• 제목/요약/키워드: truncated normal

검색결과 71건 처리시간 0.027초

Uniformly Minimum Variance Unbiased Estimation for Distributions with Support Dependign on Two Parameters

  • Hong, Chong-Sun;Park, Hyun-Jip;Lee, Chong-Cheol
    • Journal of the Korean Statistical Society
    • /
    • 제24권1호
    • /
    • pp.45-64
    • /
    • 1995
  • When a random sample is taken from a certain class of discrete and continuous distributions whose support depend on two parameters, we could find that there exists the complete and sufficient statistic for parameters which belong to a certain class, and fomulate the uniformly minimum variance unbiased estimator (UMVUE) of any estimable function. Some UMVUE's of parametric functions are illustrated for the class of the distribution. Especially, we find that the UMVUE of some estimable parametric function from the truncated normal distribution could be expressed by the version of the Mill's ratio.

  • PDF

Vibration analysis of free-fixed hyperbolic cooling tower shells

  • Kang, Jae-Hoon
    • Structural Engineering and Mechanics
    • /
    • 제55권4호
    • /
    • pp.785-799
    • /
    • 2015
  • A three-dimensional (3-D) method of analysis is presented for determining the free vibration frequencies of hyperboloidal shells free at the top edge and clamped at the bottom edge like a hyperboloidal cooling tower by the Ritz method based upon the circular cylindrical coordinate system instead of related 3-D shell coordinates which are normal and tangent to the shell midsurface. The Legendre polynomials are used as admissible displacements. Convergence to four-digit exactitude is demonstrated. Natural frequencies from the present 3-D analysis are also compared with those of straight beams with circular cross section, complete (not truncated) conical shells, and circular cylindrical shells as special cases of hyperboloidal shells from the classical beam theory, 2-D thin shell theory, and other 3-D methods.

The innate immune response transcription factor Bombyx mori Relish1 induces high-level antimicrobial peptides in silkworm

  • Kim, Seong-Wan;Kim, Seong-Ryul;Goo, Tae-Won;Choi, Kwang-Ho
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • 제37권2호
    • /
    • pp.49-54
    • /
    • 2018
  • To artificially enhance antimicrobial peptide expression in Bombyx mori, we constructed genetically engineered silkworms overexpressing Rel family transcription factor. The truncated BmRelish1 (BmRelish1t) gene contained a Rel homolog domain (RHD), nuclear localization signal (NLS), acidic and hydrophobic amino acid (AHAA)-rich region, and death domain (DD), but no ankyrin-repeat (ANK) domain. The BmRelish1t gene was controlled by B. mori cytoplasmic actin 3 promoter in the PiggyBac transposon vector. Chromosome analysis of G1 generations of a transgenic silkworm with EGFP expression confirmed stable insertion of BmRelish1t. BmRelish1t gene overexpression in transgenic silkworms resulted in higher mRNA expression levels of B. mori antimicrobial peptides such as lebocin(~20.5-fold), moricin(~8.7-fold), and nuecin(~17.4-fold) than those in normal silkworms.

Restricted maximum likelihood estimation of a censored random effects panel regression model

  • Lee, Minah;Lee, Seung-Chun
    • Communications for Statistical Applications and Methods
    • /
    • 제26권4호
    • /
    • pp.371-383
    • /
    • 2019
  • Panel data sets have been developed in various areas, and many recent studies have analyzed panel, or longitudinal data sets. Maximum likelihood (ML) may be the most common statistical method for analyzing panel data models; however, the inference based on the ML estimate will have an inflated Type I error because the ML method tends to give a downwardly biased estimate of variance components when the sample size is small. The under estimation could be severe when data is incomplete. This paper proposes the restricted maximum likelihood (REML) method for a random effects panel data model with a censored dependent variable. Note that the likelihood function of the model is complex in that it includes a multidimensional integral. Many authors proposed to use integral approximation methods for the computation of likelihood function; however, it is well known that integral approximation methods are inadequate for high dimensional integrals in practice. This paper introduces to use the moments of truncated multivariate normal random vector for the calculation of multidimensional integral. In addition, a proper asymptotic standard error of REML estimate is given.

Non-histone protein HMGB1 inhibits the repair of damaged DNA by cisplatin in NIH-3T3 murine fibroblasts

  • Yusein-Myashkova, Shazie;Ugrinova, Iva;Pasheva, Evdokia
    • BMB Reports
    • /
    • 제49권2호
    • /
    • pp.99-104
    • /
    • 2016
  • The nuclear non-histone protein high mobility group box (HMGB) 1 is known to having an inhibitory effect on the repair of DNA damaged by the antitumor drug cisplatin in vitro. To investigate the role of HMGB1 in living cells, we studied the DNA repair of cisplatin damages in mouse fibroblast cell line, NIH-3T3. We evaluated the effect of the post-synthetic acetylation and C-terminal domain of the protein by overexpression of the parental and mutant GFP fused forms of HMGB1. The results revealed that HMGB1 had also an inhibitory effect on the repair of cisplatin damaged DNA in vivo. The silencing of HMGB1 in NIH-3T3 cells increased the cellular DNA repair potential. The increased levels of repair synthesis could be "rescued" and returned to less than normal levels if the knockdown cells were transfected with plasmids encoding HMGB1 and HMGB1 K2A. In this case, the truncated form of HMGB1 also exhibited a slight inhibitory effect.

