Judul: Potensi Lampu LED (light emitting diode) sebagai Perangkap Lampu untuk Cylasformicarius Fabricius (Coleoptera: Curculionidae).
Abstrak: Cylas formicarius Fabricius (Coleoptera: Curculionidae) merupakan hama utama ubi jalar. Di Indonesia, hama ini terdapat di semua daerah penghasil ubi jalar. Serangan hama ini menyebabkan kehilangan hasil sebesar 10% hingga 80%. Serangan C. formicarius tidak hanya terjadi di lapang, namun telur dan larvanya yang berada dalam umbi dapat juga terbawa hingga ke tempat penyimpanan atau tempat penjualan (pasar). Berbagai upaya telah dilakukan untuk mengendalikan C. formicarius, diantaranya sanitasi, menanam varietas tahan, stek sehat, pembumbunan, rotasi tanaman, penggunaan insektisida, feromon seks, penggunaan cendawan entomofaga Beauveria bassiana, pelepasan imago steril dan kombinasi antara feromon seks dan cendawan Beauveria bassiana.
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Judul: Keefektifan Cendawan Metarhizium brunneum Petch terhadap Hama Ubi Jalar Cylas formicarius Fabricius (Coleoptera: Brentidae)
Abstrak: Cylas formicarius Fabr. merupakan hama utama pada ubi jalar (Ipomoea batatas) dan tersebar di seluruh dunia. Salah satu musuh alami penting hama tersebut adalah cendawan genus Metarhizium. Imago C. formicarius diberi perlakuan suspensi konidia M. brunneum pada kerapatan 0, 106, 107, 108, dan 109 konidia/ml. Sebagai pembanding digunakan cendawan Beauveria bassiana pada kerapatan yang sama. Aplikasi dilakukan dengan metode semprot terhadap serangga. Dengan kerapatan konidia 109/ml cendawan M. brunneum mampu mengakibatkan kematian C. formicarius hingga 95% pada hari ke-10 setelah perlakuan. Pada hari ke-10 diperoleh LC50 sebesar 4.2x106 konidia/ml dan LC95 sebesar 5.7x109 konidia/ml pada M. brunneum, sedangkan nilai LC50 dan LC95 B. bassiana berturut-turut sebesar 2.0x108 konidia/ml dan 4.3x1010 konidia/ml. Dengan menggunakan kerapatan konidia 109/ml, diperoleh LT50 3.73 hari dan LT95 7.82 hari (M. brunneum) dan LT50 6.00 hari dan LT95 23.16 hari (B. bassiana). Dari hasil yang diperoleh dapat disimpulkan bahwa M. brunneum efektif untuk mengendalikan C. formicarius.
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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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