Judul: Analysis Stock Price Using Black-Scholes Model and Runge-Kutta Orde 4.
Abstrak: Saham merupakan surat tanda kepemilikan suatu perusahaan. Analisis saham dan parameter yang digunakan penting untuk memberikan keuntungan yang besar dimasa yang akan datang. Black-Schole merupakan sebuah model untuk menganalisis opsi menggunakan Brownian motion. Opsi saham di Indonesia sudah tidak berlaku, oleh karena itu pada penelitian kali ini menggunakan Black Schole model dengan Runge Kutta Orde 4 untuk menganalisis harga saham PT Bank Rakyat Indonesia Tbk (BBRI) dengan error sebesar 2.27%, Bank Cabang Asia Tbk (BBCA) dengan error sebesar 2.00%, serta PT Bank Mandiri Tbk (BMRI) dengan error sebesar 2.44%. Nilai error ratarata yang kecil tersebut dapat membuktikan model ini dapat digunakan untuk menganalisis harga saham.
Keyword: Black-Scholes, Brownian, Stock

Judul: Consumer Goods Stock Price Prediction Using the Modified Black-Scholes Equation
Abstrak: Besarnya volume perdagangan di pasar saham menyebabkan harga saham yang semakin fluktuatif menyebabkan meningkatnya resiko yang ada sehingga diperlukan analisa untuk menganalisis kemungkinan kenaikkan, penurunan, dan harga saham di waktu mendatang. Penelitian ini bertujuan untuk memprediksi harga saham consumer goods menggunakan persamaan Black-Scholes yang diselesaikan dengan metode Runge-Kutta dan menganalisis pengaruh suku bunga terhadap hasil prediksi. Penelitian dilakukan dengan membuat model berdasarkan persamaan Black-Scholes termodifikasi dan diselesaikan menggunakan metode Runge-Kutta orde empat. Hasil penelitian menunjukkan model memiliki MAPE 4.99% yang diinterpretasikan sebagai sangat baik dengan nilai MDA 72%. dan hubungan suku bunga dengan harga saham yang berbanding terbalik., The large volume of trading in the stock market causes stock prices to fluctuate, increasing the risk involved, therefore analysis is needed to analyse the possibility of increases, decreases, and stock prices in the future. This research aims to predict the price of consumer goods stocks using the Black-Scholes equation solved by the Runge-Kutta method and analyse the effect of interest rates on the prediction results. The research was conducted by creating a model based on the modified Black-Scholes equation and solved using the fourth-order Runge-Kutta method. The results showed that the model has a MAPE of 4.99% which is interpreted as very good with a MDA of 72% and the relationship between interest rates and stock prices is inversely proportional.
Keyword: Black-Scholes equation, interest rate, stock price, Runge-Kutta method

Judul: Synthesis of Apatite - Chitosan Composite Using Duck Eggshell and Chitosan with Temperature and pH Control
Abstrak: Composite of apatite-chitosan was prepared by using chitosan as polymer matrix. Calcium phosphate was prepared from CaO and (NH4)2HPO4, which the ratio Ca : P had to be 1.67. Chitosan is produced by deacetilase from biopolymer chitin. Duck eggshell (95% CaCO3) as starting material was converted to be calcium oxide (CaO) through calcinations with temperature 1000oC for 5 hours. In-situ and ex-situ methods were prepared from apatite and chitosan (dissolved with acetate acid 2%). Calcium phosphate prepared for bone implantation, but it is too fragile and brittle to be implant into the body. So addition of chitosan can decrease crystalinity and increase mechanic characteristic (tougher). Composite apatite-chitosan was resulted by fast precipitation. Fast precipitation was held in a breaker glass with nitrogen atmosphere, under controlled temperature at 37oC and pH 7, in order to increase amount of hydroxyapatite. Precipitation with CaO which was dropped by (NH4)2HPO4. Hydroxyapatite and chitosan were appearing at samples with in-situ and ex-situ methods which indicating by peak matching of XRD (closed lattice parameter, crystal size), overlapping at FTIR spectra and supporting by SEM picture (homogenous and agglomerated particle). However, it still needs further research to examine biocompatibility osteoconductive degree of sample by in-vivo and in-vitro test.
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