A decoupled approach for optimal estimation of transfer function parameters from input-output data

1994 ◽  
Vol 42 (5) ◽  
pp. 1275-1278 ◽  
Author(s):  
A.K. Shaw
Keyword(s):  
Transfer Function ◽  
Optimal Estimation ◽  
Input Output ◽  
Output Data

Damage Identification Using Sensitivity-Enhancing Control and Identified Models

2005 ◽  
Vol 128 (2) ◽  
pp. 210-220 ◽  
Author(s):  
Jason A. Solbeck ◽  
Laura R. Ray
Keyword(s):  
Transfer Function ◽  
Closed Loop ◽  
Damage Identification ◽  
Structural Models ◽  
Damage Parameter ◽  
Measured Parameter ◽  
Parameter Vector ◽  
Input Output ◽  
Output Data ◽  
Torsional System

This paper investigates a coherence approach for locating structural damage using modal frequencies and transfer function parameters identified from input-output data using Observer/Kalman filter identification (OKID). Autonomous damage identification using such forward methods generally require (i) a structural model by which to relate measured and predicted modal properties induced by damage, and (ii) good sensitivity of modal parameter changes to damage states. Using the coherence approach, a damage parameter vector comprised of a finite set of modal frequencies and transfer function parameters is hypothesized for each damage case using either identified or analytic structural models. Measured parameter vectors are extracted from experimental input-output data for a damaged structure using OKID and are compared to hypotheses to determine the most likely damage state. The richness of the parameter vector set, which is comprised of high-quality frequency measurements and lower-quality transfer function parameters, is evaluated in order to determine the ability to uniquely localize damage. The method is evaluated experimentally using a three-degree-of-freedom torsional system and a space-frame truss. Damage parameter hypotheses are generated from a model of the healthy structure developed by system identification in the torsional system, and an analytic model is used to generate damage hypotheses for the truss structure. Feedback control laws enhance the parameter vectors by including closed-loop modal frequencies in order to reduce noise sensitivity and improve uniqueness of parameter vector hypotheses to each damage case. Results show improvements in damage identification using damage parameter vectors comprised of open- and closed-loop modal frequencies, even when model error exists in structural models used to form damage parameter vector hypotheses.

The Parameters Identification of Airplane Flutter Model Based Global Nonlinear Separable Least Square Method

2012 ◽  
Vol 490-495 ◽  
pp. 2774-2779
Author(s):  
Jie Yao ◽  
Jian Hong Wang
Keyword(s):  
Transfer Function ◽  
Least Square Method ◽  
Least Square ◽  
Model Parameters ◽  
Transfer Function Model ◽  
Input Output ◽  
Function Model ◽  
Output Data ◽  
Noisy Input ◽  
Least Square Problem

considering the noisy input-output data, this paper come up with an idea extending the deviation compensation least square (CLS)to the nonlinear separable least square (NSLS).The least square method employed nonlinear separable least square adaptive to the noisy situation is able to identify accurately the airplane flutter model parameters. Combining the transfer function model, this algorithm successfully converts the identification of noisy system into nonlinear separable least square problem. The square deviation of two noises and the model parameter of the transfer function can be estimated separately by using of above algorithm.

Development of System Identification for Piezoelectric Patch Actuator

2015 ◽  
Vol 761 ◽  
pp. 245-249
Author(s):  
Mohd Nazmin Maslan ◽  
Z. Jamaludin ◽  
Muhamad Arfauz A. Rahman ◽  
Lokman Abdullah ◽  
Mohd Lutfan Abd Latib ◽  
...  
Keyword(s):  
System Identification ◽  
Transfer Function ◽  
Least Square ◽  
Input Output ◽  
Output Data ◽  
Piezoelectric Patch ◽  
Direct Measurements ◽  
Highly Nonlinear

This paper presents the development of the system identification (SI) for the highly nonlinear piezoelectric patch actuator. The transfer function is determined by using the nonlinear least square (NLS) method after the direct measurements of input-output data are taken from the actuator that is installed on a well-equipped platform. The results were validated to ensure that the transfer function derived fits well with the experimental output.

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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