and 2, and elevation for typology 3. This study also found that the best decision tree algorithm criteria were information gain for typology 1 and 2 and gini index for typology 3. The combination produces Kappa Accuracy (KA) of 97,30%, 98,80% and 99,21% for each typology. This study concludes that the vegetation index variable is more reliable in identifying built-up land cover classes than socio-biogeophysical variables.
Keyword: pohon keputusan, mesin pembelajar, indeks vegetasi, sosio-biogeofisik, decision tree, machine learning, vegetation index, socio-biogeophysics

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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