• 제목/요약/키워드: Multiple Effect

검색결과 6,661건 처리시간 0.031초

부호유향그래프와 동적 부분최소자승법에 기반한 화학공정의 다중이상진단 (Multiple-Fault Diagnosis for Chemical Processes Based on Signed Digraph and Dynamic Partial Least Squares)

  • 이기백;신동일;윤인섭
    • 제어로봇시스템학회논문지
    • /
    • 제9권2호
    • /
    • pp.159-167
    • /
    • 2003
  • This study suggests the hybrid fault diagnosis method of signed digraph (SDG) and partial least squares (PLS). SDG offers a simple and graphical representation for the causal relationships between process variables. The proposed method is based on SDG to utilize the advantage that the model building needs less information than other methods and can be performed automatically. PLS model is built on local cause-effect relationships of each variable in SDG. In addition to the current values of cause variables, the past values of cause and effect variables are inputted to PLS model to represent the Process armies. The measured value and predicted one by dynamic PLS are compared to diagnose the fault. The diagnosis example of CSTR shows the proposed method improves diagnosis resolution and facilitates diagnosis of masked multiple-fault.

Optimization Methodology of Multiple Air Hole Effects in Substrate Integrated Waveguide Applications

  • Kim, Jin-Yang;Chun, Dong-Wan;Ryu, Christopher Jayun;Lee, Hai-Young
    • Journal of electromagnetic engineering and science
    • /
    • 제18권3호
    • /
    • pp.160-168
    • /
    • 2018
  • A wide spectrum of potential applications using substrate integrated waveguide (SIW) technologies in conjunction with air hole regions is introduced, and an efficient optimization methodology to cope with the multiple air hole effect in SIW applications is proposed. The methodology adopts a genetic algorithm to obtain optimum air hole dimensions for the specific propagation constant that can be accurately calculated using the recursive and closed form equations presented. The optimization results are evaluated by designing an SIW bandpass filter, and they show excellent performance. The optimization methodology using the proposed equations is effective in performance enhancement for the purposes of low loss and broadband SIW applications.

Identifying Multiple Leverage Points ad Outliers in Multivariate Linear Models

  • Yoo, Jong-Young
    • Communications for Statistical Applications and Methods
    • /
    • 제7권3호
    • /
    • pp.667-676
    • /
    • 2000
  • This paper focuses on the problem of detecting multiple leverage points and outliers in multivariate linear models. It is well known that he identification of these points is affected by masking and swamping effects. To identify them, Rousseeuw(1985) used robust estimators of MVE(Minimum Volume Ellipsoids), which have the breakdown point of 50% approximately. And Rousseeuw and van Zomeren(1990) suggested the robust distance based on MVE, however, of which the computation is extremely difficult when the number of observations n is large. In this study, e propose a new algorithm to reduce the computational difficulty of MVE. The proposed method is powerful in identifying multiple leverage points and outlies and also effective in reducing the computational difficulty of MVE.

  • PDF

A Study on Detection of Influential Observations on A Subset of Regression Parameters in Multiple Regression

  • Park, Sung Hyun;Oh, Jin Ho
    • Communications for Statistical Applications and Methods
    • /
    • 제9권2호
    • /
    • pp.521-531
    • /
    • 2002
  • Various diagnostic techniques for identifying influential observations are mostly based on the deletion of a single observation. While such techniques can satisfactorily identify influential observations in many cases, they will not always be successful because of some mask effect. It is necessary, therefore, to develop techniques that examine the potentially influential effects of a subset of observations. The partial regression plots can be used to examine an influential observation for a single parameter in multiple linear regression. However, it is often desirable to detect influential observations for a subset of regression parameters when interest centers on a selected subset of independent variables. Thus, we propose a diagnostic measure which deals with detecting influential observations on a subset of regression parameters. In this paper, we propose a measure M, which can be effectively used for the detection of influential observations on a subset of regression parameters in multiple linear regression. An illustrated example is given to show how we can use the new measure M to identify influential observations on a subset of regression parameters.

Nonparametric Bayesian Multiple Change Point Problems

  • Kim, Chansoo;Younshik Chung
    • Journal of the Korean Statistical Society
    • /
    • 제31권1호
    • /
    • pp.1-16
    • /
    • 2002
  • Since changepoint identification is important in many data analysis problem, we wish to make inference about the locations of one or more changepoints of the sequence. We consider the Bayesian nonparameteric inference for multiple changepoint problem using a Bayesian segmentation procedure proposed by Yang and Kuo (2000). A mixture of products of Dirichlet process is used as a prior distribution. To decide whether there exists a single change or not, our approach depends on nonparametric Bayesian Schwartz information criterion at each step. We discuss how to choose the precision parameter (total mass parameter) in nonparametric setting and show that the discreteness of the Dirichlet process prior can ha17e a large effect on the nonparametric Bayesian Schwartz information criterion and leads to conclusions that are very different results from reasonable parametric model. One example is proposed to show this effect.