The Comparison of Clinical Assessment Tools for the Foot Posture

  • Lee, Jin-Yi;Choi, Jong-Duk
    • 한국전문물리치료학회지
    • /
    • 제19권3호
    • /
    • pp.115-123
    • /
    • 2012
  • It is important to assess foot posture when investigating the relationship between lower extremity dysfunctions and foot types. Although several measurements of static foot posture have been used, there is no consensus regarding clinical measurements for foot posture. The aim of this study is to explore the differences among navicular drift (NDt), foot posture index (FPI), arch index (AI), dorsal arch height ratio (DAHR), normal navicular height truncated (NNHt) and to discover the most effective measurement. After foot types were classified by navicular drop test (NDp), clinical measurements of NDt, FPI, AI, DAHR, and NNHt were performed on 64 subjects' feet. ANOVA analysis was used for the variance of the difference between the NDp and the five kinds of clinical measurements, and the level of significance was set at ${\alpha}$=.05. The results showed that all five clinical measurements demonstrated significant differences with navicular drop. In post-hoc, FPI and NNHt showed significant differences in all foot types. The five clinical measurements are suitable the classification of foot types through the NDp. Therefore, it could be possible to assess correct and objective foot posture by using FPI and NNHt.

고온고압수중에서 접촉형상에 따른 마멸거동 분석 (Analysis of Wear Behaviour Corresponding to Contact Shape in High Temperature and High Pressure Environment)

  • 송주선;김형규;이영호;김재훈
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 2004년도 학술대회지
    • /
    • pp.31-36
    • /
    • 2004
  • In this paper, fretting wear tests were conducted in air at room temperature (RT) and in water at high temperature and high pressure (HTHP) environment to analyze the wear characteristic. As for the supporting condition between the tube and spring/dimple, the gap of 0.2 mm in air at RT and the normal force of 10 N and the slip of $50\;{\mu}\;m$ in water at HTHP were applied. Four different shapes of spring/dimple specimen (type A, B, C, D) were used. Detail eaxamination of wear scar was also performed using SEM micrographs. As a result, in the case of the spring of truncated wedge, severer wear occurs than the others. Protrusion part was found and larger in air at RT. It is thought that the difference in the wear volume and the protrusion is caused by the different wear mechanism corresponding to the different environment.

  • PDF

Buckling analysis of laminated composite cylindrical shell subjected to lateral displacement-dependent pressure using semi-analytical finite strip method

  • Khayat, Majid;Poorveis, Davood;Moradi, Shapour
    • Steel and Composite Structures
    • /
    • 제22권2호
    • /
    • pp.301-321
    • /
    • 2016
  • The objective of this paper is to investigate buckling behavior of composite laminated cylinders by using semi-analytical finite strip method. The shell is subjected to deformation-dependent loads which remain normal to the shell middle surface throughout the deformation process. The load stiffness matrix, which is responsible for variation of load direction, is also throughout the deformation process. The shell is divided into several closed strips with alignment of their nodal lines in the circumferential direction. The governing equations are derived based on the first-order shear deformation theory with Sanders-type of kinematic nonlinearity. Displacements and rotations of the shell middle surface are approximated by combining polynomial functions in the meridional direction and truncated Fourier series along with an appropriate number of harmonic terms in the circumferential direction. The load stiffness matrix, which is responsible for variation of load direction, is also derived for each strip and after assembling, global load stiffness matrix of the shell is formed. The numerical illustrations concern the pressure stiffness effect on buckling pressure under various conditions. The results indicate that considering pressure stiffness causes buckling pressure reduction which in turn depends on various parameters such as geometry and lay-ups of the shell.

비비례 감쇠시스템의 해석을 위한 효율적인 모드 중첩법 (Efficient Mode Superposition Method for Non-Classically Damped Systems)

  • 조상원;조지성;박선규;이인원
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2000년도 춘계학술대회논문집
    • /
    • pp.549-555
    • /
    • 2000
  • The improved mode superposition methods for non-classically damped systems are presented in this paper. Generally, the mode superposition method uses a relatively small subset of the normal modes of structures. The mode acceleration method and the modal truncation augmentation method improve the results of the mode superposition method by considering effects of truncated high modes. For using these methods to analyze non-classically damped systems, the systems are approximated to the classically damped systems and thereby the errors are induced. In this paper, the mode acceleration method and the modal truncation augmentation method are expanded to analyze the non-classically damped systems. The applicability of the expanded methods is verified by closed form solutions and numerical examples. The expanded modal truncation augmentation method is conditionally stable depending on the pattern of the external loading in the non-classically damped systems whereas the expanded mode acceleration method is stable for the all cases of loading. In the stable case, the results are the same with those of the expanded mode acceleration method.

  • PDF

Numerical and experimental assessments of focused microwave thermotherapy system at 925 MHz

  • Kim, Jang-Yeol;Lee, Kwang-Jae;Kim, Bo-Ra;Jeon, Soon-Ik;Son, Seong-Ho
    • ETRI Journal
    • /
    • 제41권6호
    • /
    • pp.850-862
    • /
    • 2019
  • This work investigated three-dimensional (3D) focused microwave thermotherapy (FMT) at 925 MHz for a human tissue mimicking phantom using the time reversal (TR) principle for musculoskeletal disorders. We verified the proposed TR algorithm by evaluating the possibility of 3D beam focusing through simulations and experiments. The simulation, along with the electromagnetic and thermal analyses of the human tissue mimicking phantom model, was conducted by employing the Sim4Life commercial tool. Experimental validation was conducted on the developed FMT system using a fabricated human tissue mimicking phantom. A truncated threshold method was proposed to reduce the unwanted hot spots in a normal tissue region, wherein a beam was appropriately focused on a target position. The validation results of the simulation and experiments obtained by utilizing the proposed TR algorithm were shown to be acceptable. Effective beam focusing at the desired position of the phantom could be achieved.