Şefki Kolozali

Dr. Şefki Kolozali

Embedded and Intelligent Systems, School of Computer Science and Electronic Engineering (CSEE), University of Essex, Colchester CO4 3SQ, UK

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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28 September 2018 in IEEE Internet of Things Journal
Verified
Journal Article
Closed access
Şefki KolozaliŞefki Kolozali
Şefki Kolozali
DKDaniel Kuemper
Daniel Kuemper
RTRalf Tonjes
Ralf Tonjes
MBMaria Bermudez-Edo
Maria Bermudez-Edo
NFNazli Farajidavar
Nazli Farajidavar
TIThorben Iggena
Thorben Iggena
An increasing number of cities are confronted with challenges resulting from the rapid urbanisation and new demands that a rapidly growing digital economy imposes on current applications and information systems. Smart city applications enable city authorities to monitor, manage and provide plans for public resources and infrastructures in city environments, while offering citizens and businesses to develop and use intelligent services in cities. However, providing such smart city applications gives rise to several issues such as semantic heterogeneity and trustworthiness of data sources, and extracting up-to-date information in real time from large-scale dynamic data streams. In order to address these issues, we propose a novel framework with an efficient semantic data processing pipeline, allowing for real-time observation of the pulse of a city. The proposed framework enables efficient semantic integration of data streams and complex event processing on top of real-time data aggregation and quality analysis in a Semantic Web environment. To evaluate our system, we use real-time sensor observations that have been published via an open platform called Open Data Aarhus by the City of Aarhus. We examine the framework utilising Symbolic Aggregate Approximation to reduce the size of data streams, and perform quality analysis taking into account both single and multiple data streams. We also investigate the optimisation of the semantic data discovery and integration based on the proposed stream quality analysis and data aggregation techniques.

12 February 2024 in IEEE Journal of Biomedical and Health Informatics
Verified
Journal Article
Closed access
Şefki KolozaliŞefki Kolozali
Şefki Kolozali
SWSara L White
Sara L White
Shane NorrisShane Norris
Shane Norris
MFMaria Fasli
Maria Fasli
AHAlastair van Heerden
Alastair van Heerden
This study aims to explore the potential of Internet of Things (IoT) devices and explainable Artificial Intelligence (AI) techniques in predicting biomarker values associated with GDM when measured 13 - 16 weeks prior to diagnosis. We developed a system that forecasts biomarkers such as LDL, HDL, triglycerides, cholesterol, HbA1c, and results from the Oral Glucose Tolerance Test (OGTT) including fasting glucose, 1-hour, and 2-hour post-load glucose values. These biomarker values are predicted based on sensory measurements collected around week 12 of pregnancy, including continuous glucose levels, short physical movement recordings, and medical background information. To the best of our knowledge, this is the first study to forecast GDM-associated biomarker values 13 to 16 weeks prior to the GDM screening test, using continuous glucose monitoring devices, a wristband for activity detection, and medical background data. We applied machine learning models, specifically Decision Tree and Random Forest Regressors, along with Coupled-Matrix Tensor Factorisation (CMTF) and Elastic Net techniques, examining all possible combinations of these methods across different data modalities. The results demonstrated good performance for most biomarkers. On average, the models achieved Mean Squared Error (MSE) between 0.29 and 0.42 and Mean Absolute Error (MAE) between 0.23 and 0.45 for biomarkers like HDL, LDL, cholesterol, and HbA1c. For the OGTT glucose values, the average MSE ranged from 0.95 to 2.44, and the average MAE ranged from 0.72 to 0.91. Additionally, the utilisation of CMTF with Alternating Least Squares technique yielded slightly better results (0.16 MSE and 0.07 MAE on average) compared to the well-known Elastic Net feature selection technique. While our study was conducted with a limited cohort in South Africa, our findings offer promising indications regarding the potential for predicting biomarker values in pregnant women through the integration of wearable devices and medical background data in the analysis. Nevertheless, further validation on a larger, more diverse cohort is imperative to substantiate these encouraging results.

30 April 2023 in Neural Computing and Applications
Verified
Journal Article
Open access
PDF file
Şefki KolozaliŞefki Kolozali
Şefki Kolozali
LCLia Chatzidiakou
Lia Chatzidiakou
RJRoderic Jones
Roderic Jones
JQJennifer Kathleen Quint
Jennifer Kathleen Quint
FKFrank Kelly
Frank Kelly
BBBenjamin Barratt
Benjamin Barratt
In this study, we present a cohort study involving 106 COPD patients using portable environmental sensor nodes with attached air pollution sensors and activity-related sensors, as well as daily symptom records and peak flow measurements to monitor patients’ activity and personal exposure to air pollution. This is the first study which attempts to predict COPD symptoms based on personal air pollution exposure. We developed a system that can detect COPD patients’ symptoms one day in advance of symptoms appearing. We proposed using the Probabilistic Latent Component Analysis (PLCA) model based on 3-dimensional and 4-dimensional spectral dictionary tensors for personalised and population monitoring, respectively. The model is combined with Linear Dynamic Systems (LDS) to track the patients’ symptoms. We compared the performance of PLCA and PLCA-LDS models against Random Forest models in the identification of COPD patients’ symptoms, since tree-based classifiers were used for remote monitoring of COPD patients in the literature. We found that there was a significant difference between the classifiers, symptoms and the personalised versus population factors. Our results show that the proposed PLCA-LDS-3D model outperformed the PLCA and the RF models between 4 and 20% on average. When we used only air pollutants as input, the PLCA-LDS-3D forecasting results in personalised and population models were 48.67 and 36.33% accuracy for worsening of lung capacity and 38.67 and 19% accuracy for exacerbation of COPD patients’ symptoms, respectively. We have shown that indicators of the quality of an individual’s environment, specifically air pollutants, are as good predictors of the worsening of respiratory symptoms in COPD patients as a direct measurement.

1 April 2021 in mHealth
Verified
Journal Article
Open access
PDF file
AHAlastair Van Heerden
Alastair Van Heerden
WCW. Scott Comulada
W. Scott Comulada
Şefki KolozaliŞefki Kolozali
Şefki Kolozali
Brandon KohrtBrandon Kohrt
Brandon Kohrt
Drawing open the curtain on home-based interventions