• Radiation Oncology Journal
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• v.33 no.2
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• pp.66-74
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• 2015

Trace elements play crucial role in the maintenance of genome stability in the cells. Many endogenous defense enzymes are containing trace elements such as superoxide dismutase and metalloproteins. These enzymes are contributing in the detoxification of reactive oxidative species (ROS) induced by ionizing radiation in the cells. Zinc, copper, manganese, and selenium are main trace elements that have protective roles against radiation-induced DNA damages. Trace elements in the free salt forms have protective effect against cell toxicity induced by oxidative stress, metal-complex are more active in the attenuation of ROS particularly through superoxide dismutase mimetic activity. Manganese-complexes in protection of normal cell against radiation without any protective effect on cancer cells are more interesting compounds in this topic. The aim of this paper to review the role of trace elements in protection cells against genotoxicity and side effects induced by ionizing radiation.

• The Journal of Fisheries Business Administration
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• v.39 no.1
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• pp.63-85
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• 2008

The objective of this study is to review the methodology of economic analysis of fishing ports by examining the economical feasibilities of a national fishing port (Jeongja Port) in Ulsan. This study utilized market value evaluation method to measure the benefits and costs related to the development of ports. The benefit variables are income effects resulting from the developments while the cost variables are sum of construction costs and maintenance costs. The income effects are measured in two ways: (1) income from individual project resulting from the developments, (2) the income effects by utilizing investment multipliers. The results shows that the BC ratio (Benefits/Costs) of Jeongja port by using (1) income from individual project resulting from the developments was 1.07 while the BC ratio by using (2) the income effects by utilizing investment multipliers was 1.10 due to a relative short period of useful life for investment multipliers. However, the income variable utilizing investment multipliers is more sensitive to the period of duration than the income variable from individual project.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.56 no.3
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• pp.142-147
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• 2007

Infrared thermography is one of the most valuable and cost-effective diagnostic techniques for predictive maintenance on electrical systems. For the electric installations, the thermographies can identify major problems, which if left unattended could lead to breakdowns. The result thermal images depend upon operator skills, inspection technique, and load and weather conditions. When the thermographer is applied to remote monitoring, the conditions of the systems are not perfectly analyzed because operators are hard to know the weather's effects of the installed place. Therefore, this paper defines the effects by weather conditions which will influence the final results. The purpose of this paper is to define the weather effects that a thermographer needs to consider for successful condition analysis.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.125-131
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• 2008

This research tries to analyze and investigate the effects of the noise reduction test for the sound-absorbing materials installed tentatively on Metro Line 5. Though the noise reduction effects of each sound-absorbing material showed that there was about $2{\sim}5\;dB$ compared with before and after of the tentative installation, it shows that the noise reduction effects are reducing because of the section change condition such as dust absorption and the rail abrasion as time passes after the tentative installation. Also, many difficulties are occurring in the maintenance of the orbit facilities because of the installation of sound-absorbing materials. Though various abroad products for noise reduction are imported like this, the researches for the noise reduction effect increase for this and the improvement direction are being required because of the poor circumstance of the efficiency aspect compared to the economic investment effect because those are not suited to the character of domestic Metro.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.12-20
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• 2016

Along with the change of national accounting, the importance of systematic management of assets is emphasized and the awareness that the concept termed Asset Management should be introduced to the construction field too to manage facilities. The present study is a basic study for the introduction of the concept Asset Management and proposed accounting guidelines(proposal) for public building maintenance cost that can clarify maintenance cost accounting. Existing literatures and current accounting standards were examined and the actual states of maintenance cost accounting of public buildings in A metropolitan city were examined to draw problems. For the practice guidelines(proposal), the types and contents of government office building maintenance expenditures were analyzed and items that must be treated as OPEX and CAPEX were presented. Expert interviews were conducted to verify the reliability of the items presented. The practice guidelines(proposal) were applied to the public buildings in A metropolitan city to identify situations of changes in asset values and review the effects of the practice guidelines(proposal) on increases in asset values. When applied to practices, the practice guidelines(proposal) suggested in the present study are considered to increase building asset values and provide consistent financial information to help stakeholders' decision making.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6A
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• pp.965-976
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• 2006

A realistic lifetime seismic-reliability based approach is unavoidable to perform Life-Cycle Cost (LCC)-effective optimum design, maintenance, and retrofitting of structures against seismic risk. So far, though a number of researchers have proposed the LCC-based seismic design and retrofitting methodologies, most researchers have only focused on the methodological point. Accordingly, in most works, they have not been quantitatively considered critical factors such as the effects of seismic retrofit, maintenance, and environmental stressors on lifetime seismic reliability assessment of deteriorating structures. Thus, in this study, a systemic lifetime seismic reliability analysis methodology is proposed and a program HPYER-DRAIN2DX-DS is developed to perform the desired lifetime seismic reliability analysis. To demonstrate the applicability of the program, it is applied to an example bridge with or without seismic retrofit and maintenance strategies. From the numerical investigation, it may be positively stated that HYPER-DRAIN2DX-DS can be utilized as a useful numerical tool for LCC-effective optimum seismic design, maintenance, and retrofitting of bridges.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6A
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• pp.977-988
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• 2006

