Butte Gotu - Academia.edu (original) (raw)

Papers by Butte Gotu

Stochastic environmental research and risk assessment, Jun 25, 2024

RePEc: Research Papers in Economics, 1998

Necessary and su cient conditions for the equality of ordinary least squares and generalized leas... more Necessary and su cient conditions for the equality of ordinary least squares and generalized least squares estimators in the linear regression model with rst-order spatial error processes are given.

COVID

What are the effects of Corona Virus Disease 19 (COVID-19) on inflation, unemployment, and GDP in... more What are the effects of Corona Virus Disease 19 (COVID-19) on inflation, unemployment, and GDP in Africa? Using geo-coded cross-sectional data taken from the World Health Organization and International Monetary Fund, we investigate the spatial distribution of COVID-19 and its effects on inflation, unemployment, and Gross Domestic Product (GDP) in Africa by employing the Geographic Information System (GIS), multivariate analysis of covariance (MANCOVA), and spatial statistics. The entire dataset was analyzed using Stata, ArcGIS, and R software. The result shows (1) that there is evidence of a spatial pattern of COVID-19 cases and death rate clustering behavior in Africa, verifying the existence of spatial autocorrelation. The result also reveals (2) that COVID-19 has a negative effect on unemployment, inflation, and GDP in Africa. We confirmed that (3) temperature, rainfall, and humidity were statistically significantly associated with the spread of the COVID-19 pandemic in Africa. T...

Technical reports, 1998

o f D o r t m und, Germany During the past thirty y ears, there has been considerable concern abo... more o f D o r t m und, Germany During the past thirty y ears, there has been considerable concern about combination of forecasts. Many of the articles and books dedicated to this speci c area explain and demonstrate that combining multiple individual forecasts can improve forecast accuracy. The improvement in accuracy mainly depends on forecast combination techniques which range from simple combinations like a veraging the forecasts to more complex ones that use the Bayesian approach. This paper provides a bibliography of selected articles and books related to the combination of forecasts in various disciplines and is intended to be a catalog for locating contributions in research areas focusing on the theory and applications of combining forecasts. The bibliography includes recent articles and is as up-to-date as possible.

Scientific Programming

In this study, an effective robust PCA is developed for joint image alignment and recovery via L ... more In this study, an effective robust PCA is developed for joint image alignment and recovery via L 2,1 norms and affine transformations. To alleviate the potential impacts of outliers, heavy sparse noises, occlusions, and illuminations, the L 2,1 norms along with affine transformations are taken into consideration. The determination of the parameters involved and the updating affine transformations is arranged in the form of a constrained convex optimization problem. To reduce the computation load, we also further decompose the error as sparse error and Gaussian noise; additionally, the alternating direction method of multipliers (ADMM) is considered to develop a new set of recursive equations to update the optimization parameters and the affine transformations iterative. The convergence of the derived updating equation is explained as well. Conducted simulations illustrate that the new method is superior to the baseline works in terms of precision on some public databases.

: Conditions for the consistency of the estimator s 2 of the variance of the disturbance oe 2 u u... more : Conditions for the consistency of the estimator s 2 of the variance of the disturbance oe 2 u under first-order spatial error processes are given. Key words: Ordinary least squares, Consistency, Spatial error process, Spatial correlation. 1 Introduction Consider the linear regression model for spatial correlation y = Xfi + u ; u = C ffl ; (1) where y is a T \Theta 1 observable random vector, X is a T \Theta k matrix of known constants with full column rank k, fi is a k \Theta 1 vector of unknown parameters, ffl is a T \Theta 1 random vector with expectation zero and covariance matrix Cov(ffl) = oe 2 ffl I (I is the T -dimensional identity matrix and oe 2 ffl an unknown positive scalar). C denotes a T \Theta T matrix such that the product CC 0 is positive definite and has identical diagonal elements. The ordinary least squares (OLS) estimator of the unknown parameter fi in model (1) is given by fi = (X 0 X) \Gamma1 X 0 y with the covariance matrix Cov( fi) = oe ...

