• Title/Summary/Keyword: study model

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Modeling of shallow landslides in an unsaturated soil slope using a coupled model

  • Kim, Yongmin;Jeong, Sangseom
    • Geomechanics and Engineering
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    • v.13 no.2
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    • pp.353-370
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    • 2017
  • This paper presents a case study and numerical investigation to study the hydro-mechanical response of a shallow landslide in unsaturated slopes subjected to rainfall infiltration using a coupled model. The coupled model was interpreted in details by expressing the balance equations for soil mixture and the coupled constitutive equations. The coupled model was verified against experimental data from the shearing-infiltration triaxial tests. A real case of shallow landslide occurred on Mt. Umyeonsan, Seoul, Korea was employed to explore the influence of rainfall infiltration on the slope stability during heavy rainfall. Numerical results showed that the coupled model accurately predicted the poromechanical behavior of a rainfall-induced landslide by simultaneously linking seepage and stress-strain problems. It was also found that the coupled model properly described progress failure of a slope in a highly transient condition. Through the comparisons between the coupled and uncoupled models, the coupled model provided more realistic analysis results under rainfall. Consequently, the coupled model was found to be feasible for the stability and seepage analysis of practical engineering problems.

A study on the adaptive predictive control of steam-reforming plant using bilinear model (쌍일차 모델을 이용한 스팀개질 플랜트의 적응예측제어에 관한 연구)

  • 오세천;여영구
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.156-159
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    • 1996
  • An adaptive predictive control for steam-reforming plant which consist of a steam-gas reformer and a waste heat steam-boiler was studied by using MIMO bilinear model. The simulation experiments of the process identification were performed by using linear and bilinear models. From the simulation results it was found that the bilinear model represented the dynamic behavior of a steam-reforming plant very well. ARMA model was used in the process identification and the adaptive predictive control. To verify the performance and effectiveness of the adaptive predictive controller proposed in this study the simulation results of steam-reforming plant control based on bilinear model were compared to those of linear model. The simulation results showed that the adaptive predictive controller based on bilinear model provides better performance than those of linear model.

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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.

A Simulation Study on Cardiac Activation Process Using the Three Dimensional Ventricular Model (3차원 심실모델을 이용한 심장의 활성화 과정에 대한 시뮬레이션 연구)

  • Lee, Kyoung-Joung;Park, Gum-Soo;Yun, Hyung-Ro
    • Journal of Biomedical Engineering Research
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    • v.13 no.2
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    • pp.97-106
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    • 1992
  • The cardiac activation process uslng three dimensional ventricular model is simulated. To study this theme, we constructed a cardiac ventricular model and simulated the cardiac activation process using the action potential duration and the activation time. The cardiac ventricular model is generated by the loglcal combination of the elliptic equations. The action potential duration could be obtained from the fact that It Is linearly distributed between model cells. The cardiac activation process was simulated by the law of "all-or-none". Based on the activation time and the action potential duration the cardiac potential at the arbitrary time after the activation of the model cell was computed. To test the validity of model, the comparison of the results of model simulation with the physiological data was performed. In conclusion, this model shows the simular results which is comparable to the 1 Pal conduction of the cardlac excitation.xcitation.

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Durability Analysis on Fatigue of Caliper Cylinder (캘리퍼 실린더의 피로에 대한 내구성 해석)

  • Han, Moonsik;Cho, Jaeung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.2
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    • pp.208-213
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    • 2015
  • In this study, two models due to the configuration of caliper cylinder among the parts of automotive brake system are studied by structural and fatigue analysis. As the maximum equivalent stress at model 2 becomes 1.5 times lower than model 1, model 2 can endure load higher than model 1. In case of fatigue damage analysis on model 1 and 2, model 1 has the damage area more than model 2. Fatigue damage at model 1 happen more than model 2. These study results can be effectively utilized with the design on caliper cylinder by anticipating prevention against its damage and investigating durability.

A Study on the Determinants of Drinking Demand and Expenditure of College Students

  • Lee, Seung-gil
    • International journal of advanced smart convergence
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    • v.10 no.4
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    • pp.215-224
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    • 2021
  • The purpose of this study is to estimate the factors that affect college students' drinking needs and spending. An analysis model to estimate the determinants affecting drinking needs was applied with a truncated Poisson model and a truncated negative binomial model. Tests to select more appropriate models of the two types were made using the comparison of log-likelihood function and the over-dispersion test. The analysis result was interpreted by applying the truncated negative binomial model as the truncated Poisson model showed over-dispersion. We also applied the Tobit model to analyze the determinantsthat affect college students' expenditure on drinking. According to the analysis, gender, grade, allowance and parental occupation were the factors influencing statistics, and gender, type of household income, and student religion were the factors influencing expenditure.

