emmanuel ekpenyong | Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria (original) (raw)

Papers by emmanuel ekpenyong

Hacettepe Journal of Mathematics and Statistics, 2014

Traffic flows at three signalized junctions in Uyo metropolis were considered and the data used f... more Traffic flows at three signalized junctions in Uyo metropolis were considered and the data used for the analysis were collected during peak periods (morning and evening) for three consecutive days. The perfor-mance measures of congestion such as the average queue length, arrival and saturation flow rates as well as the average waiting time of vehicle per cycle have been calculated for a better understanding of the traffic situation in the city by motorists and proper vehicular logistics. With the random nature in which vehicles arrive and depart, we assumed a Poisson arrival process and deterministic (constant) service time with the service rate µ = 1/s which incorporate both the stochastic and deterministic components of delay es-timation. Using the concept of the Canadian delay model in Hellinga and Liping (2001), we obtained the overall delay given an observation interval. An estimate of the mean overall delay which is the average time a vehicle could be delayed at any signalized...

Pakistan Journal of Statistics and Operation Research, 2011

Communications in Statistics - Theory and Methods, 2015

Journal of Mathematics Research, 2014

An alternative ratio estimator is proposed for a finite population mean of a study variable Y in ... more An alternative ratio estimator is proposed for a finite population mean of a study variable Y in simple random sampling using information on the mean of an auxiliary variable X, which is highly correlated with Y. Expressions for the bias and the mean square error of the proposed estimator are obtained. Both analytical and numerical comparisons have shown the proposed alternative estimator to be more efficient than some existing ones. The bias of the proposed estimator is also found to be negligible for all populations considered, indicating that the estimator is as good as the regression estimator and better than the other estimators under consideration.

International Journal of Advanced Statistics and Probability, 2014

This work considers the application of Periodogram and Fourier Series Analysis to model all-items... more This work considers the application of Periodogram and Fourier Series Analysis to model all-items monthly inflation rates in Nigeria from 2003 to 2011. The main objectives are to identify inflation cycles, fit a suitable model to the data and make forecasts of future values. To achieve these objectives, monthly all-items inflation rates for the period were obtained from the Central Bank of Nigeria (CBN) website. Periodogram and Fourier series methods of analysis are used to analyze the data. Based on the analysis, it was found that inflation cycle within the period was fifty one (51) months, which coincides with the two administrations within the period. Further, appropriate significant Fourier series model comprising the trend, seasonal and error components is fitted to the data and this model is further used to make forecast of the inflation rates for thirteen months. These forecasts compare favourably with the actual values for the thirteen months.

We seek to proffer estimates of the parameters of the dependent variable having a polynomial rela... more We seek to proffer estimates of the parameters of the dependent variable having a polynomial relationship with the independent variable, specifically that of order two. The variances of the mean and total estimates of the dependent variable are derived. The efficiency and precision of the method are shown by comparing its estimates with those of linear regression and elemental sampling methods through the use of sampled data by simple random sampling without replacement from simulated data.