Yegnanew A. Shiferaw

Prof. Yegnanew A. Shiferaw

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 July 2019 in Physica A: Statistical Mechanics and its Applications
Verified
Journal Article
Closed access
YSYegnanew A. Shiferaw
Yegnanew A. Shiferaw

30 April 2020 in Sustainability
Verified
Journal Article
Open access
PDF file
SDSIMANGELE DLAMINI
SIMANGELE DLAMINI
STSolomon Gebramariam Tesfamichael
Solomon Gebramariam Tesfamichael
YSYegnanew A. Shiferaw
Yegnanew A. Shiferaw
TMTholang Mokhele
Tholang Mokhele
In environment-nature discourse, determinants of environmental perceptions and attitudes vary significantly making it difficult to draw generalisations on their significance for particular locales. In this paper, we explore the key socio-demographic factors affecting environmental perceptions and attitudes for a socio-economically diverse area of Gauteng province, South Africa, using a generalised ordered logit model (gologit) approach. Personal level variables like gender, education level, employment status, age, population group, migration status and external variables such as dwelling type and electricity availability, obtained through a questionnaire, were assessed as determinants of environmental perceptions and attitudes. Statistical results indicated that dwelling type, gender, education level, place of birth and employment status were strong determinants of environmental attitudes. Population group (Coloured and White), dwelling type, electricity availability, employment status and education level (from primary only up to matric) were found to be significant predictors of environmental perceptions. Education level, dwelling type and employment status were therefore the common explanatory variables from the analysis, giving prominence to material values that people attach to environmental attitudes and perceptions. Age had no influence on both environmental perceptions and attitudes. The results from this article can provide a foundation for segmentation of anthropocentric factors for environmental planning and strategy formulation within the province.

25 April 2023 in Economies
Verified
Journal Article
Open access
PDF file
YSYegnanew A. Shiferaw
Yegnanew A. Shiferaw
The main aim of this paper is to examine the dynamic relationship between the three pillars of the economy: unemployment, inflation, and GDP in Ethiopia using the cross-wavelet transform (XWT) analysis, the multivariate Student-t generalized autoregressive score (GAS) model, and the autoregressive distributed lag (ARDL) model. The dynamics between the three indicators were also investigated using the Toda–Yamamoto (TY) causality test. The empirical findings from the XWT method suggest a relationship between unemployment, inflation, and GDP, though the relationship varies over time and frequency. The estimation results from the multivariate Student-t GAS model show that the correlation between unemployment (overall, male, female, and youth) and inflation is highly significant, indicating that the correlation is dynamic. A dynamic relationship exists between GDP and unemployment, except for females and young people. The ARDL approach’s findings showed that unemployment significantly negatively impacted GDP. However, it was found that inflation significantly increased GDP. The general conclusion drawn from this study’s findings is that unemployment significantly affects GDP and inflation. Therefore, the government should aggressively implement policies to reduce unemployment, especially youth unemployment. Additionally, the administration must rehabilitate the country’s badly damaged economy and formalize a lasting cessation of hostilities between the federal government and the Tigray People’s Liberation Front (TPLF).

17 August 2024 in Algorithms
Verified
Journal Article
Open access
PDF file
Musa JaitehMusa Jaiteh
Musa Jaiteh
EPEdith Phalane
Edith Phalane
YSYegnanew A. Shiferaw
Yegnanew A. Shiferaw
KVKaren Alida Voet
Karen Alida Voet
RPRefilwe Nancy Phaswana-Mafuya
Refilwe Nancy Phaswana-Mafuya
Several machine learning (ML) techniques have demonstrated efficacy in precisely forecasting HIV risk and identifying the most eligible individuals for HIV testing in various countries. Nevertheless, there is a data gap on the utility of ML algorithms in strengthening HIV testing worldwide. This systematic review aimed to evaluate how effectively ML algorithms can enhance the efficiency and accuracy of HIV testing interventions and to identify key outcomes, successes, gaps, opportunities, and limitations in their implementation. This review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A comprehensive literature search was conducted via PubMed, Google Scholar, Web of Science, Science Direct, Scopus, and Gale OneFile databases. Out of the 845 identified articles, 51 studies were eligible. More than 75% of the articles included in this review were conducted in the Americas and various parts of Sub-Saharan Africa, and a few were from Europe, Asia, and Australia. The most common algorithms applied were logistic regression, deep learning, support vector machine, random forest, extreme gradient booster, decision tree, and the least absolute shrinkage selection operator model. The findings demonstrate that ML techniques exhibit higher accuracy in predicting HIV risk/testing compared to traditional approaches. Machine learning models enhance early prediction of HIV transmission, facilitate viable testing strategies to improve the efficiency of testing services, and optimize resource allocation, ultimately leading to improved HIV testing. This review points to the positive impact of ML in enhancing early prediction of HIV spread, optimizing HIV testing approaches, improving efficiency, and eventually enhancing the accuracy of HIV diagnosis. We strongly recommend the integration of ML into HIV testing programs for efficient and accurate HIV testing.

