Judul: Analysis of the Fishing System for Hairtail Fish (Trichiurus sp.) at the Cikidang Fish Landing Base, Pangandaran Regency
Abstrak: Penurunan sumberdaya ikan layur di perairan Pangandaran dikhawatirkan akan berdampak kepada kegiatan perikanan layur di Pangkalan Pendaratan Ikan Cikidang, Namun informasi mengenai kegiatan perikanan layur masih belum banyak dikaji secara ilmiah. Penelitian ini bertujuan untuk mengetahui kondisi perikanan layur saat ini, menganalisis faktor-faktor penurunan hasil tangkapan layur, menyusun strategi pengembangan perikanan layur di kawasan Pangkalan Pendaratan Ikan Cikidang, Kabupaten Pangandaran. Metode pengumpulan data yang digunakan adalah pengumpulan data statistik dan wawancara dengan teknik purposive sampling. Analisis data yang digunakan berupa analisis deskriptif, pendekatan sistem, dan SWOT. Hasil penelitian menunjukan bahwa nelayan menggunakan gillnet dan pancing ulur dengan kapal berukuran ≤ 5 GT untuk menangkap ikan layur. Mesh size badan pada gillnet yang digunakan berukuran 0,5 – 1 inci, The decline in hairtail fish (Trichiurus sp.) resources in Pangandaran waters is feared to have an impact on hairtail fish activities at the Cikidang Fish Landing Base, but information about hairtail fish activities is still not widely studied scientifically. This study aims to determine the current condition of hairtail fish, analyze the factors of decreasing hairtail fish catches, develop strategies for the development of hairtail fish in at the Cikidang Fish Landing Base area, Pangandaran Regency. The data collection method used is statistical data collection and interviews with purposive sampling techniques. Data analysis used in the form of descriptive analysis, system approach, and SWOT. The results showed that fishermen used gillnets and hand lines with vessels measuring ≤ 5 GT to catch hairtail fish. The body mesh size of the gillnet used is 0.5 – 1 inch
Keyword: Analisis, sistem, perikanan layur

Judul: The Fishing Season and Catch Feasibility of Hairtail fish (Trichiurus spp) in Palabuhanratu Fishing Port.
Abstrak: Ikan layur (Trichiurus spp) merupakan ikan demersal ekonomis penting dan salah satu komoditas ekspor yang potensial di PPN Palabuhanratu, Sukabumi. Ikan layur di Teluk Palabuhanatu dominan ditangkap menggunakan alat tangkap pancing layur. Informasi mengenai musim penangkapan dianggap sebagai faktor penting agar kegiatan penangkapan ikan efektif dan efisien. Penelitian ini betujuan untuk mengetahui pola musim penangkapan ikan layur, Catch Per Unit Effort, kelayakan hasil tangkapan, dan korelasi antara panjang total dengan panjang mulut dan lebar bukaan mulut ikan layur. Penelitian ini menggunakan metode penelitian deskriptif dengan jenis penelitian studi kasus. Metode analisis data yang digunakan yaitu metode rata-rata bergerak, analisis CPUE, metode hubungan panjang berat, dan analisis regresi linear. Hasil penelitian menunjukkan pola musim ikan layur terdapat pada bulan April, Juni, Agustus, September, Oktober, dan November berdasarkan nilai indeks musim penangkapan. Catch Per Unit Effort (CPUE) tertinggi dari pancing layur tahun 2015-2019 terjadi pada tahun 2019 dan nilai CPUE bulanan tertinggi pada bulan Oktober. Ukuran rata-rata ikan layur lebih besar dari kali pertama matang gonad dan masuk kedalam kategori layak tangkap. Korelasi antara panjang total dan panjang mulut serta lebar bukaan mulut dapat dijadikan acuan dalam menentukan panjang dan lebar mata pancing yang digunakan dalam alat tangkap pancing layur., Hairtail fish (Trichiurus spp) is an economically important demersal fish and one of the potential export commodities in PPN Palabuhanratu, Sukabumi. Mostly, hairtails in Palabuhanratu Bay are caught by hand line. The information of hairtails season is considered as an important factor to make fish activities are more effective and efficient. Objectives of this research are to understanding about the hairtail fishing season, catch per unit effort (CPUE), the feasibility of catches and correlation between total length with mouth length and mouth opening width of hairtail fish. This research was applied descriptive methods with case study. Data analysis was used moving average, CPUE, fish lenght and weight relations methods, and linear regression analysis. The results of this research showed the fishing season occured in April, June, August, September, October, and November. The highest Catch Per Unit Effort (CPUE) value of hand line from 2015-2019 was in 2019 and the highest monthly CPUE values was in October. The average size of haitail fish is larger than length of maturity and into the category of worth catching. correlation between total length with mouth length and mouth opening width of hairtail fish can be use as a reference in determining the length and width of the hook which is used in fishing gear.
Keyword: CPUE, Layak Tangkap, Musim Ikan, Pelabuhanratu,  Pancing Layur, CPUE, fish season, hand line, Palabuhanratu, worth catching

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology