• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.103-110
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• 2019

In order to reduce the accidents occurring at construction sites, it is necessary to approach with harmonious measures considering various aspects such as systems, training, facilities, and protection equipments. Suggestion of safe construction method can be a good alternative. In the previous study, the half-depth precast deck with RC rib panel was proposed as an alternative method for safe bridge deck construction, and the performance required by the design code was verified through a four-point bending test. But the actual bridge deck is subjected to the repetitive action of the wheel load rather than the bending condition due to the four-point load. In this study, fatigue test was performed by repeating the wheel load $2{\times}10^6$ cycles to verify the safety of the half-depth precast deck with RC rib panel under actual conditions. As a result, fatigue effect due to repetition of wheel load was not significant in terms of serviceability such as crack width and deflection. In the residual strength test conducted after the fatigue test, the half-depth precast deck with RC rib panel failed by punching shear which is typical failure mode of bridge decks and the residual strength was similar to the punching strength of the RC and PSC bridge decks in spite of the fatigue effects.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.11
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• pp.27-35
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• 2018

The purpose of this study is to examine the effects of boundary RC frame(composed of one tie-beam and two tie-columns) on seismic performance of unreinforced masonry walls to suggest alternative way for seismic design of unreinforced masonry wall structures. Two test specimens are prepared, one is a typical unreinforced masonry wall and another is alternative unreinforced masonry wall with additional boundary RC frame. The structural experiments were carried out to evaluate the difference of seismic resistance performance between two test specimens with or without the boundary RC frames. From the test results, it was found that the failure mode of unreinforced masonry wall fundamentally changed from 'brittle' to 'ductile' by the installing of boundary RC frames. And, the maximum load and energy dissipation capacity of the test specimen with boundary RC frame was increased about 1.6~1.7 and 2~3 times respectively compared with a typical unreinforced masonry wall specimen.

• Journal of the Korean GEO-environmental Society
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• v.12 no.3
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• pp.37-46
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• 2011

To investigate the applicability of Precious Slag Ball as the alternative material such as vertical drains, it is necessary to check the drainage effect of it in the field construction. In order to attain an successful design it is important to predict problems encountered in field construction. Accordingly, in this study the laboratory tests were executed under different conditions before applying of the field. 4 cases including Precious Slag Ball, sand+Precious Slag Ball, pack Precious Slag Ball and sand as vertical drains were conducted, and under the base of the laboratory tests the field test was executed and analyzed. By the upper results it is apposite to use Precious Slag Ball as vertical drains.

• East Asian Journal of Business Economics (EAJBE)
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• v.8 no.4
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• pp.29-43
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• 2020

Purpose - Although it has been 10 years since the university technology holding company was launched, it is currently facing operational limitations. The purpose of this study is to study the growth strategy of university technology holding companies by investigating the status and problems of university technology holding companies. Research design, data, and methodology - In this study, the status of university technology holding companies was analyzed based on the survey data issued by the University Technology Holding Companies Association. Due to the lack of research on university technology holding companies, policy alternatives were suggested by examining problems based on literature research. Result - In this study, an alternative to strengthening the competitiveness of technology holding companies and supporting policies was suggested. As a result of the research, it was discovered as a policy alternative to enhance the independence of technology-owned subsidiaries, develop outstanding talents, and expand the marketing of support programs to create results based on technology holding companies. Conclusion - In previous studies, alternatives to technology commercialization policies have been suggested, but studies on the role and status of detailed technology holding companies are insufficient, and the operation system of technology holding companies and discovery of future growth models are insufficient compared to overseas cases. Therefore, in this study, various policy innovation measures are presented as examples.

• The Journal of Information Systems
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• v.30 no.4
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• pp.43-69
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• 2021

Purpose Although companies occupied the network market take the advantageous position first and can be successful in securing users over a certain size, it is important to satisfy the customers' demand and prevent the outflow of users toward a new alternative SNS. What is more, there are frequent changes in the flow of users toward new SNSs. Despite these dynamic market circumstances, there is a lack of research to explain the switching behaviors of SNS users. Design/methodology/approach The objective of this study is to explain and verify a specified migration theory(Push-Pull-Mooring model) focused on SNS fatigue in the psychological point of view, as well as reviewing previous studies on functional and technical characteristics of SNSs themselves. Moreover, this study tried to highlight factors affecting users actual SNS switch rather than their switching intention. Findings According to the statistical analysis, the most influenced pull factor to switch SNS was the alternative attractiveness. On the other hand, undesired relationship burden, service innovation and important mooring factors to prevent users' SNS switch. This study has a significant contribution to the theory, which analyzed users' actual SNS switch, and examined SNS users' psychological factors(SNS fatigue), reviewing the characteristics of existing services. To secure more users and to keep them, companies providing social network service need to develop differentiated strategies by analyzing psychological characteristics of various users.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.190-202
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• 2021

