Onuwa Okwuashi

Analysis of risks associated with facilities management outsourcing

Purpose – The purpose of this study is to analyse the risk factors associated with outsourcing of facilities management (FM) services.Design/methodology/approach – The study administered questionnaires on 146 registered members of International Facilities Management Association (IFMA), Nigeria chapter, who carry out their professional practice in Lagos, Nigeria. The survey, conducted in February, 2011 targeted facilities managers, property managers, maintenance officers and procurement officers cutting across the three levels of management. A total of 61 of them returned valid questionnaires, giving a response rate of 41.8 percent.Findings – Findings reveal that “poor quality of services” was rated the most critical risk factor associated with facilities management outsourcing, while “security” and “inexperience” closely followed in that order. Also, there was no significant difference in the rankings of the stakeholders on more than 75 percent of the factors.Research limitations/implications – Most pract...

On the potentials of multiple climate variables in assessing the spatio-temporal characteristics of hydrological droughts over the Volta Basin

Multiple drought episodes over the Volta basin in recent reports may lead to food insecurity and loss of revenue. However, drought studies over the Volta basin are rather generalised and largely undocumented due to sparse ground observations and unsuitable framework to determine their space-time occurrence. In this study, we examined the utility of standardised indicators (standardised precipitation index (SPI), standardised runoff index (SRI), standardised soil moisture index (SSI), and multivariate standardised drought index (MSDI)) and Gravity Recovery and Climate Experiment (GRACE) derived terrestrial water storage to assess hydrological drought characteristics over the basin. In order to determine the space-time patterns of hydrological drought in the basin, Independent Component Analysis (ICA), a higher order statistical technique was employed. The results show that SPI and SRI exhibit inconsistent behaviour in observed wet years presupposing a non-linear relationship that reflects the slow response of river discharge to precipitation especially after a previous extreme dry period. While the SPI and SSI show a linear relationship with a correlation of 0.63, the correlation between the MSDIs derived from combining precipitation/river discharge and precipitation/soil moisture indicates a significant value of 0.70 and shows an improved skill in hydrological drought monitoring over the Volta basin during the study period. The ICA-derived spatio-temporal hydrological drought patterns show Burkina Faso and the Lake Volta areas as predominantly drought zones. Further, the statistically significant negative correlations of pacific decadal oscillations (0.39 and 0.25) with temporal evolutions of drought in Burkina Faso and Ghana suggest the possible influence of low frequency large scale oscillations in the observed wet and dry regimes over the basin. Finally, our approach in drought assessment over the Volta basin contributes to a broad framework for hydrological drought monitoring that will complement existing methods while looking forward to a longer record of GRACE observations.

An Evaluation of Personnel Training Policies of Construction Companies in Nigeria

Abstract Construction companies are the engines that propel the construction sector of any nation’s economy, and are therefore expected to vigorously train their workforce to effectively match this responsibility. This study investigates the personnel training policies of construction companies in Nigeria. Structured questionnaire was used to collect data from two categories of respondents namely, the technical and managerial personnel using simple random sampling technique. They were analyzed using the basic descriptive and inferential statistical tools. Spearman rank correlation was used to test the level of agreement between the two categories of personnel on the methods of training in their companies. Findings reveal among others that there is a disparity in the training policies of most companies regarding both categories of staff and did not favour the technical personnel. On-the-job training is the most effective method of staff development in the companies. The research has provided insight into key areas that require urgent action at the strategic level of management. Specifically, it has brought into focus perceived disparity between the level of training accorded the lower and higher cadre personnel.

Significant factors influencing outsourcing decision for facilities management (FM) services: A study on Nigeria’s public hospitals

Purpose – The purpose of this paper is to investigate and conceptualise significant factors influencing decision to outsource facilities management (FM) services in Nigeria’s public hospitals. Design/methodology/approach – Data for this study were collected using a cross-sectional questionnaire survey. A total of 85 responses were received from the six states comprising the study area while 11 of them were discarded due to missing data resulting in 74 usable responses. This gave an overall response rate of 61 per cent. Data collected were analysed using descriptive and inferential statistics as well as principal component analysis. Findings – Findings revealed that 25 of the 31 factors were significant in explaining the decision to outsource FM service in Nigeria’s public hospitals; while 15 of them grouped into six broad categories were selected based on their factor loadings during further analysis. Besides, it was also established from the study that “to improve performance standard”, “to improve quali...

