• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.4
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• pp.474-482
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• 2021

An average of two to three typhoons that occur in the Philippines or Taiwan pass through Korea each year owing to the influence of the geographical location and western winds. Because Jinhae Bay is known as Korea's representative typhoon refuge, it is filled with ships during typhoons and later becomes saturated with ships anchored to the surrounding routes. If a strong wind drags an anchored ship, a collision accident may occur because of the short distance between the ships. Therefore, a systematic anchoring safety management of Jinhae Bay is required. In this study, the minimum wind speeds of a dragging anchor based on the water depths of Jinhae Bay anchorages were investigated. When 7-9 shackles were given, the minimum wind speeds were 48-63, 46-61, and 39-54 knots at depths of 20, 35, and 50 m, respectively. As the water depth increased, the length of the cable laid on the sea bed became shorter than 5 m owing to the external force, and the minimum wind speed showed a significant difference of 4-8 knots. In addition, ships with high holding power anchors (AC-14 type) had higher minimum wind speeds than ships with conventional anchors (ASS type). Finally, it was confirmed that at a depth of 50 m, dragging easily occurred even when a high holding power anchor was applied.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.45-52
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• 2020

An open-spandrel arch bridges, which consists of slab deck, arch rib, and vertical members, shows a various level of moment and axial forces according to the supporting boundary condition of arch rib and vehicle speeds. Also, the definition of impact factor accepts any kind of response parameters, not only displacement response at slab deck. The present study considers concrete open-spandrel arch bridges constrained with fixed conditions at the ends of arch rib and investigates the impact factor variation due to moving load speeds, response parameters, measuring locations, and vertical member spacing ratio of the bridges. The results of Reference model show that the impact factor is biggest when the reactive moment resulted at the vehicle-inducing opposite end of the arch rib is applied. The peak impact factor is a similar level obtained for the middle of the span adjacent to the slab deck center, but it is 19% higher than the peak impact factor calculated using the axial force developed at the same location. Reducing the spacing ratio of the vertical members as half as the reference model whose ratio is 1/9.375 produces a similar level of the moment-based peak impact factor compared to the reference model. However, when the spacing ratio is doubled, the peak impact factor is 4.4 times greater than the reference model.

• Convergence Security Journal
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• v.20 no.4
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• pp.227-236
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• 2020

Peacekeeping operations (PKO), which were based mainly on military operations in the Cold War era, have become diverse in the post-Cold War era. The history of the PKO of Korean police began in 1994 as two policemen were deployed to Somalia for rebuilding law and order in this country, but the role of Korean police in PKO has been limited so far, compared to that of Korean military. At this point when global conflicts escalate does the UN urge its 193 member states to conduct diverse PKO. In particular, maintaining law and order as the primary duty of police is required strictly for law enforcement while the warring country is being rebuilt. In this regard, some member states such as US, China, and Germany have deployed police force in order to play its role in a direct or indirect manner. On the contrary, the extent of the contribution of Korean police in PKO is too insignificant to measure. To this end, here in the present study were analyzed first the trend of global conflicts and the circumstance of law and order in the conflict regions. Then the PKO of police from countries including Republic of Korea, US, China, and Germany were compared, and so was the chronological change of PKO. Last, a measure to expand the capacity of Korean police and for its active role in PKO was proposed.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.375-382
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• 2021

Adolescents with disabilities have unnatural behavior and language, which makes it difficult to use soft and flexible language and behavior, and lack of learning experience has limitations in not being free in mature behavioral communication. Eurhythmics musical rhythm elements were divided into time and space, power and weight, and balance and fluidity and reflected in teaching and learning so that adolescents with disabilities could have comfortable, creative, and original thoughts that bring about changes in thawing. In order to increase the effectiveness of education in the direction of observing the effect of improving self-esteem, communication, and creativity of adolescents with disabilities, the study guide applying the Eurhythmics rhythm element was fused with music education, art education, and physical education, and interviewed by selecting research participants. Based on the questionnaire, an observation method suitable for the study of adolescents with disabilities was conducted. As a result of the study, it was observed that the educational effect of the disabled youth was improved as a result of conducting the class by applying the Eurhythmics rhythm elements time and space, force and weight, balance and fluidity by integrating music, art, and physical education(line dance, playtime). Therefore, to supplement the limitations in this learning process, various educational methods applicable to the education of youth with disabilities, a support system that can reflect Eurhythmics education through physical play, and a method to properly compose various learning tools do.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.4
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• pp.205-212
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• 2021

Offshore jacket structures generally comprise steel members, and the safety standard for jacket structures typically focuses on the steel components. However, large amounts of concrete grouting is filled in the legs of the Gageocho jacket structure to aid in the recovery from typhoon damage. This paper proposes a safe and lightweight design for the Gageocho ocean research station comprising steel members instead of large amounts of concrete reinforcement in the legs. Based on the actual design, the structural members are grouped according to their functional roles, and the inner diameter of the cross-section in each design group is defined as a design variable. Structural optimization is carried out using a genetic algorithm to minimize the total weight of the structure. To satisfy the conservative safety standards in the offshore field, both the maximum stress and the unity check criteria are considered as design constraints during optimization. For enhanced safety confidence, extreme environmental conditions are assumed. The maximum marine attachment thickness and the section erosion in the splash zone are applied. Additionally, the design load is defined as the force induced by extreme waves, winds, and currents aligned in the same direction. All the loading directions surrounding the structure are considered to design the structure in a balanced and safe manner. As a result, compared with the current structure, the proposed structure features a 45% lighter design, satisfying the strict offshore safety criteria.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.291-298
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• 2022

