Judul: Asian Option Pricing for PT Telkom stock using Monte Carlo Simulation with Variance Reduction Techniques
Abstrak: Opsi Asia adalah opsi yang nilai payoff-nya bergantung pada rata-rata harga underlying asset selama masa hidup opsi. Harga opsi Asia sulit ditentukan secara analitik, sehingga perlu dilakukan penaksiran nilai dengan menggunakan simulasi numerik. Metode Monte Carlo adalah salah satu simulasi numerik yang dapat digunakan untuk menentukan harga opsi. Metode simulasi Monte Carlo standar memerlukan jumlah partisi waktu dan pembangkitan data yang cukup besar untuk menghasilkan nilai pendekatan yang cukup akurat dalam menentukan harga opsi. Akibatnya diperlukan jumlah iterasi yang banyak. Untuk mengurangi jumlah iterasi dan meningkatkan efisiensi, digunakan teknik reduksi varian yang dapat meningkatkan akurasi penduga dengan penurunan standar deviasi sampel. Metode Monte Carlo dengan teknik reduksi antithetic variates menghasilkan varian yang lebih kecil dibandingkan dengan simulasi Monte Carlo standar., Asian options are options whose payoff value depends on the average price of the underlying asset over the life of the option. Asian option prices are difficult to determine analytically, so estimating the value using numerical simulations is necessary. The Monte Carlo method is a numerical simulation that can determine option prices. The standard Monte Carlo simulation method requires a large enough number of time partitions and data generation to produce a reasonably accurate approximate value in determining option prices. As a result, a large number of iterations are required. To reduce the number of iterations and increase efficiency, a variance reduction technique is used, which can increase the accuracy of the estimator by decreasing the sample standard deviation. The Monte Carlo method with the antithetic variates reduction technique produces smaller variances compared to standard Monte Carlo simulations.
Keyword: antithetic variates, Asian option, Monte Carlo, variance reduction

Judul: Perbandingan Metode Monte Carlo Standar dan Monte Carlo dengan Reduksi Variansi dalam Menentukan Harga Opsi Eropa
Abstrak: Metode simulasi Monte Carlo adalah metode yang memanfaatkan hukum bilangan besar dalam perhitungannya, di mana semakin banyak jumlah iterasi yang dilakukan maka semakin baik pendekatan nilai eksaknya. Metode simulasi Monte Carlo diketahui memiliki tingkat akurasi yang rendah, oleh karena itu diperlukan teknik reduksi variansi untuk meningkatkan akurasi. Pada penelitian ini dilakukan perbandingan antara metode Monte Carlo standar dan Monte Carlo dengan reduksi variansi dalam penentuan harga opsi Eropa. Teknik reduksi variansi yang digunakan adalah peubah acak antitesis dan peubah kontrol optimal. metode Monte Carlo dengan teknik peubah acak antitesis dan peubah kontrol optimal menghasilkan variansi yang lebih kecil dibanding metode Monte Carlo standar. Dari ketiga metode yang dibaningkan, metode Monte Carlo dengan teknik peubah antitesis adalah metode yang paling efisien, karena menghasilkan variansi yang paling kecil pada setiap iterasi., The Monte Carlo simulation method is a method that utilizes the law of large numbers in its calculations, where the more the number of iterations, the better the approach to the exact value. The Monte Carlo simulation method is known to have a low level of accuracy, therefore a variance reduction technique is needed to improve its accuracy. In this study, a comparison is made between the standard Monte Carlo method and the Monte Carlo method with variance reduction method in determining European option prices. The variance reduction techniques used are the antithetic and control variates. The Monte Carlo method with the antithetic and control variates produce variances that are smaller than the standard Monte Carlo method. From the three methods that being compared, the Monte Carlo method with the antithetic variates technique is the most efficient method, because it produces the smallest variance in each iteration.
Keyword: antithetic variates, control variates, European options, Monte Carlo simulation, variance reduction

Judul: Heterologous Expression Of Endo-Β-Xylanase From Bacillus Pumilus Strain Bcrs-01 In Escherichia Coli.
Abstrak: Xylanases are glycoside hydrolase family 11 which depolymerise xylan in the plant cell wall, the most excessive form of hemicellulose. Endo-β-xylanases (EC 3.2.1.8) are most important to breakdown β-1,4-glicoside bond of xylan to produce disaccaride xyloolygosaccaride (XOs) and xylose (monomer). Bovine rumen fluids have potential to obtain endo-β-xylanase produced of bacteria. The objectives of this study were to obtain xylanase producing bacteria and to express xynA gene encoding endo-β-xylanase from bacterium in Escherichia coli. Twenty nine isolate bacteria have been succesfully isolated from bovine rumen fluid in agar medium containing birchwood xylan. Isolate BCRS-01 bacterium was previously screened for the high production of xylanase. Based on 16S rRNA gene sequence analysis, BCRS-01 showed high similarity (99%) to Bacillus pumilus (accession number NR043241). The crude xylanase had optimal activity at 55oC, pH 7.0. Furthermore, the crude xylanase exhibited broad pH stability from 4.0 to 10.0 and remained more than 60% and 40% of its activity after incubation at pH 4.0 until 10.0, respectively for 60 min. It also showed a stability at temperature 25-50oC since it retained 80% and 50% of its activity when incubated at 50oC or 30 and 60 min, respectively. The xylanase activity was strongly inhibited by Ca2+ and Cu2+ at concentration 10 mM, and as little as 1 mM for Mn2+. Therefore, this xylanase has potentially used as additive feeds in animal feed industry. The DNA sequence xynA gene encoded endo-β-xylanase was amplified and cloned into the expression vector pET-15by under the control of T7 promoter. The recombinant protein had succesfully expressed in Escherichia coli BL21 (DE3) pLysS. A protein recombinant of approximately, 26.7 kDa was observed on the SDS-PAGE analysis. Crude extract of recombinant endo-β-xylanase demonstrated activity of enzyme at 56 U mL-1 using birchwood xylan as a substrate at 55oC for 10 min.
Keyword: Bacillus pumilus, bovine rumen fluid, endo-β-xylanase, heterologous expression.