scholarly journals Assessing Drivers’ Physiological Responses Using Consumer Grade Devices

2019 ◽  
Vol 9 (24) ◽  
pp. 5353 ◽  
Author(s):  
Timotej Gruden ◽  
Kristina Stojmenova ◽  
Jaka Sodnik ◽  
Grega Jakus
Keyword(s):  
Standard Deviation ◽  
User Interfaces ◽  
User Study ◽  
Physiological Responses ◽  
Wearable Devices ◽  
Mean Value ◽  
Driver Assistance Systems ◽  
Ecg Signals ◽  
Driving Scenario ◽  
Different Levels

The ability to measure drivers’ physiological responses is important for understanding their state and behavior under different driving conditions. Such measurements can be used in the development of novel user interfaces, driver profiling, advanced driver assistance systems, etc. In this paper, we present a user study in which we performed an evaluation of two commercially available wearable devices for assessment of drivers’ physiological signals. Empatica’s E4 wristband measures blood volume pulse (BVP), inter-beat interval (IBI), galvanic skin response (GSR), temperature, and acceleration. Bittium’s Faros 360 is an electrocardiographic (ECG) device that can record up to 3-channel ECG signals. The aim of this study was to explore the use of such devices in a dynamic driving environment and their ability to differentiate between different levels of driving demand. Twenty-two participants (eight female, 14 male) aged between 18 and 45 years old participated in the study. The experiment compared three phases: Baseline (no driving), easy driving scenario, and demanding driving scenario. Mean and median heart rate variability (HRV), standard deviation of R–R intervals (SDNN), HRV variables for shorter time frames (standard deviation of the average R–R intervals over a shorter period—SDANN and mean value of the standard deviations calculated over a shorter period—SDNN index), HRV variables based on successive differences (root mean square of successive differences—RMSSD and percentage of successive differences, greater than 50 ms—pNN50), skin temperature, and GSR were observed in each phase. The results showed that motion artefacts due to driving affect the GSR recordings, which may limit the use of wrist-based wearable devices in a driving environment. In this case, due to the limitations of the photoplethysmography (PPG) sensor, E4 only showed differences between non-driving and driving phases but could not differentiate between different levels of driving demand. On the other hand, the results obtained from the ECG signals from Faros 360 showed statistically significant differences also between the two levels of driving demand.

scholarly journals Comparative evaluation of WIMP and immersive natural finger interaction: a user study on CAD assembly modeling

2021 ◽  
Author(s):  
Marius Fechter ◽  
Benjamin Schleich ◽  
Sandro Wartzack
Keyword(s):  
User Interfaces ◽  
User Study ◽  
Spatial Location ◽  
Ease Of Use ◽  
Natural Interaction ◽  
Assembly Modeling ◽  
3D Space ◽  
Computer Mouse ◽  
Study Results ◽  
Assembly Procedure

AbstractVirtual and augmented reality allows the utilization of natural user interfaces, such as realistic finger interaction, even for purposes that were previously dominated by the WIMP paradigm. This new form of interaction is particularly suitable for applications involving manipulation tasks in 3D space, such as CAD assembly modeling. The objective of this paper is to evaluate the suitability of natural interaction for CAD assembly modeling in virtual reality. An advantage of the natural interaction compared to the conventional operation by computer mouse would indicate development potential for user interfaces of current CAD applications. Our approach bases on two main elements. Firstly, a novel natural user interface for realistic finger interaction enables the user to interact with virtual objects similar to physical ones. Secondly, an algorithm automatically detects constraints between CAD components based solely on their geometry and spatial location. In order to prove the usability of the natural CAD assembly modeling approach in comparison with the assembly procedure in current WIMP operated CAD software, we present a comparative user study. Results show that the VR method including natural finger interaction significantly outperforms the desktop-based CAD application in terms of efficiency and ease of use.

scholarly journals Blood Oxygenation Level Dependent Magnetic Resonance Imaging (MRI), Dynamic Contrast Enhanced MRI and Diffusion Weighted MRI for Benign and Malignant Breast Cancer Discrimination: A Preliminary Experience

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2421
Author(s):  
Roberta Fusco ◽  
Vincenza Granata ◽  
Mauro Mattace Raso ◽  
Paolo Vallone ◽  
Alessandro Pasquale De Rosa ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Univariate Analysis ◽  
Mean Value ◽  
Blood Oxygenation ◽  
Breast Lesions ◽  
Dce Mri ◽  
Malignant Lesions ◽  
The Mean ◽  
And Diffusion ◽  
Skewness And Kurtosis

Purpose. To combine blood oxygenation level dependent magnetic resonance imaging (BOLD-MRI), dynamic contrast enhanced MRI (DCE-MRI), and diffusion weighted MRI (DW-MRI) in differentiation of benign and malignant breast lesions. Methods. Thirty-seven breast lesions (11 benign and 21 malignant lesions) pathologically proven were included in this retrospective preliminary study. Pharmaco-kinetic parameters including Ktrans, kep, ve, and vp were extracted by DCE-MRI; BOLD parameters were estimated by basal signal S0 and the relaxation rate R2*; and diffusion and perfusion parameters were derived by DW-MRI (pseudo-diffusion coefficient (Dp), perfusion fraction (fp), and tissue diffusivity (Dt)). The correlation coefficient, Wilcoxon-Mann-Whitney U-test, and receiver operating characteristic (ROC) analysis were calculated and area under the ROC curve (AUC) was obtained. Moreover, pattern recognition approaches (linear discrimination analysis and decision tree) with balancing technique and leave one out cross validation approach were considered. Results. R2* and D had a significant negative correlation (−0.57). The mean value, standard deviation, Skewness and Kurtosis values of R2* did not show a statistical significance between benign and malignant lesions (p > 0.05) confirmed by the ‘poor’ diagnostic value of ROC analysis. For DW-MRI derived parameters, the univariate analysis, standard deviation of D, Skewness and Kurtosis values of D* had a significant result to discriminate benign and malignant lesions and the best result at the univariate analysis in the discrimination of benign and malignant lesions was obtained by the Skewness of D* with an AUC of 82.9% (p-value = 0.02). Significant results for the mean value of Ktrans, mean value, standard deviation value and Skewness of kep, mean value, Skewness and Kurtosis of ve were obtained and the best AUC among DCE-MRI extracted parameters was reached by the mean value of kep and was equal to 80.0%. The best diagnostic performance in the discrimination of benign and malignant lesions was obtained at the multivariate analysis considering the DCE-MRI parameters alone with an AUC = 0.91 when the balancing technique was considered. Conclusions. Our results suggest that the combined use of DCE-MRI, DW-MRI and/or BOLD-MRI does not provide a dramatic improvement compared to the use of DCE-MRI features alone, in the classification of breast lesions. However, an interesting result was the negative correlation between R2* and D.

Rigorous time-domain analysis of statistically oriented graphene sheet fluctuations

2017 ◽  
Vol 36 (5) ◽  
pp. 1351-1363 ◽  
Author(s):  
Athanasios N. Papadimopoulos ◽  
Stamatios A. Amanatiadis ◽  
Nikolaos V. Kantartzis ◽  
Theodoros T. Zygiridis ◽  
Theodoros D. Tsiboukis
Keyword(s):  
Monte Carlo ◽  
Standard Deviation ◽  
Finite Difference ◽  
Surface Waves ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Mean Value ◽  
Content Type ◽  
The Mean ◽  
Difference Time

Purpose Important statistical variations are likely to appear in the propagation of surface plasmon polariton waves atop the surface of graphene sheets, degrading the expected performance of real-life THz applications. This paper aims to introduce an efficient numerical algorithm that is able to accurately and rapidly predict the influence of material-based uncertainties for diverse graphene configurations. Design/methodology/approach Initially, the surface conductivity of graphene is described at the far infrared spectrum and the uncertainties of its main parameters, namely, the chemical potential and the relaxation time, on the propagation properties of the surface waves are investigated, unveiling a considerable impact. Furthermore, the demanding two-dimensional material is numerically modeled as a surface boundary through a frequency-dependent finite-difference time-domain scheme, while a robust stochastic realization is accordingly developed. Findings The mean value and standard deviation of the propagating surface waves are extracted through a single-pass simulation in contrast to the laborious Monte Carlo technique, proving the accomplished high efficiency. Moreover, numerical results, including graphene’s surface current density and electric field distribution, indicate the notable precision, stability and convergence of the new graphene-based stochastic time-domain method in terms of the mean value and the order of magnitude of the standard deviation. Originality/value The combined uncertainties of the main parameters in graphene layers are modeled through a high-performance stochastic numerical algorithm, based on the finite-difference time-domain method. The significant accuracy of the numerical results, compared to the cumbersome Monte Carlo analysis, renders the featured technique a flexible computational tool that is able to enhance the design of graphene THz devices due to the uncertainty prediction.

scholarly journals An image dehazing algorithm based on double priors constraint

2018 ◽  
Vol 189 ◽  
pp. 04009
Author(s):  
Kun Liu ◽  
Shiping Wang ◽  
Linyuan He ◽  
Duyan Bi ◽  
Shan Gao
Keyword(s):  
Standard Deviation ◽  
Mean Value ◽  
Experimental Results ◽  
Dark Channel Prior ◽  
Image Dehazing ◽  
Color Distortion ◽  
Local Media ◽  
Dark Channel

Aiming at the color distortion of the restored image in the sky region, we propose an image dehazing algorithm based on double priors constraint. Firstly, we divided the haze image into sky and non-sky regions. Then the Color-lines prior and dark channel prior are used for estimating the transmission of sky and non-sky regions respectively. After introducing color-lines prior to correct sky regions restored by the dark channel prior, we get an accurate transmission. Finally, the local media mean value and standard deviation are used to refine the transmission to obtain the dehazing image. Experimental results show that the algorithm has obvious advantages in the recovery of the sky area.

Effect of season on thermoregulatory responses and energy expenditure of goats on semi-arid range in India

2002 ◽  
Vol 139 (1) ◽  
pp. 87-93 ◽  
Author(s):  
A. K. SHINDE ◽  
RAGHAVENDRA BHATTA ◽  
S. K. SANKHYAN ◽  
D. L. VERMA
Keyword(s):  
Heart Rate ◽  
Heat Stress ◽  
Solar Radiation ◽  
Energy Expenditure ◽  
Arid Regions ◽  
Physiological Responses ◽  
Face Mask ◽  
Mean Value ◽  
The Mean ◽  
Semi Arid

A study of the physiological responses and energy expenditure of goats was carried out from June 1999 to May 2000 by conducting two experiments: one on bucks maintained on stall feeding in autumn 1999 (Expt 1) followed by year-round grazing on native ranges over three seasons: monsoon, winter and summer (Expt 2). Physiological responses and energy expenditure (EE) measurements of housed and grazing goats were recorded at 06.00 h and 14.00 h for 5 consecutive days in each season. Goats were fixed with a face mask and meteorological balloon for collection of expired air and measurement of EE. Respiration rate (RR) at 06.00 h was similar in all seasons (14 respiration/min) except in the monsoon, where a significantly (P<0.05) higher value (26 respiration/min) was recorded. At 14.00 h, RR was higher in monsoon and summer (81 and 91 respiration/min) than in winter (52 respiration/min). Irrespective of the season, heart rate (HR) was higher at 14.00 h (86 beat/min) than at 06.00 h (64 beat/min). The rise of rectal temperature (RT) from morning (06.00 h) to peak daily temperature (14.00 h) was 0.9 °C in housed goats in autumn and 1.0, 2.1 and 2.0 °C in grazing goats during monsoon, winter and summer, respectively. The mean value was 1.7 °C. Skin temperature (ST) was lowest in winter (30.1 °C) and highest at 14.00 h in summer (40.3 °C). Energy expenditure of goats at 06.00 h was 32.7 W in winter and significantly (P<0.05) increased to 52.0 W in summer and 107.8 W in monsoon. At 14.00 h, EE was 140.2 W in winter and increased to 389.0 W and 391.3 W respectively in monsoon and summer. It is concluded that monsoon and summer are both stressful seasons in semi-arid regions. Animals should be protected from direct solar radiation during the hottest hours of the day to ameliorate the effect of heat stress.

Synchronous Issue of IR-Based Large Scale Volume Localization System

2014 ◽  
Vol 496-500 ◽  
pp. 1643-1647
Author(s):  
Ying Feng Wu ◽  
Gang Yan Li
Keyword(s):  
Standard Deviation ◽  
Mobile Robot ◽  
Large Volume ◽  
Large Scale ◽  
Image Acquisition ◽  
Mean Value ◽  
Network Synchronization ◽  
Localization System ◽  
Localization Performance ◽  
The Mean

IR-based large scale volume localization system (LSVLS) can localize the mobile robot working in large volume, which is constituted referring to the MSCMS-II. Hundreds cameras in LSVLS must be connected to the control station (PC) through network. Synchronization of cameras which are mounted on different control stations is significant, because the image acquisition of the target must be synchronous to ensure that the target is localized precisely. Software synchronization method is adopted to ensure the synchronization of camera. The mean value of standard deviation of eight cameras mounted on two workstations is 12.53ms, the localization performance of LSVLS is enhanced.

Precise computation of the direct and indirect topographic effects of Helmert's 2nd method of condensation using SRTM30 digital elevation model

2011 ◽  
Vol 1 (4) ◽  
pp. 305-312 ◽  
Author(s):  
Y. Wang
Keyword(s):  
Standard Deviation ◽  
Digital Elevation Model ◽  
Outer Zone ◽  
Mean Value ◽  
Constant Density ◽  
Topographic Effects ◽  
Topographic Effect ◽  
Digital Elevation ◽  
The Mean ◽  
Elevation Model

Precise computation of the direct and indirect topographic effects of Helmert's 2nd method of condensation using SRTM30 digital elevation modelThe direct topographic effect (DTE) and indirect topographic effect (ITE) of Helmert's 2nd method of condensation are computed using the digital elevation model (DEM) SRTM30 in 30 arc-seconds globally. The computations assume a constant density of the topographic masses. Closed formulas are used in the inner zone of half degree, and Nagy's formulas are used in the innermost column to treat the singularity of integrals. To speed up the computations, 1-dimensional fast Fourier transform (1D FFT) is applied in outer zone computations. The computation accuracy is limited to 0.1 mGal and 0.1cm for the direct and indirect effect, respectively.The mean value and standard deviation of the DTE are -0.8 and ±7.6 mGal over land areas. The extreme value -274.3 mGal is located at latitude -13.579° and longitude 289.496°, at the height of 1426 meter in the Andes Mountains. The ITE is negative everywhere and has its minimum of -235.9 cm at the peak of Himalayas (8685 meter). The standard deviation and mean value over land areas are ±15.6 cm and -6.4 cm, respectively. Because the Stokes kernel does not contain the zero and first degree spherical harmonics, the mean value of the ITE can't be compensated through the remove-restore procedure under the Stokes-Helmert scheme, and careful treatment of the mean value in the ITE is required.

Verification of Plastic Interactive Systems

i-com ◽  
2015 ◽  
Vol 14 (3) ◽  
Author(s):  
Raquel Oliveira ◽  
Sophie Dupuy-Chessa ◽  
Gaëlle Calvary
Keyword(s):  
Power Plant ◽  
User Interfaces ◽  
Nuclear Power ◽  
Interactive Systems ◽  
System Model ◽  
Equivalence Checking ◽  
The Past ◽  
Different Levels ◽  
Formal Techniques

AbstractInteractive systems have largely evolved over the past years. Nowadays, different users can interact with systems on different devices and in different environments. The user interfaces (UIs) are expected to cope with such variety. Plastic UIs have the capacity to adapt to changes in their context of use while preserving usability. Such capability enhances UIs, however, it adds complexity on them. We propose an approach to verifying interactive systems considering this adaptation capability of the UIs. The approach applies two formal techniques: model checking, to the verification of properties over the system model, and equivalence checking, to compare different versions of a UI, thereby identifying different levels of UI equivalence. We apply the approach to a case study in the nuclear power plant domain in which several UI are analyzed, properties are verified, and the level of equivalence between them is demonstrated.

