• Journal of Navigation and Port Research
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• v.35 no.2
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• pp.173-178
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• 2011

This study determined the ship replacement life expectancy from an economic perspective. There are many ambiguities in the cost for calculation of economic lifespan, and these were expressed as fuzzy numbers. Also, a fuzzy cost model using fuzzy numbers was developed and suggested as a more practical analysis method than the existing cost model. And the suggested fuzzy model was used to determine the economic lifespan for various types of container ships. As the result, Without fuzziness, the economic lifespan of 5000 TEU Ships was found to be 19 years. it was found that the greater the container ship, the greater the economic lifespan was.

• Journal of the Korean Home Economics Association
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• v.50 no.4
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• pp.1-10
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• 2012

The purpose of this study was to examine the impact of attachment across an individual's lifespan. The present study investigated how father attachment in childhood influences adult student's school adjustment and explored the mediating effect of self-esteem between those two variables. Five hundred and twenty-nine adult students who were enrolled in S Cyber University were participants in this study. Subjects' ages ranged from 20-59. They were issued with a questionnaire addressing their present self-esteem level, attachment toward their father in childhood, and school adjustment. The results from SEM analysis indicated that adult students' self-esteem completely mediated between their attachment to their father in childhood and their school adjustment in adulthood. This result shows that a secure attachment to a father in childhood is related to child's own internal working model, and that positive self-esteem is related to social interactions including school adjustment.

• Earthquakes and Structures
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• v.9 no.1
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• pp.73-91
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• 2015

The effectiveness of tuned mass dampers (TMDs) in reducing the seismic response of civil structures is still a debated issue. The few studies regarding TMDs on inelastic structures indicate that they would perform well under moderate earthquake loading, when the structure remains linear or weakly nonlinear, while tending to fail under severe ground shaking, when the structure experiences strong nonlinearities. TMD seismic efficiency should be therefore rationally assessed by considering to which extent moderate and severe earthquakes respectively contribute to the expected cost of damages and losses over the lifespan of the structure. In this paper, a method for evaluating, in a life-cycle cost (LCC) perspective, the seismic effectiveness of TMDs on inelastic building structures is presented and exemplified on the SAC LA 9-storey steel moment-resisting frame benchmark building. Results show that the LCC concept may provide an appropriate alternative to traditional performance criteria for the evaluation of the effectiveness of TMDs and that TMD installation on typical existing middle-rise buildings in high seismic hazard regions may significantly reduce building lifetime cost despite the poor control performance observed under the most severe seismic events.

• The Korean Journal of Community Living Science
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• v.26 no.2
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• pp.375-386
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• 2015

This study examines the effects of parent-child attachment across the child's life from a life-span developmental perspective. The study investigates the effects of a child's attachment to his or her mother in childhood on his or her school attachment as an adult student and explores the role of self-esteem as a mediator of the relationship between these two variables. A total of 529 S Cyber University students taking social welfare classes participated in this study. These students completed a questionnaire about their present level of self-esteem, attachment to their mother in childhood, and school adjustment. According to the SEM results, adult students' self-esteem fully mediated the relationship between their mother-child attachment in childhood and their school adjustment in adulthood. Attachment security for the mother in childhood was related to the child's own internal working model, and positive self-esteem was related to school adjustment.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.11a
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• pp.72-76
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• 2009

Along with the heightening development of modern medical technology in the world, the economy and quality of lifestyle has contributed to the increase in the average lifespan. Therefore the issue to deal with the aging population is becoming an important social issue. As aging population becomes a serious social problem, the issue of supporting the senior citizens is confronted with a more difficult situation. From the perspective of senior citizen's physical and social and economic situations, there are great difficulties to deal with, like lowered physical ability compared to the rest of population. Therefore the supply of senior welfare facility that is based on senior citizen's physical characteristics yet provides the opportunity to be independent needs to provided rather than just planning a simple facility that provides living accommodations. This research examines thereinto welfare center's usage of residential circulation system from the senior welfare facilities' type classification to understand the actual usage problem and presents a circulation plan that will resolve the problem.

• Medical Lasers
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• v.9 no.1
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• pp.34-38
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• 2020

Recently, various lasers and energy-based devices (EBDs) have been widely used in aesthetic procedures. Although using lasers and energy-based aesthetic procedures presents a potential risk to doctors, nurses, and patients, aesthetic procedures tend to be performed without the necessary precautions. For injury prevention, it is essential to follow safety rules and be aware of potential accidents. Furthermore, it is important to understand the basic principles of the devices, including the different optical and electrical properties. Acquiring the exact knowledge to control a device is important for two reasons; to maintain a safer operating environment and prolong the lifespan of expensive devices. This review briefly summarizes the knowledge needed for better and safer aesthetic procedures and the proper control of aesthetic devices.