Feasibility study of improved particle swarm optimization in kriging metamodel based structural model updating

  • Qin, Shiqiang;Hu, Jia;Zhou, Yun-Lai;Zhang, Yazhou;Kang, Juntao
    • Structural Engineering and Mechanics
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    • v.70 no.5
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    • pp.513-524
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    • 2019
  • This study proposed an improved particle swarm optimization (IPSO) method ensemble with kriging model for model updating. By introducing genetic algorithm (GA) and grouping strategy together with elite selection into standard particle optimization (PSO), the IPSO is obtained. Kriging metamodel serves for predicting the structural responses to avoid complex computation via finite element model. The combination of IPSO and kriging model shall provide more accurate searching results and obtain global optimal solution for model updating compared with the PSO, Simulate Annealing PSO (SimuAPSO), BreedPSO and PSOGA. A plane truss structure and ASCE Benchmark frame structure are adopted to verify the proposed approach. The results indicated that the hybrid of kriging model and IPSO could serve for model updating effectively and efficiently. The updating results further illustrated that IPSO can provide superior convergent solutions compared with PSO, SimuAPSO, BreedPSO and PSOGA.

Numerical Model Updating for Bridge Maintenance Using Digital-Twin Model (교량 유지관리용 디지털 트윈 모델 구축을 위한 수치해석모델 개선 기법)

  • Yoon, Sang-Gwi;Shin, Soobong;Shin, Do Hyoung
    • Journal of KIBIM
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    • v.8 no.4
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    • pp.34-40
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    • 2018
  • As the number of aged bridges increases, the development of efficient bridge maintenance techniques is becoming more important. Particularly, there have been many studies on digital-twin models of bridges for maintenance and SHM (Structure Health Monitering). However, in order to use the digital-twin model for maintenance of the bridge, the model updating process that matches the structural response between the real bridge and the digital-twin bridge model must be done. This study presents a model updating method that adjusts bridge's stiffness and boundary condition with genetic algorithm (GA) using static displacements and verified proposed updating method through field test on PSC girder bridge. This study also proposes a conceptual idea to construct an efficient bridge maintenance system by applying the updated numerical analysis model to the digital-twin model.

The Effect of Cross-Model's Product Demonstration and Product Involvement on Attitudes toward the Ad

  • Taemin Kim
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.2
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    • pp.254-260
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    • 2023
  • Recently, the cross-model strategy of using male models in advertisements for women's cosmetics has been increasingly utilized. Academics have begun to discuss and study cross-model advertisements, but most of the studies have focused on the effects of the presence of a cross model. We investigated the effects of a crossmodel's product demonstration as an advertising creative strategy on consumer's attitudes toward the ad. We examined the effects of a male model demonstrating the advertised products for women's cosmetics on female consumers' attitudes toward the ad. As a result, we found that when a male model demonstrated a product in a women's product advertisement, consumers' attitudes toward the ad were more positive the higher their product involvement. Therefore, product involvement was found to be a moderating variable in the effect of cross-model product demonstration on attitudes toward the ad. This study contributes to the line of research on the effect of cross-model and product demonstration advertising, providing practical implications for advertising practitioners.

The Development of an Organizational Socialization Process Model for New Nurses using a System Dynamics Approach (시스템다이내믹스를 이용한 신규간호사의 조직사회화과정 모델 개발)

  • Choi Soon-Ook
    • Journal of Korean Academy of Nursing
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    • v.35 no.2
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    • pp.323-335
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    • 2005
  • Purpose: The purpose of this study was to examine the problems and relevant variables for effective Organizational Socialization of new nurses, to produce a causal map, to build up a simulation model and to test its validity. Method: The basic data was collected from Sep. 2002 to July 2003. The Organizational Socialization process of new nurses was analyzed through a model simulation. The VENSIM 5.0b DSS program was used to develop the study model. Result: This Model shows interrelation of these result variables: organizational commitment, job satisfaction, job performance, intention of leaving the work setting, decision making ability, and general results of Organizational Socialization. The model's factors are characteristic of organization and individual values, task-related knowledge and skills, and emotion and communication that affects new nurses' socialization process. These elements go through processes of anticipatory socialization, encounter, change and acquisition. The Model was devised to induce effective Organizational Socialization results within 24 months of its implementation. The basic model is the most efficient and will also contribute to the development of knowledge in the body of nursing. Conclusion: This study will provide proper direction for new Nurse's Organizational Socialization. Therefore, developing an Organizational Socialization Process Model is meaningful in a sense that it could provide a framework that could create effective Organizational Socialization for new nurses.