• Title/Summary/Keyword: Mixed Methods

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A Study on the mixed mode of Gyro (자이로의 혼합모드 연구)

  • 노영환;방효충;이상용;황규진
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.30-30
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    • 2000
  • In the three axis control of satellite by using reaction wheel and gyro, a Gyro carries out measuring of the attitude angie and the attitude angular velocity. The Gyro is operated by the electronic part and the mechanic actuator. The digital part of the electronic part is consisted of the FPGA (Field Programmable Gate Array), which is one of the methods for designing VLSI (Very Large Scale Integrated Circuit), and the mechanic actuator processes the input/output data by the dynamic model. In the research of the mixed mode of Gyro, the simulation is accomplished by SABER of the mixed mode simulator and the results for the practical implementation of the satellite ACS (Attitude Control System) interfaced with the data processing are proposed.

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A spatial heterogeneity mixed model with skew-elliptical distributions

  • Farzammehr, Mohadeseh Alsadat;McLachlan, Geoffrey J.
    • Communications for Statistical Applications and Methods
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    • v.29 no.3
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    • pp.373-391
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    • 2022
  • The distribution of observations in most econometric studies with spatial heterogeneity is skewed. Usually, a single transformation of the data is used to approximate normality and to model the transformed data with a normal assumption. This assumption is however not always appropriate due to the fact that panel data often exhibit non-normal characteristics. In this work, the normality assumption is relaxed in spatial mixed models, allowing for spatial heterogeneity. An inference procedure based on Bayesian mixed modeling is carried out with a multivariate skew-elliptical distribution, which includes the skew-t, skew-normal, student-t, and normal distributions as special cases. The methodology is illustrated through a simulation study and according to the empirical literature, we fit our models to non-life insurance consumption observed between 1998 and 2002 across a spatial panel of 103 Italian provinces in order to determine its determinants. Analyzing the posterior distribution of some parameters and comparing various model comparison criteria indicate the proposed model to be superior to conventional ones.

Development of Mixed $H_2$/$H_{\infty}$ Controller Design Algorithms for Singular Systems with Time Delay

  • Kim, Jong-Hae
    • Transactions on Control, Automation and Systems Engineering
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    • v.3 no.3
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    • pp.139-145
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    • 2001
  • In this paper, we consider the H$_2$(or guaranteed cost control) and H$_{\infty}$ controller design methods for singular(or descriptor) systems with input time delay. Also, a mixed H$_2$and H$_{\infty}$ controller design algorithm is treated by combination of the proposed H$_2$and H$_{\infty}$ controller design method. The sufficient conditions for the existence of controllers and controller design methods are introduced at each Lemma and Theorem. Furthermore, we present optimization problems to get the upper bound of performance measures. The proposed methods are checked by examples.

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Methods and Techniques for Variance Component Estimation in Animal Breeding - Review -

  • Lee, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.3
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    • pp.413-422
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    • 2000
  • In the class of models which include random effects, the variance component estimates are important to obtain accurate predictors and estimators. Variance component estimation is straightforward for balanced data but not for unbalanced data. Since orthogonality among factors is absent in unbalanced data, various methods for variance component estimation are available. REML estimation is the most widely used method in animal breeding because of its attractive statistical properties. Recently, Bayesian approach became feasible through Markov Chain Monte Carlo methods with increasingly powerful computers. Furthermore, advances in variance component estimation with complicated models such as generalized linear mixed models enabled animal breeders to analyze non-normal data.

A Study on the Design-parameter of Mixed Ground by Using Cement-type Stabilizer (시멘트계 고화재에 의해 혼합처리된 지반의 설계정수에 관한 연구)

  • 천병식;임해식;전진규
    • Journal of the Korean Geotechnical Society
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    • v.16 no.2
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    • pp.79-89
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    • 2000
  • The application of stabilization method has increased because of short construction periods, no environmental problems with dumped and replaced soil, assurance of required strength and economical effect with mid to small size construction. The unconfined and triaxial(UU-condition) compression tests were executed with each mixing sample for the study of the improvement effects and the effect of design-parameters by the stabilization methods. Three typical stabilizers, which are representative in Korea, were applied in this study, and three common soils(very soft clay, general weathered soil, common clay), which are common in Korea, were used in this study. In this study, the effect of engineering factors(soils, stabilizers and water contents, etc.) which are important parameters for the improvement effects of mixed ground by stabilizers, was analyzed. As results, the tendencies of design-parameters(unconfined compression strength, deformation modulus and strength parameter) are presented and the criteria of the application of stabilization methods are suggested.

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Flexible Mixed decomposition Method for Large Scale Linear Programs: -Integration of a Network of Process Models-

  • Ahn, Byong-Hun;Rhee, Seung-Kyu
    • Journal of the Korean Operations Research and Management Science Society
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    • v.11 no.2
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    • pp.37-50
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    • 1986
  • In combining dispersed optimization models, either primal or dual(or both) decomposition method widely used as an organizing device. Interpreting the methods economically, the concepts of price and resource-directive coordination are generally well accepted. Most of deomposition/ integration methods utilize either primal information of dual information, not both, from subsystems, while some authors have developed mixed decomposition approaches employing two master problems dealing primal and dual proposals separately. In this paper a hybrid decomposition method is introduced, where one hybrid master problem utilizes the underlying relationships between primal and dual information from each subsystem. The suggested method is well justified with respect to the flexibility in information flow pattern choice (some prices and other quantities) and to the compatibility of subdivision's optimum to the systemwide optimum, that is often lacking in conventional decomposition methods such as Dantzig-Wolfe's. A numerical example is also presented to illustrate the suggested approach.

