• Title/Summary/Keyword: hierarchical approach

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Joint HGLM approach for repeated measures and survival data

  • Ha, Il Do
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.4
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    • pp.1083-1090
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    • 2016
  • In clinical studies, different types of outcomes (e.g. repeated measures data and time-to-event data) for the same subject tend to be observed, and these data can be correlated. For example, a response variable of interest can be measured repeatedly over time on the same subject and at the same time, an event time representing a terminating event is also obtained. Joint modelling using a shared random effect is useful for analyzing these data. Inferences based on marginal likelihood may involve the evaluation of analytically intractable integrations over the random-effect distributions. In this paper we propose a joint HGLM approach for analyzing such outcomes using the HGLM (hierarchical generalized linear model) method based on h-likelihood (i.e. hierarchical likelihood), which avoids these integration itself. The proposed method has been demonstrated using various numerical studies.

Joint Hierarchical Semantic Clipping and Sentence Extraction for Document Summarization

  • Yan, Wanying;Guo, Junjun
    • Journal of Information Processing Systems
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    • v.16 no.4
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    • pp.820-831
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    • 2020
  • Extractive document summarization aims to select a few sentences while preserving its main information on a given document, but the current extractive methods do not consider the sentence-information repeat problem especially for news document summarization. In view of the importance and redundancy of news text information, in this paper, we propose a neural extractive summarization approach with joint sentence semantic clipping and selection, which can effectively solve the problem of news text summary sentence repetition. Specifically, a hierarchical selective encoding network is constructed for both sentence-level and document-level document representations, and data containing important information is extracted on news text; a sentence extractor strategy is then adopted for joint scoring and redundant information clipping. This way, our model strikes a balance between important information extraction and redundant information filtering. Experimental results on both CNN/Daily Mail dataset and Court Public Opinion News dataset we built are presented to show the effectiveness of our proposed approach in terms of ROUGE metrics, especially for redundant information filtering.

A Hierarchical Bayesian Model for Survey Data with Nonresponse

  • Han, Geunshik
    • Journal of the Korean Statistical Society
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    • v.30 no.3
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    • pp.435-451
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    • 2001
  • We describe a hierarchical bayesian model to analyze multinomial nonignorable nonresponse data. Using a Dirichlet and beta prior to model the cell probabilities, We develop a complete hierarchical bayesian analysis for multinomial proportions without making any algebraic approximation. Inference is sampling based and Markove chain Monte Carlo methods are used to perform the computations. We apply our method to the dta on body mass index(BMI) and show the model works reasonably well.

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Availability Analysis of Single Sensor Node using Hierarchical Model (계층적 모델을 이용한 단일 센서 노드의 가용성 분석)

  • Yoon, Young Hyun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.5 no.2
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    • pp.87-93
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    • 2009
  • In this paper, we propose and evaluate the availability of single sensor node using a hierarchial modeling approach. We divides a sensor node into a software and hardware and analyze failures of each component. We construct Markov chains to represent the components of a sensor node, and then we construct a hierarchical model which use fault tree in upper level and Markov chains in lower level. We evaluate the availability and down of single sensor node.

Efficient Rolling Shutter Distortion Removal using Hierarchical Block-based Motion Estimation

  • Lee, Donggeun;Choi, Kang-Sun
    • IEIE Transactions on Smart Processing and Computing
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    • v.3 no.4
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    • pp.205-211
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    • 2014
  • This paper reports an efficient algorithm for accurate rolling shutter distortion removal. A hierarchical global motion estimation approach for a group of blocks reduces the level of computation by three orders of magnitude. In addition, the motion of each scanline is determined accurately by averaging two candidates obtained through cubic spline interpolation. The experimental results show that the proposed method produces accurate motion information with significant computation reduction and corrects the rolling shutter distortion effectively.

Hierarchical image and Kalman filter-based active shape model for non-rigid object tracking (비정형 객체추적을 위한 계층적 영상과 Kalman Filter기반 능동형태모델)

  • 강진영;기현종;신정호;백준기
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.445-448
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    • 2003
  • In this paper, we present a hierarchical approach of an enhanced active shape model for video tracking. Kalman filter is used. To estimate a dynamic shape in video object tracking. The experimental results show that the proposed hierarchical active shape model using Kalman filter is efficient.

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A Hierarchical Classification Method for Verification of Seal Imprint (계층적 분류방식에 의한 인영 검증)

  • 김진희;심재창;현기호;하영호
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.28B no.11
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    • pp.904-912
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    • 1991
  • Automatic recognition of seal imprint has been required in the oriental countries. In this paper, a hierarchical approach for seal imprint verification is presented. Global features are used for seal imprint description in the first step. In the second step, conventional and several proposed local features are used to detect useful informations such as size, distribution and relative position of stroke length from seal imprint. In the last step, seal imprints are classified into one of three categories 'accept', 'ambiguous' and reject', based on the hierarchical classification. Experimental results show good performance on classification and recognition.

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Sampling Based Approach to Hierarchical Bayesian Estimation of Reliability Function

  • Younshik Chung
    • Communications for Statistical Applications and Methods
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    • v.2 no.2
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    • pp.43-51
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    • 1995
  • For the stress-strengh function, hierarchical Bayes estimations considered under squared error loss and entropy loss. In particular, the desired marginal postrior densities ate obtained via Gibbs sampler, an iterative Monte Carlo method, and Normal approximation (by Delta method). A simulation is presented.

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Model Coupling Technique for Level Access in Hierarchical Simulation Models and Its Applications (계층의 구조를 갖는 시뮬레이션 모델에 있어서 단계적 접근을 위한 모델연결 방법론과 그 적용 예)

  • 조대호
    • Journal of the Korea Society for Simulation
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    • v.5 no.2
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    • pp.25-40
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    • 1996
  • Modeling of systems for intensive knowledge-based processing requires a modeling methodology that makes efficient access to the information in huge data base models. The proposed level access mothodology is a modeling approach applicable to systems where data is stored in a hierarchical and modular modules of active memory cells(processor/memory pairs). It significantly reduces the effort required to create discrete event simulation models constructed in hierarchical, modular fashion for above application. Level access mothodology achieves parallel access to models within the modular, hierarchical modules(clusters) by broadcasting the desired operations(e.g. querying information, storing data and so on) to all the cells below a certain desired hierarchical level. Level access methodology exploits the capabilities of object-oriented programming to provide a flexible communication paradigm that combines port-to-port coupling with name-directed massaging. Several examples are given to illustrate the utility of the methodology.

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Likelihood-Based Inference on Genetic Variance Component with a Hierarchical Poisson Generalized Linear Mixed Model

  • Lee, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.8
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    • pp.1035-1039
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    • 2000
  • This study developed a Poisson generalized linear mixed model and a procedure to estimate genetic parameters for count traits. The method derived from a frequentist perspective was based on hierarchical likelihood, and the maximum adjusted profile hierarchical likelihood was employed to estimate dispersion parameters of genetic random effects. Current approach is a generalization of Henderson's method to non-normal data, and was applied to simulated data. Underestimation was observed in the genetic variance component estimates for the data simulated with large heritability by using the Poisson generalized linear mixed model and the corresponding maximum adjusted profile hierarchical likelihood. However, the current method fitted the data generated with small heritability better than those generated with large heritability.