Judul: Categorization in Macaca fascicularis.
Abstrak: Categorization is an ability to group individuals or events into different classes mediated by conceptualized mental images. There are several levels of categorization and within a taxonomy the levels are nested. At the most concrete level of categorization, all or most members of the category shared common physical attributes that differ from other categories. The higher the level of category, the fewer common attributes between members of the group. In addition to humans, the ability to categorize has also been proposed in animals. One example of categorization in animal is species discrimination. Using matching-tosample task, present experiment tested ability of the long-tailed macaque (Macaca fascicularis) in discriminating dichotomous-stimuli of different animals. The species has been shown to be able to see photos as representations of real object so I used facial photos of humans and animals for the stimuli. First, I tested their ability to classify humans and macaques into separate group. Second, I tested their ability to discriminate their conspecific from other macaques. And the last, I tested whether the subjects were able to discriminate non-human animals from humans. In all of these experiments I found that the subjects showed high performance in categorizing objects, even when I discarded details of visual informations, such as color and local shapes. The ability to identify objects with reduced representation of physical properties means the subjects were able to generalize attributes of members of the group. This would indicate that the subjects created a higher level abstraction. On the other hand, in discriminating intrageneric macaque species I found that they were able to extract uniqueness of each species. More over, I also found that the subjects were able to put photos of non-human animals that shared very few similarities in physical percepts into one group. I suggested that the subjects could create a more abstract concept based on non-percepts relations as a basis to put the objects into one category. Thus, I concluded that M. fascicularis were able to perform multiple levels of categorizations.
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Judul: Hierarki Jantan Dewasa pada Dua Kelompok Monyet Ekor Panjang (Macaca fascicularis) di Situs Ciung Wanara Karangkamulyan, Ciamis
Abstrak: Dominance defines as the ability in having greater priority to get more access to all sources. Arrangement of dominant and subordinate are defined as hierarchy. Long-tailed macaques live in a group of multi-males and multi-females, therefore interaction such as social behavior are depended on their hierarchy. This study aimed to determine hierarchy of adult males in two troops of long-tailed macaques (M. fascicularis), Pangcalikan and Sabung Ayam troops on Ciung Wanara sites Karangkamulyan, Ciamis. Present study used focal animal sampling and ad libitum sampling methods. The hierarchical structure determination used a three methods, namely sociometric matrix, feed stocking analysis and some activities that may have a role to determine hierarchy. The hierarchy of Pangcalikan troops were: Ba, Co, Tr, X, X2, and Me on a descending order, and the hierarchy of Sabung ayam troops were: Ku and Ma on a descending order as well which arranged linearly for both troops.
Keyword: Macaca fascicularis, long-tailed macaques, hierarchy, Ciung Wanara, adult male

Judul: Strategi Long Straddle dan Bull Spreads untuk Lindung Nilai Crude Oil
Abstrak: Konflik Geopolitik Rusia-Ukraina, pemotongan produksi OPEC+, dan China mempercepat vaksinisasi menyebabkan harga crude oil meningkat. Lindung nilai menggunakan strategi opsi dapat menjadi solusi untuk mengurangi risiko jika menghadapi kondisi bullish di masa depan. Penelitian ini menggunakan tiga strategi opsi, yaitu long straddle, bull call spread, dan bull put spread. Berdasarkan hasil perhitungan, ketiga strategi opsi memiliki keuntungan maksimum dan kerugian maksimum pada kondisi dan nilai yang berbeda-beda jika terjadi peningkatan spot price. Long straddle lebih menguntungkan pada kondisi bullish atau bearish, sedangkan bull call spread lebih menguntungkan pada kondisi neutral. Harga jual lindung nilai long straddle merupakan yang terendah pada kondisi bearish dan bullish, sedangkan pada kondisi neutral harga jual lindung nilai terendah terjadi ketika diterapkan strategi bull call spread.
Keyword: Crude oil