Judul: Kajian Model Hidden Markov Kontinu dengan Proses  Observasi Zero Delay dan Aplikasinya pada Harga Gabah  Kering Panen.
Abstrak: Rantai Markov merupakan proses stokastik dengan sifat bahwa kejadian di masa yang akan datang hanya dipengaruhi oleh kejadian masa sekarang. Setiap kejadian berkaitan erat dengan penyebab kejadian tersebut. Jika penyebab kejadian tidak diamati secara langsung dan membentuk rantai Markov, maka pasangan kejadian dan penyebabnya dapat dimodelkan dengan model hidden Markov (HMM). Misalkan 􀜺􀵌􁈼􀜺􀯞;􀝇􀗐􀔳􁈽 adalah rantai Markov dengan state berhingga yang bersifat homogen dan diasumsikan tidak diamati secara langsung, sedangkan 􀜻􀵌􁈼􀜻􀯞;􀝇􀗐􀔳􁈽 adalah proses observasinya. Pasangan proses stokastik 􁈼􁈺􀜺􀯞,􀜻􀯞􁈻􁈽 merupakan model hidden Markov.
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Judul: Kajian Model Hidden Markov Diskret dan Aplikasinya pada Harga Gabah Kering Panen
Abstrak: A discrete hidden Markov model is a model which consists of the cause of event and observations process. This model assumes that the cause of event is Markov chain which is not observed directly. The observations process has discrete-range. Parameters of this model are transition probabilities and expectation of observations process. They are estimated by using the maximum likelihood method and expectation maximization algorithm. The estimation procedure involves change of measure. The estimation of parameters uses Mathematica 6.0, a functional programming based algebraic computer systems. The model is then applied to the price of harvest dry rice from January 2000 until March 2007. The estimated parameters are used to calculate expectation of harvest dry rice price. The result of this study shows that the discrete hidden Markov model can be applied to model the harvest dry rice price.
Keyword: Markov chain, Discrete hidden markov model, Expectation maximization algorithm

Judul: Separation of Neodymium from U3Si2/Al Fuel Plate for Burn-Up Determination
Abstrak: Neodymium is a common fission product produced in nuclear fission reactions. Neodymium in this study was chosen as a burn-up indicator for U3Si2/Al fuel element plates because the neodymium isotope is a stable fission product with a fairly high yield. Some procedures were carried out to separate neodymium, starting with the separation of cesium isotopes (137Cs, 134Cs) through the precipitation method, then separation of uranium isotopes (235U, 238U) and plutonium isotopes (239Pu, 238Pu) with Dowex 1x8 ion exchange resin, and separation of neodymium (Nd), samarium (Sm), as well as cerium (Ce) with Dowex 1x4 ion exchange resin. The Cs recovery reached 99.95%. The U and Pu isotopes resulting from the separation are subjected to an electrodeposition process and the weight of each isotope can be measured with an alpha spectrometer. The separation results of Nd from Sm and Ce have been proven using an XRF spectrometer. The neodymium isotopes separation was corrected using the standard addition method, and an average total Nd content of 2.4 ppm was obtained in the PEB U3Si2/Al bottom solution. It is hoped that this separation method can be applied in determining burn-up of nuclear fuel.
Keyword: neodymium, burn-up indicator, U3Si2/Al fuel plate