• Title/Summary/Keyword: Measurement-based Model

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Mode shape expansion with consideration of analytical modelling errors and modal measurement uncertainty

  • Chen, Hua-Peng;Tee, Kong Fah;Ni, Yi-Qing
    • Smart Structures and Systems
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    • v.10 no.4_5
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    • pp.485-499
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    • 2012
  • Mode shape expansion is useful in structural dynamic studies such as vibration based structural health monitoring; however most existing expansion methods can not consider the modelling errors in the finite element model and the measurement uncertainty in the modal properties identified from vibration data. This paper presents a reliable approach for expanding mode shapes with consideration of both the errors in analytical model and noise in measured modal data. The proposed approach takes the perturbed force as an unknown vector that contains the discrepancies in structural parameters between the analytical model and tested structure. A regularisation algorithm based on the Tikhonov solution incorporating the L-curve criterion is adopted to reduce the influence of measurement uncertainties and to produce smooth and optimised expansion estimates in the least squares sense. The Canton Tower benchmark problem established by the Hong Kong Polytechnic University is then utilised to demonstrate the applicability of the proposed expansion approach to the actual structure. The results from the benchmark problem studies show that the proposed approach can provide reliable predictions of mode shape expansion using only limited information on the operational modal data identified from the recorded ambient vibration measurements.

Conceptualizing 5G's of Green Marketing for Retail Consumers and Validating the Measurement Model Through a Pilot Study

  • ANSARI, Hafiz Waqas Ahmed;FAUZI, Waida Irani Mohd;SALIMON, Maruf Gbadebo
    • Journal of Distribution Science
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    • v.20 no.4
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    • pp.33-50
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    • 2022
  • Purpose: This pilot study aims to conceptualize a new green marketing mix for retail consumers based on Stimulus-Organism-Response (SOR) model. Moreover, it also aims to conceptualize a testable research model of new green marketing mix with consumers' green purchasing behavior, and to validate the measurement model with traditional as well as modern suggested validating techniques. Research design, data and methodology: A pilot test data from 75 respondents of retail buyers of energy-efficient electric appliances in Pakistan were tested for the confirmatory factor analysis (CFA) by examining a measurement model of the construct through different validation techniques (like Composite Reliability, McDonald's Omega (ω), rho (ρA), HTMT, etc.) as heretofore these scales were not validated through these modern methods. Results: The results revealed that the instrument has a certain degree of reliability and validity through different validating techniques. All the measurement items reach the suggested threshold values. Conclusions: Therefore, this study conceptualized an integrated framework of all the three stakeholders of the environment (government, companies, and public or consumers) to achieve environmental sustainability. Hence, future studies can extend these findings and conduct a full-scale study to establish an empirical relationship between the 5G's of green marketing for retailing businesses and consumers' green purchase behavior.

Productivity Measurement Model Based on Quality Cost (품질 코스트를 적용한 생산성측정 모형)

  • Lee, Jae-Ung;Sin, Yong-Baek
    • Journal of Korean Society for Quality Management
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    • v.21 no.2
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    • pp.48-60
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    • 1993
  • We have depended upon the quantitative analysis for productivity measurement. and excluded the qualitative analysis from productivity measurement. But I think that the qualitative analysis must be considered so as to get a effective productivity measurement This paper intened to establish improvement productivity measurement adopted quality cost of all the qualitative elements.

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Precision Displacement Measurement of Three-DOF Micro Motions Using Position Sensitive Detector and Spherical Reflector (PSD와 구면반사를 이용한 3자유도 미소 변위의 정밀측정)

  • 이재욱;조남규
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.7
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    • pp.99-104
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    • 2003
  • A precision displacement measurement system of 3-DOF micro motions is proposed in this paper. The measurement system is composed of two diode lasers, two quadratic PSDs, two beam splitters and a sphere whose surface is highly reflective. In this measurement system, the sphere reflector is mounted on the platform of positioning devices whose 3-DOF translational motions are to be measured, and the sensitive areas of two PSDs are oriented toward the center point of the sphere reflector. Each laser beam emitted from two diode laser sources is reflected at the surface of sphere and arrives at two PSDs. Each PSD serves as a 2-dimensional sensor, providing the information on the 3-dimensional position of the sphere. In this paper, we model the relationship between the outputs of two PSDs and 3-DOF translational motions of the sphere mounted on the object. Based on a deduced measurement model, we perform measurement simulation and evaluate the performance of the proposed measurement system: linearity, sensitivity, and measurement error. The simulation results show that the proposed measurement system can be valid means of precision displacement measurement of 3-dimensional micro motions.

Nozzle Swing Angle Measurement Involving Weighted Uncertainty of Feature Points Based on Rotation Parameters

  • Liang Wei;Ju Huo;Chen Cai
    • Current Optics and Photonics
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    • v.8 no.3
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    • pp.300-306
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    • 2024
  • To solve the nozzle swing angle non-contact measurement problem, we present a nozzle pose estimation algorithm involving weighted measurement uncertainty based on rotation parameters. Firstly, the instantaneous axis of the rocket nozzle is constructed and used to model the pivot point and the nozzle coordinate system. Then, the rotation matrix and translation vector are parameterized by Cayley-Gibbs-Rodriguez parameters, and the novel object space collinearity error equation involving weighted measurement uncertainty of feature points is constructed. The nozzle pose is obtained at this step by the Gröbner basis method. Finally, the swing angle is calculated based on the conversion relationship between the nozzle static coordinate system and the nozzle dynamic coordinate system. Experimental results prove the high accuracy and robustness of the proposed method. In the space of 1.5 m × 1.5 m × 1.5 m, the maximum angle error of nozzle swing is 0.103°.