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Development of 360° virtual reality videos and common videos for cardiac arrest recognition : A sequential mixed methods study (심장정지 인지를 위한 360° 가상현실과 일반 동영상 개발 : 순차적 혼합 연구)

  • Jung, Eun-Kyung;Shin, Jun Ho
    • The Korean Journal of Emergency Medical Services
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    • v.25 no.2
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    • pp.55-69
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    • 2021
  • Purpose: This study aimed to develop 360° virtual reality videos and common videos for cardiac arrest recognition. Methods: A sequential mixed methods study was conducted, using qualitative interviews (with a total of seven experts) and a quantitative survey. Results: First, the cardiac arrest situation should be developed within 2-3 minutes after witnessing the patient collapse, for each of the four cardiac arrest videos about apnea, gasping, seizure, gasping, and seizure. Second, the education program should be designed so that the education on cardiac arrest recognition can proceed before CPR practice begins. Conclusion: 360° virtual reality videos and common videos for cardiac arrest recognition can play an important role in the education of the general public about cardiac arrest experience.

Estimation Methods for Population Pharmacokinetic Models using Stochastic Sampling Approach (확률적 표본추출 방법을 이용한 집단 약동학 모형의 추정과 검증에 관한 고찰)

  • Kim, Kwang-Hee;Yoon, Jeong-Hwa;Lee, Eun-Kyung
    • The Korean Journal of Applied Statistics
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    • v.28 no.2
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    • pp.175-188
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    • 2015
  • This study is about estimation methods for the population pharmacokinetic and pharmacodymic model. This is a nonlinear mixed effect model, and it is difficult to find estimates of parameters because of nonlinearity. In this study, we examined theoretical background of various estimation methods provided by NONMEM, which is the most widely used software in the pharmacometrics area. We focused on estimation methods using a stochastic sampling approach - IMP, IMPMAP, SAEM and BAYES. The SAEM method showed the best performance among methods, and IMPMAP and BAYES methods showed slightly less performance than SAEM. The major obstacle to a stochastic sampling approach is the running time to find solution. We propose new approach to find more precise initial values using an ITS method to shorten the running time.

Comparative Study on the Micellization of SDS/Brij 30, DBS/Brij 30, and SDS/DBS Mixed Surfactant Systems in Pure Water (순수 물에서 SDS/Brij 30, DBS/Brij 30 및 SDS/DBS 혼합계면활성제의 미셀화에 대한 비교연구)

  • Lee, Byung-Hwan;Park, In-Jung
    • Journal of the Korean Chemical Society
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    • v.55 no.3
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    • pp.379-384
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    • 2011
  • The critical micelle concentration (CMC) and the counter ion binding constant (B) for the mixed micellizations of DBS (sodium dodecylbenzenesulfonate), SDS (sodium dodecylsulfate), and Brij 30 (polyoxyethylene(4) lauryl ether) at $25^{\circ}C$ in pure water were determined by the use of electric conductivity and surface tension measuring methods. Various thermodynamic parameters ($X_i,\;{\gamma}i,\;C_i,\;a_i^M,\;{\beta}$, and ${\Delta}H_{mix}$) were calculated and compared with each other mixed surfactant system by means of the equations derived from the nonideal mixed micellar model. The results show that the SDS molecule interacts more strongly with Brij 30 molecule than DBS molecule and that the SDS/Brij 30 mixed surfactant system has the greatest negative deviation from the ideal mixed micellar model and the SDS/DBS mixed system has followed almost the ideal mixed micellar model.

Study on Isolative Determination Methylephedrine Hydrochloride and Ephedrine Hydrochloride in the Mixed Preparation (혼합제제중 Methylephedrine Hydrochloride와 Ephedrine Hydrochloride의 분리정량에 관한 연구)

  • Ko, In-Suk
    • Korean Journal of Pharmacognosy
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    • v.1 no.3
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    • pp.93-99
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    • 1970
  • There have been reported by several workers for the isolation and determination of the amine derivatives as Metbylephedrine Hydrochloride and Ephedrine Hydrochloride adopting neutralization method, steam distillation method, non-aqous titration method, ion-exchange resin method, titration method after acetylation, colorimetric method, gravimetric method, iodine titration method and gas chromatography. Those methods mentioned in above, can be practically applied for the sample which is not mixed one mith the other amine compounds. Presently, it has not shown on the isolative determination of the mixed sample of amine derivatives. In this paper, it is discussed on the isolative determination of Methylephedrine Hydrochloride as the tertiary amine compound and Ephedrine Hydrochloride as the secondary amine compound. According to the results of the experiment, it could be summarized as follows: 1. There is no time-variation on the color reaction of Methylephedrine Hydrochloride and Ephedrine Hydrochloride with the color reagent, bromcresolgreen. And Methylephedrine Hydrochloride and Ephedrine Hydrochloride, respectively, can be determined spectrophotometrically by means oft his color reaction. 2. For the isolation of Methylephedrine Hydrochloride and Ephedrine Hydrochloride from the mixed sample, Methylephedrine Hydrochloride can be eluted by chloroform, while Ephedrine Hydrochloride by the mixed solvent of chloroform and ethylalcohol (2:1), from the celite column adsorbed at pH6.4 followed by extraction with ether undersodium hydroxide alkali re action. 3. When the sample is mixed with quinine hydrochloride, dihydrocodeine bitartate, and noscapine, these mixed compounds can be eliminated by means of stram distillation. 4. When the sample is mixed with chlorpheniramine maleate, dextromethorphan hydrobromide and diphenhydramine hydrochloride, the mixed compounds can be eliminated by means of steam distillation and celite adsorption column chromatography, In conclusion, the isolative determination method for Methylephedrine Hydrochloride and Ephedrine Hydrochloride studied in this paper, indicates with the excellent reproducibility and accuracy.

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