• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.117-121
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• 2005

In this paper, an approximate time-effective approach to rigid-plastic finite element method is presented with its solution scheme and a volume compensation method is proposed to simulate rotary forging processes. The applicability is examined by comparing the results obtained by the presented approach with those by the conventional approach. The approach is applied to simulation of a rotary forging process fur a wheel bearing assembly. The analyzed results are compared with the experimental results.

• Structural Engineering and Mechanics
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• v.82 no.6
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• pp.785-799
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• 2022

The effect of earthquakes in earthquake resistant structure design stages is influenced by the highest ground acceleration value, which is generally a strength-based approach in seismic codes. In this context, an energy-oriented approach can be suggested as an alternative to evaluate structure demands. Contrary to the strength-based approach, the strength and displacement demands of the structure cannot be evaluated separately, but can be evaluated together. In addition, in the energy-oriented approach, not only the maximum effects of earthquakes are taken into account, but also the duration of the earthquake. In this respect, it can be said that the use of energy-oriented earthquake parameters is a more rational approach besides being an alternative. In this study, strength and energy-oriented approaches of earthquake parameters of 11 different periods of single degree of freedom systems were evaluated over 28 different earthquake situations. The energy spectra intended to be an alternative to the traditional acceleration spectra were created using the acceleration parameter equivalent to the input energy. Two new energy parameters, which take into account the effective duration of the earthquake, are proposed, and the relationship between the strength-oriented spectral acceleration parameters and the energy parameters used in the literature is examined by correlation study. According to the results obtained, it has been seen that energy oriented earthquake parameters, which give close values in similar period situations, will be a good alternative to strength oriented earthquake parameters. It was observed that the energy parameters were affected by the effective duration of the earthquake, unlike the strength-based parameters. It has been revealed that the newly proposed energy parameters considering the effective duration give good correlations. Finally, it was concluded that the energy parameters can be used in the design, and the newly proposed effective energy parameters can shorten the analysis durations.

• Korean Journal of Child Studies
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• v.25 no.6
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• pp.131-152
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• 2004

This study used meta-analysis to synthesize the effectiveness of the project approach. After reviewing 51 studies, we analyzed the effect size of 119 articles published between 1990 and 2002 using SAS 8.2 program. The grand average of the project approach effectiveness was 1.03. This implies that the experimental group that employing the project approach is more effective than control group by the 35 percentile. We also found that the project approach is more effective for preschool children group (1.21, 89%) than for the elementary school children group (0.88, 81%). Specific variables regarding the effectiveness of the project approach were analyzed and its consequences were discussed.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.684-689
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• 2008

In this study, homogenization method combined with the effective interface model for the characterization of properties of the nanoparticulate composites is developed. In order to characterize particle size effect of nanocomposites, effective interface model has been developed. The application range of analytical micromechanics approach is limited because a simple analytical approach is valid only for simple and uniform geometry of fiber particles. Therefore this study focuses on the analysis of mechanical properties of the effect interface through the continuum homogenization method instead of using analytical micromechanics approach. Using the homogenization method, elastic stiffness properties of the effective interface are numerically evaluated and compared with the analytically obtained micromechanics solutions. The suggested homogenization method is expected to be applied to optimization problems for nanocomposite design.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.4
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• pp.69-87
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• 2006

This paper proposes an effective approach for the part-machine grouping(PMG) based on the non-binary part-machine incidence matrix in which real manufacturing factors such as the operation sequences with multiple visits to the same machine and production volumes of parts are incorporated and each entry represents actual moves due to different operation sequences. The proposed approach adopts Fuzzy ART neural network to quickly create the Initial part families and their machine cells. A new performance measure to evaluate and compare the goodness of non-binary block diagonal solution is suggested. To enhance the poor solution due to category proliferation inherent to most artificial neural networks, a supplementary procedure reassigning parts and machines is added. To show effectiveness of the proposed approach to large-size PMG problems, a psuedo-replicated clustering procedure is designed. Experimental results with intermediate to large-size data sets show effectiveness of the proposed approach.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.2
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• pp.494-510
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• 2024

