1,954 results
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2. Experimental Study on Forecasting Mathematical Model of Drying Shrinkage of Recycled Aggregate Concrete
- Author
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Yuanchen Guo and Xue Wang
- Subjects
Aggregate (composite) ,Article Subject ,Waste management ,lcsh:Mathematics ,General Mathematics ,General Engineering ,lcsh:QA1-939 ,Pulp and paper industry ,Drying time ,lcsh:TA1-2040 ,Error analysis ,Fly ash ,lcsh:Engineering (General). Civil engineering (General) ,Expansive ,Mathematics ,Shrinkage - Abstract
On the basis of basic law in AASHTO2007 model, the forecasting mathematical model of drying shrinkage of recycled aggregate concrete (RAC) is established by regression analysis and experimental study. The research results show that (1) with the replacement rate of RCA increases, the drying shrinkage value of RAC increases; this trend is even more obvious in the early drying time. (2) The addition of fly ash can inhibit the drying shrinkage of RAC, but the effect is not very obvious. Specifically, the addition of fly ash will increase the shrinkage to some extent when the mixing amount is 20%. (3) The addition of expansive agent can obviously inhibit the shrinkage of RAC; the inhibition affection is better than that of fly ash. (4) The forecasting mathematical models of drying shrinkage of RAC established in this paper have high accuracy and rationality according to experiment validation and error analysis.
- Published
- 2012
3. Investigation of NIR spectra pre-processing methods combined with multivariate regression for determination of moisture in powdered industrial egg
- Author
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Douglas Fernandes Barbin, Suzana Lucy Nixdorf, Vinicius Ricardo Acquaro Junior, Lycio Shinji Watanabe, Tiago Bervelieri Madeira, and Yuri Renan Bovolenta
- Subjects
Multivariate statistics ,General Computer Science ,General Mathematics ,near-infrared spectroscopy (NIRS) ,General Physics and Astronomy ,Shelf life ,Chemometrics ,thermobalance ,Partial least squares regression ,Sample preparation ,calibration model ,lcsh:Science (General) ,Water content ,Mathematics ,Moisture ,General Engineering ,General Chemistry ,chemometrics ,Pulp and paper industry ,lcsh:TA1-2040 ,oven reference method ,PLS ,General Earth and Planetary Sciences ,Principal component regression ,Química Analítica ,lcsh:Engineering (General). Civil engineering (General) ,lcsh:Q1-390 - Abstract
High productivity and meantime perishability of in natura eggs, make powdered egg attractive for patisseries and pasta industries. Water reduction in 65%, extends shelf life from 1 to 12 months, preventing also Salmonella . Maximum powdered egg moisture allowed by Brazilian law is 6.0% (w w -1 ). However, its determination by reference technique (oven at 105 o C for 8 hour) is lengthy for processing industry. Therefore, the purpose of this study was to investigate the influence of several spectral pre-processing techniques in the application of near-infrared spectroscopy associated with chemometrics models for determination of moisture content in powdered egg, without the need of sample preparation and destruction, held at 0.5 min. Several pre-treatment techniques were evaluated to ensure spectral data reliability such as: standard normal variation; multiplicative scatter correction; smoothing and detrend. The principal component regression (PCR) and partial least squares (PLS) were evaluated with and without pre-treatment. The best results were observed in NIR/PLS model (49 samples), providing an adequate correlation (r) of 0.96, for cross-validation. Using 21 samples as prediction set, NIR/PLS showed relative error (RE) < 2.0%, compared to primary methods oven and thermobalance, indicating to be suitable for industrial quality control.
- Published
- 2018
4. Representing Smoothed Spectrum Estimate with the Cauchy Integral
- Author
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Ming Li
- Subjects
Signal processing ,Quantitative Biology::Neurons and Cognition ,Article Subject ,Physics::Instrumentation and Detectors ,lcsh:Mathematics ,General Mathematics ,Astrophysics::High Energy Astrophysical Phenomena ,Short paper ,Mathematical analysis ,Spectrum (functional analysis) ,General Engineering ,Spectral density ,lcsh:QA1-939 ,Computer Science::Numerical Analysis ,lcsh:TA1-2040 ,Physics::Space Physics ,lcsh:Engineering (General). Civil engineering (General) ,Cauchy's integral formula ,Mathematics - Abstract
Estimating power spectrum density (PSD) is essential in signal processing. This short paper gives a theorem to represent a smoothed PSD estimate with the Cauchy integral. It may be used for the approximation of the smoothed PSD estimate.
- Published
- 2012
- Full Text
- View/download PDF
5. Optimisation of the alcoholic fermentation of aqueous jerivá pulp extract
- Author
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Sandra Regina Masetto Antunes, Dionísio Borsato, Pedro Henrique Weirich Neto, Rodolfo Lopes Coppo, Silvia Borba, and Guilherme Arielo Rodrigues Maia
- Subjects
experimental design ,General Computer Science ,General Mathematics ,General Physics and Astronomy ,engineering.material ,Ethanol fermentation ,yeast ,chemistry.chemical_compound ,Yeast extract ,Response surface methodology ,lcsh:Science (General) ,Mathematics ,Aqueous solution ,Chromatography ,Ethanol ,Pulp (paper) ,General Engineering ,General Chemistry ,Factorial experiment ,Yeast ,simplex optimisation ,chemistry ,lcsh:TA1-2040 ,engineering ,General Earth and Planetary Sciences ,lcsh:Engineering (General). Civil engineering (General) ,lcsh:Q1-390 - Abstract
The objective of this research is to determinate the optimum conditions for the alcoholic fermentation process of aqueous jerivá pulp extract using the response surface methodology and simplex optimisation technique. The incomplete factorial design 3³ was applied with the yeast extract, NH4H2PO4 and yeast as the independent variables and the alcohol production yield as the response. The regression analysis indicated that the model is predictive, and the simplex optimisation generated a formulation containing 0.35 g L-1 yeast extract, 6.33 g L-1 yeast and 0.30 g L-1NH4H2PO4 for an optimum yield of 85.40% ethanol. To validate the predictive equation, the experiment was carried out in triplicate under optimum conditions, and an average yield of 87.15% was obtained. According to a t-test, no significant difference was observed (on the order of 5%) between the average value obtained and the value indicated by the simplex optimisation technique. The objective of this research is to determinate the optimum conditions for the alcoholic fermentation process of aqueous jerivá pulp extract using the response surface methodology and simplex optimisation technique. The incomplete factorial design 3³ was applied with the yeast extract, NH4H2PO4 and yeast as the independent variables and the alcohol production yield as the response. The regression analysis indicated that the model is predictive, and the simplex optimisation generated a formulation containing 0.35 g L-1 yeast extract, 6.33 g L-1 yeast and 0.30 g L-1 NH4H2PO4 for an optimum yield of 85.40% ethanol. To validate the predictive equation, the experiment was carried out in triplicate under optimum conditions, and an average yield of 87.15% was obtained. According to a t-test, no significant difference was observed (on the order of 5%) between the average value obtained and the value indicated by the simplex optimisation technique.
- Published
- 2014
6. Parameter Identification of Tractor-Semitrailer Model under Steering and Braking
- Author
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Qin Shi, Yiming Li, and Duoyang Qiu
- Subjects
Tractor ,0209 industrial biotechnology ,business.product_category ,Article Subject ,General Mathematics ,02 engineering and technology ,020901 industrial engineering & automation ,0203 mechanical engineering ,Control theory ,Genetic algorithm ,medicine ,Mathematics ,lcsh:Mathematics ,Yaw ,General Engineering ,Stiffness ,020302 automobile design & engineering ,lcsh:QA1-939 ,Axle ,lcsh:TA1-2040 ,Lookup table ,medicine.symptom ,lcsh:Engineering (General). Civil engineering (General) ,business ,Test data ,Interpolation - Abstract
This paper describes a valuable linear yaw-roll tractor-semitrailer (TST) model with five-degree-of-freedom (DOFs) for control algorithm development when steering and braking. The key parameters, roll stiffness, axle cornering stiffness, and fifth-wheel stiffness, are identified by the genetic algorithm (GA) and multistage genetic algorithm (MGA) based on TruckSim outputs to increase the accuracy of the model. Thus, the key parameters of the simplified model can be modified according to the real-time vehicle states by online lookup table and interpolation. The TruckSim vehicle model is built referring to the real tractor (JAC-HFC4251P1K7E33ZTF6×2) and semitrailer (Luyue LHX9406) used in the field test later. The validation of the linear yaw-roll model of a tractor-semitrailer using field test data is presented in this paper. The field test in the performance testing ground is detailed, and the test data of roll angle, roll rate, and yaw rate are compared with the outputs of the model with maps of the key parameters. The results indicate that the error of the tractor’s roll angle and semitrailer’s roll angle between model data and test data is 1.13% and 1.24%, respectively. The roll rate and yaw rate of the tractor and semitrailer are also in good agreement.
- Published
- 2019
7. Model of Automobile Parts Sale Prediction Based on Nonlinear Periodic Gray GM(1,1) and Empirical Research
- Author
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Canlin Wang and Lixiong Gong
- Subjects
Article Subject ,Differential equation ,lcsh:Mathematics ,020209 energy ,General Mathematics ,General Engineering ,02 engineering and technology ,lcsh:QA1-939 ,Nonlinear system ,Empirical research ,lcsh:TA1-2040 ,Approximation error ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,lcsh:Engineering (General). Civil engineering (General) ,Gray (horse) ,Algorithm ,Mathematics - Abstract
The traditional predictive method cannot fully reflect the complex nonlinear characteristics and regularities of automobile and parts sales data, so the prediction precision is not high. The purpose of this paper is to propose the gray GM(1,1) nonlinear periodic predictive model by introducing the seasonal variation index to improve predictive accuracy of the single GM(1,1) model. Firstly, the paper analyzes concept of GM(1,1) and then proposes the gray GM(1,1) nonlinear periodic predictive model to forecast automobile parts sales. The model algorithm used gray theory and accumulated technology to generate new data and set up unified differential equations to find the fitting curve of automobile parts sales prediction by the seasonal variation index to remove random elements. Lastly, the gray GM(1,1) nonlinear periodic predictive model is used for empirical analysis; the result of example shows that the model proposed in the paper is feasible. The superiority of the proposed predictive model compared with the single gray GM(1,1) model is demonstrated. The reliability of this model is experienced by the accuracy test, which provides a theoretical guidance for the prediction of automobile part sales. And the average relative error is reduced by 8.52% compared with the single GM(1,1) model.
