• Title/Summary/Keyword: E-Model

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$K-{\varepsilon}-{\tau}$ 난류모델을 이용한 축대칭 엔진 실린더내 유동장의 수치해석 (The Numerical Analysis on In-cylinder Flow Fields of an Axisymmetric Engine Using $K-{\varepsilon}-{\tau}$ Turbulence Model)

  • 최재성
    • Journal of Advanced Marine Engineering and Technology
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    • 제23권5호
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    • pp.711-718
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    • 1999
  • Current turbulence models including modified $K-{\varepsilon}-{\tau}$ turbulence model do not predict compression effect on turbulence accurately in an internal combustion engine. The $K-{\varepsilon}-{\tau}$ turbulence model was suggested to improve the predictability of compression effect by We et al. In this paper a numeri-cal study was performed to clarify the applicability of the $K-{\varepsilon}-{\tau}$ turbulenc model to the calculation of the in-cylinder flow of an axisymmetric engine. THe results using $K-{\varepsilon}-{\tau}$ turbulence model are compared to those from the modified $K-{\varepsilon}-{\tau}$ turbulence model and experimental data. The mean veloc-ity and rms velocity profiles using $K-{\varepsilon}-{\tau}$ turbulence model showed a better agreement with an experimental data than those of modifid $K-{\varepsilon}-e$ turbulence model.

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Enhanced Distance Dynamics Model for Community Detection via Ego-Leader

  • Cai, LiJun;Zhang, Jing;Chen, Lei;He, TingQin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권5호
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    • pp.2142-2161
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    • 2018
  • Distance dynamics model is an excellent model for uncovering the community structure of a complex network. However, the model has poor robustness. To improve the robustness, we design an enhanced distance dynamics model based on Ego-Leader and propose a corresponding community detection algorithm, called E-Attractor. The main contributions of E-Attractor are as follows. First, to get rid of sensitive parameter ${\lambda}$, Ego-Leader is introduced into the distance dynamics model to determine the influence of an exclusive neighbor on the distance. Second, based on top-k Ego-Leader, we design an enhanced distance dynamics model. In contrast to the traditional model, enhanced model has better robustness for all networks. Extensive experiments show that E-Attractor has good performance relative to several state-of-the-art algorithms.

A Study on the Factors Affecting E-logistics Systems in the Chinese Logistics Industry

  • Yu, Liu;Bae, Jung-Han
    • International Commerce and Information Review
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    • 제2권1호
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    • pp.25-48
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    • 2009
  • With the rapid growth of e-logistics in the global logistics industry, it is important to gain further insight into this growing segment of Chinese logistics industry. The current situation in China consists of many small and medium-sized logistics firms. Furthermore, e-logistics is still relatively undeveloped in the majority of the Chinese logistics companies and presently there are still many problems unresolved. This paper attempted to review the concepts and theoretical background of e-logistics systems from previous studies. After acknowledging the essential issues related to e-logistics systems, a research model based on the theory acceptance model was designed and tested. The key factors to the e-logistics system (reliability, maintainability, software, facility and transportation) were validated through the modeling and testing process. Included in the modelling and testing process are other related factors of e-logistics process, logistics information system and added value as dependent variables in this model. The results of this study confirm that the e-logistics Process is affected by transportation, while maintainability and software factors influence logistics information system. reliability, maintainability, facility and transportation are significant factors associated with added value. This research aimed to provide theoretical and practical contribution to Chinese logistics companies and to give some insights into e-logistics system as a whole. The paper also provided some useful theoretical implication and practical guidelines for the development of e-logistics system in the chinese logistics industry.

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A Study on the Factors Affecting E-logistics Systems in the Chinese Logistics Industry

  • Yu, Liu;Bae, Jung-Han
    • 통상정보연구
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    • 제11권2호
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    • pp.3-26
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    • 2009
  • With the rapid growth of e-logistics in the global logistics industry, it is important to gain further insight into this growing segment of Chinese logistics industry. The current situation in China consists of many small and medium-sized logistics firms. Furthermore, e-logistics is still relatively undeveloped in the majority of the Chinese logistics companies and presently there are still many problems unresolved. This paper attempted to review the concepts and theoretical background of e-logistics systems from previous studies. After acknowledging the essential issues related to e-logistics systems, a research model based on the theory acceptance model was designed and tested. The key factors to the e-logistics system (reliability, maintainability, software, facility and transportation) were validated through the modeling and testing process. Included in the modelling and testing process are other related factors of e-logistics process, logistics information system and added value as dependent variables in this model. The results of this study confirm that the e-logistics Process is affected by transportation, while maintainability and software factors influence logistics information system. reliability, maintainability, facility and transportation are significant factors associated with added value. This research aimed to provide theoretical and practical contribution to Chinese logistics companies and to give some insights into e-logistics system as a whole. The paper also provided some useful theoretical implication and practical guidelines for the development of e-logistics system in the chinese logistics industry.