Background: Landscape metrics have been widely applied to quantifying the relationship between land surface temperature and urban spatial patterns and have received acceptable verification from landscape ecologists but some studies have shown their inaccurate results. The objective of the study is to compare landscape metrics and texture-based measures as alternative indices in measuring urban heterogeneity effects on LST at multiple scales. Results: The statistical results showed that the correlation between urban landscape heterogeneity and LST increased as the spatial extent (scale) of under-study landscapes increased. Overall, landscape metrics showed that the less fragmented, the more complex, larger, and the higher number of patches, the lower LST. The most significant relationship was seen between edge density (ED) and LST (r = - 0.47) at the sub-region scale. Texture measures showed a stronger relationship (R² = 34.84% on average) with LST than landscape metrics (R² = 15.33% on average) at all spatial scales, meaning that these measures had a greater ability to describe landscape heterogeneity than the landscape metrics. Conclusion: This study suggests alternative measures for overcoming landscape metrics shortcomings in estimating the effects of landscape heterogeneity on LST variations and gives land managers and urban planners new insights into urban design.

• Journal of Distribution Science
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• v.20 no.8
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• pp.115-121
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• 2022

Purpose: This article aims to explore the distribution of technological innovation and environmental policy challenges to respond to COVID-19. The study also attempts to tackle a paradigm shift in science and technology policies against the pandemic and a desirable direction for environmental policies. The COVID-19 pandemic has been the one that rapidly changed global people's lifestyle. For the spread of a terrible infectious disease could not be avoided, regardless of a highly industrialized society. Research design, data and methodology: This study basically employs a qualitative approach as a methodology. This study is based on the fact that environmental pollution, various natural disasters continuously occur, and there are many unforeseeable parts, despite remarkable development of scientific technology, and that the circumstances are becoming more complex. Results: This study noted that scientific technology civilization formed due to industrial revolutions can deteriorate environment and increase environmental threat factors. As an alternative to this, this study investigates alternative discussions on how the 4th Industrial Revolution can help scientific technology and human environment to harmoniously coexist and develop. Conclusions: It implies that this study focuses on the possibility of overcoming this crisis through science and technology innovation, although mankind is in crisis of COVID-19 due to excessive human development.

• Journal of Surface Science and Engineering
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• v.56 no.2
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• pp.125-136
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• 2023

Recently, ammonia has emerged as an alternative energy source that can reduce carbon emissions in various industries. Ammonia is used as a fuel in internal combustion engines because it contains no carbon in its components and does not emit any carbon when burned. It is also used in various fields such as fertilizer production, refrigeration, cleaning and disinfection, and drug manufacturing due to its unique characteristics, such as high volatility and easy solubility in water. However, it is highly corrosive to metals and is a toxic gas that can pose a risk to human health, so caution must be exercised when using it. In particular, stress corrosion cracking may occur in containers or manufacturing facilities made of carbon-manganese steel or nickel steel, so special care is needed. As ammonia has emerged as an alternative fuel for reducing carbon emissions, there is a need for a rapid response. Therefore, based on a deep understanding of the causes and mechanisms of ammonia corrosion, it is important to develop new corrosion inhibitors, improve corrosion monitoring and prediction systems, and study corrosion prevention design.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.10
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• pp.75-84
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• 1997

This paper describes the development of an integrating method for process planning and scheduling activities for block assembly in shipbuilding. A block is composed of several steel plates and steel sections with the predetermined shapes according to the ship design. The parts which constitute the block are manufac- tured by cutting and/or bending operations, which are termed as machining operation in this paper. The machining operation is the first process for block assembly which influences the remaining block assembly processes. Thus process planning and scheduling for machining operation to manufacture parts for block are very important to meet the assembly schedule in the shipyard. An integrating method for process plan- ning and scheduling is developed by introducing the concept of distributed process planning and scheduling composed of initial planning, alternative planning and final planning stages. In initial planning stage, nesting parts information and machining emthods are generated for each steel plate. In alternative plan- ning stage, machine groups are selected and workcenter dispatching information is generated. In final planning stage, cutting sequences are determined. The integrated system is tested by case study. The result shows that the integrated system is more efficient than existing manual planning system.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2288-2297
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• 2023

Current designs of both large reactor units and small modular reactors utilize a nuclear fuel with increasing enrichment. This increasing demand for better nuclear fuel utilization is a challenge for nuclear fuel handling facilities. The operation with higher enriched fuels leads to reduced reserves to legislative and safety criticality limits of spent fuel transport, storage and final disposal facilities. Design changes in these facilities are restricted due to a boron content in steel and aluminum alloys that are limited by rolling, extrusion, welding and other manufacturing processes. One possible solution for spent fuel pools and casks is the burnup credit method that allows decreasing very high safety margins associated with the fresh fuel assumption in spent fuel facilities. This solution can be supplemented or replaced by an alternative solution based on placing the neutron absorber material directly into the fuel assembly, where its efficiency is higher than between fuel assemblies. A neutron absorber permanently fixed in guide tubes decreases system reactivity more efficiently than absorber sheets between the fuel assemblies. The paper summarizes possibilities of fixed neutron absorbers for various nuclear fuel and fuel handling facilities. Moreover, an absorber material was optimized to propose alternative options to boron. Multiple effective absorbers that do not require steel or aluminum alloy compatibility are discussed because fixed absorbers are placed inside zirconium or steel cladding.