scholarly journals Precise piecewise affine models from input-output data

2014 ◽  
Author(s):  
Rajeev Alur ◽  
Nimit Singhania
Keyword(s):  
Input Output ◽  
Output Data ◽  
Piecewise Affine ◽  
Affine Models

scholarly journals Two steps piecewise affine identification of nonlinear systems

2012 ◽  
Vol 22 (4) ◽  
pp. 371-388 ◽  
Author(s):  
Juraj Števek ◽  
Alexander Szűcs ◽  
Michal Kvasnica ◽  
Miroslav Fikar ◽  
Štefan Kozák
Keyword(s):  
Approximation Error ◽  
Nonlinear Function ◽  
Analytic Form ◽  
Optimization Techniques ◽  
Input Output ◽  
Output Data ◽  
One Dimensional ◽  
Piecewise Affine ◽  
Affine Model ◽  
Multivariate Systems

Given a set of input-output measurements, the paper proposes a method for approximation of a nonlinear system by a piecewise affine model (PWA). First step of the two-stage procedure is identification from input-output data, in order to obtain an appropriate nonlinear function in analytic form. The analytic expression of the model can be represented either by a static nonlinear function or by a dynamic system and can be obtained using a basis function expansion modeling approach. Subsequently we employ nonlinear programming to derive optimal PWA approximation of the identified model such that the approximation error is minimized. Moreover, we show that approximation of multivariate systems can be transformed into a series of one-dimensional approximations, which can be solved efficiently using standard optimization techniques.

Parameter Identification of Piecewise Affine Dynamic Models from Input–Output Data

2003 ◽  
Vol 36 (6) ◽  
pp. 21-26
Author(s):  
Silvio Simani ◽  
Sergio Beghelli ◽  
Cesare Fantuzzi ◽  
Riccardo Rovatti
Keyword(s):  
Parameter Identification ◽  
Dynamic Models ◽  
Input Output ◽  
Output Data ◽  
Piecewise Affine

scholarly journals Statistical Inference for Piecewise Affine System Identification

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hong Jianwang ◽  
Ricardo A. Ramirez-Mendoza ◽  
Xiang Yan
Keyword(s):  
System Identification ◽  
Unknown Parameter ◽  
Recursive Least Squares ◽  
Parameter Vector ◽  
Input Output ◽  
Output Data ◽  
Piecewise Affine ◽  
Affine System ◽  
Piecewise Affine System ◽  
Unknown Parameter Vector

This short note studies the problem of piecewise affine system identification, being a special nonlinear system based on our previous contribution on it. Two different identification strategies are proposed to achieve our mission, such as centralized identification and distributed identification. More specifically, for centralized identification, the total observed input-output data are used to estimate all unknown parameter vectors simultaneously without any consideration on the classification process. But for distributed identification, after the whole observed input-output data are classified into their own right subregions, then part input-output data, belonging to the same subregion, are applied to estimate the unknown parameter vector. Whatever the centralized identification and distributed identification, the final decision is to determine the unknown parameter vector in one linear form, so the recursive least squares algorithm and its modified form with the dead zone are studied to deal with the statistical noise and bounded noise, respectively. Finally, one simulation example is used to compare the identification accuracy for our considered two identification strategies.

scholarly journals Method of value chain mapping with international input–output data: application to the agricultural value chain in three Greater Mekong Subregion countries

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ikuo Kuroiwa
Keyword(s):  
Value Chain ◽  
Value Added ◽  
Input Output ◽  
Output Data ◽  
Primary Input ◽  
Goods And Services ◽  
Unit Structure ◽  
Data Application ◽  
Final Output ◽  
Greater Mekong Subregion

AbstractExtending the technique of unit structure analysis, which was originally developed by Ozaki (J Econ 73(5):720–748, 1980), this study introduces a method of value chain mapping that uses international input–output data and reveals both the upstream and downstream transactions of goods and services, as well as primary input (value added) and final output (final demand) transactions, which emerge along the entire value chain. This method is then applied to the agricultural value chain of three Greater Mekong Subregion countries: Thailand, Vietnam, and Cambodia. The results show that the agricultural value chain has been increasingly internationalized, although there is still room to benefit from participating in global value chains, especially in a country such as Cambodia. Although there are some constraints regarding the methodology and data, the method proves useful in tracing the entire value chain.

scholarly journals AOIO: Application Oriented I/O Optimization for Buffer Management

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 573
Author(s):  
Xiaochang Li ◽  
Zhengjun Zhai ◽  
Xin Ye
Keyword(s):  
System Performance ◽  
Simulation Experiment ◽  
Buffer Management ◽  
Input Output ◽  
Output Data ◽  
Program Counter ◽  
Efficient Management ◽  
Management Scheme ◽  
Buffer Cache ◽  
Management Schemes

Emerging scale-out I/O intensive applications are broadly used now, which process a large amount of data in buffer/cache for reorganization or analysis and their performances are greatly affected by the speed of the I/O system. Efficient management scheme of the limited kernel buffer plays a key role in improving I/O system performance, such as caching hinted data for reuse in future, prefetching hinted data, and expelling data not to be accessed again from a buffer, which are called proactive mechanisms in buffer management. However, most of the existing buffer management schemes cannot identify data reference regularities (i.e., sequential or looping patterns) that can benefit proactive mechanisms, and they also cannot perform in the application level for managing specified applications. In this paper, we present an A pplication Oriented I/O Optimization (AOIO) technique automatically benefiting the kernel buffer/cache by exploring the I/O regularities of applications based on program counter technique. In our design, the input/output data and the looping pattern are in strict symmetry. According to AOIO, each application can provide more appropriate predictions to operating system which achieve significantly better accuracy than other buffer management schemes. The trace-driven simulation experiment results show that the hit ratios are improved by an average of 25.9% and the execution times are reduced by as much as 20.2% compared to other schemes for the workloads we used.

The Design of Avionics System Interfaces Emulation and Verification Platform Based on QAR Data

2014 ◽  
Vol 668-669 ◽  
pp. 879-883 ◽  
Author(s):  
Yi Gang Sun ◽  
Li Sun
Keyword(s):  
Mathematical Modeling ◽  
Theoretical Data ◽  
Environmental Data ◽  
Input Output ◽  
Output Data ◽  
Running Performance ◽  
Excitation Signal ◽  
Data Platform ◽  
System Verification ◽  
System Interfaces

In order to avoid the complex mathematical modeling and ensure the reliability of avionics system verification, this paper has designed an interfaces emulation and verification platform of avionics system based on QAR data. Platform includes 2 parts: Emulator and Simulator. Simulator generates the flight environmental data which is come from QAR and transforms the data into excitation signal of devices. Emulator emulates the interface features of avionic devices according to the ICD and can be replaced with real devices. By comparing the actual input-output data of devices with QAR theoretical data, this platform can evaluate the running performance of avionic systems or devices and the rationality of the ICD.

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