Judul: Preferensi Penggunaan Alat Gerak Orangutan (Pongo pygmaeus) pada Aktivitas Makan di Pusat Primata Schmutzer
Abstrak: Feeding activity is one of the orangutan behavior which is needed to determine the usage of its hand preferences. Limb usage preferences is related to the asymmetrical reflection or lateralized of brain usage. Each hand is controlled by the opposite hemisphere of the brain. This research addressed to determine limb usage preferences of orangutan during feeding activity. The object of this research was nine Bornean orangutans (Pongo pygmaeus) with different age and sex. Feeding activity was divided into two categories, i.e. Reaching for food (RFF) and Taking food to the mouth (TFM). The postures of orangutan were distinguished into five classifications, i.e. sit, pronograde stand, orthograde stand, suspend, and lie. The dominance of right or left handedness was analysed using z-test. Orangutans more common performed unimanual feeding than two limb feeding. Three orangutans showed right handedness during RFF and TFM activities. Two limb feeding (hand-hand or hand-foot combination) was performed by adult orangutans. Sit was the posture most common during feeding activity.
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Judul: Aktivitas Makan dan Preferensi Pakan Orangutan Sumatera (Pongo abelii Lesson, 1827) di Resort Bukit Lawang, Taman Nasional Gunung Leuser
Abstrak: Orangutans are one of the primates which known as great apes and it is endemic in the island of Sumatera. This research was done at Sumatran Orangutan Viewing Center in Bukit Lawang. The aim of this study is to know the feed preferences and feeding activities of sumatran orangutan. The methods used in this study are Focal Animal Sampling which is done by following one individual orangutans during a certain period and single swath method in three different plots. The observations showed that orangutan’s feeding activity are smaller than resting and moving activity. There are 47 kinds of food that was eaten by orangutans. This food consisting of 5 habitus that is a tree, liana, herbaceous, clumps, and epiphyte. The part of plants that mostly consumed are leaves as much as 48,61%, fruit 27,49%, others (termites, ants, insects, soil) 12,75%, bark 7,17%, and flower 3,98%. Based on the feed preferences, the preferred type of feed are sibolangit (Garcinia lateriflora), rattan (Calamus sp.), and rambung (Vernonia arborea).
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Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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