• Title/Summary/Keyword: empirical modeling

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Satellite Remote Sensing of Groundwater: modeling, algorithm development and validation

  • Ghulam, Abduwasit;Qin, Qiming
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1383-1385
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    • 2003
  • Remote sensing has been widely used in the exploration of groundwater. In this paper, on the establishment of empirical function between ground water and soil moisture content 6S code is used to reduce uncertainties in the remote sensing of groundwater. Then ground water levels are calculated using 6S corrected and uncorrected ETM+ image along with isochronous meteorological information. Greater correspondence between field examined and satellite monitoring data is obtained from corrected image than from the uncorrected image.

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Dispute of Part-Whole Representation in Conceptual Modeling (부분-전체 관계에 관한 개념적 모델링의 논의에 관하여)

  • Kim, Taekyung;Park, Jinsoo;Rho, Sangkyu
    • Journal of Intelligence and Information Systems
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    • v.18 no.4
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    • pp.97-116
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    • 2012
  • Conceptual modeling is an important step for successful system development. It helps system designers and business practitioners share the same view on domain knowledge. If the work is successful, a result of conceptual modeling can be beneficial in increasing productivity and reducing failures. However, the value of conceptual modeling is unlikely to be evaluated uniformly because we are lack of agreement on how to elicit concepts and how to represent those with conceptual modeling constructs. Especially, designing relationships between components, also known as part-whole relationships, have been regarded as complicated work. The recent study, "Representing Part-Whole Relations in Conceptual Modeling : An Empirical Evaluation" (Shanks et al., 2008), published in MIS Quarterly, can be regarded as one of positive efforts. Not only the study is one of few attempts of trying to clarify how to select modeling alternatives in part-whole design, but also it shows results based on an empirical experiment. Shanks et al. argue that there are two modeling alternatives to represent part-whole relationships : an implicit representation and an explicit one. By conducting an experiment, they insist that the explicit representation increases the value of a conceptual model. Moreover, Shanks et al. justify their findings by citing the BWW ontology. Recently, the study from Shanks et al. faces criticism. Allen and March (2012) argue that Shanks et al.'s experiment is lack of validity and reliability since the experimental setting suffers from error-prone and self-defensive design. They point out that the experiment is intentionally fabricated to support the idea, as such that using concrete UML concepts results in positive results in understanding models. Additionally, Allen and March add that the experiment failed to consider boundary conditions; thus reducing credibility. Shanks and Weber (2012) contradict flatly the argument suggested by Allen and March (2012). To defend, they posit the BWW ontology is righteously applied in supporting the research. Moreover, the experiment, they insist, can be fairly acceptable. Therefore, Shanks and Weber argue that Allen and March distort the true value of Shanks et al. by pointing out minor limitations. In this study, we try to investigate the dispute around Shanks et al. in order to answer to the following question : "What is the proper value of the study conducted by Shanks et al.?" More profoundly, we question whether or not using the BWW ontology can be the only viable option of exploring better conceptual modeling methods and procedures. To understand key issues around the dispute, first we reviewed previous studies relating to the BWW ontology. We critically reviewed both of Shanks and Weber and Allen and March. With those findings, we further discuss theories on part-whole (or part-of) relationships that are rarely treated in the dispute. As a result, we found three additional evidences that are not sufficiently covered by the dispute. The main focus of the dispute is on the errors of experimental methods: Shanks et al. did not use Bunge's Ontology properly; the refutation of a paradigm shift is lack of concrete, logical rationale; the conceptualization on part-whole relations should be reformed. Conclusively, Allen and March indicate properly issues that weaken the value of Shanks et al. In general, their criticism is reasonable; however, they do not provide sufficient answers how to anchor future studies on part-whole relationships. We argue that the use of the BWW ontology should be rigorously evaluated by its original philosophical rationales surrounding part-whole existence. Moreover, conceptual modeling on the part-whole phenomena should be investigated with more plentiful lens of alternative theories. The criticism on Shanks et al. should not be regarded as a contradiction on evaluating modeling methods of alternative part-whole representations. To the contrary, it should be viewed as a call for research on usable and useful approaches to increase value of conceptual modeling.

