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        검색결과 174

        9.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 방사형 K-공간 획득 기법 중 하나인 JET 기법을 적용하여 어깨관절 자기공명영상 검사에서의 움직임 인공물과 노이즈를 감소 효과를 평가하였다. 2023년 2월 1일부터 3월 31일까지 어깨관절 자기공명영상 검사를 받 은 35명을 대상으로 선정하여 후향적으로 분석하였다. 평가는 JET 기법 적용 여부에 따라 신호 대 노이즈 비, 평균 대 표준편차 비, 움직임 인공물 발생 여부에 대한 영상 평가를 수행하였다. JET 기법을 적용한 그룹에서는 신호 대 노이즈 비, 평균 대 표준편차 비, 움직임 인공물 발생 여부에 대한 영상 평가 값이 통계적으로 유의하게 높게 나타났다(p<0.05). 본 연구를 통해 어깨관절 자기공명영상 검사 시 JET 기법의 도입은 움직임 인공물의 감소뿐만 아니라 신호 대 노이즈 비와 평균 대 표준편차 비가 향상된 영상을 얻을 수 있음을 확인하였다. 이러한 결과는 JET 기법이 어깨관절 영상 취득에 유용하게 활용될 수 있을 것으로 판단되며, 더 나아가 다양한 부위에 적용되는데 있어 서도 기여할 수 있을것으로 예상된다.
        4,000원
        10.
        2023.11 구독 인증기관·개인회원 무료
        The primary objective of this study is to evaluate a systematic design’s effectivity in remediating actual uranium-contaminated soil. The emphasis was placed on practical and engineering aspects, particularly in assessing the capabilities of a zero liquid discharge system in treating wastewater derived from soil washing. The research method involved a purification procedure for both the uranium-contaminated soil and its accompanying wastewater. Notably, the experimental outcomes demonstrated successful uranium separation from the contaminated soil. The treated soil could be self-disposed of, as its uranium concentration fell below 1.0 Bq·g−1, a level endorsed by the International Atomic Energy Agency for radionuclide clearance. The zero liquid discharge system’s significance lay in its distillation process, which not only facilitated the reuse of water from the separated filtrate but also allowed for the self-disposal of high-purity Na2SO4 within the residues of the distilled filtrate. Through a comparative economic analysis involving direct disposal and the application of a remediation process for uranium-contaminated soil, the comprehensive zero liquid discharge system emerged as a practical and viable choice. The successful demonstration of the design and practicality of the proposed zero liquid discharge system for treating wastewater originating from real uranium-contaminated soil is poised to have a lasting impact.
        12.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Choosing to perform squats on an unstable surface potentially offers advantages surpassing those of their stable counterpart. Objectives: The purpose of this study was to compare muscle activation during squats on stable and unstable surfaces and investigate the relationship among thigh muscles. Design: Observational study. Methods: Nineteen adults participated in this study. The stable surface consisted of a flat floor. The unstable surface involved the use of an air cushion. An air cushion was positioned beneath each foot of the study participants. Surface electromyography was employed to measure muscle activation. %MVC was calculated by measuring muscle activation during squat execution and manual muscle testing. Results: The comparison of muscle activation during squats between stable and unstable surfaces revealed a significant difference in the rectus femoris and biceps femoris (P<.05). On stable surfaces, positive correlations were observed in the rectus femoris, vastus lateralis, and vastus medialis (P<.05). On unstable surfaces, positive correlations were found between the rectus femoris and vastus medialis (P<.05). Conclusion: This study observed an increase in muscle activation of the rectus femoris and biceps femoris during squats on an unstable support surface compared to a stable support surface.
        4,000원
        13.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Coating a culture plate with molecules that aid in cell adhesion is a technique widely used to produce animal cell cultures. Extracellular matrix (ECM) is known for its efficiency in promoting adhesion, survival, and proliferation of adherent cells. Gelatin, a cost-effective type of ECM, is widely used in animal cell cultures including feeder-free embryonic stem (ES) cells. However, the optimal concentration of gelatin is a point of debate among researchers, with no studies having established the optimal gelatin concentration. Methods: In this study, we coated plastic plates with gelatin in a concentrationdependent manner and assessed Young’s modulus using atomic force microscopy (AFM) to investigate the microstructure of the surface of each plastic plate. The adhesion, proliferation, and differentiation of the ESCs were compared and analyzed revealing differences in surface microstructure dependent on coating concentration. Results: According to AFM analysis, there was a clear difference in the microstructure of the surface according to the presence or absence of the gelatin coating, and it was confirmed that there was no difference at a concentration of 0.5% or more. ES cell also confirmed the difference in cell adhesion, proliferation, and differentiation according to the presence or absence of gelatin coating, and also it showed no difference over the concentration of 0.5%. Conclusions: The optimum gelatin-coating for the maintenance and differentiation of ES cells is 0.5%, and the gelatin concentration-mediated microenvironment and ES cell signaling are closely correlated.
        4,000원
        14.
        2023.07 구독 인증기관·개인회원 무료
        This study empirically verified the endorsement effect of a restaurant platform as a reliable third-party organization on changes in customers’ attitudes toward restaurants by measuring big data-based consumption values using customers’ reviews and applying difference-in-differences. The results indicated that endorsement effects are effective when specific cues are provided and under unusual circumstances such as the pandemic.
        15.
        2023.05 구독 인증기관·개인회원 무료
        Since the National R&D Innovation Act was enacted in 2022, it became a crucial issue how to qualify or improve R&D activities and disseminate their outcomes. Many organizations have referred to various quality management standards such as the American National Standards Institute/American Society for Quality (ANSI/ASQ) Z1.13, International Organization for Standardization (ISO) 9001, and the American Society of Mechanical Engineers Nuclear Quality Assurance-1 (ASME NQA-1), as a means to set up their own quality system. ISO is the international standard for implementing a quality management system (QMS), which provides a framework and principles for managing an organization’s QMS, with the aim of ensuring that the organization consistently provide products or services that meet regulatory requirements. ISO 9001 can cover all aspects of an organization’s operations, and it can also be expanded to include R&D areas. The introduction of ISO 9001 to R&D aims to improve R&D practices and establish a standardized process framework for conducting R&D. ANSI/ASQ Z1.13 provides quality guidelines for research and consists of 10 sections covering various aspects of research quality, emphasizing ethical conduct, clear objectives, reliable data collection, and analysis. ASME NQA-1 is one of quality assurance standards for nuclear facility applications, but it has been extended and applied to R&D activities in the nuclear fields. It just focuses on planning, procedures, documentation, competence, equipment, and material control. KINAC has conducted extensive research on verifying and regulating nuclear activities while providing support for national nonproliferation technologies and policies. In addition to the quantitative growth achieved so far, efforts are being made to establish a qualitative and integrated management system. As a first step to achieve this goal, this study reviewed international standards and methodologies for research quality and derived the key components for R&D quality management. Moreover, the appropriate outline of quality management system framework was proposed for R&D as a regulatory support process, based on the ISO 9001. The implementation of quality management standards and procedures for R&D in KINAC, which could lead to improved research practices, more reliable data collection and analysis and increased efficiency in conducting R&D activities.
        16.
