Judul: Perbandingan Waktu Eksekusi Metode Titik Interior dalam Menyelesaikan Masalah Optimisasi Linier menggunakan Mathematica dan Scilab
Abstrak: Terdapat dua metode yang biasa digunakan untuk menyelesaikan optimisasi linier, yaitu metode titik interior dan metode simpleks. Pada metode titik interior, pergerakan titik-titik menuju solusi optimal melewati bagian dalam daerah fisibel. Sedangkan pada metode simpleks, pergerakan titik-titik terjadi sepanjang simpul polihedron. Pada karya ilmiah ini, dilakukan perbandingan waktu eksekusi metode titik interior dalam menyelesaikan optimisasi linier menggunakan perangkat lunak matematika, yaitu Mathematica dan Scilab. Variabel dan kendala dari masalah optimisasi linier dipilih beragam dari kasus yang relatif sedikit ke kasus yang relatif banyak. Hasil yang diperoleh menunjukkan bahwa waktu eksekusi metode titik interior menggunakan Mathematica cenderung lebih cepat dibandingkan metode titik interior menggunakan Scilab untuk semua kasus optimisasi linier dengan ukuran beragam.
Keyword: mathematica, metode karmarkar, metode titik interior, optimisasi linier, scilab, waktu eksekusi

Judul: Perbandingan Waktu Eksekusi Metode Simpleks dan Metode Titik Interior dalam Menyelesaikan Masalah Optimasi Linear Menggunakan Mathematica
Abstrak: There are two famous methods for solving linear optimization problems, namely simplex method and interior point method. In the simplex method, to find an optimal solution, the algorithm moves from vertex to vertex. While in the interior point method, the algorithm moves in the interior of the feasible region of the problem. In this paper we compare the execution time of the simplex method and the interior point method in solving several linear optimization problems by using a mathematical software, that is Mathematica. The size of problems are chosen from small to relatively big. The main result is that the interior point method is faster than the simplex method for big size problems
Keyword: execution time, linear optimization, interior point method, simplex method

Judul: Studi Taksonomi Katak Subgenus Papurana (Lesson, 1831) dari Halmahera (Anura, Ranidae, Hylarana), Studi Taksonomi Katak Subgenus Papurana (Lesson, 1831) dari Halmahera (Anura, Ranidae, Hylarana
Abstrak: I reevaluated taxonomic of subgenus Papurana position from Halmahera based on morphological and molecular analyses. My results show that two separate species occur on the Halmahera Island, each nested within two distinct clades (hereafter papua clade and celebensis clade), one of which corresponds to H. moluccana (celebensis clade) and the other to an unidentified species (papua clade). By p-distance ranging from 6.9 to 11.5% on the 16S rRNA gene, the unidentified species (Hylarana sp.) is genetically different from all congeners of the papua clade. The Hylarana sp. can be distinguished from all congeners by following combination of charactes: vomer teeth in two oblique rows with narrow inter-vomer distance; snout rounded dorsally; dorsum with few scattered cone-shaped tubercles that are black with white tips; distinct skin folds (ridges) on the dorsal side of the thigh coinciding with dark brown cross bars; a marbled pattern on the ventral side of the thigh and yellowish groin. I also present new data for H. daemeli, H. volkerjane, and H. arfaki from the western region of Papua. Furthermore, I found that H. celebensis has numerous mtDNA lineages, indicating cryptic diversity within the celebensis clade. The discovery of two separate species on Halmahera necessitates more research into the biogeographic history of Hylarana in Northern Moluccas.
Keyword: frog, Halmahera, Hylarana, morphology, Papurana, phylogenetic