• Title/Summary/Keyword: Theoretical model

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

  • Suh Baek-Soo;Lee Jae-Young;Kim Yong-In;Lee Chang-Hwan
    • Geophysics and Geophysical Exploration
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    • v.5 no.2
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    • pp.78-83
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    • 2002
  • The finite element method combined with the sensitivity method is adopted for 2-dimensionl Fourier transform inversion. To improve the efficiency of inversion calculation, multi-resolution wavelet method is proposed., Theoretical data which is obtained from above method is shown to examine the proposed method. Theoretical model assumes that underground cavity is located in limestone area. In theoretical model, 16 current and potential electrodes are located to get theoretical data. It is shown that the about inversion method is very exact and useful calculation method, in case the larger model is very small such as under ground cavity.

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

  • Choi, Se-Young;Koo, Jeong-Seo;You, Won-Hee
    • Journal of the Korean Society for Railway
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    • v.14 no.3
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    • pp.203-210
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    • 2011
  • This study formulates the theoretical wheel-set model to evaluate wheel-climbing derailments of rolling stock due to collision, and verifies this theory with dynamic simulations. The impact forces occurring during collision are transmitted from a car body to axles through suspensions. As a result of combinations of horizontal and vertical forces applied to axles, rolling stock may lead to derailment. The derailment type will depend on the combinations of the horizontal and vertical forces, flange angle and friction coefficient. According to collision conditions, the wheel-lift, wheel-climbing or roll-over derailments can occur between wheel and rail. In this theoretical derailment model of wheelset, the wheel-climbing derailment types are classified into Climb-over, Climb/roll-over, and pure Roll-over according to derailment mechanism between wheel and rail, and we proposed the theoretical conditions to generate each derailment mechanism. The theoretical wheel-set model was verified by dynamic simulations.

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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    • v.24 no.12
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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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    • 2008.06a
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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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    • v.1 no.1
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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.

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

  • Kim, Young-Wann
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.7
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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.

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

  • Han, Dae-Woong;Lee, Seung-Yop;Cho, Sang-Ho
    • Proceedings of the KSME Conference
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    • 2008.11a
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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
    • Journal of Distribution Science
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    • v.12 no.5
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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.

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

  • Lee, Jeong-Ho
    • International Commerce and Information Review
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    • v.8 no.2
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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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