Judul: Studi Recruitment Karang dan Organisme Bentik pada Artificial Biorock, Pulau Pramuka-DKI Jakarta
Abstrak: Rekrutmen karang adalah proses dimana juvenil karang, yang dihasilkan melalui reproduksi, melekat pada substrat dan tumbuh menjadi bagian dari populasi karang. Akresi mineral didefinisikan sebagai proses pembentukan mineral padat dan merupakan salah satu metode pembentukan terumbu karang buatan dengan menggunakan prinsip kalsifikasi, metode ini dikenal dengan istilah biorock. Biorock diharapkan dapat menjadi substrat untuk penempelan larva karang, sehingga dapat dijadikan sebagai salah satu inovasi rehabilitasi terumbu karang yang mengalami kerusakan. Pengamatan rekrutmen karang dan biota bentik lainnya dilakukan sebulan sekali selama bulan April hingga Oktober 2010. Pada umumnya unit yang didominasi alga dan ascidian dengan perlakuan biorock pada bulan pertama pengamatan. Di akhir pengamatan, kami menemukan sepuluh genera karang dari enam famili di biorock. Kami mengamati peningkatan genera karang sebanyak tiga kali lipat selama T0-T6; Pavona, Millepora dan Stylophora. Namun pertambahan spesies karang tidak terjadi pada perlakuan non-biorock, hanya ada enam genera dan tiga famili yang diamati selama periode penelitian. Kepadatan rekrutmen karang tertinggi ditemukan pada perlakuan biorock (45 koloni/unit) dibandingkan non biorock (33 koloni/unit).
Keyword: akresi mineral, biorock, rekrutmen karang, biologi karang, reproduksi karang

Judul: Studi Recruitment Karang dan Organisme Bentik pada Artificial Biorock, Pulau Pramuka-DKI Jakarta
Abstrak: Coral recruitment is a process where juvenile coral, generated through reproduction, attached to substrates and grow to become part of coral populations. Mineral accretion defined as a process of formation of solid minerals and is one method for forming artificial reefs by using the principle of calcification, this method is known as biorock. Biorock expected to be a substrate for coral larvae settlement, so it can be used as one of the innovations of rehabilitation of coral reefs that were damaged. Observation of coral and other benthic organism recruitment were carried out once in a month during April to October 2010. In general algal and ascidians dominated unit with biorock treatment at the first month of observation. At the end of observation, we found ten coral genera from six families at biorock. We observed an increase of coral genera as much as three fold during T0-T6; Pavona, Millepora and Stylophora. However coral species increment did not occur in non-biorock treatment, there were only six genera and three families observed through out the study period. The highest coral recruitment density was found at biorock treatment (45 colonies/unit) compare to non biorock (33 colony/unit).
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Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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