• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.314-319
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• 2011

Energy Cost has been rapidly increased with the internal heat gain of data center to keep the temperature condition. But the cooling units for server systems are fully operated to satisfy the indoor temperature condition, it results in the excessive energy consumption. In this study, various cooling systems were studied for data center and cold aisle containment system was proved to be the best solution for server cooling system. Because it protects the cooling zone from the hot aisle space. Effective cooling and prohibition of recirculation air from hot aisle was possible by the cold aisle containment system.

• Journal of Preventive Medicine and Public Health
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• v.19 no.1 s.19
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• pp.1-15
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• 1986

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.15 no.1
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• pp.46-52
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• 2019

This work proposes a noncontact ultrasonic transducer for detecting wall-thinning of containment liner plates of nuclear power plants by measuring their thickness without physical contact. Because the containment liner plate is designed to prevent atmospheric leakage of radioactive substances under severe nuclear accident, its wall-thinning inspection is important for safety of nuclear power plants. Wall-thinning investigation of containment liner plates have been carried out by measuring their thickness with contact-type ultrasonic thickness gauge by inspectors and needs a lot of time and cost. As an alternative, an electromagnetic acoustic transducer measuring precisely thickness of containment liner plates without any physical contact or couplant was suggested in this research. A transducer generating and measuring shear ultrasonic waves in thickness direction was designed and wave field produced by the transducer was analyzed to verify the design. The working performance of the suggested transducer was tested with carbon steel plate specimens with various thicknesses. The test result shows that the proposed transducer can measure thickness of the specimens precisely without any couplant and implies that swift scanning of wall-thinning of containment liner plates will be possible with the proposed transducer.

• Journal of the Korea Institute of Building Construction
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• v.15 no.6
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• pp.653-660
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• 2015

Technologies for reducing construction duration are key factors in nuclear power plant construction projects, as a reduction in construction duration at the construction phase leads to a reduction in construction cost and an increase in profits through the early operation of the nuclear power plant. To analyze the constructability of the height of single-layer placement of formwork for the Reactor Containment Building (RCB) exterior wall through lateral pressure according to the height of concrete placement, the deformation criteria for formwork, and a new form design, 'MIDAS GEN (hereinafter referred to as MIDAS)' is used in this study. The cost and workload of formwork are derived according to the unit of height of the RCB exterior wall. Based on the result, it was found that the higher the RCB exterior wall, the higher the material cost, and the less the construction duration and the less the total number of formwork layers. Based on this result, it is believed that the material cost and the construction duration can be appropriately determined according to the formwork height.

• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.1005-1014
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• 2009

The Dual Unit Optimizer 2000 MWe (DUO2000) is put forward as a new design concept for large power nuclear plants to cope with economic and safety challenges facing the $21^{st}$ century green and sustainable energy industry. DUO2000 is home to two nuclear steam supply systems (NSSSs) of the Optimized Power Reactor 1000 MWe (OPR1000)-like pressurized water reactor (PWR) in single containment so as to double the capacity of the plant. The idea behind DUO may as well be extended to combining any number of NSSSs of PWRs or pressurized heavy water reactors (PHWRs), or even boiling water reactors (BWRs). Once proven in water reactors, the technology may even be expanded to gas cooled, liquid metal cooled, and molten salt cooled reactors. With its in-vessel retention external reactor vessel cooling (IVR-ERVC) as severe accident management strategy, DUO can not only put the single most querulous PWR safety issue to an end, but also pave the way to very promising large power capacity while dispensing with the huge redesigning cost for Generation III+ nuclear systems. Five prototypes are presented for the DUO2000, and their respective advantages and drawbacks are considered. The strengths include, but are not necessarily limited to, reducing the cost of construction by decreasing the number of containment buildings from two to one, minimizing the cost of NSSS and control systems by sharing between the dual units, and lessening the maintenance cost by uniting the NSSS, just to name the few. The latent threats are discussed as well.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.342-347
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• 2015

Floating LNG is a new concept which is used as LNG regasification/receiving facility and for LNG production/export facility. LNG Floating Production Storage and Offloading(FPSO) concept will put vitality into marginal gas fields which were delayed because of excessive investment cost in the world. LNG Floating Storage Regasification Unit(FSRU) also provides commercially competitive and effective solutions to the areas where onshore infrastructure is not well established. LNG cargo containment system is one of the key functions for FLNG to store produced LNG on a floating structure. This paper presents a new technology related to a LNG containment system; a combined cargo containment system utilizing the advantages of iIndependent tank type and membrane system. Technical advantages have been validated through research work.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.425-431
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• 2015

