African Journal of Empirical Research
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Normalized Difference Vegetation Index (NDVI) as an indicator of bio-remediation efficiency in crude oil-impacted soils in Ogoni-land: A case study of Eleme local government area, Rivers State, Nigeria
Get PDFEleme, a sub-region of Ogoni-land in Rivers State, Nigeria, has experienced decades of severe environmental degradation due to crude oil contamination, resulting in ecosystem disruption and reduced vegetation health. In line with the United Nations Decade on Ecosystem Restoration (2021–2030), this study assesses the ecological impact and bio-remediation efficiency of four remediated sites; Nkeleoken-Alode (LOT 04), Elelenwo Manifold-Akpajo (LOT 46 and LOT 56), and Ajeokpori Well 3-Okuluebu (LOT 54), under Phase I of the UNEP Ogoni-land Environmental Restoration Project. The study employed Normalized Difference Vegetation Index (NDVI) analysis to evaluate vegetation health and restoration trends across four historical epochs: 1994 (pre-contamination baseline), 2004 and 2014 (periods of high contamination), and 2024 (post-remediation). Satellite-derived NDVI data were processed using Landsat imagery (30 m resolution), and NDVI changes were analyzed to quantify vegetation vigor, variance, and ecosystem recovery. Results showed that NDVI values decreased sharply between 1994 and 2014, reaching negative thresholds in some LOTs, indicating severe ecological degradation due to crude oil pollution. For example, LOT 46 recorded an NDVI decline from 0.434 (1994) to –0.020 (2014), a 104.6% drop in vegetation vigor, Post-remediation in 2024, all LOTs demonstrated positive NDVI recovery, with LOT 54 rising from –0.0875 (2004) to 0.1275 (2024), representing a 164% increase, highlighting effective remediation outcomes. LOTs treated with bio-augmentation products such as Micro SOLUTION® and KEEN® exhibited stronger vegetation rebound than others, suggesting the effectiveness of tailored remediation strategies. The study finds that vegetation health improved significantly post-remediation, with gradual increases in NDVI values across sites indicating partial ecosystem restoration and enhanced vegetation vigor. However, residual hydrocarbon stress persists in some areas, warranting continued site-specific interventions. This research contributes valuable empirical evidence on the use of NDVI as a cost-effective monitoring tool for post-bioremediation assessment in crude oil-impacted regions. It underscores the need for integrated, location-specific bio-remediation and restoration strategies to enhance long-term ecological resilience in Ogoni-land and similar environments globally
Second order extended ensemble Kalman filter with stochastically perturbed innovation for initializing artificial neural network weights
Get PDFArtificial neural networks are widely applied in solving non-linear state-space dynamic models, yet the challenge of inaccurate initial weights remains a critical bottleneck. Weight initialization methods significantly influence convergence speed and model efficiency. While conventional approaches such as random initialization and filtering techniques are commonly used, the Bayesian method—though highly accurate—suffers from the computational burden of inverting highdimensional matrices. This study has developed a novel solution: the Second Order Extended Ensemble Filter with Perturbed Innovation (SoEEFPI). Developed from a second-order Taylor expansion of the stochastically perturbed KushnerStratonovich equation, SoEEFPI provides a tractable numerical solution to the inverse covariance matrix problem. Validation is conducted using the Lorenz63 system, comparing SoEEFPI’s performance to that of the Kalman-Bucy Filter (SoEKBF) and the First Order Extended Ensemble Filter (FoEEF) in MATLAB. Furthermore, SoEEFPI is employed to initialize neural network weights, yielding a new model whose convergence time, RMSE, and epoch count are evaluated. Results demonstrate improved convergence efficiency and accuracy, positioning SoEEFPI as a robust alternative for neural network initialization
Traffic sign recognition using local directional histogram of oriented gradients
