Workload Classification Research Articles

Understanding Power Gating Mechanism Based on Workload Classification of Modern Heterogeneous Many-Core Mobile Platform in the Dark Silicon Era

The rapid progress in mobile computing necessitates energy efficient solutions to support substantially diverse and complex workloads. Heterogeneous many core platforms are progressively being adopted in contemporary embedded implementations for high performance at low power cost estimations. These implementations experience diverse workloads that offer drastic opportunities to improve energy efficiency. In this paper, we propose a novel per core power gating (PCPG) approach based on workload classifications (WLC) for drastic energy cost minimization in the dark silicon era. Core of our paradigm is to use an integrated sleep mode management based on workloads classification indicated by the performance counters. A number of real applications benchmark (PARSEC) are adopted as a practical example of diverse workloads, including memory- and CPU-intensive ones. In this paper, these applications are exercised on Samsung Exynos 5422 heterogeneous many core system showing up to 37% to 110% energy efficient when compared with our most recent published work, and ondemand governor, respectively. Furthermore, we illustrate low-complexity and low-cost runtime per core power gating algorithm that consistently maximize IPS/Watt at all state space.

Assessment of cognitive workload using simultaneous EEG and fNIRS: A comparison of feature combinations

The assessment of cognitive workload is a critical component in evaluating mental activity. It is essential in psychology, especially in professions with heightened cognitive demands, such as aviation and surgery. Even marginal improvements in workload assessment can substantially enhance safety and overall performance. This study aimed to improve the accuracy of cognitive workload assessment by employing a combined EEG+fNIRS approach with a minimal number of features. The Tunable Q-factor Wavelet Transform (TQWT) was applied to signals from EEG and fNIRS to extract relevant features. TQWT was chosen for its ability to adapt to the oscillatory behavior of the signal, and the features extracted from the transform facilitated the differentiation between different signal classes. This study introduced six proposed approaches, with the first focusing on EEG signals, the second on fNIRS signals, and the subsequent three to six approaches involving combinations of these two signals. Features evaluation highlighted the pivotal role of channels related to the frontal region and sub-bands associated with alpha and theta rhythms in EEG signals. Additionally, the very low-frequency range and the primary undecomposed signal in fNIRS signals contributed significantly to cognitive workload classification. The classification results demonstrated the efficacy of combining EEG and fNIRS signals in cognitive workload detection, providing higher accuracy than single-signal approaches. Compared to other feature combination approaches, the proposed approach based on Canonical Correlation Analysis (CCA) with a linear SVM classifier achieved superior accuracy across all investigated cognitive workload levels, with accuracies of 99.6 %, 99.4 %, 98.9 %, and 97.5 % for the 0-back vs. 3-back, 0-back vs. 2-back, 2-back vs. 3-back, and 0-back vs. 2-back vs. 3-back comparisons, respectively.

A performance-based mental workload identification method for special vehicle crews

Detecting the mental workload state of armored vehicle crews is of great significance for monitoring the driving state of the crew and improving comprehensive combat effectiveness. In this manuscript, we propose a performance-based mental workload identification method and carry out experimental validation to improve the accuracy of crew mental workload identification and realize the effective classification of mental workload. Based on the virtual simulation system of the special vehicle crew task, this manuscript selects 20 subjects for the mental workload experiment of special vehicle crews. The experiment collected NASA-TLX scale, EEG, eye-tracking data, and performance data. The results show that the mental workload of the crews fluctuates in the segmented tasks of complex operations in typical scenes of special vehicles. The method of determining mental workload using NASA-TLX generates label noise in classification, which is not suitable for special vehicle tasks. Performance-based mental workload identification method is able to recognize fluctuations in the crew's mental workload during segmented tasks. Performance-based and NASA-TXL-based methods were classified using linear discriminant analysis. The results show that the accuracy of the method based on performance is improved by 15.72 %. This manuscript found the NASA-TXL scale is not suitable for the complex tasks of special vehicles, and proposed a performance-based identification method that can help to categorize the mental workload states of special vehicle crews.

EEG workload estimation and classification: a systematic review.

