Evaluating Machine Learning Classifiers to detect Android Malware

Background: Early identification of probable post-traumatic stress disorder (PTSD) can lead to early intervention and treatment.Aims: This study aimed to evaluate supervised machine learning (ML) classifiers for the identification of probable PTSD in those who are serving, or have recently served in the United Kingdom (UK) Armed Forces.Methods: Supervised ML classification techniques were applied to a military cohort of 13,690 serving and ex-serving UK Armed Forces personnel to identify probable PTSD based on self-reported service exposures and a range of validated self-report measures. Data were collected between 2004 and 2009.Results: The predictive performance of supervised ML classifiers to detect cases of probable PTSD were encouraging when compared to a validated measure, demonstrating a capability of supervised ML to detect the cases of probable PTSD. It was possible to identify which variables contributed to the performance, including alcohol misuse, gender and deployment status. A satisfactory sensitivity was obtained across a range of supervised ML classifiers, but sensitivity was low, indicating a potential for false negative diagnoses.Conclusions: Detection of probable PTSD based on self-reported measurement data is feasible, may greatly reduce the burden on public health and improve operational efficiencies by enabling early intervention, before manifestation of symptoms.

Malware detection at the hardware level has emerged recently as a promising solution to improve the security of computing systems. Hardware-based malware detectors take advantage of Machine Learning (ML) classifiers to detect pattern of malicious applications at run-time. These ML classifiers are trained using low-level features such as processor Hardware Performance Counters (HPCs) data which are captured at run-time to appropriately represent the application behaviour. Recent studies show the potential of standard ML-based classifiers for detecting malware using analysis of large number of microarchitectural events, more than the very limited number of HPC registers available in today’s microprocessors which varies from 2 to 8. This results in executing the application more than once to collect the required data, which in turn makes the solution less practical for effective run-time malware detection. Our results show a clear trade-off between the performance of standard ML classifiers and the number and diversity of HPCs available in modern microprocessors. This paper proposes a machine learning-based solution to break this trade-off to realize effective run-time detection of malware. We propose ensemble learning techniques to improve the performance of the hardware-based malware detectors despite using a very small number of microarchitectural events that are captured at run-time by existing HPCs, eliminating the need to run an application several times. For this purpose, eight robust machine learning models and two well-known ensemble learning classifiers applied on all studied ML models (sixteen in total) are implemented for malware detection and precisely compared and characterized in terms of detection accuracy, robustness, performance (accuracy × robustness), and hardware overheads. The experimental results show that the proposed ensemble learning-based malware detection with just 2 HPCs using ensemble technique outperforms standard classifiers with 8 HPCs by up to 17%. In addition, it can match the robustness and performance of standard ML-based detectors with 16 HPCs while using only 4 HPCs allowing effective run-time detection of malware.

Regulating inflammatory microglia presents a promising strategy for treating neurodegenerative and autoimmune disorders, yet effective therapeutic agents delivery to these cells remains a challenge. This study investigates modified lipid nanoparticles (LNP) for mRNA delivery to hyperactivated microglia, particularly those with pro-inflammatory characteristics, utilizing supervised machine learning (ML) classifiers. We developed and screened a library of 216 LNP formulations with varying lipid compositions, N/P ratios, and hyaluronic acid (HA) modifications. The transfection efficiency of eGFP mRNA was assessed in the BV-2 murine microglia cell line under different immunological states, including resting and activated conditions (LPS-activated and IL4/IL13-activated). ML-guided morphometric analysis tracked the phenotypes of various microglia subtypes before and after transfection. Four supervised ML classifiers were investigated to predict transfection efficiency and phenotypic changes based on LNP design parameters. The Multi-Layer Perceptron (MLP) neural network emerged as the best-performing model, achieving weighted F1-scores ≥0.8. While it accurately predicted responses from LPS-activated and resting cells, it struggled with IL4/IL13-activated cells. The MLP model was validated by predicting the performance of four unseen LNP formulations delivering eGFP mRNA to LPS-activated BV2 cells. HA-LNP2 emerged as optimal formulation for delivering target IL10 mRNA, effectively suppressing inflammatory phenotypes, evidenced by shifts in cell morphology, increased IL10 expression, and reduced TNF-α levels. We also evaluated HA-LNP2 on LPS-activated human iPSC-derived microglia, confirming its efficacy in modulating inflammatory responses. This study highlights the potential of tailored LNP design and ML techniques to enhance mRNA therapy for neuroinflammatory disorders by leveraging carrier’s immunogenic properties to modulate microglial responses.

