Statistical Characteristic Law of Average Deviation of Solar Elevation in Different Regions

: The aim of the present study was to develop quantitative structure-activity relationship (QSAR) models, based on molecular descriptors to predict the oral acute toxicity (LD50) of organophosphate compounds. The QSAR models based on genetic algorithm-multiple linear regression (GA-MLR) and back-propagation artificial neural network (BP-ANN) methods were proposed. The prediction experiment showed that the BP-ANN method was a reliable model for screening molecular descriptors, and molecular descriptors obtained by BP-ANN models could well characterize the molecular structure of each compound. It was indicated that among molecular descriptors to predict the LD50 (mgkg-1) of organophosphates, ALOGP2, RDF030u, RDF065p and GATS5m descriptors have more importance than the other descriptors. Also BP-ANN approach with the values of root mean square error (RMSE= 0.00168), square correlation coefficient (R2= 0.9999) and absolute average deviation (AAD=0.6981631) gave the best outcome, and the model predictions were in good agreement with experimental data. The proposed model may be useful for predicting LD50 (mgkg-1) of new compounds of similar class.

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Development of an Improved Rapidly Exploring Random Trees Algorithm for Static Obstacle Avoidance in Autonomous Vehicles

Sensors ◽

10.3390/s21062244 ◽

2021 ◽

Vol 21 (6) ◽

pp. 2244

Author(s):

S. M. Yang ◽

Y. A. Lin

Keyword(s):

Path Planning ◽

Obstacle Avoidance ◽

Autonomous Vehicles ◽

Autonomous Vehicle ◽

Optimal Path ◽

Random Trees ◽

Average Deviation ◽

Lane Changes ◽

Path Smoothing ◽

Rapidly Exploring Random Trees

Safe path planning for obstacle avoidance in autonomous vehicles has been developed. Based on the Rapidly Exploring Random Trees (RRT) algorithm, an improved algorithm integrating path pruning, smoothing, and optimization with geometric collision detection is shown to improve planning efficiency. Path pruning, a prerequisite to path smoothing, is performed to remove the redundant points generated by the random trees for a new path, without colliding with the obstacles. Path smoothing is performed to modify the path so that it becomes continuously differentiable with curvature implementable by the vehicle. Optimization is performed to select a “near”-optimal path of the shortest distance among the feasible paths for motion efficiency. In the experimental verification, both a pure pursuit steering controller and a proportional–integral speed controller are applied to keep an autonomous vehicle tracking the planned path predicted by the improved RRT algorithm. It is shown that the vehicle can successfully track the path efficiently and reach the destination safely, with an average tracking control deviation of 5.2% of the vehicle width. The path planning is also applied to lane changes, and the average deviation from the lane during and after lane changes remains within 8.3% of the vehicle width.

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Influence of patient motion on quantitative accuracy in cardiac 15O-water positron emission tomography

Journal of Nuclear Cardiology ◽

10.1007/s12350-021-02550-9 ◽

2021 ◽

Author(s):

Jonny Nordström ◽

Hendrik J. Harms ◽

Tanja Kero ◽

Jens Sörensen ◽

Mark Lubberink

Keyword(s):

Motion Detection ◽

Detection Algorithm ◽

Clinical Effects ◽

Average Deviation ◽

Patient Motion ◽

Motion Data ◽

Positron Emission ◽

Quantitative Accuracy ◽

Pet Ct ◽

Using Data

Abstract Background Patient motion is a common problem during cardiac PET. The purpose of the present study was to investigate to what extent motions influence the quantitative accuracy of cardiac 15O-water PET/CT and to develop a method for automated motion detection. Method Frequency and magnitude of motion was assessed visually using data from 50 clinical 15O-water PET/CT scans. Simulations of 4 types of motions with amplitude of 5 to 20 mm were performed based on data from 10 scans. An automated motion detection algorithm was evaluated on clinical and simulated motion data. MBF and PTF of all simulated scans were compared to the original scan used as reference. Results Patient motion was detected in 68% of clinical cases by visual inspection. All observed motions were small with amplitudes less than half the LV wall thickness. A clear pattern of motion influence was seen in the simulations with a decrease of myocardial blood flow (MBF) in the region of myocardium to where the motion was directed. The perfusable tissue fraction (PTF) trended in the opposite direction. Global absolute average deviation of MBF was 3.1% ± 1.8% and 7.3% ± 6.3% for motions with maximum amplitudes of 5 and 20 mm, respectively. Automated motion detection showed a sensitivity of 90% for simulated motions ≥ 10 mm but struggled with the smaller (≤ 5 mm) simulated (sensitivity 45%) and clinical motions (accuracy 48%). Conclusion Patient motion can impair the quantitative accuracy of MBF. However, at typically occurring levels of patient motion, effects are similar to or only slightly larger than inter-observer variability, and downstream clinical effects are likely negligible.

