• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.725-728
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• 2005

The scattering problem of the randomly rough surface is examined by the method of moments(MoM), small perturbation method (SPM), integral equation method (IEM) and the semi-empirical polarimetic model. To apply the numerical technique of the MoM to microwave scattering from a rough surface, at first, many independent randomly rough surfaces with a rms height and a correlation length are generated with Gaussian random deviate. Then, an efficient Monte Carlo simulation technique is applied to estimate the scattering coefficients of the surfaces.

• Transactions of Materials Processing
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• v.8 no.5
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• pp.520-526
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• 1999

In this study a practical formula based on the experime수 랙 the estimation of load in the non-circular tube extrusion with the mandrel is proposed by using the effective extrusion ratio. Through some experiments for the several shaped sections, the coefficients of the empirical equation are determined by ticine as a model material at room temperature. The proposed empirical formula for the estimation of extrusion load will be applicable to the non-steady state as well as steady state for the extrusion of various shaped tubes from hollow billets.

• Asia pacific journal of information systems
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• v.21 no.2
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• pp.19-42
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• 2011

This paper proposes a new framework to predict decision performance by investigating the cognitive fit of decision makers. We assume that every decision maker has two kinds of schema: emotional and rational. Cognitive fit is believed to have a close relationship with the two schemata and decision performance. In the literature on decision performance there is few studies investigating the relationship between the two schemata and cognitive fit. Therefore, our research purposes are twofold: (1) to provide a theoretical basis for the proposed framework describing the causal relationships among the two schemata, cognitive fit. and decision performance, and (2) to empirically prove its validity in the application to an Internet shopping environment. Based on the questionnaires from 104 respondents, we used a second order, confirmatory factor analysis (CFA) model to extract valid constructs, and a structural equation model (SEM) to calculate path coefficients and prove the statistical validity of our proposed research model. The experimental results supported our research model.

• Culinary science and hospitality research
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• v.13 no.2
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• pp.163-173
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• 2007

The purpose of this study is to measure the effects of behavioral intention. A total of 273 questionnaires were completed. The equation model was used to measure the causal effect. The results demonstrated that the confirmatory factor analysis model provided an excellent model fit. The comprehensive model yielded a significantly better fit to the data and accounted for a greater share of the variance in behavioral intentions than the five competing models. The effects of satisfaction, perceived value and service quality on behavioral intention were statistically significant. As expected, service quality and value had significant effects on satisfaction. Service quality and perceived sacrifice had significant effects on value. Moreover, service quality and value perceptions had an indirect influence on behavioral intentions. The overall findings offer strong empirical support for the intuitive notion that improving service quality can increase favorable behavioral intentions and decrease unfavorable intentions.

• Asia pacific journal of information systems
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• v.3 no.1
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• pp.54-87
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• 1993

This exploratory study addressed the issue of effective EUC management, based on the sociotechnical theory. Extensive literature review gave birth to a set of critical success factors in EUC. With those factors, a basic EUC model was developed. Then the model was tested in the domestic industry to find its validity. It was also attemped to develop a structural equation model in which critical factors for sucessful implementation of EUC are arranged by the result of empirical survey. In the final model, technical support, computer experience, user control, and top management support were included as exogenous factors. Thses contructs were found to influence directly or indirectly three endogenous factors, user satisfaction, computer use, and performance.

• Journal of Communications and Networks
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• v.16 no.1
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• pp.92-97
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• 2014

A novel method for extracting frequency slippage signal from radar full pulse sequence is presented. For the radar full pulse sequence received by radar interception receiver, radio frequency (RF) and time of arrival (TOA) of all pulses constitute a two-dimensional information sequence. In a complex and intensive electromagnetic environment, the TOA of pulses is distributed unevenly, randomly, and in a nonstationary manner, preventing existing methods from directly analyzing such time series and effectively extracting certain signal features. This work applies Gaussian noise insertion and structure function to the TOA-RF information sequence respectively such that the equalization of time intervals and correlation processing are accomplished. The components with different frequencies in structure function series are separated using empirical mode decomposition. Additionally, a chaos detection model based on the Duffing equation is introduced to determine the useful component and extract the changing features of RF. Experimental results indicate that the proposed methodology can successfully extract the slippage signal effectively in the case that multiple radar pulse sequences overlap.

• Ocean Systems Engineering
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• v.10 no.1
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• pp.49-65
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• 2020

In this study, the effects of inclined shaft angle on the hydro-acoustic performance of cavitating marine propellers are investigated by a numerical method developed before and Brown's empirical formula. The cavitating blades are represented by source and vortex elements. The cavity characteristics of the blades such as cavitation form, cavity volume, cavity length etc., are computed at a given cavitation number and at a set advance coefficient. A lifting surface method is applied for these calculations. The numerical lifting surface method is validated with experimental results of DTMB 4119 model benchmark propeller. After calculation of hydrodynamic characteristics of the cavitating propeller, noise spectrum and overall sound pressure level (OASPL) are computed by Brown's equation. This empirical equation is also validated with another numerical results found in the literature. The effects of inclined shaft angle on thrust coefficient, torque coefficient, efficiency and OASPL values are examined by a parametric study. By modifying the inclination angles of propeller, the thrust, torque, efficiency and OASPL are computed and compared with each other. The influence of the inclined shaft angle on cavity patterns on the blades are also discussed.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.69-80
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• 1999

The strengthening of reinforced concrete structures by externally bonded GFRP has become increasingly common in resent years. However the analysis and design method for GFRP plate strengthening of RC beams is not well established yet. The purpose of present paper is, therefore, to define the failure mechanism and failure behavior of strengthened RC beam using GFRP and then to propose a resonable method for the calculation of interface debonding load for those beams. From the experimental results of beams strengthened by GFRP, the influence of length and thickness, width of plate on the interfacial debonding failure behavior of beam is studied and, on the basis of test results, the semi-empirical equation to predict debonding load is developed. The proposed theory based on nonlinear analysis and critical flexural crack width, predicts relatively well the debonding failure load of test beams and may be efficiently used in the analysis and design of strengthened RC beams using GFRP.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.407-408
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• 2019

This thesis determines the research framework and scale design of leisure food E-Commerce consumer satisfaction degree by referring to previous theoretical model of customer satisfaction degree, the universal satisfaction evaluation index system, and the characteristics of leisure food E-Commerce in China. In this research, consumers who have bought leisure food online are taken as the research object, data are collected by questionnaires, and exploratory factor method is used to screen valid sample data. Through the Empirical Analysis which includes Descriptive Statistical Analysis, Reliability and Validity Analysis and Structural Equation Modeling, it is concluded that website design, logistics delivery service, commodity quality, and after-sales service are the main service quality on which the Leisure food E-Commerce enterprises should take focus. The service quality has significant positive influences on satisfaction degree. On the other hand consumer satisfaction has a significant positive influence on customer loyalty, which will create more earnings for the Leisure food E-Commerce enterprises.

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.78-83
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• 2013

The traffic culture index is used as a major index in evaluating the traffic safety services of local governments and also serve as important data for the planning and implementation of traffic safety services. However, as the traffic culture index gradually became a standard for comparison among local governments, in part, certain cases arose which questioned the grounds for selecting variables for the index and the validity of the index in terms of its influential relationship between evaluation items. This study analyzed the index's influential relationship by utilizing a PLS structural equation model based on the evaluation results of the 2011 traffic culture index. A variable-linking model was created which recognized the relativity taking into account of the indirect effects between latent variables and this model was proven to be a model suitable in explaining the traffic culture index with a 97.8% explanation power. It was found that traffic safety(0.530), driving behavior(0.527), pedestrian behavior(0.187) and vulnerable road users(0.147), in such order, had an effect on the traffic culture index. It was also found that human casualties due to traffic accidents under "traffic safety" and traffic light compliance rate under "driving behavior" had an important effect. The study showed that motor vehicle share in illegal parking in school zones did not have a valid explanation power regarding "vulnerable road users".