Judul: Kelayakan Usaha Perikanan Cast net di Pelabuhan Perikanan Nizam Zachman Jakarta.
Abstrak: Armada kapal cast net terus bertambah di PPS Nizam Zachman Jakarta (PPSNZJ) karena banyak pengusaha cumi-cumi pemula yang baru terjun bisnis perikanan cumi-cumi dan menjadi salah satu faktor bertambahnya armada disana. Sehingga menyebabkan tingginya kompetisi saing antar pengusaha. Penelitian ini bertujuan mengevaluasi produktivitas dan kelayakan usaha cast net di PPSNZJ guna meberikan informasi untuk perencaan bisnis yang dapat digunakan oleh seseorang yang akan mencoba bisnis sektor perikanan cumi-cumi. Dilakukan melalui metode accidental sampling dengan teknik wawancara. Data dianalisis secara deskriptif kualitatif untuk hasil kelayakan usaha non-finansial dan dianalisis secara kuantitatif untuk produktivitas dan kelayakan usaha finansial. Sampel meliputi kapal cast net berukuran 20-30 GT, 31-50 GT, dan 51-100 GT. Hasilnya kelayakan usaha perikanan cast net menunjukkan bahwa kapal dengan ukuran 31-50 GT dan 51-100 GT termasuk kategori finansial layak usaha, sedangkan untuk ukuran 20-30 GT termasuk kategori finansial tidak layak usaha., The fleet of cast net vessels continues to grow at PPS Nizam Zachman Jakarta (PPSNZJ) because there are many new squid entrepreneurs who have just entered the squid fisheries business and are one of the factors for the increase in the fleet there. This has led to high competition among entrepreneurs. This study aims to evaluate the productivity and feasibility of the cast net business at PPSNZJ in order to provide information for business planning that can be used by someone who will try the squid fishery sector business. Conducted through accidental sampling method with interview technique. Data were analyzed descriptively qualitatively for non-financial business feasibility results and quantitatively analyzed for productivity and financial business feasibility. Samples included cast net vessels of 20-30 GT, 31-50 GT, and 51-100 GT. The results of cast net fishery business feasibility showed that vessels of 31-50 GT and 51-100 GT were categorized as financially viable, while those of 20-30 GT were categorized as financially unviable.
Keyword: business feasibility, cast net, Nizam Zachman Ocean Fishing Port Jakarta, productivity, squid

Judul: Kebutuhan Perbekalan Melaut pada Unit Penangkapan Cast Net 51-100 GT di Pelabuhan Perikanan Samudera Nizam Zachman Jakarta.
Abstrak: Kegiatan penangkapan pada kapal cast net 51-100 GT membutuhkan berbagai komponen perbekalan. Perbekalan yang dibawa selama ini selalu mengalami kekurangan karena trip operasinya cukup lama, yaitu sekitar 3-4 bulan. Penelitian ini bertujuan untuk mendeskripsikan kondisi umum, mengidentifikasi jenis perbekalan, menghitung kebutuhan perbekalan aktual, dan mendeskripsikan penanganan perbekalan pada unit penangkapan cast net. Penelitian yang dilaksanakan di Pelabuhan Perikanan Samudera Nizam Zachman Jakarta dilakukan dengan metode survei menggunakan teknik wawancara. Teknik pengambilan sampel dengan purposive sampling. Analisis data yang digunakan adalah analisis deskriptif secara kuantitatif dan kualitatif. Hasil penelitian menunjukkan bahwa kapal cast net 51-100 GT menggunakan alat tangkap jala jatuh dengan target tangkapan utamanya adalah cumi-cumi. Jenis perbekalan yang digunakan pada unit penangkapan cast net terdiri perbekalan solar, air bersih, minyak pelumas, dan konsumsi. Kebutuhan biaya untuk perbekalan kapal cast net 51-100 GT adalah Rp 1.708.072.500,00/unit/tahun yang dialokasikan untuk solar 88,72%, minyak pelumas 1,54%, air bersih 0,18%, dan perbekalan konsumsi 9,56%. Tindakan yang dilakukan jika perbekalan tidak mencukupi selama kegiatan penangkapan yaitu pengiriman perbekalan dari fishing base ke fishing ground oleh pemilik kapal. Adapun tindakan saat perbekalan berlebih dibagikan kepada rombongan nelayan lain saat menuju fishing base., Fishing activities on 51-100 GT cast net vessels require various components of supplies. The supplies carried during this time always experience a shortage because the operation trip is around 3-4 months long. The study aims to describe the general condition of cast net fisheries, identify the types of supplies in the cast net fishing unit, calculate the actual supply needs in the cast net fishing unit, and describe the handling of supplies in the cast net fishing unit. The research was conducted at the Nizam Zachman Ocean Fishing Port Jakarta using a survey method using interview techniques. The sampling technique was purposive sampling. The data analysis used was descriptive quantitative and qualitative analysis. The results showed that 51-100 GT cast net vessels use fall net fishing gear, with the main target catch being squid. The supplies used in cast net fishing units consist of diesel fuel, clean water, lubricating oil, and consumption. The cost requirement for supplies for 51-100 GT cast net vessels was IDR 1,704,232,500.00/unit/year, allocated for diesel fuel 88.52%, lubricating oil 1.76%, clean water 0.18%, and consumption supplies 9.54%. The action taken if there are insufficient supplies during fishing activities is the delivery of supplies from the fishing base to the fishing ground by the boat owner. The actions are taken when the excess supplies are distributed to other fishing groups heading to the fishing base.
Keyword: cast net, supplies, consumption, handling, PPSNZ

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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