scholarly journals Improving the Usability of Organizational Data Systems

2021 ◽  
Vol 16 (1) ◽  
pp. 21
Author(s):  
Chung-Yi Hou ◽  
Matthew S. Mayernik
Keyword(s):  
User Interfaces ◽  
User Study ◽  
Data Repository ◽  
Data Systems ◽  
User Interactions ◽  
Data Repositories ◽  
Web Interfaces ◽  
Design And Implementation ◽  
Usability Assessment ◽  
Assessment Techniques

For research data repositories, web interfaces are usually the primary, if not the only, method that data users have to interact with repository systems. Data users often search, discover, understand, access, and sometimes use data directly through repository web interfaces. Given that sub-par user interfaces can reduce the ability of users to locate, obtain, and use data, it is important to consider how repositories’ web interfaces can be evaluated and improved in order to ensure useful and successful user interactions. This paper discusses how usability assessment techniques are being applied to improve the functioning of data repository interfaces at the National Center for Atmospheric Research (NCAR). At NCAR, a new suite of data system tools is being developed and collectively called the NCAR Digital Asset Services Hub (DASH). Usability evaluation techniques have been used throughout the NCAR DASH design and implementation cycles in order to ensure that the systems work well together for the intended user base. By applying user study, paper prototype, competitive analysis, journey mapping, and heuristic evaluation, the NCAR DASH Search and Repository experiences provide examples for how data systems can benefit from usability principles and techniques. Integrating usability principles and techniques into repository system design and implementation workflows helps to optimize the systems’ overall user experience.

scholarly journals Time-to-Boundary Function to Study the Development of Upright Stance Control in Children

2017 ◽  
Vol 11 (1) ◽  
pp. 49-58
Author(s):  
Carmen D'Anna ◽  
Maurizio Schmid ◽  
Andrea Scorza ◽  
Salvatore A. Sciuto ◽  
Luisa Lopez ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Postural Control ◽  
Postural Stability ◽  
Age Groups ◽  
Boundary Function ◽  
Mean Value ◽  
Upright Stance ◽  
Eyes Closed ◽  
The Mean ◽  
Spatio Temporal

Background: The development of postural control across the primary school time horizon is a complex process, which entails biomechanics modifications, the maturation of cognitive ability and sensorimotor organization, and the emergence of anticipatory behaviour. Postural stability in upright stance has been thus object of a multiplicity of studies to better characterize postural control in this age span, with a variety of methodological approaches. The analysis of the Time-to-Boundary function (TtB), which specifies the spatiotemporal proximity of the Centre of Pressure (CoP) to the stability boundaries in the regulation of posture in upright stance, is among the techniques used to better characterize postural stability in adults, but, as of now, it has not yet been introduced in developmental studies. The aim of this study was thus to apply this technique to evaluate the development of postural control in a sample population of primary school children. Methods: In this cross-sectional study, upright stance trials under eyes open and eyes closed were administered to 107 healthy children, divided into three age groups (41 for Seven Years' Group, Y7; 38 for Nine Years' Group, Y9; 28 for Eleven Years' Group, Y11). CoP data were recorded to calculate the Time-to-Boundary function (TtB), from which four spatio-temporal parameters were extracted: the mean value and the standard deviation of TtB minima (Mmin, Stdmin), and the mean value and the standard deviation of the temporal distance between two successive minima (Mdist, Stddist). Results: With eyes closed, Mmin and Stdmin significantly decreased and Mdist and Stddist increased for the Y7 group, at Y9 Mmin significantly decreased and Stddist increased, while no effect of vision resulted for Y11. Regarding age groups, Mmin was significantly higher for Y9 than Y7, and Stdmin for Y9 was higher than both Y7 and Y11; Mdist and Stddist resulted higher for Y11 than for Y9. Conclusion: From the combined results from the spatio-temporal TtB parameters, it is suggested that, at 9 years, children look more efficient in terms of exploring their limits of stability than at 7, and at 11 the observed TtB behaviour hints at the possibility that, at that age, they have almost completed the maturation of postural control in upright stance, also in terms of integration of the spatio-temporal information.

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