Judul: Struktur komunitas ikan yang berasosiasi dengan ekosistem Padang Lamun di Perairan Tanjung Merah, Sulawesi Utara
Abstrak: Perairan Sulawesi Utara khususnya Tanjung Merah, mempunyai ekosistem padang lamun yang cukup yaitu mencapai panjang antara 174-240 meter. Secara ekologis dan ekonomis pada lamun menjadi penting karena menopang kehidupan biota laut di sekitarnya dan sedang mendapat tekanan akibat industri pelayaran yang berkembang di Bitung, Sulawesi Selatan.
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Judul: Struktur Komunitas Lamun di Perairan Pagerungan, Jawa Timur.
Abstrak: Perairan Pagerungan terletak di Kepulauan Kangean, Jawa Timur. Pada perairan tersebut terdapat tiga ekosistem yang produktif yaitu mangrove, terumbu karang dan padang lamun. Ekosistem lamun merupakan salah satu ekosistem di laut dangkal yang mempunyai peranan penting dalam kehidupan biota laut dan merupakan salah satu ekosistem bahari yang paling produktif, sehingga mampu mendukung potensi sumberdaya yang tinggi pula. Seiring dengan meningkatnya aktivitas di daerah pesisir, telah memberikan tekanan terhadap ekosistem padang lamun. Di lain pihak walaupun sudah mengalami tekanan, namun penelitian tentang lamun masih sangat sedikit. Padahal informasi tersebut sangat penting untuk mene1aah pentingnya manfaat lamun dan pengelolaannya di masa yang akan datang. Penelitian ini bertujuan untuk mengetahui struktur komunitas lamun di perairan Pagerungan. Hasil penelitian ini diharapkan berguna sebagai infomasi dasar untuk lebih memahami fungsi dan faktor ekologis serta informasi dasar dalam pemanfaatan serta pengelolaan padang lamun. Disamping itu juga untuk melengkapi informasi tentang keberadaan lamun di Indonesia.
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Judul: The Effects of Variance of Interest rate to Variance of Annuity Future Values
Abstrak: Time value of money is a concept that refers to the difference of the value of money due to time difference. The value of money for present time would not be the same as the value of money in the future. The value of money for present time is called as Present Value (PV) of the money and the value of money for future time is called Future Value (FV) of the money. Determination the value of money, for present and future time, depends on the time and rate of return. The value of money is determined by several factors such as inflation, fluctuation of interest rates, and government policy in securities and taxation. Due to fluctuation of the value of money we need a FV formulation, it is useful for knowing whether an investment can be profitable or not, and this information is useful also in budget analysis. Annuity is defined as a series of payments made for a specific period. The payment, fixed or varied, can be made at the beginning or at the end of the period. Annuity paid at the beginning of the period is called annuity-due and annuity paid at the end of the period is called immediate annuity-certain. The accumulated value of the annuity after few years later is called as a final value or a future value. Burnecki et al. (2003) have discussed about the FV of a fixed-rate annuity in which payments are made according to the arithmetic or geometric series. They have also examined FV for annuities in which payments are made according to arithmetic or geometric series with random rates of interest. This paper examines FV for annuity-due in which payments are made according to arithmetic or geometric series with interest rates as a random variable, which is normal distribution ,  . Future value formula is expressed in recursive form. FV for annuity-due which payments are made according to the arithmetic or geometric series with random rates of interest is calculated by theoretical way and simulation way. The random rates of interest is denoted as k k i  i  , where k i an independent random variable; i is a constant and k  is a random variable which has normal distribution ,  . By using the determined parameters, a sequence of random rates of interest are generated for theoretical calculation. Meanwhile for the simulation, the random rates of interest is generated 1000 times for the simulation. The generated data give mean value, variance, and standard deviation. Moreover, error of mean value, variance, and standard deviation from the theoretical and simulation results are calculated. Error calculation uses Symmetric Mean Absolute Percentage Error (SMAPE). The smaller the value of SMAPE is the more accurate the simulation. The interest rate variances are varied from 0.000036 to 0.0001 to study the relationship between variance of rates of interest and variance of future value. The theoretical and simulation results show that when the variance of random rates of interest increases, then the variance of FV increases linearly. FV of the annuity-due in
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