Judul: Hubungan Durasi Tidur, Night Time Eating, dan Aktivitas Fisik dengan Status Gizi Mahasiswa Gizi dan Non Gizi di IPB.
Abstrak: Penelitian ini bertujuan menganalisis hubungan durasi tidur, night time eating, dan aktivitas fisik dengan status gizi mahasiswa gizi dan non gizi di Institut Pertanian Bogor. Desain penelitian yang digunakan adalah cross sectional dengan contoh mahasiswa gizi 30 orang dan non gizi 31 orang. Data yang dikumpulkan meliputi karakteristik contoh, data antropometri, karakteristik sosial ekonomi keluarga, durasi tidur, kebiasaan night time eating, data konsumsi dan aktivitas fisik yang diperoleh melalui kuesioner dan wawancara. Data antropometri diperoleh melalui pengukuran secara langsung. Sebagian besar contoh gizi (76.7%) dan non gizi (74.2%) berstatus gizi normal. Status gizi overweight pada contoh gizi sebanyak 20.0% dan non gizi 12.9%. Contoh berstatus gizi kurang lebih banyak pada contoh non gizi (12.9%) dibandingkan contoh gizi (3.3%). Terdapat perbedaan yang signifikan pada pendapatan orang tua (p<0.05) dan perbedaan yang sangat signifikan pada uang saku, tingkat pendidikan ibu, dan durasi tidur antara kedua kelompok (p<0.01). Contoh gizi memiliki durasi tidur yang lebih singkat (5.0±1.05 jam) dibandingkan non gizi (5.6±0.80 jam). Contoh gizi memiliki frekuensi night time eating dengan kategori sering (>4 kali/minggu) lebih tinggi dibandingkan non gizi. Tingkat aktivitas fisik contoh tergolong kategori ringan. Tidak terdapat hubungan signifikan antara durasi tidur, night time eating, dan aktivitas fisik dengan status gizi (p>0.05).
Keyword: aktivitas fisik, durasi tidur, night time eating, status gizi

Judul: Relationship between Diet Quality, Sleep Quality, and  Physical Activity with the Nutritional Status of IPB Students.
Abstrak: Permasalahan gizi saat ini pada kelompok dewasa awal adalah permasalahan gizi ganda, yang disebabkan berbagai faktor, diantaranya kualitas diet, kualitas tidur, dan aktivitas fisik. Penelitian ini bertujuan menganalisis hubungan kualitas diet, kualitas tidur, dan aktivitas fisik terhadap status gizi mahasiswa tingkat akhir IPB. Desain penelitian adalah cross sectional study, dilaksanakan Desember 2022 sampai Januari 2023 pada 40 mahasiswa. Pengumpulan data dilakukan dengan wawancara, pengukuran antropometri, dan pengisian kuesioner. Hasil penelitian menunjukkan sebagian besar subjek (68%) memiliki pengetahuan gizi cukup. Hampir seluruh subjek (95%) memiliki kualitas diet rendah berdasarkan Diet Quality Index International (DQI-I). Lebih dari 3/4 subjek (77,5%) memiliki kualitas tidur buruk berdasarkan Pittsburgh Sleep Quallity Indeks (PSQI). Hampir separuh subjek (42,5%) memiliki aktivitas fisik sedang berdasarkan International Physical Activity Questionnaire (IPAQ-SF). Status gizi hampir 2/3 subjek normal (65%). Hasil Uji korelasi Spearman menunjukkan tidak ada hubungan signifikan (p>0.05) antara pengetahuan gizi dengan kualitas diet, kualitas diet dengan status gizi, kualitas tidur dengan status gizi, dan aktivitas fisik dengan status gizi. Terdapat kecenderungan skor pengetahuan gizi baik pada subjek dengan kualitas diet tinggi, kecenderungan skor kualitas diet rendah dan skor kualitas tidur buruk pada subjek dengan status gizi tidak normal. Kata kunci: aktivitas fisik, kualitas diet, kualitas tidur, pengetahuan gizi, status gizi, Current nutritional problem in early adulthood is double burden malnutrition, caused by various factors, including diet quality, sleep quality and physical activity. This study aims to analyze relationship between diet quality, sleep quality and physical activity on the nutritional status IPB final year students. Research design was cross-sectional study, carried out from December 2022 to January 2023 on 40 students. Data collection was carried out by interviews, anthropometric measurements, and filling out questionnaires. Results showed majority subjects (68%) had sufficient nutritional knowledge. Almost all subjects (95%) had low diet quality based on Diet Quality Index International (DQI-I). More than 3/4 subjects (77.5%) had poor sleep quality based on Pittsburgh Sleep Quality Index (PSQI). Almost half of subjects (42.5%) had moderate physical activity based on International Physical Activity Questionnaire (IPAQ-SF). Nutritional status of almost 2/3 subjects was normal (65%). Results of Spearman correlation test showed no significant relationship (p>0.05) between nutritional knowledge and diet quality, diet quality and nutritional status, sleep quality and nutritional status, physical activity and nutritional status. There was tendency for good nutritional knowledge scores in subjects with high diet quality, tendency for low diet quality scores and poor sleep quality scores in subjects with abnormal nutritional status
Keyword: diet quality, nutritional knowledge, nutritonal status, physical activity, sleep quality

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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