Judul: Fishing Season and Allowable Catch Size of Hairtail Fish (Trichiurus sp.) in Cikidang Fishing Port
Abstrak: Ikan layur (Trichiurus sp.) merupakan ikan demersal ekonomis penting yang sering dimanfaatkan untuk tujuan ekspor. Tingginya permintaan ekspor menyebabkan meningkatnya upaya penangkapan. Sifat ikan layur yang mempunyai ruaya rendah serta kecenderungan menetap, sehingga memiliki daya tahan yang rendah terhadap tekanan penangkapan. Produksi ikan layur di PPI Cikidang mengalami penurunan sebesar 27.846 kg tahun 2020 menjadi 21.925 kg tahun 2021. Penentuan pola musim penangkapan dan menentukan ukuran ikan layak tangkap dengan mengestimasi ukuran ikan pertama kali matang gonad (length at first maturity) penting dalam upaya penangkapan yang lebih efektif dan berkelanjutan. Hasil penelitian menunjukan bahwa 82% ikan layur di lokasi studi layak tangkap, yakni dengan length at first maturity (Lm) sebesar 50,6 cm. Catch Per Unit Effort (CPUE) tertinggi dari alat tangkap drift gillnet tahun 2017-2021 terjadi pada tahun 2018 dengan musim puncak penangkapan ikan layur terjadi selama 6 bulan yaitu pada musim timur (Juli, Agustus, dan September) musim peralihan (Oktober, dan November) dan musim barat (Desember)., The hairtail fish (Trichiurus sp.) is an economically important demersal fish targeted for the export market. The high demand for exports has led to an increase in fishing efforts. The hairtail fish is a demersal fish with behaviour of low fecundity and is relatively sedentary, resulting in being subject to fishing pressure. The hairtail fish landing in PPI Cikidang tend to decline from 27,846 kg in 2020 to 21,925 kg in 2021. Determining the seasonal fishing pattern and establishing the allowable capture size of the fish by estimating the length at first maturity (Lm) is biologically important to as basic information in achieving more effective and sustainable fishing management. The research results showed that 82% of the hairtail fish sample from the study location exceeded the Lm, and biologically allowable to sustainable catch, with a length at first maturity (Lm) of 50.6 cm. The highest Catch Per Unit Effort (CPUE) from drift gillnet fishing gear from the year 2017 to 2021 was recorded in the year 2018, with the peak fishing season for the fish occurring for six months, specifically during the eastern season (July, August, and September), the transitional season (October and November), and the western season (December).
Keyword: drift gillnet, allowable catch size, hairtail fish, seasonal fishing patterns, trichiurus sp., ikan 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: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
Keyword: