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        검색결과 166

        1.
        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
        2.
        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.
        4.
        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
        5.
        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
        6.
        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.
        7.
        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.
        8.
        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
        9.
        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
        12.
        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.
        13.
        2022.10 구독 인증기관·개인회원 무료
        In a nuclear power plant, the activated corrosion products are deposited on the reactor coolant system. The activated corrosion products must be removed to reduce the radiation exposure to workers before maintaining or decommissioning of the nuclear power plant. In order to remove the remove the activated duplex oxide layer generated on the reactor coolant system in the pressurized water reactor (PWR), the Cyclic SP (Sulfuric acid/Permanganate)-HyBRID (Hydrazine Based Reductive metal Ion Decontamination) process developed by KAERI (Korea Atomic Energy Research Institute) can be used. After applying the Cyclic SP-HyBRID process, a sulfate-rich waste powder containing the radionuclide is generated, and the radioactive powder has to be stabilized for final disposal. In the previous study, it was confirmed that the low-temperature sintering method can be applied to immobilize the sulfate-rich waste powder. Thus, immobilization of the Cyclic SP-HyBRID process waste powder was carried out by the low-temperature sintering method using a low melting point glass, and the physicochemical and radiological characteristics of a waste form were evaluated in this study. As a result, the compressive strength of the waste form increased with increasing sintering temperature and sintering time. It is considered that the result was caused by the difference in the band gap between the bismuth borate and zinc borate, which are the products during the sintering process. It was verified that the physical stability was maintained after the 107 Gy of irradiation test. In addition, it was confirmed that the radioactive metal hydroxides contained in the waste powder converted to metal oxide forms, which have the lower solubility, at the sintering temperature. Finally, the waste form was evaluated as a low-level radioactive waste from the concentration of radionuclides contained in the waste form.
        14.
        2022.10 구독 인증기관·개인회원 무료
        Nuclear power plants, like other national critical infrastructures, could be under the threat of terrorism or other malicious action. Thus, a nuclear power plant has a robust security system that includes security guards, sensors, barriers, access control systems, lights, and alarm stations with security procedures. However, an effective security system is hard to design because a chain is only as strong as its weakest link, and there could be a vulnerable hole even in the robust security system. Thus, an effective security system requires the evaluation of all possible scenarios. Evaluation software for security system effectiveness assists in systematically assessing all the possible attack scenarios. Many countries developed security effectiveness evaluation software. The first software was developed by the U.S. Sandia National Laboratories in the 1980s. Now there are several commercially available software packages with a function to simulate limited-scope combat between security guards and attacking enemies. However, academic communication is comparatively weak because it may contain sensitive information on the vulnerability of nuclear power plants. We developed original software called Tools for Evaluating Security Systems (TESS) to identify the most vulnerable path to the designated target and model the security systems of all South Korean nuclear power plants. We also used commercial security effectiveness evaluation software, AVERT, to model the same nuclear power plants. TESS was developed to verify the results of commercial security effectiveness evaluation software for the purpose of regulatory use. For the feasibility test, we compared the results of two software with those of force-on-force (FoF) exercises in nuclear power plants. According to the relevant Act, every nuclear power plant site should perform the FoF exercises every year. KINAC was in charge of evaluating the FoF exercise and used several of its results for the study. In the results, even in some differences in detail, the two software and FoF exercises showed qualitative similarity. Conclusively, evaluation software is a useful tool to design and/or assess the security systems of nuclear power plants. We modeled the security systems of all South Korean nuclear power plants, and compared the developed software, a commercial software and FoF exercises. The results showed qualitative similarity. We provided the results of evaluation to nuclear operators for the better security of nuclear power plants.
        15.
