• Title/Summary/Keyword: Kim's model

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A viscoelastic constitutive model of rubber under small oscillatory loads superimposed on large static deformation (정적 대변형에 중첩된 미소 동적 하중을 견디는 고무재료의 점탄성 구성방정식에 관한 연구)

  • Kim, Bong-Kyu;Youn, Sung-Kie
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.280-285
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    • 2000
  • A viscoelastic constitutive equation of rubber that is under small oscillatory load superimposed on large static deformation is proposed. The proposed model is derived through linearization of Simo's viscoelastic constitutive model and reference configuration transformation. The proposed constitutive equation is extended to a generalized viscoelastic constitutive equation that includes widely used Mormin's model as a special case using objective stress increment. Static deformation correction factor is introduced to consider the influence of Pre-strain on the relaxation function. The proposed constitutive model is tested fer dynamic behavior of rubber specimens with different carbon black contents. It is concluded from the test that the viscoelastic constitutive equation for filled rubber must include the influence of the static deformation on the time effects. The suggested constitutive equation with static deformation correction factor shows good agreement with test values.

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Numerical analysis of a three-dimensional turbulent wall-jet flow (3차원 난류 벽면제트 유동의 수치해석)

  • Ryu, S.Y.;Choi, D.H.;Kim, S.J.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.479-484
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    • 2000
  • A Navier-stokes based finite volume method has been developed to analyze an incompressible, steady state, turbulent wall-jet flow. The standard k-e model, the RNG ${\kappa}-{\varepsilon}$ model and their nonlinear counterparts are adopted as a closure relationship. Comparison with the experimental data shows that a linear ${\kappa}-{\varepsilon}$ model performs satisfatorily for two-dimensional wall-jet flows. However, as the flow becomes three dimensional, the linear model fails to predict the spanwise jet growth accurately and the nonlinear model needs to be adopted to capture three-dimensional flow characteristics.

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Sub-surface Stress Analysis on Spur Gear Teeth in the EHL Conditions

  • Koo, Young-Pil;Kim, Tae-Wan;Cho, Yong-Joo
    • KSTLE International Journal
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    • v.5 no.1
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    • pp.14-22
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    • 2004
  • The sub-surface stress field beneath the gear's contact surface caused by the surface pressure in lubricated condition is analyzed. To evaluate the influence of the clearances between a gear tooth and a pinion tooth on the stress field, two kinds of tooth profile models - conventional cylinder contact model and new numerical model - were chosen. Kinematics of the gear is taken into account to obtain the numerical model which is the accurate geometric clearances between a gear tooth and a pinion tooth. Transient elasto-hydrodynamic lubrication (EHL) analysis is performed to get the surface pressure. The sub-stress field is obtained by using Love's rectangular patch solution. The analysis results show that the sub-surface stress is quite dependent on both the surface pressures and the profile models. The maximum effective stress of the new model is lower than that of the old model. The depth where the maximum effective stress occurs in the new model is not proportional to the intensity of the external load.

Determinant Factors Including Functional Attributes for Accepting Digital Multimedia Broadcasting Service (기능적 속성을 고려한 DMB 서비스의 채택 결정요인 분석)

  • Kim, Soo-Hyun
    • Journal of Information Technology Applications and Management
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    • v.14 no.4
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    • pp.61-74
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    • 2007
  • In this paper we consider the Digital Multimedia Broadcasting (DMB) Service that starts recently in Korea and gains popularity. DMB makes it possible to watch high quality TV programs while we are in motion. The service provider or the service researcher are interested in the factors that influence the user's choice of new service such as DMB. Understanding the factors make them create the powerful marketing strategies and develop the new service or product that is attractive for users. We therefore find the factors influencing the user's choice of DMB service, and propose a model for analyzing the relationship between the factors and the intention of buying. The model is based on the Technology Acceptance Model (TAM). We extend the TAM by adding factors including functional attributes of DMB service. We survey the significant functional attributes influencing the intention of buying by using the proposed model.

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Numerical and Experimental Study on Spray Atomization Characteristics of GDI Injector (직접 분사식 가솔린 기관 인젝터의 분무 미립화 특성에 대한 해석 및 실험적 연구)

  • Lee, C.S.;Rhyu, Y.;Kim, H.J.;Park, S.W.
    • Journal of ILASS-Korea
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    • v.7 no.3
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    • pp.1-6
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    • 2002
  • In this study numerical and experimental study on the spray atomization characteristics of a GDI injector is performed. To carry out numerical analysis, four hybrid models that are composed of conical sheet disintegration model, LISA model, DDB model, and RT model are used. The experimental results to evaluate the prediction accuracy of hybrid models are obtained by using phase Doppler particle analyzer and spray visualization system. It is shown that the prediction accuracy of hybrid model concerning spray developing process and spray tip penetration is good for all hybrid models, but the hybrid breakup models show different prediction of accuracy in the case of local radial SMD distribution.

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A Value-oriented System Integration Project Sizing and Cost Estimation Model (가치중심의 SI (System Integration) 사업 규모 및 비용산정 모형 구축 연구)

  • Kim, Hyun-Soo
    • Asia pacific journal of information systems
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    • v.8 no.3
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    • pp.101-118
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    • 1998
  • The purpose of this study is to construct a value-oriented sizing and cost estimation model for system integration projects. In particular, this study is to build a system architecture design and integration cost model, and a network design and implementation cost model. Unlike software development projects, system integration projects include knowledge-intensive professional services on system architecture and network design areas. Because of these work's high invisibility, the cost of these services is hard to estimate and measure. Therefore, we need to develop value-oriented cost models. This study presents 6 value-oriented cost models, and tests statistical significance of these models with real system integration project data. The results show that cost factors on these models are valid, and models are statistically significant. Future work is needed to integrate various cost models and apply the whole model to field projects to increase model's prediction accuracy.

