Judul: Aktivitas Fisik, Konsumsi, Status Gizi, dan Tingkat Kebugaran Atlet Remaja Taekwondo dan Gulat
Abstrak: Tujuan penelitian ini adalah menganalisis hubungan antara tingkat aktivitas fisik, tingkat kecukupan gizi, status gizi, dengan tingkat kebugaran atlet taekwondo dan gulat. Penelitian ini menggunakan desain studi kasus yang melibatkan 25 orang atlet taekwondo dan gulat. Penelitian dilakukan pada bulan Mei sampai Juni 2018 di PPOP DKI Jakarta. Data yang dikumpulkan terdiri atas karakteristik contoh, aktivitas fisik, konsumsi makanan, status gizi, dan tingkat kebugaran. Hasil uji korelasi Pearson antar variabel menunjukan bahwa terdapat hubungan yang signifikan antara tingkat aktivitas fisik dengan tingkat kebugaran (p<0.05; r=0.512), namun tidak terdapat hubungan yang signifikan antara tingkat kecukupan energi, protein, lemak, dan karbohidrat serta status gizi dengan tingkat kebugaran.
Keyword: aktivitas fisik, tingkat kecukupan gizi, status gizi, tingkat kebugaran

Judul: Hubungan Konsumsi Pangan dan Status Gizi dengan Tingkat Kebugaran Atlet Taekwondo Remaja di Pemusatan Latihan Nasional Cipayung, Bogor
Abstrak: The general objective of study was to analyze food consumption, adequacy ratio, nutritional status, and fitness level of adolescents taekwondo athletes in Centralization of National Training Cipayung, Bogor. The research used cross sectional study design with 23 adolescents athletes as samples. The primary data included characteristic of samples, nutritional status by anthropometry (body mass index), and food consumption. The secondary data included fitness level by bleep test (VO2 max values), sit and reach test (flexibility), sit up and squat jump (muscle endurance), and overview of the study site which was Centralization of National Training. The study showed that overall athletes has normal nutritional status. Most athletes were lack of sufficient levels of energy and protein. There was positive correlations between the ages of athletes with flexibility (p<0,05, r=0,456) and muscle endurance (sit up test) (p<0,05, r=0,456). The correlations between with fitness level (VO2 max) was positive significantly correlated (p<0,05, r=0,456).
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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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