• Title/Summary/Keyword: Model comparison

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Analytical study of wind-rain-induced cable vibration : 2DOF model

  • Wang, L.Y.;Xu, Y.L.
    • Wind and Structures
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    • v.6 no.4
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    • pp.291-306
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    • 2003
  • Many investigations have been conducted to find out the reason behind wind-rain-induced cable vibration in cable-stayed bridges. A single-degree-of-freedom (SDOF) analytical model, which could capture main features of wind-rain-induced cable vibration, was recently presented by the writers. This paper extends the SDOF model to a 2DOF model by including the equation of motion of upper rivulet. The interaction between the upper rivulet and the cable is described in terms of nonlinear damping force, linear restoring force, and inertia force. The computed results using the 2DOF model are first compared with the results from simulated wind-rain tunnel tests, and the comparison is found satisfactory in general. The possible mechanisms of wind-rain-induced cable vibration are discussed and a parametric study is then conducted. Finally, the computed results using the 2DOF model are compared with those predicted by the SDOF model. The 2DOF model is found better than the SDOF model but the SDOF model is still acceptable for its simplicity.

The Comparison of Performance of Turbulence Model for a Transonic Axial Compressor Rotor (천음속 축류 압축기 동익의 유동장에 대한 난류 모델의 성능비교)

  • Han, Yong-Jin;Kim, Kwang-Yong;Ko, Sung-Ho
    • 유체기계공업학회:학술대회논문집
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    • 2002.12a
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    • pp.209-214
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    • 2002
  • The present study is to compare the performance of turbulence models in the analysis of the complex flowfield of an axial flow compressor. Baldwin-Lomax turbulence model and k-$\omega$ turbulence model were selected for the comparison. The thin-layer Wavier-Stokes equation was calculated by explicit, finite-difference numerical scheme. A spatially-varying time-step and an implicit residual smoothing were used to improve convergence. Experimental measurements for NASA rotor 37 were cited fer the comparison with numerical data. The compared two turbulence models gave similar performance over all except for total pressure.

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The Impact of Trust on User Acceptance of Mobile Banking : An Empirical Study on Comparison with Internet Banking Users of Wooribank (모바일뱅킹 사용의도에 신뢰가 미치는 영향 : 우리은행 인터넷뱅킹 사용자와의 비교를 중심으로)

  • Lee, Sang-Chul;Gu, Ja-Chul;Shu, Yong-Ho
    • Journal of Korean Society for Quality Management
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    • v.33 no.3
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    • pp.59-70
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    • 2005
  • The purpose of this research is to identify the impact of trust on user acceptance of mobile banking and to identify if causalities among these factors are different between Internet and mobile banking. To test this model, this research applies the technology acceptance model(TAM) that incorporates trust. Additionally, this research use structural equation modeling to test the model and examine cross-group differences using a multi-group comparison method. The empirical results indicate that all path is significant expect the path from trust to intention to use. The results of a multi-group comparison test indicated that the path from trust to attitude, from trust to intention to use, from perceived usefulness to attitude and from perceived to intention to use are different between Internet and mobile banking.

On Multiple Comparison of Geometric Means of Exponential Parameters via Graphical Model (그래프 모형을 이용한 지수분포 모수들의 기하평균 비교에 관한 연구)

  • Kim, Dae-Hwang;Kim, Hea-Jung
    • The Korean Journal of Applied Statistics
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    • v.19 no.3
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    • pp.447-460
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    • 2006
  • This paper develops a multiple comparison method for finding an optimal ordering of K geometric means of exponential parameters. This is based on the paired comparison experimental arrangement whose results can naturally be represented by a completely oriented graph. Introducing posterior preference probabilities and stochastic transitivity conditions to the graph, we obtain a new graphical model that yields criteria for the optimal ordering in the multiple comparison. Necessary theories involved in the method and some computational aspects are provided. Some numerical examples are given to illustrate the efficiency of the suggested method.

Discrimination of neutrons and gamma-rays in plastic scintillator based on spiking cortical model

  • Bing-Qi Liu;Hao-Ran Liu;Lan Chang;Yu-Xin Cheng;Zhuo Zuo;Peng Li
    • Nuclear Engineering and Technology
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    • v.55 no.9
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    • pp.3359-3366
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    • 2023
  • In this study, a spiking cortical model (SCM) based n-g discrimination method is proposed. The SCM-based algorithm is compared with three other methods, namely: (i) the pulse-coupled neural network (PCNN), (ii) the charge comparison, and (iii) the zero-crossing. The objective evaluation criteria used for the comparison are the FoM-value and the time consumption of discrimination. Experimental results demonstrated that our proposed method outperforms the other methods significantly with the highest FoM-value. Specifically, the proposed method exhibits a 34.81% improvement compared with the PCNN, a 50.29% improvement compared with the charge comparison, and a 110.02% improvement compared with the zero-crossing. Additionally, the proposed method features the second-fastest discrimination time, where it is 75.67% faster than the PCNN, 70.65% faster than the charge comparison and 38.4% slower than the zero-crossing. Our study also discusses the role and change pattern of each parameter of the SCM to guide the selection process. It concludes that the SCM's outstanding ability to recognize the dynamic information in the pulse signal, improved accuracy when compared to the PCNN, and better computational complexity enables the SCM to exhibit excellent n-γ discrimination performance while consuming less time.

