scholarly journals Multi-scale Simulation in Railway Planning and Operation

2012 ◽  
Vol 23 (6) ◽  
pp. 511-517 ◽  
Author(s):  
Yong Cui ◽  
Ullrich Martin
Keyword(s):  
Simulation Model ◽  
Process Simulation ◽  
Level Of Detail ◽  
Smooth Transition ◽  
Simulation Methods ◽  
Multi Scale ◽  
Railway Planning ◽  
The Moment ◽  
Discrete Scaling ◽  
Planning And Operation

Simulation methods are widely used in railway planning and operation. However, at the moment there are no applicable solutions in the process simulation for a smooth transition among different infrastructure levels on the basis of a unified structure with consistent algorithm. In this paper, a multi-scale simulation model is designed with consideration of the level of detail of the investigated infrastructure model and the homogeneity of the processes running in the simulation model. A comprehensive and synthesized view of railway planning and operation is therefore obtained. Within the multi-scale simulation model, railway planning and operation processes can be simulated, evaluated and optimized consistently. KEY WORDS: railway planning, simulation, multi-scale, aggregation, discrete scaling, continuous scaling, homogenous process, inhomogeneous process

Simulation model of the process of functioning and restoration of the network clock network synchronization

2020 ◽  
Vol 4 ◽  
pp. 83-90
Author(s):  
Andrey Kanaev ◽  
◽  
Maria Sakharova ◽  
Evgeny Oparin ◽  
Keyword(s):  
Simulation Model ◽  
Network Synchronization ◽  
Key Indicator ◽  
Clock Network ◽  
Mode Of Transmission ◽  
The Moment

This article provides a simulation model of the process of functioning and restoration of a network clock network (CNS), which is distinguished by the completeness of accounting for the states of the process of functioning of the CNS network. The key indicator of the process of functioning of the CNS network is the duration of the control cycle of the CNS network, which is understood as the time from the moment a failure occurs on the CNS network until the moment the mode of transmission of synchronization signals is restored. On the basis of the developed simulation model of the process of functioning and restoration of the CNS network, the duration of the control cycle of the CNS network is estimated depending on the time spent in individual states of the process of functioning of the TSS network and on the characteristics of individual subsystems of the CNS system. The results obtained can serve as a basis for developing sound strategies and plans for managing the CNS network.

scholarly journals Forgery Detection in Digital Images by Multi-Scale Noise Estimation

2021 ◽  
Vol 7 (7) ◽  
pp. 119
Author(s):  
Marina Gardella ◽  
Pablo Musé ◽  
Jean-Michel Morel ◽  
Miguel Colom
Keyword(s):  
Noise Model ◽  
Correlated Noise ◽  
Forgery Detection ◽  
Color Channel ◽  
Image Block ◽  
Multi Scale ◽  
Compressed Images ◽  
Inconsistency Analysis ◽  
Highly Correlated ◽  
The Moment

A complex processing chain is applied from the moment a raw image is acquired until the final image is obtained. This process transforms the originally Poisson-distributed noise into a complex noise model. Noise inconsistency analysis is a rich source for forgery detection, as forged regions have likely undergone a different processing pipeline or out-camera processing. We propose a multi-scale approach, which is shown to be suitable for analyzing the highly correlated noise present in JPEG-compressed images. We estimate a noise curve for each image block, in each color channel and at each scale. We then compare each noise curve to its corresponding noise curve obtained from the whole image by counting the percentage of bins of the local noise curve that are below the global one. This procedure yields crucial detection cues since many forgeries create a local noise deficit. Our method is shown to be competitive with the state of the art. It outperforms all other methods when evaluated using the MCC score, or on forged regions large enough and for colorization attacks, regardless of the evaluation metric.

Multi-scale flooding hazards evaluation using a nested flood simulation model: Case study of Jamuna River, Bangladesh

2021 ◽  
pp. 1-38
Author(s):  
Masakazu Hashimoto ◽  
Kenji Kawaike ◽  
Tomonori Deguchi ◽  
Shammi Haque ◽  
Arpan Paul ◽  
...  
Keyword(s):  
Simulation Model ◽  
Model Case ◽  
Flood Simulation ◽  
Multi Scale ◽  
Flooding Hazards

scholarly journals A Joint-space Position Control-based Approach to Haptic Rendering of Stiff Objects using Gain Scheduling

2021 ◽  
Vol 103 (3) ◽  
Author(s):  
Yang Wang ◽  
Lei Feng ◽  
Kjell Andersson
Keyword(s):  
Simulation Model ◽  
Position Control ◽  
Gain Scheduling ◽  
Joint Space ◽  
Haptic Rendering ◽  
Smooth Transition ◽  
Position Controller ◽  
Detailed Simulation ◽  
Stability Issues ◽  
Computing Models

AbstractHaptic rendering often deals with interactions between stiff objects. A traditional way of force computing models the interaction using a spring-damper system, which suffers from stability issues when the desired stiffness is high. Instead of computing a force, this paper continues to explore shifting the focus to rendering an interaction with no penetration, which can be accomplished by using a position controller in the joint space using the encoders as feedback directly. In order to make this approach easily adaptable to any device, an alternative way to model the dynamics of the device is also presented, which is to linearize a detailed simulation model. As a family of linearized models is used to approximate the full dynamic model of the system, it is important to have a smooth transition between multiple sets of controller gains generated based on these models. Gain scheduling is introduced to improve the performance in certain areas and a comparison among three controllers is conducted in a simulation setup.

scholarly journals Simulation model of a pulsed spiral hydro-mechanical energy converter in the heat supply system of a building

2020 ◽  
Vol 10 (3) ◽  
pp. 388-397
Author(s):  
Anton A. Golyanin ◽  
◽  
Aleksey P. Levtsev ◽  
Anton V. Vdovin ◽  
◽  
...  
Keyword(s):  
Simulation Model ◽  
Water Pressure ◽  
Mechanical Energy ◽  
Heat Supply System ◽  
Design Parameters ◽  
Energy Converter ◽  
Electric Generator ◽  
Flow Energy ◽  
The Moment ◽  
Experimental Values

The objective was to develop a mathematical simulation model of a pulsed spiral hydro-mechanical flow energy converter with a variable speed operating in a pulsed mode. This simulation model can be used for calculating the optimal parameters of such devices. The mechanical energy generated by pulsed liquid can be applied in the driving gear of mini-hydroelectric generators working without drops in water pressure, pumping stations and heat networks providing pressure reduction, as well as in heater fans operating in damp or explosion-hazardous facilities. Pulsed spiral hydro-mechanical energy converters can be used for converting the energy of a liquid flow into rotational motion, which can be further transferred to an electric generator or capacitor. In this study, using the example of a hydro-mechanical converter with a cone-shaped coil, the equations of torque depending on the change in the frequency of flow interruption, the moment of inertia and the resistance in the supports were obtained. Design charts were built for the torque of a hydro-mechanical converter with a cone-shaped coil for a number of coil turns equal to 4 pcs., square tube section 0.00011 m2, and the length of the initial round 0.176 m. The validity of the equations was confirmed by a physical experiment with sufficient accuracy. The conducted comparison of simulated and experimental values showed their agreement with an error of less than 5%. According to the simulation results, design parameters for different models have their own characteristics.

scholarly journals Multiproduct biorefinery optimal design: application to the acetone-butanol-ethanol system

2020 ◽  
Vol 75 ◽  
pp. 9 ◽  
Author(s):  
Ségolène Belletante ◽  
Ludovic Montastruc ◽  
Michel Meyer ◽  
Heri Hermansyah ◽  
Stéphane Negny
Keyword(s):  
Decision Support ◽  
Optimal Design ◽  
Process Simulation ◽  
Decision Support Tool ◽  
Energy Integration ◽  
Support Tool ◽  
Multi Scale ◽  
Acetone Butanol Ethanol ◽  
Ethanol System

The bioproduct from biomass appears to be major interests for future years given the spectacular and fast advances in microbiology. But the industrial developments of the new bioproducts production struggle to follow this constant and massive creation. Therefore, to estimate the potential of new bioproducts is necessary to pre-design biorefineries with the highest relevance. This study proposes a methodology assessing the relevance of such industrialized production. The presented tool is a multi-scale methodology describing a decision-support tool for the determination of an optimal biorefinery from a superstructure through process simulation, and economic and environmental evaluations. To optimize the biorefinery, energy integration is also applied on the selected processes, because a biorefinery needs a large amount of energy to operate, especially in the pretreatment and purification steps of the process due to huge water flowrate. Thus, the tool designs an efficient, profitable and sustainable biorefinery. We demonstrate our methodology capabilities with the acetone, butanol and ethanol production (ABE system) from lignocellulosic biomass, especially from wood wastes.

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