Judul: The Effect of Snacking, Physical Activity, and Nutrition Intake on The Occurrence of Student Obesity at SDN Pondokcina 1 Depok
Abstrak: Skripsi ini bertujuan menganalisis perbedaan dan pengaruh karakteristik subjek dan sosial ekonomi keluarga, kebiasaan snacking, pemilihan snack, aktivitas fisik, dan asupan zat gizi pada siswa SD antara status gizi obese dan normal. Penelitian ini menggunakan desain studi cross-sectional dengan jumlah subjek 60 anak. Data kebiasaan snacking diukur menggunakan kuesioner Semi Quantitative Food Frequency Questionnaire, pemilihan snack menggunakan Food Choices Questionnaire, aktivitas fisik dan asupan makanan menggunakan recall 2x24 jam. Hasil menunjukkan perbedaan signifikan (p<0,05) pada nilai tengah frekuensi snacking, jenis snack camilan, aktivitas fisik weekday, tingkat kecukupan zat gizi energi, protein, lemak, dan karbohidrat, serta nilai tengah asupan serat antara subjek normal dan obese. Tidak terdapat perbedaan signifikan (p>0,05) jenis snack minuman dan makanan sepinggan, kategori frekuensi snacking, faktor pemilihan snack, dan tingkat kecukupan serat. Faktor yang memengaruhi kejadian obesitas, yaitu tingkat kecukupan karbohidrat (OR=6,14). Tingkat kecukupan karbohidrat yang berlebih menyebabkan obesitas., The purpose of this thesis was to analyze the differences and effects between subject and family socioeconomic characteristics, snacking habits, snack selection, physical activity, and fiber intake in elementary school students on obese and normal nutritional status. This study used a cross-sectional study design with a total of 60 children. The data of snacking habits were measured using the Semi Quantitative Food Frequency Questionnaire, snack preferences using the Food Choices Questionnaire, physical activity and food intake using 2x24 hour recall. The results showed significant differences (p<0.05) in the median values of snacking frequency, types of snacks, weekday physical activity, nutrition adequacy levels of energy, protein, fat, and carbohydrates, as well as the median values of fiber intake between normal and obese subjects. There were no significant differences (p>0.05) in the types of beverage and one dish meal, snacking frequency categories, snack preference factors, and fiber adequacy levels. The factor that affected the occurrence of obesity was the level of carbohydrate adequacy (OR=6.14). Excessive carbohydrate adequacy level can cause obesity.
Keyword: obesity, physical activity, nutrition intake, snacking habits

Judul: Hubungan Sedentary Time, Kebiasaan Snacking, dan Aktivitas Fisik dengan Status Gizi serta Komposisi Lemak Tubuh Siswa di SDN Karang Pawulang Kota Bandung
Abstrak: Aktivitas fisik yang rendah disertai konsumsi snack yang berlebihan dapat mengarah pada kejadian obesitas. Penelitian ini bertujuan untuk menganalisis hubungan kebiasaan snacking, aktivitas fisik, dan lama sedentary time dengan status gizi dan komposisi lemak tubuh siswa SDN Karang Pawulang Bandung. Desain penelitian yang digunakan adalah cross sectional study dengan jumlah subjek sebanyak 78 orang siswa kelas 5. Hasil uji Mann-Whitney menunjukan terdapat perbedaan yang signifikan (p = 0.025) mengenai lama tidur siang berdasarkan jenis kelamin. Uji korelasi Spearman menunjukan terdapat korelasi yang signifikan antara status gizi dengan lama screen time (r= 0.234, p= 0.03), total sedentary time (r= 0.579, p=0.000), dan aktifitas fisik (r=-0.339, p = 0.002). Sedangkan komposisi lemak tubuh memiiki korelasi yang signifikan dengan lama sedentary time (r = 0.234, p=0.039) dan frekuensi konsumsi sayur (r= -0.264, p=0.019). Namun, tidak ditemukan korelasi yang signifikan (p >0.05) antara sedentary time dengan kebiasaan konsumsi snack, sayur, dan buah.
Keyword: aktivitas fisik, kebiasaan snacking, lemak tubuh, status gizi, sedentary time

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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