• 제목/요약/키워드: operational techniques

검색결과 366건 처리시간 0.019초

A comparative study on the subspace based system identification techniques applied on civil engineering structures

  • Bakir, Pelin Gundes;Alkan, Serhat;Eksioglu, Ender Mete
    • Smart Structures and Systems
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    • 제7권2호
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    • pp.153-167
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    • 2011
  • The Subspace based System Identification Techniques (SSIT) have been very popular within the research circles in the last decade due to their proven superiority over the other existing system identification techniques. For operational (output only) modal analysis, the stochastic SSIT and for operational modal analysis in the presence of exogenous inputs, the combined deterministic stochastic SSIT have been used in the literature. This study compares the application of the two alternative techniques on a typical school building in Istanbul using 100 Monte Carlo simulations. The study clearly shows that the combined deterministic stochastic SSIT performs superior to the stochastic SSIT when the techniques are applied on noisy data from low to mid rise stiff structures.

국내기업에서의 JIT 운용기법 중요성 평가에 관한 연구 -Compatibility를 이용한 AHP를 중심으로- (A Study on the Evaluation of JIT Operational Techniques in the Domestic Industries -Using Compatibility in the AHP-)

  • 구일섭;임익성;김태성
    • 산업경영시스템학회지
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    • 제21권48호
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    • pp.241-251
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    • 1998
  • The purpose of this study is to evaluate the relative importance of seven JIT operational techniques in Domestic industries. These techniques are used to improve manufacturing effectiveness and efficiency such as : Setup time reduction, Kanban, Multi-functional worker, U type layout, Andon(line stop), Atonomation, and Smoothing production. The new analytic hierarchy process(AHP) model is used in order to evaluate the relative importance of the seven JIT operational techniques which are used to increase the manufacturing effectiveness and efficiency. To aggregate the multi-divisions priorities, in this paper, we suggest a way which decision maker can exclude outlier matrix from group by using the concept of the compatibility in AHP.

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OPERATIONAL IDENTITIES FOR HERMITE-PSEUDO LAGUERRE TYPE MATRIX POLYNOMIALS AND THEIR APPLICATIONS

  • Bin-Saad, Maged G.;Pathan, M.A.
    • 호남수학학술지
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    • 제41권1호
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    • pp.35-49
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    • 2019
  • In this work, it is shown that the combination of operational techniques and the use of the principle of quasi-monomiality can be a very useful tool for a more general insight into the theory of matrix polynomials and for their extension. We explore the formal properties of the operational rules to derive a number of properties of certain class of matrix polynomials and discuss the operational links with various known matrix polynomials.

Operational Modal Analysis of a Wind Turbine Wing Using Acoustical Excitation

  • H. Konstantin Hansen;H. Herlufsen;N. Moller
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문집
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    • pp.863-868
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    • 2002
  • Operational Modal Analysis also known as Ambient Modal Analysis has an increasing interest in mechanical engineering. Especially on big structures where the excitation and not less important the determination of the forces is most often a problem. In a structure like a wind turbine wing where the modes occur both close in frequency and hi-directional the ambient excitation has big advantages. In this paper modal parameters are identified from the wing by operational modal analysis. For the parameter identification both parametric and non-parametric techniques are used. Advantages and disadvantages are discussed and results from the different techniques are compared

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ON SEQUENCE OF FUNCTIONS

  • Salehbhai, Ibrahim A.;Prajapati, Jyotindra C.;Shukla, Ajay K.
    • 대한수학회논문집
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    • 제28권1호
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    • pp.123-134
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    • 2013
  • Operational techniques have drawn the attention of several researchers in the study of sequence of functions and polynomials. An attempt is made to introduce a new sequence of functions by using operational techniques. Some generating relations and finite summation formulae have been obtained. The corresponding MAPLE code for obtaining above sequence of functions for different values of parameters was also discussed.

Requirement Analysis and Optimal Design of an Operational Change Detection Software

  • Lee, Young-Ran;Bang, Ki-In;Shin, Dong-Seok;Jeong, Soo;Kim, Kyung-Ok
    • 대한원격탐사학회지
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    • 제20권3호
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    • pp.189-196
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    • 2004
  • This paper describes what an operational change detection tool requires and the software which was designed and developed according to the requirements. The top requirement for the application of the software to operational change detection was identified: minimization of false detections, missing detections and operational cost. In order to meet such a requirement, the software was designed with the concept that the ultimate decision and isolation of changes must be performed manually by visual interpretation and all automatic algorithms and/or visualization techniques must be defined as support functions. In addition, the modular structure of the proposed software enables the addition of a new support function with the minimum development cost and minimum change of the operational environment.

