• Korean Journal of Construction Engineering and Management
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• v.11 no.3
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• pp.64-71
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• 2010

Since 2010, it is estimated that the old building to be dismantled potentially will be about 8.9 million house in domestic country. Consequently, now domestic demolition market size of about 1.5 trillion won is forecasted to be grow rapidly into the size of 5.8 trillion won. But in the domestic country, preparation of the raw and regulation for the demolition industry is very insufficient compared with advanced country, and the related research is also very insufficient. Therefore, in this study, it is performed to analyse and predict a trend of domestic demolition market after analysing a current trend in overseas demolition industry. A demolition industry is a related industry fallen behind over 25 years compared with a construction industry. The exact analysis of those trends will make it possible to set the standard for demolition waste management. Also this study suggests methods be able to develop the demolition industry into main area of construction industry through those analysis.

• The Journal of the Korea Contents Association
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• v.8 no.11
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• pp.65-73
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• 2008

In this study, we have looked into the cellular phone consumption behavior of seniors who are 50-65 years old because of the prediction that senior cellular phone market will be expanded. Therefore, we made up a questionnaire which is based on theoretical study about silver consumer and marketing, and we also analyzed main features and differences of senior and active senior after split by lifestyle analysis. Through the analysis result, we found out the practical approaching way for the items that seniors' dissatisfaction was high and inquired whether it's possible turning into interface's direct input system or not. As a result, we discovered the change of a pattern of behavior by the increase of seniors's experience, differences of consumption behavior factors by lifestyle, and the possibility of market value of new interface.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.2
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• pp.47-53
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• 2014

The paper investigates the limit state of deflection for short and medium span steel girder bridges. Deflection depends on stiffness of steel girders and integrity of the reinforced concrete slab (composite action). Load and resistance parameters are treated as random variables. A probabilistic model is developed for prediction of the deflection. The structural performance can be affected by deterioration of components, in particular corrosion of steel girders. In addition, the creep of concrete can greatly influence the deflection of composite structures. Therefore, the statistical models for creep and corrosion of structural steel are incorporated in the model. Structures designed according to the AASHTO LRFD Code are considered. Load and resistance models are developed to account for time-variability of the parameters. Monte Carlo simulations are used to estimate the deflections and probabilities of serviceability failure. Different span lengths and girder spacing are considered for structures designed as moment-controlled and deflection-controlled. A summary of obtained results is presented.

• Journal of the Korean GEO-environmental Society
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• v.16 no.12
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• pp.13-22
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• 2015

Developed ground cavity due to leakage of decrepit old sewer pipe causes ground surface settlement and brittle fracture of pavement. Recently, for 5 years, frequency of occurrence of ground subsidence phenomenon tends to increase rapidly and/or steadily. It is difficult to investigate ground surface settlement and/or subsidence in urban area because most ground surfaces are covered with asphalt or concrete pavement. In this research, therefore, ground surface settlement, influence zone and settlement of sewer pipe were analyzed using finite element method. Not only reinforced effect of pseudo-plastic backfill that is applied to prevent ground surface settlement or subsidence spot, was compared and analyzed using numerical analysis program, but also direct shear test was carried out to determine strength parameters of pseudo-plastic backfill.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.9 s.339
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• pp.65-70
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• 2005

For the base station or repeater which is in operation as part of a mobile communication system, any kind of degradation in antenna performance such as lowered gam or increased VSWR which maybe due to aging of antenna, connector corrosion or other environmental factors, is difficult to detect and react to immediately. In this paper, a VSWR measurement device which is capable of detecting the VSWR of a PCS forward path ($1,840\~1,870$MHz) antenna in operation in real time without any interruption in service is developed. Such regular measurement will allow the prediction of any serious failures and insure reliable operation of the antenna. All components of the antenna VSWR measurement device was researched so that the whole system could be produced and shown to be accurate in measuring the YSWR of an actual RF repeater in operation, proving it's effectiveness.