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Simulation and Experimental Study of the Near Field Probe in the Form of a Folded Dipole for Measuring Glucose Concentration

Applied Sciences ◽

10.3390/app11125415 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5415

Author(s):

Aleksandr Gorst ◽

Kseniya Zavyalova ◽

Aleksandr Mironchev ◽

Andrey Zapasnoy ◽

Andrey Klokov

Keyword(s):

Experimental Measurement ◽

Glucose Concentration ◽

Field Experiments ◽

Near Field ◽

Vector Network Analyzer ◽

Human Hand ◽

Physical Parameters ◽

Network Analyzer ◽

Frequency Range ◽

Average Deviation

The article investigates the near-field probe of a special design to account for changes in glucose concentration. The probe is designed in such a way that it emits radiation in both directions from its plane. In this paper, it was proposed to modernize this design and consider the unidirectional emission of the probe in order to maximize the signal and reduce energy loss. We have done extensive research for both bidirectional and unidirectional probe designs. Numerical simulations and field experiments were carried out to determine different concentrations of glucose (0, 4, 5.3, 7.5 mmol/L). Numerical modeling of a unidirectional probe showed that the interaction of radiation generated by such a probe with a multilayer structure simulating a human hand showed a better result and high sensitivity compared to a bidirectional probe. Further, based on the simulation results, a phantom (physical model) of a human hand was recreated from layers with dielectric properties as close as possible to the properties of materials during simulation. The probe was constructed from a copper tube and matched both the geometric and physical parameters of the model. The experimental measurement was carried out using a vector network analyzer in the frequency range 2–10 GHz. The experimental measurement was carried out using a vector network analyzer in the frequency range 2–10 GHz for the unidirectional and bidirectional probes. Further, the results of the experiment were compared with the results of numerical simulation. According to the results of multiple experiments, it was found that the average deviation between the concentrations was 2 dB for a unidirectional probe and 0.4 dB for a bidirectional probe. Thus, the sensitivity of the unidirectional probe was 1.5 dB/(mmol/L) for the bidirectional one 0.3 dB/(mmol/L). Thus, the improved design of the near-field probe can be used to record glucose concentrations.

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Ro-vibrational energies of cesium dimer and lithium dimer with molecular attractive potential

Scientific Reports ◽

10.1038/s41598-021-85761-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

C. A. Onate ◽

T. A. Akanbi ◽

I. B. Okon

Keyword(s):

Thermal Properties ◽

Attractive Potential ◽

Average Deviation ◽

Radial Wave ◽

Lithium Dimer ◽

Temperature Parameter ◽

Vibrational Energies ◽

Experimental Values ◽

Uvarov Method ◽

Potential Parameters

AbstractAn approximate solution of the Schrӧdinger equation for a molecular attractive potential was obtained using the parametric Nikiforov–Uvarov method. The energy equation and the corresponding radial wave functions were calculated. The effects of the potential parameters on the energy eigenvalues were examined. The thermal properties under the molecular attractive potential were calculated and the behaviour of the thermal properties with the maximum quantum state (λ) and the temperature parameter (β) respectively, were studied. Using the molecular spectroscopic parameters, the Rydberg–Klein–Rees (RKR) of cesium dimer and lithium dimer were both obtained and compared with the experimental values. The RKR values of both cesium dimer and lithium dimer calculated aligned with the observed values. The deviation and average deviation of the RKR for each molecule were also calculated.