The goal of this study is to develop a realistic methodology for determination of the Life-Cycle Cost (LCC)-effective optimal seismic retrofit and maintenance strategy of deteriorating bridges. The proposed methodology is based on the concept of minimum LCC which is expressed as the sum of present value of seismic retrofit costs, expected maintenance costs, and expected economic losses with the constraints such as design requirements and acceptable risk of death. The proposed methodology is applied to the LCC-effective optimal seismic retrofit and maintenance strategy of a steel bridge considered as a example bridge in the accompanying study, and various conditions such as corrosion environments and Average Daily Traffic Volumes (ADTVs) are considered to investigate the effects on total expected LCC. In addition, to verify the validity of the developed methodology, the results are compared with the existing methodology. From the numerical investigation, it may be positively expected that the proposed methodology can be effectively utilized as a practical tool for the decision-making of LCC-effective optimal seismic retrofit and maintenance strategy of deteriorating bridges.

• Journal of Korea Water Resources Association
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• v.47 no.7
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• pp.657-670
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• 2014

We researched the vegetation restoration of 5 urban streams Mugeo-choen, Yaksa-choen, Yeocheon-choen, Myeongjeong-choen and Cheokgwa-choen in Ulsan established as nature-friendly streams by improving water quality and river environment. Ecological restoration effects have resulted from the establishment of streams, which involved supplying sufficient maintenance water for each streams, eliminating the covered sections, preventing the inflow of wastewater, doing vegetation composition, since 5 to 10 years ago. The vegetation inhabitations were compared according to the conditions of physical characteristics and water quality, inland and foreland. In the Cheokgwa-cheon, which is almost a natural river, the ecological integrity of the vegetation population has been maintained quite well. The Mugeo-cheon and the Meongjeong-cheon have cleanly shown the vegetation restoration effects resulting from supplying sustainable maintenance water and wastewater treatments. In the Yaksa-cheon and the Yeocheon-cheon, on the other hand, the vegetation restoration effects and inhabitations were low due to the inflow of wastewater and sledges in some part of stream though the improvement of water quality.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.127-140
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• 1991

The Primary purpose of this study is to investigate factors and variables which have significant effects on user satisfaction with recreational facilities in Taejong-Dae recreational complex, thereby establishing indices of planning and development of urban parks and open space. To test the causal models of this research, the date were gathered by self-administered questionnaires from 967 households in Pusan City which were selected by the multi-stage probability sampling methood. The analysis of the multi-stage primarily consists of two phase : The first analysis dealt exploratory factor analysis which identified major factors involved in satisfaction with recreational activities and facilities in Taejong-Dae recreational complex and the second analysis tested the fit of the causal models of this research by employing LISREL methodology. There are three advantages of using LISREL over other multivariate analysis methods : First, measurement error is allowed and calculated in LISREL, otherwise there is a risk of seriously misleading estimates of coefficients ; Second, LISREL deals with latent variables or unmeasured variables ; Third, it enables to test causal relations among variables. The factors analysis identified that five factors are involved in satisfaction with recreational facilities. The five factors of satisfaction with recreational facilities are space for repose and relaxation, active recreation facilities such as pool and zoo, physical exercise facility, convenience and maintenance facility, and linear facility, and linear facility for walking. The second phase analysis tested the fit of the causal models for satisfaction with recreational facilities to the data and identified statistically significant causal linkage among overall satisfaction with Taejong-Dae recreational complex, other endogenous factors and exogenous variables. Overall fits of both causal models were very good. Among endogenous factors, facility for repose and relaxation. linear facility for walking, active recreation facility, facility for convenience and maintenance were identified as having significant effects on overall satisfaction. Exogenous variables which have significant effects on endogenous variables wer also identified. These significant relationships indicate important factors and variables that should be considered in planning and development of the recreational complex. On the basis of these significant causal relationships, implications for planning and the delovepment of Taejong-Dae recreational complex were suggested.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.4
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• pp.385-391
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• 2020

Denture adhesive is a material used to improve the retention and stability of the denture. And denture adhesive is divided into soluble and insoluble type. It improves the retention, stability of dentures, and masticatory functions of patients. Maintenance like cleansing and periodic follow up is essential. Almost of dental clinicians are only simply aware of the effects of denture adhesives and often rely on the manufacturer's instructions on precautions and maintenance. The purpose of this study is to examine the properties, effects, and precautions of denture adhesives, and to present clinical guidelines for patients and professionals.