• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.259-268
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• 2016

The service life evaluation in RC(Reinforced Concrete) structure exposed to chloride attack can be classified into deterministic and probabilistic method, and it significantly varies with design parameters. The present work derives PDF (Probability of Durability Failure) and the related service life considering time-dependent diffusion coefficient and internal parameters such as reference diffusion coefficient, critical chloride content, and time-exponent. When critical chloride content increases to 133.3%, the changing ratios of service life are 134.0~145.4% for deterministic method and 149.2%~152.5% for probabilistic method, respectively. In the case of increasing time-exponent to 200%, they increase to 323.8% for deterministic method and 346.0% for probabilistic method. Through adopting time-diffusion coefficient for probabilistic method, reasonable service life evaluation can be achieved, and it is also verified that increasing time-exponent through mineral admixture is very effective to extension of service life in RC structure.

• Journal of the Korean Home Economics Association
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• v.44 no.8
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• pp.127-142
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• 2006

This study, systematically evaluated the services provided by consumer organization site in order to improve the possessing problems or deficient aspects and present a desirable direction for instituting the planning of a new consumer group site. An evaluation of the level with respect to contents of consumer organization site showed that communication had the lowest grade while design had the highest. There were some technical errors related to accessibility of the site. An examination of the quality of consultation showed that success rate was low and the contents of the consultation were inadequate. However, compared with service quality of the consumer organization site estimated in the year of 2000, the current service showed significant improvements in terms of the overall quantity of information.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.43-53
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• 2018

Recently, public service for the improvement of quality of life and life support such as safety, aging, disaster, welfare, housing, economy, urban environment, traffic etc are actively developed based on open public data, and the spread of the network and the necessity of everyday life, smartphones are playing a role in providing public services. Currently, the development of science is changing the life expectancy of human beings and changing into social structure in which aged people become bigger due to various social conditions and low fertility and aging problems. However, the elderly who do not have easy access to information are very uncomfortable in dealing with mobile devices with very low accessibility and utilization of public services provided by mobile phones. Therefore, this study recategorizes the condition of the elderly presented in the previous study and identifies the problem through case analysis provided for the elderly. Also, we summarize the hierarchy of the core items of the existing interface design and derive it as an improvement index of the public service design for the improvement of the information accessibility of the elderly, and propose a design method to improve the utilization of the public service provided through the mobile device.

• Korean Institute of Interior Design Journal
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• v.20 no.2
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• pp.85-93
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• 2011

The Japanese housing market has implemented management and operation systems of community service ahead of the Korean market. This paper examines case studies of Japanese community services by reviewing related studies, studying homepages, and conducting in-depth interviews with management staff. The goal of this study is to find marketing strategies and the proper management practices in preparation for the upcoming low-fertility and aging society. The results of this study are as follows: 1) After Japan's bubble economy burst in 1985, so called that incorporated various community facilities with life services were introduced to the Japanese housing market in order to cope with the diversifying family types and lifestyles. This new trend was also due in part to customers' increasing demands for convenient urban condominiums. 2) In Japan, many developers and construction companies have run the management of community service programs and created new business models in collaboration with other affiliated companies. However, many of these programs have been found even more successful and reliable when the facility management companies collaborate with local service providers instead of relying solely on affiliated companies. 3) The early stage of life services began with "front-desk services", but these have evolved into more upgraded "concierge services" that can provide residents with tailored services and conveniences. Furthermore, some of the service providers have encouraged resident participation in the process of designing and implementing their community services. 4) In Korea, most construction companies and developers are still oriented toward providing hardware such as spaces and facilities in developing their community services. Therefore, companies with high market reputations must seek alternative ways to maintain and enhance their brand values by implementing new approaches in collaboration with both affiliated companies and local service providers. This can be done by finding new notions of managing and operating community services through research and development.

• Journal of Power Electronics
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• v.14 no.1
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• pp.135-142
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• 2014

In the design of battery chargers, limiting the output ripple current according to the manufacturer's recommendation is important for reliable service and extended battery life. Ripple components can cause internal heating of the battery and thus reduce the service life of the battery. Care must be exerted in the design of the switching converter for the charge application through the accurate estimation of the output current ripple value. This study proposes a method to reduce the output current ripple of the converter and presents a detailed analysis of the output current ripple of the DC-DC boost converter to provide a guideline for the design of the battery charger.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.46-47
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• 2012

In the design of the battery charger it is important to limit the ripple current and voltage according to the manufacturer's recommendation for the reliable service and the extended life of the battery. However, it is often overlooked that these ripple components can cause internal heating of the battery, thereby reducing its service life. Thus the care must be taken in the design of the switching converter for the charge application through the accurate estimation of the output ripple values. In this research analysis on the output ripple of the dc-dc converter is detailed to provide a guideline for the design of the battery charger.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.743-746
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• 1999

One of the main deteriorating factors that affect the service life of concrete structures is the corrosion of reinforcement. The chlorides penetrate the concrete, destroy the passive layer surrounding the steel, and help initiate the steel corrosion. A Corrosion Prediction System(CPS) has been developed to assist the engineer in analyzing the service life of existing sea-shore structures and future concrete repairs by calculate the chloride diffusion in concrete. The CPS calculates mixing design, physical properties or recent chloride profiles. The CPS can be used to evaluate changes in concrete cover, chloride loads, and environmental conditions in different structural designs.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.32-39
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• 2018

Repairing timing and the extended service life with repairing are very important for cost estimation during operation. Conventionally used model for repair cost shows a step-shaped cost elevation without consideration of variability of extended service life due to repairing. In the work, RC(Reinforced Concrete) Column is considered for probabilistic evaluation of repairing number and cost. Two mix proportions are prepared and chloride behavior is evaluated with quantitative exterior conditions. The repairing frequency and cost are investigated with varying service life and the extended service life with repairing which were derived from the chloride behavior analysis. The effect of COV(Coefficient of Variation) on repairing frequency is small but the 1st repairing timing is shown to be major parameter. The probabilistic model for repairing cost is capable of reducing the number of repairing with changing the intended service life unlike deterministic model of repairing cost since it can provide continuous repair cost with time.

• Journal of Service Research and Studies
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• v.8 no.1
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• pp.1-12
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• 2018

The current research investigates an optimal design for the service system, which refers to the entire process of implementing, providing, and utilizing wisdom assets. We analyzed the intrinsic commonality of wisdom assets and services, and carried out research based on optimality in fidelity to service essence. The essential characteristics of service are horizontality, interactivity, harmonization, and relationship. It is suggested that the operating process can be implemented in the best condition when the wisdom asset service system is designed based on the four essential characteristics of services. It has been demonstrated that the entire process of production, delivery, marketing and quality control of wisdom contents can be designed on the basis of the essence of wisdom and service. After designing a basic service model, detailed service models are presented. The purpose of this study was to solve the problems of the material civilization society which is suffering mentally and to design the social service model which is high in productivity but mentally healthy. By supplementing and deepening the results of this study, it will be possible to develop and implement desirable social service model in which all societies live a happy life.

• International Journal of Concrete Structures and Materials
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• v.2 no.2
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• pp.137-143
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• 2008

In recent years, much research work has been performed on durability design and long-term performance of concrete structures in marine environments. In particular, the development of new procedures for probability-based durability design has been shown to provide a more realistic basis for the analysis. This approach has been successfully applied to several new concrete structures, where requirements for a more controlled durability and service life have been specified. For reinforced concrete structures in a marine environment, it is commonly assumed that the dominant degradation mechanism is the corrosion of the reinforcement due to the presence of chlorides. The design approach is based on the verification of durability limit states, examples of which are: depassivation of reinforcement, cracking and spalling due to corrosion, and collapse due to cross section loss of reinforcement. With this design approach the probability of failure can be determined as a function of time. In the present paper, a probability-based durability performance analysis is used in order to demonstrate the importance of the durability design approach of concrete structures in marine environments. In addition, the sensitivity of the various durability parameters affecting and controlling the durability of concrete structures in a marine environment is studied. Results show that the potential of this approach to assist durability design decisions making process is great. Based the crucial information generated, it is possible to prolong the service life of structures while simultaneously optimizing the final design solution.