Judul: Determination of Upwelling Locations As An Indicator of Potential Fishing Ground Area in The Southern Waters of Yogyakarta
Abstrak: Informasi tentang daerah penangkapan ikan bagi nelayan di Perairan Selatan Yogyakarta masih terbatas sehingga operasi penangkapan ikan menjadi tidak efisien. Hal ini dapat diatasi dengan menentukan keberadaan lokasi upwelling sebagai indikator DPI potensial. Metode untuk mengidentifikasi lokasi upwelling dilakukan dengan menganalisis dan menginterpretasi data spasiotemporal data suhu permukaan laut, klorofil-a, dan anomali tinggi muka laut yang diunduh dari Marine Copernicus yang dapat dijadikan sebagai acuan untuk mengeksplor karakteristik dan potensi DPI. Lokasi upwelling perlu verifikasi dan validasi menggunakan data spot penangkapan dan hasil tangkapan untuk membuktikan bahwa lokasi upwelling dapat dijadikan sebagai indikator DPI potensial. Nilai SPL, klorofil-a, dan TML pada musim timur mendukung adanya lokasi upwelling di Perairan Selatan Yogyakarta.Puncak upwelling terjadi di bulan Agustus yang ditandai dengan nilai SPL terendah, klorofil-a tertinggi, dan TML terendah. Puncak musim penangkapan ditandai dengan jumlah hasil tangkapan dan nilai CPUE (Catch per Unit Effort) tertinggi terjadi di bulan Agustus. Hasil validasi dan verifikasi lokasi upwelling teridentifikasi pada spot 1, 2, dan 3 pada bulan Agustus dan September., Information about fishing ground areas for fishermen in the Southern Waters of Yogyakarta is still limited so that fishing operations become inefficient. This can be overcome by determining the presence of upwelling locations as an indicator of potential FGA. The method for identifying upwelling locations is carried out by analyzing and interpreting the spatiotemporal data of sea surface temperature, chlorophyll-a, and sea surface height data downloaded from Marine Copernicus which can be used as a reference for exploring the characteristics and potential of FGA. Upwelling locations need to be verified and validated using data on fishing spots and catches to prove that upwelling locations can be used as indicators of potential FGA. The values of SST, chlorophyll-a, and SSH in the east monsoon support upwelling location in the Southern Waters of Yogyakarta. The peak of upwelling occurred in August which was marked by the lowest SST value, the highest chlorophyll-a, and the lowest SSH. The peak of fishing season is marked by the number of catches and CPUE (Catch per Unit Effort) reached the highest value in August. The results of the validation and verification of upwelling locations were identified at spots 1, 2, and 3 in August and September.
Keyword: Chlorophyll-a, FGA, Southern Waters of Yogyakarta, SST, Upwelling

Judul: Analysis of Potential Fishing Ground In Bangka Waters
Abstrak: Suhu permukaan laut merupakan indikasi umum yang mudah diteliti dengan teknik penginderaan jauh yang dapat digunakan untuk mengetahui pola distribusi SPL secara horizontal, sehingga fenomena front dapat diketahui. Konsentrasi fitoplankton dapat diidentifikasi dari citra Sea WiFS, fitoplankton sangat menentukan besarnya produktivitas primer perairan. Fenomena oseanografi yang dapat diamati melalui teknologi penginderaan jauh antara lain thermal front karena merupakan perangkap bagi zat hara dari kedua massa air yang bertemu sehingga merupakan feeding ground bagi ikan pelagis dan merupakan fishing ground bagi nelayan. Suhu rata-rata bulan April 28,5�C, thermal front berada di sebelah barat bagian atas pulau Bangka dan thermal front juga terdapat di bagian timur pulau Bangka tetapi, suhu thermal front dibagian timur lebih rendah dari sebelah barat. Bulan Juli terdapat sedikit daerah thermal front jika dibandingkan dengan bulan-bulan sebelumnya dengan kisaran suhu 28-29�C yang menyebar secara merata. Bulan Agustus dengan kisaran suhu dominan 2930�C, SPL dibagian timur lebih dominan tinggi dari sebelah timurnya, sedangkan untuk bulan September suhu relatif rendah. Hasil tangkapan ikan menggunakan indikator alat tangkap gillnet., The objective of this research is to assess the potential fishing ground based on the oceanographic phenomena such as thermal front in Bangka waters and its surroundings by using NOAA/AVHRR data. To analyze the existences of Potential Fishing Ground, therebare five data categories, i.e: NOAA-16/AVHRR, Sea WIFS, Indonesian Current Map, Indonesian Wind Maps, Fishing Catch Data, that take into account. The location of this research, geographycallys, which is lay on 105-107 E and 1°20'-3'7' S. Sea surface temperature (SST) is estimated from NOAA-16/AVHRR data by using Mc.Milin and Crosby's algorithm. Isotherms of SST distribution maps is used to locate the upwelling and the thermal front area and by overlaying with location of fishing grounds and catchs maps the area potential fishing ground is assessed. The result of the research showed that the distribution pattern of sea surface temperature in Bangka waters is around 24°C -28,5°C. Furthermore, according to fishing activity from the fishermen during May and October indicated that the potential fishing ground through this period highly related to the temperature between 24°C-26°C and the current between 1-2 m/s. There is no indicatioan of occuance upwelling in area studied; the fotential fishing grounds are locate in the high leapsaline side of the thermal front; wich are most the cases also the water massurs of low salinity
Keyword: Fishing ground, Feeding ground

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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