Tide modelling using support vector machine regression

Abstract This research explores the novel use of support vector machine regression (SVMR) as an alternative model to the conventional least squares (LS) model for predicting tide levels. This work is based on seven harmonic constituents: M2, S2, N2, K2, K1, O1 and P1. The SVMR is modelled with four kernel functions: linear, polynomial, Gaussian radial basis function and neural. The computed r-square and root mean square error for the linear, polynomial, Gaussian radial basis function and neural SVMR kernels as well the LS indicate a strong correlation between the observed and predicted tides. But for the linear kernel the results of all the kernels are slightly better than the LS. The statistical tests of the difference between the observed tide and the LS and SVMR predicted tides and between the LS and SVMR predicted tides are insignificant at the 95% confidence level.

GIS-based simulation of land use change

This paper describes an application of ArcGIS to simulate land use changes in Lagos, Nigeria, using both Ordinary Least Squares (OLS) regression and Geographically Weighted Regression (GWR), over three epochs - 1963-1978, 1978-1984 and 1984-2000. Twelve salient, causal factors thought to be related to urban land use change in Lagos were used, such as distance to water, distance to residential structures, income potential and population potential. OLS was used to establish the regression coefficients, gauge the significance of each explanatory variable and estimate conformity with linear regression criteria. GWR was then used to simulate the urban form based on the results of the OLS model. For the three epochs the respective Kappa statistics for the simulated maps were 0.8858, 0.8366 and 0.8812, indicating an almost perfect agreement with the data of 1978, 1984 and 2000.

Exploring evapotranspiration dynamics over Sub-Sahara Africa (2000–2014)

Monitoring changes in evapotranspiration (ET) is useful in the management of water resources in irrigated agricultural landscapes and in the assessment of crop stress and vegetation conditions of drought-vulnerable regions. Information on the impacts of climate variability on ET dynamics is profitable in developing water management adaptation strategies. Such impacts, however, are generally unreported and not conclusively determined in some regions. In this study, changes in MODIS (Moderate Resolution Imaging Spectroradiometer)-derived ET (2000–2014) over large proportions of Sub-Sahara Africa (SSA) are explored. The multivariate analyses of ET over SSA showed that four leading modes of observed dynamics in ET, accounting for about 90% of the total variability, emanated mostly from some sections of the Sudano-Sahel and Congo basin. Based on Man-Kendall’s statistics, significant positive trends (α = 0.05) in ET over the Central African Republic and most parts of the Sahel region were observed. Over much of the Congo basin nonetheless, ET showed significant (α = 0.05) distributions of widespread negative trends. These trends in ET were rather found to be consistent with observed changes in model soil moisture but not in all locations, perhaps due to inconsistent trends in maximum rainfall and land surface temperature. However, the results of spatio-temporal drought analysis confirm that the extensive ET losses in the Congo basin were somewhat induced by soil moisture deficits. Amidst other prominent drivers of ET, the dynamics of ET over the terrestrial ecosystems of SSA appear to be a more complex phenomenon that may transcend natural climate variations.

Tide modelling using the Kalman filter

Abstract Away from the conventional Least Squares method of predicting tide, this research explores the use of the Kalman Filter. This work is based on seven harmonic constituents: M2, S2, N2, K2, K1, O1 and P1. The computed tidal form factor F = 0.1955 indicates that the tide is semi-diurnal, which is an indication that the result of the experiment can be trusted, since Nigerian coastal waters are characteristically semi-diurnal in nature. The computed r2 for the Kalman Filter and Least Squares are r2 = 0.9708 and r2 = 0.9668, respectively. This result indicates that the result of the Kalman Filter is slightly better than the Least Squares.