Judul: Determinan dan Invers Matriks Skew Circulant dengan Entri Bilangan Pell
Abstrak: Matriks skew circulant adalah matriks persegi yang entrinya bergeser satu kolom ke kanan secara berurutan dengan seluruh entri sebelum diagonal utama akan bernilai negatif. Entri-entri dari matriks skew circulant dapat diisi dengan entri berbagai bilangan, salah satunya yaitu bilangan Pell. Pada karya ilmiah ini, determinan dan invers matriks skew circulant dengan entri bilangan Pell diformulasikan. Pembuktian formulasi determinan matriks skew circulant dengan entri bilangan Pell dilakukan berdasarkan serangkaian operasi baris dasar sehingga diperoleh matriks segitiga atas. Sedangkan pembuktian formulasi pada inversnya berlandaskan sifat-sifat ekuivalensi dari hasil kombinasi operasi baris dasar dan operasi kolom dasar., Skew circulant matrix is a square matrix whose entries are shifted one column to the right and all entries before the main diagonal will be negative.The entries of the circulant skew matrix can be filled in various numbers, one of which is the Pell number. In this scientific work, the determinant and inverse of skew circulant matrices with the entry of the Pell number are formulated. The substantiation of the determinant formulation of the circulant skew matrix with the entry of the Pell numbers is carried out on the basis of a series of elementary row operations so that an upper triangular matrix is obtained. Meanwhile, the proof of the formulation in the inverse is based on the equivalence proprties of the results of a combination of elementary row and column operations.
Keyword: circulant matrix, circulant skew matrix, determinant, inverse, Pell numbers

Judul: Determinant and Inverse Circulant Matrix with Pell Numbers Entries
Abstrak: Matriks circulant adalah matriks yang entrinya bergeser satu kolom ke kanan secara berurutan, sehingga untuk mengetahui seluruh entrinya dapat dilihat hanya dari kolom pertama. Salah satu sifat yang dimiliki matriks circulant adalah bahwa inversnya juga berupa circulant. Entri-entri matriks circulant dapat menggunakan entri berbagai bilangan, salah satunya adalah bilangan Pell. Pada karya ilmiah ini, determinan dan invers matriks circulant dengan entri bilangan Pell diformulasikan. Pembuktian formulasi determinan matriks circulant dengan entri bilangan Pell dilakukan berdasarkan serangkaian operasi baris dasar sehingga diperoleh mariks segitiga atas. Sedangkan pembuktian formulasi inversnya berlandaskan sifat-sifat ekuivalensi dari hasil kombinasi operasi baris dasar atau operasi kolom dasar., A circulant matrix is a matrix whose entries are shifted one column to the right in sequence, so to find out all the entries can be seen only from the first column. One of the properties of a circulant matrix is that its inverse is also a circulant. Circulant matrix entries can use entries of various numbers, one of which is Pell's number. In this scientific paper, the determinant and the inverse of the circulant matrix with Pell number entries formulated. Proof of the determinant formulation matrix circulant with Pell number entries performed based on a series of base row operations so that the upper triangular matrix is obtained. While the proof of the inverse formulation based on the equivalence properties of the result combination of base row operations or base column operations.
Keyword: circulant matrices, determinant, inverse,, Pell numbers

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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