We can state undoubtedly that Bangla language is rich enough to work with and implement various Natural Language Processing (NLP) tasks. Though it needs proper attention, hardly NLP field has been explored with it. In this age of digitalization, large amount of Bangla news contents are generated in online platforms. Some of the contents are inappropriate for the children or aged people. With the motivation to filter out news contents easily, the aim of this work is to perform document level sentiment analysis (SA) on Bangla online news. In this respect, the dataset is created by collecting news from online Bangla newspaper archive. Further, the documents are manually annotated into positive and negative classes. Composite process technique of “Pipeline” class including Count Vectorizer, transformer (TF-IDF) and machine learning (ML) classifiers are employed to extract features and to train the dataset. Six supervised ML classifiers (i.e. Multinomial Naive Bayes (MNB), K-Nearest Neighbor (K-NN), Random Forest (RF), (C4.5) Decision Tree (DT), Logistic Regression (LR) and Linear Support Vector Machine (LSVM)) are used to analyze the best classifier for the proposed model. There has been very few works on SA of Bangla news. So, this work is a small attempt to contribute in this field. This model showed remarkable efficiency through better results in both the validation process of percentage split method and 10-fold cross validation. Among all six classifiers, RF has outperformed others by 99% accuracy. Even though LSVM has shown lowest accuracy of 80%, it is also considered as good output. However, this work has also exhibited surpassing outcome for recent and critical Bangla news indicating proper feature extraction to build up the model.

Does Multiple Criteria Decision Aiding (MCDA) improve the process of evaluating Machine Learning (ML) algorithms, when critical criteria of fairness are concurrently considered, beyond predictive power? To address this question, we employ several notions of fairness, such as Demographic Parity, Equalized Odds, and Lack of Disparate Mistreatment, and we appraise a set of supervised ML classifiers, under one of the most popular MCDA outranking methods, that is, the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) II. Moreover, to avoid any arbitrary choice in the importance attached to the criteria we apply the Stochastic Multicriteria Acceptability Analysis (SMAA), providing information in statistical terms through simulations. The empirical testing is processed over well-known databases, with several representative sub-datasets, securing variation in terms of observations’ volume. Overall, a series of ranking patterns that persists in the evaluation of the ML classifiers, across the utilized MCDA methodology and datasets, offers valuable relevant insights and documents specific useful interpretations. The obtained findings provide robust support that MCDA can be effectively exploited for the appraisal of ML classifiers, when aiming at the simultaneous consideration of critical fairness metrics, apart from the typical dimensions related to predictive power.

To develop and internally validate a machine learning (ML) model that identifies older outpatients with MCI using routine electronic health record (EHR) data. We conducted a retrospective cross-sectional study of community outpatients aged ≥60 years in Zhejiang, China. Structured EHR predictors included demographics, comorbidities/medications, lifestyle, and visit patterns. The outcome was adjudicated MCI based on cognitive screening (MoCA plus supplemental tests). Supervised ML classifiers were compared using 10-fold cross-validation and an independent held-out test set; class imbalance was addressed with SMOTE. Performance was assessed by the area under the ROC curve (AUC) and by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and F1 score. The test set included ~640 patients (≈20% MCI). Gradient Boosting performed best: cross-validation mean AUC 0.855 (SD 0.031) and accuracy 0.862 (SD 0.013); test AUC 0.850, accuracy 0.833, and F1 0.402. At the default threshold, sensitivity was 0.286 and specificity 0.967 (PPV 0.679; NPV 0.847). Prioritizing sensitivity (~0.82) lowered specificity (~0.64). At a high-sensitivity threshold of 0.159, the model achieved a sensitivity of 0.802 with a specificity of 0.751 (PPV 0.441; NPV 0.939). Important predictors included older age, female sex, lower education, smaller family size, and higher depression scores. An ML model using routine outpatient EHR can discriminate MCI in older adults (AUC ≈ 0.85), supporting potential for automated, low-cost screening in primary care. Using the predicted probabilities generated in this analysis, we assessed calibration and conducted a decision-curve analysis. While the model shows good discrimination and calibration, external validation is still required to confirm clinical utility and refine operating thresholds.

