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: Rancang Bangun Alat Elektronik Pengukur Indeks Warna Daun Padi Untuk Rekomendasi Pemupukan Nitrogen
Abstrak: Nondestructive nitrogen monitoring for rice leaf is necessary for applying site specific nitrogen recommendation. Electronic SPAD chlorophyll meter device from Konica Minolta and IRRI-Leaf Color Chart now is the most known tools for measuring rice leaf index which have correlated reading with leaf nitrogen content. Both device is using leaf color properties principles to gave index value for estimating leaf nitrogen content. In this research, a new Prototype of leaf color measurement portable device has been build using TAOS TCS230 RGB Color Sensor. This device is using white LED light source to get reflection from rice leaf. Value read from sensor within range 400-600 nm will be processed in microcontroller to gave color value, leaf index and nitrogen fertilizer amount to be applied in the rice field. Performance test result indicate that the device has worked well on distinguishing colors as calibrated with GretagMacbeth color patch. Using BWD calibration the devices display XYZ and RGB color value as well as the BWD unit and fertilizer recommendation.
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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