Judul: Penggunaan Metode Homotopi untuk Menyelesaikan Persamaan KdV (Korteweg-de Vries)
Abstrak: Natural phenomena can be explained using nonlinear mathematical models. In this paper, we studied the solution of KdV equation using the Homotopy method. The KdV equation is used for describing both surface and internal waves. One of the solutions is called a solitary wave. The use of homotopy method to solve the KdV equation required a nonlinear operator which was determined by the nonlinear form of the KdV equation itself. Based on this operator, a recursive formula was obtained to get a sequence of the KdV solution. The higher the sequence order of the sequence used, the closer to the exact solution of the KdV equation.
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Judul: Penggunaan Metode Analisis Homotopi pada Penyelesaian Persamaan Schrodinger-KdV
Abstrak: Schrodinger-KdV equations are mathematical model that can be applied in determining the maximum height of the bichromatic wave packet wrapper. These equations form nonlinear partial differential equations. Solution of Schrodinger- KdV equations are done by using homotopy analysis method. The use of homotopy analysis method is done by defining a homotopy function. Homotopy function requires auxiliary parameter that can be used to control the convergence area of the solution of Schrodinger-KdV equations. The obtained solution is in the form of recursive formula with given initial approach in the form of hyperbolic function. The use of homotopy analysis method is highly efficient and effective to solve Schrodinger-KdV equations, and the resulting error is very small.
Keyword: Bogor Agricultural University (IPB), Schrodinger-KdV equations, partial differential equation, homotopy analysis method, bichromatic wave

Judul: Aktivitas Makan dan Status Gizi Lutung Perak (Trachypithecus cristatus) di Pusat Primata Schmutzer, Taman Margasatwa Ragunan, Jakarta
Abstrak: Silvered leaf monkeys (Trachypithecus cristatus) are primate that live in groups on trees and consume leaves. The feeding activities of silvered leaf monkey relates to the fulfillment of their dialy energy. The energy is needed for the continuity of the group existence. The feeding activities of silvered leaf monkeys have several activities. They are observing, taking, sorting, processing, biting, chewing, ingesting, pulling out their mouth, and disposing the feed. The study aimed to identify the feeding activities, kind and composition of feed, nutrient consumption and energy of silvered leaf monkeys (Trachypithecus cristatus) in Schmutzer Primate Center (PPS), Ragunan Zoo, Jakarta. Data is collected from June to September 2011 with total of 480 hours observations. The data collection for the feeding activities was performed using ad libitum and focal animal sampling methods. Based on the observations, there were three types of activities with the highest frequency. Such as resting, locomotion, and feeding activity at 44.87%, 40.89%, and 38.70%. Respectively the chewing feed activities on infants were the higest of the feeding activities (36.90%). Silvered leaf monkeys in Schmutzer Primate Center (PPS) have good palatability in type of lamtoro leaves (Leucaena glauca). The result of the study revealed that adult and infants monkeys have sufficient dry matter and protein consumption (40,5 g/BW/d, 8 g/BW/d and 63 g/BW/d, 12,5 g/BW/d), but less for fat and energy (2,37 g/BW/d, 23,87 kcal/BW/d and 3,75 g/BW/d, 37 kcal/BW/d), while nutrient recommendation
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