scholarly journals Performance Study of Impact-Point Estimation Systems Using Two Types of Acoustic Sensor Arrangement Methods

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Shin Hur ◽  
EunJoong Lee ◽  
Jongseong Won ◽  
Duck-Gyu Lee ◽  
Kyungjun Song ◽  
...  
Keyword(s):  
Shock Wave ◽  
Theoretical Calculations ◽  
Estimation Algorithm ◽  
Absolute Error ◽  
Point Estimation ◽  
Acoustic Sensor ◽  
Impact Point ◽  
Performance Study ◽  
Estimation System ◽  
The Impact

In this study, a shooting experiment is carried out with an acoustic sensor array that can detect shock wave at high-sound pressures and withstand the shock wave of the bullet. Delta- and H-type of acoustic sensor units are constructed. The measured values of the temporal arrival differences estimated based on the distance between the acoustic sensors are then compared with the theoretical calculations according to the types of bullets and shooting distance. In addition, an impact-point estimation system (IPES) is fabricated, which comprises delta- and H-type sensor units, a target, signal processing device, and an impact point estimation algorithm. The impact points on the target caused by the shooting experiment are compared with those calculated using the impact point estimation algorithm. Finally, the mean absolute error MAE between the actual and the calculated impact-point coordinates is calculated, and the performances of the delta- and H-type IPES are evaluated.

scholarly journals Computational Evaluation of Shock Wave Interaction with a Cylindrical Water Column

2021 ◽  
Vol 11 (11) ◽  
pp. 4934
Author(s):  
Viola Rossano ◽  
Giuliano De Stefano
Keyword(s):  
Shock Wave ◽  
Water Column ◽  
Wave Interaction ◽  
Navier Stokes ◽  
Plane Shock ◽  
Governing Equations ◽  
Computational Evaluation ◽  
Air Water Interface ◽  
The Mean ◽  
The Impact

Computational fluid dynamics was employed to predict the early stages of the aerodynamic breakup of a cylindrical water column, due to the impact of a traveling plane shock wave. The unsteady Reynolds-averaged Navier–Stokes approach was used to simulate the mean turbulent flow in a virtual shock tube device. The compressible flow governing equations were solved by means of a finite volume-based numerical method, where the volume of fluid technique was employed to track the air–water interface on the fixed numerical mesh. The present computational modeling approach for industrial gas dynamics applications was verified by making a comparison with reference experimental and numerical results for the same flow configuration. The engineering analysis of the shock–column interaction was performed in the shear-stripping regime, where an acceptably accurate prediction of the interface deformation was achieved. Both column flattening and sheet shearing at the column equator were correctly reproduced, along with the water body drift.

scholarly journals Photovoltaic Power Forecasting: Assessment of the Impact of Multiple Sources of Spatio-Temporal Data on Forecast Accuracy

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1432
Author(s):  
Xwégnon Ghislain Agoua ◽  
Robin Girard ◽  
Georges Kariniotakis
Keyword(s):  
Satellite Images ◽  
Forecast Accuracy ◽  
Absolute Error ◽  
Data Sources ◽  
Test Case ◽  
Temporal Data ◽  
Multiple Sources ◽  
Forecasting Error ◽  
Spatio Temporal ◽  
The Impact

The efficient integration of photovoltaic (PV) production in energy systems is conditioned by the capacity to anticipate its variability, that is, the capacity to provide accurate forecasts. From the classical forecasting methods in the state of the art dealing with a single power plant, the focus has moved in recent years to spatio-temporal approaches, where geographically dispersed data are used as input to improve forecasts of a site for the horizons up to 6 h ahead. These spatio-temporal approaches provide different performances according to the data sources available but the question of the impact of each source on the actual forecasting performance is still not evaluated. In this paper, we propose a flexible spatio-temporal model to generate PV production forecasts for horizons up to 6 h ahead and we use this model to evaluate the effect of different spatial and temporal data sources on the accuracy of the forecasts. The sources considered are measurements from neighboring PV plants, local meteorological stations, Numerical Weather Predictions, and satellite images. The evaluation of the performance is carried out using a real-world test case featuring a high number of 136 PV plants. The forecasting error has been evaluated for each data source using the Mean Absolute Error and Root Mean Square Error. The results show that neighboring PV plants help to achieve around 10% reduction in forecasting error for the first three hours, followed by satellite images which help to gain an additional 3% all over the horizons up to 6 h ahead. The NWP data show no improvement for horizons up to 6 h but is essential for greater horizons.

Analysis of the Samples of Fe-Cu-Nb-Si-B Amorphous Alloys Obtained by Dynamic Compacting Method

2005 ◽  
Vol 903 ◽  
Author(s):  
Victor A. Golubev ◽  
Andrey V. Strikanov ◽  
Grigory A. Potemkin ◽  
Ludmila V. Zueva ◽  
Aleksey V. Golubev ◽  
...  
Keyword(s):  
Shock Wave ◽  
Amorphous Alloys ◽  
Analysis Data ◽  
Xrd Analysis ◽  
Soft Magnetic ◽  
Scanning Calorimetry ◽  
Soft Magnetic Alloys ◽  
Nano Crystalline ◽  
The Impact ◽  
Magnetic Conductivity

AbstractThe Dynamic Compacting (DC) method is promising method to produce considerable-size nonporous wares. The phenomenon is based on the impact of shock wave on the initial powders of amorphous alloys. Every time when the shock wave propagates through the bulk of substance then the temperature rises substantially. Therefore there is a need of study of the DC’s effect on the structure and properties of the amorphous alloys. The results of the thermal analysis (in particular, Differential Scanning Calorimetry) of the samples of the soft magnetic alloys are presented in the report. These results concern with amorphous alloys of 5BDSR, GM414, 10NSR trademarks before DC and after DC, respectively. It is shown there is single low-temperature endothermic peak (near 300C) and there are several high temperature exothermic peaks (near 540C, 650C, and 700C). The first peak is related to glass-transition, the following peaks are related to formation of nano-crystalline phases. It was proved by XRD analysis data. The optimal regimes of the thermal processing of final wares were chosen on the base of thermal- and XRD-analysis. The study of the effects of these regimes on the properties (magnetic conductivity, specific losses etc.) of the circular magnetic conductors was executed. In particular, thermal- as well as thermo-magnetic processing of magnetic conductors based on 5BDSR amorphous alloy (after DC) essentially improves their magnetic properties. For example, magnetic conductivity fÝ increases approximately by factor 17 with respect to the magnitude before DC.

The Impact Analysis of Coal’s Elastic Energy on the Coal and Gas Outburst Shock Wave

2012 ◽  
Vol 616-618 ◽  
pp. 390-395
Author(s):  
Cheng Wu Li ◽  
Tian Bao Gao ◽  
Shan Yang Wei ◽  
Teng Li
Keyword(s):  
Shock Wave ◽  
Elastic Energy ◽  
Impact Analysis ◽  
Dynamic Theory ◽  
Coal And Gas Outburst ◽  
Calculation Formula ◽  
Theory Analysis ◽  
Gas Outburst ◽  
Quantitative Calculation ◽  
The Impact

According to the gas dynamic theory, this paper deduces the approximate calculation formula on elastic energy of a tons of coal through theory analysis, and then gets the quantitative calculation method between incident overpressure and reflected overpressure of the coal and gas outburst shock wave. The calculation formula in this paper is in line with the measured values, and so its validity has been verified. The analysis result shows that the effect of the elastic energy during the process of coal and gas outburst should be considered when the depth of the coal seam is great and the coal’s modulus of elasticity is small.

scholarly journals Structural Properties of G,T-Parallel Duplexes

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Anna Aviñó ◽  
Elena Cubero ◽  
Raimundo Gargallo ◽  
Carlos González ◽  
Modesto Orozco ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Structural Properties ◽  
Theoretical Calculations ◽  
Md Simulations ◽  
Theoretical Studies ◽  
Duplex Structure ◽  
Strong Stabilization ◽  
The Stability ◽  
The Impact