Artificial intelligence (AI) is a tool thought to revolutionize the field of reproductive medicine in the years to come. Specifically, machine learning (ML), which is a subset of AI methods used to detect patterns and make predictions based on large datasets, has been used in ART to predict implantation outcome, embryo transfer strategies or adverse outcomes for IVF treatments (for a review see, Wang et al., 2019). However, ML methods have not yet been widely adopted in medically assisted reproduction (MAR). This slow uptake could be due to a lack of in-depth interdisciplinary communication between ML experts and clinicians/embryologists, as well as some uncertainty on how ML models could be generalized for different populations. The February edition of the ESHRE Journal Club discussed a paper from Yland et al. (2022) where the authors compared different ML algorithms to predict the chance of pregnancy in couples actively trying to conceive (without undergoing MAR). By using data from the Pregnancy Study Online (PRESTO), a web-based prospective cohort study of 4133 couples in North America (Wise et al., 2015), the authors analysed 163 potential variables and used supervised ML classification algorithms to identify the strength of each variable in predicting pregnancy outcomes of couples across the fertility spectrum (infertile: <12 menstrual cycles; subfertile: within 6 menstrual cycles; and fecundability: the average probability of pregnancy per menstrual cycle). The authors were able to predict pregnancy with a discrimination as high as 71.2% and identify the variables that most consistently predicted conception. These variables included lifestyle and reproductive characteristics such as age, BMI, history of infertility, daily use of vitamins or folic acid, intercourse timing, diet quality and reduced stress. ESHRE Journal Club discussion focused on promoting interdisciplinarity among ML and reproductive medicine specialists. It hosted 50 participants on Twitter together with experts Michelle Perugini, Vajira Thambawita and authors Jennifer Yland, Yannis Paschalidis and Lauren Wise. The discussion resulted in 902 tweets and around 1 million impressions over a 24-h period.

Freshwater ecosystems play a crucial role in maintaining ecological balance and supporting biodiversity. Assessing water quality and identifying pollution factors affected by seasonal changes is of utmost importance. The traditional approach for identifying pollution sources and seasonal water quality assessment is often labor-intensive, time-consuming, and complex. In response, our study introduces a hybrid receptor, multivariate statistical and machine learning (ML) based framework as an alternative. Positive matrix factorization (PMF) and receptor model were used to identify key pollutant sources, while Principal Component Analysis (PCA) was used to corroborate pollutant sources. Additionally, various supervised ML classification algorithms are used to predict and identify pollution sources on full physicochemical datasets and reduced in situ parameter scenarios. ML model stability and generalization capacity were evaluated using learning curves, cross-validation method. The findings indicate significant seasonal variability in water quality index, ranging from 38.5 (poor) to 78.6 (good). PMF and PCA revealed three dominant pollution factors, such as biogeochemical processes, sediment resuspension/nutrient influx, and anthropogenic pollution, affecting the seasonal water quality by 15-30%, 25-45%, and 40-70%, respectively. Model performance indicators using confusion matrices, ROC-AUC, and other evaluation metrics, for full dataset identified XGBoost as the best model, achieving the highest accuracy of 96.3%, followed by CatBoosting (93.6%), Random Forest (93.6%), Support Vector Classifier (91.8%), K-Nearest Neighbors (87.2%) and Decision Tree (84.3%). However, with the in situ data the ML models show stable and consistent classification accuracy in the range of approximately 70-81%. Overall, the modelling framework provides an effective approach for capturing seasonal variability and pollution source attribution, contributing to improved ecological understanding and predictive management of freshwater system.