- Published
- 2019
8. Active-Side Calculation Method for a Backhoe Hydraulic Excavator with Incomplete Digging Resistance in a Normal State
- Author
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Liu Jurong, Zhang Junfeng, Sun Haoran, Ren Zhigui, Wang Junli, Liang Yang, and Jin Chen
- Subjects
0209 industrial biotechnology ,Article Subject ,General Mathematics ,02 engineering and technology ,Kinematics ,law.invention ,Stress (mechanics) ,020901 industrial engineering & automation ,Position (vector) ,law ,Mathematics ,Backhoe loader ,Normal force ,business.industry ,lcsh:Mathematics ,General Engineering ,04 agricultural and veterinary sciences ,Structural engineering ,lcsh:QA1-939 ,Digging ,Excavator ,lcsh:TA1-2040 ,040103 agronomy & agriculture ,Bending moment ,0401 agriculture, forestry, and fisheries ,lcsh:Engineering (General). Civil engineering (General) ,business - Abstract
The digging resistance in a normal state is the key to excavator design and automated excavation. It is difficult to accurately predict, simulate, or directly measure the digging resistance in a normal state due to uncertainties in the soil properties and excavation parameters. In this paper, a research idea is proposed that uses the working device as the entry point to indirectly calculate the digging resistance in a normal state by measuring the motion parameters and the cylinder pressure intensity. Based on the rule of combination for spatial force systems, a method for combining and projecting the system of the digging resistance is proposed in which the system is projected as six parts, and the tangential force, normal force, and bending moment in the plane of symmetry of the working device are the objects of the solution to avoid redundant equations. Based on kinematics and dynamics models of the excavator and the force and moment equilibrium conditions of the working device, equations for the active-side calculation of the incomplete digging resistance are derived. Based on these equations, the motion parameters of the working device and data on the cylinder pressure intensity obtained by measurement are used to calculate the incomplete digging resistance. The validation scheme and process proposed use the incomplete digging resistance as the external load to obtain the simulated stress of the working device through transient analysis. The simulated stress and the measured stress corresponding to the position of the measurement point are extracted and compared. The results show that there is a difference in the size of the numerical value between the simulated and measured stress, but the variation law is highly consistent, which validates the calculation method. In this paper, an active-side calculation method is provided for the incomplete digging resistance in a normal state without considering the soil-tool interaction relationships, which lays a theoretical foundation for the study of the digging resistance characteristics in a normal state, as well as excavator design and automated excavation.
- Published
- 2019
9. Stabilization of Discrete-Time Delayed Systems in Presence of Actuator Saturation Based on Wirtinger Inequality
- Author
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Richa Negi, Quanxin Zhu, and Vipin Chandra Pal
- Subjects
Convex hull ,0209 industrial biotechnology ,Article Subject ,Stability criterion ,lcsh:Mathematics ,General Mathematics ,General Engineering ,Linear matrix inequality ,02 engineering and technology ,lcsh:QA1-939 ,020901 industrial engineering & automation ,Discrete time and continuous time ,lcsh:TA1-2040 ,Computer Science::Systems and Control ,Control theory ,Control system ,Full state feedback ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Convex combination ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
This paper examines the stability analysis of discrete-time control systems particularly during the event of actuator saturation and time-varying state delay. With the help of Wirtinger inequality along with Lyapunov-Krasovskii functional gain of state feedback controller is determined for stabilization of above system. The saturation nonlinearity is represented in the terms of convex hull. A new linear matrix inequality (LMI) criterion is settled with reciprocally convex combination based inequality which is dependent on delay. The proposed criterion is less conservative in concern to increase the delay bound and a controller is also simulated for real time problem of missile control system in this paper. It is also attained that projected stability criterion is less conservative compared to other outcomes. Furthermore, an optimization procedure together with LMI constraints has been proposed to maximize the attraction of domain.
- Published
- 2019
10. Algebraic Formulation for Moderately Thick Elastic Frames, Beams, Trusses, and Grillages within Timoshenko Theory
- Author
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Wojciech Gilewski and Jan Pełczyński
- Subjects
Article Subject ,Plane (geometry) ,lcsh:Mathematics ,General Mathematics ,Mathematical analysis ,Diagonal ,0211 other engineering and technologies ,General Engineering ,Truss ,02 engineering and technology ,lcsh:QA1-939 ,021001 nanoscience & nanotechnology ,Space (mathematics) ,Matrix (mathematics) ,Algebraic equation ,lcsh:TA1-2040 ,021105 building & construction ,Compressibility ,Algebraic number ,lcsh:Engineering (General). Civil engineering (General) ,0210 nano-technology ,Mathematics - Abstract
The paper is dedicated to the algebraic formulation of elastic frame equations. The obtained set of equations describe deformations of moderately thick frames made of both compressible and incompressible bars, grillages of rigid or pin-joined connections, and trusses. Plane as well as space structures are presented. The paper is an extension of the article of T. Lewiński written in 2001 related to thin bars. Algebraic equations with diagonal constitutive matrix are original and suitable for various engineering applications and for educational purposes.
- Published
- 2019
11. Application of Adomian Decomposition Method to Bounded and Unbounded Stokes’ Problems
- Author
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Ray-Yeng Yang and Chi-Min Liu
- Subjects
Article Subject ,lcsh:Mathematics ,General Mathematics ,General Engineering ,02 engineering and technology ,Function (mathematics) ,lcsh:QA1-939 ,01 natural sciences ,010305 fluids & plasmas ,Exact solutions in general relativity ,Flow (mathematics) ,lcsh:TA1-2040 ,Bounded function ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Applied mathematics ,Padé approximant ,020201 artificial intelligence & image processing ,Boundary value problem ,lcsh:Engineering (General). Civil engineering (General) ,Adomian decomposition method ,Variable (mathematics) ,Mathematics - Abstract
The well-known Stokes’ problems are reexamined by applying the Adomian decomposition method (ADM) associated with other mathematical techniques in this paper. Both the finite-depth (bounded) and infinite-depth (unbounded) cases are analyzed. The present paper raises and deals with two major concerns. The first one is that, for Stokes’ problems, it lacks one boundary condition at the expansion point to fully determine all coefficients of the ADM solution in which an unknown function appears. This unknown function which is dependent on the transformed variable will be determined by the boundary condition at the far end. The second concern is that the derived solution begins to deviate from the exact solution as the spatial variable grows for the unbounded problems. This can be greatly improved by introducing the Padé approximant to satisfy the boundary condition at the far end. For the second problems, the derived ADM solution can be easily separated into the steady-state and the transient parts for a deeper comprehension of the flow. The present result shows an excellent agreement with the exact solution. The ADM is therefore verified to be a reliable mathematical method to analyze Stokes’ problems of finite and infinite depths.
- Published
- 2018
12. FTS and FTB of Conformable Fractional Order Linear Systems
- Author
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Omar Naifar, Bao-wei Wu, Mohamed Ali Hammami, and Abdellatif Ben Makhlouf
- Subjects
0209 industrial biotechnology ,Article Subject ,lcsh:Mathematics ,General Mathematics ,Linear system ,General Engineering ,Order (ring theory) ,010103 numerical & computational mathematics ,02 engineering and technology ,Conformable matrix ,lcsh:QA1-939 ,01 natural sciences ,Stability (probability) ,Fractional calculus ,020901 industrial engineering & automation ,lcsh:TA1-2040 ,Control theory ,0101 mathematics ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
In this paper, an extension of some existing results related to finite-time stability (FTS) and finite-time boundedness (FTB) into the conformable fractional derivative is presented. Illustrative example is presented at the end of the paper to show the effectiveness of the proposed result.
- Published
- 2018
13. Novel Two-Stage Method for Low-Order Polynomial Model
- Author
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Xiuli Shen, Cheng Yan, and Fushui Guo
- Subjects
Surface (mathematics) ,Polynomial ,Article Subject ,lcsh:Mathematics ,General Mathematics ,0211 other engineering and technologies ,General Engineering ,Sampling (statistics) ,Statistical model ,02 engineering and technology ,lcsh:QA1-939 ,Nonlinear system ,020303 mechanical engineering & transports ,Polynomial and rational function modeling ,0203 mechanical engineering ,lcsh:TA1-2040 ,Applied mathematics ,Response surface methodology ,lcsh:Engineering (General). Civil engineering (General) ,Engineering design process ,021106 design practice & management ,Mathematics - Abstract
One of the most popular statistical models is a low-order polynomial response surface model, i.e., a polynomial of first order or second order. These polynomials can be used for global metamodels in weakly nonlinear simulation to approximate their global tendency and local metamodels in response surface methodology (RSM), which has been studied in various applications in engineering design and analysis. The order of the selected polynomial determines the number of sampling points (input combinations) and the resulting accuracy (validity, adequacy). This paper derives a novel method to obtain an accurate high-order polynomial while requiring fewer sampling points. This method uses a two-stage procedure such that the second stage modifies the low-order polynomial estimated in the first stage; this second stage does not require new points. This paper evaluates the performance of the method numerically by using several test functions. These numerical results show that the proposed method can provide more accurate predictions than the traditional method.
