Judul: Production Performance of Sand Lobster Panulirus homarus Nursery Puerulus Stadia in Sinking Cages with Different Shapes
Abstrak: Budidaya lobster pasir (Panulirus homarus) dihadapkan kepada tingkat kelangsungan hidup dan pertumbuhan yang rendah, salah satunya disebabkan oleh faktor lingkungan dan bentuk wadah. Wadah berbentuk bulat lazim digunakan dalam budidaya lobster di Vietnam yang memiliki kinerja produksi tinggi, sementara di Indonesia wadah yang lazim digunakan berbentuk kubus. Wadah tersebut tidak memiliki sudut mati atau dead area sehingga dapat menyesuaikan tingkah laku berenang mundur lobster. Penelitian ini bertujuan menganalisis pengaruh penggunaan bentuk wadah silinder dan kubus terhadap kinerja produksi pendederan lobster pasir di KJA. Penelitian ini dilakukan di PT. Saibatin, Pesawaran, Lampung. Lobster yang berasal dari Pesisir Barat Krui, Lampung memiliki bobot rata-rata 0,26±0,01 g dan panjang rata-rata 2,19±0,1 cm. Sebagai perlakuan, benih lobster dipelihara dalam karamba jaring tenggelam (KJTe) berbahan pipa PVC dan waring dengan mesh size 4 mm berbentuk kubus berukuran 606060 cm3 dan silinder berdiameter 68 cm dan tinggi 60 cm. Lobster dipelihara dengan kepadatan 92 ekor/m3 atau sebanyak 20 ekor tiap karamba selama 40 hari dan diberi pakan berupa ikan rucah sekali sehari pada 17:00 WIB sebanyak 10% dari biomassanya. Lobster dipelihara selama 40 hari dan dilakukan pengukuran parameter berupa tingkat kelangsungan hidup, laju pertumbuhan mutlak bobot, laju pertumbuhan panjang mutlak, laju pertumbuhan bobot spesifik, laju pertumbuhan spesifik panjang, tingkah laku, jumlah molting, serta rasio konversi pakan. Suhu, pH, dan oksigen terlarut, salinitas, amonia, nitrit, dan nitrat yang diukur selama penelitian berada pada kisaran optimum untuk lobster. Hasil penelitian ini menunjukkan bahwa pendederan lobster pasir dalam karamba tenggelam berbentuk silinder menghasilkan kinerja produksi yang lebih baik dibanding karamba tenggelam berbentuk kubus., The cultivation of sand lobster (Panulirus homarus) is faced with low survival and growth rates, one of which is caused by environmental factors and container shape. Round-shaped containers are commonly used in lobster farming in Vietnam which has high production performance, while in Indonesia the commonly used containers are cube-shaped. The container does not have a dead angle or dead area so that it can adjust the behavior of swimming backwards lobsters. This study aims to analyze the effect of the use of cylindrical and cube container shapes on the production performance of sand lobster deriving in KJA. This research was conducted at PT. Saibatin, Pesawaran, Lampung. Lobsters originating from the West Coast of Krui, Lampung have an average weight of 0.26±0.01 g and an average length of 2.19±0.1 cm. As a treatment, lobster fry are kept in a sinking net cage (KJTe) made of PVC and waring pipes with a mesh size of 4 mm in the form of a cube measuring 606060 cm3 and a cylinder with a diameter of 68 cm and a height of 60 cm. Lobsters are kept with a density of 92 heads / m3 or as many as 20 heads per caramba for 40 days and are fed in the form of trash fish once a day at 17:00 WIB as much as 10% of their biomass. Lobsters are kept for 40 days and parameters are measured in the form of survival rate, absolute growth rate of weight, absolute growth rate of length, weight-specific growth rate, length specific growth rate, behavior,
Keyword: bentuk wadah, karamba jaring tenggelam, puerulus lobster pasir, sudut mati, tank shape, sinking net cage, sand lobster puerulus, dead corner

Judul: Production Performance of Spiny Lobster Panulirus  homarus Grow-out I in Submersible Net Cage by Different Depth
Abstrak: Aplikasi keramba jaring tenggelam (KJTe) merupakan salah satu alternatif untuk meningkatkan kinerja produksi pada budidaya lobster. Penelitian ini bertujuan untuk menganalisis kinerja produksi pembesaran I lobster pasir dalam KJTe pada berbagai kedalaman. Penelitian dilakukan di Balai Sea Farming Pusat Kajian Sumberdaya Pesisir dan Laut, Institut Pertanian Bogor (PKSPL-IPB), Pulau Semak Daun, Kabupaten Administratif Kepulauan Seribu, DKI Jakarta. Penelitian menggunakan rancangan acak lengkap dengan dua perlakuan yaitu kedalaman dasar KJTe 3,6 m dan 5,6 m dari permukaan air, dengan tiga kali ulangan. Lobster pasir dari hasil tangkapan nelayan di Ujung Genteng, Sukabumi berukuran 124,45±0,17 g/ekor dan panjang 13,93±0,13 cm dipelihara dalam KJTe 1 m × 0,6 m × 0,6 m dengan kepadatan 22 ekor per m2 atau 8 ekor per keramba selama 40 hari. Lobster diberi ikan rucah sebanyak 10% dari biomassa atau sekitar 51 – 99 g per hari, dua kali sehari dengan mengangkat KJTe sampai permukaan air, kemudian pakan disebar. Bobot, panjang lobster dan fisika-kimia perairan diukur setiap 10 hari. Pengukuran dan pengamatan meliputi tingkat kelangsungan hidup, laju pertumbuhan spesifik (panjang dan bobot), laju pertumbuhan mutlak (panjang dan bobot), rasio konversi pakan, produktivitas, dan tingkah laku lobster. Hasil penelitian menunjukkan tingkat kelangsungan hidup dan produktivitas lobster pada KJTe di kedalaman 5,6 m lebih baik sebesar 66,67% dan 0,104 kg m-2 dibandingkan dengan yang lebih dangkal (P < 0,05). Pembesaran I lobster pasir pada keramba jaring tenggelam disarankan pada kedalaman 5,6 m., The application of sinking net cages (KJTe) is one alternative to improve production performance in lobster aquaculture. This study aims to analyze the production performance of sand lobster rearing I in KJTe at various depths. The research was conducted at the Sea Farming Center for the Study of Coastal and Marine Resources, Bogor Agricultural University (PKSPL-IPB), Semak Daun Island, Thousand Islands Administrative District, DKI Jakarta. The study used a completely randomized design with two treatments, namely the bottom depth of KJTe 3,6 m and 5,6 m from the water surface, with three replications. Sand lobster caught by fishermen in Ujung Genteng, Sukabumi measuring 124,45±0,17 g/head and 13,93±0,13 cm long, was reared in 1 m × 0,6 m × 0,6 m KJTe with a density of 22 fish/m2 or 8 fish per cage for 40 days. Lobsters were fed with trash fish as much as 10% of the biomass or about 51 – 99 g per day, twice a day by lifting the KJTe to the surface of the water, then the feed was distributed. Lobster weight, length, and physical-chemistry of the waters were measured every 10 days. Measurements and observations included survival rate, specific growth rate (length and weight), absolute growth rate (length and weight), feed conversion ratio, productivity, and lobster behavior. The results showed that the survival rate and productivity of lobsters at KJTe at a depth of 5,6 m were better than 66,67% and 0,104 kg m-2 those at shallower ones (P < 0,05). Grow-out of I sand lobster in submersible cages is recommended at a depth of 5,6 m.
Keyword: kelangsungan hidup, pertumbuhan, produktivitas, growth, productivity, survival rate

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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