Electroencephalography (EEG) has evolved into an indispensable instrument for estimating cognitive workload in various domains. ML and DL techniques have been increasingly employed to develop accurate workload estimation and classification models based on EEG data. The goal of this systematic review is to compile the body of research on EEG workload estimation and classification using ML and DL approaches. The PRISMA procedures were followed in conducting the review, searches were conducted through databases at SpringerLink, ACM Digital Library, IEEE Explore, PUBMED, and Science Direct from the beginning to the end of February 16, 2024. Studies were selected based on predefined inclusion criteria. Data were extracted to capture study design, participant demographics, EEG features, ML/DL algorithms, and reported performance metrics. Out of the 125 items that emerged, 33 scientific papers were fully evaluated. The study designs, participant demographics, and EEG workload measurement and categorization techniques used in the investigations differed. SVM, CNN, and hybrid networks are examples of ML and DL approaches that were often used. Analyzing the accuracy scores achieved by different ML/DL models. Furthermore, a relationship was noted between sample frequency and model accuracy, with higher sample frequencies generally leading to improved performance. The percentage distribution of ML/DL methods revealed that SVMs, CNNs, and RNNs were the most commonly utilized techniques, reflecting their robustness in handling EEG data. The comprehensive review emphasizes how ML may be used to identify mental workload across a variety of disciplines using EEG data. Optimizing practical applications requires multimodal data integration, standardization efforts, and real-world validation studies. These systems will also be further improved by addressing ethical issues and investigating new EEG properties, which will improve human-computer interaction and performance assessment.

Classification of mental workload with EEG analysis by using effective connectivity and a hybrid model of CNN and LSTM

Estimation of mental workload from electroencephalogram (EEG) signals aims to accurately measure the cognitive demands placed on an individual during multitasking mental activities. By analyzing the brain activity of the subject, we can determine the level of mental effort required to perform a task and optimize the workload to prevent cognitive overload or underload. This information can be used to enhance performance and productivity in various fields such as healthcare, education, and aviation. In this paper, we propose a method that uses EEG and deep neural networks to estimate the mental workload of human subjects during multitasking mental activities. Notably, our proposed method employs subject-independent classification. We use the “STEW” dataset, which consists of two tasks, namely “No task” and “simultaneous capacity (SIMKAP)-based multitasking activity”. We estimate the different workload levels of two tasks using a composite framework consisting of brain connectivity and deep neural networks. After the initial preprocessing of EEG signals, an analysis of the relationships between the 14 EEG channels is conducted to evaluate effective brain connectivity. This assessment illustrates the information flow between various brain regions, utilizing the direct Directed Transfer Function (dDTF) method. Then, we propose a deep hybrid model based on pre-trained Convolutional Neural Networks (CNN) and Long Short-Term Memory (LSTM) for the classification of workload levels. The accuracy of the proposed deep model achieved 83.12% according to the subject-independent leave-subject-out (LSO) approach. The pre-trained CNN + LSTM approaches to EEG data have been found to be an accurate method for assessing the mental workload.

Brainwaves in the Cloud: Cognitive Workload Monitoring Using Deep Gated Neural Network and Industrial Internet of Things

Monitoring and classifying cognitive workload in real time is vital for optimizing human–machine interactions and enhancing performance while ensuring safety, particularly in industrial scenarios. Considering this significance, the authors aim to formulate a cognitive workload monitoring system (CWMS) by leveraging the deep gated neural network (DGNN), a hybrid model integrating bi-directional long short-term memory (Bi-LSTM) and gated recurrent unit (GRU) networks. In our experimental setup, each of the four virtual users is equipped with a Raspberry Pi Zero W module to ensure efficient data transmission, thereby enhancing the reliability and efficacy of the monitoring process. This seamless monitoring framework utilizes the constrained application protocol (CoAP) and the Things Board platform to evaluate cognitive workload in real time. The most popular EEG benchmark dataset, the STEW is utilized for workload classification in this study. We employ the short-time Fourier transformation (STFT) to extract frequency bands corresponding to users in both high and low cognitive workload modes. The proposed DGNN models achieve a perfect accuracy of 99.45%, outperforming every previous state-of-the-art model. We meticulously monitored critical parameters, including latency, classification processing time, and cognitive workload levels. This research demonstrates the importance of continuous monitoring for increasing productivity and safety in industries by introducing a novel method of real-time cognitive workload monitoring. The implementation codes for each experiment are documented and made available for reproducibility.

