scholarly journals One approach in evaluating the overflow probability using the infinite fluid-flow queue

2011 ◽  
Vol 24 (1) ◽  
pp. 1-8
Author(s):  
Branimir Trenkic ◽  
Mihajlo Stefanovic
Keyword(s):  
Spectral Analysis ◽  
Fluid Flow ◽  
Real Time ◽  
Practical Significance ◽  
Spectral Approach ◽  
Fluid Queues ◽  
Qbd Processes ◽  
Overflow Probability ◽  
Fluid Flow Queue ◽  
Overflow Probabilities

If it is going to have practical significance, the evaluation of overflow probabilities must be (1) precise, (2) computationally stable and (3) real time compatible. The existing approximation expressions are gotten by using the traditional fluid-flow analytic techniques, which are mostly based on spectral analysis. The limitation of this approach comes from numerical difficulties caries by the spectral approach. In this paper, we suggested a fluid-flow approach in evaluating the overflow probability, which fully satisfies the above stated criteria, and removes the numerical difficulties of existing methods. The authors approach is based on the renewal argument and exploiting the similarity between fluid queues and Quasi-Birth-and-Death (QBD) processes.

scholarly journals Near-surface real-time seismic imaging using parsimonious interferometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sherif M. Hanafy ◽  
Hussein Hoteit ◽  
Jing Li ◽  
Gerard T. Schuster
Keyword(s):  
Fluid Flow ◽  
Real Time ◽  
Temporal Resolution ◽  
Seismic Imaging ◽  
Time Lapse ◽  
Rock Properties ◽  
Recording Time ◽  
Near Surface ◽  
Arrival Times ◽  
Order Of Magnitude

AbstractResults are presented for real-time seismic imaging of subsurface fluid flow by parsimonious refraction and surface-wave interferometry. Each subsurface velocity image inverted from time-lapse seismic data only requires several minutes of recording time, which is less than the time-scale of the fluid-induced changes in the rock properties. In this sense this is real-time imaging. The images are P-velocity tomograms inverted from the first-arrival times and the S-velocity tomograms inverted from dispersion curves. Compared to conventional seismic imaging, parsimonious interferometry reduces the recording time and increases the temporal resolution of time-lapse seismic images by more than an order-of-magnitude. In our seismic experiment, we recorded 90 sparse data sets over 4.5 h while injecting 12-tons of water into a sand dune. Results show that the percolation of water is mostly along layered boundaries down to a depth of a few meters, which is consistent with our 3D computational fluid flow simulations and laboratory experiments. The significance of parsimonious interferometry is that it provides more than an order-of-magnitude increase of temporal resolution in time-lapse seismic imaging. We believe that real-time seismic imaging will have important applications for non-destructive characterization in environmental, biomedical, and subsurface imaging.

TAD-Net: An approach for real-time action detection based on temporal convolution network and graph convolution network in digital twin shop-floor

Digital Twin ◽  
2021 ◽  
Vol 1 ◽  
pp. 10
Author(s):  
Qing Hong ◽  
Yifeng Sun ◽  
Tingyu Liu ◽  
Liang Fu ◽  
Yunfeng Xie
Keyword(s):  
Real Time ◽  
Sequence Data ◽  
Network Models ◽  
Human Action ◽  
Practical Significance ◽  
Shop Floor ◽  
Action Detection ◽  
Digital Twin ◽  
Actual Application ◽  
Production Processes

Background: Intelligent monitoring of human action in production is an important step to help standardize production processes and construct a digital twin shop-floor rapidly. Human action has a significant impact on the production safety and efficiency of a shop-floor, however, because of the high individual initiative of humans, it is difficult to realize real-time action detection in a digital twin shop-floor. Methods: We proposed a real-time detection approach for shop-floor production action. This approach used the sequence data of continuous human skeleton joints sequences as the input. We then reconstructed the Joint Classification-Regression Recurrent Neural Networks (JCR-RNN) based on Temporal Convolution Network (TCN) and Graph Convolution Network (GCN). We called this approach the Temporal Action Detection Net (TAD-Net), which realized real-time shop-floor production action detection. Results: The results of the verification experiment showed that our approach has achieved a high temporal positioning score, recognition speed, and accuracy when applied to the existing Online Action Detection (OAD) dataset and the Nanjing University of Science and Technology 3 Dimensions (NJUST3D) dataset. TAD-Net can meet the actual needs of the digital twin shop-floor. Conclusions: Our method has higher recognition accuracy, temporal positioning accuracy, and faster running speed than other mainstream network models, it can better meet actual application requirements, and has important research value and practical significance for standardizing shop-floor production processes, reducing production security risks, and contributing to the understanding of real-time production action.

The Uniform Distribution of a Fluid Flowing Through a Perforated Pipe

1950 ◽  
Vol 17 (4) ◽  
pp. 431-438
Author(s):  
Willard M. Dow
Keyword(s):  
Fluid Flow ◽  
High Capacity ◽  
Practical Significance ◽  
Linear Rate ◽  
Gaseous Fuels ◽  
Extended Range ◽  
Flow Through ◽  
Perforated Pipe ◽  
Special Case ◽  
Theoretical Results

Abstract A theoretical analysis is made of the flow through a perforated pipe with a closed end for the special case of a constant linear rate of discharge along the length of the pipe. The results of the fluid-flow considerations are applicable to many practical manifold systems. The practical significance of the results with respect to pipe burners for gaseous fuels is emphasized as the results make possible the design of simple high-capacity and extended-range pipe burners of industrial importance. The capacity of commercially available pipe burners may be increased several hundred per cent. The validity of the theoretical results was verified by experiment.

