• Journal of the Korean Data and Information Science Society
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• 제17권2호
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• pp.559-568
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• 2006

In this paper, we develop the noninformative priors for the linear mixed models when the parameter of interest is the ratio of variance components. We developed the first and second order matching priors. We reveal that the one-at-a-time reference prior satisfies the second order matching criterion. It turns out that the two group reference prior satisfies a first order matching criterion, but Jeffreys' prior is not first order matching prior. Some simulation study is performed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.137-144
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• 1999

Recently a removable soil nail is demanded due to problems beyond of economical and engineering purpose. In this study removable soil nails are developed and field pull-out tests are carried out 16 times in order to analysis pull-out characteristics of the removable soil nail. For the spacing and the installed position of fixed socket, the length of the soil nail, and W/C ratio of cement grout in the removable soil nail, pull-out characteristics of pull-out tests are analyzed. From the pull-out characteristics of removable soil nails, it is found that the spacing of fixed socket and W/C ratio of cement grout are important design parameters.

• 한국IT서비스학회지
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• 제5권3호
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• pp.1-23
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• 2006

Today, Organizations should be equipped with flexibility in order to cope with rapidly changing environment in management. By doing so, they are able to grow and obtain their superior competitiveness in highly developed economic arena. Recently, Enterprise Architecture is actively constructed to perform such a change flexibly. In this regard, it is crucial to figure out some risk factors for the organizations that place an order. Besides, it is also important to find out the quality of EA and some risk factors caused by the organizations that receive an order. Lastly, it is absolutely important to verify the relationship between such factors and outcomes of EA. In this aspect, this study will verify risk factors made by the former organizations and investigate the quality of EA and its outcome by proving the said relationship. In doing so, it will suggest an appropriate direction for the companies that will build up or perform EA successfully.

• Journal of the Korean Data and Information Science Society
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• 제24권6호
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• pp.1521-1529
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• 2013

In this paper, we develop noninformative priors for the generalized Pareto distribution when the scale parameter is of interest. We developed the rst order and the second order matching priors. We revealed that the second order matching prior does not exist. It turns out that the reference prior and Jeffrey's prior do not satisfy a first order matching criterion, and Jeffreys' prior, the reference prior and the matching prior are different. Some simulation study is performed and a real example is given.

• Asia pacific journal of information systems
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• 제30권2호
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• pp.439-456
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• 2020

In online shopping, "out-of-stock" and "sold-out" are used to indicate product unavailability, and this unavailability and its effects on consumers' behaviors have been studied with great interest for practical purposes. However, few studies have specifically discussed out-of-stock and sold-out products in the same paper. We hypothesized that consumers might cognitively interpret items marked out-of-stock and sold-out differently, and in this paper, we studied these potential differences from the perspectives of consumers' emotions, behaviors, and loyalty based on the stimulus-organism-response framework. In order to explore the differences, we used a multi-method approach that consisted of experiments, surveys, and interviews. Specifically, we built an experimental website on which the same products were categorized as either out-of-stock or sold-out, and we measured the participants' emotions, attitudes, and intentions after the experiment. After two weeks, we conducted interviews to confirm our results and to learn more about consumers' everyday behavior. In the results, males and females demonstrated differences in emotion, behaviors, and loyalty with the interaction effects of an item's being marked out-of-stock versus sold-out. We found that the consumers demonstrated different levels of loyalty based on whether the item was marked out-of-stock or sold-out. We discuss the strategic implications of our findings.

• Journal of applied mathematics & informatics
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• 제35권5_6호
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• pp.477-493
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• 2017

The dual generalized order statistics is a unified model which contains the well known decreasingly ordered random variables like order statistics and lower record values. With this definition we give simple expressions for single and product moments of dual generalized order statistics from Dagum distribution. The results for order statistics and lower records are deduced from the relations derived and some computational works are also carried out. Further, a characterizing result of this distribution on using the conditional moment of the dual generalized order statistics is discussed. These recurrence relations enable computation of the means, variances and covariances of all order statistics for all sample sizes in a simple and efficient manner. By using these relations, we tabulate the means, variances, skewness and kurtosis of order statistics and record values of the Dagum distribution.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.622-625
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• 2008

While the research for flow over a circular cylinder has been actively carried out up to the present, it has been known that the flow has not been clarified even now. Various complex flow and aero-acoustic characteristics exist around a circular cylinder such as flow separation, wake and pressure wave propagation. In this paper, research was carried out for wake flow and aeroacoustics over a circular cylinders by using high order, high resolution techniques that are used in two dimensional aero- acoustic analysis. OpenMP parallel processing method was used. For the numerical result, the periodic characteristic of Strouhal Number due to vortex shedding was comparatively analyzed with other experiment values and two dimensional numerical results.

• Steel and Composite Structures
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• 제30권6호
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• pp.517-534
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• 2019

In this paper, the effects of inevitable out-of-plane defects on the postbuckling behavior of single-layered graphene sheets (SLGSs) under in-plane loadings are investigated based on nonlocal first order shear deformation theory (FSDT) and von-Karman nonlinear model. A generic imperfection function, which takes the form of the products of hyperbolic and trigonometric functions, is employed to model out-of-plane defects as initial geometrical imperfections of SLGSs. Nonlinear equilibrium equations are derived from the principle of virtual work and variational formulation. The postbuckling equilibrium paths of imperfect graphene sheets (GSs) are presented by solving the governing equations via isogeometric analysis (IGA) and Newton-Raphson iterative method. Finally, the sensitivity of the postbuckling behavior of GS to shape, amplitude, extension on the surface, and location of initial imperfection is studied. Results showed that the small scale and initial imperfection effects on the postbuckling behavior of defective SLGS are important and cannot be ignored.

• 산업경영시스템학회지
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• 제18권36호
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• pp.349-363
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• 1995

The purpose of the study was to estimate and analyze the rates of return to educational investment. The study was designed to estimate the social and private rates of return to educational investment by school level and sex in order to measure education's economic value with a viewpoint of human capital theory. The produced result of this study are as follows. The social rates of return to education turned out to be male high school 7.94%, male junior college 3.74%, male university 8.50% female high school 4.30%, female junior college 10.11%, female university 6.92%. The private rates of return to education turned out to be male high school 8.41%, male junior college 3.39%, male university 8.38%, female high school 7.90%, female junior college 10.34%, female university 7.33%, In order to measure economic value of educational investment, rates of return to education were compared with those to physical capital investment. Social rates of return to education turned out to be profitable for female junior college, while for private rates of return to education turned out to be profitable in all school levels except for male junior college.

• Corrosion Science and Technology
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• 제5권4호
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• pp.123-128
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• 2006

It was analyzed the causes of boiler tube rupture due to a degradation and corrosion on the boiler tubes in fossil power plant. The experiments were carried out among samples taken from the operating facilities. The result were analyzed based on experimental results from mechanical strength, microstructure observation, and hardness measurement in order to determine the cause of local rupture on boiler tubes. In general, 2.25Cr-1Mo steel generates carbides, it is coarsened, its ductility and strength abruptly decreased as degradation is in progress, In order to confirm this phenomenon, we observed changes of the mount of Cr and Mo of carbide by carrying out EDX chemical composition analysis. The amount of Cr and Mo in the degraded material or service exposed material gradually increased the amount of Mo but initially they were almost maintained at the same amount. Furthermore, we observed that the carbide become coarsened both in the grain and at the grain boundary. Tensile test was carried out to measure a material hardness and to recognize a drop-off of hardness. Overall result for tensile strength and hardness turned out to be lower than new material and mechanical strength and hardness was degraded as the material degradation was in progress.