- Published
- 2018
14. Hysteresis Modelling of Mechanical Systems at Nonstationary Vibrations
- Author
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A. D. Shalashilin and A. N. Danilin
- Subjects
0209 industrial biotechnology ,Polynomial ,Article Subject ,Differential equation ,lcsh:Mathematics ,General Mathematics ,Mathematical analysis ,General Engineering ,02 engineering and technology ,lcsh:QA1-939 ,Damper ,Vibration ,Mechanical system ,Hysteresis ,020303 mechanical engineering & transports ,020901 industrial engineering & automation ,0203 mechanical engineering ,lcsh:TA1-2040 ,Black box ,Pendulum (mathematics) ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
This paper considers and reviews a number of known phenomenological models, used to describe hysteretic effects of various natures. Such models consider hysteresis system as a “black box” with experimentally known input and output, related via formal mathematical dependence to parameters obtained from the best fit to experimental data. In particular, we focus on the broadly used Bouc-Wen and similar phenomenological models. The current paper shows the conditions which the Bouc-Wen model must meet. An alternative mathematical model is suggested where the force and kinematic parameters are related by a first-order differential equation. In contrast to the Bouc-Wen model, the right hand side is a polynomial with two variables representing hysteresis trajectories in the process diagram. This approach ensures correct asymptotic approximation of the solution to the enclosing hysteresis cycle curves. The coefficients in the right side are also determined experimentally from the hysteresis cycle data during stable oscillations. The proposed approach allows us to describe hysteretic trajectory with an arbitrary starting point within the enclosed cycle using only one differential equation. The model is applied to the description of forced vibrations of a low-frequency pendulum damper.
- Published
- 2018
15. Solubility Optimal System for Supercritical Fluid Extraction Based on a New Nonlinear Temperature-Pressure Decoupling Model Constructed with Unequal-Interval Grey Optimal Models and Peng-Robinson Models
- Author
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Wen You and Binglin Li
- Subjects
Article Subject ,lcsh:Mathematics ,General Mathematics ,010401 analytical chemistry ,General Engineering ,Supercritical fluid extraction ,Mimo nonlinear systems ,02 engineering and technology ,lcsh:QA1-939 ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Nonlinear system ,Temperature and pressure ,Singularity ,lcsh:TA1-2040 ,Control theory ,Decoupling (probability) ,Solubility ,lcsh:Engineering (General). Civil engineering (General) ,0210 nano-technology ,Nonlinear coupling ,Mathematics - Abstract
This paper presents a new solubility optimal system to improve the efficiency of supercritical fluid extraction (SFE). The major contribution is a nonlinear temperature-pressure decoupling model constructed with unequal-interval grey optimal models (UEIGOMs) and Peng-Robinson models (PRMs). The linear parts of temperature and pressure process can be constructed with UEIGOM, respectively. The nonlinear parts of temperature and pressure process can be described by PRMs, respectively. The whole nonlinear model cannot be input-output decoupled resulting from the singularity of decoupling matrix for PRM. This problem on input-output nondecoupling can be transformed to the problem on disturbance decoupling for a class of MIMO nonlinear systems. Therefore, the whole nonlinear coupling model can be disturbance decoupled. Furthermore, solubility optimal method is presented in the paper; it can calculate the optimal pressure according to the given temperature, namely, optimal working points, to maximize solubility for SFE process. The feasibility, effectiveness, and practicality of the proposed nonlinear temperature-pressure decoupling model constructed with UEIGOMs and PRMs are verified by SFE experiments in biphenyl. Experiments using the designed solubility optimal system are carried out to demonstrate the effectiveness in control scheme, simplicity in structure, and flexibility in implementation for the proposed solubility optimal system based on a new nonlinear temperature-pressure coupling model constructed with UEIGOMs and PRMs.
- Published
- 2018
16. An Improvement for Fuzzy Stochastic Goal Programming Problems
- Author
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Shu-Cheng Lin, Han-Wen Tuan, and Peterson Julian
- Subjects
Mathematical optimization ,Index (economics) ,Article Subject ,Linear programming ,lcsh:Mathematics ,General Mathematics ,General Engineering ,02 engineering and technology ,Extension (predicate logic) ,lcsh:QA1-939 ,Fuzzy logic ,020202 computer hardware & architecture ,lcsh:TA1-2040 ,Goal programming ,0202 electrical engineering, electronic engineering, information engineering ,Random environment ,020201 artificial intelligence & image processing ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
We examined the solution process for linear programming problems under a fuzzy and random environment to transform fuzzy stochastic goal programming problems into standard linear programming problems. A previous paper that revised the solution process with the lower-side attainment index motivated our work. In this paper, we worked on a revision for both-side attainment index to amend its definition and theorems. Two previous examples were used to examine and demonstrate our improvement over previous results. Our findings not only improve the previous paper with both-side attainment index, but also provide a theoretical extension from lower-side attainment index to the both-side attainment index.
- Published
- 2017
17. A Scientific Decision Framework for Supplier Selection under Interval Valued Intuitionistic Fuzzy Environment
- Author
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Raghunathan Krishankumar, Kattur Soundarapandian Ravichandran, and R. Ramprakash
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,Article Subject ,lcsh:Mathematics ,General Mathematics ,General Engineering ,Intuitionistic fuzzy ,TOPSIS ,Vagueness ,02 engineering and technology ,lcsh:QA1-939 ,computer.software_genre ,Interval valued ,020901 industrial engineering & automation ,Ranking ,lcsh:TA1-2040 ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Data mining ,ELECTRE ,Decision-making ,lcsh:Engineering (General). Civil engineering (General) ,computer ,Selection (genetic algorithm) ,Mathematics - Abstract
This paper proposes a new scientific decision framework (SDF) under interval valued intuitionistic fuzzy (IVIF) environment for supplier selection (SS). The framework consists of two phases, where, in the first phase, criteria weights are estimated in a sensible manner using newly proposed IVIF based statistical variance (SV) method and, in the second phase, the suitable supplier is selected using ELECTRE (ELimination and Choice Expressing REality) ranking method under IVIF environment. This method involves three categories of outranking, namely, strong, moderate, and weak. Previous studies on ELECTRE ranking reveal that scholars have only used two categories of outranking, namely, strong and weak, in the formulation of IVIF based ELECTRE, which eventually aggravates fuzziness and vagueness in decision making process due to the potential loss of information. Motivated by this challenge, third outranking category, called moderate, is proposed, which considerably reduces the loss of information by improving checks to the concordance and discordance matrices. Thus, in this paper, IVIF-ELECTRE (IVIFE) method is presented and popular TOPSIS method is integrated with IVIFE for obtaining a linear ranking. Finally, the practicality of the proposed framework is demonstrated using SS example and the strength of proposed SDF is realized by comparing the framework with other similar methods.
- Published
- 2017
18. Synthesis of Adaptive Robust Controllers for a Class of Nonlinear Systems with Input Saturations
- Author
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Tomohiro Kubo, Tsuyoshi Matsuki, Hidetoshi Oya, and Kenta Oba
- Subjects
0209 industrial biotechnology ,Class (set theory) ,Article Subject ,Matching (graph theory) ,lcsh:Mathematics ,General Mathematics ,MathematicsofComputing_NUMERICALANALYSIS ,General Engineering ,02 engineering and technology ,Linear matrix ,lcsh:QA1-939 ,Nonlinear system ,020901 industrial engineering & automation ,lcsh:TA1-2040 ,Control theory ,Simple (abstract algebra) ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
This paper deals with a design problem of an adaptive robust controller for a class of nonlinear systems with specified input saturations. For the nonlinear system under consideration, the nonlinearity means unknown perturbations and satisfies the matching condition. In this paper, we show that sufficient conditions for the existence of the proposed adaptive robust controller giving consideration to input saturations are given in terms of linear matrix inequalities (LMIs). Finally, simple illustrative examples are shown.
- Published
- 2017
19. The Global Optimal Algorithm of Reliable Path Finding Problem Based on Backtracking Method
- Author
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Jian Zhao, Hu Shao, Liang Shen, and Long Zhang
- Subjects
050210 logistics & transportation ,Mathematical optimization ,Correctness ,Article Subject ,Backtracking ,lcsh:Mathematics ,General Mathematics ,05 social sciences ,General Engineering ,02 engineering and technology ,Fast path ,lcsh:QA1-939 ,Longest path problem ,lcsh:TA1-2040 ,0502 economics and business ,Shortest path problem ,Path (graph theory) ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,lcsh:Engineering (General). Civil engineering (General) ,Yen's algorithm ,Algorithm ,Dijkstra's algorithm ,Mathematics - Abstract
There is a growing interest in finding a global optimal path in transportation networks particularly when the network suffers from unexpected disturbance. This paper studies the problem of finding a global optimal path to guarantee a given probability of arriving on time in a network with uncertainty, in which the travel time is stochastic instead of deterministic. Traditional path finding methods based on least expected travel time cannot capture the network user’s risk-taking behaviors in path finding. To overcome such limitation, the reliable path finding algorithms have been proposed but the convergence of global optimum is seldom addressed in the literature. This paper integrates the K-shortest path algorithm into Backtracking method to propose a new path finding algorithm under uncertainty. The global optimum of the proposed method can be guaranteed. Numerical examples are conducted to demonstrate the correctness and efficiency of the proposed algorithm.
