• 제목/요약/키워드: empirical modeling

검색결과 972건 처리시간 0.031초

Mechanistic Pharmacokinetic/pharmacodynamic Modeling in Isolated Perfused Organs and at the Whole-Body Level

  • Weiss, Michael
    • 대한약학회:학술대회논문집
    • /
    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
    • /
    • pp.218-219
    • /
    • 2002
  • In the past, the development of pharmacokinetic/pharmacodynamic (PK/PD) models for quantitating the time course of drug responses was mainly based on two types of models, the empirical effect compartment model that simply accounts for the delay between effect and plasma concentration (hysteresis) and the mechanism-based so-called indirect response model. The first approach traces back to a paper by Segre (1) and its application was popularized by Holford and Sheiner (2); indirect response models were introduced by Jusko's group (3). (omitted)

  • PDF

EKMA를 이용한 수원시의 장래 오존농도 예측 (Prediction of Ozone Concentration in Suwon by Empirical Kinetic Modeling Approach)

  • 서정배;장영기
    • 한국대기환경학회:학술대회논문집
    • /
    • 한국대기환경학회 1999년도 추계학술대회 논문집
    • /
    • pp.368-370
    • /
    • 1999
  • 고농도의 오존 농도를 예측ㆍ평가하기 위해서는 대상지역의 기상조건과 풍상쪽(up wind)으로부터의 오존ㆍ오존전구물질(precursor)의 중ㆍ장거리이동, VOCs 및 NOx의 배경농도 및 배출량과 관련된 VOC/NOx의 농도 특성을 파악하는 것이 필수적이다. 따라서 대상지역의 VOCs/NOx의 농도 특성에 따라 차후 고농도의 오존 생성을 예방하기 위한 오존전구물질의 저감대책이 결정되어지므로 대상지역의 광화학특성을 파악하는 것이 선행되어져야 한다.(중략)

  • PDF

신생 하이테크 산업의 동적 성장 과정과 생존 경쟁 전략: 한국 이동 전화 산업 실증 분석 (Dynamics of Industry Consolidation and Sustainable Competitive Strategy: An Empirical Portrait of Korean Telecommunications Industry)

  • 김보원;박경배
    • 한국경영과학회:학술대회논문집
    • /
    • 한국경영과학회 2004년도 추계학술대회 및 정기총회
    • /
    • pp.17-20
    • /
    • 2004
  • This research is focusing on industry dynamics of Korean Mobile Telecommunications Industry. Industry data from 1997 to April 2004 are used to analyze industry dynamics through variety use of case study and system dynamics modeling. As results, we found the importance of initial endowment, firm reputation, and handset subsidy strategy. Along with these player-based characteristics, government impacts on dynamics of competition are also investigated.

  • PDF

MSET PERFORMANCE OPTIMIZATION THROUGH REGULARIZATION

  • HINES J. WESLEY;USYNIN ALEXANDER
    • Nuclear Engineering and Technology
    • /
    • 제37권2호
    • /
    • pp.177-184
    • /
    • 2005
  • The Multivariate State Estimation Technique (MSET) is being used in Nuclear Power Plants for sensor and equipment condition monitoring. This paper presents the use of regularization methods for optimizing MSET's predictive performance. The techniques are applied to a simulated data set and a data set obtained from a nuclear power plant currently implementing empirical, on-line, equipment condition monitoring techniques. The results show that regularization greatly enhances the predictive performance. Additionally, the selection of prototype vectors is investigated and a local modeling method is presented that can be applied when computational speed is desired.

Experimental Investigation and Modeling of the Specific Enthalpy Distribution in a Spray Cone

  • Ellendt, N.;Uhlenwinkel, V.
    • 한국분말야금학회:학술대회논문집
    • /
    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
    • /
    • pp.58-59
    • /
    • 2006
  • In Spray Forming, specific enthalpy is a key parameter in the deposition process as it influences the thermal condition of the impinging droplets as well as that of the deposit surface. An empirical model for the distribution of specific enthalpy in the spray cone was developed as an easy to handle alternative to numerical models with which the descriptive partial differential equations are solved numerically. The model results were compared with the experimental data to validate its applicability.

  • PDF

옴니채널의 지각된 편리성과 유용성이 옴니채널 사용과 소비자-브랜드 관계에 미치는 영향 (Omnichannel's Perception Effect on Omnichannel Use and Customer-Brand Relationship)

