• Journal of KSNVE
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• v.8 no.1
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• pp.75-80
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• 1998

It is a well known fact that the shaker used in the vibration test interacts with the test structure and thus influences the test results. A two degree of freedom model of shaker is suggested and the vibration parameters of this model is experimentally extracted. According to this experimental results, the vibration parameters of the shaker can vary with respect to the test structure as well as the stinger used in the connecting mechanism. It is also found that the vibration parameters of the shaker provided by the manufacturer can not be accurate and these parameter values should be revaluated based on the test environments.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.2
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• pp.121-129
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• 1993

Plane strain punch stretching test (PSST) was developed to evaluate stamping formability of sheet materials. In this test, the rectangular specimen of sheet material is uniformly stretched up to fracture by raising a specially designed punch to certainly assure plane strain stretching deformation along the longitudinal direction of the specimen. The stamping formability was evaluated by limit punch height(LPH) in plane strain punch stretching test compared to limit dome height(LDH) in hemispherical punch stretching test. LPH-value in PSST well ranks the stamping formability of various material and correlates with press performance. Moreover by using ultrasonic thickness gauge the plane strain intercept-limit plane strain(FLCo)-in forming limit curve can be accurately determined from thickness measurement around the fracture area. The FLCo derived from thickness measurement well correlates with the results from circle grid analysis for the deformed circle grid marked on the surface of the specimen.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.4
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• pp.120-127
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• 2008

A military vehicle undergoes normal to extreme driving conditions, which consequently induce the fatigue and fracture of cabin and frame. So, it is important to estimate the fatigue life of two components at an initial design stage. In this paper, Modal Superposition Method(MSM) was applied to evaluate the durability performance of a small-sized military truck. For reliable durability analysis, a Virtual Test Lab(VTL) Model was established by correlation with experimental results. These data were extracted from actual driving test, modal test, and SPMD(Suspension Parameter Measuring Device) test. This process shows that Virtual Fatigue Analysis can be a useful approach in the development of military vehicles as well as commercial vehicles.

• Journal of KSNVE
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• v.3 no.1
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• pp.39-46
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• 1993

The seismic qualification for the class 1E battery of Korea Multipurpose Research Reactor was accomplished by the analysis as well as testing. The full rack consists of 4 similar sections of typical frame structure and contains 60 cells. However, since the seismic qualification was required on the frame structure and only on 3 aged ones among 60 dells, 2 sections of the full rack were assembled as a test rack with 28 cells including the 3 aged cells for an economic test. Seismic analysis for the full rack was carried out using the finite element program ANSYS. The modal parameters identified from the resonance search thest on the test rack were used to the seismic analysis of the full rack. It was confirmed that the test rack could represent the full rack with regards to seismic responses and function of cells, and that the full rack and aged cells were qualified to the given seismic test requirements.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.49-54
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• 2002

This paper describes a systematic way of simultaneously identifying the ambient pore pressure and the rigidity index (=G/s$\_$u/) of soil by applying an optimization technique to the piezocone dissipation test result. An ambient pore pressure and optimal rigidity index were determined by minimizing the differences between theoretical excess pore pressures developed by Randolph ＆ Wroth(1979) and measured excess pore pressures from piezocone using optimization technique. The effectiveness of the proposed back-analysis method was examined against the well-documented performance of piezocone dissipation tests (Tanaka ＆ Sakagami, 1989), from the viewpoints of proper determination of selected target parameters and saving of test duration. It is shown that the proposed back-analysis method can evaluate properly the ambient pore pressure and the rigidity index by using only the early phase of the dissipation test data. Also, it is shown that with the optimized rigidity index and ambient pore pressure the proposed back-analysis method permits the horizontal coefficient of consolidation to be identified rationally.