- Published
- 2017
20. Response of Duffing Oscillator with Time Delay Subjected to Combined Harmonic and Random Excitations
- Author
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N. D. Anh and D. N. Hao
- Subjects
Stationary distribution ,Article Subject ,Computer simulation ,lcsh:Mathematics ,General Mathematics ,Mathematical analysis ,Degenerate energy levels ,General Engineering ,Duffing equation ,Probability density function ,02 engineering and technology ,Auxiliary function ,lcsh:QA1-939 ,01 natural sciences ,010305 fluids & plasmas ,020303 mechanical engineering & transports ,Transformation (function) ,0203 mechanical engineering ,lcsh:TA1-2040 ,Control theory ,0103 physical sciences ,Harmonic ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
This paper aims to investigate the stationary probability density functions of the Duffing oscillator with time delay subjected to combined harmonic and white noise excitation by the method of stochastic averaging and equivalent linearization. By the transformation based on the fundamental matrix of the degenerate Duffing system, the paper shows that the displacement and the velocity with time delay in the Duffing oscillator can be computed approximately in non-time delay terms. Hence, the stochastic system with time delay is transformed into the corresponding stochastic non-time delay equation in Ito sense. The approximate stationary probability density function of the original system can be found by combining the stochastic averaging method, the equivalent linearization method, and the technique of auxiliary function. The response of Duffing oscillator is investigated. The analytical results are verified by numerical simulation results.
- Published
- 2017
21. Infrared Dim and Small Targets Detection Method Based on Local Energy Center of Sequential Image
- Author
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Zhenming Peng, Xiangsuo Fan, Jianlin Zhang, Yongmei Huang, and Zhiyong Xu
- Subjects
020301 aerospace & aeronautics ,Article Subject ,Basis (linear algebra) ,Infrared ,business.industry ,lcsh:Mathematics ,General Mathematics ,General Engineering ,02 engineering and technology ,lcsh:QA1-939 ,Image (mathematics) ,0203 mechanical engineering ,lcsh:TA1-2040 ,0202 electrical engineering, electronic engineering, information engineering ,Preprocessor ,Clutter ,020201 artificial intelligence & image processing ,Computer vision ,Noise (video) ,Artificial intelligence ,lcsh:Engineering (General). Civil engineering (General) ,Anisotropy ,business ,Energy (signal processing) ,Mathematics - Abstract
In order to detect infrared (IR) dim and small targets in a strong clutter background, a method based on local energy center of sequential image is proposed. This paper began by using improved anisotropy for background prediction (IABP), followed by target enhancement by improved high-order cumulates (HOC). Finally, on the basis of image preprocessing, the paper constructs a sequential image energy center detection algorithm that integrates the neighborhood, continuity, area, and energy and other motion characteristics of the target. Experiments showed that the improved anisotropic background predication could be loyal to the true background of the original image to the maximum extent, presenting a superior overall performance to other background prediction methods; the improved HOC significantly increased the signal-noise ratio of images; when the signal-noise ratio (SNR) is lower than 2.5 dB, the proposed method could effectively eliminate noise and detect targets.
- Published
- 2017
22. Solution to Two-Dimensional Steady Inverse Heat Transfer Problems with Interior Heat Source Based on the Conjugate Gradient Method
- Author
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Huangchao Jia, Li Zhang, Xiaogang Sun, and Shoubin Wang
- Subjects
Observational error ,Article Subject ,Convective heat transfer ,lcsh:Mathematics ,General Mathematics ,Mathematical analysis ,General Engineering ,010103 numerical & computational mathematics ,02 engineering and technology ,Inverse problem ,lcsh:QA1-939 ,Thermal conduction ,01 natural sciences ,020303 mechanical engineering & transports ,0203 mechanical engineering ,lcsh:TA1-2040 ,Conjugate gradient method ,Heat transfer ,0101 mathematics ,lcsh:Engineering (General). Civil engineering (General) ,Gradient method ,Boundary element method ,Mathematics - Abstract
The compound variable inverse problem which comprises boundary temperature distribution and surface convective heat conduction coefficient of two-dimensional steady heat transfer system with inner heat source is studied in this paper applying the conjugate gradient method. The introduction of complex variable to solve the gradient matrix of the objective function obtains more precise inversion results. This paper applies boundary element method to solve the temperature calculation of discrete points in forward problems. The factors of measuring error and the number of measuring points zero error which impact the measurement result are discussed and compared with L-MM method in inverse problems. Instance calculation and analysis prove that the method applied in this paper still has good effectiveness and accuracy even if measurement error exists and the boundary measurement points’ number is reduced. The comparison indicates that the influence of error on the inversion solution can be minimized effectively using this method.
- Published
- 2017
23. Analysis of Hull Girder Ultimate Strength and Residual Strength Based on IACS CSR-H
- Author
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Hong Zhou, Gui-jie Shi, and Da-wei Gao
- Subjects
Article Subject ,business.industry ,General Mathematics ,lcsh:Mathematics ,General Engineering ,020101 civil engineering ,02 engineering and technology ,Structural engineering ,Nonlinear finite element method ,lcsh:QA1-939 ,0201 civil engineering ,Residual strength ,Naval architecture ,020303 mechanical engineering & transports ,Shipbuilding ,0203 mechanical engineering ,lcsh:TA1-2040 ,Hull ,Girder ,Ultimate tensile strength ,business ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
In order to express the safety level of hull structures, IACS Common Structure Rules of Bulk Carriers and Oil Tankers (CSR-H) makes new requirements of hull girder ultimate strength. Compared with original CSR (i.e., CSR-OT and CSR-BC), partial safety factors of hull girder ultimate strength in CSR-H have been partly modified, and new requirements of residual strength have been added in the rules for hull safety after grounded/collided damage. This paper compares the rule requirements of ultimate strength in CSR-H and CSR-OT/CSR-BC and explains the technical background of rule requirements. The hull girder ultimate strength is mainly analyzed by SMITH method in rule requirements due to fast and stable calculation results. This paper also uses nonlinear finite element method (NFEM) to explain the critical influence factors for hull girder ultimate strength implied in the rule requirements. Based on 5 typical Bulk Carriers and 4 typical Oil Tankers, the influence of hull girder ultimate strength and residual strength in CSR-H has been evaluated for ship building industry. The actual ship evaluation results can be used to instruct the new CSR-H ship design.
- Published
- 2019
24. Free In-Plane Vibrations of Orthotropic Rectangular Plates by Using an Accurate Solution
- Author
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Qingshan Wang, Rui Zhong, Yuan Cao, Dongtao Wu, and Dong Shao
- Subjects
Article Subject ,lcsh:Mathematics ,General Mathematics ,Numerical analysis ,Mathematical analysis ,Reference data (financial markets) ,General Engineering ,02 engineering and technology ,lcsh:QA1-939 ,021001 nanoscience & nanotechnology ,Orthotropic material ,Finite element method ,Vibration ,Matrix (mathematics) ,020303 mechanical engineering & transports ,0203 mechanical engineering ,lcsh:TA1-2040 ,Golden section search ,Boundary value problem ,lcsh:Engineering (General). Civil engineering (General) ,0210 nano-technology ,Mathematics - Abstract
Many numerical methods have been developed for in-plane vibration of orthotropic rectangular plates with various boundary conditions; however, the exact results for such structures with elastic boundary conditions are very scarce. Therefore, the object of this paper is to present an accurate solution for free in-plane vibration of orthotropic rectangular plates with various boundary conditions by the method of reverberation ray matrix (MRRM) and improved golden section search (IGSS) algorithm. The boundary condition studied in this paper is defined as that a set of opposite edges is with one kind of simply supported boundary conditions, while the other set is with any kind of classical and general elastic boundary conditions or their combination. Its accuracy, reliability, and efficiency are verified by some numerical examples where the results are compared with other exact solutions in the published literature and the FEA results based on the ABAQUS software. Finally, some new accurate results for free in-plane vibration of orthotropic rectangular plates with elastic boundary conditions are examined and further can be treated as the reference data for other approximate methods or accurate solutions.
- Published
- 2019
- Full Text
- View/download PDF
25. Applications of Fractional Lower Order Frequency Spectrum Technologies to Bearing Fault Analysis
- Author
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Junbo Long, Haibin Wang, and Peng Li
- Subjects
0209 industrial biotechnology ,Article Subject ,General Mathematics ,Gaussian ,lcsh:Mathematics ,General Engineering ,02 engineering and technology ,Covariance ,Fault (power engineering) ,lcsh:QA1-939 ,Stable distribution ,symbols.namesake ,020901 industrial engineering & automation ,Autoregressive model ,Side lobe ,lcsh:TA1-2040 ,Frequency domain ,0202 electrical engineering, electronic engineering, information engineering ,symbols ,020201 artificial intelligence & image processing ,Autoregressive–moving-average model ,lcsh:Engineering (General). Civil engineering (General) ,Algorithm ,Mathematics - Abstract
The traditional spectral analysis method is used to study the characteristics of bearing fault signals in frequency domain, which is reasonable and effective in general cases. However, it is proved that the fault signals have heavy tails in this paper, which are α stable distribution, and 1<α<2, and even the noises belong to α stable distribution. Then the conventional spectral analysis methods degenerate and even fail under α stable distribution environment. Several improved frequency spectral analysis methods are proposed employing fractional lower order covariation or fractional lower order covariance in this paper, including fractional lower order Blackman-Tukey covariation spectrum (FLOBTCS), fractional lower order periodogram covariation spectrum (FLOPCS), and fractional lower order welch covariation spectrum (FLOWCS). In order to suppress side lobe and improve resolution, we present novel fractional lower order autoregression (FLO-AR) and fractional lower order autoregressive moving average (FLO-ARMA) parameter model frequency spectrum methods, and the calculation steps are summarized. The proposed spectrum methods are compared with the existing methods based on second-order statistics under Gaussian and SαS distribution environments, and the results show that the new algorithms have better performance than the traditional methods. Finally, the improved methods are applied to estimate frequency spectrums of the normal and outer race fault signals, and it is demonstrated that they are effective for fault diagnosis.
- Published
- 2019
26. Stochastic Dynamics of Discrete-Time Fuzzy Random BAM Neural Networks with Time Delays
- Author
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Sufang Han, Guoxin Liu, and Tianwei Zhang
- Subjects
0209 industrial biotechnology ,Artificial neural network ,Article Subject ,lcsh:Mathematics ,General Mathematics ,General Engineering ,Fixed-point theorem ,Periodic sequence ,02 engineering and technology ,lcsh:QA1-939 ,Fuzzy logic ,Moment (mathematics) ,020901 industrial engineering & automation ,Exponential stability ,Discrete time and continuous time ,lcsh:TA1-2040 ,0202 electrical engineering, electronic engineering, information engineering ,Applied mathematics ,020201 artificial intelligence & image processing ,lcsh:Engineering (General). Civil engineering (General) ,Stochastic neural network ,Mathematics - Abstract
By using the semidiscrete method of differential equations, a new version of discrete analogue of stochastic fuzzy BAM neural networks was formulated, which gives a more accurate characterization for continuous-time stochastic neural networks than that by the Euler scheme. Firstly, the existence of the 2p-th mean almost periodic sequence solution of the discrete-time stochastic fuzzy BAM neural networks is investigated with the help of Minkowski inequality, Hölder inequality, and Krasnoselskii’s fixed point theorem. Secondly, the 2p-th moment global exponential stability of the discrete-time stochastic fuzzy BAM neural networks is also studied by using some analytical skills in stochastic theory. Finally, two examples with computer simulations are given to demonstrate that our results are feasible. The main results obtained in this paper are completely new, and the methods used in this paper provide a possible technique to study 2p-th mean almost periodic sequence solution and 2p-th moment global exponential stability of semidiscrete stochastic fuzzy models.
- Published
- 2019
- Full Text
- View/download PDF
27. Analysis of Concrete-Filled Square Steel Tube Short Columns under Eccentric Loading
- Author
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Qifeng Shan, Jingming Cai, Jiawei Tan, and Xiaopeng Li
- Subjects
Mathematics, Interdisciplinary Applications ,Technology ,Materials science ,Article Subject ,General Mathematics ,media_common.quotation_subject ,Engineering, Multidisciplinary ,020101 civil engineering ,02 engineering and technology ,Concentric ,Eccentric loading ,Square (algebra) ,0201 civil engineering ,Engineering ,0203 mechanical engineering ,Eccentric ,Eccentricity (behavior) ,media_common ,Science & Technology ,business.industry ,lcsh:Mathematics ,General Engineering ,Structural engineering ,PERFORMANCE ,lcsh:QA1-939 ,020303 mechanical engineering & transports ,Contact mechanics ,lcsh:TA1-2040 ,Physical Sciences ,Steel tube ,Astrophysics::Earth and Planetary Astrophysics ,lcsh:Engineering (General). Civil engineering (General) ,business ,Mathematics ,BEHAVIOR - Abstract
The concrete-filled square steel tube (CFSST) columns have been widely applied in structural engineering. Although many constitutive models have been proposed to describe CFSST short columns under concentric loading, the applicability of the existing concentric model in the analysis of CFSST short columns under eccentric loading has not been properly verified. In this paper, the eccentric behaviors of CFSST short columns were investigated with the software of ABAQUS/standard. It was found that the contact stress between steel tube and inner concrete was seriously affected by eccentric ratios, indicating that the confinement effect of steel tube on inner concrete was different under concentric and eccentric loading. In this paper, a new stress-strain model of inner concrete which considered the influence of eccentricity was developed and verified with existing experimental results. It was found that the proposed stress-strain model was more accurate in simulating the eccentric behaviors of CFSST short columns.
- Published
- 2019
- Full Text
- View/download PDF
28. A New Stability Analysis of Uncertain Delay Differential Equations
- Author
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Yufu Ning and Xiao Wang
- Subjects
0209 industrial biotechnology ,Article Subject ,General Mathematics ,lcsh:Mathematics ,General Engineering ,02 engineering and technology ,Delay differential equation ,lcsh:QA1-939 ,Stability (probability) ,Measure (mathematics) ,020901 industrial engineering & automation ,lcsh:TA1-2040 ,0202 electrical engineering, electronic engineering, information engineering ,sort ,Applied mathematics ,020201 artificial intelligence & image processing ,Almost surely ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
This paper first provides a concept of almost sure stability for uncertain delay differential equations and analyzes this new sort of stability. In addition, this paper derives three sufficient conditions for uncertain delay differential equations being stable almost surely. Finally, the relationship between almost sure stability and stability in measure for uncertain delay differential equations is discussed.
- Published
- 2019
29. Similarity Solution and Heat Transfer Characteristics for a Class of Nonlinear Convection-Diffusion Equation with Initial Value Conditions
- Author
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Yunbin Xu
- Subjects
Convection ,Diffusion equation ,Partial differential equation ,Article Subject ,General Mathematics ,lcsh:Mathematics ,010102 general mathematics ,Mathematical analysis ,General Engineering ,Similarity solution ,lcsh:QA1-939 ,01 natural sciences ,Matrix similarity ,010101 applied mathematics ,Nonlinear system ,lcsh:TA1-2040 ,Heat transfer ,Initial value problem ,0101 mathematics ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
A class of nonlinear convection-diffusion equation is studied in this paper. The partial differential equation is converted into nonlinear ordinary differential equation by introducing a similarity transformation. The asymptotic analytical solutions are obtained by using double-parameter transformation perturbation expansion method (DPTPEM). The influences of convection functional coefficientk(z)and power law indexnon the heat transport characteristics are discussed and shown graphically. The comparison with the numerical results is presented and it is found to be in excellent agreement. The method and technique used in this paper have the significance in studying other engineering problems.
- Published
- 2019
- Full Text
- View/download PDF
30. Evaluation of robust functions for data reconciliation in thermal systems
- Author
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Regina França, Domingos Fabiano de Santana Souza, and Antonio Martins de Oliveira Junior
- Subjects
Chemical process ,General Computer Science ,020209 energy ,General Mathematics ,General Physics and Astronomy ,02 engineering and technology ,robustness ,ALARM ,Robustness (computer science) ,Thermal ,Statistics ,0202 electrical engineering, electronic engineering, information engineering ,lcsh:Science (General) ,nonlinear systems ,Mathematics ,General Engineering ,Cauchy distribution ,General Chemistry ,set measures ,Set point ,Nonlinear system ,efficiency ,lcsh:TA1-2040 ,Outlier ,General Earth and Planetary Sciences ,Reconciliação de Dados ,lcsh:Engineering (General). Civil engineering (General) ,lcsh:Q1-390 - Abstract
Process variables regularly control and evaluate industrial processes. Information with gross errors may in some cases not be attenuated by function reconciliation and change the calculation of process balance, leading optimization results towards non-feasible regions or to optimal sites. A promising alternative for reconciling functions is the use of robust functions. Current paper considers the above scenario and evaluates the fitness of some robust functions in solving in steady state chemical processes data reconciliation problems represented by linear and nonlinear systems in the presence of gross errors. Traditional Cauchy, Fair, Contaminated Normal and Logistic robust functions are used in the reconciliation problem where their estimates are compared to those obtained with the use of the latest features, such as New Target and Alarm. Rates for gross errors in tests were limited between 4 and 10σ of the measured current and elaborated a region of outliers. Results showed that New Target and Alarm functions are different from the others as the magnitude of the gross error increases, tending towards true rates specified by set point. Process variables regularly control and evaluate industrial processes. Information with gross errors may in some cases not be attenuated by function reconciliation and change the calculation of process balance, leading optimization results towards non-feasible regions or to optimal sites. A promising alternative for reconciling functions is the use of robust functions. Current paper considers the above scenario and evaluates the fitness of some robust functions in solving in steady state chemical processes data reconciliation problems represented by linear and nonlinear systems in the presence of gross errors. Traditional Cauchy, Fair, Contaminated Normal and Logistic robust functions are used in the reconciliation problem where their estimates are compared to those obtained with the use of the latest features, such as New Target and Alarm. Rates for gross errors in tests were limited between 4 and 10σ of the measured current and elaborated a region of outliers. Results showed that New Target and Alarm functions are different from the others as the magnitude of the gross error increases, tending towards true rates specified by set point.
- Published
- 2016
31. Two-Dimensional Far Field Source Locating Method with Nonprior Velocity
- Author
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Xiaowen Liu, Peng Liu, Manyi Wang, Juanjuan Li, and Qing Chen
- Subjects
Article Subject ,lcsh:Mathematics ,General Mathematics ,General Engineering ,Geometry ,Near and far field ,02 engineering and technology ,lcsh:QA1-939 ,010502 geochemistry & geophysics ,01 natural sciences ,Stability (probability) ,020501 mining & metallurgy ,Hyperbola ,0205 materials engineering ,lcsh:TA1-2040 ,Position (vector) ,Convergence (routing) ,Asymptote ,lcsh:Engineering (General). Civil engineering (General) ,Algorithm ,Fuzzy locating system ,Linear equation ,0105 earth and related environmental sciences ,Mathematics - Abstract
Relative position of seismic source and sensors has great influence on locating accuracy, particularly in far field conditions, and the accuracy will decrease seriously due to limited calculation precision and prior velocity error. In order to improve the locating accuracy of far field sources by isometric placed sensors in a straight line, a new locating method with nonprior velocity is proposed. After exhaustive research, this paper states that the hyperbola which is used for locating will be very close to its asymptote when seismic source locates in far field of sensors; therefore, the locating problem with prior velocity is equivalent to solving linear equations and the problem with nonprior velocity is equivalent to a nonlinear optimization problem with respect to the unknown velocity. And then, this paper proposed a new locating method based on a one-variable objective function with respect to the unknown velocity. Numerical experiments show that the proposed method has faster convergence speed, higher accuracy, and better stability.
- Published
- 2016
32. Periodic Event-Triggered Condition Design for the Consensus of Multiagent Systems with Communication Delays
- Author
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Kai Gao, Weirong Liu, Liran Li, Feng Zhou, and Zhiwu Huang
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,Article Subject ,lcsh:Mathematics ,General Mathematics ,Multi-agent system ,Control (management) ,General Engineering ,Stability (learning theory) ,Sampling (statistics) ,020207 software engineering ,02 engineering and technology ,lcsh:QA1-939 ,Linear dynamical system ,020901 industrial engineering & automation ,Consensus ,lcsh:TA1-2040 ,Control theory ,0202 electrical engineering, electronic engineering, information engineering ,Exponential decay ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics ,Event (probability theory) - Abstract
This paper focuses on the periodic event-triggered consensus problem for multiagent systems under undirected graph. In the periodic event-triggered control, the event condition is tested only periodically to decide when to exert the control behaviors and when to broadcast the sampling data. Two sets of event-triggered strategies combining with sampled-data control are designed based on an exponential decay function and a quadratic Lyapunov function, respectively. Some useful theorems for these two periodic event-triggered strategies about the choice of period are derived to guarantee the asymptotical stability of the closed-loop multiagent systems. In addition, this paper gives a sufficient condition about the bounds of communication delay for the multiagent systems. It is rigorously proved that the overall system will achieve the consensus under the proposed strategy if the period and time delay satisfy the theorems. Finally, we extend these solutions to general linear dynamical systems. Simulation results are presented to show the effectiveness.
- Published
- 2016
33. Modeling Portfolio Optimization Problem by Probability-Credibility Equilibrium Risk Criterion
- Author
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Ye Wang, Yanju Chen, and YanKui Liu
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,Optimization problem ,Article Subject ,lcsh:Mathematics ,General Mathematics ,General Engineering ,02 engineering and technology ,lcsh:QA1-939 ,Fuzzy logic ,Constraint (information theory) ,Variable (computer science) ,020901 industrial engineering & automation ,lcsh:TA1-2040 ,Convex optimization ,0202 electrical engineering, electronic engineering, information engineering ,Expected return ,Portfolio ,020201 artificial intelligence & image processing ,Portfolio optimization ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
This paper studies the portfolio selection problem in hybrid uncertain decision systems. Firstly the return rates are characterized by random fuzzy variables. The objective is to maximize the total expected return rate. For a random fuzzy variable, this paper defines a new equilibrium risk value (ERV) with credibility level beta and probability level alpha. As a result, our portfolio problem is built as a new random fuzzy expected value (EV) model subject to ERV constraint, which is referred to as EV-ERV model. Under mild assumptions, the proposed EV-ERV model is a convex programming problem. Furthermore, when the possibility distributions are triangular, trapezoidal, and normal, the EV-ERV model can be transformed into its equivalent deterministic convex programming models, which can be solved by general purpose optimization software. To demonstrate the effectiveness of the proposed equilibrium optimization method, some numerical experiments are conducted. The computational results and comparison study demonstrate that the developed equilibrium optimization method is effective to model portfolio selection optimization problem with twofold uncertain return rates.
- Published
- 2016
34. Problems on Solving Matrix Aggregation in Group Decision-Making by Glowworm Swarm Optimization
- Author
-
Yaping Li
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,Article Subject ,lcsh:Mathematics ,General Mathematics ,media_common.quotation_subject ,Glowworm swarm optimization ,General Engineering ,02 engineering and technology ,Information loss ,lcsh:QA1-939 ,Adaptability ,Universality (dynamical systems) ,Group decision-making ,020901 industrial engineering & automation ,lcsh:TA1-2040 ,Fuzzy matrix ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Multi-swarm optimization ,lcsh:Engineering (General). Civil engineering (General) ,media_common ,Mathematics - Abstract
Judgment matrix aggregation, as an important part of group decision-making, has been widely and deeply studied due to the universality and importance of group decision-making in the management field. For the variety of judgment matrix in group decision-making, the matrix aggregation result can be obtained by using the mode of glowworm swarm optimization. First, this paper introduces the basic principle of the glowworm swarm optimization (GSO) algorithm and gives the improved GSO algorithm to solve the matrix aggregation problems. In this approach, the consistency ratio is introduced to the objective function of the glowworm swarm optimization, thus reducing the subjectivity and information loss in the aggregation process. Then, the improved GSO algorithm is applied to the solution of the deterministic matrix and the fuzzy matrix. The method optimization can provide an effective and relatively uniform aggregation method for matrix aggregation. Finally, through comparative analysis, it is shown that the method of this paper has certain advantages in terms of adaptability, accuracy, and stability to solving the matrix aggregation problems.
- Published
- 2016
35. Fuzzy Risk Analysis for a Production System Based on the Nagel Point of a Triangle
- Author
-
Handan Akyar, Anadolu Üniversitesi, Fen Fakültesi, Matematik Bölümü, and Akyar, Handan
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,Fuzzy classification ,Article Subject ,lcsh:Mathematics ,General Mathematics ,General Engineering ,02 engineering and technology ,lcsh:QA1-939 ,Type-2 fuzzy sets and systems ,Defuzzification ,020901 industrial engineering & automation ,Fuzzy transportation ,lcsh:TA1-2040 ,Fuzzy mathematics ,0202 electrical engineering, electronic engineering, information engineering ,Fuzzy set operations ,Fuzzy number ,020201 artificial intelligence & image processing ,Fuzzy associative matrix ,lcsh:Engineering (General). Civil engineering (General) ,Algorithm ,Mathematics - Abstract
WOS: 000374093400001, Ordering and ranking fuzzy numbers and their comparisons play a significant role in decision-making problems such as social and economic systems, forecasting, optimization, and risk analysis problems. In this paper, a new method for ordering triangular fuzzy numbers using the Nagel point of a triangle is presented. With the aid of the proposed method, reasonable properties of ordering fuzzy numbers are verified. Certain comparative examples are given to illustrate the advantages of the new method. Many papers have been devoted to studies on fuzzy ranking methods, but some of these studies have certain shortcomings. The proposed method overcomes the drawbacks of the existing methods in the literature. The suggested method can order triangular fuzzy numbers as well as crisp numbers and fuzzy numbers with the same centroid point. An application to the fuzzy risk analysis problem is given, based on the suggested ordering approach., Anadolu University Scientific Research Projects Commission [1403F077], This study was supported by the Anadolu University Scientific Research Projects Commission under Grant no. 1403F077.
- Published
- 2016
36. A New Method Applied to the Quadrilateral Membrane Element with Vertex Rigid Rotational Freedom
- Author
-
Xiao-Wei Gao, Jun Lv, and Yunfei Liu
- Subjects
Vertex (computer graphics) ,Article Subject ,General Mathematics ,Shell (structure) ,Geometry ,02 engineering and technology ,Topology ,01 natural sciences ,law.invention ,0203 mechanical engineering ,law ,Local coordinates ,Cartesian coordinate system ,0101 mathematics ,Mathematics ,Quadrilateral ,lcsh:Mathematics ,General Engineering ,Order (ring theory) ,lcsh:QA1-939 ,010101 applied mathematics ,020303 mechanical engineering & transports ,Membrane ,lcsh:TA1-2040 ,Element (category theory) ,lcsh:Engineering (General). Civil engineering (General) - Abstract
In order to improve the performance of the membrane element with vertex rigid rotational freedom, a new method to establish the local Cartesian coordinate system and calculate the derivatives of the shape functions with respect to the local coordinates is introduced in this paper. The membrane elements with vertex rigid rotational freedom such as GQ12 and GQ12M based on this new method can achieve higher precision results than traditional methods. The numerical results demonstrate that the elements GQ12 and GQ12M with this new method can provide better membrane elements for flat shell elements. Furthermore, this new method presented in this paper offers a new approach for other membrane elements used in flat shell element to improve the computing accuracy.
- Published
- 2016
37. Nonlinear Alignment and Its Local Linear Iterative Solution
- Author
-
Zhengming Ma, Zengrong Zhan, and Sumin Zhang
- Subjects
Article Subject ,General Mathematics ,Invariant manifold ,02 engineering and technology ,Topology ,Pseudo-Riemannian manifold ,symbols.namesake ,020204 information systems ,Local coordinates ,0202 electrical engineering, electronic engineering, information engineering ,Mathematics::Symplectic Geometry ,Mathematics ,Manifold alignment ,lcsh:Mathematics ,Mathematical analysis ,General Engineering ,lcsh:QA1-939 ,Mathematics::Geometric Topology ,lcsh:TA1-2040 ,Piecewise linear manifold ,Local tangent space alignment ,symbols ,Normal coordinates ,020201 artificial intelligence & image processing ,Mathematics::Differential Geometry ,lcsh:Engineering (General). Civil engineering (General) ,Center manifold - Abstract
In manifold learning, the aim of alignment is to derive the global coordinate of manifold from the local coordinates of manifold’s patches. At present, most of manifold learning algorithms assume that the relation between the global and local coordinates is locally linear and based on this linear relation align the local coordinates of manifold’s patches into the global coordinate of manifold. There are two contributions in this paper. First, the nonlinear relation between the manifold’s global and local coordinates is deduced by making use of the differentiation of local pullback functions defined on the differential manifold. Second, the method of local linear iterative alignment is used to align the manifold’s local coordinates into the manifold’s global coordinate. The experimental results presented in this paper show that the errors of noniterative alignment are considerably large and can be reduced to almost zero within the first two iterations. The large errors of noniterative/linear alignment verify the nonlinear nature of alignment and justify the necessity of iterative alignment.
- Published
- 2016
38. Consensus of High-Order Linear Multiagent Systems with Multitype Switching Topologies Based on the Dynamic Dwell Time Approach
- Author
-
Yaxiao Zhang, Yangzhou Chen, and Xiaojun Qu
- Subjects
0209 industrial biotechnology ,Article Subject ,lcsh:Mathematics ,General Mathematics ,Multi-agent system ,General Engineering ,Stability (learning theory) ,02 engineering and technology ,lcsh:QA1-939 ,Topology ,Network topology ,Computer Science::Multiagent Systems ,Linear map ,Dwell time ,020901 industrial engineering & automation ,Consensus ,lcsh:TA1-2040 ,Computer Science::Systems and Control ,Control theory ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,High order ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics - Abstract
This paper investigates the consensus problem of high-order continuous-time linear multiagent systems (LMASs) with multitype switching topologies which include both consensusable and unconsensusable communication topologies. A linear transformation is introduced, which equivalently transforms the consensus problem into the stability problem of a corresponding switched system, along with a necessary and sufficient condition to analyze the consensus problem. This paper is aimed at studying the impact of a switching rule on communication topologies for consensus of LMASs. Based on the dynamic dwell time method, a sufficient condition is derived for consensus of LMASs. It is shown that, with switching signals that satisfy this switching rule, LMASs can achieve consensus under directed switching communication topologies. A numerical example is provided to illustrate the effectiveness of the theoretical results.
- Published
- 2016
39. Sensor Location Problem for Network Traffic Flow Derivation Based on Turning Ratios at Intersection
- Author
-
Xianzhi Shao, Lijun Sun, and Minhua Shao
- Subjects
050210 logistics & transportation ,021103 operations research ,Article Subject ,Intersection (set theory) ,lcsh:Mathematics ,General Mathematics ,05 social sciences ,0211 other engineering and technologies ,General Engineering ,02 engineering and technology ,lcsh:QA1-939 ,Network topology ,Flow network ,Set (abstract data type) ,Traffic flow (computer networking) ,Flow (mathematics) ,lcsh:TA1-2040 ,0502 economics and business ,lcsh:Engineering (General). Civil engineering (General) ,Coefficient matrix ,Greedy algorithm ,Algorithm ,Simulation ,Mathematics - Abstract
The sensor location problem (SLP) discussed in this paper is to find the minimum number and optimum locations of the flow counting points in the road network so that the traffic flows over the whole network can be inferred uniquely. Flow conservation system at intersections is formulated firstly using the turning ratios as the prior information. Then the coefficient matrix of the flow conservation system is proved to be nonsingular. Based on that, the minimal number of counting points is determined to be the total number of exclusive incoming roads and dummy roads, which are added to the network to represent the trips generated on real roads. So the task of SLP model based on turning ratios is just to determine the optimal sensor locations. The following analysis in this paper shows that placing sensors on all the exclusive incoming roads and dummy roads can always generate a unique network flow vector for any network topology. After that, a detection set composed of only real roads is proven to exist from the view of feasibility in reality. Finally, considering the roads importance and cost of the sensors, a weighted SLP model is formulated to find the optimal detection set. The greedy algorithm is proven to be able to provide the optimal solution for the proposed weighted SLP model.
- Published
- 2016
40. Analysis of the Stability and Hopf Bifurcation of Currency Supply Delay in an Opened Kaldorian Business Cycle Model
- Author
-
Liming Zhao and Zhipei Zhao
- Subjects
Equilibrium point ,Hopf bifurcation ,Article Subject ,Computer simulation ,lcsh:Mathematics ,General Mathematics ,010102 general mathematics ,General Engineering ,lcsh:QA1-939 ,01 natural sciences ,Stability (probability) ,symbols.namesake ,Exchange rate ,lcsh:TA1-2040 ,Currency ,0103 physical sciences ,Business cycle ,symbols ,0101 mathematics ,lcsh:Engineering (General). Civil engineering (General) ,010301 acoustics ,Mathematical economics ,Mathematics - Abstract
First of all, we establish a three-dimension open Kaldorian business cycle model under the condition of the fixed exchange rate. Secondly, with regard to the model, we discuss the existence of equilibrium point and the stability of the system near it with a time delay in currency supply as the bifurcating parameters of the system. Thirdly, we discuss the existence of Hopf bifurcation and investigate the stability of periodic solution generated by the Hopf bifurcation; then the direction of the Hopf bifurcation is given. Finally, a numerical simulation is given to confirm the theoretical results. This paper plays an important role in theoretical researching on the model of business cycle, and it is crucial for decision-maker to formulate the macroeconomic policies with the conclusions of this paper.
- Published
- 2016
41. Novel 3-Scroll Chua’s Attractor with One Saddle-Focus and Two Stable Node-Foci
- Author
-
Kaibin Chu, Huagan Wu, Zhengwei Zhu, and Hui Qian
- Subjects
Equilibrium point ,Article Subject ,General Mathematics ,lcsh:Mathematics ,General Engineering ,Chaotic ,MathematicsofComputing_NUMERICALANALYSIS ,Topology ,lcsh:QA1-939 ,01 natural sciences ,Analog multiplier ,010305 fluids & plasmas ,law.invention ,Nonlinear Sciences::Chaotic Dynamics ,law ,lcsh:TA1-2040 ,0103 physical sciences ,Attractor ,Operational amplifier ,Node (circuits) ,lcsh:Engineering (General). Civil engineering (General) ,010301 acoustics ,Saddle ,Electronic circuit ,Mathematics - Abstract
With new three-segment piecewise-linearity in the classic Chua’s system, two new types of 2-scroll and 3-scroll Chua’s attractors are found in this paper. By changing the outer segment slope of the three-segment piecewise-linearity as positive, the new 2-scroll Chua’s attractor has emerged from one zero index-1 saddle-focus and two symmetric stable nonzero node-foci. In particular, by newly introducing a piecewise-linear control function, an improved Chua’s system only with one zero index-2 saddle-focus and two stable nonzero node-foci is constructed, from which a 3-scroll Chua’s attractor is converged. Some remarks for Chua’s nonlinearities and the generating chaotic attractors are discussed, and the stabilities at the three equilibrium points are then analyzed, upon which the emerging mechanisms of the novel 2-scroll and 3-scroll Chua’s attractors are explored in depth. Furthermore, an analog electronic circuit built with operational amplifier and analog multiplier is designed and hardware circuit experiments are measured to verify the numerical simulations. These novel 2-scroll and 3-scroll Chua’s attractors reported in this paper are completely different from the classic Chua’s attractors, which will enrich the dynamics of the classic Chua’s system.
- Published
- 2018
42. A New Approach to Derive Priority Weights from Additive Interval Fuzzy Preference Relations Based on Logarithms
- Author
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Chengxiang Yin, Wenning Hao, Xingdang Kang, Xiuli Qi, and Hongjun Zhang
- Subjects
0209 industrial biotechnology ,Transitive relation ,Article Subject ,Logarithm ,Linear programming ,General Mathematics ,lcsh:Mathematics ,General Engineering ,Linear model ,02 engineering and technology ,Interval (mathematics) ,lcsh:QA1-939 ,Fuzzy logic ,020901 industrial engineering & automation ,Consistency (statistics) ,lcsh:TA1-2040 ,0202 electrical engineering, electronic engineering, information engineering ,Applied mathematics ,020201 artificial intelligence & image processing ,lcsh:Engineering (General). Civil engineering (General) ,Preference (economics) ,Mathematics - Abstract
This paper investigates the consistency definition and the weight-deriving method for additive interval fuzzy preference relations (IFPRs) using a particular characterization based on logarithms. In a recently published paper, a new approach with a parameter is developed to obtain priority weights from fuzzy preference relations (FPRs), then a new consistency definition for the additive IFPRs is defined, and finally linear programming models for deriving interval weights from consistent and inconsistent IFPRs are proposed. However, the discussion of the parameter value is not adequate and the weights obtained by the linear models for inconsistent IFPRs are dependent on alternative labels and not robust to permutations of the decision makers’ judgments. In this paper, we first investigate the value of the parameter more thoroughly and give the closed form solution for the parameter. Then, we design a numerical example to illustrate the drawback of the linear models. Finally, we construct a linear model to derive interval weights from IFPRs based on the additive transitivity based consistency definition. To demonstrate the effectiveness of our proposed method, we compare our method to the existing method on three numerical examples. The results show that our method performs better on both consistent and inconsistent IFPRs.
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- 2018
43. Multiple Nontrivial Solutions for a Class of Biharmonic Elliptic Equations with Sobolev Critical Exponent
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Xiaoyong Qian, Jun Wang, and Maochun Zhu
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Pure mathematics ,Article Subject ,General Mathematics ,lcsh:Mathematics ,010102 general mathematics ,General Engineering ,MathematicsofComputing_NUMERICALANALYSIS ,Mathematics::Analysis of PDEs ,Multiplicity (mathematics) ,lcsh:QA1-939 ,01 natural sciences ,010101 applied mathematics ,Sobolev space ,Elliptic curve ,lcsh:TA1-2040 ,Bounded function ,Biharmonic equation ,0101 mathematics ,lcsh:Engineering (General). Civil engineering (General) ,Critical exponent ,Mathematics - Abstract
In this paper, we study the existence and multiplicity of nontrivial solutions for a class of biharmonic elliptic equation with Sobolev critical exponent in a bounded domain. By using the idea of the previous paper, we generalize the results and prove the existence and multiplicity of nontrivial solutions of the biharmonic elliptic equations.
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- 2018
44. Further Results on Diagonally Invariant Exponential Stability of Switching Linear Systems
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Mihaela-Hanako Matcovschi and Octavian Pastravanu
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0209 industrial biotechnology ,Article Subject ,lcsh:Mathematics ,General Mathematics ,020208 electrical & electronic engineering ,Linear system ,Diagonal ,General Engineering ,Matrix norm ,02 engineering and technology ,Invariant (physics) ,lcsh:QA1-939 ,020901 industrial engineering & automation ,Exponential stability ,lcsh:TA1-2040 ,0202 electrical engineering, electronic engineering, information engineering ,Applied mathematics ,lcsh:Engineering (General). Civil engineering (General) ,Analysis method ,Eigenvalues and eigenvectors ,Mathematics - Abstract
The concept of diagonally invariant exponential stability (DIES) was originally introduced for single-model linear systems and subsequently expanded in the study of linear systems with interval-type uncertainties and linear systems with arbitrary switching. The results presented in this article refer to new approaches to DIES characterization for arbitrary switching systems, which exploit mathematical tools completely different from earlier work. The previous papers are based on the properties of matrix norms and measures applied to the constituent matrices defining the switching system, while the present paper uses the eigenvalues and eigenvectors of the column and row representatives built for a set of matrices derived from the constituent matrices of the switching system. The applicability of previous and new results, respectively, is illustrated by case studies (in both continuous- and discrete-time) that lead to relevant comparisons between the two classes of analysis methods.
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- 2018
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45. Exponential Stability of Antiperiodic Solution for BAM Neural Networks with Time-Varying Delays
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Quanxin Zhu, Xiaofei Li, and Chuan Qin
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Lyapunov function ,Artificial neural network ,Article Subject ,General Mathematics ,lcsh:Mathematics ,010102 general mathematics ,General Engineering ,02 engineering and technology ,lcsh:QA1-939 ,01 natural sciences ,symbols.namesake ,Exponential stability ,Control theory ,lcsh:TA1-2040 ,Negative feedback ,0202 electrical engineering, electronic engineering, information engineering ,symbols ,020201 artificial intelligence & image processing ,0101 mathematics ,lcsh:Engineering (General). Civil engineering (General) ,Mathematics ,Leakage (electronics) - Abstract
In this paper, a kind of BAM neural networks with leakage delays in the negative feedback terms and time-varying delays in activation functions was considered. By constructing a suitable Lyapunov function and using inequality techniques, some sufficient conditions to ensure the existence and exponential stability of antiperiodic solutions of these neural networks were derived. These conditions extend some results recently appearing in recent papers. Lastly, an example is given to show the feasibility of these conditions.
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- 2018
46. Bounding the Dynamics of a Chaotic-Cancer Mathematical Model
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Corina Plata, Paul A. Valle, Diana Gamboa, and Luis N. Coria
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0301 basic medicine ,Lyapunov stability ,education.field_of_study ,Mathematical model ,Article Subject ,lcsh:Mathematics ,General Mathematics ,Population ,General Engineering ,Chaotic ,Ode ,lcsh:QA1-939 ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,lcsh:TA1-2040 ,030220 oncology & carcinogenesis ,Ordinary differential equation ,Attractor ,Applied mathematics ,Initial value problem ,lcsh:Engineering (General). Civil engineering (General) ,education ,Mathematics - Abstract
The complexity of cancer has motivated the development of different approaches to understand the dynamics of this large group of diseases. One that may allow us to better comprehend the behavior of cancer cells, in both short- and long-term, is mathematical modelling through ordinary differential equations. Several ODE mathematical models concerning tumor evolution and immune response have been formulated through the years, but only a few may exhibit chaotic attractors and oscillations such as stable limit cycles and periodic orbits; these dynamics are not that common among cancer systems. In this paper, we apply the Localization of Compact Invariant Sets (LCIS) method and Lyapunov stability theory to investigate the global dynamics and the main factors involved in tumor growth and immune response for a chaotic-cancer system presented by Itik and Banks in 2010. The LCIS method allows us to compute what we define as the localizing domain, which is formulated by the intersection of all lower and upper bounds of each cells population in the nonnegative octant, R+,03. Bounds of this domain are given by inequalities in terms of the system parameters. Then, we apply Lyapunov stability theory and LaSalle’s invariance principle to establish existence conditions of a global attractor. The latter implies that given any nonnegative initial condition, all trajectories will go to the largest compact invariant set (a stable equilibrium point, limit cycles, periodic orbits, or a chaotic attractor) located either inside or at the boundaries of the localizing domain. In order to complement our analysis, numerical simulations are performed throughout the paper to illustrate all mathematical results and to better explain their biological implications.
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- 2018
- Full Text
- View/download PDF
47. A New Method of Blind Source Separation Using Single-Channel ICA Based on Higher-Order Statistics
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Guangkuo Lu, Ping Wei, Manlin Xiao, and Huaguo Zhang
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Article Subject ,lcsh:Mathematics ,General Mathematics ,MIMO ,General Engineering ,Higher-order statistics ,lcsh:QA1-939 ,Independent component analysis ,Blind signal separation ,Nonlinear system ,Dimension (vector space) ,lcsh:TA1-2040 ,Control theory ,Piecewise ,State space ,lcsh:Engineering (General). Civil engineering (General) ,Algorithm ,Mathematics - Abstract
Methods of utilizing independent component analysis (ICA) give little guidance about practical considerations for separating single-channel real-world data, in which most of them are nonlinear, nonstationary, and even chaotic in many fields. To solve this problem, a three-step method is provided in this paper. In the first step, the measured signal which is assumed to be piecewise higher order stationary time series is introduced and divided into a series of higher order stationary segments by applying a modified segmentation algorithm. Then the state space is reconstructed and the single-channel signal is transformed into a pseudo multiple input multiple output (MIMO) mode using a method of nonlinear analysis based on the high order statistics (HOS). In the last step, ICA is performed on the pseudo MIMO data to decompose the single channel recording into its underlying independent components (ICs) and the interested ICs are then extracted. Finally, the effectiveness and excellence of the higher order single-channel ICA (SCICA) method are validated with measured data throughout experiments. Also, the proposed method in this paper is proved to be more robust under different SNR and/or embedding dimension via explicit formulae and simulations.
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- 2015
48. Applying BAT Evolutionary Optimization to Image-Based Visual Servoing
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Sabrina Vega-Maldonado, J. Arámburo-Lizárraga, Gerardo Garcia-Gil, Daniel Zaldivar, Marco Pérez-Cisneros, and Erik Cuevas
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Article Subject ,business.industry ,lcsh:Mathematics ,General Mathematics ,Visibility (geometry) ,General Engineering ,Workspace ,lcsh:QA1-939 ,Visual servoing ,Visual control ,Constraint (information theory) ,Model predictive control ,lcsh:TA1-2040 ,Trajectory ,Computer vision ,Artificial intelligence ,lcsh:Engineering (General). Civil engineering (General) ,business ,Quaternion ,Mathematics - Abstract
This paper presents a predictive control strategy for an image-based visual servoing scheme that employs evolutionary optimization. The visual control task is approached as a nonlinear optimization problem that naturally handles relevant visual servoing constraints such as workspace limitations and visibility restrictions. As the predictive scheme requires a reliable model, this paper uses a local model that is based on the visual interaction matrix and a global model that employs 3D trajectory data extracted from a quaternion-based interpolator. The work assumes a free-flying camera with 6-DOF simulation whose results support the discussion on the constraint handling and the image prediction scheme.
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- 2015
49. Guitar Chords Classification Using Uncertainty Measurements of Frequency Bins
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Gabriel Avina-Cervantes, Jesus Guerrero-Turrubiates, Sheila Esmeralda Gonzalez-Reyna, and Sergio Ledesma
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Article Subject ,business.industry ,lcsh:Mathematics ,General Mathematics ,Fast Fourier transform ,General Engineering ,Pattern recognition ,Feature selection ,A-weighting ,Fundamental frequency ,lcsh:QA1-939 ,Thresholding ,lcsh:TA1-2040 ,Frequency domain ,Harmonics ,Chord (music) ,Artificial intelligence ,lcsh:Engineering (General). Civil engineering (General) ,business ,Mathematics - Abstract
This paper presents a method to perform chord classification from recorded audio. The signal harmonics are obtained by using the Fast Fourier Transform, and timbral information is suppressed by spectral whitening. A multiple fundamental frequency estimation of whitened data is achieved by adding attenuated harmonics by a weighting function. This paper proposes a method that performs feature selection by using a thresholding of the uncertainty of all frequency bins. Those measurements under the threshold are removed from the signal in the frequency domain. This allows a reduction of 95.53% of the signal characteristics, and the other 4.47% of frequency bins are used as enhanced information for the classifier. An Artificial Neural Network was utilized to classify four types of chords: major, minor, major 7th, and minor 7th. Those, played in the twelve musical notes, give a total of 48 different chords. Two reference methods (based on Hidden Markov Models) were compared with the method proposed in this paper by having the same database for the evaluation test. In most of the performed tests, the proposed method achieved a reasonably high performance, with an accuracy of 93%.
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- 2015
50. Joint Motion Deblurring and Superresolution from Single Blurry Image
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He Linyang, Gang Li, and Jinghong Liu
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Deblurring ,Article Subject ,business.industry ,lcsh:Mathematics ,General Mathematics ,Low resolution ,Motion blur ,Kernel density estimation ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,General Engineering ,Inverse problem ,lcsh:QA1-939 ,Superresolution ,Reconstruction problem ,Kernel (image processing) ,lcsh:TA1-2040 ,Computer vision ,Artificial intelligence ,lcsh:Engineering (General). Civil engineering (General) ,business ,Mathematics - Abstract
Currently superresolution from a motion blurred image still remains a challenging task. The conventional approach, which preprocesses the blurry low resolution (LR) image with a deblurring algorithm and employs a superresolution algorithm, has the following limitation. The high frequency texture of the image is unavoidably lost in the deblurring process and this loss restricts the performance of the subsequent superresolution process. This paper presents a novel technique that performs motion deblurring and superresolution jointly from one single blurry image. The basic idea is to regularize the ill-posed reconstruction problem using an edge-preserving gradient prior and a sparse kernel prior. This method derives from an inverse problem approach under an efficient optimization scheme that alternates between blur kernel estimation and superresolving until convergence. Furthermore, this paper proposes a simple and efficient refinement formulation to remove artifacts and render better deblurred high resolution (HR) images. The improvements brought by the proposed combined framework are demonstrated by the processing results of both simulated and real-life images. Quantitative and qualitative results on challenging examples show that the proposed method outperforms the existing state-of-the-art methods and effectively eliminates motion blur and artifacts in the superresolved image.
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- 2015
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