Judul: Habitat Suitability Analysis of the Yellow-Crested  Cockatoo (Cacatua sulphurea) on Komodo Island Komodo National Park
Abstrak: Kaktua-kecil jambul-kuning merupakan salah satu satwa dilindungi yang terdapat di Pulau Komodo, Taman Nasional Komodo. Pemodelan kesesuaian habitat dapat membantu memberikan informasi spasial terkait tingkat kesesuaian dan distribusi kakatua. Penelitian ini bertujuan untuk mengidentifikasi hubungan parameter lingkungan dan tingkat kesesuaian habitat. Penelitian dilaksanakan pada tanggal 23 Februari – 9 Maret 2023 untuk mendapatkan data kehadiran kakatua dan validasi tutupan lahan. Hasil penelitian menujukkan bahwa terdapat 25 variabel yang memengaruhi pemodelan habitat dan ketinggian merupakan variabel tertinggi yang memberikan kontribusi terhadap pemodelan habitat. Pulau Komodo memiliki 1,35% luasan habitat yang sesuai bagi kakatua pada 5 lokasi berbeda yaitu Loh Liang, Loh Sebita, Loh Wau, Loh Wenci dan Loh Lawi karena kakatua memanfaatkan hutan musim dan bergerak berdasarkan ketinggian Pulau Komodo. Populasi aktual kakatua di Pulau Komodo sebesar 752 individu yang tersebar di berbagai lokasi. Diketahui bahwa kakatua-kecil jambul-kuning menyukai habitat terfragmentasi yang merupakan gabungan dari hutan musim dan savana.
Keyword: Habitat, Kakatua-kecil Jambul Kuning, Kesesuaian

Judul: Populasi dan Habitat Kakatua-Kecil Jambul-Kuning di Bentang Alam Mbeliling Bagian Barat, Kabupaten Manggarai Barat, Nusa Tenggara Timur
Abstrak: Cacatua sulphurea parvula or yellow-crested cockatoo were spread distributed at Sunda Kecil Archipelago, Nusa Tenggara, except at Sumba Island. This species amount in the nature is very small, caused by the illegal hunting and trading. The purpose of this research is to get the information about population and habitat of the cockatoo in Flores, especially at the western part of Mbeliling Landscape. Cocatoo census was conducted by look-down method at vantage points when cockatoo flew passed by. Habitat analysis was carried out with vegetation analysis. The census showed that there were two groups of cockatoo, consisted of 69 cockatoos in Tao hill and 15 cockatoos in Nggoer River. Flight pattern of each group ranged 0-100 meters above the sea level and crossed mangrove forest, savanna, monsoon forest and cultivation plant vegetation. The vegetation analysis resulted Ceiba petandra or silk-cotton tree as the tree that most used by cockatoo and had the highest TIV (Tree Importance Value), 47,48%. Cockatoo’s foods which observed were crown flower (Calotropis gigantea), and Moringa olifera. The population of Cockatoo which observed at western part of Mbeliling Landscape was estimated came from Rinca Island, Komodo National Park. It can be concluded that the location might be only used by rhe cockatoo came from Rinca Island as their daily exploration area for foraging.
Keyword: habitat., ecology, population, Flores, Cacatua sulphurea parvula

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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