27 January 2025 in JMIR Research Protocols
Verified
Journal Article
Open access
Musa JaitehMusa Jaiteh
Musa Jaiteh
EPEdith Phalane
Edith Phalane
YSYegnanew A. Shiferaw
Yegnanew A. Shiferaw
RPRefilwe Nancy Phaswana-Mafuya
Refilwe Nancy Phaswana-Mafuya
Background: HIV testing is the cornerstone of HIV prevention and a pivotal step in realizing the Joint United Nations Program on HIV/AIDS (UNAIDS) goal of ending AIDS by 2030. Despite the availability of relevant survey data, there exists a research gap in using machine learning (ML) to analyze and predict HIV testing among adults in South Africa. Further investigation is needed to bridge this knowledge gap and inform evidence-based interventions to improve HIV testing. Objective: This study aims to determine consistent predictors of HIV testing by applying supervised ML algorithms in repeated adult population-based surveys in South Africa. Methods: A retrospective analysis of multiwave cross-sectional survey data will be conducted to determine the predictors of HIV testing among South African adults aged 18 years and older. A supervised ML technique will be applied across the five cycles of the South African National HIV Prevalence, Incidence, Behavior, and Communication Survey (SABSSM) surveys. The Human Science Research Council (HSRC) conducted the SABSSM surveys in 2002, 2005, 2008, 2012, and 2017. The available SABSSM datasets will be imported to RStudio (version 4.3.2; Posit Software, PBC) to clean and remove outliers. A chi-square test will be conducted to select important predictors of HIV testing. Each dataset will be split into 80% training and 20% test samples. Logistic regression, support vector machines, random forests, and decision trees will be used. A cross-validation technique will be used to divide the training sample into k-folds, including a validation set, and models will be trained on each fold. The models’ performance will be evaluated on the validation set using evaluation metrics such as accuracy, precision, recall, F1-score, area under curve-receiver operating characteristics, and confusion matrix. Results: The SABSSM datasets are open access datasets available on the HSRC database. Ethics approval for this study was obtained from the University of Johannesburg Research and Ethics Committee on April 23, 2024 (REC-2725-2024). The authors were given access to all five SABSSM datasets by the HSRC on August 20, 2024. The datasets were explored to identify the independent variables likely influencing HIV testing uptake. The findings of this study will determine consistent variables predicting HIV testing uptake among the South African adult population over the course of 20 years. Furthermore, this study will evaluate and compare the performance metrics of the 4 different ML algorithms, and the best model will be used to develop an HIV testing predictive model. Conclusions: This study will contribute to existing knowledge and deepen understanding of factors linked to HIV testing beyond traditional methods. Consequently, the findings would inform evidence-based policy recommendations that can guide policy makers to formulate more effective and targeted public health approaches toward strengthening HIV testing. International Registered Report Identifier (IRRID): DERR1-10.2196/59916

2 March 2020 in GIScience & Remote Sensing
Verified
Journal Article
Closed access
MPMargaret Phiri
Margaret Phiri
YSYegnanew A. Shiferaw
Yegnanew A. Shiferaw
STSolomon Gebramariam Tesfamichael
Solomon Gebramariam Tesfamichael
Climatic factors such as rainfall and temperature play a vital role in the growth characteristics of vegetation. While the relationship between climate and vegetation growth can be accurately predicted in instances where vegetation is homogenous, this becomes complex to determine in heterogeneous vegetation environments. The aim of this paper was to study the relationship between remotely-sensed monthly vegetation indices (i.e. Normalized Difference Vegetation Index and Enhanced Vegetation Index) and climatic variables (temperature and precipitation) using time-series analysis at the biome-level. Specifically, the autoregressive distributed lag model (ARDL1 and ARDL2, corresponding respectively to one month and two month lags) and the Koyck-transformed distributed lag model were used to build regression models. All three models estimated NDVI and EVI fairly accurately in all biomes (Relative Root-Mean-Squared-Error (RMSE): 12.0–26.4%). Biomes characterized by relative homogeneity (Grassland, Savanna, Indian Ocean Coastal Belt and Forest Biomes) achieved the most accurate estimates due to the dominance of a few species. Comparisons of lag size (one month compared to two months) generally showed similarities (Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC) and log-likelihood) with quite high comparability in certain biomes – this indicates the utility of the ARDL1 and ARDL2 model, depending on the availability of appropriate data. These findings demonstrate the variation in estimation linked to the biome, and thus the validity of biome-level correlation of climatic data and vegetation indices.