Chapter 6 - Cardiovascular disease prediction using machine learning models and ensemble technique

Wireless Sensor Networks (WSNs) are the key underlying technology of the Internet of Things (IoT); however, these networks are energy constrained. Security has become a major challenge with the significant increase in deployed sensors, necessitating effective detection and mitigation approaches. Machine learning (ML) is one of the most effective methods for building cyber-attack detection systems. This paper presents a lightweight ensemble-based ML approach, Weighted Score Selector (WSS), for detecting cyber-attacks in WSNs. The proposed approach is implemented using a blend of supervised ML classifiers, in which the most effective classifier is promoted dynamically for the detection process to gain higher detection performance quickly. We compared the performance of the proposed approach to three classical ensemble techniques: Boosting-based, Bagging-based, and Stacking-based. The performance comparison was conducted in terms of accuracy, probability of false alarm, probability of detection, probability of misdetection, model size, processing time, and average prediction time per sample. We applied two independent feature selection techniques. We utilized the simulation-based labeled dataset, WSN-DS, that comprises samples of four internal network-layer Denial of Service attack types: Grayhole, Blackhole, Flooding, and TDMA scheduling, in addition to normal traffic. The simulation revealed promising results for our proposed approach.

Introduction: The 30–50% non-response rate to cardiac resynchronization therapy (CRT) calls for improved patient selection and optimized pacing lead placement. The study aimed to develop a novel technique using patient-specific cardiac models and machine learning (ML) to predict an optimal left ventricular (LV) pacing site (ML-PS) that maximizes the likelihood of LV ejection fraction (LVEF) improvement in a given CRT candidate. To validate the approach, we evaluated whether the distance DPS between the clinical LV pacing site (ref-PS) and ML-PS is associated with improved response rate and magnitude.Materials and methods: We reviewed retrospective data for 57 CRT recipients. A positive response was defined as a more than 10% LVEF improvement. Personalized models of ventricular activation and ECG were created from MRI and CT images. The characteristics of ventricular activation during intrinsic rhythm and biventricular (BiV) pacing with ref-PS were derived from the models and used in combination with clinical data to train supervised ML classifiers. The best logistic regression model classified CRT responders with a high accuracy of 0.77 (ROC AUC = 0.84). The LR classifier, model simulations and Bayesian optimization with Gaussian process regression were combined to identify an optimal ML-PS that maximizes the ML-score of CRT response over the LV surface in each patient.Results: The optimal ML-PS improved the ML-score by 17 ± 14% over the ref-PS. Twenty percent of the non-responders were reclassified as positive at ML-PS. Selection of positive patients with a max ML-score >0.5 demonstrated an improved clinical response rate. The distance DPS was shorter in the responders. The max ML-score and DPS were found to be strong predictors of CRT response (ROC AUC = 0.85). In the group with max ML-score > 0.5 and DPS< 30 mm, the response rate was 83% compared to 14% in the rest of the cohort. LVEF improvement in this group was higher than in the other patients (16 ± 8% vs. 7 ± 8%).Conclusion: A new technique combining clinical data, personalized heart modelling and supervised ML demonstrates the potential for use in clinical practice to assist in optimizing patient selection and predicting optimal LV pacing lead position in HF candidates for CRT.

As technology advances so does its adoption in industry and our everyday lives. We use technology to better our daily tasks whether at home or in the workplace. In the workplace there are many benefits of implementing new technologies to improve processes and products while at the same time being cautious about associated costs. Costs associated with incorporating new digital technologies include but are not limited to hardware and software, system integration, testing, and employee training. Now that we have entered the era of the Fourth Industrial Revolution, there are many opportunities for improvements in manufacturing that involve Smart Digital Technologies. Quality Inspection (QI) is a common process in the manufacturing industry. This process serves to identify and locate defects based on preassigned product features. It can be used to find defect causes during the manufacturing process. QI is an established process that is often conducted manually. However, with the opportunity afforded by core Industry 4.0 technologies like Machine Learning (ML), the QI process is increasingly automated. A literature review on the topic of Image Based QI shows that today the designs of fixed single camera based QI systems inspect only one side of a product. In case multiple sides of a product need to be inspected, more datapoints are acquired via either multiple cameras or moving the camera system which affects the length of process, task complexity, cost, and data storage. This thesis explores the application of a mirror system in the design of a QI station to overcome this current limitation and potentially lower the number of processing tasks and increase the inspection ability of one automated station. The images acquired for the QI experiment present a simultaneous, multi-side (five sides) view of a product with similar accuracy. The experiment is set up with three major parts: 1) a physical setup of a mirror-enhanced camera system for part QI; 2) a set of test parts with two types of simulated common surface defects (additional material and scratches) to create the data set for analysis, and 3) a Python-based ML model to analyze the data set and evaluate the system’s ability to correctly identify errors on multiple sides of the specimens. The results show that the setup successfully identified the majority of surface errors on all sides of the part with an accuracy of at least 85% when applying an Artificial Neural Network based supervised ML classification approach. This

