Judul: Pengaruh Populasi Cacing Tanah Eisenia foetida, Pupuk NPK dan Kapur terhadap Produktivitas dan Kualitas Sorgum (Sorghum bicolor L. Moench) Varietas Numbu pada Latosol Dramaga
Abstrak: Eisenia foetida is known as potential earthworm to reorganize the organic matter into inorganic matter that are beneficial to plants. This research aimed to determine the influence of population of earthworm E. foetida, NPK fertilizer and lime to productivity and nutritional quality of sorghum (Sorghum bicolor L. Moench) in Latosol Dramaga. The observed variables were the vertical height of plants, number of leaves, fresh weight, dry matter, crude protein, crude fiber and content of calcium. This research used factorial completely randomized design 2x2x3 with 3 replications. The results showed that the combination NPK fertilizer and earthworm significantly (P<0.05) increased the productivity of the plant. The Quality of nutrition, crude protein and calcium (Ca), significantly increased (P<0.05) and respectively influenced by NPK fertilizer and lime. Whereas the crude fiber, very markedly decreased (P<0.01) in influenced by the interaction between NPK fertilizers and earthworm.
Keyword: Sorghum bicolor L. Moench,, NPK fertilizer, lime, latosol, Earthworm Eisenia foetida

Judul: Evaluasi Produktivitas Tanaman Sorghum (Sorghum bicolor) Varietas Numbu Terhadap Pemberian Vermikompos dan Cacing Tanah Eisenia foetida
Abstrak: Vermicompost is organic fertilizer which is created by worm contribution. Vermicompost can increase hara content that needed by plant to grow. This study was conducted to evaluate productivity of Sorghum bicolor (L.) Moench by adding vermicompost and worm Eisenia foetida in different level. The measured parameters in this study were plant height, amount of leaves, as fed weight, dry matter weight and nutrient quality that composed by N (Nitrogen), P (Phospor), and K (Potasium). The study was arranged by factorial completely randomized design 3x3 with 3 replications. The first factor was vermicompost addition level 0%, 12.5% and 25%, the second factor was Eisenia foetida worm addition level 0, 16 and 32 heads. The result showed that by 25% vermicompost adding, it increased productivity and nutrient quality of Sorghum bicolor plant (P<0.05). On the other hand, the addition of Eisenia foetida worm affected the vertical height of plants but it did not influence nutrient quality of Sorghum bicolor plant
Keyword: vermicompost., Sorghum bicolor (L.) Moench, Earthworm Eisenia foetida, Bogor Agricultural University (IPB)

Judul: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix