A General Methodology for Optimized Takagi-Sugeno Fuzzy Modeling of Nonlinear Continuous Fermenter for Biofuels (Ethanol) Production Using Golden Section Search Approach

2014 ◽  
Author(s):  
Alfredo Diaz Jacome ◽  
Marco Sanjuan Mejia
Keyword(s):  
Experimental Data ◽  
Ethanol Production ◽  
Search Algorithm ◽  
Golden Section ◽  
Nonlinear Behavior ◽  
Fuzzy Modeling ◽  
Biodiesel Production ◽  
Inference System ◽  
General Methodology ◽  
Highly Nonlinear

The overcoming inclusion of biotechnology in biofuels industry involves several challenges among which are found the variety of operational cycles, the highly nonlinear behavior of the processes and the need for measurement of intermediate variables. In order to reproduce biological conversion of biodiesel production discharge products into other biofuels, experimental data from ethanol production from glycerol/glucose mixture was analyzed implementing fuzzy techniques to investigate and model the nonlinear behavior of the process. This paper presents a general methodology for TS fuzzy modeling based on a novel approach on data structured regression which consists on combination of fuzzy c-regression model and clustering using a golden search algorithm approach to adjust the proper number of membership functions to fit the model and minimize the statistic difference among the experimental data, simulated data and the Fuzzy Inference System results.

scholarly journals Prediction of dissolved oxygen in reservoirs using adaptive network-based fuzzy inference system

2011 ◽  
Vol 14 (1) ◽  
pp. 167-179 ◽  
Author(s):  
Vesna Ranković ◽  
Jasna Radulović ◽  
Ivana Radojević ◽  
Aleksandar Ostojić ◽  
Ljiljana Čomić
Keyword(s):  
Experimental Data ◽  
Water Quality ◽  
Dissolved Oxygen ◽  
Fuzzy Inference System ◽  
Fuzzy Inference ◽  
Adaptive Network ◽  
Inference System ◽  
Fuzzy Models ◽  
Highly Nonlinear ◽  
Input Variables

Predicting water quality is the key factor in the water quality management of reservoirs. Since a large number of factors affect the water quality, traditional data processing methods are no longer good enough for solving the problem. The dissolved oxygen (DO) level is a measure of the health of the aquatic system and its prediction is very important. DO dynamics are highly nonlinear and artificial intelligence techniques are capable of modelling this complex system. The objective of this study was to develop an adaptive network-based fuzzy inference system (ANFIS) to predict the DO in the Gruža Reservoir, Serbia. The fuzzy model was developed using experimental data which were collected during a 3-year period. The input variables analysed in this paper are: water pH, water temperature, total phosphate, nitrites, ammonia, iron, manganese and electrical conductivity. The selection of an appropriate set of input variables is based on the building of ANFIS models for each possible combination of input variables. Results of fuzzy models are compared with measured data on the basis of correlation coefficient, mean absolute error and mean square error. Comparing the predicted values by ANFIS with the experimental data indicates that fuzzy models provide accurate results.

Fuzzy Modeling of a Nonlinear Continuous Fermentation Bioreactor for Ethanol Production

2012 ◽  
Author(s):  
Alfredo Díaz Jácome ◽  
Marco Sanjuan
Keyword(s):  
Ethanol Production ◽  
Fuzzy Inference ◽  
Continuous Fermentation ◽  
Nonlinear Behavior ◽  
Correlation Factor ◽  
Inlet Temperature ◽  
Kinetics Parameters ◽  
Inference System ◽  
Fuzzy Techniques ◽  
Basic Equations

Ethanol production from glucose was analyzed implementing fuzzy techniques to investigate and model the nonlinear behavior of the process. The model simulated involves the basic equations of a chemostat including the dependence of kinetics parameters on temperature and mass transfer of oxygen. For the identification of nonlinearities. Steady-state values for inlet temperature, the flow of refrigerant and the initial concentration of substrate are 25 ° C, 18 L / h and 60 g / L glucose, respectively. The implementation of the Fuzzy Inference System (FIS) was based on a Mamdani inference engine, and also that the defuzzification method implemented was centroid and the weight of the trapeziums describing the output from 15 to 30 g/L affects considerably. After evaluating and comparing the results of the simulation with FIS results, and calculating the correlation between Predicted and Expected values, it is concluded that correlation factor for the entire simulation and FIS was around 0.9. The lack of fitness is evaluated and analyzed after the comparison of results.

On the Optimal Precoder Design for Energy-Efficient and Secure MIMO Systems

2017 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Tung T. Vu ◽  
Ha Hoang Kha
Keyword(s):  
Energy Efficiency ◽  
Mimo Systems ◽  
Search Algorithm ◽  
Multiple Input Multiple Output ◽  
Research Work ◽  
Computational Cost ◽  
Optimal Solution ◽  
Secrecy Rate ◽  
Highly Nonlinear ◽  
Precoder Design

In this research work, we investigate precoder designs to maximize the energy efficiency (EE) of secure multiple-input multiple-output (MIMO) systems in the presence of an eavesdropper. In general, the secure energy efficiency maximization (SEEM) problem is highly nonlinear and nonconvex and hard to be solved directly. To overcome this difficulty, we employ a branch-and-reduce-and-bound (BRB) approach to obtain the globally optimal solution. Since it is observed that the BRB algorithm suffers from highly computational cost, its globally optimal solution is importantly served as a benchmark for the performance evaluation of the suboptimal algorithms. Additionally, we also develop a low-complexity approach using the well-known zero-forcing (ZF) technique to cancel the wiretapped signal, making the design problem more amenable. Using the ZF based method, we transform the SEEM problem to a concave-convex fractional one which can be solved by applying the combination of the Dinkelbach and bisection search algorithm. Simulation results show that the ZF-based method can converge fast and obtain a sub-optimal EE performance which is closed to the optimal EE performance of the BRB method. The ZF based scheme also shows its advantages in terms of the energy efficiency in comparison with the conventional secrecy rate maximization precoder design.

Fuzzy Modeling to Simulate Surface Roughness in CNC Turning of AISI 1045 Steel

2011 ◽  
Vol 486 ◽  
pp. 262-265
Author(s):  
Amit Kohli ◽  
Mudit Sood ◽  
Anhad Singh Chawla
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Process Parameters ◽  
Fuzzy Model ◽  
Fuzzy Modeling ◽  
Cnc Machine ◽  
Model Based ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
1045 Steel

The objective of the present work is to simulate surface roughness in Computer Numerical Controlled (CNC) machine by Fuzzy Modeling of AISI 1045 Steel. To develop the fuzzy model; cutting depth, feed rate and speed are taken as input process parameters. The predicted results are compared with reliable set of experimental data for the validation of fuzzy model. Based upon reliable set of experimental data by Response Surface Methodology twenty fuzzy controlled rules using triangular membership function are constructed. By intelligent model based design and control of CNC process parameters, we can enhance the product quality, decrease the product cost and maintain the competitive position of steel.

Benchmark of a Novel Aero-Elastic Simulation Code for Small Scale VAWT Analysis

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
David Marten ◽  
Matthew Lennie ◽  
George Pechlivanoglou ◽  
Christian Oliver Paschereit ◽  
Alessandro Bianchini ◽  
...  
Keyword(s):  
Experimental Data ◽  
Wind Turbine ◽  
Open Source ◽  
Structural Model ◽  
Element Model ◽  
Small Scale ◽  
Elastic Model ◽  
Element Analysis ◽  
Simulation Code ◽  
Highly Nonlinear

After almost 20 years of absence from research agendas, interest in the vertical axis wind turbine (VAWT) technology is presently increasing again, after the research stalled in the mid 90's in favor of horizontal axis wind turbines (HAWTs). However, due to the lack of research in past years, there are a significantly lower number of design and certification tools available, many of which are underdeveloped if compared to the corresponding tools for HAWTs. To partially fulfill this gap, a structural finite element analysis (FEA) model, based on the Open Source multiphysics library PROJECT::CHRONO, was recently integrated with the lifting line free vortex wake (LLFVW) method inside the Open Source wind turbine simulation code QBlade and validated against numerical and experimental data of the SANDIA 34 m rotor. In this work, some details about the newly implemented nonlinear structural model and its coupling to the aerodynamic solver are first given. Then, in a continuous effort to assess its accuracy, the code capabilities were here tested on a small-scale, fast-spinning (up to 450 rpm) VAWT. The study turbine is a helix shaped, 1 kW Darrieus turbine, for which other numerical analyses were available from a previous study, including the results coming from both a one-dimensional beam element model and a more sophisticated shell element model. The resulting data represented an excellent basis for comparison and validation of the new aero-elastic coupling in QBlade. Based on the structural and aerodynamic data of the study turbine, an aero-elastic model was then constructed. A purely aerodynamic comparison to experimental data and a blade element momentum (BEM) simulation represented the benchmark for QBlade aerodynamic performance. Then, a purely structural analysis was carried out and compared to the numerical results from the former. After the code validation, an aero-elastically coupled simulation of a rotor self-start has been performed to demonstrate the capabilities of the newly developed model to predict the highly nonlinear transient aerodynamic and structural rotor response.

scholarly journals A Unified Analysis for the Free Vibration of the Sandwich Piezoelectric Laminated Beam with General Boundary Conditions under the Thermal Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Guohua Gao ◽  
Ningze Sun ◽  
Dong Shao ◽  
Yongqiang Tao ◽  
Wei Wu
Keyword(s):  
Free Vibration ◽  
Boundary Conditions ◽  
Thermal Environment ◽  
Search Algorithm ◽  
Golden Section ◽  
Shear Deformation Theory ◽  
Simulation Software ◽  
Elastic Boundary ◽  
Piezoelectric Beam ◽  
Elastic Boundary Conditions

This article mainly analyzes the free vibration characteristic of the sandwich piezoelectric beam under elastic boundary conditions and thermal environment. According to the first-order shear deformation theory and Hamilton’s principle, the thermo-electro-elastic coupling equations of the sandwich piezoelectric beam are obtained. Meanwhile, elastic boundary conditions composed of an array of springs are introduced, and the displacement variables and external potential energy of the beam are expressed as wave functions. By using the method of reverberation-ray matrix to integrate and solve the governing equations, a search algorithm based on golden-section search is introduced to calculate the required frequency parameters. A series of numerical results are compared with those reported in literature studies and obtained by simulation software to verify the correctness and versatility of the search algorithm. In addition, three parametric research cases are proposed to investigate the frequency parameters of sandwich piezoelectric beams with elastic restraint conditions, material parameters, thickness ratio, different temperature rises, and external electric potential.

Extreme Value Statistics of Large Container Ship Roll

2016 ◽  
Vol 60 (02) ◽  
pp. 92-100
Author(s):  
Oleg Gaidai ◽  
Gaute Storhaug ◽  
Arvid Naess
Keyword(s):  
Nonlinear Behavior ◽  
Extreme Value Statistics ◽  
Ship Motions ◽  
Primary Concern ◽  
Container Ship ◽  
Highly Nonlinear ◽  
Extreme Response ◽  
Measured Time ◽  
Time Histories ◽  
Large Container

The paper describes a method for prediction of large container ship extreme roll angles occurring during sailing in harsh weather. Rolling is coupled with other ship motions and exhibits highly nonlinear behavior. Risk of losing containers due to a large roll is primary concern for ship transport. Because of non-stationarity and complicated nonlinearities of both waves and ship motions, it is a considerable challenge to model such a phenomenon. In case of extreme motions, the role of nonlinearities dramatically increases, activating effects of second and higher order. Moreover, laboratory tests may also be questioned because of the scaling and the sea state choice. Therefore, data measured on actual ships during their voyages in harsh weather provide a unique insight into statistics of ship motions. The aim of this work is to benchmark state of art method, which makes it possible to extract the necessary information about the extreme response from onboard measured time histories. The method proposed in this paper opens up the possibility to predict simply and efficiently both short- and long-term extreme response statistics.

Numerical Modeling of Time-Dependent Deformations of Concrete at 3D Analysis of Structures

2020 ◽  
Author(s):  
◽  
Ante Džolan
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Concrete Structures ◽  
Real Life ◽  
Nonlinear Behavior ◽  
3D Analysis ◽  
Actual Behavior ◽  
Realistic Simulation ◽  
Highly Nonlinear ◽  
Prestressed Structures

Concrete is a material with highly nonlinear behavior. In parallel, there are numerous secondary effects in concrete, such as aging, shrinkage, and creep, which further complicate the realistic simulation of reinforced concrete and prestressed concrete structures. In modern times, due to bolder construction, increasing spans and high rising construction, the need for realistic simulation of the behavior of concrete structures under conditions of various types of loads is becoming more pronounced. On the other hand, models with a small number of real-life parameters that can describe the actual behavior of concrete as accurately as possible are necessary. One such model, the previously developed model Precon 3D, which is based on a small number of parameters and can very well describe the behavior of concrete, reinforced concrete and prestressed structures for short-term static loads was taken as the basis for this work. Through this work, the numerical model Precon 3D has been upgraded with a model for following the behavior of concrete during time, i.e. the model has been upgraded with a model of creep and shrinkage of concrete, which is necessary for following the behavior of prestressed structures. The developed software has been tested against several experimental examples from the literature, with a very good match between numerical and experimental results.

scholarly journals Takagi-Sugeno Fuzzy Modeling and PSO-Based Robust LQR Anti-Swing Control for Overhead Crane

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Xuejuan Shao ◽  
Jinggang Zhang ◽  
Xueliang Zhang
Keyword(s):  
Linear Quadratic Regulator ◽  
Pso Algorithm ◽  
Fuzzy Modeling ◽  
Linear Matrix ◽  
Feedback Gain ◽  
Overhead Crane ◽  
Linear Quadratic ◽  
Highly Nonlinear ◽  
The Stability ◽  
Takagi Sugeno

The dynamic model of overhead crane is highly nonlinear and uncertain. In this paper, Takagi-Sugeno (T-S) fuzzy modeling and PSO-based robust linear quadratic regulator (LQR) are proposed for anti-swing and positioning control of the system. First, on the basis of sector nonlinear theory, the two T-S fuzzy models are established by using the virtual control variables and approximate method. Then, considering the uncertainty of the model, robust LQR controllers with parallel distributed compensation (PDC) structure are designed. The feedback gain matrices are obtained by transforming the stability and robustness of the system into linear matrix inequalities (LMIs) problem. In addition, particle swarm optimization (PSO) algorithm is used to overcome the blindness of LQR weight matrix selection in the design process. The proposed control methods are simple, feasible, and robust. Finally, the numeral simulations are carried out to prove the effectiveness of the methods.

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