Effect of Omni-Channel Use and Customer-Brand Relationship (소비자 옴니채널 성향과 소비자-브랜드 관계에 관한 연구: 브랜드 경험 조절효과)

  • Park, Seung-Hwan
    • Journal of Distribution Science
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    • v.14 no.11
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    • pp.129-138
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    • 2016
  • Purpose - The ICT(information and communications technologies) development is affecting consumer behaviors on selecting channel or distribution system. This study aims to advance our knowledge about the factors influencing omni-channel behaviors. This study considers the positive brand experience as the moderating variable into the relationship between omini-channel use intention and consumer brand relation. Also, the effect of positive brand experience on consumer-brand relation is researched. Research design, data, and methodology - This study conducted an empirical test with the subject as customers who purchase goods or service through on-off cross channel simultaneously. The research model is developed from prior literatures about influencing variables on channel selection. The structure of this study is designed to identify causal relationships between the variables. 268 survey data from the questionnaire survey which is conducted to target customers who use online and offline channels, is used for empirical analysis. This study validates generality with descriptive statistics and data reliability with Cronbach's alpha value. The exploratory factor analysis is used for value purification. Then, the confirmatory factor analysis is conducted for structural equation modeling. Finally, the execute structural equation modeling is analyzed to confirm the hypotheses Results - First, the two causal influences between perceived performance risk and the propensity of omni-channel and between price consciousness and the propensity of omni-channel are verified through the empirical test. Second, the result identifies that the propensity of omni-channel is influenced on consumer-brand relationship. Third, the AMOS analysis proves that the moderating variable, positive brand experience, has significant positive impact on consumer-brand relationship. This significant relationship is highly supported by the regression analysis between brand experience and propensity of omni-channel because it results that positive brand experience has positive impact on the propensity of omni-channel. All hypotheses are verified to be true. Conclusions - Based on the empirical result, this study confirms that perceived performance risk and price consciousness are the important factors influencing propensity of omni-channel. According to the additional analysis, the moderating variable and positive brand experience plays important role between the propensity of omni-channel and consumer-brand relationship. Furthermore, positive brand experience influences more on consumer-brand relationship than non-positive brand experience.

Modeling and Simulation Framework for Assessing Interference in Multi-Hop Wireless Ad Hoc Networks

  • Woo, Shin-Uk;Hong, Jin-Pyo;Kim, Hwang-Nam
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.3 no.1
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    • pp.26-51
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    • 2009
  • In this paper, we propose an empirical framework for modeling and emulating interference in multi-hop wireless ad-hoc networks. Wireless interference causes wide variation in the frame delivery rate at a link, and thus we cannot represent the state of the link with only two states, connected state and disconnected state, as in wired networks. We first investigate wireless interference in detail, in order to accurately calibrate the interference and identify its underlying attributes, and then we simulate the diverse occurrences and effects of interference, after incorporating the scheme into a simulation tool. Based on these observations, we devise a modeling and simulation framework with several control parameters, and perform an extensive set of simulation studies. The simulation results indicate that the proposed framework enables us to examine various attributes of wireless interferences and their effects on wireless network protocols and systems.

Customer satisfaction and competitiveness in Global Company: Structural Equation Modeling(SEM) approach to identify the role quality factor (글로벌 기업의 고객만족과 경쟁력 모델 구축: 품질요인확인을 위한 구조방정식모델 적용)

  • Kim, Gye Soo;Park, Jong Cheol
    • Journal of Korean Society for Quality Management
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    • v.43 no.1
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    • pp.43-56
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    • 2015
  • Purpose: In this research, We made the conceptual frameworks for SEM(Structural Equation Modeling) on Global quality's origin and empirical research. Developing conceptual frameworks is an important step in theory building and theory testing. This research model was developed by strong theoretical foundation which is quality and systematical model. Methods: Questionnaire was developed, and data was collected and analyzed for this study. The analysis was conducted using SEM(Structural Equation Modeling). Results: Results show that process quality and interaction quality are important drivers in customer satisfaction. Customer satisfaction is strongly impact on customer loyalty(repeated purchase). Conclusion: In turbulent business era, Global company require not only excellent quality but also create customer oriented culture and control over operation in the foreign country.

