Judul: Kajian Teoritis Nilai Eigen Matriks Toeplitz Simetrik Real dan Definit Positif.
Abstrak: Matriks Toeplitz adalah matriks berukuran 𝑛×𝑛 yang memiliki entri-entri yang sama pada diagonal yang sama. Pada karya ilmiah ini akan dilakukan pengkajian secara teoritis nilai eigen genap dan ganjil dari matriks Toeplitz simetrik real dan definit positif. Penghitungan nilai eigen didasarkan pada faktorisasi polinomial karakteristik menjadi polinomial karakteristik genap dan ganjil.
Keyword: matriks Toeplitz, polinomial karakteristik, nilai eigen, nilai eigen genap, nilai eigen ganjil

Judul: Inverse Eigenvalue Problem Untuk Matriks Tridiagonal Simetrik
Abstrak: Inverse eigenvalue problem adalah proses mengonstruksi suatu matriks yang mempertahankan struktur tertentu dari data tertentu. Biasanya Data yang digunakan dapat berupa informasi sebagian dari nilai eigen atau vektor eigen. Beberapa jenis matriks yang sering dibahas dalam inverse eigenvalue problem adalah Matriks Tridiagonal Simetrik, Matriks Jacobi, Matriks Toeplitz, dan matriks Hermitian. Dalam karya ilmiah ini, jenis matriks yang dibahas adalah Matriks Tridiagonal Simetrik beserta dua kasus khusus yaitu matriks tridiagonal simetrik dengan diagonal utama tak negatif dan matriks tridiagonal simetrik dengan diagonal utama bernilai konstan. Dalam setiap kasus tersebut masing-masing memeliki syarat perlu dan cukup yang dibahas dalam lema dan teorema.
Keyword: Inverse eigenvalue problem, Matriks Tridiagonal Simetrik, Nilai Eigen

Judul: Macroalgae development as feeding stimulants for the adult sea urchin (Tripneustes gratilla Linnaeus 1758)
Abstrak: Development of artificial feed for somatic growth and gonad quality is one of the focus of research on sea urchin aquaculture activities. Palatability is important factor when developing artificial feed for aquaculture diets. This study investigated the effects of macroalgae (Sargassum polycystum, Gracilaria lichenoides, and Ulva reticulata) as feeding stimulants to artificial diets consumption and gonad profile for the adult sea urchin Tripneustes gratilla, by three feeding trials. Previously starved T. gratilla were held in replicated (3X) 50 L aquaria with recirculation water system (in the first feeding trial) and flow through water system (in the second and third feeding trial). In the first feeding trial, preference of T. gratilla for dried macroalgae was assessed in choice feeding experiment. T. gratilla displayed significant preference for the agar containing dried U. reticulata at 20% agar weight over nine other diets treatment when they were offered simultaneously. Total protein, energy and the ratio of protein to energy in the dried macroalgae had no correlation on agar consumption by T. gratilla. Three artificial diets were made by incorporating one of each of these dried macroalgae at 5% feed weight used in the second feeding trial. Although no significant difference in artificial diets containing dried macroalgae, urchins fed diets containing dried macroalgae consumed more than basal diet when they were offered as single diet. These results indicate that dried macroalgae added to the artificial diets act as feeding stimulants and increasing the acceptability of artificial sea urchin diets. The third feeding trial used dried U. reticulata as feeding stimulant to artificial diet. Data suggest that artificial diet containing 10% dried U. reticulata boosting feed consumption and significantly increasing nutrient accumulation, gonad index, egg diameter and fix gonad color.
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