• Title/Summary/Keyword: functional model

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Application of Model-Based Systems Engineering to Large-Scale Multi-Disciplinary Systems Development (모델기반 시스템공학을 응용한 대형복합기술 시스템 개발)

  • Park, Joong-Yong;Park, Young-Won
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.8
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    • pp.689-696
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    • 2001
  • Large-scale Multi-disciplinary Systems(LMS) such as transportation, aerospace, defense etc. are complex systems in which there are many subsystems, interfaces, functions and demanding performance requirements. Because many contractors participate in the development, it is necessary to apply methods of sharing common objectives and communicating design status effectively among all of the stakeholders. The processes and methods of systems engineering which includes system requirement analysis; functional analysis; architecting; system analysis; interface control; and system specification development provide a success-oriented disciplined approach to the project. This paper shows not only the methodology and the results of model-based systems engineering to Automated Guided Transit(AGT) system as one of LMS systems, but also propose the extension of the model-based tool to help manage a project by linking WBS (Work Breakdown Structure), work organization, and PBS (Product Breakdown Structure). In performing the model-based functional analysis, the focus was on the operation concept of an example rail system at the top-level and the propulsion/braking function, a key function of the modern automated rail system. The model-based behavior analysis approach that applies a discrete-event simulation method facilitates the system functional definition and the test and verification activities. The first application of computer-aided tool, RDD-100, in the railway industry demonstrates the capability to model product design knowledge and decisions concerning key issues such as the rationale for architecting the top-level system. The model-based product design knowledge will be essential in integrating the follow-on life-cycle phase activities. production through operation and support, over the life of the AGT system. Additionally, when a new generation train system is required, the reuse of the model-based database can increase the system design productivity and effectiveness significantly.

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The Study on Functional State, Self Efficacy, and Life Satisfaction in the Elderly with Decreased Visual Acuity (시력저하노인의 기능상태, 자기효능감, 삶의 만족에 관한 연구)

  • Cha, Ki Jung;Eun, Young
    • Journal of muscle and joint health
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    • v.20 no.3
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    • pp.225-234
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    • 2013
  • Purpose: This purpose of study was to investigate the relationships among functional state, self-efficacy, and life satisfaction in the elderly with decreased visual acuity. Methods: The subjects were 162 elderly people from the G university hospital. Functional state was measured by Late-Life Function and Disability Instrument (LLFDI) and Minimum Data Set-Home Care version 2.0 (MDS HC 2.0). Self-efficacy and Life satisfaction were measured by the tool of Rho & Lee (2011) and Yoon (2007). Data were analyzed using t-test, ANOVA, Pearson's Correlation Coefficient, and logistic regression. Results: The daily life function was significantly associated with self-efficacy and vision decrease. The regression model with these two variables explained 35.6% of the variance of daily life function. IADL was significantly associated with vision decrease, age, gender, and self-efficacy. The regression model with the three variables explained 52.9% of the variance of IADL. Life satisfaction is significantly associated with self-efficacy, daily life function, vision decrease and IADL. The last regression model with the four variables explained 51.8% of the variance of life satisfaction. Conclusion: The levels of functional state, self-efficacy and life satisfaction in the elderly with decreased visual acuity were low. Self-efficacy was an important factor that influences on the functional state and life satisfaction. Therefore, nursing interventions that can enhance the self-efficacy are required in order to increase the functional state and life satisfaction in the elderly with decreased visual acuity.

EXISTENCE OF PERIODIC SOLUTIONS IN FERROELECTRIC LIQUID CRYSTALS

  • Park, Jinhae
    • Journal of the Chungcheong Mathematical Society
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    • v.23 no.3
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    • pp.571-588
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    • 2010
  • We introduce the Landau-de Gennes model in order to understand molecular structures in ferroelectric liquid crystals. We investigate equilibrium configurations of the governing energy functional by means of bifurcation analysis. In particular, we obtain periodic solutions of the functional, which is a signature of a rich variety of applications of ferroelectric materials.

ON STRICT STATIONARITY OF NONLINEAR ARMA PROCESSES WITH NONLINEAR GARCH INNOVATIONS

  • Lee, O.
    • Journal of the Korean Statistical Society
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    • v.36 no.2
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    • pp.183-200
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    • 2007
  • We consider a nonlinear autoregressive moving average model with nonlinear GARCH errors, and find sufficient conditions for the existence of a strictly stationary solution of three related time series equations. We also consider a geometric ergodicity and functional central limit theorem for a nonlinear autoregressive model with nonlinear ARCH errors. The given model includes broad classes of nonlinear models. New results are obtained, and known results are shown to emerge as special cases.

