Judul: Penyelesaian Model Tahap Terhingga dan Takhingga pada Proses Keputusan Markov dan Aplikasinya di Bidang Pertanian.
Abstrak: Markov decision process is a decision making process using Markov chain for stochastic models. The aim of this paper is to formulate a stochastic model involving states, actions and rewards. Further, the model is applied into agricultural sector, especially on determination of the optimal revenue based on actions specified. Also to determine an optimal policy that maximizes the reward. The methods used in this study are the complete enumeration, the policy iteration and the linear programming methods. Among the methods used, the most efficient method is the policy iteration. Based on the data used, determination of the policy using those three methods concluded that farmers would not use fertilizer when the soil fertility is good, and will use fertilizer when the soil fertility are moderate or low. Especially, for the case of the discount 0.7, the agricultural problem resulting the same policy with the case of no discount rate.
Keyword: policy iteration., Markov decision process, linear programming, enumeration

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: Prevalence of Bird Lice on Rock Pigeon (Columba livia) in 99Wonderland Park, Selangor, Malaysia
Abstrak: Rock Pigeon (Columba livia) have coexisted with humans for thousands of years and are used for various purposes such as food and in sports. Rock pigeons may have the potential to be infested with a wide range of ectoparasites, which can have a significant impact on their life cycle. This study aims to measure the prevalence of Columba livia with bird lice in 99Wonderland Park, Selangor, Malaysia in the year 2020 and to ascertain the impact of bird lice on the health of these infested birds. Data were collected from clinical records for the month of January to December in the year 2020 from 99Wonderland Park, Selangor, Malaysia. Lice were identified in 42 of the 80 Rock pigeons examined so, the overall prevalence of lice infestations was 52.5%. The prevalence of ectoparasites was found to be higher in young Rock pigeons (60.4%) as compared to adult Rock pigeons (37.4%). Columbicola columbae (wing lice) and Colpocephalum turbinatum (body lice) are two species of lice that have been detected. Body lice were more prevalent in young Columba livia birds at 47.6% whereas wing lice were more prevalent in adult Columba livia birds at 16.7%. Most of the lice were found in the thorax and abdomen area followed by the head and neck area., Merpati Batu (Columba livia) telah hidup berdampingan dengan manusia selama ribuan tahun dan digunakan untuk berbagai keperluan seperti makanan dan olahraga. Merpati batu dapat terinfestasi dengan berbagai ektoparasit, yang dapat berdampak signifikan pada siklus hidup mereka. Penelitian ini bertujuan untuk mengetahui prevalensi Columba livia dengan kutu burung di 99 Wonderland Park, Selangor, Malaysia pada tahun 2020 dan untuk memastikan dampaknya terhadap kesehatan burung yang terinfestasi. Data dikumpulkan dari catatan klinis dari bulan Januari hingga Desember tahun 2020 dari 99Wonderland Park, Selangor, Malaysia. Kutu diidentifikasi pada 42 dari 80 merpati batu yang diperiksa sehingga, prevalensi keseluruhan infestasi kutu adalah 52,5%. Prevalensi ektoparasit ditemukan lebih tinggi pada merpati batu muda (60,4%) dibandingkan dengan merpati batu dewasa (37,4%). Columbicola columbae (kutu sayap) dan Colpocephalum turbinatum (kutu badan) adalah dua spesies kutu yang telah ditemukan. Kutu badan lebih banyak ditemukan pada burung Columba livia muda sebesar 47,6% sedangkan kutu sayap lebih banyak ditemukan pada burung Columba livia dewasa sebesar 16,7%. Sebagian besar kutu ditemukan di daerah dada dan abdomen diikuti daerah kepala dan leher.
Keyword: Columba livia, prevalence, ectoparasite, wing lice, body lice, Columba livia, prevalensi, ektoparasit, kutu sayap, kutu badan