• Title/Summary/Keyword: mixed method

Search Result 5,243, Processing Time 0.03 seconds

Characterization of the mixed soil with waste and application to geotechnical field (폐기물을 포함한 혼합토의 특성 및 지반공학분야에의 응용)

  • 이기호
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2001.11a
    • /
    • pp.72-84
    • /
    • 2001
  • In order to utilize mass of oyster shells for a partial substitute material for reclamation, we investigate the shear characteristics of dredged sluge mixed with oyster shells. the apparent modulus of elasticity of the this mixture are obtained from the triaxial compression tests and is utilized to characterize the apparent modulus of elastic of the oyster shells by carrying out some numerical analysis based upon the homogenization theory. We got the conclusion by a series of experiment, 1) It is verified that modulus of elasticity of dredged clay is improved by mixing with oyster shells. 2) The homogenization method for deducing apparent modulus of elasticity of oyster shells, which can consider micro-structure of mixed soil, is introduced. The elastic modulus is affected from the skeleton structure of oyster shell. The effect of 49kPa is bigger than that of 98kPa.

  • PDF

Bayesian mixed models for longitudinal genetic data: theory, concepts, and simulation studies

  • Chung, Wonil;Cho, Youngkwang
    • Genomics & Informatics
    • /
    • v.20 no.1
    • /
    • pp.8.1-8.14
    • /
    • 2022
  • Despite the success of recent genome-wide association studies investigating longitudinal traits, a large fraction of overall heritability remains unexplained. This suggests that some of the missing heritability may be accounted for by gene-gene and gene-time/environment interactions. In this paper, we develop a Bayesian variable selection method for longitudinal genetic data based on mixed models. The method jointly models the main effects and interactions of all candidate genetic variants and non-genetic factors and has higher statistical power than previous approaches. To account for the within-subject dependence structure, we propose a grid-based approach that models only one fixed-dimensional covariance matrix, which is thus applicable to data where subjects have different numbers of time points. We provide the theoretical basis of our Bayesian method and then illustrate its performance using data from the 1000 Genome Project with various simulation settings. Several simulation studies show that our multivariate method increases the statistical power compared to the corresponding univariate method and can detect gene-time/ environment interactions well. We further evaluate our method with different numbers of individuals, variants, and causal variants, as well as different trait-heritability, and conclude that our method performs reasonably well with various simulation settings.

A Study on the Analysis of the Circulation Planning Importance in mixed-use Buildings (주상복합 건축물의 동선계획 중요도 분석에 관한 연구)

  • Kim, Young-Sun;Yang, Seung-Jung;Jun, Han-Jong
    • Journal of the Architectural Institute of Korea Planning & Design
    • /
    • v.34 no.12
    • /
    • pp.103-112
    • /
    • 2018
  • High-rise mixed-use buildings are consisted of various facilities and circulations. Since various facilities and circulations are planned in a single site, circulation planning should be established after identifying the exact characteristics of facility and circulation. To this end, the components of the circulation planning in accordance with the formation of facility types are analyzed through the survey of experts based on Delphi Method. To identify the characteristics of the mixed-use buildings, by figuring out how the elements of circulation planning which are sought to be important by the planner has been reflected through analysis of the correlation between two sections. Researching on the circulation between two sections through Delphi Method and reflected circulation planning, it reaches the conclusion that the circulation of planning on the subject building is applied following the importance. In other words, the components of circulation planning which were sought to be important by the planner are reflected significantly when they planned the circulation planning on that mixed-use buildings. However, in case of design on the outdoor vehicle circulation, minimizing on the vehicle circulation at the 1st floor is not applied for the majority of the subject buildings different from the importance. In early 2000, high end residential buildings designed for mixed-use building have been specialized at vehicle-centered outdoor space and hotel style drop-off. Contrastively, sizable outdoor space at the 1st floor is designed to open to the residents and the local by minimizing the vehicle circulation in recent. Finally it shows that the way of circulation planning has been changed in accordance with time and trend.

A POSTERIORI L(L2)-ERROR ESTIMATES OF SEMIDISCRETE MIXED FINITE ELEMENT METHODS FOR HYPERBOLIC OPTIMAL CONTROL PROBLEMS

  • Hou, Tianliang
    • Bulletin of the Korean Mathematical Society
    • /
    • v.50 no.1
    • /
    • pp.321-341
    • /
    • 2013
  • In this paper, we discuss the a posteriori error estimates of the semidiscrete mixed finite element methods for quadratic optimal control problems governed by linear hyperbolic equations. The state and the co-state are discretized by the order $k$ Raviart-Thomas mixed finite element spaces and the control is approximated by piecewise polynomials of order $k(k{\geq}0)$. Using mixed elliptic reconstruction method, a posterior $L^{\infty}(L^2)$-error estimates for both the state and the control approximation are derived. Such estimates, which are apparently not available in the literature, are an important step towards developing reliable adaptive mixed finite element approximation schemes for the control problem.

A Study on the Change of Volume and Temperature in Aqueous Binary Solvent with Ethanol (물과 에탄을 이성분 혼합용매 계에서 부피 및 온도 변화에 관한 연구)

  • 김용권;임귀택
    • Journal of Korean Elementary Science Education
    • /
    • v.20 no.1
    • /
    • pp.139-147
    • /
    • 2001
  • This paper is to study on the change of volume and temperature of the solution which mixed water with ethanol. And its main purpose is to examine closely how the volume changes, and to find the method to maximize the change of the volume. The summaries for results of the study are; First, we were known that water and ethanol are homogeneously mixed. But two solvents does not mix homogeneously by different specific gravity at early stages. Second, we could see that the volume changed large at homogeneous mixed water with ethanol by stirrer, the change of volume is the largest value when water mixed with ethanol in the ratio of one to one. Third, when water mixed with ethanol in the ratio of one to one, the change of temperature is very large by activated hydrogen bond. We conclude that it is the best result when ratio of water and ethanol is one to one and the solution is well mixed.

  • PDF

Development of Continuous/Discrete Mixed $H_2$/H$\infty$ Filtering Design Algorithms for Time Delay Systems

  • Kim, Jong-Hae
    • Transactions on Control, Automation and Systems Engineering
    • /
    • v.2 no.3
    • /
    • pp.163-168
    • /
    • 2000
  • The problems of mixed $H_2/H_{\infty}$ filtering design fer continuous and discrete time linear systems with time delay are investigated. The main purpose is to design a stable mixed $H_2/H_{\infty}$ filter which minimizes the H$_2$Performance measure satisfying a prescribed H$_{\infty}$ norm bound on the closed loop system in continuous-time case and discrete-time case, respectively. The sufficient conditions of existence of filter, the mixed $H_2/H_{\infty}$ filter design method, and the upper bound of performance measure are proposed by LMI(linear matrix inequality) techniques in terms of all finding variables. Also, we present optimization problems in order to get the optimal mixed $H_2/H_{\infty}$ filter in continuous and discrete time case, respectively.

  • PDF

Performance analysis of mixed-flow fans considering the low flow characteristics (저유량 특성을 고려한 사류 송풍기의 성능 해석)

  • Oh, Hyoung Woo;Kim, Kwang-Yong
    • 유체기계공업학회:학술대회논문집
    • /
    • 2000.12a
    • /
    • pp.110-115
    • /
    • 2000
  • The mean streamline analysis using the empirical loss correlations has been developed for performance prediction of industrial mixed-flow fan impellers in the present study. New simple, but effective, models for the additional Euler input work characteristic and an internal recirculation loss due to internal flow reversal under the low flowrate conditions are proposed in this paper. Comparison of overall performance predictions with six sets of test data of mixed-flow fans is accomplished to demonstrate the accuracy of the proposed models. Predicted performance curves by the present set of loss models agree fairly well with experimental data for a variety of mixed-flow fan impellers over the entire operating conditions. The prediction method presented herein can be used efficiently in the conceptual design phase of mixed-flow fan impellers.

  • PDF

Fatigue Crack Propagation Behavior under Mixed Mode Loading (혼합모드 하중에서의 피로균열 전파거동)

  • 송삼홍;이정무;최병호
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.481-484
    • /
    • 2000
  • Practical structures are subject not only to tension but also to shear and torsional loading. Even under uniaxial loading, when the load is not perpendicular to the crack plane, mixed mode crack can occur. Hence, it is necessary to evaluate the fatigue behavior under mixed mode loading. In this study, the propagation behavior of the fatigue crack of the STS304 steels under mixed mode loading condition was investigated. The mode I and II stress intensity factors of CTS specimen were calculated using elastic finite element method with experimental results. The fatigue crack propagation under mixed mode was evaluated by the effective stress intensity factor proposed by Tanaka.

  • PDF

Solving Mixed Strategy Equilibria of Multi-Player Games with a Transmission Congestion (다자게임 전력시장에서 송전선 혼잡시의 복합전략 내쉬균형 계산)

  • Lee, Kwang-Ho
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.55 no.11
    • /
    • pp.492-497
    • /
    • 2006
  • Nash Equilibrium (NE) is essential to investigate a participant's bidding strategy in a competitive electricity market. The transmission line constraints make it difficult to compute the NE due to causing a mixed strategy NE instead of a pure strategy NE. Computing a mixed strategy is more complicated in a multi-player game. The competition among multi-participants is modeled by a two-level hierarchical optimization problem. A mathematical programming approach is widely used in finding this equilibrium. However, there are difficulties to solving a mixed strategy NE. This paper presents two propositions to add heuristics to the mathematical programming method. The propositions are based on empirical studies on mixed strategies in numerous sample systems. Based on the propositions a new formulation is provided with a set of linear and nonlinear equations, and an algorithm is suggested for using the prepositions and the newly-formulated equations.