Users' Impulsive Bidding Behavior in C2C Auction Platform (C2C 옥션 플랫폼 사용자의 충동적 입찰행동에 관한 연구)

  • Park, Sang-Cheol;Kim, Jong-Uk
    • The Journal of Information Systems
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    • v.25 no.4
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    • pp.63-85
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    • 2016
  • Purpose While the popularity of C2C auction platforms such as eBay is gradually decreased, this domain is still undermined to explain online bidding behaviors. Online bidders sometimes engage in impulsive bidding due to some of the online auction characteristics. Therefore, this study develops and tests a model of the impulsive bidding exhibited by online bidders in C2C auction platforms. Based on S-O-R framework, our model posits that both perceived time-pressure and competition intensity affect cognitive absorption which ultimately influences the impulsive bidding. Design/methodology/approach This study collected survey data from 214 C2C auction participants, who have prior experience on impulsive bidding and tested both measurement model and structural model by using CB-SEM (covariate-based structural equation modelling) technique. In this study, by using AMOS 20.0, we tested the measurement model for its overall fit, item reliability, and validity and further conducted the structural model to test our proposed hypotheses. Findings Based on our results, we found that perceived tim-pressure and competition intensity were positively related to cognitive absorption. We also found that the cognitive absorption was positively associated with impulsive bidding behavior. In this study, by developing our research model in S-O-R framework, we provide an alternative theoretical mechanism to describe online impulsive bidding behavior.

Robust Nonlinear Speed Control of PM Synchronous Motor using Adaptive and Sliding Mode Control Techniques (적응제어와 슬라이딩제어를 이용한 영구자석 동기전동기의 비선형 강인제어)

  • 백인철;김경화;윤명중
    • Proceedings of the KIPE Conference
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    • 1997.07a
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    • pp.70-78
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    • 1997
  • A DSP-based nonlinear speed control of a permanent magnet synchronous motor(PMSM) which is robust to unknown parameter variations and speed measurement error is presented. The model reference adaptive system(MRAS) based adaptation mechanisms for the estimation of slowly varying parameters are derived using the Lyapunov stability theory. For the disturbances or quickly varying parameters, a quasi-linearized and decoupled model including the influence of parameter variations and speed measurement error on the nonlinear speed control of the PMSM is derived. Based on this model, a boundary layer integral sliding mode controller to improve the robustness and performance of a PMSM drive is designed and compared with the conventional controller. To show the validity of the proposed control scheme, simulations and experimental works are carried out and compared with the conventional control scheme.

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Implementation of Automated Motor Fault Diagnosis System Using GA-based Fuzzy Model (유전 알고리즘기반 퍼지 모델을 이용한 모터 고장 진단 자동화 시스템의 구현)

  • Park, Tae-Geun;Kwak, Ki-Seok;Yoon, Tae-Sung;Park, Jin-Bae
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.24-26
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    • 2005
  • At present, KS-1000 which is one of a commercial measurement instrument for motor fault diagnosis has been used in industrial field. The measurement system of KS-1000 is composed of three part : harmonic acquisition, signal processing by KS-1000 algorithm, diagnosis for motor fault. First of all, voltage signal taken from harmonic sensor is analysed for frequency by KS-1000 algorithm. Then, based on the result values of analysis skilled expert makes a judgment about whether motor system is the abnormality or degradation state. But the expert system such a motor fault diagnosis is very difficult to bring the expectable results by mathematical modeling due to the complexity of judgment process. In this reason, we propose an automation system using fuzzy model based on genetic algorithm(GA) that builded a qualitative model of a system without priori knowledge about a system provided numerical input output data.

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Application of Neural Network Based on On-Machine-Measurement Data for Machining Error Compensation (절삭가공오차보상을 위한 기상측정 데이터기반 신경회로망의 응용)

  • 서태일;박균명;조명우;윤길상
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.04a
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    • pp.376-381
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    • 2001
  • This paper presents a methodology of machining error compensation by using Artificial Neural Network(ANN) model based on the inspection database of On-Machine-Measurement(OMM) system. First, the geometric errors of the machining center and the probing errors are significantly reduced through compensation processes. Then, we acquire machining error distributions from a specimen workpiece. In order to efficiently analyze the machining errors, we define two characteristic machining error parameters. These can be modeled by using an ANN model, which allows us to determine the machining errors in the domain of considered cutting conditions. Based on this ANN model, we try to correct the tool path in order to effectively reduce the errors by using an iterative algorithm. The iterative algorithm allows us to integrate changes of the cutting conditions according to the corrected tool path. Experimentation is carried out in order to validate the approaches proposed in this paper.

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Design of Adaptive Fuzzy IMM Algorithm for Tracking the Maneuvering Target with Time-varying Measurement Noise

  • Kim, Hyun-Sik;Kim, In-Ho
    • International Journal of Control, Automation, and Systems
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    • v.5 no.3
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    • pp.307-316
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    • 2007
  • In real system application, the interacting multiple model (IMM) based algorithm operates with the following problems: it requires less computing resources as well as a good performance with respect to the various target maneuvering, it requires a robust performance with respect to the time-varying measurement noise, and further, it requires an easy design procedure in terms of its structures and parameters. To solve these problems, an adaptive fuzzy interacting multiple model (AFIMM) algorithm, which is based on the basis sub-models defined by considering the maneuvering property and the time-varying mode transition probabilities designed by using the mode probabilities as the inputs of the fuzzy decision maker whose widths are adjusted, is proposed. To verify the performance of the proposed algorithm, a radar target tracking is performed. Simulation results show that the proposed AFIMM algorithm solves all problems in the real system application of the IMM based algorithm.