• Land and Housing Review
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• v.4 no.2
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• pp.201-209
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• 2013

The purpose of this study is to get some data to repair the existing apartment housings to energy saving house : The data are a repair requirement, a repair preference, and so on. For this purpose, an interview was carried out for the dwellers who is living in the estates constructed in about 10 years ago. If there would be a financial support of the government, which is to make a loan 1,400 thousand won and the 3.5% interest, then the 53% of dwellers have agreed to repair their houses. And the best preference repair item was a window, the items what is disturbed to their ordinary life would be not easy to be repaired. This survey has limited to only the apartment housings, so the additional survey will be carried out to get the data to practise the government's Green Home project for existing houses.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.4
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• pp.335-343
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• 2017

The Newman-Raju formula and contour integral-based finite element analyses(FEAs) have been widely used to assess crack growth rates and residual lives at crack locations in ships or offshore structures, but the Newman-Raju formula is known to be less accurate for the complicated weld details and the conventional FEA-based contour integral approach needs concentrated efforts to construct FEA models. Recently, an extended finite element method(XFEM) has been proposed to reduce those modeling efforts with reliable accuracy. Stress intensity factors(SIFs) from the approaches such as the Newman-Raju formula, conventional FEA-based J-integral, and XFEM-based J-integral were compared for an infinitely long plate with a propagating elliptic crack. It was concluded that the XFEM approach was far reliable in terms of prediction ability of SIFs. Assuming a 25 year-aged coast guard patrol ship had the prescribed cracks at the bracket toes attached to longitudinal stiffeners in way of deck and bottom, SIFs were derived based on the three approaches. To obtain axial tension loads acting on the longitudinal stiffeners, long term hull girder bending moments were assumed to obey Weibull distribution of which two parameters were decided from a reference (DNV, 2014). For the complicated weld details, it was concluded that the XFEM approach could cost-effectively and accurately estimate the crack growth rates and residual lives of ship structures.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.803-815
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• 2021

As the world's aging population increases, the aging problem in China, which has a huge population, has reached a serious situation. Therefore, this study intends to present the CCRC model of smart home care. Seven application factors of CCRC of smart home care and problems of CCRC of smart home care in China were derived through theoretical review and case analysis. Based on this, this study presented a value proposition for the 7 application elements of smart home care CCRC tailored to China's aging status and future technology demand. First, it improves the environmental atmosphere and increases the comfort of the spatial environment. Second, we value the physical and environmental safety of the elderly. Third, online convenience services are provided. Fourth, we guarantee the health and psychological health of the elderly. Fifth, it increases the efficiency of responding to unexpected situations. Sixth, predict the physical condition and surrounding environment of the elderly. Seventh, add more recreational rides. Through this, we expect to improve the quality of life by providing a safe and comfortable smart service environment for the elderly.

• 한국노년학
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• v.29 no.3
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• pp.1025-1041
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• 2009

The purpose of this study is to evaluate the effects of a web-based senescence preparation program for the provision of information and education on aging. A non-equivalent control group pretest-posttest design was used. The subjects were 70 middle-aged adults (experimental group: 36, control group: 34) living in Daegu city. The experimental group participated in a web-based senescence preparation program for 10 weeks, where 10 subjects were covered (5 physical, 3 mental/psychological, and 2 social/environmental). As compared to the control group, the knowledge of the experimental group increased significantly, and there was a significant change in their attitudes toward the elderly and old age plans. These results suggest that a web-based senescence preparation program can predict people's old age and help in their preparation. Further, this program is expected to offer individualized learning opportunities to many learners in various settings.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.357-359
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• 2022

The market for eco-friendly food materials by online distribution is rapidly growing due to major environmental pollution such as air, soil, and water quality, and radical changes in living patterns caused by COVID-19. In addition, because of the aging population and the decrease in agricultural-related population due to social structural changes, aquaponics is emerging as a system that can solve problems such as independence of old economic activities, environmental protection, and securing healthy and safe food. This paper aims to design an intelligent plant growth measurement system among intelligent aquaponics production management modules for optimal growth environment derivation and quantitative production prediction by converging various ICT technologies into existing aquaponics systems. In particular, the focus is on designing systems suitable for production sites that do not have high-performance processing resources, and we propose a module configuration plan for production environments and training data and prediction systems.