• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.117-123
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• 2009

This study is to investigate the characteristics of scour around pipeline in current and hydraulic model tests were performed. All the model test are 45 cases, which were conducted with velocities of 0.2 m/s to 0.5 m/s and pipe diameters of 45, 60, 90 mm. The developments of scour around pipeline were observed and equilibrium scour depths were recorded due to variation of pipe diameter and current velocity. According to the results, the equilibrium scour depth was proportional to current velocity and pipe diameter. The effect of diameter of pipeline on the equilibrium scour depth was bigger than current velocity. The correlations of relative scour depth and dimensionless number such as a Reynolds number, Shields number, and Froude number were analyzed. The Froude number and the relative scour depth had a high correlation of 0.900.

• Archives of design research
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• v.21
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• pp.161-170
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• 1997

The study as explained above has been progressed as follows: Through the theoretical required for projecting the corporate's exhibition at exposition, the justifiability of this study was recognized. To approach the pavilion of exhibition the importance of marketing communication at the corporate and its forming process were suggested, and the public information of the corporate as a medium of its marketing communication was under-stood. - With regard to the exhibiting event as its method, general constituents and contents of it were closely looked into, and on the exposition, as a kind of corporate's event and a place for the reciprocally exchangeable communication between the corporate and the public, a general study was done. - The importance of identification of the corporate's image for the corporate to participate in an exposition and its analytic method were refined in the stages of 'basic image' and 'serve image', and the general process in which the corporate is processing the image of its own pusiness since its participation in exposition was suggested in terms a model, dividing it into the stages of inspection & analysis and design.

• Journal of the Korean GEO-environmental Society
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• v.16 no.12
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• pp.13-22
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• 2015

Developed ground cavity due to leakage of decrepit old sewer pipe causes ground surface settlement and brittle fracture of pavement. Recently, for 5 years, frequency of occurrence of ground subsidence phenomenon tends to increase rapidly and/or steadily. It is difficult to investigate ground surface settlement and/or subsidence in urban area because most ground surfaces are covered with asphalt or concrete pavement. In this research, therefore, ground surface settlement, influence zone and settlement of sewer pipe were analyzed using finite element method. Not only reinforced effect of pseudo-plastic backfill that is applied to prevent ground surface settlement or subsidence spot, was compared and analyzed using numerical analysis program, but also direct shear test was carried out to determine strength parameters of pseudo-plastic backfill.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.525-532
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• 2015

In order to determine the testicular cycle of the Asian toad, Bufo gargarizans, adult males of the species were captured around Jeongeup city (Jeollabuk-do, Korea) during March, 2012 to February, 2013 and the gonadosomatic index (GSI) and the changes of germ cells in their testes were investigated throughout the year. The study indicated that the spermatogenesis in the seminiferous tubule of testes began in April and became most active in July. The recorded GSI was the highest and the cross area of seminiferous tubule was the widest in this period. The seminiferous tubules at the post spawning stage appeared in February, the largest amounts occurred in March and primary spermatogonia also appeared in this period. The GSI and the cross area of seminiferous tubules were found to be the lowest in March, indicating a testicular cycle with potentially continuous spermatogenic process. According to the findings above, it is confirmed that testicular spermatogenesis takes place actively between April to July in male Asian toad and that their breeding season is February to March.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.557-564
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• 2019

The purpose of this study was to examine the influencing factors of job engagement among Korean police officers. This was the secondary analysis of data from the 5th Korean Working Conditions Survey (KWCS). The study subjects included 185 Korean police officers. Collected data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation and multiple regression with IBM SPSS Statistics 24.0 program. Job insecurity (${\beta}=-.34$, p<.001), job reward (${\beta}=.39$, p<.001), subjective health status (${\beta}=.22$, p<.001), and organizational justice (${\beta}=.20$, p=.002) were significant influencing factors on job engagement, explaining 59.3% of the variance (F=34.26, p<.001). Effective and systematic strategies to improve Korean police officers' job engagement should focus on job reward, job insecurity, subjective health status, and organizational justice. The results of this study can be utilized as base data to improve Korean police officers' job engagement.

• Composites Research
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• v.35 no.3
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• pp.161-174
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• 2022

SiC fiber-reinforced SiC matrix composite is a promising accident-tolerant fuel cladding material to improve the safety of light water nuclear reactors. Compared to the current zirconium alloy fuel cladding as well as metallic accident-tolerant fuel cladding, SiC composite fuel cladding has exceptional accident-tolerance such as excellent structural integrity and extremely low corrosion rate during severe accident of light water nuclear reactors, which reduces reactor core temperature and delays core degradation processes. In this paper, we introduce the concept, technical issues, and properties of SiC composite accident-tolerant fuel cladding during operation and accident scenarios of light water nuclear reactors.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.2
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• pp.26-33
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• 2011

Recently, the use of buried glass fiber reinforced plastic (GRP) pipes is widespread and ever increasing trend in the industry. GRP pipes are attractive for use in harsh environments, such as for the collection and transmission of liquids which are abrasive and/or corrosive. The structural behavior of a GRP pipes buried under the ground is different from that of a rigid one made of concrete or clay, for example. A GRP pipe buried under the ground is deflected circumferentially by several percent and the stresses in the pipe are mainly compressive stresses. A GRP pipes has been introduced by a number of manufacturers for selection and used by underground pipeline designers. In all cases, the modified Spangler's equation is recommended by these manufacturers for predicting the ring deflection of these pipes under dead and live loads. In this paper, the ring deflection of buried GRP pipe is evaluated and discussed based on the result of analytical investigation.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1998.06a
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• pp.777-780
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• 1998

• 수도
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• s.46
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• pp.18-24
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• 1988

• Applied Biological Chemistry
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• v.2
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• pp.1-4
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• 1961