Judul: Analisis Stabilitas Morfologi Tanaman Kopi Robusta Menggunakan Metode AMMI pada Data Multilokasi
Abstrak: Produktivitas tanaman kopi di Indonesia masih jauh dibawah potensi. Hal itu terjadi karena penggunaan bibit yang bukan berasal dari klon unggul dan kemampuan adaptasi tanaman berdasarkan lokasinya. Salah satu cara yang dapat dilakukan untuk meningkatkan produktivitas tanaman kopi adalah dengan melakukan seleksi klon. Tujuan dari penelitian ini adalah mengidentifikasi klon kopi robusta yang stabil, spesifik, dan unggul pada percobaan multilokasi menggunakan analisis AMMI (Additive Main Effect and Multiplicative Interaction) berdasarkan metode range equalization. Data yang digunakan adalah data terkait karakter morfologi yaitu tinggi tanaman, panjang daun, dan lebar daun tanaman kopi robusta. Tujuh klon kopi robusta diuji dan ditanam di empat lokasi, yaitu di Sukabumi, Temanggung, dan dua lokasi di Lampung. Rancangan percobaan yang digunakan adalah rancangan acak kelompok lengkap dengan tiga ulangan. Hasil penelitian ini menunjukkan bahwa berdasarkan respon gabungan, terdapat dua klon stabil yaitu klon BP 534 dan klon R1 (R2017-1). Selain sebagai klon stabil, klon BP 534 juga merupakan klon unggul yang direkomendasikan untuk ditanam di semua lokasi percobaan, sedangkan klon spesifik atau klon dengan hasil rataan respon yang tinggi adalah klon BP 939 yang lebih baik ditanam di Edufarm Lampung dan klon R2017-2 yang lebih baik ditanam di Kebun Percobaan Pakuwon Sukabumi., The productivity of coffee plants in Indonesia is still far below its potential. This was due to the use of seeds that did not come from superior clones and the adaptability of plants based on their location. One way to increase the productivity of coffee plants is to do clone selection. This study aimed to identify stable, specific, and superior robusta coffee clones in multi-location trials using AMMI (Additive Main Effect and Multiplicative Interaction) analysis based on the range equalization method. The data used are morphological character data, namely plant height, leaf length, and leaf width of the robusta coffee plant. Seven robusta coffee clones were tested and planted in four locations, namely in Sukabumi, Temanggung, and two locations in Lampung. The experimental design used was a complete randomized block design with three replications. The results of this study indicate that based on the combined response, there are two stable clones, namely clone BP 534 and clone R1 (R2017-1). Apart from being a stable clone, BP 534 clone is also a superior clone which is recommended for planting in all experimental locations, while a specific clone or clone with a high response rate is BP 939 clone which is better planted in Edufarm Lampung and clone R2017-2 which is more well grown in the Sukabumi Pakuwon Experimental Garden.
Keyword: AMMI, klon, kopi robusta, multilokasi, range equalization

Judul: Pengujian Multilokasi Beberapa Klon Unggul Harapan Kopi Robusta
Abstrak: Tujuan dari beberapa program pemuliaan tanaman kopi adalah menghasilkan klon anjuran. Salah satu syarat suatu klon dapat dilepas sebagai klon anjuran adalah klon yang mampu berdayahasil tinggi dalam berbagai kondisi lingkungan. Pengujian multilokasi dilakukan untuk menentukan stabilitas dan pola hasil k10n yang diujikan. Jika interaksi antara klon dan lingkungan nyata, maka dapat dilakukan uji lanjut tentang stabilitas f daya adaptabilitas klon-klon yang dicobakan.
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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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