Judul: Study Spatial and Temporal of Coral Reef State and Reef Fish Community after Tsunami In Weh and Aceh Islands Waters
Abstrak: The Tsunami in Aceh had caused to the damage of the Aceh nese reefs ecosystem. However, the ability to recover is naturally found in the coral reef. The purpose of the research are to determine percentages of hard coral cover and coral recruitment in Weh and Aceh Islands. The research was conducted in 2006, 2008, 2009, and 2011. The research was done in Aceh islands, utilization areas, marine natural tourist park (TWAL) and regional marine conservation areas (KKLD). Point Intercept Transect (PIT) and square transect Methods were applied in the research. The research showed that the percentages of hard coral cover in 2011 in Aceh island and utilization areas are 49,38% and 34,16 %, respectively. On the other hand, in marine natural tourist park (TWAL) and regional marine conservation areas (KKLD) are 32,66% and 41,27 % respectively. The percentages of coral cover had increased from 2006, 2008 to 2009. Meanwhile in the percentages of coral cover marine natural tourist park (TWAL) and regional marine conservation areas (KKLD) decreased in 2011. The highest recruitment occurred in 2008 in all survey areas and decreased in 2009. Thus, this study concluded that there existed a recovery of coral reef ecosystem with an increase in the percentage of hard coral cover and coral recruitment from 2006 to 2011. The highest abundances of reef fish in 2011 were found in marine natural tourist park (TWAL) with total amount and biomasses of 15.559 individual/ha and 1.574,43 kg/ha, respectively.
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Judul: Study Of Coral Bleaching to the State of Coral Reef and Reef Fish in Weh Island, Sabang
Abstrak: Sea surface temperature (SST) in Aceh waters had increased 4 oC which reach 33oC. This was the highest temperature recorded compared to the normal averages of 28-30 oC. The rise of SST had led to the death of coral reef. The peak of coral bleaching or bleaching index (BI) occurred on May 2010 which was 45.84 %. Meanwhile, it decreased on July 2010 and February 2011 which were (21,44 and 0,36%), respectively. The genera of Acropora and Pocillopora had a severe impact to the rise of SST which obviously led to the death. Both genera experienced 95% and 80% of bleaching on May 2011 and suffered severe death on July 2011. In addition, these genera were the most vulnerable to the coral bleaching phenomenon. However, there were some coral genera that can tolerate to the environmental changes, among them were Diplostrea and Montipora. The coral bleaching also affected the hard coral cover. In every observation points, the percentages of hard coral cover decreased by 10 to 25 %, The highest decrease percentages of hard coral cover occurred in Tourism regions where in 2009 hard coral cover decreased from 43,54 to 32,39% in 2011. This is because in this region, bleaching index (BI) reached the highest value of 77.07% than in Panglima Laot region and Free Zone which only reached 60.78% and 58.50%, respectively. The high levels of coral mortality resulted to the increasing of algal recruitment or raise percentages of Algal cover. The highest Algal cover found in Sumur Tiga and Ujung Seurawan. Both location showed the raise percentages of Algal cover in 2011 which were 20-35% (48,7% and 51,7%) than in 2009 (13,8% and 32,8%).
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Judul: Analysis of M/G/1 Queue Model with Two Phases of Service and Bernoulli Feedback System
Abstrak: Model antrean M/G/1 dengan sistem feedback Bernoulli adalah model antrean dengan proses kedatangan mengikuti proses Poisson. Pada karya ilmiah ini dibahas sistem antrean M/G/1 dengan dua fase layanan. Setelah layanan pertama selesai, pelanggan dapat memilih untuk meninggalkan sistem dengan peluang ... dst, The M/G/1 queueing model with the Bernoulli feedback system is a queueing model with the arrival process following the Poisson process. In this manuscript M/G/1 queueing system with two phases of service is discussed. After the first service is completed, the customer can choose to leave the system with probability ... dst
Keyword: queue, Bernoulli, probability generating function, expected value