• Journal of the Korean Society for Railway
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• v.20 no.3
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• pp.356-364
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• 2017

The process of inspecting electric railway vehicles is complicated and these vehicles accompany a risk of safety accidents. This developed system will be a great help in simplifying the shunting process and be very useful in terms of ensuring safety and providing user convenience. In this paper, the results of performance evaluation tests are studied on a movable catenary system for railway vehicles that secured mechanical durability, convenience, and operator safety by applying a specific rigid bar catenary of an existing mobile train line. We presented an analysis of the basic characteristics for site installation including sorting. In conclusion, this developed system was obtained in good results through durability test, durable mechanical load test and safety test in require specifications.

• Journal of the Korean Home Economics Association
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• v.41 no.11
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• pp.201-214
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• 2003

The purpose of this research was to develop the education program for post-divorce adjustment and to evaluate effectiveness of the program. This program was consisted of eight sessions and applied to divorced parents. It was focused for the understanding of grief processes for adults, recovery by forgiveness, children's responses and coping strategies to divorce, open minded relationship between parents and children, and enhancement of self-esteem to be healthy single parent. Results of paired t-test showed that there were significant differences between pre-test and post-test, and the effectiveness remained until follow-up. In conclusion, this program was thought to be effective for improving self-esteem, divorce coping competency and minimizing of the depressions. Continual education is thought to be necessary for maintaining of the effectiveness to the divorced parents.

• Journal of the Korean Ceramic Society
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• v.54 no.4
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• pp.314-322
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• 2017

This study investigates changes in the mechanical behavior, such as changes in indentation load-displacement curve, wear resistance and contact fatigue resistance of thermal barrier coatings (TBCs) by thermal cycling test and thermal shock test. Relatively dense and porous TBCs on nickel-based bondcoat/superalloy are prepared; the highest temperature applied during thermal durability test is $1350^{\circ}C$. The results indicate that the porous TBCs have relatively longer lifetime during thermal cycling and thermal shock tests, while denser TBCs have relatively higher wear and contact fatigue resistance. The mechanical behavior is influenced by sintering of the TBCs by exposure to high temperature during tests.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.4
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• pp.141-156
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• 1999

Recently expanded and enhanced software system inevitably demands serious managerial considerations on its maintenance cost. This study proposes a systematic and thorough assessment model for software development methods to the end of maintainability, incorporation ISO 9126 quality standards-based criteria. The Analytic Network Process (ANP) is employed in our model to find the effect of any dependency among the items of the criteria and the alternative methods. This study then applies the model empirically in order to evaluate the efficacies of the Structured Method and the Objected-Oriented Method. At first, this study performs the test on the existence and direction of any dependency under the three types of assumptions, and then determines the relative dominance of the two methods.

• Journal of Technology Innovation
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• v.8 no.2
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• pp.119-143
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• 2000

The main objective of this study is to test hypotheses by empirical study on the technology transfer from a national institute to small and medium sized enterprises(SMEs) in the Korean electronic devices industry. The important findings of the study are as follows: First, the success of the technology transfer from national institute to SMEs depends on the character of the project manager such as research experience and academic degree level. Second, the success of the technology transfer is related to the nature of the research project, especially to the technology life cycle stage but insignificantly to the amount of R&D fund and duration. Third, another success factor for technology transfer is the joint technology development between institute and SMEs, which is due to the possibility of early commercialization of the technology development project. Fourth, the hypothesis about the relationship between the project selection and evaluation results and technology transfer success is not statistically supported.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.4
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• pp.277-284
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• 2018

The Satellite-based Augmentation System (SBAS), as a safety critical system, should be verified on an ongoing basis to ensure the adequate performance. This study proposes two methods to evaluate the performance of SBAS satellite correction. Analysis methods based on precise ephemeris and measurement were applied to present an evaluation method for SBAS satellite correction, and a test was performed based on real data. The precise ephemeris-based analysis method had no limitations on the position of the test user and showed a high precision, enabling an accurate performance analysis in various positions. Although the measurement-based analysis method has the advantage of fast data interval, it showed a relatively lower accuracy due to the effects of various error factors. Compared with the precise ephemeris-based analysis method, there was a large difference of more than 5 m at the beginning of smoothing filter, and a difference less than 50 cm when filtered for more than an hour.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.3
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• pp.19-28
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• 2001

