• Journal of the Korean Institute of Gas
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• v.25 no.5
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• pp.19-29
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• 2021

Due to the climate changing, the world's countries are tightening regulations on CO2 and air pollutants emission to solve them. In addition, eco friendly vehicles is increasing to replace automobiles in internal combustion engine. Recently, the government is supporting the expansion of hydrogen refueling infrastructure and localization of core equipment in refueling facilities according to the hydrogen economy road map. In this study, design of the Excess flow limiting device in FCEV cylinder valve using by finite element analysis and performed performance tests on prototype. Major test results as hydrostatic strength, continued operation, operation, pressure impulse, leakage showed that the excess flow limiting device meets the performance requirements according to ISO 12619-2 and ISO 12619-11.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.73-79
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• 2018

In the west coast, south coast, and river basin, the use of geotextile mats has been increasing to improve the soft ground for making industrial facilities space and farmland. As an initial step to improve the vast and soft ground, the geotextile mats are laid and bonded to increase the bearing capacity of the wide ground for supporting construction equipment. Seam strength of geotextile mats exert a force only about 50% of the tensile strength of the fabric, which causes problems such as uplift and sinking in the soft ground. In this study, various types of geosynthetic matting techniques were investigated and the tensile strength of each method was compared and analyzed. Numerical analysis shows that stress increment in the ground due to the overburden load decreases when the seam strength of the geosynthetics mats is increased. When the seam strength was increased to 60, 70 and 80%, the bearing capacity of ground by geotextile mat was increased.

• Convergence Security Journal
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• v.17 no.5
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• pp.133-142
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• 2017

Breaking away from the blind faith of internal military security network, current military security demands strengthening measure on the H/W, controlling measure against information communications within the military, strengthening measure on the linkage point of the military and universal internal networks, legal supplementation, sucurity management ofn the military facilities from outsourcing services supporting the military. By analyzing the danger of military organizations hacking and real hacking cases, policy establishment for strengthening the security on military network hacking, legal supplementation and controlling measure for the outsourcing services are the pragmatic counter measures against military security hacking considering the peculiarities of military rather than the application of physical containment linked with information communications technology on the H/W safety measures.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.228-235
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• 2019

The purpose of this study is to explore the experiences and challenges of public guardianship services project for the mental disabled as a system of supporting the decision-making and the rights advocacy. For this purpose, interviews with 11 social workers who act as public guardians were conducted and a model of practice was suggested through analysis using the grounded theory of Strauss and Corbin(1998). As a results, the possibility of rights advocacy through public guardian services for the mentally disabled, the positive change of attitude of the facilities and the establishment of direction for the restoration of rights for the mentally disabled were derived. Public guardians experienced excessive empowerment of their guardians or difficulties in the process of their duties, but were also able to defend the rights of the mental disabled and support self-determination right. Through this study, expansion of budgets and expansion of beneficiaries for public guardianship services, establishment of infrastructure for integration in the community, set-up a support organization for public guardian services and Raising awareness of the mental disabled and public guardian services were suggested.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.112-120
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• 2021

Recently, the number of consumers using digital online distribution platforms is increasing. This caused the rapid growth of the e-commerce market and increased delivery volume in urban areas. The logistics system, designed ar006Fund the city center to handle the delivery volume, operates a delivery system from the outskirts of the city to the urban area using cargo trucks. This maintains an ecosystem of high-cost and inefficient structures that increase social costs such as road traffic congestion and environmental problems. To solve this problem, research is being conducted worldwide to establish a high-efficiency urban joint logistics system using urban railway facilities and underground space infrastructure existing in existing cities. The joint logistics system begins with linking unmanned delivery automation services that link terminal delivery such as cargo classification and stacking, infrastructure construction that performs cargo transfer function by separating from passengers such as using cargo platform. To this end, it is necessary to apply the device to the vertical and horizontal transportation machine supporting the vertical transfer in the flat space of the joint logistics terminal, which is the base technology for transporting cargo using the transfer robot to the destination designated as a freight-only urban railway vehicle. Therefore, this paper aims to derive holistic viewpoints needs for design requirements for vertical and vertical transportation machines and freight transportation standard containers, which are underground railway logistics transport devices to be constructed by urban logistics ecosystem changes.

