• Nuclear Engineering and Technology
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• 제30권4호
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• pp.342-352
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• 1998

A nuclear design feasibility of soluble boron free(SBF core for the medium-sized(600MWe) PWR was investigated. The result conformed that soluble boron free operation could be performed by using current PWR proven technologies. Westinghouse advanced reactor, AP-600 was chosen as a design prototype. Design modification was applied for the assembly design with burnable poison and control rod absorber material. In order to control excess reactivity, large amount of gadolinia integral burnable poison rods were used and B4C was used as a control rod absorber material. For control of bottom shift axial power shape due to high temperature feedback in SBF core, axial zoning of burnable poison was applied to the fuel assemblies design. The combination of enrichment and rod number zoning for burnable poison could make an excess reactivity swing flat within around 1% and these also led effective control on axial power offset and peak pin power, The safety assessment of the designed core was peformed by the calculation of MTC, FTC and shutdown margin. MTC in designed SBF core was greater around 6 times than one of Ulchin unit 3&4. Utilization of enriched BIO(up to 50w1o) in B4C shutdown control rods provided enough shutdown margin as well as subcriticality at cold refueling condition.

• 중환자간호학회지
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• 제11권3호
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• pp.71-84
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• 2018

Purpose : This study develop a Video Recording-Based Standardized Handoff (VRSH) program at shift change for ward nurses. Methods : The study was conducted in five medical, three surgical, and one comprehensive nursing care service wards affiliated with a secondary general hospital. In this methodological study, the VRSH program was developed between April and December, 2017. It is noted that 65 nurses who were involved in the VRSH program participated in this study. Results : In line with the modified Situation, Background, Assessment, Recommendation tool, the VRSH program consisted of three phases. In the VRSH program, the average time for handoff duration was 3-5 minutes per patient. More than 90% of the ward nurses were satisfied with the VRSH program since it benefited them by reducing overtime work and improving the performance, as well as effective communication, of nurses. The content analysis of nurses' VRSH program experience, revealed three categories and eight sub-categories. Conclusions : This study provides evidence that the VRSH program improves effective nursing performance and, the handoff communication and relationships between nurses. Future studies on large sample sizes and multiple settings are required to substantially evaluate the impact of the VRSH program on clinical outcomes.

• 대한간호학회지
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• 제35권7호
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• pp.1401-1409
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• 2005

Purpose: Infants at neonatal intensive care units (NICU) are invariably exposed to various procedural and environmental stimuli. The study was performed to compare the pain responses in three NICU stimulants and to examine the clinical feasibility for NICU infants using CRIES, FLACC and PIPP. Method: In a correlational study, a total of 94 NICU stimulants including angio-catheter insertions, trunk-rubbings and loud noises, was observed for pain responses among 64 infants using CRIES, FLACC and PIPP. Results: A significant difference was identified among the mean scores in CRIES($F_{(2, 91)}$=47.847, p=.000), FLACC($F_{(2, 91)}$=41.249, p=.000) and PIPP($F_{(2. 91)}$=16.272, p=.000) to three stimulants. In a Post-hoc Scheff test, an angio-catheter insertion showed the highest scores in CRIES, FLACC and PIPP compared to the other two stimulations. A strong correlation was identified between CRIES and FLACC in all three stimulations(.817 < r < .945) while inconsistent findings were identified between PIPP and CRIES or FLACC. Conclusions: The results of the study support that CRIES and FLACC are reliable and clinically suitable pain measurements for NICU infants. Further studies are needed in data collection time-point as well as clinical feasibility on PIPP administration to assess pain response in infants, including premature infants.

• 대한원격탐사학회지
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• 제35권1호
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• pp.83-92
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• 2019

Land cover (LC) is an important factor in socioeconomic and environmental studies. According to various studies, a number of LC maps, including global land cover (GLC) datasets, are made using polar orbit satellite data. Due to the insufficiencies of reference datasets in Northeast Asia, several LC maps display discrepancies in that region. In this paper, we performed a feasibility assessment of LC mapping using Geostationary Ocean Color Imager (GOCI) data over Northeast Asia. To produce the LC map, the GOCI normalized difference vegetation index (NDVI) was used as an input dataset and a level-2 LC map of South Korea was used as a reference dataset to evaluate the LC map. In this paper, 7 LC types(urban, croplands, forest, grasslands, wetlands, barren, and water) were defined to reflect Northeast Asian LC. The LC map was produced via principal component analysis (PCA) with K-means clustering, and a sensitivity analysis was performed. The overall accuracy was calculated to be 77.94%. Furthermore, to assess the accuracy of the LC map not only in South Korea but also in Northeast Asia, 6 GLC datasets (IGBP, UMD, GLC2000, GlobCover2009, MCD12Q1, GlobeLand30) were used as comparison datasets. The accuracy scores for the 6 GLC datasets were calculated to be 59.41%, 56.82%, 60.97%, 51.71%, 70.24%, and 72.80%, respectively. Therefore, the first attempt to produce the LC map using geostationary satellite data is considered to be acceptable.

• 통합자연과학논문집
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• 제15권2호
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• pp.89-97
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• 2022

This paper presents the comprehensive feasibility study of solar mini-grid project located in Bajhang District, Sudur Paschim Province, Nepal. The study has been conducted with the aim of developing a suitable size solar mini-grid system to meet electricity demand of proposed settlements of the village people. The study forecasts that the estimated average daily peak power consumption of load is about 20kW and average daily energy demand of load is about 100-150kWh/day in the base year 2022. The shared ratio of productive end uses is about 25% of the total power consumption and about 27% of the total energy demand, which will be used for small business/income generation activities and required 45kWp size solar power generation mini-grid system. The estimated project cost for the proposed 45kW solar mini-grid system technology, including 3 years of operation & maintenance, as well as power distribution network up to end user's premises is about 0.24 million USD. It is concluded that 45kWp photovoltaic mini-grid is feasible for the location.

• 한국해양공학회지
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• 제37권6호
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• pp.238-246
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• 2023

This paper proposes an effective inertia coefficient (EIC) in the Morison equation for better wave-force calculations. The OC4 semi-submersible floating offshore wind turbine (FOWT) platform was considered to test the feasibility. Large diffraction at large Keulegan-Carpenter (KC) numbers and the interaction between columns can result in errors in estimating the wave force using the Morison equation with a theoretical inertia coefficient, which can be corrected by the EIC as a function of the wave period and direction. The horizontal and vertical wave forces were calculated using the Morison equation and potential theory at each column, wave period, and wave direction. The EICs of each column were then obtained, resulting in a minimal difference between the Morison inertia force and the wave excitation force by the potential theory. The EICs, wave forces, phase angles, and dynamic motions were compared to confirm the feasibility of an EIC concept under regular and random waves.

• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1654-1666
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• 2024

The goal of this research is to propose a way to maximize small modular reactor (SMR) utilization to gain better market feasibility in support of carbon neutrality. For that purpose, a comprehensive tool was developed, combining off-design thermohydraulic models, economic objective models (levelized cost of electricity, annual profit), non-economic models (saved CO2), a parameter input sampling method (Latin hypercube sampling, LHS), and a multi-objective evolutionary algorithm (Non-dominated Sorting Algorithm-2, NSGA2 method) for optimizing a SMR-combined heat and power cycle (CHP) system design. Considering multiple objectives, it was shown that NSGA2+LHS method can find better optimal solution sets with similar computational costs compared to a conventional weighted sum (WS) method. Out of multiple multi-objective optimal design configurations for a 105 MWe design generation rating, a chosen reference SMR-CHP system resulted in its levelized cost of electricity (LCOE) below $60/MWh for various heat prices, showing economic competitiveness for energy market conditions similar to South Korea. Examined economic feasibility may vary significantly based on CHP heat prices, and extensive consideration of the regional heat market may be required for SMR-CHP regional optimization. Nonetheless, with reasonable heat market prices (e.g. district heating prices comparable to those in Europe and Korea), SMR can still become highly competitive in the energy market if coupled with a CHP system.

• Journal of Preventive Medicine and Public Health
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• 제41권1호
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• pp.10-16
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• 2008

Objectives : Korea faces a number of challenges to meet demands in the area of geriatric professional medicine in a country with a rapidly ageing population. We evaluated the satisfaction and feasibility of the current education certification for geriatric physicians. Methods : Geriatric physicians who were deemed qualified by the Korean Geriatrics Society during the period of 2001 to 2005 (n=2,200) were asked to complete structured questionnaires sent to them by mail about their satisfaction of and need for certificates of education, as well as their opinions on their geriatric specialty training. A total of 419 physicians responded. Descriptive analysis and hierarchical regression were performed to rate the respondents' satisfaction, the characteristics of the need for clarity and utility in education certification, and the characteristics of their patients. Results : Although most respondents were satisfied with their education certification, those who had more elderly patients, aged 65 or older, and those who had more cognitively impaired patients, rated their education as significantly lower than did other physicians. Both groups expressed the need for more the comprehensive care and assessment concerning of their education. Multiple regression analysis indicated that satisfaction with geriatric physician qualification was associated with a physician's age, specialty, and percentage of elderly patients. Conclusions : This study suggests that the current system of education certification is limited in terms of feasibility and physician satisfaction.

• 상하수도학회지
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• 제35권2호
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• pp.163-174
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• 2021

Heatwaves are one of the most common phenomena originating from changes in the urban thermal environment. They are caused mainly by the evapotranspiration decrease of surface impermeable areas from increases in temperature and reflected heat, leading to a dry urban environment that can deteriorate aspects of everyday life. This study aimed to calculate daily maximum ground surface temperature affecting heatwaves, to quantify the effects of urban thermal environment control through water cycle restoration while validating its feasibility. The maximum surface temperature regression equation according to the impermeable area ratios of urban land cover types was derived. The estimated values from daily maximum ground surface temperature regression equation were compared with actual measured values to validate the calculation method's feasibility. The land cover classification and derivation of specific parameters were conducted by classifying land cover into buildings, roads, rivers, and lands. Detailed parameters were classified by the river area ratio, land impermeable area ratio, and green area ratio of each land-cover type, with the exception of the rivers, to derive the maximum surface temperature regression equation of each land cover type. The regression equation feasibility assessment showed that the estimated maximum surface temperature values were within the level of significance. The maximum surface temperature decreased by 0.0450℃ when the green area ratio increased by 1% and increased by 0.0321℃ when the impermeable area ratio increased by 1%. It was determined that the surface reduction effect through increases in the green area ratio was 29% higher than the increasing effect of surface temperature due to the impermeable land ratio.

• Smart Structures and Systems
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• 제32권1호
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• pp.1-7
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• 2023

In modal analysis, the mode shape reflects the vibration characteristics of the structure, and thus it is widely performed for finite element model updating and structural health monitoring. Generally, the acceleration-based mode shape is suitable to express the characteristics of structures for the translational vibration; however, it is difficult to represent the rotational mode at boundary conditions. A tilt sensor and gyroscope capable of measuring rotational mode are used to analyze the overall behavior of the structure, but extracting its mode shape is the major challenge under the small vibration always. Herein, we conducted a feasibility study on a multi-mode shape estimating approach utilizing a single physical quantity signal. The basic concept of the proposed method is to receive multi-metric dynamic responses from two sensors and obtain mode shapes through bridge loading test with relatively large deformation. In addition, the linear transformation matrix for estimating two mode shapes is derived, and the mode shape based on the gyro sensor data is obtained by acceleration response using ambient vibration. Because the structure's behavior with respect to translational and rotational mode can be confirmed, the proposed method can obtain the total response of the structure considering boundary conditions. To verify the feasibility of the proposed method, we pre-measured dynamic data acquired from five accelerometers and five gyro sensors in a lab-scale test considering bridge structures, and obtained a linear transformation matrix for estimating the multi-mode shapes. In addition, the mode shapes for two physical quantities could be extracted by using only the acceleration data. Finally, the mode shapes estimated by the proposed method were compared with the mode shapes obtained from the two sensors. This study confirmed the applicability of the multi-mode shape estimation approach for accurate damage assessment using multi-dimensional mode shapes of bridge structures, and can be used to evaluate the behavior of structures under ambient vibration.