Tag Archives: Error Correction

Effect of Climate Change on Food Crop Production in Southeast, Nigeria: A Co-Integration Model Approach (Published)

This paper studied the effect of climate change on selected food crop production in Southeast, Nigeria. The data were sourced from National Root Crops Research Institute, Umudike, National Bureau of Statistics and the Central Bank of Nigeria (CBN) bulletin. Data on crop yield and climate variables from 1984 to 2014 were collected. Descriptive Statistics, Co-integration analysis and Error Correction Model were adopted. The finding reveals unsteady climatic pattern with peak points across the period under review. The Augmented Dickey-Fuller test for unit root reveals that yam; maize and cassava outputs were non stationary but became stationary after the differencing. All climate variables showed stationary at first level. Result shows the existence of one co-integrating vector in the three models. The results shows that the coefficients of ECM(-1) which indicates speed of adjustment of the crop outputs to the equilibrium when a disturbance has occurred are -0.365 (p<0.01), -0.211 (p<0.05) and  -0.599 (p<0.001) for yam, maize and cassava output models respectively. The coefficients of multiple determination (R2) for yam, maize and cassava were 0.611, 0.440 and 0.2669 respectively. In yam model, the coefficients show that all variables except lagged yam output and temperature have positive relationship with the yam output; the coefficients of lagged maize output, rain days and temperature are negative while rainfall volume, humidity and sunshine are positive in maize model and in cassava model, coefficients of rainfall volume, rain days, sunshine and lagged cassava output are positive while temperature and humidity are negative. Results show that climate change impacted yam and maize output. It is recommended that adequate mitigation and adaptive measures be put in place to reduce the effect of climate change in order to achieve an appreciable agricultural productivity.

Keywords: Climate Variables, Co-integration, Error Correction, Food Crops, Southeast Nigeria


Arguments have risen about whether teacher corrective feedback is necessary for students or not; in other words, does error correction benefit students? Feedback is one of the factors in Skinner’s operant conditioning model of learning closely tied to behaviourist learning theory. In this learning model, feedback is equated with positive or negative reinforcement. This paper sought to identify the role played by teacher correction feedback in the success of students in correcting errors during revision. The study is based on the hypothesis that there is a relationship between feedback mechanism applied to student errors and students’ success in correcting errors during revision. The study makes use of a longitudinal, quasi-experimental design. Two Form 4 classes from one private co-educational secondary school were used comprising 28 males and 40 females of ages 16 years to 21 years. The results reveal that students manage to correct most of the errors made in the original essays after reviewing the correction feedback by teachers in the long term.

Keywords: Error Correction, Feedback, Teacher correction, negative reinforcement, quasi-experimental design, revision


Utilizing Adaptive Finite Automaton (AFA) to implement Adaptive Digitized Straight Line Segments (ADSLS) actuating as exploration automaton of a boundary, we propose an alternative for the available researches on dominant point detection in which primitives are composed by ADSLS. Consequently, this method is shown by simulations to be effective to represent adaptive regions of support and adequate for the complexities of real world scenarios like a shape classifier. Furthermore, even being based in the simple underlying mechanism of Finite Automaton (FA), ADSLS is able to adapt, reacting to circumstance stimuli in a single pass, also presenting learning capability.

Keywords: Adaptive Systems, Automata, Computational Geometry, Error Correction, Pattern Recognition

The Determinants of Foreign Reserves in Nigeria (Review Completed - Accepted)

It has been seen that Foreign exchange reserves adequacy is a key component of good macroeconomic management. The modified version of the buffer stock model was applied to assess the determinants of foreign reserve in Nigeria. The study regressed foreign reserve variable on macroeconomic variables: real income, interest rate differential (a measure of opportunity cost), exchange rate volatility, financial openness, current account vulnerability, benchmark stock of reserves, and the demand for foreign exchange. In order to avoid any spurious regression results, the time series data from 1970 -2010 was subjected to stationarity tests. The ADF cointegration procedure used suggested the existence of long run relationships. Hence, the short run dynamics was examined by means of an error correction model. The empirical evidence shows that growth in Nigeria’s foreign reserves is not influenced in the long run by current account vulnerability (proxied by trade opennes), the opportunity cost of holding reserves (DID) and the benchmark stock of reserves but by other determinants such as the real Gross Domestic Products (Y), exchange rate volatility (Ev), financial openness (Fop), and the demand for foreign exchange (DFex).

Keywords: Benchmark, Buffer Stock, Cointegration, Determinants, Error Correction, Foreign Reserves, Long-Run, Short-Run