Judul: Karakteristik Hasil Tangkapan Tuna Berdasarkan Aspek Biologi dan Oseanografi di Perairan Palabuhanratu
Abstrak: Informasi yang lengkap dan akurat mengenai karakteristik oseanografi dan biologi sumber daya ikan di suatu perairan sangat diperlukan untuk keberlanjutan pengelolaan perikanan. Tujuan dari penelitian ini adalah untuk mengetahui sebaran spasial dan temporal CPUE ikan tuna hasil tangkapan longline di Teluk Palabuhanratu yang dikaitkan dengan parameter oseanografi, dan menganalisis hubungan panjang dan berat ikan tuna hasil tangkapan yang didaratkan di PPN Palabuhanratu. Metode analisis yang digunakan yaitu analisis catch per unit effort (CPUE), sebaran spasial dan temporal CPUE ikan tuna dan analisis hubungan panjang dan berat. Hasil penelitian menunjukkan CPUE rawai tuna tertinggi terjadi pada bulan Agustus 2017 sebesar 1280 kg/trip dan terendah pada bulan Desember 2019 sebesar 32,1 kg/trip. Rawai tuna secara spasial menyebar acak di Teluk Palabuhanratu pada koordinat 7o-9o LS dan 105o-108o BT, dengan karakteristik oseanografi yakni berada pada suhu perairan 28o C, salinitas 33,7 ppt dan kelimpahan klorofil 0,12 mg/L. Hubungan panjang dan berat ikan tuna madidihang didapatkan nilai b sebesar 2,8675. Uji–t terhadap nilai b pada selang kepercayaan 98% diperoleh pola pertumbuhan ikan tuna sirip kuning bersifat alometrik negatif (b < 3).
Keyword: biology, characteristics, length, oceanography, weight, yellowfin tuna

Judul: Kajian Bioekonomi Perikanan Rawai Tuna di PPN Palabuhanratu, Sukabumi, Jawa Barat
Abstrak: High demand and production of tuna fish in PPN Palabuhanratu has caused exploitation of tuna increased and potentially affect the biological condition and sustainability of fishing business. This study aimed to know biological condition, utilization status, and optimum management of tuna fish resources. Diversity index of shannon-wiener (H’), length at first maturity, length-weight relationships, and bioeconomy model was used in this study for data analyses. Result of this study show that the H’ value was 1.60-2.42. Based on the length at first maturity parameter, 3.84 - 41.02 % for bigeye tuna, 0.72% for yellowfin tuna, and 65.63% for swordfish was lower than unallowable catch size. The length-weight relationships of bigeye and yellowfin tuna were indicated negative allometric growth model, whereas swordfish positive allometry. Actual effort of tuna fishery in PPN Palabuhanratu was not indicated a biological overfishing condition, however it indicated an economical overfishing condition. Bioeconomy optimalization was achieved at fishing effort of 597 trips, production of 2481.14 tons, and economic rent of Rp 67.704.000.000,-.
Keyword: PPN Palabuhanratu, tuna longline, tuna, bioeconomy

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.
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