Simplified FE Analysis for the Design of Pedicle Screw System (척추경 나사못 시스템의 설계를 위한 단순 유한요소해석)

  • 정일섭;안면환
    • Journal of Biomedical Engineering Research
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    • v.21 no.6
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    • pp.559-566
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    • 2000
  • Methodology for finite element analysis of vertebral column and pedicle screw system, which circumvents the tremendous difficulties in geometric, material, and structural modeling, is proposed. The simplification is focused on the modeling of the cancellous bone in vertebral body the intervertebral disc. and the instrumented internal fixation devices. Each proposed modeling technique is justified to result in reasonable accuracy. These methods are believed to be suitable for the development of pedicle screw systems, not only because modeling itself is much simpler. but also because reliable empirical data for disc stiffness may be incorporated with little additional effort, and presumably frequent design change may be easily reflected on the analysis.

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Empirical Closed Loop Modeling of a Suspension System Using Neural Network (신경회로망을 응용한 현가장치의 폐회로 시스템 규명)

  • Kim, I.Y.;Chong, K.T.;Hong, D.P.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.7
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    • pp.29-38
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    • 1997
  • A closed-loop system modeling of an active/semiactive suspension system has been accomplished through an artificial neural network. A 7DOF full model as a system's equation of motion has been derived and an output feedback linear quadratic regulator has been designed for control purpose. A training set of a sample data has been obtained through a computer simulation. A 7DOF full model with LQR controller simulated under several road conditions such as sinusoidal bumps and rectangular bumps. A general multilayer perceptron neural network is used for dynamic modeling and target outputs are fedback to the a layer. A backpropagation method is used as a training algorithm. Model validation of new dataset have been shown through computer simulations.

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Packed Bed Methane Chemical-Looping Reforming System Modeling for the Application to the Hydrogen Production (수소 생성을 위한 고정상 메탄 매체 순환 개질 시스템 모델링)

  • HA, JONGJU;SONG, SOONHO
    • Journal of Hydrogen and New Energy
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    • v.28 no.5
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    • pp.453-458
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    • 2017
  • A study on the modeling of the methane Chemical Looping Reforming system was carried out. It is aimed to predict the temperature and concentration behavior of the product through modeling of oxygen carrier fixed bed reactors composed of multiple stacks. In order to design the reaction system, first of all, the flow rate of the hydrogen to be produced was calculated. The flow rate ratio of the oxidation/reduction reactor was calculated considering the heat of reaction between adjacent reactors. Finally, in this paper, kinetic model including empirical coefficients was suggested.

Study on Wind Power Prediction model based on Spatial Modeling (공간모델링 기반의 풍력발전출력 예측 모델에 관한 연구)

  • Jung, Solyoung;Hur, Jin;Choy, Young-do
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.163-168
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    • 2015
  • In order to integrate high wind generation resources into power grid, it is an essential to predict power outputs of wind generating resources. As wind farm outputs depend on natural wind resources that vary over space and time, spatial modeling based on geographic information such as latitude and longitude is needed to estimate power outputs of wind generation resources. In this paper, we introduce the basic concept of spatial modeling and present the spatial prediction model based on Kriging techniques. The empirical data, wind farm power output in Texas, is considered to verify the proposed prediction model.

Object-Oriented Modeling Activity and Systems Development Success: Theory and Empirical Exploration (객체지향 시스템 모델링 활동과 시스템개발 성공: 이론과 실증적 탐색)

  • An, Joon-Mo
    • Asia pacific journal of information systems
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    • v.10 no.4
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    • pp.37-56
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    • 2000
  • This study proposes the concept and measurement of object-oriented systems modelling activity based on the previous research in the area of systems engineering, object-oriented modelling, and information systems. The modelling activity is related to information systems development success for exploring the correlation of each other. The object-oriented modeling activity is found to be related to user satisfaction with developed information systems, But the modeling activity does not have relation to the other successes, such as cost, development schedule, and maintenance. This study contributes to systems development modeling research, systems success, and object-oriented systems modelling research. Practically, the results support the usefulness of object-oriented modelling effort in the field in terms of user satisfaction.

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