Judul: Perbandingan Metode Monte Carlo dan Kuasi Monte Carlo dalam Penentuan Harga Opsi Eropa
Abstrak: Opsi adalah suatu kontrak antara dua pihak di mana pemegang opsi mempunyai hak untuk membeli atau menjual suatu aset tertentu dengan harga yang telah ditentukan, pada atau sebelum waktu jatuh tempo. Opsi sebagai produk derivatif dapat mengurangi dampak risiko dalam berinvestasi dengan melakukan hedging (lindung nilai). Opsi Eropa merupakan opsi yang hanya dapat dieksekusi pada saat jatuh tempo. Karya ilmiah ini membahas penentuan harga opsi Eropa dengan menggunakan metode Monte Carlo dan Kuasi Monte Carlo dan hasilnya dibandingkan dengan harga opsi standar yang telah dihitung dengan menggunakan model Black Scholes. Berdasarkan hasil penghitungan, metode Kuasi Monte Carlo lebih cepat konvergen dengan galat relatif yang lebih kecil dibandingkan dengan metode Monte Carlo dalam penentuan harga opsi Eropa. Dengan demikian, dapat disimpulkan bahwa metode Kuasi Monte Carlo merupakan metode yang lebih baik dibandingkan metode Monte Carlo dalam penentuan harga opsi Eropa.
Keyword: opsi Eropa, Black Scholes, Monte Carlo, Kuasi Monte Carlo

Judul: European Option Pricing Using the Monte Carlo Method and the Finite Difference Method
Abstrak: Harga opsi Eropa umumnya dihitung menggunakan model Black-Scholes. Model ini dapat digunakan ketika asumsinya terpenuhi. Perdagangan opsi pada kenyataannya tidak memenuhi beberapa asumsi, sehingga model Black-Scholes tidak dapat memberikan solusi analitik untuk harga opsi. Hal ini menjadi alasan dibutuhkannya metode numerik untuk menghitung harga opsi Eropa. Pada penelitian ini digunakan dua metode numerik, yaitu metode Monte Carlo yang menghitung harga opsi dengan melakukan simulasi harga saham dan metode beda hingga yang melakukan diskretisasi pada persamaan diferensial parsial. Karya ilmiah ini memeriksa kekonvergenan untuk tiap metode. Selanjutnya, diperiksa pengaruh dari beberapa parameter terhadap harga opsi menggunakan metode beda hingga. Waktu jatuh tempo opsi dengan harga opsi memiliki hubungan yang berbeda untuk kondisi tertentu dan volatilitas harga saham berbanding lurus dengan harga opsi., European option prices are generally calculated using the Black-Scholes model. This model can be used when the assumptions are fulfilled. In fact, options trading does not fulfill several assumptions so the Black-Scholes model cannot provide an analytical solution for option prices. This is the reason for the need of numerical methods to calculate European option prices. This study uses numerical methods such as the Monte Carlo method which calculates option prices by simulating stock prices and the finite difference method which performs discretization on partial differential equations. This paper examines the convergence for each method. Next, we examine the effect of several parameters on the option price using the finite difference method. The expiration time of the option and the option price has a different relationship for certain conditions and the volatility of the stock price is directly proportional to the option price.
Keyword: European option, finite difference method, Monte Carlo method, option

Judul: Analysis of genomic dna fragment involved in acid- aluminium tolerance in bradyrhizobium japonicum
Abstrak: Bradyrhizobium japonicum is one of Rhizobia species which generally form root nodule on soybean plant (Glycine max). In association with leguminous plant, root nodule bacteria (RNB) fix atmospheric nitrogen (N2) into NH3 which can be used for plant growth. Soil acidity is a significant problem affecting agricultural production in many areas of the world. Lowering pH of the soil can affect soil organisms including the microflora. Among the biological system affected by the decrease in soil pH are those between RNB and leguminous plants. It could affect the association result between them in fixing nitrogen. In the previous work, screening indigenous B. japonicum strains which tolerant to acid-aluminium has been reported. The potential strains were strains BJ11, BJ38, and KDR15. These tolerant strains could become a source of genetic material exploration which involved in acid-Al tolerance in B. japonicum. Transposon delivery was carried out through conjugation between Escherichia coli S17-1 (λ pir) carrying pUTmini-Tn5Km1 and acid-Al tolerant B. japonicum at 1:1 ratio. Frequency of transconjugation was in the range of 10-8–10-6 cells per recipients. A mutant AAS11.2 did not able to grow on the Ayanaba medium (pH 4.5) supplemented with 50 μM aluminium. AAS11.2 was able to form root nodule on siratro plant indicating that the gene involved in acid-Al tolerance was not related with nodulation. A 0.8 kb of the genomic DNA fragment flanking transposon involved in acid-Al tolerance was successfully isolated by inverse polymerase chain reaction (inverse PCR) from AAS11.2 genome. This fragment was subsequently cloned into pGEM-T Easy (∼3 kb) to yield a recombinant plasmid, designated as pGEMT-11 (∼3.8 kb), and sequenced. DNA sequenced analysis revealed that the genomic DNA fragment sequence had high homology with yhfK gene encoding putative inner membrane protein from Salmonella typhimurium (79% identity and 84% similarity, E-value= 1.0xe-100) which function as efflux transporter.
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