• Title/Summary/Keyword: Empirical modeling

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Single Line-to-ground Fault Location and Information Modeling Based on the Interaction between Intelligent Distribution Equipment

  • Wang, Lei;Luo, Wei;Weng, Liangjie;Hu, Yongbo;Li, Bing
    • Journal of Electrical Engineering and Technology
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    • v.13 no.5
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    • pp.1807-1813
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    • 2018
  • In this paper, the fault line selection and location problems of single line-to-ground (SLG) fault in distribution network are addressed. Firstly, the adaptive filtering property for empirical mode decomposition is formulated. Then in view of the different characteristics showed by the intrinsic mode functions(IMF) under different fault inception angles obtained by empirical mode decomposition, the sign of peak value about the low-frequency IMF and the capacitance transient energy is chosen as the fault line selection criteria according to the different proportion occupied by the low-frequency components. Finally, the fault location is determined based upon the comparison result with adjacent fault passage indicators' (FPI) waveform on the strength of the interaction between the distribution terminal unit(DTU) and the FPI. Moreover, the logic nodes regarding to fault line selection and location are newly expanded according to IEC61850, which also provides reference to acquaint the DTU or FPI's function and monitoring. The simulation results validate the effectiveness of the proposed fault line selection and location methods.

A Semi-empirical Model for Microwave Polarimetric Radar Backscattering from Bare Soil Surfaces

  • Oh, Yi-Sok
    • Korean Journal of Remote Sensing
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    • v.10 no.2
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    • pp.17-35
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    • 1994
  • A semi-empirical model for microwave polarimetric radar backscattering from bare soil surfaces was developed using polarmetric radar measurements and the knowledge based on the theoretical and numerical solutions. The microwave polarimetric backscatter measurements were conducted for bare soil surfaces under a variety of roughness and moisture conditions at L-, C-, and X-band frequencies at incidence angles ranging from 10` to 70`. Since the accrate target parameters as well as the radar parameters are necessary for radar scattering modeling, a complete and accurate set of ground truth data were also collected using a laser profile meter and dielectric probes for each surface condition, from which accurate measurements were made of the rms height, correlation length, and dielectric constant. At first, the angular and spectral dependencies of the measured radar backscatter for a wide range of roughnesses and moisture conditions are examined. Then, the measured scattering behavior was tested using theoretical and numerical solutions. Based on the experimental observations and the theoretical and numerical solutions, a semi-empirical model was developed for backscattering coeffients in terms of the surface roughness parameters and the relative dielectric constant of the soil surface. The model was found to yield very good agreement with the backscattering measurements of this study as well as with independent measurements.

Mass Flow Characteristics and Empirical Modeling of R22 Flowing through Electronic Expansion Valves (R22를 적용한 전자팽창밸브의 냉매유량 특성 및 유량예측 모델링)

  • Park, Cha-Sik;Lee, Sun-Il;Kim, Yong-Chan;Lee, Young-Soo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.11
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    • pp.881-887
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    • 2006
  • The objective of this study are to analyze the flow characteristics of R22 flowing through EEVs and to develop an empirical correlation to predict the refrigerant flow rate. The mass flow rates of EEVs with different geometries were measured at various condensing temperatures, subcoolings, and EEV openings. Based on the experimental data, an empirical correlation for mass flow predictions in EEVs was developed by modifying the orifice equation. The correlation showed good agreement with the measured data for R22 with average and standard deviations of 1.4% and 6.1%, respectively. Approximately 90% of the measured data were within ${\pm}10%$ of the predictions.

An Empirical Study on the Chinese Customer's Repurchase Intention of Mobile Contents Service (중국 모바일 콘텐츠 서비스의 소비자 재구매의도에 관한 실증연구)

  • Zhang, Rui;Moon, Tae Soo
    • The Journal of Information Systems
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    • v.33 no.2
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    • pp.27-45
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    • 2024
  • Purpose The purpose of this study is to understand the important characteristics of mobile content services and to provide better content services to Chinese consumers by understanding consumer behavioral psychology about mobile content services and empirically analyzing research models with perceived usefulness, perceived enjoyment, customer attitudes, and repurchase intentions based on motivation theory. Design/methodology/approach Based on Deci(1975) Self-Determination Theory and Heijden(2004) research model, this study developed a research framework that includes perceived usefulness and perceived enjoyment to influence on repurchase intention. A questionnaire survey was conducted targeting Chinese consumers using mobile content services, and 272 valid responses were analyzed using Structural Equation Modeling (SEM). Findings According to the results of empirical analysis in this study, Chinese consumers were found to feel repurchase intention by positive impact of perceived usefulness and perceived enjoyment in the use of mobile content service. Chinese consumers still use mobile content a lot from a utilitarian perspective in relation to social life or job performance, and there is no positive effect on the use of mobile content related to perceived enjoyment. The results of this study provide the empirical results of a research model that integrates motivation theory and technology acceptance theory for the development of the mobile content industry in the future, and provide necessary insights for managers of companies that develop and distribute mobile content service.

