Judul: Projection Analysis of Skipjack Tuna (Katsuwonus pelamis) Landed at Cilacap Ocean Fishing Port
Abstrak: Ikan cakalang (Katsuwonus pelamis) salah satu komoditas utama di PPS Cilacap dimanfaatkan sebagai bahan baku untuk industri cold storage dan industri pengolahan. Jumlah ikan cakalang yang didaratkan mengalami fluktuasi selama periode 10 tahun terakhir. Tujuan penelitian ini adalah mendeskripsikan kondisi umum perikanan cakalang, menentukan metode proyeksi yang tepat dan memproyeksikan pendaratan ikan cakalang serta menyusun strategi pengadaan ikan cakalang untuk kebutuhan industri di PPS Cilacap. Metode penelitian adalah wawancara dengan teknik purposive sampling dan dianalisis menggunakan analisis deskriptif, analisis proyeksi dan analisis SWOT. Perikanan cakalang di PPS Cilacap didominasi kapal 21-30 GT dengan alat tangkap pancing ulur. Metode rata-rata bergerak tertimbang dengan bobot binomial 3 terpilih karena memiliki nilai MAPE dan MSE terkecil yaitu 37,67% dan 2.316,52. Proyeksi pendaratan ikan cakalang di PPS Cilacap tahun 2023 sebesar 4.831,92 ton. Rekomendasi strategi pengadaan ikan cakalang untuk industri di PPS Cilacap yaitu melakukan kerja sama dengan dengan pelabuhan lain dalam menunjang ketersediaan bahan baku, peningkatan dan pengembangan kualitas SDM perikanan, pengembangan fasilitas pelabuhan (kolam pelabuhan) untuk menunjang penambahan jumlah armada penangkapan ikan, dan peningkatan kinerja dalam monitoring dan pendataan logbook penangkapan ikan., Skipjack tuna (Katsuwonus pelamis), one of main commodities in PPS Cilacap used as a raw material for cold storage and processing industries. Its production has fluctuated over the last 10 years. This made the port manager unable to ensure the ability to produce fish for the coming year. The purpose of this study was to describe the general condition of skipjacks, determine the appropriate projection model and project the skipjack tuna landed and develop a strategy for procurement of skipjack’s industrial needs in PPS Cilacap. The research method is interview with purposive sampling technique, descriptive, projection, and SWOT analysis. Skipjack fishing in PPS Cilacap is dominated by 21-30 GT vessels with handline fishing gear. Weighted moving average method with binomial 3 was chosen because it has the lowest MAPE and MSE values (37.67% and 2.316,52). Projected production of skipjack at PPS Cilacap in 2023 is 4.831,92 tons. Recommendations for the skipjack procurement industrial strategy at PPS Cilacap are collaborating with other ports to support the availability of raw materials, improving and developing the quality of fisheries human resources, developing port facilities (port pools) to support the increasing of fishing fleets, and improving performance in monitoring and collecting fishing logbook data.
Keyword: Handline, PPS Cilacap, Projection, Skipjack tuna, Weighted moving average

Judul: Parameter Dinamika Populasi Ikan Cakalang (Katsuwonus pelamis Linnaeus, 1758) yang Didaratkan di PPS Cilacap, Provinsi Jawa Tengah.
Abstrak: Skipjack tuna (Katsuwonus pelamis) is a large pelagic fish that have important economic value in the Indian Ocean and also as a dominant fish landed in PPS Cilacap, Central Java. The aim of this research is to determine the population dynamics parameter of skipjack tuna in the Indian Ocean. This research was in December 2014 until March 2015. The data analysis conducted are sex ratios, gonad maturity, first lenght maturity, length frequency distribution and age, lenght and weight relationship, growth parameters, exploitation rate, and the surplus production model. The results shown growth of skipjack tuna move slow (K = 0,3). Lenght infinity (L∞) of skipjack tuna is 992,6303 mm, the exploitation rate is 0,93 and called as overexploited. Maximum sutainable yield (MSY) is about 3354,3 ton per year and optimum effort amount is 1700 trip per year. Management efforts to control fishing effort and restrictions of the fishing season.
Keyword: Skipjack, Cilacap, population indicator, management

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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