• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.214-220
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• 2011

This paper studies about the assessment of thermal performance between wet ondol system and electric ondol system. Electrical ondol systems shows faster warm-up time, higher floor surface temperature distribution and lower power consumption than wet ondol system. However, if we provide heat regularly wet ondol system which has more heat capacity shows greater thermal storage than electric ondol system. Therefore, we could conclude that wet ondol system which keeps temperature regularly by the thermal storage show better energy-efficiency in case of using the central heating and district heating system. However, Electrical ondol system shows better efficiency in case of using the space during short time or individual heating systems which needs to heat quickly. The Experiment says that electric ondol system has more benefits on timing to reach the set temperature and energy-efficiency than wet ondol system.

• Journal of Korean Academy of Nursing
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• v.44 no.4
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• pp.418-427
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• 2014

Purpose: Objectives of this study were to investigate the association between efficiency and quality of health care in Long-term Care Hospitals (LTCH) and determine related factors that would enable achievement of both high efficiency and high quality at the same time. Methods: Major data sources were the "2012 Korean Assessment of Propriety by Long-term Care Hospitals" obtained from the Health Insurance Review & Assessment Service. Cost variables were supplemented by a National Tax Service accounting document. First, data envelopment analysis was performed by generating efficiency scores for each LTCH. Second, matrix analysis was conducted to ascertain association between efficiency and quality. Lastly, kruskal-wallis and mann-whitney tests were conducted to identify related factors. Results: First, efficiency and quality of care are not in a relationship of trade-offs; thus, LTCH can be confident that high efficiency-high quality can be achieved. Second, LTCH with a large number of beds, longer tenure of medical personnel, and adequate levels of investment were more likely to have improved quality as well as efficiency. Conclusion: It is essential to enforce legal standards appropriate to the facilities, reduce turnover of nursing staff, and invest properly in human resources. These consequences will help LTCH to maintain the balance of high efficiency-high quality in the long-run.

• Geomechanics and Engineering
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• v.22 no.3
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• pp.207-217
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• 2020

Slope reliability analysis and risk assessment for spatially variable soils under rainfall infiltration are important subjects but they have not been well addressed. This lack of study may in part be due to the multiple and diverse evaluation indexes and the low computational efficiency of Monte-Carlo simulations. To remedy this, this paper proposes a highly efficient computational method for investigating random field problems for slopes. First, the probability density evolution method (PDEM) is introduced. This method has high computational efficiency and does not need the tens of thousands of numerical simulation samples required by other methods. Second, the influence of rainfall on slope reliability is investigated, where the reliability is calculated from based on the safety factor curves during the rainfall. Finally, the uncertainty of the sliding mass for the slope random field problem is analyzed. Slope failure consequences are considered to be directly correlated with the sliding mass. Calculations showed that the mass that slides is smaller than the potential sliding mass (shallow surface sliding in rainfall). Sliding mass-based risk assessment is both needed and feasible for engineered slope design. The efficient PDEM is recommended for problems requiring lengthy calculations such as random field problems coupled with rainfall infiltration.

• Journal of Environmental Science International
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• v.22 no.3
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• pp.269-279
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• 2013

In this paper, an environmental assessment was carried out on the whole process of industrial business activities to establish a basic plan for climate change mitigation and energy independency. The whole process was divided into each discharge process in terms of water, air, solid waste, green house gases and refractory organic compounds. The flowcharts and basic unit of process were analysed for three years (2008-2010), being utilized as basic information for the life cycle assessment. It was found that the unit loading for the whole process significantly depends on changes in the operation rate change and highly concentrated wastewater inflow. About 35% of solid waste production was reduced by improving the incineration method with co-combustion in coal boiler, generating about 57% of electricity used for the whole process, and consequently reducing the energy costs. As the eco-efficiency index was found to be more than 1, compared to the previous years, it can be said that improvement in general has taken place.

• Structural Engineering and Mechanics
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• v.69 no.3
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• pp.317-326
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• 2019

This research aims to assess the tight seismic risk curve of the intake tower at Geumgwang reservoir by considering the recorded historical earthquake data in the Korean Peninsula. The seismic fragility, a significant part of risk assessment, is updated by using Bayesian inference to consider the uncertainties and computational efficiency. The reservoir is one of the largest reservoirs in Korea for the supply of agricultural water. The intake tower controls the release of water from the reservoir. The seismic risk assessment of the intake tower plays an important role in the risk management of the reservoir. Site-specific seismic hazard is computed based on the four different seismic source maps of Korea. Probabilistic Seismic Hazard Analysis (PSHA) method is used to estimate the annual exceedance rate of hazard for corresponding Peak Ground Acceleration (PGA). Hazard deaggregation is shown at two customary hazard levels. Multiple dynamic analyses and a nonlinear static pushover analysis are performed for deriving fragility parameters. Thereafter, Bayesian inference with Markov Chain Monte Carlo (MCMC) is used to update the fragility parameters by integrating the results of the analyses. This study proves to reduce the uncertainties associated with fragility and risk curve, and to increase significant statistical and computational efficiency. The range of seismic risk curve of the intake tower is extracted for the reservoir site by considering four different source models and updated fragility function, which can be effectively used for the risk management and mitigation of reservoir.

