• Communications for Statistical Applications and Methods
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• v.14 no.1
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• pp.81-92
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• 2007

This paper consider trinomial group testing concerned with classification of N given units into one of k disjoint categories. In this paper, we propose Bayesian inference for estimating individual category proportions using the trinomial group testing model proposed by Bar-Lev et al. (2005). We compared a relative efficience (RE) based on the mean squared error (MSE) of MLE and Bayes estimators with various prior information. The impact of different prior specifications on the estimates is also investigated using selected prior distribution. The impact of different priors on the Bayes estimates is modest when the sample size and group size we large.

• Archives of design research
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• v.17 no.2
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• pp.221-230
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• 2004

Existing usability testing method, particularly lab-based usability testing, has been widely implemented for development of user interface. However, the method has critical disadvantages such as high cost, time and effort, unnatural testing environment, and lack of user's direct participation in information architecture. With these backgrounds, this paper aims to develop the web-based participatory tool with particular focus on card sorting. Our tool was developed for allowing user to participate in card sorting with his own computer through web. All the data generated while user is participating in the test are automatically sent to the server, which makes it very easy to collect card sorting data. Users can drag cards of interface elements directly and build the interface structure in their own from their computer-screen so that they can represent their mental models on interface structure of testing website. These functions of our tool can help designers to implement card sorting without tedious and time consuming procedures and improve the method of usability testing by reinforcing user's active participation in building an information architecture.

• Proceedings of the Korea Society of Design Studies Conference
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• 2003.05a
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• pp.32-33
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• 2003

• Journal of Korean Society for Quality Management
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• v.22 no.2
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• pp.33-40
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• 1994

Most software reliability models and other methods attempt to estimate some measures based on its fault history. There are several phases of the software life cycle including testing phase. We can propose it's stopping rule to decide when to stop the testing and pass it on to the next phase by considering the detailed structure of software and calculating the failure rate when each fault was detected. Downs (1985) proposed a method which was developed for estimating the failure rate applicable only to two-level profiles. In this paper, I extended to profiles involving more levels.

• Bulletin of the Korean Mathematical Society
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• v.47 no.5
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• pp.889-905
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• 2010

In this paper, a distribution free approach to the parameter estimation of a simple bilinear model with periodic coefficients is presented. The proposed method relies on minimum distance estimator based on the autocovariances of the squared process. Consistency and asymptotic normality of the estimator, as well as hypotheses testing, are derived. Numerical experiments on simulated data sets are presented to highlight the theoretical results.

• Journal of the Korean Statistical Society
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• v.27 no.2
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• pp.189-195
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• 1998

In this paper, we are concerned with the problem of testing the randomness of the coefficients in a first order autoregressive model. A consistent test based on prediction error is suggested. It is shown that under the null hypothesis, the test statistic is asymptotically normal.

• Journal of the Korean Data and Information Science Society
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• v.19 no.2
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• pp.621-634
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• 2008

This paper addresses the problem of testing whether the means in several inverse Gaussian populations with heterogeneity are equal. The analysis of reciprocals for the equality of inverse Gaussian means needs the assumption of equal scale parameters. We propose Bayesian model selection procedures for testing equality of the inverse Gaussian means under the noninformative prior without the assumption of equal scale parameters. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the objective Bayesian model selection procedures based on the fractional Bayes factor and the intrinsic Bayes factor under the reference prior. Simulation study and real data analysis are provided.

• 한국경영정보학회:학술대회논문집
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• 2008.06a
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• pp.701-711
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• 2008

SCM(Supply Chain Management) is one of the important issues in internet-based business environment. This study intends to suggest a research model to investigate the influence of environmental, organizational, technical factors on successful SCM system implementation. The purpose of this study is to analyze the influence of the organizational characteristics of SCM adoption on successful implementation of SCM systems, including the moderating effects of competitiveness. 122 companies data were collected by survey. The results of hypothesis testing showed that project management is the most important determinants to influence successful SCM system implementation. In addition to that, top management support, IS maturity have positive influence to successful implementation of SCM systems in direct effect model. Also, the results of hypothesis testing in moderating effect model show that competitiveness has a positive impact to successful implementation of SCM systems.

• Journal of the Korean Statistical Society
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• v.35 no.2
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• pp.167-177
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• 2006

An important role of statistical analysis in science is interpreting observed data as evidence, that is 'what do the data say?'. Although standard statistical methods (hypothesis testing, estimation, confidence intervals) are routinely used for this purpose, the theory behind those methods contains no defined concept of evidence and no answer to the basic question 'when is it correct to say that a given body of data represent evidence supporting one statistical hypothesis against another?' (Royall, 1997). In this article, we use likelihood ratios to measure evidence provided by record values in favor of a hypothesis and against an alternative. This hypothesis is concerned on mean of an exponential model and prediction of future record values.

• Smart Structures and Systems
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• v.14 no.5
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• pp.883-900
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• 2014

Shape memory alloys (SMA) can dissipate energy through hysteresis cycles without significant residual deformation. This paper describes the fabrication and testing of copper-based SMA hourglass-shaped plates for use in energy dissipation devices and the development of a numerical model to reproduce the experiments. The plates were tested under cyclic flexural deformations, showing stable hysteresis cycles without strength degradation. A detailed nonlinear numerical model was developed and validated with the experimental data, using as input the constitutive relationship for the material determined from cyclic tests of material coupons under tension loading. The model adequately reproduces the experimental results. The study is focused on the exploitation of SMA in the martensite phase.