Judul: Analisis perikanan cakalang (Katsuwonus pelamis) di Teluk Bone : hubungan aspek biologi dan faktor lingkungan
Abstrak: Fishing activities targeting skipjack tuna (Katsuwonus pelamis) take place in the Bone Bay. The bay is part of the Indonesia Fisheries Management Area or WPPI 713 that covers Makassar strait, Flores sea and Bali sea. This study describes some biological characteristics of the skipjack tuna in three pre-defined fishing zones, i.e. the North Zone (Districts of Luwu, Luwu Utara, Luwu Timur, Wajo and Palopo city), the Centre Zone (District of Bone) and the South Zone (District of Sinjai). Such information is very important for developing fisheries management strategies in the bay. The objectives of the study are to analyze biological characteristics of the skipjack tuna caught in the Bay, to calculate and interpretate of CPUE of the fisheries, to analyze dynamics of fishing and fish production in relation to oceanography condition, and to determine a concept of fisheries management of the Bone Bay. Data were obtained from fishing activities conducted by local fishermen from January to December 2007, local fisheries statistics and internet-published data of sea surface temperature (SST) and chlorophyll (Chl) content. Seasonal and annual total fishing effort and fish production for a period of 11 years (1996-2006) were analyzed. Seven statistical parameters of the factors for SST and Chl were calculated and correlated with the fisheries statistics. The b coefficients for length-weight relationship in the three zones were equal to 3. The average fork-length (FL) of the fish in each zone showed similar trends, i.e it increased from January to June, then stabilized until December. Using von Bertalanffy’s growth model, the maximum FL (i.e.,76 cm) will be reached when fish at age of 84 months while the length at first maturity of the fish is 46,5 cm (FL). Overall, the average size of the skipjack tuna caught by pole and liners in January-April are small (31,5-46,3 cm, FL), from May to June the fish is larger (48,5-56,6 cm, FL), then the average size become smaller from July to December (33,7-48,2 cm, FL). From January to May, the size of the fish in the North Zone is generally smaller than in the two other zones. From May to August, the size of the fish in the South Zone is generally larger than in the two other zones. From September to December the size of the fish is generally similar among the three zones, but smaller than the size of the fish caught in the South Zone in June. Regardless of fish size composition, the MSYSS of Bay-wide shared fish stock is 15.783 tons/year with Fopt is 12.626 trips/year. However, considering length at first maturity of the species, the catch allocation for the North Zone should be 573 tons/year with fishing effort of 409 trips/year, catch in the Center Zone should be 5.820 tons/year with fishing effort of 3.279 trips/year, while in the South Zone should be 2.210 tons with fishing effort of 1.688 trips/year. The relationship between fish production and SST/Chl, for both seasonal and quarterly in the North, Central and South Zones were categorized as type 11, 10 and 5, respectively. Significant correlations were identified between SST/Chl and production of
Keyword: Katsuwonus pelamis, Overfishing, Renewable resources, Spawning ground, Nursery ground, Feeding ground, Skipjack tuna, Fisheries management, Shared fish stock, Fishing zone, Bone Bay

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: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik