Modal Voltages of Linear and Nonlinear Structures Using Distributed Artificial Neurons

1999 ◽  
Author(s):  
R. V. Howard ◽  
W. K. Chai ◽  
H. S. Tzou
Keyword(s):  
Elastic Shell ◽  
Dynamic State ◽  
Neural Signals ◽  
Double Curvature ◽  
Artificial Neurons ◽  
In Situ Sensors ◽  
Linear And Nonlinear ◽  
Euler Bernoulli Beam ◽  
Theoretical Results

Abstract Laminated or embedded distributed neurons on structural components serve as in-situ sensors monitoring structure’s dynamic state and health status. Thin film piezoelectric patches are perfect candidates for this purpose. A generic piezoelectric neuron concept is introduced first, followed by definitions of neural signals generated by an arbitrary neuron laminated on a generic nonlinear double-curvature elastic shell. This generic neuron theory can be applied to a large class of linear and nonlinear common geometries, e.g., spheres, cylindrical shells, plates, etc. To demonstrate the neuron concept, an Euler-Bernoulli beam laminated with segmented neurons is studied. Neural signals and modal voltages are presented. Theoretical results are compared with experimental data favorably.

Distributed Modal Voltages of Nonlinear Paraboloidal Shells With Distributed Neurons

2004 ◽  
Vol 126 (1) ◽  
pp. 47-53 ◽  
Author(s):  
H. S. Tzou ◽  
J. H. Ding
Keyword(s):  
Dynamic Responses ◽  
Dynamic State ◽  
Structural Components ◽  
Shells Of Revolution ◽  
Membrane Component ◽  
Fully Integrated ◽  
In Situ Sensors ◽  
Membrane Components ◽  
Paraboloidal Shell

Effective health monitoring and distributed control of advanced structures depends on accurate measurements of dynamic responses of elastic structures. Conventional sensors used for structural measurement are usually add-on “discrete” devices. Lightweight distributed thin-film piezoelectric neurons fully integrated (laminated or embedded) with structural components can serve as in-situ sensors monitoring structure’s dynamic state and health status. This study is to investigate modal voltages and detailed signal contributions of linear or nonlinear paraboloidal shells of revolution laminated with piezoelectric neurons. Signal generation of distributed neuron sensors laminated on paraboloidal shells is defined first, based on the open-voltage assumption and Maxwell’s principle. The neuron signal of a linear paraboloidal shell is composed of a linear membrane component and a linear bending component; the signal of a nonlinear paraboloidal shell is composed of nonlinear and linear membrane components and a linear bending component due to the von Karman geometric nonlinearity. Signal components and distributed modal voltages of linear and nonlinear paraboloidal shells with various curvatures and thickness are investigated.

Spatially Distributed Signals of Nonlinear Paraboloidal Shells With Distributed Neurons

2001 ◽  
Author(s):  
H. S. Tzou ◽  
J. H. Ding
Keyword(s):  
Dynamic Responses ◽  
Dynamic State ◽  
Structural Components ◽  
Shells Of Revolution ◽  
Fully Integrated ◽  
Spatially Distributed ◽  
In Situ Sensors ◽  
Membrane Components ◽  
Paraboloidal Shell

Abstract Effective health monitoring and distributed control of advanced structures depends on accurate measurements of dynamic responses of elastic structures. Conventional sensors used for structural measurement are usually add-on “discrete” devices. Lightweight distributed thin-film piezoelectric neurons fully integrated (laminated or embedded) with structural components can serve as in-situ sensors monitoring structure’s dynamic state and health status. This study is to investigate modal voltages and detailed signal contributions of linear or nonlinear paraboloidal shells of revolution laminated with piezoelectric neurons. Signal generation of distributed neuron sensors laminated on paraboloidal shells is defined first, based on the open-voltage assumption and Maxwell’s principle. The neuron signal of a linear paraboloidal shell is composed of a linear membrane component and a linear bending component; the signal of a nonlinear paraboloidal shell governed by the von Karman geometric nonlinearity is composed of nonlinear and linear membrane components and a linear bending component. Signal components and distributed modal voltages of linear and nonlinear paraboloidal shells with various curvatures and thickness are investigated.

scholarly journals A Convergent Collocation Approach for Generalized Fractional Integro-Differential Equations Using Jacobi Poly-Fractonomials

Mathematics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 979
Author(s):  
Sandeep Kumar ◽  
Rajesh K. Pandey ◽  
H. M. Srivastava ◽  
G. N. Singh
Keyword(s):  
Differential Equation ◽  
Fractional Derivative ◽  
Collocation Method ◽  
Caputo Fractional Derivative ◽  
Fractional Derivatives ◽  
Special Cases ◽  
Collocation Approach ◽  
Linear And Nonlinear ◽  
Simulation Results ◽  
Theoretical Results

In this paper, we present a convergent collocation method with which to find the numerical solution of a generalized fractional integro-differential equation (GFIDE). The presented approach is based on the collocation method using Jacobi poly-fractonomials. The GFIDE is defined in terms of the B-operator introduced recently, and it reduces to Caputo fractional derivative and other fractional derivatives in special cases. The convergence and error analysis of the proposed method are also established. Linear and nonlinear cases of the considered GFIDEs are numerically solved and simulation results are presented to validate the theoretical results.

The role of forest deadwood in rockfall protection

2021 ◽  
Author(s):  
Adrian Ringenbach ◽  
Peter Bebi ◽  
Perry Bartelt ◽  
Andrin Caviezel
Keyword(s):  
Basal Area ◽  
Spruce Forest ◽  
Runout Distance ◽  
In Situ Sensors ◽  
Efficient Protection ◽  
Cost Efficient ◽  
Study Sites ◽  
Rockfall Protection

<p>Forests with a high density and basal area of living trees are known for their function as natural and cost-efficient protection against rockfall. The role of deadwood, however, is less understood. We address this knowledge gap in this contribution as we present the results of repeated real-scale experiments in a) a montane beech-spruce forest with and without deadwood and b) in a subalpine scrub mountain pine-spruce forest with deadwood. We used artificial rocks with either an equant or platy shape, masses between 45 kg and 800 kg (≈ 0.3 m3), and equipped with in-situ sensors to gain insights into rotational velocities and impact-accelerations. Clusters of deadwood and erected root plates reduced the mean runout distance at both study sites. For site a), we found that more rocks were stopped behind lying than living trees and that the stopping effect of deadwood was greater for equant compared to platy rock shapes. Site b) revealed a braking effect of scrub mountain pines for relatively small (45 kg), but also a visible reduction in rotational velocities for the 800 kg rocks sensor stream. We conclude that deadwood must be taken into account in rockfall modeling and the management of rockfall protection forests.</p>

scholarly journals Development of In-Situ Sensors for CO2 to Fuel Process

2020 ◽  
Author(s):  
Mohammad Houkan ◽  
Omar Shehata ◽  
Karthik Kannan ◽  
John-John Cabibihan ◽  
Aboubakr M. Abdullah ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Cost Effective ◽  
Conversion Process ◽  
Conversion Yield ◽  
In Situ Sensors

Conversion of CO2 into fuel is an interesting and promising field. However, the conversion yield is hard to measure during the conversion process. Here, we have developed two techniques to measure the amount of CO2 while the reaction is taking place. First method is colorimetry, where a chemical is added to the solution, and it changes color depending on the resulting product. The second method is the atomization of the resulting solution. Thereafter, the results were measured by a gas sensor. The prepared sensors are cost effective and portable to use.

scholarly journals ROAD TEMPERATURE MODELLING WITHOUT IN-SITU SENSORS

2017 ◽  
Vol 12 (4) ◽  
pp. 241-247 ◽  
Author(s):  
Karol Opara ◽  
Jan Zieliński
Keyword(s):  
Energy Balance ◽  
Urban Areas ◽  
Initial Conditions ◽  
Forecast Error ◽  
Weather Data ◽  
Forecast Errors ◽  
The Road ◽  
In Situ Sensors ◽  
Pavement Temperature