LIE ALGEBRA AND OPERATIONAL TECHNIQUES ON THREE-VARIABLE HERMITE POLYNOMIALS

  • Shahwan, M.J.S.;Bin-Saad, Maged G.
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제24권1호
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    • pp.35-44
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    • 2017
  • The present paper aims at harnessing the technique of Lie Algebra and operational methods to derive and interpret generating relations for the three-variable Hermite Polynomials $H_n$(x, y, z) introduced recently in [2]. Certain generating relations for the polynomials related to $H_n$(x, y, z) are also obtained as special cases.

Modal Testing of Mechanical Structures Subject to Operational Excitation Forces

  • Gade, Svend;Moller, Nis B.;Herlufsen, Henrik;Brincker, Rune;Andersen, Palle
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.1162-1165
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    • 2001
  • Operational Modal Analysis also known as Output Only Modal Analysis has in the recent years been used for extracting modal parameters of civil engineering structures and is now becoming popular for mechanical structures. The advantage of the method is that no artificial excitation need to be applied to the structure or force signals to be measured. All the parameter estimation is based upon the response signals, thereby minimising the work of preparation for the test. This test case is a controlled lab set-up enabling different parameter estimation methods techniques to be used and compared to the Operational Modal Analysis. For Operational Modal Analysis two different estimation techniques are used: a non-parametric technique based on Frequency Domain Decomposition (FDD), and a parametric technique working on the raw data in time domain, a data driven Stochastic Subspace Identification (SS!) algorithm. These are compared to other methods such as traditional Modal Analysis.

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운행 중 변형형상을 이용한 에어컨 실내기 캐비닛의 소음/진동 특성 파악 및 제어 (Noise, vibration Characteristic Identification and Noise Control of Indoor Air-Conditioner's Cabinet using Operational Deflection Shape)

  • 이성진;오재응;이정윤;강태호
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.830-833
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    • 2004
  • An indoor package air-conditioner (PAC) has complex noise sources such as motor noise and fluid noise caused by the fan motor, heat transfer and shroud. Sound intensity techniques and ODS(Operational deflection shape) techniques are applied to identify the noise characteristics of an indoor air-conditioner's cabinet. The sound intensity is used to visualize the noise source locations. and the ODS to visualize the vibration pattern and to obtain the dynamic characteristics of the noise source. Acoustic intensity and operational deflection distribution are obtained in space domains as well as frequency domains. Using the visual information of source locations and its dynamic characteristics, the damping patch is applied to reduce structure borne noise in the cabinet. As a result, the noise emitted by the cabinet is reduced by 5dB.

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Development of the Expert Seasonal Prediction System: an Application for the Seasonal Outlook in Korea

  • Kim, WonMoo;Yeo, Sae-Rim;Kim, Yoojin
    • Asia-Pacific Journal of Atmospheric Sciences
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    • 제54권4호
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    • pp.563-573
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    • 2018
  • An Expert Seasonal Prediction System for operational Seasonal Outlook (ESPreSSO) is developed based on the APEC Climate Center (APCC) Multi-Model Ensemble (MME) dynamical prediction and expert-guided statistical downscaling techniques. Dynamical models have improved to provide meaningful seasonal prediction, and their prediction skills are further improved by various ensemble and downscaling techniques. However, experienced scientists and forecasters make subjective correction for the operational seasonal outlook due to limited prediction skills and biases of dynamical models. Here, a hybrid seasonal prediction system that grafts experts' knowledge and understanding onto dynamical MME prediction is developed to guide operational seasonal outlook in Korea. The basis dynamical prediction is based on the APCC MME, which are statistically mapped onto the station-based observations by experienced experts. Their subjective selection undergoes objective screening and quality control to generate final seasonal outlook products after physical ensemble averaging. The prediction system is constructed based on 23-year training period of 1983-2005, and its performance and stability are assessed for the independent 11-year prediction period of 2006-2016. The results show that the ESPreSSO has reliable and stable prediction skill suitable for operational use.