Get PDFHistogram of Oriented Gradients (HOG) describes an image gradient by calculating vertical and horizontal gradient magnitudes and directions. HOG uses a one-dimensional (1D) centered derivative mask [−1, 0, +1] for horizontal gradient and its rotations at 90o for vertical gradient. This technique only considers four neighboring pixels while calculating image gradient at a particular pixel. Every pixel in an image carries subtle information and therefore all pixels should be considered when deriving image gradient. Therefore, given a pixel pi, all its N = 2(d+1) neighbors should be considered when calculating the gradient at distance d from pi. This paper proposes Local Directional Histogram of Oriented Gradients (LD-HOG), which, given pixel pi, it calculates the gradient at distance d = 1 from pi by considering all the eight neighbors of pi. The proposed operator calculates the image gradient at 0o, 45o, 90o and 1350. These image gradients are used to generate two HOG histograms. Maximum pooling techniques were applied to combine the two histograms. Experimental results on the German traffic sign detection benchmark (GTSDB) dataset show that LD-HOG (average precision = 0.90, average recall = 0.90 and average F1-score =0.90) out performs HOG (average precision = 0.84, average recall = 0.82 and average F1-score = 0.83) in traffic sign recognition. The averages of the two extractors (HOG and LD-HOG) were calculated from experimental results after applying Support Vector Machine (SVM), Random Forest (RF) and Decision Tree (DT) machine learning classifiers. Stratified K-Fold Cross-Validation was done on the proposed LD-HOG using SVM, RF and DT. Validation results show that SVM performed better with 99 percent, followed by RF with 96 percent. DT was had 76 percent
Coping strategies adopted by intimate partner violence survivors: A comprehensive analysis in Dar es Salaam, Tanzania
Get PDFGlobally, 27% of ever-married women have experienced intimate partner violence at some point in their lives. In Tanzania, intimate partner violence is also an alarmingly prevalent problem affecting 39% of ever-married women aged 15–49 at some point in their lifetime. In the Dar es Salaam region, reports show increasing intimate partner homicides and divorce cases. This study, guided by Resilience Theory, analysed the coping strategies intimate partner survivors use to manage violent experiences at the household level in the Dar es Salaam region, Tanzania. Using a cross-sectional mixed-methods approach, data were collected through questionnaires, in-depth interviews, and focus group discussions. Quantitative data from 280 systematically sampled survivors were analyzed using descriptive statistics, while qualitative data from two religious leaders, nine social welfare officials, and 34 intimate survivors were thematically analyzed. The findings revealed that separation (30%), escape avoidance (25%), and problem-solving (18%) were considered as effective coping strategies, while fighting back (15%) and self-control (12%) were regarded as unproductive ones. This challenges conventional ideas that equate resilience with confrontation or emotional suppression. Based on the findings, the study recommends prioritizing survivor-informed coping strategies and adopting inclusive, multi-sectorial, and tailored support interventions that involve the government, religious leaders, and non-governmental organizations
The relationship between market orientation and firm innovativeness: Do gender roles matter? Evidence from food processing firms in Arusha, Tanzania
Get PDFFood-processing enterprises contribute significantly to the global economy. Yet, many struggle in their growth and face early failure. Innovation, therefore, becomes critical to their survival. This paper investigates how market orientation (MO) influences innovativeness in Tanzanian food-processing firms and tests whether gender roles moderate that relationship. The study is echoed in dynamic capability theory supported by institutional theory. The study employed an explanatory cross-sectional survey design. The simple random sampling technique was used to obtain a sample of 224 food processing firms from the population of 284 registered food processing firms which had updated their business licence in the year 2022/2023. The data were collected using a structured questionnaire which comprised Likert-scale questions. The analysis of the objectives was done by using structural equation modelling (SEM). The findings reveal that all of the MO dimensions had a positive and significant effect on innovativeness. Customer orientation had (β = 0.372, p < 0.001), competitor orientation had (β = 0.404, p < 0.001), and inter-functional coordination had (β = 0.196, p = 0.035). Gender roles moderated customer and competitor orientation links. The findings imply that firms that stay sharply focused on their markets by listening to customers, keeping an eye on competitors and making sure their teams work smoothly together tend to be more innovative. Furthermore, owner/managers should build a routine of gathering customer feedback, track competitor moves, and encourage teamwork. Policy makers offering trainings, networking events and targeted support can help smaller firms develop this market-orientated mindset and spark more innovation across the whole sector
