Judul: Uji Vigor Benih Cabai Rawit (Capsicum sp.) dengan Metode Radicle Emergence menggunakan Analisis Citra Digital
Abstrak: The application of digital image processing technology with imageJ software at seed vigour test (Radicle Emergence test) is to obtain quantitative data of seed diameter/length, and radicle length at each observation period. Observations of the radicle emergence were carried out every three hours interval starting from 72 to 126 hours after planting. This research was conducted by observing the number of seeds that have four categories of radicle length 1mm, 2mm, 50% seed length (pjb), and seed length (pjb), and performed correlation analysis on several benchmarks of seed quality in the laboratory ( germination, vigor index, maximum growth potential, and growth rate) and in nurseries (number of leaves, plant height, and percentage of growth). Based on the test results, the radicle length category 1mm (84 hour) and 2mm (93 hour) had a strong correlation with the seed vigor benchmark (vigor index, growth rate, and percentage of growth in nursery), while the radicle length category ≥ 50% pjb and ≥ pjb only had a strong correlation with vigor index and growth rate at the same time.
Keyword: digital image processing, radicle length, rapid test of seed quality, seed

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: 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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