Network Coding-Based Fault Diagnosis Protocol for Dynamic Networks

  • Jarrah, Hazim;Chong, Peter Han Joo;Sarkar, Nurul I.;Gutierrez, Jairo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.4
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    • pp.1479-1501
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    • 2020
  • Dependable functioning of dynamic networks is essential for delivering ubiquitous services. Faults are the root causes of network outages. The comparison diagnosis model, which automates fault's identification, is one of the leading approaches to attain network dependability. Most of the existing research has focused on stationary networks. Nonetheless, the time-free comparison model imposes no time constraints on the system under considerations, and it suits most of the diagnosis requirements of dynamic networks. This paper presents a novel protocol that diagnoses faulty nodes in diagnosable dynamic networks. The proposed protocol comprises two stages, a testing stage, which uses the time-free comparison model to diagnose faulty neighbour nodes, and a disseminating stage, which leverages a Random Linear Network Coding (RLNC) technique to disseminate the partial view of nodes. We analysed and evaluated the performance of the proposed protocol under various scenarios, considering two metrics: communication overhead and diagnosis time. The simulation results revealed that the proposed protocol diagnoses different types of faults in dynamic networks. Compared with most related protocols, our proposed protocol has very low communication overhead and diagnosis time. These results demonstrated that the proposed protocol is energy-efficient, scalable, and robust.

Performance analysis of the web site model which uses asp.net Ajax (ASP.NET Ajax를 이용한 웹 페이지 모델의 성능 분석)

  • Park, Tae-Heung;Go, Chan
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2008.10b
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    • pp.675-679
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    • 2008
  • The case which uses Ajax from the research which sees compared existing in case and have as how much effectiveness, comparison analyzed. Performance comparison from the research which sees, in order to compare the environment which is suitable the web site which is used actually most the web site model of existing which uses ASP and the web site which uses ASP.NET Ajax constructed the sample site from same condition and comparison analyzed. Two site models a data creates, comparison analyzed amendment, elimination and question right time answer back speed etc. respectively. With the comparative analytical result which leads an experiment the web site model of existing with the fact that the answer back speed of the model which uses Ajax improves.

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Evaluation and Comparison of the Solubility Models for Solute in Monosolvents

  • Min-jie Zhi;Wan-feng Chen;Yang-bo Xi
    • Korean Chemical Engineering Research
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    • v.62 no.1
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    • pp.53-69
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    • 2024
  • The solubility of Cloxacillin sodium in ethanol, 1-propanol, isopropanol, and acetone solutions was measured at different temperatures. The melting property was also tested by using a differential scanning calorimeter (DSC). Then, the solubility data were fitted using Apelblat equation and λh equation, respectively. The Wilson model and NRTL model were not utilized to correlate the test data, since Cloxacillin sodium will decompose directly after melting. For comparison purposes, the four empirical models, i.e., Apelblat equation, λh equation, Wilson model and NRTL Model, were evaluated by using 1155 solubility curves of 103 solutes tested under different monosolvents and temperatures. The comparison results indicate that the Apelblat equation is superior to the others. Furthermore, a new method (named the calculation method) for determining the Apelblat equation using only three data points was proposed to solve the problem that there may not be enough solute in the determination of solubility. The log-logistic distribution function was used to further capture the trend of the correlation and to make better quantitative comparison between predicted data and the experimental ones for the Apelblat equation determined by different methods (fitting method or calculation method). It is found that the proposed calculation method not only greatly reduces the number of test data points, but also has satisfactory prediction accuracy.

Evaluation of Two-Equation Turbulence Models with Surface Roughness Effect (표면 거칠기 효과를 고려한 2-방정식 난류 모델의 성능평가)

  • Yoon, Joon-Yong;Chun, Jung-Min;Kang, Seung-Kyu;Byun, Sung-Joon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.12
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    • pp.1681-1690
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    • 2003
  • The effect of roughness is a change in the velocity and turbulence distributions near the surface. Turbulence models with surface roughness effect are applied to the fully developed flow in a two-dimensional, rough wall channel. Modified wall function model, low-Reynolds number k-$\varepsilon$ model, and k-$\omega$ model are selected for comparison. In order to make a fair comparison, the calculation results are compared with the experimental data. The modified wall function model and the low-Reynolds number k-$\varepsilon$ model require further refinement, while the k-$\omega$ model of Wilcox performs remarkably well over a wide range of roughness values.

A Study on Turbulent Flame Propagation Model of S. I. Engines (스파크 점화기관의 난류 화염전파모델에 관한 연구)

  • 유욱재;최인용;전광민
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.10
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    • pp.2787-2796
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    • 1994
  • The modeling of combustion process is an important part in an engine simulation program. In this study, calculated results using a conventional B-K model and the other model which is called GESIM were compared with experimentally measured data of a three-cylinder spark-ignition engine under wide range of operating conditions. The burn rates calculated from the combustion models were compared with the burn rate calculated from the one-zone heat release analysis that uses measured pressure data as an input data. As a result of the two models' comparison, the GESIM combustion model conformed to be closer to the data acquired from the experiment in wide operating ranges. The GESIM model has been improved by introducing a variable that considers the flame size, the area of flame conacting the piston surface into the model, based on the comparison between the experimental result and the calculated results. The improved combustion model predicts experimental results more precisely than that of GESIM combustion model.