Unintentional wellbore deviation presents persistent challenges in drilling operations, often leading to cumulative trajectory irregularities that can compromise downhole equipment reliability and production performance. This study presents an integrated framework that combines machine learning (ML)-based prediction of deviation risk with a tortuosity-based engineering diagnostic to interpret the geometric and operational consequences of deviation. Using well-log-derived formation and geomechanical properties, multiple supervised ML classifiers are developed and evaluated, with the Random Forest (RF) model demonstrating robust performance in identifying deviation-prone intervals. The RF model demonstrated strong predictive performance, achieving a test accuracy of 96.67%, cross-validation accuracy of 98.31%, precision of 97%, recall of 99%, F1-score of 98%, ROC-AUC of 0.9975, PR-AUC of 0.9946, MCC of 0.963, and a log-loss of 0.647. A comprehensive feature importance and sensitivity analysis revealed features such as formation density, shale volume, and Poisson's ratio as the top classifiers, accounting for 46.4%, 28.5%, and 19.2%, respectively, of the model's decision-making criteria. To translate the deviation risk into physically interpretable trajectory complexity, a three-dimensional tortuosity index is incorporated, capturing cumulative curvature arising from frequent inclination and azimuth changes along the wellbore. Application to field wells from a major onshore unconventional basin in the United States with documented artificial lift system failures indicated that elevated vertical-section tortuosity is associated with specific failure mechanisms, including sucker rod and tubing-related failures, highlighting the mechanical relevance of trajectory quality beyond directional control. In contrast, analysis of lateral-section tortuosity showed no observable association with first-year production normalized by lateral length, consistent with prior findings that tortuosity in the lateral section does not directly impair production performance. By linking formation-driven deviation risk, trajectory complexity, and mechanical implications, the proposed framework provides a practical methodology for planning-stage deviation risk characterization and post-drill assessment of wellbore quality, supporting informed well design and artificial lift decision-making.

In the era of Internet of Things (IoT), Malware has been proliferating exponentially over the past decade. Traditional anti-virus software are ineffective against modern complex Malware. In order to address this challenge, researchers have proposed hardware-assisted Malware detection (HMD) using hardware performance counters (HPCs). The HPCs are used to train a set of machine learning (ML) classifiers, which in turn, are used to distinguish benign programs from Malware. Recently, adversarial attacks have been designed by introducing perturbations in the HPC traces using an adversarial sample predictor to misclassify a program for specific HPCs. These attacks are designed with the basic assumption that the attacker is aware of the HPCs being used to detect Malware. Since modern processors consist of hundreds of HPCs, restricting to only a few of them for Malware detection aids the attacker. In this article, we propose a moving target defense (MTD) for this adversarial attack by designing multiple ML classifiers trained on different sets of HPCs. The MTD randomly selects a classifier; thus, confusing the attacker about the HPCs or the number of classifiers applied. We have developed an analytical model which proves that the probability of an attacker to guess the perfect HPC-classifier combination for MTD is extremely low (in the range of $10^{-1864}$ for a system with 20 HPCs). Our experimental results prove that the proposed defense is able to improve the classification accuracy of HPC traces that have been modified through an adversarial sample generator by up to 31.5%, for a near perfect (99.4%) restoration of the original accuracy.

Due to the exponential growth of digital platforms and the Internet era around us, particularly: cyberattacks facilitated by malware have become increasingly diversified and complex. The increase in malware strains has created an increased demand for advanced detection methods that can handle a large volume of data quickly. In this study, we use machine learning classifiers along with optimum feature vector extraction using principal component analysis (PCA) and Particle swarm optimization (PSO) to get better malware detection and classification. The key classifiers of this method are logistic regression (LR), Naive Bayes (NB), nearest neighbor (KNN), and decision trees (ID3 and C4. 5). PCA and PSO are successful methods for reducing the feature set without hindering or even improving the classification results; therefore, experimental results show that using feature reduction techniques with these classifiers provides (i) very high detection accuracy and (ii) lower computational complexity. These can be seen as evidence for the usefulness of hybrid approaches in enhancing malware detection performance on large-scale data sets.