Judul: Development of Radicle Emergence Test on  Soybean Seeds (Glycine max L.) using Digital Image Processing
Abstrak: Pengolahan citra digital merupakan suatu teknik yang dapat digunakan untuk mengidentifikasi mutu benih dalam waktu singkat. Penelitian ini bertujuan mengembangkan metode pengujian cepat vigor pada benih kedelai (Glycine maxL.) menggunakan metode pemunculan radikula atau radicle emergence (RE) dengan pengolahan citra digital. Penelitian ini menggunakan rancangan kelompok lengkap teracak dengan empat ulangan dan dikecambahkan pada suhu 25 ± 2 ºC. Pengambilan citra dilakukan setiap dua jam sekali dalam rentang waktu 36-54 jam setelah benih dikecambahkan. Penelitian ini dilakukan dengan mengamati jumlah benih yang memiliki panjang radikula = 2 mm. Data panjang radikula tersebut kemudian dianalisis korelasi dan regresi terhadap tolok ukur mutu fisiologis benih, antara lain daya berkecambah, indeks vigor, potensi tumbuh maksimum, kecepatan tumbuh, dan mean radicle emergence time (MRET). Penelitian yang dilakukan memperoleh hubungan korelasi kuat antara panjang radikula = 2 mm dengan tolok ukur indeks vigor, kecepatan tumbuh, dan MRET pada benih kontrol serta korelasi kuat pada tolok ukur daya berkecambah dan indeks vigor pada cekaman salinitas NaCl konsentrasi 0,35% dan 0,7%. Korelasi kuat antara panjang radikula = 2 mm dengan tolok ukur vigor benih lainnya pada waktu pengecambahan 44 jam., Digital image processing is a technique that can be used to identify seed quality in a short time. This research aims to develop a rapid vigor testing method for soybean (Glycine max L.) seeds using the radicle emergence (RE) method with digital image processing. This research used a randomized complete group design with one factor with four replications and germinated at 25 ± 2 ºC. Images were taken every two hours within 36-54 hours after the seeds were germinated. This research was conducted by observing the number of seeds that had radicle length = 2 mm. The radicle length data was then analyzed for correlation and regression against the benchmarks of seed physiological quality, including germination, vigor index, maximum growth potential, growth speed, and mean radicle emergence time (MRET). The research conducted obtained a strong correlation on the benchmarks of vigor index, growth speed, and MRET in control seeds and a strong correlation on the benchmarks of germination and vigor index under NaCl salinity stress concentrations of 0.35% and 0.7%. Strong correlation between radicle length = 2 mm and other seed vigor benchmarks at germination time of 44 hours.
Keyword: ImageJ, percentage of radicula growth amount, germination period, seed viability, seed vigor

Judul: Development of Soybean (Glycine max (L.) Merr.) Seed Vigor Test Method using Digital Image Processing
Abstrak: Pengujian vigor benih memerlukan pengembangan metode yang lebih cepat, efisien, dan akurat. Teknologi pengolahan citra digital merupakan salah satu pengembangan uji cepat vigor benih. Penelitian ini bertujuan mengembangkan metode uji cepat vigor benih pada tanaman kedelai dengan menggunakan pengolahan citra digital. Citra benih kedelai dikuantifikasikan menggunakan aplikasi citra digital untuk mendapatkan data numerik yang dapat diolah dan dianalisis dengan tolok ukur yaitu daya berkecambah, indeks vigor, potensi tumbuh maksimum, jumlah daun, tinggi tanaman, dan daya tumbuh lapang. Penelitian ini dilaksanakan pada Januari hingga Maret 2021 di Laboratorium Pengujian Benih dan Kebun Percobaan Sawah Baru, Departemen Agronomi dan Hortikultura, Fakultas Pertanian, Institut Pertanian Bogor. Penelitian ini menggunakan empat varietas benih kedelai yaitu Gepak kuning, Anjasmoro, Grobogan dan Detap 1. Rancangan percobaan yang digunakan dalam penelitian adalah Rancangan Kelompok Lengkap Teracak (RKLT). Hasil pengujian menunjukkan bahwa rata-rata panjang radikula dan persentase jumlah pertumbuhan radikula dengan pengolahan citra digital memiliki korelasi yang erat dengan tolok ukur daya berkecambah, indeks vigor, jumlah daun 4 MST, dan daya tumbuh lapang, dengan periode pengecambahan yang efektif dapat dimulai pada jam ke 36., Seed vigor test requires a faster, efficient, and more accurate method of development. The digital image processing technology is a development of seed vigor test. This research aims to develop a rapid test method of seed vigor on soybean using digital image processing. The image of soybean seeds quantified by image process application to obtain numerical data for analyzed with the parameters which were percentage of germination, vigor index, maximum growth potential, number of leaves, plant height, and field growth capacity. This research was conducted from January to March 2021 at the Seed Quality Testing Laboratory and Sawah Baru Experimental Station, Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University. This research used four varieties of soybean seeds: Gepak Kuning, Anjasmoro, Grobogan, and Detap 1. The experimental design that used on this research was a Randomized Completely Block Design (RCBD). The test results showed that the average length of radicle and the percentage of total radicle growth with digital image processing is closely correlated with the parameters which are the percentage of germination, vigor index, number of leaves on 4 weeks after planting, and field growth capacity with an effective germination period can be started at 36 hours.
Keyword: field growth capacity, vigor index, length of radicle, germination period

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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