DA-9701: A New Multi-Acting Drug for the Treatment of Functional Dyspepsia

  • Kwon, Yong Sam;Son, Miwon
    • Biomolecules & Therapeutics
    • /
    • 제21권3호
    • /
    • pp.181-189
    • /
    • 2013
  • Motilitone$^{(R)}$ (DA-9701) is a new herbal drug that was launched for the treatment of functional dyspepsia in December 2011 in Korea. The heterogeneous symptom pattern and multiple causes of functional dyspepsia have resulted in multiple drug target strategies for its treatment. DA-9701, a compound consisting of a combination of Corydalis Tuber and Pharbitidis Semen, has being developed for treatment of functional dyspepsia. It has multiple mechanisms of action such as fundus relaxation, visceral analgesia, and prokinetic effects. Furthermore, it was found to significantly enhance meal-induced gastric accommodation and increase gastric compliance in dogs. DA-9701 also showed an analgesic effect in rats with colorectal distension induced visceral hypersensitivity and an antinociceptive effect in beagle dogs with gastric distension-induced nociception. The pharmacological effects of DA-9701 also include conventional effects, such as enhanced gastric emptying and gastrointestinal transit. The safety profile of DA-9701 is also preferable to that of other treatments.

Shaking table experiment on a steel storage tank with multiple friction pendulum bearings

  • Zhang, Ruifu;Weng, Dagen;Ge, Qingzi
    • Structural Engineering and Mechanics
    • /
    • 제52권5호
    • /
    • pp.875-887
    • /
    • 2014
  • The aim of the shaking table experiment is to verify the isolation effect of a storage liquid tank with multiple friction pendulum bearings. A 1:20 scale model of a real storage liquid tank that is widely used in the petroleum industry was examined by the shaking table test to compare its anchored base and isolated base. The seismic response of the tank was assessed by employing the time history input. The base acceleration, wave height and tank wall stress were used to evaluate the isolation effect. Finally, the influences of the bearing performance that characterizes the isolated tank, such as the friction force and residual displacement, were discussed.

이중게이트 구조의 Junctionless FET 의 성능 개선에 대한 연구 (Development of Gate Structure in Junctionless Double Gate Field Effect Transistors)

  • 조일환;서동선
    • 전기전자학회논문지
    • /
    • 제19권4호
    • /
    • pp.514-519
    • /
    • 2015
  • 본 논문에서는 이중 게이트 junctionless MOSFET 의 성능 최적화를 위하여 다중 게이트 형태를 적용하여 평가한다. 금속 게이트들 사이의 일함수가 서로 다르므로 다중 게이트 구조를 적용할 경우 금속게이트 길이에 따라 소스와 드레인 주변의 전위를 조절할 수 있다. 동작 전류와 누설 전류 그리고 동작 전압은 게이트 구조에 의해 조절이 가능하며 이로 인한 동작 특성 최적화가 가능하다. 본 연구에서는 반도체 소자 시뮬레이션을 통하여 junctionless MOSFET 의 최적화를 구현하고 분석하는 연구를 수행 한다.

다중열원 보조가공을 위한 평판 시편의 예열 효과에 관한 해석적 연구 (An Analytical Study on the Preheating Effect of Flat Workpiece in Thermally Assisted Machining by Multi Heat Sources)

  • 문성호;이춘만
    • 한국정밀공학회지
    • /
    • 제33권8호
    • /
    • pp.629-634
    • /
    • 2016
  • Laser-assisted machining (LAM) is one of the most effective methods of processing difficult-to-cut materials, such as titanium alloys and various ceramics. However, it is associated with problems such as the inability of the laser heat source to generate an appropriate preheating temperature. To solve the problem, thermally assisted machining with multiple heat sources is proposed. In this study, thermal analysis of multiple heat sources by laser and arc is performed according to power, heat source size, and leading heat source position. Then, the results are analyzed according to each condition. The results of this analysis can be used as a reference to predict preheating temperature in thermally assisted machining with multiple heat sources.

다중 이산 연속선택모형(MDCEV)을 이용한 한국 소비자의 신선육 구매 결정 요인 (The application of Multiple Discrete Continuous Extreme Value Model on fresh meat purchase in Korea)

  • 송철호;엄진용;장익훈;최영찬
    • 농촌지도와개발
    • /
    • 제24권4호
    • /
    • pp.249-264
    • /
    • 2017
  • Modeling the consumer demand of fresh meat requires its distinct feature which other types of food product does not have. Most of the fresh meat products are likely to be unbranded, bought on a weight basis and affected by macro shocks such as seasonality, holiday effect and the disease incidence. Furthermore, consumers tend to purchase multiple categories of fresh meat in a week. Therefore, we apply a multiple discrete/continuous model on fresh meat consumption data to study the effect of macro shocks on fresh meat sales as well as of price change. As a result shows, Each fresh meat is relatively more likely to be bought in peak season of each fresh meat compared with imported pork which is set as a 'reference category' in this analysis. For clarity of the effect of disease incidence, we perform further analysis regarding the effect of livestock disease on fresh meat purchase probability. It shows that the avian flu in 2014 has strong negative impact on the purchase probability of chicken and the foot-and-mouth disease has negative impact on the purchase probability of pork and beef for part of outbreak periods.