Judul: The Impact of Covid-19 Pandemic on Fish Marketing Activities at Palabuhanratu Fish Auction
Abstrak: Pandemi covid-19 menyebabkan terbatasnya kegiatan di tengah masyarakat dan hal tersebut diduga akan berdampak pada kegiatan pemasaran di Tempat Pelelangan Ikan (TPI) Palabuhanratu. Tujuan penelitian ini adalah mengidentifikasi dampak covid-19 terhadap aktivitas pemasaran ikan di TPI Palabuhanratu, membandingkan keuntungan pedagang ikan pada saat sebelum covid-19 dengan saat pandemi covid-19 dan merekomendasikan strategi untuk mengatasi dampak covid-19 terhadap aktivitas pemasaran ikan di TPI Palabuhanratu. Penelitian ini menggunakan metode studi kasus. Teknik pengambilan data untuk tujuan pertama dan kedua menggunakan metode accidental sampling serta tujuan ketiga menggunakan metode purposive sampling. Analisis data terdiri dari analisis deskriptif metode skoring, analisis keuntungan usaha, dan matriks SWOT. Hasil penelitian menunjukkan bahwa berdasarkan persepsi responden, terjadi beberapa perubahan aktivitas pemasaran ikan pada saat pandemi seperti menurunnya jumlah konsumen, harga jual ikan menurun, pendapatan pedagang menurun, serta menurunnya jumlah ikan yang dijual. Keuntungan pedagang mengalami penurunan hingga 50% yang berpengaruh terhadap biaya usaha dan total penerimaan para pedagang. Strategi dalam mengatasi dampak pandemi covid-19 terhadap aktivitas pemasaran ikan di TPI Palabuhanratu ialah penguatan sistem lelang, peningkatan fasilitas pendistribusian hasil tangkapan ke industri maupun pasar diluar daerah TPI, menyediakan layanan internet dan sosisalisasi digital marketing kepada para pedagang, menambah cold storage, dan melakukan sistem resi gudang ikan., Covid-19 pandemic caused limited activities in public and it is expected to have an impact on marketing activities at the Palabuhanratu Fish Auction (TPI). The purpose of this research are to identify the impact of covid-19 on fish marketing activities at TPI Palabuhanratu, compare the profits of fish traders in the time before covid-19 with during the covid-19 pandemic and recommend strategies to overcome the impact of covid-19 on fish marketing activities in TPI Palabuhanratu. This research use case study methods. Data collection techniques for the first and second purpose use accidental sampling methods as well as for the third-purpose using purposive sampling methods. Data analysis consists of descriptive analysis of scoring methods, profit analysis, and SWOT matrix. Result showed that based on respondents perception there were several changes in fish marketing activities during the pandemic such as declining consumer numbers, declining fish selling prices, declining merchant income, and decreasing the number of fish sold. Traders profits decreased by up to 50% which affects business costs and total acceptance of traders. Strategies in overcoming the impact of the covid-19 pandemic on fish marketing activities in TPI Palabuhanratu are strengthening the auction system, improving the distribution of catch facilities to industries and markets outside the TPI area, providing internet services and digital marketing socialization to traders, adding cold storage, and conducting fish warehouse receipt systems.
Keyword: Covid-19, Ikan, Palabuhanratu, Pedagang, Pemasaran

Judul: Analysis of the Impact of COVID-19 Pandemic on  the Supply Chain of Fish Resources in Indonesia
Abstrak: Pandemi COVID-19 saat ini dengan cepat menyebar ke seluruh dunia yang menyebabkan dampak sosial dan ekonomi yang luas. Beberapa dampak buruk dapat dirasakan oleh seluruh dunia dan Indonesia, salah satunya pada sektor perikanan. Penelitian ini bertujuan menganalisis dinamika rantai pasok sumber daya ikan dalam perspektif produksi, ekspor dan impor perikanan di Indonesia selama pandemi COVID-19. Data yang diambil adalah data produksi, ekspor, dan impor produk perikanan dari Kementerian Kelautan dan Perikanan Republik Indonesia dengan rentang waktu Januari 2018 - Juni 2021. Hasil yang didapatkan menunjukkan bahwa selama pandemi COVID-19 terjadi penurunan volume produksi perikanan yang tidak berbeda nyata. Sektor ekspor dan impor juga sempat mengalami penurunan volume di awal pandemi, namun kemudian volumenya kembali stabil dan terus meningkat, begitu pula untuk ekspor produk komoditas unggulan perikanan Indonesia yang volume dan nilainya juga meningkat selama pandemi. Secara keseluruhan, volume produksi terdampak negatif oleh pandemi, sedangkan volume ekspor dan impor terdampak positif oleh pandemi., The current COVID-19 pandemic is rapidly spreading across the globe and causing wide-ranging social and economic impacts. Some of the bad impacts can be felt by the whole world, including Indonesia in the fisheries sector. This study aims to analyze the dynamics of the supply chain of fish resources in the perspective of fishery production, export and import in Indonesia during the COVID-19 pandemic. The data taken is data on production, exports, and imports of fishery products from the Ministry of Maritime Affairs and Fisheries of the Republic of Indonesia from of January 2018 to June 2021. The results obtained indicate that during the COVID-19 pandemic there was a decrease in the volume of fishery production that was not too significant. The export and import sectors also experienced a decline in volume at the beginning of the pandemic. However, the volume stabilized and continued to increase, as well as exports of Indonesia's leading fishery commodities, whose volume and value also increased during the pandemic. Overall, production volume was negatively affected by the pandemic, while export and import volume was positively affected by the pandemic.
Keyword: COVID-19, Fisheries, Indonesia, COVID-19, fisheries, Indonesia,, supply chain

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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