Judul: Nilai Eigen, Spektral Norm, dan Determinan dari Matriks Circulant dengan Entri Bilangan Generalized.
Abstrak: Pada karya ilmiah ini akan dibahas tentang matriks circulant yaitu matriks yang memiliki urutan bilangan sesuai dengan baris pertama. Matriks circulant memiliki nilai eigen, spektral norm, dan determinan. Karya ilmiah ini bertujuan mengkaji secara teoritis tentang mencari nilai eigen, spektral norm, dan determinan dari matriks circulant. Dari hasil pembuktian diperoleh bahwa spektral norm adalah nilai maximum dari nilai eigen. Sedangkan determinan dipengaruhi oleh perkalian nilai eigen pada matriks circulant. Selanjutntya diberikan contoh – contoh aplikasi dengan entri bilangan Generalized Tribonacci dan Generalized Pell untuk menunjukkan bahwa teorema berlaku.
Keyword: Bilangan Generalized Tribonacci, Bilangan Generalized Pell contoh aplikasi, determinan, matriks circulant, nilai eigen, spektral norm

Judul: Nilai Eigen, Determinan dan Norm Matriks Circulant dengan Entri Bilangan k-Fibonacci
Abstrak: Matriks circulant adalah matriks yang entrinya bergeser satu kolom ke kanan secara berurutan pada baris berikutnya. Entri–entri matriks circulant dapat diisi dengan berbagai barisan bilangan, salah satunya adalah bilangan k–Fibonacci. Berdasarkan definisinya, pada karya ilmiah ini, nilai eigen, determinan dan norm matriks circulant dengan entri bilangan k–Fibonacci diformulasikan secara eksplisit. Kemudian, contoh kalkulasi berdasarkan rumusan tersebut diberikan sebagai ilustrasi., A circulant matrix is a matrix whose entries are shifted one column to the right in succession in the next row. Circulant matrix entries can be filled in various sequence of numbers, one of which is k–Fibonacci number. In this scientific paper, based on the definition, the eigenvalues, determinants and norms of the circulant matrix with the entries of k–Fibonacci numbers are formulated explicitly. Then, examples of the calculation of the obtained formulas are given as illustrations.
Keyword: circulant matrix, determinants, eigen values, matrix norms, k-Fibonacci number

Judul: Amfibi sebagai satwa peliharaan: Ekspor, Impor dan Perdagangan Domestik
Abstrak: Indonesia has exported amphibian as frozen frog legs (listed since 1969 under fishery product) for consumption and live amphibian (listed since 1983 under reptilian class in forestry product) for pets. There are also live amphibian trading in local level i.e in markets and malls. This research aims to identify amphibian species exported and imported by investigating document from related administration and to identify amphibian species traded in domestic market by observation at Jakarta. Research is primarily conducted by processing quota data taken from Department of Forestry Republic of Indonesia database in Jakarta. Market observation was carried out in 18 locations (3 markets and 15 malls) in Jakarta. I carried out interview with trader and export business, which related to net trading live amphibians for pets. Respondent was choosen using snowball sampling manner. Name of species is written according to Iskandar & Coljin (2000). If there is no such record in the checklist (for example species are from outside Indonesia), then the species name is written according to Frost (2004). There are 56 species from eight families of wild amphibians that have pets quota between 1998-2008. Nineteen species was traded since 1983. The highest export quota is Litoria caerulea (21,37%). Allocation of highest catching quota is for BKSDA Jayapura (20,40%) and BKSDA Papua Barat (18,96%). Four species are included in IUCN Red List categories as vulnerable, among others are Limnonectes macrodon, Meristogenys jerboa, Nyctixalus margaritifer and Rhacophorus margaritifer. The number of amphibians that have export realization are 39 species. Two species of amphibian, Leptobrachium hasseltii and Rhacophorus margaritifer are amphibian species whose been known infected by chytrid fungus in the wild. The biggest species exported is Litoria caerulea (54,34%). Between 1983-1991, the biggest import amphibian for pets from Indonesia (66,13%) is Netherlands. Number of quota was relative stable in the last eight years, where as the number of export realization is more fluctuates. Amphibian species imported and re-exported between 1983-2008 come from Africa, South Asia, Malaysian, Archipelago Oceania, North America, Central America and South America. The number of pet amphibian species traded at domestic market is less than exported. Data showed that Indonesia imports 15 amphibian species between 1983-2008, However I found different species in the market that was unrecorded in the Ministry of Forestry data, which is the Fire Belly Salamander.
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