scholarly journals Model-Guided Data-Driven Optimization for Automotive Compression Ignition Engine Systems

2019 ◽  
Vol 141 (03) ◽  
pp. S16-S23 ◽  
Author(s):  
Qingyuan Tan ◽  
Xiang Chen ◽  
Ying Tan ◽  
Ming Zheng
Keyword(s):  
Optimization Problems ◽  
Model Parameters ◽  
Compression Ignition Engine ◽  
Automotive Systems ◽  
Model Based ◽  
Expected Performance ◽  
And Control ◽  
Parameter Values ◽  
Engine Systems ◽  
Operating Points

Essentially, the performance improvement of automotive systems is a multi-objective optimization problem [1–4] due to the challenges in both operation management and control. The interconnected dynamics inside the automotive system normally requires precise tuning and coordination of accessible system inputs. In the past, such optimization problems have been approximately solved through expensive calibration procedures or an off-line local model-based approaches where either a regressive model or a first-principle model is used. The model-based optimization provides the advantage of finding the optimal model parameters to allow the model to be used to predict the real system behavior reasonably [5]. However, other than the model complexities, there are practically two issues facing the integrity of these models: modeling uncertainty due to inaccurate parameter values and/or unmodeled dynamics, and locally effective range around operating points. As a result, the optimum solutions extracted from the model-based approach could be subject to failure of expected performance [6].

scholarly journals Simulations of the spread of COVID-19 and control policies in Tunisia

2021 ◽  
Author(s):  
Slimane Ben Miled ◽  
Amira Kebir
Keyword(s):  
Mass Screening ◽  
Tunisian Population ◽  
Model Parameters ◽  
Control Policies ◽  
Model Based ◽  
Asymptomatic Patients ◽  
And Control

Background: On March 11, 2020, the WHO announced that the COVID-19 outbreak had become pandemic, indicating that it was au- tonomous on several continents. Tunisia’s targeted containment and screen- ing strategy aligns with the WHO’s initial guidelines. This method is now showing its limitations. Mass screening in some countries shows that asymptomatic patients play an important role in spreading the virus through the population.Objective: Our goals are first to assess Tunisia’s COVID-19 control policies, and then understand the effect of various detection, quarantine and confinement strategies and the rule of asymptomatic patients on the spread of the virus in the Tunisian population. Methods: We develop and analyze a mathematical and epidemiologi- cal models for COVID- 19 in Tunisia. The data come from the Tunisian Health Commission dataset. Results: We calibrate different parameters of the model based on the Tunisian data, we calculate the expression of the basic reproduction num- ber R0 as a function of the model parameters and, finally, we carry out simulations of interventions and compare different strategies for suppress- ing and controlling the epidemic. Conclusions: We show that Tunisia’s control policies are effective in screening infected and asymptomatic persons.

scholarly journals Estimating the Mosquito Density in Guangzhou city, China

2021 ◽  
Author(s):  
Meili Li ◽  
Xian Zhang ◽  
Junling Ma
Keyword(s):  
Weather Data ◽  
Model Parameters ◽  
Mosquito Density ◽  
Guangzhou City ◽  
Average Temperature ◽  
Index Data ◽  
Fitted Parameter ◽  
Dependent Model ◽  
And Control ◽  
Parameter Values

Mosquito is a vector of many diseases. Predicting the trend of mosquito density is important for early warning and control of mosquito diseases. In this paper, we fit a discrete time mosquito model developed by Gong et al. in 2011, which considers the immature and adult stages, and weather dependent model parameters, to the Breteau Index and Bite Index data for Aedes aegypti in Guangzhou city, China in 2014, as well as the weather data for average temperature, precipitation, evaporation and daylight for the same period. We estimated the model parameters using the Markov Chain Monte-Carlo (MCMC) method. We find that many parameters are not identifiable. We revise and simplify the model so that the parameters of our new model are identifiable. Our results indicate that the model predicted mosquito prevalence agrees well with data. We then use the fitted parameter values against the Breteau Index and Bite Index data for Guangzhou city in 2017 and 2018, and show that the estimated parameter values are applicable for other seasons.

Development of a Jacobian Module for Advanced Pulp and Paper Simulation and Control

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 4-11
Author(s):  
MOHAMED CHBEL ◽  
LUC LAPERRIÈRE
Keyword(s):  
Control System ◽  
Nonlinear Behavior ◽  
Simulation Software ◽  
Pulp And Paper ◽  
Pid Controllers ◽  
Tuning Parameters ◽  
Pid Tuning ◽  
Fixed Set ◽  
And Control ◽  
Operating Points

Pulp and paper processes frequently present nonlinear behavior, which means that process dynam-ics change with the operating points. These nonlinearities can challenge process control. PID controllers are the most popular controllers because they are simple and robust. However, a fixed set of PID tuning parameters is gen-erally not sufficient to optimize control of the process. Problems related to nonlinearities such as sluggish or oscilla-tory response can arise in different operating regions. Gain scheduling is a potential solution. In processes with mul-tiple control objectives, the control strategy must further evaluate loop interactions to decide on the pairing of manipulated and controlled variables that minimize the effect of such interactions and hence, optimize controller’s performance and stability. Using the CADSIM Plus™ commercial simulation software, we developed a Jacobian sim-ulation module that enables automatic bumps on the manipulated variables to calculate process gains at different operating points. These gains can be used in controller tuning. The module also enables the control system designer to evaluate loop interactions in a multivariable control system by calculating the Relative Gain Array (RGA) matrix, of which the Jacobian is an essential part.

Model-based programming tools for integrated monitoring, simulation, diagnosis and control

1993 ◽  
Author(s):  
Gabor Karsai ◽  
Samir Padalkar ◽  
Hubertus Franke ◽  
Janos Sztipanovits
Keyword(s):  
Integrated Monitoring ◽  
Model Based ◽  
Programming Tools ◽  
And Control

SIALIC ACID IN THE PRIMARY AND DIFFERENTIAL DIAGNOSIS OF LUNG CANCER

2017 ◽  
Vol 63 (6) ◽  
pp. 926-932
Author(s):  
Lyudmila Belskaya ◽  
Viktor Kosenok ◽  
Ж. Массард
Keyword(s):  
Lung Cancer ◽  
Enzyme Activity ◽  
Optimization Problems ◽  
Primary Lung Cancer ◽  
Nonparametric Test ◽  
Nonsmall Cell Lung Cancer ◽  
Group Differences ◽  
Diagnosis Of Lung Cancer ◽  
And Control ◽  
Control Study

So far optimization problems for diagnostics and prognostication aids remained relevant for lung cancer as a leader in the structure of cancers. Objective: a search for regularities of changes in the saliva enzyme activity in patients with nonsmall cell lung cancer. In the case-control study, 505 people took part, divided into 2 groups: primary (lung cancer, n=290) and control (conventionally healthy, n=215). All the participants went through a questionnaire survey, saliva biochemical counts, and a histological verification of their diagnosis. The enzyme activity was measured with spectrophotometry. Between-group differences were measured with the nonparametric test. It was shown that in terms of lung cancer, we observe metabolic changes, described with the decreased de Ritis coefficient (p

Model-based Management and Control of the Bioreactions in a Collection System

2018 ◽  
Vol 2018 (13) ◽  
pp. 2700-2708 ◽  
Author(s):  
Lisha Guo ◽  
John Walton ◽  
Sovanna Tik ◽  
Zachary Scott ◽  
Keshab Raj Sharma ◽  
...  
Keyword(s):  
Collection System ◽  
Model Based ◽  
And Control

scholarly journals A Model-Based Tool for Assessing the Impact of Land Use Change Scenarios on Flood Risk in Small-Scale River Systems—Part 1: Pre-Processing of Scenario Based Flood Characteristics for the Current State of Land Use

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 102
Author(s):  
Frauke Kachholz ◽  
Jens Tränckner
Keyword(s):  
Land Use ◽  
River Flow ◽  
Land Use Changes ◽  
Small Rivers ◽  
Small Scale ◽  
Model Parameters ◽  
Ungauged Catchments ◽  
Model Based ◽  
Current State ◽  
The Impact

Land use changes influence the water balance and often increase surface runoff. The resulting impacts on river flow, water level, and flood should be identified beforehand in the phase of spatial planning. In two consecutive papers, we develop a model-based decision support system for quantifying the hydrological and stream hydraulic impacts of land use changes. Part 1 presents the semi-automatic set-up of physically based hydrological and hydraulic models on the basis of geodata analysis for the current state. Appropriate hydrological model parameters for ungauged catchments are derived by a transfer from a calibrated model. In the regarded lowland river basins, parameters of surface and groundwater inflow turned out to be particularly important. While the calibration delivers very good to good model results for flow (Evol =2.4%, R = 0.84, NSE = 0.84), the model performance is good to satisfactory (Evol = −9.6%, R = 0.88, NSE = 0.59) in a different river system parametrized with the transfer procedure. After transferring the concept to a larger area with various small rivers, the current state is analyzed by running simulations based on statistical rainfall scenarios. Results include watercourse section-specific capacities and excess volumes in case of flooding. The developed approach can relatively quickly generate physically reliable and spatially high-resolution results. Part 2 builds on the data generated in part 1 and presents the subsequent approach to assess hydrologic/hydrodynamic impacts of potential land use changes.

scholarly journals Model-Based Slippage Estimation to Enhance Planetary Rover Localization with Wheel Odometry

2021 ◽  
Vol 11 (12) ◽  
pp. 5490
Author(s):  
Anna Maria Gargiulo ◽  
Ivan di Stefano ◽  
Antonio Genova
Keyword(s):  
Inertial Measurement Unit ◽  
Correction Method ◽  
Harsh Environments ◽  
Measurement Unit ◽  
Planetary Rovers ◽  
Model Based ◽  
Accurate Knowledge ◽  
And Control ◽  
Wheeled Vehicles ◽  
Rover Localization

The exploration of planetary surfaces with unmanned wheeled vehicles will require sophisticated software for guidance, navigation and control. Future missions will be designed to study harsh environments that are characterized by rough terrains and extreme conditions. An accurate knowledge of the trajectory of planetary rovers is fundamental to accomplish the scientific goals of these missions. This paper presents a method to improve rover localization through the processing of wheel odometry (WO) and inertial measurement unit (IMU) data only. By accurately defining the dynamic model of both a rover’s wheels and the terrain, we provide a model-based estimate of the wheel slippage to correct the WO measurements. Numerical simulations are carried out to better understand the evolution of the rover’s trajectory across different terrain types and to determine the benefits of the proposed WO correction method.

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