• Steel and Composite Structures
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• v.51 no.1
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• pp.53-61
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• 2024

Aluminum foams sandwich panel (AFSP) has been used in engineering field, where cyclic loading is used in most of the applications. In this paper, the fatigue life of AFSP prepared by the bonding method was investigated through a three-point bending test. The mathematical statistics method was used to analyze the influence of different plate thicknesses and core densities on the bending fatigue life. The macroscopic fatigue failure modes and damage mechanisms were observed by scanning electron microscopy (SEM). The results indicate that panel thickness and core layer density have a significant influence on the bending fatigue life of AFSP and their dispersion. The damage mechanism of fatigue failure to cells in aluminum foam is that the initial fatigue crack begins the cell wall, the thinnest position of the cell wall or the intersection of the cell wall and the cell ridge, where stress concentrations are more likely to occur. The fatigue failure of aluminum foam core usually starts from the semi-closed unit of the lower layer, and the fatigue crack propagates layer by layer along the direction of the maximum shear stress. The results can provide a reference for the practical engineering design and application of AFSP.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.312-320
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• 2011

The goal of this paper is to examine the effects of a CDSS(Clinical Decision Support System) for drug prescription on organizational performance in medical institutions using POC(Point Of Care) systems. For achieving this goal, evaluation factors for influencing performance of information system were identified by using the performance evaluation model for CDSS. In the results, there was significant causality between each evaluation domain except system quality domain. In addition, the system quality of CDSS for optimal drug prescription has no influence on user satisfaction. But information quality has positive influence on user satisfaction which has also a positive influence on organizational performance.

• Journal of Korean Society on Water Environment
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• v.31 no.3
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• pp.313-318
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• 2015

To study the influence of changes in river discharge on water quality of the main stem of the Geum River, we investigated variation of inflow load from tributaries with river discharge. We also studied the mixing behavior of pollutants during mixing of waters of the main stem and Gap Stream. For this study, we collected water quality data such as suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) representing pre-monsoon, monsoon, and post-monsoon events of 2013 from a website of Water Information System. Based on inflow load, the Gap and Miho streams may be ones of tributaries which may largely influence water quality of main stem in upper river region. The Suksung and Nonsan Streams seemed to further affect water quality downstream. Results of modified EMMA indicated SS and TP may have another source(besides Gap Stream) at pre-monsoon, monsoon, and post-monsoon period. In contrast, TN and organic matter (BOD, COD, TOC) were conservative at pre-monsoon and post-monsoon. However, when river discharge increased, these pollutants may also came from unspecified non-point sources. Therefore, we need to attempt to find non-point sources for the pollutants in the main channel of upper Geum River region.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.60 no.1
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• pp.57-70
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• 2024

In order to present a predictive drift model, Jeju National University's training ship was tested for about 11 hours and 40 minutes, and 81 samples that selected one of the entire samples at ten-minute intervals were subjected to regression analysis after verifying outliers and influence points. In the outlier and influence point analysis, although there is a part where the wind direction exceeds 1 in the DFBETAS (difference in Betas) value, the CV (cumulative variable) value is 6%, close to 1. Therefore, it was judged that there would be no problem in conducting multiple regression analyses on samples. The standard regression coefficient showed how much current and wind affect the dependent variable. It showed that current speed and direction were the most important variables for drift speed and direction, with values of 47.1% and 58.1%, respectively. The analysis showed that the statistical values indicated the fit of the model at the significance level of 0.05 for multiple regression analysis. The multiple correlation coefficients indicating the degree of influence on the dependent variable were 83.2% and 89.0%, respectively. The determination of coefficients were 69.3% and 79.3%, and the adjusted determination of coefficients were 67.6% and 78.3%, respectively. In this study, a more quantitative prediction model will be presented because it is performed after identifying outliers and influence points of sample data before multiple regression analysis. Therefore, many studies will be active in the future by combining them.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.348-356
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• 2012

This study is identifying early takeoff phenomenon in relational network like SNS and investigates influence of innovator or hub at early takeoff and diffusion size at takeoff point. The major finding of this study are as follows. First, multinominal-logit analysis conducted to explore the impact of innovator and hub at early stage of information diffusion and early takeoff. Hub in early stage of information diffusion impact early takeoff. Second, our study shows that innovator and hub at early stage of information diffusion impact diffusion size at takeoff point. Third, hub is more impact early takeoff and diffusion size at takeoff point then innovator. This study provides implication for professionals by confirming hub's influence in study of successful information diffusion by early takeoff. The limitation and future direction are discussed.

• Journal of Korean Society for Quality Management
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• v.41 no.2
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• pp.209-220
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• 2013

Purpose: This paper compares and discusses the influence on the quality classification of Kano's questionnaire which is used for the Kano model(Kano et al., 1984), the 3-point Likert-scale newly proposed by Kano and the 5-point Likert-scale presented in this study. Methods: For the comparison, the current study conducts a survey of 631 television viewers. The classification results of the three methods are then compared with those of direct classification which is adopted as a standard for classification of quality attributes. Results: The agreement rates between the results using conventional Kano's questionnaire and the results using direct classification is higher than the results using 3-point and 5-point Likert-scales. In addition, the attributes grouped as must-be or attractive in the direct classification appear to be classified as one-dimensional attributes in the Likert-scales. Conclusion: In comparison with the convensional Kano's questionnaire, the Likert-scale questions highly tend to classify the quatity attributes as one-dimensional. Although the classification results of the 3-point and 5-point Likert-scales are the same, the 5-point Likert-scale has the advantage to classify quality attributes in more detail.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.352-357
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• 2007

The objective of this study is to find the optimal set-point of a hybrid Plant, which is combined by renewable energy plant of the GSHP(Ground Source Heat Pump) and the conventional plant(chiller, boiler). The work presented in this study was carried out by using the EnergyPlus(Version 2.0). In order to validate the simulation model, field data were measured from a building. The GSHP was used as a base plant and the conventional plant as the assistant plant. Various temperatures were controlled (zone summer set-point, zone winter set-point, chilled water temperature, hot water temperature) to find the optimal set-point temperature of the system. The influence of the various set-points were analyzed seasonally.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.25-32
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• 1999

A single outlier can influence on the least squares estimators and can invalidate analysis based on these estimators. The Cook's statistic has been introduced to measure influence of individual data point on parameter estimation and the quantile of the F distribution is recommended as a reference value. but in practice subjective judgement is applied in the choice of appropriate quantile. A simple reference value is introduced in this paper which is developed by approximating conditional quantities of Cook's measure. The performance of the proposed criterion is evaluated through analysis of real data set.

• MALSORI
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• no.42
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• pp.1-13
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• 2001

This paper deals with non-rhoticity of Korean and Cantonese in English loanword adaptation. These two languages have quite different cultural and historical backgrounds with respect to English. The influence of the American accent prevails in Korea while in Cantonese the influence is British. However, the treatment of coda-/r/ from English illustrates that both languages are the same in that they use a non-rhotic accent. The main point of this paper is to show that the non-rhoticity of these two languages must be accounted for by their native phonological systems rather than extralinguistic factors such as historical. social and / or cultural backgrounds.

• Journal of the Korean Statistical Society
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• v.22 no.1
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• pp.27-37
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• 1993

Since the analytic expression for a diagnostic in the logistic regression model is not available, one-step estimation is often used by a case-deletion point of view. In this paper, infinitesimal perturbation approach is used, and it is shown that the scale transformation of infinitesimal perturbation approach is eventually equal to the weighted perturbation of local influence approach and the replacement measure. Also, multiple cases deletion for the masking effect is considered.