• Structural Engineering and Mechanics
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• v.55 no.5
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• pp.979-999
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• 2015

This paper proposes a novel reliability analysis method which computes reliability index, most probable point and probability of failure of uncertain systems more efficiently and accurately with compared to Monte Carlo, first-order reliability and response surface methods. It consists of Initial and Simulation steps. In Initial step, a number of space-filling designs are selected throughout the variables space, and then in Simulation step, performances of most of samples are estimated via interpolation using the space-filling designs, and only for a small number of the samples actual performance function is used for evaluation. In better words, doing so, we use a simple interpolation function called "reduced" function instead of the actual expensive-to-evaluate performance function of the system to evaluate most of samples. By using such a reduced function, total number of evaluations of actual performance is significantly reduced; hence, the method can be called Reduced Function Evaluations method. Reliabilities of six examples including series and parallel systems with multiple failure modes with truncated and/or non-truncated random variables are analyzed to demonstrate efficiency, accuracy and robustness of proposed method. In addition, a reliability-based design optimization algorithm is proposed and an example is solved to show its good performance.

• The Journal of Fisheries Business Administration
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• v.49 no.4
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• pp.37-52
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• 2018

Busan is a representative of ocean cities in South Korea, which attracts many Chinese tourists. As a number of Chinese tourists increase, Chinese tourists' evaluations of sightseeing resources in Busan appear extremely important. However, there are few researches on Chinese tourists' evaluations of sightseeing in Busan. The purpose of this paper is to analyze Chinese tourists' evaluations of Busan tourism. Chinese tourists who travel to Busan are chosen as research objects and several aspects including marine, fisheries and general tourism are investigated to evaluate the tourists' overall satisfaction of the tourism in Busan. IPA analysis, factor analysis multiple regression analysis are used for the research. The results are as follows. Chinese tourists' evaluations of the importance and performance level of variables on Busan tourism were significantly different (total 19 of 25 variables) and the performance was lower than importance. This means the outputs of the various Busan tourism elements do not live up to their expectations. The findings show that Chinese visitors have high satisfaction on infrastructures of fisheries tourism (e.g. cleanness of aquatic product tourism facilities and sanitary state on fishery products), but low satisfaction in terms of the contents (e.g. unique cooking method experience of seafood and traditional seafood cooking consumption). The factors of fisheries tourism (e.g. product services of fisheries tourism and the attractiveness of seafood in Busan) never affect their satisfaction and intention to revisit and recommend the city.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.44-49
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• 2001

This paper is concerned with development of a multi-attribute structured decision model. In this study, we used AHP(analytic hierarchy process) and fuzzy set ranking methodology to overcome the multi-attributes structured decision problems ; such as multi-objective, multi-criterion, and multi-attributes. We proposed a 2-step approach : 1) individual evaluation and 2) integration of individual evaluations. In the first step, we define the performance factors and construct ana]isis structure, and in the second step performance evaluation by individual evaluators, and in second step, the results of individual evaluations are integrate. Also we developed a systematic and practical computer program to solve the problems according to the proposed methods. The proposed approach was known to be effective through a set of sample problems.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.851-854
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• 1998

In recent years, a cost-effective voltage-source type single-ended resonant-load inverter using MOS gate power switching devices and its related resonant inverter topologies have been commonly used for induction-heated cooking appliances because of relatively-lowered switching losses, simple circuit topology, low cost, compactness and low harmonic current in utility AC side. This paper present some comparative performance evaluations of IGBTs as sample devices in each generation and MOS controlled Thyristor(MCT) incorporated into the voltage-source type single-ended load resonant inverter for induction-heating rice cookers used for consumer power electronic applications, in which the output power can be regulated on the basis of Frequency Modulation Scheme.

• Journal of Families and Better Life
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• v.19 no.5
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• pp.15-32
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• 2001

The purpose of this study were to develop family welfare service program on interrelationship improvements of children. For this purpose, programs related to children that is performed by social welfare agency and that is based on group psychotherapy were included. The results were as follows. First. programs related to children that is performed by social welfare agency are insufficient to evaluations of plans, performance and outputs. In particular, speciality of social worker in perform on programs in related to children is absent. Second, programs of interrelationship improvements of children based on group pychotherapy were specialized in evaluations of plans, performance and output. Through out this analysis, the program of interrelationship improvements of children is developed. This program is based on group psychotherapy, include art therapy, sociodrama.

