• 한국태양에너지학회 논문집
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• 제31권5호
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• pp.126-133
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• 2011

The current world wide interest in environmental issues has moved from energy conservation to $CO_2$emission reduction. Recently, according to the increase in demand for water resources, insufficient potable water circumstance is supposed, unless there are corresponding in crease in water conservation and water recycling. This study has attempted to analyze $CO_2$emission reduction by water saving strategies like installation water saving devices, rain water harvesting and grey water system. To do this, this research investigates applicable water conservative strategies by literature review and calculated total water saving. The results show that (1) firstly, the water usage and $CO_2$ emission could be reduced up to 44%, (2) $CO_2$ emission reduction by water saving devices and rainwater harvesting system is about 47.7%, and (3) water usage and $CO_2$ emission reduction by grey water system is about 66%. In the future, this paper will be utilized for water management from the early design stage to maintenance stage of water glutton building.

• 한국의료질향상학회지
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• 제29권2호
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• pp.2-14
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• 2023

Purpose: This study aimed to identify strategies to enhance the competencies of patient safety coordinators in Korea. Methods: Fourteen participants from nine hospitals were interviewed between May and November 2022. Qualitative content analysis was used to analyze the data. Results: As for the strategies to enhance patient safety management competency, 3 themes and 11 sub-themes were derived. The first theme was 'Having individual competence as a patient safety coordinator', and the sub-themes were 'Communication skills with members', 'Flexible thinking from multiple perspectives', and 'Preparing for administrative work competencies that they had not experienced as a nurse.' The second theme was 'Responding strategically to promote improvement activities', and the sub-themes for it were 'Multi-angle approach to the problem', 'A careful approach so as not to be taken as criticism in the field', 'Increasing the possibility of improvement activities through awareness', 'Activating the network between patient safety coordinators', and 'Expanding learning opportunities through patient safety case analysis.' The third theme was 'Obtaining support to facilitate patient safety activities', and the sub-themes for this were 'Improving staff awareness of patient safety', 'Providing a training course for nurse professional of patient safety', and 'Expanding the manpower allocation standard of patient safety coordinators.' Conclusion: This study explored personal competencies such as document writing and computer utilization capabilities, focused on ways to improve the field of patient safety management, and emphasized the need for organizational and political support.

• The Korean Journal of Physiology and Pharmacology
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• 제28권2호
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• pp.129-143
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• 2024

Sulfur dioxide (SO₂), a novel endogenous gas signaling molecule, is involved in the regulation of cardiac function. Exerting a key role in progression of hyperthyroidism-induced cardiomyopathy (HTC), myocardial fibrosis is mainly caused by myocardial apoptosis, leading to poor treatment outcomes and prognoses. This study aimed to investigate the effect of SO₂ on the hyperthyroidism-induced myocardial fibrosis and the underlying regulatory mechanisms. Elisa, Masson staining, Western-Blot, transmission electron microscope, and immunofluorescence were employed to evaluate the myocardial interstitial collagen deposition, endoplasmic reticulum stress (ERS), apoptosis, changes in endogenous SO₂, and Hippo pathways from in vitro and in vivo experiments. The study results indicated that the hyperthyroidism-induced myocardial fibrosis was accompanied by decreased cardiac function, and down-regulated ERS, apoptosis, and endogenous SO₂-producing enzyme aspartate aminotransferase (AAT)1/2 in cardiac myocytes. In contrast, exogenous SO₂ donors improved cardiac function, reduced myocardial interstitial collagen deposition, up-regulated AAT1/2, antagonized ERS and apoptosis, and inhibited excessive activation of Hippo pathway in hyperthyroid rats. In conclusion, the results herein suggested that SO₂ inhibited the overactivation of the Hippo pathway, antagonized ERS and apoptosis, and alleviated myocardial fibrosis in hyperthyroid rats. Therefore, this study was expected to identify intervention targets and new strategies for prevention and treatment of HTC.

• 공학교육연구
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• 제18권3호
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• pp.13-23
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• 2015

This paper attempts to take an in-depth study of the importance of teams and their creativity according to changes of recent design paradigm in engineering and to draw conclusions of the sub-domains and their element extraction. For this purpose, theoretical consideration was reviewed to present the definition of creativity and its sub-domains and elements. Besides, the two steps of expert validation test were conducted to extract the definition of creativity and its sub-domains and elements. The team creativity is defined as a team ability to come up with fresh and useful ideas and to lead them to get meaningful results through cooperative interactions among team members to solve problems given to them based on each member's creativity. Totally, 4 subs -domains and 16 sub-elements were extracted to get to know their influence on the team creativity. This includes a team size, characteristics of team members, and a team structure in team organization domain. To evaluate team atmosphere, elements such as sensibility, fellowship, teamwork, reliability, autonomy and open minded feature are included. In the team activity domain, strategies for solving problems, activities for divergent thinking, activities for convergence thinking and team interaction are included. Also, the sub-domain for team management includes a task, process and conflict management.

• Applied Science and Convergence Technology
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• 제23권2호
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• pp.72-82
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• 2014

Lithium-ion batteries (LIBs) have become popular electrochemical devices. Due to the unique advantages of LIBs in terms of high operating voltage, high energy density, low self-discharge, and absence of memory effects, their application range, which was primarily restricted to portable electronic devices, is now being extended to high-power applications, such as electric vehicles (EVs) and hybrid electrical vehicles (HEVs). Among various anode materials, $Li_4Ti_5O_{12}$ (LTO) is believed to be a promising anode material for high-power LIBs due to its advantages of high working potential and outstanding cyclic stability. However, the rate performance of LTO is limited by its intrinsically low electronic conductivity and poor $Li^+$ ion diffusion coefficient. This review highlights the recent progress in improving the rate performance of LTO through doping, compositing, and nanostructuring strategies.

• Computers and Concrete
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• 제30권1호
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• pp.43-74
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• 2022

Machine learning technique is recently opening new opportunities to identify the complex shear transfer mechanisms of reinforced concrete (RC) beam members. This study employed 1224 shear test specimens to train decision tree-based machine learning (ML) programs, by which strong correlations between shear capacity of RC beams and key input parameters were affirmed. In addition, shear contributions of concrete and shear reinforcement (the so-called V_c and V_s) were identified by establishing three independent ML models trained under different strategies with various combinations of datasets. Detailed parametric studies were then conducted by utilizing the well-trained ML models. It appeared that the presence of shear reinforcement can make the predicted shear contribution from concrete in RC beams larger than the pure shear contribution of concrete due to the intervention effect between shear reinforcement and concrete. On the other hand, the size effect also brought a significant impact on the shear contribution of concrete (V_c), whereas, the addition of shear reinforcements can effectively mitigate the size effect. It was also found that concrete tends to be the primary source of shear resistance when shear span-depth ratio a/d<1.0 while shear reinforcements become the primary source of shear resistance when a/d>2.0.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2084-2094
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• 2021

Delta-form-based methods for solving high order spatial discretization schemes are introduced into the reactor S_N transport equation. Due to the nature of the delta-form, the final numerical accuracy only depends on the residuals on the right side of the discrete equations and have nothing to do with the parts on the left side. Therefore, various high order spatial discretization methods can be easily adopted for only the transport term on the right side of the discrete equations. Then the simplest step or other robust schemes can be adopted to discretize the increment on the left hand side to ensure the good iterative convergence. The delta-form framework makes the sweeping and iterative strategies of various high order spatial discretization methods be completely the same with those of the traditional S_N codes, only by adding the residuals into the source terms. In this paper, the flux limiter method and weighted essentially non-oscillatory scheme are used for the verification purpose to only show the advantages of the introduction of delta-form-based solving methods and other high order spatial discretization methods can be also easily extended to solve the S_N transport equations. Numerical solutions indicate the correctness and effectiveness of delta-form-based solving method.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1254-1266
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• 2024

This study investigates the application of supercritical carbon dioxide (S-CO₂) direct-cycle micro modular reactors (MMRs) in primary frequency control (PFC), which is a scenario characterized by significant load fluctuations that has received less attention compared to secondary load-following. Using a modified GAMMA + code and a deep neural network-based turbomachinery off-design model, the authors conducted an analysis to assess the behavior of the reactor core and fluid system under different PFC scenarios. The results indicate that the acceptable range for sudden relative electricity output (REO) fluctuations is approximately 20%p which aligns with the performance of combined-cycle gas turbines (CCGTs) and open-cycle gas turbines (OCGTs). In S-CO₂ direct-cycle MMRs, the control of the core operates passively within the operational range by managing coolant density through inventory control. However, when PFC exceeds 35%p, system control failure is observed, suggesting the need for improved control strategies. These findings affirm the potential of S-CO₂ direct-cycle MMRs in PFC operations, representing an advancement in the management of grid fluctuations while ensuring reliable and carbon-free power generation.

• 한국통신학회:학술대회논문집
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• 한국통신학회 2006년도 하계종합학술발표회 논문 초록집
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• pp.653-653
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• 2006

• 한국초등수학교육학회지
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• 제20권4호
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• pp.717-735
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• 2016

본 연구의 목적은 나머지가 있는 나눗셈 문장제에 대한 초등학교 6학년 학생들의 해결 전략 및 오류를 조사함으로써 나머지가 있는 나눗셈 문장제 지도에 대한 교수학적 시사점을 얻는 것이다. 초등학교에서 나눗셈에 대한 학습이 완료되는 시기인 초등학교 6학년 학생 177명을 대상으로 40분간 총 15문항의 검사 문항으로 구성된 검사지를 적용하고, 학생들이 작성한 문항의 답안을 분석함으로써 연구 대상이 문제해결 과정에서 사용한 해결 전략 및 오류를 파악하였다. 검사 결과와 관련하여 주목할 것은 학생들이 나머지가 있는 나눗셈 문장제를 해결하기 위해 주로 사용한 전략과 높은 성공률을 보인 전략이 일치하지 않았으며, 중 집단의 학생들이 다른 집단의 학생들에 비해 보조 전략을 빈번하게 사용했다는 점이다. 또한 학생들의 오류가 빈번하게 나타난 것은 해석과 식 세우기 단계였다. 특히 하 집단의 학생들에게서 식 세우기 오류가 주로 발견된 것에 비해, 상 집단의 학생들은 주로 해석 단계에서 오류를 보였다. 이와 같은 분석 결과에 기초한 논의로부터 나머지가 있는 나눗셈 문장제 지도에 대한 교수학적 시사점을 제안하였다.