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Optical Imaging of Magnetic Particle Cluster Oscillation and Rotation in Glycerol

Journal of Imaging ◽

10.3390/jimaging7050082 ◽

2021 ◽

Vol 7 (5) ◽

pp. 82

Author(s):

River Gassen ◽

Dennis Thompkins ◽

Austin Routt ◽

Philippe Jones ◽

Meghan Smith ◽

...

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Magnetic Particles ◽

Magnetic Particle ◽

Barium Hexaferrite ◽

Optical Microscope ◽

Simplified Model ◽

Particle Cluster ◽

Average Deviation ◽

Cross Sectional

Magnetic particles have been evaluated for their biomedical applications as a drug delivery system to treat asthma and other lung diseases. In this study, ferromagnetic barium hexaferrite (BaFe12O19) and iron oxide (Fe3O4) particles were suspended in water or glycerol, as glycerol can be 1000 times more viscous than water. The particle concentration was 2.50 mg/mL for BaFe12O19 particle clusters and 1.00 mg/mL for Fe3O4 particle clusters. The magnetic particle cluster cross-sectional area ranged from 15 to 1000 μμm2, and the particle cluster diameter ranged from 5 to 45 μμm. The magnetic particle clusters were exposed to oscillating or rotating magnetic fields and imaged with an optical microscope. The oscillation frequency of the applied magnetic fields, which was created by homemade wire spools inserted into an optical microscope, ranged from 10 to 180 Hz. The magnetic field magnitudes varied from 0.25 to 9 mT. The minimum magnetic field required for particle cluster rotation or oscillation in glycerol was experimentally measured at different frequencies. The results are in qualitative agreement with a simplified model for single-domain magnetic particles, with an average deviation from the model of 1.7 ± 1.3. The observed difference may be accounted for by the fact that our simplified model does not include effects on particle cluster motion caused by randomly oriented domains in multi-domain magnetic particle clusters, irregular particle cluster size, or magnetic anisotropy, among other effects.

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Cultivation of Saccharomyces cerevisiae with Feedback Regulation of Glucose Concentration Controlled by Optical Fiber Glucose Sensor

Sensors ◽

10.3390/s21020565 ◽

2021 ◽

Vol 21 (2) ◽

pp. 565

Author(s):

Lucie Koštejnová ◽

Jakub Ondráček ◽

Petra Majerová ◽

Martin Koštejn ◽

Gabriela Kuncová ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Optical Fiber ◽

Glucose Concentration ◽

Glucose Sensor ◽

Ruthenium Complex ◽

Feedback Regulation ◽

Regulation System ◽

Sensitive Layer ◽

Average Deviation ◽

Glucose Content

Glucose belongs among the most important substances in both physiology and industry. Current food and biotechnology praxis emphasizes its on-line continuous monitoring and regulation. These provoke increasing demand for systems, which enable fast detection and regulation of deviations from desired glucose concentration. We demonstrated control of glucose concentration by feedback regulation equipped with in situ optical fiber glucose sensor. The sensitive layer of the sensor comprises oxygen-dependent ruthenium complex and preimmobilized glucose oxidase both entrapped in organic–inorganic polymer ORMOCER®. The sensor was placed in the laboratory bioreactor (volume 5 L) to demonstrate both regulations: the control of low levels of glucose concentrations (0.4 and 0.1 mM) and maintenance of the glucose concentration (between 2 and 3.5 mM) during stationary phase of cultivation of Saccharomyces cerevisiae. Response times did not exceed 6 min (average 4 min) with average deviation of 4%. Due to these regulation characteristics together with durable and long-lasting (≥2 month) sensitive layer, this feedback regulation system might find applications in various biotechnological processes such as production of low glucose content beverages.

