58,862 research outputs found

    A Maximum Entropy Procedure to Solve Likelihood Equations

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    In this article, we provide initial findings regarding the problem of solving likelihood equations by means of a maximum entropy (ME) approach. Unlike standard procedures that require equating the score function of the maximum likelihood problem at zero, we propose an alternative strategy where the score is instead used as an external informative constraint to the maximization of the convex Shannon\u2019s entropy function. The problem involves the reparameterization of the score parameters as expected values of discrete probability distributions where probabilities need to be estimated. This leads to a simpler situation where parameters are searched in smaller (hyper) simplex space. We assessed our proposal by means of empirical case studies and a simulation study, the latter involving the most critical case of logistic regression under data separation. The results suggested that the maximum entropy reformulation of the score problem solves the likelihood equation problem. Similarly, when maximum likelihood estimation is difficult, as is the case of logistic regression under separation, the maximum entropy proposal achieved results (numerically) comparable to those obtained by the Firth\u2019s bias-corrected approach. Overall, these first findings reveal that a maximum entropy solution can be considered as an alternative technique to solve the likelihood equation

    A Discussion of the Geology and an Isopach Map of the Pennsylvanian System in Wyoming and Adjacent Areas

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    Pennsylvanian strata in Wyoming and adjacent areas have been the subject of much work and discussion. Most of the work has been due to the economic importance of the system as an oil producer in this region. Oil production from strata of Pennsylvanian age is rather recent history; and therefore, much of the available information is local­ized and incomplete

    Analisis Profitabilitas Keripik Singkong pada Industri Rumah Tangga Pasundan di Kota Palu

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    The study aims to determine the amount of revenue and profitability of the business value of cassava chips in the industry "Pasundan" in the city of Palu. The research was conducted on a month from November to December 2015. The number of respondents as many as four people. The analysis tool used is the analysis of revenue and profitability analysis. The results showed that the amount of revenue earned processed cassava chips business on domestic industry "Pasundan" during November-December 2015 amounted to Rp 17.856.592with an average of Rp8.928.296. Profitability average value obtained domestic Industry "Pasundan" of November-December 2015 through computation ROI of 89,39% means that the value of profitability shows that the company earned a net profit of invested capital which is equal to 89,39% per month in restore assets owned domestic industry "Pasundan"

    A Geological Report on South Boulder Canyon and The Mayflower Mine-Renova Areas

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    The purpose of this report is to serve as a written explanation of the accompanying geologic maps and columnar sec­tion. Each year the senior students in mining and geological engineering at the Montana School of Mines spend two weeks in the field where they learn the fundamentals of geologic mapping and related field studies. An additional week is spent at the school where maps are assembled, prints made, end other work is done in preparation for the writing of the report

    Culex tarsalis is a competent vector species for Cache Valley virus

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    Background: Cache Valley virus (CVV) is a mosquito-borne orthobunyavirus endemic in North America. The virus is an important agricultural pathogen leading to abortion and embryonic lethality in ruminant species, especially sheep. The importance of CVV in human public health has recently increased because of the report of severe neurotropic diseases. However, mosquito species responsible for transmission of the virus to humans remain to be determined. In this study, vector competence of three Culex species mosquitoes of public health importance, Culex pipiens, Cx. tarsalis and Cx. quinquefasciatus, was determined in order to identify potential bridge vector species responsible for the transmission of CVV from viremic vertebrate hosts to humans. Results: Variation of susceptibility to CVV was observed among selected Culex species mosquitoes tested in this study. Per os infection resulted in the establishment of infection and dissemination in Culex tarsalis, whereas Cx. pipiens and Cx. quinquefasciatus were highly refractory to CVV. Detection of viral RNA in saliva collected from infected Cx. tarsalis provided evidence supporting its role as a competent vector. Conclusions: Our study provided further understanding of the transmission cycles of CVV and identifies Cx. tarsalis as a competent vector
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