The structure of G,T-parallel-stranded duplexes of DNA carrying similar amounts of adenine and guanine residues is studied by means of molecular dynamics (MD) simulations and UV- and CD spectroscopies. In addition the impact of the substitution of adenine by 8-aminoadenine and guanine by 8-aminoguanine is analyzed. The presence of 8-aminoadenine and 8-aminoguanine stabilizes the parallel duplex structure. Binding of these oligonucleotides to their target polypyrimidine sequences to form the corresponding G,T-parallel triplex was not observed. Instead, when unmodified parallel-stranded duplexes were mixed with their polypyrimidine target, an interstrand Watson-Crick duplex was formed. As predicted by theoretical calculations parallel-stranded duplexes carrying 8-aminopurines did not bind to their target. The preference for the parallel-duplex over the Watson-Crick antiparallel duplex is attributed to the strong stabilization of the parallel duplex produced by the 8-aminopurines. Theoretical studies show that the isomorphism of the triads is crucial for the stability of the parallel triplex.

scholarly journals Analysis of Errors in the Estimation of Impact Positions in Plate-Like Structure through the Triangulation Formula by Piezoelectric Sensors Monitoring

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3426 ◽  
Author(s):  
Eugenio Marino-Merlo ◽  
Andrea Bulletti ◽  
Pietro Giannelli ◽  
Marco Calzolai ◽  
Lorenzo Capineri
Keyword(s):  
Propagation Velocity ◽  
Lamb Waves ◽  
Correlation Method ◽  
Time Of Arrival ◽  
Impact Point ◽  
Laboratory Procedure ◽  
Impact Position ◽  
Set Up ◽  
Two Parameters ◽  
The Impact

The structural health monitoring (SHM) of critical structures is a complex task that involves the use of different sensors that are also aimed at the identification of the location of the impact point using ultrasonic sensors. For the evaluation of the impact position, reference is often made to the well-known triangulation method. This method requires the estimation of the differential time of arrival (DToA) and the group velocity of the Lamb waves propagating into a plate-like structure: the uncertainty of these two parameters is taken into consideration as main cause of localization error. The work proposes a simple laboratory procedure based on a set-up with a pair of sensors that are symmetrically placed with respect to the impact point, to estimate the uncertainty of the DToA and the propagation velocity estimates. According to a theoretical analysis of the error for the impact position, the experimental uncertainties of DToA and the propagation velocity are used to estimate the overall limit of the SHM system for the impact positioning. Because the error for the DToA estimate depends also on the adopted signal processing, three common methods are selected and compared: the threshold, the correlation method, and a likelihood algorithm. Finally, the analysis of the positioning error using multisensory configuration is reported as useful for the design of the SHM system.

scholarly journals Hydrodynamic Ram Effect Caused by Debris Hypervelocity Impact on Satellite Tank

2019 ◽  
Vol 9 (20) ◽  
pp. 4200 ◽  
Author(s):  
Beilei Zhao ◽  
Jiguang Zhao ◽  
Cunyan Cui ◽  
Yongsheng Duan
Keyword(s):  
Shock Wave ◽  
Angular Velocity ◽  
Hypervelocity Impact ◽  
Filling Ratio ◽  
Maximum Diameter ◽  
Residual Velocity ◽  
Hydrodynamic Ram ◽  
Ram Effect ◽  
The Impact ◽  
Bulge Height

To study the hydrodynamic ram effect caused by the debris hypervelocity impact on the satellite tank, a numerical simulation of the spherical debris impacting the satellite tank at the velocity of 7000 m/s was carried out based on ANSYS/LS-DYNA software. The attenuation law of debris velocity, the propagation process of the shock wave and the deformation of the tank walls were investigated. The influences of the liquid-filling ratio, the magnitude, and direction of angular velocity on the hydrodynamic ram effect were analyzed. Results show that the debris velocity decreased rapidly and the residual velocity was 263 m/s when the debris passed through the tank. The shock wave was hemispherical, and the pressure of shock wave was the smallest at the element with an angle of 90° to the impact line. The maximum diameter of the front perforation was larger than that of the back perforation and the bulge height on the front wall was smaller than that on the back wall. With the decrease of the liquid-filling ratio, the diameter of the perforations and bulge height decreased. When the debris impacted the satellite tank with the angular velocity in the x direction, the debris trajectory did not deflect. When the debris impacted the satellite tank with the angular velocities in the y and z direction, the debris trajectory deflected to the negative direction of the z axis and y axis, respectively. The magnitude of the angular velocity affects the residual velocity of debris and the diameter of perforations.