        2023.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Water electrolysis holds great potential as a method for producing renewable hydrogen fuel at large-scale, and to replace the fossil fuels responsible for greenhouse gases emissions and global climate change. To reduce the cost of hydrogen and make it competitive against fossil fuels, the efficiency of green hydrogen production should be maximized. This requires superior electrocatalysts to reduce the reaction energy barriers. The development of catalytic materials has mostly relied on empirical, trial-and-error methods because of the complicated, multidimensional, and dynamic nature of catalysis, requiring significant time and effort to find optimized multicomponent catalysts under a variety of reaction conditions. The ultimate goal for all researchers in the materials science and engineering field is the rational and efficient design of materials with desired performance. Discovering and understanding new catalysts with desired properties is at the heart of materials science research. This process can benefit from machine learning (ML), given the complex nature of catalytic reactions and vast range of candidate materials. This review summarizes recent achievements in catalysts discovery for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The basic concepts of ML algorithms and practical guides for materials scientists are also demonstrated. The challenges and strategies of applying ML are discussed, which should be collaboratively addressed by materials scientists and ML communities. The ultimate integration of ML in catalyst development is expected to accelerate the design, discovery, optimization, and interpretation of superior electrocatalysts, to realize a carbon-free ecosystem based on green hydrogen.
        4,600원
        17.
        2023.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This paper explores possibilities of using language learning autobiographies as a form of identity texts in order to produce suggestions for critical teacher education. Specifically, we examined what insights we might gain by reframing Korean pre-service teachers’ autobiographies as a form of identity texts to develop reflective teachers, who affirm their identities and language learning histories. We thematically analyzed autobiographical reflection papers on English learning experiences of 73 undergraduate students enrolled in a compulsory elementary English education course at a public university in South Korea. The analysis revealed the predominance of referral to English private education experiences and a sense of linguistic insecurity felt by these pre-service teachers, who would later teach in public schools. Based on these findings, we provide suggestions for critical teacher education to foster critical language awareness and identity investment for the students. We conclude that language learning autobiographies, while incorporating characteristics of identity texts, might be a useful tool for critical pedagogies.
        6,600원
        20.
        2022.10 구독 인증기관·개인회원 무료
        As the management procedure for self-disposal wastes stored in the radiation controlled area within the Korea Atomic Energy Research Institute (KAERI) have been established, and the types and quantities of wastes are increasing. In order to carry out the disposal of wastes with various generation histories, we expanded the processing range from surface contaminated waste, which was already in progress, to volumetric contaminated waste. In this paper, a case study of self-disposal of volumetric contaminated radioactive waste for which final disposal has been completed is described. In order to carry out of self-disposal of volumetric contaminated waste, it is important to collect representative samples and prove their representativenss. Based on this, a treatment plan was established after reviewing the history of the waste to be disposed of, and the treatment work was carried out as follows; waste collection, classification by size and shape, radiation (activity) measurement, sampling of representative samples, radioactivity concentration analysis, notification to regulatory bodies and question-and-answer, final disposal. The waste is judged have no potential for contamination because the polywood used to set the flat floor between the steel frame and floorboards in the experimental greenhouse didn’t come into contact with radioactive material. However, due to the conservative approach to the presence or absence of contamination, the treatment plan was established assuming volumetric contaminated waste. The type of waste is single wood, and the major contaminating radionuclides are Sr-85 and Cs-137. After the waste was collected and sorted by size and shape, it was weighed and a representative sampling amount and sampling method were set up. A direct method of surface contamination was performed on the entire area, and the representative sample was divided into three groups of homogenized population samples using the trisection method, with three points (upper/middle/below) were sampled at a 200:1 ratio, and radioactivity concentration analysis was conducted. After confirming that the concentration was below the allowable concentration for selfdisposal, the final disposal was completed after receiving approval after reporting to the regulatory body. As a result of radioactivity concentration analysis of representative samples, the maximum radioactivity concentration for each nuclide was Sr-85: < MDC (0.00178), Cs-137 : 0.00183 Bq/g (Sr-85 : 1 Bq/g, Cs-137 : 0.1 Bq/g), which meets the nuclide allowable concentration standard. It was confirmed that the total maximum fraction of 0.02 Bq/g satisfies the criteria (In the case of mixed nuclides, the sum of the fraction is less than 1). This paper introduces the establishment and implementation of self-disposal procedures based on the experience of self-disposal of radioactive waste with volumetric contaminants, and is going to utilize it as a basic material for self-disposal of radioactive waste with volumetric contaminants that will continue in the future and contribute to the reduction of radioactive wastes.
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