• Title/Summary/Keyword: Single-model

Search Result 7,226, Processing Time 0.033 seconds

Equivalent Continuum Model for the Single Wall Carbon Nanotube (Single Wall Carbon Nanotube의 등가 연속체 모델에 대한 연구)

  • 김병구;전흥재
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2003.04a
    • /
    • pp.227-234
    • /
    • 2003
  • In this study, an equivalent continuum model for single wall carbon nanotube is proposed. The model links interatomic potentials and atom structure of a materials to a constitutive model on the continuum level. The Young's modulus and shear modulus were predicted by the model. The predictions were in good agreement with the prior experimental results available in the literatures. Also, the strain energy of the carbon nanotube was predicted as a function of the radius of the carbon nanotube.

  • PDF

Estimation of Single Evoked Potential Using ARX Model and Adaptive Filter (ARX 모델과 적응 필터를 이용한 단일 유발 전위의 추정)

  • 김명남;조진호
    • Journal of Biomedical Engineering Research
    • /
    • v.10 no.3
    • /
    • pp.303-308
    • /
    • 1989
  • A new estimationn mothod of single-EP(evoked potential) using adaptive algorithm and paralnetrlc model is proposed. Since the EEG(eletroencephalogram) signal is stationary in short time interval the AR(autoregressive) parameters of the EEG are estimated by the Burg algorithm using the EEG of prestimulus interval. After stimulus, the single-EP is estimated by adaptive algorithm. The validity of this method is verified by the simulation for generated auditory single-EP based on parametric model.

  • PDF

Probabilistic Evaluation on Prediction Accuracy of the Strains by Double Surface and Single Surface Constitutive Model (확률론에 의환 Double Surface와 Single Surface 구성모델의 변형을 예측 정도의 평가)

  • Jeong, Jin Seob;Song, Young Sun;Kim, Chan Kee
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.14 no.1
    • /
    • pp.217-229
    • /
    • 1994
  • A probabilistic method was employed to compare the prediction accuracy of axial and volumetric strains of Lade's double surface model with that of single surface model. Several experiments were conducted to examine the variabilities of soil parameters for two models using Back-ma river sand. Mean values and standard deviations of soil parameters obtained from experimental data were used for the evaluation of the uncertainty of analyzed strains by the first order approximation. It is shown that the variabilities of parameters in the single surface model are more consistent than those of the double surface model. However, in the accuracy of axial strain by probabilistic analysis, double surface model is more stable than single surface model. It is also shown that two models are excellent in view of the accuracy of the volumetric strain. The method given in this paper may be effectively utilized to estimate the constitutive model because other results of the comparison of two models coincide with those of this paper.

  • PDF

Prediction for Stress-Strain Behavior of Remolded Clay using Single Surface Constitutive Model (Single Surface 구성모델을 이용한 재성형 점토의 응력-변형률 거동 예측)

  • 이강일
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.42 no.3
    • /
    • pp.97-106
    • /
    • 2000
  • The study is closely relevant to Lade's single work hardening model. This model has been shown to have good applicability to cohesive soils. However the validation of this model on the clayey soils has not been satisfactorily reported. To scrutinize the applicability of this model on clayey foundation the laboratory tests for Kwangyang clayey soils were performed using the improved cubical triaxial test apparatus designed originally by Lade. A computer program was developed by which soil parameters for the single work-hardening model can be rationally determined by deleting some dispersed test data generated usually at the initial stage of laboratory tests. And using the program numerical analysis of the cubical clayey specimens using intermediate principal stress was carried out and a good agreement between observed values and numerical results was found.

  • PDF

Understanding the Use of Coal Char Kinetic Models in commercial CFD Codes (상용 CFD 코드에서 사용되는 촤 반응속도 모델에 대한 이해)

  • Kim, Daehee;Choi, Sangmin
    • 한국연소학회:학술대회논문집
    • /
    • 2013.06a
    • /
    • pp.91-94
    • /
    • 2013
  • Commercial computational fluid dynamics (CFD) codes traditionally rely on the computational efficiency of the simplified single-film apparent char kinetic model to predict char particle temperatures and char conversion rates in pulverized coal boilers. The aim of this study is to evaluate the reliability of the single-film apparent kinetic model and to suggest the importance of proper use of this model. For this, a parametric study was conducted with a consideration of main parameters such as Stefan flow, product species, particle evolution, and kinetic parameters.

  • PDF

A Study on Kano Model Based Global Sustainable Quality Innovation Index of Single PPM Quality Innovation Movement (Kano Model을 기반으로 한 Single PPM 품질혁신운동의 글로벌 지속가능 품질혁신(GSQI) 지수에 관한 연구)

  • Lee, Hoe-Sik;Lee, Myung-Joo;Jeong, Hae-Jun
    • Journal of the Korea Society of Computer and Information
    • /
    • v.12 no.4
    • /
    • pp.209-219
    • /
    • 2007
  • Since 100PPM Quality Certification System has been established by the Industrial Advancement Administration in 1995, 100PPM duality Innovation movement has contributed much to the enhancement of qualify competitiveness of Korea's parts industry. And in 2000, raised to a higher level, Single PPM qualify Certification System has been established by the Small and Medium Business Adminstration. The quality target is below the 10ppm(parts per million) in outgoing qualify and delivered goods plus field claim. Recently 1.818 companies is received Single PPM Quality Certification from Government. Single PPM Quality Innovation movement is perfection movement which is suitable for 21C's social-economical criteria to pursuit of zero defect. The purpose of this study is to suggest the Kano Model based Global Sustainable duality Innovation(GSQI) Index to improve current problems of Single PPM Quality Innovation Movement.

