• 제목/요약/키워드: Theoretical Model

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다중분해능 웨이브렛에 의한 지하공동모형의 전기비저항 역산 (Resistivity Inversion of Underground Cavity Model Using a Multi-Resolution Wavelet)

  • 서백수;이재영;김용인;이창환
    • 지구물리와물리탐사
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    • 제5권2호
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    • pp.78-83
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    • 2002
  • 본 논문에서는 유한 요소법과 민감도를 이용한 역산 알고리즘을 결합하여 물리 탐사에서 많이 사용되는 시추공-시추공 모형의 2차원 푸리에 정식화에 따른 역산문제에 적용하였다. 역산기법의 효율향상을 위해 웨이브렛의 다중 분해능 특성을 응용한 기법을 적용하였고 타당성은 수치해석을 통한 데이터를 이용하여 검증하였다. 이론모형으로는 석회암 지하공동을 존재한다고 설정하여 이론모형 지하공동모형에 16개의 전류 및 전위 전극을 사용하여 계산을 행하였다. 본 연구에 의해서 지하공동과 같은 작은 영역의 불연속 매질일 경우, 이 역산법이 정확하고 적용이 용이한 해석법임을 알 수 있었다. .

철도차량 충돌에 의한 타고오름 탈선거동 예측을 위한 단일윤축 이론모델 개발 (Development of a Theoretical Wheelset Model to Predict Wheel-climbing Derailment Behaviors Caused by Rolling Stock Collision)

  • 최세영;구정서;유원희
    • 한국철도학회논문집
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    • 제14권3호
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    • pp.203-210
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    • 2011
  • 본 논문에서는 열차 충돌로 발생되는 충격으로 차축에 큰 수직하중 및 수평하중이 부과될 때 플랜지가 레일을 타고 오르는 탈선현상을 예측할 수 있는 단일 윤축의 이론적 탈선 모델을 연구하였다. 철도차량 충돌 시 크게 타고오름(wheel-climbing), 들려오름(lift-up), 전복(roll-over) 등과 이들의 복합유형탈선이 발생할 수 있다. 타고오름 및 복합 유형의 탈선은 세 가지(Climb-over, Climb/roll-over, Roll-over)로 정의할 수 있다. 본 논문에서는 충돌 후 탈선거동을 예측하기 위하여 타고오름 및 복합 유형 탈선에 대한 단일윤축 이론모델을 제안하고, 정의한 세 가지 탈선거동이 발생하기 위한 조건을 제시하였다. 타고오름 및 복합 유형의 탈선거동을 예측하기 위하여 제안된 단일윤축 이론모델의 타당성을 단순플랜지 형상 윤축모델을 사용한 동역학 시뮬레이션을 통하여 검증하고, 타당성을 보인다.

Theoretical Study on Hydrophobicity of Amino Acids by the Solvation Free Energy Density Model

  • Kim, Jun-Hyoung;Nam, Ky-Youb;Cho, Kwang-Hwi;Choi, Seung-Hoon;Noh, Jae-Sung;No, Kyoung-Tai
    • Bulletin of the Korean Chemical Society
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    • 제24권12호
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    • pp.1742-1750
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    • 2003
  • In order to characterize the hydrophobic parameters of N-acetyl amino acid amides in 1-octanol/water, a theoretical calculation was carried out using a solvation free energy density model. The hydrophobicity parameters of the molecules are obtained with the consideration of the solvation free energy over the solvent volume surrounding the solute, using a grid model. Our method can account for the solvent accessible surface area of the molecules according to conformational variations. Through a comparison of the hydrophobicity of our calculation and that of other experimental/theoretical works, the solvation free energy density model is proven to be a useful tool for the evaluation of the hydrophobicity of amino acids and peptides. In order to evaluate the solvation free energy density model as a method of calculating the activity of drugs using the hydrophobicity of its building blocks, the contracture of Bradykinin potentiating pentapeptide was also predicted from the hydrophobicity of each residue. The solvation free energy density model can be used to employ descriptors for the prediction of peptide activities in drug discovery, as well as to calculate the hydrophobicity of amino acids.

The Effects of Fit and Social Construction on Individual Performance

  • Im, Ghi-Young
    • 한국경영정보학회:학술대회논문집
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    • 한국경영정보학회 2008년도 춘계학술대회
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    • pp.29-34
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    • 2008
  • This study examines the effects of information and communication technologies on individual performance. The literature has paid a considerable amount of attention to social influence as a determinant of individual behavior. We combine task-technology fit with concepts from adaptive structuration theory to specify social influence. In our model, we suggest that individuals should receive support from proper social construction to have additional performance improvement. Empirical data from 317 individuals across 43 teams in 10 companies is used to assess the theoretical model. Our theoretical model received support from the data.