SINET: Ethiopian Journal of Science, 2000

Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch ge... more Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. Terms of use: Documents in EconStor may be saved and copied for your personal and scholarly purposes. You are not to copy documents for public or commercial purposes, to exhibit the documents publicly, to make them publicly available on the internet, or to distribute or otherwise use the documents in public. If the documents have been made available under an Open Content Licence (especially Creative Commons Licences), you may exercise further usage rights as specified in the indicated licence.

Saving represents one of the most predictable determinants of successful personal and economic de... more Saving represents one of the most predictable determinants of successful personal and economic development. People desire to save although they tend to postpone saving until they have higher-paying jobs or some stability in their lives. However, in developing countries, where opportunities for structured and institutionalized saving are rare, people could perhaps begin saving earlier than expected. The purpose of this study has been to assess saving habits and identify factors that influence the saving habits of employees at Deber Birhan town. A sample of 480 was collected from employees on saving habit at Debre Birhan town during February, 2010 to October, 2011. Saving habit was measured according to multi method tool that incorporates self report, visual analog scale and economic identification test. Descriptive, Binary logistic regression and Bayesian statistical methods were used. The result indicates that 47.29% employees had no saving experience and 52.71% of the respondents h...

Research Papers in Economics, 1998

During the past thirty years, there has been considerable concern about combination of forecasts.... more During the past thirty years, there has been considerable concern about combination of forecasts. Many of the articles and books dedicated to this specific area explain and demonstrate that combining multiple individual forecasts can improve forecast accuracy. The improvement in accuracy mainly depends on forecast combination techniques which range from simple combinations like averaging the forecasts to more complex ones that use the Bayesian approach. This paper provides a bibliography of selected articles and books related to the combination of forecasts in various disciplines and is intended to be a catalog for locating contributions in research areas focusing on the theory and applications of combining forecasts. The bibliography includes recent articles and is as up-to-date as possible.

BACKGROUND Since early 1980s when AIDS was first recognized, there has been uncertainty about the... more BACKGROUND Since early 1980s when AIDS was first recognized, there has been uncertainty about the future trend and the ultimate dimensions of the pandemic. This uncertainty persists because of difficulties in measuring HIV incidence and prevalence with a substantial degree of precision in a given population. One of the many factors for the lack of precision is the problem of obtaining representative data sources that can be extrapolated to the general population. National and regional HIV estimates for Ethiopia are derived from ANC based HIV surveillance data. Alternative data sources have not been exhaustively explored as potential tools to monitor the trend of HIV/ AIDS epidemic in the country. OBJECTIVE To estimate the magnitude and trend of HIV/AIDS epidemic using data from the routine VCT services as an alternative data source to ANC sentinel surveillance data. METHODS The study used secondary data sources from all government, private and NGO VCT centers, of the period of 2003-...

Statistical Papers, 2001

Ethiopian medical journal, 2010

Since early 1980s when AIDS was first recognized, there has been uncertainty about the future tre... more Since early 1980s when AIDS was first recognized, there has been uncertainty about the future trend and the ultimate dimensions of the pandemic. This uncertainty persists because of difficulties in measuring HIV incidence and prevalence with a substantial degree of precision in a given population. One of the many factors for the lack of precision is the problem of obtaining representative data sources that can be extrapolated to the general population. National and regional HIV estimates for Ethiopia are derived from ANC based HIV surveillance data. Alternative data sources have not been exhaustively explored as potential tools to monitor the trend of HIV/ AIDS epidemic in the country. To estimate the magnitude and trend of HIV/AIDS epidemic using data from the routine VCT services as an alternative data source to ANC sentinel surveillance data. The study used secondary data sources from all government, private and NGO VCT centers, of the period of 2003-2005 in Addis Ababa. For the ...