• Smart Structures and Systems
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• 제8권4호
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• pp.343-365
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• 2011

Structural system identification (SSI) is an inverse problem of difficult solution. Currently, difficulties lie in the development of algorithms which can cater to large size problems. In this paper, a parameter estimation technique based on evolutionary strategy is presented to overcome some of the difficulties encountered in using the traditional system identification methods in terms of convergence. In this paper, a non-traditional form of system identification technique employing evolutionary algorithms is proposed. In order to improve the convergence characteristics, it is proposed to employ immune algorithms which are proved to be built with superior diversification mechanism than the conventional evolutionary algorithms and are being used for several practical complex optimisation problems. In order to reduce the number of design variables, domain decomposition methods are used, where the identification process of the entire structure is carried out in multiple stages rather than in single step. The domain decomposition based methods also help in limiting the number of sensors to be employed during dynamic testing of the structure to be identified, as the process of system identification is carried out in multiple stages. A fifteen storey framed structure, truss bridge and 40 m tall microwave tower are considered as a numerical examples to demonstrate the effectiveness of the domain decomposition based structural system identification technique using immune algorithm.

• 한국건설관리학회논문집
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• 제4권2호
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• pp.109-117
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• 2003

건설사업은 그 규모와 복잡성으로 인하여 다른 산업에 비해 위험에 대한 노출수위가 크고, 그 형태도 다양하다. 따라서, 건설사업에서 위험을 인지하고 대응하는 일련의 위험관리 과정은 정확하고 체계적으로 수행되어야 한다. 위험관리 과정에서 위험인지 단계는 다양한 위험요인의 인지와 그 위험의 성격을 규정하는 단계이고. 이러한 위험인지 단계에서 위험분류체계는 사업에 내재된 다양한 위험을 인지하게 해주는 유용한 도구이다. 본 연구에서는 기존 위험분류체계의 문제점을 개선하고 재정립함으로서, 실질적인 건설사업에서 위험인지 도구로서 활용될 수 있는 사업단계별, 계약주체별 체크리스트를 제안하였다.

• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1293-1302
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• 1999

In this paper, an on-line process scheme is presented for implementation of a intelligent on-line modeling of nonlinear complex system. The proposed on-line process scheme is composed of FNN-based model algorithm and PLC-based simulator, Here, an adaptive fuzzy-neural networks and HCM(Hard C-Means) clustering method are used as an intelligent identification algorithm for on-line modeling. The adaptive fuzzy-neural networks consists of two distinct modifiable sturctures such as the premise and the consequence part. The parameters of two structures are adapted by a combined hybrid learning algorithm of gradient decent method and least square method. Also we design an interface S/W between PLC(Proguammable Logic Controller) and main PC computer, and construct a monitoring and control simulator for real process system. Accordingly the on-line identification algorithm and interface S/W are used to obtain the on-line FNN model structure and to accomplish the on-line modeling. And using some I/O data gathered partly in the field(plant), computer simulation is carried out to evaluate the performance of FNN model structure generated by the on-line identification algorithm. This simulation results show that the proposed technique can produce the optimal fuzzy model with higher accuracy and feasibility than other works achieved previously.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2642-2649
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• 2023

A real-time unmeasured dynamic response prediction process for the nuclear power plant pressure pipeline is proposed and its performance is tested in the test-loop system (KAERI). The aim of the process is to predict unmeasurable or unreachable dynamic responses such as acceleration, velocity, and displacement by using a limited amount of directly measured physical responses. It is achieved by combining a well-constructed finite element model and robust inverse force identification algorithm. The pressure pipeline system is described by using the displacement-pressure vibro-acoustic formulation to consider fully filled liquid effect inside the pipeline structure. A robust multiphysics modal projection technique is employed for the real-time sensor synchronized prediction. The inverse force identification method is also derived and employed by using Bathe's time integration method to identify the full-field responses of the target system from the modal domain computation. To validate the performance of the proposed process, an experimental test is extensively performed on the nuclear power plant pressure pipeline test-loop under operation conditions. The results show that the proposed identification process could well estimate the unmeasured acceleration in both frequency and time domain faster than 32,768 samples per sec.