Les représentations que les apprenants Kenyans de Français langue étrangère se font de la France, des Français et de la langue française
Get PDFCet article se focalise sur les représentations sociales et sociolinguistiques que se construisent les élèves kenyans du FLE à l’égard de la France, des Français et de la langue française en 2023. Celles-ci s’insèrent dans le domaine de sociolinguistique et didactiques des langues. Le Kenya, pays anglophone dont la politique linguistique repose sur le bilinguisme anglais-kiswahili, offre un enseignement de plusieurs langues étrangères, parmi lesquelles figurent le français, une matière facultative. Cependant, cette langue demeure l’une des disciplines la moins choisie et la plus abandonnée au fil du parcours secondaire. Il apparaît nécessaire d’interroger les dimensions subjectives et symboliques de cette déperdition, notamment les représentations sociales et affectives que les apprenants kényans se construisent à propos de la France, des Français et de la langue française. L’objectif principal de cette étude a consisté à comprendre les facteurs affectifs et représentationnels qui influencent les attitudes des apprenants vis-à-vis de la langue française. Ancrée sur la théorie de l’affectivité (Tomkins1962), cette étude s’est tâchée d’examiner les pratiques représentationnelles des élèves kenyans dans le comté de Kakamega, au Kenya, à propos de la France, des Français et de la langue française. Elle a poursuivi les objectifs ci-après : saisir les représentations des apprenants kenyans de la France ; établir les images que ceux-ci se font des Français et de déceler les perceptions des apprenants kenyans vis-à-vis de la langue française. L’étude a opté pour l’approche mixte articulant les approches qualitatives et quantitatives. La population a été constituée de 291 élèves dans 24 écoles qui proposent le français comme matière dès la première à la quatrième année d’études dans le comté de Kakamega. Les données ont été récoltées auprès de 81 élèves de la quatrième année, ce niveau étant le plus propice à partager sur leur expérience lors de l’apprentissage du FLE. L’étude a établi que les apprenants kenyans du FLE ont des représentations dévalorisantes et que les représentations positives émergent principalement dans des environnements d’apprentissage où les élèves se sentent valorisés, écoutés et impliqués. Les enseignants de FLE pourraient adopter des pratiques pédagogiques qui engagent affectivement les apprenants comme l’a montré cette étude.ABSTRACT
This article focuses on the social and sociolinguistic representations that Kenyan students learning French as a foreign language develop about France, the French people and the french language in the year 2023. These images lie under the social linguistic and language pedagogy. Kenya is one of the English-speaking nations with its language policy grounded on the English-Kiswahili bilingualism, where a variety of foreign languages are taught, including French as an optional subject. Nevertheless, the language is one of the most commonly dropped subjects in secondary school. It thus seems obligatory to challenge the subjective and symbolic aspects of this attrition especially the social and emotional images that Kenyan learners have developed concerning France, the French people and the French language. The primary aim of the study was to learn the affective and representational variables that shape the attitude of learners towards the French language. Based on the theory of affectivity (Tomkins, 1962), the research aimed at investigating the representational practices of Kenyan students in Kakamega County, on France, the French people, and the French language. It had the following objectives : to capture the representations of the Kenyan learners towards France ; to determine the images that they develop about the French people ; and to see the perceptions of the Kenyan learners in regard to the French language. The research adopted the mixed method, with the use of both qualitative and quantitative analysis. The population was comprised of 291 students in 24 schools which teach French as a subject from form one to four in Kakamega County. A sample size of 81 form four students was used to gather data because this group was deemed the most appropriate to give their learning experiences in the field of foreign language learning (FLE). This analysis has revealed that Kenyan FLE students have devaluing representations and positive representations are primarily produced in learning contexts where students feel appreciated, heard and engaged. Pedagogical practices that empower the emotional aspect of the learners could thus be adopted by teachers of FLE as evidenced by this study.