  • PDF

A Study on the Heat Release Analysis to Compensate the Error due to Assumption of Single Zone in Diesel Engine (디젤 기관 단일 영역 모델 열발생율 계산의 오차 보상에 관한 연구)

  • Ryu Seung-Hyup;Kim Ki-Doo;Yoon Wook-Hyeon;Ha Ji-Soo
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.30 no.5
    • /
    • pp.572-579
    • /
    • 2006
  • Accurate heat release analysis based on the cylinder pressure trace is important for evaluating combustion process of diesel engines. However, traditional single-zone heat release models (SZM) have significant limitations due mainly to their simplified assumptions of uniform charge and homogeneity while neglecting local temperature distribution inside cylinder during combustion process. In this study, a heat release analysis based on single-zone model has been evaluated by comparison with computational simulation result using Fire-code, which is based on multidimensional model (MDM). The limitations of the single-zone assumption have been estimated, To overcome these limitations, an improved model that includes the effects of spatial non-uniformity has been applied. From this improved single-zone heat release model (Improved-SZM), two effective values of specific heat ratios, denoted by ${\gamma}_V$ and ${\gamma}_H$ in this study, have been introduced. These values are formulated as the function of charge temperature changing rate and overall equivalence ratio. Also, it is applied that each equation of ${\gamma}_V$ and ${\gamma}_H$ has respectively different slopes according to several meaningful periods during combustion progress. The heat release analysis results based on improved single-zone model gives a good agreement with FIRE-code results over the whole range of operating conditions of target engine, Hyundai HiMSEN H21/32.

A numerical investigation of seismic performance of large span single-layer latticed domes with semi-rigid joints

  • Zhang, Huidong;Han, Qinghua
    • Structural Engineering and Mechanics
    • /
    • v.48 no.1
    • /
    • pp.57-75
    • /
    • 2013
  • It is still inadequate for investigating the highly nonlinear and complex mechanical behaviors of single-layer latticed domes by only performing a force-based demand-capacity analysis. The energy-based balance method has been largely accepted for assessing the seismic performance of a structure in recent years. The various factors, such as span-to-rise ratio, joint rigidity and damping model, have a remarkable effect on the load-carrying capacity of a single-layer latticed dome. Therefore, it is necessary to determine the maximum load-carrying capacity of a dome under extreme loading conditions. In this paper, a mechanical model for members of the semi-rigidly jointed single-layer latticed domes, which combines fiber section model with semi-rigid connections, is proposed. The static load-carrying capacity and seismic performance on the single-layer latticed domes are evaluated by means of the mechanical model. In these analyses, different geometric parameters, joint rigidities and roof loads are discussed. The buckling behaviors of members and damage distribution of the structure are presented in detail. The sensitivity of dynamic demand parameters of the structures subjected to strong earthquakes to the damping is analyzed. The results are helpful to have a better understanding of the seismic performance of the single-layer latticed domes.

The Torque Characteristics Analysis of the Single-Phase Switched Reluctance Motor According to the Starting Method (기동 방법에 따른 단상 SRM의 토크 특성 해석)

  • Kim, Jun-Ho;Kim, IL-Jung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.26 no.9
    • /
    • pp.40-46
    • /
    • 2012
  • The single-phase switched reluctance motor(SRM) has only one inductance variation and the positive torque is generated in the restricted section. So, it cannot be started by itself. To solve this problem, many researchers have addressed the several starting method for the single-phase SRM. This paper is focused on the torque characteristics of the single-phase SRM according to starting method. The four major starting method - permanent magnet, saturable stator pole, to grade the rotor, stepped rotor pole - is selected to analyze the torque characteristics. The analysis model of each starting method is designed to changed the pole shape or inserting other material in the basic model. The torque characteristics of each analysis model is obtained by using FEM analysis. The FEM analysis is performed at incremental rotor positions over half inductance cycle in any one pole with 250AT, 500AT, 750AT. The distortion factor of each analysis model is analyzed through the FFT to compare the distortion between basic model and four analysis model.

Probabilistic Evaluation on Prediction of the Strains by Single Surface Constitutive Model (확률론에 의한 Single Surface 구성모델의 변형률 예측능력 평가)

  • Jeong, Jin Seob;Song, Young Sun;Kim, Chan Kee
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.13 no.3
    • /
    • pp.163-172
    • /
    • 1993
  • A probabilistic approach for evaluation of prediction of the strains using Lade's single surface constitutive model was employed, based on first-order approximate mean and variance. Several experiments such as isotropic compression and drained triaxial compression tests were conducted to examine the variabilities of soil parameters for Lade's model. By taking into account the results of the experimental data such as mean values and standard deviations of soil parameter's, a new probabilistic approach, which explains the uncertainty of computed strains, is applied. The magnitude of the COV for each parameter and the correlation coefficient between the two parameters can be effectively used for reducing the number of the parameters for the model. It is concluded that Lade's single surface constitutive model is surperior model for the prediction of the strain, because the COV of strains is under the "0.51".

  • PDF