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: 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: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix