• Title/Summary/Keyword: Selection Response

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An Accurate and Efficient Method for Selecting and Scaling Ground Motions Considering Target Response Spectrum Mean and Variance (목표스펙트럼의 평균과 분산을 고려한 지반운동 선정과 배율조정계수 결정방법)

  • Ha, Seong Jin;Park, Mi Yeong;Han, Sang Whan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.5
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    • pp.331-340
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    • 2016
  • It is important to select proper ground motions for obtaining accurate results from response history analyses. The purpose of this study is to propose an accurate and efficient method that does not require excessive computation for selecting and scaling ground motions to match target response spectrum mean and variance. The proposed method is conceptually simple and straightforward, and it does not use a simulation algorithm that requires a sophisticated subroutine program. In this method, the desired number of ground motions are sequentially scaled and selected from a ground motion library. The proposed method gives the best selection results using Sum of Square Error and has the smallest value(=0.14). Also, The accuracy and consistency of the proposed method are verified by comparing the selection results of the proposed method with those of existing methods.

Bayesian estimation for finite population proportion under selection bias via surrogate samples

  • Choi, Seong Mi;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.6
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    • pp.1543-1550
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    • 2013
  • In this paper, we study Bayesian estimation for the finite population proportion in binary data under selection bias. We use a Bayesian nonignorable selection model to accommodate the selection mechanism. We compare four possible estimators of the finite population proportions based on data analysis as well as Monte Carlo simulation. It turns out that nonignorable selection model might be useful for weekly biased samples.

Sensor selection approach for damage identification based on response sensitivity

  • Wang, Juan;Yang, Qing-Shan
    • Structural Monitoring and Maintenance
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    • v.4 no.1
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    • pp.53-68
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    • 2017
  • The response sensitivity method in time domain has been applied extensively for damage identification. In this paper, the relationship between the error of damage identification and the sensitivity matrix is investigated through perturbation analysis. An index is defined according to the perturbation amplify effect and an optimal sensor placement method is proposed based on the minimization of that index. A sequential sub-optimal algorithm is presented which results in consistently good location selection. Numerical simulations with a two-dimensional high truss structure are conducted to validate the proposed method. Results reveal that the damage identification using the optimal sensor placement determined by the proposed method can identify multiple damages of the structure more accurately.

A Bayesian Variable Selection Method for Binary Response Probit Regression

  • Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.28 no.2
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    • pp.167-182
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    • 1999
  • This article is concerned with the selection of subsets of predictor variables to be included in building the binary response probit regression model. It is based on a Bayesian approach, intended to propose and develop a procedure that uses probabilistic considerations for selecting promising subsets. This procedure reformulates the probit regression setup in a hierarchical normal mixture model by introducing a set of hyperparameters that will be used to identify subset choices. The appropriate posterior probability of each subset of predictor variables is obtained through the Gibbs sampler, which samples indirectly from the multinomial posterior distribution on the set of possible subset choices. Thus, in this procedure, the most promising subset of predictors can be identified as the one with highest posterior probability. To highlight the merit of this procedure a couple of illustrative numerical examples are given.

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A Study on Determinants Affecting At-home Laver Consumption Expenditures : Type II Tobit Model Treating Sample Selection Bias (김 가정 소비 지출의 결정 요인 분석 : 선택 편의를 고려한 Type II 토빗 모형을 이용하여)

  • Lee, Min-Kyu;Park, Eun-Young
    • The Journal of Fisheries Business Administration
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    • v.40 no.3
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    • pp.147-167
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    • 2009
  • The objective of this study is to analyze the determinants of at-home laver consumption expenditures using the data from a survey of households implemented in 2009. It happened that non-response ratios of monthly expenditures on dry laver and flavored laver among sampled households are 18.8% and 25.6%. Accordingly, this study tries to analyze the determinants affecting at-home laver consumption expenditures by using type II tobit model, one of sample selection models, to deal with sample selection bias caused from non-response data. Analysis results show the age variable positively affects expenditures on dry laver but negatively contributes to expenditures on flavored laver. In addition, the household size, the household's income, the degree of preference for laver have positive relationships with both expenditures. Household size elasticity and income elasticity of the expenditure on dry laver are estimated as 0.220 and 0.251. In the case of flavored laver, these elasticities are estimated as 0.484 and 0.261. Such analysis results can provide information on division of the at-home laver consumption market into groups with high willingness to expense and implementation of detailed marketing strategies to increase at-home laver consumption. The methodology of this study can be applied to consumer preference analysis on other marine products and other analyses on sample with non-response data in the fishery research.

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Characteristics of Spectral Matched Ground Motions Time Histories According to Seed Ground Motion Selection (원본 지반운동 시간이력에 따른 스펙트럼 부합 시간이력의 특성)

  • Choi, Da Seul;Ji, Hae Yeon;Kim, Jung Han
    • Journal of the Earthquake Engineering Society of Korea
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    • v.25 no.1
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    • pp.43-52
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    • 2021
  • According to several seismic design standards, a ground motion time history should be selected similar to the design response spectrum, or a ground motion time history should be modified by matching procedure to the design response spectrum through the time-domain method. For the response spectrum matching procedure, appropriate seed ground motions need to be selected to maintain recorded earthquake accelerogram characteristics. However, there are no specific criteria for selecting the seed ground motions for applying this methodology. In this study, the characteristics of ground motion time histories between seed motions and spectral matched motions were compared. Intensity measures used in the design were compared, and their change by spectral matching procedure was quantified. In addition, the seed ground motion sets were determined according to the response spectrum shape, and these sets analyzed the response of nonlinear and equivalent linear single degrees of freedom systems to present the seed motion selection conditions for spectral matching. As a result, several considerations for applying the time domain spectral matching method were presented.

Estimation of amplification of slope via 1-D site response analysis (1차원 지반응답해석을 통한 사면의 증폭특성 규명)

  • Yun, Se-Ung;Park, Du-Hee
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.620-625
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    • 2009
  • The seismic slope stability is most often evaluated by the pseudo-static limit analysis, in which the earthquake loading is simplified as static inertial loads acting in horizontal and/or vertical directions. The transient loading is represented by constant acceleration via the pseudostatic coefficients. The result of a pseudostatic analysis is governed by the selection of the value of the pseudostatic coefficient. However, selection of the value is very difficult and often done in an ad hoc manner without a sound physical reasoning. In addition, the maximum acceleration is commonly estimated from the design guideline, which cannot accurately estimate the dynamic response of a slope. There is a need to perform a 2D dynamic analysis to properly define the dynamic response characteristics. This paper develops the modified one-dimensional seismic site response analysis. The modified site response analysis adjusts the density of the layers to simulate the change in mass and weight of the layers of the slope with depth. Multiple analyses are performed at various locations within the slope to estimate the change in seismic response of the slope. The calculated peak acceleration profiles with depth from the developed procedure are compared to those by the two-dimensional analyses. Comparisons show that the two methods result in remarkable match.

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Genetic Improvement of Some Traits in Four Strains of Silkworm, Bombyx mori L.

  • Moghaddam S. H. Hosseini;Jomeh K. N. Emam;Mirhosseini S. Z.;Gholamy M. R.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.10 no.2
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    • pp.95-99
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    • 2005
  • A breeding plan was carried out on four commercial strains of silkworm (Bombyx mori L.) 101, 102, 103 and 104 to improve some important traits. Genetic gain or response to selection $({\Delta}G)$, heritability of cocoon shell weight (CSW) and specific combining ability effects were estimated to determine the strains that can be improved. Strain 101 had lowest heritabitity, ${\Delta}G$ and viability. Strain 102 was acceptable in selection response but its viability was low. Therefore these two strains were not suitable for more selection. As a result, only lines 103 and 104 were chosen for further improvement. Intra population selection based on independent culling level method practiced from third to sixth generation for both productive and viability traits simultaneously. While CSW and CW had increasingly enhanced during primary generations, they went slightly up after third generation. According to negative genetic correlation, viability decreased during primary generations, but after third generation that paid attention to balanced development of both productive and viability traits, viability increased so that the pupation rate reached to $91\%$ in 103 and $97\%$ in 104 for last generation $(G_8)$.

Animal Breeding: What Does the Future Hold?

  • Eisen, E.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.3
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    • pp.453-460
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    • 2007
  • An overview of developments important in the future of animal breeding is discussed. Examples from the application of quantitative genetic principles to selection in chickens and mice are given. Lessons to be learned from these species are that selection for production traits in livestock must also consider selection for reproduction and other fitness-related traits and inbreeding should be minimized. Short-term selection benefits of best linear unbiased predictor methodology must be weighed against long-term risks of increased rate of inbreeding. Different options have been developed to minimize inbreeding rates while maximizing selection response. Development of molecular genetic methods to search for quantitative trait loci provides the opportunity for incorporating marker-assisted selection and introgression as new tools for increasing efficiency of genetic improvement. Theoretical and computer simulation studies indicate that these methods hold great promise once genotyping costs are reduced to make the technology economically feasible. Cloning and transgenesis are not likely to contribute significantly to genetic improvement of livestock production in the near future.

An Intention-Response Model based on Mirror Neuron and Theory of Mind using Modular Behavior Selection Networks (모듈형 행동선택네트워크를 이용한 거울뉴런과 마음이론 기반의 의도대응 모델)

  • Chae, Yu-Jung;Cho, Sung-Bae
    • Journal of KIISE
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    • v.42 no.3
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    • pp.320-327
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    • 2015
  • Although service robots in various fields are being commercialized, most of them have problems that depend on explicit commands by users and have difficulty to generate robust reactions of the robot in the unstable condition using insufficient sensor data. To solve these problems, we modeled mirror neuron and theory of mind systems, and applied them to a robot agent to show the usefulness. In order to implement quick and intuitive response of the mirror neuron, the proposed intention-response model utilized behavior selection networks considering external stimuli and a goal, and in order to perform reactions based on the long-term action plan of theory of mind system, we planned behaviors of the sub-goal unit using a hierarchical task network planning, and controled behavior selection network modules. Experiments with various scenarios revealed that appropriate reactions were generated according to external stimuli.