• Journal of the Korea Convergence Society
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• v.13 no.2
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• pp.293-302
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• 2022

The purpose of this study was to identify the problems and improvement plans of grouphome management, by analyzing the sizes and items of children grouphome budgets of national and local governments. Major results of this study were as follows. First, the most crucial issue regarding labor costs within child grouphome budget, was that there was a significant difference in conditions between workers in similar institutions and regions. Small-sized institutions operated under a system that inevitably required excessive workload for workers, leading to exhaustion. Second, the support of operation expenses was absolutely insufficient to meet the general and special needs of children, and the relative differences between facilities of the same type were also identified. Third, children grouphome had limitations in stable business planing and implementation due to the absence of business expense support. Through this analysis, this paper discussed appropriate budget supporting measures regarding children grouphome, in order to ensure equal protection of grouphome children.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.319-319
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• 2023

Flows of water in the environment (e.g. in a river or estuary) generally occur in complex conditions. This complexity can hinder a general understanding of flows and their related sedimentary processes, such as erosion and deposition. To gain insight in simplified, controlled conditions, hydraulic flumes are a popular type of laboratory research equipment. Linear flumes use pumps to recirculation water. This isn't appropriate for the investigation of cohesive sediments as pumps can break fragile cohesive sediment flocs. To overcome this limitation, the rotating annular flume (RAF) was developed. While not having pumps, a side-effect is that unwanted secondary circulations can occur. To counteract this, the top and bottom lid rotate in opposite directions. Furthermore, a larger flume is considered better as it has less curvature and secondary circulation. While only a few RAFs exist, they are important for theoretical research which often underlies numerical models. Many of the first-generation of RAFs have come into disrepair. As new measurement techniques and models become available, there is still a need to research cohesive sediment erosion and deposition in facilities such as a RAF. New RAFs also can have the advantage of being automatic instead of manually operated, thus improving data quality. To further advance our understanding of cohesive sediment erosion and deposition processes, a large, automatic RAF (1.72 m radius, 0.495 m channel depth, 0.275 m channel width) has been constructed at the Hydraulic Laboratory at Chungnam National University (CNU), Korea. The RAF has the ability to simulate both unidirectional (river) and bidirectional (tide) flows with supporting instrumentation for measuring turbulence, bed shear stress, suspended sediment concentraiton, floc size, bed level, and bed density. Here we present the current status and future prospect of the CNU RAF. In the future, calibration of the rotation rate with bed shear stress and experiments with unidirectional and bidirectional flow using cohesive kaolinite are expected. Preliminary results indicate that the CNU RAF is a valuable tool for fundamental cohesive sediment transport research.

• Journal of Convergence for Information Technology
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• v.12 no.2
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• pp.17-22
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• 2022

Currently, the housing supply rate exceeds 100%, and the penetration rate continues to increase. This housing supply rate is changing from quantitative supply-oriented to improving the quality of the residential environment in housing service policies. Despite the increase in the housing supply rate, practical access to the vulnerable class is still difficult and there are many areas that are insufficient to use housing services when necessary. In addition, the demand for residential services is increasing due to the expansion of the scope of the vulnerable class. In order to compensate for these problems, facilities and joint occupancy that cannot guarantee independent living are mainly established, although a supply plan is established for the vulnerable by expanding policies and support projects. This paper proposes an IoT environment-based housing support system for vulnerable groups to support housing services for vulnerable groups. The proposal system improves the quality of the residential environment and provides service-oriented support services. Through the proposal system, appropriate social participation opportunities can be provided by improving the quality of life of the vulnerable and supporting a residential environment where independent living is possible.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.5
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• pp.211-218
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• 2016

This study focuses on the evaluation on the satisfaction of school education system based on perception levels of students corresponding to school locations. Twenty eight variables concerning with school education system were selected based on literature review and six factors such as reliability, sympathy, student supporting system, teachers' ability, principal physical environments, secondary physical environments were extracted by factor analysis. Satisfaction evaluation was performed by SERVPERP model based on perception level, and differences among respondents as well as school locations were analyzed by t-test and ANOVA. The results said there is no difference on teachers' ability factors. Especially, perception levels of students in rural area were lower than those in urban area except teachers' ability and secondary physical environments factors. Most respondents dissatisfy the school education system and they have no intention to recommend their school facilities (hardware) as well as educational programs (software) to other students in different schools.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.54.4-55
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• 2021

The Seoul National University AGN Monitoring Project (SAMP) is a welldesigned long-term AGN reverberation mapping project. SAMP focuses on the luminous AGNs out to z~0.5 with relative long time lags between AGN continuum and broad emission lines and aims to probe the high-end of the AGN broad line region (BLR) size-luminosity (R-L) relation. The pilot observations started in October 2015 for 100 AGNs to confirm the variability and the H and [O III] emission line strengths. Based on the initial variability test, 48 quasars has been continued spectroscopic monitoring since Feb. 2016 with Lick 3m and MDM 2.4m telescopes with a cadence of ~20 days. Supporting photometric monitoring in B and V band was conducted at multiple facilities including the MDM 1.3m, LOAO, and DOAO telescopes with a cadence of ~10 days. By the time of Feb. 2021, we have obtained five years spectroscopic and photometric data. More than 30 AGNs shows significant variability in five-year baseline and 16 of them show well detected lags between B-band and H. Here, we report some examples of SAMP light curves and lag detections using the first five-year data as well as the location of our 16 targets in the AGN BLR R-L relation. These measurements are consistent with the existing R-L relation and located at the high-end. With the coming data, SAMP are hopefully to report more AGNs with well detected lags. Our results demonstrate the general feasibility and potential of long-term reverberation project with medium cadence for luminous AGNs.