scholarly journals RELACIÓN ENTRE MOTIVACIÓN, LOCUS DE CONTROL, HABITOS DE ESTUDIO Y RENDIMIENTO EN ESTUDIANTES UNIVERSITARIOS DE LA FACULTAD DE INGENIERÍA INDUSTRIAL Y DE SISTEMAS DE LA UNIVERSIDAD NACIONAL DE INGENIERIA

2016 ◽  
Vol 26 (1) ◽  
pp. 31
Author(s):  
Mario Heinrich Fisfalen Huerta
Keyword(s):  
Academic Performance ◽  
Locus Of Control ◽  
Correlation Analysis ◽  
Study Habits ◽  
Performance Study ◽  
Need For Affiliation ◽  
Need For Power ◽  
Number Of Factors ◽  
Study Results ◽  
The Impact

RESUMENEl rendimiento académico de los estudiantes depende de una serie de factores principalmente internos al estudiante; dentro de los cuales los hábitos de estudio juegan un rol muy importante, así como la motivación de los estudiantes y el locus de control. En el presente trabajo, se hace un estudio de la relación entre rendimiento académico, hábitos de estudio, motivación y locus de control; analizando la incidencia de las tres últimas variables sobre la primera. Para lo cual se aplica la técnica de la encuesta así como escalas de motivación, de hábitos de estudio y de locus de control; analizando los resultados con el empleo de técnicas estadísticas como el análisis de correlación, el análisis de varianza y el análisis de correlación. Los resultados del estudio muestran que los hábitos de estudio, así como la motivación hacia la afiliación y la motivación al logro inciden significativamente en el rendimiento académico de la muestra, conformada por estudiantes de la Facultad de Ingeniería Industrial y de Sistemas.Palabras clave.- Rendimiento académico, Hábitos de estudio, Necesidad de logro, Necesidad de filiación, Necesidad de poder, Locus-D control.ABSTRACTThe academic performance of students depends on a number of factors, mostly psycological; within which studying habits play an important role, as well as student motivation and locus of control. In this work, a study of the relationship between academic performance, study habits, motivation and locus of control is made; analyzing the impact of the last three variables over the first. For which the survey technique is applied and scales of motivation, study habits and locus of control; analyzing the results with the use of statistical techniques such as correlation analysis, analysis of variance and correlation analysis. The study results show that the study habits and motivation for affiliation and motivation to achieve significant impact on the academic performance of the sample, formed by students of the School of Industrial and Systems Engineering.Key words.- Academic performance, Study habits, Need for achievement, Need for affiliation, Need for power, Control-D locus.

scholarly journals Geomagnetic field disturbances from the fall of the Lipetsk (june 21, 2018) and Chelyabinsk (february 15, 2013) meteorites

2019 ◽  
Vol 485 (3) ◽  
pp. 361-365
Author(s):  
A. A. Spivak ◽  
S. A. Riabova
Keyword(s):  
Delay Time ◽  
Geomagnetic Field ◽  
Maximum Effect ◽  
Impact Point ◽  
Cosmic Body ◽  
Meteorite Impact ◽  
Geomagnetic Disturbances ◽  
Geophysical Observatory ◽  
Earth’S Atmosphere ◽  
The Impact

Based on the Chelyabinsk (February 13, 2013) and Lipetsk (June 21, 2018) events, disturbances in the Earth's geomagnetic field, which were induced by the fall of these meteorites, were studied. Based on the data provided by geomagnetic observatories of the INTERMAGNET network and the mid-latitude Mikhnevo geophysical observatory (IDG RAS), it was established that the fall of meteorites through the Earth's atmosphere, in general, induces geomagnetic disturbances of up to 5 nT at distances up to 2700 km from the impact point of a cosmic body; the maximum effect is reached with a delay time ranging from ~5 to ~10 min, and the duration of the period of the induced geomagnetic field disturbances varies from ~5 to ~20 min. The estimation dependencies of the amplitude and duration of induced geomagnetic disturbances from a distance from the meteorite impact points are proposed.

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