• Title/Summary/Keyword: empirical modeling

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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 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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A Study on Dynamic Structural Analysis for Blast Vibration by using Semi-Empirical Method (준 경험적 방법에 의한 발파진동원의 특성과 구조물 동적 해석에 관한 연구)

  • 손성완;김준호;정석영;홍성경;김동용
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.271-276
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    • 2001
  • Most engineers, related to soil and civil dynamic field, have been interested in the dynamic response of building transmitted from soil and rock to structure due to blasting. However it is not easy to estimate the dynamic response of structures and utilities due to blasting by using analytical method because of difficulties of soil modeling, prediction of excitation force and so on. In this paper, dynamic response analysis have been performed to predict vibration levels of structure due to blasting and the semi-empirical method. which is based on vibration measurement data. has been employed to consider blast vibration characteristics.

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Emotional Leadership, Leader Legitimacy, and Work Engagement in Retail Distribution Industry

  • HA, Seonmi;YOUN, SaJean;MOON, Jaeseung
    • Journal of Distribution Science
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    • v.18 no.7
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    • pp.27-36
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    • 2020
  • Purpose: The study examines how emotional leadership affects employee attitude towards work engagement. Leader legitimacy perception is chosen as the mediating variable to understand the effect of emotional leadership on employee work engagement. Research design, data and methodology: The research model is based on theory and empirical research findings in order to examine the mediating effect of leader legitimacy perception on the relationship between the manager's emotional leadership and employee work engagement. For this purpose, a survey was conducted among 188 employees of domestic retail distributors. Confirmatory factor analysis (CFA) and survey data confirmed the construct, and the hypothesis was tested by using structural equation modeling (SEM). Results: a) Emotional leadership has positive influence on leader legitimacy; b) Leader legitimacy is positively related to work engagement; c) Leader legitimacy mediates a positive relationship between emotional leadership and work engagement. However, there is no direct effect on work engagement (of employees) from emotional leadership standpoint. Conclusion: Based on the empirical results, implications and future research directions are discussed.

Impacts of E-Intermediary Use on Export Performance: A Resource Based View Perspective

  • Cho, Hyuk-Soo
    • Journal of Information Technology and Architecture
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    • v.10 no.1
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    • pp.13-22
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    • 2013
  • The Internet has motivated firms to participate in electronic commerce. With the development of electronic commerce, SMEs (small- and medium-sized enterprises) may be forced to use e-intermediaries in export marketing. This study aims at assessing e-intermediaries in various aspects. Empirical and theoretical studies are conducted to investigate determinants and effects of eintermediary use in export marketing. Based on resource-based view (RBV), the study develops a conceptual model that can address the question of which international competence and export performance are closely related to e-intermediary use by SMEs. Based on literature review and theoretical foundations, this study made four hypotheses. With AMOS, structural equation modeling (SEM) was used for testing four hypotheses. The empirical findings support all hypotheses. Last, this study suggests examining comprehensive internal and external factors in terms of e-intermediary use as an interesting topic for future research.

An Empirical Analysis of Orientation Relationship of Korean Freight Forwarders with Chinese Forwarders (한국운송주선업체의 중국업체에 대한 관계지향성 인식에 관한 연구)

  • Cho, Sam-Hyun
    • Journal of Navigation and Port Research
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    • v.28 no.8
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    • pp.699-707
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    • 2004
  • The purpose of this paper is to conduct an empirical analysis in order to how cooperative relationships such as joint venture, management cooperation and agency contracts affect the business performance of Korean freight forwarders. In order to fulfill the paper objective, this paper examines the roles of freight forwarders and business environment of Chinese markets.