Keywords: Affectivity, French as a Foreign Language, Perceptions, Representation
Organizational culture and performance of the orphan and vulnerable children (OVC) program of the Presbyterian Church, Njoro, Nakuru County, Kenya
Get PDFThe contribution made by faith-based institutions in Kenya has been increasing in the provision of care and support for Orphans and Vulnerable Children (OVC) alongside government and non-government schemes. Performance issues continue to exist, especially in religiously linked programs. The OVC program of the Presbyterian Church of East Africa (PCEA) in Njoro, Nakuru County, has faced declining donor finances, high turnover of staff, and shrinking coverage of its intended beneficiaries. The research was guided by clearly defined objectives that aimed to examine the effect of employee engagement, reward systems, and organizational values and to assess the effect of stakeholder engagement, all on the performance of the OVC program in PCEA Church Njoro, Nakuru County. Schein’s Organizational Culture Theory provided a comprehensive lens for analyzing the performance of the PCEA OVC program. This theory explained how shared values, engagement, and internal cohesion affect organizational effectiveness. A descriptive survey design guided data collection of the qualitative and quantitative data. Data collection targeted a population of 2,592 beneficiaries who are in or using the OVC program. A total of 335 participants were realized from the population through stratified and simple random sampling methods in the bid to attain a wide range of representation. Structured questionnaires and key informant interviews were used in data collection. Quantitative data was tested against descriptive statistics and logistic regression analysis in an attempt to determine the direction and magnitude of the relationship between organizational culture and program performance. Themes were employed to code qualitative data to complement and enrich the quantitative data findings. Research evidence identified that all four organizational culture constructs—reward system, employee participation, stakeholder engagement, and organizational values—each exerted a statistically significant effect on the OVC program performance. Specifically, the study found that employee involvement in decision-making, acknowledgement of good performance, reinforcement of common values, and involvement of stakeholders in planning and program evaluation were factors that promoted effectiveness, accountability, and satisfaction of beneficiaries. The above findings again affirm that there is a need to foster a better positive organizational culture as a strategic means towards maximizing the efficacy and sustainability of faith-based social programs. This study completes the existing literature gap by tackling the church-based OVC interventions, an issue that has been lightly touched under academic research in Kenya. It presents evidence-informed findings that are able to inform church leadership, program management, and development policy decision-making on what to do regarding making the decision to integrate inner systems for improving service delivery. The study is particularly relevant in the context of increasing calls for transparency, performance, and effectiveness by donor-funded child welfare organizations. According to the study, PCEA and similar organizations invest in employee development, equitable reward systems, values-based leadership, and involvement-based program management practices as a way of becoming sustainable in the long term when dealing with vulnerable children
A Literature Review on the Influence of Training on Improving Employee Performance
Get PDFNumerous studies have been undertaken to explore the influence of training on employee performance on a global scale. Findings from these studies consistently indicate that training significantly improves employee performance. This study sought to extrapolate insights on this subject matter based on a comprehensive literature review. The study was grounded in Human Capital Theory, emphasising the critical nature of investing in employee training. The literature revealed that training positively impacts performance by augmenting employee knowledge and skills, enhancing motivation, alleviating anxiety, achieving targets, and cultivating loyalty and commitment. Consequently, it is recommended that organisations prioritise investments in employee training initiatives, recognising employees as their most asset. Considering the rapidly evolving global landscape and intensified competition, training has emerged as an imperative for private and public organisations striving to thrive in the fiercely competitive global arena. Training methods such as coaching, job rotation, apprenticeship, and induction have been found to influence employee performance positively. Consequently, organisations and management teams must embrace diverse training practices and methods attuned to the organisation\u27s culture and structure, available resources, individual attributes, and the requisites of teams, groups, and departments. A methodical approach to training development, using competence criteria for trainer selection, and exploring alternative motivational strategies to stimulate employee engagement is indispensable for organisational success