• The Journal of the Korea Contents Association
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• v.17 no.2
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• pp.1-12
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• 2017

This study investigated the effect of parental attachment on interpersonal competence and psychological well-being of college students. 625 college students completed self-administered questionnaires. Reliability test, ANOVA, Duncan ex-post analysis, and hierarchical regression analysis on data were used. Study results showed that parental attachement and interpersonal competence had significant effects on college students' psychological well-being. Results also depicted gender differences in the relationship of study variables; students' interpersonal competence demonstrated partial mediation effect in the relation of attachment with the same-sex parent and psychological well-being, while complete mediation effect in that of attachment with the opposite-sex parent and psychological well-being, These findings suggest that gender-conscious university policies to promote interpersonal competence among students are greatly needed to ensure psychological well-being of the student population.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.59-65
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• 2005

Step-drawdown test has been generally conducted to evaluate productivity or efficiency of both aquifer and well. In general step-drawdown test, pumping with a low constant discharge rate is conducted in the first stage until the drawdown within the well stabilizes. And then the groundwater is pumped with a higher rate in the next step until the drawdown stabilizes once more. This process is repeated at least three times (steps), with the equal duration. In this paper we tried to review some critical problems related to the step-drawdown test, which were revealed in the process of field practices and analyses. The problems, referred in this paper are mainly associated with the incorrect conceptual approach for analysis and incomplete data collection in the field test.

• Journal of the Korean Society of Safety
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• v.23 no.4
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• pp.67-71
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• 2008

Formwork is a temporary structure that supports its weight and that of fresh concrete as well as construction live loads. Slab formwork consists of sheathing, stringer, hanger and shore. In construction site, pipe supports are usually used as shores which are consisted of the slab formwork. In this study, compressive strength of 80 pipe supports was measured by knife edge test and plate test. Buckling load of pipe supports was analyzed by structural analysis program(MlDAS). Theoretical buckling load with/without initial deformation was got by theoretical analysis. According to these results, buckling load which was analyzed by structural analysis program(MlDAS) was larger than compressive strength of knife edge test and plate test. Theoretical buckling load without initial deformation was larger than compressive strength of knife edge test and plate test. But Theoretical buckling load with initial deformation was lower than compressive strength of knife edge test and plate test. Initial deformation equation for test method according to the pipe support length was suggested. Therefore, the present study results will be used to design the slab formwork safely.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.4
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• pp.47-61
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• 2018

Purpose : The aim of this study was to test the mediating effect of resilience, self-esteem, and social support on the relationship between the mental health and well-being of high school students. Methods : This structured questionnaire survey was conducted with 409 high school students in G province. The collected data were analyzed using SPSS 20.0 program with descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, regression analysis and sobel test. Results : As a result, there were significant correlations among mental health, resilience, self-esteem, social support, and well-being. Resilience and social support showed partial mediating effects on the relationship between the mental health and well-being of high school students. Self-esteem showed a fully mediating effect. Conclusion : Therefore, to reduce mental health problems among high school students and to enhance their well-being, it is necessary for schools to develop mental health education programs and to apply effective mental health improvement strategies using resilience, self-esteem, and social support as mediators.

• Journal of the Korean earth science society
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• v.41 no.6
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• pp.670-683
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• 2020

The purpose of this study was to develop a test tool for convergence problem solving skill. To this end, constructs of convergence problem solving skill were defined in three domains: convergence attributes, convergence thinking, and convergence literacy domains. Thirty-seven pilot items were developed on the basis of the sub-categories for each domain that was defined through intensive literature review; problem solving & convergent thinking and creative thinking for convergence thinking domain, individual and social propensity for the convergence attributes domain, and convergence literacy as convergence literacy domain. Through an exploratory factor analysis, 30 items in the constructs of the test tool were confirmed. A confirmatory factor analysis result showed that the five construct models well captured the covariance between all the items well. Finally a statistical result shows that the reliability of the items and constructs were well established (Cronbach's α value= .963). Thus, the test tool for convergence problem solving skill developed in this study was statistically reliable.