Judul: Pola Sebaran Ikan Pelagis di Sekitar Rumpon Portable di Perairan Ambon
Abstrak: Pengoperasian rumpon portable belum pernah dilakukan pada perairan laut dalam sehingga informasi terkait sebaran dan tingkah laku ikan masih minim diketahui. Informasi penyebaran ikan berdasarkan parameter lingkungan dan kedalaman perairan sangat penting untuk menunjuang keberhasilan operasi penangkapan. Tujuan penelitian ini adalah untuk menghitung gaya apung dan gaya tenggelam pada rumpon portable, mengidentifikasi pola sebaran schooling ikan, dan mengidentifikasi sebaran suhu permukaan laut di sekitar rumpon portable. Metode penelitian menggunakan Observasi lapang sebanyak dua trip operasi penangkapan dimulai dari bulan Oktober-November 2021. Data yang digunakan pada penelitian ini adalah data akustik berupa sebaran schooling serta data sekunder berupa suhu yang diperoleh dari website oseanografi https://marine.copernicus.eu/. Hasil penelitian menunjukan bahwa Rumpon portable memiliki gaya apung sebesar 98164,91 gs, dan gaya tengeglam 90763,91 gs. Ekstra bouyancy rumpon portable sebesar 75%. Sebaran schooling ikan pelagis di sekitar rumpon portable cenderung membentuk kelompok dengan jumlah yang besar pada waktu pagi dan siang dibandingkan dengan malam hari. Sebaran schooling berdasarkan kedalaman cenderung berada di permukaan pada waktu pagi dan siang di kedalaman 5-39 m, sedangkan pada malam hari berada pada kedalaman yang lebih rendah antara 40-60 m. Keberadaan schooling ikan di sekitar rumpon portable berada pada suhu antara 25-30 ., The operation of portable FADs has never been carried out in deep sea waters, so information regarding the distribution and behavior of fish is still minimal. Information on fish distribution based on environmental parameters and water depth is very important to support the success of fishing operations. The study aimed to calculate the buoyancy and sinking forces on portable FADs, identify distribution patterns of schooling fish, and identify the distribution of sea surface temperature around portable FADs. The research used field observationon as many as two fishing operation trips starting from October-November 2021. The data used in this study were acoustic in the form of schooling distribution and secondary data in the form of temperature obtained from the oceanographic website https://marine.copernicus.eu/. The results showed that the FAD portable has a buoyancy force of 98164,91 gs, and a sinking force of 90763,91 gs. Extra bouyancy of portable FADs is 75%. The distribution of pelagic schooling fish around portable FADs tends to form groups with large numbers in the morning and afternoon compared to at night. The distribution of schooling based on depth tends to be on the surface in the morning and afternoon at a depth of 5-39 m, while at night, it is at a lower depth of between 40-60 m. The presence of schooling fish around portable FADs is at a temperature between 25-30 .
Keyword: Banda Sea, purse seine, portable FAD, schooling, temperature

Judul: Karakteristik Biologi Hasil Tangkapan pada Rumpon Portable di Perairan Palabuhanratu Sukabumi, Jawa Barat.
Abstrak: FADs are fishing tools are installed in the sea which serves to lure the fish to gather. Portable FADs is FADs not place in a fixed manner in waters, but it’s used when going to do activity of fishing. The purpose of this research was to analyze the abundance of plankton, analyze the level of maturity of the fish gonads, stomach contents of fish, analyzing and calculating the index of diversity, uniformity, and the dominance of plankton that is around rumpon portable. Location research and data retrieval is in the waters of Palabuhanratu, Sukabumi of West Java. Fish tend to search of food in the area which is rich in resources food he liked .The research was done in 6 days in the waters of palabuhanratu. Total catch of fish are 179 fish with 4 species, 106 yellow fin tuna, 68 skipjack, 4 lemadang, and 1 salem. The highest level of maturity gonad for tuna is TKG I which is not worth catching fish, and skipjack is mostly TKG IV and TKG V which is worth catching fish so that portable FADs is more effective operated for catching skipjack. Composition of food were identified are small fish, shrimp, crustaceans, squid, and crab. The highest abundance of phytoplankton on the 6th day of phytoplankton abundance value of 8.2161 cells/m3 and the highest zooplankton abundances on day 5 of 5,034 individuals/m3 with are dominated by the genus Rhizosolenia sp. The value of the diversity index ranges between 1,016-2,352, uniformity index ranges between 0.489 to 1, and the dominance index plankon ranges between 0.101 to 0.570.
Keyword: abundance, fish agregating device (FADs), portable, catch

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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