        2022.10 구독 인증기관·개인회원 무료
        It is still questionable if the Nuclear Damage Compensation Act can be applied to security accidents on nuclear facilities caused by hacking or drone attacks. If the Act is applied, the nuclear operator shall be liable for compensation for the damage even if there is no negligence, and no other person shall be liable. If it is not, victims must prove the negligence of nuclear operators and not only nuclear operators but also suppliers must be responsible. According to Article 5 of this Act, a nuclear operator cannot operate a reactor before signing liability insurance contract or a compensation contract or depositing in order to compensate for nuclear damage. The liability insurance contract includes the hacking accident, but it is not applied to drone attacks since only hacking accident is included in design basis accidents. However, Article 2 of this Act defines a nuclear accident as an event that may cause nuclear damage so it can be said that the ‘event’ includes intentional attacks. Article 3 stipulates that nuclear operators are not liable for compensation for damages caused by armed conflicts, hostile acts between countries, or civil war or rebellion. Therefore, if nuclear power plant is attacked by missiles from North Korea, the nuclear operator is not liable for compensation. And, it can be interpreted that the nuclear operator is liable for compensation for damages caused by actions of a third party that do not fall under this category. According to the Act on Indemnity Agreement For Nuclear Damage Compensation, nuclear damage caused during normal operation is included in the scope of compensation, but damage caused by actions of third parties is excluded. In the end, damage caused by actions of third parties is included in the scope of nuclear damage, but not included in the loss compensated by the government. According to the Act on Physical Protection, the Nuclear Safety & Security Commission is required to establish a design basis threat that is the standard for designing and evaluating physical protection systems. Therefore, it is reasonable to include the contents of design basis threats in liability insurance, or to apply the principle of no negligence liability and focus of responsibility to protect victims, if not.
        18.
        2022.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The structural safety of prototype transport and storage containers for very low-level radioactive liquid waste was experimentally estimated for its localization development. Transport containers for radioactive liquid waste have been researched and developed, however, there are no standardized commercial containers for very low-level radioactive waste in Korea. In this study, the structural safety of the designated IP-2 type container capable of transporting and temporarily storing large amounts of very low-level liquid waste, which is generated during the operation and decommissioning of nuclear power plants, was demonstrated. The stacking and drop tests, which were conducted to determine the structural integrity of the container, verified that there was no external leakage of the contents in spite of its structural deformation due to the drop impact. This study shows the effort required for the localization of the technology used in manufacturing transport and storage containers for very low-level radioactive liquid waste, and the additional structural reinforcement of the container in which the commercial intermediate bulk container (IBC) external frame was coupled.
        4,000원
        19.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the effect of a synthetic complement peptide C3a on the outcome of Brucella abortus 544 infection in a murine macrophage cell line RAW264.7 cell. First, we determined the highest non-cytotoxic concentration of the peptide in the cell line. We also found that the peptide significantly increased the growth of the bacteria at 8 and 24 h. Although the number of bacterial CFU was also elevated at 48 and 72 h, the increases were not significant as compared to controls. We further investigated the effect of C3a peptide on the growth of Brucella by pre-incubating the peptide at various temperatures and found that the effect was reversed at 24 h post-incubation suggesting that incubation of peptide at high temperatures including 65°C or 95°C could inactivate its action. This also could indicate the beneficial effect of high temperature during infection. Although several studies reported the inhibitory effect of different antimicrobial peptides including C3a, the present study preliminarily revealed that it had no positive contribution on the control of B. abortus 544 infection in vitro and indirectly to its receptor, CD88, which belongs to GPCR. Moreover, the encouraged further exploration of the effect of other similar peptides would be performed for the purpose of finding Brucella-host cell interaction for the control of disease progression.
        4,000원
        20.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The fruit stalk of Hovenia dulcis (H.dulcis) is traditionally used to relieve hangovers in Korea. Theracurmin is a highly absorbable curcumin preparation which increases the bioavailability of curcumin. Curcumin is known for its antioxidant and anti-inflammatory effects. However, the role of this combination in lowering alcohol levels in the body, thereby alleviating the severity of alcohol-induced hangover has not been investigated. Therefore, we conducted a study to investigate the eliminatory effects of a health drink containing the extract of the H. dulcis fruit stalk and theracurmin (theracurmin drink) on ethanol-induced hangover in rats. The theracurmin drink delivered orally to rats 30 mins before the administration of 40% ethanol (5 g/kg body weight), lowered the concentration of ethanol and acetaldehyde in the blood samples collected 1, 3, and 5 h after ethanol administration. Furthermore, the theracurmin drink increased the activities of alcohol dehydrogenase and aldehyde dehydrogenase enzymes. The effectiveness of the theracurmin drink was thus superior to that of other health drink products, suggesting that its consumption may alleviate or prevent an alcohol-induced hangover.
        4,000원
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