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전자우편의 활용과 성과에 관한 연구 (A Study on E-Mail Utilization and Perceived Impacts)

  • 문용은
    • 한국정보시스템학회지:정보시스템연구
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    • 제8권2호
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    • pp.29-47
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    • 1999
  • Most organization are using E-mail(electronic mail) currently, but we seldom see the organizational success from the E-mail utilization strategically. There are many research which are focusing on the selection and usage of E-mail as a electronic communication media based on Information Richness Theory and Critical Social Theory. The purpose of this study is to investigate the effects by using E-mail through providing the model of perceived impacts. This model considers the moderate factors such as top management supports, organizational usage, and organizational pressure based on CST. Also it provides the guideline how to use E-mail strategically.

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거리에 비례하는 오차를 고려한 eLoran 항법 알고리즘 (eLoran Navigation Algorithm Considering Errors Proportional to the Range)

  • 송세필;최헌호;김영백;이상정;박찬식
    • 전기학회논문지
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    • 제60권12호
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    • pp.2326-2332
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    • 2011
  • eLoran is enhanced Loran-C and eLoran is researched for as GPS backup system because this system is resistant to signal interference and has high accuracy. TOA measurements of eLoran include errors proportional to the range such as PF, SF, ASF and EF. Therefore these error factors must be compensated for improved accuracy of position. Generally, error models or GPS aided compensation methods are used, but these methods are limited by lack of infrastructure or system performance. Therefore, this paper proposes new model of error factors included in eLoran TOA measurements and navigation algorithm using this model. Error factors in this model are sum of a certain size of error and error proportional to the range. And feasibility and performance of proposed navigation algorithm are verified by using raw measurements.

A Study on Economic Value for Non-market Properties of e-Business

  • Kim, Min-Cheol
    • 한국전자거래학회:학술대회논문집
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    • 한국전자거래학회 2005년도 e-Biz World Conference 2005
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    • pp.293-298
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    • 2005
  • This paper is a study on the model that measures economic values for the non-market properties of e-Business. For development of this model, first of all, we reviewed the properties of e-Business service, and looked around the relation between customer satisfaction and/or payment value and e-Business properties. In addition, we checked the method to measure economic values of these properties. This measurement method is the contingent valuation method which is a method of measuring the value of the environmental product. We modified it to adapt to the e-Business. Finally, in this paper, we proposed an economic value model which measures the value of willingness to pay(WTP) to our objectives. However, there could be some restrictions at the time when surveying empirically. Therefore, the succeeding study should be done in order to improve these restrictions some day.

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e-러닝 기반 경영과학 강의방식에 관한 사례연구 (Case Study: e-Learning for Management Sciences Course)

  • 엄명용;김태웅
    • 경영과학
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    • 제26권3호
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    • pp.37-54
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    • 2009
  • E-learning is a networked phenomenon allowing for instant revisions and distribution, and goes beyond training and instruction to the delivery of information and tools to improve performance. The proponents of e-learning emphasizes that students learn more effectively when they interact and are involved with other students participating in similar endeavors. The paper outlines the process of development and design of e-learning based Management Sciences course, with the aim of ensuring widespread use, in undergraduate business program. Experiences in introducing students to e-learning course are reported. Feedback from students has been very positive but also indicates the need for ongoing support and direction. In addition, a survey was used to identify the determinants of students' academic performance of Management Science, and PLS based model is developed to analyze the results. Statistical results concerning the hypothesized model are provided.

전문용어기반 eDocument 관리 방안에 관한 연구 (A Study on eDocument Management Using Professional Terminologies)

  • 김명옥
    • 한국전자거래학회지
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    • 제7권2호
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    • pp.21-38
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    • 2002
  • Document retrieval (DR) has been a serious issue for long in the field of Office Information Management. Nowadays, our daily work is becoming heavily dependent on the usage of information collected from the internet, and the DR methods on the Web has become an important issue which is studied more than any other topic by many researchers. The main purpose of this study is to develop a model to manage business documents by integrating three major methodologies used in the field of electronic library and information retrieval: Metadata, Thesaurus, and Index/Reversed Index. In addition, we have added a new concept of eDocument, which consists of metadata about unit documents and/or unit document themselves. eDocument is introduced as a way to utilize existing document sources. The core concepts and structures of the model were introduced, and the architecture of the eDocument management system has been proposed. Test (simulation) result of the model and the direction for the future studies were also mentioned.

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