• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.09a
• /
• pp.115-119
• /
• 2001

Contaminant retardation factor is derived from the colloidal and contaminant transport equations for a four-phase porous medium: an aqueous phase, two mobile colloidal phases, and a solid matrix. It is assumed that the contaminant sorption to solid matrix and colloidal particles and the colloidal deposition on solid matrix follow the linear isotherms. The behavior of the contaminant retardation factor in response to the change of model parameters is examined employing the experimental data of Magee et al. (1991) and Jenkins and Lion (1993). In the four-phase system, the contaminant retardation factor is determined by both the contaminant association with solid matrix and colloidal particles and the colloidal deposition on solid matrix. The contaminant mobility is enhanced when the affinity of contaminants to mobile colloids increases. In addition, as the affinity of colloids to solid matrix decreases, the contaminant mobility increases.

• ETRI Journal
• /
• v.39 no.6
• /
• pp.841-850
• /
• 2017

We investigate neural network image reconstruction for magnetic particle imaging. The network performance strongly depends on the convolution effects of the spectrum input data. The larger convolution effect appearing at a relatively smaller nanoparticle size obstructs the network training. The trained single-layer network reveals the weighting matrix consisting of a basis vector in the form of Chebyshev polynomials of the second kind. The weighting matrix corresponds to an inverse system matrix, where an incoherency of basis vectors due to low convolution effects, as well as a nonlinear activation function, plays a key role in retrieving the matrix elements. Test images are well reconstructed through trained networks having an inverse kernel matrix. We also confirm that a multi-layer network with one hidden layer improves the performance. Based on the results, a neural network architecture overcoming the low incoherence of the inverse kernel through the classification property is expected to become a better tool for image reconstruction.

• Proceedings of the KIEE Conference
• /
• 1998.07c
• /
• pp.1027-1029
• /
• 1998

The method of building the system state matrix described here is the direct method which constructs elements of state matrix directly by the algebraic expressions from the machine data with time constants. From this method, it is reasonable to confirm the structure of state matrix and the relation of submatrices and elements efficiently. In this paper the interrelationship of submatrices of system matrix is investigated and a constitution of system matrix considering time constants.

• Journal of the Korean Data and Information Science Society
• /
• v.20 no.1
• /
• pp.39-48
• /
• 2009

Fisher information matrix plays an important role in statistical inference of unknown parameters. Especially, it is used in objective Bayesian inference which derives to the posterior distribution using a noninformative prior distribution and is an example of metric functions in geometry. The more parameters for estimating in a distribution are, the more complicate derivation of the Fisher information matrix for the distribution is. In this paper, we derive to the Fisher information matrix for 3-parameters Weibull distribution which is used in reliability theory using Mathematica programs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.5
• /
• pp.125-133
• /
• 2006

This paper presents comparison results of Step Response Model of Dynamic Matrix Control(DMC) for a drum-type boiler-turbine system of a fossil power plant. Two possible kinds of step response models are investigated in designing the DMC, one is developed with the linearization of theoretical model and the other is developed with the process step-test data. Then, the control performances of each model-based DMC are simulated and evaluated. It is observed that the simulation results with the step-response model based on the test data show satisfactory results, while the linearized model is not suitable for the control of boiler-turbine system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.2
• /
• pp.194-202
• /
• 1998

This paper describes a hardware implementation method of a Petri Net-based controller. A flexible and systematic implementation method, based on look-up tables, is suggested, which enables to build high speed Petri net-based controllers. The suggested method overcomes the inherent speed limit that arises from the microprocessors by using of matrix-based look-up tables. Based on the matrix framework, this paper suggests various specific data path structures as well as a basic data path structure, accompanied by evolution algorithms, for sub-class Petri nets. A new sub-class Petri net, named Biarced Petri Net, resolves memory explosion problem that usually comes with matrix-based look-up tables. The suggested matrix-based method based on the Biarced Petri net has as good efficiency and expendability as the list-based methods. This paper shows the usefulness of the suggested method, evaluating the size of the look-up tables and introducing an architecture of the signal processing unit of a programmable controller. The suggested implementation method is supported by an automatic design support program.

• Journal of the Korean Home Economics Association
• /
• v.47 no.8
• /
• pp.13-24
• /
• 2009

This study investigated college students' time management behavior and time satisfaction according to the use of the time-matrix. Data were collected from 400 college students in Seoul by a self-administered questionnaire. Collected data were subjected to descriptive and comparative statistical analyses using the software SPSS(version 12.0). The conclusions of this study were as follows; 1. The use of time-matrix was categorized into 4 task groups: (1) not urgent but important, (2) urgent but notimportant, (3) neither urgent nor important, (4) urgent and important. 2. Time-management-behavior of planning was categorized into 3 components: standard setting, reality overlapping and implementing into 3 components(i.e., checking, adjusting, facilitating condition). 3. In all domains except overlapping, 'not urgent but importance' was the most popular managerial behavior. 4. However, 'neither urgent nor important' was voted the most popular in terms of managerial satisfaction. This study provides useful knowledge on managerial time-use categorization. Furthermore also contributes towards the knowledge base of time-managerial behaviors and dispels stereotypical-thinking that only bing busy all the time using is an indication of good time management behavior. Finally, this study advocates use of the time-matrix to achieve efficient time management.

• International journal of advanced smart convergence
• /
• v.9 no.4
• /
• pp.42-51
• /
• 2020

In this paper, the authors propose the pseudo complex correlation coefficient (PCCC) of the two complex random variables (RV), because the four real correlation coefficients (RCC) of the corresponding four real RVs cannot be obtained only from the complex correlation coefficient (CCC) of given two complex RV. Such observation is motivated by the general statement; "The complex jointly-Gaussian random M-vector cannot be completely described by the complex covariance matrix, even though the real Gaussian random 2M-vector can be completely descried by the real covariance matrix. Therefore, in order to describe completely the complex jointly-Gaussian random M-vector, we need an additional matrix, namely the complex pseudo-covariance matrix, along with the complex covariance matrix." Then, we apply PCCC to correlated information sources (CIS) for non-orthogonal multiple access (NOMA) in 5G system, and investigate impact of the proposed PCCC on the achievable data rate of the stronger channel user in the conventional successive interference cancellation (SIC) NOMA with CIS. It is shown that for the given same CCC, the achievable data rates with the different PCCC are different, because the corresponding RCC are different. We also show that as the absolute value of the same CCC increases, the impact of the different PCCC becomes more significant.

• Coupled systems mechanics
• /
• v.10 no.6
• /
• pp.509-520
• /
• 2021

Fiber-reinforced concrete (FRC) is a composite material where small fibers made from steel or polypropylene or similar material are embedded into concrete matrix. In a material model each constituent should be adequately described, especially the interface between the matrix and fibers that is determined with the 'bond-slip' law. 'Bond-slip' law describes relation between the force in a fiber and its displacement. Bond-slip relation is usually obtained from tension laboratory experiments where a fiber is pulled out from a matrix (concrete) block. However, theoretically bond-slip relation could be determined from bending experiments since in bending the fibers in FRC get pulled-out from the concrete matrix. We have performed specially designed laboratory experiments of three-point beam bending with an intention of using experimental data for determination of material parameters. In addition, we have formulated simple layered model for description of the behavior of beams in the three-point bending test. It is not possible to use this 'forward' beam model for extraction of material parameters so an inverse model has been devised. This model is a basis for formulation of an inverse model that could be used for parameter extraction from laboratory tests. The key assumption in the developed inverse solution procedure is that some values in the formulation are known and comprised in the experimental data. The procedure includes measured data and its derivative, the formulation is nonlinear and solution is obtained from an iterative procedure. The proposed method is numerically validated in the example at the end of the paper and it is demonstrated that material parameters could be successfully recovered from measured data.

• Journal of Integrative Natural Science
• /
• v.7 no.3
• /
• pp.208-213
• /
• 2014

National-wide and/or large scale sample surveys generally use complex sample design. Traditional Pearson chi-square test is not appropriate for the categorical complex sample data. Rao-Scott suggested an adjustment method for Pearson chi-square test, which uses the average of eigenvalues of design matrix of cell probabilities. This study is to compare the efficiency of Rao-Scott first order adjusted test to Wald test for homogeneity between two populations using 2009 Gyeongnam regional education offices's customer satisfaction survey (2009 GREOCSS) data. The 2009 GREOCSS data were collected based on stratified three-stage cluster sampling with probability proportional to size. The empirical results show that the Rao-Scott adjusted test statistic using only the variances of cell probabilities is very close to the Wald test statistic, which uses the covariance matrix of cell probabilities, under the 2009 GREOCSS data based. However it is necessary to be cautious to use the Rao-Scott first order adjusted test statistic in the place of Wald test because its efficiency is decreasing as the relative variance of eigenvalues of the design matrix of cell probabilities is increasing, specially more when the number of degrees of freedom is small.