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Analysis of Radial Inflow Turbine Losses Operating with Supercritical Carbon Dioxide

Energies ◽

10.3390/en14123561 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3561

Author(s):

Antti Uusitalo ◽

Aki Grönman

Keyword(s):

Fluid Dynamic ◽

Dynamic Simulations ◽

Average Deviation ◽

Loss Analysis ◽

Specific Speed ◽

Loss Models ◽

Rotor Losses ◽

Radial Turbines ◽

Design Power ◽

Good Agreement

The losses of supercritical CO2 radial turbines with design power scales of about 1 MW were investigated by using computational fluid dynamic simulations. The simulation results were compared with loss predictions from enthalpy loss correlations. The aim of the study was to investigate how the expansion losses are divided between the stator and rotor as well as to compare the loss predictions obtained with the different methods for turbine designs with varying specific speeds. It was observed that a reasonably good agreement between the 1D loss correlations and computational fluid dynamics results can be obtained by using a suitable set of loss correlations. The use of different passage loss models led to high deviations in the predicted rotor losses, especially with turbine designs having the highest or lowest specific speeds. The best agreement in respect to CFD results with the average deviation of less than 10% was found when using the CETI passage loss model. In addition, the other investigated passage loss models provided relatively good agreement for some of the analyzed turbine designs, but the deviations were higher when considering the full specific speed range that was investigated. The stator loss analysis revealed that despite some differences in the predicted losses between the methods, a similar trend in the development of the losses was observed as the turbine specific speed was changed.

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A Flow Stress Model of 300M Steel for Isothermal Tension

Materials ◽

10.3390/ma14020252 ◽

2021 ◽

Vol 14 (2) ◽

pp. 252

Author(s):

Rongchuang Chen ◽

Shiyang Zhang ◽

Xianlong Liu ◽

Fei Feng

Keyword(s):

Flow Stress ◽

Constitutive Model ◽

Tensile Deformation ◽

Flow Behavior ◽

Tensile Tests ◽

Uniaxial Tensile ◽

Model Parameters ◽

Average Deviation ◽

Cross Sectional ◽

300M Steel

To investigate the effect of hot working parameters on the flow behavior of 300M steel under tension, hot uniaxial tensile tests were implemented under different temperatures (950 °C, 1000 °C, 1050 °C, 1100 °C, 1150 °C) and strain rates (0.01 s−1, 0.1 s−1, 1 s−1, 10 s−1). Compared with uniaxial compression, the tensile flow stress was 29.1% higher because dynamic recrystallization softening was less sufficient in the tensile stress state. The ultimate elongation of 300M steel increased with the decrease of temperature and the increase of strain rate. To eliminate the influence of sample necking on stress-strain relationship, both the stress and the strain were calibrated using the cross-sectional area of the neck zone. A constitutive model for tensile deformation was established based on the modified Arrhenius model, in which the model parameters (n, α, Q, ln(A)) were described as a function of strain. The average deviation was 6.81 MPa (6.23%), showing good accuracy of the constitutive model.

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Detecting the normal-direction in automated aircraft manufacturing based on adaptive alignment

Science Progress ◽

10.1177/0036850420981212 ◽

2020 ◽

Vol 103 (4) ◽

pp. 003685042098121

Author(s):

Ying Zhang ◽

Hongchang Ding ◽

Changfu Zhao ◽

Yigen Zhou ◽

Guohua Cao

Keyword(s):

Calibration Method ◽

Adaptive Method ◽

Normal Direction ◽

Detection Accuracy ◽

Average Deviation ◽

Important Indicator ◽

Aircraft Manufacturing ◽

Direction Detection ◽

Hole Making ◽

Vertical Accuracy

In aircraft manufacturing, the vertical accuracy of connection holes is important indicator of the quality of holes making. Aircraft products have high requirements for the vertical accuracy of holes positions. When drilling and riveting are performed by an automatic robotic system, assembly errors, bumps, offsets and other adverse conditions, can affects the accuracy of manufacturing and detection, and in turn the fatigue performance of the entire structure. To solve this problem, we proposed a technology for detecting the normal-direction based on the adaptive alignment method, built a mathematical model for posture alignment, and studied the calibration method and mechanism of the detection device. Additionally, we investigated techniques for error compensation using an electronic theodolite and other devices when the adaptive method is used for detection. In verification experiments of the method, multiple sets of results demonstrated that the key technical indicators are as follows: normal accuracy <0.5°, average deviation after correction =0.0667°. This method can effectively compensate the errors affecting hole making work in automated manufacturing, and further improve the positioning accuracy and normal-direction detection accuracy of the robot.

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