Generating Complicated Models for Time Series Using Genetic Programming

  • Yoshihara, Ikuo;Yasunaga, Moritoshi
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.146.4-146
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    • 2001
  • Various methods have been proposed for the time series prediction. Most of the conventional methods only optimize parameters of mathematical models, but to construct an appropriate functional form of the model is more difficult in the first place. We employ the Genetic Programming (GP) to construct the functional form of prediction models. Our method is distinguished because the model parameters are optimized by using Back-Propagation (BP)-like method and the prediction model includes discontinuous functions, such as if and max, as node functions for describing complicated phenomena. The above-mentioned functions are non-differentiable, but the BP method requires derivative. To solve this problem, we develop ...

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Redundant 디지털 시스템에서의 고장진단에 관한 연구

  • 김기섭;김정선
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1983.10a
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    • pp.112-117
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    • 1983
  • In this paper, a functional m-redundant system, which is me-fault tolerant, is defined based on the graph-theory. This system is designed to be t fault-diagnosable by comparing its unit's outcomes without additive test functions, and so, the system down for diagnosis is not needed. the diagnostic model for this system is presented and this effectively uses system's redundancy. It is shown that this model can be converted into Preparata's model. Thus, the diagnostic characteristics of a functional m-redundant system is analyzed by the methods originated by Preparata et al..

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Prediction of concrete strength using serial functional network model

  • Rajasekaran, S.;Lee, Seung-Chang
    • Structural Engineering and Mechanics
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    • v.16 no.1
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    • pp.83-99
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    • 2003
  • The aim of this paper is to develop the ISCOSTFUN (Intelligent System for Prediction of Concrete Strength by Functional Networks) in order to provide in-place strength information of the concrete to facilitate concrete from removal and scheduling for construction. For this purpose, the system is developed using Functional Network (FN) by learning functions instead of weights as in Artificial Neural Networks (ANN). In serial functional network, the functions are trained from enough input-output data and the input for one functional network is the output of the other functional network. Using ISCOSTFUN it is possible to predict early strength as well as 7-day and 28-day strength of concrete. Altogether seven functional networks are used for prediction of strength development. This study shows that ISCOSTFUN using functional network is very efficient for predicting the compressive strength development of concrete and it takes less computer time as compared to well known Back Propagation Neural Network (BPN).

Software development project management using Agile methodology (Agile 방법론을 이용한 소프트웨어 개발 프로젝트관리)

  • kim, tai-dal
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.1
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    • pp.155-162
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    • 2016
  • In recent years, hoping the interaction of individuals and rather than software development process and tools, and customers want software that works first, rather than a comprehensive document, in cooperation with the customer, rather than the developer negotiate a contract, to each other stick to the plan I think even more so than the value that corresponds to the change. In view of this, software development is given the autonomy and motivation to project team rather than process-oriented and have a passion and vision and human relations oriented management approach is required. In recent years, increasing the productivity benefits of agile development processes, improved quality, efficiency and customer satisfaction as is demonstrated in the methodology selected to promote the project, attention was given to the experts. Contemporary demands with regard to the methodology chosen to meet your needs, in this paper in the organization, and to solve the problems of product-based Cross functional team proposed methodology Feature Team model, this model is an organizational Cross functional team and the team is not the outcome (product) basis, were examined for the model that points to progress the development across multiple product as a functional unit, value-plan through the driven agile technique-based model and proposed a difference. And the domain analysis, required extraction by conventional JAD (joint application development) meeting the targets for the object-oriented modeling, in modeling and organize, review, aware in advance and the UML Structure and Behavior Diagrams and proposed to proceed with the project.

Structural Equation Modeling on Quality of Life in Older Adults with Osteoarthritis (퇴행성 관절염 노인의 삶의 질 구조모형)

  • Oh, Jihyun;Yi, Myungsun
    • Journal of Korean Academy of Nursing
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    • v.44 no.1
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    • pp.75-85
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    • 2014
  • Purpose: The aim of this study was to explore how individual factors, physiologic factors, symptoms, environmental factors, functional status and health perception predict the quality of life (QOL) for older adults with osteoarthritis and to provide guidelines for interventions and strategies to improve QOL in these patients. The conceptual model was based on the Wilson and Cleary's Model. Methods: Data were analyzed using SPSS WIN 20.0 and AMOS 19.0 program. Results: The proposed model was a good fit for the data based on the model fit indices. Based on the constructed model, individual factors, social support, functional status and health perception were founded to have direct effects on QOL. Symptom had a indirect effect on QOL. Social support had a significant effect on QOL, and this model explained 63.6% of the variance in QOL. Conclusion: The results of this study suggest that nursing strategies to increase QOL in this population should contain social support to promote QOL and manage functional limitations and health perception.