• Title/Summary/Keyword: heavy tail

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Robust Bayesian Models for Meta-Analysis

  • Kim, Dal-Ho;Park, Gea-Joo
    • Journal of the Korean Data and Information Science Society
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    • v.11 no.2
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    • pp.313-318
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    • 2000
  • This article addresses aspects of combining information, with special attention to meta-analysis. In specific, we consider hierarchical Bayesian models for meta-analysis under priors which are scale mixtures of normal, and thus have tail heavier than that of the normal. Numerical methods of finding Bayes estimators under these heavy tailed prior are given, and are illustrated with an actual example.

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APP Tail 1 (PAT1) Interacts with Kinesin Light Chains (KLCs) through the Tetratricopeptide Repeat (TPR) Domain (APP tail 1 (PAT1)과 kinesin light chains (KLCs)의 tetratricopeptide repeat (TPR) domain을 통한 결합)

  • Jang, Won Hee;Kim, Sang-Jin;Jeong, Young Joo;Jun, Hee Jae;Moon, Il Soo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.22 no.12
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    • pp.1608-1613
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    • 2012
  • A conventional kinesin, KIF5/Kinesin-I, transports various cargoes along the microtubule through interaction between its light chain subunit and the cargoes. Kinesin light chains (KLCs) interact with many different cargoes using their tetratricopeptide repeat (TPR) domain, but the mechanism underlying recognition and binding of a specific cargo has not yet been completely elucidated. We used the yeast two-hybrid assay to identify proteins that interact with the TPR domain of KLC1. We found an interaction between the TPR domain of KLC1 and an amyloid precursor protein (APP)-binding protein PAT1 (protein interacting with APP tail 1). The yeast two-hybrid assay demonstrated that the TPR domain-containing region of KLC1 mediated binding to the C-terminal tail region of PAT1. PAT1 also bound to KLC2 but not to kinesin heavy chains (KIF5A, KIF5B, and KIF5C) in the yeast two-hybrid assay. These protein-protein interactions were also observed in the glutathione S-transferase (GST) pull-down assay and by co-immunoprecipitation. Anti-PAT1 antibody as well as anti-APP anti-body co-immunoprecipitated KLC and KHCs associated with PAT1 from mouse brain extracts. These results suggest that PAT1 could mediate interactions between Kinesin-I and APP containing vesicles.

Evaluation of engineering characteristics and field applicability of inorganic thixotropic-grout for backfilling of shield TBM tail voids (쉴드 TBM 뒤채움용 무기계 가소성 그라우트의 공학적 특성 및 현장적용성 평가)

  • Kim, Dae-Hyeon;Jung, Du-Hwoe;Jeong, Gyeong-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.12 no.1
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    • pp.75-85
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    • 2010
  • The focus of this study is to evaluate the field applicability of the newly developed inorganic thixotropic-grout in various ways. In order to do this, the volume stability and the permeability of the inorganic thixotropic-grout have been measured and compared to the existing silica type grouts. In addition, the filling capability of the grout into the tail void has been evaluated through both an experiment with a miniature tail-void filling equipment and a test filling at the shield TBM construction site. The volume loss of the inorganic thixotropic-grout after a 14 day-curing under the atmosphere condition was appeared to be minimal. The excellent waterproofing ability of the inorganic thixotropic-grout was confirmed through a permeability test. The toxicity of the inorganic thixotropic-grout has been evaluated through a toxicity test of aquatic fishes (KS M 0111) and the pH value of the liquid eluviated from inorganic thixotropic-grout was measured as an average of 8.0 and a fatality rate of goldfish after 96 hours was 10% or so. The existence of harmful heavy metals in the liquid eluviated from the inorganic thixotropic-grout has been also examined through an atomic absorption spectroscopy (AAS) test. Any of harmful heavy metals were not detected and the detected level of $Cr^{6+}$ and Cd was far below the standard. Based on both an experiment with a miniature tail-void filling equipment and a test filling at the shield TBM construction site, the filling ability of inorganic thixotropic-grout into the tail void was proved to be excellent.

Two Kinesins from Arabidopsis, KatB and KatC, Have a Second Microtubule-binding Site in the Tail Domain