scholarly journals Local and Global Gestalt Laws: A Neurally Based Spectral Approach

2017 ◽  
Vol 29 (2) ◽  
pp. 394-422 ◽  
Author(s):  
Marta Favali ◽  
Giovanna Citti ◽  
Alessandro Sarti
Keyword(s):  
Mathematical Model ◽  
Spectral Analysis ◽  
Group Theory ◽  
Visual Cortex ◽  
Connectivity Matrix ◽  
Spectral Approach ◽  
Good Continuation ◽  
Functional Architecture ◽  
Lie Group Theory ◽  
Gestalt Laws

This letter presents a mathematical model of figure-ground articulation that takes into account both local and global gestalt laws and is compatible with the functional architecture of the primary visual cortex (V1). The local gestalt law of good continuation is described by means of suitable connectivity kernels that are derived from Lie group theory and quantitatively compared with long-range connectivity in V1. Global gestalt constraints are then introduced in terms of spectral analysis of a connectivity matrix derived from these kernels. This analysis performs grouping of local features and individuates perceptual units with the highest salience. Numerical simulations are performed, and results are obtained by applying the technique to a number of stimuli.

scholarly journals Model of the dynamics of a wheeled vehicle for a complex of full-scale-mathematical modeling

2020 ◽  
Vol 1 (4) ◽  
pp. 46-60
Author(s):  
B.B. Kositsyn ◽  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Real Time ◽  
Block Diagram ◽  
Plane Motion ◽  
Full Scale ◽  
Practical Significance ◽  
Modes Of Operation ◽  
Wheeled Vehicle ◽  
Full Scale Tests

Introduction. The use of the method of full-scale-mathematical modeling in “real time” opens up wide opportunities associated with the analysis of the modes of operation of the “man – vehicle – environment” system, as well as the study of the loading of units and assemblies of vehicles. The existing research complexes of full-scale mathematical modeling are suitable for obtaining most of the indicators usually determined by full-scale tests. The difference lies in the ability to fully control the course of virtual testing, recording any parameters of the vehicle movement, taking into account the “human factor”, as well as complete safety of the experiment. Purpose of research. The purpose of this work is to create a mathematical model of the dynam-ics of a wheeled vehicle, suitable for use in such a complex of full-scale mathematical modeling and assessment of the load of transmission units in conditions close to real operation. Methodology and methods. The proposed model is based on the existing model of the dynamics of a wheeled vehicle developed at Bauman Moscow State Technical University. Within the framework of the model, the dynamics of a vehicle is described as a plane motion of a rigid body in a horizontal plane. The principle of possible displacements is applied to determine the normal reac-tions of the bearing surface. The interaction of the wheel with the ground in the plane of the support base is described using an approach based on the “friction ellipse” concept. To enable the driver and operator of the full-scale mathematical modeling complex to drive a virtual vehicle in “real time” mode, the mathematical model is supplemented with a control system that communicates between the control parameter set by the driver by pressing the accelerator and brake pedals and the control actions of the vehicle's transmission units, such as: an electric machine, an internal combustion en-gine, a hydrodynamic retarder and a brake system. The article presents a block diagram of the de-veloped control algorithm, as well as approbation of the system's operation in a complex of full-scale mathematical modeling. Results and scientific novelty. A mathematical model of the dynamics of a wheeled vehicle was developed. It opens up wide possibilities for studying the modes of operation of the “driver-vehicle-environment” system in “real time”, using a complex of full-scale mathematical modeling. Practical significance. A mathematical model of the dynamics of a wheeled vehicle was devel-oped. It is supplemented with an algorithm for the distribution of traction / braking torques between the transmission units, which provide a connection between the driver's pressing on the accelerator / brake pedal and the control parameters of each of the units.

scholarly journals Real-Time Human in the Loop MBS Simulation in the Fraunhofer Robot-Based Driving Simulator

2014 ◽  
Vol 61 (2) ◽  
pp. 270-285 ◽  
Author(s):  
Michael Kleer ◽  
Andrey Gizatullin ◽  
Klaus Dreßler ◽  
Steffen Müller
Keyword(s):  
Real Time ◽  
Driving Simulator ◽  
Practical Significance ◽  
Time Model ◽  
Test Drive ◽  
The Real ◽  
Transport Delay ◽  
Human In The Loop ◽  
Acceleration Signal ◽  
Time Calculation

Abstract The paper encompasses the overview of hardware architecture and the systems characteristics of the Fraunhofer driving simulator. First, the requirements of the real-time model and the real-time calculation hardware are defined and discussed in detail. Aspects like transport delay and the parallel computation of complex real-time models are presented. In addition, the interfacing of the models with the simulator system is shown. Two simulator driving tests, including a fully interactive rough terrain driving with a wheeled excavator and a test drive with a passenger car, are set to demonstrate system characteristics. Furthermore, the simulator characteristics of practical significance, such as simulator response time delay, simulator acceleration signal bandwidth obtained from artificial excitation and from the simulator driving test, will be presented and discussed.

scholarly journals Optical Spectral Analysis of Real-Time TDDFT Using Maximum Entropy Method

2015 ◽  
Vol 14 (3) ◽  
pp. 71-73 ◽  
Author(s):  
Mitsuki TOOGOSHI ◽  
Satoru S. KANO ◽  
Yasunari ZEMPO
Keyword(s):  
Spectral Analysis ◽  
Maximum Entropy ◽  
Real Time ◽  
Maximum Entropy Method ◽  
Entropy Method
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