• 제목/요약/키워드: conjugate distribution

검색결과 91건 처리시간 0.021초

Bayesian Estimation for Reliability in a System Consisting of the Left Truncated Exponential Components

  • Park, Man-Gon;Jung, Yun-Sung
    • 품질경영학회지
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    • 제17권1호
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    • pp.19-34
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    • 1989
  • In this paper, we propose the Bayes estimators of the reliability for a system consisting of the left-truncated exponential components under the truncated normal distribution as a conjugate prior distribution and squared - error loss function on the series, parallel and k-out-of-m : G system. And we compare the proposed Bayes estimators of the system reliability each other in terms of MSE performances and stabilities by the Monte Carlo simulation.

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공정능력자수에 대한 깁스샘플링 추정 (Some Process Capability Indices Using Gibbs Sampling)

  • 김평구;김희철
    • 품질경영학회지
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    • 제26권1호
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    • pp.88-98
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    • 1998
  • Process capability indices are used to determine whether a production process is capable of producing items within a specified tolerance. Using conditional distribution, we study some process capability indices ${\hat{C}}_{Gp}$, ${\hat{C}}_{Gpk}$, ${\hat{C}}_{Gpm}$ under conjugate prior distribution. We consider some process capability indices with Gibbs sampling method. Also, we examine some small sample properties related to these estimaters by some simulations.

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Self-Assembled Polymeric Nanoparticles of Poly(ethylene glycol) Grafted Pullulan Acetate as a Novel Drug Carrier

  • Jung, Sun-Woong;Jeong, Young-Il;Kim, Young-Hoon;Kim, Sung-Ho
    • Archives of Pharmacal Research
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    • 제27권5호
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    • pp.562-569
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    • 2004
  • Self-assembling nanospheres of hydrophobized pullulan have been developed. Pullulan acetate (PA), as hydrophobized pullulan, was synthesized by acetylation. Carboxymethylated poly(ethylene-glycol) (CMPEG) was introduced into pullulan acetate (PA) through a coupling reaction using N, N'-dicyclohexyl carbodiimide (DCC). A synthesized PA-PEG-PA (abbreviated as PEP) conjugate was confirmed by Fourier transform-infrared (FT-IR) spectroscopy. Since PEP conjugates have amphiphilic characteristics in aqueous solution, polymeric nanoparticles of PEP conjugates were prepared using a simple dialysis method in water. From the analysis of fluorescence excitation spectra primarily, the critical association concentration (CAC) of this conjugate was found to be 0.0063 g/L. Observations by scanning electron microscopy (SEM) showed the spherical morphologies of the PEP nanoparticles. The particle size distribution of the PEP conjugates was determined using photon correlation spectroscopy (PCS) and the intensity-average particle size was 193.3 ${\pm}$ 13.53 nm with a unimodal distribution. Clonazepam (CNZ), as a model drug, was easy to entrap into polymeric nanoparticles of the PEP conjugates. The drug release behavior was mainly diffusion controlled from the core portion.

전기자동차 배터리 팩 형상이 배터리 셀 주위의 강제대류에 미치는 영향에 대한 수치해석 (A Numerical Study on the Effect of Battery-pack Shape of Electric Vehicle on the Forced Convection Around Battery Cells)

  • 김교현;김태완;우만경;전병진;최형권
    • 반도체디스플레이기술학회지
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    • 제16권1호
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    • pp.16-21
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    • 2017
  • In this paper, the effect of battery-package shape of electric vehicle on the forced convection around a group of battery cells has been numerically investigated. Simulations for the two package shapes with straight/curved ducts have been conducted to examine the two design factors; the maximum temperature and the temperature deviation of a group of cells which influence the cell durability. The simulation of the conjugate heat transfer has been simplified by employing an equivalent thermal conductivity of cell that consists of various materials. It has been found that the maximum temperature and the temperature deviation of curved duct were lower than those of straight duct. Velocity fields have also been examined to describe the temperature distribution of a group of cells and the position of maximum temperature was found to be related to the dead zone of flow field.

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평판핀에서의 강제대류-전도 과도 복합열전달에 관한 연구 (A study on unsteady conjugate forced convection-conduction heat transfer from a plate fin)

  • 조진호;이상균
    • 오토저널
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    • 제11권1호
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    • pp.20-30
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    • 1989
  • The unsteady conjugate forced convection-conduction heat transfer from a plate fin is numerically studied. The external forced flow is steady but the temperature of the fin base is an exponential change with time. Therefore, the unsteady energy equations of the fluid and the fin are solved simultaneously under the conditions of equality in heat flux and temperature at the fluid-fin interface at every instant of time. Numerical results are given for various quantities of interest including the local heat transfer coefficient, the local heat flux, the total heat transfer rate and the temperature distribution of fin under the effects of the convection-conduction parameter and the ratio of thermal diffusivities. The results of the present numerical solution have been compared with those of the conventional fin theory.