Since the construction of Kori 1 was completed in 1978, the construction projects for nuclear power plant are increasingly expanded into domestic and foreign sites. However, some of construction sites of nuclear power plant have the problems of process delay and cost loss due to lack of ability of risk management. The construction of reactor containment building in nuclear power plant is especially dotted with many risk factors because it needs professional skills and large-scale resources due to long duration compared with different construction phase. Therefore, it needs the study that analyzes risk factors expected in construction of reactor containment building and suggests way of stable performance of projects. So, this study assesses risk factors of construction of reactor containment building. For the objectives, this study uses survey for group of minority specialists of 36 experts. The risks of 24 factors is classified by criterions of process, cost, safety, and quality and the results of assessment is analyzed by analytic hierarchy process. As the results, the importance and priority of risk factors classified by each criterion were calculated and the applicability of analytic hierarchy process was identified to analyze risk factors of nuclear power plant construction. These will be baseline data for risk management in construction phase of reactor containment building.

• Nuclear Engineering and Technology
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• v.16 no.4
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• pp.217-223
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• 1984

The feasibility of not employing recombiners rather using the postaccident Purge system alone to control hydrogen concentration in the containment following a LOCA, is analyzed in this paper. For this study, the hydrogen concentration in the containment, hydrogen removal through the purge system, and additional off-site dose due to hydrogen purge were calculated. The economic justification of a hydrogen recombiner system (2 recombiners) was also investigated by using the cost benefit concept. As a result, the purge system is sufficient to maintain the hydrogen concentration at a safe level without hydrogen recombiners, and it meets the dose limit requirements set forth in 10 CFR part 100. A hydrogen recombiner system would be justified based on cost-benefit concept for common use in a site with 4 units or more.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.330-335
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• 2000

Faults detection and containment requirements are typically allocated from a top-level specification as a percentage of total faults detection and containment, weighted by failure rate. This faults detection and containments are called as a fault coverage. The fault coverage requirements are typically allocated identically to all units in the system, without regard to complexity, cost of implementation or failure rate for each units. In this paper a simple methodology and mathematical model to support the allocation of system fault coverage rates to lower-level units by considering the inherent differences in reliability is presented. The models are formed as a form of constrained optimization. The objectives and constraints are modeled as a linear form and this problems are solved by linear programming. It is identified by simulation that the proposed solving methods for these problems are effective to such requirement allocating.

• Journal of Preventive Medicine and Public Health
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• v.22 no.4 s.28
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• pp.542-554
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• 1989

The skyrocketing inflation of medical costs has become a major health problem among most developed countries. Korea, which recently covered the entire population with National Health Insurance, is facing the same problem. The proportion of health expenditure to GNP has increased from 3% to 4.8% during the last decade. This was remarkable, if we consider the rapid economic growth during that time. A few policy analysts began to raise cost containment as an agenda, after recognizing the importance of medical cost inflation. In order to Prepare an appropriate alternative for the agenda, it is necessary to find out reasons for the cost inflation. Then, we should focus on the reasons which are controllable, and those whose control are socially desirable. This study is designed to articulate the theory of medical cost inflation through literature reviews, to find out reasons for cost inflation, by analyzing aggregated data with a deterministic model. Finally to identify determinants of changes in both medical demand and service intensity which are major reasons for cost inflation. The reasons for cost inflation are classified into cost push inflation and demand pull inflation, The former consists of increases in price and intensity of services, while the latter is made of consumer derived demand and supplier induced demand. We used a time series (1983-1987), and cross sectional (over regions) data of health insurance. The deterministic model reveals, that an increase in service intensity is a major cause of inflation in the case of inpatient care, while, more utilization, is a primary attribute in the case of physician visits. Multiple regression analysis shows that an increase in hospital beds is a leading explanatory variable for the increase in hospital care. It also reveals, that an introduction of a deductible clause, an increase in hospital beds and degree of urbanization, are statistically significant variables explaining physician visits. The results are consistent with the existing theory, The magnitude of service intensity is influenced by the level of co-payment, the proportion of old age and an increase in co-payment. In short, an increase in co-payment reduced the utilization, but it induced more intensities or services. We can conclude that the strict fee regulation or increase in the level of co-payment can not be an effective measure for cost containment under the fee for service system. Because the provider can react against the regulation by inducing more services.