EEGminer: discovering interpretable features of brain activity with learnable filters

Objective. The patterns of brain activity associated with different brain processes can be used to identify different brain states and make behavioural predictions. However, the relevant features are not readily apparent and accessible. Our aim is to design a system for learning informative latent representations from multichannel recordings of ongoing EEG activity. Approach: We propose a novel differentiable decoding pipeline consisting of learnable filters and a pre-determined feature extraction module. Specifically, we introduce filters parameterized by generalized Gaussian functions that offer a smooth derivative for stable end-to-end model training and allow for learning interpretable features. For the feature module, we use signal magnitude and functional connectivity estimates. Main results. We demonstrate the utility of our model on a new EEG dataset of unprecedented size (i.e. 721 subjects), where we identify consistent trends of music perception and related individual differences. Furthermore, we train and apply our model in two additional datasets, specifically for emotion recognition on SEED and workload classification on simultaneous task EEG workload. The discovered features align well with previous neuroscience studies and offer new insights, such as marked differences in the functional connectivity profile between left and right temporal areas during music listening. This agrees with the specialisation of the temporal lobes regarding music perception proposed in the literature. Significance. The proposed method offers strong interpretability of learned features while reaching similar levels of accuracy achieved by black box deep learning models. This improved trustworthiness may promote the use of deep learning models in real world applications. The model code is available at https://github.com/SMLudwig/EEGminer/.

Cognitive workload classification of law enforcement officers using physiological responses

Motor vehicle crashes (MVCs) are a leading cause of death for law enforcement officers (LEOs) in the U.S. LEOs and more specifically novice LEOs (nLEOs) are susceptible to high cognitive workload while driving which can lead to fatal MVCs. The objective of this study was to develop a machine learning algorithm (MLA) that can estimate cognitive workload of LEOs while performing secondary tasks in a patrol vehicle. A ride-along study was conducted with 24 nLEOs. Participants performed their normal patrol operations while their physiological responses such as heartrate, eye movement, and galvanic skin response were recorded using unobtrusive devices. Findings suggested that the random forest algorithm could predict cognitive workload with relatively high accuracy (>70%) given that it was entirely reliant on physiological signals. The developed MLA can be used to develop adaptive in-vehicle technology based on real-time estimation of cognitive workload, which can reduce the risk of MVCs in police operations.

ECG and EEG based machine learning models for the classification of mental workload and stress levels for women in different menstrual phases, men, and mixed sexes

ECG and EEG based machine learning models for the classification of mental workload and stress levels for women in different menstrual phases, men, and mixed sexes

EEG-Based Mental Workload Classification Method Based on Hybrid Deep Learning Model Under IoT.

Automatically detecting human mental workload to prevent mental diseases is highly important. With the development of information technology, remote detection of mental workload is expected. The development of artificial intelligence and Internet of Things technology will also enable the identification of mental workload remotely based on human physiological signals. In this article, a method based on the spatial and time-frequency domains of electroencephalography (EEG) signals is proposed to improve the classification accuracy of mental workload. Moreover, a hybrid deep learning model is presented. First, the spatial domain features of different brain regions are proposed. Simultaneously, EEG time-frequency domain information is obtained based on wavelet transform. The spatial and time-frequency domain features are input into two types of deep learning models for mental workload classification. To validate the performance of the proposed method, the Simultaneous Task EEG Workload public database is used. Compared with the existing methods, the proposed approach shows higher classification accuracy. It provides a novel means of assessing mental workload.

Classification of mental workload using brain connectivity and machine learning on electroencephalogram data

Mental workload refers to the cognitive effort required to perform tasks, and it is an important factor in various fields, including system design, clinical medicine, and industrial applications. In this paper, we propose innovative methods to assess mental workload from EEG data that use effective brain connectivity for the purpose of extracting features, a hierarchical feature selection algorithm to select the most significant features, and finally machine learning models. We have used the Simultaneous Task EEG Workload (STEW) dataset, an open-access collection of raw EEG data from 48 subjects. We extracted brain-effective connectivities by the direct directed transfer function and then selected the top 30 connectivities for each standard frequency band. Then we applied three feature selection algorithms (forward feature selection, Relief-F, and minimum-redundancy-maximum-relevance) on the top 150 features from all frequencies. Finally, we applied sevenfold cross-validation on four machine learning models (support vector machine (SVM), linear discriminant analysis, random forest, and decision tree). The results revealed that SVM as the machine learning model and forward feature selection as the feature selection method work better than others and could classify the mental workload levels with accuracy equal to 89.53% (± 1.36).

Assessment of Mental Workload Level Based on PPG Signal Fusion Continuous Wavelet Transform and Cardiopulmonary Coupling Technology

Mental workload is an important predisposing factor for mental illnesses such as depression and is closely related to individual mental health. However, the suboptimal accuracy of utilizing photoplethysmography (PPG) exclusively for mental workload classification has constrained its application within pertinent professional domains. To this end, this paper proposes a signal processing method that combines continuous wavelet transform (CWT) and cardiopulmonary coupling mapping (CPC) to classify mental load via a convolutional neural network (ResAttNet). The method reflects changes in mental workload, as assessed by changes in the association between heart rate variability and respiration. In this paper, the strengths and weaknesses of this method are compared with other traditional psychological workload monitoring methods, such as heart rate variability (HRV), and its validation is performed on the publicly available dataset MAUS. The experiments show that the method is significantly better than previous machine learning methods based on heart rate variability correlation. Meanwhile, the accuracy of the method proposed in this paper reaches 80.5%, which is 6.2% higher than in previous studies. It is comparable to the result of 82.4% for the ECG-based mental workload monitoring system. Therefore, the method of combining CWT and CPC has considerable potential and provides new ideas for mental workload classification.

