Judul: Batas bawah nilai eigen terkecil dari matriks simetrik real
Abstrak: Dalam perkembangan ilmu dan teknologi di kehidupan sehari-hari, banyak diterapkan penggunaan nilai eigen (eigenvalues) dan vektor eigen (eigenvectors) seperti dalam bidang ilmu matematika, mekanika, sistem dinamika, dan sebagainya. Nilai eigen dari suatu matriks sangat dipengaruhi oleh entri-entri matriksnya. Oleh karena itu, mengetahui batas bawah nilai eigen terkecil dari suatu matriks akibat perubahan entrinya menjadi sangat penting. Matriks yang dibahas pada karya ilmiah ini merupakan matriks simetrik real yang entri-entrinya terletak pada suatu selang tertentu. Penentuan batas bawah nilai eigen terkecil dari matriks simetrik real tersebut ditinjau berdasarkan ukuran matriks dan nilai titik-titik ujung selang serta digunakan metode Faddeev-Leverrier untuk menentukan polinomial karakteristik dari matriks simetrik real tersebut.
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Judul: Perhitungan Nilai Eigen Terkecil dari Matriks Toeplitz Simetrik Real dan Definit-Positif dengan Metode Single Newton
Abstrak: Suatu metode yang paling luas digunakan untuk mencari hampiran akar dari suatu fungsi adalah metode Newton. Tujuan dari karya ilmiah ini adalah menghitung nilai eigen terkecil dari matriks Toeplitz simetrik real dan definit-positif dengan menggunakan metode single Newton. Polinomial karakteristik dan turunan polinomial karakteristik sangat dibutuhkan dalam melakukan iterasi pada metode ini. Untuk menunjukkan kebenaran dari rumus-rumus yang digunakan dalam metode Newton seperti nilai eigen, polinomial karakteristik, dan turunan polinomial karakteristik, maka diberikan ilustrasi serta metode analitik untuk matriks yang berorde 2 dan 3. Hasil perhitungan nilai eigen terkecil dari suatu matriks, dalam hal ini matriks Toeplitz simetrik real dan definit-positif, yang ditentukan dengan menggunakan metode single Newton sesuai dengan metode analitik.
Keyword: matriks definit-positif Toeplitz, metode Newton, nilai eigen

Judul: In vitro propagation and micro bulb induction of shallot
Abstrak: Shallot growers use harvested bulbs as propagules for the next planting. The use of the bulbs may cause degenerative diseases. Therefore, propagation system of shallot must be sought. A series of experiments were conducted in the Department of Agronomy and Horticulture IPB and the University of Queensland from May 2007 to July 2011. The first objective in this experiment was to determine the effect of explant storage duration on in vitro shoot multiplication of shallot. The experimental results showed storage length affected the growth of culture. Twomonth stored bulbs gave the best results on the number of micro shoots, number of leaves and roots and less vitrification. Four-week-old shoots were the best used for micro-propagules in shallot micro bulb induction. The objective of the second experiment was to determine the effect of temperature on the formation of shallot micro bulbs. It was shown that room temperature influenced the number of micro bulb, bulb base diameter, the widest diameter, ratio of the widest diameter and the base diameter of shallot micro bulb (Dt / Dp), root length, shoot length, number of leaves, number of senescing leaf. Temperature of 30/27 °C was better than 20/17 oC in accelerating the process of micro-bulb formation and increased the size of shallot micro bulbs. The objective of the third experiment was to determine the effect of sucrose and paclobutrazol on micro bulb induction. No interaction between sucrose and paclobutrazol was shown. Sucrose affected plant height, number of senescing leaf, root number, root length, the weight of plantlets and micro bulb widest diameter. Sucrose concentration of 90 g L-1 was the best in inducing shallot micro bulbs. Paclobutrazol significantly affected plant height, number of senescing leaf, number and length of roots. Paclobutrazol at level 10 mg L-1 inhibited plant height, leaf number and root length. Paclobutrazol 0.1-10 mg L-1 shortened root length. Paclobutrazol at concentration of 1 and 10 mg L-1 produced an abnormal form of micro bulb. The objective of the fourth experiment was to determine the success of shallot shoot and micro bulb acclimatization. At this stage of acclimatization, micro bulbs could be successfully grown for 3 weeks after acclimatization. Micro bulb was better in acclimatization than rooted plantlet. Plants may be transplanted to the field at 2 weeks after acclimatization. It is concluded that bulb stored for two months was the best for shoot multiplication. Media MS+vit B5 and 90 g L-1 sucrose at 30 oC was the best for bulb induction. Paclobutrazol should not be used for bulb induction. Bulb was better acclimatized than planlet. The media for acclimatization was green leaf compost and husk charcoal.
Keyword: Allium ascalonicum L, micro bulb, explant age, room temperature, paclobutrazol