How Google Advertisements Attract Consumers' Call-to-action and Electronic Word-of-mouth

  • Tser-Yieth Chen;Hsueh-Ling Wu;Jiun-Hua Yun
    • Asia Marketing Journal
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    • v.26 no.2
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    • pp.77-89
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    • 2024
  • This study investigated central and peripheral route factors to assess the impact of Google Advertisements on how these factors contribute to users' call-to-action (CTA) and electronic word-of-mouth (e-WOM) behaviors. We explored the persuasive effects of Google Advertisements on consumers by using a dataset of 483 valid empirical samples from Taiwan. We employed structural equation modeling (SEM) to examine the hypotheses. The empirical results of this study indicate that both peripheral (image appeal) and central (information completeness) routes positively lead to the persuasion effect. This finding confirms that the peripheral and central routes increase the persuasion effect. The empirical results indicate that the most effective pathway was image appeal to the persuasion effect and, ultimately, to call to action. Image appeal was also determined to be a secondary pathway that enhances the persuasion effect, ultimately leading to e-WOM. These findings have valuable implications for companies seeking to attract customers to purchase electronic products through the Google search engine. The novelty of our study is that it includes the peripheral route. Our study findings were derived from the symbolic value lens, rather than the central route based solely on the utilitarian and hedonistic value perspective.

An empirical study on the sustainable modeling of the multidisciplinary care teams : focus on the chronic disease (만성질병에 있어 다원적 진료팀의 지속가능 모델개발에 관한 실증적 연구)

  • Yu, Byung-Nam
    • Journal of the Korea Safety Management & Science
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    • v.15 no.4
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    • pp.209-216
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    • 2013
  • By means of the model competition, this research analyzed the factor of patient management, the factor of policy support, and the factor of medical treatment system. Concretely, the factor of policy support forms a positive effects on the factor of medical treatment system. Practically, well-established healthcare policy provide and facilitate the effective medical treatment system. of the hospital. And, in the effective medical treatment system, hospitals try to develop the patient management of the chronic disease. From the empirical research, this paper concluded that the factor of medical treatment system. mediated by the factor of policy support. Also, the factor of medical treatment system promotes the development of patient management in the chronic disease.

A Dynamic Analysis and Evaluation of a Building Structure due to Tunnel Blast by using Semi-Empirica Method (준경험적 방법을 이용한 터널발파 작업시 인접구조물의 동적해석 및 진동영향성 평가)

  • Son, Sung-Wan;Ru, Kuk-Hyun;Chun, Jong-Kun;Nam, Young-Sik;Kim, Dong-Gi
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.772-775
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    • 2005
  • Most engineers, related to soil and civil dynamic field, have been interested in the direct dynamic design of building transmitted from soil and rock to structure due to blasting. However it is not easy to estimate the dynamic response of structures due to blasting by using analytical method because of difficulties of soil modeling, prediction of excitation force and so on. In this paper, dynamic analysis have been performed to predict vibration level and evaluate dynamic safety of structure adjacent to tunnel blast and the semi empirical method, which is based on vibration measurement data, has been employed to consider blast vibration characteristics.

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The Impact of Trust on User Acceptance of Mobile Banking : An Empirical Study on Comparison with Internet Banking Users of Wooribank (모바일뱅킹 사용의도에 신뢰가 미치는 영향 : 우리은행 인터넷뱅킹 사용자와의 비교를 중심으로)

  • Lee, Sang-Chul;Gu, Ja-Chul;Shu, Yong-Ho
    • Journal of Korean Society for Quality Management
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    • v.33 no.3
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    • pp.59-70
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    • 2005
  • The purpose of this research is to identify the impact of trust on user acceptance of mobile banking and to identify if causalities among these factors are different between Internet and mobile banking. To test this model, this research applies the technology acceptance model(TAM) that incorporates trust. Additionally, this research use structural equation modeling to test the model and examine cross-group differences using a multi-group comparison method. The empirical results indicate that all path is significant expect the path from trust to intention to use. The results of a multi-group comparison test indicated that the path from trust to attitude, from trust to intention to use, from perceived usefulness to attitude and from perceived to intention to use are different between Internet and mobile banking.

Empirical modeling of flexural and splitting tensile strengths of concrete containing fly ash by GEP

  • Saridemir, Mustafa
    • Computers and Concrete
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    • v.17 no.4
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    • pp.489-498
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    • 2016
  • In this paper, the flexural strength ($f_{fs}$) and splitting tensile strength ($f_{sts}$) of concrete containing different proportions of fly ash have been modeled by using gene expression programming (GEP). Two GEP models called GEP-I and GEP-II are constituted to predict the $f_{fs}$ and $f_{sts}$ values, respectively. In these models, the age of specimen, cement, water, sand, aggregate, superplasticizer and fly ash are used as independent input parameters. GEP-I model is constructed by 292 experimental data and trisected into 170, 86 and 36 data for training, testing and validating sets, respectively. Similarly, GEP-II model is constructed by 278 experimental data and trisected into 142, 70 and 66 data for training, testing and validating sets, respectively. The experimental data used in the validating set of these models are independent from the training and testing sets. The results of the statistical parameters obtained from the models indicate that the proposed empirical models have good prediction and generalization capability.

An empirical comparison of static fuzzy relational model identification algorithms

  • Bae, Sang-Wook;Lee, Kee-Sang;Park, Gwi-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.146-151
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    • 1994
  • An empirical comparison of static fuzzy relational models which are identified with different fuzzy implication operators and inferred by different composition operators is made in case that all the information is represented by the fuzzy discretization. Four performance measures (integral of mean squared error, maximal error, fuzzy equality index and mean lack of sharpness) are adopted to evaluate and compare the quality of the fuzzy relational models both at the numerical level and logical level. As the results, the fuzzy implication operators useful in various fuzzy modeling problems are discussed and it is empirically shown that the selection of data pairs is another important factor for identifying the fuzzy model with high quality.

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