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The Application of the Instruction Consulting Model in Elementary Science Lesson (초등학교 과학 수업에서 수업 컨설팅 모형의 적용)

  • Choi, Sun-Young;Kim, Ji-Yeoun
    • Journal of Korean Elementary Science Education
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    • v.29 no.2
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    • pp.233-241
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    • 2010
  • The purpose of this study was to apply the instruction consulting model for elementary science lesson with novice teacher. In this study the PIE(Preparation, Implementation and Evaluation stage) instruction consulting model was used. This model was introduced and offered during the electromagnet unit for sixth graders. The results of this study were as follows. First, in the assessment of the teacher's satisfaction with the instruction consulting the client teacher was found to be very satisfied. Second, the inquiry and scientific achievement for the students of the client's class were to increase in the experimental group, which demonstrated a statistically significant difference. Given the above results, the instruction consulting applied with the PIE model for novice teachers, who desire to raise the success rate of the experiment for students in the electromagnet unit of the elementary science class, helped the teachers to teach the students.

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An Information Technology Usage Level Assessment Model for Service Industry (서비스산업의 IT활용수준 평가모델 개발)

  • Kim, Hyun-Soo
    • Journal of Information Technology Services
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    • v.7 no.1
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    • pp.255-274
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    • 2008
  • The purpose of this research is to develop an information technology (IT) usage level assessment model for service industry. It is necessary to develop an assessment model for service industry's IT usage to improve service productivity. However, it is not easy to develop assessment models due to service industry's diversity. In this paper a generic IT usage assessment model for service industry has been developed and validated through a descriptive approach. Key factors affecting service productivity have been identified and analysed. A pilot test on IT usage level has been performed to investigate the relevance and importance of IT usage indicators (factors). As a result, a set of effective IT usage indicators for service industry have been found. A short-cut model and a full scale model have been proposed for efficient and effective usage. The results of this study can be used for enhancement of service industry productivity through the increase of IT usage level.

A Study on the Sale Estimate Model of a Large-Scale Store in Korea (국내 대형점의 매출추정모델 설정 방안 연구)

  • Youn, Myoung-Kil;Kim, Jong-Jin;Park, Chul-Ju;Shim, Kyu-Yeol
    • Journal of Distribution Science
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    • v.11 no.12
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    • pp.5-11
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    • 2013
  • Purpose - The purpose of this study was to construct a turnover estimation model by investigating research by Park et al. (2006) on the market area of domestic distribution. The study investigated distribution by using a new tool for the turnover estimation technique. This study developed and discussed the turnover estimation technique of Park et al. (2006), applying it to a large-scale retailer in "D"city that was suitable for on-the-spot distribution. It constructed the new model in accordance with test procedures keeping to this retail business location, to apply its procedures to a specific situation and improve the turn over estimation process. Further, it investigated the analysis and procedures of existing turnover estimation cases to provide problems and alternatives for turnover estimation for a large-scale retailer in "D"city. Finally, it also discussed problems and scope for further research. Research design, data, and methodology - This study was conducted on the basis of "virtue" studies. In other words, it took into account the special quality of the structure of Korea's trade zones. The researcher sought to verify a sale estimate model for use in a distribution industry's location. The main purpose was to enable the sale estimate model (that is, the individual model's presentation) to be practically used in real situations in Korea by supplementing processes and variables. Results - The sale estimate model is constructed, first, by conducting a data survey of the general trading area. Second, staying within the city's census of company operating areas, the city's total consumption expenditure is derived by applying the large-scale store index. Third, the probability of shopping is investigated. Fourth, the scale of sales is estimated using the process of singularity. The correct details need to be verified for the model construction and the new model will need to be a distinct sale estimate model, with this being a special quality for business conditions. This will need to be a subsequent research task. Conclusions - The study investigated, tested, and supplemented the turnover estimation model of Park et al. (2006) in a market area in South Korea. Supplementation of some procedures and variables could provide a turnover estimation model in South Korea that would be an independent model. The turnover estimation model is applied, first, by undertaking an investigation of the market area. Second, a census of the intercity market area is carried out to estimate the total consumption of the specific city. Consumption is estimated by applying indexes of large-scale retailers. Third, an investigation is undertaken on the probability of shopping. Fourth, the scale of turnover is estimated. Further studies should investigate each department as well as direct and indirect variables. The turnover estimation model should be tested to construct new models depending on the type of region and business. In-depth and careful discussion by researchers is also needed. An upgraded turnover estimation model could be developed for Korea's on-the-spot distribution.

An Analysis of the Trade Pattern of Korean Frozen Fish Products Using Gravity Model (중력모형을 이용한 우리나라 냉동 수산물의 교역형태 분석)

  • Kim, Sang-Gu;Lee, Jung-Yoon;Kim, Ki-Soo
    • The Journal of Fisheries Business Administration
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    • v.43 no.1
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    • pp.19-34
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    • 2012
  • The purpose of the paper is to find out the trade patten and characteristics of Korea's fisheries products by figuring out the factors of affecting the volume of the export of Korean frozen fisheries products based on the data of frozen fisheries (HS0303), which make up of the large volume of Korea's fisheries export using gravity model. The paper has performed regression analysis through using 624 panel data and the statistical program, STATA 12.0. In this study, we can get two results as follows: First, the total import volume of fisheries and transportation distance of trade partners have an influence on the Korea's trade of frozen fisheries products. The time and fare of transportation have also an influence on the Korea's trade of frozen fisheries products. Second, Korea's trade of frozen fisheries products is also affected by the exchange rate of currencies and settlement of FTA which could be shown as important factors in the estimation of export function of general products.