Mental Workload Assessment Using Machine Learning Techniques Based on EEG and Eye Tracking Data

The main contribution of this study was the concurrent application of EEG and eye tracking techniques during n-back tasks as part of the methodology for addressing the problem of mental workload classification through machine learning algorithms. The experiments involved 15 university students, consisting of 7 women and 8 men. Throughout the experiments, the researchers utilized the n-back memory task and the NASA-Task Load Index (TLX) subjective rating scale to assess various levels of mental workload. The results indicating the relationship between EEG and eye tracking measures and mental workload are consistent with previous research. Regarding the four-class classification task, mental workload level could be predicted with 76.59% accuracy using 34 selected features. This study makes a significant contribution to the literature by presenting a four-class mental workload estimation model that utilizes different machine learning algorithms.

LGNet: Learning local–global EEG representations for cognitive workload classification in simulated flights

Cognitive workload assessment is crucial for ensuring pilots' safety during flights. Electroencephalography (EEG) is a promising tool for monitoring cognitive workload. Convolutional neural networks (CNNs) are effective in automatically extracting local EEG representations. However, CNNs have limitations in global representations, because a global representation in CNNs normally requires CNNs to be deep enough to have a global receptive field, which normally results in overfitting. To address this issue, we propose a local and global network (LGNet) for assessing two levels of cognitive workload based on EEG during simulated flight. We fuse convolutional and Transformer layers to extract local and global representations from the EEG signals. To enhance the learning performance, we propose a novel SCCE loss, which combines the supervised contrastive loss with the traditional cross-entropy loss. We collect 32-channel EEG data from 10 subjects who perform low and high cognitive workload flight tasks with passive auditory stimuli in a flight simulator on 3 separate days, with each participant performing the task for approximately 345 min. The results show that LGNet with the SCCE loss achieves a 4-fold average classification accuracy of 91.19 % based on cross-clip data partitioning and an average classification accuracy of 83.26 % based on cross-session data partitioning when no target session data is added to the training data. These results significantly outperform classifiers based on handcrafted features and state-of-the-art deep learning methods.

Mental Workload Classification and Tasks Detection in Multitasking: Deep Learning Insights from EEG Study.

While the term task load (TL) refers to external task demands, the amount of work, or the number of tasks to be performed, mental workload (MWL) refers to the individual's effort, mental capacity, or cognitive resources utilized while performing a task. MWL in multitasking scenarios is often closely linked with the quantity of tasks a person is handling within a given timeframe. In this study, we challenge this hypothesis from the perspective of electroencephalography (EEG) using a deep learning approach. We conducted an EEG experiment with 50 participants performing NASA Multi-Attribute Task Battery II (MATB-II) under 4 different task load levels. We designed a convolutional neural network (CNN) to help with two distinct classification tasks. In one setting, the CNN was used to classify EEG segments based on their task load level. In another setting, the same CNN architecture was trained again to detect the presence of individual MATB-II subtasks. Results show that, while the model successfully learns to detect whether a particular subtask is active in a given segment (i.e., to differentiate between different subtasks-related EEG patterns), it struggles to differentiate between the two highest levels of task load (i.e., to distinguish MWL-related EEG patterns). We speculate that the challenge comes from two factors: first, the experiment was designed in a way that these two highest levels differed only in the quantity of work within a given timeframe; and second, the participants' effective adaptation to increased task demands, as evidenced by low error rates. Consequently, this indicates that under such conditions in multitasking, EEG may not reflect distinct enough patterns to differentiate higher levels of task load.

