Judul: Pembuatan Alat Penentu Warna Tanah Berdasarkan Munsell Soil Color Charts
Abstrak: Pembuatan alat penentu warna tanah memanfaatkan sensor TCS3200 sebagai pendeteksi warna yang telah dikonversi menjadi frekuensi. Alat yang telah dibuat menggunakan sumber cahaya LED berwarna putih dengan jangkauan panjang gelombang 350 nm – 780 nm. Sensor dirancang untuk mengukur nilai intensitas cahaya yang dipantulkan oleh bahan. Keluaran sensor berupa frekuensi yang nilainya proporsional terhadap intensitas cahaya yang diterima. Frekuensi keluaran sensor secara linear diubah menjadi nilai RGB untuk mengurangi riak (noise) pengukuran dan penghematan memori. Data acuan pengelompokan dibuat dalam bentuk database yang berisi notasi warna tanah dan nilai RGB. Penotasian warna didasarkan pada notasi warna yang terdapat di Munsell Soil Color Charts. Klasifikasi sampel uji ke dalam kelompok yang tersedia di database menggunakan metode jarak euclid. Hasil klasifikasi yang terbaik akan ditampilkan di LCD berupa notasi hue value/chroma seperti pada Munsell Soil Color Charts.
Keyword: Munsell, sensor warna, warna tanah

Judul: Penelitian untuk Aplikasi Mobile Munsell Soil Color Chart Berbasis Android Menggunakan Histogram Ruang Citra HVC dengan Klasifikasi k-NN
Abstrak: Soil color determination is a challenging task because of the various types of soil and the high similarity of soil color. Munsell Soil Color Chart (MSCC) is used to overcome this issue. The purpose of this research is to develop an androidbased mobile application to identify the major color of soil according to MSCC. The application utilized HVC color model with hue, value, and chroma color components. The hue color component had been the main concern of this research, although the value and chorma color components were also observed. The training data were 259 images from MSCC, with 1600 pixels each. Hue color data from these pixels were analyzed in the form of histogram and classified with k-NN. The results showed that the highest classification accuracy of hue value was 45% at k=5, this accuracy may be improved by utilizing the soil color data that are available online.
Keyword: Munsell Soil Color Chart., k-NN, HVC, Android, Bogor Agricultural University (IPB)

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