  • 임덕순;한상설
    • 유통과학연구
    • /
    • 제14권7호
    • /
    • pp.83-90
    • /
    • 2016
  • Purpose - This study focuses on new type distribution channel that named as Omnichannel. Omnichannel is developed from Multichannel which is used in many distribution channels to buy or selling goods. Omnichannel basically needs an Information and Communications Technologies(ICT) to use, so researcher conduct a Technology Acceptance Model(TAM) to research model. Customer-brand relationship was used as dependent variable to focus on the role of Omnichannel. Research design, data, and methodology - The subject of this study is customer who purchase goods or service through omnichannel. Based on the literature from the preceding research analysis of TAM and customer-brand relationship, this study was constructed by the reference to previous studies, final research model design for figure out casual relationship among perceived ease of use, perceived usefulness, omnichannel use and customer-brand relationship. From 2016 February 3 to March 17, questionnaire survey targeted customers who use online and offline channels. 273 questionnaire survey had conducted, then, 252 survey data were available for empirical analysis. Researcher provide descriptive statistics for checking generality. Cronbach's alpha value was used to check the reliability of data. Exploratory factor analysis was used for purification of values and eigenvalue checking. After EFA, Confirmatory factor analysis was used to prepare structural equation modeling with executing structural equation modeling for confirming hypothesis which developed by researcher. Results - The main results of this empirical study are as follows. First, omnichannel's perceived ease of use has positive significant effect on perceived usefulness(estimate: 0.579). Moreover, omnichannel's perceived ease of use and perceived usefulness has positive significant effect on omnichannel use(estimate: 0.325,0.648). Second, using omnichannel has positive significant effect on brand-customer relationship(estimate: 0.521). Every hypothesis adopted as researcher designed. This study found out the intermediate relationship between perceived ease of use and omnichannel use by investigating hypothesis. Conclusions - Base on the empirical result, this study confirmed that TAM theory perceived has relation with omnichannel. First, factors of TAM has positive effect on omnichannel use, so it highlights the important role of customer based interface and usefulness. Especially, perceived usefulness has high indirect influence on ease of use and use of omnichannel. It seems that when customers try to decide use or not use omnichannel, customers focus on percept benefits from omnichannel. Thus, a provider should applicate attractive price table, accurate product or service information and high switching cost strategy to emphasize the usefulness of omnichannel. Second, using omnichannel enhances the relationship between customers and brand, because there are more time and frequency to serve customers. It is important because good relationship between customers can increase the future's financial performance through word of mouse, positive brand image and loyalty to brand or company. Finally, despite of empirical result and implications, this study has limitations. First, there are only a few previous studies about omnicahnnel, so literature reviews are restricted. While set up the factors which can affect the use of omnichannel, next study should be considered with broader theories or models(ex: contingency theory). Second, omnichannel has developed from multichannel, so comparative analysis is needed between these methods because there is a possibility about different forte character of each distribution system on customer's consuming patterns.

다구찌방법을 이용한 사출성형공정의 신경회로망 모델링에 관한 연구 (A Study on Neural Network Modeling of Injection Molding Process Using Taguchi Method)

  • 최기흥;유병길;홍태민;이경돈;장낙영
    • 대한기계학회논문집A
    • /
    • 제20권3호
    • /
    • pp.765-774
    • /
    • 1996
  • Computer Integrated Manufacturing(CIM) requires models of manufacturing processes to be implemented on the computer. These models are typically used for determining optimal process control parameters or designing adaptive control systems. In spite of the progress made in the mechanistic modeling, however, empirical models derived from experimental data play a maior role in manufacturing process modeling. This paper describes the development of a meural metwork medel for injection molding. This paper describes the development of a nueral network model for injection molding process. The model uses the CAE analysis data based on Taguchi method. The developed model is, then, compared with the traditional polynomial regression model to assess the applicabilit in practice.

다변수 최적화 기법을 이용한 자동차용 고분자전해질형 연료전지 시스템 모델링에 관한 연구 (A Study of Modeling PEM Fuel Cell System Using Multi-Variable Optimization Technique for Automotive Applications)

  • 김한상;민경덕;전순일;김수환;임태원;박진호
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
    • /
    • pp.541-544
    • /
    • 2005
  • This study presents the integrated modeling approach to simulate the proton exchange membrane (PEM) fuel cell system for vehicle application. The fuel cell system consisting of stack and balance of plant (BOP) was simulated with MATLAB/Simulink environment to estimate the maximum system power and investigate the effect of BOP component sizing on system performance and efficiency. The PEM fuel cell stack model was established by using a semi-empirical modeling. To maximize the net efficiency of fuel cel1 system, multi-variable optimization code was adopted. Using this method the optimized operating values were obtained according to various system net power levels. The fuel cell model established was co-linked to AVL CRUISE, a vehicle simulation package. Through the vehicle simulation software, the fuel economy of fuel cell powered electric vehicle for two types of driving cycles was presented and compared. It is expected that this study tan be effectively employed in the basic BOP component sizing and in establishing system operation map with respect to net power level of fuel cell system.

  • PDF

Propulsion System Modeling and Reduction for Conceptual Truss-Braced Wing Aircraft Design

  • Lee, Kyunghoon;Nam, Taewoo;Kang, Shinseong
    • International Journal of Aeronautical and Space Sciences
    • /
    • 제18권4호
    • /
    • pp.651-661
    • /
    • 2017
  • A truss-braced wing (TBW) aircraft has recently received increasing attention due to higher aerodynamic efficiency compared to conventional cantilever wing aircraft. For conceptual TBW aircraft design, we developed a propulsion-and-airframe integrated design environment by replacing a semi-empirical turbofan engine model with a thermodynamic cycle-based one built upon the numerical propulsion system simulation (NPSS). The constructed NPSS model benefitted TBW aircraft design study, as it could handle engine installation effects influencing engine fuel efficiency. The NPSS model also contributed to broadening TBW aircraft design space, for it provided turbofan engine design variables involving a technology factor reflecting progress in propulsion technology. To effectively consolidate the NPSS propulsion model with the TBW airframe model, we devised a rapid, approximate substitute of the NPSS model by reduced-order modeling (ROM) to resolve difficulties in model integration. In addition, we formed an artificial neural network (ANN) that associates engine component attributes evaluated by object-oriented weight analysis of turbine engine (WATE++) with engine design variables to determine engine weight and size, both of which bring together the propulsion and airframe system models. Through propulsion-andairframe design space exploration, we optimized TBW aircraft design for fuel saving and revealed that a simple engine model neglecting engine installation effects may overestimate TBW aircraft performance.