• Tribology and Lubricants
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• v.38 no.6
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• pp.274-280
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• 2022

There is a problem that semiconductor probe pin has a short lifespan. In order to solve this problem, Ti having excellent conductivity was doped to tetrahedral amorphous carbon (ta-C) having excellent hardness and abrasion resistance. This experiment was planned through the Taguchi robust design to determine the effect of the control factor of the ta-C:Ti coating film. The effect and contribution of control factors such as Unbalanced Magnetron Sputter(UBM) discharge current, arc discharge current, temperature, and bias voltage on ta-C:Ti characteristics were analyzed from the perspective of electrical and mechanical characteristics. The UBM discharge current was set to 4, 6, and 8 A. The main control factor of thickness and resistance is the UBM discharge current, and the thickness increased and the resistance decreased as the current increased. The decrease in resistance is due to the increase in the Ti content of the ta-C:Ti coating film. The arc discharge current was set to 60, 80, and 100 A. The main control factor of hardness and wear is the arc discharge current, and as the current rises, the hardness increases and the wear area decreases. This is due to the increased ta-C content of the ta-C:Ti coating film. Since resistance and wear are important for Probe Pin, the optimal level is set from the perspective of resistance and wear and a confirmation experiment is conducted.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3335-3343
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• 2021

The impact of gamma radiation on a commercial off the shelf microcontroller board has been investigated. Three different tests have been performed to ascertain the radiation tolerance of the device from a nuclear decommissioning deployment perspective. The first test analyses the effect of radiation on the output voltage of the on-board voltage regulator during irradiation. The second test evaluated the effect of gamma radiation on the voltage characteristics of analogue and digital inputs and outputs. The final test analyses the functionality of the microcontroller when using an external, shielded voltage regulator instead of the on-board voltage regulator. The results suggest that a series of latch-ups occurs in the microcontroller during irradiation, causing increased current drain which can damage the voltage regulator if it does not have short-circuit protection. The analogue to digital conversion functionality appears to be more sensitive to gamma radiation than digital and analogue output functionality. Using an external, shielded voltage regulator can prove beneficial when used for certain applications. The collected data suggests that detaching the voltage regulator can extend the lifespan of the platform up to approximately 350 Gy.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.100-107
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• 2024

Currently, in Korea, due to the rapid aging and deterioration of facilities, the minimum Maintenance Level and Performance Level' of facilities are required by the 'Facility Safety Act' or 'Infrastructure Management Act'. Since infrastructure assets have a long lifespan and the pattern of deterioration over time is complex, it is very difficult to maintain infrastructure as 'minimum maintenance state' or 'minimum performance state' by the current way of management. 'Asset Management' shall be performed not only by a technical perspective, but also by an accounting perspective such as cost and asset value. However, due to lack of awareness of 'asset management' among stakeholder, only technical perspective management is being carried out in practice. In order to effectively manage infrastructure assets, complex consideration of various asset value factors such as budget and service as well as safety and durability are required. In this paper, we presented a theory to evaluate and quantify the road network value for efficient asset management of the road network. We also presented a method of simulation to apply the theory presented in this paper. Through simulation and the results derived from this study, it is possible to specify the budget for the future national asset management, and to optimize the strategy for the management of old road facilities.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.1
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• pp.28-40
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• 2024

Maintaining the permanence of a company in the current rapidly changing business environment is not an easy task. Rather, the lifespan of a company can be said to be gradually decreasing. As such, the author of this paper, which describes the current market environment, is the sales organization of a large company. While leading the company, I thought about how to overcome the rapidly changing market and create an organization that continues to grow. As a result, I succeeded in creating an organization that continued to grow over the past two years, and the main activity of this result was the use of sales computer. It was clear that it was an information sharing activity. This can be said to be a result of proving that a series of activities to create and share information is important for the sales organization of ICT companies to actively respond to the rapidly changing market environment. Therefore, this study attempted to examine the relationship between knowledge management and business performance in the sales field of ICT companies, which has not been covered so far. Knowledge management is a four-stage activity from a process perspective, divided into knowledge creation, knowledge storage, knowledge transfer, and knowledge utilization. did. As a result of the study, first, knowledge management activities, such as knowledge creation and knowledge storage, were found to have a significant impact on financial performance. Second, knowledge management activities such as knowledge creation, knowledge storage, knowledge transfer, and knowledge utilization were all found to have an impact on non-financial performance. In the end, this study confirmed that efforts to turn tacit knowledge into knowledge in order to respond to the ever-changing ICT market are ultimately an important factor in growing a company.