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역복사경계해석을 위한 다양한 조정법 비교 (Comparison of Regularization Techniques for an Inverse Radiation Boundary Analysis)

  • 김기완;신병선;길정기;여권구;백승욱
    • 대한기계학회논문집B
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    • 제29권8호
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    • pp.903-910
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    • 2005
  • Inverse radiation problems are solved for estimating the boundary conditions such as temperature distribution and wall emissivity in axisymmetric absorbing, emitting and scattering medium, given the measured incident radiative heat fluxes. Various regularization methods, such as hybrid genetic algorithm, conjugate-gradient method and finite-difference Newton method, were adopted to solve the inverse problem, while discussing their features in terms of estimation accuracy and computational efficiency. Additionally, we propose a new combined approach that adopts the hybrid genetic algorithm as an initial value selector and uses the finite-difference Newton method as an optimization procedure.

환기식 3중 집열창의 최적설계를 위한 수치해석 연구 (Numerical analysis for the optimum design of a triple-glazed airflow window)

  • 김홍제;황기영
    • 설비공학논문집
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    • 제9권4호
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    • pp.484-496
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    • 1997
  • The fluid flow and heat transfer characteristics of conjugate forced and natural convection in the triple-glazed airflow window, where the outer air passes through a space contrived between the interior and exterior window panes, were studied numerically by a finite volume method for the elliptic form of the Navier-Stokes equations. The investigation focused on the influence of window geometry, ventilastion rate and solar energy on the temperature, velocity distribution and thermal performance of the airflow window. The comparison between the triple-glazed airflow window and the enclosed triple-glazed window was also made to evaluate the effect of buoyancy upon which the thermal performance of the window depended.

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A Blood-brain Barrier Permeable Derivative of 5-Fluorouracil: Preparation, Intracellular Localization, and Mouse Tissue Distribution

  • Im, Jung-Kyun;Biswas, Goutam;Kim, Wan-Il;Kim, Kyong-Tai;Chung, Sung-Kee
    • Bulletin of the Korean Chemical Society
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    • 제32권3호
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    • pp.873-879
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    • 2011
  • 5-Fluorouracil (5-FU), an anticancer agent was covalently attached to the recently developed sorbitol-based G8 transporter, and the conjugate (7) with FITC was found to have an affinity toward mitochondria and to readily cross BBB to gain an entry into mouse brain. Measured by $IC_{50}$, the conjugate (9) without the fluorophore showed enhanced cytotoxic activity toward two types of multidrug-resistant cell lines. These results strongly suggest that the sorbitol-based G8 transporter can be utilized as a good CNS delivery vector.

배기계 내구시험 중의 온도 변화 예측을 위한 연구 (A Study on the Prediction of Temperature Change during the Thermal Fatigue Test of Exhaust Manifolds)

  • 이원근
    • 한국자동차공학회논문집
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    • 제11권5호
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    • pp.29-36
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    • 2003
  • Exhaust manifolds suffer from serious temperature variation during the thermal fatigue test. The spatial distribution of temperature changes at each moment. Because transient flow can not be simulated during the long period of temperature change, the simulation can not be performed by conjugate heat transfer analysis. In this study, a new procedure for transient thermal analysis is established by decoupling fluid-solid analysis. The procedure consists of (1) transient CFD calculation (2 cycles), (2) mapping heat transfer coefficient to the inner surface of solid mesh as a boundary condition of heat conduction analysis and (3) transient heat conduction analysis in the long period (30 min). The realistic temperature change can be predicted by this procedure.

Bayesian Estimators Using Record Statistics of Exponentiated Inverse Weibull Distribution

  • Kim, Yong-Ku;Seo, Jung-In;Kang, Suk-Bok
    • Communications for Statistical Applications and Methods
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    • 제19권3호
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    • pp.479-493
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    • 2012
  • The inverse Weibull distribution(IWD) is a complementary Weibull distribution and plays an important role in many application areas. In this paper, we develop a Bayesian estimator in the context of record statistics values from the exponentiated inverse Weibull distribution(EIWD). We obtained Bayesian estimators through the squared error loss function (quadratic loss) and LINEX loss function. This is done with respect to the conjugate priors for shape and scale parameters. The results may be of interest especially when only record values are stored.