Modelling of the pavement temperature facilitates winter road maintenance. It is used for predicting the glaze formation and for scheduling the spraying of the de-icing brine. The road weather is commonly forecasted by solving the energy balance equations. It requires setting the initial vertical profile of the pavement temperature, which is often obtained from the Road Weather Information Stations. The paper proposes the use of average air temperature from seven preceding days as a pseudo-observation of the subsurface temperature. Next, the road weather model is run with a few days offset. It first uses the recent, historical weather data and then the available forecasts. This approach exploits the fact that the energy balance models tend to “forget” their initial conditions and converge to the baseline solution. The experimental verification was conducted using the Model of the Environment and Temperature of Roads and the data from a road weather station in Warsaw over a period of two years. The additional forecast error introduced by the proposed pseudo-observational initialization averages 1.2 °C in the first prediction hour and then decreases in time. The paper also discusses the use of Digital Surface Models to take into account the shading effects, which are an essential source of forecast errors in urban areas. Limiting the use of in-situ sensors opens a perspective for an economical, largescale implementation of road meteorological models.

scholarly journals Copernicus: the European Earth Observation programme

2020 ◽  
Author(s):  
S. Jutz ◽  
M.P. Milagro-Pérez
Keyword(s):  
Numerical Models ◽  
Earth Observation ◽  
Environmental Data ◽  
Observation Data ◽  
The European Union ◽  
Global Environmental ◽  
In Situ Sensors ◽  
Earth Observation Data ◽  
Observation Programme

<span>The European Union-led Copernicus programme, born with the aim of developing space-based global environmental monitoring services to ensure a European autonomous capacity for Earth Observation, comprises a Space Component, Core Services, and In-situ measurements. The Space Component, coordinated by ESA, has seven Sentinel satellites in orbit, with further missions planned, and is complemented by contributing missions, in-situ sensors and numerical models, and delivers many terabytes of accurate climate and environmental data, free and open, every day to hundreds of thousands of users. This makes Copernicus the biggest provider of Earth Observation data in the world.</span>

scholarly journals Topside signature of medium-scale traveling ionospheric disturbances

2014 ◽  
Vol 32 (8) ◽  
pp. 959-965 ◽  
Author(s):  
E. S. Miller ◽  
H. Kil ◽  
J. J. Makela ◽  
R. A. Heelis ◽  
E. R. Talaat ◽  
...  
Keyword(s):  
Electric Fields ◽  
Dissociative Recombination ◽  
Middle Latitude ◽  
Topside Ionosphere ◽  
Ionospheric Disturbances ◽  
Medium Scale ◽  
Traveling Ionospheric Disturbances ◽  
Periodic Groups ◽  
In Situ Sensors

Abstract. Plasma blobs, localized plasma density enhancements that occur singularly or in periodic groups, have been observed by in situ sensors in the lower- and middle-latitude nighttime ionosphere. Traditionally, creation of blobs has been thought to be connected to equatorial plasma bubbles, which are localized plasma depletions. Here, we report the association of blobs with medium-scale traveling ionospheric disturbances (MSTIDs). On 17 January 2010, an all-sky imager on the Caribbean island of Bonaire (geographic: 12.190° N, 68.244° W; geomagnetic 22.46° N, 7.099° E) observed a nighttime electrified MSTID propagating to the southwest. At the time of the MSTID's transit, the Coupled Ion-Neutral Dynamics Investigation instrument onboard the Communication/Navigation Outage Forecasting System satellite detected a group of blobs along the same geomagnetic flux tubes. The electron density variations measured at the satellite altitude, indicating the blobs, are anticorrelated with the intensity variations of the 630.0 nm dissociative recombination emission measured on the same magnetic field lines. This relationship is explained by a modulation of the O+ profile altitude due to electric fields generated within the MSTID. This idea is supported by in situ measurements of the vertical ion velocity. We argue that common climatology between blobs and MSTIDs reported in the literature, as well as this coincident observation, suggest that blobs may be the in situ signature of MSTIDs in the topside ionosphere.

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