Judul: Aplikasi Bagan Warna Daun untuk Optimasi Pemupukan Tanaman Padi Menggunakan k-Nearest Neighbor
Abstrak: The leaf color of rice is closely associated with the adequacy of nitrogen (N) level of the ground. N deficiency symptoms that are most obvious and commonly seen is the reduction of green color of the leaf. This research developed a mobile application to identify the color of rice leaf and to determine the appropriate fertilizer. The application was built by using the histogram feature of several color components namely Red, Green, Blue in the RGB color space, Hue, Saturation Value in the HSV color space, and grayscale. K-Nearest Neighbor was choosen as the classification method. This research showed the highest average accuracy of 90.63% on the G (green), V (Value) and grayscale color component. The k-NN classification method produced the highest average accuracy of 72.62% when the value of k is equal to 3.
Keyword: Android, grayscale, histogram, HSV, color identification, k-Nearest Neighbor

Judul: Aplikasi Perangkat Uji Pupuk Berbasis Android Menggunakan Fitur Warna
Abstrak: The distribution of counterfeit fertilizer has bring many disadvantages to farmers. To overcome this issue, the Ministry of Agriculture has developed the Fertilizer Test Kit that can be used directly in the field. However, the categorization of nutrient levels are still done manually by using a color chart. Therefore the nutrient level classes are limited to 2.5%, 5%, 10%, 15%, and 20%. The purpose of this research is to improve the classification of fertilizer nutrient level, both from the precision and simplicity. K-Nearest Neighbors (kNN) is used as the classification method with k = 3, 6, and 9. The histrogram of hue component in HSV color space is treated as the feature. Classification is done with 2% resolution to Nitrogen (N) and Phosphorus (P) nutrient levels. The results showed that the best accuracy is 79.54% for N with a root mean square error value (RMSE) of 1.59 and 30% for P with RMSE 4,764. Both were obtained at k = 9.
Keyword: Bogor Agricultural University (IPB), k-nearest neighbour (kNN), Hue Saturation Value (HSV), fertilizer test kit

Judul: Katalis Eterifikasi Gliserol Berbasis Poli–(asam stirena sulfonat) dari Limbah Styrofoam.
Abstrak: Styrofoam waste can be converted to poly–(sulfonate styrene acid) (PSSA) that can be used as catalyst. The objective of this research is to get PSSA that can catalyze the etherification of glycerol and benzyl alcohol. The styrofoam waste was converted to PSSA by reacting with H2SO4 98% (as sulfonation agent) and P2O5 (as sulfonation catalyst) at 40 °C for 6 hours. Characterizations of PSSA included functional groups, sulfonation levels, water swelling, and thermal stability. The yield of PSSA was 40-55%. The success of sulfonated polystyrene was shown by –SO3H group absorption at 1157.29 cm-1. Etherification of glycerol and benzyl alcohol using PSSA catalyst was conducted at 110 °C for 12 hours. The conversion in producing mono–benzyl ether glycerol was 8.10%, 1,3–dibenzyletherglycerol 2.60%, and dibenzyl ether 9.80%. Therefore, the PSSA can be used as etherification catalyst.
Keyword: benzyl alcohol, etherification, glycerol, polystyrene, PSSA