Judul: Kajian Ekonomi Pengelolaan dan Pemanfaatan Sumberdaya Rajungan (Studi Kasus di Perairan Tangerang, Teluk Jakarta, Bekasi dan Karawang).
Abstrak: Blue swimming crab (blue crab) is one of the fisheries resource commodities that have high economic value, so the opportunities for export to different countries is widely open. Optimization of management and utilization of blue crab is important for sustaining economic benefit. This research aims to (1) analyze bioeconomic resource of blue crab in the waters of Tangerang, Jakarta Bay, Bekasi and Karawang; (2) evaluate the utilization of blue crab resources processed by “mini plant” in Dadap Village Tangerang Regency; (3) feasibility study of blue crab resource utilization based on size. Research location resource for management was conducted in the waters of Tangerang, Bay of Jakarta, Bekasi, Karawang and the utilization of blue crab was done in Dadap Village, Tangerang Regency. The research method used is the case study method. Sampling method used was purposive sampling for fishermen, the census for mini plant, and random sampling for crab processing system. Bioeconomic Gordon- Shaefer, analysis of productivity, and Cost Benefit Analysis (CBA) was used to analyze the data. Bioeconomic analysis results showed that the actual harvest is 1,152 tons/year, it has not exceeded the MEY level and economic overfishing has not occurred. Opportunity of increasing effort is possible and process of blue crab with size of above eight centimeters is more profitable and encourage a more stable stock of blue crab, processing of crab with optimum production, and increase efficiency of “mini plant” management in the long run. Government policies in controlling mesh size of blue crab fishing gear ≥ 8 cm should be strictly enforced, and processing plants do not accept and produce small crab < 8 cm, in order to achieve sustainable blue crab resource management.
Keyword: Cost Benefit Analysis., Bioeconomic, Blue Crab, Utilization, Resource Management

Judul: Strategi pengelolaan sumberdaya perikanan rajungan (Portunus pelagicus) untuk pemanfaatan berkelanjutan
Abstrak: Blue swimming crab (Portunus pelagicus) resources is one of high economic value commodity of marine products and numerous in Kolaka Regency waters. Kolaka Regency including in the Bone bay region, in which this region is the second largest contributor (21%) after the northern coast of Java (28%) of the blue swimming crab total production throughout Indonesia since 2001 until 2008. Estimated total blue swimming crab production in Kolaka Regency decreased because of increasing fishing activities, thus requiring a comprehensive study. The purpose of this study: 1) Knowing the potential resources of blue swimming crabs in the Bone bay waters, Kolaka Regency, Southeast Sulawesi Province; 2) Determine the ecological economics sustainability index of the blue swimming crab resources 3) Analyze the feasibility level of catch effort; 4) Determine the strategic management direction of the blue swimming crab resources for sustainable uses. The research shows that the alleged maximum sustainable yield (MSY) of 129 997 kg, optimum fishing effort (fMSY) equal to 21 739 trips. Sustainability index values obtained 1.63 (very good). Catch effort feasible to be developed,the value of NPV = Rp27 857 867, Net B/C = 3.15, and IRR = 60.62%. There are several fishing ground which clashed with the allocation based on local government policy. Blue swimming crab management resources require attention from governments and policymakers and all stakeholders. For that to be implemented management resources policies includes: 1) rescue policies, and (2) utilization policy, in order to create sustainability and obtained an optimal and sustainable utilization.
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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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