Unexpected massive disasters have occurred around the world, causing enormous socio-economic damage. The military has long been enacting laws, organizing organizations and establishing systems for crisis and disaster management, but it did not consider the situation when military essential functions were suspended due to unpredictable and massive disasters. With the September 11 terrorist attacks, the U.S. military has developed COOP strategy aimed at continuing military essential functions in all crisis, and is contributed to national continuity by ensuring uninterrupted national security functions. Korean military has established a crisis and disaster management system, but focuses on managing and controlling disasters and crisis situations. Korean military needs a system to guarantee military essential functions even in national crisis beyond its management capabilities. In this study, We compared and reviewed the U.S. administration and military COOP guidelines and directives, ISO22301 international standards., and developed planning guidelines suitable for the Korean military situation by responding to detailed items based on ISO22301. In particular, the U.S. military(DoD, Army, Navy, Air Force) COOP guidelines were drawn and incorporated into the guidelines(such as protection and succession of command authority, the fulfillment of essential functions and operational security, etc.). The planning guidelines are expected to be used as reference materials for the introduction of COOP systems in the military and the establishment of plans in the future.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.353-366
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• 2022

The study sets out to examine the relationship between the effects of government support, network capability, and knowledge sharing on the effects of innovative behavior on innovation performance. As digital-based networks and knowledge sharing activities are rapidly becoming common in the era of the spread of Covid-19, 357 questionnaires were analyzed for incumbent employees and the research hypotheses are verified using SPSS 24 and smart PLS 3 to prove the relationships between variables. As a result of the study, it is found that innovation performance increased when government support, network capability, and knowledge sharing increased. Innovative behavior is found to significantly mediate the relationship between network capability, knowledge sharing, and innovation performance, and government support was found to have a significant effect on network capabiltiy. Therefore, in order to induce innovative actions that are important in creating innovative results, various programs to enhance the network capabilities of entrepreneurs and promote knowledge sharing should be required as government support policies. This will serve as a driving force for entrepreneurs to voluntarily develop and implement ideas more flexibly and freely, thereby enhancing competitiveness through innovative growth of companies and industries. In other words, this study verified the effectiveness of government support in the network capability to help create innovative results by inducing innovative behavior along with knowledge sharing activities, and comprehensively demonstrated the relationship between factors in the overall structure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.6
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• pp.409-415
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• 2021

Medical waste management is becoming increasingly important, specifically in light of the current COVID-19 pandemic, as hospitals, clinics, quarantine centers, and medical research institutes are generating tons of medical waste every day. Previously, a traditional incineration process was utilized for managing medical waste, but the lack of landfill sites, and accompanying environmental concerns endanger public health. Consequently, an innovative sterilization shredding system was developed to resolve this problem. In this research, we focused on the design and numerical analysis of a shredding system for hazardous and infectious medical waste, to establish its operational performance. The shredding machine's components were modeled in a CAD application, and finite element analysis (FEA) was conducted using ABAQUS software. Static, fatigue, and dynamic loading conditions were used to analyze the structural stability of the cutting blade. The blade geometry proved to be effective based on the cutting force applied to shred medical waste. The dynamic stability of the structure was verified using modal analysis. Furthermore, an S-N curve was generated using a high cycle fatigue study, to predict the expected life of the cutting blade. Resultantly, an appropriate shredder system was devised to link with a sterilization unit, which could be beneficial in reducing the volume of medical waste and disposal time, thereof, thus eliminating environmental issues, and potential health hazards.

• Journal of Space Technology and Applications
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• v.2 no.2
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• pp.146-168
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• 2022

Witnessing current military conflicts in South China Sea and Eastern Europe, most defense analysts evaluate one of the most serious security threat toward the US is coming from the superpower competitions with Russia and China. The main means for such super power hegemonic competitions is military power and space power is a key enabler to maximize the efficiency and effectiveness of military employment. Reflecting above circumstances, the space hegemonic competition between the Unites States and China is spreading into all aspects of national powers. Under such an environment, R.O.K needs to significantly develop national space power to preserve life and assets of people in space. On the other hand, the R.O.K has a lot of limitations in launching space assets into orbits by land-based space rockets due to its geographic locations. The limitation of rocket launching direction, the failure to secure a significant area enough to secure safety and the limitation to secure open area enough to build associated facilities are among them. On this paper, I will suggest the need to build the 2nd space rocket launching site after analyzing a lot of short-falls the current 'Naro' space center face, compared to those of advanced space powers around the world.

• Korean Journal of Culture and Social Issue
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• v.26 no.4
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• pp.409-433
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• 2020

This study attempted to verify the relationship between job burnout and organizational citizenship behavior among South Korean soldiers in the Navy force by applying the Job Demands-Resource Model and Conservation of Resource Theory, and the moderated mediating effect of social capital through the work engagement and smartphone use. The mediating effect of work engagement and the moderating effect of social capital via smartphone use were examined in the relation between job burnout and organizational citizenship behavior. We combine the mediation effect model and the moderation effect model and tested the moderated mediation effect. To perform this study, the survey was conducted on the navy soldier on duty, and total of 324 data were analyzed. The results of this study were as follows: the complete mediation effect of work engagement in the relation of job burnout and organizational citizenship behavior was verified, social capital via smartphone use moderated the relation between job burnout and work engagement, and the moderated mediation effect of social capital via smartphone use in the relation between job burnout and organizational citizenship behavior through work engagement was identified. Based on the results, implications, limitations, and future research directions of the current study were discussed.