• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.11-24
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• 1999

In this paper we propose a method to test $\textit{H}$:$\rho_i$=$\gamma_i$ for 1$\leq$$\textit{i}$$\leq$$\ell$ against $\textit{K}$:$\rho_i$$\neq$$\gamma_i$ for some ｉin k-variance component random or mixed linear model where $\rho$i denotes the ratio of the i-th variance component to the error variance and $\ell$$\leq$K. The test which we call Rao-Wald test is exact and does not depend upon nuisance parameters. From a numerical study of the power performance of the test of the interaction effect for the case of a two-way random model Rao-Wald test was seen to be quite comparable to the locally best invariant (LBI) test when the nuisance parameters of the LBI test are assumed known. When the nuisance parameters of the LBI test are replaced by maximum likelihood estimators Rao-Wald test outperformed the LBI test.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.267-274
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• 2008

This paper reports generating creative ideas based on customer needs using Kano Model and Importance-Differentiation Matrix (I-D Matrix). Nowadays, every customer demands creative ideas on product innovations in order to be satisfied her needs. However, most existing methods are limited to get creative ideas that reflect customer needs. Any creative ideas that do not fully reflect customer needs are obviously more difficult to succeed in the market than those that reflect customer needs. This paper distinguishes each quality elements the customer needs in terms of Kano Model. And it presents the effective ways of generating creative ideas by I-D Matrix in order to overcome current uppermost limits.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.5
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• pp.47-57
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• 2012

A modified ignition and growth(I&G) model which is necessary to simulate the combustion phenomena of energetic materials and an analytical model determining the unknown parameters of the reaction rate equation are proposed. The modified I&G model sustains important physical implications with overcoming some problems of previous rate equations. This rate model consists of ignition term which represents the formation of the hotspot due to void collapse and growth term which means the shock to detonation transition phenomena. Also, the theoretical model is used to investigate the combustion characteristics of certain energetic materials before running Hydrocode by pre-determination of unknown parameter, $b,\;G,\;x,\;I$. The analytical model provides efficient and highly accurate results rather than previous method which simulated the unconfined-rate-stick via the numerical means.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.331-341
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• 2012

A modified Ignition and Growth(I&G) model which is necessary to simulate the combustion phenomena of energetic materials and an analytical model determining the unknown parameters of the reaction rate equation are proposed. The modified I&G model sustains important physical implications with overcoming some problems of previous rate equations. This rate model consist of Ignition term which represent the formation of the hotspot due to void collapse and Growth term which means the shock to detonation transition phenomena. Also, the theoretical model is used to investigate the combustion characteristics of certain energetic materials before running Hydrocode by pre-determination of unknown parameter, b, G, x, I. The analytical model provides efficient and highly accurate results rather than previous method which simulated the unconfined-rate-stick via the numerical means.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.1987-1998
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• 2014

Zeolite was synthesized from power station waste, coal fly ash, as an alternative low-cost adsorbent and investigated for the removal of Sr(II) and Cs(I) ions from single- and binary metal aqueous solutions. In order to investigate the adsorption characteristics, the effects of various operating parameters such as initial concentration of metal ions, contact time, and pH of the solutions were studied in a batch adsorption technique. The Langmuir model better fitted the adsorption isotherm data than the Freundlich model. The pseudo second-order model was found more applicable to describe the kinetics of system. The adsorption capacities of Sr(II) and Cs(I) ions obtained from the Langmuir model were 1.7848 mmol/g and 0.7640 mmol/g, respectively. Although the adsorption capacities of individual Sr(II) and Cs(I) ions was less in the binary-system, the sum of the total adsorption capacity (2.3572 mmol/g) of both ions in the binary-system was higher than the adsorption capacity of individual ion in the single-system. Comparing the homogeneous film diffusion model with the homogeneous particle diffusion model, the adsorption was mainly controlled by the particle diffusion process.

• Journal of Korea Game Society
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• v.20 no.6
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• pp.31-42
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• 2020

To accept more than thousands of concurrent players, MMO Game servers should use high performance I/O APIs provided by the OS. Despite the continuous improvement of the I/O models, these new I/O APIs are not applied on the applications immediately. In this study, we proposed a new MMO game server architecture using io_uring, Linux's new I/O model. We implemented the proposed architecture and achieved performance improvements of the server on a stress test benchmark with high concurrent connections.

• Korean Journal of Mathematics
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• v.30 no.1
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• pp.67-72
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• 2022

For a locus with two alleles (I^A and I^B), the frequencies of the alleles are represented by $$p=f(I^A)={\frac{2N_{AA}+N_{AB}}{2N},\;q=f(I^B)={\frac{2N_{BB}+N_{AB}}{2N}$$ where N_AA, N_AB and N_BB are the numbers of I^AI^A, I^AI^B and I^BI^B respectively and N is the total number of populations. The frequencies of the genotypes expected are calculated by using p², 2pq and q². Choi showed the method of whether some genotypes is in these probabalities. Also he calculate the probability generating function for offspring number of genotype under a diploid model( [1]). In this paper, let x(t, p) be the probability that I^A become fixed in the population by time t-th generation, given that its initial frequency at time t = 0 is p. We find adapted equations for x using the mean change of frequence of alleles and fitness of genotype. Also we apply this adapted equations to several diploid model and it also will apply to actual examples.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.6
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• pp.67-74
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• 1995

This paper proposes the step-stress type-I censoring model for analyzing the data of accelerated life test and reducing the time of accelerated life test. In order to obtain the data of accelerated life test, the step-stress accelerated life test was run with voltage stress to CMOS Hex Buffer. The Weibull distribution, the Inverse-power-law model and Maximum likelihood method were used. The iterative procedure using modified-quasi-linearization method is applied to solve the nonlinear equation. The proposed Weibull step-stress type-I censoring model exactly estimases the life time of units, while reducting the time of accelerated life test and the equipments of test.

• Korea Science and Art Forum
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• v.30
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• pp.217-230
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• 2017

The purpose of this study is to develop a theoretical model identifying how consumers accept a fashionable technology product. A systematic review of 39 influential TAM studies focusing on theory development in the context of information technology results in three tendencies, which become backbone of the model of fashionable technology acceptance. A subsequent review of the nature of fashion fleshes out the backbone with detailed propositions in the more specific context of fashionable technology. The model of fashionable technology acceptance includes key propositions of Theory of Reasoned Action, in which internal beliefs consist of functional, aesthetic and symbolic values, and other factors, such as technology features (i.e., hardware specification, software specification, brand, and price factors), environmental conditions (i.e., technical infrastructure and user occasion), individual differences (i.e., age, gender, experience, personality, aesthetic sense, fashion innovativeness, and income), and social influence (i.e., subjective norms, social reputation, and cultural difference). Implications, limitations, and suggestions for future research are also discussed.

• Journal of Animal Science and Technology
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• v.48 no.1
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• pp.29-38
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• 2006

The objective of this study was to estimate genetic variances of growth curve parameters in Hanwoo cows. The data used in this study were records from 1,083 Hanwoo cows raised at Hanwoo Experiment Station, National Livestock Research Institute(NLRI). First evaluation model(Model I) fit year-season of birth and age of dam as fixed effects and second model(Model II) added age at the final weight as a linear covariate to Model I. Heritability estimates of A, b and k from Gompertz model were 0.22, 0.11 and 0.07 using modelⅠ and 0.28, 0.11 and 0.12 using modelⅡ. Those from Von Bertalanffy model were 0.22, 0.11 and 0.07 using modelⅠ, 0.28, 0.11 and 0.12 using modelⅡ. Heritability estimates of A, b and k from Logistic model were 0.14, 0.07 and 0.05 using modelⅠ, 0.18, 0.07 and 0.12 using modelⅡ. Heritability estimates of A from Gompertz model were higher than those from Von Bertalanffy model or Logistic model in both model Ⅰand model Ⅱ. Heritability estimates of b from Logistic model were higher than those from Gompertz model or Von Bertalanffy model in both modelⅠand model Ⅱ. Heritability estimates of birth weight, weaning weight, 3 month weight, 6 month weight, 9 month weight, 12 month weight, 18 month weight, 24 month weight, 36 month weight were after linear age adjustment 0.27, 0.11, 0.19, 0.14, 0.16, 0.23, 0.52 and 0.32, respectively. Heritability estimates of birth weight, weaning weight, 3 month weight, 6 month weight, 9 month weight and 24 month weight fit by Gompertz model were larger than those estimated from linearly adjusted data. Heritability estimates of 12 month weight, 18 month weight and 36 month weight fit by Von Bertalanffy model were larger than those estimated from linearly adjusted data. In the multitrait analyses for parameters from Gompertz model, genetic and phenotypic correlations between A and k parameters were －0.47 and －0.67 using modelⅠand －0.56 and －0.63 using model Ⅱ. Those between the A and b parameters were 0.69 and 0.34 using modelⅠand 0.72 and 0.37 using model Ⅱ. Those between the b and k parameters were －0.26 and 0.01 using modelⅠand －0.30 and 0.01 using model Ⅱ. In the multitrait analyses for parameters from Von Bertalanffy model, genetic and phenotypic correlations between A and k parameters were －0.49 and －0.67 suing model Ⅰ and －0.57 and －0.70 using modelⅡ. Those between the A and b parameters were 0.61 and 0.33 using modelⅠ and 0.60 and 0.30 using model Ⅱ. Those between the b and k parameters were －0.20 and 0.02 using modelⅠ and 0.16 and 0.00 using modelⅡ. In the multitrait analyses for parameters from Logistic model, genetic and phenotypic correlations between A and k parameters were －0.43 and －0.67 using model Ⅰ and －0.50 and －0.63 using modelⅡ. Those between the A and b parameters were 0.47 and 0.22 using modelⅠ and 0.38 and 0.24 using modelⅡ. Those between the b and k parameters were －0.09 and 0.02 using model Ⅰ and －0.02 and 0.13 using model Ⅱ.