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A new theoretical model for the dynamical analysis of Nano-Bio-Structures

  • Di Sia, Paolo
    • Advances in nano research
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    • 제1권1호
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    • pp.29-34
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    • 2013
  • The conversion of mechanical energy into electrical energy at nanoscale using piezoelectric nanowire arrays has been in detail shown by deflection of nanowires. Recently it has performed an analytical model, both at classical and at quantum level, for describing the most important quantities concerning transport phenomena; the model predicts interesting peculiarities, as high initial charge diffusion in nanodevices constituting by nanowires and permits also in particular to deduce interesting informations about the devices sensitivity, focusing on the correlation between sensitivity and high initial diffusivity of these materials at nanometric level.

길이방향으로 주름진 원통셸의 진동 해석 (Vibration Analysis of Longitudinally Corrugated Cylindrical Shells)

  • 김영완
    • 한국소음진동공학회논문집
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    • 제26권7호
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    • pp.851-856
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    • 2016
  • In this paper, the free vibration characteristics of longitudinally corrugated cylindrical shells is investigated by the theoretical analysis. The equivalent homogenization model is adapted to investigate the overall mechanical behavior of these corrugated shells. The corrugated element can be represented as an orthotropic material. Both the effective extensional and flexural stiffness of this equivalent orthotropic material are considered in the analysis. To demonstrate the validity of the proposed theoretical approach, the theoretical results are compared with those from 3D finite element analysis using ANSYS commercial code. Some numerical results are presented to check the effect of the geometric properties.

외팔보형 IPMC 구동기의 이론적 모델링과 구동특성 (Theoretical Modeling and Dynamic Characteristics of a Cantilever IPMC Actuator)

  • 한대웅;이승엽
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1521-1526
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    • 2008
  • IPMC(Ionic Polymer-Metal Comosite) exhibits large deformation, having great attention in many application fields. It generates bending moment by ion exchange polymer film. It can be quickly bended by the applied voltage across the plated electrode of the polymer film. In the present paper, we derive the theoretical modeling and dynamic analysis of bending motions of IPMC actuators using the Euler-Bernoulli beam theory. The theoretical model of a cantilever IPMC actuator estimates the moment produced by the applied voltage. The dynamic characteristics, including natural frequencies and frequency response, are calculated by the theoretical model, and they are compared with the experimental results and finite element analysis. It is shown that the mathematical modeling allows precise estimation to the voltage-driven motion of the cantilever IPMC in air.

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The Impact of Acquisition Announcements on Acquiring Firms' Alliance Partners : A Research Review and Compositive Research Model for Retail Industry

  • Koo, Ja-Seung
    • 유통과학연구
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    • 제12권5호
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    • pp.15-26
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    • 2014
  • Purpose - This study addresses an acquisition's impact on a firm's strategic relationship based on findings of existing academic studies and theoretical assertions. Through examining existing research results and theoretical grounds for an acquisition's impact on various stakeholders, this study indirectly approaches the impact on stakeholders including alliance partners. Research design, data, and methodology - This research identified a variety of related theoretical foundations and empirical studies. Research objectives of prior studies mainly focused on merging firms and direct participants of acquisition activity. In addition, academic attention on the impact on rival firms has recently been growing. However, little research on alliance partners was found. Prior studies simultaneously employed event study methodology and cross-sectional analysis to make further theoretical contributions. Results and Conclusions - Based on the findings of prior studies, this research proposed a complementary research model for future academic inquiry into the impact of an acquisition on an alliance partner's return and for predicting an acquisition announcement's effect on alliance partners.

무역업체의 전자무역 이용만족과 e-충성도에 관한 연구 (A Study on Satisfaction and e-Loyalty of the Electronic Trade of the Trade Companies)

  • 이정호
    • 통상정보연구
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    • 제8권2호
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    • pp.59-78
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    • 2006
  • Considering rapid development of Internet Portal Site Contents in Korea, it is an important issue to analyze consumers' satisfaction and e-loyalty. This research develops, and empirically test a model for explaining/predicting the satisfaction and e-loyalty with internet-based Electronic Trade Site. This paper describes a theoretical model for investigating the Satisfaction and e-Loyalty of the Electronic Trade Site. This study investigates the concept of the satisfaction, e-loyalty in Electronic Trade Site and its determinants, and tries to establish e-loyalty analyzing model. The model of the satisfaction, e-loyalty electronic trade site is tested here using data from 158 samples. Based on the research model, a comprehensive set of hypotheses is formulated and a methodology for testing them is outlined. some of the hypotheses are tested empirically to demonstrate the applicability of the theoretical model. In examining the relationships of the determinants factors, service quality satisfaction show in significantly by Reliability, Information Provided, Trustworthiness, Convenience, International of contents but that show in not significantly by Interaction. In addition, Electronic Trade site retention shows indirect effect between customer satisfaction and referral. Although our research can not show the determinants of e-loyalty in the electronic trade site the empirical result give both theoretical and managerial implication for managing the consumers' satisfaction and e-loyalty in electronic trade site.

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