• Resources Recycling
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• v.22 no.4
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• pp.55-61
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• 2013

In this study, eco efficiency analysis is performed to analyze Neodymium (Nd) containing permanent magnet recycling process. Life cycle assessment (LCA) and life cycle costing (LCC) are used to apply eco efficiency analysis. In the environmental aspects, global warming potential (GWP) of 1kg permanent magnet is 1.25E + 00 kg $CO_2$ eq. and abiotic resource depletion potential (ADP) is 1.10E - 02 Sb eq. This recycling process costs about 2130 KWR. Environmental efficiency of GWP is at 6.43 and ADP is at 5.32 when compared with vigin metal. Economic efficiency is at 6.74. This study confirms that Nd containing permanent magnet recycling process is sustainable system because of environmental and economical improvement.

• Korean Journal of Organic Agriculture
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• v.30 no.3
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• pp.351-374
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• 2022

In recent years, the development of rice industry has been highly valued by the state. In hubei area, due to the development of the modernization and the shortage of labor, traditional way of rice cultivation methods is facing serious challenges, and economic benefits have become the decisive factor for the effective promotion and application of rice cultivation methods. According to the research results, first, in the input-side analysis, in the CCR model, D5, D12, D26, D28, D32, D36 farmers with high efficiency appear. The analysis result shows that among the 60 farmers, the average efficiency is 89%, and there is an inefficiency of 11%. In the BCC model, 14 farmers were identified as high-efficiency farmers, with an average efficiency of 0.9453. Second, in direct seeding cultivation of rice, the average scale efficiency is 0.9227, while the average pure technical efficiency is 0.9644. This shows that the effect of scale efficiency is greater than that of purely technical factors, ignoring the reasons for the low operational efficiency of direct seeding cultivation farmers. It can be predicted that with the further deepening of farmers' understanding of this planting mode, the proportion of rice direct seeding may be further expanded in the future. Relevant agricultural departments should further promote this technology to farmers, study the direct seeding technology using scientific methods, and evaluate the changes of this cultivation mode. The agricultural departments of government should concern about the climate risk assessment of direct seeding rice, the environmental impact assessment caused by the extensive use of herbicides, the application of mechanical technology in the process of direct seeding, the lodging of direct seeding rice, and other related issues.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.382-385
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• 2006

After incoming the notion of eco-friendly building, many organizations developed green building assessment programs and in the late of 2001, those programs were unified to one program, 'Green Building Certification(GBC)'. Many problems, however, arose after unification of programs and now the study to solve those problems is impending. The purpose of this study is to make suggestions to solve problems of GBC through analyzing characteristics of several abroad and well developed programs. The key points of the analysis were 1) characteristics of assessment organizations, 2) structures of programs, and 3) characteristics of assessment methods and systems. The results of the study showed that GBC didn't have any positive connections with the academia, the developer and the consumer, and did have lack of assessment efficiency and accuracy.

• Proceedings of the KSR Conference
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• 2006.05b
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• pp.121-128
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• 2006

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7438-7442
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• 2014

An assessment of flocculation was performed by measuring the distribution of the floc size during sedimentation in water works. The size and number of flocs have a greater effect on an evaluation of the efficiency of flocculation rather than the turbidity. The data was collected in situ using particle image velocimetry and image analysis. The measurements were carried out at a water depth of 1m. The removal efficiency of the total organic compounds, UV absorbance and turbidity depended on the size and floc size distribution in flocculation as the G value. The G value of 50 sec-1, 30 sec-1 and 10 sec-1 showed the highest degree of efficiency in the case of an inlet water turbidity of 5 NTU, and the highest degree of efficiency was observed at a G value of 65 sec-1, 40 sec-1 and 10 sec-1 when the inlet water turbidity was 263 NTU. The number of flocs with a distribution of above $1,200{\mu}m$ was 14. The dynamics between two important growth mechanisms were investigated as the energy input changed. This is a certain method that makes use of the size and number of flocs as an efficiency assessment.