• ETRI Journal
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• v.43 no.3
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• pp.549-560
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• 2021

Cyberattacks are often difficult to identify with traditional signature-based detection, because attackers continually find ways to bypass the detection methods. Therefore, researchers have introduced artificial intelligence (AI) technology for cybersecurity analysis to detect malicious PowerShell scripts. In this paper, we propose a feature optimization technique for AI-based approaches to enhance the accuracy of malicious PowerShell script detection. We statically analyze the PowerShell script and preprocess it with a method based on the tokens and abstract syntax tree (AST) for feature selection. Here, tokens and AST represent the vocabulary and structure of the PowerShell script, respectively. Performance evaluations with optimized features yield detection rates of 98% in both machine learning (ML) and deep learning (DL) experiments. Among them, the ML model with the 3-gram of selected five tokens and the DL model with experiments based on the AST 3-gram deliver the best performance.

• Korean Journal of Comparative Education
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• v.28 no.2
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• pp.1-21
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• 2018

The purpose of this study is to explore secondary school teachers' perceptions of student evaluations, focusing especially on students' performance in the classroom. The study selected Germany as a representative country where teachers' performance evaluation strongly affects students' school pathways. The researchers selected 4 English teachers and conducted in-depth interviews with them. The results indicated that German English teachers perceived students' performance as an individual evaluation and provided each student with oriented learning materials and evaluation results. The second, they used formative evaluations to confirm and motivate their students' learning process as well as peer assessments. The third, the German English teachers showed strong empowerment in the evaluation process. The fourth, they motivated to participation in-class activities teacher through performance evaluation considering fairness. Based on the results, future studies should need to observe real settings in the classroom and students' perceptions of their evaluations. the study also suggested using practical performance evaluations to enhance students' motivation and participation in the classroom. This study identified limitations of the research and made significant recommendations for future studies.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.985-992
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• 2006

Many methods for reliability analysis have been studied and one of them, a moment method, has the advantage that it doesn't require sensitivities of performance functions. The moment method for reliability analysis requires the first four moments of a performance function and then Pearson system is used for the probability of failure where the accuracy of the probability of failure greatly depends on that of the first four moments. But it is generally impossible to assess them analytically for multidimensional functions, and numerical integration is mainly used to estimate the moment. However, numerical integration requires many function evaluations and in case of involving finite element analyses, the calculation of the first fo 따 moments is very time-consuming. To solve the problem, this research proposes a new method of approximating the first four moments based on kriging metamodel. The proposed method substitutes the kriging metamodel for the performance function and can also evaluate the accuracy of the calculated moments adjusting the approximation range. Numerical examples show the proposed method can approximate the moments accurately with the less function evaluations and evaluate the accuracy of the calculated moments.

• Journal of Veterinary Clinics
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• v.32 no.4
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• pp.319-323
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• 2015

The performance of diagnostic test accuracy is usually summarized by a variety of statistics such as sensitivity, specificity, predictive value, likelihood ratio, and kappa. These indices are most commonly presented when evaluations of competing diagnostic tests are reported, and it is of utmost importance to compare the accuracies of diagnostic tests to decide on the best available test for certain medical disorder. However, it is important to emphasize that specific point values of these indices are merely estimates. If parameter estimates are reported without a measure of uncertainty (precision), knowledgeable readers cannot know the range within which the true values of the indices are likely to lie. Therefore, when evaluations of diagnostic accuracy are reported the precision of estimates should be stated in parallel. To reflect the precision of any estimate of a diagnostic performance characteristic or of the difference between performance characteristics, the computation of confidential interval (CI), an indicator of precision, is widely used in medical literatures in that CIs are more informative to interpret test results than the simple point estimates. The majority of peer-reviewed journals usually require CIs to be specified for descriptive estimates, whereas domestic veterinary journals seem less vigilant on this issues. This paper describes how to calculate the indices and associated CIs using practical examples when assessing diagnostic test performance.

• Transportation Technology and Policy
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• v.9 no.2
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• pp.77-85
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• 2012