Judul: Analisis Bioekonomi Sumber Daya Ikan Cakalang (Katsuwonus pelamis Linnaeus, 1758) di PPN Palabuhanratu, Provinsi Jawa Barat.
Abstrak: Bioeconomic analysis of skipjack tuna (Katsuwonus pelamis) was conducted to determine appropriate and sustainable fisheries resources management. This research was located in PPN Palabuhanratu, ProvinsiJawa Barat. In this research sampling was conducted four times during from December 2014 to March 2015. Data that was collected such as skipjack tuna’s length and weight, interview data, and statistical catch data of skipjack tuna. The aim of this research is to study skipjack tuna bioeconomic and sustainable yield. Exploitation rate with Ford Walford method is 0,6 per year. Surplus production model and bioconomic optimal effort of skipjack tuna is 317 trip per year with maximum sustainable yield 821 ton per year. Skipjack tuna fisheries resources utilization in this year can be estimated experience underfishing caused by some year before the utilization was overfishing. The appropriate policy that can be implied is limiting fish catch corresponding to Total Allowable Catch as big as 656 ton per year.
Keyword: Bioeconomic, skipjack tuna (Katsuwonus pelamis), Palabuhanratu

Judul: Resource Management of Skipjack (Katsuwonus pelamis) in Pelabuhanratu, Sukabumi District, West Java
Abstrak: Katsuwonus pelamis (skipjack or Skipjack Tuna) is one of the major pelagic fish commodities in Palabuhanratu Archipelagic Fishing Port (PPN Palabuhanratu) and become important aspect in the development of fisheries industrialization especialy for non-tuna species. Geographically, Palabuhanratu bay is situated in Fisheries Management Area (WPP) 573 on Indian Ocean. As the vast waters, fisheries management can be initiated from a small area, for example in the bay area. To understand the biological characteristics of fish such as skipjack (Katsuwonus pelamis Linnaeus, 1758) is crucial information to realizing fisheries resources management in some region. This research aims to determine the weight and length relationship, size composition, growth pattern and decent size of skipjack fishing in Palabuhanratu. Data obtained from the result of landing catches in PPN Palabuanratu from December 2012 to May 2013. Through a series of data catches of skipjack during the period 2002 to 2011 estimation made for catch effort at the level of Maximum Sustainable Yields (MSY), Maximum Economic Yield (MEY) and Open Access (OA). MSY, MEY and OA are the bio-economic indicator to formulate appropriate policies for Skipjack resources management in Palabuhanratu. The research was conducted on fish landed in Palabuhanratu by using payang gear, gillnet, and trolling. From the results of the calculation of the weight and length noted that males skipjack have a negative allometric growth pattern which means that its length growing faster than its weight. While skipjack females have an isometric growth which means its length growth pattern equal to its weight. The maximum length of tuna were obtained during the study was 710 mm. Length of fish for the first gonads mature was estimated of 523 mm, with the result that so the tuna catch is a the minimum worthines of cakalang fishing was 523 mm. Recognizing these data, if compared with the size of tuna caught during the study, only 11.2 % were larger than the size of a decent catch, this is an indication of the outset of the recruitment overfishing in Palabuhanratu. Total males mortality rate (Z) was 2.0988 fish per year and for females amounted to 0.8415 per year. While the rate of exploitation of both males and females are equal to 0.9 per year. The catch and effort at the level of Maximum Sustainable Yield (MSY) are 305.283 kgs /year and 3.898 trips /year. While estimating the value of the Maximum Economic Yield (MEY) and Open Access (OA) at the level 240.380 kgs/year; 2.101 trips/ year and 303.434 kgs/year ; 4.201 trips/year. Fox models analysis shows that overfishing has occurred since 2006 with the utilization rate of 129 % as calculated in the last year (2011) has undergone economic over fishing. Some forms of fisheries management proposed in this research include: restrictions on fishing quotas at MSY level of 78,32 Kgs/Trip and to MEY 114,43 Kgs/Trip; the policy of mesh size; conservation efforts; season control / fishing areas (spawning ground and fishing ground); rotation in fishing (fishing with alternate day) ; restrictions on the issuance of fishing licenses for new fishing vessels; Co-management among stakeholders; law enforcement (enforcement) and
Keyword: Pelabuhanratu Bay, Bioecological parameters, Bioeconomics, optimization, management.

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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