  • Jiang, Shiling;Li, Ming;Xu, Tao;Ren, Dongtao;Liu, Guoqin
    • BMB Reports
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    • v.40 no.1
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    • pp.44-52
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    • 2007
  • Kinesins, as a kind of microtubule-based motor proteins, have a conserved microtubule-binding site in their motor domain. Here we report that two homologous kinesins in Arabidopsis thaliana, KatB and KatC, contain a second microtubule-binding site in their tail domains. The prokaryotic-expressed N-terminal tail domain of the KatC heavy chain can bind to microtubules in an ATP-insensitive manner. To identify the precise region responsible for the binding, a serious of truncated KatC cDNAs encoding KatC N-terminal regions in different lengths, KatC1-128, KatC1-86, KatC1-73 and KatC1-63, fused to Histidine-tags, were expressed in E. coli and affinity-purified. Microtubule cosedimentation assays show that the site at amino acid residues 74-86 in KatC is important for microtubule-binding. By similarity, we obtained three different lengths of KatB N-terminal regions, KatB1-384, KatB1-77, and KatB1-63, and analyzed their microtubule-binding ability. Cosedimentation assays indicate that the KatB tail domain can also bind to microtubules at the same site as and in a similar manner to KatC. Fluorescence microscopic observations show that the microtubule-binding site at the tail domain of KatB or KatC can induce microtubules bundling only when the stalk domain is present. Through pull-down assays, we show that KatB1-385 and KatC1-394 are able to interact specifically with themselves and with each other in vitro. These findings are significant for identifying a previously uncharacterized microtubule-binding site in the two kinesin proteins, KatB and KatC, and the functional relations between them.

A new extended alpha power transformed family of distributions: properties, characterizations and an application to a data set in the insurance sciences

  • Ahmad, Zubair;Mahmoudi, Eisa;Hamedani, G.G.
    • Communications for Statistical Applications and Methods
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    • v.28 no.1
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    • pp.1-19
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    • 2021
  • Heavy tailed distributions are useful for modeling actuarial and financial risk management problems. Actuaries often search for finding distributions that provide the best fit to heavy tailed data sets. In the present work, we introduce a new class of heavy tailed distributions of a special sub-model of the proposed family, called a new extended alpha power transformed Weibull distribution, useful for modeling heavy tailed data sets. Mathematical properties along with certain characterizations of the proposed distribution are presented. Maximum likelihood estimates of the model parameters are obtained. A simulation study is provided to evaluate the performance of the maximum likelihood estimators. Actuarial measures such as Value at Risk and Tail Value at Risk are also calculated. Further, a simulation study based on the actuarial measures is done. Finally, an application of the proposed model to a heavy tailed data set is presented. The proposed distribution is compared with some well-known (i) two-parameter models, (ii) three-parameter models and (iii) four-parameter models.

A New Family of Semicircular Models: The Semicircular Laplace Distributions

  • Ahn, Byoung-Jin;Kim, Hyoung-Moon
    • Communications for Statistical Applications and Methods
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    • v.15 no.5
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    • pp.775-781
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    • 2008
  • It is developed that a family of the semicircular Laplace distributions for modeling semicircular data by simple projection method. Mathematically it is simple to simulate observations from a semicircular Laplace distribution. We extend it to the l-axial Laplace distribution by a simple transformation for modeling any arc of arbitrary length. Similarly we develop the l-axial log-Laplace distribution based on the log-Laplace distribution. A bivariate version of l-axial Laplace distribution is also developed.

An Efficient Implementation of Tornado Code for Fault Tolerance

  • Lei, Jian-Jun;Kwon, Gu-In
    • Journal of Korea Spatial Information System Society
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    • v.11 no.2
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    • pp.13-18
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    • 2009
  • This paper presents the implementation procedure of encoding and decoding algorithms for Tornado code that can provide fault tolerance for storage and transmission system. The degree distribution satisfying heavy tail distribution is produced. Based on this distribution, a good random irregular bipartite graph is attained after plenty of trails. Such graph construction is proved to be efficient, and the experiments also demonstrate that the implementation obtains good performance in terms of decoding overhead.

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Robust Bayesian Analysis in Finite Population Sampling with Auxiliary Information

  • Lee, Seung-A;Suh, Sang-Hyuck;Kim, Dal-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.4
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    • pp.1309-1317
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    • 2006
  • The paper considers some Bayes estimators of the finite population mean with auxiliary information under priors which are scale mixtures of normal, and thus have tail heavier than that of the normal. The proposed estimators are quite robust in general. Numerical methods of finding Bayes estimators under these heavy tailed priors are given, and are illustrated with an actual example.

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Power t distribution

  • Zhao, Jun;Kim, Hyoung-Moon
    • Communications for Statistical Applications and Methods
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    • v.23 no.4
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    • pp.321-334
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    • 2016
  • In this paper, we propose power t distribution based on t distribution. We also study the properties of and inferences for power t model in order to solve the problem of real data showing both skewness and heavy tails. The comparison of skew t and power t distributions is based on density plots, skewness and kurtosis. Note that, at the given degree of freedom, the kurtosis's range of the power t model surpasses that of the skew t model at all times. We draw inferences for two parameters of the power t distribution and four parameters of the location-scale extension of power t distribution via maximum likelihood. The Fisher information matrix derived is nonsingular on the whole parametric space; in addition we obtain the profile log-likelihood functions on two parameters. The response plots for different sample sizes provide strong evidence for the estimators' existence and unicity. An application of the power t distribution suggests that the model can be very useful for real data.