Judul: Penerapan Pohon Klasifikasi Dan Bootstrap Aggregating Dalam Klasifikasi Usia Menarche (Studi Kasus: Smpn Ragunan Dan Smpn 1 Dramaga).
Abstrak: Menarche adalah menstruasi pertama bagi remaja putri. Menarche cepat merupakan salah satu penyebab wanita terkena kanker payudara sedangkan menarche terlambat merupakan salah satu penyebab osteoporosis. Penelitian ini bertujuan menentukan faktor-faktor yang memengaruhi usia menarche remaja putri di SMPN Ragunan dan SMPN 1 Dramaga. Peubah respons yang digunakan yaitu kategori usia menarche (cepat, ideal, dan lambat). Metode analisis yang digunakan adalah Classification and Regression Trees (CART) dan bootsrap aggregating (bagging). CART menghasilkan pohon klasifikasi tunggal sedangkan bagging menghasilkan pohon agregat untuk meningkatkan akurasi pendugaan pohon klasifikasi tunggal. Peubah-peubah penting yang memengaruhi usia menarche pada pohon klasifikasi tunggal secara berurutan adalah jenis sekolah, asupan protein, asupan kalsium, dan asupan lemak. Sementara itu, pada pohon agregat urutannya adalah jenis sekolah, asupan kalsium, asupan protein, dan asupan lemak. Pohon agregat dengan berbagai versi replikasi memberikan ketepatan klasifikasi yang lebih baik dibandingkan pohon klasifikasi tunggal. Selain itu, hasil validasi silang lipat 5 menunjukkan bahwa ketepatan klasifikasi pohon agregat dengan 100 replikasi lebih baik dibandingkan dengan pohon klasifikasi tunggal. Pada penelitian ini, bagging mampu meningkatkan ketepatan klasifikasi pohon tunggal dari 60.00% menjadi 62.50%.
Keyword: bootstrap aggregating (bagging), Classification and Regression Trees (CART), menarche, validasi silang

Judul: Penerapan Metode CART dan Agregat Bootstrap dalam Klasifikasi Status Gizi Balita Di Kecamatan Taman Sari, Kabupaten Bogor.
Abstrak: Nutrition problem is a multidimensional problem that affect health and productivity of Indonesian society. The number of short nutritional status (stunting) and high malnutrition is a serious health problem because it picturizes life for the next 100 years. About 90% of the short children problems in the world occur in 36 countries, and the rank of Indonesia is number five. The purpose of this study is to determine the factors that affect the nutritional status of children and evaluate the stability of classification trees with bootstrap aggregating method.The research is conducted at Taman Sari subdistrict, Bogor with the number of samples 120 mothers who have toddlers. Statistical analysis used to analyze the factors that influence the nutritional status of children is the method of CART (Classification and Regression Tree). CART is a method of data exploration which uses decision tree technique. This study also applies bagging method (bootstrap aggrergating) to evaluate the stability of classification trees generated by CART. The results of the classification tree formed produces optimum tree with eight terminal nodes. Explanatory variables into the main node is the nutritional behavior. Level of accuracy for the CART method was 69.17%.The percentage of the classification on the delimitation of the best z using z-score -2.5 SD with level of accuracy 76.67% and 88.33%, and z-score -3 SDwith level of accuracy 73.33% and 79.17%. Bagging method has been able to evaluate the stability of classification trees by 79.28%.
Keyword: bootstrap aggregating, CART, the nutritional status of children

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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