Hybridization of the Multiple Decrement Model and the Markov Process Model to Estimate the Benefits of the Micro Pension Scheme in Ghana
Get PDFThe hybridization of the Multiple Decrement Model (MDM) and the Markov Process Model (MPM) has been explored to estimate the Actuarial Present Value (APV) of benefits for a micro-pension scheme designed for Ghanaian commercial drivers. The challenge of extending pension coverage to the informal sector, characterized by irregular income and limited access to formal financial systems, was addressed. The MDM was applied to decrement causes such as retirement, disability, voluntary withdrawal, and death. At the same time, the MPM was used to model the transient state, which is the involuntary withdrawal state. Demographic and economic data from Ghanaian agencies were employed, and actuarial principles were utilized to construct decrement tables, project pension benefits, and estimate annuities. A linear growth in pension benefits was observed, increasing from Gh 7,200 at age 18 to Gh 23,040 at age 64, while the total APV steadily rose, peaking at Gh 114,937.29 at retirement. The robustness of the model was confirmed through sensitivity analysis under varying discount rates, replacement rates, and survival probabilities. The findings ensured the sustainability of micro-pension schemes, offering valuable insights for policymakers and actuarial practitioners
Effect of Project Management Practices on Project Performance: A Case of Tubura Project in Nyanza District, Rwanda
Get PDFThe general objective of this research was to find out the effect of project management practices on performance of Tubura Project in Nyanza District, Rwanda. Specifically the study was guided by the following objectives: finding out the effect of project planning on performance of Tubura Project in Nyanza District, determining the effect of project implementation on performance of Tubura Project in Nyanza District and assessing the effect of project monitoring and evaluation on performance of Tubura Project in Nyanza District. This research was guided by Goal Setting Theory, Theory of Change and Resource Based View Theory.The researcher conducted both descriptive and correlational studies. Descriptive survey research use surveys to collect information on a variety of issues and correlational studies research design examined at the links that exist between variables under the study. The population of this study was 321 people including Tubura Project staff, District staff, Sector staff, Project cell committee and One acre fund employees in Nyanza District. Using Slovin\u27s formula, the researcher estimated how big of a sample was needed to get reliable findings. The researcher relied on document analysis and questionnaire methods to collect data. The researcher more easily displayed the findings in the form of numbers and statistics, giving the reader a more holistic understanding of the findings. Statistical Package for Social Sciences (SPSS) was used in the study. The findings presents a summary of a regression model, indicating a very strong positive correlation (R = 0.922) between the predictors (Project monitoring and evaluation, Project planning, Project implementation) and the performance of Tubura Project in Nyanza District. Specifically, for each unit increase in Project planning, the performance of Tubura Project in Nyanza District is expected to increase by 0.318 units (β=0.318, t=5.915, p=0.000). Similarly, project implementation, with a coefficient of 0.293, indicates that an increase in this variable is associated with a 0.293 unit increase in the performance of Tubura Project in Nyanza District (β=0.293, t=5.138, p=0.000). Project monitoring and evaluation, with a coefficient of 0.382, indicates that an increase in this variable is associated with a 0.382 unit increase in the success of Tubura Project in Nyanza District (β=0.382, t=8.061, p=0.000). In this case, this study concluded that project planning, project implementation and, project monitoring and evaluation significantly contribute to predicting the success of Tubura Project in Nyanza District. It was recommended that Tubura Project staff should be integrated Continuous capacity building and training programs into the project implementation strategy to ensure that the team is equipped with the necessary skills and knowledge to address evolving challenges and opportunities