Unbiased Parameter Estimation for Partially Observed Diffusions

In this article we consider the estimation of static parameters for partially observed diffusion process with discrete-time observations over a fixed time interval. In particular, we assume that one must time-discretize the partially observed diffusion process and work with the model with bias and consider maximizing the resulting log-likelihood. Using a novel double randomization scheme, based upon Markovian stochastic approximation we develop a new method to unbiasedly estimate the static parameters, that is, to obtain the maximum likelihood estimator with no time discretization bias. Under assumptions we prove that our estimator is unbiased and investigate the method in several numerical examples, showing that it can empirically out-perform existing unbiased methodology.Comment: 27 pages, 8 figure

Mobile network sharing trends in developing and developed mobile markets (regulations and market forces): A comparison between selected Latin American markets and Sweden

The present document has the objective of analyzing the impact of several factors that are part of mobile telecom markets into the feasibility of sharing resources as a strategy for operators to deploy their networks in a cost-efficient manner and cope with the ever increasing amount of data traffic. These factors include the situation of the operators with their distribution of market shares, the nature of national regulatory authorities, and their lines of action. The study comprises the description and analysis of three markets: Ecuador, Chile, and Sweden, as they pose very different scenarios and are useful to prove the contrast present in two different regions of the world. The results of this research work show that in order to ease the adoption of network sharing in a market, a state of fair competition must be encouraged, reflected by a good distribution of market shares between operators. This is for the most part a task of the regulators, as they must make sure to award resources to operators in an equitable manner, as well as to identify the right moments to introduce new actors into the market, as it is observed in the cases of Chile and Sweden. Additionally, the regulators must have a liberal approach in their decisions, by permitting both active and passive network sharing, as this study shows that this is not the case in Chile and Ecuador so far

Analysis of Mispronunciation of Makhārij Al-Hurūf in Arabic Hiwār Learning

This research aims to identify the locations of mispronunciations of the makhārij al-hurūf in conversations (hiwār) in the VII PPS Babussalam class in the city of Bandung. Additionally, it serves as an evaluation tool for Arabic language learning to improve the learning process and provide solutions or treatments to students to enhance their makhārij al-hurūf pronunciation. Correcting makhārij al-hurūf errors is crucial as they can affect the meaning. This research utilizes a qualitative descriptive research method. The population of this research includes all the students in the VII PPS Babussalam class in the city of Bandung, and it was conducted on May 17, 2023, at the VII PPS Babussalam class in Bandung. Data collection involved interviews, tests, and documentation, followed by analyzing all data in narrative form. Based on the research findings, it can be concluded that there are 426 mispronunciations of makhārij al-hurūf in the hiwār in the VII PPS Babussalam class in Bandung. These errors include mispronunciations in Al-Jauf (Mouth Cavity), totaling three errors with a percentage of 0.70%, falling into the deficient category; mispronunciations in Al-halq (Throat), totaling 204 errors with a percentage of 47.89%; falling into the high category; mispronunciations in al-lisān (Tongue), totaling 171 errors with a percentage of 40.14%, also falling into the high category; mispronunciations in al-syafatain (Two Lips), totaling 35 errors with a percentage of 8.22%, falling into the low category; and mispronunciations in Al-Khaiysyum (Nasal Cavity), totaling 13 errors with a percentage of 3.05%, falling into the low category. These pronunciation errors occur due to the student's lack of understanding of the correct makhārij al-hurūf pronunciation, such as not being aware of the pronunciation differences between Indonesian and Arabic, the absence of specific attention from teachers to correct each student's pronunciation, and the lack of practice. This study recommends further research in analyzing the mispronunciation of makhārij al-hurūf letters with different research objects, namely the mispronunciation of makhārij al-hurūf letters in Arabic news

An econometric analysis of risk attitudes among grass seed producers in the Willamette Valley

The present increasing need for the development of empirical hypotheses that explain the decisionmakers' behavior towards risk is to provide an understanding of the framework within which an industry operates. Such hypotheses could facilitate the implementation of policies designed to solve problems identified within an industry and could also provide some useful tools to be used for the necessary supply adjustments. Investigation of the factors that have been important in influencing risk attitudes among grass producers in Oregon's Willamette Valley is the object of this research. Educational level and age are hypothesized and empirically tested to have significant effects on farmers' risk preferences. Other factors like percentages of land under control and farm debt are also considered to be of equal importance. The interaction of the mentioned variables among themselves could, possibly, affect producers' risk behavior. Identification of factors exerting significant effects on risk aversion, measured by Pratt coefficient, was attained through using a single equation linear regression model. Individuals with less education are found to be more averters to risk than others with higher educational levels. Increased land ownership is associated with increased aversion to take risk for highly educated producers while it increases risk taking for less educated ones. Age and percent of farm debt are determined to be directly and inversely related to risk aversion, respectively. The interaction of education with percent land ownership and age significantly increased and decreased aversion to risk respectively. The inclusion of binary variables for risk neutrality and risk taking together with their interactions with the other variables resulted in different effects exerted by education and percent land ownership for risk neutral individuals. No significant differences were found to exist between the behavior of risk takers compared to risk averters, however