Judul: Analisis Musim dan Daerah Penangkapan Ikan Teri (Stolephorus spp.) Berdasarkan Kandungan Klorofil-a di Perairan Sibolga, Sumatera Utara
Abstrak: Sibolga’s waters is an area which quite strategic as a central fishery production in North Sumatra. In 2010 production of fish catches landed 16,70% of total catches production. The number of primary productivity in the waters can be estimated by chlorophyll-a concentrations. Chlorophyll-a is one of the most dominant pigment in phytoplankton and play a role in photosynthesis. Knowledge about dissemination of area and fishing season are important factors in fishing activities. The study aims to determine the distribution of chlorophyll-a in the waters of Sibolga, determine the system of anchovy fishing season (Stolephorus spp.) in the waters of Sibolga, analyzing the influence of chlorophyll-a towards the anchovies catch production, and determine the potential area for catching anchovies in the waters of Sibolga . Research method which is used is survey method. The analysis result showed that the distribution of the content of chlorophyll-a in the waters of Sibolga in 2006-2010 ranged 0,26-0,68 mg/m3 with an average value of 0,45 mg/m3. Chlorophyll-a concentration was highest in the east-west transition season (September-November), which is 0,48 mg/m3. Peak of anchovy fishing season in the waters of Sibolga can be found in the west season (December-February) with the Fishing Season Index (FSI) at 134,56%. The content of chlorophyll-a in the waters of Sibolga effect on the number of anchovies catches on the 23 day time lag. Anchovy fishing area is a floating point operation of the chart and drag seine fishing in the waters of Sibolga including potential fishing area.
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Judul: Pemanfaatan dan strategi pengembangan perikanan demersal di Sibolga Provinsi Sumatera Utara
Abstrak: Demersal fish spend most of their life cycle in deeper sea column down to sea bottom. There were two main fishing gears that employed for demersal fishing in Sibolga namely trap and handline. The objectives of this study are to estimate utilization level of demersal fish resource, to identify the demersal fish size caught by traps and hand lines, to determine growth pattern of fish caught by traps and hand lines and to determine strategy for sustainable management of demersal fisheries in the study area. This study was conducted in Sibolga from December 2011 to May 2012 using survey method. Data were analyzed by means of surplus production model, length-weight relationships, and SWOT (Strengths, Weakness, Opportunities and Threats) to formulate strategies for sustainable demersal fisheries management in Sibolga. There were four dominant and most valuable economic demersal spesies caught in Sibolga: red snapper (Lutjanus malabaricus), white snapper (Lates calcarifer), sunu grouper (Plectropormus leopardus), and trevally (Caranx sexfasciatus). The result showed that catch level of red snapper had reached the optimum sustainable yield. Meanwhile the catch level of white snappers, grouper and trevally were still below their optimum sustainable yield. Traps and hand lines were considerably sustainable fishing gears due to the majority of catches have reached their length at first maturity. SWOT analysis was formulated for demersal fisheries development strategies in Sibolga. The analysis showed that the development should be focused on export markets, minimizing IUU fishing, laboratory quality assurance and enhancing cooperation among stakeholders.
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Judul: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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