• Journal of Aerospace System Engineering
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• v.14 no.spc
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• pp.22-30
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• 2020

Composite rotor blades for rotorcraft have an intrinsic vulnerability to foreign object impact from its inherent structural characteristics of insufficient strength in the thickness direction, which may easily lead to internal structure damage. Therefore, defects and strength reducing effects caused by foreign object impact should be considered in fatigue evaluation of composite blades. For this purpose, the flaw tolerant safe-life and fail-safe concepts were adopted in fatigue evaluation since 1980s, and recently those concepts have been replaced by the damage tolerance concept. In this paper, the relevant standards for fatigue evaluation are analyzed focusing on fiber reinforced composite rotor blades used in rotorcraft. In addition, fatigue evaluation procedure of composite blades considering impact damages is proposed by reviewing the practices implemented through domestic development projects.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.761-765
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• 1995

The old Timing Controller for Control Element Drive Mechanism (CEDM) is designed as an open loop control system because it is difficult to mount sensors within the Control Element Drive Mechanism(CEDM) which is operating under the pressure boundary of the reactor vessel. In this work new method which can be used to detect the CEDM operational conditions without mounting sensors within the CEDM housing is developed in order to resolve problems of the old Timing Controller. By using the developed new method, the new Timing Controller for the CEDM is designed as a closed loop controller which has features of the control rod drop prevention, fine position control and the coil life time extension. The algorithm developed under closed loop control concept resolves most problems occurred in the old Timing Controller and improves the performance and reliability of the system. During designing and testing of the Timing Controller algorithm, the real time CEDM simulator developed here was used. And all functions of the developed algorithm were verified using CEDM simulator with the real data collected from the site. The results show that the Timing Controller performs its intended functions properly.

• Interdisciplinary Bio Central
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• v.3 no.4
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• pp.14.1-14.9
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• 2011

Protein homology detection is an important issue in comparative genomics. Because of the exponential growth of sequence databases, fast and efficient homology detection tools are urgently needed. Currently, for homology detection, sequence comparison methods using local alignment such as BLAST are generally used as they give a reasonable measure for sequence similarity. However, these methods have drawbacks in offering overall sequence similarity, especially in dealing with eukaryotic genomes that often contain many insertions and duplications on sequences. Also these methods do not provide the explicit models for speciation, thus it is difficult to interpret their similarity measure into homology detection. Here, we present a novel method based on Word Conservation Score (WCS) to address the current limitations of homology detection. Instead of counting each amino acid, we adopted the concept of 'Word' to compare sequences. WCS measures overall sequence similarity by comparing word contents, which is much faster than BLAST comparisons. Furthermore, evolutionary distance between homologous sequences could be measured by WCS. Therefore, we expect that sequence comparison with WCS is useful for the multiple-species-comparisons of large genomes. In the performance comparisons on protein structural classifications, our method showed a considerable improvement over BLAST. Our method found bigger micro-syntenic blocks which consist of orthologs with conserved gene order. By testing on various datasets, we showed that WCS gives faster and better overall similarity measure compared to BLAST.

• International Commerce and Information Review
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• v.14 no.4
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• pp.153-174
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• 2012

The purpose of this study is to analyse factors affecting performance of Global Outsourcing of the Korean Export-Importing Companies. This study aims to confirm the cause and effect relationship between independent variables; Organization Competency, Flexibility, Information Sharing and Partnership and dependent variable; the performance of Global Outsourcing. Also, another objective of this study is to discover affecting levels for the performance and activation factors of global outsourcing and to contribute to diffusion of global sourcing. This paper examined the concept and features of global sourcing and the present situation of global outsourcing at the level of domestic and overseas. From precedent studies that based on empirical studies about the transaction theory and the resource-based theory, we have derived a model with hypothesis and scale items then we conducted a survey of the Korean Export-Importing companies and empirically analysed the data. Before hypothesis testing, we conducted a basic information analysis in order to discover implication level of Global Soucring and also did reliability analysis and exploratory factor analysis using SPSS 18.0. Finally, the four hypothesis for the performance of Global Sourcing were tested with a regression model.

• Current Industrial and Technological Trends in Aerospace
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• v.9 no.1
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• pp.64-76
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• 2011

The current development trend and status of a personal air vehicle, known as the novel concept of a transportation that combines a personal car with a light general aviation aircraft, is summarized to investigate its feasibility as a future transportation. In the paper, the development programs of a personal air vehicle such as AGATE, PAVE, SATS and NGATS are first summarized, and then the design, technical development and testing activities of Terrafugia's Transition and Moller International's M400 Skycar, which will be commercialized in a short time, are reviewed. Based on the assessment of technical issues with those vehicles, the key technologies for the future development of the personal air vehicle are suggested with two basic requirements of safety and mobility.

