Judul: Pengembangan perangkat sensor tingkat warna daun untuk menentukan kebutuhan pupuk tanaman kedelai
Abstrak: Hingga saat ini rekomendasi pemupukan untuk tanaman kedelai masih bersifat umum yang diterapkan untuk semua lahan, sehingga petani mengunakan pupuk dengan takaran yang berlebihan yang menyebabkan produksi kedelai tidak optimal. Metode precision farming perlu dikembangkan guna menghasilkan pekerjaan pertanian yang efektif dan efisien. Tingkat warna daun dapat dijadikan parameter untuk menduga status hara tanaman yang nantinya akan digunakan sebagai referensi dosis pemupukan. Tujuan dari penelitian ini adalah untuk menduga kesuburan tanah melalui warna daun dan membuat peta variabel kesuburan tanah dengan perangkat sensor citra. Penelitian dilakukan di Lab. Sistem Manajemen Mekanisasi Pertanian dan Lab. Lapangan Departemen TMB IPB pada bulan Mei sampai September 2010.
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Judul: Pengembangan Sensor Warna Daun untuk Menduga Kebutuhan Pupuk pada Tanaman Padi
Abstrak: Leaf colour is an indicator of plant fertility level which can be used for predicting fertilizer need of the paddy plants. The use of leaf colour chart (LCC) is one of instruments to measure greenness level. This research used image processing technology for analysing leaf colour level according to the IRRI-LCC standard. Taking the image of paddy leaves used a cart which is equiped with a proximity sensor and a CCD camera. Proximity sensor functions sending a signal to the camera to capture an image at every certain travelling distance. The captured images were then saved in the hard disk memory. Furthermore, those images were processed with Visual Basic program for analysing leaves area and greenness level. Then, the results were transformed into an area colour map, where each patch of land contains information about fertilizer need. Beside analysing with image processing, the measurement of leaf colour level was also done manually. The result of the manual measurement was also translated into an area colour map. The results of the manual and image processing measurement were then compared for determining the accuracy level. Accuracy at the colour level 2 was 38%, the colour level 3 was 69%, and the colour level 4 was 75%. The correlation between leaf colour level and nutrient content of soil was observed by comparing the result of soil nutrient content test and leaf colour level. It was found that both averages show a strong correlation
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Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model