• Korean Chemical Engineering Research
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• 제61권1호
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• pp.89-96
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• 2023

동적 선형 블록과 정적 비선형 블록이 직렬로 연결되어 있는 Wiener형 비선형 모델은 여러 화학 공정의 동특성을 묘사하는데 널리 사용되는데, Wiener형 비선형 공정의 모델 확인은 다소 긴 공정 활성화 데이터가 필요하다. 본 연구는 이러한 단점을 보완하기 위하여 단일 계단 응답으로부터 Wiener형 비선형 공정 모델을 찾아낼 수 있는 새로운 모델 확인 방법을 제안한다. 제안된 방법은 계단 응답의 초기 응답으로부터 선형 동적 블록의 예측 응답을 얻어 선형 동적 블록의 모델을 확인하고, 이어서 비선형 정적 블록의 모델을 확인한다. 본 방법은 단일 계단 응답만을 사용하여 공정 모델 확인을 위해 필요한 공정 응답을 얻는 과정에서 시간과 비용적으로 큰 이득을 얻을 수 있다. 제안된 공정 확인 방법의 성능은 대표적인 Wiener형 비선형 공정인 pH 적정 공정과 액위 공정을 대상으로 검증되었다.

• 복식문화연구
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• 제24권4호
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• pp.417-430
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• 2016

This study had two aims. First, the study intended to identify the influences of product benefits and product identification on consumers' purchase intention, Second, it wanted to assess the moderating effects of consumers' aesthetic seeking tendency on their decision-making process. Based on the stimulus-organism-response (S-O-R) paradigm and the product personality-brand identification-purchase intention model, this study proposed a research model, the benefits-product identification-purchase intention model. To test the model, a survey was conducted of female college students; a total of 298 questionnaires were analyzed. The stimulus used was a popular model of Nike running footwear: the Luna Eclipse+2. Factor analysis and structural equation analysis were conducted to analyze the research model. The results indicate : (1) The aesthetic benefit influenced product identification positively. The aesthetic benefit, functional benefit and product identification were all positively related to purchase intention. (2) The aesthetic seeking tendency mediated the influences of product benefits on consumers' purchase intention in the decision-making process. For consumers in the 'high' level group of aesthetic seeking tendency, aesthetic benefit and social benefit affected purchase intention and for consumers in the 'low' level group of aesthetic seeking tendency, the functional benefit only affected purchase intention. Based on this study, we find evidence that product benefits and aesthetic seeking tendency play important roles in consumers' decision-making process in product purchase.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권4호
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• pp.221-225
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• 2004

This paper shows the application of artificial intelligence technique such as polynomial neural network in modeling and identification of sequencing batch reactor (SBR). A wastewater treatment process for nitrogen removal in the SBR is presented. Simulation results have shown that the nonlinear process can be modeled reasonably well by the Present scheme which is simple but efficient.

• 대한기계학회논문집
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• 제5권4호
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• pp.303-311
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• 1981

Machine tool dynamics is investigated under actual working conditions. Experimental evaluation of cutting dynamics in a lathe is made with cutting conditions and cutting positions varied. The thrust force and the toolpost and tailstock accelerations during turning process are modelled and analyzed by employing Dynamic Data System methodology. It is found that two acceleration signals are good enough to replace the thrust force, when used for machine tool identification under cutting process and for chatter detection.

• International journal of advanced smart convergence
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• 제4권2호
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• pp.84-93
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• 2015

This study is for the development of Cover Glass Grinding Processing System. This system is developed for manufacturing a mass product system grinding cover glasses with highly precise mechanism, and we improved resulted quality. In the development process, we developed a complete process technology through mechanical design, image processing technology, spindle control, mark identification algorithm etc. With this cover glass grinding development, we could developed process technology, image processing technology, organization mechanisms and control algorithms.

• 대한안전경영과학회지
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• 제17권2호
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• pp.1-11
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• 2015

Enterprise Risk Management(ERM) is aiming at the establishment of the risk management process to prevent and cope with risks in advance and is composed of Risk Identification, Risk Assessment, Risk Response and Monitoring. It is feedback through the Risk Re-identification. This study has analysed a sample of the risk management system of an airport operating corporation, for this purpose, relevant documents and examples of overseas airports have been reviewed. It has found that corporations establishing ERM have been performing identical procedures such as the process of Identification, Assessment, Effective Reporting, Communication and monitoring and so on. The A corporation has established the process for risk management and crisis management and organized for its organization and system. The risk management has the same process such as above. In this process, when the symptoms of critical crisis have been recognized, it has been transformed into crisis management system, through which, corporate-wide response has been conducted in the process of crisis status analysis, response and follow-up management. This study expects to contribute to systematic foundation for future business continuity on the basis of risks and response procedures acknowledged by this study.