• Informatization Policy
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• v.21 no.2
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• pp.49-66
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• 2014

In the last few years, cloud computing has grown from being a promising business concept to one of the fast growing segments of the IT industry. However, as more and more information on individuals and companies are placed in the cloud, concerns on just how safe the computing environment is have gradually increased. In this study, it will be explored if key characteristics of cloud computing services would affect the behavioral intention to use public cloud computing services. A conceptual model is developed and seven research hypotheses are proposed for empirical testing. The proposed model is examined through structural equation analysis. The results show that perceived risk has statistically significant effect on the privacy concern of users and the privacy concern has a negative influence on the trust. Finally, the trust has a positive effect on the attitude and the attitude has statistically significant effect on use intention. Implications of these findings are discussed for both researchers and practitioners and future research issues are raised as well.

• Journal of Gifted/Talented Education
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• v.26 no.4
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• pp.747-761
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• 2016

The purpose of this research is to study the perception of mathematical creativity through gifted elementary mathematics students. The analysis on perception for mathematical creativity was done by testing 200 elementary school students in grades 4, 5, and 6 who are receiving gifted education in elementary mathematics gifted class operated by ${\bigcirc}{\bigcirc}$ City Dept of Education through the questionnaire that was developed based on Rhodes' 4P theory. This survey asked them to name what they think is the most creative from educational programs they have as far received. Then we analyzed the reason for the students' choice of the creativity program and interviewed the teachers who had conducted chosen program. As a result of analyzing the data, these students chose as mathematical creativity primarily creative problem solving, task commitment, and interest in mathematics in such order. This result is explained through analyzing the questionnaire that was based on Rhodes' 4P theory on areas of process, product and press. The perception of mathematical creativity by the gifted mathematical students not only helps to clarify the concept of mathematical creativity but also has implication for future development for gifted education program.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.271-280
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• 2002

A probabilistic approach to identify the effects of uncertainties of soil strength parameters on searching a critical slip surface with the lowest reliability is introduced. In general construction field, it is impossible for the engineer to always gather a variety of statistical information of soil strength parameters for which lots of laboratory and in-situ soil testing are required and to use it with enough statistical knowledge. Thus, in order that the engineer may easily understand the probabilistic concept for the slope stability analysis, this study proposes a combined procedure to incorporate the engineering probabilistic tools into the existing deterministic slope stability analysis methods. Using UTEXAS 3, a slope stability analysis computer program developed by U.S. Army Corps of Engineers (U.S. COE), this study provides the results of this probabilistic slope stability analysis in terms of probability of failure or reliability index. This probabilistic method f3r slope stability analysis appears to yield more comprehensive results of slope reliability than does existing deterministic methods with safety factors alone.

• Nuclear Engineering and Technology
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• v.38 no.7
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• pp.639-656
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• 2006

In order to apply the leak before break (LBB) concept to nuclear piping systems, the dynamic strain aging effect of low carbon steel materials has to be taken into account, in compliance with the requirements of the Korean Standard Review Guide (KSRG) 3.6.3-1. For this goal, J-R tests are needed for a range of various temperatures and loading rates, including dynamic loading conditions. In the dynamic loading J-R test, the unloading compliance method can not be applied to measure the crack growth and direct current potential drop (DCPD) method; this method also has a problem defining the crack initiation point. The normalization method is known as a very useful method to determine the J-R curve under dynamic loading because it does not need additional equipment or complicated loading sequences such as electric current or unloading. This method was accepted by the American Society for Testing and Materials (ASTM) as a standard test method E1820 A15 in 2001. However, it has not yet been clearly verified yet if the normalization method is sufficiently reliable to be applied to LBB. In this study, the basic background of the J-integral, LBB and dynamic loading J-R test are explained, and the current status for dynamic loading J-R test methods are reviewed from the view point of LBB for nuclear piping. In particular, the theoretical and historical background of the normalization method which has received attention recently, is summarized. Recent studies for this method are introduced and future works are suggested that may improve the reliability of LBB for nuclear piping.

• Journal of Sport and Applied Science
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• v.5 no.1
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• pp.17-26
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• 2021

Purpose: The purpose of this study is to suggest the policy and scope of the concept of sports welfare and to present a systematic model enhancing sport welfare of the society. Research design, data, and methodology: In order to induce idea for welfare policy and conceptual sport welfare model, this study reviewed a literature discussing the functions and mechanism of sport in enhancing a sense of life quality and thus rebuilding welfare of community. Results: The study suggests these. First, sports welfare ensures the rights of sports of all citizens and has the main purpose of providing social services, creating environments against inequality, improving the quality of life and happiness for everyone to enjoy, and the range should be continued from the right to live, environments against inequality, to the improvement of life and happiness. Second, since the integrated perspective was first suggested, sports integration development will be researched as well as the direction of the development of policies of the integrated model. Basic research of indicator development will need to be proceeded to execute and evaluate the integrated model. Third, the improvement of treatment of sports welfare instructors is urgent. Namely, compared to sports-related budget and the enhancement of facilities, the poor environment of sports welfare instructors needs to be improved. Instead of only testing physical fitness and prescription, the business needs to be continued by connecting to the participants' continuous participation in sports. Conclusions: Whether sports welfare succeeds depends on the need for an active beneficiary, identification of demand, a beneficiary that can discover potential to join offline and online into one, the establishment of sports policies to promote competency development, and a direct progression is needed.