The purpose of this paper is to examine factors affecting user´s satisfaction in development of natural recreation forest(NRF) in order to answer the research question: What is the magnitude of factors affecting user´s satisfaction in development of NRF. After reviewing the literature, mechanism of outdoor recreation, and development factors in NRF, we constructed the conceptual framework and have formulated the hypothesis of this research. we have obtained data through a questionnaire, which surveyed 625 visitors at 10 of the 72 natural recreation forests in Korea in 1999, We have analyzed the data using the mean difference test, Pearson´s correlation analysis, and multiple linear regression method. We found that 1) all the development factors except recreational resources affecting user´s satisfaction have turned out to be statistically significant at one percent level. The direction of relationship between independent variable and dependent variable is the same as that of dependent variable. 2) in bivariate analysis, the relationships between user´s satisfaction and all the development factors are fairly high and statistically significant. The higher the value of development factors, the higher the degree of user´s satisfaction. 3 in multivariate analysis, such variables as the suitability of activities level of services, atmosphere, and facility have been statistically significant at one percent level, and 4) Their relative contribution of the suitability of various recreational activities, level of atmosphere, and service on dependent variable have been turned out to have 8.167, 4.889, 3.333, and 1.611 times more importance than that of the suitabity of recreational resources, respectively. The research results suggest that a guideline for the creation of marketable NFR and development of use-programs and recreational atmosphere be recommended in the planning and development process of NRF, and excessive investment on facilities is not desirable. The approach and analysis method adopted by this research is highly useful for an evaluation criterion of NRF and development of devices for increasing user´s satisfaction in NRF. It is recommended that more empirical study on individual factors affecting user´s satisfaction be performed in the future.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.151-156
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• 2003

The purpose of this study is to establish the test procedure of concrete slab track and to estimate the performance of newly developed slab track. The basic direction of conceptual design of KRRI Slab track was determined in the viewpoint of running safety, economic efficiency and maintenance costs. Based on the research results, a detailed conceptual design of KRRI slab track is suggested. For the systematic development of slab track, a comparative study is carried out, comparing merits and demerits of each slab type, and used in the design process of slab track. Slab track tests were performed at lab and the slab track system was improved by the experiment result. Site Test also were performed in test slab track.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.297-302
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• 2008

Application of genotype by environment ($G\;{\times}\;E$) interaction would be used for identifying optimum test condition of the varietal adaptation in the establishment of breeding purpose. Yield and yield components were used to perform additive main effect and multiplicative interaction (AMMI) analysis. Significant difference for $G\;{\times}\;E$ interaction were observed for all variable examined. For yield, 0.18 of total sum of squares corresponded to $G\;{\times}\;E$ interaction. Correlation analysis was carried out between genotypic scores of the first interaction principal component axis (IPCA 1) for agronomic characters. Significant correlations were observed between IPCA 1 for yield and capsule bearing stem length (CBSL), number of capsule per plant (NOC). The biplot of grain yield means for IPCA1 which accounted for 34% of the variation in total treatment sums of squares showed different reaction according to $G\;{\times}\;E$ interaction, genotypes and environments. Taegu showed relatively lower positive IPCA1 scores, and it also showed smaller coefficient variation of yield mean where it is recommendable as a optimal site for the sesame cultivar adaptation and evaluation trial. In case of variables, Yangbaek and M1 showed relatively lower IPCA1 scores, but the score direction showed opposite each other on the graph. Ansan, Miryang1, Miryang4, and Miryang6 seemed to be similar group in view of yield response against IPCA1 scores. These results will be helpful to select experimental site for sesame in Korea to minimize $G\;{\times}\;E$ interaction for the selection of promising genotype with higher stability.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.699-704
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• 2010

Tertiary unconsolidated mudstones spread throughout the eastern coast of Pohang area. Recently, the demand for high quality filling materials is increasing due to harbors and large-scale residential land development. But the features of the reclaimed land using soft mudstones have not been made clear yet. Unconsolidated rocks are diversely considered according to a different method of the applied geotechnical investigation. This study is examined that the applicability of mudstone as a harbor reclamation material through the laboratory test and pilot test. Expecially, it must be considered that the environmental characteristics of mudstone as a reclaimed materials.