Internet users are exposed to sophisticated cyberattacks that intrusion detection systems have difficulty detecting. Therefore, research is increasing on intrusion detection methods that use artificial intelligence technology for detecting novel cyberattacks. Unsupervised learning-based methods are being researched that learn only from normal data and detect abnormal behaviors by finding patterns. This study developed an anomaly-detection method based on unsupervised machines and deep learning for a network intrusion detection system (NIDS). We present a hybrid anomaly detection approach based on unsupervised learning techniques using the autoencoder (AE), Isolation Forest (IF), and Local Outlier Factor (LOF) algorithms. An oversampling approach that increased the detection rate was also examined. A hybrid approach that combined deep learning algorithms and traditional machine learning algorithms was highly effective in setting the thresholds for anomalies without subjective human judgment. It achieved precision and recall rates respectively of 88.2% and 92.8% when combining two AEs, IF, and LOF while using an oversampling approach to learn more unknown normal data improved the detection accuracy. This approach achieved precision and recall rates respectively of 88.2% and 94.6%, further improving the detection accuracy compared with the hybrid method. Therefore, in NIDS the proposed approach provides high reliability for detecting cyberattacks.

• English Language & Literature Teaching
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• v.13 no.1
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• pp.181-210
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• 2007

This study is to suggest systematic and effective reading comprehension techniques or strategies to be used in EFL reading classes. According to the definition of reading and reading process, six essential elements of reading comprehension are categorized: 1) reading speed; 2) skimming and scanning; 3) logical organization; 4) pleasure reading; 5) vocabulary; 6) cultural background and world knowledge. To present a more effective teaching and learning approach to EFL reading comprehension than ever, an experiment was performed. The hypothesis of the experimental study was that there would be a difference in students' reading speed as well as reading comprehension and vocabulary between an experimental group and a control group depending upon the teaching approaches (experimental vs. traditional). The result of the study indicates that the experimental teaching approach which intensifies speed reading and pleasure reading techniques as well as 4 other essential techniques of reading comprehension is more effective than the traditional one in teaching and learning reading comprehension.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.679-682
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• 2003

Improvement in MOS fabrication technology have led to high-density high-performance integrated circuits with MOSFET channel lengths in the sub-micron range. For devices of the size, transistor characteristics become highly sensitive to effective channel length. We propose a new approach to extract the effective channel length of MOSFET by Capacitance-Voltage (C-V) method. Gate-to-Source, Drain capacitance ( $C_{gsd}$) are measured and the effective channel length can be extracted. In addition, compared to l/$\beta$ method and Terada method, which has been point out that it fails to extract the accurate effective channel length of the devices, we prove that our approach still works well for the devices with down to sub-micron regime.e.

• The Journal of the Korea Contents Association
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• v.6 no.11
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• pp.190-201
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• 2006

A Study on the Effect of Metaphor in Public Service Advertising. The study carried out a positivistic research on university students with a view to contributing to the building of a metaphoric ad strategy by analyzing the effect of metaphoric expressions in public service advertising, which showed the following: First, the metaphoric ads using positive approach and indirect copy were effective for heightened emotional attitude of viewers. Second, the metaphoric ads using positive approach and indirect copy were effective for heightened source credibility, which was further heightened when the two were simultaneously used. Third, the metaphoric ads using positive approach and indirect copy were effective for heightened design preference, and the design preference became even preferable when the two were simultaneously used. Fourth, the metaphoric ads using indirect copy were effective for behavioral intention. The study suggested that the strategy of adopting metaphoric ads with indirect copy of positive approach was quite useful in strengthening the effect of public service advertising.

• International Journal of Quality Innovation
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• v.3 no.2
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• pp.29-37
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• 2002

This paper presents a framework for processing a structured approach of R&D investment. It presents nine steps to operate R&D investment from analysis of environment situation to review and feedback its activity. Also fundamental questions fur effective R&D management in business are discussed and after that critical eight success factors for R&D investment are discussed.