Analysis of Employee Work Posture and Physical Workload Using del Riesgo Individual Evalution and Cardio-Vascular Load Methods

The role of humans as workers is still dominant in carrying out the production process, especially activities carried out manually in Material Handling (MMH). Activities carried out using the MMH method are identified as having a high risk if they are not carried out ergonomically and with a good work system, musculoskeletal complaints can occur due to wrong work postures and physical workload. The production process for SME Barokah Tofu in Kendal Regency is still carried out manually by employees who have identified incorrect work postures due to musculoskeletal complaints and physical workload. Therefore, it is necessary to analyze work posture and physical workload of Barokah Tofu employees who have a high risk to reduce musculoskeletal complaints and high physical workload, as well as provide suggestions for improvements to Barokah Tofu. The methods used in this research are ERIN (Evaluation Del Riesgo Individual) and CVL (Cardiovascular Load). Based on the calculation results, it can be concluded that there are 2 activities that have the results of the classification of work posture and physical workload inversely, namely soybean milling and moulding of tofu where work posture has a high risk and physical workload has a low risk, and there are 2 activities that have a work posture classification result. and the physical workload is directly proportional, namely filtering cooking products with low risk and cutting tofu with high risk. Activities that have a high risk require suggestions for improvements, namely simulation of tool design and Standard Operating Procedures (SOP) for the application of ergonomic principles at work.

Characterization and Machine Learning Classification of AI and PC Workloads

Characterization and Machine Learning Classification of AI and PC Workloads

Nursing workload: use of artificial intelligence to develop a classifier model.

to describe the development of a predictive nursing workload classifier model, using artificial intelligence. retrospective observational study, using secondary sources of electronic patient records, using machine learning. The convenience sample consisted of 43,871 assessments carried out by clinical nurses using the Perroca Patient Classification System, which served as the gold standard, and clinical data from the electronic medical records of 11,774 patients, which constituted the variables. In order to organize the data and carry out the analysis, the Dataiku® data science platform was used. Data analysis occurred in an exploratory, descriptive and predictive manner. The study was approved by the Ethics and Research Committee of the institution where the study was carried out. the use of artificial intelligence enabled the development of the nursing workload assessment classifier model, identifying the variables that most contributed to its prediction. The algorithm correctly classified 72% of the variables and the area under the Receiver Operating Characteristic curve was 82%. a predictive model was developed, demonstrating that it is possible to train algorithms with data from the patient's electronic medical record to predict the nursing workload and that artificial intelligence tools can be effective in automating this activity.

Mental workload classification using convolutional neural networks based on fNIRS-derived prefrontal activity

BackgroundFunctional near-infrared spectroscopy (fNIRS) is a tool to assess brain activity during cognitive testing. Despite its usefulness, its feasibility in assessing mental workload remains unclear. This study was to investigate the potential use of convolutional neural networks (CNNs) based on functional near-infrared spectroscopy (fNIRS)-derived signals to classify mental workload in individuals with mild cognitive impairment.MethodsSpatial images by constructing a statistical activation map from the prefrontal activity of 120 subjects with MCI performing three difficulty levels of the N-back task (0, 1, and 2-back) were used for CNNs. The CNNs were evaluated using a 5 and 10-fold cross-validation method.ResultsAs the difficulty level of the N-back task increased, the accuracy decreased and prefrontal activity increased. In addition, there was a significant difference in the accuracy and prefrontal activity across the three levels (p’s < 0.05). The accuracy of the CNNs based on fNIRS-derived spatial images evaluated by 5 and 10-fold cross-validation in classifying the difficulty levels ranged from 0.83 to 0.96.ConclusionfNIRS could also be a promising tool for measuring mental workload in older adults with MCI despite their cognitive decline. In addition, this study demonstrated the feasibility of the classification performance of the CNNs based on fNIRS-derived signals from the prefrontal cortex.

Multi-class classification of control room operators’ cognitive workload using the fusion of eye-tracking and electroencephalography

Chemical process industries are hazard intensive. Most industrial accidents occur today due to human error. For safe and efficient operation, it is therefore critical to ensure optimal operator performance. With the advent of Industry 4.0 and concomitant digitalization, the role of operators has become cognitively challenging. Therefore, it is imperative to assess the cognitive performance of operators. One of the major constructs to understand cognitive performance is the cognitive workload. An increase in cognitive workload often leads to degradation in performance. Traditional assessment techniques fail to capture cognitive aspects of performance. Recently, researchers in various domains such as aviation, driving, marine, and nuclear power have started to utilize physiological measures to gauge the cognitive workload of their operators. In our previous works, we have used electroencephalography (EEG) and eye-tracking separately to assess the cognitive workload of operators in the process industries. In contrast, in this paper, we explore the benefits of their fusion in classifying process industry control room operators’ workload into low, medium, and high classes while they tackle abnormal situations. The methodology employs the fusion of metrics derived from pupil, gaze, and EEG data to train a decision tree-based model for workload classification. Our results reveal that fusion leads to an increase in classification accuracy of upto 22 %. The work has the potential to identify the expertise level of operators and hence, can be critical in ensuring their optimal performance.